Science.gov

Sample records for energy deposition sputtering

  1. Measuring the energy flux at the substrate position during magnetron sputter deposition processes

    SciTech Connect

    Cormier, P.-A.; Thomann, A.-L.; Dussart, R.; Semmar, N.; Mathias, J.; Balhamri, A.; Snyders, R.; Konstantinidis, S.

    2013-01-07

    In this work, the energetic conditions at the substrate were investigated in dc magnetron sputtering (DCMS), pulsed dc magnetron sputtering (pDCMS), and high power impulse magnetron sputtering (HiPIMS) discharges by means of an energy flux diagnostic based on a thermopile sensor, the probe being set at the substrate position. Measurements were performed in front of a titanium target for a highly unbalanced magnetic field configuration. The average power was always kept to 400 W and the probe was at the floating potential. Variation of the energy flux against the pulse peak power in HiPIMS was first investigated. It was demonstrated that the energy per deposited titanium atom is the highest for short pulses (5 {mu}s) high pulse peak power (39 kW), as in this case, the ion production is efficient and the deposition rate is reduced by self-sputtering. As the argon pressure is increased, the energy deposition is reduced as the probability of scattering in the gas phase is increased. In the case of the HiPIMS discharge run at moderate peak power density (10 kW), the energy per deposited atom was found to be lower than the one measured for DCMS and pDCMS discharges. In these conditions, the HiPIMS discharge could be characterized as soft and close to a pulsed DCMS discharge run at very low duty cycle. For the sake of comparison, measurements were also carried out in DCMS mode with a balanced magnetron cathode, in the same working conditions of pressure and power. The energy flux at the substrate is significantly increased as the discharge is generated in an unbalanced field.

  2. Diffusion enhancement due to low-energy ion bombardment during sputter etching and deposition

    NASA Astrophysics Data System (ADS)

    Eltoukhy, A. H.; Greene, J. E.

    1980-08-01

    The effects of low-energy ion bombardment on enhancing elemental diffusion rates at both heterojunction interfaces during film deposition and over the compositionally altered layer created during sputter etching alloy targets have been considered. Depth dependent enhanced interdiffusion coefficients, expressed as D*(x)=D*(0) exp(-x/Ld), where D*(0) is more than five orders of magnitude greater than thermal diffusion values, were measured in InSb/GaSb multilayer structures deposited by multitarget bias sputering. D*(0) was determined from the amplitude u of the compositional modulation in the multilayered films (layer thicknesses between 20 and 45 Å) as measured by superlattice x-ray diffraction techniques. The value of D*(0) was found to increase from 3×10-17 to 1×10-16 cm2/sec as the applied substrate bias was increased from 0 to -75 V. However even at Va=0, the diffusion coefficient was enhanced owing to an induced substrate potential with respect to the positive space-charge region in the Ar discharge. The diffusion length of Ld of the ion bombardment created defects was ˜1000 Å. Enhanced diffusion also has a significiant effect on the altered layer thickness xe and the total sputtering time te (or ion dose) required to reach steady state during ion etching of multielement targets. The effects of using an exponentially depth dependent versus a constant value of the enhanced diffusion coefficient on calculated values of xe and te in single-phase binary alloys were considered. The results show that both xe and te are considerably larger using a depth dependent D*(x), when Ldsputter etching. However, when Ld≳D*(0)/v, the usual case for most sputtering applications, the two solutions approach each other.

  3. Ion beam sputter etching and deposition of fluoropolymers

    NASA Technical Reports Server (NTRS)

    Banks, B. A.; Sovey, J. S.; Miller, T. B.; Crandall, K. S.

    1978-01-01

    Fluoropolymer etching and deposition techniques including thermal evaporation, RF sputtering, plasma polymerization, and ion beam sputtering are reviewed. Etching and deposition mechanism and material characteristics are discussed. Ion beam sputter etch rates for polytetrafluoroethylene (PTFE) were determined as a function of ion energy, current density and ion beam power density. Peel strengths were measured for epoxy bonds to various ion beam sputtered fluoropolymers. Coefficients of static and dynamic friction were measured for fluoropolymers deposited from ion bombarded PTFE.

  4. Ion beam sputter etching and deposition of fluoropolymers

    NASA Technical Reports Server (NTRS)

    Banks, B. A.; Sovey, J. S.; Miller, T. B.; Crandall, K. S.

    1978-01-01

    Fluoropolymer etching and deposition techniques including thermal evaporation, RF sputtering, plasma polymerization, and ion beam sputtering are reviewed. Etching and deposition mechanisms and material characteristics are discussed. Ion beam sputter etch rates for polytetrafluoroethylene (PTFE) were determined as a function of ion energy, current density and ion beam power density. Peel strengths were measured for epoxy bonds to various ion beam sputtered fluoropolymers. Coefficients of static and dynamic friction were measured for fluoropolymers deposited from ion bombarded PTFE.

  5. Sputtering - A vacuum deposition method for coating material.

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1972-01-01

    The sputtering method is discussed in terms of the unique features which sputter offers in depositing coatings. These features include versatility, momentum transfer, configuration of target, precise controls, and a relatively slow deposition rate. Sputtered films are evaluated in terms of adherence, coherence, and the internal stresses. The observed strong adherence is attributed to the high kinetic energies of the sputtered material, sputter etched surface, and the submicroscopic particle size. Film thickness can be controlled to a millionth of a centimeter. Very adherent films of sputtered PTFE (teflon) can be deposited in a single operation on any type of material and on any geometrical configuration.

  6. Sputtering - A vacuum deposition method for coating material.

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1972-01-01

    The sputtering method is discussed in terms of the unique features which sputter offers in depositing coatings. These features include versatility, momentum transfer, configuration of target, precise controls, and a relatively slow deposition rate. Sputtered films are evaluated in terms of adherence, coherence, and the internal stresses. The observed strong adherence is attributed to the high kinetic energies of the sputtered material, sputter etched surface, and the submicroscopic particle size. Film thickness can be controlled to a millionth of a centimeter. Very adherent films of sputtered PTFE (teflon) can be deposited in a single operation on any type of material and on any geometrical configuration.

  7. RF-sputter deposited flexible copper oxide thin films for electrochemical energy storage

    NASA Astrophysics Data System (ADS)

    Purusottam Reddy, B.; Sivajee Ganesh, K.; Park, Si-Hyun; Hussain, O. M.

    2017-07-01

    Flexible Cu-O thin films were grown on different metal coated non rigid polyimide substrates by the RF-magnetron sputtering and their microstructure and supercapacitive properties were studied. The Raman and XRD studies confirms the formation of a single Cu2O phase with predominant (111) orientation. Surface topography observations revealed that as the percentage of lattice mismatch of Cu2O lattice and substrate lattice is greater the average grain size tends to decrease. The Cu2O films deposited on Ti-Kapton, Ni-Kapton and Pt-Kapton substrates exhibited maximum specific capacitances of 255, 273 and 350 F g-1 correspondingly at a constant current density of 1 A g-1. The observed maximum specific capacitance for CuxO thin films deposited on Pt-Kapton substrates is due to the lower lattice mismatch, high work function of the metal, availability of (111) planes and highly available active area.

  8. Sputtering. [as deposition technique in mechanical engineering

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1976-01-01

    This paper primarily reviews the potential of using the sputtering process as a deposition technique; however, the manufacturing and sputter etching aspects are also discussed. Since sputtering is not regulated by classical thermodynamics, new multicomponent materials can be developed in any possible chemical composition. The basic mechanism for dc and rf sputtering is described. Sputter-deposition is described in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter-etching, target geometry (coating complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also described are some of the specific industrial areas which are turning to sputter-deposition techniques.

  9. Sputtering. [as deposition technique in mechanical engineering

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1976-01-01

    This paper primarily reviews the potential of using the sputtering process as a deposition technique; however, the manufacturing and sputter etching aspects are also discussed. Since sputtering is not regulated by classical thermodynamics, new multicomponent materials can be developed in any possible chemical composition. The basic mechanism for dc and rf sputtering is described. Sputter-deposition is described in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter-etching, target geometry (coating complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also described are some of the specific industrial areas which are turning to sputter-deposition techniques.

  10. Determination of deposited flux and energy of sputtered tungsten atoms on every stages of transport in HiPIMS discharge

    NASA Astrophysics Data System (ADS)

    Desecures, M.; de Poucques, L.; Bougdira, J.

    2017-02-01

    A time-resolved tunable diode-laser (DL) induced fluorescence (TR-TDLIF) technique has been used to identify different populations of atoms (on different stages of transport) to determine their corresponding deposited energy and flux. The temporal dimension permits the splitting of the processes of sputtering during the discharge and particles transport in the post-discharge where atoms and flux velocity distribution functions (AVDF, FVDF) of each population were measured varying the discharge parameters (power, voltage, pressure, and distance from target). Tungsten (W) was chosen, being an interesting case in terms of sputtered atom transport, considering its weight which implies weak changes of directivity or energy transfer after collisions with the buffer gas. The high temporal and spectral resolutions of TR-TDLIF are the keys for the distinction of the atoms populations and the stage corresponding to the transition from the ballistic to diffusive regime of transport was observed for the first time and named quasi-diffusive regime. Thus, the ability to dissociate populations of atoms and to determine their deposited flux and energy may be of great interest to adjust film properties as desired for applications.

  11. Sputter Deposition of Metallic Sponges

    SciTech Connect

    Jankowski, A F; Hayes, J P

    2002-01-18

    Metallic films are grown with a sponge-like morphology in the as-deposited condition using planar magnetron sputtering. The morphology of the deposit is characterized by metallic continuity in three dimensions with continuous porosity on the sub-micron scale. The stabilization of the metallic sponge is directly correlated with a limited range for the sputter deposition parameters of working gas pressure and substrate temperature. This sponge-like morphology augments the features as generally understood in the classic zone models of growth for physical vapor deposits. Nickel coatings are deposited with working gas pressures up to 4 Pa and for substrate temperatures up to 1100 K. The morphology of the deposits is examined in plan and in cross-section with scanning electron microscopy. The parametric range of gas pressure and substrate temperature (relative to absolute melt point) for the deposition processing under which the metallic sponges are produced appear universal for many metals, as for example, including gold, silver, and aluminum.

  12. Energy harvesting based on piezoelectric AlN and AlScN thin films deposited by high rate sputtering

    NASA Astrophysics Data System (ADS)

    Frach, Peter; Barth, Stephan; Bartzsch, Hagen; Gloess, Daniel

    2017-05-01

    Aluminum nitride (AlN) is a piezoelectric material often used as thin film in SAW/BAW devices. Furthermore, there is an increasing interest in its use for energy harvesting applications. Despite it has a relatively low piezoelectric coefficient, it is a suitable choice for energy harvesting applications and due to its low dielectric constant and good mechanical properties. In addition, it is a lead-free material. The films were deposited by reactive pulsed magnetron sputtering using the Double Ring Magnetron DRM 400. This sputter source together with suitable powering and process control allows depositing piezoelectric AlN very homogeneously on 8" substrates with deposition rates of up to 200 nm/min. With the developed technology, film thicknesses of several ten microns are technically and economically feasible. Moreover, by adjusting process parameters accordingly, it is possible to tune properties, like film stress, to application specific requirements. Additionally, it is known that the doping of AlN with Scandium results in a significantly increased piezoelectric coefficient. The influence of process parameters and Sc concentration on film properties were determined by piezometer, pulse echo, SEM, XRD, EDS and nanoindentation measurements. Energy harvesting measurements were done using an electromechanical shaker system for the excitation of defined vibrations and a laservibrometer for determination of the displacement of the samples. The generated power was measured as function of electric load at resonance. An rms power of up to 140μW using AlN films and of 350μW using AlScN films was generated on Si test pieces of 8x80mm2. Furthermore, energy harvesting measurements using manually bended steel strips of 75x25mm2 coated with AlScN were carried out as well. When using only a single actuation, energy of up to 8μJ could be measured. By letting the system vibrate freely, the damped vibration at resonance 50Hz resulted in a measured energy of 420μJ.

  13. REACTIVE SPUTTER DEPOSITION OF CHROMIUM NITRIDE COATINGS

    EPA Science Inventory

    The effect of substrate temperature and sputtering gas compositon on the structure and properties of chromium-chromium nitride films deposited on C-1040 steel using r.f. magnetron sputter deposition was investigated. X-ray diffraction analysis was used to determine the structure ...

  14. REACTIVE SPUTTER DEPOSITION OF CHROMIUM NITRIDE COATINGS

    EPA Science Inventory

    The effect of substrate temperature and sputtering gas compositon on the structure and properties of chromium-chromium nitride films deposited on C-1040 steel using r.f. magnetron sputter deposition was investigated. X-ray diffraction analysis was used to determine the structure ...

  15. Sputtering: A vacuum deposition method for coating material

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1972-01-01

    The sputtering process is described in terms of its features: versatility, momentum transfer, configuration of target, precise controls and the relatively slow deposition rate. Sputtered films are evaluated in terms of adherence, coherence, and internal stresses. The strong adherence is attributed to the high kinetic energies of the sputtered material, sputter etched (cleaned) surface, and the submicroscopic particle size. An illustration is a sputtered solid film lubricant such as MoS2. Friction tests were conducted on a thin, 2000 A deg thick MoS2 film. These films are very dense and without observable pinholes, and the particle to particle cohesion is strong. Tolerances (film thickness) can be controlled to a millionth of a centimeter. Very adherent films of sputtered Teflon can be deposited in a single operation on any type of material (metal, glass, paper) and on any geometrical configuration with a dense adherent film.

  16. Transport Phenomena of Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, S.; Su, C.; Lehoczky, S. L.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Various high quality epitaxial films, especially oxides, have been synthesized using off-axis sputtering deposition. In this presentation, we report the experiment results of ZnO films grown by the off-axis sputtering deposition. Films were synthesized in temperatures ranged from room temperature to 600 C, and pressures from 5 mTorr to 150 mTorr. Film growth rate was measured by surface profilometer, ellipsometer, and wavelength dispersive spectrometry. Due to the collisions between the sputtered species and the residue gases, the kinetic energy of species was reduced and the transport of depositing species changed from a ballistic movement for low pressure to a diffusive drift for high pressure in which the transport species were almost thermalized. The measurements show an increase of growth rates along the gravity vector when the Knudsen number of transport species is less than 0.05, which suggests that gravity affected the transport characterization in off-axis sputtering deposition. Because the product of pressure (p) and travel distance (d) of sputtered species, pd, exceeds several mTorr-cm during film deposition, the classical simulations for sputtering process in high vacuum system may not be applied. Based on these experimental measurements, a transport process of the off-axis sputtering deposition is proposed. Several models including the Monte Carlo method and gravity-driven flow dynamics simulation will be discussed.

  17. Transport Phenomena of Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, S.; Su, C. H.; Lehoczky, S. L.; Zhang, S.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Various high quality epitaxial films, especially oxides, have been synthesized using off-axis sputtering deposition. In this presentation, we report the experiment results of ZnO films grown by the off-axis sputtering deposition. Films were synthesized in temperatures ranged from room temperature to 600 C, and pressures from 5 mTorr to 150 mTorr. Film growth rate was measured by surface profilometer, ellipsometer, and wavelength dispersive spectrometry. Due to the collisions between the sputtered species and the residue gases, the kinetic energy of species was reduced and the transport of depositing species changed from a ballistic movement for low pressure to a diffuse drift for high pressure in which the transport species were almost thermalized. The measurements show an increase of growth rates along the gravity vector when the Knodson (Knudsen??) number of transport species is less than 0.05, which suggests that gravity affected the transport characterization in off-axis sputtering deposition. Because the product of pressure (p) and travel distance (d) of sputtered species, p exceeds several mTorr-cm during film deposition, the classical simulations for sputtering process in high vacuum system may not be applied. Based on these experimental measurements, a transport process of the off-axis sputtering deposition is proposed. Several methods including the Monte Carlo method and gravity-driven flow dynamics simulation will be discussed.

  18. Transport Phenomena of Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, S.; Su, C. H.; Lehoczky, S. L.; Zhang, S.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Various high quality epitaxial films, especially oxides, have been synthesized using off-axis sputtering deposition. In this presentation, we report the experiment results of ZnO films grown by the off-axis sputtering deposition. Films were synthesized in temperatures ranged from room temperature to 600 C, and pressures from 5 mTorr to 150 mTorr. Film growth rate was measured by surface profilometer, ellipsometer, and wavelength dispersive spectrometry. Due to the collisions between the sputtered species and the residue gases, the kinetic energy of species was reduced and the transport of depositing species changed from a ballistic movement for low pressure to a diffuse drift for high pressure in which the transport species were almost thermalized. The measurements show an increase of growth rates along the gravity vector when the Knodson (Knudsen??) number of transport species is less than 0.05, which suggests that gravity affected the transport characterization in off-axis sputtering deposition. Because the product of pressure (p) and travel distance (d) of sputtered species, p exceeds several mTorr-cm during film deposition, the classical simulations for sputtering process in high vacuum system may not be applied. Based on these experimental measurements, a transport process of the off-axis sputtering deposition is proposed. Several methods including the Monte Carlo method and gravity-driven flow dynamics simulation will be discussed.

  19. Transport Phenomena of Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, S.; Su, C.; Lehoczky, S. L.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Various high quality epitaxial films, especially oxides, have been synthesized using off-axis sputtering deposition. In this presentation, we report the experiment results of ZnO films grown by the off-axis sputtering deposition. Films were synthesized in temperatures ranged from room temperature to 600 C, and pressures from 5 mTorr to 150 mTorr. Film growth rate was measured by surface profilometer, ellipsometer, and wavelength dispersive spectrometry. Due to the collisions between the sputtered species and the residue gases, the kinetic energy of species was reduced and the transport of depositing species changed from a ballistic movement for low pressure to a diffusive drift for high pressure in which the transport species were almost thermalized. The measurements show an increase of growth rates along the gravity vector when the Knudsen number of transport species is less than 0.05, which suggests that gravity affected the transport characterization in off-axis sputtering deposition. Because the product of pressure (p) and travel distance (d) of sputtered species, pd, exceeds several mTorr-cm during film deposition, the classical simulations for sputtering process in high vacuum system may not be applied. Based on these experimental measurements, a transport process of the off-axis sputtering deposition is proposed. Several models including the Monte Carlo method and gravity-driven flow dynamics simulation will be discussed.

  20. Surface free energy of non-stick coatings deposited using closed field unbalanced magnetron sputter ion plating

    NASA Astrophysics Data System (ADS)

    Sun, Chen-Cheng; Lee, Shih-Chin; Dai, Shyue-Bin; Tien, Shein-Long; Chang, Chung-Chih; Fu, Yaw-Shyan

    2007-02-01

    Semiconductor IC packaging molding dies require wear resistance, corrosion resistance and non-sticking (with a low surface free energy). The molding releasing capability and performance are directly associated with the surface free energy between the coating and product material. The serious sticking problem reduces productivity and reliability. Depositing TiN, TiMoS, ZrN, CrC, CrN, NiCr, NiCrN, CrTiAlN and CrNiTiAlN coatings using closed field unbalanced magnetron sputter ion plating, and characterizing their surface free energy are the main object in developing a non-stick coating system for semiconductor IC molding tools. The contact angle of water, diiodomethane and ethylene glycol on the coated surfaces were measured at temperature in 20 °C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the coatings and their components (dispersion and polar) were calculated using the Owens-Wendt geometric mean approach. The surface roughness was investigated by atomic force microscopy (AFM). The adhesion force of these coatings was measured using direct tensile pull-off test apparatus. The experimental results showed that NiCrN, CrN and NiCrTiAlN coatings outperformed TiN, ZrN, NiCr, CiTiAlN, CrC and TiMoS coatings in terms of non-sticking, and thus have the potential as working layers for injection molding industrial equipment, especially in semiconductor IC packaging molding applications.

  1. Influence of low-energy plasma annealing on structural and optical properties of silver nanoclusters grown by magnetron sputtering deposition

    NASA Astrophysics Data System (ADS)

    Antad, V.; Simonot, L.; Babonneau, D.

    2014-03-01

    Structural and optical modifications induced by low-energy (≤80 eV) bias-plasma annealing of silver nanoclusters (2-25 nm) grown by magnetron sputtering deposition are reported. By combining postmortem structural characterizations and real-time optical measurements, we show that etching effects associated with enhanced Ag mobility result in progressive and irreversible changes of both the morphology and organization of the nanoclusters (i.e., decrease of the cluster size and intercluster distance as well as increase of their out-of-plane aspect ratio). Surface plasmon resonance bands of the nanoclusters are also modified by plasma treatment, which causes a blue-shift together with an amplitude decrease and a narrowing of the band. In addition, the kinetics of plasma-induced modifications can be easily controlled by varying the applied bias voltage. Therefore, plasma annealing could emerge as an efficient alternative to more traditional thermal annealing treatments for tuning the plasmonic properties of noble metal nanoclusters with great flexibility.

  2. Sputtering

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1976-01-01

    The potential of using the sputtering process as a deposition technique is reviewed; however, the manufacturing and sputter etching aspects are also discussed. The basic mechanism for dc and rf sputtering is described. Sputter deposition is presented in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter etching, target geometry (coating and complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also discussed are some of the specific industrial areas which are turning to sputter deposition techniques.

  3. Low-Energy Sputtering Research

    NASA Technical Reports Server (NTRS)

    Ray, P. K.; Shutthanandan, V.

    1999-01-01

    An experimental study is described to measure low-energy (less than 600 eV) sputtering yields of molybdenum with xenon ions using Rutherford backscattering spectroscopy (RBS) and secondary neutral mass spectroscopy (SNMS). An ion gun was used to generate the ion beam. The ion current density at the target surface was approximately 30 (micro)A/sq cm. For RBS measurements, the sputtered material was collected on a thin aluminum strip which was mounted on a semi-circular collector plate. The target was bombarded with 200 and 500 eV xenon ions at normal incidence. The differential sputtering yields were measured using the RBS method with 1 MeV helium ions. The differential yields were fitted with a cosine fitting function and integrated with respect to the solid angle to provide the total sputtering yields. The sputtering yields obtained using the RBS method are in reasonable agreement with those measured by other researchers using different techniques. For the SNMS measurements, 150 to 600 eV xenon ions were used at 50deg angle of incidence. The SNMS spectra were converted to sputtering yields for perpendicular incidence by normalizing SNMS spectral data at 500 eV with the yield measured by Rutherford backscattering spectrometry. Sputtering yields as well as the shape of the yield-energy curve obtained in this manner are in reasonable agreement with those measured by other researchers using different techniques. Sputtering yields calculated by using two semi-spherical formulations agree reasonably well with measured data. The isotopic composition of secondary ions were measured by bombarding copper with xenon ions at energies ranging from 100 eV to 1.5 keV. The secondary ion flux was found to be enriched in heavy isotopes at low incident ion energies. The heavy isotope enrichment was observed to decrease with increasing impact energy. Beyond 700 eV, light isotopes were sputtered preferentially with the enrichment remaining nearly constant.

  4. Ion beam sputter deposited zinc telluride films

    NASA Technical Reports Server (NTRS)

    Gulino, D. A.

    1986-01-01

    Zinc telluride is of interest as a potential electronic device material, particularly as one component in an amorphous superlattice, which is a new class of interesting and potentially useful materials. Some structural and electronic properties of ZnTe films deposited by argon ion beam sputter deposition are described. Films (up to 3000 angstroms thick) were deposited from a ZnTe target. A beam energy of 1000 eV and a current density of 4 mA/sq cm resulted in deposition rates of approximately 70 angstroms/min. The optical band gap was found to be approximately 1.1 eV, indicating an amorphous structure, as compared to a literature value of 2.26 eV for crystalline material. Intrinsic stress measurements showed a thickness dependence, varying from tensile for thicknesses below 850 angstroms to compressive for larger thicknesses. Room temperature conductivity measurement also showed a thickness dependence, with values ranging from 1.86 x 10 to the -6th/ohm cm for 300 angstrom film to 2.56 x 10 to the -1/ohm cm for a 2600 angstrom film. Measurement of the temperature dependence of the conductivity for these films showed complicated behavior which was thickness dependent. Thinner films showed at least two distinct temperature dependent conductivity mechanisms, as described by a Mott-type model. Thicker films showed only one principal conductivity mechanism, similar to what might be expected for a material with more crystalline character.

  5. Effect of different ion beam energy on properties of amorphous carbon film fabricated by ion beam sputtering deposition (IBSD)

    NASA Astrophysics Data System (ADS)

    Bai, Lichun; Zhang, Guangan; Wu, Zhiguo; Wang, Jun; Yan, Pengxun

    2011-09-01

    Amorphous carbon (a-C) films were fabricated by ion beam sputtering technique. The influence of sputtering ion beam energy on bonding structure, morphologic, mechanical properties, tribological properties and corrosion resistance of a-C films are investigated systematically. Morphology study shows that lowest surface roughness exists for mid-ion beam energy. Improved adhesion is observed for the films that are prepared under high ion beam energy, attributed to film graphitization, low residual stress and mixed interface. Relatively, a-C films prepared with ion beam energy of 2 keV exhibits optimum sp 3 bond content, mechanical properties and corrosion resistance. It is found that the wear rate of DLC films decrease with increased ion beam energy in general, consistent with the varied trend of the H/ E value which has been regarded as a suitable parameter for predicting wear resistance of the coatings. The correlation of the sp 3 bond fraction in the films estimated from Raman spectroscopy with residual stress, nanohardness and corrosion resistance has been established.

  6. Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance.

    PubMed

    Sharma, Shailesh; Gahan, David; Scullin, Paul; Doyle, James; Lennon, Jj; Vijayaraghavan, Rajani K; Daniels, Stephen; Hopkins, M B

    2016-04-01

    A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system.

  7. Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance

    SciTech Connect

    Sharma, Shailesh; Gahan, David Scullin, Paul; Doyle, James; Lennon, Jj; Hopkins, M. B.; Vijayaraghavan, Rajani K.; Daniels, Stephen

    2016-04-15

    A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system.

  8. Ion beam sputter deposited zinc telluride films

    NASA Technical Reports Server (NTRS)

    Gulino, D. A.

    1985-01-01

    Zinc telluride is of interest as a potential electronic device material, particularly as one component in an amorphous superlattice, which is a new class of interesting and potentially useful materials. Some structural and electronic properties of ZnTe films deposited by argon ion beam sputter depoairion are described. Films (up to 3000 angstroms thick) were deposited from a ZnTe target. A beam energy of 1000 eV and a current density of 4 mA/sq. cm. resulted in deposition rates of approximately 70 angstroms/min. The optical band gap was found to be approximately 1.1 eV, indicating an amorphous structure, as compared to a literature value of 2.26 eV for crystalline material. Intrinsic stress measurements showed a thickness dependence, varying from tensile for thicknesses below 850 angstroms to compressive for larger thicknesses. Room temperature conductivity measurement also showed a thickness dependence, with values ranging from 1.86 x to to the -6/ohm. cm. for 300 angstrom film to 2.56 x 10 to the -1/ohm. cm. for a 2600 angstrom film. Measurement of the temperature dependence of the conductivity for these films showed complicated behavior which was thickness dependent. Thinner films showed at least two distinct temperature dependent conductivity mechanisms, as described by a Mott-type model. Thicker films showed only one principal conductivity mechanism, similar to what might be expected for a material with more crystalline character.

  9. Continuous Sputter Deposition Coating of Long Monofilaments

    DTIC Science & Technology

    2014-04-01

    terminal. A length of fishing line, microtubing, or polylactic acid (PLA) coated with copper could be left to cure within an epoxy, and upon removal...inductance, capacitance, resistance min minute MSD magnetron sputter deposition PLA polylactic acid RPM revolutions per minute R resistance (units

  10. High-power sputtering employed for film deposition

    NASA Astrophysics Data System (ADS)

    Shapovalov, V. I.

    2017-07-01

    The features of high-power magnetron sputtering employed for the films’ deposition are reviewed. The main physical phenomena accompanying high-power sputtering including ion-electron emission, gas rarefaction, ionization of sputtered atoms, self-sputtering, ion sound waves and the impact of the target heating are described.

  11. Reactive sputter deposition of boron nitride

    SciTech Connect

    Jankowski, A.F.; Hayes, J.P.; McKernan, M.A.; Makowiecki, D.M.

    1995-10-01

    The preparation of fully dense, boron targets for use in planar magnetron sources has lead to the synthesis of Boron Nitride (BN) films by reactive rf sputtering. The deposition parameters of gas pressure, flow and composition are varied along with substrate temperature and applied bias. The films are characterized for composition using Auger electron spectroscopy, for chemical bonding using Raman spectroscopy and for crystalline structure using transmission electron microscopy. The deposition conditions are established which lead to the growth of crystalline BN phases. In particular, the growth of an adherent cubic BN coating requires 400--500 C substrate heating and an applied {minus}300 V dc bias.

  12. Contamination control in ion beam sputter-deposited films

    NASA Astrophysics Data System (ADS)

    Pearson, David I. C.; Pochon, Sebastien; Cooke, Mike

    2013-09-01

    The conventional wisdom to guarantee high purity thin films in IBSD has been to use a large vacuum chamber usually in excess of 1 m3. The chamber size was important to minimise the effect of reflected high energy particles from the target surface sputtering chamber materials onto the substrate and to allow the use of large targets to avoid beam overspill onto chamber furniture. An improved understanding of beam trajectories and re-sputtered material paths has allowed the deposition of thin films with very low metallic impurity content in a chamber volume below 0.5 m3. Thus, by optimizing the sputter ion source, target and substrate configuration, and by arranging suitable shielding made of an appropriate material in the process chamber, the levels of contaminants in the deposited films have been reduced to a minimum. With this optimum hardware arrangement, the ion beam process parameters were then optimized with respect to the ppm levels of contaminants measured in the films by SIMS analysis. Using the deposition of SiO2 as a standard material for DSIMS composition analysis and impurity level determination, it has been shown that our IBS deposition tool is capable of depositing films with contamination levels of <50ppm for the total of all metal impurities in the deposited films.

  13. Energy spectrum of sputtered uranium

    NASA Technical Reports Server (NTRS)

    Weller, R. A.; Tombrello, T. A.

    1977-01-01

    The fission track technique for detecting uranium 235 was used in conjunction with a mechanical time-of-flight spectrometer to measure the energy spectrum in the region 1 eV to 1 keV of material sputtered from a 93% enriched U-235 foil by 80 keV Ar-40(+) ions. The spectrum was found to exhibit a peak in the region 2-4 eV and to decrease approximately as E to the -1.77 power for E is approximately greater than 100 eV. The design, construction and resolution of the mechanical spectrometer are discussed and comparisons are made between the data and the predictions of the ramdom collision cascade model of sputtering.

  14. Investigating the Mg-Si Binary System via Combinatorial Sputter Deposition As High Energy Density Anodes for Lithium-Ion Batteries.

    PubMed

    Schmuelling, Guido; Winter, Martin; Placke, Tobias

    2015-09-16

    Mg-Si thin films with various elemental compositions ranging from 0≤x≤1 in MgxSi(1-x) were obtained via combinatorial magnetron sputter deposition of Si and Mg in order to improve the electrochemical lithiation/delithiation process of pure Si by embedding Si in an active Mg-Si matrix. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Raman spectroscopy methods were used to investigate the morphology, stoichiometry, and structure of the different thin film samples. Constant current charge/discharge cycling revealed significant electrochemical changes depending on the Mg content in comparison to the pure Si active material improving the capacity retention to 96% over 400 cycles.

  15. Sputtering deposition and characterization of ultrathin amorphous carbon films

    NASA Astrophysics Data System (ADS)

    Lu, Wei

    1999-11-01

    This dissertation focuses on experimental investigations of ultrathin, ultrasmooth amorphous carbon (a-C) films deposited on Si(100) substrates by radio frequency (RF) sputtering and characterization of the nanomechanical and nanotribological properties and thermal stability of the films. Ultrathin a-C films of thickness 5--100 nm and typical root-mean-square roughness of 0.15--1 nm were deposited on ultrasmooth Si(100) substrates using pure argon as the sputtering gas. A low-pressure RF argon discharge model was used to analyze the plasma parameters in the film growth environment. These plasma parameters correlate the deposition conditions with the film growth processes. Atomic force microscopy (AFM) and surface force microscopy (SFM) were used to characterize the nanomechanical and nanotribological properties of the a-C films. X-ray photoelectron spectroscopy (XPS) was used to investigate the compositions and microstructures of the films. Sputter-etching measurements of the a-C films by energetic argon ion bombardment were used to study the surface binding energy of carbon atoms in a-C films deposited under different conditions. The dependence of film properties on deposition conditions was studied, and relations between nanomechanical and nanotribological properties were discussed in terms of a modified deformation index. The deformation and nanotribology mechanisms of the a-C films were compared with those of other films, such as TiC and Cr films (both 100 nm thick), and bulk Si(100). Reactive RF sputtering of nitrogenated amorphous carbon (a-CNx) films was investigated by introducing nitrogen into the a-C films during film growth by using an argon-nitrogen gas mixture as the sputtering gas. The alloying effect of nitrogen on the film growth and properties, such as hardness and surface energy, was studied and interpreted in terms of the changes in the plasma environment induced due to differences in the composition of the sputtering gas mixture. The thermal

  16. Simulation of sputter deposition in dc magnetrons

    NASA Astrophysics Data System (ADS)

    Evstatiev, Evstati; Cluggish, Brian

    2010-11-01

    Material sputter deposition has a multitude of industrial applications. Our goal at FAR-TECH, Inc., is a complete numerical simulation of a dc magnetron device. We intend to modify existing FAR-TECH, Inc. code to include flexible geometry manipulation, the most current atomic physics data, add transport of neutral atoms across the device, and model deposition on the substrate. Currently, dc magnetron simulation codes have limited geometry manipulation capabilities; however, this is important if design optimization is intended. Another uncommon feature in dc magnetron simulation codes is parallel performance. Since PIC simulations may take extremely long times (weeks), we are parallelizing our codes to achieve shorter run times. (Codes based on hybrid models perform faster, but have the disadvantage of having to know accurately the diffusion coefficients of electrons across the magnetic field lines.) We report preliminary results of this effort.

  17. Magnetron sputtering system for coatings deposition with activation of working gas mixture by low-energy high-current electron beam

    NASA Astrophysics Data System (ADS)

    Gavrilov, N. V.; Kamenetskikh, A. S.; Men'shakov, A. I.; Bureyev, O. A.

    2015-11-01

    For the purposes of efficient decomposition and ionization of the gaseous mixtures in a system for coatings deposition using reactive magnetron sputtering, a low-energy (100-200 eV) high-current electron beam is generated by a grid-stabilized plasma electron source. The electron source utilizes both continuous (up to 20 A) and pulse-periodic mode of discharge with a self-heated hollow cathode (10-100 A; 0.2 ms; 10-1000 Hz). The conditions for initiation and stable burning of the high-current pulse discharge are studied along with the stable generation of a low-energy electron beam within the gas pressure range of 0.01 - 1 Pa. It is shown that the use of the electron beam with controllable parameters results in reduction of the threshold values both for the pressure of gaseous mixture and for the fluxes of molecular gases. Using such a beam also provides a wide range (0.1-10) of the flux density ratios of ions and sputtered atoms over the coating surface, enables an increase in the maximum pulse density of ion current from plasma up to 0.1 A, ensures an excellent adhesion, optimizes the coating structure, and imparts improved properties to the superhard nanocomposite coatings of (Ti,Al)N/a-Si3N4 and TiC/-a-C:H. Mass-spectrometric measurements of the beam-generated plasma composition proved to demonstrate a twofold increase in the average concentration of N+ ions in the Ar-N2 plasma generated by the high-current (100 A) pulsed electron beam, as compared to the dc electron beam.

  18. Sputtering Threshold Energies of Heavy Ions

    NASA Technical Reports Server (NTRS)

    Mantenieks, Maris A.

    1999-01-01

    Sputter erosion in ion thrusters has been measured in lifetests at discharge voltages as low as 25 V. Thruster operation at this discharge voltage results in component erosion rates sufficiently low to satisfy most mission requirements. It has been recognized that most of the internal sputtering in ion thrusters is done by doubly charged ions. Knowledge of the sputtering threshold voltage of a xenon molybdenum system would be beneficial in understanding the sputtering process as well as making more accurate calculations of the sputtering rates of ion thruster components. Sputtering threshold energies calculated from various formulations found in the literature results in values ranging from 28 to 200 eV. It is evident that some of these formulations cannot be relied upon to provide sputtering thresholds with any degree of accuracy. This paper re-examines the threshold energies measurements made in the early sixties by Askerov and Sena, and Stuart and Wehner. The threshold voltages as derived by Askerov and au have been reevaluated by using a different extrapolation method of sputter yields at low ion energies. The resulting threshold energies are in general similar to those measured by Stuart and Wehner. An empirical relationship is derived,for mercury and xenon ions for the ratio of the sputtering threshold energy to the sublimation energy as a function of the ratio of target to ion atomic mass.

  19. Mass Deposition, Etching and Sputtering Effects of Low-Energy N+ Ion Irradiation on Solid Fly Ash

    NASA Astrophysics Data System (ADS)

    Miao, Chunguang; Wang, Xiangqin

    2013-12-01

    Fly ash is an industrial waste created when coal is burned to generate electrical power. In the present study, we used low-energy nitrogen ion implantation on fly ash to improve its surface properties. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) were used to study the changes of physical and chemical properties of fly ash after N+ ion implantation, and the mechanism of fly ash modified by ion implantation. In the optimal implantation with energy of 5 keV and dose of 15D0, the ion beam could effectively increase the specific surface area (approximately 150% increase) of the fly ash. Lots of scratches were generated in the surface of the fly ash after N+ ion implantation, therefore it is good for enhancing the specific surface area. Experimental results show that the ion implantation could open the chemical bonds of Si-O, Si-Al and Al-O, and deposit nitrogen ions on the surface of fly ash.

  20. Sputter-deposited fuel cell membranes and electrodes

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Jeffries-Nakamura, Barbara (Inventor); Chun, William (Inventor); Ruiz, Ron P. (Inventor); Valdez, Thomas I. (Inventor)

    2001-01-01

    A method for preparing a membrane for use in a fuel cell membrane electrode assembly includes the steps of providing an electrolyte membrane, and sputter-depositing a catalyst onto the electrolyte membrane. The sputter-deposited catalyst may be applied to multiple sides of the electrolyte membrane. A method for forming an electrode for use in a fuel cell membrane electrode assembly includes the steps of obtaining a catalyst, obtaining a backing, and sputter-depositing the catalyst onto the backing. The membranes and electrodes are useful for assembling fuel cells that include an anode electrode, a cathode electrode, a fuel supply, and an electrolyte membrane, wherein the electrolyte membrane includes a sputter-deposited catalyst, and the sputter-deposited catalyst is effective for sustaining a voltage across a membrane electrode assembly in the fuel cell.

  1. Modeling of iron oxide deposition by reactive ion beam sputtering

    SciTech Connect

    Puech, Laurent; Dubarry, Christophe; Ravel, Guillaume; Vito, Eric de

    2010-03-15

    An analytic model of deposition is applied on reactive ion beam sputtering to optimize the properties of iron oxide thin films. This model will be able to predict deposition rate and phase contents. Among its hypotheses, we assume oxygen adsorption at the surface of the target to explain variations of deposition rate for oxygen flow. This hypothesis is validated by chemical analyses on iron targets. An ellipsoidal distribution of probability is introduced to model sputtered matter distribution from iron target and to calculate sputtering yield. Comparison between experimental and calculated deposition rates validates previously assumed hypotheses.

  2. Sputter deposition of metallic thin film and directpatterning

    SciTech Connect

    Ji, L.; Chen, Y.; Jiang, X.; Ji, Q.; Leung, K.-N.

    2005-09-09

    A compact apparatus is developed for deposition of metal thin film. The system employs an RF discharge plasma source with a straight RF antenna, which is made of or covered with deposition material, serving as sputtering target at the same time. The average deposition rate of copper thin film is as high as 450nm/min. By properly allocating the metal materials on the sputtering antenna, mixture deposition of multiple metal species is achieved. Using an ion beam imprinting scheme also taking advantage of ion beam focusing technique, two different schemes of direct patterning deposition process are developed: direct depositing patterned metallic thin film and resistless ion beam sputter patterning. Preliminary experiments have demonstrated direct pattern transfer from a template with feature size of micro scale; patterns with more than 10x reduction are achieved by sputtering patterning method.

  3. Low-temperature crystallization of TiO2 films by sputter deposition

    NASA Astrophysics Data System (ADS)

    Taga, Yasunori; Yamada, Naoomi

    2010-04-01

    Crystalline TiO2 film was formed on PET(polyethlene terephthalate) film by radio frequency sputter deposition method using a sintered TiO2 target by adding H2O gas to Ar gas for sputtering. X-ray diffraction analysis revealed that the crystal structure of the film of 100 nm thick was confirmed to be anatase crystallites of TiO2. In order to elucidate the mechanism of low temperature crystallization thus observed, direct measurement of surface temperature of growing films during sputter deposition was carried out by two methods of an infrared thermometer from the outside of vacuum chamber and a thermocouple attached to the growing film surface. Upon the beginning of sputter deposition in Ar gas, film temperature increased rapidly and became constant at 120°C after 30 min. Addition of H2O gas to Ar gas for sputtering resulted in further increase in film temperature and reached to 230 °C depending on the deposition conditions. Furthermore, photocatalytic performance of decomposition of methylene blue was examined to be enhanced remarkably as a result of crystallization of the film. It was concluded that low temperature crystallization of TiO2 film by sputter deposition was explained in terms of local heating of thin shallow surface region of growing film by kinetic energy deposition of sputtered particles.

  4. Effect of sputtering power on the growth of Ru films deposited by magnetron sputtering

    SciTech Connect

    Jhanwar, Prachi; Kumar, Arvind; Rangra, K. J.; Verma, Seema

    2016-04-13

    Ruthenium is deposited by DC magnetron sputtering at different powers and is characterized. The effect of sputtering power on the electrical and structural properties of the film is investigated experimentally. High resolution X-ray diffraction is used to characterize the microstructure of Ru films deposited on SiO{sub 2} surface. The peak (002) is more sharp and intense with full width at half maximum (FWHM) of 0.37° at 250W. The grain size increases with increase in sputtering power improving the crystallinity of the film. The film deposited at high sputtering power also showed lower resistivity (12.40 µΩ-cm) and higher mobility (4.82 cm{sup 2}/V.s) as compared to the film deposited at low power. The surface morphology of the film is studied by atomic force microscopy (AFM).

  5. Effect of sputtering power on the growth of Ru films deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Jhanwar, Prachi; Kumar, Arvind; Verma, Seema; Rangra, K. J.

    2016-04-01

    Ruthenium is deposited by DC magnetron sputtering at different powers and is characterized. The effect of sputtering power on the electrical and structural properties of the film is investigated experimentally. High resolution X-ray diffraction is used to characterize the microstructure of Ru films deposited on SiO2 surface. The peak (002) is more sharp and intense with full width at half maximum (FWHM) of 0.37° at 250W. The grain size increases with increase in sputtering power improving the crystallinity of the film. The film deposited at high sputtering power also showed lower resistivity (12.40 µΩ-cm) and higher mobility (4.82 cm2/V.s) as compared to the film deposited at low power. The surface morphology of the film is studied by atomic force microscopy (AFM).

  6. Sputter deposition of lithium silicate - lithium phosphate amorphous electrolytes

    SciTech Connect

    Dudney, N.J.; Bates, J.B.; Luck, C.F. ); Robertson, J.D. . Dept. of Chemistry)

    1991-01-01

    Thin films of an amorphous lithium-conducting electrolyte were deposited by rf magnetron sputtering of ceramic targets containing Li{sub 4}SiO{sub 4} and Li{sub 3}PO{sub 4}. The lithium content of the films was found to depend more strongly on the nature and composition of the targets than on many other sputtering parameters. For targets containing Li{sub 4}SiO{sub 4}, most of the lithium was found to segregate away from the sputtered area of the target. Codeposition using two sputter sources achieves a high lithium content in a controlled and reproducible film growth. 10 refs., 4 figs.

  7. Deposition of reactively ion beam sputtered silicon nitride coatings

    NASA Technical Reports Server (NTRS)

    Grill, A.

    1982-01-01

    An ion beam source was used to deposit silicon nitride films by reactively sputtering a silicon target with beams of Ar + N2 mixtures. The nitrogen fraction in the sputtering gas was 0.05 to 0.80 at a total pressure of 6 to 2 millionth torr. The ion beam current was 50 mA at 500 V. The composition of the deposited films was investigated by auger electron spectroscopy and the rate of deposition was determined by interferometry. A relatively low rate of deposition of about 2 nm. one-tenth min. was found. AES spectra of films obtained with nitrogen fractions higher than 0.50 were consistent with a silicon to nitrogen ratio corresponding to Si3N4. However the AES spectra also indicated that the sputtered silicon nitride films were contaminated with oxygen and carbon and contained significant amounts of iron, nickel, and chromium, most probably sputtered from the holder of the substrate and target.

  8. Thermochromism of sputter-deposited vanadium oxyfluoride coatings

    SciTech Connect

    Khan, K.A.; Granqvist, C.G.

    1990-12-31

    Thermochromism offers interesting possibilities for controlling the radiative throughput through windows, as well as for numerous other applications. The purpose of this brief paper is to point at the potential and prospects of using sputter-deposited vanadium oxyfluoride coatings. A thermochromic coating, suitable for energy-efficient windows, is characterized by a transmittance which drops as the temperature goes above a certain comfort temperature.Thermochromism in VO{sub 2}-based materials is well known; it is connected with a reversible structural transition from a low-temperature monoclinic phase to a high-temperature phase with metallic-like properties. The metallic phase is characterized by a plasma wavelength at {approximately} 1 {mu}m. Hence it is possible to accomplish a temperature-dependent modulation of the near-infrared transmittance. In order to produce a practically useful window coating, the VO{sub 2}-based material must be processed suitably. The authors discuss how magnetron sputtering can be used for (potential) large-area deposition. Among the many alternative approaches for depressing the phase change temperature they note the replacement of oxygen by fluorine and the introduction of stress either from the substrate or from a suitable overlayer. The work reported here deals with fluorination through reactive sputter deposition. A key result, reported below, is that the fluorination leads to a significant decrease of the luminous absorptance. Finally, it may be that a practical window coating must invoke a three-layer design with a VO{sub 2}-based coating embedded between antireflecting dielectric layers; this latter point will not be pursued further here.

  9. Deposition Rates of High Power Impulse Magnetron Sputtering: Physics and Economics

    SciTech Connect

    Anders, Andre

    2009-11-22

    Deposition by high power impulse magnetron sputtering (HIPIMS) is considered by some as the new paradigm of advanced sputtering technology, yet this is met with skepticism by others for the reported lower deposition rates, if compared to rates of more conventional sputtering of equal average power. In this contribution, the underlying physical reasons for the rate changes are discussed, including (i) ion return to the target and self-sputtering, (ii) the less-than-linear increase of the sputtering yield with increasing ion energy, (iii) yield changes due to the shift of species responsible for sputtering, (iv) changes to due to greater film density, limited sticking, and self-sputtering on the substrate, (v) noticeable power losses in the switch module, (vi) changes of the magnetic balance and particle confinement of the magnetron due to self-fields at high current, and (vii) superposition of sputtering and sublimation/evaporation for selected materials. The situation is even more complicated for reactive systems where the target surface chemistry is a function of the reactive gas partial pressure and discharge conditions. While most of these factors imply a reduction of the normalized deposition rate, increased rates have been reported for certain conditions using hot targets and less poisoned targets. Finally, some points of economics and HIPIMS benefits considered.

  10. Deposition rates of high power impulse magnetron sputtering: Physics and economics

    SciTech Connect

    Anders, Andre

    2010-07-15

    Deposition by high power impulse magnetron sputtering (HIPIMS) is considered by some as the new paradigm of advanced sputtering technology, yet this is met with skepticism by others for the reported lower deposition rates, if compared to rates of more conventional sputtering of equal average power. In this contribution, the underlying physical reasons for the rate changes are discussed, including (i) ion return to the target and self-sputtering, (ii) the less-than-linear increase in the sputtering yield with increasing ion energy, (iii) yield changes due to the shift of species responsible for sputtering, (iv) changes due to greater film density, limited sticking, and self-sputtering on the substrate, (v) noticeable power losses in the switch module, (vi) changes in the magnetic balance and particle confinement of the magnetron due to self-fields at high current, and (vii) superposition of sputtering and sublimation/evaporation for selected materials. The situation is even more complicated for reactive systems where the target surface chemistry is a function of the reactive gas partial pressure and discharge conditions. While most of these factors imply a reduction in the normalized deposition rate, increased rates have been reported for certain conditions using hot targets and less poisoned targets. Finally, some points of economics and HIPIMS benefits are considered.

  11. Sputter deposition of nanocrystalline beta-SiC films and molecular dynamics simulations of the sputter process.

    PubMed

    Ziebert, Carlos; Ye, Jian; Ulrich, Sven; Prskalo, Alen-Pilip; Schmauder, Siegfried

    2010-02-01

    Thin nanocrystalline films of silicon carbide (SiC) have been deposited on Si substrates by rf magnetron sputtering in pure Ar atmosphere. Simultaneously classical molecular dynamics (MD) simulations of sputtering of beta-SiC by Ar atoms were performed using IMD and Materials Explorer software with a combination of the Tersoff and the Ziegler-Biersack-Littmark (ZBL) potential in order to get more insight into the sputter process. In experiments the bias voltage (0 to -40 V) has been varied at constant substrate temperature of 900 degrees C to investigate the influence on the composition, the constitution and the mechanical properties of crystalline beta-SiC films. At second the substrate temperature has been varied between 900 degrees C and 100 degrees C to find the minimum substrate temperature that is needed to get nanocrystalline beta-SiC under the applied sputter conditions (ceramic SiC target, 300 W rf power, 18 cm target-substrate distance, 50 sccm Ar gas flow, 0.26 Pa total gas pressure). The films have been characterized by electron probe micro-analysis (EPMA), X-ray diffraction (XRD), Raman spectroscopy and atomic force microscopy (AFM). Hardness and residual stress have been investigated by nanoindentation and wafer bending. In the MD simulations the sputter yield was determined as a function of the energy of the incident Ar atoms (in the interesting range for sputter deposition, i.e., 50-1000 eV). To our knowledge this is the first time that the sputter yield of a SiC target was determined as a function of the energy of the incident Ar atoms in the low energy range by using MD simulations and compared with experimental results.

  12. Development of latent fingerprints using preferential DC sputter deposition.

    PubMed

    Kent, K; Stoilovic, M

    1995-03-21

    It was shown that a DC metal sputtering process with thermalised atoms, preferentially deposits metal onto fingerprint ridges. This method can be successfully used for the development of latent fingerprints. Four target metals were tested--copper, zinc, platinum, and gold--with platinum showing superior results for latent fingerprint development on clear polythene substrates. A comparison of platinum sputtering and cyanoacrylate fuming followed by rhodamine-6G staining, was conducted for 1-year-old fingerprint deposits. Platinum sputtering showed significantly higher sensitivity, and produced better overall results.

  13. Sputter deposition for multi-component thin films

    DOEpatents

    Krauss, Alan R.; Auciello, Orlando

    1990-01-01

    Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams.

  14. Sputter deposition for multi-component thin films

    DOEpatents

    Krauss, A.R.; Auciello, O.

    1990-05-08

    Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams. 10 figs.

  15. View factor modeling of sputter-deposition on micron-scale-architectured surfaces exposed to plasma

    SciTech Connect

    Huerta, C. E. Matlock, T. S.; Wirz, R. E.

    2016-03-21

    The sputter-deposition on surfaces exposed to plasma plays an important role in the erosion behavior and overall performance of a wide range of plasma devices. Plasma models in the low density, low energy plasma regime typically neglect micron-scale surface feature effects on the net sputter yield and erosion rate. The model discussed in this paper captures such surface architecture effects via a computationally efficient view factor model. The model compares well with experimental measurements of argon ion sputter yield from a nickel surface with a triangle wave geometry with peak heights in the hundreds of microns range. Further analysis with the model shows that increasing the surface pitch angle beyond about 45° can lead to significant decreases in the normalized net sputter yield for all simulated ion incident energies (i.e., 75, 100, 200, and 400 eV) for both smooth and roughened surfaces. At higher incident energies, smooth triangular surfaces exhibit a nonmonotonic trend in the normalized net sputter yield with surface pitch angle with a maximum yield above unity over a range of intermediate angles. The resulting increased erosion rate occurs because increased sputter yield due to the local ion incidence angle outweighs increased deposition due to the sputterant angular distribution. The model also compares well with experimentally observed radial expansion of protuberances (measuring tens of microns) in a nano-rod field exposed to an argon beam. The model captures the coalescence of sputterants at the protuberance sites and accurately illustrates the structure's expansion due to deposition from surrounding sputtering surfaces; these capabilities will be used for future studies into more complex surface architectures.

  16. Investigation of structural, optical and electrical properties of (Ti,Nb)Ox thin films deposited by high energy reactive magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Mazur, Michal; Kaczmarek, Danuta; Prociow, Eugeniusz; Domaradzki, Jaroslaw; Wojcieszak, Damian; Bocheński, Jakub

    2014-09-01

    In this work the results of investigations of the titanium-niobium oxides thin films have been reported. The thin films were manufactured with the aid of a modified reactive magnetron sputtering process. The aim of the research was the analysis of structural, optical and electrical properties of the deposited thin films. Additionally, the influence of post-process annealing on the properties of studied coatings has been presented. The as-deposited coatings were amorphous, while annealing at 873 K caused a structural change to the mixture of TiO2 anatase-rutile phases. The prepared thin films exhibited good transparency with transmission level of ca. 50 % and low resistivity varying from 2 Ωcm to 5×10-2 Ωcm, depending on the time and temperature of annealing. What is worth to emphasize, the sign of Seebeck coefficient changed after the annealing process from the electron to hole type electrical conduction.

  17. Sputter deposition of stress-controlled piezoelectric AlN and AlScN films for ultrasonic and energy harvesting applications.

    PubMed

    Barth, Stephan; Bartzsch, Hagen; Gloess, Daniel; Frach, Peter; Herzog, Thomas; Walter, Susan; Heuer, Henning

    2014-08-01

    This paper reports on the deposition and characterization of piezoelectric AlN and AlXSc1-XN layers. Characterization methods include XRD, SEM, active thermo probe, pulse echo, and piezometer measurements. A special focus is on the characterization of AlN regarding the mechanical stress in the films. The stress in the films changed between -2.2 GPa (compressive) and 0.2 GPa (tensile) and showed a significant dependence on film thickness. The cause of this behavior is presumed to be the different mean grain sizes at different film thicknesses, with bigger mean grain sizes at higher thicknesses. Other influences on film stress such as the sputter pressure or the pulse mode are presented. The deposition of gradient layers using those influences allowed the adjustment of film stress while retaining the piezoelectric properties.

  18. Sputter deposition with nearly-parallel coating flux

    SciTech Connect

    Patten, J.W.; McClanahan, E.D.; Moss, R.W.; Bayne, M.A.

    1981-04-01

    A method for producing a dense, nearly-parallel flux of sputtered atoms is described. This method allows sputter depositing films having substantially 100% of theoretical density. The sputtering chamber contains a target having a surface that is substantially parallel to the direction of the particles impinging upon the substrate surface, the distance between the most remote portion of the substrate surface receiving the particles and the target surface emitting the particles in a direction parallel to the substrate surface being relatively small. The pressure in the vessel is maintained less than about .65 Pa to limit scattering and permit line-of-sight deposition. The angles of incidence of the particles impinging upon the substrate surface do not vary greatly even when the target surface area is greatly expanded to increase the deposition rate. An experimental sputtering system is described. Deposition rates are given as a function of distance from the target edge and distance from the target plane. Metallography of sputter deposited Ni is presented.

  19. Integration of in situ RHEED with magnetron sputter deposition for atomic layer controlled growth

    NASA Astrophysics Data System (ADS)

    Podkaminer, Jacob P.

    Epitaxial thin films continue to be one of the most promising topics within electronic materials research. Sputter deposition is one process by which these films can be formed and is a widely used growth technique for a large range of technologically important material systems. Epitaxial films of carbides, nitrides, metals, oxides and more can all be formed during the sputter process which offers the ability to deposit smooth and uniform films from the research level up to an industrial scale. This tunable kinematic deposition process excels in easily adapting for a large range of environments and growth procedures. Despite the vast advantages associated with sputter deposition, there is a significant lack of in situ analysis options during sputtering. In particular, the area of real time atomic layer control is severely deficient. Atomic layer controlled growth of epitaxial thin films and artificially layered superlattices is critical for both understanding their emergent phenomena and engineering novel material systems and devices. Reflection high-energy electron diffraction (RHEED) is one of the most common in situ analysis techniques during thin film deposition that is rarely used during sputtering due to the strong permanent magnets in magnetron sputter sources and their effect on the RHEED electron beam. In this work we have solved this problem and designed a novel way to deter the effect of the magnets for a wide range of growth geometries and demonstrate the ability for the first time to have layer by layer control during sputter deposition by in situ RHEED. A novel growth chamber that can seamlessly change between pulsed laser deposition and sputtering with RHEED for the growth of complex heterostructures has been designed and implemented. Epitaxial thin films of LaAlO3, La1-xSrxMnO3, and SrRuO3 have all been deposited by sputtering and shown to exhibit clear and extended RHEED oscillations. To solve the magnet issue, a finite element model has been

  20. On the evolution of film roughness during magnetron sputtering deposition

    SciTech Connect

    Turkin, A. A.; Pei, Y. T.; Shaha, K. P.; Chen, C. Q.; Vainshtein, D. I.; De Hosson, J. Th. M.

    2010-11-15

    The effect of long-range screening on the surface morphology of thin films grown with pulsed-dc (p-dc) magnetron sputtering is studied. The surface evolution is described by a stochastic diffusion equation that includes the nonlocal shadowing effects in three spatial dimensions. The diffusional relaxation and the angular distribution of the incident particle flux strongly influence the transition to the shadowing growth regime. In the magnetron sputtering deposition the shadowing effect is essential because of the configuration of the magnetron system (finite size of sputtered targets, rotating sample holder, etc.). A realistic angular distribution of depositing particles is constructed by taking into account the cylindrical magnetron geometry. Simulation results are compared with the experimental data of surface roughness evolution during 100 and 350 kHz p-dc deposition, respectively.

  1. Low-energy sputterings with the Monte Carlo Program ACAT

    NASA Astrophysics Data System (ADS)

    Yamamura, Y.; Mizuno, Y.

    1985-05-01

    The Monte Carlo program ACAT was developed to determine the total sputtering yields and angular distributions of sputtered atoms in physical processes. From computer results of the incident-energy dependent sputterings for various ion-target combinations the mass-ratio dependence and the bombarding-angle dependence of sputtering thresholds was obtained with the help of the Matsunami empirical formula for sputtering yields. The mass-ratio dependence of sputtering thresholds is in good agreement with recent theoretical results. The threshold energy of light-ion sputtering is a slightly increasing function of angle of incidence, while that of heavy-ion sputtering has a minimum value near theta = 60 deg. The angular distributions of sputtered atoms are also calculated for heavy ions, medium ions, and light ions, and reasonable agreements between calculated angular distributions and experimental results are obtained.

  2. Coating of nanoporous membranes: atomic layer deposition versus sputtering.

    PubMed

    Grigoras, K; Airaksinen, V M; Franssila, S

    2009-06-01

    Nanoporous anodic alumina membranes and silicon samples with plasma etched nanopores have been coated with zinc oxide or gold layer using atomic layer deposition (ALD) or sputtering, respectively. In the case of ALD process, the precursor pulses were extended, compared with planar substrate coating. Thick (60 microm) anodic alumina membranes have been conformally coated with zinc oxide ALD layer. Metal sputtering technique was used just for opposite purpose--to minimize the penetration of gold into the pores during gold-coating of the top and bottom surfaces of the membrane. Scanning electron microscopy (SEM) has been used to investigate the layer thickness, uniformity and conformality inside the nanopores.

  3. Low Energy Sputtering Experiments for Ion Engine Lifetime Assessment

    NASA Technical Reports Server (NTRS)

    Duchemin Olivier B.; Polk, James E.

    1999-01-01

    The sputtering yield of molybdenum under xenon ion bombardment was measured using a Quartz Crystal Microbalance. The measurements were made for ion kinetic energies in the range 100-1keV on molybdenum films deposited by magnetron sputtering in conditions optimized to reproduce or approach bulk-like properties. SEM micrographs for different anode bias voltages during the deposition are compared, and four different methods were implemented to estimate the density of the molybdenum films. A careful discussion of the Quartz Crystal Microbalance is proposed and it is shown that this method can be used to measure mass changes that are distributed unevenly on the crystal electrode surface, if an analytical expression is known for the differential mass-sensitivity of the crystal and the erosion profile. Finally, results are presented that are in good agreement with previously published data, and it is concluded that this method holds the promise of enabling sputtering yield measurements at energies closer to the threshold energy in the very short term.

  4. Deposition of PTFE thin films by ion beam sputtering and a study of the ion bombardment effect

    NASA Astrophysics Data System (ADS)

    He, J. L.; Li, W. Z.; Wang, L. D.; Wang, J.; Li, H. D.

    1998-02-01

    Ion beam sputtering technique was employed to prepare thin films of Polytetrafluroethylene (PTFE). Simultaneous ion beam bombardment during film growth was also conducted in order to study the bombardment effects. Infrared absorption (IR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis was used to evaluate the material's integrity. It was found that PTFE thin films could be grown at room temperature by direct sputtering of a PTFE target. The film's composition and structure were shown to be dependent on the sputtering energy. Films deposited by single sputtering at higher energy (˜1500 eV) were structurally quite similar to the original PTFE material. Simultaneous ion beam bombarding during film growth caused defluorination and structural changes. Mechanism for sputtering deposition of such a polymeric material is also discussed.

  5. Composition and structure of sputter deposited erbium hydride thin films

    SciTech Connect

    ADAMS,DAVID P.; ROMERO,JUAN A.; RODRIGUEZ,MARK A.; FLORO,JERROLD A.; BANKS,JAMES C.

    2000-05-10

    Erbium hydride thin films are grown onto polished, a-axis {alpha} Al{sub 2}O{sub 3} (sapphire) substrates by reactive ion beam sputtering and analyzed to determine composition, phase and microstructure. Erbium is sputtered while maintaining a H{sub 2} partial pressure of 1.4 x 10{sup {minus}4} Torr. Growth is conducted at several substrate temperatures between 30 and 500 C. Rutherford backscattering spectrometry (RBS) and elastic recoil detection analyses after deposition show that the H/Er areal density ratio is approximately 3:1 for growth temperatures of 30, 150 and 275 C, while for growth above {approximately}430 C, the ratio of hydrogen to metal is closer to 2:1. However, x-ray diffraction shows that all films have a cubic metal sublattice structure corresponding to that of ErH{sub 2}. RBS and Auger electron that sputtered erbium hydride thin films are relatively free of impurities.

  6. Method to control deposition rate instabilities—High power impulse magnetron sputtering deposition of TiO{sub 2}

    SciTech Connect

    Kossoy, Anna E-mail: anna.kossoy@gmail.com; Magnusson, Rögnvaldur L.; Tryggvason, Tryggvi K.; Leosson, Kristjan; Olafsson, Sveinn

    2015-03-15

    The authors describe how changes in shutter state (open/closed) affect sputter plasma conditions and stability of the deposition rate of Ti and TiO{sub 2} films. The films were grown by high power impulse magnetron sputtering in pure Ar and in Ar/O{sub 2} mixture from a metallic Ti target. The shutter state was found to have an effect on the pulse waveform for both pure Ar and reactive sputtering of Ti also affecting stability of TiO{sub 2} deposition rate. When the shutter opened, the shape of pulse current changed from rectangular to peak-plateau and pulse energy decreased. The authors attribute it to the change in plasma impedance and gas rarefaction originating in geometry change in front of the magnetron. TiO{sub 2} deposition rate was initially found to be high, 1.45 Å/s, and then dropped by ∼40% during the first 5 min, while for Ti the change was less obvious. Instability of deposition rate poses significant challenge for growing multilayer heterostructures. In this work, the authors suggest a way to overcome this by monitoring the integrated average energy involved in the deposition process. It is possible to calibrate and control the film thickness by monitoring the integrated pulse energy and end growth when desired integrated pulse energy level has been reached.

  7. Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation.

    PubMed

    Schroeder, J L; Thomson, W; Howard, B; Schell, N; Näslund, L-Å; Rogström, L; Johansson-Jõesaar, M P; Ghafoor, N; Odén, M; Nothnagel, E; Shepard, A; Greer, J; Birch, J

    2015-09-01

    We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (>50 keV), high photon flux (>10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (<1 s) two-dimensional (2D) detector, permits time-resolved in situ structural analysis of thin film formation processes. The high-energy synchrotron-radiation based x-rays result in small scattering angles (<11°), allowing large areas of reciprocal space to be imaged with a 2D detector. The system has been designed for use on the 1-tonne, ultra-high load, high-resolution hexapod at the P07 High Energy Materials Science beamline at PETRA III at the Deutsches Elektronen-Synchrotron in Hamburg, Germany. The deposition system includes standard features of a typical UHV deposition system plus a range of special features suited for synchrotron radiation studies and industry-relevant processes. We openly encourage the materials research community to contact us for collaborative opportunities using this unique and versatile scientific instrument.

  8. Microstructure and Electrical Properties of Antimony Telluride Thin Films Deposited by RF Magnetron Sputtering on Flexible Substrate Using Different Sputtering Pressures

    NASA Astrophysics Data System (ADS)

    Khumtong, T.; Sukwisute, P.; Sakulkalavek, A.; Sakdanuphab, R.

    2017-05-01

    The microstructural, electrical, and thermoelectric properties of antimony telluride (Sb2Te3) thin films have been investigated for thermoelectric applications. Sb2Te3 thin films were deposited on flexible substrate (polyimide) by radiofrequency (RF) magnetron sputtering from a Sb2Te3 target using different sputtering pressures in the range from 4 × 10-3 mbar to 1.2 × 10-2 mbar. The crystal structure, [Sb]:[Te] ratio, and electrical and thermoelectric properties of the films were analyzed by grazing-incidence x-ray diffraction (XRD) analysis, energy-dispersive x-ray spectroscopy (EDS), and Hall effect and Seebeck measurements, respectively. The XRD spectra of the films demonstrated polycrystalline structure with preferred orientation of (015), (110), and (1010). A high-intensity spectrum was found for the film deposited at lower sputtering pressure. EDS analysis of the films revealed the effects of the sputtering pressure on the [Sb]:[Te] atomic ratio, with nearly stoichiometric films being obtained at higher sputtering pressure. The stoichiometric Sb2Te3 films showed p-type characteristics with electrical conductivity, carrier concentration, and mobility of 35.7 S cm-1, 6.38 × 1019 cm-3, and 3.67 cm2 V-1 s-1, respectively. The maximum power factor of 1.07 × 10-4 W m-1 K-2 was achieved for the film deposited at sputtering pressure of 1.0 × 10-2 mbar.

  9. Microstructure and Electrical Properties of Antimony Telluride Thin Films Deposited by RF Magnetron Sputtering on Flexible Substrate Using Different Sputtering Pressures

    NASA Astrophysics Data System (ADS)

    Khumtong, T.; Sukwisute, P.; Sakulkalavek, A.; Sakdanuphab, R.

    2017-02-01

    The microstructural, electrical, and thermoelectric properties of antimony telluride (Sb2Te3) thin films have been investigated for thermoelectric applications. Sb2Te3 thin films were deposited on flexible substrate (polyimide) by radiofrequency (RF) magnetron sputtering from a Sb2Te3 target using different sputtering pressures in the range from 4 × 10-3 mbar to 1.2 × 10-2 mbar. The crystal structure, [Sb]:[Te] ratio, and electrical and thermoelectric properties of the films were analyzed by grazing-incidence x-ray diffraction (XRD) analysis, energy-dispersive x-ray spectroscopy (EDS), and Hall effect and Seebeck measurements, respectively. The XRD spectra of the films demonstrated polycrystalline structure with preferred orientation of (015), (110), and (1010). A high-intensity spectrum was found for the film deposited at lower sputtering pressure. EDS analysis of the films revealed the effects of the sputtering pressure on the [Sb]:[Te] atomic ratio, with nearly stoichiometric films being obtained at higher sputtering pressure. The stoichiometric Sb2Te3 films showed p-type characteristics with electrical conductivity, carrier concentration, and mobility of 35.7 S cm-1, 6.38 × 1019 cm-3, and 3.67 cm2 V-1 s-1, respectively. The maximum power factor of 1.07 × 10-4 W m-1 K-2 was achieved for the film deposited at sputtering pressure of 1.0 × 10-2 mbar.

  10. Deposition and characterization of magnetron sputtered bcc tantalum

    NASA Astrophysics Data System (ADS)

    Patel, Anamika

    The goal of this thesis was to provide scientific and technical research results for developing and characterizing tantalum (Ta) coatings on steel substrates deposited by DC magnetron sputtering. Deposition of tantalum on steel is of special interest for the protection it offers to surfaces, e.g. the surfaces of gun barrels against the erosive wear of hot propellant gases and the mechanical damage caused by the motion of launching projectiles. Electro-plated chromium is presently most commonly used for this purpose; however, it is considered to be carcinogenic in its hexavalent form. Tantalum is being investigated as non-toxic alternative to chromium and also because of its superior protective properties in these extreme environments. DC magnetron sputtering was chosen for this investigation of tantalum coatings on steel substrates because it is a versatile industrial proven process for deposition of metals. Sputter deposited Ta films can have two crystallographic structures: (1) body center cubic (bcc) phase, characterized by high toughness and high ductility and (2) a tetragonal beta phase characterized by brittleness and a tendency to fail under stress. It was found in this work that the bcc Ta coatings on steel can be obtained reliably by either of two methods: (1) depositing Ta on a submicron, stoichiometric TaN seed layer reactively sputtered on unheated steel and (2) depositing Ta directly on steel heated above a critical temperature. For argon sputtering gas this critical temperature was found to be 400°C at a pressure of 5 mtorr. With the heavier krypton gas, this critical temperature is reduced to 350°C. X-ray diffraction (XRD) was used to investigate the structure of tantalum and nitride films, and the composition of the nitride films was measured by nuclear reaction analyses (NRA), which were used to study in detail the enhancement of the bcc phase of Ta on steel. The scratch adhesion tests performed with a diamond hemispherical tip of radius 200 mum

  11. Sputter deposited Terfenol-D thin films for multiferroic applications

    NASA Astrophysics Data System (ADS)

    Mohanchandra, K. P.; Prikhodko, S. V.; Wetzlar, K. P.; Sun, W. Y.; Nordeen, P.; Carman, G. P.

    2015-09-01

    In this paper, we study the sputter deposition and crystallization process to produce high quality Terfenol-D thin film (100 nm) with surface roughness below 1.5 nm. The Terfenol-D thin film was produced using DC magnetron sputtering technique with various sputtering parameters and two different crystallization methods, i.e. substrate heating and post-annealing. Several characterization techniques including WDS, XRD, TEM, AFM, SQUID and MOKE were used to determine the physical and magnetic properties of the Terfenol-D films. TEM studies reveal that the film deposited on the heated substrate has large grains grown along the film thickness producing undesirable surface roughness while the film crystallized by post-annealing method shows uniformly distributed small grains producing a smooth surface. The Terfenol-D film was also deposited onto (011) cut PMN-PT single crystal substrate. With the application of an electric field the film exhibited a 1553 Oe change in coercivity with an estimated saturation magnetostriction of λs = 910 x 10-6.

  12. Sputter deposited beryllium fuel capsules for NIF

    SciTech Connect

    Alford, C.S.

    1998-02-12

    The objective of our effort is to systematically study the properties of films produced under different conditions, with an emphasis on improving surface morphology and microstructure while studying permeability and capsule strength. We have made extensive use of atomic force and electron microscopy to determine the microstructure of the films, along with composition probes (mainly x-ray fluorescence) to quantify the chemical structure. Our studies can be roughly divided into three categories. First, there are those in which the effects of substrate biasing have been investigated. This includes varying the substrate voltage from 0 to 120 V and applying an intermittent bias. Next there are studies of Be combined with boron, a non-soluble dopant Because of it`s low Z this dopant is of particular interest for x-ray related applications. Finally, there are experiments in which pulses of nitrogen are admitted to the vacuum chamber during deposition. The layers of nitride formed tended to disrupt the growth of Be grains, leading to a more fine-grained microstructure. For all these studies, we have most often used hollow plastic spheres for our substrate material. However, there have been some samples deposited on glass spheres or silicon flats.

  13. Sputter deposition system for controlled fabrication of multilayers

    SciTech Connect

    Di Nardo, R.P.; Takacs, P.Z.; Majkrzak, C.F.; Stefan, P.M.

    1985-06-01

    A detailed description of a sputter deposition system constructed specifically for the fabrication of x-ray and neutron multilayer monochromators and supermirrors is given. One of the principal design criteria is to maintain precise control of film thickness and uniformity over large substrate areas. Regulation of critical system parameters is fully automated so that response to feedback control information is rapid and complicated layer thickness sequences can be deposited accurately and efficiently. The use of either dc or rf magnetron sources makes it possible to satisfy the diverse material requirements of both x-ray and neutron optics.

  14. Gravity-Related Transport Process in Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehozeku, S. L.

    2000-01-01

    In the synthesis of epitaxial oxide films, reactive off-axis sputtering deposition techniques have demonstrated the advantages of fabricating high quality epitaxial films. Due to the collisions between the sputtered species and the residue gases, the kinetic energy of species was reduced and the transport of depositing species changed from a ballistic movement to a diffusive drift in which the transport species were almost thermalized. A gravity effect could appear in the transport process. Three transport regimes were observed when the growth pressures vary from 5 mTorr to 150 mTorr. Film growth rate, depositing orientations, crystal structure, surface morphology, and compositions were characterized. A gravity related phenomenon was revealed in film growth at the relative low growth pressures.

  15. Gravity-Related Transport Process in Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehozeku, S. L.

    2000-01-01

    In the synthesis of epitaxial oxide films, reactive off-axis sputtering deposition techniques have demonstrated the advantages of fabricating high quality epitaxial films. Due to the collisions between the sputtered species and the residue gases, the kinetic energy of species was reduced and the transport of depositing species changed from a ballistic movement to a diffusive drift in which the transport species were almost thermalized. A gravity effect could appear in the transport process. Three transport regimes were observed when the growth pressures vary from 5 mTorr to 150 mTorr. Film growth rate, depositing orientations, crystal structure, surface morphology, and compositions were characterized. A gravity related phenomenon was revealed in film growth at the relative low growth pressures.

  16. Optical and electrical properties of thin NiO films deposited by reactive magnetron sputtering and spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Parkhomenko, H. P.; Solovan, M. N.; Mostovoi, A. I.; Orletskii, I. G.; Parfenyuk, O. A.; Maryanchuk, P. D.

    2017-06-01

    Thin NiO films are deposited by reactive magnetron sputtering and spray pyrolysis. The main optical constants, i.e., refractive index n(λ), absorption coefficient α(λ), extinction coefficient k(λ), and thickness d, are determined. The temperature dependence of the resistance of thin films is found, and the activation energy of films deposited by different methods is determined.

  17. Electrostatic particle trap for ion beam sputter deposition

    DOEpatents

    Vernon, Stephen P.; Burkhart, Scott C.

    2002-01-01

    A method and apparatus for the interception and trapping of or reflection of charged particulate matter generated in ion beam sputter deposition. The apparatus involves an electrostatic particle trap which generates electrostatic fields in the vicinity of the substrate on which target material is being deposited. The electrostatic particle trap consists of an array of electrode surfaces, each maintained at an electrostatic potential, and with their surfaces parallel or perpendicular to the surface of the substrate. The method involves interception and trapping of or reflection of charged particles achieved by generating electrostatic fields in the vicinity of the substrate, and configuring the fields to force the charged particulate material away from the substrate. The electrostatic charged particle trap enables prevention of charged particles from being deposited on the substrate thereby enabling the deposition of extremely low defect density films, such as required for reflective masks of an extreme ultraviolet lithography (EUVL) system.

  18. Potential energy sputtering of EUVL materials

    SciTech Connect

    Pomeroy, J M; Ratliff, L P; Gillaspy, J D; Bajt, S

    2004-07-02

    Of the many candidates employed for understanding the erosion of critical Extreme Ultraviolet Lithography (EUVL) components, potential energy damage remains relatively uninvestigated. Unlike the familiar kinetic energy sputtering, which is a consequence of the momentum transferred by an ion to atoms in the target, potential energy sputtering occurs when an ion rapidly collects charge from the target as it neutralizes. Since the neutralization energy of a singly charged ion is typically on the order of 10 eV, potential energy effects are generally neglected for low charge state ions, and hence the bulk of the sputtering literature. As an ion's charge state is increased, the potential energy (PE) increases rapidly, e.g. PE(Xe{sup 1+})= 11 eV, PE(Xe{sup 10+}) = 810 eV, PE(Xe{sup 20+}) = 4.6 keV, etc. By comparison, the binding energy of a single atom on a surface is typically about 5 eV, so even relatively inefficient energy transfer mechanisms can lead to large quantities of material being removed, e.g. 25% efficiency for Xe{sup 10+} corresponds to {approx} 40 atoms/ion. By comparison, singly charged xenon ions with {approx} 20 keV of kinetic energy sputter only about 5 atoms/ion at normal incidence, and less than 1 atom/ion at typical EUV source energies. EUV light sources are optimized for producing approximately 10{sup 16} xenon ions per shot with an average charge state of q=10 in the core plasma. At operational rates of {approx}10 kHz, the number of ions produced per second becomes a whopping 10{sup 20}. Even if only one in a billion ions reaches the collector, erosion rates could reach {approx}10{sup 12} atoms per second, severely reducing the collector lifetime (for an average yield of 10 atoms/ion). In addition, efforts to reduce contamination effects may contribute to reduced neutralization and even larger potential energy damages rates (discussed further below). In order to provide accurate estimates for collector lifetimes and to develop mitigation schemes

  19. Sputter deposition of semiconductor superlattices for thermoelectric applications

    SciTech Connect

    Wagner, A.V.; Foreman, R.J.; Farmer, J.C.; Barbee, T.W.

    1996-11-01

    Theoretical dramatic improvement of the thermoelectric properties of materials by using quantum confinement in novel semiconductor nanostructures has lead to considerable interest in the thermoelectric community. Therefore, we are exploring the critical materials issues for fabrication of quantum confined structures by magnetron sputtering in the lead telluride and bismuth telluride families of materials. We have synthesized modulated structures from thermoelectric materials with bilayer periods of as little as 3.2 nm and shown that they are stable at deposition temperatures high enough to grow quality films. Issues critical to high quality film growth have been investigated such as nucleation and growth conditions and their effect on crystal orientation and growth morphology. These investigations show that nucleating the film at a temperature below the growth temperature of optimum electronic properties produces high quality films. Our work with sputter deposition, which is inherently a high rate deposition process, builds the technological base necessary to develop economical production of these advanced materials. High deposition rate is critical since, even if efficiencies comparable with CFC based refrigeration systems can be achieved, large quantities of quantum confined materials will be necessary for cost-competitive uses.

  20. Modeling the reactive sputter deposition of Ti-doped VOx thin films

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Yu, He; Gu, De-En; Guo, Rui; Dong, Xiang; Jiang, Ya-Dong; Wu, Rui-Lin

    2015-06-01

    In this paper an original numerical model, based on the standard Berg model, is used to simulate the growth mechanism of Ti-doped VOx deposited with changing oxygen flow during reactive sputtering deposition. Ti-doped VOx thin films are deposited using a V target with Ti inserts. The effects of titanium inserts on the discharge voltage, deposition rate, and the ratio of V/Ti are investigated. By doping titanium in the vanadium target, the average sputtering yield decreases. In this case, the sputter erosion reduces, which is accompanied by a reduction in the deposition rate. The ratio between V content and Ti content in the film is measured using energy-dispersive x-ray spectroscopy (EDX). A decrease in the vanadium concentration with the increasing of the oxygen flow rate is detected using EDX. Results show a reasonable agreement between numerical and experimental data. Project partially supported by the National Natural Science Foundation of China (Grant Nos. 61405027, 61421002, and 61235006) and the Postdoctoral Science Foundation of China (Grant No. 2014M562296).

  1. Real-time and in situ monitoring of sputter deposition with RHEED for atomic layer controlled growth

    NASA Astrophysics Data System (ADS)

    Podkaminer, J. P.; Patzner, J. J.; Davidson, B. A.; Eom, C. B.

    2016-08-01

    Sputter deposition is a widely used growth technique for a large range of important material systems. Epitaxial films of carbides, nitrides, metals, oxides and more can all be formed during the sputter process which offers the ability to deposit smooth and uniform films from the research level up to an industrial scale. This tunable kinematic deposition process excels in easily adapting for a large range of environments and growth procedures. Despite the vast advantages, there is a significant lack of in situ analysis options during sputtering. In particular, the area of real time atomic layer control is severely deficient. Atomic layer controlled growth of epitaxial thin films and artificially layered superlattices is critical for both understanding their emergent phenomena and engineering novel material systems and devices. Reflection high-energy electron diffraction (RHEED) is one of the most common in situ analysis techniques during thin film deposition that is rarely used during sputtering due to the effect of the strong permanent magnets in magnetron sputter sources on the RHEED electron beam. In this work we have solved this problem and designed a novel way to deter the effect of the magnets for a wide range of growth geometries and demonstrate the ability for the first time to have layer-by-layer control during sputter deposition by in situ RHEED.

  2. Orientation Effects in ZnO Films Using Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, S.; George, M. A.

    1999-01-01

    ZnO is a wide-band-gap oxide material and has been used in numerous applications. It is also a good substrate for fabricating GaN-based (a blue laser candidate) devices. Off-axis sputtering technique is one of the best techniques in synthesizing oxide materials because negative ion bombardment and particle kinetic energy is greatly reduced when adatoms condense on substrates. Since the sputtered material from the target arrive on the substrate surface at a 90 deg. configuration, which differs from the normal sputtering geometry, it is expected that the film uniformity and composition distributions will be affected. However, the details of these properties and mechanisms have not been well studied. ZnO films are synthesized on (0001) sapphire and quartz substrates by off-axis sputtering deposition in various oxygen/argon mixture ratios and pressures at different temperatures. Substrates and sputtering sources are placed at three different orientations that are orthogonal to each other. The normal direction of a substrate is parallel to the gravity vector and the other is perpendicular to it. Film thickness profiles at different growth orientations are determined using a profimeter. All films grown at high temperatures have highly textured structures on quartz substrates and epitaxially grow on sapphire substrates. Because of this process, the film surface is very smooth. X-ray diffraction, scanning probe microscopy, and Fourier transfer infrared spectroscopy, and electrical measurements will be used to characterize these films. Detailed results will be discussed in the presentation.

  3. Orientation Effects in ZnO Films Using Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, S.; George, M. A.

    1999-01-01

    ZnO is a wide-band-gap oxide material and has been used in numerous applications. It is also a good substrate for fabricating GaN-based (a blue laser candidate) devices. Off-axis sputtering technique is one of the best techniques in synthesizing oxide materials because negative ion bombardment and particle kinetic energy is greatly reduced when adatoms condense on substrates. Since the sputtered material from the target arrive on the substrate surface at a 90 deg. configuration, which differs from the normal sputtering geometry, it is expected that the film uniformity and composition distributions will be affected. However, the details of these properties and mechanisms have not been well studied. ZnO films are synthesized on (0001) sapphire and quartz substrates by off-axis sputtering deposition in various oxygen/argon mixture ratios and pressures at different temperatures. Substrates and sputtering sources are placed at three different orientations that are orthogonal to each other. The normal direction of a substrate is parallel to the gravity vector and the other is perpendicular to it. Film thickness profiles at different growth orientations are determined using a profimeter. All films grown at high temperatures have highly textured structures on quartz substrates and epitaxially grow on sapphire substrates. Because of this process, the film surface is very smooth. X-ray diffraction, scanning probe microscopy, and Fourier transfer infrared spectroscopy, and electrical measurements will be used to characterize these films. Detailed results will be discussed in the presentation.

  4. Ion-beam and dual-ion-beam sputter deposition of tantalum oxide films

    NASA Astrophysics Data System (ADS)

    Cevro, Mirza; Carter, George

    1995-02-01

    Ion-beam sputter deposition (IBS) and dual-ion-beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. The optical properties, i.e., refractive index and extinction coefficient, of IBS films were determined in the 250- to 1100-nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n 2.06 at (lambda) equals 550 nm. Films deposited using DIBS, i.e., deposition assisted by low energy Ar and O2 ions (Ea equals 0 to 300 eV) and low current density (Ji equals 0 to 40 (mu) A/cm2), showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy, whereas composition of the film and contaminants were determined by Rutherford backscattering spectroscopy (RBS). Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target whereas assisted deposition slightly increased the Ar content. Stress in the IBS-deposited films was measured by the bending technique. IBS-deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals

  5. Ion beam and dual ion beam sputter deposition of tantalum oxide films

    NASA Astrophysics Data System (ADS)

    Cevro, Mirza; Carter, George

    1994-11-01

    Ion beam sputter deposition (IBS) and dual ion beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. Optical properties ie refractive index and extinction coefficient of IBS films were determined in the 250 - 1100 nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n equals 2.06 at (lambda) equals 550 nm. Films deposited using DIBS ie deposition assisted by low energy Ar and O2 ions (Ea equals 0 - 300 eV) and low current density (Ji equals 0 - 40 (mu) A/cm2) showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy while composition of the film and contaminants were determined by Rutherford scattering spectroscopy. Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target while assisted deposition slightly increased the Ar content. Stress in the IBS deposited films was measured by the bending technique. IBS deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals 35 (mu) A/cm2. All

  6. Molecular dynamics simulation of gold cluster growth during sputter deposition

    NASA Astrophysics Data System (ADS)

    Abraham, J. W.; Strunskus, T.; Faupel, F.; Bonitz, M.

    2016-05-01

    We present a molecular dynamics simulation scheme that we apply to study the time evolution of the self-organized growth process of metal cluster assemblies formed by sputter-deposited gold atoms on a planar surface. The simulation model incorporates the characteristics of the plasma-assisted deposition process and allows for an investigation over a wide range of deposition parameters. It is used to obtain data for the cluster properties which can directly be compared with recently published experimental data for gold on polystyrene [M. Schwartzkopf et al., ACS Appl. Mater. Interfaces 7, 13547 (2015)]. While good agreement is found between the two, the simulations additionally provide valuable time-dependent real-space data of the surface morphology, some of whose details are hidden in the reciprocal-space scattering images that were used for the experimental analysis.

  7. Molecular dynamics simulation of gold cluster growth during sputter deposition

    SciTech Connect

    Abraham, J. W. Bonitz, M.; Strunskus, T.; Faupel, F.

    2016-05-14

    We present a molecular dynamics simulation scheme that we apply to study the time evolution of the self-organized growth process of metal cluster assemblies formed by sputter-deposited gold atoms on a planar surface. The simulation model incorporates the characteristics of the plasma-assisted deposition process and allows for an investigation over a wide range of deposition parameters. It is used to obtain data for the cluster properties which can directly be compared with recently published experimental data for gold on polystyrene [M. Schwartzkopf et al., ACS Appl. Mater. Interfaces 7, 13547 (2015)]. While good agreement is found between the two, the simulations additionally provide valuable time-dependent real-space data of the surface morphology, some of whose details are hidden in the reciprocal-space scattering images that were used for the experimental analysis.

  8. Characterization of Niobium Oxide Films Deposited by High Target Utilization Sputter Sources

    SciTech Connect

    Chow, R; Ellis, A D; Loomis, G E; Rana, S I

    2007-01-29

    High quality, refractory metal, oxide coatings are required in a variety of applications such as laser optics, micro-electronic insulating layers, nano-device structures, electro-optic multilayers, sensors and corrosion barriers. A common oxide deposition technique is reactive sputtering because the kinetic mechanism vaporizes almost any solid material in vacuum. Also, the sputtered molecules have higher energies than those generated from thermal evaporation, and so the condensates are smoother and denser than those from thermally-evaporated films. In the typical sputtering system, target erosion is a factor that drives machine availability. In some situations such as nano-layered capacitors, where the device's performance characteristics depends on thick layers, target life becomes a limiting factor on the maximizing device functionality. The keen interest to increase target utilization in sputtering has been addressed in a variety of ways such as target geometry, rotating magnets, and/or shaped magnet arrays. Also, a recent sputtering system has been developed that generates a high density plasma, directs the plasma beam towards the target in a uniform fashion, and erodes the target in a uniform fashion. The purpose of this paper is to characterize and compare niobia films deposited by two types of high target utilization sputtering sources, a rotating magnetron and a high density plasma source. The oxide of interest in this study is niobia because of its high refractive index. The quality of the niobia films were characterized spectroscopically in optical transmission, ellipsometrically, and chemical stoichiometry with X-ray photo-electron spectroscopy. The refractive index, extinction coefficients, Cauchy constants were derived from the ellipsometric modeling. The mechanical properties of coating density and stress are also determined.

  9. Nitrogen incorporation in sputter deposited molybdenum nitride thin films

    SciTech Connect

    Stöber, Laura Patocka, Florian Schneider, Michael Schmid, Ulrich; Konrath, Jens Peter Haberl, Verena

    2016-03-15

    In this paper, the authors report on the high temperature performance of sputter deposited molybdenum (Mo) and molybdenum nitride (Mo{sub 2}N) thin films. Various argon and nitrogen gas compositions are applied for thin film synthetization, and the amount of nitrogen incorporation is determined by Auger measurements. Furthermore, effusion measurements identifying the binding conditions of the nitrogen in the thin film are performed up to 1000 °C. These results are in excellent agreement with film stress and scanning electron microscope analyses, both indicating stable film properties up to annealing temperatures of 500 °C.

  10. Low energy sputtering of cobalt by cesium ions

    NASA Technical Reports Server (NTRS)

    Handoo, A.; Ray, Pradosh K.

    1989-01-01

    An experimental facility to investigate low energy (less than 500 eV) sputtering of metal surfaces with ions produced by an ion gun is described. Results are reported on the sputtering yield of cobalt by cesium ions in the 100 to 500 eV energy range at a pressure of 1 times 10(exp -6) Torr. The target was electroplated on a copper substrate. The sputtered atoms were collected on a cobalt foil surrounding the target. Co-57 was used as a tracer to determine the sputtering yield.

  11. Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized by sputter deposition

    DOE PAGES

    An, Zhinan; Jia, Haoling; Wu, Yueying; ...

    2015-05-04

    The concept of high configurational entropy requires that the high-entropy alloys (HEAs) yield single-phase solid solutions. However, phase separations are quite common in bulk HEAs. A five-element alloy, CrCoCuFeNi, was deposited via radio frequency magnetron sputtering and confirmed to be a single-phase solid solution through the high-energy synchrotron X-ray diffraction, energy-dispersive spectroscopy, wavelength-dispersive spectroscopy, and transmission electron microscopy. The formation of the solid-solution phase is presumed to be due to the high cooling rate of the sputter-deposition process.

  12. Reactive sputter deposition of tungsten nitride thin films

    NASA Astrophysics Data System (ADS)

    Baker, Colin C.; Shah, S. Ismat

    2002-09-01

    Tungsten nitride (WNx) thin films were deposited by reactively sputtering a pure W target in an argon/nitrogen atmosphere. The nitrogen concentration in the growth chamber was varied from 2% to 60%. Film growth and properties were studied as a function of nitrogen concentration in the films. The cathode current and voltage variations during the film growth indicated cathode poisoning when the nitrogen concentration in the chamber was in the range of 2%-5%. This poisoning was accompanied by a reduced film growth rate. However, both the cathode current and deposition rate decrease were small due to the low resistivity and similar sputter yield of the WNx phase formed at the surface of the target and pure W. X-ray photoelectron spectroscopy analyses showed that the films were composed of approx33 at. % nitrogen when the nitrogen concentration in the chamber was greater than 10%. X-ray diffraction (XRD) analysis confirmed that the films were predominantly W2N with the characteristic (111) peak at 2theta]=37.7[deg. Slight shifts in the (111) peak position were due to excess nitrogen incorporation in interstitial positions, which caused lattice distortions. Postdeposition annealing removed the excess interstitial nitrogen and the XRD peaks shifted closer to the characteristic value. copyright 2002 American Vacuum Society.

  13. Sputter deposition of silicon oxynitride gradient and multilayer coatings.

    PubMed

    Weber, Jörn; Bartzsch, Hagen; Frach, Peter

    2008-05-01

    The optical properties of silicon oxynitride films deposited by reactive dc magnetron sputtered films have been investigated. In particular the absorption characteristics of silicon nitride thin films in the visible spectrum and their optical bandgap were analyzed with regard to their composition and deposition properties. It can be shown that there is a significant difference between the absorption in the visible spectrum and the optical bandgap for these layers. The influence of unipolar and bipolar pulse modes on the optical layer properties is presented. The extinction coefficient for silicon nitride single layers could be reduced to a value of 2 x 10(-4) at 500 nm without external heating. There is also the dependence of the absorption of silicon oxynitride layers on the discharge voltage. We present the resulting spectra of rugate and edge filters that consist of these layers and offer lower absorption than single layers.

  14. Enhanced sputter yields of ion irradiated Au nano particles: energy and size dependence.

    PubMed

    Holland-Moritz, Henry; Scheeler, Sebastian; Stanglmair, Christoph; Pacholski, Claudia; Ronning, Carsten

    2015-08-14

    Hexagonally arranged Au nanoparticles exhibiting a broad Gaussian-shaped size distribution ranging from 30 nm to 80 nm were deposited on Si substrates and irradiated with Ar(+) and Ga(+) ions with various energies from 20 to 350 keV and 1 to 30 keV, respectively. The size and energy dependence of the sputter yield were measured using high-resolution scanning electron microscopy image analysis. These results were compared to simulation results obtained by iradina, a Monte Carlo code, which takes the specifics of the nano geometry into account. The experimental sputter yields are significantly higher than simulated sputter yields for both bulk and the nano geometry. The difference can be clearly attributed to thermally driven effects, which significantly increase the measured sputter yields.

  15. Strontium-substituted hydroxyapatite coatings deposited via a co-deposition sputter technique.

    PubMed

    Boyd, A R; Rutledge, L; Randolph, L D; Meenan, B J

    2015-01-01

    The bioactivity of hydroxyapatite (HA) coatings can be modified by the addition of different ions, such as silicon (Si), lithium (Li), magnesium (Mg), zinc (Zn) or strontium (Sr) into the HA lattice. Of the ions listed here, strontium substituted hydroxyapatite (SrHA) coatings have received a lot of interest recently as Sr has been shown to promote osteoblast proliferation and differentiation, and reduce osteoclast activity. In this study, SrHA coatings were deposited onto titanium substrates using radio frequency (RF) magnetron co-sputtering (and compared to those surfaces deposited from HA alone). FTIR, XPS, XRD, and SEM techniques were used to analyse the different coatings produced, whereby different combinations of pure HA and 13% Sr-substituted HA targets were investigated. The results highlight that Sr could be successfully incorporated into the HA lattice to form SrHA coatings. It was observed that as the number of SrHA sputtering targets in the study were increased (increasing Sr content), the deposition rate decreased. It was also shown that as the Sr content of the coatings increased, so did the degree of preferred 002 orientation of the coating (along with obvious changes in the surface morphology). This study has shown that RF magnetron sputtering (specifically co-sputtering), offers an appropriate methodology to control the surface properties of Sr-substituted HA, such as the crystallinity, stoichiometry, phase purity and surface morphology.

  16. RF magnetron sputter deposition and analysis of strontium-doped lead zirconate titanate thin films

    NASA Astrophysics Data System (ADS)

    Sriram, Sharath; Bhaskaran, Madhu; Holland, Anthony S.; Fardin, Ernest; Kandasamy, Sasikaran

    2006-01-01

    The paper investigates conditions for depositing perovskite-oriented strontium-doped lead zirconate titanate (PSZT) thin films using RF magnetron sputtering. PSZT is a material that can exhibit high piezoelectric and ferroelectric properties. The deposition was conducted using an 8/65/35 PSZT sputtering target. The effects of sputtering conditions and the deposition rates for films sputtered onto several surfaces (including gold and platinum coated substrates) were studied. Combinations of in-situ heating during sputtering and post-deposition Rapid Thermal Annealing (RTA) were performed and resulting phases determined. RTA was carried out in argon to observe their effects. The sputtered films were analyzed by Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), and X-Ray Photoelectron Spectroscopy (XPS). Results show dramatic differences in the grain structure of the deposited films on the different surfaces. The stoichiometry of the sputtered films is demonstrated using XPS. In the case of gold and platinum coated substrates, sputtering was also carried out for different durations, to establish the growth rate of the film, and to observe the variation in grain size with sputtering duration. The deposited thin films were resistant to most chemical wet etchants and were Ion Beam Etched (IBE) at 19 nm/min.

  17. Physics of arcing, and implications to sputter deposition

    SciTech Connect

    Anders, Andre

    2003-12-15

    Arcing is a well-known, unwanted discharge regime observed on the surface of sputtering targets. The discharge voltage breaks down to less than 50 V while the current jumps to elevated levels. Arcing is unwanted because it prevents uniform deposition and creates particulates. The issue of arcing has been dealt with by target surface conditioning and by using modern power supplies that have arc suppression incorporated. With increasing quality requirements in terms of uniformity of coatings, and absence of particulates, especially for electrochromic and other advanced coatings applications, the issue of arcing warrants a closer examination with the goal to find other, physics-based, and hopefully better approaches of arcing prevention. From a physics point of view, the onset of arcing is nothing else than the transition of the discharge to a cathodic arc mode, which is characterized by the ignition of non-stationary arc spots. Arc spots operate by a sequence of microexplosions, enabling explosive electron emission, as opposed to secondary electron emission. Arc spots and their fragments have a size distribution in the micrometer and sub-micrometer range, and a characteristic time distribution that has components shorter than microseconds. Understanding the ignition conditions of arc spots are of central physical interest. Spot ignition is associated with electric field enhancement, which can be of geometric nature (roughness,particles), or chemical nature (e.g. oxide formation) and related local accumulation of surface charge. Therefore, it is clear that these issues are of particular concern when operating with high-density plasmas, such as in high-power pulsed sputtering, and when using reactive sputter gases.

  18. Low-damage high-throughput grazing-angle sputter deposition on graphene

    SciTech Connect

    Chen, C.-T.; Gajek, M.; Raoux, S.; Casu, E. A.

    2013-07-15

    Despite the prevalence of sputter deposition in the microelectronics industry, it has seen very limited applications for graphene electronics. In this letter, we report systematic investigation of the sputtering induced damages in graphene and identify the energetic sputtering gas neutrals as the primary cause of graphene disorder. We further demonstrate a grazing-incidence sputtering configuration that strongly suppresses fast neutral bombardment and retains graphene structure integrity, creating considerably lower damage than electron-beam evaporation. Such sputtering technique yields fully covered, smooth thin dielectric films, highlighting its potential for contact metals, gate oxides, and tunnel barriers fabrication in graphene device applications.

  19. Controlling ion fluxes during reactive sputter-deposition of SnO{sub 2}:F

    SciTech Connect

    Jäger, Timo Romanyuk, Yaroslav E.; Tiwari, Ayodhya N.; Anders, André

    2014-07-21

    Magnetron sputtering of fluorine-doped tin oxide (FTO) is a scalable deposition method for large-area transparent conducting films used in fenestration, photovoltaics, and other applications. The electrical conductivity of sputtered FTO is, however, lower than that of spray-pyrolized FTO because of the ion damage induced by high energy ions leading to a reduction of the crystal quality in sputtered FTO films. In this study, various ion species present during the reactive sputtering of a metallic tin target in a mixed Ar/O{sub 2}/CF{sub 4} atmosphere are systematically characterized by energy and mass spectrometry, and possible ways of controlling the ion fluxes are explored. Ion energy distribution functions (IEDFs) of the negative ions F{sup −} and O{sup −} exhibit large peaks at an energy corresponding to the full target voltage. Although the applied partial pressure of CF{sub 4} is about 1/30 than that of O{sub 2}, the obtained IEDFs of F{sup −} and O{sup −} have comparable peak height, which can be attributed to a higher electronegativity of F. The IEDFs of positively charged O{sup +}, O{sub 2}{sup +}, Ar{sup +}, and Sn{sup +} species have their peaks around 2–8 eV. To control ion fluxes a solenoid or permanent magnets were placed between the target and the mass spectrometer. The flux of positive ions could be varied by several orders of magnitude as a function of the applied current through the solenoid, whereas the high-energy (>100 eV) negative F{sup −} and O{sup −} ions were not notably deflected. By using permanent magnets with the B-field orthogonal to the ion trajectory, the flux of O{sup −} ions could be decreased by two orders and the exposure to the high-energy F{sup −} ions was completely suppressed.

  20. Magnetic Phases of Sputter Deposited Thin-Film Erbium

    PubMed Central

    Witt, J. D. S.; Cooper, J. F. K.; Satchell, N.; Kinane, C. J.; Curran, P. J.; Bending, S. J.; Langridge, S.; Heyderman, L. J.; Burnell, G.

    2016-01-01

    We present a detailed structural and magnetic characterization of sputter deposited thin film erbium, determined by x-ray diffraction, transport measurements, magnetometry and neutron diffraction. This provides information on the onset and change of the magnetic state as a function of temperature and applied magnetic field. Many of the features of bulk material are reproduced. Also of interest is the identification of a conical magnetic state which repeats with a wavevector parallel to the c axis τc = 4/17 in units of the reciprocal lattice parameter c*, which is a state not observed in any other thin film or bulk measurements. The data from the various techniques are combined to construct magnetic field, temperature (H, T)–phase diagrams for the 200 nm-thick Er sample that serves as a foundation for future exploitation of this complex magnetic thin film system. PMID:27966662

  1. Magnetic Phases of Sputter Deposited Thin-Film Erbium

    NASA Astrophysics Data System (ADS)

    Witt, J. D. S.; Cooper, J. F. K.; Satchell, N.; Kinane, C. J.; Curran, P. J.; Bending, S. J.; Langridge, S.; Heyderman, L. J.; Burnell, G.

    2016-12-01

    We present a detailed structural and magnetic characterization of sputter deposited thin film erbium, determined by x-ray diffraction, transport measurements, magnetometry and neutron diffraction. This provides information on the onset and change of the magnetic state as a function of temperature and applied magnetic field. Many of the features of bulk material are reproduced. Also of interest is the identification of a conical magnetic state which repeats with a wavevector parallel to the c axis τc = 4/17 in units of the reciprocal lattice parameter c*, which is a state not observed in any other thin film or bulk measurements. The data from the various techniques are combined to construct magnetic field, temperature (H, T)-phase diagrams for the 200 nm-thick Er sample that serves as a foundation for future exploitation of this complex magnetic thin film system.

  2. Sputter-deposited Be ablators for NIF target capsules

    SciTech Connect

    McEachern, R.; Clford, C.; Cook, R.; Makowiecki, E.; Wallace, R.

    1997-03-26

    We have performed a series of preliminary experiments to determine whether sputter deposition of doped Be is a practical route to producing NIF target capsules with Be ablators. Films ranging in thickness from 7 to {approximately} 120 {micro}m have been deposited on spherical polymer mandrels using a bounce pan to ensure uniform coating. With no voltage bias applied to the pan, relatively porous coatings were formed that were highly permeable to hydrogen. The surface finish of these films ranged from {approximately}250 nm rms for 13-{micro}m-thick films to a minimum of {approximately}75 nm rms for an 80-{micro}m-thick film. Application of a voltage bias was found to significantly modify the film morphology. At a bias of 120 V, 7-{micro}m-thick films with a dense, fine-grained microstructure were produced. These capsules had a reflective surface with a 50 nm rms roughness. Finally, to demonstrate the ability to produce a graded dopant profile, a coating was produced in which the concentration of added Cu was varied from 2.5 atom % at the beginning to zero after 40 {micro}m of deposition.

  3. Ion induced stress relaxation in dense sputter-deposited DLC thin films

    NASA Astrophysics Data System (ADS)

    Aijaz, Asim; Kubart, Tomas

    2017-07-01

    Deposition of high-density and low-stress hydrogen-free diamond like carbon (DLC) thin films is demonstrated using a pulsed ionized sputtering process. This process is based on high power impulse magnetron sputtering, and high C ionization is achieved using Ne as the sputtering gas. The intrinsic compressive stress and its evolution with respect to ion energy and ion flux are explained in terms of the compressive stress based subplantation model for DLC growth by Davis. The highest mass density was ˜2.7 g/cm3, and the compressive stresses did not exceed ˜2.5 GPa. The resulting film stresses are substantially lower than those achieved for the films exhibiting similar mass densities grown by filtered cathodic vacuum arc and pulsed laser deposition methods. This unique combination of high mass density and low compressive stress is attributed to the ion induced stress relaxation during the pulse-off time which corresponds to the post thermal spike relaxation timescales. We therefore propose that the temporal ion flux variations determine the magnitude of the compressive stress observed in our films.

  4. Sensitivity of ion-induced sputtering to the radial distribution of energy transfers: A molecular dynamics study

    SciTech Connect

    Mookerjee, S.; Khan, S. A.; Roy, A.; Beuve, M.; Toulemonde, M.

    2008-07-15

    Using different models for the deposition of energy on the lattice and a classical molecular dynamics approach to the subsequent transport, we evaluate how the details of the energy deposition model influence sputtering yield from a Lennard-Jones target irradiated with a MeV/u ion beam. Two energy deposition models are considered: a uniform, instantaneous deposition into a cylinder of fixed radius around the projectile ion track, used in earlier molecular dynamics and fluid dynamics simulations of sputtering yields; and an energy deposition distributed in time and space based on the formalism developed in the thermal spike model. The dependence of the sputtering yield on the total energy deposited on the target atoms is very sensitive to the energy deposition model. To clarify the origin of this strong dependence, we explore the role of the radial expansion of the electronic system prior to the transfer of its energy to the lattice. The results imply that observables such as the sputtering yield may be used as signatures of the fast electron-lattice energy transfer in the electronic energy-loss regime, and indicate the need for more experimental and theoretical investigations of these processes.

  5. Characterization of HfO2-SiO2 rugate multilayers deposited by ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Rauhut, R.; Nehls, K.; Mechold, L.

    2014-10-01

    Ion beam sputtering (IBS) is a deposition technique being well known for resulting in very dense and damage resistant coatings due to high kinetic energies of the sputtered atoms. While different layers are deposited homogeneously, abrupt interfaces between the materials are the most susceptible part of the stack. Therefore we aim for an improvement of the laser damage threshold by sputtering material mixtures. Using a target with high- and low-index material next to each other, arbitrary refractive indices can be realized by adjusting the target axis. Our material system of choice is HfO2- SiO2, already yielding good results with non-rugate coatings. A comparison in terms of laser damage threshold between these designs and varying refractive index coatings will be shown.

  6. Structural, electrical, and optical properties of diamondlike carbon films deposited by dc magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Broitman, E.; Lindquist, O. P. A.; Hellgren, N.; Hultman, L.; Holloway, B. C.

    2003-11-01

    The electrical and optical properties of diamondlike carbon films deposited by direct current magnetron sputtering on Si substrates at room temperature have been measured as a function of the ion energy (Eion) and ion-to-carbon flux (Jion/JC). The results show that, in the ranges of 5 eV<=Eion<=85 eV and 1.1<=Jion/JC<=6.8, the presence of defective graphite formed by subplanted C and Ar atoms, voids, and the surface roughness, are the dominant influences on the resistivity and optical absorption.

  7. A Magnetron Sputter Deposition System for the Development of Multilayer X-Ray Optics

    NASA Technical Reports Server (NTRS)

    Broadway, David; Ramsey, Brian; Gubarev, Mikhail

    2014-01-01

    The proposal objective is to establish the capability to deposit multilayer structures for x-ray, neutron, and EUV optic applications through the development of a magnetron sputtering deposition system. A specific goal of this endeavor is to combine multilayer deposition technology with the replication process in order to enhance the MSFC's position as a world leader in the design of innovative X-ray instrumentation through the development of full shell replicated multilayer optics. The development of multilayer structures is absolutely necessary in order to advance the field of X-ray astronomy by pushing the limit for observing the universe to ever increasing photon energies (i. e. up to 200 keV or higher); well beyond Chandra (approx. 10 keV) and NuStar's (approx. 75 keV) capability. The addition of multilayer technology would significantly enhance the X-ray optics capability at MSFC and allow NASA to maintain its world leadership position in the development, fabrication and design of innovative X-ray instrumentation which would be the first of its kind by combining multilayer technology with the mirror replication process. This marriage of these technologies would allow astronomers to see the universe in a new light by pushing to higher energies that are out of reach with today's instruments.To this aim, a magnetron vacum sputter deposition system for the deposition of novel multilayer thin film X-ray optics is proposed. A significant secondary use of the vacuum deposition system includes the capability to fabricate multilayers for applications in the field of EUV optics for solar physics, neutron optics, and X-ray optics for a broad range of applications including medical imaging.

  8. A Magnetron Sputter Deposition System for the Development of X-Ray Multilayer Optics

    NASA Technical Reports Server (NTRS)

    Broadway, David

    2015-01-01

    The project objective is to establish the capability to deposit multilayer structures for x-ray, neutron, and extreme ultraviolet (EUV) optic applications through the development of a magnetron sputtering deposition system. A specific goal of this endeavor is to combine multilayer deposition technology with the replication process in order to enhance NASA Marshall Space Flight Center's (MSFC's) position as a world leader in the design of innovative x-ray instrumentation through the development of full shell replicated multilayer optics. The development of multilayer structures are absolutely necessary in order to advance the field of x-ray astronomy by pushing the limit for observing the universe to ever-increasing photon energies (i.e., up to 200 keV or higher), well beyond Chandra's (approx.10 keV) and NuStar's (approx.75 keV) capability. The addition of multilayer technology would significantly enhance the x-ray optics capability at MSFC and allow NASA to maintain its world leadership position in the development, fabrication, and design of innovative x-ray instrumentation, which would be the first of its kind by combining multilayer technology with the mirror replication process. This marriage of these technologies would allow astronomers to see the universe in a new light by pushing to higher energies that are out of reach with today's instruments. To this aim, a magnetron vacuum sputter deposition system for the deposition of novel multilayer thin film x-ray optics is proposed. A significant secondary use of the vacuum deposition system includes the capability to fabricate multilayers for applications in the field of EUV optics for solar physics, neutron optics, and x-ray optics for a broad range of applications including medical imaging.

  9. Initial deposition of calcium phosphate ceramic on polystyrene and polytetrafluoroethylene by rf magnetron sputtering deposition

    NASA Astrophysics Data System (ADS)

    Feddes, B.; Wolke, J. G. C.; Jansen, J. A.; Vredenberg, A. M.

    2003-03-01

    Calcium phosphate (CaP) coatings can be applied to improve the biological performance of polymeric medical implants. A strong interfacial bond between ceramic and polymer is required for clinical applications. Because the chemical structure of an interface plays an important role in the adhesion of a coating, we studied the formation of the interface between CaP and polystyrene (PS) and polytetrafluoroethylene (PTFE). The coating was deposited in a radio frequency (rf) magnetron sputtering deposition system. Prior to the deposition, some samples received an oxygen plasma pretreatment. We found that the two substrates show a strongly different reactivity towards CaP. On PS a phosphorus and oxygen enrichment is present at the interface. This is understood from POx complexes that are able to bind to the PS. The effects of the plasma pretreatment are overruled by the deposition process itself. On PTFE, a calcium enrichment and an absence of phosphorus is found at the interface. The former is the result of CaF2-like material being formed at the interface. The latter may be the result of phosphorus reacting with escaping fluorine to a PF3 molecule, which than escapes from the material as a gas molecule. We found that the final structure of the interface is mostly controlled by the bombardment of energetic particles escaping either from the plasma or from the sputtering target. The work described here can be used to understand and improve the adhesion of CaP coatings deposited on medical substrates.

  10. Thermochromic VO2 thin films deposited by magnetron sputtering for smart window applications

    NASA Astrophysics Data System (ADS)

    Fortier, Jean-Philippe

    "Smart" windows are a perfect innovative example of technology that reduces our energy dependence and our impact on the environment while saving on the economical point of view. With the use of vanadium dioxide (VO2), a thermochromic compound, and this, as a thin coating, it would in fact be possible to control the sun's transmission of infrared light (heat) as a function of the surrounding environment temperature. In other words, its optical behavior would allow a more effective management of heat exchanges between a living venue and the outdoor environment. However, this type of window is still in a developmental stage. First, the oxide's deposition is not simple in nature. Based on a conventional deposition technique called magnetron sputtering mainly used in the fenestration industry, several factors such as the oxygen concentration and the substrate temperature during deposition can affect the coating's thermochromic behavior, and this, by changing its composition and crystallinity. Other control parameters such as the deposition rate, the pressure in the sputtering chamber and the choice of substrate may also modify the film microstructure, thereby varying its optical and electrical properties. In addition, several issues still persist as to its commercial application. For starters, the material's structural transition, related to the change of its optical properties, only occurs around 68°C. In addition, its low transparency and natural greenish colour are not visually appealing. Then, to this day, the deposition temperature required to crystallize and form the thermochromic oxide remains an obstacle for a possible large-scale application. Ultimately, although the material's change in temperature has been shown to be advantageous in situations of varying climate, the existing corrective solutions to these issues generate a deterioration of the thermochromic behavior. With no practical expertise on the material, this project was undertaken with certain

  11. Electrical and Structural Properties of Tin-Doped Indium Oxide Films Deposited by DC Sputtering at Room Temperature

    NASA Astrophysics Data System (ADS)

    Song, Pung; Shigesato, Yuzo; Kamei, Masayuki; Yasui, Itaru

    1999-05-01

    Tin-doped indium oxide (ITO) films were deposited on soda-lime glass plates without substrate heating by dc magnetron sputtering. Crystallinity and electrical properties of the films were investigated by X-ray diffraction and Hall-effect measurements, which showed clear dependence on target substrate distance (T S) and on total gas pressure (Ptot) during deposition. Degradation in crystallinity was observed at relatively high or low Ptot, where the upper or lower Ptot level for depositing films with high crystallinity was increased with decreasing T S. Based on a hard sphere collision model, the crystallinity of the films was considered to be strongly affected both by the kinetic energy of sputtered In (or Sn) particles and by the bombardment of high energy particles arriving at the growing film surface. The former could enhance the crystallinity, whereas the latter degraded both the crystallinity and conductivity. Such degradation in electrical properties was mainly due to a decrease in carrier density.

  12. Measurements and Modelling of Sputtering Rates with Low Energy Ions

    NASA Astrophysics Data System (ADS)

    Ruzic, David N.; Smith, Preston C.; Turkot, Robert B., Jr.

    1996-10-01

    The angular-resolved sputtering yield of Be by D+, and Al by Ar+ was predicted and then measured. A 50 to 1000 eV ion beam from a Colutron was focused on to commercial grade and magnetron target grade samples. The S-65 C grade beryllium samples were supplied by Brush Wellman and the Al samples from TOSOH SMD. In our vacuum chamber the samples can be exposed to a dc D or Ar plasma to remove oxide, load the surface and more-nearly simulate steady state operating conditions in the plasma device. The angular distribution of the sputtered atoms was measured by collection on a single crystal graphite witness plate. The areal density of Be or Al (and BeO2 or Al2O3, after exposure to air) was then measured using a Scanning Auger Spectrometer. Total yield was also measured by deposition onto a quartz crystal oscillator simultaneously to deposition onto the witness plate. A three dimensional version of vectorized fractal TRIM (VFTRIM3D), a Monte-Carlo computer code which includes surface roughness characterized by fractal geometry, was used to predict the angular distribution of the sputtered particles and a global sputtering coefficient. Over a million trajectories were simulated for each incident angle to determine the azimuthal and polar angle distributions of the sputtered atoms. The experimental results match closely with the simulations for total yield, while the measured angular distributions depart somewhat from the predicted cosine curve.

  13. Evaluation of target power supplies for krypton storage in sputter-deposited metals

    SciTech Connect

    Greenwell, E.N.; McClanahan, E.D.; Moss, R.W.

    1986-04-01

    Implantation of /sup 85/Kr in a growing sputtered metal deposit has been studied for the containment of /sup 85/Kr recovered from the reprocessing of spent nuclear fuel. PNL, as part of DOE's research program for /sup 85/Kr storage, has developed krypton trapping storage devices (KTSDs) in a range of sizes for ''cold'' and radioactive testing. The KTSD is a stainless steel canister that contains a sputtering target for depositing an amorphous rare-earth transition metal on the inner wall and simultaneously implanting low-energy krypton ions in the growing deposit. This report covers the design requirements for the target power supply and the description, testing and evaluation of three basic designs. The designs chosen for evaluation were: (1) a standard commercial power supply with an external PNL-designed current interrupter, (2) a commercially manufactured power supply with an integral series-type interrupter, and (3) a commercially manufactured power supply with an integral shunt-type interrupter. The units were compared on the basis of performance, reliability, and life-cycle cost. 8 refs., 9 figs., 2 tabs.

  14. Optical and structural properties of sputter-deposited nanocrystalline Cu2O films: effect of sputtering gas.

    PubMed

    Chandra, R; Chawla, A K; Ayyub, P

    2006-04-01

    We report the effect of the atomic mass of the sputtering gas (He, Ne, Ar, Kr, and Xe) on the structure and optical properties of nanocrystalline cuprous oxide (Cu2O) thin films deposited by dc magnetron sputtering. The crystal structure and surface morphology were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM) respectively. We find that the atomic mass of the sputtering gas significantly affects the primary crystallite size as well as the surface morphology and texture. Optical reflectance and transmission measurements show that the nanocrystalline thin films are transparent over most of the visible region. The HOMO-LUMO gap obtained from optical absorption spectra show a size-dependent quantum shift with respect to the bulk band gap reported for Cu2O (2.1 eV).

  15. Electrostatic quadrupole plasma mass spectrometer measurements during thin film depositions using simultaneous matrix assisted pulsed laser evaporation and magnetron sputtering

    SciTech Connect

    Hunter, C. N.; Check, M. H.; Muratore, C.; Voevodin, A. A.

    2010-05-15

    A hybrid plasma deposition process, combining matrix assisted pulsed laser evaporation (MAPLE) of carbon nanopearls (CNPs) with magnetron sputtering of gold was investigated for growth of composite films, where 100 nm sized CNPs were encapsulated into a gold matrix. Composition and morphology of such composite films was characterized with x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy (TEM) analysis. Carbon deposits on a gold magnetron sputter target and carbon impurities in the gold matrices of deposited films were observed while codepositing from gold and frozen toluene-CNP MAPLE targets in pure argon. Electrostatic quadrupole plasma analysis was used to determine that a likely mechanism for generation of carbon impurities was a reaction between toluene vapor generated from the MAPLE target and the argon plasma originating from the magnetron sputtering process. Carbon impurities of codeposited films were significantly reduced by introducing argon-oxygen mixtures into the deposition chamber; reactive oxygen species such as O and O+ effectively removed carbon contamination of gold matrix during the codeposition processes. Increasing the oxygen to argon ratio decreased the magnetron target sputter rate, and hence hybrid process optimization to prevent gold matrix contamination and maintain a high sputter yield is needed. High resolution TEM with energy dispersive spectrometry elemental mapping was used to study carbon distribution throughout the gold matrix as well as embedded CNP clusters. This research has demonstrated that a hybrid MAPLE and magnetron sputtering codeposition process is a viable means for synthesis of composite thin films from premanufactured nanoscale constituents, and that cross-process contaminations can be overcome with understanding of hybrid plasma process interaction mechanisms.

  16. Supported plasma sputtering apparatus for high deposition rate over large area

    DOEpatents

    Moss, Ronald W.; McClanahan, Jr., Edwin D.; Laegreid, Nils

    1977-01-01

    A supported plasma sputtering apparatus is described having shaped electrical fields in the electron discharge region between the cathode and anode and the sputter region between the target and substrate while such regions are free of any externally applied magnetic field to provide a high deposition rate which is substantially uniform over a wide area. Plasma shaping electrodes separate from the anode and target shape the electrical fields in the electron discharge region and the sputter region to provide a high density plasma. The anode surrounds the target to cause substantially uniform sputtering over a large target area. In one embodiment the anode is in the form of an annular ring surrounding a flat target surface, such anode being provided with a ribbed upper surface which shields portions of the anode from exposure to sputtered material to maintain the electron discharge for a long stable operation. Several other embodiments accomplish the same result by using different anodes which either shield the anode from sputtered material, remove the sputtered coating on the anode by heating, or simultaneously mix sputtered metal from the auxiliary target with sputtered insulator from the main target so the resultant coating is conductive. A radio frequency potential alone or together with a D.C. potential, may be applied to the target for a greater sputtering rate.

  17. Study on platinum thermal sensitive films deposited using magnetic sputtering

    NASA Astrophysics Data System (ADS)

    Cai, Changlong; Liu, Weiguo; Zhou, Shun; Zhai, Yujia

    2012-10-01

    The infrared imaging detecting technology has broad application prospects in military and civilian fields. The bolometer is one of mainstream uncooled infrared detectors, because it has many advantages, for example, light weight, wide dynamic range, excellent response linearity, and without refrigeration and chopper which leads to low manufacturing cost. In many infrared detecting sensitive materials, Pt films have wider linear range, lower noise, and compatibility with silicon integrated process excellently. In this paper, Pt sensitive films were deposited by means of magnetron sputtering, the preparation process of Pt films for the infrared imaging detecting unit was studied, the temperature coefficient of resistance (TCR) of Pt films can be improved by vacuum annealing to achieve 1.737 ‰/K. The micro-structure and micro-fabrication process of infrared imaging detecting unit based on Pt films were designed, and the heating character of infrared imaging detecting unit based on Pt films was measured using I-V character testing system. Testing results shown that, the properties of fabricated infrared thermal imaging detecting unit based on Pt films were better, Its TCR is about 1.64 ‰/K, and its thermal response is better.

  18. Accelerated life test of sputtering and anode deposit spalling in a small mercury ion thruster

    NASA Technical Reports Server (NTRS)

    Power, J. L.

    1975-01-01

    Tantalum and molybdenum sputtered from discharge chamber components during operation of a 5 centimeter diameter mercury ion thruster adhered much more strongly to coarsely grit blasted anode surfaces than to standard surfaces. Spalling of the sputtered coating did occur from a coarse screen anode surface but only in flakes less than a mesh unit long. The results were obtained in a 200 hour accelerated life test conducted at an elevated discharge potential of 64.6 volts. The test approximately reproduced the major sputter erosion and deposition effects that occur under normal operation but at approximately 75 times the normal rate. No discharge chamber component suffered sufficient erosion in the test to threaten its structural integrity or further serviceability. The test indicated that the use of tantalum-surfaced discharge chamber components in conjunction with a fine wire screen anode surface should cure the problems of sputter erosion and sputtered deposits spalling in long term operation of small mercury ion thrusters.

  19. Oxygen Interstitial Defects in Sc2O3 Thin Films Deposited with Reactive Ion Beam Sputtering

    NASA Astrophysics Data System (ADS)

    Schiltz, Drew; Langston, Peter; Krous, Erik; Patel, Dinesh; Markosyan, Ashot; Route, Rodger; Menoni, Carmen; Colorado State University Team; Stanford University Team

    2014-03-01

    Numerous defects may develop when depositing amorphous thin films with reactive ion beam sputtering, including interstitials and vacancies. In many cases, these defects limit the functionality of the film, degrading both the mechanical and optical properties. This study aims to investigate the nature of oxygen interstitial point defects in scandium oxide thin films and characterize the effect on composition, optical absorption and mechanical stress. The films are deposited with argon ion beam sputtering of a scandium metal target. The density of defects is correlated with the oxygen partial pressure, revealing an optimal condition where defects are minimized. Furthermore, the defect density also demonstrates a direct correlation with the main ion beam accelerating voltage. The native oxygen defects behave as shallow levels, with binding energies in the 1-2 eV range. Work supported by the DoD Office of Naval Research and the High Energy Laser Program of the DoD Joint Technology Office. National Science Foundation Engineering Research Center for Extreme Ultraviolet Science and Technology, Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA.

  20. Substrate Frequency Effects on Cr x N Coatings Deposited by DC Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Obrosov, Aleksei; Naveed, Muhammad; Volinsky, Alex A.; Weiß, Sabine

    2016-11-01

    Controlled ion bombardment is a popular method to fabricate desirable coating structures and modify their properties. Substrate biasing at high frequencies is a possible technique, which allows higher ion density at the substrate compared with DC current bias. Moreover, high ion energy along with controlled adatom mobility would lead to improved coating growth. This paper focuses on a similar type of study, where effects of coating growth and properties of DC magnetron-sputtered chromium nitride (Cr x N) coatings at various substrate bias frequencies are discussed. Cr x N coatings were deposited by pulsed DC magnetron sputtering on Inconel 718 and (100) silicon substrates at 110, 160 and 280 kHz frequency at low duty cycle. Coating microstructure and morphology were studied by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), scratch adhesion testing and nanoindentation. Results indicate a transformation of columnar into glassy structure of Cr x N coatings with the substrate bias frequency increase. This transformation is attributed to preferential formation of the Cr2N phase at high frequencies compared with CrN at low frequencies. Increase in frequency leads to an increase in deposition rate, which is believed to be due to increase in plasma ion density and energy of the incident adatoms. An increase in coating hardness along with decrease in elastic modulus was observed at high frequencies. Scratch tests show a slight increase in coating adhesion, whereas no clear increase in coating roughness can be found with the substrate bias frequency.

  1. Substrate Frequency Effects on Cr x N Coatings Deposited by DC Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Obrosov, Aleksei; Naveed, Muhammad; Volinsky, Alex A.; Weiß, Sabine

    2017-01-01

    Controlled ion bombardment is a popular method to fabricate desirable coating structures and modify their properties. Substrate biasing at high frequencies is a possible technique, which allows higher ion density at the substrate compared with DC current bias. Moreover, high ion energy along with controlled adatom mobility would lead to improved coating growth. This paper focuses on a similar type of study, where effects of coating growth and properties of DC magnetron-sputtered chromium nitride (Cr x N) coatings at various substrate bias frequencies are discussed. Cr x N coatings were deposited by pulsed DC magnetron sputtering on Inconel 718 and (100) silicon substrates at 110, 160 and 280 kHz frequency at low duty cycle. Coating microstructure and morphology were studied by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), scratch adhesion testing and nanoindentation. Results indicate a transformation of columnar into glassy structure of Cr x N coatings with the substrate bias frequency increase. This transformation is attributed to preferential formation of the Cr2N phase at high frequencies compared with CrN at low frequencies. Increase in frequency leads to an increase in deposition rate, which is believed to be due to increase in plasma ion density and energy of the incident adatoms. An increase in coating hardness along with decrease in elastic modulus was observed at high frequencies. Scratch tests show a slight increase in coating adhesion, whereas no clear increase in coating roughness can be found with the substrate bias frequency.

  2. Modular deposition chamber for in situ X-ray experiments during RF and DC magnetron sputtering.

    PubMed

    Krause, Bärbel; Darma, Susan; Kaufholz, Marthe; Gräfe, Hans Hellmuth; Ulrich, Sven; Mantilla, Miguel; Weigel, Ralf; Rembold, Steffen; Baumbach, Tilo

    2012-03-01

    A new sputtering system for in situ X-ray experiments during DC and RF magnetron sputtering is described. The outstanding features of the system are the modular design of the vacuum chamber, the adjustable deposition angle, the option for plasma diagnostics, and the UHV sample transfer in order to access complementary surface analysis methods. First in situ diffraction and reflectivity measurements during RF and DC deposition of vanadium carbide demonstrate the performance of the set-up.

  3. In situ stress evolution during and after sputter deposition of Al thin films.

    PubMed

    Pletea, M; Koch, R; Wendrock, H; Kaltofen, R; Schmidt, O G

    2009-06-03

    The stress, growth, and morphology evolution of Al thin films up to 300 nm thick, sputter deposited at a constant rate of 0.04 nm s(-1) onto thermally oxidized Si(100) substrates have been investigated for various sputter pressures in the range from 0.05 to 6 Pa. The stress evolution has been studied during and after the film deposition by means of in situ substrate curvature measurements using an optical two-beam deflection method. In order to obtain insight into the mechanisms of stress generation and relaxation, the microstructure of the films was investigated by scanning electron microscopy, focused-ion-beam microscopy, and atomic force microscopy. The stress evolution during the early stage of deposition of films is consistent with the Volmer-Weber growth mode known for metals with high adatom mobility. For thicker films, the compressive stress increases in the sputter pressure range of 0.05-0.5 Pa, whereas at even higher sputter pressures a transition from compressive to tensile stress takes place. This transition is correlated with a change from a relatively dense to a more porous microstructure characterized by decreasing mass density and increasing electrical resistivity with increasing sputter pressure. The dependence of the stress and microstructure on the sputter pressure can be consistently understood through a combination of the stress mechanisms for vapor and sputter deposited films proposed in the literature.

  4. [Spectrum diagnostics for optimization of experimental parameters in thin films deposited by magnetron sputtering].

    PubMed

    Guo, Qing-Lin; Cui, Yong-Liang; Chen, Jian-Hui; Zhang, Jin-Ping; Huai, Su-Fang; Liu, Bao-Ting; Chen, Jin-Zhong

    2010-12-01

    The plasma emission spectra generated during the deposition process of Si-based thin films by radio frequency (RF) magnetron sputtering using Cu and Al targets in an argon atmosphere were acquired by the plasma analysis system, which consists of a magnetron sputtering apparatus, an Omni-lambda300 series grating spectrometer, a CCD data acquisition system and an optical fiber transmission system. The variation in Cu and Al plasma emission spectra intensity depending on sputtering conditions, such as sputtering time, sputtering power, the target-to-substrate distance and deposition pressure, was studied by using the analysis lines Cu I 324. 754 nm, Cu I 327. 396 nm, Cu I 333. 784 nm, Cu I 353. 039 nm, Al I 394. 403 nm and Al I 396. 153 nm. Compared with the option of experimental parameters of thin films deposited by RF magnetron sputtering, it was shown that emission spectra analysis methods play a guiding role in optimizing the deposition conditions of thin films in RF magnetron sputtering.

  5. Direct current magnetron sputtering deposition of InN thin films

    NASA Astrophysics Data System (ADS)

    Cai, Xing-Min; Hao, Yan-Qing; Zhang, Dong-Ping; Fan, Ping

    2009-10-01

    In this paper, InN thin films were deposited on Si (1 0 0) and K9 glass by reactive direct current magnetron sputtering. The target was In metal with the purity of 99.999% and the gases were Ar (99.999%) and N 2 (99.999%). The properties of InN thin films were studied. Scanning electron microscopy (SEM) shows that the film surface is very rough and energy dispersive X-ray spectroscopy (EDX) shows that the film contains In, N and very little O. X-ray diffraction (XRD) and Raman scattering reveal that the film mainly contains hexagonal InN. The four-probe measurement shows that InN film is conductive. The transmission measurement demonstrates that the transmission of InN deposited on K9 glass is as low as 0.5% from 400 nm to 800 nm.

  6. Threshold energies of light-ion sputtering and heavy-ion sputtering as a function of angle of incidence

    NASA Astrophysics Data System (ADS)

    Yamamura, Y.

    1984-03-01

    The angular dependence of threshold energies has been investigated for light-ion sputtering and heavy-ion sputtering, and simple expressions for the angular dependences of threshold energies are derived for these two cases. For not-too-large angles of incidence, the threshold energy of heavy-ion sputtering is a decreasing function of the angle of incidence because of the anisotropy of the velocity distribution of recoil atoms, while the threshold energy of light-ion sputtering shows a weak angular dependence. For grazing angles of incidence, the threshold energies of these two cases are increasing functions of the angle of incidence because of surface scattering. In order to examine these theoretical angular dependences of threshold energies, the computer simulations have been performed using the ACAT code. It is found that in the near-threshold regime the angular dependences of sputtering yield by heavy ions are much different from those by light ions.

  7. Synthesis of atomic layers of hybridized h-BNC by depositing h-BN on graphene via ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Meng, J. H.; Zhang, X. W.; Liu, H.; Yin, Z. G.; Wang, D. G.; Wang, Y.; You, J. B.; Wu, J. L.

    2016-10-01

    We report the deposition of hexagonal boron nitride (h-BN) on graphene by ion beam sputtering deposition. Both graphene domains and films synthesized by chemical vapor deposition were used as substrates. In the case of graphene domains, it was found that the h-BN domains were preferentially grown on the baked Cu surface instead of graphene due to the highly catalytic activity of Cu. On the other hand, the higher ejection energy of sputtered particles leads to the mixing of boron/nitrogen atoms and carbon atoms. Consequently, the h-BNC films consisting of the hybrid atomic layers of h-BN and graphene domains were formed when the graphene films were used as substrates. This work provides a promising and accessible route for the synthesis of hybridized h-BNC material.

  8. Deposition of Tungsten Thin Films on Flexible Polymer Substrates by Direct-Current Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Huo, Zhenxuan; Jiao, Xiangquan; Zhong, Hui; Shi, Yu

    2015-11-01

    We have investigated thin tungsten films deposited on polymer substrates by direct-current magnetron sputtering under different conditions. Unlike tungsten films deposited on rigid substrates, films on polymer substrates grew at appropriate sputtering power, low sputtering pressure, and low substrate temperature. High sputtering power results in tungsten films with good crystal orientation, compact microstructure, and low electrical resistivity. However, high-power sputtering damages the polymer substrates. Enhancing sputtering pressure substantially degrades tungsten orientation and increases electrical resistivity. Furthermore, a slight increase in substrate temperature results in tungsten films with good crystal orientation, a dense microstructure, and low electrical resistivity. Nonetheless, a high substrate temperature results in soft and deformed polymer substrates; this degrades tungsten crystal orientation and substantially roughens tungsten films. On the basis of this study, compact and flat tungsten films with low electrical resistivity can be obtained at a sputtering power of 69 W, a sputtering pressure of 1 Pa, a substrate temperature of 100°C, and a distance between target and substrate of 60 mm.

  9. Effects of sputtering power on properties of copper oxides thin films deposited on glass substrates

    SciTech Connect

    Ooi, P. K.; Ng, S. S.; Abdullah, M. J.

    2015-04-24

    Copper oxides are deposited by radio frequency sputtering using copper target in the mixture of argon and oxygen gasses. The structural and optical properties of the copper oxides deposited at different sputtering powers have been investigated. All the films are single phase polycrystalline. At low RF power (100 W), the film is monoclinic structure of cupric oxide (CuO). Meanwhile, the films are cubic structure of cuprous oxide (Cu2O) at higher RF power. Field emission scanning electron microscopy images show the films have different morphologies with small grain size and consist of a lot of voids. The analysis of energy dispersive X-ray spectroscopy shows that the ratio of Cu to O is increased as the RF power increased. From the ultraviolet–visible spectroscopy, the films have a broad absorption edge in the range of 300–500 nm. The band gap of the films grown at RF power of 100 W, and 120 W and above, were 1.18 eV and 2.16 eV, respectively.

  10. Binary and ternary NiTi-based shape memory films deposited by simultaneous sputter deposition from elemental targets

    SciTech Connect

    Sanjabi, S.; Cao, Y.Z.; Sadrnezhaad, S.K.; Barber, Z.H.

    2005-09-15

    The most challenging requirement for depositing NiTi-based shape memory thin films is the control of film composition because a small deviation can strongly shift the transformation temperatures. This article presents a technique to control film composition via adjustment of the power supplied to the targets during simultaneous sputter deposition from separate Ni, Ti, and X (e.g., Hf) targets. After optimization of sputter parameters such as working gas pressure, target-substrate distance, and target power ratio, binary Ni{sub 100-x}Ti{sub x} thin films were fabricated and characterized by energy dispersive x-ray spectroscopy in a scanning electron microscope (to measure the film composition and uniformity), in situ x-ray diffraction (to identify the phase structures), and differential scanning calorimetry (to indicate the transformation and crystallization temperatures). To explore the possibility of depositing ternary shape memory NiTi-based thin films with a high temperature transformation >100 deg. C, a Hf target was added to the NiTi deposition system. Annealing was carried out in a high vacuum furnace slightly above the films' crystallization temperatures (500 and 550 deg. C for NiTi and NiTiHf films, respectively). Differential scanning calorimetry (DSC) results of free-standing films illustrated the dependence of transformation temperatures on film composition: Ap and Mp (referring to the austenitic and martensitic peaks in the DSC curve) were above room temperature in near equiatomic NiTi and Ti-rich films, but below it in Ni-rich films. In NiTiHf films, the transformation temperatures were a function of Hf content, reaching as high as 414 deg. C (Ap) at a Hf content of 24.4 at. %. Atomic force microscopy revealed nanostructure surface morphology of both NiTi and NiTiHf films. Detailed characterization showed that the film properties were comparable with those of NiTi and NiTiHf bulk alloys.

  11. Solutions for discharge chamber sputtering and anode deposit spalling in small mercury ion thrusters

    NASA Technical Reports Server (NTRS)

    Power, J. L.; Hiznay, D. J.

    1975-01-01

    Proposed solutions to the problems of sputter erosion and sputtered material spalling in the discharge chamber of small mercury ion thrusters are presented. The accelerated life test evaluated three such proposed solutions: (1) the use of tantalum as a single low sputter yield material for the exposed surfaces of the discharge chamber components subject to sputtering, (2) the use of a severely roughened anode surface to improve the adhesion of the sputter-deposited coating, and (3) the use of a wire cloth anode surface in order to limit the size of any coating flakes which might spall from it. Because of the promising results obtained in the accelerated life test with anode surfaces roughened by grit-blasting, experiments were carried out to optimize the grit-blasting procedure. The experimental results and an optimal grit-blasting procedure are presented.

  12. Adhesion analysis for chromium nitride thin films deposited by reactive magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Rusu, F. M.; Merie, V. V.; Pintea, I. M.; Molea, A.

    2016-08-01

    The thin film industry is continuously growing due to the wide range of applications that require the fabrication of advanced components such as sensors, biological implants, micro-electromechanical devices, optical coatings and so on. The selection regarding the deposition materials, as well as the deposition technology influences the properties of the material and determines the suitability of devices for certain real-world applications. This paper is focused on the adhesion force for several chromium nitride thin films obtained by reactive magnetron sputtering. All chromium nitride thin films were deposited on a silicon substrate, the discharge current and the argon flow being kept constant. The main purpose of the paper is to determine the influence of deposition parameters on the adhesion force. Therefore some of the deposition parameters were varied in order to study their effect on the adhesion force. Experimentally, the values of the adhesion force were determined in multiple points for each sample using the spectroscopy in point mode of the atomic force microscope. The obtained values were used to estimate the surface energy of the CrN thin films based on two existing mathematical models for the adhesion force when considering the contact between two bodies.

  13. Nanoscale compositional analysis of NiTi shape memory alloy films deposited by DC magnetron sputtering

    SciTech Connect

    Sharma, S. K.; Mohan, S.; Bysakh, S.; Kumar, A.; Kamat, S. V.

    2013-11-15

    The formation of surface oxide layer as well as compositional changes along the thickness for NiTi shape memory alloy thin films deposited by direct current magnetron sputtering at substrate temperature of 300 °C in the as-deposited condition as well as in the postannealed (at 600 °C) condition have been thoroughly studied by using secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, and scanning transmission electron microscopy-energy dispersive x-ray spectroscopy techniques. Formation of titanium oxide (predominantly titanium dioxide) layer was observed in both as-deposited and postannealed NiTi films, although the oxide layer was much thinner (8 nm) in as-deposited condition. The depletion of Ti and enrichment of Ni below the oxide layer in postannealed films also resulted in the formation of a graded microstructure consisting of titanium oxide, Ni{sub 3}Ti, and B2 NiTi. A uniform composition of B2 NiTi was obtained in the postannealed film only below a depth of 200–250 nm from the surface. Postannealed film also exhibited formation of a ternary silicide (Ni{sub x}Ti{sub y}Si) at the film–substrate interface, whereas no silicide was seen in the as-deposited film. The formation of silicide also caused a depletion of Ni in the film in a region ∼250–300 nm just above the film substrate interface.

  14. Microstructure, hydrogenation and optical behavior of Mg-Ni multilayer films deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Wang, X. L.; Qiao, Y. Q.; Xia, X. H.; Tu, J. P.

    2011-04-01

    Mg-Ni multilayer films with sequential Mg and Ni layers were prepared by direct current magnetron sputtering. The substrate temperature influences the microstructure of the films greatly. The film deposited at 298 K exhibits multilayered structure, while the film shows nanocrystalline/amorphous composite structure at the deposition temperature of 473 K. The optical properties between hydrogenation/dehydrogenation states of the films were performed using spectrophotometer in visible light region. The film deposited at 473 K can switch from mirror-like metallic state towards brownish yellow transparent state under 0.6 MPa H2 at 298 K, and the optical transmittance modulation reaches up to 20% both at a wavelength of 770 nm and IR region, while the film deposited at 298 K exhibits low optical change, and the optical switching behavior can hardly be found. The extra free energy stored in the boundary of the nanocrystallines benefits the formation of magnesium-based hydride, resulting in the enhancement of the optical switching properties of the Mg-Ni film deposited at 473 K.

  15. Deposition of adherent Ag-Ti duplex films on ceramics in a multiple-cathode sputter deposition system

    NASA Technical Reports Server (NTRS)

    Honecy, Frank S.

    1992-01-01

    The adhesion of Ag films deposited on oxide ceramics can be increased by first depositing intermediate films of active metals such as Ti. Such duplex coatings can be fabricated in a widely used three target sputter deposition system. It is shown here that the beneficial effect of the intermediate Ti film can be defeated by commonly used in situ target and substrate sputter cleaning procedures which result in Ag under the Ti. Auger electron spectroscopy and wear testing of the coatings are used to develop a cleaning strategy resulting in an adherent film system.

  16. Visible-light active thin-film WO{sub 3} photocatalyst with controlled high-rate deposition by low-damage reactive-gas-flow sputtering

    SciTech Connect

    Oka, Nobuto Murata, Akiyo; Nakamura, Shin-ichi; Jia, Junjun; Shigesato, Yuzo; Iwabuchi, Yoshinori; Kotsubo, Hidefumi

    2015-10-01

    A process based on reactive gas flow sputtering (GFS) for depositing visible-light active photocatalytic WO{sub 3} films at high deposition rates and with high film quality was successfully demonstrated. The deposition rate for this process was over 10 times higher than that achieved by the conventional sputtering process and the process was highly stable. Furthermore, Pt nanoparticle-loaded WO{sub 3} films deposited by the GFS process exhibited much higher photocatalytic activity than those deposited by conventional sputtering, where the photocatalytic activity was evaluated by the extent of decomposition of CH{sub 3}CHO under visible light irradiation. The decomposition time for 60 ppm of CH{sub 3}CHO was 7.5 times more rapid on the films deposited by the GFS process than on the films deposited by the conventional process. During GFS deposition, there are no high-energy particles bombarding the growing film surface, whereas the bombardment of the surface with high-energy particles is a key feature of conventional sputtering. Hence, the WO{sub 3} films deposited by GFS should be of higher quality, with fewer structural defects, which would lead to a decrease in the number of centers for electron-hole recombination and to the efficient use of photogenerated holes for the decomposition of CH{sub 3}CHO.

  17. Effects of Process Parameters on the Deposition Rate, Hardness, and Corrosion Resistance of Tungsten Carbide Coatings Deposited by Reactive Sputtering

    NASA Astrophysics Data System (ADS)

    Park, Yunkyu; Lim, Jongmin; Lee, Chongmu

    2005-05-01

    The reactive sputter deposition of tungsten carbide (WCx) films as an alternative to chromium electroplating was studied. The effects of rf power, pressure, sputtering gas composition, and substrate temperature on the deposition rate of the WCx coatings were investigated. The effects of rf power and sputtering gas composition on the hardness and corrosion resistance of the WCx coatings were also investigated. X-ray diffraction (XRD) and Auger electron spectroscopy (AES) analyses were performed to determine the structures and compositions of the films, respectively. The hardnesses of the films were measured using a nanoindenter. The microstructures of the films were observed by scanning electron microscopy. The corrosion resistances of the films were evaluated using a salt-spray test. The deposition rate of the films was proportional to rf power and inversely proportional to the CH4 content of the sputtering gas. The deposition rate increased linearly with increasing chamber pressure. The hardness of the WCx coatings increased as rf power increased. The highest hardness was obtained at a CH4 concentration of 10 vol.% in the sputtering gas. The hardness of the WCx film deposited under optimal conditions was much higher than that of the electroplated chromium film, although the corrosion resistance of the former was slightly lower than that of the latter.

  18. Plasma sputtering depositions with colloidal masks for fabrication of nanostructured surfaces with enhanced photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Demeter, Alexandra; Tiron, Vasile; Lupu, Nicoleta; Stoian, George; Sirghi, Lucel

    2017-06-01

    Titanium oxide/silicon oxide (TiO2/SiO2) 2D patterns were obtained by magnetron sputtering depositions of Ti on close-packed and size-reduced colloidal masks on Si and quartz substrates, followed by mask lift-off and ending with thermal oxidation. The physical processes involved in growing 2D Ti patterns and their oxidation are analyzed. For the magnetron sputtering deposition, two regimes are considered: the low-pressure regime when the flux of sputtered atoms is anisotropic, and the high-pressure regime, when the flux of sputtered atoms is isotropic due to frequent collisions. Moreover, magnetron sputtering operation modes, such as dc sputtering and high power impulse sputtering, are compared. The changes in pattern size and morphology determined by the oxidation of the Ti patterns and Si substrate are analyzed. The hydrophilicity induced by UV-light irradiation and the visible-light photocatalytic activity towards the degradation of the methylene blue of the fabricated TiO2/SiO2 patterns were considerably higher when compared to the performances of uniform TiO2 films.

  19. Plasma sputtering depositions with colloidal masks for fabrication of nanostructured surfaces with enhanced photocatalytic activity.

    PubMed

    Demeter, Alexandra; Tiron, Vasile; Lupu, Nicoleta; Stoian, George; Sirghi, Lucel

    2017-06-23

    Titanium oxide/silicon oxide (TiO2/SiO2) 2D patterns were obtained by magnetron sputtering depositions of Ti on close-packed and size-reduced colloidal masks on Si and quartz substrates, followed by mask lift-off and ending with thermal oxidation. The physical processes involved in growing 2D Ti patterns and their oxidation are analyzed. For the magnetron sputtering deposition, two regimes are considered: the low-pressure regime when the flux of sputtered atoms is anisotropic, and the high-pressure regime, when the flux of sputtered atoms is isotropic due to frequent collisions. Moreover, magnetron sputtering operation modes, such as dc sputtering and high power impulse sputtering, are compared. The changes in pattern size and morphology determined by the oxidation of the Ti patterns and Si substrate are analyzed. The hydrophilicity induced by UV-light irradiation and the visible-light photocatalytic activity towards the degradation of the methylene blue of the fabricated TiO2/SiO2 patterns were considerably higher when compared to the performances of uniform TiO2 films.

  20. Impact of sputter deposition parameters on molybdenum nitride thin film properties

    NASA Astrophysics Data System (ADS)

    Stöber, L.; Konrath, J. P.; Krivec, S.; Patocka, F.; Schwarz, S.; Bittner, A.; Schneider, M.; Schmid, U.

    2015-07-01

    Molybdenum and molybdenum nitride thin films are presented, which are deposited by reactive dc magnetron sputtering. The influence of deposition parameters, especially the amount of nitrogen during film synthesization, to mechanical and electrical properties is investigated. The crystallographic phase and lattice constants are determined by x-ray diffraction analyses. Further information on the microstructure as well as on the biaxial film stress are gained from techniques such as transmission electron microscopy, scanning electron microscopy and the wafer bow. Furthermore, the film resistivity and the temperature coefficient of resistance are measured by the van der Pauw technique starting from room temperature up to 300 °C. Independent of the investigated physical quantity, a dominant dependence on the sputtering gas nitrogen content is observed compared to other deposition parameters such as the plasma power or the sputtering gas pressure in the deposition chamber.

  1. A new highly automated sputter equipment for in situ investigation of deposition processes with synchrotron radiation

    SciTech Connect

    Doehrmann, Ralph; Botta, Stephan; Buffet, Adeline; Santoro, Gonzalo; Schlage, Kai; Schwartzkopf, Matthias; Risch, Johannes F. H.; Mannweiler, Roman; Roth, Stephan V.; Bommel, Sebastian; Brunner, Simon; Metwalli, Ezzeldin; Mueller-Buschbaum, Peter

    2013-04-15

    HASE (Highly Automated Sputter Equipment) is a new mobile setup developed to investigate deposition processes with synchrotron radiation. HASE is based on an ultra-high vacuum sputter deposition chamber equipped with an in-vacuum sample pick-and-place robot. This enables a fast and reliable sample change without breaking the vacuum conditions and helps to save valuable measurement time, which is required for experiments at synchrotron sources like PETRA III at DESY. An advantageous arrangement of several sputter guns, mounted on a rotative flange, gives the possibility to sputter under different deposition angles or to sputter different materials on the same substrate. The chamber is also equipped with a modular sample stage, which allows for the integration of different sample environments, such as a sample heating and cooling device. The design of HASE is unique in the flexibility. The combination of several different sputtering methods like standard deposition, glancing angle deposition, and high pressure sputter deposition combined with heating and cooling possibil-ities of the sample, the large exit windows, and the degree of automation facilitate many different grazing incidence X-ray scattering experiments, such as grazing incidence small and wide angle X-ray scattering, in one setup. In this paper we describe in detail the design and the performance of the new equipment and present the installation of the HASE apparatus at the Micro and Nano focus X-ray Scattering beamline (MiNaXS) at PETRA III. Furthermore, we describe the measurement options and present some selected results. The HASE setup has been successfully commissioned and is now available for users.

  2. A new highly automated sputter equipment for in situ investigation of deposition processes with synchrotron radiation.

    PubMed

    Döhrmann, Ralph; Botta, Stephan; Buffet, Adeline; Santoro, Gonzalo; Schlage, Kai; Schwartzkopf, Matthias; Bommel, Sebastian; Risch, Johannes F H; Mannweiler, Roman; Brunner, Simon; Metwalli, Ezzeldin; Müller-Buschbaum, Peter; Roth, Stephan V

    2013-04-01

    HASE (Highly Automated Sputter Equipment) is a new mobile setup developed to investigate deposition processes with synchrotron radiation. HASE is based on an ultra-high vacuum sputter deposition chamber equipped with an in-vacuum sample pick-and-place robot. This enables a fast and reliable sample change without breaking the vacuum conditions and helps to save valuable measurement time, which is required for experiments at synchrotron sources like PETRA III at DESY. An advantageous arrangement of several sputter guns, mounted on a rotative flange, gives the possibility to sputter under different deposition angles or to sputter different materials on the same substrate. The chamber is also equipped with a modular sample stage, which allows for the integration of different sample environments, such as a sample heating and cooling device. The design of HASE is unique in the flexibility. The combination of several different sputtering methods like standard deposition, glancing angle deposition, and high pressure sputter deposition combined with heating and cooling possibilities of the sample, the large exit windows, and the degree of automation facilitate many different grazing incidence X-ray scattering experiments, such as grazing incidence small and wide angle X-ray scattering, in one setup. In this paper we describe in detail the design and the performance of the new equipment and present the installation of the HASE apparatus at the Micro and Nano focus X-ray Scattering beamline (MiNaXS) at PETRA III. Furthermore, we describe the measurement options and present some selected results. The HASE setup has been successfully commissioned and is now available for users.

  3. A new highly automated sputter equipment for in situ investigation of deposition processes with synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Döhrmann, Ralph; Botta, Stephan; Buffet, Adeline; Santoro, Gonzalo; Schlage, Kai; Schwartzkopf, Matthias; Bommel, Sebastian; Risch, Johannes F. H.; Mannweiler, Roman; Brunner, Simon; Metwalli, Ezzeldin; Müller-Buschbaum, Peter; Roth, Stephan V.

    2013-04-01

    HASE (Highly Automated Sputter Equipment) is a new mobile setup developed to investigate deposition processes with synchrotron radiation. HASE is based on an ultra-high vacuum sputter deposition chamber equipped with an in-vacuum sample pick-and-place robot. This enables a fast and reliable sample change without breaking the vacuum conditions and helps to save valuable measurement time, which is required for experiments at synchrotron sources like PETRA III at DESY. An advantageous arrangement of several sputter guns, mounted on a rotative flange, gives the possibility to sputter under different deposition angles or to sputter different materials on the same substrate. The chamber is also equipped with a modular sample stage, which allows for the integration of different sample environments, such as a sample heating and cooling device. The design of HASE is unique in the flexibility. The combination of several different sputtering methods like standard deposition, glancing angle deposition, and high pressure sputter deposition combined with heating and cooling possibil-ities of the sample, the large exit windows, and the degree of automation facilitate many different grazing incidence X-ray scattering experiments, such as grazing incidence small and wide angle X-ray scattering, in one setup. In this paper we describe in detail the design and the performance of the new equipment and present the installation of the HASE apparatus at the Micro and Nano focus X-ray Scattering beamline (MiNaXS) at PETRA III. Furthermore, we describe the measurement options and present some selected results. The HASE setup has been successfully commissioned and is now available for users.

  4. Physics of arcing, and implications to sputter deposition

    SciTech Connect

    Anders, Andre

    2005-03-15

    Arc and glow discharges are defined based on their cathode processes. Arcs are characterized by collective electron emission, which can be stationary with hot cathodes (thermionic arcs), or non-stationary with cold cathodes (cathodic arcs). A brief review on cathodic arc properties serves as the starting point to better understand arcing phenomena in sputtering. Although arcing occurs in both metal and reactive sputtering, it is more of an issue in the reactive case. Arcing occurs if sufficiently high field strength leads to thermal runaway of an electron emission site. The role of insulating layers and surface potential adjustment through current leakage is highlighted. In the situation of magnetron sputtering with ''racetrack'', the need for a model with two spatial dimensions is shown. In many cases, arcing is initiated by breakdown of dielectric layers and inclusions. It is most efficiently prevented if formation and excessive charge-up of dielectric layers and inclusions can be avoided.

  5. \\A Gravity-Related Transport in Reactive Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, C.-H.; Lehozeky, S. L.

    2000-01-01

    An experiment was designed to investigate the transport characterization of reactive off- axis sputtering deposition. Three transport regions were observed when the growth pressures vary from 5 mtorr to 150 mtorr. A new gravity-related phenomenon was revealed in film growth at relatively high growth pressures. This effect is related to the collision process or thermalization of transport species. This study also suggests a design for the substrate holder orientation in the off-axis sputtering system.

  6. \\A Gravity-Related Transport in Reactive Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, C.-H.; Lehozeky, S. L.

    2000-01-01

    An experiment was designed to investigate the transport characterization of reactive off- axis sputtering deposition. Three transport regions were observed when the growth pressures vary from 5 mtorr to 150 mtorr. A new gravity-related phenomenon was revealed in film growth at relatively high growth pressures. This effect is related to the collision process or thermalization of transport species. This study also suggests a design for the substrate holder orientation in the off-axis sputtering system.

  7. The effects of changing deposition conditions on the similarity of sputter-deposited fluorocarbon thin films to bulk PTFE

    NASA Astrophysics Data System (ADS)

    Zandona, Philip

    Solid lubrication of space-borne mechanical components is essential to their survival and the continued human exploration of space. Recent discoveries have shown that PTFE when blended with alumina nanofillers exhibits greatly improved physical performance properties, with wear rates being reduced by several orders of magnitude. The bulk processes used to produce the PTFE-alumina blends are limiting. Co-sputter deposition of PTFE and a filler material overcomes several of these limitations by enabling the reduction of particle size to the atomic level and also by allowing for the even coating of the solid lubricant on relatively large areas and components. The goal of this study was to establish a baseline performance of the sputtered PTFE films as compared to the bulk material, and to establish deposition conditions that would result in the most bulk-like film possible. In order to coax change in the structure of the sputtered films, sputtering power and deposition temperature were increased independently. Further, post-deposition annealing was applied to half of the deposited film in an attempt to affect change in the film structure. Complications in the characterization process due to increasing film thickness were also examined. Bulk-like metrics for characterization processes the included Fourier transform infrared spectroscopy (FTIR), X-ray spectroscopy (XPS), nanoindentation via atomic force microscopy, and contact angle of water on surface measurements were established. The results of the study revealed that increasing sputtering power and deposition temperature resulted in an increase in the similarity between the fluorocarbon films and the bulk PTFE, at a cost of affecting the potential of the film thicknesses, either by affecting the deposition process directly, or by decreasing the longevity of the sputtering targets.

  8. Limits of carrier mobility in Sb-doped SnO{sub 2} conducting films deposited by reactive sputtering

    SciTech Connect

    Bissig, B. Jäger, T.; Tiwari, A. N.; Romanyuk, Y. E.; Ding, L.

    2015-06-01

    Electron transport in Sb-doped SnO{sub 2} (ATO) films is studied to unveil the limited carrier mobility observed in sputtered films as compared to other deposition methods. Transparent and conductive ATO layers are deposited from metallic tin targets alloyed with antimony in oxygen atmosphere optimized for reactive sputtering. The carrier mobility decreases from 24 cm{sup 2} V{sup −1} s{sup −1} to 6 cm{sup 2} V{sup −1} s{sup −1} when increasing the doping level from 0 to 7 at. %, and the lowest resistivity of 1.8 × 10{sup −3} Ω cm corresponding to the mobility of 12 cm{sup 2} V{sup −1} s{sup −1} which is obtained for the 3 at. % Sb-doped ATO. Temperature-dependent Hall effect measurements and near-infrared reflectance measurements reveal that the carrier mobility in sputtered ATO is limited by ingrain scattering. In contrast, the mobility of unintentionally doped SnO{sub 2} films is determined mostly by the grain boundary scattering. Both limitations should arise from the sputtering process itself, which suffers from the high-energy-ion bombardment and yields polycrystalline films with small grain size.

  9. Structural and optical properties of gold-incorporated diamond-like carbon thin films deposited by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Majeed, Shahbaz; Siraj, K.; Naseem, S.; Khan, Muhammad F.; Irshad, M.; Faiz, H.; Mahmood, A.

    2017-07-01

    Pure and gold-doped diamond-like carbon (Au-DLC) thin films are deposited at room temperature by using RF magnetron sputtering in an argon gas-filled chamber with a constant flow rate of 100 sccm and sputtering time of 30 min for all DLC thin films. Single-crystal silicon (1 0 0) substrates are used for the deposition of pristine and Au-DLC thin films. Graphite (99.99%) and gold (99.99%) are used as co-sputtering targets in the sputtering chamber. The optical properties and structure of Au-DLC thin films are studied with the variation of gold concentration from 1%-5%. Raman spectroscopy, atomic force microscopy (AFM), Vickers hardness measurement (VHM), and spectroscopic ellipsometry are used to analyze these thin films. Raman spectroscopy indicates increased graphitic behavior and reduction in the internal stresses of Au-DLC thin films as the function of increasing gold doping. AFM is used for surface topography, which shows that spherical-like particles are formed on the surface, which agglomerate and form larger clusters on the surface by increasing the gold content. Spectroscopy ellipsometry analysis elucidates that the refractive index and extinction coefficient are inversely related and the optical bandgap energy is decreased with increasing gold content. VHM shows that gold doping reduces the hardness of thin films, which is attributed to the increase in sp2-hybridization.

  10. Limits of carrier mobility in Sb-doped SnO2 conducting films deposited by reactive sputtering

    NASA Astrophysics Data System (ADS)

    Bissig, B.; Jäger, T.; Ding, L.; Tiwari, A. N.; Romanyuk, Y. E.

    2015-06-01

    Electron transport in Sb-doped SnO2 (ATO) films is studied to unveil the limited carrier mobility observed in sputtered films as compared to other deposition methods. Transparent and conductive ATO layers are deposited from metallic tin targets alloyed with antimony in oxygen atmosphere optimized for reactive sputtering. The carrier mobility decreases from 24 cm2 V-1 s-1 to 6 cm2 V-1 s-1 when increasing the doping level from 0 to 7 at. %, and the lowest resistivity of 1.8 × 10-3 Ω cm corresponding to the mobility of 12 cm2 V-1 s-1 which is obtained for the 3 at. % Sb-doped ATO. Temperature-dependent Hall effect measurements and near-infrared reflectance measurements reveal that the carrier mobility in sputtered ATO is limited by ingrain scattering. In contrast, the mobility of unintentionally doped SnO2 films is determined mostly by the grain boundary scattering. Both limitations should arise from the sputtering process itself, which suffers from the high-energy-ion bombardment and yields polycrystalline films with small grain size.

  11. Spatial distribution of electrical properties for Al-doped ZnO films deposited by dc magnetron sputtering using various inert gases

    SciTech Connect

    Sato, Yasushi; Ishihara, Keita; Oka, Nobuto; Shigesato, Yuzo

    2010-07-15

    Spatial distribution of electrical properties of Al-doped ZnO (AZO) films deposited by magnetron sputtering was investigated. To adjust the intensity of bombardment by high-energy particles, the AZO films were deposited using Ar, Kr, or Xe gas with varying plasma impedance. The spatial distribution of the electrical properties clearly depends on the sputtering gas. In the case of using Kr or Xe, the resistivity of the films in front of the target center and erosion areas was significantly enhanced, in contrast with Ar. This was attributed to an enhancement in bombardment damage due to the increased sputtering voltages required for Kr or Xe discharges. The increase in plasma impedance was due to the smaller coefficients for secondary-electron emission of the target surface by Kr or Xe impingements, which leads to the larger sputtering voltage.

  12. Energy and angular distributions of sputtered atoms at normal incidence

    NASA Astrophysics Data System (ADS)

    Yamamura, Y.; Takiguchi, T.; Ishida, M.

    1991-12-01

    The Monte Carlo simulation code ACAT has been applied to investigate the angular distribution and the energy distribution of atoms sputtered from Cu and Nb targets by normally incident Ar+ ions. It is found that there are two important effects which affect the angular distributions and the energy distributions of sputtered atoms, i.e., the anisotropic effect and the bulk recoil effect. The former effects means that the recoil flux keeps the memory of the incident ion-beam direction because of the incomplete cascade, while the latter one means the contributions of recoils generated at the deeper layer to the angular and the energy distributions of sputtered atoms. The anisotropic effect is important in the low energy region, and it makes the angular distribution under-cosine and the high energy tail of the energy distribution fall off faster than the Thompson distribution. The bulk recoil effect makes angular distribution be over-cosine and the peak position of the energy distribution be shifted to somewhat higher energies.

  13. STEM-EELS analysis reveals stable high-density He in nanopores of amorphous silicon coatings deposited by magnetron sputtering.

    PubMed

    Schierholz, Roland; Lacroix, Bertrand; Godinho, Vanda; Caballero-Hernández, Jaime; Duchamp, Martial; Fernández, Asunción

    2015-02-20

    A broad interest has been showed recently on the study of nanostructuring of thin films and surfaces obtained by low-energy He plasma treatments and He incorporation via magnetron sputtering. In this paper spatially resolved electron energy-loss spectroscopy in a scanning transmission electron microscope is used to locate and characterize the He state in nanoporous amorphous silicon coatings deposited by magnetron sputtering. A dedicated MATLAB program was developed to quantify the helium density inside individual pores based on the energy position shift or peak intensity of the He K-edge. A good agreement was observed between the high density (∼35-60 at nm(-3)) and pressure (0.3-1.0 GPa) values obtained in nanoscale analysis and the values derived from macroscopic measurements (the composition obtained by proton backscattering spectroscopy coupled to the macroscopic porosity estimated from ellipsometry). This work provides new insights into these novel porous coatings, providing evidence of high-density He located inside the pores and validating the methodology applied here to characterize the formation of pores filled with the helium process gas during deposition. A similar stabilization of condensed He bubbles has been previously demonstrated by high-energy He ion implantation in metals and is newly demonstrated here using a widely employed methodology, magnetron sputtering, for achieving coatings with a high density of homogeneously distributed pores and He storage capacities as high as 21 at%.

  14. Optical properties study of silicon oxynitride films deposited by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Zhu, Yong; Gu, Peifu; Ye, Hui; Shen, Weidong

    2004-12-01

    Graded refractive index Silicon Oxy-nitride thin films were deposited by RF magnetron reactive sputtering at different N2/O2 flow ratio. The effects of gas flow ratio on the refractive index, extinction coefficient and composition were studied using UV-VIS spectrophotometer, XPS and FTIR characterization methods. A simple and accurate method is presented for determination of the optical constants and physical thickness of thin films. Which was consisted in fitting the experimental transmission curve with the help of the physical model. The relationship between composition and optical gap and dispersion energy was analyzed using Wemple DiDomenico single-oscillator model. As a result, the samples" refractive index can be controlled from 1.92 to 1.46 by adjusting the gas flow ratio, and the optical gap lies between 5eV~6.5eV.

  15. Electrochromism in sputter deposited W1-y MoyO3 thin films

    NASA Astrophysics Data System (ADS)

    Arvizu, M. A.; Granqvist, C. G.; Niklasson, G. A.

    2016-02-01

    Electrochromic (EC) properties of tungsten-molybdenum oxide (W1-y MoyO3) thin films were investigated. The films were deposited on indium tin oxide covered glass by reactive DC sputtering from tungsten and molybdenum targets. Elemental compositions of the W1-y MoyO3 films were determined by Rutherford back scattering. Voltammetric cycling was performed in an electrolyte of 1 M LiClO4 in propylene carbonate. An increase in molybdenum content in the EC films caused both a shift towards higher energies and a lowering of the maximum of the optical absorption band, as compared with WO3 EC films. Durability under electrochemical cycling was diminished for W1-y MoyO3 EC films.

  16. Effects of nitrogen ion implantation time on tungsten films deposited by DC magnetron sputtering on AISI 410 martensitic stainless steel

    SciTech Connect

    Malau, Viktor Ilman, Mochammad Noer Iswanto, Priyo Tri Jatisukamto, Gaguk

    2016-03-29

    Nitrogen ion implantation time on tungsten thin film deposited on surface of AISI 410 steel has been performed. Tungsten thin film produced by dc magnetron sputtering method was deposited on AISI 410 martensitic stainless steel substrates, and then the nitrogen ions were implanted on tungsten thin film. The objective of this research is to investigate the effects of implantation deposition time on surface roughness, microhardness, specific wear and corrosion rate of nitrogen implanted on tungsten film. Magnetron sputtering process was performed by using plasma gas of argon (Ar) to bombardier tungsten target (W) in a vacuum chamber with a pressure of 7.6 x 10{sup −2} torr, a voltage of 300 V, a sputter current of 80 mA for sputtered time of 10 minutes. Nitrogen implantation on tungsten film was done with an initial pressure of 3x10{sup −6} mbar, a fluence of 2 x 10{sup 17} ions/cm{sup 2}, an energy of 100 keV and implantation deposition times of 0, 20, 30 and 40 minutes. The surface roughness, microhardness, specific wear and corrosion rate of the films were evaluated by surfcorder test, Vickers microhardness test, wear test and potentiostat (galvanostat) test respectively. The results show that the nitrogen ions implanted deposition time on tungsten film can modify the surface roughness, microhardness, specific wear and corrosion rate. The minimum surface roughness, specific wear and corrosion rate can be obtained for implantation time of 20 minutes and the maximum microhardness of the film is 329 VHN (Vickers Hardness Number) for implantation time of 30 minutes. The specific wear and corrosion rate of the film depend directly on the surface roughness.

  17. Effects of nitrogen ion implantation time on tungsten films deposited by DC magnetron sputtering on AISI 410 martensitic stainless steel

    NASA Astrophysics Data System (ADS)

    Malau, Viktor; Ilman, Mochammad Noer; Iswanto, Priyo Tri; Jatisukamto, Gaguk

    2016-03-01

    Nitrogen ion implantation time on tungsten thin film deposited on surface of AISI 410 steel has been performed. Tungsten thin film produced by dc magnetron sputtering method was deposited on AISI 410 martensitic stainless steel substrates, and then the nitrogen ions were implanted on tungsten thin film. The objective of this research is to investigate the effects of implantation deposition time on surface roughness, microhardness, specific wear and corrosion rate of nitrogen implanted on tungsten film. Magnetron sputtering process was performed by using plasma gas of argon (Ar) to bombardier tungsten target (W) in a vacuum chamber with a pressure of 7.6 x 10-2 torr, a voltage of 300 V, a sputter current of 80 mA for sputtered time of 10 minutes. Nitrogen implantation on tungsten film was done with an initial pressure of 3x10-6 mbar, a fluence of 2 x 1017 ions/cm2, an energy of 100 keV and implantation deposition times of 0, 20, 30 and 40 minutes. The surface roughness, microhardness, specific wear and corrosion rate of the films were evaluated by surfcorder test, Vickers microhardness test, wear test and potentiostat (galvanostat) test respectively. The results show that the nitrogen ions implanted deposition time on tungsten film can modify the surface roughness, microhardness, specific wear and corrosion rate. The minimum surface roughness, specific wear and corrosion rate can be obtained for implantation time of 20 minutes and the maximum microhardness of the film is 329 VHN (Vickers Hardness Number) for implantation time of 30 minutes. The specific wear and corrosion rate of the film depend directly on the surface roughness.

  18. Single target sputter deposition of alloy nanoparticles with adjustable composition via a gas aggregation cluster source

    NASA Astrophysics Data System (ADS)

    Vahl, Alexander; Strobel, Julian; Reichstein, Wiebke; Polonskyi, Oleksandr; Strunskus, Thomas; Kienle, Lorenz; Faupel, Franz

    2017-04-01

    Alloy nanoparticles with variable compositions add a new dimension to nanoscience and have many applications. Here we suggest a novel approach for the fabrication of variable composition alloy nanoparticles that is based on a Haberland type gas aggregation cluster source with a custom-made multicomponent target for magnetron sputtering. The approach, which was demonstrated here for gold-rich AgAu nanoparticles, combines a narrow nanoparticle size distribution with in operando variation of composition via the gas pressure as well as highly efficient usage of target material. The latter is particularly attractive for precious metals. Varying argon pressure during deposition, we achieved in operando changes of AgAu alloy nanoparticle composition of more than 13 at%. The alloy nanoparticles were characterized by x-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy. The characteristic plasmon resonances of multilayer nanoparticle composites were analyzed by UV-vis spectroscopy. Tuning of the number of particles per unit area (particle densities) within individual layers showed an additional degree of freedom to tailor the optical properties of multilayer nanocomposites. By extension of this technique to more complex systems, the presented results are expected to encourage and simplify further research based on plasmonic multi-element nanoparticles. The present method is by no means restricted to plasmonics or nanoparticle based applications, but is also highly relevant for conventional magnetron sputtering of alloys and can be extended to in operando control of alloy concentration by magnetic field.

  19. Single target sputter deposition of alloy nanoparticles with adjustable composition via a gas aggregation cluster source.

    PubMed

    Vahl, Alexander; Strobel, Julian; Reichstein, Wiebke; Polonskyi, Oleksandr; Strunskus, Thomas; Kienle, Lorenz; Faupel, Franz

    2017-04-28

    Alloy nanoparticles with variable compositions add a new dimension to nanoscience and have many applications. Here we suggest a novel approach for the fabrication of variable composition alloy nanoparticles that is based on a Haberland type gas aggregation cluster source with a custom-made multicomponent target for magnetron sputtering. The approach, which was demonstrated here for gold-rich AgAu nanoparticles, combines a narrow nanoparticle size distribution with in operando variation of composition via the gas pressure as well as highly efficient usage of target material. The latter is particularly attractive for precious metals. Varying argon pressure during deposition, we achieved in operando changes of AgAu alloy nanoparticle composition of more than 13 at%. The alloy nanoparticles were characterized by x-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy. The characteristic plasmon resonances of multilayer nanoparticle composites were analyzed by UV-vis spectroscopy. Tuning of the number of particles per unit area (particle densities) within individual layers showed an additional degree of freedom to tailor the optical properties of multilayer nanocomposites. By extension of this technique to more complex systems, the presented results are expected to encourage and simplify further research based on plasmonic multi-element nanoparticles. The present method is by no means restricted to plasmonics or nanoparticle based applications, but is also highly relevant for conventional magnetron sputtering of alloys and can be extended to in operando control of alloy concentration by magnetic field.

  20. Structural analysis of ferromagnetic Ni-Mn-Sn thin films fabricated by co-sputter deposition

    NASA Astrophysics Data System (ADS)

    Guvenc, Sema; Yumak, Mehmet; Nedelcos, A. Quintana; Llamazares, J. L. Sanchez; Garcia, Carlos Garcia

    2015-03-01

    Ferromagnetic Ni-Mn-X (Sn, In) alloys are predicted as potential candidates for energy efficient Magnetocaloric Effect (MCE) technologies. The MCE is the basis of magnetic refrigeration and it leads to a groundbreaking progress on conventional refrigeration methods. In our research, Ni-Mn-Sn thin films were fabricated by co-sputter deposition method. The Mn losses due to the high Mn vapor pressure produce a deviation from the desired Ni50Mn37Sn13 composition, which are partially compensated by increasing power of the Mn target gun. A systematic study of thin film co-sputter fabrication was divided into three stages; i) a Ni-Mn-Sn target was evaporated at different temperatures in order to study the grain size temperature dependence, ii) the nominal chemical composition (Ni50Mn37Sn13) was reached by controlling the power value applied to the Mn target, iii) the dependence of the phase transformation temperature with the grain size of the thin film alloys was studied. Grain size can be controlled by modifying the substrate temperature (Ts) .

  1. Studies of aluminium coatings deposited by vacuum evaporation and magnetron sputtering.

    PubMed

    Garbacz, H; Wieciński, P; Adamczyk-Cieślak, B; Mizera, J; Kurzydłowski, K J

    2010-03-01

    The paper presents the results of investigations of the microstructures and properties of the aluminium coatings deposited by vacuum evaporation and magnetron sputtering. These coatings generally have a very refined microstructure with elongated nano-grains. However, the surface topography of the aluminium coating deposited by vacuum evaporation is more developed, its microstructure is less homogeneous and more porous. The residual tensile stresses in the aluminium coating deposited by magnetron sputtering are close to 130 MPa, and the texture is relatively pronounced. Vacuum evaporation does not induce residual stresses in the coatings and the texture is very weak. The results obtained indicate that the aluminium coatings produced by magnetron sputtering are more suitable for the diffusive Ti-Al intermetallic layers.

  2. Large-area few-layer MoS2 deposited by sputtering

    NASA Astrophysics Data System (ADS)

    Huang, Jyun-Hong; Chen, Hsing-Hung; Liu, Pang-Shiuan; Lu, Li-Syuan; Wu, Chien-Ting; Chou, Cheng-Tung; Lee, Yao-Jen; Li, Lain-Jong; Chang, Wen-Hao; Hou, Tuo-Hung

    2016-06-01

    Direct magnetron sputtering of transition metal dichalcogenide targets is proposed as a new approach for depositing large-area two-dimensional layered materials. Bilayer to few-layer MoS2 deposited by magnetron sputtering followed by post-deposition annealing shows superior area scalability over 20 cm2 and layer-by-layer controllability. High crystallinity of layered MoS2 was confirmed by Raman, photo-luminescence, and transmission electron microscopy analysis. The sputtering temperature and annealing ambience were found to play an important role in the film quality. The top-gate field-effect transistor by using the layered MoS2 channel shows typical n-type characteristics with a current on/off ratio of approximately 104. The relatively low mobility is attributed to the small grain size of 0.1-1 μm with a trap charge density in grain boundaries of the order of 1013 cm-2.

  3. Deposition of vanadium carbide thin films using compound target sputtering and their field emission

    SciTech Connect

    Liao, M.Y.; Gotoh, Y.; Tsuji, H.; Ishikawa, J.

    2005-09-15

    Vanadium carbide (VC) thin films were deposited on silicon substrates by direct sputtering of a VC target in an argon atmosphere. The structure, composition, and electrical properties of the films were investigated as functions of deposition conditions. The crystallographic structure of the film was strongly related to the argon pressure. VC films with (111) preferred orientation were formed at 2.0 Pa regardless of the substrate temperature examined, while amorphous films were obtained at the lowest pressure of 0.5 Pa. It was shown that carbon segregation within the film was difficult to avoid, but could be suppressed to some degree. To make a full understanding of the compositional variation in compound target sputtering process, deposition of chromium carbide thin films was also performed. Some common mechanisms involved in compound target sputtering process were discussed. Field emission measurements revealed that the VC film is a good electron emitter.

  4. Deposition of vanadium carbide thin films using compound target sputtering and their field emission

    NASA Astrophysics Data System (ADS)

    Liao, M. Y.; Gotoh, Y.; Tsuji, H.; Ishikawa, J.

    2005-09-01

    Vanadium carbide (VC) thin films were deposited on silicon substrates by direct sputtering of a VC target in an argon atmosphere. The structure, composition, and electrical properties of the films were investigated as functions of deposition conditions. The crystallographic structure of the film was strongly related to the argon pressure. VC films with (111) preferred orientation were formed at 2.0 Pa regardless of the substrate temperature examined, while amorphous films were obtained at the lowest pressure of 0.5 Pa. It was shown that carbon segregation within the film was difficult to avoid, but could be suppressed to some degree. To make a full understanding of the compositional variation in compound target sputtering process, deposition of chromium carbide thin films was also performed. Some common mechanisms involved in compound target sputtering process were discussed. Field emission measurements revealed that the VC film is a good electron emitter.

  5. Binding energy effects in cascade evolution and sputtering

    SciTech Connect

    Robinson, M.T.

    1995-06-01

    The MARLOWE model was extended to include a binding energy dependent on the local crystalline order, so that atoms are bound less strongly to their lattice sites near surfaces or associated damage. Sputtering and cascade evolution were studied on the examples of self-ion irradiations of Cu and Au monocrystals. In cascades, the mean binding energy is reduced {approximately}8% in Cu with little dependence on the initial recoil energy; in Au, it is reduced {approximately}9% at 1 keV and {approximately}15% at 100 keV. In sputtering, the mean binding energy is reduced {approximately}8% in Cu and {approximately}15% in Au with little energy dependence; the yields are increased about half as much. Most sites from which sputtered atoms originate are isolated in both metals. Small clusters of such sites occur in Cu, but there are some large clusters in Au, especially in [111] targets. There are always more large clusters with damage-dependent binding than with a constant binding energy, but only a few clusters are compact enough to be regarded as pits.

  6. Energy distributions of sputtered copper neutrals and ions

    NASA Technical Reports Server (NTRS)

    Lundquist, T. R.

    1978-01-01

    Direct quantitative analysis of surfaces by secondary ion mass spectrometry will depend on an understanding of the yield ratio of ions to neutrals. This ratio as a function of the energy of the sputtered particles has been obtained for a clean polycrystalline copper surface sputtered by 1000-3000 eV Ar(+). The energy distributions of both neutral and ionized copper were measured with a retarding potential analyzer using potential modulation differentiation and signal averaging. The maximum for both distributions is identical and occurs near 2.5 eV. The energy distributions of neutrals is more sharply peaked than that of the ions, presumably as a consequence of more efficient nutralization of slow escaping ions by the mobile electrons of copper. The ion-neutral ratio is compared with results from various ionization models.

  7. Energy distributions of sputtered copper neutrals and ions

    NASA Technical Reports Server (NTRS)

    Lundquist, T. R.

    1978-01-01

    Direct quantitative analysis of surfaces by secondary ion mass spectrometry will depend on an understanding of the yield ratio of ions to neutrals. This ratio as a function of the energy of the sputtered particles has been obtained for a clean polycrystalline copper surface sputtered by 1000-3000 eV Ar(+). The energy distributions of both neutral and ionized copper were measured with a retarding potential analyzer using potential modulation differentiation and signal averaging. The maximum for both distributions is identical and occurs near 2.5 eV. The energy distributions of neutrals is more sharply peaked than that of the ions, presumably as a consequence of more efficient nutralization of slow escaping ions by the mobile electrons of copper. The ion-neutral ratio is compared with results from various ionization models.

  8. Formation of cubic boron-nitride by the reactive sputter deposition of boron

    SciTech Connect

    Jankowski, A.F.; Hayes, J.P.; Makowiecki, D.W.; McKeman, M.A.

    1997-03-01

    Boron-nitride films are synthesized by RF magnetron sputtering boron targets where the deposition parameters of gas pressure, flow and composition are varied along with substrate temperature and applied bias. The films are analyzed using Auger electron spectroscopy, transmission electron microscopy, nanoindentation, Raman spectroscopy and x-ray absorption spectroscopy. These techniques provide characterization of film composition, crystalline structure, hardness and chemical bonding, respectively. Reactive, rf-sputtering process parameters are established which lead to the growth of crystalline BN phases. The deposition of stable and adherent boron nitride coatings consisting of the cubic phase requires 400 `C substrate heating and the application of a 300 V negative bias.

  9. Sputter deposition of Al-doped ZnO films with various incident angles

    SciTech Connect

    Sato, Yasushi; Yanagisawa, Kei; Oka, Nobuto; Nakamura, Shin-ichi; Shigesato, Yuzo

    2009-09-15

    Al-doped ZnO (AZO) films were sputter deposited on glass substrates heated at 200 degree sign C under incident angles of sputtered particles at 0 degree sign (incidence normal to substrate), 20 deg., 40 deg., 60 deg., and 80 deg. In the case of normal incidence, x-ray diffraction pole figures show a strong [001] preferred orientation normal to the film surface. In contrast, in the case wherein the incident angles were higher than 60 degree sign , the [001] orientation inclined by 25 deg. - 35 deg. toward the direction of sputtered particles. Transmission electron microscopy revealed that the tilt angle of the [001] orientation increased with increasing angle of the incident sputtered particles, whereas the columnar structure did not show any sign of inclination with respect to the substrate plane.

  10. Closed-cell foams produced from sputter-deposited aluminum. [experiments on earth and in space environment

    NASA Technical Reports Server (NTRS)

    Patten, J. W.; Greenwell, E. N.

    1977-01-01

    Sputter deposited aluminum containing argon was melted to produce foam, both in the earth's gravitational field and in a zero-gravity space environment. Experiments leading to trapping of up to 270 ppm argon sputtering gas in pure aluminum during high-rate dc triode sputter deposition are discussed. Conduct of the melting experiments and design of the furnace used are described. Metallography; an analysis of bubble size, distribution, and morphology; and a preliminary description of the kinetics are also presented.

  11. Closed-cell foams produced from sputter-deposited aluminum. [experiments on earth and in space environment

    NASA Technical Reports Server (NTRS)

    Patten, J. W.; Greenwell, E. N.

    1977-01-01

    Sputter deposited aluminum containing argon was melted to produce foam, both in the earth's gravitational field and in a zero-gravity space environment. Experiments leading to trapping of up to 270 ppm argon sputtering gas in pure aluminum during high-rate dc triode sputter deposition are discussed. Conduct of the melting experiments and design of the furnace used are described. Metallography; an analysis of bubble size, distribution, and morphology; and a preliminary description of the kinetics are also presented.

  12. Deposition of Visible Light Active Photocatalytic Bismuth Molybdate Thin Films by Reactive Magnetron Sputtering.

    PubMed

    Ratova, Marina; Kelly, Peter J; West, Glen T; Xia, Xiaohong; Gao, Yun

    2016-01-22

    Bismuth molybdate thin films were deposited by reactive magnetron co-sputtering from two metallic targets in an argon/oxygen atmosphere, reportedly for the first time. Energy dispersive X-ray spectroscopy (EDX) analysis showed that the ratio of bismuth to molybdenum in the coatings can be effectively controlled by varying the power applied to each target. Deposited coatings were annealed in air at 673 K for 30 min. The crystalline structure was assessed by means of Raman spectroscopy and X-ray diffraction (XRD). Oxidation state information was obtained by X-ray photoelectron spectroscopy (XPS). Photodegradation of organic dyes methylene blue and rhodamine B was used for evaluation of the photocatalytic properties of the coatings under a visible light source. The photocatalytic properties of the deposited coatings were then compared to a sample of commercial titanium dioxide-based photocatalytic product. The repeatability of the dye degradation reactions and photocatalytic coating reusability are discussed. It was found that coatings with a Bi:Mo ratio of approximately 2:1 exhibited the highest photocatalytic activity of the coatings studied; its efficacy in dye photodegradation significantly outperformed a sample of commercial photocatalytic coating.

  13. Deposition of Visible Light Active Photocatalytic Bismuth Molybdate Thin Films by Reactive Magnetron Sputtering

    PubMed Central

    Ratova, Marina; Kelly, Peter J.; West, Glen T.; Xia, Xiaohong; Gao, Yun

    2016-01-01

    Bismuth molybdate thin films were deposited by reactive magnetron co-sputtering from two metallic targets in an argon/oxygen atmosphere, reportedly for the first time. Energy dispersive X-ray spectroscopy (EDX) analysis showed that the ratio of bismuth to molybdenum in the coatings can be effectively controlled by varying the power applied to each target. Deposited coatings were annealed in air at 673 K for 30 min. The crystalline structure was assessed by means of Raman spectroscopy and X-ray diffraction (XRD). Oxidation state information was obtained by X-ray photoelectron spectroscopy (XPS). Photodegradation of organic dyes methylene blue and rhodamine B was used for evaluation of the photocatalytic properties of the coatings under a visible light source. The photocatalytic properties of the deposited coatings were then compared to a sample of commercial titanium dioxide-based photocatalytic product. The repeatability of the dye degradation reactions and photocatalytic coating reusability are discussed. It was found that coatings with a Bi:Mo ratio of approximately 2:1 exhibited the highest photocatalytic activity of the coatings studied; its efficacy in dye photodegradation significantly outperformed a sample of commercial photocatalytic coating. PMID:28787867

  14. Chemical sputtering by H2+ and H3+ ions during silicon deposition

    NASA Astrophysics Data System (ADS)

    Landheer, K.; Goedheer, W. J.; Poulios, I.; Schropp, R. E. I.; Rath, J. K.

    2016-08-01

    We investigated chemical sputtering of silicon films by Hy+ ions (with y being 2 and 3) in an asymmetric VHF Plasma Enhanced Chemical Vapor Deposition (PECVD) discharge in detail. In experiments with discharges created with pure H2 inlet flows, we observed that more Si was etched from the powered than from the grounded electrode, and this resulted in a net deposition on the grounded electrode. With experimental input data from a power density series of discharges with pure H2 inlet flows, we were able to model this process with a chemical sputtering mechanism. The obtained chemical sputtering yields were (0.3-0.4) ± 0.1 Si atom per bombarding Hy+ ion at the grounded electrode and at the powered electrode the yield ranged from (0.4 to 0.65) ± 0.1. Subsequently, we investigated the role of chemical sputtering during PECVD deposition with a series of silane fractions SF (SF(%) = [SiH4]/[H2]*100) ranging from SF = 0% to 20%. We experimentally observed that the SiHy+ flux is not proportional to SF but decreasing from SF = 3.4% to 20%. This counterintuitive SiHy+ flux trend was partly explained by an increasing chemical sputtering rate with decreasing SF and partly by the reaction between H3+ and SiH4 that forms SiH3+.

  15. ZrN coatings deposited by high power impulse magnetron sputtering and cathodic arc techniques

    SciTech Connect

    Purandare, Yashodhan Ehiasarian, Arutiun; Hovsepian, Papken; Santana, Antonio

    2014-05-15

    Zirconium nitride (ZrN) coatings were deposited on 1 μm finish high speed steel and 316L stainless steel test coupons. Cathodic Arc (CA) and High Power Impulse Magnetron Sputtering (HIPIMS) + Unbalanced Magnetron Sputtering (UBM) techniques were utilized to deposit coatings. CA plasmas are known to be rich in metal and gas ions of the depositing species as well as macroparticles (droplets) emitted from the arc sports. Combining HIPIMS technique with UBM in the same deposition process facilitated increased ion bombardment on the depositing species during coating growth maintaining high deposition rate. Prior to coating deposition, substrates were pretreated with Zr{sup +} rich plasma, for both arc deposited and HIPIMS deposited coatings, which led to a very high scratch adhesion value (L{sub C2}) of 100 N. Characterization results revealed the overall thickness of the coatings in the range of 2.5 μm with hardness in the range of 30–40 GPa depending on the deposition technique. Cross-sectional transmission electron microscopy and tribological experiments such as dry sliding wear tests and corrosion studies have been utilized to study the effects of ion bombardment on the structure and properties of these coatings. In all the cases, HIPIMS assisted UBM deposited coating fared equal or better than the arc deposited coatings, the reasons being discussed in this paper. Thus H+U coatings provide a good alternative to arc deposited where smooth, dense coatings are required and macrodroplets cannot be tolerated.

  16. Stress reduction in sputter deposited films using nanostructured compliant layers by high working-gas pressures

    NASA Astrophysics Data System (ADS)

    Karabacak, Tansel; Senkevich, Jay. J.; Wang, Gwo-Ching; Lu, Toh-Ming

    2005-07-01

    We present a strategy of stress reduction in sputter deposited films by a nano-compliant layer at the substrate using physically self-assembled nanostructures obtained at high working-gas pressures prior to the deposition of a continuous film. This technique is all in situ, and the nanostructures are made of the same material as the deposited thin film and requires no lithography process. This nanostructured layer has a lower material density and can act as a compliant layer to reduce the stress of the subsequently deposited continuous film grown under low gas pressure. By using this approach we were able to reduce stress values significantly in sputter deposited tungsten films and the strategy of alternating high and low Ar gas pressures leads to the growth of much thicker films without delamination.

  17. Properties of electrochromic nickel-vanadium oxide films sputter-deposited from nonmagnetic alloy target

    NASA Astrophysics Data System (ADS)

    Avendano, Esteban; Azens, Andris; Niklasson, Gunnar A.

    2001-11-01

    In this study we investigate the structure, composition, diffusion coefficient, and electrochromic properties of nickel-vanadium oxide films as a function of deposition conditions. Polycrystalline films have been deposited by DC magnetron sputtering from a nonmagnetic target of Ni0.93V0.07 in an atmosphere of O2/Ar and Ar/O2/H2, with the gas flow ratios varied systematically to cover the range from nearly-metallic to overoxidized films. The results contradict the usual view that films deposited in O2/Ar are dark brown in their as-deposited state. While such films can easily be deposited, the optimum electrochromic properties have been observed at O2/Ar ratios giving nearly transparent films. Addition of hydrogen to the sputtering atmosphere improved cycling stability of the films. The diffusion coefficient has been determined by the Galvanostatic Intermittent Titration Technique (GITT).

  18. Disorder-free sputtering method on graphene

    SciTech Connect

    Qiu Xue Peng; Shin Young Jun; Niu Jing; Kulothungasagaran, Narayanapillai; Kalon, Gopinadhan; Yang, Hyunsoo; Qiu Caiyu; Yu Ting

    2012-09-15

    Deposition of various materials onto graphene without causing any disorder is highly desirable for graphene applications. Especially, sputtering is a versatile technique to deposit various metals and insulators for spintronics, and indium tin oxide to make transparent devices. However, the sputtering process causes damage to graphene because of high energy sputtered atoms. By flipping the substrate and using a high Ar pressure, we demonstrate that the level of damage to graphene can be reduced or eliminated in dc, rf, and reactive sputtering processes.

  19. Sputter deposition onto ionic liquids: Simple and clean synthesis of highly dispersed ultrafine metal nanoparticles

    SciTech Connect

    Torimoto, Tsukasa; Okazaki, Ken-ichi; Kiyama, Tomonori; Hirahara, Kaori; Tanaka, Nobuo; Kuwabata, Susumu

    2006-12-11

    Sputter deposition of gold (Au) onto ionic liquids (ILs) resulted in the formation of highly dispersed Au nanoparticles without additional chemical species, such as reducing and/or stabilizing agents. The Au nanoparticles in 1-ethyl-3-methylimidazolium tetrafluoroborate had an average diameter (d{sub av}) of 5.5 nm with a standard deviation ({sigma}) of 0.86 nm, while sputter deposition onto N,N,N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide resulted in the formation of much smaller Au nanoparticles with d{sub av} of 1.9 nm and {sigma} of 0.46 nm. Prolongation of sputtering time results in a higher concentration of Au nanoparticles in ILs, but did not cause a remarkable change in their size.

  20. Structural disordering studies of Cu6PS5I-based thin films deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Studenyak, Ihor; Rybak, Stefan; Bendak, Andrii; Izai, Vitalii; Guranich, Pavlo; Kúš, Peter; Mikula, Marian

    2016-12-01

    Cu6PS5I-based thin films were deposited onto silicate glass substrates by magnetron sputtering. With Cu content increase, a red shift of the optical transmission spectra as well as increase of the total electric conductivity are observed. A typical Urbach bundle are revealed, the temperature behaviour of the Urbach absorption edge in thin films are explained by strong electron-phonon interaction. Temperature dependences of the absorption edge energy position and the Urbach energy for thin film are well described in Einstein model. The influence of different type of disordering on the Urbach tail is studied.

  1. High power impulse magnetron sputtering and related discharges: scalable plasma sources for plasma-based ion implantation and deposition

    SciTech Connect

    Anders, Andre

    2009-09-01

    High power impulse magnetron sputtering (HIPIMS) and related self-sputtering techniques are reviewed from a viewpoint of plasma-based ion implantation and deposition (PBII&D). HIPIMS combines the classical, scalable sputtering technology with pulsed power, which is an elegant way of ionizing the sputtered atoms. Related approaches, such as sustained self-sputtering, are also considered. The resulting intense flux of ions to the substrate consists of a mixture of metal and gas ions when using a process gas, or of metal ions only when using `gasless? or pure self-sputtering. In many respects, processing with HIPIMS plasmas is similar to processing with filtered cathodic arc plasmas, though the former is easier to scale to large areas. Both ion implantation and etching (high bias voltage, without deposition) and thin film deposition (low bias, or bias of low duty cycle) have been demonstrated.

  2. Internal Energies of Ion-Sputtered Neutral Tryptophan and Thymine Molecules Determined by Vacuum Ultraviolet Photoionization

    SciTech Connect

    Zhou, Jia; Takahashi, Lynelle; Wilson, Kevin R.; Leone, Stephen R.; Ahmed, Musahid

    2010-03-11

    Vacuum ultraviolet photoionization coupled to secondary neutral mass spectrometry (VUV-SNMS) of deposited tryptophan and thymine films are performed at the Chemical Dynamics Beamline. The resulting mass spectra show that while the intensity of the VUV-SNMS signal is lower than the corresponding secondary ion mass spectroscopy (SIMS) signal, the mass spectra are significantly simplified in VUV-SNMS. A detailed examination of tryptophan and thymine neutral molecules sputtered by 25 keV Bi3 + indicates that the ion-sputtered parent molecules have ~;;2.5 eV of internal energy. While this internal energy shifts the appearance energy of the photofragment ions for both tryptophan and thymine, it does not change the characteristic photoionizaton efficiency (PIE) curves of thymine versus photon energy. Further analysis of the mass spectral signals indicate that approximately 80 neutral thymine molecules and 400 tryptophan molecules are sputtered per incident Bi3 + ion. The simplified mass spectra and significant characteristic ion contributions to the VUV-SNMS spectra indicate the potential power of the technique for organic molecule surface analysis.

  3. A high power impulse magnetron sputtering model to explain high deposition rate magnetic field configurations

    NASA Astrophysics Data System (ADS)

    Raman, Priya; Weberski, Justin; Cheng, Matthew; Shchelkanov, Ivan; Ruzic, David N.

    2016-10-01

    High Power Impulse Magnetron Sputtering (HiPIMS) is one of the recent developments in the field of magnetron sputtering technology that is capable of producing high performance, high quality thin films. Commercial implementation of HiPIMS technology has been a huge challenge due to its lower deposition rates compared to direct current Magnetron Sputtering. The cylindrically symmetric "TriPack" magnet pack for a 10 cm sputter magnetron that was developed at the Center for Plasma Material Interactions was able to produce higher deposition rates in HiPIMS compared to conventional pack HiPIMS for the same average power. The "TriPack" magnet pack in HiPIMS produces superior substrate uniformity without the need of substrate rotation in addition to producing higher metal ion fraction to the substrate when compared to the conventional pack HiPIMS [Raman et al., Surf. Coat. Technol. 293, 10 (2016)]. The films that are deposited using the "TriPack" magnet pack have much smaller grains compared to conventional pack DC and HiPIMS films. In this paper, the reasons behind the observed increase in HiPIMS deposition rates from the TriPack magnet pack along with a modified particle flux model is discussed.

  4. BN coatings deposition by magnetron sputtering of B and BN targets in electron beam generated plasma

    NASA Astrophysics Data System (ADS)

    Kamenetskikh, A. S.; Gavrilov, N. V.; Koryakova, O. V.; Cholakh, S. O.

    2017-05-01

    Boron nitride coatings were deposited by reactive pulsed magnetron sputtering of B and BN targets (50 kHz, 10 µs for B; 13.56 MHz for BN) at 2-20 mA/cm2 ion current density on the substrate. The effect of electron beam generated plasma on characteristics of magnetron discharge and phase composition of coatings was studied.

  5. Optical properties and environmental stability of oxide coatings deposited by reactive sputtering.

    PubMed

    Edlou, S M; Smajkiewicz, A; Al-Jumaily, G A

    1993-10-01

    Refractory metal-oxide coatings are deposited by reactive dc magnetron sputtering in an oxygen environment. The optical constants and the environmental stability of silicon oxide, aluminium oxide, hafnium oxide, zirconium oxide, tantalum oxide, titanium oxide, and a blend of hafnium oxide with silicon oxide are investigated. Properties of both single-layer and multilayer interference filters are examined.

  6. Analysis of Molten Salt and Sputter-Deposited Coatings on Steel Cylinders

    DTIC Science & Technology

    1999-10-01

    environment. X-ray analysis of the coatings revealed a low-hardness, randomly-oriented, body - centered - cubic , alpha-phase tantalum. Formation of tantalum...analysis of several sputter-deposited tantalum specimens revealed coatings consisting of soft body - centered - cubic alpha-phase and hard tetragonal beta-phase tantalum.

  7. Pressure Effect in ZnO Films Using Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, C.-H.; Lehoczky, S. L.; Peters, P.; George, M. A.

    1999-01-01

    ZnO films are deposited on (0001) sapphire, (001) Si and quartz substrates using the off-axis reactive magnetron sputtering deposition. Based on film thickness measurements, three transport regions of sputtered particles are observed when films are deposited in the pressure regions of 5 mtorr - 150 mtorr. X-ray diffraction, scanning probes microscopy, and electrical measurements are also used to characterize these films. The full width at half maximum of theta rocking curves for epitaxial films is less than 0.5 deg. In textured films, it rises to several degrees. The epitaxial films deposited at high pressure reveal a flat surface with some hexagonal facets. The density of hexagonal facets decreases when the growth pressure is reduced. The resistivity of these epitaxial films also depends on the growth pressures. A relationship between the pressure effects and film properties are discussed.

  8. Pressure Effect in ZnO Films Using Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, C.-H.; Lehoczky, S. L.; Peters, P.; George, M. A.

    1999-01-01

    ZnO films are deposited on (0001) sapphire, (001) Si and quartz substrates using the off-axis reactive magnetron sputtering deposition. Based on film thickness measurements, three transport regions of sputtered particles are observed when films are deposited in the pressure regions of 5 mtorr - 150 mtorr. X-ray diffraction, scanning probes microscopy, and electrical measurements are also used to characterize these films. The full width at half maximum of theta rocking curves for epitaxial films is less than 0.5 deg. In textured films, it rises to several degrees. The epitaxial films deposited at high pressure reveal a flat surface with some hexagonal facets. The density of hexagonal facets decreases when the growth pressure is reduced. The resistivity of these epitaxial films also depends on the growth pressures. A relationship between the pressure effects and film properties are discussed.

  9. Morphology and Structure of ZnO Films Synthesized by Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, C.-H.; Lehoczky, S. L.

    1999-01-01

    ZnO is a wide-band-gap oxide material that has many applications. A new potential application of ZnO material is for light emitting devices since its structure and electrical properties are similar to that of the GaN material (a blue laser candidate). It also is a good substrate for fabricating GaN-based devices. Off-axis sputtering technique has revealed great potential in synthesizing excellent oxide materials because the negative ion bombardment is greatly reduced when adatoms condense on substrates. The surface of films grown by off-axis sputtering will be much smoother than that produced in a regular sputtering configuration. A growth mechanism is studied by investigating the morphology and structure of ZnO films under different growth conditions and orientations. ZnO films are deposited on (0001) sapphire and quartz substrates by off- axis sputtering deposition at various oxygen/argon mixture ratios and pressures and at different temperatures. All films reveal highly textured structures on quartz substrates and epitaxial growth on sapphire substrates. Two off-axis configurations, vertical and horizontal orientations are conducted to study the process of film growth, surface morphology, and film structure. X-ray diffraction, scanning probe microscopy, and electrical measurements are used to characterize these films. Detailed results will be discussed in the presentation. Keywords: ZnO, Photonic material, Off-axis sputtering, Growth mechanism

  10. Fluoropolymer Films Deposited by RF Plasma Sputtering of Polytetrafluoroethylene Using Inert Gases

    NASA Technical Reports Server (NTRS)

    Golub, Morton A.; Wydeven, Theodore; Kliss, Mark (Technical Monitor)

    1998-01-01

    The FT-IR (Fourier Transform Infrared), UV (Ultraviolet) and XPS (X Ray Photoelectron Spectroscopy) spectra of fluoropolymer films (SPTFE) deposited by rf (radio frequency) plasma sputtering of polytetrafluoroethylene (PTFE), using Ne, Kr and Xe as sputtering gases, were obtained and compared with prior spectra for SPTFE formed using He and Ar. The F/C (fluorine / carbon) ratios for SPTFE films (1.44-1.55), obtained at a rf power of 10 W, were essentially the same for all five rare gases, there being no trend of decreasing fluorine content in the SPTFE product with increasing atomic weight of the sputtering gas - contrary to the momentum transfer notion advanced by M. E. Ryan, et al. Increasing rf power from 10 to 50 W resulted in successively lower F/C ratios for SPTFE (e.g., from 1.55 to 1.21 in the case of Xe plasma-sputtered PTFE), accompanied by sputtering of the glass reactor and deposition of fragments of sodium aluminum silicate occurring at 40 W and above. In order to achieve a "Teflon-like" SPTFE structure (i.e., products with as high a F/C ratio as possible) in a given plasma reactor, an optimum rf power must be found, which in the present case was approximately 10 W.

  11. Morphology and Structure of ZnO Films Synthesized by Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, C.-H.; Lehoczky, S. L.

    1999-01-01

    ZnO is a wide-band-gap oxide material that has many applications. A new potential application of ZnO material is for light emitting devices since its structure and electrical properties are similar to that of the GaN material (a blue laser candidate). It also is a good substrate for fabricating GaN-based devices. Off-axis sputtering technique has revealed great potential in synthesizing excellent oxide materials because the negative ion bombardment is greatly reduced when adatoms condense on substrates. The surface of films grown by off-axis sputtering will be much smoother than that produced in a regular sputtering configuration. A growth mechanism is studied by investigating the morphology and structure of ZnO films under different growth conditions and orientations. ZnO films are deposited on (0001) sapphire and quartz substrates by off- axis sputtering deposition at various oxygen/argon mixture ratios and pressures and at different temperatures. All films reveal highly textured structures on quartz substrates and epitaxial growth on sapphire substrates. Two off-axis configurations, vertical and horizontal orientations are conducted to study the process of film growth, surface morphology, and film structure. X-ray diffraction, scanning probe microscopy, and electrical measurements are used to characterize these films. Detailed results will be discussed in the presentation. Keywords: ZnO, Photonic material, Off-axis sputtering, Growth mechanism

  12. Fluoropolymer Films Deposited by RF Plasma Sputtering of Polytetrafluoroethylene Using Inert Gases

    NASA Technical Reports Server (NTRS)

    Golub, Morton A.; Wydeven, Theodore; Kliss, Mark (Technical Monitor)

    1998-01-01

    The FT-IR (Fourier Transform Infrared), UV (Ultraviolet) and XPS (X Ray Photoelectron Spectroscopy) spectra of fluoropolymer films (SPTFE) deposited by rf (radio frequency) plasma sputtering of polytetrafluoroethylene (PTFE), using Ne, Kr and Xe as sputtering gases, were obtained and compared with prior spectra for SPTFE formed using He and Ar. The F/C (fluorine / carbon) ratios for SPTFE films (1.44-1.55), obtained at a rf power of 10 W, were essentially the same for all five rare gases, there being no trend of decreasing fluorine content in the SPTFE product with increasing atomic weight of the sputtering gas - contrary to the momentum transfer notion advanced by M. E. Ryan, et al. Increasing rf power from 10 to 50 W resulted in successively lower F/C ratios for SPTFE (e.g., from 1.55 to 1.21 in the case of Xe plasma-sputtered PTFE), accompanied by sputtering of the glass reactor and deposition of fragments of sodium aluminum silicate occurring at 40 W and above. In order to achieve a "Teflon-like" SPTFE structure (i.e., products with as high a F/C ratio as possible) in a given plasma reactor, an optimum rf power must be found, which in the present case was approximately 10 W.

  13. Energy spectrum of sputtered uranium - A new technique

    NASA Technical Reports Server (NTRS)

    Weller, R. A.; Tombrello, T. A.

    1978-01-01

    The fission track technique for detecting U-235 has been used in conjunction with a mechanical time-of-flight spectrometer in order to measure the energy spectrum in the region 1 eV to 1 keV of material sputtered from a 93% enriched U-235 foil by 80 keV Ar-40(+) ions. The spectrum was found to exhibit a peak in the region 2-4 eV and to decrease approximately as E exp -1.77 for E not less than 100 eV. The design, construction and resolution of the mechanical spectrometer are discussed and comparisons are made between the data and the predictions of the random collision cascade model of sputtering.

  14. Energetic deposition of metal ions: Observation of self-sputtering and limited sticking for off-normal angles of incidence

    SciTech Connect

    Wu, Hongchen; Anders, Andre

    2009-09-15

    The deposition of films under normal and off-normal angle of incidence has been investigated to show the relevance of non-sticking of and self-sputtering by energetic ions, leading to the formation of neutral atoms. The flow of energetic ions was obtained using a filtered cathodic arc system in high vacuum and therefore the ion flux had a broad energy distribution of typically 50-100 eV per ion. The range of materials included Cu, Ag, Au, Ti, and Ni. Consistent with molecular dynamics simulations published in the literature, the experiments show, for all materials, that the combined effects of non-sticking and self-sputtering are very significant, especially for large off-normal angles. Modest heating and intentional introduction of oxygen background affect the results.

  15. Silicon oxynitride films deposited by reactive high power impulse magnetron sputtering using nitrous oxide as a single-source precursor

    SciTech Connect

    Hänninen, Tuomas Schmidt, Susann; Jensen, Jens; Hultman, Lars; Högberg, Hans

    2015-09-15

    Silicon oxynitride thin films were synthesized by reactive high power impulse magnetron sputtering of silicon in argon/nitrous oxide plasmas. Nitrous oxide was employed as a single-source precursor supplying oxygen and nitrogen for the film growth. The films were characterized by elastic recoil detection analysis, x-ray photoelectron spectroscopy, x-ray diffraction, x-ray reflectivity, scanning electron microscopy, and spectroscopic ellipsometry. Results show that the films are silicon rich, amorphous, and exhibit a random chemical bonding structure. The optical properties with the refractive index and the extinction coefficient correlate with the film elemental composition, showing decreasing values with increasing film oxygen and nitrogen content. The total percentage of oxygen and nitrogen in the films is controlled by adjusting the gas flow ratio in the deposition processes. Furthermore, it is shown that the film oxygen-to-nitrogen ratio can be tailored by the high power impulse magnetron sputtering-specific parameters pulse frequency and energy per pulse.

  16. Deposition of PTFE thin films by RF plasma sputtering on <1 0 0> silicon substrates

    NASA Astrophysics Data System (ADS)

    Bodas, Dhananjay S.; Mandale, A. B.; Gangal, S. A.

    2005-05-01

    Polymers have been studied extensively due to the wonderful array of properties presented by them. Polymer materials can be coated/deposited by various techniques like sputtering (magnetron, ion beam, RF or dc), plasma polymerization, etc. and can be used in coatings, paint industries, etc. The present study deals with the RF sputter deposition of poly(tetrafluoro ethylene) (PTFE), commonly known as Teflon. Depositions were carried out on mirror polished silicon <1 0 0> substrates at different powers in the range of 100-200 W. The deposition time was kept constant at 60 min. The sputtered film shows lower contact angle of 50° with water and 44° with diiodomethane, a lower interfacial tension value of 0.76 dyne/cm, indicating hydrophilicity and good adhesion of the film with the substrate. FTIR indicates presence of C sbnd F, C sbnd F 2 bonding groups in the deposited film. Further, XPS study shows presence of CF 3 (292.2 eV), CF 2 (290.8 eV), C-F (288.0 eV) and C sbnd CF (286.4 eV) moieties indicating deposition of PTFE films at higher power levels of plasma.

  17. Properties of RF sputtered cadmium telluride (CdTe) thin films: Influence of deposition pressure

    SciTech Connect

    Kulkarni, R. R.; Pawbake, A. S.; Waykar, R. G.; Rondiya, S. R.; Jadhavar, A. A.; Pandharkar, S. M.; Karpe, S. D.; Diwate, K. D.; Jadkar, S. R.

    2016-04-13

    Influence of deposition pressure on structural, morphology, electrical and optical properties of CdTe thin films deposited at low substrate temperature (100°C) by RF magnetron sputtering was investigated. The formation of CdTe was confirmed by low angle XRD and Raman spectroscopy. The low angle XRD analysis revealed that the CdTe films have zinc blende (cubic) structure with crystallites having preferred orientation in (111) direction. Raman spectra show the longitudinal optical (LO) phonon mode peak ∼ 165.4 cm{sup -1} suggesting high quality CdTe film were obtained over the entire range of deposition pressure studied. Scanning electron microscopy analysis showed that films are smooth, homogenous, and crack-free with no evidence of voids. The EDAX data revealed that CdTe films deposited at low deposition pressure are high-quality stoichiometric. However, for all deposition pressures, films are rich in Cd relative to Te. The UV-Visible spectroscopy analysis show the blue shift in absorption edge with increasing the deposition pressure while the band gap show decreasing trend. The highest electrical conductivity was obtained for the film deposited at deposition pressure 1 Pa which indicates that the optimized deposition pressure for our sputtering unit is 1 Pa. Based on the experimental results, these CdTe films can be useful for the application in the flexible solar cells and other opto-electronic devices.

  18. Properties of RF sputtered cadmium telluride (CdTe) thin films: Influence of deposition pressure

    NASA Astrophysics Data System (ADS)

    Kulkarni, R. R.; Pawbake, A. S.; Waykar, R. G.; Rondiya, S. R.; Jadhavar, A. A.; Pandharkar, S. M.; Karpe, S. D.; Diwate, K. D.; Jadkar, S. R.

    2016-04-01

    Influence of deposition pressure on structural, morphology, electrical and optical properties of CdTe thin films deposited at low substrate temperature (100°C) by RF magnetron sputtering was investigated. The formation of CdTe was confirmed by low angle XRD and Raman spectroscopy. The low angle XRD analysis revealed that the CdTe films have zinc blende (cubic) structure with crystallites having preferred orientation in (111) direction. Raman spectra show the longitudinal optical (LO) phonon mode peak ˜ 165.4 cm-1 suggesting high quality CdTe film were obtained over the entire range of deposition pressure studied. Scanning electron microscopy analysis showed that films are smooth, homogenous, and crack-free with no evidence of voids. The EDAX data revealed that CdTe films deposited at low deposition pressure are high-quality stoichiometric. However, for all deposition pressures, films are rich in Cd relative to Te. The UV-Visible spectroscopy analysis show the blue shift in absorption edge with increasing the deposition pressure while the band gap show decreasing trend. The highest electrical conductivity was obtained for the film deposited at deposition pressure 1 Pa which indicates that the optimized deposition pressure for our sputtering unit is 1 Pa. Based on the experimental results, these CdTe films can be useful for the application in the flexible solar cells and other opto-electronic devices.

  19. Structural and mechanical properties of diamond-like carbon films deposited by direct current magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Broitman, E.; Hellgren, N.; Czigány, Zs.; Twesten, R. D.; Luning, J.; Petrov, I.; Hultman, L.; Holloway, B. C.

    2003-07-01

    The microstructure, morphology, and mechanical properties of diamond-like carbon (DLC) films deposited by direct current magnetron sputtering were investigated for microelectromechanical systems applications. Film properties were found to vary markedly with the ion energy (Eion) and ion-to-carbon flux ratio (Jion/JC). Cross-sectional high-resolution transmission electron microscopy revealed an amorphous microstructure. However, the presence of nanometer-sized domains at Eion~85 eV was detected. Film stresses, σ, which were compressive in all cases, ranged from 0.5 to 3.5 GPa and depended on the flux ratio as well as ion energy. The hardness (H), Young's moduli (ɛ), and elastic recovery (R) increased with Eion to maximum values of H=27 GPa, ɛ=250 GPa, and R=68% at Eion=85 eV and Jion/JC=4.4. However, near edge x-ray absorption fine structure and electron energy-loss spectrum analysis showed that the sp2/sp3 content of the films does not change with Eion or Jion/JC. The measured change in mechanical properties without a corresponding change in sp2/sp3 ratio is not consistent with any previously published models. We suggest that, in the ranges 5 eV <=Eion<=85 eV and 1.1 <=Jion/JC<=6.8, the presence of defective graphite formed by subplanted C and Ar atoms has the dominant influence on the mechanical properties of DLC films.

  20. Improvement in luminance efficiency of organic light emitting diodes by suppression of secondary electron bombardment of substrate during sputter deposition of top electrode films

    NASA Astrophysics Data System (ADS)

    Hamaguchi, Daichi; Kobayashi, Shin-ichi; Uchida, Takayuki; Sawada, Yutaka; Lei, Hao; Hoshi, Yoichi

    2016-10-01

    In this study, we investigated the degradation mechanisms of the luminance performance of organic light-emitting diodes (OLEDs) when their top electrode films were deposited by sputter deposition process. During the sputter deposition of the top electrode films, the suppression of the incidence of high-energy electrons on the substrate was attempted using various methods. As a result, we found that during electrode deposition, the incidence of the high-energy secondary electrons, which were emitted from the target surface, on the substrate was the main cause of the significant degradation of the luminance performance. It was also found that the application of a magnetic field by setting permanent magnets near the substrate holder and the insertion of a shield plate near the target cathode were effective in suppressing the incidence of secondary electrons on the substrate.

  1. Permanent magnet properties of sputter-deposited (FeCo)NdB films (abstract)

    NASA Astrophysics Data System (ADS)

    Sellmyer, D. J.; Zhao, Z. R.; Shan, Z. S.; Zhao, J. G.

    1987-04-01

    Studies have been performed on sputtered thin films of Co-doped FeNdB alloys near the 14:2:1 composition. The films were rf sputter deposited onto mica substrates using a single bulk target of composition Fe71.5Co5Nd16.5B7. The thickness of the films ranged from 1 to 10 μm. Heat treatments were given to the samples at temperatures between 500 and 650 °C and in fields parallel to the films. The films deposited at 22 °C are amorphous with Tc =240 °C. After crystallization of the tetragonal 14:2:1 phase at 600 °C, Tc increased to 410 °C, and the room-temperature magnetization was σs ≂100 emu/g. Films annealed at 600 °C show a coercive force Hc >10 kOe and remanent induction Bs ≂10 kG. Films deposited at 622 °C and in the presence of an in-plane field of 1.3 kOe exhibit either in-plane or perpendicular anisotropy depending on sputtering parameters. The sputtering conditions affect the c-axis texturing of the films, as shown by x-ray diffraction. Correlations have been made between film-growth conditions, microstructure, and magnetic properties for these thin-film permanent magnets.

  2. Visible-light active photocatalytic WO3 films loaded with Pt nanoparticles deposited by sputtering.

    PubMed

    Murata, Akiyo; Oka, Nobuto; Nakamura, Shinichi; Shigesato, Yuzo

    2012-06-01

    Visible-Light active photocatalytic tungsten trioxide (WO3) films were deposited at a substrate temperature of 800 degrees C by dc reactive magnetron sputtering using a W metal target. In addition, Platinum (Pt) was deposited on the WO3 film surfaces at room temperature, also by sputtering. In the early stages of Pt growth, formation of Pt nanoparticles could be expected because of the island structure observed in Volmer-Weber-type growth mode. The surface coverage of Pt on the WO3 films was estimated quantitatively by X-ray photoelectron spectroscopy and was found to be approximately 60% after 7 s deposition. High resolution electron microscopy (HREM) demonstrated that Pt nanoparticles with a diameter of about 2.5 nm were generated and dispersed uniformly on the entire surface area of the columnar polycrystalline WO3 films. These Pt-loaded films exhibited high photocatalytic activity in the decomposition of acetaldehyde (CH3CHO) under visible light irradiation.

  3. Microstructural evaluation of NiTi-based films deposited by magnetron sputtering

    SciTech Connect

    Crăciunescu, Corneliu M. Mitelea, Ion Budău, Victor; Ercuţa, Aurel

    2014-11-24

    Shape memory alloy films belonging to the NiTi-based systems were deposited on heated and unheated substrates, by magnetron sputtering in a custom made system, and their structure and composition was analyzed using electron microscopy. Several substrates were used for the depositions: glass, Cu-Zn-Al, Cu-Al-Ni and Ti-NiCu shape memory alloy ribbons and kapton. The composition of the Ti-Ni-Cu films showed limited differences, compared to the one of the target and the microstructure for the DC magnetron sputtering revealed crystallized structure with features determined on peel off samples from a Si wafer. Both inter and transcrystalline fractures were observed and related to the interfacial stress developed on cooling from deposition temperature.

  4. The Effects of Sputtering Target Preparation and Deposition Temperature on ZnTe:Cu Film Properties

    SciTech Connect

    Faulkner, Brooke R.; Ohno, T. R.; Burst, James M.; Duenow, Joel N.; Perkins, Craig L.; To, Bobby; Gessert, Timothy A.

    2015-06-14

    A back contact containing a sputtered ZnTe:Cu interface layer can produce high-performing thin-film CdS/CdTe photovoltaic devices. We have found that varying the ZnTe:Cu sputtering target fabrication processes and deposition temperature can affect material properties of the ZnTe:Cu films and the resulting device performance. Two different target 'recipes' with various copper contents were used to study changes in the compositional, structural, optical, and electrical properties of ZnTe:Cu films. Substrate temperature during deposition was also varied to investigate the temperature dependence of the films. It was found that the target recipe, Cu concentration in the target, and deposition temperature affect the composition of the ZnTe:Cu films, which impacts their structural, optical, and electrical properties.

  5. Formation of metal nanoparticles by short-distance sputter deposition in a reactive ion etching chamber

    SciTech Connect

    Nie Min; Meng, Dennis Desheng; Sun Kai

    2009-09-01

    A new method is reported to form metal nanoparticles by sputter deposition inside a reactive ion etching chamber with a very short target-substrate distance. The distribution and morphology of nanoparticles are found to be affected by the distance, the ion concentration, and the sputtering time. Densely distributed nanoparticles of various compositions were fabricated on the substrates that were kept at a distance of 130 mum or smaller from the target. When the distance was increased to 510 mum, island structures were formed, indicating the tendency to form continuous thin film with longer distance. The observed trend for nanoparticle formation is opposite to the previously reported mechanism for the formation of nanoparticles by sputtering. A new mechanism based on the seeding effect of the substrate is proposed to interpret the experimental results.

  6. Structural and optical properties of CdO thin films deposited by RF magnetron sputtering technique

    SciTech Connect

    Kumar, G. Anil Reddy, M. V. Ramana; Reddy, Katta Narasimha

    2014-04-24

    Cadmium oxide (CdO) thin films were deposited on glass substrate by r.f. magnetron sputtering technique using a high purity (99.99%) Cd target of 2-inch diameter and 3 mm thickness in an Argon and oxygen mixed atmosphere with sputtering power of 50W and sputtering pressure of 2×10{sup −2} mbar. The prepared films were characterized by X-ray diffraction (XRD), optical spectroscopy and scanning electron microscopy (SEM). The XRD analysis reveals that the films were polycrystalline with cubic structure. The visible range transmittance was found to be over 70%. The optical band gap increased from 2.7 eV to2.84 eV with decrease of film thickness.

  7. Metal-AlN cermet solar selective coatings deposited by direct current magnetron sputtering technology

    NASA Astrophysics Data System (ADS)

    Zhang, Qi-Chu

    1998-02-01

    A series of metal-aluminium nitride (M-AlN) cermet materials for solar selective coatings was deposited by a novel direct current (d.c.) magnetron sputtering technology. Aluminium nitride was used as the ceramic component in the cermets, and stainless steel (SS), nickel-based alloy 0022-3727/31/4/003/img1 (NiCr), molybdenum-based alloy 0022-3727/31/4/003/img2 (TZM) and tungsten were used as the metallic components. The aluminium nitride ceramic and metallic components of the cermets were deposited by simultaneously running both an aluminium target and another metallic target in a gas mixture of argon and nitrogen. The ceramic component was deposited by d.c. reactive sputtering and the metallic component by d.c. non-reactive sputtering. The total sputtering gas pressure was 0.8-1.0 Pa and the partial pressure of reactive nitrogen gas was set at 0.020-0.025 Pa which is sufficiently high to ensure that a nearly pure AlN ceramic sublayer was deposited by d.c. reactive sputtering. Because of the excellent nitriding resistance of stainless steel and the other alloys and metal, a nearly pure metallic sublayer was deposited by d.c. sputtering at this low nitrogen partial pressure. A multilayered system, consisting of alternating metallic and AlN ceramic sublayers, was deposited by substrate rotation. This multisublayer system can be considered as a macrohomogeneous cermet layer with metal volume fraction determined by controlling the thicknesses of metallic and ceramic sublayers. Following this procedure, M-AlN cermet solar selective coatings with a double cermet layer structure were deposited. The films of these selective surfaces have the following structure: a low metal volume fraction cermet layer is placed on a high metal volume fraction cermet layer which in turn is placed on an aluminium metal infrared reflection layer. The top surface layer consists of an aluminium nitride antireflection layer. A solar absorptance of 0.92-0.96 and a normal emittance of 0.03-0.05 at

  8. Tuning of refractive index in Al-doped ZnO films by rf-sputtering using oblique angle deposition

    NASA Astrophysics Data System (ADS)

    Martín-Tovar, E. A.; Denis-Alcocer, E.; Díaz, E. Chan y.; Castro-Rodríguez, R.; Iribarren, A.

    2016-07-01

    Al-doped ZnO thin films were grown by rf-sputtering using the oblique angle deposition technique. The films are formed by tilted dense nanocolumns according to the substrate inclination during the growth. The film refractive index changed 16% due to the film nanocolumn tilt from 0° to 13.5°, which corresponded to substrate inclination from 0° to 75°, respectively. Band gap energy was found to diminish, which was associated to local redistribution of Al concentration x in the Al x Zn1-x O solid solution around the x \\cong 0.02 average.

  9. Zinc Oxide Thin Films Fabricated with Direct Current Magnetron Sputtering Deposition Technique

    SciTech Connect

    Hoon, Jian-Wei; Chan, Kah-Yoong; Krishnasamy, Jegenathan; Tou, Teck-Yong

    2011-03-30

    Zinc oxide (ZnO) is a very promising material for emerging large area electronic applications including thin-film sensors, transistors and solar cells. We fabricated ZnO thin films by employing direct current (DC) magnetron sputtering deposition technique. ZnO films with different thicknesses ranging from 100 nm to 1020 nm were deposited on silicon (Si) substrate. The deposition pressure was varied from 12 mTorr to 25 mTorr. The influences of the film thickness and the deposition pressure on structural properties of the ZnO films were investigated using Mahr surface profilometer and atomic force microscopy (AFM). The experimental results reveal that the film thickness and the deposition pressure play significant role in the structural formation of the deposited ZnO thin films. ZnO films deposited on Si substrates are promising for variety of thin-film sensor applications.

  10. Destructive and constructive routes to prepare nanostructures on surfaces by low-energy ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Rauschenbach, Bernd; Frost, Frank

    2016-10-01

    Various approaches for the preparation of nanostructures with dimension on macroscopic areas are known. In contrast to cost-intensive top-down lithographic techniques, various bottom-up methods based on ion beam technologies to form large arrays of nanostructured surfaces are well established. In principle, it can be distinguished between two routes at the preparation of nanostructures by low-energy ion bombardment sputtering. The destructive route is characterized that under certain conditions, given by the self-organization processes, the ion beam induced erosion process can lead to the formation of e.g. well-ordered Si nanostructures like dots or ripples on the surface. Using a constructive route, i.e. glancing angle deposition by ion beam sputtering, sculptured thin films consisting of various nanostructures of several shapes, such as inclined and vertical columns, screws, and spirals, were deposited on Si substrates. It will be shown that morphology, shape, and diameter of the structures are influenced and can thus be controlled by adjusting various deposition parameters, including substrate temperature and ratio of substrate rotational speed to film deposition rate.

  11. Physical properties of rf magnetron sputter deposited NiO:WO3 thin films

    NASA Astrophysics Data System (ADS)

    Usha, K. S.; Sivakumar, R.; Sanjeeviraja, C.; Ichimura, M.

    2015-01-01

    The present study describes various physical properties of mixed nickel-tungsten oxide (NiO:WO3) (95:5) thin films prepared on glass substrate by rf magnetron sputtering due to the variation in rf power (100, 150, and 200 W). X-ray diffraction study shows that all the deposited films are amorphous in nature. The maximum transmittance of 97% in the infrared region was observed for the film deposited at 100 W rf power. A systematic reduction in the optical band gap is observed with increasing rf power, which is associated with the rf power induced effect leading to the production of localized states near the band edges of NiO:WO3. The Urbach energy (EU) value was found to increase with rf power, which may be due to the increased defects in the NiO matrix. From the optical study, we have evaluated various parameters such as refractive index, packing density, lattice dielectric constant, ratio between free carrier density and free carrier effective mass, plasma frequency, and dispersion energy parameters, etc. These results are discussed and correlated well with the light of possible mechanisms underlying the phenomena. The compositional purity of the film was confirmed by energy dispersive x-ray analysis (EDAX) and Auger electron spectroscopic (AES) measurements. The Raman spectra of NiO:WO3 films show two peaks corresponding to one-phonon LO mode at 560 cm-1 and two-phonon LO mode at 1100 cm-1 due to the vibrations of Ni-O bonds and a strong peak at 860 cm-1 corresponds to the stretching vibration of W-O pair in the WO6 group. The band edge emission at 369 nm was observed in photoluminescence spectra.

  12. From atoms to layers: in situ gold cluster growth kinetics during sputter deposition

    NASA Astrophysics Data System (ADS)

    Schwartzkopf, Matthias; Buffet, Adeline; Körstgens, Volker; Metwalli, Ezzeldin; Schlage, Kai; Benecke, Gunthard; Perlich, Jan; Rawolle, Monika; Rothkirch, André; Heidmann, Berit; Herzog, Gerd; Müller-Buschbaum, Peter; Röhlsberger, Ralf; Gehrke, Rainer; Stribeck, Norbert; Roth, Stephan V.

    2013-05-01

    The adjustment of size-dependent catalytic, electrical and optical properties of gold cluster assemblies is a very significant issue in modern applied nanotechnology. We present a real-time investigation of the growth kinetics of gold nanostructures from small nuclei to a complete gold layer during magnetron sputter deposition with high time resolution by means of in situ microbeam grazing incidence small-angle X-ray scattering (μGISAXS). We specify the four-stage growth including their thresholds with sub-monolayer resolution and identify phase transitions monitored in Yoneda intensity as a material-specific characteristic. An innovative and flexible geometrical model enables the extraction of morphological real space parameters, such as cluster size and shape, correlation distance, layer porosity and surface coverage, directly from reciprocal space scattering data. This approach enables a large variety of future investigations of the influence of different process parameters on the thin metal film morphology. Furthermore, our study allows for deducing the wetting behavior of gold cluster films on solid substrates and provides a better understanding of the growth kinetics in general, which is essential for optimization of manufacturing parameters, saving energy and resources.The adjustment of size-dependent catalytic, electrical and optical properties of gold cluster assemblies is a very significant issue in modern applied nanotechnology. We present a real-time investigation of the growth kinetics of gold nanostructures from small nuclei to a complete gold layer during magnetron sputter deposition with high time resolution by means of in situ microbeam grazing incidence small-angle X-ray scattering (μGISAXS). We specify the four-stage growth including their thresholds with sub-monolayer resolution and identify phase transitions monitored in Yoneda intensity as a material-specific characteristic. An innovative and flexible geometrical model enables the extraction

  13. Structural and optical properties of ZnS thin films deposited by RF magnetron sputtering

    PubMed Central

    2012-01-01

    Zinc sulfide [ZnS] thin films were deposited on glass substrates using radio frequency magnetron sputtering. The substrate temperature was varied in the range of 100°C to 400°C. The structural and optical properties of ZnS thin films were characterized with X-ray diffraction [XRD], field emission scanning electron microscopy [FESEM], energy dispersive analysis of X-rays and UV-visible transmission spectra. The XRD analyses indicate that ZnS films have zinc blende structures with (111) preferential orientation, whereas the diffraction patterns sharpen with the increase in substrate temperatures. The FESEM data also reveal that the films have nano-size grains with a grain size of approximately 69 nm. The films grown at 350°C exhibit a relatively high transmittance of 80% in the visible region, with an energy band gap of 3.79 eV. These results show that ZnS films are suitable for use as the buffer layer of the Cu(In, Ga)Se2 solar cells. PMID:22221917

  14. Influence of the composition of BCN films deposited by reactive magnetron sputtering on their properties.

    PubMed

    Martínez, C; Kyrsta, S; Cremer, R; Neuschütz, D

    2002-10-01

    Compounds of the B--C--N system are very promising to produce superhard coatings with good tribological, chemical, and thermal properties. To investigate the influence of the composition of BCN films on their properties, films with five different compositions at nearly constant nitrogen content were deposited on silicon wafers by magnetron sputtering from hexagonal boron nitride and graphite targets operated in RF and DC mode, respectively. The compositions and binding states of the films were determined by XPS. The nitrogen content was found to be almost constant for all films at about a 40 at-%, whereas boron and carbon compositions ranged between 15-35 and 25-50 at-%, respectively. The electronic and bonding structure of the coatings were analyzed by REELS using three different electron beam energies to obtain information at different depths. An increase of the carbon content of the films resulted in a significant shift of the pi-pi* interband transition with respect to the energy loss corresponding to h-BN. The absence of the pi-pi* transition in the energy loss spectra acquired at a beam energy of 1900 eV indicates the existence of a very thin overlayer mostly sp(2) bonded and probably with a distorted hexagonal structure. The position of the bulk plasmon losses corresponded to the hexagonal phase for the overlayer and presented a shift of more than 1.5 eV to the higher energy loss direction for the spectra obtained at 1900 eV beam energy. This shift and the absence of the sp(2)-bond fingerprint induced the possibility of an underlying disordered structure with a majority of sp(3) bonds.

  15. Ion beam sputtering of Ti: Influence of process parameters on angular and energy distribution of sputtered and backscattered particles

    NASA Astrophysics Data System (ADS)

    Lautenschläger, T.; Feder, R.; Neumann, H.; Rice, C.; Schubert, M.; Bundesmann, C.

    2016-10-01

    In the present study, the influence of ion energy and geometrical parameters onto the angular and energy distribution of secondary particles for sputtering a Ti target with Ar ions is investigated. The angular distribution of the particle flux of the sputtered Ti atoms was determined by the collection method, i.e. by growing Ti films and measuring their thickness. The formal description of the particle flux can be realized by dividing it into an isotropic and an anisotropic part. The experimental data show that increasing the ion energy or decreasing the ion incidence angle lead to an increase of the isotropic part, which is in good agreement with basic sputtering theory. The energy distribution of the secondary ions was measured using an energy-selective mass spectrometer. The energy distribution of the sputtered target ions shows a maximum at an energy between 10 eV and 20 eV followed by a decay proportional to E-n, which is in principle in accordance with Thompson's theory, followed by a high energetic tail. When the sum of incidence angle and emission angle is increased, the high-energetic tail expands to higher energies and an additional peak due to direct sputtering events may occur. In the case of backscattered primary Ar ions, a maximum at an energy between 5 eV and 10 eV appears and, depending on the scattering geometry, an additional broad peak at a higher energy due to direct scattering events is observed. The center energy of the additional structure shifts systematically to higher energies with decreasing scattering angle or increasing ion energy. The experimental results are compared to calculations based on simple elastic two-particle-interaction theory and to simulations done with the Monte Carlo code SDTrimSP. Both confirm in principle the experimental findings.

  16. Texture evolution in nanocrystalline iron films deposited using biased magnetron sputtering

    SciTech Connect

    Vetterick, G.; Taheri, M. L.; Baldwin, J. K.; Misra, A.

    2014-12-21

    Fe thin films were deposited on sodium chloride (NaCl) substrates using magnetron sputtering to investigate means of texture control in free standing metal films. The Fe thin films were studied using transmission electron microscopy equipped with automated crystallographic orientation microscopy. Using this technique, the microstructure of each film was characterized in order to elucidate the effects of altering deposition parameters. The natural tendency for Fe films grown on (100) NaCl is to form a randomly oriented nanocrystalline microstructure. By careful selection of substrate and deposition conditions, it is possible to drive the texture of the film toward a single (100) orientation while retaining the nanocrystalline microstructure.

  17. Electrical performance of low cost cathodes prepared by plasma sputtering deposition in microbial fuel cells.

    PubMed

    Lefebvre, Olivier; Tang, Zhe; Fung, Martin P H; Chua, Daniel H C; Chang, In Seop; Ng, How Y

    2012-01-15

    Microbial fuel cells (MFCs) could potentially be utilized for a variety of applications in the future from biosensors to wastewater treatment. However, the amount of costly platinum (Pt) used as a catalyst should be minimized via innovative deposition methods such as sputtering. In addition, alternative and low-cost catalysts, such as cobalt (Co), should be sought. In this study, ultra low Pt or Co cathodes (0.1 mg cm(-2)) were manufactured by plasma sputtering deposition and scanning electron micrographs revealed nano-clusters of metal catalyst in a porous structure favorable to the three-phase heterogeneous catalytic reaction. When operated in single-chamber air-cathode MFCs, sputtered-Co cathodes generated on average the same power as sputtered-Pt cathodes (0.27 mW cell(-1)) and only 27% less than conventional Pt-ink cathodes with a catalyst load 5 times higher (0.5 mg cm(-2)). Finally, microscopy and molecular analyses showed evidence of biocatalysis activity on metal-free cathodes.

  18. Evaluation of thin amorphous calcium phosphate coatings on titanium dental implants deposited using magnetron sputtering.

    PubMed

    Yokota, Sou; Nishiwaki, Naruhiko; Ueda, Kyosuke; Narushima, Takayuki; Kawamura, Hiroshi; Takahashi, Tetsu

    2014-06-01

    Calcium phosphate is used for dental material because of its biocompatibility and osteoconductivity. Amorphous calcium phosphate (ACP) coatings deposited by magnetron sputtering can control their thickness and absorbability. This study aimed to evaluate and characterize ACP coatings deposited via magnetron sputtering. It was hypothesized that ACP coatings would enhance bone formation and be absorbed rapidly in vivo. ACP coatings that are 0.5 μm in thickness were deposited via magnetron sputtering on dental implants. Uncoated implants served as controls. The effect of the ACP coatings in vivo was investigated in New Zealand white rabbit. To evaluate the effect of the ACP coatings on the bone response of the implants, the removal torque, implant stability quotient, and histomorphometric analysis were performed on the implants at 1, 2, and 4 weeks after implantation. Results of the x-ray diffraction analyses confirmed the deposition of ACP coatings. Images from the scanning electron microscopy revealed that the coatings were dense, uniform, and 0.5 μm in thickness and that they were absorbed completely. Mechanical stability and bone formation in the case of the ACP-coated implants were higher than those of control. These results suggest that implants coated with thin ACP layers improve implant fixation and accelerate bone response.

  19. Fabrication and physico-mechanical properties of thin magnetron sputter deposited silver-containing hydroxyapatite films

    NASA Astrophysics Data System (ADS)

    Ivanova, A. A.; Surmeneva, M. A.; Tyurin, A. I.; Pirozhkova, T. S.; Shuvarin, I. A.; Prymak, O.; Epple, M.; Chaikina, M. V.; Surmenev, R. A.

    2016-01-01

    As a measure of the prevention of implant associated infections, a number of strategies have been recently applied. Silver-containing materials possessing antibacterial activity as expected might have wide applications in orthopedics and dentistry. The present work focuses on the physico-chemical characterization of silver-containing hydroxyapatite (Ag-HA) coating obtained by radio frequency (RF) magnetron sputtering. Mechanochemically synthesized Ag-HA powder (Ca10⿿xAgx(PO4)6(OH)2⿿x, x = 1.5) was used as a precursor for sputtering target preparation. Morphology, composition, crystallinity, physico-mechanical features (Young's modulus and nanohardness) of the deposited Ag-HA coatings were investigated. The sputtering of the nanostructured multicomponent target at the applied process conditions allowed to deposit crystalline Ag-HA coating which was confirmed by XRD and FTIR data. The SEM results revealed the formation of the coating with the grain morphology and columnar cross-section structure. The EDX analysis confirmed that Ag-HA coating contained Ca, P, O and Ag with the Ca/P ratio of 1.6 ± 0.1. The evolution of the mechanical properties allowed to conclude that addition of silver to HA film caused increase of the coating nanohardness and elastic modulus compared with those of pure HA thin films deposited under the same deposition conditions.

  20. Solar Ion Sputter Deposition in the Lunar Regolith: Experimental Simulation Using Focused-Ion Beam Techniques

    NASA Technical Reports Server (NTRS)

    Christoffersen, R.; Rahman, Z.; Keller, L. P.

    2012-01-01

    As regions of the lunar regolith undergo space weathering, their component grains develop compositionally and microstructurally complex outer coatings or "rims" ranging in thickness from a few 10 s to a few 100's of nm. Rims on grains in the finest size fractions (e.g., <20 m) of mature lunar regoliths contain optically-active concentrations of nm size metallic Fe spherules, or "nanophase Fe(sup o)" that redden and attenuate optical reflectance spectral features important in lunar remote sensing. Understanding the mechanisms for rim formation is therefore a key part of connecting the drivers of mineralogical and chemical changes in the lunar regolith with how lunar terrains are observed to become space weathered from a remotely-sensed point of view. As interpreted based on analytical transmission electron microscope (TEM) studies, rims are produced from varying relative contributions from: 1) direct solar ion irradiation effects that amorphize or otherwise modify the outer surface of the original host grain, and 2) nanoscale, layer-like, deposition of extrinsic material processed from the surrounding soil. This extrinsic/deposited material is the dominant physical host for nanophase Fe(sup o) in the rims. An important lingering uncertainty is whether this deposited material condensed from regolith components locally vaporized in micrometeorite or larger impacts, or whether it formed as solar wind ions sputtered exposed soil and re-deposited the sputtered ions on less exposed areas. Deciding which of these mechanisms is dominant, or possibility exclusive, has been hampered because there is an insufficient library of chemical and microstructural "fingerprints" to distinguish deposits produced by the two processes. Experimental sputter deposition / characterization studies relevant to rim formation have particularly lagged since the early post-Apollo experiments of Hapke and others, especially with regard to application of TEM-based characterization techniques. Here

  1. Reactive Ar ion beam sputter deposition of TiO2 films: Influence of process parameters on film properties

    NASA Astrophysics Data System (ADS)

    Bundesmann, C.; Lautenschläger, T.; Thelander, E.; Spemann, D.

    2017-03-01

    Several sets of TiO2 films were grown by Ar ion beam sputter deposition under systematic variation of ion energy and geometrical parameters (ion incidence angle and polar emission angle). The films were characterized concerning thickness, growth rate, structural properties, composition, mass density, and optical properties. The film thicknesses show a cosine-like angular distribution, and the growth rates were found to increase with increasing ion incidence angle and ion energy. All films are amorphous and stoichiometric, but can contain a considerable amount of backscattered primary particles. The atomic fraction of Ar particles decreases systematically with increasing scattering angle, independent from ion energy and ion incidence angle. Mass density and index of refraction show similar systematic variations with ion energy and geometrical parameters. The film properties are mainly influenced by the scattering geometry, and only slightly by ion energy and ion incidence angle. The variations in the film properties are tentatively assigned to changes in the angular and energy distribution of the sputtered target particles and back-scattered primary particles.

  2. Resputtering effect during MgO buffer layer deposition by magnetron sputtering for superconducting coated conductors

    SciTech Connect

    Xiao, Shaozhu; Shi, Kai; Deng, Shutong; Han, Zhenghe; Feng, Feng Lu, Hongyuan; Qu, Timing; Zhu, Yuping; Huang, Rongxia

    2015-07-15

    In this study, MgO thin films were deposited by radio-frequency magnetron sputtering. The film thickness in the deposition area directly facing the target center obviously decreased compared with that in other areas. This reduction in thickness could be attributed to the resputtering effect resulting from bombardment by energetic particles mainly comprising oxygen atoms and negative oxygen ions. The influences of deposition position and sputtering pressure on the deposition rate were investigated. Resputtering altered the orientation of the MgO film from (111) to (001) when the film was deposited on a single crystal yttria-stabilized zirconia substrate. The density distribution of energetic particles was calculated on the basis of the measured thicknesses of the MgO films deposited at different positions. The divergence angle of the energetic particle flux was estimated to be approximately 15°. The energetic particle flux might be similar to the assisting ion flux in the ion beam assisted deposition process and could affect the orientation of the MgO film growth.

  3. Chemical bonding, optical constants, and electrical resistivity of sputter-deposited gallium oxide thin films

    NASA Astrophysics Data System (ADS)

    Ramana, C. V.; Rubio, E. J.; Barraza, C. D.; Miranda Gallardo, A.; McPeak, Samantha; Kotru, Sushma; Grant, J. T.

    2014-01-01

    Gallium oxide (Ga2O3) thin films were made by sputter deposition employing a Ga2O3 ceramic target for sputtering. The depositions were made over a wide range of substrate temperatures (Ts), from 25 to 600 °C. The effect of Ts on the chemical bonding, surface morphological characteristics, optical constants, and electrical properties of the grown films was evaluated using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), spectroscopic ellipsometry (SE), and four-point probe measurements. XPS analyses indicate the binding energies (BE) of the Ga 2p doublet, i.e., the Ga 2p3/2 and Ga 2p1/2 peaks, are located at 1118.0 and 1145.0 eV, respectively, characterizing gallium in its highest chemical oxidation state (Ga3+) in the grown films. The core level XPS spectra of O 1s indicate that the peak is centered at a BE ˜ 531 eV, which is also characteristic of Ga-O bonds in the Ga2O3 phase. The granular morphology of the nanocrystalline Ga2O3 films was evident from AFM measurements, which also indicate that the surface roughness of the films increases from 0.5 nm to 3.0 nm with increasing Ts. The SE analyses indicate that the index of refraction (n) of Ga2O3 films increases with increasing Ts due to improved structural quality and packing density of the films. The n(λ) of all the Ga2O3 films follows the Cauchy's dispersion relation. The room temperature electrical resistivity was high (˜200 Ω-cm) for amorphous Ga2O3 films grown at Ts = RT-300 °C and decreased to ˜1 Ω-cm for nanocrystalline Ga2O3 films grown at Ts ≥ 500-600 °C. A correlation between growth conditions, microstructure, optical constants, and electrical properties of Ga2O3 films is derived.

  4. Chemical bonding, optical constants, and electrical resistivity of sputter-deposited gallium oxide thin films

    SciTech Connect

    Ramana, C. V. Rubio, E. J.; Barraza, C. D.; Miranda Gallardo, A.; McPeak, Samantha; Kotru, Sushma; Grant, J. T.

    2014-01-28

    Gallium oxide (Ga{sub 2}O{sub 3}) thin films were made by sputter deposition employing a Ga{sub 2}O{sub 3} ceramic target for sputtering. The depositions were made over a wide range of substrate temperatures (T{sub s}), from 25 to 600 °C. The effect of T{sub s} on the chemical bonding, surface morphological characteristics, optical constants, and electrical properties of the grown films was evaluated using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), spectroscopic ellipsometry (SE), and four-point probe measurements. XPS analyses indicate the binding energies (BE) of the Ga 2p doublet, i.e., the Ga 2p{sub 3/2} and Ga 2p{sub 1/2} peaks, are located at 1118.0 and 1145.0 eV, respectively, characterizing gallium in its highest chemical oxidation state (Ga{sup 3+}) in the grown films. The core level XPS spectra of O 1s indicate that the peak is centered at a BE ∼ 531 eV, which is also characteristic of Ga-O bonds in the Ga{sub 2}O{sub 3} phase. The granular morphology of the nanocrystalline Ga{sub 2}O{sub 3} films was evident from AFM measurements, which also indicate that the surface roughness of the films increases from 0.5 nm to 3.0 nm with increasing T{sub s}. The SE analyses indicate that the index of refraction (n) of Ga{sub 2}O{sub 3} films increases with increasing T{sub s} due to improved structural quality and packing density of the films. The n(λ) of all the Ga{sub 2}O{sub 3} films follows the Cauchy's dispersion relation. The room temperature electrical resistivity was high (∼200 Ω-cm) for amorphous Ga{sub 2}O{sub 3} films grown at T{sub s} = RT-300 °C and decreased to ∼1 Ω-cm for nanocrystalline Ga{sub 2}O{sub 3} films grown at T{sub s} ≥ 500–600 °C. A correlation between growth conditions, microstructure, optical constants, and electrical properties of Ga{sub 2}O{sub 3} films is derived.

  5. Photovoltaic properties of ferroelectric BaTiO3 thin films RF sputter deposited on silicon

    NASA Technical Reports Server (NTRS)

    Dharmadhikari, V. S.; Grannemann, W. W.

    1982-01-01

    Ferroelectric thin films of BaTiO3 have been successfully deposited on n-type silicon substrates at temperatures above 500 C by RF sputtering in an O2/Ar atmosphere. Analysis by X-ray diffraction patterns show that films deposited at room temperature are amorphous. At temperatures above 500 C, crystalline BaTiO3 films with a tetragonal structure are obtained. The polarization-electric field (P-E) hysteresis loops and a broad peak in the dielectric constant versus temperature curve at Curie point indicate that the RF sputtered BaTiO3 films are ferroelectric. An anomalous photovoltaic effect is observed in these thin films which is related to the remanent polarization of the material. The results on open-circuit and short-circuit measurements provide an important basis for a better understanding of the role of photovoltaic field, photovoltaic current, and the pyroelectric properties in photoferroelectric domain switching.

  6. Thermal Stability of Photosensitive Bragg Gratings in Sputter-Deposited Germanosilicate Glass

    SciTech Connect

    POTTER JR.,BARRETT G.; POTTER,KELLY SIMMONS; DUNBAR,TIMOTHY D.

    2000-07-24

    The thermal stability of photo-imprinted Bragg gratings formed in reactive-atmosphere, RF-magnetron sputtered germanosilicate thin films was evaluated in terms of point defect modifications observed during isochronal annealing. Optical and magnetic spectroscopes were utilized to evaluate structural relaxation in these sputtered glasses on both a local and medium-range size scale. Depending upon the substrate temperature used during deposition, significant structural rearrangement was found to occur with increasing post-deposition anneal temperature to 600 C. This resulted in changes in the photobleaching response of the material itself as the identity of optically active structural defects evolved. Based on a color center model for photosensitivity in these materials and measured changes in optical absorption with annealing, the thermal stability of a photo-imprinted Bragg grating was modeled. Good qualitative agreement with experiment was observed.

  7. Sputtering deposition of Al-doped zinc oxide thin films using mixed powder targets

    NASA Astrophysics Data System (ADS)

    Ohshima, Tamiko; Maeda, Takashi; Tanaka, Yuki; Kawasaki, Hiroharu; Yagyu, Yoshihito; Ihara, Takeshi; Suda, Yoshiaki

    2016-01-01

    Sputtering deposition generally uses high-density bulk targets. Such a fabrication process has various problems including deterioration of the material during heating and difficulty in mixing a large number of materials in precise proportions. However, these problems can be solved by using a powder target. In this study, we prepared Al-doped ZnO (AZO) as transparent conductive thin films by radio-frequency magnetron sputtering with powder and bulk targets. Both the powder and bulk targets formed crystalline structures. The ZnO (002) peak was observed in the X-ray diffraction measurements. The mean transparency and resistivity of the films prepared with the powder target were 82% and 0.548 Ω · cm, respectively. The deposition rate with the powder target was lower than that with the bulk target.

  8. Third-order nonlinear optical response of colloidal gold nanoparticles prepared by sputtering deposition

    NASA Astrophysics Data System (ADS)

    Castro, Hemerson P. S.; Wender, Heberton; Alencar, Márcio A. R. C.; Teixeira, Sergio R.; Dupont, Jairton; Hickmann, Jandir M.

    2013-11-01

    The nonlinear optical responses of gold nanoparticles dispersed in castor oil produced by sputtering deposition were investigated, using the thermally managed Z-scan technique. Particles with spherical shape and 2.6 nm of average diameter were obtained and characterized by transmission electron microscopy and small angle X-ray scattering. This colloid was highly stable, without the presence of chemical impurities, neither stabilizers. It was observed that this system presents a large refractive third-order nonlinear response and a negligible nonlinear absorption. Moreover, the evaluation of the all-optical switching figures of merit demonstrated that the colloidal nanoparticles prepared by sputtering deposition have a good potential for the development of ultrafast photonic devices.

  9. Third-order nonlinear optical response of colloidal gold nanoparticles prepared by sputtering deposition

    SciTech Connect

    Castro, Hemerson P. S.; Alencar, Márcio A. R. C.; Hickmann, Jandir M.; Wender, Heberton; Teixeira, Sergio R.; Dupont, Jairton

    2013-11-14

    The nonlinear optical responses of gold nanoparticles dispersed in castor oil produced by sputtering deposition were investigated, using the thermally managed Z-scan technique. Particles with spherical shape and 2.6 nm of average diameter were obtained and characterized by transmission electron microscopy and small angle X-ray scattering. This colloid was highly stable, without the presence of chemical impurities, neither stabilizers. It was observed that this system presents a large refractive third-order nonlinear response and a negligible nonlinear absorption. Moreover, the evaluation of the all-optical switching figures of merit demonstrated that the colloidal nanoparticles prepared by sputtering deposition have a good potential for the development of ultrafast photonic devices.

  10. Submicrometer Hollow Bioglass Cones Deposited by Radio Frequency Magnetron Sputtering: Formation Mechanism, Properties, and Prospective Biomedical Applications.

    PubMed

    Popa, A C; Stan, G E; Besleaga, C; Ion, L; Maraloiu, V A; Tulyaganov, D U; Ferreira, J M F

    2016-02-01

    This work reports on the unprecedented magnetron sputtering deposition of submicrometric hollow cones of bioactive glass at low temperature in the absence of any template or catalyst. The influence of sputtering conditions on the formation and development of bioglass cones was studied. It was shown that larger populations of well-developed cones could be achieved by increasing the argon sputtering pressure. A mechanism describing the growth of bioglass hollow cones is presented, offering the links for process control and reproducibility of the cone features. The composition, structure, and morphology of the as-synthesized hollow cones were investigated by energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), grazing incidence geometry X-ray diffraction (GIXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM)-selected area electron diffraction (SAED). The in vitro biological performance, assessed by degradation tests (ISO 10993-14) and cytocompatibility assays (ISO 10993-5) in endothelial cell cultures, was excellent. This allied with resorbability and the unique morphological features make the submicrometer hollow cones interesting candidate material devices for focal transitory permeabilization of the blood-brain barrier in the treatment of carcinoma and neurodegenerative disorders.

  11. Sputtering temperature dependent growth kinetics and CO2 sensing properties of ZnO deposited over porous silicon

    NASA Astrophysics Data System (ADS)

    Martínez, L.; Holguín-Momaca, J. T.; Karthik, T. V. K.; Olive-Méndez, S. F.; Campos-Alvarez, J.; Agarwal, V.

    2016-10-01

    We report the growth kinetics and sensing properties of ZnO deposited over macro-porous silicon substrates at 400 and 600 °C using magnetron-sputtering technique. Scanning electron microscopy was employed to investigate the morphology and the particle size of the ZnO nanoparticles (NPs). The grain growth kinetics was analyzed with the help of the phenomenological equation rn =k0 texp(- Q / RT) finding an activation energy Q = 13.92 kJ/mol. The grain growth exponent (n = 2.85) for the growth at 400 °C corresponds to an Ostwald ripening process, while the growth at 600 °C is described by n = 1.66 implying a higher growth rate attributed to a high surface diffusion of add-atoms contributing to the formation of larger grains. The sensing response of the complete structure has been tested at different temperatures. The highest sensitivity, S ∼10, was obtained at a sensor temperature of 300 °C on the ZnO NPs sputtered on to the porous silicon substrate at 400 °C. The high response is attributed to the infiltration, uniform and homogenous distribution of the ZnO NPs into the pores. ZnO NPs sputtered at 400 °C are found to be smaller than those grown at 600 °C, exhibiting a larger surface-area/volume ratio and hence increasing the oxygen adsorption resulting in an enhanced CO2 sensitivity.

  12. Note: the influence of exploding foil shape on energy deposition.

    PubMed

    Zeng, Qingxuan; Lv, Junjun; Li, Mingyu

    2013-06-01

    The main influence factors of exploding bridge foil were studied in order to improve energy utilization of the explosion foil initiator. "Square" and "curving" shaped bridge foils were fabricated using magnetron sputtering and chemical etching techniques, and the key dimension of the bridge foil was measured using surface profiler. Commercial software MATLAB was employed to calculate the burst current, burst voltage, and energy deposition. Simulation results were in good agreement with experiment data. In this study, the energy deposition ratio of "square" shaped bridge is between 45%-50%, while the value of "curving" shaped bridge is between 55%-75%.

  13. Ti-Nb thin films deposited by magnetron sputtering on stainless steel

    SciTech Connect

    Gonzalez, E. David; Niemeyer, Terlize C.; Afonso, Conrado R. M.; Nascente, Pedro A. P.

    2016-03-15

    Thin films of Ti-Nb alloys were deposited on AISI 316L stainless steel substrate by magnetron sputtering, and the structure, composition, morphology, and microstructure of the films were analyzed by means of x-ray diffraction (XRD), (scanning) transmission electron microscopy (TEM) coupled with energy-dispersive x-ray spectroscopy, atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). Thin films of four compositions were produced: Ti{sub 85}Nb{sub 15} (Ti-26 wt. % Nb), Ti{sub 80}Nb{sub 20} (Ti-33 wt. % Nb), Ti{sub 70}Nb{sub 30} (Ti-45 wt. % Nb), and Ti{sub 60}Nb{sub 40} (Ti-56 wt. % Nb). Structural characterization by XRD indicated that only the β phase was present in the thin films and that the increase in the Nb content modified the alloy film texture. These changes in the film texture, also detected by TEM analysis, were attributed to different growth modes related to the Nb content in the alloy films. The mean grain sizes measured by AFM increased with the Nb amount (from 197 to 222 nm). XPS analysis showed a predominance of oxidized Ti and Nb on the film surfaces and an enrichment of Ti.

  14. Synthesis of ZnO:As Films Using Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, S. L.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    As a novel oxide semiconductor material, ZnO is interesting for use in many applications. For fabricating electronic devices, it is important to have n- and p- type ZnO materials. Arsenic has been proven to be one of the p-type dopants for ZnO materials. However, information in studying the ZnAsO ternary compound films has been scarce. In order to investigate the morphology, structure and electrical properties of ZnAsO ternary compounds, ZnO:As films have been synthesized using off-axis sputtering deposition on various substrates including (100) Si and (0001) sapphire crystals. Films are grown under various growth conditions. ZnO:As targets with the atomic weight ratios of arsenic to zinc from 0.01 to 0.10 are used for film synthesis. The growth temperatures and pressures range from 350 to 550C and 5 to 150 mTorr, respectively. Argon to oxygen gas ratio for film growth is varied to examine the film quality as well. Film surface morphology, crystal structure, and compositions, are characterized using atomic force microscopy, x-ray diffraction, and energy dispersive spectroscopy, respectively. The compositions of target material and ZnO:As films grown under various conditions are then assessed. The electrical properties were also measured. The detail of these measurements will be discussed in the presentation.

  15. Microwave ion beam sources for reactive etching and sputter deposition applications

    NASA Astrophysics Data System (ADS)

    Jolly, T. W.; Blackborrow, P.

    1990-01-01

    There are important industrial applications for broadbeam microwave ion beam sources which give current densities in the range 0.1-4.0 mA/cm2 at energies between 100 and 1500 eV. These include machines for the production of multilayer optical coatings by means of ion beam sputter deposition, and cassette-to-cassette machines for inert and reactive ion beam etching of semiconductor wafers. In both cases, the ability to run reliably, and at high power for several hundred hours without unscheduled maintenance is most valuable, and may well justify the extra cost of such a source over the conventional Kaufman hot-filament source. The sources discussed in this article use dual high-power grids of pyrolytic graphite, using a self-aligning design, to produce uniform ion beams with diameters of up to l2 cm. Stabilities of better than 1% over several hundred hours of operation are achieved. The design of the discharge chamber and grids enables operation on most inert and reactive gas mixtures. Typical run data and beam profiles obtained when running on argon, oxygen, and chlorine will be presented.

  16. Synthesis of ZnO:As Films Using Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, S. L.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    As a novel oxide semiconductor material, ZnO is interesting for use in many applications. For fabricating electronic devices, it is important to have n- and p- type ZnO materials. Arsenic has been proven to be one of the p-type dopants for ZnO materials. However, information in studying the ZnAsO ternary compound films has been scarce. In order to investigate the morphology, structure and electrical properties of ZnAsO ternary compounds, ZnO:As films have been synthesized using off-axis sputtering deposition on various substrates including (100) Si and (0001) sapphire crystals. Films are grown under various growth conditions. ZnO:As targets with the atomic weight ratios of arsenic to zinc from 0.01 to 0.10 are used for film synthesis. The growth temperatures and pressures range from 350 to 550C and 5 to 150 mTorr, respectively. Argon to oxygen gas ratio for film growth is varied to examine the film quality as well. Film surface morphology, crystal structure, and compositions, are characterized using atomic force microscopy, x-ray diffraction, and energy dispersive spectroscopy, respectively. The compositions of target material and ZnO:As films grown under various conditions are then assessed. The electrical properties were also measured. The detail of these measurements will be discussed in the presentation.

  17. From atoms to layers: in situ gold cluster growth kinetics during sputter deposition.

    PubMed

    Schwartzkopf, Matthias; Buffet, Adeline; Körstgens, Volker; Metwalli, Ezzeldin; Schlage, Kai; Benecke, Gunthard; Perlich, Jan; Rawolle, Monika; Rothkirch, André; Heidmann, Berit; Herzog, Gerd; Müller-Buschbaum, Peter; Röhlsberger, Ralf; Gehrke, Rainer; Stribeck, Norbert; Roth, Stephan V

    2013-06-07

    The adjustment of size-dependent catalytic, electrical and optical properties of gold cluster assemblies is a very significant issue in modern applied nanotechnology. We present a real-time investigation of the growth kinetics of gold nanostructures from small nuclei to a complete gold layer during magnetron sputter deposition with high time resolution by means of in situ microbeam grazing incidence small-angle X-ray scattering (μGISAXS). We specify the four-stage growth including their thresholds with sub-monolayer resolution and identify phase transitions monitored in Yoneda intensity as a material-specific characteristic. An innovative and flexible geometrical model enables the extraction of morphological real space parameters, such as cluster size and shape, correlation distance, layer porosity and surface coverage, directly from reciprocal space scattering data. This approach enables a large variety of future investigations of the influence of different process parameters on the thin metal film morphology. Furthermore, our study allows for deducing the wetting behavior of gold cluster films on solid substrates and provides a better understanding of the growth kinetics in general, which is essential for optimization of manufacturing parameters, saving energy and resources.

  18. Comparison of DC and RF magnetron sputtering systems for Electrochromic W/Ti Thin Film Deposition

    NASA Astrophysics Data System (ADS)

    Teke, Erdogan; Kiristi, Melek; Uygun Oksuz, Aysegul; Bozduman, Ferhat; Gulec, Ali; Oksuz, Lutfi; Hala, Ahmed M.

    2013-10-01

    In this study electrochromic tungsten-titanium thin films were deposited on ITO (indium thin oxide) glasses by using both DC and RF magnetron sputtering techniques. The discharges have been operated in same discharge power, geometry and argon/oxygen mixture pressure for comparison. The voltage and current characteristics and optical emission spectrums of both plasma systems will be given. The plasma parameters are determined by a double probe. ITO thin films coating electrical, optical and morphological characteristics will be compared.

  19. Composition control of PZT thin films by varying technological parameters of RF magnetron sputter deposition

    NASA Astrophysics Data System (ADS)

    Pronin, V. P.; Dolgintsev, D. M.; Pronin, I. P.; Senkevich, S. V.; Kaptelov, E. Yu; Sergienko, A. Yu

    2017-07-01

    The article presents the effect of technological parameters of RF magnetron sputtering on the concentration of components of thin-film ferroelectric structures based on lead zirconate titanate PZT in the region of the morphotropic phase boundary. It is shown that by changing the distance from the target to the substrate and the pressure of the working gas mixture Ar + O2, it is possible to vary the composition of the deposited thin layers.

  20. Fabrication of black-gold coatings by glancing angle deposition with sputtering.

    PubMed

    Vitrey, Alan; Alvarez, Rafael; Palmero, Alberto; González, María Ujué; García-Martín, José Miguel

    2017-01-01

    The fabrication of black-gold coatings using sputtering is reported here. Glancing angle deposition with a rotating substrate is needed to obtain vertical nanostructures. Enhanced light absorption is obtained in the samples prepared in the ballistic regime with high tilt angles. Under these conditions the diameter distribution of the nanostructures is centered at about 60 nm and the standard deviation is large enough to obtain black-metal behavior in the visible range.

  1. Transparent and Conductive Cadmium-Tin Oxide Films Deposited by Atom Beam Sputtering

    NASA Astrophysics Data System (ADS)

    Nakazawa, Tatsuo; Ito, Kentaro

    1988-09-01

    Transparent and conductive cadmium-tin oxide films with resistivities of 9× 10-4 Ω cm and transmittance higher than 80% over the visible range were prepared by atom beam sputtering. The structure of the deposited film was amorphous and its composition was highly deficient in CdO compared with Cd2SnO4. This CTO film was used as the window layer of a heterojunction solar cell.

  2. Fabrication of black-gold coatings by glancing angle deposition with sputtering

    PubMed Central

    Vitrey, Alan; Alvarez, Rafael; Palmero, Alberto; González, María Ujué

    2017-01-01

    The fabrication of black-gold coatings using sputtering is reported here. Glancing angle deposition with a rotating substrate is needed to obtain vertical nanostructures. Enhanced light absorption is obtained in the samples prepared in the ballistic regime with high tilt angles. Under these conditions the diameter distribution of the nanostructures is centered at about 60 nm and the standard deviation is large enough to obtain black-metal behavior in the visible range. PMID:28326233

  3. Investigation of Optical and Electrochromic Properties of Tungsten Oxide Deposited with Horizontal DC and DC Pulse Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Chen, Hsi-Chao; Jan, Der-Jun; Chen, Chien-Han

    2012-04-01

    The proposal of this research was to compare the optical and electrochromic properties of tungsten oxide (WO3) thin films deposited with a horizontal direct current (DC) and DC pulse magnetron sputtering. These WO3 thin films were deposited onto indium tin oxide (ITO) glass and p-type silicon substrate at different gas ratios of oxygen and argon. The variation in the transmittance between the coloring and bleaching was important for the smart window. WO3 thin films have good electrochromic properties at gas ratios of oxygen/argon (O2/Ar) of 0.7 and 0.6 for DC and DC pulse magnetron sputtering, respectively. However, WO3 thin films deposited by DC pulse magnetron sputtering have better optical and electrochromic properties than the films deposited by DC magnetron sputtering.

  4. Biaxial texture development in aluminum nitride layers during off-axis sputter deposition

    SciTech Connect

    Deng Ruopeng; Muralt, Paul; Gall, Daniel

    2012-09-15

    Polycrystalline aluminum nitride (AlN) layers were deposited by pulsed-dc reactive magnetron sputtering from a variable deposition angle {alpha} = 0 Degree-Sign -84 Degree-Sign in 5 mTorr pure N{sub 2} at room temperature. X-ray diffraction pole figure analyses show that layers deposited from a normal angle ({alpha} = 0 Degree-Sign ) exhibit fiber texture, with a random in-plane grain orientation and the c-axis tilted by 42 Degree-Sign {+-} 2 Degree-Sign off the substrate normal, yielding wurtzite AlN grains with the {l_brace}1012{r_brace} plane approximately parallel ({+-}2 Degree-Sign ) to the substrate surface. However, as {alpha} is increased to 45 Degree-Sign , two preferred in-plane grain orientations emerge, with populations I and II having the c-axis tilted toward and away from the deposition flux, by 53 Degree-Sign {+-} 2 Degree-Sign and 47 Degree-Sign {+-} 1 Degree-Sign off the substrate normal, respectively. Increasing {alpha} further to 65 Degree-Sign and 84 Degree-Sign , results in the development of a single population II with a 43 Degree-Sign {+-} 1 Degree-Sign tilt. This developing biaxial texture is attributed to a competitive growth mode under conditions where the adatom mobility is sufficient to cause intergrain mass transport, but insufficient for the thermodynamically favored low energy {l_brace}0001{r_brace} planes to align parallel to the layer surface. Consequently, AlN nuclei are initially randomly oriented and form a kinetically determined crystal habit exposing {l_brace}0001{r_brace} and {l_brace}1120{r_brace} facets. The expected direction of its highest growth rate is 49 Degree-Sign {+-} 5 Degree-Sign tilted relative to the c-axis, in good agreement with the 42 Degree-Sign -53 Degree-Sign measured tilt. The in-plane preferred orientation for {alpha} > 0 Degree-Sign is well explained by the orientation dependence in the cross section of the asymmetric pyramidal nuclei to capture directional deposition flux. The observed tilt is ideal for

  5. HF treatment effect for carbon deposition on silicon (111) by DC sputtering technique

    SciTech Connect

    Aji, A. S. Darma, Y.

    2014-03-24

    Surface modifications of Si (111) substrate by HF solution for thin film carbon deposition have been systematically studied. Thin film carbon on Si (111) has been deposited using DC Unbalanced Magnetron Sputtering with carbon pellet doped by 5% Fe as the target. EDAX characterization confirmed that the carbon fraction on Si substrate much higher by dipping a clean Si substrate by HF solution before sputtering process in comparison with carbon fraction on Si substrate just after conventional RCA. Moreover, SEM and AFM images show the uniform thin film carbon on Si with HF treatment, in contrast to the Si without HF solution treatment. These experimental results suggest that HF treatment of Si surface provide Si-H bonds on top Si surface that useful to enhance the carbon deposition during sputtering process. Furthermore, we investigate the thermal stability of thin film carbon on Si by thermal annealing process up to 900 °C. Atomic arrangements during annealing process were characterized by Raman spectroscopy. Raman spectra indicate that thin film carbon on Si is remaining unchanged until 600 °C and carbon atoms start to diffuse toward Si substrate after annealing at 900 °C.

  6. Structural and compositional characterization of RF sputter-deposited Ni-Cr + Cr2O3 films

    NASA Technical Reports Server (NTRS)

    Bhushan, B.

    1980-01-01

    An RF-sputtered chrome oxide coating with metallic binders was developed. The chrome oxide coating has high-temperature capabilities and is wear resistant, and has some self-lubricating properties. A nichrome metallic binder was added in the coating to improve its ductility without significant loss in the hardness. The sputtering parameters were optimized to obtain a smooth coating with the maximum adherence. The coatings were applied using bias-sputter and sputter-deposit modes on the heat treated and annealed foil substrates. The coating applied on annealed foils using the sputter-deposit mode was smooth and had the best adherence. Metallurgical examinations showed that the coating was Ni-Cr + Cr2O3. The coating as applied was amorphous and it crystallized during substrate heat treatment.

  7. DCEMS Study of Thin Stainless Steel Films Deposited by RF Sputtering of AISI316L

    SciTech Connect

    Nomura, K.; Iio, S.; Ujihira, Y.; Terai, T.

    2005-04-26

    Thin stainless steel films were prepared on SiO2/Si plate heated at 100 deg. C and 400 deg. C using AISI316L as target, by a RF magnetron Ar sputtering method. RF sputtered-deposited films and the oxidized surface layers by post heating were characterized by depth selective conversion electron Moessbauer spectroscopy (DCEMS) using a He+5%CH4 gas proportional counter. The as-deposited films consisted of magnetic phases, the magnetic orientation of which had a tendency to be perpendicular to the surface of the film. In the case of the deposited films at substrate temperature of 100 deg. C, a small amount of Fe2O3 and ferritic stainless steel formed by post-heating in air. A magnetic subcomponent and a austenite phase were formed in the films deposited at substrate temperature of 400 deg. C. {alpha}-Fe2O3 and magnetite formed easily on the top and middle layers of the films by post-heating in air. The oxide states of the films deposited at different temperatures of substrate were clearly distinguished by post-heating. Thus it was found by DCEMS that the structures of the deposited films were strongly affected by the preparation method and the temperature of the substrate.

  8. Molecular dynamics study on low-energy sputtering of carbon material by Xe ion bombardment

    NASA Astrophysics Data System (ADS)

    Muramoto, T.; Hyakutake, T.

    2013-05-01

    The low-energy sputtering of carbon material under Xe ion bombardment is studied through the molecular dynamics (MD) simulation. For the normal incidence of Xe, the MD result of sputtering yield almost agrees with the experimental result by Williams et al. (AIAA-2004-3788). However, the experimental result shows a less incident angle dependence than the MD result because the experiment performed on a rough surface. It is found that the sputtered particles have memory of the projectile because the sputtered particles by the low-energy projectile undergo only a few collisions before the ejection. Low density of an amorphous carbon surface brings the decrease of the sputtering yield and the increase of high-energy sputtered atoms.

  9. High power pulsed magnetron sputtering: A method to increase deposition rate

    SciTech Connect

    Raman, Priya McLain, Jake; Ruzic, David N; Shchelkanov, Ivan A.

    2015-05-15

    High power pulsed magnetron sputtering (HPPMS) is a state-of-the-art physical vapor deposition technique with several industrial applications. One of the main disadvantages of this process is its low deposition rate. In this work, the authors report a new magnetic field configuration, which produces deposition rates twice that of conventional magnetron's dipole magnetic field configuration. Three different magnet pack configurations are discussed in this paper, and an optimized magnet pack configuration for HPPMS that leads to a higher deposition rate and nearly full-face target erosion is presented. The discussed magnetic field produced by a specially designed magnet assembly is of the same size as the conventional magnet assembly and requires no external fields. Comparison of deposition rates with different power supplies and the electron trapping efficiency in complex magnetic field arrangements are discussed.

  10. Structural and nanomechanical characterization of niobium films deposited by DC magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Li, X.; Cao, W. H.; Tao, X. F.; Ren, L. L.; Zhou, L. Q.; Xu, G. F.

    2016-05-01

    Nb thin films were deposited onto Si wafers by direct current (DC) magnetron sputtering at different deposition pressures. The microstructure and nanomechanical properties of Nb films were investigated by scanning electron microscope, X-ray diffractometer, transmission electron microscope, atomic force microscope and nanoindenter. The results revealed that the grain size, thickness, surface roughness, the reduced elastic modulus ( Er) and hardness ( H) values of Nb thin films increased at the pressure range of 0.61-0.68 Pa. Meanwhile, the porosity of Nb films decreased with the increase in deposition pressure. The lattice deformation of Nb thin films changed from negative to positive with the increase in deposition pressure. It is concluded that deposition pressure influences the microstructure and nanomechanical properties of Nb films.

  11. Electrochemical properties of sputter-deposited MoO{sub 3} films in lithium microbatteries

    SciTech Connect

    Ramana, C. V.; Atuchin, V. V.; Groult, H.; Julien, C. M.

    2012-07-15

    Molybdenum oxide (MoO{sub 3}) films were prepared by magnetron sputtering using an Mo target. The films were sputtered in the reactive atmosphere of an argon-oxygen gas mixture under various substrate temperatures, T{sub s}, and oxygen partial pressures, p(O{sub 2}). The effects of the growth conditions on the microstructure were examined using reflection high-energy electron diffraction and x-ray photoelectron spectroscopy. The analyses indicate that stoichiometric and polycrystalline MoO{sub 3} films were obtained at T{sub s} = 445 Degree-Sign C and p(O{sub 2}) = 61%. The applicability of the sputtered MoO{sub 3} films for lithium microbattery application has been demonstrated. The discharge-charge profiles, the kinetics of lithium intercalation process in the film, and the cycling behavior have been investigated in detail to understand the effect of microstructure on the electrochemical performance.

  12. Optimizing the sputter deposition process of polymers for the Storing Matter technique using PMMA.

    PubMed

    Turgut, Canan; Sinha, Godhuli; Lahtinen, Jouko; Nordlund, Kai; Belmahi, Mohammed; Philipp, Patrick

    2016-10-01

    Quantitative analyses in secondary ion mass spectrometry (SIMS) become possible only if ionization processes are controlled. The Storing Matter technique has been developed to circumvent this so-called matrix effect, primarily for inorganic samples, but has also been extended to organic samples. For the latter, it has been applied to polystyrene in order to investigate the extent of damage in the polymer, its fragmentation during the sputter deposition process and the effect of the deposition process on the spectra taken by Time-of-Flight SIMS (ToF-SIMS). In this work, a multi-technique approach, which employs the Storing Matter technique for deposition and ToF-SIMS and X-ray photoelectron spectroscopy for characterization, is used to enhance the control of the deposition process, including the thickness of the deposit, the alteration of the source film and the influence of polymer composition on the Storing Matter process. Poly (methyl methacrylate) (PMMA) is used for this work. More detailed information about the sticking of polymer fragments on the metal collector is obtained by density functional theory calculations. This work allows for the conclusion that a part of the fragments deposited on the collector surface diffuses on the latter, reacts and recombines to form larger fragments. The behaviour observed for PMMA is similar to polystyrene, showing that oxygen has no major influence on the processes occurring during the sputter deposition process. Additionally, we have developed a new methodology using 2D ToF-SIMS images of the deposit to monitor the deposit thickness and to identify surface contaminations. The latter are not only located at the position of the deposit but all over the collector surface. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Impurity-free vacancy disordering of quantum heterostructures with SiOxNy encapsulants deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    McKerracher, I. R.; Fu, L.; Tan, H. H.; Jagadish, C.

    2008-08-01

    Post-growth techniques such as impurity-free vacancy disordering (IFVD) are simple and effective avenues to monolithic integration of optoelectonic components. Sputter deposition of encapsulant films can enhance quantum well intermixing through IFVD and an additional mechanism involving surface damage during the sputtering process. In this study, these two mechanisms were compared in a multi-quantum well structure. The compositions of different silicon oxy-nitride films were controlled by sputter deposition in different ambient gases. These different encapsulants were used to initiate IFVD in the same heterostructure and the observed intermixing is compared to the film properties.

  14. Reactive magnetron sputtering deposition of bismuth tungstate onto titania nanoparticles for enhancing visible light photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Ratova, Marina; Kelly, Peter J.; West, Glen T.; Tosheva, Lubomira; Edge, Michele

    2017-01-01

    Titanium dioxide - bismuth tungstate composite materials were prepared by pulsed DC reactive magnetron sputtering of bismuth and tungsten metallic targets in argon/oxygen atmosphere onto anatase and rutile titania nanoparticles. The use of an oscillating bowl placed beneath the two magnetrons arranged in a co-planar closed field configuration enabled the deposition of bismuth tungstate onto loose powders, rather than a solid substrate. The atomic ratio of the bismuth/tungsten coatings was controlled by varying the power applied to each target. The effect of the bismuth tungstate coatings on the phase, optical and photocatalytic properties of titania was investigated by X-ray diffraction, energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET) surface area measurements, transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy and an acetone degradation test. The latter involved measurements of the rate of CO2 evolution under visible light irradiation of the photocatalysts, which indicated that the deposition of bismuth tungstate resulted in a significant enhancement of visible light activity, for both anatase and rutile titania particles. The best results were achieved for coatings with a bismuth to tungsten atomic ratio of 2:1. In addition, the mechanism by which the photocatalytic activity of the TiO2 nanoparticles was enhanced by compounding it with bismuth tungstate was studied by microwave cavity perturbation. The results of these tests confirmed that such enhancement of the photocatalytic properties is due to more efficient photogenerated charge carrier separation, as well as to the contribution of the intrinsic photocatalytic properties of Bi2WO6.

  15. Fabrication of nanobaskets by sputter deposition on porous substrates and uses thereof

    NASA Technical Reports Server (NTRS)

    Johnson, Paige Lea (Inventor); Teeters, Dale (Inventor)

    2010-01-01

    A method of producing a nanobasket and the applications or uses thereof. The method includes the steps of providing a substrate with at least one (1) pore having diameters of about one (1) nanometer to about ten (10) micrometers. Material is deposited by sputter-coating techniques along continuous edges of the pores to form a capped or partially capped nanotube or microtube structure, termed a nanobasket. Either a single material may be used to form nanobaskets over the pores or, alternately, a layered structure may be created wherein an initial material is deposited followed by one or more other materials to form nanobaskets over the pores.

  16. Adherence of ion beam sputter deposited metal films on H-13 steel

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.

    1980-01-01

    An electron bombardment argon ion source was used to sputter deposit 17 different metal and metal oxide films ranging in thickness from 1 to 8 micrometers on H-13 steel substrates. The film adherence to the substrate surface was measured using a tensile test apparatus. Comparisons in bond strength were made between ion beam, ion plating, and RF deposited films. A protective coating to prevent heat checking in H-13 steel dies used for aluminum die casting was studied. The results of exposing the coated substrates to temperatures up to 700 degrees are presented.

  17. Study on mixed vanadium oxide thin film deposited by RF magnetron sputtering and its application

    NASA Astrophysics Data System (ADS)

    Ling, Zhang; Jianhui, Tu; Hao, Feng; Jingzhong, Cui

    Vanadium oxide (VOx) thin films were deposited on fused quartz using a pure metal vanadium target by RF reactive magnetron sputtering technique. Film microstructure, valence state, optical transmittance properties were studied. The mixed valence VOx thin films deposited with different thickness were found to be amorphous. And the optical transmittance curves are flatness in certain wavelength region. These films can be used to control the relative light intensity of the rubidium light beam between the rubidium lamp and the vapor cell, in order to optimize the working parameters of the rubidium frequency standard (RAFS).

  18. Time resolved ion energy distribution functions of non-reactive and reactive high power impulse magnetron sputtering of titanium

    NASA Astrophysics Data System (ADS)

    Grosse, Katharina; Breilmann, Wolfgang; Maszl, Christian; Benedikt, Jan; von Keudell, Achim

    2016-09-01

    High power impulse magnetron sputtering (HiPIMS) is a technique for thin film deposition and can be operated in reactive and non-reactive mode. The growth rate of HiPIMS in non-reactive mode reduces to 30% compared to direct current magnetron sputtering (dcMS) at same average power. However, the quality of the coatings produced with HiPIMS is excellent which makes these plasmas highly appealing. In reactive mode target poisoning is occurring which changes the plasma dynamics. An advantage of reactive HiPIMS is that it can be operated hysteresis-free which can result in a higher growth rate compared to dcMS. In this work thin films are deposited by a HiPIMS plasma which is generated by short pulses of 100 μs with high power densities in the range of 1 kW/cm2. Ar and Ar/N2 admixtures are used as a working gas to sputter a 2'' titanium target. The particle transport is analysed with time resolved ion energy distribution functions which are measured by a mass spectrometer with a temporal resolution of 2 μs. Phase resolved optical emission spectroscopy is executed to investigate the particle dynamics of different species. The time and energy resolved particle fluxes in non-reactive and reactive mode are compared and implications on the sputter process are discussed.

  19. Energy dependence of ion-induced sputtering yields from monatomic solids at normal incidence

    SciTech Connect

    Yamamura, Y.; Tawara, H.

    1996-03-01

    The ion-induced sputtering yields from monatomic solids at normal incidence are presented graphically for various ion-target combinations as a function of the incident ion energy. To supplement the experimental data, sputtering yields are calculated by the Monte Carlo simulation code ACAT for some ion-target combinations. Each graph shows the available experimental and ACAT data points, together with the sputtering yields calculated by an empirical formula whose parameters determined from the best fit to available data.

  20. Molecular dynamics study of non-equilibrium energy transport from a cylindrical track: Part II. Spike models for sputtering yield

    NASA Astrophysics Data System (ADS)

    Bringa, E. M.; Johnson, R. E.; Dutkiewicz, Ł .

    1999-05-01

    Thermal spike models have been used to calculate the yields for electronic sputtering of condensed-gas solids by fast ions. In this paper molecular dynamics (MD) calculations are carried out to describe the evolution of solid Ar and O 2 following the excitation of a cylindrical track in order to test spike models. The calculated sputtering yields were found to depend linearly on the energy deposition per unit path length, d E/d x, at the highest d E/d x. This is in contrast to the spike models and the measured yields for a number of condensed-gas solids which depend quadratically on d E/d x at high d E/d x. In paper I [E.M. Bringa, R.E. Johnson, Nucl. Instr. and Meth. B 143 (1998) 513] we showed that the evolution of energy from the cylindrical track was, typically, not diffusive, as assumed in the spike models. Here we show that it is the description of the radial transport and the absence of energy transport to the surface, rather than the treatment of the ejection process, that accounts for the difference between the analytic spike models and the MD calculations. Therefore, the quadratic dependence on d E/d x of the measured sputtering yield reflects the nature of the energizing process rather than the energy transport. In this paper we describe the details of the sputtering process and compare the results here for crystalline samples to the earlier results for amorphous solids.

  1. Microscopic structure and electrical transport property of sputter-deposited amorphous indium-gallium-zinc oxide semiconductor films

    NASA Astrophysics Data System (ADS)

    Yabuta, H.; Kaji, N.; Shimada, M.; Aiba, T.; Takada, K.; Omura, H.; Mukaide, T.; Hirosawa, I.; Koganezawa, T.; Kumomi, H.

    2014-06-01

    We report on microscopic structures and electrical and optical properties of sputter-deposited amorphous indium-gallium-zinc oxide (a-IGZO) films. From electron microscopy observations and an x-ray small angle scattering analysis, it has been confirmed that the sputtered a-IGZO films consist of a columnar structure. However, krypton gas adsorption measurement revealed that boundaries of the columnar grains are not open-pores. The conductivity of the sputter-deposited a-IGZO films shows a change as large as seven orders of magnitude depending on post-annealing atmosphere; it is increased by N2-annealing and decreased by O2-annealing reversibly, at a temperature as low as 300°C. This large variation in conductivity is attributed to thermionic emission of carrier electrons through potential barriers at the grain boundaries, because temperature dependences of the carrier density and the Hall mobility exhibit thermal activation behaviours. The optical band-gap energy of the a-IGZO films changes between before and after annealing, but is independent of the annealing atmosphere, in contrast to the noticeable dependence of conductivity described above. For exploring other possibilities of a-IGZO, we formed multilayer films with an artificial periodic lattice structure consisting of amorphous InO, GaO, and ZnO layers, as an imitation of the layer-structured InGaZnO4 homologous phase. The hall mobility of the multilayer films was almost constant for thicknesses of the constituent layer between 1 and 6 Å, suggesting rather small contribution of lateral two-dimensional conduction It increased with increasing the thickness in the range from 6 to 15 Å, perhaps owing to an enhancement of two-dimensional conduction in InO layers.

  2. Chemical and physical sputtering effects on the surface morphology of carbon films grown by plasma chemical vapor deposition

    SciTech Connect

    Vazquez, Luis

    2009-08-01

    We have studied the influence of chemical and physical sputtering on the surface morphology of hydrogenated carbon films deposited on silicon substrates by bias-enhanced electron cyclotron resonance chemical vapor deposition. Atomic force microscopy based power spectrum density (PSD) and roughness analysis have been used to investigate the film morphology. This study has been possible due to the appropriate choice of the experimental variables, in particular, gas mixture, resulting in either nitrogen-free (a-C:H) or nitrogenated carbon (a-CN:H) films, and substrate bias (V{sub b}). Under these conditions, chemical sputtering is present for a-CN:H deposition but it is negligible for a-C:H film growth, while physical sputtering processes appear for both systems for V{sub b}<=-85 V. When physical sputtering does not operate, the film growth with simultaneous chemical sputtering leads to a characteristic a-CN:H granular surface morphology. Furthermore, PSD analysis reveals that a spatial correlation of the a-CN:H film surface roughness, up to distances approx300 nm, becomes a fingerprint of the coexistence of growth and chemical erosion processes on the film morphology. However, once physical sputtering takes place, the influence of chemical sputtering by reactive nitrogen species on the final surface morphology becomes negligible and both a-CN:H and a-C:H film morphologies are ultrasmooth.

  3. Hall mobility of cuprous oxide thin films deposited by reactive direct-current magnetron sputtering

    SciTech Connect

    Lee, Yun Seog; Winkler, Mark T.; Siah, Sin Cheng; Brandt, Riley; Buonassisi, Tonio

    2011-05-09

    Cuprous oxide (Cu{sub 2}O) is a promising earth-abundant semiconductor for photovoltaic applications. We report Hall mobilities of polycrystalline Cu{sub 2}O thin films deposited by reactive dc magnetron sputtering. High substrate growth temperature enhances film grain structure and Hall mobility. Temperature-dependent Hall mobilities measured on these films are comparable to monocrystalline Cu{sub 2}O at temperatures above 250 K, reaching 62 cm{sup 2}/V s at room temperature. At lower temperatures, the Hall mobility appears limited by carrier scattering from ionized centers. These observations indicate that sputtered Cu{sub 2}O films at high substrate growth temperature may be suitable for thin-film photovoltaic applications.

  4. Intrinsic anomalous surface roughening of TiN films deposited by reactive sputtering

    SciTech Connect

    Auger, M. A.; Vazquez, L.; Sanchez, O.; Cuerno, R.; Castro, M.; Jergel, M.

    2006-01-15

    We study surface kinetic roughening of TiN films grown on Si(100) substrates by dc reactive sputtering. The surface morphology of films deposited for different growth times under the same experimental conditions were analyzed by atomic force microscopy. The TiN films exhibit intrinsic anomalous scaling and multiscaling. The film kinetic roughening is characterized by a set of local exponent values {alpha}{sub loc}=1.0 and {beta}{sub loc}=0.39, and global exponent values {alpha}=1.7 and {beta}=0.67, with a coarsening exponent of 1/z=0.39. These properties are correlated to the local height-difference distribution function obeying power-law statistics. We associate this intrinsic anomalous scaling with the instability due to nonlocal shadowing effects that take place during thin-film growth by sputtering.

  5. Properties of AlN films deposited by reactive ion-plasma sputtering

    SciTech Connect

    Bert, N. A.; Bondarev, A. D.; Zolotarev, V. V.; Kirilenko, D. A.; Lubyanskiy, Ya. V.; Lyutetskiy, A. V.; Slipchenko, S. O.; Petrunov, A. N.; Pikhtin, N. A. Ayusheva, K. R.; Arsentyev, I. N.; Tarasov, I. S.

    2015-10-15

    The properties of SiO{sub 2}, Al{sub 2}O{sub 3}, and AlN dielectric coatings deposited by reactive ion-plasma sputtering are studied. The refractive indices of the dielectric coatings are determined by optical ellipsometry. It is shown that aluminum nitride is the optimal material for achieving maximum illumination of the output mirror of a semiconductor laser. A crystalline phase with a hexagonal atomic lattice and oxygen content of up to 10 at % is found by transmission electron microscopy in the aluminum-nitride films. It is found that a decrease in the concentration of residual oxygen in the chamber of the reactive ion-plasma sputtering installation makes it possible to eliminate the appearance of vertical pores in the bulk of the aluminum-nitride film.

  6. Gasochromic Properties of Nanostructured Tungsten Oxide Films Prepared by Sputtering Deposition

    NASA Astrophysics Data System (ADS)

    Takano, Katsuyoshi; Inouye, Aichi; Yamamoto, Shunya; Sugimoto, Masaki; Yoshikawa, Masahito; Nagata, Shinji

    2007-09-01

    The effects of surface morphology on the gasochromic properties of tungsten trioxide (WO3) films are reported. WO3 films with various crystalline structures and surface morphologies are prepared by reactive rf magnetron sputtering by adjusting the substrate temperature and oxygen concentration in a sputtering gas during deposition. Grain structures on these films were confirmed by atomic force microscopy observation. The gasochromic properties of the WO3 films coated with a palladium catalyst were examined on the basis of a change in optical transmittance with 645-nm-wavelength light in 1% hydrogen in argon gas. WO3 films with a (001) orientation show sufficient gasochromic properties for their application to fiber-optic hydrogen gas sensors. The growth of the nanocrystalline structure in the WO3 films seems to improve gasochromic properties.

  7. Surface treatment effect on Si (111) substrate for carbon deposition using DC unbalanced magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Aji, A. S.; Sahdan, M. F.; Hendra, I. B.; Dinari, P.; Darma, Y.

    2015-04-01

    In this work, we studied the effect of HF treatment in silicon (111) substrate surface for depositing thin layer carbon. We performed the deposition of carbon by using DC Unbalanced Magnetron Sputtering with carbon pallet (5% Fe) as target. From SEM characterization results it can be concluded that the carbon layer on HF treated substrate is more uniform than on substrate without treated. Carbon deposition rate is higher as confirmed by AFM results if the silicon substrate is treated by HF solution. EDAX characterization results tell that silicon (111) substrate with HF treatment have more carbon fraction than substrate without treatment. These results confirmed that HF treatment on silicon Si (111) substrates could enhance the carbon deposition by using DC sputtering. Afterward, the carbon atomic arrangement on silicon (111) surface is studied by performing thermal annealing process to 900 °C. From Raman spectroscopy results, thin film carbon is not changing until 600 °C thermal budged. But, when temperature increase to 900 °C, thin film carbon is starting to diffuse to silicon (111) substrates.

  8. Surface treatment effect on Si (111) substrate for carbon deposition using DC unbalanced magnetron sputtering

    SciTech Connect

    Aji, A. S. Sahdan, M. F.; Hendra, I. B.; Dinari, P.; Darma, Y.

    2015-04-16

    In this work, we studied the effect of HF treatment in silicon (111) substrate surface for depositing thin layer carbon. We performed the deposition of carbon by using DC Unbalanced Magnetron Sputtering with carbon pallet (5% Fe) as target. From SEM characterization results it can be concluded that the carbon layer on HF treated substrate is more uniform than on substrate without treated. Carbon deposition rate is higher as confirmed by AFM results if the silicon substrate is treated by HF solution. EDAX characterization results tell that silicon (111) substrate with HF treatment have more carbon fraction than substrate without treatment. These results confirmed that HF treatment on silicon Si (111) substrates could enhance the carbon deposition by using DC sputtering. Afterward, the carbon atomic arrangement on silicon (111) surface is studied by performing thermal annealing process to 900 °C. From Raman spectroscopy results, thin film carbon is not changing until 600 °C thermal budged. But, when temperature increase to 900 °C, thin film carbon is starting to diffuse to silicon (111) substrates.

  9. Energy and mass dependence of isotopic enrichment in sputtering

    SciTech Connect

    Shutthanandan, V.; Zhang, J.; Ray, Pradosh

    2003-05-01

    When a solid surface containing more than one component is bombarded by energetic particles, the sputtered flux is found to deviated from the stoichiometric composition of the target. This is known as preferential sputtering. Usually the sputtered flux is enriched with the lighter-mass particles, particularly at small emission angles. As the bombardment of the target is continued, the target surface becomes depleted in the particles that are preferentially emitted and a steady state is eventually established, where the ratio of the sputtered particles becomes equal to the natural abundance ratio of the particles in the target.

  10. Bimodal substrate biasing to control γ-Al{sub 2}O{sub 3} deposition during reactive magnetron sputtering

    SciTech Connect

    Prenzel, Marina; Kortmann, Annika; Stein, Adrian; Keudell, Achim von; Nahif, Farwah; Schneider, Jochen M.

    2013-09-21

    Al{sub 2}O{sub 3} thin films have been deposited at substrate temperatures between 500 °C and 600 °C by reactive magnetron sputtering using an additional arbitrary substrate bias to tailor the energy distribution of the incident ions. The films were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The film structure being amorphous, nanocrystalline, or crystalline was correlated with characteristic ion energy distributions. The evolving crystalline structure is connected with different levels of displacements per atom (dpa) in the growing film as being derived from TRIM simulations. The boundary between the formation of crystalline films and amorphous or nanocrystalline films was at 0.8 dpa for a substrate temperature of 500 °C. This threshold shifts to 0.6 dpa for films grown at 550 °C.

  11. Photocatalytic activity of bipolar pulsed magnetron sputter deposited TiO2/TiWOx thin films

    NASA Astrophysics Data System (ADS)

    Weng, Ko-Wei; Hu, Chung-Hsuan; Hua, Li-Yu; Lee, Chin-Tan; Zhao, Yu-Xiang; Chang, Julian; Yang, Shu-Yi; Han, Sheng

    2016-08-01

    Titanium oxide films were formed by sputtering and then TiWOx films were deposited by bipolar pulsed magnetron sputtering with pure titanium and tungsten metal targets. The sputtering of titanium oxide with tungsten enhanced the orientation of the TiO2 (1 0 1) plane of the specimen assemblies. The main varying parameter was the tungsten pulse power. Titanium oxide sputtered with tungsten using a pulsing power of 50 W exhibited a superior hydrophilic property, and a contact angle of 13.1°. This fabrication conditions maximized the photocatalytic decomposition of methylene blue solution. The mechanism by which the titanium oxide was sputtered with tungsten involves the photogeneration of holes and electron traps, inhibiting the hole-electron recombination, enhancing hydrophilicity and reducing the contact angle.

  12. SiNx coatings deposited by reactive high power impulse magnetron sputtering: Process parameters influencing the residual coating stress

    NASA Astrophysics Data System (ADS)

    Schmidt, S.; Hänninen, T.; Wissting, J.; Hultman, L.; Goebbels, N.; Santana, A.; Tobler, M.; Högberg, H.

    2017-05-01

    The residual coating stress and its control is of key importance for the performance and reliability of silicon nitride (SiNx) coatings for biomedical applications. This study explores the most important deposition process parameters to tailor the residual coating stress and hence improve the adhesion of SiNx coatings deposited by reactive high power impulse magnetron sputtering (rHiPIMS). Reactive sputter deposition and plasma characterization were conducted in an industrial deposition chamber equipped with pure Si targets in N2/Ar ambient. Reactive HiPIMS processes using N2-to-Ar flow ratios of 0 and 0.28-0.3 were studied with time averaged positive ion mass spectrometry. The coatings were deposited to thicknesses of 2 μm on Si(001) and to 5 μm on polished CoCrMo disks. The residual stress of the X-ray amorphous coatings was determined from the curvature of the Si substrates as obtained by X-ray diffraction. The coatings were further characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, and nanoindentation in order to study their elemental composition, morphology, and hardness, respectively. The adhesion of the 5 μm thick coatings deposited on CoCrMo disks was assessed using the Rockwell C test. The deposition of SiNx coatings by rHiPIMS using N2-to-Ar flow ratios of 0.28 yield dense and hard SiNx coatings with Si/N ratios <1. The compressive residual stress of up to 2.1 GPa can be reduced to 0.2 GPa using a comparatively high deposition pressure of 600 mPa, substrate temperatures below 200 °C, low pulse energies of <2.5 Ws, and moderate negative bias voltages of up to 100 V. These process parameters resulted in excellent coating adhesion (ISO 0, HF1) and a low surface roughness of 14 nm for coatings deposited on CoCrMo.

  13. Experimental design approach for deposition optimization of RF sputtered chalcogenide thin films devoted to environmental optical sensors.

    PubMed

    Baudet, E; Sergent, M; Němec, P; Cardinaud, C; Rinnert, E; Michel, K; Jouany, L; Bureau, B; Nazabal, V

    2017-06-14

    The development of the optical bio-chemical sensing technology is an extremely important scientific and technological issue for diagnosis and monitoring of diseases, control of industrial processes, environmental detection of air and water pollutants. Owing to their distinctive features, chalcogenide amorphous thin films represent a keystone in the manufacture of middle infrared integrated optical devices for a sensitive detection of biological or environmental variations. Since the chalcogenide thin films characteristics, i.e. stoichiometric conformity, structure, roughness or optical properties can be affected by the growth process, the choice and control of the deposition method is crucial. An approach based on the experimental design is undoubtedly a way to be explored allowing fast optimization of chalcogenide film deposition by means of radio frequency sputtering process. Argon (Ar) pressure, working power and deposition time were selected as potentially the most influential factors among all possible. The experimental design analysis confirms the great influence of the Ar pressure on studied responses: chemical composition, refractive index in near-IR (1.55 µm) and middle infrared (6.3 and 7.7 µm), band-gap energy, deposition rate and surface roughness. Depending on the intended application and therefore desired thin film characteristics, mappings of the experimental design meaningfully help to select suitable deposition parameters.

  14. In situ analyses on negative ions in the sputtering process to deposit Al-doped ZnO films

    SciTech Connect

    Tsukamoto, Naoki; Watanabe, Daisuke; Saito, Motoaki; Sato, Yasushi; Oka, Nobuto; Shigesato, Yuzo

    2010-07-15

    The origin of high energy negative ions during deposition of aluminum doped zinc oxide (AZO) films by dc magnetron sputtering of an AZO (Al{sub 2}O{sub 3}: 2.0 wt %) target was investigated by in situ analyses using the quadrupole mass spectrometer combined with the electrostatic energy analyzer. High energy negative oxygen (O{sup -}) ions which possessed the kinetic energy corresponding to the cathode sheath voltage were detected. The maximum flux of the O{sup -} ions was clearly observed at the location opposite to the erosion track area on the target. The flux of the O{sup -} ions changed hardly with increasing O{sub 2} flow ratio [O{sub 2}/(Ar+O{sub 2})] from 0% to 5%. The kinetic energy of the O{sup -} ions decreased with decreasing cathode sheath voltage from 403 to 337 V due to the enhancement of the vertical maximum magnetic field strength at the cathode surface from 0.025 to 0.100 T. The AZO films deposited with the lower O{sup -} bombardment energy showed the higher crystallinity and improved the electrical conductivity.

  15. Sputtering of cobalt and chromium by argon and xenon ions near the threshold energy region

    NASA Technical Reports Server (NTRS)

    Handoo, A. K.; Ray, P. K.

    1993-01-01

    Sputtering yields of cobalt and chromium by argon and xenon ions with energies below 50 eV are reported. The targets were electroplated on copper substrates. Measurable sputtering yields were obtained from cobalt with ion energies as low as 10 eV. The ion beams were produced by an ion gun. A radioactive tracer technique was used for the quantitative measurement of the sputtering yield. Co-57 and Cr-51 were used as tracers. The yield-energy curves are observed to be concave, which brings into question the practice of finding threshold energies by linear extrapolation.

  16. Sputtering of cobalt and chromium by argon and xenon ions near the threshold energy region

    NASA Technical Reports Server (NTRS)

    Handoo, A. K.; Ray, P. K.

    1993-01-01

    Sputtering yields of cobalt and chromium by argon and xenon ions with energies below 50 eV are reported. The targets were electroplated on copper substrates. Measurable sputtering yields were obtained from cobalt with ion energies as low as 10 eV. The ion beams were produced by an ion gun. A radioactive tracer technique was used for the quantitative measurement of the sputtering yield. Co-57 and Cr-51 were used as tracers. The yield-energy curves are observed to be concave, which brings into question the practice of finding threshold energies by linear extrapolation.

  17. Molecular dynamics analysis of metal surface sputtering due to bombardment of high energy particles

    SciTech Connect

    Kumar, K. Kishore; Donbosco, Ferdin Sagai; Kumar, Rakesh

    2014-12-09

    Dependence of sputtering yield of Cu (100) and Ni (100) metal surface by bombardment of 200 Ar ions at various energies and angles of projections is investigated in this paper. The sputtering yield has been calculated by performing molecular dynamics simulation and the same is compared with experiments and theoretical predictions wherever possible. Additionally the kinetic energy, velocity and scattering angle distribution for sputtered and incident atoms are also observed. The results obtained from the present molecular dynamics simulations are found to be in good agreement with experimental data and theoretical estimates. It is observed that the sputtering yield increases as the energy of the bombarding ion increases. Furthermore as the incidence angle increases, the sputtering yield increases until a specific angle and then decreases as normal incidence is approached.

  18. Effects of Sputtering Energy on Surface Defect Formation on Ge(110)

    NASA Astrophysics Data System (ADS)

    MacIntyre, Samantha; van Zijll, Marshall; Stenger, Bret; Norton, Michael; Oguri, Noelle; Chiang, Shirley

    2013-03-01

    Pyramid-shaped defects were observed in STM images to form on clean Ge(110) surfaces as a result of argon ion sputtering. By periodically imaging the samples after various numbers of sputtering and annealing cycles, we systematically studied the formation of these defects as a function of the Ar+ ion sputtering energy. Although the number and size of pyramids increased with sputtering energy from 100 to 200eV, the sample sputtered with 300eV ions showed a very flat surface with very few pyramids. The sample sputtered with 400eV ions appears to have mountain ranges of highly stepped regions with numerous pyramids on the edges, separated by flat valleys of reconstructed c(8x10) surface. Many pyramids are capped by a cluster of atoms, probably carbon, which may have served as the nucleation site. To explain the dependence of defect formation on sputtering energy, we present a mechanism involving competition between uncovering parts of new pyramids and breaking down older pyramids. Using different sputtering energies for controlled defect formation could be an effective tool for controlling island growth at defects on substrates. Funded by NSF CHE-0719504 and NSF PHY-1004848.

  19. Control of the stabilization of cubic boron nitride thin films deposited by unbalanced magnetron sputtering and dc pulsed substrate biasing

    NASA Astrophysics Data System (ADS)

    Otano-Rivera, Wilfredo

    The formation of cubic boron nitride (cBN) thin films deposited by unbalanced magnetron sputtering and dc pulsed substrate biasing has been studied. Thin films were deposited at different pressures and negative bias voltages to study the effect of the energetic bombardment on the stabilization conditions of the cubic phase of BN thin films. It is shown that it is possible to clearly define a stabilization window for cBN by controlling the sputtering deposition process parameters of pressure and negative substrate bias. It is also shown that at higher deposition pressures charge exchange and momentum transfer collisions in the plasma sheath reduce the bombardment energy of the particles. These collisional processes result in the use of a higher substrate bias voltages for increasing gas pressures in order to maintain the momentum per arriving boron atom, P/a, imparted to the growing film inside the stabilization window for the cubic phase. The end result is a trend where the substrate bias voltage for the formation of cBN increases negatively as a function of pressure times sheath thickness. A series of films were also deposited on different types of substrates in order to study the effects of chemistry and epitaxy on the nucleation of cBN. It was possible to nucleate the BN cubic phase on a wide variety of substrates. Diamond coated silicon substrates were the only ones that showed a marked effect on the nucleation of the cBN, where the FWHM of the FTIR signal was reduced two-fold as compared to the FTIR signal of films deposited on silicon under similar deposition conditions. The experimental results suggest that there is a threshold energy for the bombarding ions below which it is not possible to nucleate cBN. This result, in combination with the fact that P/a controls the cBN stabilization during the nucleation stage and other reported observations pertinent to the cBN thin film formation, leads to a proposed mechanism for the nucleation and growth stages of cBN.

  20. Sputter Deposition of Yttrium-Barium Superconductor and Strontium Titanium Oxide Barrier Layer Thin Films

    NASA Astrophysics Data System (ADS)

    Truman, James Kelly

    1992-01-01

    The commercial application of superconducting rm YBa_2Cu_3O_{7 -x} thin films requires the development of deposition methods which can be used to reproducibly deposit films with good superconducting properties on insulating and semiconducting substrates. Sputter deposition is the most popular method to fabricate Y-Ba-Cu-O superconductor thin films, but when used in the standard configuration suffers from a deviation between the compositions of the Y-Ba-Cu-O sputter target and deposited films, which is thought to be primarily due to resputtering of the film by negative ions sputtered from the target. In this study, the negative ions were explicitly identified and were found to consist predominantly O^-. The sputter yield of O^- was found to depend on the Ba compound used in the fabrication of Y -Ba-Cu-O targets and was related to the electronegativity difference between the components. An unreacted mixture of rm Y_2O_3, CuO, and BaF_2 was found to have the lowest O^- yield among targets with Y:Ba:Cu = 1:2:3. The high yield of O^- from rm YBa_2Cu_3O _{7-x} was found to depend on the target temperature and be due to the excess oxygen present. The SIMS negative ion data supported the composition data for sputter-deposited Y-Ba-Cu-O films. Targets using BaF _2 were found to improve the Ba deficiency, the run-to-run irreproducibility and the nonuniformity of the film composition typically found in sputtered Y -Ba-Cu-O films. Superconducting Y-Ba-Cu-O films were formed on SrTiO_3 substrates by post-deposition heat treatment of Y-Ba-Cu-O-F films in humid oxygen. The growth of superconducting rm YBa_2Cu_3O_{7-x}, thin films on common substrates such as sapphire or silicon requires the use of a barrier layer to prevent the deleterious interaction which occurs between Y-Ba-Cu-O films and these substrates. Barrier layers of SrTiO_3 were studied and found to exhibit textured growth with a preferred (111) orientation on (100) Si substrates. However, SrTiO_3 was found to be

  1. Bioactive glass thin films deposited by magnetron sputtering technique: The role of working pressure

    NASA Astrophysics Data System (ADS)

    Stan, G. E.; Marcov, D. A.; Pasuk, I.; Miculescu, F.; Pina, S.; Tulyaganov, D. U.; Ferreira, J. M. F.

    2010-09-01

    Bioglass coatings were prepared by radio frequency magnetron sputtering deposition at low temperature (150 °C) onto silicon substrates. The influence of argon pressure values used during deposition (0.2 Pa, 0.3 Pa and 0.4 Pa) on the short-range structure and biomineralization potential of the bioglass coatings was studied. The biomineralization capability was evaluated after 30 days of immersion in simulated body fluid. SEM-EDS, XRD and FTIR measurements were performed. The tests clearly showed strong biomineralization features for the bioglass films. The thickness of the chemically grown hydroxyapatite layers was more than twice greater for the BG films deposited at the highest working pressure, in comparison to those grown on the films obtained at lower working pressures. The paper attempts to explain this experimental fact based on structural and compositional considerations.

  2. Investigation of phase transformation behavior in sputter deposited PtMn thin films

    SciTech Connect

    Ji, C. -X.; Ladwig, Peter F.; Ott, Ronald D; Yang, Y.; Yang, Joshua J.; Chang, Y. Austin; Linville, Eric S.; Gao, Jenny; Pant, Bharat B.

    2006-01-01

    Sputter-deposited, equiatomic PtMn thin films have application in giant magnetoresistive spin valves, tunneling magnetoresistive spin valves, and magnetic random access memory. However, the as-deposited films are found to be a disordered A1 phase in a paramagnetic state rather than an antiferromagnetic phase with L1{sub 0} structure, which is needed for device operation. Therefore, a postannealing step is required to induce the phase transformation from the as-deposited A1 face-centered-cubic phase to the antiferromagnetic L1{sub 0} phase. The A1 to L1{sub 0} metastable transformation was studied by x-ray diffraction and differential-scanning calorimetry. An exothermic transformation enthalpy of -12.1 kJ/mol of atoms was determined. The transformation kinetics were simulated using the Johnson-Mehl-Avrami analysis.

  3. Development of mid-frequency AC reactive magnetron sputtering for fast deposition of Y2O3 buffer layers

    NASA Astrophysics Data System (ADS)

    Xiong, Jie; Xia, Yudong; Xue, Yan; Zhang, Fei; Guo, Pei; Zhao, Xiaohui; Tao, Bowan

    2014-02-01

    A reel-to-reel magnetron sputtering system with mid-frequency alternating current (AC) power supply was used to deposit double-sided Y2O3 seed layer on biaxially textured Ni-5 at.%W tape for YBa2Cu3O7-δ coated conductors. A reactive sputtering process was carried out using two opposite symmetrical sputtering guns with metallic yttrium targets and water vapor for oxidizing the sputtered metallic atoms. The voltage control mode of the power supply was used and the influence of the cathode voltage and ArH2 pressure were systematically investigated. Subsequently yttrium-stabilized zirconia (YSZ) barrier and CeO2 cap layers were deposited on the Y2O3 buffered substrates in sequence, indicating high quality and uniform double-sided structure and surface morphology of such the architecture.

  4. A new technique for measuring sputtering yields at high energies

    NASA Technical Reports Server (NTRS)

    Qiu, Y.; Griffith, J. E.; Tombrello, T. A.

    1984-01-01

    The use of thin, self-supporting carbon catcher foils allows one to measure sputtering yields in a broad range of materials with high sensitivity. Analyzing the foils with Rutherford forward scattering, sputtered Al, Si and P surface densities down to 5 x 10 to the 13th per sq cm with uncertainties of about 20 percent have been measured.

  5. Three-Dimensional, Fibrous Lithium Iron Phosphate Structures Deposited by Magnetron Sputtering.

    PubMed

    Bünting, Aiko; Uhlenbruck, Sven; Sebold, Doris; Buchkremer, H P; Vaßen, R

    2015-10-14

    Crystalline, three-dimensional (3D) structured lithium iron phosphate (LiFePO4) thin films with additional carbon are fabricated by a radio frequency (RF) magnetron-sputtering process in a single step. The 3D structured thin films are obtained at deposition temperatures of 600 °C and deposition times longer than 60 min by using a conventional sputtering setup. In contrast to glancing angle deposition (GLAD) techniques, no tilting of the substrate is required. Thin films are characterized by X-ray diffraction (XRD), Raman spectrospcopy, scanning electron microscopy (SEM), cyclic voltammetry (CV), and galvanostatic charging and discharging. The structured LiFePO4+C thin films consist of fibers that grow perpendicular to the substrate surface. The fibers have diameters up to 500 nm and crystallize in the desired olivine structure. The 3D structured thin films have superior electrochemical properties compared with dense two-dimensional (2D) LiFePO4 thin films and are, hence, very promising for application in 3D microbatteries.

  6. Influence of process parameter variation on the reflectivity of sputter-deposited W--C multilayer diffraction gratings

    SciTech Connect

    Sager, B.; Benson, P.; Jahoda, K.; Jacobs, J.R.; Bloch, J.J.; Sanders, W.T.; Lagally, M.G.

    1986-05-01

    Multilayer W--C diffraction gratings with nominal d spacings of 35 A have been fabricated by magnetron sputter deposition. The peak and integrated reflectivities of these films have been measured with AlK/sub ..cap alpha../ x rays and compared to theoretical values. The rms surface roughness has been evaluated. The influence of several sputtering-system process parameters on the reflectivities has been investigated.

  7. Controlled growth of few-layer hexagonal boron nitride on copper foils using ion beam sputtering deposition.

    PubMed

    Wang, Haolin; Zhang, Xingwang; Meng, Junhua; Yin, Zhigang; Liu, Xin; Zhao, Yajuan; Zhang, Liuqi

    2015-04-01

    Ion beam sputtering deposition (IBSD) is used to synthesize high quality few-layer hexagonal boron nitride (h-BN) on copper foils. Compared to the conventional chemical vapor deposition, the IBSD technique avoids the use of unconventional precursors and is much easier to control, which should be very useful for the large-scale production of h-BN in the future.

  8. Shape-memory properties in Ni-Ti sputter-deposited film

    NASA Technical Reports Server (NTRS)

    Busch, J. D.; Johnson, A. D.; Lee, C. H.; Stevenson, D. A.

    1990-01-01

    A Ni-Ti alloy, generically called nitinol, was prepared from sputtering targets of two different compositions on glass substrates using a dc magnetron source. The as-deposited films were amorphous in structure and did not exhibit a shape memory. The amorphous films were crystallized with a suitable annealing process, and the transformation properties were measured using differential scanning calorimetry. The annealed films demonstrated a strong shape-memory effect. Stress/strain measurements and physical manipulation were used to evaluate the shape recovery. These tests demonstrated sustained tensile stresses of up to 480 MPa in the high-temperature phase, and a characteristic plastic deformation in the low-temperature phase.

  9. Shape-memory properties in Ni-Ti sputter-deposited film

    NASA Technical Reports Server (NTRS)

    Busch, J. D.; Johnson, A. D.; Lee, C. H.; Stevenson, D. A.

    1990-01-01

    A Ni-Ti alloy, generically called nitinol, was prepared from sputtering targets of two different compositions on glass substrates using a dc magnetron source. The as-deposited films were amorphous in structure and did not exhibit a shape memory. The amorphous films were crystallized with a suitable annealing process, and the transformation properties were measured using differential scanning calorimetry. The annealed films demonstrated a strong shape-memory effect. Stress/strain measurements and physical manipulation were used to evaluate the shape recovery. These tests demonstrated sustained tensile stresses of up to 480 MPa in the high-temperature phase, and a characteristic plastic deformation in the low-temperature phase.

  10. Nanoscale and macroscale aluminum nitride deposition via reactive magnetron sputtering method

    NASA Astrophysics Data System (ADS)

    Zhang, Guanghai

    The growth of group III nitrides is receiving a great deal of attention due to their potential as materials for optoelectronic devices in the blue to ultraviolet spectral range. This dissertation is primarily focused on deposition of aluminum nitride thin films on both nanofibers and macroscale silicon substrates via reactive magnetron sputtering. The objectives include investigating the feasibility of coating nanofibers to prepare high quality (smooth and crystalline) nanotubes, nanofiber hetero structures and using buffer layers to improve the quality of macroscale AlN thin films. To satisfy the need of nanoscale semiconductor materials, deposition of AlN on poly (meta-phenylene isophthalamide) MPD-I nano-fiber (template) was investigated via reactive magnetron sputtering. The electrospun high-temperature nanofibers with uniform dimensions were heated up to 300°C or higher. The coatings on the fibers were continuous and their morphology and crystal structure (either hexagonal wurtzite structure or cubic zinc-blende structure) were controlled by changing the deposition conditions. After removing the fiber core with organic solvent or by pyrolysis, AlN nanotubes (hollow structures) with inner diameter of 50--100 nm were achieved. As the nanoscale building blocks, nanoscale semiconductor heterostructures with modulated composition can facilitate the generation of devices with various functions. In this work, SiO2-AlN core-shell nanofiber heterostructures with SiO2 core and AlN shell were created by electro-spinning and reactive magnetron sputtering methods. Also the AlN coating (shell) was designed with different morphologies and crystalline properties by controlling the deposition conditions. The critical operating parameters for the formation of different morphologies of AlN shells were investigated. In practice, AlN thin film materials are still widely used for microelectronic and optoelectronic devices. To investigate and develop semiconducting AlN films, the

  11. Nanostructured Ti-Ta thin films synthesized by combinatorial glancing angle sputter deposition.

    PubMed

    Motemani, Yahya; Khare, Chinmay; Savan, Alan; Hans, Michael; Paulsen, Alexander; Frenzel, Jan; Somsen, Christoph; Mücklich, Frank; Eggeler, Gunther; Ludwig, Alfred

    2016-12-09

    Ti-Ta alloys are attractive materials for applications in actuators as well as biomedical implants. When fabricated as thin films, these alloys can potentially be employed as microactuators, components for micro-implantable devices and coatings on surgical implants. In this study, Ti100-x Ta x (x = 21, 30) nanocolumnar thin films are fabricated by glancing angle deposition (GLAD) at room temperature using Ti73Ta27 and Ta sputter targets. Crystal structure, morphology and microstructure of the nanostructured thin films are systematically investigated by XRD, SEM and TEM, respectively. Nanocolumns of ∼150-160 nm in width are oriented perpendicular to the substrate for both Ti79Ta21 and Ti70Ta30 compositions. The disordered α″ martensite phase with orthorhombic structure is formed in room temperature as-deposited thin films. The columns are found to be elongated small single crystals which are aligned perpendicular to the [Formula: see text] and [Formula: see text] planes of α″ martensite, indicating that the films' growth orientation is mainly dominated by these crystallographic planes. Laser pre-patterned substrates are utilized to obtain periodic nanocolumnar arrays. The differences in seed pattern, and inter-seed distances lead to growth of multi-level porous nanostructures. Using a unique sputter deposition geometry consisting of Ti73Ta27 and Ta sputter sources, a nanocolumnar Ti-Ta materials library was fabricated on a static substrate by a co-deposition process (combinatorial-GLAD approach). In this library, a composition spread developed between Ti72.8Ta27.2 and Ti64.4Ta35.6, as confirmed by high-throughput EDX analysis. The morphology over the materials library varies from well-isolated nanocolumns to fan-like nanocolumnar structures. The influence of two sputter sources is investigated by studying the resulting column angle on the materials library. The presented nanostructuring methods including the use of the GLAD technique along with pre

  12. Nanostructured Ti-Ta thin films synthesized by combinatorial glancing angle sputter deposition

    NASA Astrophysics Data System (ADS)

    Motemani, Yahya; Khare, Chinmay; Savan, Alan; Hans, Michael; Paulsen, Alexander; Frenzel, Jan; Somsen, Christoph; Mücklich, Frank; Eggeler, Gunther; Ludwig, Alfred

    2016-12-01

    Ti-Ta alloys are attractive materials for applications in actuators as well as biomedical implants. When fabricated as thin films, these alloys can potentially be employed as microactuators, components for micro-implantable devices and coatings on surgical implants. In this study, Ti100-x Ta x (x = 21, 30) nanocolumnar thin films are fabricated by glancing angle deposition (GLAD) at room temperature using Ti73Ta27 and Ta sputter targets. Crystal structure, morphology and microstructure of the nanostructured thin films are systematically investigated by XRD, SEM and TEM, respectively. Nanocolumns of ˜150-160 nm in width are oriented perpendicular to the substrate for both Ti79Ta21 and Ti70Ta30 compositions. The disordered α″ martensite phase with orthorhombic structure is formed in room temperature as-deposited thin films. The columns are found to be elongated small single crystals which are aligned perpendicular to the (20\\bar{4}) and (204) planes of α″ martensite, indicating that the films’ growth orientation is mainly dominated by these crystallographic planes. Laser pre-patterned substrates are utilized to obtain periodic nanocolumnar arrays. The differences in seed pattern, and inter-seed distances lead to growth of multi-level porous nanostructures. Using a unique sputter deposition geometry consisting of Ti73Ta27 and Ta sputter sources, a nanocolumnar Ti-Ta materials library was fabricated on a static substrate by a co-deposition process (combinatorial-GLAD approach). In this library, a composition spread developed between Ti72.8Ta27.2 and Ti64.4Ta35.6, as confirmed by high-throughput EDX analysis. The morphology over the materials library varies from well-isolated nanocolumns to fan-like nanocolumnar structures. The influence of two sputter sources is investigated by studying the resulting column angle on the materials library. The presented nanostructuring methods including the use of the GLAD technique along with pre-patterning and a

  13. Sputtering yields of carbon based materials under high particle flux with low energy

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Nagase, A.; Dairaku, M.; Akiba, M.; Araki, M.; Okumura, Y.

    1995-04-01

    A new ion source which can produce high particle flux beams at low energies has been developed. This paper presents preliminary results on the sputtering yield of the carbon fiber reinforced composites (CFCs) measured with the new ion source. The sputtering yields of 1D and 2D CFCs, which are candidate materials for the divertor armour tiles, have been measured by the weight loss method under the hydrogen and deuterium particle fluxes of 2 ˜ 7 × 10 20/m 2 s at 50 ˜ 150 eV. Preferential sputtering of the matrix was observed on CFCs which included the matrix of 40 ˜ 60 w%. The energy dependence of the sputtering yields was weak. The sputtering yields of CFCs normally irradiated with deuterium beam were from 0.073 to 0.095, and were around three times larger than those with hydrogen beam.

  14. Absolute sputtering yields from solid Ne by low energy He+ and Arq+ (1 >= q >= 6) impact

    NASA Astrophysics Data System (ADS)

    Fujita, Shinya; Tachibana, Takayuki; Koizumi, Tetsuo; Hirayama, Takato

    2009-04-01

    Absolute sputtering yields from the surface of solid Ne by low energy He+ and Arq+ (1 >= q >= 6) impact are measured. Very large sputtering yields (300 atoms/ion for 1 keV He+ impact, and 3000 atoms/ion for 1keV Ar+ impact) have been observed. A significant dependence of the sputtering yields on the chage state, i.e. the potential energy, of the incident ion for Arq+ has not been observed because it is estimated to be much smaller than that of the kinetic sputtering, which suggests that the mechanism of potential sputtering is similar to those known for the electron- and photon-stimulated desorption processes.

  15. Interface and Strain Energy Revolution Texture Map To Predict Structure and Optical Properties of Sputtered PbSe Thin Films.

    PubMed

    Sun, Xigui; Gao, Kewei; Pang, Xiaolu; Yang, Huisheng

    2016-01-13

    The preferred growth orientation of the sputtered lead selenide (PbSe) thin films on Si(100) substrates was thermodynamically simulated and calculated on the basis of the density functional theory. The results showed that the total free energy variation during the grain growth is dominated by the interface and strain energy minimization under certain conditions, indicating that the preferred growth orientation and related optical properties of the PbSe thin films can be effectively modified by these two energy variations. Thermodynamically, the PbSe[200] and PbSe[220] preferred orientations are obtained when the interface and strain energy minimization dominate the total free energy variation, respectively. A texture map related to the interface and strain energy revolution was obtained, which can be used to predict the structure and optical properties of the sputtered PbSe thin films, and its applicability was confirmed by the real X-ray diffraction and Fourier transform infrared spectroscopy experimental results of four midfrequency sputtered PbSe thin films with designed thickness and microstrain deposited on Si(100) substrates.

  16. Structure and mechanical properties of Ti-Si-N films deposited by combined DC/RF reactive unbalanced magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Ding, X. Z.; Zeng, X. T.; Liu, Y. C.; Yang, Q.; Zhao, L. R.

    2004-11-01

    Ti-Si-N nanocomposite films with Si content between 0 and 13.5 at. % were deposited by combined DC/RF reactive unbalanced magnetron sputtering. The composition, structure, and mechanical properties of the as-deposited Ti-Si-N films were measured by energy dispersive analysis of x rays, x-ray diffraction (XRD), and nanoindentation experiments, respectively. All of the Ti-Si-N films exhibited a higher hardness than pure TiN films deposited under similar conditions. The highest hardness (~41 GPa) was obtained in the film with Si content of about 8 at. %. Ti-Si-N films also exhibited a higher resistance to plastic deformation (i.e., higher ratio H3/E*2) than pure TiN. XRD patterns revealed that the as-deposited films were composed of cubic TiN crystallites with a preferential orientation of (111). With increase of RF power applied to the Si targets, the TiN (111) peak intensity or TiN crystallite size increased in the lower RF power range but decreased in the higher RF power range, showing a maximum at an RF power of 500 W (power density ~1.14 W/cm2), corresponding to a Si content of about 5 at. % in the film.

  17. Reactive sputter deposition of pyrite structure transition metal disulfide thin films: Microstructure, transport, and magnetism

    SciTech Connect

    Baruth, A.; Manno, M.; Narasimhan, D.; Shankar, A.; Zhang, X.; Johnson, M.; Aydil, E. S.; Leighton, C.

    2012-09-01

    Transition metal disulfides crystallizing in the pyrite structure (e.g., TMS{sub 2}, with TM = Fe, Co, Ni, and Cu) are a class of materials that display a remarkably diverse array of functional properties. These properties include highly spin-polarized ferromagnetism (in Co{sub 1-x}Fe{sub x}S{sub 2}), superconductivity (in CuS{sub 2}), an antiferromagnetic Mott insulating ground state (in NiS{sub 2}), and semiconduction with close to optimal parameters for solar absorber applications (in FeS{sub 2}). Exploitation of these properties in heterostructured devices requires the development of reliable and reproducible methods for the deposition of high quality pyrite structure thin films. In this manuscript, we report on the suitability of reactive sputter deposition from metallic targets in an Ar/H{sub 2}S environment as a method to achieve exactly this. Optimization of deposition temperature, Ar/H{sub 2}S pressure ratio, and total working gas pressure, assisted by plasma optical emission spectroscopy, reveals significant windows over which deposition of single-phase, polycrystalline, low roughness pyrite films can be achieved. This is illustrated for the test cases of the ferromagnetic metal CoS{sub 2} and the diamagnetic semiconductor FeS{sub 2}, for which detailed magnetic and transport characterization are provided. The results indicate significant improvements over alternative deposition techniques such as ex situ sulfidation of metal films, opening up exciting possibilities for all-sulfide heterostructured devices. In particular, in the FeS{sub 2} case it is suggested that fine-tuning of the sputtering conditions provides a potential means to manipulate doping levels and conduction mechanisms, critical issues in solar cell applications. Parenthetically, we note that conditions for synthesis of phase-pure monosulfides and thiospinels are also identified.

  18. Effect of dry air on interface smoothening in reactive sputter deposited Co/Ti multilayer

    NASA Astrophysics Data System (ADS)

    Biswas, A.; Porwal, A.; Bhattacharya, Debarati; Prajapat, C. L.; Ghosh, Arnab; Nand, Mangla; Nayak, C.; Rai, S.; Jha, S. N.; Singh, M. R.; Bhattacharyya, D.; Basu, S.; Sahoo, N. K.

    2017-09-01

    Top surface roughness and interface roughness are one of the key elements which determine the performance of X-ray and neutron thin film multilayer devices. It has been observed that by mixing air with argon in sputtering ambience during deposition of Co layers, polarized neutron reflectivity (PNR) of Co/Ti supermirror polarizers can be improved substantially. Cross-sectional HRTEM measurement reveals that sharper interfaces in the supermirror can be achieved in case of deposition of the multilayer under mixed ambience of argon and air. In order to investigate this interface modification mechanism further, in this communication two sets of tri-layer Co/Ti/Co samples and 20-layer Co/Ti periodic multilayer samples have been prepared; in one set all the layers are deposited only under argon ambience and in the other set, Co layers are deposited under a mixed ambience of argon and air. These samples have been characterized by measuring specular and non-specular X-ray reflectivities (GIXR) with X-rays of 1.54 Å wavelength and polarized neutron reflectivity (PNR) with neutron of 2.5 Å wavelength at grazing angle of incidence. It has been observed that the X-ray and neutron specular reflectivities at Bragg peaks of 20 layer periodic multilayer increase when Co layers are deposited under mixed ambience of argon and air. The detail information regarding the effect of air on the interfaces and magnetic properties has been obtained by fitting the measured spectra. The above information has subsequently been supplemented by XRD and magnetic measurements on the samples. XPS and XANES measurements have also been carried out to investigate whether cobalt oxide or cobalt nitride layers are being formed due to use of air in sputtering ambience.

  19. Reactive sputter deposition of pyrite structure transition metal disulfide thin films: Microstructure, transport, and magnetism

    NASA Astrophysics Data System (ADS)

    Baruth, A.; Manno, M.; Narasimhan, D.; Shankar, A.; Zhang, X.; Johnson, M.; Aydil, E. S.; Leighton, C.

    2012-09-01

    Transition metal disulfides crystallizing in the pyrite structure (e.g., TMS2, with TM = Fe, Co, Ni, and Cu) are a class of materials that display a remarkably diverse array of functional properties. These properties include highly spin-polarized ferromagnetism (in Co1-xFexS2), superconductivity (in CuS2), an antiferromagnetic Mott insulating ground state (in NiS2), and semiconduction with close to optimal parameters for solar absorber applications (in FeS2). Exploitation of these properties in heterostructured devices requires the development of reliable and reproducible methods for the deposition of high quality pyrite structure thin films. In this manuscript, we report on the suitability of reactive sputter deposition from metallic targets in an Ar/H2S environment as a method to achieve exactly this. Optimization of deposition temperature, Ar/H2S pressure ratio, and total working gas pressure, assisted by plasma optical emission spectroscopy, reveals significant windows over which deposition of single-phase, polycrystalline, low roughness pyrite films can be achieved. This is illustrated for the test cases of the ferromagnetic metal CoS2 and the diamagnetic semiconductor FeS2, for which detailed magnetic and transport characterization are provided. The results indicate significant improvements over alternative deposition techniques such as ex situ sulfidation of metal films, opening up exciting possibilities for all-sulfide heterostructured devices. In particular, in the FeS2 case it is suggested that fine-tuning of the sputtering conditions provides a potential means to manipulate doping levels and conduction mechanisms, critical issues in solar cell applications. Parenthetically, we note that conditions for synthesis of phase-pure monosulfides and thiospinels are also identified.

  20. Effects of Sputtering Parameters on AlN Film Growth on Flexible Hastelloy Tapes by Two-Step Deposition Technique.

    PubMed

    Peng, Bin; Gong, Dongdong; Zhang, Wanli; Jiang, Jianying; Shu, Lin; Zhang, Yahui

    2016-08-10

    AlN thin films were deposited on flexible Hastelloy tapes and Si (100) substrate by middle-frequency magnetron sputtering. A layer of Y₂O₃ films was used as a buffer layer for the Hastelloy tapes. A two-step deposition technique was used to prepare the AlN films. The effects of deposition parameters such as sputtering power, N₂/Ar flow rate and sputtering pressure on the microstructure of the AlN thin films were systematically investigated. The results show that the dependency of the full width at half maximum (FWHM) of AlN/Y₂O₃/Hastelloy on the sputtering parameters is similar to that of AlN/Si (100). The FWHM of the AlN (002) peak of the prepared AlN films decreases with increasing sputtering power. The FWHM decreases with the increase of the N₂/Ar flow rate or sputtering pressure, and increases with the further increase of the N₂/Ar flow rate or sputtering pressure. The FWHM of the AlN/Y₂O₃/Hastelloy prepared under optimized parameters is only 3.7° and its root mean square (RMS) roughness is 5.46 nm. Based on the experimental results, the growth mechanism of AlN thin films prepared by the two-step deposition process was explored. This work would assist us in understanding the AlN film's growth mechanism of the two-step deposition process, preparing highly c-axis-oriented AlN films on flexible metal tapes and developing flexible surface acoustic wave (SAW) sensors from an application perspective.

  1. Effects of Sputtering Parameters on AlN Film Growth on Flexible Hastelloy Tapes by Two-Step Deposition Technique

    PubMed Central

    Peng, Bin; Gong, Dongdong; Zhang, Wanli; Jiang, Jianying; Shu, Lin; Zhang, Yahui

    2016-01-01

    AlN thin films were deposited on flexible Hastelloy tapes and Si (100) substrate by middle-frequency magnetron sputtering. A layer of Y2O3 films was used as a buffer layer for the Hastelloy tapes. A two-step deposition technique was used to prepare the AlN films. The effects of deposition parameters such as sputtering power, N2/Ar flow rate and sputtering pressure on the microstructure of the AlN thin films were systematically investigated. The results show that the dependency of the full width at half maximum (FWHM) of AlN/Y2O3/Hastelloy on the sputtering parameters is similar to that of AlN/Si (100). The FWHM of the AlN (002) peak of the prepared AlN films decreases with increasing sputtering power. The FWHM decreases with the increase of the N2/Ar flow rate or sputtering pressure, and increases with the further increase of the N2/Ar flow rate or sputtering pressure. The FWHM of the AlN/Y2O3/Hastelloy prepared under optimized parameters is only 3.7° and its root mean square (RMS) roughness is 5.46 nm. Based on the experimental results, the growth mechanism of AlN thin films prepared by the two-step deposition process was explored. This work would assist us in understanding the AlN film’s growth mechanism of the two-step deposition process, preparing highly c-axis–oriented AlN films on flexible metal tapes and developing flexible surface acoustic wave (SAW) sensors from an application perspective. PMID:28773806

  2. Structure, optical properties and thermal stability of HfErO films deposited by simultaneous RF and VHF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Zhang, H. Y.; He, H. J.; Zhang, Z.; Jin, C. G.; Yang, Y.; Wang, Y. Y.; Zhuge, L. J.; Ye, C.; Wu, X. M.

    2015-05-01

    HfErO films are deposited on Si substrates by simultaneous radio frequency (RF) and very high frequency (VHF) magnetron sputtering technique. The content of the doped ingredient of Er and the body composition of HfO x are, respectively, controlled through the VHF and RF powers. Low content of Er doping in the HfErO films can be achieved, because the VHF source of 27.12 MHz has higher ion energy and lower ion flux than the RF source resulting in low sputtering rate in the magnetron sputtering system. The structure, optical properties and thermal stability of the HfErO films are investigated in this work. Results show that the doped content of Er is independently controlled by the VHF power. The oxygen vacancies are created by the Er incorporation. The hafnium in the HfErO films forms mixed valence of Hf2+ and Hf4+. The HfErO films are composed with the structures of HfO2, HfO and ErO x , which can be optimized through the VHF power. At high VHF power, the Hf-Er-O bonds are formed, which demonstrates that the Er atoms are doped into the lattice of HfO2 in the HfErO films. The HfErO films have bad thermal stability as the crystallization temperature decreases from 900 to 800 °C. After thermal annealing, cubic phase of HfO2 are stabilized, which is ascribed to the oxygen vacancies creation by the Er incorporation. The optical properties such as the refractive index and the optical band gap of the HfErO films are optimized by the VHF power.

  3. A global plasma model for reactive deposition of compound films by modulated pulsed power magnetron sputtering discharges

    NASA Astrophysics Data System (ADS)

    Zheng, B. C.; Wu, Z. L.; Wu, B.; Li, Y. G.; Lei, M. K.

    2017-05-01

    A spatially averaged, time-dependent global plasma model has been developed to describe the reactive deposition of a TiAlSiN thin film by modulated pulsed power magnetron sputtering (MPPMS) discharges in Ar/N2 mixture gas, based on the particle balance and the energy balance in the ionization region, and considering the formation and erosion of the compound at the target surface. The modeling results show that, with increasing the N2 partial pressure from 0% to 40% at a constant working pressure of 0.3 Pa, the electron temperature during the strongly ionized period increases from 4 to 7 eV and the effective power transfer coefficient, which represents the power fraction that effectively heats the electrons and maintains the discharge, increases from about 4% to 7%; with increasing the working pressure from 0.1 to 0.7 Pa at a constant N2 partial pressure of 25%, the electron temperature decreases from 10 to 4 eV and the effective power transfer coefficient decreases from 8% to 5%. Using the modeled plasma parameters to evaluate the kinetic energy of arriving ions, the ion-to-neutral flux ratio of deposited species, and the substrate heating, the variations of process parameters that increase these values lead to an enhanced adatom mobility at the target surface and an increased input energy to the substrate, corresponding to the experimental observation of surface roughness reduction, the microstructure transition from the columnar structure to the dense featureless structure, and the enhancement of phase separation. At higher N2 partial pressure or lower working pressure, the modeling results demonstrate an increase in electron temperature, which shifts the discharge balance of Ti species from Ti+ to Ti2+ and results in a higher return fraction of Ti species, corresponding to the higher Al/Ti ratio of deposited films at these conditions. The modeling results are well correlated with the experimental observation of the composition variation and the microstructure

  4. Structural, surface, optical, and mechanical properties of Zn3N2 thin films prepared by sputtering deposition

    NASA Astrophysics Data System (ADS)

    Wen, Ting; Jiang, Nanke; Georgiev, Daniel G.; Jayatissa, Ahalapitiya H.

    2010-04-01

    Zinc nitride and zinc oxide can have wide range applications owing to their band-gap changes and controlling capability of n-type to p-type behavior by impurity doping. Thus, zinc oxy-nitrides can be utilized to design novel photonic devices such as solar cells, UV-Visible devices, and light emitting diodes. In this paper, feasibility of tuning the optical and electronic properties of zinc oxynitride thin films in an rf magnetron sputtering deposition. It was found that the change of gas composition such as Ar: N2: O2 can change the properties of zinc nitride films for a wide range. The absorption coefficient of zinc nitride films were larger than zinc oxide thin films in low photon energy range, in particular visible region of the spectrum. These results indicated that the zinc nitride may find suitable applications in solar cells and photonic devices.

  5. Thickness dependence of the preferred orientation of Mn-Zn ferrite thin films deposited by ion-beam sputtering

    NASA Astrophysics Data System (ADS)

    Cho, Hae Seok; Kim, Hyeong Joon

    1995-07-01

    The thickness dependence of the preferred orientation of the Cu or Ti added Mn-Zn ferrite thin films deposited on SiO2(1000 Å)/Si(100) at 350 °C by ion-beam sputtering was investigated. A mosaic target, consisting of a single-crystal (110) Mn-Zn ferrite with a metal strip on it, was employed as the target. The (hhh) preferred orientation, formed at the initial growth stage, of the Cu added Mn-Zn ferrite film changed to the (h00) preferred orientation with increasing film thickness, while the initially formed (h00) preferred orientation of the Ti added one was enhanced with increasing film thickness. Such different behaviors were discussed in terms of the surface energy and the preferred growth orientation of the ferrite film. The thickness dependence of magnetic properties of the ferrite films was also investigated.

  6. Study of Electrical and Optical Properties of Cu-ASSISTED Amorphous Carbon Thin Films Deposition by DC Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Hassannia, Sara; Elahi, Seyed Mohammad; Boochani, Arash

    2013-09-01

    Cu incorporated amorphous carbon thin films have been prepared by DC-magnetron sputtering using a bi-component Cu-C composite target. The properties of the films have been investigated by X-ray diffraction, energy dispersive X-ray analysis, atomic force microscopy, FTIR, Raman and UV-vis spectroscopies. The results show that the films are amorphous with major distorted sp2 graphite bonds as well as carbon nanotubes. Sputtering simulation shows that the chemical composition of the films is Cu0.066C0.934. Cu addition results in the formation of new type of carbon nanotubes (CNT) with new radial Breathing mode located at 236 cm-1. Cu induces an increase in the density of defects due to bundles of CNT's. Moreover the films are transparent in visible range and highly reflective in mid-infrared region. Electrical characterization shows that the pure carbon deposited films are semiconductor while the copper assisted thin films behave like metal and their sheet resistance is comparable with sheet resistance of conventional conductive electrodes.

  7. Apparent critical behaviour of sputter-deposited magnetoelectric antiferromagnetic Cr2O3 films near Néel temperature

    NASA Astrophysics Data System (ADS)

    Al-Mahdawi, M.; Shiokawa, Y.; Pati, S. P.; Ye, S.; Nozaki, T.; Sahashi, M.

    2017-04-01

    Chromium(III) oxide is a collinear antiferromagnet with a linear magnetoelectric effect. We are presenting the measurements of the magnetoelectric susceptibility α of a sputter-deposited 500 nm film and a bulk single-crystal substrate of Cr2O3. We investigated the magnetic phase-transition and the critical exponent β of the sublattice magnetization near Néel temperature. For the film, an exponent of 0.49(1) was found below 293 K, and changed to 1.06(4) near the Néel temperature of 298 K. For the bulk substrate, the exponent was constant at 0.324(4). We investigated the reversal probability of antiferromagnetic domains during magnetoelectric field cooling. For the sputtered films, reversal probability was zero above 298 K and stabilized only below 293 K. We attribute this behaviour to formation of grains during film growth, which gives different intergrain and intragrain exchange-coupling energies. The reversal probability dependence on the magnitude of cooling magnetic field could be explained by a phenomenological model. For the bulk substrate, reversal probability was stabilized immediately at the Néel temperature of 307.6 K.

  8. Deuterium Retention in the Co-Deposition Carbon Layers Deposited by Radio-Frequency Magnetron Sputtering in D2 Atmosphere

    NASA Astrophysics Data System (ADS)

    Zhang, Wei-Yuan; Shi, Li-Qun; Zhang, Bin; Hu, Jian-Sheng

    2014-05-01

    Carbon is deposited on C and Si substrates by rf magnetron plasma sputtering in a D2 atmosphere. The deposited layers are examined with ion beam analysis and thermal desorption spectroscopy (TDS). The growth rates of the layers deposited on Si decrease with increasing substrate temperature, while increase significantly with the increase of D2 pressure. Meanwhile, the deuterium concentrations in the layers deposited on the Si substrates decrease from 30% to 2% and from 31% to 1% on the C substrates, respectively, when the substrate temperature varies from 350K to 900 K. Similarly, the D concentration in the layer on the Si substrates increases from 3.4% to 47%, and from 8% to 35% on the C substrates when the D2 pressure increases from 0.3Pa to 8.0Pa. D desorption characterized by TDS is mainly in the forms of D2, HD, HDO, CD4, and C2D4, and a similar release peak occurs at 645 K. The release peak of D2 molecules at 960K can be attributed to the escaped gas from the thin co-deposited deuterium-rich carbon layer in the form of C-D bonding.

  9. A New Formula for Energy Spectrum of Sputtered Atoms Due to Low-Energy Light Ions

    NASA Astrophysics Data System (ADS)

    Kenmotsu, Takahiro; Yamamura, Yasunori; Ono, Tadayoshi; Kawamura, Takaichi

    A new formula has been derived to describe the energy spectrum of sputtered atoms from a target material bombarded by light ions. We assume that sputtered atoms bombarded by low-energy light ions are mainly primary knock-on atoms which are created by large-angle backscattered light ions. The escape processes of recoil atoms are estimated on the basis of the Falcone-Sigmund model. The new formula has the dependence on the incident energy of a projectile. We have compared the new formula with simulation results calculated with ACAT code for a Fe target material bombarded by 50eV, 100eV and 500eV D+ ions. Good agreements are found for 50eV and 100eV D+ ions.

  10. Properties of a-C:H:Si thin films deposited by middle-frequency magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Jiang, Jinlong; Wang, Yubao; Du, Jinfang; Yang, Hua; Hao, Junying

    2016-08-01

    The silicon doped hydrogenated amorphous carbon (a-C:H:Si) films were prepared on silicon substrates by middle-frequency magnetron sputtering silicon target in an argon and methane gas mixture atmosphere. The deposition rate, chemical composition, structure, surface properties, stress, hardness and tribological properties in the ambient air of the films were systemically investigated using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscopy (AFM), nanoindentation and tribological tester. The results show that doped silicon content in the films is controlled in the wide range from 39.7 at.% to 0.2 at.% by various methane gas flow rate, and methane flow rate affects not only the silicon content but also its chemical bonding structure in the films due to the transformation of sputtering modes. Meanwhile, the sp3 carbon component in the films linearly increases with increasing of methane flow rate. The film deposited at moderate methane flow rate of 40-60 sccm exhibits the very smooth surface (RMS roughness 0.4 nm), low stress (0.42 GPa), high hardness (21.1 GPa), as well as low friction coefficient (0.038) and wear rate (1.6 × 10-7 mm3/Nm). The superior tribological performance of the films could be attributed to the formation and integral covering of the transfer materials on the sliding surface and their high hardness.

  11. Property investigation and sputter deposition of dispersion-hardened copper for fatigue specimen fabrication

    NASA Technical Reports Server (NTRS)

    Mcclanahan, E. D.; Busch, R.; Moss, R. W.

    1973-01-01

    Sputter-deposited alloys of dispersion-hardenable Cu-0.25 vol% SiC and Cu-0.50 vol% SiC and precipitation-hardenable Cu-0.15 wt% Zr and Cu-0.05 wt% Mg-0.15 wt% Zr-0.40 wt% Cr were investigated for selection to evaluate fatigue specimen performance with potential application in fabricating regeneratively cooled rocket thrust chambers. Yield strengths in the 700 to 1000-MN/sq m range were observed with uniform elongation ranging from 0.5 to 1.5% and necking indicative of greater ductility. Electrical conductivity measured as an analog to thermal conductivity gave values 90% IACS for Cu-0.15 wt% Zr and Cu-0.05 wt% Mg-0.15 wt% Zr-0.40 wt% Cr. A 5500-g sputtered deposit of Cu-0.15 wt% Zr alloy, 12.29 mm (0.484 in.) average thickness in the fatigue specimen gage length, was provided to NASA on one of their substrates.

  12. Comparison of the Fatigue Performance of Commercially Produced Nitinol Samples versus Sputter-Deposited Nitinol

    NASA Astrophysics Data System (ADS)

    Siekmeyer, Gerd; Schüßler, Andreas; de Miranda, Rodrigo Lima; Quandt, Eckhard

    2014-07-01

    Self-expanding vascular implants are typically manufactured from Nitinol tubing, using laser cutting, shape setting, and electropolishing processes. The mechanical and fatigue behavior of those devices are affected by the raw material and its processing such as the melting process and subsequent warm and cold forming processes. Current trends focus on the use of raw material with fewer inclusions to improve the fatigue performance. Further device miniaturization and higher fatigue life requirements will drive the need toward smaller inclusions and new manufacturing methods. As published previously, the high-cycle fatigue region of medical devices from standard processed Nitinol is usually about 0.4-0.5% half-alternating strain. However, these results highly depend on the ingot and semi-finished materials, the applied manufacturing processes, the final dimensions of test samples, and applied test methods. Fabrication by sputter deposition is favorable, because it allows the manufacturing of micro-patterned Nitinol thin-film devices without small burrs, heat-affected zones, microcracks, or any contamination with carbides, as well as the fabrication of complex components e.g., 3D geometries. Today, however, there is limited data available on the fatigue behavior for real stent devices based on such sputter-deposited Nitinol. A detailed study (e.g., using metallographic methods, corrosion, tensile, and fatigue testing) was conducted for the first time in order to characterize the micro-patterned Nitinol thin-film material.

  13. Thermal crystallization of sputter-deposited amorphous Ge films: Competition of diamond cubic and hexagonal phases

    NASA Astrophysics Data System (ADS)

    Okugawa, M.; Nakamura, R.; Ishimaru, M.; Yasuda, H.; Numakura, H.

    2016-12-01

    Following our previous studies on crystallization induced by electron irradiation, we have investigated the crystallization of sputter-deposited amorphous germanium films by heat treatments. On continuous heating, samples aged for 3 days and 4 months at room temperature crystallized at 500°C to form coarse spherical particles of a hexagonal structure, of about 100 nm in diameter, whereas samples aged for 7 months turned to homogeneous nanograins of the diamond cubic structure at 600°C. When the films aged for 4 months at room temperature were annealed at 350°C for 2 h and then heated, they crystallized at 550°C to form a mixture of the two microstructures, and those annealed at 350°C and further at 500°C for 1 h crystallized at 600°C mostly to nanograins. Crystallization by electron irradiation at 350°C to 4-month-aged samples has also been studied. With increasing annealing time at 350°C, coarse particles of a hexagonal structure ceased to appear, and were replaced by fine nanograins of the diamond cubic structure. These observations can be understood in terms of structural instability of sputter-deposited amorphous films. Medium-range ordered clusters must initially be present in the films and serve as nuclei of the metastable hexagonal phase. They are unstable, however, and are eliminated by annealing, resulting in the reduction in size and number of coarse particles with a metastable structure.

  14. Reactive Radiofrequency Sputtering-Deposited Nanocrystalline ZnO Thin-Film Transistors

    NASA Astrophysics Data System (ADS)

    Li, Shao-Juan; He, Xin; Han, De-Dong; Sun, Lei; Wang, Yi; Han, Ru-Qi; Chan, Man-Sun; Zhang, Sheng-Dong

    2012-01-01

    The structural and electrical properties of ZnO films deposited by reactive radiofrequency sputtering with a metallic zinc target are systematically investigated. While the as-deposited ZnO film is in a poly-crystalline structure when the partial pressure of oxygen (pO2) is low, the grain size abruptly decreases to a few nanometers as pO2 increases to a critical value, and then becomes almost unchanged with a further increase in pO2. In addition, the resistivity of the ZnO films shows a non-monotonic dependence on pO2, including an abrupt transition of about seven orders of magnitude at the critical pO2. Thin-film transistors (TFTs) with the nanocrystalline ZnO films as channel layers have an on/off current ratio of more than 107, an off-current in the order of pA, a threshold voltage of about 4.5 V, and a carrier mobility of about 2cm2/(V·s). The results show that radiofrequency sputtered ZnO with a zinc target is a promising candidate for high-performance ZnO TFTs.

  15. X-ray absorption spectroscopic studies of sputter-deposited LaNiO3 thin films on Si substrate

    NASA Astrophysics Data System (ADS)

    Lee, Hsin-Yi; Wu, Tai-Bor; Lee, Jyh-Fu

    1996-08-01

    X-ray absorption spectroscopy (XAS) was applied to investigate the growth behavior of LaNiO3 thin films on Si substrate deposited via radio frequency magnetron sputtering at high temperature. The thickness of deposited film was always proportional to the sputtering time. However, the Ni-to-La ratio in the film was found to decrease with increasing substrate temperature. It is due to a loss of Ni on high-temperature deposition which lowers the film growth rate and leads to a gradual structural change. Nevertheless, the oxidation states of both Ni atom and La atom in the thin films were not influenced by the substrate temperature or sputtering time. All the XAS evidence was consistent with the results from x-ray reflectivity, x-ray diffraction, and chemical analysis.

  16. Stress and magnetoelastic properties control of amorphous Fe{sub 80}B{sub 20} thin films during sputtering deposition

    SciTech Connect

    Fernandez-Martinez, I.; Costa-Kraemer, J. L.; Briones, F.

    2008-06-01

    In situ stress measurements during sputtering deposition of amorphous Fe{sub 80}B{sub 20} films are used to control their stress and magnetoelastic properties. The substrate curvature induced by the deposited film is measured optically during growth and quantitatively related to the deposition induced accumulated stress. The resulting magnetic properties are later correlated with the measured stress for a wide range of sputtering pressures [(2-25)x10{sup -3} mbar]. A significant tensile stress develops at the film-substrate interface during the early growth stages (initial 2-3 nm). At a critical thickness, a transition is observed from tensile to compressive stress, which is associated with amorphous island coalescence. By further increasing the thickness, a compressive stress follows, which is related to the local distortion induced by the ion peening effect. The Monte Carlo simulations of the sputtering process describe quantitatively the experimental results as a function of the Ar pressure and target bias voltage.

  17. Time dependence of carbon film deposition on SnO{sub 2}/Si using DC unbalanced magnetron sputtering

    SciTech Connect

    Alfiadi, H. Aji, A. S. Darma, Y.

    2014-02-24

    Carbon deposition on SnO{sub 2} layer has been demonstrated at low temperature using DC unbalanced magnetron-sputtering technique for various time depositions. Before carbon sputtering process, SnO{sub 2} thin layer is grown on silicon substrate by thermal evaporation method using high purity Sn wire and then fully oxidizes by dry O{sub 2} at 225°C. Carbon sputtering process was carried out at pressure of 4.6×10{sup −2} Torr by keeping the substrate temperature of 300 °C for sputtering deposition time of 1 to 4 hours. The properties of SnO{sub 2}/Si structure and carbon thin film on SnO{sub 2} is characterized using SEM, EDAX, XRD, FTIR, and Raman Spectra. SEM images and XRD spectra show that SnO2 thin film has uniformly growth on Si substrate and affected by annealing temperature. Raman and FTIR results confirm the formation of carbon-rich thin film on SnO{sub 2}. In addition, XRD spectra indicate that some structural change occur by increasing sputtering deposition time. Furthermore, the change of atomic structure due to the thermal annealing is analized by XRD spectra and Raman spectroscopy.

  18. Surface Texture and Structure of ZnO Films Synthesized by Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, Sandor L.; George, M. A.; Lowndes, D. H.

    1999-01-01

    Morphology and structure of ZnO films deposited on (0001) sapphire and glass substrates by off-axis sputtering are investigated at various temperatures and pressures. All films show highly textured structures on glass substrates and epitaxial growth on sapphire substrates. The full width at half maximum of theta rocking curves for epitaxial films is less than 0.5 degrees. In textured films, it rises to several degrees. The trend of surface textures in films grown at low pressures is similar to those grown at high temperatures. A morphology transition from large well-defined hexagonal grains to flat surface was observed at a pressure of 50 mtorr and temperature of 550 C. The experiment results are explained by the transport behavior of depositing species.

  19. Characterization of sputtered zirconium nitride films deposited at various argon:nitrogen ratio

    NASA Astrophysics Data System (ADS)

    Patel, Nicky P.; Chauhan, Kamlesh V.; Kapopara, Jaydeep M.; Jariwala, Nayan N.; Rawal, Sushant K.

    2016-09-01

    Zirconium nitride films were deposited by reactive magnetron sputtering using argon as inert gas and nitrogen as reactive gas. The nitrogen flow rate in argon:nitrogen ratio was increased from 4sccm to 20sccm by an increment of 4sccm. The effect of increment in nitrogen flow rate on various properties of deposited zirconium nitride films are reported in this paper. The structural characterization was done by X-Ray diffraction which confirms (011) peak of Zr3N4 and a very low intensity (111) peak of Zr3N4. Optical properties was investigated by Uv-Vis-NIR spectrophotometer which showed that the films were transparent and maximum transmittance observed was around 82%. The wettability properties was investigated by contact angle goniometer which showed the films were hydrophobic and maximum contact angle achieved was 99.50.

  20. Adherence of ion beam sputter deposited metal films on H-13 steel

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.

    1980-01-01

    An electron bombardment argon ion source sputter deposited 17 metals and metal oxides on H-13 steel. The films ranged 1 to 8 micrometers in thickness and their adherence was generally greater than the capacity of the measuring device; adherence quality depended on proper precleaning of the substrate before deposition. N2 or air was introduced for correct stoichiometry in metallic compounds. Au, Ag, MgO, and Ta5Si3 films 8 microns thick have bond strength equal to 1 micron coatings; the bond strength of pure metallic films up to 5 microns thick was greater than the epoxy to film bond (8000 psi). The results of exposures of coated material to temperatures up to 700 C are presented.

  1. Fluoride antireflection coatings for deep ultraviolet optics deposited by ion-beam sputtering.

    PubMed

    Yoshida, Toshiya; Nishimoto, Keiji; Sekine, Keiichi; Etoh, Kazuyuki

    2006-03-01

    Optically high quality coatings of fluoride materials are required in deep ultraviolet (DUV) lithography. We have applied ion-beam sputtering (IBS) to obtain fluoride films with smooth surfaces. The extinction coefficients were of the order of 10(-4) at the wavelength of 193 nm due to the reduction of their absorption loss. The transmittance of the MgF2/GdF3 antireflection coating was as high as 99.7% at the wavelength of 193 nm. The surfaces of the IBS deposited films were so smooth that the surface roughness of the A1F3/GdF3 film was comparable with that of the CaF2 substrate. The MgF2/GdF3 coating fulfilled the temperature and humidity requirements of military specification. Thus, the IBS deposited fluoride films are promising candidate for use in the DUV lithography optics.

  2. Surface properties and biocompatibility of nanostructured TiO2 film deposited by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Majeed, Asif; He, Jie; Jiao, Lingrui; Zhong, Xiaoxia; Sheng, Zhengming

    2015-02-01

    Nanostructured TiO2 films are deposited on a silicon substrate using 150-W power from the RF magnetron sputtering at working pressures of 3 to 5 Pa, with no substrate bias, and at 3 Pa with a substrate bias of -50 V. X-ray diffraction (XRD) analysis reveals that TiO2 films deposited on unbiased as well as biased substrates are all amorphous. Surface properties such as surface roughness and wettability of TiO2 films, grown in a plasma environment, under biased and unbiased substrate conditions are reported according to the said parameters of RF power and the working pressures. Primary rat osteoblasts (MC3T3-E1) cells have been cultured on nanostructured TiO2 films fabricated at different conditions of substrate bias and working pressures. The effects of roughness and hydrophilicity of nanostructured TiO2 films on cell density and cell spreading have been discussed.

  3. High-frequency magnetic properties of Zn ferrite films deposited by magnetron sputtering

    SciTech Connect

    Guo Dangwei; Zhu Jingyi; Yang Yuancai; Fan Xiaolong; Chai Guozhi; Sui Wenbo; Zhang Zhengmei; Xue Desheng

    2010-02-15

    The effect of thermal annealing on structural and magnetic properties has been investigated for Zn ferrite films deposited on Si (111) substrates using radio frequency magnetron sputtering. The saturation magnetization at room temperature was enhanced upto 303 emu/cm{sup 3} by annealing at relatively low temperature of 200 deg. C and decreased at higher temperatures. The complex permeability {mu}={mu}{sup '}-i{mu}{sup ''} values of the ferrite films as-deposited and annealed at 200 and 400 deg. C were measured at frequency upto 5 GHz. These films exhibited better high-frequency properties, especially, the film annealed at 200 deg. C had a large {mu}{sup '} of 19.5 and high resonance frequency f{sub r} of 1.61 GHz. And the reason was investigated preliminarily based on the bianisotropy model.

  4. Surface Texture and Structure of ZnO Films Synthesized by Off-Axis Sputtering Deposition

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, Sandor L.; George, M. A.; Lowndes, D. H.

    1999-01-01

    Morphology and structure of ZnO films deposited on (0001) sapphire and glass substrates by off-axis sputtering are investigated at various temperatures and pressures. All films show highly textured structures on glass substrates and epitaxial growth on sapphire substrates. The full width at half maximum of theta rocking curves for epitaxial films is less than 0.5 degrees. In textured films, it rises to several degrees. The trend of surface textures in films grown at low pressures is similar to those grown at high temperatures. A morphology transition from large well-defined hexagonal grains to flat surface was observed at a pressure of 50 mtorr and temperature of 550 C. The experiment results are explained by the transport behavior of depositing species.

  5. Deposition of vanadium oxide films by direct-current magnetron reactive sputtering

    NASA Technical Reports Server (NTRS)

    Kusano, E.; Theil, J. A.; Thornton, John A.

    1988-01-01

    It is demonstrated here that thin films of vanadium oxide can be deposited at modest substrate temperatures by dc reactive sputtering from a vanadium target in an O2-Ar working gas using a planar magnetron source. Resistivity ratios of about 5000 are found between a semiconductor phase with a resistivity of about 5 Ohm cm and a metallic phase with a resistivity of about 0.001 Ohm cm for films deposited onto borosilicate glass substrates at about 400 C. X-ray diffraction shows the films to be single-phase VO2 with a monoclinic structure. The VO2 films are obtained for a narrow range of O2 injection rates which correspond to conditions where cathode poisoning is just starting to occur.

  6. Surface properties and biocompatibility of nanostructured TiO2 film deposited by RF magnetron sputtering.

    PubMed

    Majeed, Asif; He, Jie; Jiao, Lingrui; Zhong, Xiaoxia; Sheng, Zhengming

    2015-01-01

    Nanostructured TiO2 films are deposited on a silicon substrate using 150-W power from the RF magnetron sputtering at working pressures of 3 to 5 Pa, with no substrate bias, and at 3 Pa with a substrate bias of -50 V. X-ray diffraction (XRD) analysis reveals that TiO2 films deposited on unbiased as well as biased substrates are all amorphous. Surface properties such as surface roughness and wettability of TiO2 films, grown in a plasma environment, under biased and unbiased substrate conditions are reported according to the said parameters of RF power and the working pressures. Primary rat osteoblasts (MC3T3-E1) cells have been cultured on nanostructured TiO2 films fabricated at different conditions of substrate bias and working pressures. The effects of roughness and hydrophilicity of nanostructured TiO2 films on cell density and cell spreading have been discussed.

  7. Deposition and characterization of molybdenum thin films using dc-plasma magnetron sputtering

    SciTech Connect

    Khan, Majid; Islam, Mohammad

    2013-12-15

    Molebdenum (Mo) thin films were deposited on well-cleaned soda-lime glass substrates using DC-plasma magnetron sputtering. In the design of experiment deposition was optimized for maximum beneficial characteristics by monitoring effect of process variables such as deposition power (100–200 W). Their electrical, structural and morphological properties were analyzed to study the effect of these variables. The electrical resistivity of Mo thin films could be reduced by increasing deposition power. Within the range of analyzed deposition power, Mo thin films showed a mono crystalline nature and the crystallites were found to have an orientation along [110] direction. The surface morphology of thin films showed that a highly dense micro structure has been obtained. The surface roughness of films increased with deposition power. The adhesion of Mo thin films could be improved by increasing the deposition power. Atomic force microscopy was used for the topographical study of the films and to determine the roughness of the films. X-ray diffractrometer and scanning electron microscopy analysis were used to investigate the crystallinity and surface morphology of the films. Hall effect measurement system was used to find resistivity, carrier mobility and carrier density of deposited films. The adhesion test was performed using scotch hatch tape adhesion test. Mo thin films prepared at deposition power of 200 W, substrate temperature of 23°C and Ar pressure of 0.0123 mbar exhibited a mono crystalline structure with an orientation along (110) direction, thickness of ∼550 nm and electrical resistivity value of 0.57 × 10{sup −4} Ω cm.

  8. Non-conventional photocathodes based on Cu thin films deposited on Y substrate by sputtering

    NASA Astrophysics Data System (ADS)

    Perrone, A.; D'Elia, M.; Gontad, F.; Di Giulio, M.; Maruccio, G.; Cola, A.; Stankova, N. E.; Kovacheva, D. G.; Broitman, E.

    2014-07-01

    Copper (Cu) thin films were deposited on yttrium (Y) substrate by sputtering. During the deposition, a small central area of the Y substrate was shielded to avoid the film deposition and was successively used to study its photoemissive properties. This configuration has two advantages: the cathode presents (i) the quantum efficiency and the work function of Y and (ii) high electrical compatibility when inserted into the conventional radio-frequency gun built with Cu bulk. The photocathode was investigated by scanning electron microscopy to determine surface morphology. X-ray diffraction and atomic force microscopy studies were performed to compare the structure and surface properties of the deposited film. The measured electrical resistivity value of the Cu film was similar to that of high purity Cu bulk. Film to substrate adhesion was also evaluated using the Daimler-Benz Rockwell-C adhesion test method. Finally, the photoelectron performance in terms of quantum efficiency was obtained in a high vacuum photodiode cell before and after laser cleaning procedures. A comparison with the results obtained with a twin sample prepared by pulsed laser deposition is presented and discussed.

  9. R.F. Sputtering Deposition of Buffer Layers for Si/YBCO Integrated Microelectronics

    NASA Astrophysics Data System (ADS)

    Rombolà, G.; Ballarini, V.; Chiodoni, A.; Gozzelino, L.; Mezzetti, E.; Minetti, B.; Pirri, C. F.; Tresso, E.; Camerlingo, C.

    The aim of the present work is the optimization of the Si/buffer-layer/YBCO multilayer deposition process so as to grow superconducting films of quality suitable for device applications. The structural properties of the Si/CeO2 system, obtained by RF magnetron sputtering of CeO2 targets in Ar atmosphere, have been studied. More than 50 films have been deposited and some of them submitted to post-deposition annealing treatments both in N2 and O2 atmospheres. The presence of an unwanted amorphous SiO2 layer at the Si/CeO2 interface compromises the YBCO c-axis orientation, and therefore the sharpness of the R versus T transition. A newly designed deposition system has been realized: it has been specially conceived for obtaining bi- and tri-layers, adopting two targets in YSZ and CeO2, respectively. Results on YSZ/Si and CeO2/YSZ/Si systems obtained with the new machine are presented and discussed: (100) oriented YSZ films with nominal thickness of 40 nm have been obtained. The CeO2 film subsequently deposited has the desired (100) orientation. The YBCO film, in the final YBCO/YSZ/CeO2/Si configuration, is c-axis oriented.

  10. Thermochromism of metal-doped VO{sub 2} films deposited by dual-target sputtering

    SciTech Connect

    Jin, P.; Tazawa, M.; Yoshimura, K.; Miki, T.; Igarashi, K.; Tanemura, S.

    1994-12-31

    There are several kinds of chromogenic materials such as photochromic material, electrochromic material and thermochromic material, of which the thermochromic one is known for its optical properties (transmittance and reflectance) being able to change reversibly upon temperature. Among the chromogenic materials feasible to smart window coatings, thermochromic (TC) one has recently received increasing attention, since a window with TC coating enables automatic control of the energy throughputs of the solar radiation as well as the environmental radiation in response to the ambient temperature. Here, thermochromic VO{sub 2} films were prepared by reactive magnetron sputtering under various conditions of substrate temperature, total sputter pressure and oxygen flow ratio and characterized by XRD, RBS, AFM and spectrophotometry. Films with VO{sub 2} single phase were formed from a fairly low substrate temperature of 300 C by precisely controlling the oxygen flow ratio. The use of vanadium nucleated substrates significantly improved the crystallinity of VO{sub 2}. Tungsten doped V{sub 1{minus}x}W{sub x}O{sub 2} films with x = 0--0.26 were formed by dual-target sputtering and the thermochromism of films was evaluated. The tungsten doping linearly decreased {tau}{sub c} by 24 C/at.%W with a reduction in the hysteresis loop width.

  11. Spatial and temporal evolution of ion energies in high power impulse magnetron sputtering plasma discharge

    NASA Astrophysics Data System (ADS)

    Hecimovic, A.; Ehiasarian, A. P.

    2010-09-01

    High power impulse magnetron sputtering (HIPIMS) is a novel deposition technology successfully implemented on full scale industrial machines. HIPIMS utilizes short pulses of high power delivered to the target in order to generate high amount of metal ions. The life-span of ions between the pulses and their energy distribution could strongly influence the properties and characteristics of the deposited coating. In modern industrial coating machines the sample rotates on a substrate holder and changes its position and distance with regard to the magnetron. Time resolved measurements of the ion energy distribution function (IEDF) at different distances from the magnetron have been performed to investigate the temporal evolution of ions at various distances from target. The measurements were performed using two pressures, 1 and 3 Pa to investigate the influence of working gas pressure on IEDF. Plasma sampling energy-resolved mass spectroscopy was used to measure the IEDF of Ti1+, Ti2+, Ar1+, and Ar2+ ions in HIPIMS plasma discharge with titanium (Ti) target in Ar atmosphere. The measurements were done over a full pulse period and the distance between the magnetron and the orifice of the mass spectrometer was changed from 25 to 215 mm.

  12. Electrical and mechanical characterization of chemical vapor deposition of tungsten on sputter-deposited TiN layers

    NASA Astrophysics Data System (ADS)

    Zhang, S.-L.; Palmans, R.; Petersson, C. S.; Maex, K.

    1995-12-01

    Tungsten (W) films are deposited from tungsten hexafluoride on sputter-deposited TiN adhesion layers in a cold-wall chemical vapor deposition reactor. The film resistivity of the W films is found to be thickness dependent. It decreases monotonically with increasing film thickness. Typical resistivity values of 40-nm-thick W films are about 19.3-23.4 μΩ cm, depending on the structure of the underlying TiN layer used. The resistivity of a 980-nm-thick W film is 9.8 μΩ cm. Oxygen and fluorine impurities, as well as structural difference in the W films are found to be the major causes for the resistivity variations. Lowering impurity level and/or increasing W crystallite size can decrease film resistivity. The stress of all the W films is found to be tensile, independent of the structure of the TiN layers. However, the absolute value of the stress is intimately associated with the structure of the TiN layers. The stress values can differ by a factor of more than 2 for the 40-nm-thick W films deposited on the different underlying TiN layers. The amplitude of stress also monotonically decreases with increasing film thickness. Consequently, the difference in stress induced by the difference in the underlying TiN layers gradually disappears as the film thickness increases. A strong correlation between the stress and the film texture is found.

  13. Effects of crystallographic plane and co-deposited element on the growth of ion-sputter induced Si nano-cone arrays: a mechanism study

    NASA Astrophysics Data System (ADS)

    Song, Sheng-Chi; Qiu, Ying; Hao, Hong-Chen; Lu, Ming

    2015-06-01

    Self-organized Si nano-cone arrays induced by Ar+ ion sputtering on different Si crystallographic planes with different co-deposited alien atoms are investigated. The Si planes are (100), (110), and (111) ones, and the alien elements are Ta, Mo, Fe, and C, respectively. It is found that the growth of Si nano-cone arrays is insensitive to the initial crystallographic plane, but depends strongly on the co-deposited element. For the same Ar+ ion dose and sample temperature, the smaller the activation energy between the co-deposited element and Si is, the larger the average cone height and base diameter are. It is found that the preferential sputtering does not play an important role in the nano-cone formation. A model based on the concepts of classical surface-curvature-dependent sputtering yield and the formation of stationary silicide is proposed, which explains the observed results. The results of microstructural and compositional analysis support the proposed model.

  14. Conductive ZnO:Zn Composites for High-Rate Sputtering Deposition of ZnO Thin Films

    NASA Astrophysics Data System (ADS)

    Zhou, Li Qin; Dubey, Mukul; Simões, Raul; Fan, Qi Hua; Neto, Victor

    2015-02-01

    We report an electrically conductive composite prepared by sintering ZnO and metallic Zn powders. Microstructure analysis combined with electrical conductivity studies indicated that when the proportion of metallic Zn reached a threshold (˜20 wt.%), a metal matrix was formed in accordance with percolation theory. This composite has potential as a sputtering target for deposition of high-quality ZnO. Use of the ZnO:Zn composite completely eliminates target poisoning effects in reactive sputtering of the metal, and enables deposition of thin ZnO films at rates much higher than those obtained by sputtering of pure ZnO ceramic targets. The optical transmittance of the ZnO films prepared by use of this composite is comparable with that of films produced by radio frequency sputtering of pure ZnO ceramic targets. The sputtering characteristics of the conductive ZnO:Zn composite target are reported, and possible mechanisms of the high rate of deposition are also discussed.

  15. High rate reactive magnetron sputter deposition of Al-doped ZnO with unipolar pulsing and impedance control system

    SciTech Connect

    Nishi, Yasutaka; Hirohata, Kento; Tsukamoto, Naoki; Sato, Yasushi; Oka, Nobuto; Shigesato, Yuzo

    2010-07-15

    Al-doped ZnO (AZO) films were deposited on quartz glass substrates, unheated and heated to 200 deg. C, using reactive sputtering with a special feedback system of discharge impedance combined with midfrequency pulsing. A planar Zn-Al alloy target was connected to the switching unit, which was operated in a unipolar pulse mode. The oxidation of the target surface was precisely controlled by a feedback system for the entire O{sub 2} flow ratio including ''the transition region''. The deposition rate was about 10-20 times higher than that for films deposited by conventional sputtering using an oxide target. A deposition rate of AZO films of 390 nm/min with a resistivity of 3.8x10{sup -4} {Omega} cm and a transmittance in the visible region of 85% was obtained when the films were deposited on glass substrates heated to 200 deg. C with a discharge power of 4 kW.

  16. Real-Time Monitoring of Morphology and Optical Properties during Sputter Deposition for Tailoring Metal-Polymer Interfaces.

    PubMed

    Schwartzkopf, Matthias; Santoro, Gonzalo; Brett, Calvin J; Rothkirch, André; Polonskyi, Oleksandr; Hinz, Alexander; Metwalli, Ezzeldin; Yao, Yuan; Strunskus, Thomas; Faupel, Franz; Müller-Buschbaum, Peter; Roth, Stephan V

    2015-06-24

    The reproducible low-cost fabrication of functional metal-polymer nanocomposites with tailored optoelectronic properties for advanced applications remains a major challenge in applied nanotechnology. To obtain full control over the nanostructural evolution at the metal-polymer interface and its impact on optoelectronic properties, we employed combined in situ time-resolved microfocus grazing incidence small angle X-ray scattering (μGISAXS) with in situ UV/vis specular reflectance spectroscopy (SRS) during sputter deposition of gold on thin polystyrene films. On the basis of the temporal evolution of the key scattering features in the real-time μGISAXS experiment, we directly observed four different growth regimes: nucleation, isolated island growth, growth of larger aggregates via partial coalescence, and continuous layer growth. Moreover, their individual thresholds were identified with subnanometer resolution and correlated to the changes in optical properties. During sputter deposition, a change in optical reflectivity of the pristine gray-blue PS film was observed ranging from dark blue color due to the presence of isolated nanoclusters at the interface to bright red color from larger Au aggregates. We used simplified geometrical assumptions to model the evolution of average real space parameters (distance, size, density, contact angle) in excellent agreement with the qualitative observation of key scattering features. A decrease of contact angles was observed during the island-to-percolation transition and confirmed by simulations. Furthermore, a surface diffusion coefficient according to the kinetic freezing model and interfacial energy of Au on PS at room temperature were calculated based on a real-time experiment. The morphological characterization is complemented by X-ray reflectivity, optical, and electron microscopy. Our study permits a better understanding of the growth kinetics of gold clusters and their self-organization into complex nanostructures

  17. Fluoropolymer Films Deposited by Argon Ion-Beam Sputtering of Polytetrafluoroethylene

    NASA Technical Reports Server (NTRS)

    Golub, Morton A.; Banks, Bruce A.; Kliss, Mark (Technical Monitor)

    1998-01-01

    The FT-IR, XPS and UV spectra of fluoropolymer films (SPTFE-I) deposited by argon ion-beam sputtering of polytetrafluoroethylene (PTFE) were obtained and compared with prior corresponding spectra of fluoropolymer films (SPTFE-P) deposited by argon rf plasma sputtering of PTFE. Although the F/C ratios for SPTFE-I and -P (1.63 and 1.51) were similar, their structures were quite different in that there was a much higher concentration of CF2 groups in SPTFE-I than in SPTFE-P, ca. 61 and 33% of the total carbon contents, respectively. The FT-IR spectra reflect that difference, that for SPTFE-I showing a distinct doublet at 1210 and 1150 per centimeter while that for SPTFE-P presents a broad, featureless band at ca. 1250 per centimeter. The absorbance of the 1210-per centimeter band in SPTFE-I was proportional to the thickness of the film, in the range of 50-400 nanometers. The SPTFE-I was more transparent in the UV than SPTFE-P at comparable thickness. The mechanism for SPTFE-I formation likely involves "chopping off" of oligomeric segments of PTFE as an accompaniment to "plasma" polymerization of TFE monomer or other fluorocarbon fragments generated in situ from PTFE on impact with energetic Ar ions. Data are presented for SPTFE-I deposits and the associated Ar(+) bombarded PTFE targets where a fresh target was used for each run or a single target was used for a sequence of runs.

  18. Structure and properties of uranium oxide thin films deposited by pulsed dc magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Lin, Jianliang; Dahan, Isaac; Valderrama, Billy; Manuel, Michele V.

    2014-05-01

    Crystalline uranium oxide thin films were deposited in an unbalanced magnetron sputtering system by sputtering from a depleted uranium target in an Ar + O2 mixture using middle frequency pulsed dc magnetron sputtering. The substrate temperature was constantly maintained at 500 °C. Different uranium oxide phases (including UO2-x, UO2, U3O7 and U3O8) were obtained by controlling the percentage of the O2 flow rate to the total gas flow rate (f) in the chamber. The crystal structure of the films was characterized using X-ray diffraction and the microstructure of the films was studied using transmission electron microscopy and atom probe tomography. When the f was below 10%, the film contains a mixture of metallic uranium and UO2-x phases. As the f was controlled in the range of 10-13%, UO2 films with a (2 2 0) preferential orientation were obtained. The oxide phase rapidly changed to a mixture of U3O7 and U3O8 as the f was increased to the range of 15-18%. Further increasing the f to 20% and above, polycrystalline U3O8 thin films with a (0 0 1) preferential orientation were formed. The hardness and Young's modulus of the uranium oxide films were evaluated using nanoindentation. The film containing a single UO2 phase exhibited the maximum hardness of 14.3 GPa and a Young's modulus of 195 GPa. The UO2 thin film also exhibited good thermal stability in that no phase change was observed after annealing at 600 °C in vacuum for 104 h.

  19. Magnetic field strength influence on the reactive magnetron sputter deposition of Ta2O5

    NASA Astrophysics Data System (ADS)

    Hollerweger, R.; Holec, D.; Paulitsch, J.; Rachbauer, R.; Polcik, P.; Mayrhofer, P. H.

    2013-08-01

    Reactive magnetron sputtering enables the deposition of various thin films to be used for protective as well as optical and electronic applications. However, progressing target erosion during sputtering results in increased magnetic field strengths at the target surface. Consequently, the glow discharge, the target poisoning, and hence the morphology, crystal structure and stoichiometry of the prepared thin films are influenced. Therefore, these effects were investigated by varying the cathode current Im between 0.50 and 1.00 A, the magnetic field strength B between 45 and 90 mT, and the O2/(Ar + O2) flow rate ratio Γ between 0% and 100%. With increasing oxygen flow ratio a substoichiometric TaOx oxide forms at the metallic Ta target surface which further transfers to a non-conductive tantalum pentoxide Ta2O5, impeding a stable dc glow discharge. These two transition zones (from Ta to TaOx and from TaOx to Ta2O5) shift to higher oxygen flow rates for increasing target currents. In contrast, increasing the magnetic field strength (e.g., due to sputter erosion) mainly shifts the TaOx to Ta2O5 transition to lower oxygen flow rates while marginally influencing the Ta to TaOx transition. To allow for a stable dc glow discharge (and to suppress the formation of non-conductive Ta2O5 at the target) even at Γ = 100% either a high target current (Im ⩾ 1 A) or a low magnetic field strength (B ⩽ 60 mT) is necessary. These conditions are required to prepare stoichiometric and fully crystalline Ta2O5 films.

  20. Electrical and optical properties of Ta-Si-N thin films deposited by reactive magnetron sputtering

    SciTech Connect

    Oezer, D.; Sanjines, R.; Ramirez, G.; Rodil, S. E.

    2012-12-01

    The electrical and optical properties of Ta{sub x}Si{sub y}N{sub z} thin films deposited by reactive magnetron sputtering from individual Ta and Si targets were studied in order to investigate the effects of nitrogen and silicon contents on both properties and their correlation to the film microstructure. Three sets of fcc-Ta{sub x}Si{sub y}N{sub z} thin films were prepared: sub-stoichiometric Ta{sub x}Si{sub y}N{sub 0.44}, nearly stoichiometric Ta{sub x}Si{sub y}N{sub 0.5}, and over-stoichiometric Ta{sub x}Si{sub y}N{sub 0.56}. The optical properties were investigated by near-normal-incidence reflectivity and ellipsometric measurements in the optical energy range from 0.375 eV to 6.8 eV, while the d.c. electrical resistivity was measured in the van der Pauw configuration from 20 K to 300 K. The optical and electrical measurements were interpreted using the standard Drude-Lorentz model and the so-called grain boundary scattering model, respectively. The electronic properties were closely correlated with the compositional and structural modifications of the Ta{sub x}Si{sub y}N{sub z} films due to variations in the stoichiometry of the fcc-TaN{sub z} system and the addition of Si atoms. According to the nitrogen and silicon contents, fcc-Ta{sub x}Si{sub y}N{sub z} films can exhibit room temperature resistivity values ranging from 10{sup 2} {mu}{Omega} cm to about 6 Multiplication-Sign 10{sup 4} {mu}{Omega} cm. The interpretation of the experimental temperature-dependent resistivity data within the Grain Boundary Scattering model, combined with the results from optical investigations, showed that the mean electron transmission probability G and the free carriers concentration, N, are the main parameters that control the transport properties of these films. The results indicated that the correlation between electrical and optical measurements with the chemical composition and the nanostructure of the Ta{sub x}Si{sub y}N{sub z} thin films provides a pertinent and

  1. Stress anisotropy and stress gradient in magnetron sputtered films with different deposition geometries

    SciTech Connect

    Zhao, Z.B.; Yalisove, S.M.; Bilello, J.C.

    2006-03-15

    Mo films were deposited via magnetron sputtering with two different deposition geometries: dynamic deposition (moving substrate) and static deposition (fixed substrate). The residual stress and structural morphologies of these films were investigated, with particular focus on in-plane anisotropy of the biaxial stress and stress gradient across the film thickness. The results revealed that the Mo films developed distinct states of residual stress, which depended on both deposition geometry and film thickness. With the dynamic geometry, the Mo films generally exhibited anisotropic stress. Both the degree of anisotropy and the magnitude of stress varied as functions of film thickness. The variation of stress was linked to the evolution of anisotropic microstructures in the films. The Mo films from the static geometry developed isotropic residual stress, which was more compressive and noticeably larger in magnitude than that of the Mo films from the dynamic geometry. Aside from these disparities, the two types of Mo films (i.e., anisotropic and isotropic) exhibited notably similar trends of stress variation with film thickness. Depth profiling indicated the presence of large stress gradients for the Mo films, irrespective of the deposition geometries. This observation seems to be consistent with the premise that Mo films develop a zone T structure, which is inherently inhomogeneous along the film thickness. Moreover, the largest stress gradient for both types of deposition geometries arises at roughly the same film depth ({approx}240 nm from substrate), where the stresses sharply transits from highly compressive to less compressive or even tensile. This appears to correspond to the boundary region that separates two distinct stages of microstructural evolution, a feature unique to zone T-type structure.

  2. Growth, structure and stability of sputter-deposited MoS2 thin films.

    PubMed

    Kaindl, Reinhard; Bayer, Bernhard C; Resel, Roland; Müller, Thomas; Skakalova, Viera; Habler, Gerlinde; Abart, Rainer; Cherevan, Alexey S; Eder, Dominik; Blatter, Maxime; Fischer, Fabian; Meyer, Jannik C; Polyushkin, Dmitry K; Waldhauser, Wolfgang

    2017-01-01

    Molybdenum disulphide (MoS2) thin films have received increasing interest as device-active layers in low-dimensional electronics and also as novel catalysts in electrochemical processes such as the hydrogen evolution reaction (HER) in electrochemical water splitting. For both types of applications, industrially scalable fabrication methods with good control over the MoS2 film properties are crucial. Here, we investigate scalable physical vapour deposition (PVD) of MoS2 films by magnetron sputtering. MoS2 films with thicknesses from ≈10 to ≈1000 nm were deposited on SiO2/Si and reticulated vitreous carbon (RVC) substrates. Samples deposited at room temperature (RT) and at 400 °C were compared. The deposited MoS2 was characterized by macro- and microscopic X-ray, electron beam and light scattering, scanning and spectroscopic methods as well as electrical device characterization. We find that room-temperature-deposited MoS2 films are amorphous, of smooth surface morphology and easily degraded upon moderate laser-induced annealing in ambient conditions. In contrast, films deposited at 400 °C are nano-crystalline, show a nano-grained surface morphology and are comparatively stable against laser-induced degradation. Interestingly, results from electrical transport measurements indicate an unexpected metallic-like conduction character of the studied PVD MoS2 films, independent of deposition temperature. Possible reasons for these unusual electrical properties of our PVD MoS2 thin films are discussed. A potential application for such conductive nanostructured MoS2 films could be as catalytically active electrodes in (photo-)electrocatalysis and initial electrochemical measurements suggest directions for future work on our PVD MoS2 films.

  3. Stoichiometric SrTiO3 Films via High Pressure Oxygen Sputter Deposition

    NASA Astrophysics Data System (ADS)

    Ambwani, Palak; Jalan, Bharat; Leighton, Chris

    2013-03-01

    Defect management in epilayers of semiconducting complex oxides such as SrTiO3 is a topic of considerable contemporary interest. Recent work has shown that sufficiently precise control over stoichiometry and defects in SrTiO3 enables facile n-type doping, record high mobilities, and even simultaneous observation of quantum oscillations and superconductivity. Such progress has typically been made using techniques such as oxygen/LASER MBE or high-temperature PLD. In this work we demonstrate, via homoepitaxy on SrTiO3(001), that RF high pressure oxygen sputtering from a ceramic target is similarly capable of growth of high-quality, stoichiometric SrTiO3 films. We show that optimization of the deposition temperature (above 750 °C) and oxygen pressure (above 2.5 mBar) leads to the deposition of films indistinguishable from the substrate via grazing incidence and wide-angle x-ray scattering. The importance of a pre-treatment of the substrates in oxygen above 900 °C is emphasized. The defect density/stoichiometry was further probed via the transport properties of vacuum annealed samples with controlled O vacancy density. Finally, we also demonstrate that the stoichiometry and defect density of films deposited under non-optimal conditions can be remarkably improved via post-deposition heat treatment. Work supported by NSF DMR and NSF MRSEC.

  4. Magnetism of Amorphous and Nano-Crystallized Dc-Sputter-Deposited MgO Thin Films

    PubMed Central

    Mahadeva, Sreekanth K.; Fan, Jincheng; Biswas, Anis; Sreelatha, K.S.; Belova, Lyubov; Rao, K.V.

    2013-01-01

    We report a systematic study of room-temperature ferromagnetism (RTFM) in pristine MgO thin films in their amorphous and nano-crystalline states. The as deposited dc-sputtered films of pristine MgO on Si substrates using a metallic Mg target in an O2 containing working gas atmosphere of (N2 + O2) are found to be X-ray amorphous. All these films obtained with oxygen partial pressure (PO2) ~10% to 80% while maintaining the same total pressure of the working gas are found to be ferromagnetic at room temperature. The room temperature saturation magnetization (MS) value of 2.68 emu/cm3 obtained for the MgO film deposited in PO2 of 10% increases to 9.62 emu/cm3 for film deposited at PO2 of 40%. However, the MS values decrease steadily for further increase of oxygen partial pressure during deposition. On thermal annealing at temperatures in the range 600 to 800 °C, the films become nanocrystalline and as the crystallite size grows with longer annealing times and higher temperature, MS decreases. Our study clearly points out that it is possible to tailor the magnetic properties of thin films of MgO. The room temperature ferromagnetism in MgO films is attributed to the presence of Mg cation vacancies.

  5. Structural and gasochromic properties of WO3 films prepared by reactive sputtering deposition

    NASA Astrophysics Data System (ADS)

    Yamamoto, S.; Hakoda, T.; Miyashita, A.; Yoshikawa, M.

    2015-02-01

    The effects of deposition temperature and film thickness on the structural and gasochromic properties of tungsten trioxide (WO3) films used for the optical detection of diluted cyclohexane gas have been investigated. The WO3 films were prepared on SiO2 substrates by magnetron sputtering, with the deposition temperature ranging from 300 to 550 °C in an Ar and O2 gas mixture. The films were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), and Rutherford backscattering spectroscopy (RBS). The gasochromic properties of the WO3 films, coated with a catalytic Pt layer, were examined by exposing them to up to 5% cyclohexane in N2 gas. It was found that (001)-oriented monoclinic WO3 films, with a columnar structure, grew at deposition temperatures between 400 and 450 °C. Furthermore, (010)-oriented WO3 films were preferably formed at deposition temperatures higher than 500 °C. The gasochromic characterization of the Pt/WO3 films revealed that (001)-oriented WO3 films, with cauliflower-like surface morphology, were appropriate for the optical detection of cyclohexane gas.

  6. Surface roughness and interface width scaling of magnetron sputter deposited Ni/Ti multilayers

    SciTech Connect

    Maidul Haque, S.; Biswas, A.; Tokas, R. B.; Bhattacharyya, D.; Sahoo, N. K.; Bhattacharya, Debarati

    2013-09-14

    Using an indigenously built r.f. magnetron sputtering system, several single layer Ti and Ni films have been deposited at varying deposition conditions. All the samples have been characterized by Grazing Incidence X-ray Reflectivity (GIXR) and Atomic Force Microscopy to estimate their thickness, density, and roughness and a power law dependence of the surface roughness on the film thickness has been established. Subsequently, at optimized deposition condition of Ti and Ni, four Ni/Ti multilayers of 11-layer, 21-layer, 31-layer, and 51-layer having different bilayer thickness have been deposited. The multilayer samples have been characterized by GIXR and neutron reflectivity measurements and the experimental data have been fitted assuming an appropriate sample structure. A power law correlation between the interface width and bilayer thickness has been observed for the multilayer samples, which was explained in the light of alternate roughening/smoothening of multilayers and assuming that at the interface the growth “restarts” every time.

  7. Role of Sputter Deposition Rate in Tailoring Nanogranular Gold Structures on Polymer Surfaces.

    PubMed

    Schwartzkopf, Matthias; Hinz, Alexander; Polonskyi, Oleksandr; Strunskus, Thomas; Löhrer, Franziska C; Körstgens, Volker; Müller-Buschbaum, Peter; Faupel, Franz; Roth, Stephan V

    2017-02-15

    The reproducible low-cost fabrication of functional polymer-metal interfaces via self-assembly is of crucial importance in organic electronics and organic photovoltaics. In particular, submonolayer and nanogranular systems expose highly interesting electrical, plasmonic, and catalytic properties. The exploitation of their great potential requires tailoring of the structure on the nanometer scale and below. To obtain full control over the complex nanostructural evolution at the polymer-metal interface, we monitor the evolution of the metallic layer morphology with in situ time-resolved grazing-incidence small-angle X-ray scattering during sputter deposition. We identify the impact of different deposition rates on the growth regimes: the deposition rate affects primarily the nucleation process and the adsorption-mediated growth, whereas rather small effects on diffusion-mediated growth processes are observed. Only at higher rates are initial particle densities higher due to an increasing influence of random nucleation, and an earlier onset of thin film percolation occurs. The obtained results are discussed to identify optimized morphological parameters of the gold cluster ensemble relevant for various applications as a function of the effective layer thickness and deposition rate. Our study opens up new opportunities to improve the fabrication of tailored metal-polymer nanostructures for plasmonic-enhanced applications such as organic photovoltaics and sensors.

  8. Structural transition in sputter-deposited amorphous germanium films by aging at ambient temperature

    SciTech Connect

    Okugawa, M.; Nakamura, R. Numakura, H.; Ishimaru, M.; Watanabe, K.; Yasuda, H.

    2016-06-07

    The structure of amorphous Ge (a-Ge) films prepared by sputter-deposition and the effects of aging at ambient temperature and pressure were studied by pair-distribution-function (PDF) analysis from electron scattering and molecular dynamics simulations. The PDFs of the as-deposited and aged samples for 3–13 months showed that the major peaks for Ge-Ge bonds decrease in intensity and broaden with aging for up to 7 months. In the PDFs of a-Ge of molecular dynamics simulation obtained by quenching liquid at different rates, the major peak intensities of a slowly cooled model are higher than those of a rapidly cooled model. Analyses on short- and medium-range configurations show that the slowly cooled model includes a certain amount of medium-range ordered (MRO) clusters, while the rapidly cooled model includes liquid-like configurations rather than MRO clusters. The similarity between experimental and computational PDFs implies that as-deposited films are similar in structure to the slowly cooled model, whereas the fully aged films are similar to the rapidly cooled model. It is assumed that as they undergo room-temperature aging, the MRO clusters disintegrate and transform into liquid-like regions in the same matrix. This transition in local configurations is discussed in terms of instability and the non-equilibrium of nanoclusters produced by a vapor-deposition process.

  9. Indium oxide-based transparent conductive films deposited by reactive sputtering using alloy targets

    NASA Astrophysics Data System (ADS)

    Miyazaki, Yusuke; Maruyama, Eri; Jia, Junjun; Machinaga, Hironobu; Shigesato, Yuzo

    2017-04-01

    High-quality transparent conductive oxide (TCO) films, Sn-doped In2O3 (ITO) and In2O3–ZnO (IZO), were successfully deposited on either synthetic silica or polyethylene terephthalate (PET) substrates in the “transition region” by reactive dc magnetron sputtering using In–Zn and In–Sn alloy targets, respectively, with a specially designed plasma emission feedback system. The composition, crystallinity, surface morphology, and electrical and optical properties of the films were analyzed. All of the IZO films were amorphous, whereas the ITO films were polycrystalline over a wide range of deposition conditions. The minimum resistivities of the IZO and ITO films deposited on the heated PET substrates at 150 °C were 3.3 × 10‑4 and 5.4 × 10‑4 Ω·cm, respectively. By applying rf bias to unheated PET substrates, ITO films with a resistivity of 4.4 × 10‑4 Ω·cm were deposited at a dc self-bias voltage of ‑60 V.

  10. Structural transition in sputter-deposited amorphous germanium films by aging at ambient temperature

    NASA Astrophysics Data System (ADS)

    Okugawa, M.; Nakamura, R.; Ishimaru, M.; Watanabe, K.; Yasuda, H.; Numakura, H.

    2016-06-01

    The structure of amorphous Ge (a-Ge) films prepared by sputter-deposition and the effects of aging at ambient temperature and pressure were studied by pair-distribution-function (PDF) analysis from electron scattering and molecular dynamics simulations. The PDFs of the as-deposited and aged samples for 3-13 months showed that the major peaks for Ge-Ge bonds decrease in intensity and broaden with aging for up to 7 months. In the PDFs of a-Ge of molecular dynamics simulation obtained by quenching liquid at different rates, the major peak intensities of a slowly cooled model are higher than those of a rapidly cooled model. Analyses on short- and medium-range configurations show that the slowly cooled model includes a certain amount of medium-range ordered (MRO) clusters, while the rapidly cooled model includes liquid-like configurations rather than MRO clusters. The similarity between experimental and computational PDFs implies that as-deposited films are similar in structure to the slowly cooled model, whereas the fully aged films are similar to the rapidly cooled model. It is assumed that as they undergo room-temperature aging, the MRO clusters disintegrate and transform into liquid-like regions in the same matrix. This transition in local configurations is discussed in terms of instability and the non-equilibrium of nanoclusters produced by a vapor-deposition process.

  11. Sputtering deposition of P-type SnO films with SnO₂ target in hydrogen-containing atmosphere.

    PubMed

    Hsu, Po-Ching; Hsu, Chao-Jui; Chang, Ching-Hsiang; Tsai, Shiao-Po; Chen, Wei-Chung; Hsieh, Hsing-Hung; Wu, Chung-Chih

    2014-08-27

    In this work, we had investigated sputtering deposition of p-type SnO using the widely used and robust SnO2 target in a hydrogen-containing reducing atmosphere. The effects of the hydrogen-containing sputtering gas on structures, compositions, optical, and electrical properties of deposited SnOx films were studied. Results show that polycrystalline and SnO-dominant films could be readily obtained by carefully controlling the hydrogen gas ratio in the sputtering gas and the extent of reduction reaction. P-type conductivity was unambiguously observed for SnO-dominant films with traceable Sn components, exhibiting a p-type Hall mobility of up to ∼3 cm(2) V(-1) s(-1). P-type SnO thin-film transistors using such SnO-dominant films were also demonstrated.

  12. Deposition and characterization of TiZrV-Pd thin films by dc magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Wang, Jie; Zhang, Bo; Xu, Yan-Hui; Wei, Wei; Fan, Le; Pei, Xiang-Tao; Hong, Yuan-Zhi; Wang, Yong

    2015-12-01

    TiZrV film is mainly applied in the ultra-high vacuum pipes of storage rings. Thin film coatings of palladium, which are added onto the TiZrV film to increase the service life of nonevaporable getters and enhance H2 pumping speed, were deposited on the inner face of stainless steel pipes by dc magnetron sputtering using argon gas as the sputtering gas. The TiZrV-Pd film properties were investigated by atomic force microscope (AFM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-Ray Diffraction (XRD). The grain size of TiZrV and Pd films were about 0.42-1.3 nm and 8.5-18.25 nm respectively. It was found that the roughness of TiZrV films is small, about 2-4 nm, but for Pd film it is large, about 17-19 nm. The PP At. % of Pd in TiZrV/Pd films varied from 86.84 to 87.56 according to the XPS test results. Supported by National Natural Science Funds of China (11205155) and Fundamental Research Funds for the Central Universities (WK2310000041)

  13. Properties of All-Solid Lithium-Ion Rechargeable Batteries Deposited by RF Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Zhu, R. J.; Ren, Y.; Geng, L. Q.; Chen, T.; Li, L. X.; Yuan, C. R.

    2013-08-01

    Amorphous V2O5, LiPON and Li2Mn2O4 thin films were fabricated by RF magnetron sputtering methods and the morphology of thin films were characterized by scanning electron microscopy. Then with these three materials deposited as the anode, solid electrolyte, cathode, and vanadium as current collector, a rocking-chair type of all-solid-state thin-film-type Lithium-ion rechargeable battery was prepared by using the same sputtering parameters on stainless steel substrates. Electrochemical studies show that the thin film battery has a good charge-discharge characteristic in the voltage range of 0.3-3.5 V, and after 30 cycles the cell performance turned to become stabilized with the charge capacity of 9 μAh/cm2, and capacity loss of single-cycle of about 0.2%. At the same time, due to electronic conductivity of the electrolyte film, self-discharge may exist, resulting in approximately 96.6% Coulombic efficiency.

  14. Structure and morphology of magnetron sputter deposited ultrathin ZnO films on confined polymeric template

    NASA Astrophysics Data System (ADS)

    Singh, Ajaib; Schipmann, Susanne; Mathur, Aakash; Pal, Dipayan; Sengupta, Amartya; Klemradt, Uwe; Chattopadhyay, Sudeshna

    2017-08-01

    The structure and morphology of ultra-thin zinc oxide (ZnO) films with different film thicknesses on confined polymer template were studied through X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS). Using magnetron sputter deposition technique ZnO thin films with different film thicknesses (<10 nm) were grown on confined polystyrene with ∼2Rg film thickness, where Rg ∼ 20 nm (Rg is the unperturbed radius of gyration of polystyrene, defined by Rg = 0.272 √M0, and M0 is the molecular weight of polystyrene). The detailed internal structure, along the surface/interfaces and the growth direction of the system were explored in this study, which provides insight into the growth procedure of ZnO on confined polymer and reveals that a thin layer of ZnO, with very low surface and interface roughness, can be grown by DC magnetron sputtering technique, with approximately full coverage (with bulk like electron density) even in nm order of thickness, in 2-7 nm range on confined polymer template, without disturbing the structure of the underneath template. The resulting ZnO-polystyrene hybrid systems show strong ZnO near band edge (NBE) and deep-level (DLE) emissions in their room temperature photoluminescence spectra, where the contribution of DLE gets relatively stronger with decreasing ZnO film thickness, indicating a significant enhancement of surface defects because of the greater surface to volume ratio in thinner films.

  15. Carbon film deposition on SnO2/Si(111) using DC unbalanced magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Aji, A. S.; Darma, Y.

    2013-09-01

    In this paper, carbon deposition on SnO2 layer using DC unbalanced magnetron-sputtering technique at low temperature has been systematically studied. Sputtering process were carried out at pressure of 4.6×10-2 Torr by keeping the substrate temperature at 300 °C. SnO2 were growth on silicon (111) substrate using thermal evaporation and continuing with dry oxidation of Sn at 225 °C. Thermal evaporation for high purity Sn was conducted by maintain the current source as high as 40 ampere. The quality of SnO2 on Si(111) and the characteristic of carbon thin film on SnO2 were analized by mean XRD, FTIR and Raman spectra. XRD analysis shows that SnO2 film is growth uniformly on Si(111). FTIR and Raman spectra confirm the formation of thin film carbon on SnO2. Additionally, thermal annealing for some sample series have been performed to study their structural stability. The change of atomic structure due to thermal annealing were analized by Raman and XRD spectra.

  16. Carbon film deposition on SnO{sub 2}/Si(111) using DC unbalanced magnetron sputtering

    SciTech Connect

    Aji, A. S.; Darma, Y.

    2013-09-09

    In this paper, carbon deposition on SnO{sub 2} layer using DC unbalanced magnetron-sputtering technique at low temperature has been systematically studied. Sputtering process were carried out at pressure of 4.6×10{sup −2} Torr by keeping the substrate temperature at 300 °C. SnO{sub 2} were growth on silicon (111) substrate using thermal evaporation and continuing with dry oxidation of Sn at 225 °C. Thermal evaporation for high purity Sn was conducted by maintain the current source as high as 40 ampere. The quality of SnO{sub 2} on Si(111) and the characteristic of carbon thin film on SnO{sub 2} were analized by mean XRD, FTIR and Raman spectra. XRD analysis shows that SnO{sub 2} film is growth uniformly on Si(111). FTIR and Raman spectra confirm the formation of thin film carbon on SnO{sub 2}. Additionally, thermal annealing for some sample series have been performed to study their structural stability. The change of atomic structure due to thermal annealing were analized by Raman and XRD spectra.

  17. Work Function Modification of Tungsten-Doped Indium Oxides Deposited by the Co-Sputtering Method.

    PubMed

    Oh, Gyujin; Jeon, Jia; Lee, Kyoung Su; Kim, Eun Kyu

    2016-05-01

    We have studied the work function modification of tungsten-doped indium oxides (IWOs) through the co-sputtering of indium oxide (In2O3) and indium tungsten oxide (In2O3 80 wt% + WO3 20 wt%) via a radio frequency (RF) magnetron sputtering system. By controlling the elemental deposition of IWOs, the resultant work functions varied from 4.37 eV to 4.1 eV. The IWO thin films showed excellent properties for application as transparent conducting oxide materials in the region of 0 to 2.43 at.% of tungsten versus the total metal content. The carrier concentration of n-type IWO thin films varied from 8.39 x 10(19) cm(-3) to 8.58 x 10(21) cm(-3), while the resistivity varied from 3.15 x 10(-4) Ωcm to 2.26 x 10(-3) Ωcm. The largest measured optical band gap was 3.82 eV determined at 2.43 at.% of tungsten atoms relative to the total amount of metal atoms, while the smallest optical band gap was 3.6 eV at 4.78 at.% of tungsten. IWO films containing more than 2.43 at.% of tungsten atoms relative to the total number of metal atoms revealed an average transmittance of over 80% within the visible light region.

  18. Thick sputtered tantalum coatings for high-temperature energy conversion applications

    SciTech Connect

    Stelmakh, Veronika Peykov, Daniel; Chan, Walker R.; Senkevich, Jay J.; Joannopoulos, John D.; Soljačić, Marin; Celanovic, Ivan; Castillo, Robert; Coulter, Kent; Wei, Ronghua

    2015-11-15

    Thick sputtered tantalum (Ta) coatings on polished Inconel were investigated as a potential replacement for bulk refractory metal substrates used for high-temperature emitters and absorbers in thermophotovoltaic energy conversion applications. In these applications, high-temperature stability and high reflectance of the surface in the infrared wavelength range are critical in order to sustain operational temperatures and reduce losses due to waste heat. The reflectance of the coatings (8 and 30 μm) was characterized with a conformal protective hafnia layer as-deposited and after one hour anneals at 700, 900, and 1100 °C. To further understand the high-temperature performance of the coatings, the microstructural evolution was investigated as a function of annealing temperature. X-ray diffraction was used to analyze the texture and residual stress in the coatings at four reflections (220, 310, 222, and 321), as-deposited and after anneal. No significant changes in roughness, reflectance, or stress were observed. No delamination or cracking occurred, even after annealing the coatings at 1100 °C. Overall, the results of this study suggest that the thick Ta coatings are a promising alternative to bulk substrates and pave the way for a relatively low-cost and easily integrated platform for nanostructured devices in high-temperature energy conversion applications.

  19. Low temperature growth study of nano-crystalline TiO2 thin films deposited by RF sputtering

    NASA Astrophysics Data System (ADS)

    Safeen, K.; Micheli, V.; Bartali, R.; Gottardi, G.; Laidani, N.

    2015-07-01

    Precise control of the various structural phases of TiO2 at a low temperature is particularly important for practical applications. In this work, the deposition conditions for the growth of anatase and rutile phase at a low temperature (⩽300 °C) were optimized. TiO2 films were deposited by radio frequency (RF) sputtering of a ceramic TiO2 target in argon and argon-oxygen plasma (10 and 20% O2) at room temperature. For the films deposited in pure Ar and 20% O2, the growth temperature was varied from 25 to 400 °C. The plasma properties were investigated using optical emission spectroscopy (OES) in a wide range of values of gas composition (0-50% O2 in Ar-O2 mixture). The structural and chemical properties were characterized by means of x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). The results indicate that O2 addition to the Ar-O2 gas mixture significantly changed the density of the plasma species (Ar, Ar+, Ti, Ti+ and O), which in turn influence the crystal structure and surface chemistry of the prepared films. Anatase phase was obtained for the films grown in Ar-O2 plasma over the whole range of temperature. In contrast, the films deposited in argon discharge largely persist in amorphous phase at temperature ⩽200 °C and revealed the formation of single rutile phase at ⩾300 °C. The oxygen vacancies detected by XPS analysis for the films deposited in Ar plasma facilitate the growth of a rutile phase at low temperature (˜300 °C). Our results demonstrate that oxygen negative ions, oxygen vacancies and surface energy conditions at the substrate are the key parameters controlling the phase of the prepared films at low temperature.

  20. Enhanced sputtering yields of carbon due to accumulation of low-energy Xe ions

    NASA Astrophysics Data System (ADS)

    Kenmotsu, T.; Wada, M.; Hyakutake, T.; Muramoto, T.; Nishida, M.

    2009-05-01

    We have calculated the sputtering yields of carbon and molybdenum under xenon ion bombardment by a Monte Carlo code ACAT which simulates binary collision events in solids. The yields of carbon calculated with ACAT differ from the experimental data below the threshold energy predicted from the semi-empirical formula proposed by Yamamura and Tawara. Meanwhile, the results of ACAT with 14% xenon atoms retained in graphite are in good agreement with the experimental data and the xenon retention in carbon plays an important role in reducing the threshold energy for carbon sputtering. In order to estimate the experimental sputtering yields of carbon, a simplified formula is proposed in the frame of the semi-empirical formula. The formula predicts the yield curve close to the reported sputtering yields of carbon for the condition that carbon target retains 14% xenon atoms.

  1. A thermalized ion explosion model for high energy sputtering and track registration

    NASA Technical Reports Server (NTRS)

    Seiberling, L. E.; Griffith, J. E.; Tombrello, T. A.

    1980-01-01

    A velocity spectrum of neutral sputtered particles as well as a low resolution mass spectrum of sputtered molecular ions was measured for 4.74 MeV F-19(+2) incident of UF4. The velocity spectrum is dramatically different from spectra taken with low energy (keV) bombarding ions, and is shown to be consistent with a hot plasma of atoms in thermal equilibrium inside the target. A thermalized ion explosion model is proposed for high energy sputtering which is expected to describe track formation in dielectric materials. The model is shown to be consistent with the observed total sputtering yield and the dependence of the yield on the primary ionization rate of the incident ion.

  2. Correlations between structure, composition and electrical properties of tungsten/tungsten oxide periodic multilayers sputter deposited by gas pulsing

    NASA Astrophysics Data System (ADS)

    Potin, Valérie; Cacucci, Arnaud; Martin, Nicolas

    2017-01-01

    W/WOx multilayered thin films have been deposited by DC reactive sputtering using the reactive gas pulsing process. It is implemented to produce regular alternations of metal-oxide compounds at the nanometric scale. Structure and growth have been investigated by high resolution transmission electron microscopy, scanning transmission electron microscopy, X-ray energy dispersive spectroscopy and electron energy loss spectroscopy. Regularity of tungsten-based alternations, quality of interfaces as well as oxygen presence through the multilayered structure have been determined and linked to the growth conditions. Chemical information was obtained from the energy dispersive X-ray spectroscopy and low-loss electron energy loss spectroscopy. As they can be related to the chemical composition of the periodic layers, the position and the broadening of the bulk plasmon peak were studied. For the smallest periods (<10 nm), the presence of oxygen has been pointed out in the metal-rich layer whereas for the thickest ones (100 nm), pure metal is only present. Finally, relationships have been established between in situ growth conditions, structural and chemical parameters and electrical properties in periodic multilayers.

  3. Comparative Study of As-Deposited ZnO Thin Films by Thermal Evaporation, Pulsed Laser Deposition and RF Sputtering Methods for Electronic and Optoelectronic Applications

    NASA Astrophysics Data System (ADS)

    Vyas, Sumit; Giri, Pushpa; Singh, Shaivalini; Chakrabarti, P.

    2015-10-01

    Zinc oxide (ZnO) thin films have been deposited on Si substrate and glass substrate using thermal evaporation, pulsed laser deposition (PLD) and radio-frequency (RF) sputtering methods. The structural, surface morphological, optical and electrical properties of ZnO thin films deposited by these three methods were investigated and compared systematically using x-ray diffractometer, atomic force microscopy, ellipsometric and current-voltage ( I- V) measurement. The ZnO films deposited by RF sputtering method were highly oriented along the (002) plane. The ZnO films grown by thermal evaporation and PLD methods exhibited a polycrystalline nature. The surface roughness was found to be the least and the transparency in the visible region was the highest for the films grown by the RF sputtering method as compared to the films grown by the other two methods. The I- V characteristics reveal that the Pd:Au/ZnO (RF-sputtered) Schottky contact exhibited a better value of ideality factor, series resistance and barrier height as compared to the values obtained for Pd:Au/ZnO (thermally evaporated and pulse laser-deposited) Schottky contacts. The optical bandgap was found to be almost the same for the films grown by all three methods and was estimated to be around 3.2 eV.

  4. Fabrication of InGaN thin-film transistors using pulsed sputtering deposition

    PubMed Central

    Itoh, Takeki; Kobayashi, Atsushi; Ueno, Kohei; Ohta, Jitsuo; Fujioka, Hiroshi

    2016-01-01

    We report the first demonstration of operational InGaN-based thin-film transistors (TFTs) on glass substrates. The key to our success was coating the glass substrate with a thin amorphous layer of HfO2, which enabled a highly c-axis-oriented growth of InGaN films using pulsed sputtering deposition. The electrical characteristics of the thin films were controlled easily by varying their In content. The optimized InGaN-TFTs exhibited a high on/off ratio of ~108, a field-effect mobility of ~22 cm2 V−1 s−1, and a maximum current density of ~30 mA/mm. These results lay the foundation for developing high-performance electronic devices on glass substrates using group III nitride semiconductors. PMID:27383148

  5. Highly transparent conductive ITO/Ag/ITO trilayer films deposited by RF sputtering at room temperature

    NASA Astrophysics Data System (ADS)

    Ren, Ningyu; Zhu, Jun; Ban, Shiliang

    2017-05-01

    ITO/Ag/ITO (IAI) trilayer films were deposited on glass substrate by radio frequency magnetron sputtering at room temperature. A high optical transmittance over 94.25% at the wavelength of 550 nm and an average transmittance over the visual region of 88.04% were achieved. The calculated value of figure of merit (FOM) reaches 80.9 10-3 Ω-1 for IAI films with 15-nm-thick Ag interlayer. From the morphology and structural characterization, IAI films could show an excellent correlated electric and optical performance if Ag grains interconnect with each other on the bottom ITO layer. These results indicate that IAI trilayer films, which also exhibit low surface roughness, will be well used in optoelectronic devices.

  6. Control over the preferred orientation of CIGS films deposited by magnetron sputtering using a wetting layer

    NASA Astrophysics Data System (ADS)

    Yan, Yong; Jiang, Fan; Liu, Lian; Yu, Zhou; Zhang, Yong; Zhao, Yong

    2016-01-01

    A growth method is presented to control the preferred orientation in chalcopyrite CuIn x Ga1- x Se2 (CIGS) thin films grown by magnetron sputtering. Films with (220/204) and (112) preferred orientation as well as randomly oriented films were prepared. The effects of an In2Se3 wetting layer and the working pressure on the texture transition phenomena were examined. A large-grained CIGS film with (220/204) texture was formed at 400°C with the inclusion of a thin (80 nm) In2Se3 layer and liquid phase (excess copper selenide phase) formation, and the reaction mechanism is proposed. The device deposited at 2.0 Pa on an In2Se3 layer exhibited the optimal electrical properties. [Figure not available: see fulltext.

  7. HRTEM Microstructural Characterization of β-WO3 Thin Films Deposited by Reactive RF Magnetron Sputtering

    PubMed Central

    Faudoa-Arzate, A.; Arteaga-Durán, A.; Saenz-Hernández, R.J.; Botello-Zubiate, M.E.; Realyvazquez-Guevara, P.R.; Matutes-Aquino, J.A.

    2017-01-01

    Though tungsten trioxide (WO3) in bulk, nanosphere, and thin film samples has been extensively studied, few studies have been dedicated to the crystallographic structure of WO3 thin films. In this work, the evolution from amorphous WO3 thin films to crystalline WO3 thin films is discussed. WO3 thin films were fabricated on silicon substrates (Si/SiO2) by RF reactive magnetron sputtering. Once a thin film was deposited, two successive annealing treatments were made: an initial annealing at 400 °C for 6 h was followed by a second annealing at 350 °C for 1 h. Film characterization was carried out by X-ray diffraction (XRD), high-resolution electron transmission microscopy (HRTEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The β-WO3 final phase grew in form of columnar crystals and its growth plane was determined by HRTEM. PMID:28772559

  8. HRTEM Microstructural Characterization of β-WO3 Thin Films Deposited by Reactive RF Magnetron Sputtering.

    PubMed

    Faudoa-Arzate, A; Arteaga-Durán, A; Saenz-Hernández, R J; Botello-Zubiate, M E; Realyvazquez-Guevara, P R; Matutes-Aquino, J A

    2017-02-17

    Though tungsten trioxide (WO3) in bulk, nanosphere, and thin film samples has been extensively studied, few studies have been dedicated to the crystallographic structure of WO3 thin films. In this work, the evolution from amorphous WO3 thin films to crystalline WO3 thin films is discussed. WO3 thin films were fabricated on silicon substrates (Si/SiO2) by RF reactive magnetron sputtering. Once a thin film was deposited, two successive annealing treatments were made: an initial annealing at 400 °C for 6 h was followed by a second annealing at 350 °C for 1 h. Film characterization was carried out by X-ray diffraction (XRD), high-resolution electron transmission microscopy (HRTEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The β-WO3 final phase grew in form of columnar crystals and its growth plane was determined by HRTEM.

  9. Effect of gas ratio on tribological properties of sputter deposited TiN coatings

    NASA Astrophysics Data System (ADS)

    Chavda, Mahesh R.; Chauhan, Kamlesh V.; Rawal, Sushant K.

    2016-05-01

    Titanium nitride (TiN) coatings were deposited on Si, corning glass, pins of mild steel (MS, ϕ3mm), aluminium (Al, ϕ4mm) and brass (ϕ6mm) substratesby DC magnetron sputtering. The argon and nitrogen (Ar:N2)gas ratio was precisely controlled by Mass Flow Controller (MFC) and was varied systematically at diffract values of 10:10,12:08, 16:04 and 18:02sccm. The structural properties of TiN coatings were characterized by X-ray diffraction (XRD) and its surface topography was studied using field emission scanning electron microscopy (FE-SEM). The tribological properties of TiN coatings were investigated using pin-on-disc tribometer.

  10. Controlling the optical properties of sputtered-deposited LixV2O5 films

    NASA Astrophysics Data System (ADS)

    Muñoz-Castro, M.; Berkemeier, F.; Schmitz, G.; Buchheit, A.; Wiemhöfer, H.-D.

    2016-10-01

    This study examines the influence of lithium intercalation on the optical properties of vanadium pentoxide films. The films with a thickness between 400 and 1000 nm were prepared by DC magnetron sputter deposition. Cyclic voltammetry and chronopotentiometry were used to set a well defined lithiation state of the LixV2O5 films between x = 0 and x = 1. The optical properties of these films were measured by optical reflectometry in the wavelength range between 500 and 1700 nm. From the reflectance data, the refractive index and the extinction coefficient of the films were finally calculated as a function of the wavelength using Cauchy's dispersion model. The results confirm that the optical behavior of LixV2O5 films varies significantly upon lithium insertion. It is demonstrated that the changes produced in the optical properties are completely reversible within the limits of permanent structure changes.

  11. Residual stresses in sputter-deposited copper/330 stainless steel multilayers

    SciTech Connect

    Zhang, X.; Misra, A.

    2004-12-15

    The evolution of residual stresses as a function of bilayer period from 10 nm to 1 {mu}m in sputter-deposited Cu/330 stainless-steel (SS) multilayered films is evaluated by the substrate curvature technique. The multilayer stress evolution is compared with residual stresses in single layer Cu films and single layer 330 SS films, also measured by substrate curvature technique, with respective film thicknesses varying from 5 to 500 nm. Both single layer and multilayer films exhibit high tensile residual stresses that increase with decreasing layer thickness, but are found to be lower than the respective yield strengths. The intrinsic tensile residual stress evolution with film thickness is explained using the island coalescence model. The difference between the multilayer residual stress and the average residual stresses in single-layered Cu and 330 SS films is interpreted in terms of interface stress.

  12. Corrosion protection of metal implants by hard biocompatible ceramic coatings deposited by radio-frequency sputtering.

    PubMed

    Sella, C; Martin, J C; Lecoeur, J; Bellier, J P; Harmand, M F; Naji, A; Davidas, J P; Le Chanu, A

    1990-01-01

    Most metals used for orthopaedic and stomatology implants and prostheses belong to the families of titanium or nickel-based and cobalt-based superalloys designed for advanced technology industries (e.g. space, aeronautic and nuclear industries). Ideal materials should be as insoluble and biologically compatible as possible. In the present paper the corrosion behaviour of Ni-Cr and Co-Cr alloys in biological media is evaluated through potentiodynamic polarization tests. It is shown that these metals exhibit some minor release of the component elements and degradation products, which may induce cytotoxic and allergic effects. The corrosion resistance of these alloys can be strongly enhanced by hard ceramic coatings deposited by radio-frequency sputtering. The biocompatibility of coated and uncoated metals is compared from differentiated human cell cultures.

  13. Thermal stability of sputter deposited nanomosaic rutile TiO{sub 2}

    SciTech Connect

    Aita, Carolyn Rubin

    2009-07-15

    A domain structure based on the rutile lattice with a large density of (1/2)<011>{l_brace}011{r_brace}-type stacking faults is found in sputter deposited TiO{sub 2} films [J. Vac. Sci. Technol. A 24, 2054 (2006)]. The thermal stability of nanomosaic rutile at moderate temperature is reported here. Films are annealed at 973 K for 0.25-15 h, characterized by x-ray diffraction. A Johnson-Mehl-Avrami-Kolmogorov analysis indicates impeded crystallite growth. A dislocation-locking mechanism is proposed for this behavior. Partial dislocations with (1/2)<011> Burgers vectors that bound the stacking faults glide on intersecting {l_brace}011{r_brace} slip planes and react to produce sessile stair rod dislocations. Without the high temperature required for dislocation climb, (1/2)<011>{l_brace}011{r_brace}-type faults inherent to nanomosaic rutile provide thermal stability against massive crystallite growth.

  14. The physical properties of AZO films deposited by RF magnetron sputtering in hydrogen-diluted argon

    NASA Astrophysics Data System (ADS)

    Kim, Jwayeon; Han, Jungsu; Jin, Hyunjoon; Kim, Youhyuk; Park, Kyeongsoon

    2014-08-01

    The properties of AZO (98-wt% ZnO, 2-wt% Al2O3) films produced in pure Ar and Ar (98%) + H2 (2%) (H2-diluted Ar) by radio-frequency (RF) magnetron sputtering were investigated as functions of the substrate temperatures. H2-diluted Ar improved the electrical properties of the AZO films fabricated at low substrate temperatures, but this benefit gradually diminished with increasing substrate temperature. This phenomenon was explained by O-H stretching in the Zn-O bond at low temperatures and by the formation of oxygen vacancies at high temperatures. The average optical transmission was over ~85%, and the orientation of the AZO films deposited both in pure Ar and in H2-diluted Ar was in the [002] direction.

  15. Growth of sputter-deposited metamagnetic epitaxial Ni-Co-Mn-In films

    SciTech Connect

    Niemann, R.; Schultz, L.; Faehler, S.

    2012-05-01

    Metamagnetic thin films represent a promising geometry for more efficient magnetocaloric cooling applications due to a fast heat transfer. Here, we identify suitable growth conditions to obtain epitaxial Ni-Mn-In-Co films with a metamagnetic transition in vicinity of room temperature. We show that both increased substrate temperature and target aging result in loss of indium. This can be attributed to evaporation and preferential sputtering, respectively. We present a model that treats the effect of target aging and temperature dependence of evaporation on the film composition independently and enables predictions of the film composition as a function of initial target composition, target age, and deposition temperature. Furthermore, our analysis reveals that a sufficient degree of chemical B2 order is required for a transformation, in addition to an appropriate film composition.

  16. Lithium diffusion in sputter-deposited Li4Ti5O12 thin films

    NASA Astrophysics Data System (ADS)

    Wunde, F.; Berkemeier, F.; Schmitz, G.

    2012-10-01

    Li4Ti5O12 (LTO) thin films are deposited by dc-ion beam sputtering at different oxygen partial pressures and different substrate temperatures. In order to investigate, how these two parameters influence the atomic structure, the specimens are characterized by X-ray diffraction and transmission electron microscopy. Electrochemical characterization of the films is done by cyclic voltammetry and chrono-potentiometry. To determine an averaged chemical diffusion coefficient of lithium, a method is developed, evaluating c-rate tests. The results obtained by this method are compared to results obtained by the well established galvanostatic intermittent titration technique (GITT), which is used to determine a concentration dependent diffusion coefficient of lithium in LTO.

  17. Sputter deposition of large area YBa 2Cu 3O 7-δ thin films

    NASA Astrophysics Data System (ADS)

    Wagner, G.; García Gonzáles, E.; Numssen, K.; Habermeier, H.-U.

    1994-12-01

    The utilization of a sputtering system equipped with three planar magnetron guns in off-axis geometry results in very homogeneous films spreading an area of two inches in diameter. During deposition the substrate is directly heated by the thermal radiation of quartz lamps. No thermal contact is required between the heater and the substrate. The temperature of the substrate surface is controlled using an infrared pyrometer with adapted emissivity calibration taking into account the different optical properties of the film and the substrate. In DC resistance measurements the films show a T c around 90 K and a superlinear temperature dependence in the normal state. The resistance ratio Γ = R(300K)/R(100K) ranges up to 4.0 and the resistance at T=0 clearly extrapolates to negative values.

  18. Thermal transport properties of nanocrystalline Bi-Sb-Te thin films prepared by sputter deposition

    SciTech Connect

    Liao, C.-N.; Wang, Y.-C.; Chu, H.-S.

    2008-11-15

    Grain-size dependent thermal conductivity of sputtered nanocrystalline Bi-Sb-Te thin films was measured by a 3{omega} method. By changing deposition temperature from 100 deg. C to room temperature, the mean grain size of the Bi-Sb-Te films decreased from 83 to 26 nm and the lattice thermal conductivity reduced from 0.79 to 0.45 W/mK proportionally. The effect of grain boundary on lattice thermal conductivity can be described by an effective thermal boundary resistance that was determined in the range of 0.56-1.8x10{sup -8} m{sup 2}K/W for the nanocrystalline Bi-Sb-Te thin films studied.

  19. Fabrication of InGaN thin-film transistors using pulsed sputtering deposition

    NASA Astrophysics Data System (ADS)

    Itoh, Takeki; Kobayashi, Atsushi; Ueno, Kohei; Ohta, Jitsuo; Fujioka, Hiroshi

    2016-07-01

    We report the first demonstration of operational InGaN-based thin-film transistors (TFTs) on glass substrates. The key to our success was coating the glass substrate with a thin amorphous layer of HfO2, which enabled a highly c-axis-oriented growth of InGaN films using pulsed sputtering deposition. The electrical characteristics of the thin films were controlled easily by varying their In content. The optimized InGaN-TFTs exhibited a high on/off ratio of ~108, a field-effect mobility of ~22 cm2 V‑1 s‑1, and a maximum current density of ~30 mA/mm. These results lay the foundation for developing high-performance electronic devices on glass substrates using group III nitride semiconductors.

  20. Characterization of aluminum--aluminum nitride coatings sputter deposited using the pulsed gas process

    SciTech Connect

    Springer, R.W.; Hosford, C.D.

    1982-03-01

    A dc triode magnetron has been used to produce free-standing Al/Al+AlN lamellar foils by sputter deposition. The 5-..mu..m-thick foils produced on both flat substrates as well as curved substrates exhibited good specularity as well as excellent mechanical properties. The pulse spacing was varied from zero to 100-nm spacing. The yield strength of the material was found to obey the Hall--Petch relation sigma/sub y/s = 230+0.07/d1/2, where sigma/sub y/s is in MPa. Auger electron spectroscopy and secondary ion mass spectroscopy indicate that the large flow stress of 230 MPa must be due to grain refinement of the extended source and not an impurity effect. The result is that limitations of masking found in uniaxial flux sources for curved surfaces can be removed allowing the high quality coating of more general shapes.

  1. Characterization of aluminum/aluminum nitride coatings sputter deposited using the pulsed-gas process

    SciTech Connect

    Springer, R.W.; Hosford, C.D.

    1981-01-01

    A dc triode magnetron has been used to produce freestanding Al/Al + AlN lamellar foils by sputter deposition. The 5-..mu..m-thick foils produced on both flat substrates as well as curved substrates exhibited good specularity as well as excellent mechanical properties. The pulse spacing was varied from none to 100-nm spacing. The yield strength of the material was found to obey the Hall-Petch relation sigma/sub ys/ = 230 + .07/d/sup 1/2/, where sigma/sub ys/ is in MPa. Auger electron Spectroscopy and Secondary Ion Mass Spectroscopy indicate that the large flow stress of 230 MPa must be due to grain refinement of the extended source and not an impurity effect. The result is that limitations of masking found in uniaxial flux sources for curved surfaces can be removed allowing the high quality coating of more general shapes.

  2. Structural and optical properties of Cu:silica nanocomposite films prepared by co-sputtering deposition

    NASA Astrophysics Data System (ADS)

    Battaglin, G.; Cattaruzza, E.; Gonella, F.; Polloni, R.; Scremin, B. F.; Mattei, G.; Mazzoldi, P.; Sada, C.

    2004-03-01

    Copper-containing silica films were synthesized by radiofrequency (rf) co-sputtering deposition technique, and then heat-treated in different annealing atmospheres, i.e. either oxidizing or reducing, with the aim to develop suitable preparation methodologies for controlling the composite structure. Characterization of the samples along the various preparation steps was performed by Rutherford backscattering spectrometry (RBS), transmission electron microscopy and optical absorption spectroscopy. The nonlinear optical coefficient n2 of the nanocomposite films was estimated by the Z-scan technique. Experimental observations showed that copper migration and aggregation depend critically on the annealing conditions, giving rise to quite different stable structures. In particular, for samples heat-treated first in air and then in a H2-Ar gas mixture, the oxidizing atmosphere drives copper towards the surface while the reducing one promotes the subsequent clusterization in a well defined region.

  3. Effect of gas ratio on tribological properties of sputter deposited TiN coatings

    SciTech Connect

    Chavda, Mahesh R.; Chauhan, Kamlesh V.; Rawal, Sushant K.

    2016-05-06

    Titanium nitride (TiN) coatings were deposited on Si, corning glass, pins of mild steel (MS, ϕ3mm), aluminium (Al, ϕ4mm) and brass (ϕ6mm) substratesby DC magnetron sputtering. The argon and nitrogen (Ar:N{sub 2})gas ratio was precisely controlled by Mass Flow Controller (MFC) and was varied systematically at diffract values of 10:10,12:08, 16:04 and 18:02sccm. The structural properties of TiN coatings were characterized by X-ray diffraction (XRD) and its surface topography was studied using field emission scanning electron microscopy (FE-SEM). The tribological properties of TiN coatings were investigated using pin-on-disc tribometer.

  4. Synthesis of alloy AuCu nanoparticles with the L1₀ structure in an ionic liquid using sputter deposition.

    PubMed

    Suzuki, Shushi; Tomita, Yousuke; Kuwabata, Susumu; Torimoto, Tsukasa

    2015-03-07

    Sputter deposition onto ionic liquids (ILs) was applied to synthesize AuCu bimetallic alloy nanoparticles (NPs) dispersed in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF4). A mixed target of Au and Cu materials was used for simultaneous sputter deposition onto the IL under an Ar pressure of 10 Pa. Two types of heating procedures within the range of 323-573 K were examined for control of the structures of NPs, particularly addressing the phase transition of the alloy NPs from the face centered cubic (fcc) structure to the L1₀ structure. One was heating after the sputter deposition in N2 at atmospheric pressure for 1 h. Another was a combination of heating during the sputter deposition and subsequent heating under an Ar pressure from 0.5 to 0.8 Pa for 1 h. Although both cases exhibited lowering of the phase transition temperatures compared with the temperature for the bulk, the latter procedure at 423 K only provided the NPs (approx. 5 nm) consisting of the L1₀ structure in the dispersed manner. A mechanism for forming the L1₀ structure was proposed for explaining the difference between results obtained using the two procedures.

  5. Thermal conductivity of nitride films of Ti, Cr, and W deposited by reactive magnetron sputtering

    SciTech Connect

    Jagannadham, Kasichainula

    2015-05-15

    Nitride films of Ti, Cr, and W were deposited using reactive magnetron sputtering from metal targets in argon and nitrogen plasma. TiN films with (200) orientation were achieved on silicon (100) at the substrate temperature of 500 and 600 °C. The films were polycrystalline at lower temperature. An amorphous interface layer was observed between the TiN film and Si wafer deposited at 600 °C. TiN film deposited at 600 °C showed the nitrogen to Ti ratio to be near unity, but films deposited at lower temperature were nitrogen deficient. CrN film with (200) orientation and good stoichiometry was achieved at 600 °C on Si(111) wafer but the film deposited at 500 °C showed cubic CrN and hexagonal Cr{sub 2}N phases with smaller grain size and amorphous back ground in the x-ray diffraction pattern. An amorphous interface layer was not observed in the cubic CrN film on Si(111) deposited at 600 °C. Nitride film of tungsten deposited at 600 °C on Si(100) wafer was nitrogen deficient, contained both cubic W{sub 2}N and hexagonal WN phases with smaller grain size. Nitride films of tungsten deposited at 500 °C were nonstoichiometric and contained cubic W{sub 2}N and unreacted W phases. There was no amorphous phase formed along the interface for the tungsten nitride film deposited at 600 °C on the Si wafer. Thermal conductivity and interface thermal conductance of all the nitride films of Ti, Cr, and W were determined by transient thermoreflectance technique. The thermal conductivity of the films as function of deposition temperature, microstructure, nitrogen stoichiometry and amorphous interaction layer at the interface was determined. Tungsten nitride film containing both cubic and hexagonal phases was found to exhibit much higher thermal conductivity and interface thermal conductance. The amorphous interface layer was found to reduce effective thermal conductivity of TiN and CrN films.

  6. Deposition of ScAIN thin film using RF-sputtering method

    NASA Astrophysics Data System (ADS)

    Fujii, Satoshi; Kadena, Hayate; Hashimoto, Ken-ya

    2017-07-01

    High-Sc-content ScAlN thin films have attracted significant attention because of their strong piezoelectric properties. Akiyama et al. found that the piezoelectricity of ScAlN thin films increased monotonically with increasing Sc concentration, r. The piezoelectricity reached a maximum at r = 43 at%, at which the piezoelectric coefficient, d33, was five times that of pure AlN. The Akiyama group showed that the d33 of a ScAlN thin film with a high Sc content and wurtzite structure would be much larger than that of the 43 at% Sc film, as calculated by first-principles methods. However, ScAlN thin films typically exhibit a rock-salt rather than a wurtzite structure with increasing Sc content, because ScN has a rock-salt structure at thermal equilibrium. In this report, we studied the deposition of ScAlN thin films using a RF-sputtering method, and it's characterization to clarify the deposition conditions needed for films with high piezoelectricity. The result of micro-Raman spectroscopy measurement shows that, as the Sc content of the ScAlN thin film increases, the peak at ˜800 nm-1 of the A1 mode, due to Sc atoms in the Al sites of the wurtzite structure, shifts to lower frequency for these sputtering conditions. This means that Sc atoms occupy Al sites in the wurtzite structure in the thin film until the Sc content reaches 33%. This phenomenon was also observed for AlGaN thin films. The peak near 700 cm-1 for the ScN thin film, ascribed to a cubic structure, is deformed with increasing Al content.

  7. RF Magnetron Sputtering Deposited W/Ti Thin Film For Smart Window Applications

    NASA Astrophysics Data System (ADS)

    Oksuz, Lutfi; Kiristi, Melek; Bozduman, Ferhat; Uygun Oksuz, Aysegul

    2014-10-01

    Electrochromic (EC) devices can change reversible and persistent their optical properties in the visible region (400-800 nm) upon charge insertion/extraction according to the applied voltage. A complementary type EC is a device containing two electrochromic layers, one of which is anodically colored such as vanadium oxide (V2 O5) while the other cathodically colored such as tungsten oxide (WO3) which is separated by an ionic conduction layer (electrolyte). The use of a solid electrolyte such as Nafion eliminates the need for containment of the liquid electrolyte, which simplifies the cell design, as well as improves safety and durability. In this work, the EC device was fabricated on a ITO/glass slide. The WO3-TiO2 thin film was deposited by reactive RF magnetron sputtering using a 2-in W/Ti (9:1%wt) target with purity of 99.9% in a mixture gas of argon and oxygen. As a counter electrode layer, V2O5 film was deposited on an ITO/glass substrate using V2O3 target with the same conditions of reactive RF magnetron sputtering. Modified Nafion was used as an electrolyte to complete EC device. The transmittance spectra of the complementary EC device was measured by optical spectrophotometry when a voltage of +/-3 V was applied to the EC device by computer controlled system. The surface morphology of the films was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) (Fig. 2). The cyclic voltammetry (CV) for EC device was performed by sweeping the potential between +/-3 V at a scan rate of 50 mV/s.

  8. Silica sputtering as a novel collective stationary phase deposition for microelectromechanical system gas chromatography column: feasibility and first separations.

    PubMed

    Vial, J; Thiébaut, D; Marty, F; Guibal, P; Haudebourg, R; Nachef, K; Danaie, K; Bourlon, B

    2011-05-27

    Since the late 1970s, approaches have been proposed to replace conventional gas chromatography apparatus with silicon-based microfabricated separation systems. Performances are expected to be improved with miniaturization owing to the reduction of diffusion distances and better thermal management. However, one of the main challenges consists in the collective and reproducible fabrication of efficient microelectromechanical system (MEMS) gas chromatography (GC) columns. Indeed, usual coating processes or classical packing with particulate matters are not compatible with the requirements of collective MEMS production in clean room facilities. A new strategy based on the rerouting of conventional microfabrication techniques and widely used in electronics for metals and dielectrics deposition is presented. The originality lies in the sputtering techniques employed for the deposition of the stationary phase. The potential of these novel sputtered stationary phases is demonstrated with silica sputtering applied to the separation of light hydrocarbons and natural gases. If kinetic characteristics of the sputtered open tubular columns were acceptable with 2500 theoretical plates per meter, the limited retention and resolution of light hydrocarbons led us to consider semipacked sputtered columns with rectangular pillars allowing also significant reduction of typical diffusion distances. In that case separations were greatly improved because retention increased and efficiency was close to 5000 theoretical plates per meter. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Sputter target

    DOEpatents

    Gates, Willard G.; Hale, Gerald J.

    1980-01-01

    The disclosure relates to an improved sputter target for use in the deposition of hard coatings. An exemplary target is given wherein titanium diboride is brazed to a tantalum backing plate using a gold-palladium-nickel braze alloy.

  10. Non-conducting interfaces of LaAlO{sub 3}/SrTiO{sub 3} produced in sputter deposition: The role of stoichiometry

    SciTech Connect

    Dildar, I. M.; Boltje, D. B.; Hesselberth, M. H. S.; Aarts, J.; Xu, Q.; Zandbergen, H. W.; Harkema, S.

    2013-03-25

    We have investigated the properties of interfaces between LaAlO{sub 3} films grown on SrTiO{sub 3} substrates singly terminated by TiO{sub 2}. We used RF sputtering in a high-pressure oxygen atmosphere. The films are smooth, with flat surfaces. Transmission electron microscopy shows sharp and continuous interfaces with some slight intermixing. The elemental ratio of La to Al, measured by the energy dispersive X-ray technique, is found to be 1.07. Importantly, we find these interfaces to be non-conducting, indicating that the sputtered interface is not electronically reconstructed in the way reported for films grown by pulsed laser deposition because of the different interplays among stoichiometry, mixing, and oxygen vacancies.

  11. Growth and surface characterization of sputter-deposited molybdenum oxide thin films

    SciTech Connect

    Ramana, Chintalapalle V.; Atuchin, Victor V.; Kesler, V. G.; Kochubey, V. A.; Pokrovsky, L. D.; Shutthanandan, V.; Becker, U.; Ewing, Rodney C.

    2007-04-15

    Molybdenum oxide thin films were produced by magnetron sputtering using a molybdenum (Mo) target. The sputtering was performed in a reactive atmosphere of argon-oxygen gas mixture under varying conditions of substrate temperature (Ts) and oxygen partial pressure (pO2). The effect of Ts and pO2 on the growth and microstructure of molybdenum oxide films was examined in detail using reflection high-energy electron diffraction (RHEED), Rutherford backscattering spectrometry (RBS), energy dispersive X-ray spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) measurements. The analyses indicate that the effect of Ts and pO2 on the microstructure and phase of the grown molybdenum oxide thin films is remarkable. RHEED and RBS results indicate that the films grown at 445 *C under 62.3% O2 pressure were stoichiometric and polycrystalline MoO3. Films grown at lower pO2 were nonstoichiometric MoOx films with the presence of secondary phase. The microstructure of the grown Mo oxide films is discussed and conditions were optimized to produce phase pure, stoichiometric, and highly textured polycrystalline MoO3 films.

  12. Sputtered tungsten-based ternary and quaternary layers for nanocrystalline diamond deposition.

    PubMed

    Walock, Michael J; Rahil, Issam; Zou, Yujiao; Imhoff, Luc; Catledge, Shane A; Nouveau, Corinne; Stanishevsky, Andrei V

    2012-06-01

    Many of today's demanding applications require thin-film coatings with high hardness, toughness, and thermal stability. In many cases, coating thickness in the range 2-20 microm and low surface roughness are required. Diamond films meet many of the stated requirements, but their crystalline nature leads to a high surface roughness. Nanocrystalline diamond offers a smoother surface, but significant surface modification of the substrate is necessary for successful nanocrystalline diamond deposition and adhesion. A hybrid hard and tough material may be required for either the desired applications, or as a basis for nanocrystalline diamond film growth. One possibility is a composite system based on carbides or nitrides. Many binary carbides and nitrides offer one or more mentioned properties. By combining these binary compounds in a ternary or quaternary nanocrystalline system, we can tailor the material for a desired combination of properties. Here, we describe the results on the structural and mechanical properties of the coating systems composed of tungsten-chromium-carbide and/or nitride. These WC-Cr-(N) coatings are deposited using magnetron sputtering. The growth of adherent nanocrystalline diamond films by microwave plasma chemical vapor deposition has been demonstrated on these coatings. The WC-Cr-(N) and WC-Cr-(N)-NCD coatings are characterized with atomic force microscopy and SEM, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and nanoindentation.

  13. Structural and ellipsometric study on tailored optical properties of tantalum oxynitride films deposited by reactive sputtering

    NASA Astrophysics Data System (ADS)

    Bousquet, Angélique; Zoubian, Fadi; Cellier, Joël; Taviot-Gueho, Christine; Sauvage, T.; Tomasella, Eric

    2014-11-01

    Oxynitride materials, which offer the possibility of merging oxide and nitride properties, are increasingly studied for this reason. This paper focuses on assessing the optical properties of tantalum oxynitride thin films deposited by pure tantalum target sputtering in an Ar/O2/N2 reactive atmosphere. First, by changing the oxygen to reactive gas flow rate ratio, and using thermal post-treatment, we deposited films with elemental compositions studied by Rutherford backscattering spectroscopy, ranging from a nitride (close to Ta3N5) to an oxide (close to Ta2O5) with various structures analyzed by x-ray diffraction. Their optical properties were investigated in depth by spectroscopic ellipsometry and UV-visible spectroscopy. For the ellipsometry investigation, we propose a model combining the Tauc-Lorentz law and additional Lorentz oscillator: the first contribution is linked to a semi-conductor or insulator film matrix, and the second one to the presence of conductive TaN crystals. Ellipsometry thus appears as a powerful tool to investigate complex materials such as tantalum oxynitrides. Moreover, we demonstrated that using this deposition method we were able to finely tune the film refractive index from 3.4 to 2.0 (at 1.96 eV) and the optical band gap, specifically from 1.3 to 2.7 eV.

  14. Effect of amorphous C films deposited by RF magnetron sputtering on smoothing K9 glass substrate

    NASA Astrophysics Data System (ADS)

    Deng, Songwen; Qi, Hongji; Wei, Chaoyang; Yi, Kui; Fan, Zhengxiu; Shao, Jianda

    2009-12-01

    Soft X-ray multilayer reflectors must be deposited on super-smooth surface such as super-polished silicon wafers or glasses, which are complicate, time-consuming and expensive to produce. To overcome this shortage, C films deposited by RF magnetron sputtering were considered to smooth the K9 glass substrates' surface in the present paper. The structure of C films was systematically studied by XRD and Raman spectrum. The surface morphology and rms-roughness were obtained by AFM. Then, we calculated the impact of the C layers on the reflectivity curve of Mo/Si soft X-ray multilayer reflector around 13.5 nm. The C films exhibit typical amorphous state. With the increasing of power and thickness, the content of sp3 hybrid bonding decreases while the amount or size of well-organized graphite clusters increases. The surface rms-roughness decreases from 2.4 nm to 0.62 nm after smoothed by an 80 nm thick C layer deposited in 500 W, which is the smoothest C layer surface we have obtained. The calculation results show that the theoretical normal incidence reflectivity of Mo/Si multilayer at 13.5 nm increases from 7% to 63%.

  15. Sputtering of carbon using hydrogen ion beams with energies of 60-800 eV

    NASA Astrophysics Data System (ADS)

    Sidorov, Dmitry S.; Chkhalo, Nikolay I.; Mikhailenko, Mikhail S.; Pestov, Alexey E.; Polkovnikov, Vladimir N.

    2016-11-01

    This article presents the result of a study on the sputtering of carbon films by low-energy hydrogen ions. In particular, the etching rate and surface roughness were measured. The range of energies where the sputtering switches from pure chemical to a combination of chemical and physical mechanisms was determined. It is shown that Sigmund's theory for ion etching does not work well for fields of energy less than 150 eV and that it accurately describes the dependence of a sputtering coefficient on ion energy for energies greater than 300 eV. A strong smoothing effect for the surface of carbon film was also found. This result is interesting in itself and for its significance for the manufacture of super-smooth surfaces for X-ray applications.

  16. Atomic scale calculations of tungsten surface binding energy and beryllium-induced tungsten sputtering

    NASA Astrophysics Data System (ADS)

    Yang, Xue; Hassanein, Ahmed

    2014-02-01

    Tungsten surface binding energy is calculated using classical molecular dynamic simulations with three many-body potentials. We present the consistency in tungsten sputtering yield by beryllium bombardment between molecular dynamic LAMMPS code and binary collision approximation ITMC code using the new surface binding energy (11.75 eV). The commonly used heat of sublimation value (8.68 eV) could lead to overestimated sputtering yield results. The analysis of the sputtered tungsten angular distributions show that molecular dynamic accurately reproduced the [1 1 1] most prominent preferential ejection directions in bcc tungsten, while the distinct shapes by typical MC codes such as ITMC code is caused by the treatment of amorphous target. The ITMC calculated emitted tungsten energy profile matches the Thompson energy spectrum, while the molecular dynamic results generally follow the Falcone energy spectrum.

  17. Influence of metal co-deposition on silicon nanodot patterning dynamics during ion-beam sputtering

    NASA Astrophysics Data System (ADS)

    Gago, R.; Redondo-Cubero, A.; Palomares, F. J.; Vázquez, L.

    2014-10-01

    We address the impact of metal co-deposition in the nanodot patterning dynamics of Si(100) surfaces under normal-incidence 1 keV Ar+ ion-beam sputtering (IBS). In particular, the effect of both the metal nature (Fe or Mo) and flux has been studied. Morphological and compositional evolution were followed by atomic force microscopy (AFM) and Rutherford backscattering spectrometry, respectively. For the same type of impurity, the dynamics is faster for a higher co-deposition flux, which also drives to larger asymptotic roughness and wavelength. Mo co-deposition yields rougher surfaces for a lower metal coverage than Fe and, remarkably, higher ordered patterns. X-ray photoelectron spectroscopy reveals the formation of silicide bonds even before pattern onset, stressing the relevant role of the affinity of the co-deposited metals for silicon. Further, current-sensing AFM performed at the initial and asymptotic stages indicates that the nanodot structures are metal-rich, resulting in coupled compositional and morphological patterns. These results are discussed in terms of phase segregation, morphology-driven local flux variations of impurities and silicide formation. This analysis reveals that the underlying (concurrent) mechanisms of pattern formation are complex since many processes can come into play with a different relative weight depending on the specific patterning conditions. From a practical point of view, it is shown that, by proper selection of the process parameters, IBS with metal co-deposition can be used to tune the dynamics and pattern properties and, interestingly, to produce highly ordered arrays.

  18. Deposition and characterization of titania-silica optical multilayers by asymmetric bipolar pulsed dc sputtering of oxide targets

    NASA Astrophysics Data System (ADS)

    Sagdeo, P. R.; Shinde, D. D.; Misal, J. S.; Kamble, N. M.; Tokas, R. B.; Biswas, A.; Poswal, A. K.; Thakur, S.; Bhattacharyya, D.; Sahoo, N. K.; Sabharwal, S. C.

    2010-02-01

    Titania-silica (TiO2/SiO2) optical multilayer structures have been conventionally deposited by reactive sputtering of metallic targets. In order to overcome the problems of arcing, target poisoning and low deposition rates encountered there, the application of oxide targets was investigated in this work with asymmetric bipolar pulsed dc magnetron sputtering. In order to evaluate the usefulness of this deposition methodology, an electric field optimized Fabry Perot mirror for He-Cd laser (λ = 441.6 nm) spectroscopy was deposited and characterized. For comparison, this mirror was also deposited by the reactive electron beam (EB) evaporation technique. The mirrors developed by the two complementary techniques were investigated for their microstructural and optical reflection properties invoking atomic force microscopy, ellipsometry, grazing incidence reflectometry and spectrophotometry. From these measurements the layer geometry, optical constants, mass density, topography, surface and interface roughness and disorder parameters were evaluated. The microstructural properties and spectral functional characteristics of the pulsed dc sputtered multilayer mirror were found to be distinctively superior to the EB deposited mirror. The knowledge gathered during this study has been utilized to develop a 21-layer high-pass edge filter for radio photoluminescence dosimetry.

  19. Photocatalytic property of titanium dioxide thin films deposited by radio frequency magnetron sputtering in argon and water vapour plasma

    NASA Astrophysics Data System (ADS)

    Sirghi, L.; Hatanaka, Y.; Sakaguchi, K.

    2015-10-01

    The present work is investigating the photocatalytic activity of TiO2 thin films deposited by radiofrequency magnetron sputtering of a pure TiO2 target in Ar and Ar/H2O (pressure ratio 40/3) plasmas. Optical absorption, structure, surface morphology and chemical structure of the deposited films were comparatively studied. The films were amorphous and included a large amount of hydroxyl groups (about 5% of oxygen atoms were bounded to hydrogen) irrespective of the intentional content of water in the deposition chamber. Incorporation of hydroxyl groups in the film deposited in pure Ar plasma is explained as contamination of the working gas with water molecules desorbed by plasma from the deposition chamber walls. However, intentional input of water vapour into the discharge chamber decreased the deposition speed and roughness of the deposited films. The good photocatalytic activity of the deposited films could be attributed hydroxyl groups in their structures.

  20. Influence of oxygen on characteristics of Zn(O,S) thin films deposited by RF magnetron sputtering

    SciTech Connect

    Choi, Ji Hyun; Garay, Adrian Adalberto; Hwang, Su Min; Chung, Chee Won

    2015-07-15

    Zn(O,S) thin films were successfully deposited by reactive sputtering using Ar and O{sub 2} gas mixtures at 473 K. X-ray diffraction patterns revealed that the well crystallized Zn(O,S) films were deposited with increasing oxygen concentration in O{sub 2}/Ar, resulting in a shift of the Zn peak of 28.5° to a higher angle, closer to the ZnO peak of 34.4°. Zn(O,S) films were composed of grains agglomerated from small particles, which grew gradually with increasing oxygen concentration. The depth profiles and energy dispersive spectroscopy results of the films indicated that the O/(O+S) ratio increased from 0.04 to 0.81, and all Zn(O,S) films were Zn rich with uniform concentrations of each component. X-ray photoelectron spectroscopy revealed that, as the oxygen concentration increased to 2%, the ZnS films were transformed to Zn(O,S) films via substitution of oxygen for sulfur.

  1. Effect of sputtering power on Cd/Zn atomic ratio and optical properties of Cu2ZnxCd1-xSnS4 thin films deposited by magnetron sputtering: An experimental and first-principle study

    NASA Astrophysics Data System (ADS)

    Xu, Na; Li, Pingting; Hao, Yunxing; Wang, Xin; Meng, Lei

    2016-09-01

    Cu2ZnxCd1-xSnS4 (CZCTS) thin films were deposited on soda-lime glass (SLG) substrates by rf magnetron sputtering. It is found that the Cd/Zn atomic ratio of kesterite CZCTS increases with the enhancement of sputtering power. The structural, surface morphology and optical properties of the CZCTS thin films deposited at different sputtering power were systemically investigated. The X-ray diffraction (XRD) measurements indicate that all CZCTS thin films are polycrystalline with kesterite structure and no impurity phase is observed. The variation of Cd/Zn atomic ratio in CZCTS results in the shift of the optical bandgap.

  2. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  3. Optical Properties of TiO2 Films Deposited by Reactive Electron Beam Sputtering

    NASA Astrophysics Data System (ADS)

    Kruchinin, V. N.; Perevalov, T. V.; Atuchin, V. V.; Gritsenko, V. A.; Komonov, A. I.; Korolkov, I. V.; Pokrovsky, L. D.; Shih, Cheng Wei; Chin, Albert

    2017-10-01

    Titanium dioxide (anatase, a-TiO2) films have been prepared by electron beam sputtering of a TiO2 target in reactive atmosphere and their structural, microstructural, and optical properties were evaluated by reflection high- energy electron diffraction (RHEED) and x-ray diffraction (XRD) analyses, atomic force microscopy (AFM), and spectroscopic ellipsometry (SE). Different reflection models for determination of film optical parameters were tested and compared. The dispersive optical parameters were defined using the Tauc-Lorentz model by SE in the photon energy range of E = 1.12-4.96 eV. The films were transparent at E < 3 eV, but noticeable absorption was detected at E > 3 eV. The bandgap was estimated at the level of E g ≈ 3.44 eV.

  4. Study on re-sputtering during CN{sub x} film deposition through spectroscopic diagnostics of plasma

    SciTech Connect

    Liang, Peipei; Yang, Xu; Li, Hui; Cai, Hua; Sun, Jian; Xu, Ning; Wu, Jiada

    2015-10-15

    A nitrogen-carbon plasma was generated during the deposition of carbon nitride (CN{sub x}) thin films by pulsed laser ablation of a graphite target in a discharge nitrogen plasma, and the optical emission of the generated nitrogen-carbon plasma was measured for the diagnostics of the plasma and the characterization of the process of CN{sub x} film deposition. The nitrogen-carbon plasma was recognized to contain various species including nitrogen molecules and molecular ions excited in the ambient N{sub 2} gas, carbon atoms and atomic ions ablated from the graphite target and CN radicals. The temporal evolution and spatial distribution of the CN emission and their dependence on the substrate bias voltage show two groups of CN radicals flying in opposite directions. One represents the CN radicals formed as the products of the reactions occurring in the nitrogen-carbon plasma, revealing the reactive deposition of CN{sub x} film due to the reactive expansion of the ablation carbon plasma in the discharge nitrogen plasma and the effective formation of gaseous CN radicals as precursors for CN{sub x} film growth. The other one represents the CN radicals re-sputtered from the growing CN{sub x} film by energetic plasma species, evidencing the re-sputtering of the growing film accompanying film growth. And, the re-sputtering presents ion-induced sputtering features.

  5. Dielectric, optical and electric studies on nanocrystalline Ba5Nb4O15 thin films deposited by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Anil Kumar, C.; Pamu, D.

    2015-06-01

    We report the fabrication of nanocrystalline Ag/BNO/Pt/Ti/SiO2/Si thin film capacitors by RF magnetron sputtering with different film thicknesses. The effect of Ba5Nb4O15 (BNO) thickness on structural, microstructural, electrical, optical and dielectric properties is investigated for the first time. BNO sputtering target prepared is by mechanochemical synthesis method to eliminate the subordinate phases. As deposited thin films were X-ray amorphous and crystallinity is induced after annealing at 700 °C. Upon annealing, refractive indices of the films enhanced whereas the bandgap is decreased and are in the range of 1.89-2.16 and 4.07-4.24, respectively. With an increase in thickness, the dielectric properties improved substantially, which is described by the representation of a dead layer connected in series with a bulk region of the BNO film. The extracted values of thickness and dielectric constant for the dead layer found to be 15.21 nm and 37.03, correspondingly. The activation energy of the mobile charge carriers obtained using the Arrhenius relation are found to be 0.254, 0.036 and 0.027 eV, for the films with 150, 250 and 450 nm, respectively. The leakage current density found to decrease with thickness and found to be 2.5 × 10-6 A/cm2 at applied voltage of 50 kV/cm. The J-E characteristics of the BNO films show a combined response of grain, grain boundaries and film-electrode interfaces. It is interesting to note that in the negative electric field region, conduction is ohmic in nature whereas in the positive field region BNO films exhibit both ohmic and the space charge-limited current mechanisms. The achieved dielectric, electrical and optical properties make these films suitable for MIC, CMOS and optoelectronic applications.

  6. Sputtering and ion plating for aerospace applications

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1981-01-01

    Sputtering and ion plating technologies are reviewed in terms of their potential and present uses in the aerospace industry. Sputtering offers great universality and flexibility in depositing any material or in the synthesis of new ones. The sputter deposition process has two areas of interest: thin film and fabrication technology. Thin film sputtering technology is primarily used for aerospace mechanical components to reduce friction, wear, erosion, corrosion, high temperature oxidation, diffusion and fatigue, and also to sputter-construct temperature and strain sensors for aircraft engines. Sputter fabrication is used in intricate aircraft component manufacturing. Ion plating applications are discussed in terms of the high energy evaporant flux and the high throwing power. Excellent adherence and 3-dimensional coverage are the primary attributes of this technology.

  7. Sputtering and ion plating for aerospace applications

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1981-01-01

    Sputtering and ion plating technologies are reviewed in terms of their potential and present uses in the aerospace industry. Sputtering offers great universality and flexibility in depositing any material or in the synthesis of new ones. The sputter deposition process has two areas of interest: thin film and fabrication technology. Thin film sputtering technology is primarily used for aerospace mechanical components to reduce friction, wear, erosion, corrosion, high temperature oxidation, diffusion and fatigue, and also to sputter-construct temperature and strain sensors for aircraft engines. Sputter fabrication is used in intricate aircraft component manufacturing. Ion plating applications are discussed in terms of the high energy evaporant flux and the high throwing power. Excellent adherence and 3 dimensional coverage are the primary attributes of this technology.

  8. Differences in the bone differentiation properties of MC3T3-E1 cells on polished bulk and sputter-deposited titanium specimens.

    PubMed

    Oya, Kei; Tanaka, Yuta; Moriyama, Yoshihisa; Yoshioka, Yuki; Kimura, Tsuyoshi; Tsutsumi, Yusuke; Doi, Hisashi; Nomura, Naoyuki; Noda, Kazuhiko; Kishida, Akio; Hanawa, Takao

    2010-08-01

    The roughness and cleanness of a titanium surface must be controlled in order to investigate the expression mechanism of hard tissue compatibility on titanium. In this study, osteogenic MC3T3-E1 cells were cultured and differentiation-induced on bulk and sputter-deposited titanium specimens, and the osteogenesis were investigated. For the preparation of bulk specimens, titanium discs were mirror-polished. On the other hand, titanium was sputter-deposited on smooth and clean cover glasses as sputter-deposited specimens. As a result, no significant difference was observed in the cell morphology and attached number. On the other hand, the time showing maximum activity in the alkaline phosphatase and gene expressions, which are related to bone differentiation on the bulk titanium, were superior to those on the sputter-deposited titanium. From the surface observation of the specimens with a scanning electron microscope and a scanning probe microscope, the surface on the sputter-deposited titanium was more uniform and cleaner than that on the bulk titanium. According to X-ray photoelectron spectroscopy, the thickness of surface oxide film on the sputter-deposited titanium was smaller than that on the bulk titanium. In addition, the proportions of TiO and Ti(2)O(3) in the surface oxide film on the sputter-deposited titanium were larger than those on the bulk titanium. These differences might influence the differentiation of osteoblastic cells.

  9. Indium tin oxide films deposited by thermionic-enhanced DC magnetron sputtering on unheated polyethylene terephthalate polymer substrate

    SciTech Connect

    Lan, Y.F.; Peng, W.C.; Lo, Y.H.; He, J.L.

    2009-08-05

    Indium tin oxide thin films were deposited onto polyethylene terephthalate substrates via thermionic enhanced DC magnetron sputtering at low substrate temperatures. The structural, optical and electrical properties of these films are methodically investigated. The results show that compared with traditional sputtering, the films deposited with thermionic emission exhibit higher crystallinity, and their optical and electrical properties are also improved. Indium tin oxide films deposited by utilizing thermionic emission exhibit an average visible transmittance of 80% and an electrical resistivity of 4.5 x 10{sup -4} {Omega} cm, while films made without thermionic emission present an average visible transmittance of 74% and an electrical resistivity of 1.7 x 10{sup -3} {Omega} cm.

  10. The influence of discharge power and heat treatment on calcium phosphate coatings prepared by RF magnetron sputtering deposition.

    PubMed

    Yonggang, Yan; Wolke, J G C; Yubao, Li; Jansen, J A

    2007-06-01

    Ca-P coatings with different Ca/P ratio and composition were successfully prepared by RF magnetron sputtering deposition. The Ca/P ratio, phase composition, structure and morphological properties were characterized by XRD, FTIR, EDS and SEM analyses. All the as-sputtered coatings were amorphous and after IR-irradiation the coatings altered into a crystalline phase. The obtained coatings had a Ca/P ratio that varied from 0.55 to 2.10 and different phase compositions or mixtures of apatite, beta-pyrophosphate and beta-tricalciumphosphate structures were formed. Evidently, the phase compositions of the sputtered coatings are determined not only by the discharge power ratio of the hydroxylapatite and calcium pyrophosphate targets but also by the annealing temperature.

  11. Magnetic and magneto-optical properties of Co/Nb-codoped TiO2 films deposited by gas flow sputtering

    NASA Astrophysics Data System (ADS)

    Sakuma, H.; Nagamatsu, T.; Kashiwakura, T.; Ishii, K.

    2010-04-01

    Titanium dioxide thin films codoped with Co and Nb (Co/Nb-codoped TiO2 films) were fabricated by a low-energy deposition process, gas flow sputtering. No metallic Co or Nb phase was detected by X-ray diffraction and X-ray photoelectron spectroscopy, suggesting that the Co and Nb ions have the oxidation states 2+ and 5+, respectively. The films show a relatively large Faraday rotation and magnetic circular dichroism on the order of 103 deg/cm.

  12. Characterization and Performance of Magnetron-Sputtered Zirconium Coatings Deposited on 9Cr-1Mo Steel

    NASA Astrophysics Data System (ADS)

    Singh, Akash; Murugesan, Somasundaram; Parameswaran, P.; Priya, R.; Thirumurugessan, R.; Muthukumar, N.; Mohandas, E.; Kamachi Mudali, U.; Krishnamurthi, J.

    2016-11-01

    Zirconium coatings of different thicknesses have been deposited at 773 K on 9Cr-1Mo steel substrate using pulsed DC magnetron sputtering. These coatings were heat treated in vacuum at two different temperatures (1173 and 1273 K) for one hour. X-ray diffraction (XRD) analysis of Zr-coated samples revealed the formation of α-phase (HCP structure) of Zr. XRD analysis of heat-treated samples show the presence of Zr3Fe and Zr2Fe intermetallics. The lattice parameter of these coatings was calculated, and it matches with the bulk values when the thickness reached 2µm. In order to understand this, crystallite size and strain values of these coatings were calculated from XRD plots employing Williamson-Hall method. In order to assess the performance of the coatings, systematic corrosion tests were carried out. The corrosion current density calculated from the polarization behavior showed that the corrosion current density of the uncoated 9Cr-1Mo steel was higher than the coated sample before and after the heat treatment. Studies using electrochemical impedance spectroscopy confirmed that the coated steel has higher impedance than the uncoated steel. The corrosion resistance of 9Cr1Mo steel had improved after Zr coating. However, the corrosion resistance of the coating after heat treatment decreased when compared to the as-deposited coating. The microstructure and composition of the surface oxide film influence the corrosion resistance of the Zr-coated 9Cr1Mo steel.

  13. Nanomechanical and microstructural characterization of sputter deposited ZnO thin films

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Vipul; Chowdhury, Rajib; Jayaganthan, R.

    2016-12-01

    The nano-mechanical properties of ZnO thin films deposited at different substrate temperature such as (RT) 25 °C, 100 °C, 200 °C, and 300 °C using DC-sputtering on Corning glass substrate were investigated. The ZnO thin films are found to be predominately c-axis (002) oriented. The crystal structure is sensitive to increasing substrate temperature and new set of crystal planes become visible at 300 °C as thin films become highly polycrystalline. The presence of (103) crystal plane is more pronounced with the increasing substrate temperature. However, high crystallinity and peak intensity ratio I(002)/I(103) (counts) is highest for thin films deposited at 100 °C, which is attributed for high hardness and better adhesive properties observed for ZnO thin films. Concomitantly, no major sudden burst of displacement 'pop-in' event in load-displacement curve of thin films observed during indentation, indicating the films are dense with low defects and adhered strongly to the substrate.

  14. C-axis orientated AlN films deposited using deep oscillation magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Lin, Jianliang; Chistyakov, Roman

    2017-02-01

    Highly <0001> c-axis orientated aluminum nitride (AlN) films were deposited on silicon (100) substrates by reactive deep oscillation magnetron sputtering (DOMS). No epitaxial favored bond layer and substrate heating were applied for assisting texture growth. The effects of the peak target current density (varied from 0.39 to 0.8 Acm-2) and film thickness (varied from 0.25 to 3.3 μm) on the c-axis orientation, microstructure, residual stress and mechanical properties of the AlN films were investigated by means of X-ray diffraction rocking curve methodology, transmission electron microscopy, optical profilometry, and nanoindentation. All AlN films exhibited a <0001> preferred orientation and compressive residual stresses. At similar film thicknesses, an increase in the peak target current density to 0.53 Acm-2 improved the <0001> orientation. Further increasing the peak target current density to above 0.53 Acm-2 showed limited contribution to the texture development. The study also showed that an increase in the thickness of the AlN films deposited by DOMS improved the c-axis alignment accompanied with a reduction in the residual stress.

  15. Thermochromic VO{sub 2} nanorods made by sputter deposition: Growth conditions and optical modeling

    SciTech Connect

    Li Shuyi; Niklasson, Gunnar A.; Granqvist, Claes G.; Namura, Kyoko; Suzuki, Motofumi

    2013-07-21

    Reactive dc magnetron sputtering onto glass-based substrates yielded deposits of thermochromic VO{sub 2} with well-developed nanorods and nanowires. Their formation was promoted by high substrate temperature (above {approx}500 Degree-Sign C), sufficient film thickness, proper inlet of the reactive gas, dispersed gold 'seeds,' and pronounced substrate roughness. Rutherford back scattering ascertained mass thicknesses, scanning electron microscopy depicted the nanostructures, and glancing incidence X-ray diffraction proved that single-phase VO{sub 2} was normally formed. Spectrophotometric measurements of total and diffuse transmittance and reflectance on VO{sub 2} thin films, at room temperature and {approx}100 Degree-Sign C, allowed us to determine complex dielectric functions below and above the 'critical' temperature for thermochromic switching ({approx}68 Degree-Sign C). These data were then used in computations based on the Bruggeman effective medium theory applied to randomly oriented prolate spheroidal structural units to derive the optical properties of the deposits. Experimental and computed data on spectral absorptance were found to be in good qualitative agreement.

  16. Highly phosphorus-doped crystalline Si layers grown by pulse-magnetron sputter deposition

    NASA Astrophysics Data System (ADS)

    Fenske, Frank; Gorka, Benjamin

    2009-04-01

    The electrical properties of highly phosphorus-doped crystalline silicon films deposited by pulse-magnetron sputtering were studied. The films were grown, 450 nm thick, on Si(100) and Si(111) wafers at low substrate temperatures Ts of 450-550 °C and post-treated by rapid thermal annealing (RTA) and plasma hydrogenation (PH). In the case of films grown on Si(100), at all values of Ts postgrowth treatment by RTA resulted in an increase in the dopant activation up to 100% and of the Hall mobility to about bulklike values of 50 cm2 V-1 s-1. This result suggests high structural quality of the films on Si(100). The Si(111) films, which are typically more defective, exhibit a completely different behavior with a strong dependence of the electrical dopant activation and the Hall mobility on Ts. By post-treatment a maximum P donor activation level of 22% could be obtained. The variation in the post-treatment procedure (RTA+PH and PH+RTA) for the films deposited at high Ts showed that PH results only in minor changes in the film properties. The different influence of RTA and PH is discussed in terms of the different defect structure of the films. These investigations reveal that high Ts and after-treatment by RTA are the main preconditions for optimal electrical film properties.

  17. Structure evolution of zinc oxide thin films deposited by unbalance DC magnetron sputtering

    SciTech Connect

    Aryanto, Didik; Marwoto, Putut; Sugianto; Sudiro, Toto; Birowosuto, Muhammad D.

    2016-04-19

    Zinc oxide (ZnO) thin films are deposited on corning glass substrates using unbalanced DC magnetron sputtering. The effect of growth temperature on surface morphology and crystallographic orientation of ZnO thin film is studied using atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The surface morphology and crystallographic orientation of ZnO thin film are transformed against the increasing of growth temperature. The mean grain size of film and the surface roughness are inversely and directly proportional towards the growth temperature from room temperature to 300 °C, respectively. The smaller grain size and finer roughness of ZnO thin film are obtained at growth temperature of 400 °C. The result of AFM analysis is in good agreement with the result of XRD analysis. ZnO thin films deposited in a series of growth temperatures have hexagonal wurtzite polycrystalline structures and they exhibit transformations in the crystallographic orientation. The results in this study reveal that the growth temperature strongly influences the surface morphology and crystallographic orientation of ZnO thin film.

  18. Biocompatibility and Surface Properties of TiO2 Thin Films Deposited by DC Magnetron Sputtering

    PubMed Central

    López-Huerta, Francisco; Cervantes, Blanca; González, Octavio; Hernández-Torres, Julián; García-González, Leandro; Vega, Rosario; Herrera-May, Agustín L.; Soto, Enrique

    2014-01-01

    We present the study of the biocompatibility and surface properties of titanium dioxide (TiO2) thin films deposited by direct current magnetron sputtering. These films are deposited on a quartz substrate at room temperature and annealed with different temperatures (100, 300, 500, 800 and 1100 °C). The biocompatibility of the TiO2 thin films is analyzed using primary cultures of dorsal root ganglion (DRG) of Wistar rats, whose neurons are incubated on the TiO2 thin films and on a control substrate during 18 to 24 h. These neurons are activated by electrical stimuli and its ionic currents and action potential activity recorded. Through X-ray diffraction (XRD), the surface of TiO2 thin films showed a good quality, homogeneity and roughness. The XRD results showed the anatase to rutile phase transition in TiO2 thin films at temperatures between 500 and 1100 °C. This phase had a grain size from 15 to 38 nm, which allowed a suitable structural and crystal phase stability of the TiO2 thin films for low and high temperature. The biocompatibility experiments of these films indicated that they were appropriated for culture of living neurons which displayed normal electrical behavior. PMID:28788667

  19. Rapidly switched wettability of titania films deposited by dc magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Shirolkar, Mandar; Kazemian Abyaneh, Majid; Singh, Akanksha; Tomer, Anju; Choudhary, Ram; Sathe, Vasant; Phase, Deodatta; Kulkarni, Sulabha

    2008-08-01

    Rapid switching (5-15 minutes) in the wettability of titania (TiO2) thin films in the anatase phase has been observed after UV irradiation. The film surface becomes superhydrophilic when exposed to UV radiation. The relationship between wettability, thickness and crystallinity of TiO2 films has been investigated. Amorphous and anatase TiO2 thin films have been deposited by varying the argon to oxygen gas ratio, using the reactive dc magnetron sputtering technique. It was found that the gas ratio primarily affects thickness, crystallinity, morphology and wettability of the films. The highest contact angle that has been reported so far, namely, 170°-176°, has been observed for film thickness varying from 112-500 nm in the case of pristine anatase TiO2 films. On the other hand, amorphous films show a variation in the contact angle from 120° to 140° as the thickness varied from 70 to 145 nm. The deposition is extremely robust and has an ultralow hysteresis in the contact angle. The films exhibit a morphology similar to the lotus leaf and the water hyacinth.

  20. Vanadium oxide thin films for bolometric applications deposited by reactive pulsed dc sputtering

    SciTech Connect

    Fieldhouse, N.; Pursel, S. M.; Carey, R.; Horn, M. W.; Bharadwaja, S. S. N.

    2009-07-15

    Vanadium oxide (VO{sub x}) thin films were deposited by reactive pulse dc magnetron sputtering process using a pure vanadium metal target. The structural, microstructure, and electrical properties were correlated as a function of processing parameters such as substrate temperature, Ar:O partial pressures ratios, and pulsed dc power to fabricate these films. The VO{sub x} films deposited at various substrate temperatures between 30 and 300 degree sign C using a range of oxygen to argon partial pressure ratios exhibited huge variation in their microstructure even though most of them are amorphous to x-ray diffraction technique. In addition, the electrical properties such as temperature coefficient of resistance (TCR), resistivity, and noise levels were influenced by film microstructure. The TCRs of the VO{sub x} films were in the range of -1.1% to -2.4% K{sup -1} having resistivity values of 0.1-100 {Omega} cm. In particular, films grown at lower substrate temperatures with higher oxygen partial pressures have shown finer columnar grain structure and exhibited larger TCR and resistivity.

  1. Thermochromic VO2 nanorods made by sputter deposition: Growth conditions and optical modeling

    NASA Astrophysics Data System (ADS)

    Li, Shu-Yi; Namura, Kyoko; Suzuki, Motofumi; Niklasson, Gunnar A.; Granqvist, Claes G.

    2013-07-01

    Reactive dc magnetron sputtering onto glass-based substrates yielded deposits of thermochromic VO2 with well-developed nanorods and nanowires. Their formation was promoted by high substrate temperature (above ˜500 °C), sufficient film thickness, proper inlet of the reactive gas, dispersed gold "seeds," and pronounced substrate roughness. Rutherford back scattering ascertained mass thicknesses, scanning electron microscopy depicted the nanostructures, and glancing incidence X-ray diffraction proved that single-phase VO2 was normally formed. Spectrophotometric measurements of total and diffuse transmittance and reflectance on VO2 thin films, at room temperature and ˜100 °C, allowed us to determine complex dielectric functions below and above the "critical" temperature for thermochromic switching (˜68 °C). These data were then used in computations based on the Bruggeman effective medium theory applied to randomly oriented prolate spheroidal structural units to derive the optical properties of the deposits. Experimental and computed data on spectral absorptance were found to be in good qualitative agreement.

  2. Transparent conducting amorphous Zn-Sn-O films deposited by simultaneous dc sputtering

    NASA Astrophysics Data System (ADS)

    Moriga, Toshihiro; Hayashi, Yukako; Kondo, Kumiko; Nishimura, Yusuke; Murai, Kei-Ichiro; Nakabayashi, Ichiro; Fukumoto, Hidenori; Tominaga, Kikuo

    2004-07-01

    The films of ZnO-SnO2 system were deposited on glass substrates by simultaneous dc magnetron sputtering apparatus, in which ZnO and SnO2:Sb (Sb2O5 3 wt % doped) targets faced each other. The substrate temperatures were maintained at 150, 250, and 350 °C, respectively. As an experimental parameter, current ratio δ=IZn/(IZn+ISn), which corresponds to ZnO target current (IZn) divided by the sum of ZnO and SnO2:Sb target currents (IZn+ISn), was adopted. Amorphous transparent films appeared for 0.50<=δ<=0.73, which could be correlated to compositions as [Zn]/([Sn]+[Zn])=0.33-0.67 by x-ray fluorescent analysis. At [Zn]/([Sn]+[Zn])=1/2 (δ=0.62), 2/3 (δ=0.73) and all other ratios in as-deposited films, neither crystalline ZnSnO3 nor Zn2SnO4 was obtained. Minimum resistivity of 4-6×10-2 Ω cm was found at δ=0.50, whose composition was approximately SnO2.ZnSnO3. Resistivity increased linearly with an increase of the current ratio, until the composition reached Zn2SnO4. The amorphous phase showed a constant Hall mobility of ~10 cm2/V s and a linear decrease in carrier concentration with increasing Zn content. .

  3. Room temperature deposition of crystalline indium tin oxide films by cesium-assisted magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Lee, Deuk Yeon; Baik, Hong-Koo

    2008-08-01

    Indium tin oxide (ITO) films were deposited on a Si (1 0 0) substrate at room temperature by cesium-assisted magnetron sputtering. Including plasma characteristics, the structural, electrical, and optical properties of deposited films were investigated as a function of cesium partial vapor pressure controlled by cesium reservoir temperature. We calculated the cesium coverage on the target surface showing maximum formation efficiency of negative ions by means of the theoretical model. Cesium addition promotes the formation efficiency of negative ions, which plays important role in enhancing the crystallinity of ITO films. In particular, the plasma density was linearly increased with cesium concentrations. The resultant decrease in specific resistivity and increase in transmittance (82% in the visible region) at optimum cesium concentration (4.24 × 10 -4 Ω cm at 80 °C of reservoir temperature) may be due to enhanced crystallinity of ITO films. Excess cesium incorporation into ITO films resulted in amorphization of its microstructure leading to degradation of ITO crystallinity. We discuss the cesium effects based on the growth mechanism of ITO films and the plasma density.

  4. Studies on Nanostructure Aluminium Thin Film Coatings Deposited using DC magnetron Sputtering Process

    NASA Astrophysics Data System (ADS)

    Singh M, Muralidhar; G, Vijaya; MS, Krupashankara; Sridhara, B. K.; Shridhar, T. N.

    2016-09-01

    Nanostructured thin film metallic coatings has become an area of intense research particularly in applications related solar, sensor technologies and many other optical applications such as laser windows, mirrors and reflectors. Thin film metallic coatings were deposited using DC magnetron sputtering process. The deposition rate was varied to study its influence on optical behavior of Aluminum thin films at a different argon flow rate. Studies on the optical response of these nanostructure thin film coatings were characterized using UV-VIS-NIR spectrophotometer with integrating sphere in the wavelength range of (250-2500nm) and Surface morphology were carried out using atomic force microscope with roughness ranging from 2 to 20nm and thickness was measured using Dektak measuring instrument. The reflection behavior of aluminium coatings on polycarbonate substrates has been evaluated. UV-VIS-NIR Spectrophotometer analysis indicates higher reflectance of 96% for all the films in the wavelength range of 250 nm to 2500 nm. Nano indentation study revealed that there was a considerable change in hardness values of the films prepared at different conditions.

  5. Surface modification of tantalum pentoxide coatings deposited by magnetron sputtering and correlation with cell adhesion and proliferation in in vitro tests

    NASA Astrophysics Data System (ADS)

    Zykova, A.; Safonov, V.; Goltsev, A.; Dubrava, T.; Rossokha, I.; Donkov, N.; Yakovin, S.; Kolesnikov, D.; Goncharov, I.; Georgieva, V.

    2016-03-01

    The effect was analyzed of surface treatment by argon ions on the surface properties of tantalum pentoxide coatings deposited by reactive magnetron sputtering. The structural parameters of the as-deposited coatings were investigated by means of transmission electron microscopy, atomic force microscopy and scanning electron microscopy. X-ray diffraction profiles and X-ray photoelectron spectra were also acquired. The total surface free energy (SFE), the polar, dispersion parts and fractional polarities, were estimated by the Owens-Wendt-Rabel-Kaeble method. The adhesive and proliferative potentials of bone marrow cells were evaluated for both Ta2O5 coatings and Ta2O5 coatings deposited by simultaneous bombardment by argon ions in in vitro tests.

  6. Morphology and structure evolution of tin-doped indium oxide thin films deposited by radio-frequency magnetron sputtering: The role of the sputtering atmosphere

    SciTech Connect

    Nie, Man Mete, Tayfun; Ellmer, Klaus

    2014-04-21

    The microstructure and morphology evolution of tin-doped indium oxide (ITO) thin films deposited by radio-frequency magnetron sputtering in different sputtering atmospheres were investigated by X-ray diffraction, X-ray reflectivity, and atomic force microscopy. The surface roughness w increases with increasing film thickness d{sub f}, and exhibits a power law behavior w ∼ d{sub f}{sup β}. The roughness decreases with increasing O{sub 2} flow, while it increases with increasing H{sub 2} flow. The growth exponent β is found to be 0.35, 0.75, and 0.98 for depositions in Ar/10%O{sub 2}, pure Ar, and Ar/10%H{sub 2} atmospheres, respectively. The correlation length ξ increases with film thickness also with a power law according to ξ ∼ d{sub f}{sup z} with exponents z = 0.36, 0.44, and 0.57 for these three different gas atmospheres, respectively. A combination of local and non-local growth modes in 2 + 1 dimensions is discussed for the ITO growth in this work.

  7. Evaluation of structure and material properties of RF magnetron sputter-deposited yttria-stabilized zirconia thin films

    NASA Astrophysics Data System (ADS)

    Piascik, Jeffrey Robert

    Over the past several decades, research has focused on utilizing ceramic materials in new technological applications. Their uses have been primarily in applications that involve high temperatures or corrosive environments. Unfortunately, ceramic materials have been limited especially since they can be brittle, failing in a sudden and catastrophic manner. A strong emphasis on understanding mechanical properties of ceramics and ways to improving their strength and toughness, has led to many new technologies. The present work is part of a larger research initiative that is aimed at using RF magnetron sputter deposition of yttria-stabilized zirconia to improve the fracture toughness of brittle substrates (more specifically dental ceramics). Partially-stabilized zirconia (PSZ) has been studied extensively, due to its high temperature stability and stress-induced tetragonal to monoclinic (T⇒M) martensitic phase transformation. RF magnetron sputtering was chosen as the deposition method because of its versatility, especially the ability to deposit oxides at low temperatures. Initial investigations focused on the development of process-structure-properties of YSZ sputtered deposited thin films. The YSZ thin films were deposited over a range of temperatures (22--300°C), pressures (5--25 mTorr), and gas compositions (Ar:O2 ratio). Initial studies characterized a select set of properties in relation to deposition parameters including: refractive index, structure, and film stress. X-ray Diffraction (XRD) showed that the films are comprised of mainly monoclinic and tetragonal crystal phases. The film refractive index determined by prism coupling, depends strongly on deposition conditions and ranged from 1.959 to 2.223. Wafer bow measurements indicate that the sputtered YSZ films can have initial stress ranging from 86 MPa tensile to 192 MPa compressive, depending on the deposition parameters. Exposure to ambient conditions (25°C, 75% relative humidity) led to large increase

  8. Dielectric properties of tetragonal tungsten bronze films deposited by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Bodeux, Romain; Michau, Dominique; Josse, Michaël; Maglione, Mario

    2014-12-01

    Tetragonal tungsten bronze (TTB) films have been synthesised on Pt(111)/TiO2/SiO2/Si substrates from Ba2LnFeNb4O15 ceramics (Ln = La, Nd, Eu) by RF magnetron sputtering. X-ray diffraction measurements evidenced the multi-oriented nature of films with some degrees of preferential orientation along (111). The dependence of the dielectric properties on temperature and frequency has been investigated. The dielectric properties of the films are similar to those of the bulk, i.e., ɛ ˜150 and σ ˜10-6 Ω-1 cm-1 at 1 MHz and room temperature. The films exhibit two dielectric anomalies which are attributed to Maxwell Wagner polarization mechanism and relaxor behaviour. Both anomalies are sensitive to post-annealing under oxygen atmosphere and their activation energies are similar Ea ˜0.30 eV. They are explained in terms of electrically heterogeneous contributions in the films.

  9. The influence of precursor films on CIGS films prepared by ion beam sputtering deposition

    NASA Astrophysics Data System (ADS)

    Zhao, Jun; Fan, Ping; Liang, Guangxing; Zheng, Zhuanghao; Zhang, Dongping; Chen, Chaoming

    2013-12-01

    The CuInGa(CIG) precursor films were grown by ion beam sputtering continuously CuGa/CuIn and CuIn/CuGa, and then selenized CIG to fabricate CIGS absorber films on molybdenum substrates . They were annealed in the same vacuum chamber and under the same temperature (500°C). The CIGS thin films were characterized with X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) in order to study the microstructures, composition, surface morphology, electrical properties, respectively. The results showed that the CIGS thin films appeared smooth and compact with a sequence of Mo/CuGa/CuIn/Se, which were mainly of chalcopyrite structure. The CIGS thin films got the strongest diffraction peak intensity and were with good crystalline quality.

  10. Annealing induced morphological modifications in PTFE films deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Tripathi, S.; De, Rajnarayan; Rao, K. Divakar; Haque, S. Maidul; Misal, J. S.; Prathap, C.; Das, S. C.; Ganesan, V.; Sahoo, N. K.

    2017-05-01

    As grown RF magnetron sputtered polytetrafluoroethylene (PTFE) thin films were subjected to vacuum annealing at optimized elevated temperature of 200° C for varying time duration and corresponding surface morphological changes were recorded. The columnar structures appearing after an annealing duration of 2 hours are interesting for fabrication of rough PTFE surfaces towards possible applications in hydrophobicity along with high transmission. Supported by transmission data, the AFM images show a transformation of smooth PTFE surface with less than 2 nm rms roughness to a very rough surface. The results are interpreted in terms of thermal energy induced modifications only at the surface without any change in the original bonding structure on the surface and inside the sample. Preliminary studies indicate that the optimization of roughness and transmission together on such surfaces may lead to high water contact angles.

  11. C/CrC nanocomposite coating deposited by magnetron sputtering at high ion irradiation conditions

    SciTech Connect

    Zhou, Z.; Rainforth, W. M.; Gass, M. H.; Bleloch, A.; Ehiassarian, A. P.; Hovsepian, P. Eh.

    2011-10-01

    CrC with the fcc NaCl (B1) structure is a metastable phase that can be obtained under the non-equilibrium conditions of high ion irradiation. A nano-composite coating consisting of amorphous carbon embedded in a CrC matrix was prepared via the unbalanced magnetron sputtering of graphite and Cr metal targets in Ar gas with a high ionized flux (ion-to-neutral ratio Ji/Jn = 6). The nanoscale amorphous carbon clusters self-assembled into layers alternated by CrC, giving the composite a multilayer structure. The phase, microstructure, and composition of the coating were characterized using x-ray diffraction, transmission electron microscopy, and aberration corrected scanning transmission electron microscopy coupled with electron energy loss spectroscopy. The interpretation of the true coating structure, in particular the carbide type, is discussed.

  12. Phase Control of RF Sputtered SnSx with Post-Deposition Annealing for a Pseudo-Homojunction Photovoltaic Device

    NASA Astrophysics Data System (ADS)

    Nasr, J. R.; Cordell, J. J.; Gurunathan, R. L.; Brownson, J. R. S.; Horn, M. W.

    2017-02-01

    Tin (II) Monosufide (SnS) is an interesting material for thin film photovoltaics. n- and p-type sputter-deposited SnSx have been investigated for use in a homojunction photovoltaic device. Post-deposition vacuum heat treatment of as-deposited amorphous films was found to produce n-type SnSx and p-type SnS depending upon in situ vacuum anneal time and temperature. Annealing temperatures varied from 300°C to 400°C at durations from 20 min to 60 min under high vacuum. Results show clear photoresponse for both n-type and p-type using Pd contacts.

  13. Reticle blanks for extreme ultraviolet lithography: Ion beam sputter deposition of low defect density Mo/Si multilayers

    SciTech Connect

    Vernon, S.P.; Kania, D.R.; Kearney, P.A.; Levesque, R.A.; Hayes, A.V.; Druz, B.; Osten, E.; Rajan, R.; Hedge, H.

    1996-06-24

    We report on growth of low defect density Mo/Si multilayer (ML) coatings. The coatings were grown in a deposition system designed for EUVL reticle blank fabrication. Complete, 81 layer, high reflectance Mo/Si ML coatings were deposited on 150 mm dia (100) oriented Si wafer substrates using ion beam sputter deposition. Added defects, measured by optical scattering, correspond to defect densities of 2x10{sup -2}/cm{sup 2}. This represents a reduction in defect density of Mo/Si ML coatings by a factor of 10{sup 5}.

  14. Energy Deposition Processes in Titan's Upper Atmosphere

    NASA Technical Reports Server (NTRS)

    Sittler, Edward C., Jr.; Bertucci, Cesar; Coates, Andrew; Cravens, Tom; Dandouras, Iannis; Shemansky, Don

    2008-01-01

    Most of Titan's atmospheric organic and nitrogen chemistry, aerosol formation, and atmospheric loss are driven from external energy sources such as Solar UV, Saturn's magnetosphere, solar wind and galactic cosmic rays. The Solar UV tends to dominate the energy input at lower altitudes of approximately 1100 km but which can extend down to approximately 400 km, while the plasma interaction from Saturn's magnetosphere, Saturn's magnetosheath or solar wind are more important at higher altitudes of approximately 1400 km, but the heavy ion plasma [O(+)] of approximately 2 keV and energetic ions [H(+)] of approximately 30 keV or higher from Saturn's magnetosphere can penetrate below 950km. Cosmic rays with energies of greater than 1 GeV can penetrate much deeper into Titan's atmosphere with most of its energy deposited at approximately 100 km altitude. The haze layer tends to dominate between 100 km and 300 km. The induced magnetic field from Titan's interaction with the external plasma can be very complex and will tend to channel the flow of energy into Titan's upper atmosphere. Cassini observations combined with advanced hybrid simulations of the plasma interaction with Titan's upper atmosphere show significant changes in the character of the interaction with Saturn local time at Titan's orbit where the magnetosphere displays large and systematic changes with local time. The external solar wind can also drive sub-storms within the magnetosphere which can then modify the magnetospheric interaction with Titan. Another important parameter is solar zenith angle (SZA) with respect to the co-rotation direction of the magnetospheric flow. Titan's interaction can contribute to atmospheric loss via pickup ion loss, scavenging of Titan's ionospheric plasma, loss of ionospheric plasma down its induced magnetotail via an ionospheric wind, and non-thermal loss of the atmosphere via heating and sputtering induced by the bombardment of magnetospheric keV ions and electrons. This

  15. Energy Deposition Processes in Titan's Upper Atmosphere

    NASA Technical Reports Server (NTRS)

    Sittler, Edward C., Jr.; Bertucci, Cesar; Coates, Andrew; Cravens, Tom; Dandouras, Iannis; Shemansky, Don

    2008-01-01

    Most of Titan's atmospheric organic and nitrogen chemistry, aerosol formation, and atmospheric loss are driven from external energy sources such as Solar UV, Saturn's magnetosphere, solar wind and galactic cosmic rays. The Solar UV tends to dominate the energy input at lower altitudes of approximately 1100 km but which can extend down to approximately 400 km, while the plasma interaction from Saturn's magnetosphere, Saturn's magnetosheath or solar wind are more important at higher altitudes of approximately 1400 km, but the heavy ion plasma [O(+)] of approximately 2 keV and energetic ions [H(+)] of approximately 30 keV or higher from Saturn's magnetosphere can penetrate below 950km. Cosmic rays with energies of greater than 1 GeV can penetrate much deeper into Titan's atmosphere with most of its energy deposited at approximately 100 km altitude. The haze layer tends to dominate between 100 km and 300 km. The induced magnetic field from Titan's interaction with the external plasma can be very complex and will tend to channel the flow of energy into Titan's upper atmosphere. Cassini observations combined with advanced hybrid simulations of the plasma interaction with Titan's upper atmosphere show significant changes in the character of the interaction with Saturn local time at Titan's orbit where the magnetosphere displays large and systematic changes with local time. The external solar wind can also drive sub-storms within the magnetosphere which can then modify the magnetospheric interaction with Titan. Another important parameter is solar zenith angle (SZA) with respect to the co-rotation direction of the magnetospheric flow. Titan's interaction can contribute to atmospheric loss via pickup ion loss, scavenging of Titan's ionospheric plasma, loss of ionospheric plasma down its induced magnetotail via an ionospheric wind, and non-thermal loss of the atmosphere via heating and sputtering induced by the bombardment of magnetospheric keV ions and electrons. This

  16. Chemical sputtering by H{sub 2}{sup +} and H{sub 3}{sup +} ions during silicon deposition

    SciTech Connect

    Landheer, K. Poulios, I.; Rath, J. K.; Goedheer, W. J.; Schropp, R. E. I.

    2016-08-07

    We investigated chemical sputtering of silicon films by H{sub y}{sup +} ions (with y being 2 and 3) in an asymmetric VHF Plasma Enhanced Chemical Vapor Deposition (PECVD) discharge in detail. In experiments with discharges created with pure H{sub 2} inlet flows, we observed that more Si was etched from the powered than from the grounded electrode, and this resulted in a net deposition on the grounded electrode. With experimental input data from a power density series of discharges with pure H{sub 2} inlet flows, we were able to model this process with a chemical sputtering mechanism. The obtained chemical sputtering yields were (0.3–0.4) ± 0.1 Si atom per bombarding H{sub y}{sup +} ion at the grounded electrode and at the powered electrode the yield ranged from (0.4 to 0.65) ± 0.1. Subsequently, we investigated the role of chemical sputtering during PECVD deposition with a series of silane fractions S{sub F} (S{sub F}(%) = [SiH{sub 4}]/[H{sub 2}]*100) ranging from S{sub F} = 0% to 20%. We experimentally observed that the SiH{sub y}{sup +} flux is not proportional to S{sub F} but decreasing from S{sub F} = 3.4% to 20%. This counterintuitive SiH{sub y}{sup +} flux trend was partly explained by an increasing chemical sputtering rate with decreasing S{sub F} and partly by the reaction between H{sub 3}{sup +} and SiH{sub 4} that forms SiH{sub 3}{sup +}.

  17. Characterisation of sputter deposited niobium and boron interlayer in the copper-diamond system.

    PubMed

    Hell, J; Chirtoc, M; Eisenmenger-Sittner, C; Hutter, H; Kornfeind, N; Kijamnajsuk, P; Kitzmantel, M; Neubauer, E; Zellhofer, K

    2012-09-15

    In most metal matrix composites (MMCs) interfaces are decisive but hard to manipulate. Especially copper-carbon composites can exhibit excellent mechanical and thermal properties only if the Cu/C interface is modified by an optimised interlayer. Due to the excellent thermal conductivity and mechanical stability of diamond this form of carbon is preferred as reinforcement in heat sink materials (copper-diamond composite) which are often subjected to severe thermal and mechanical loads. In the present case niobium and boron interlayers of various thicknesses were deposited on diamond and vitreous carbon substrates by magnetron sputter deposition. After the coverage of all samples by a copper film, a part of the samples was subjected to heat treatment for 30 min at 800 °C under high vacuum (HV) to simulate the thermal conditions during the production of the composite material by uniaxial hot pressing. De-wetting during heat treatment leads to the formation of holes or humps in the Cu coating. This effect was investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). A comparison of time-of-flight secondary ion mass spectroscopy (TOF SIMS) profiles of heat treated samples with those of as deposited ones showed the influence of interdiffusion during the heating process. Diffusion behaviour and chemical composition of the interface were also studied by cross sectional transmission electron microscopy (X-TEM) investigations using focused ion beam (FIB) cut samples. The thermal contact resistance (TCR) of the interface was calculated from results obtained from modulated infrared radiometry (IR). Thin interlayers suppressed de-wetting most effectively and consequently the TCR at the Cu-diamond interface was found to decrease. Therefore they are promising candidates for optimising the Cu-diamond interface.

  18. Sputtering of lithiated and oxidated carbon surfaces by low-energy deuterium irradiation

    NASA Astrophysics Data System (ADS)

    Domínguez-Gutiérrez, F. J.; Krstić, P. S.

    2017-08-01

    We study sputtering of lithiated and oxidized amorphous carbon surfaces by deuterium impact in energy range 5-30 eV. Using classical molecular dynamics, we obtain the sputtering yield, the mass and energy spectra, as well as the angular distribution of ejected atoms and molecules of the surfaces saturated by accumulated deuterium impacts. Our results are compared with existing experimental and theoretical data for amorphous a-C:D surfaces, showing that presence of lithium reduces erosion of carbon, while oxygen further enhances this effect.

  19. Characterization of the ion cathode fall region in relation to the growth rate in plasma sputter deposition

    NASA Astrophysics Data System (ADS)

    Palmero, A.; van Hattum, E. D.; Rudolph, H.; Habraken, F. H. P. M.

    2007-02-01

    In plasma-assisted magnetron sputtering, the ion cathode fall region is the part of the plasma where the DC electric field and ion current evolve from zero to their maximum values at the cathode. These quantities are straightforwardly related to the deposition rate of the sputtered material. In this work we derive simple relations for the measurable axially averaged values of the ion density and the ion current at the ion cathode fall region and relate them with the deposition rate. These relations have been tested experimentally in the case of an argon plasma in a magnetron sputtering system devoted to depositing amorphous silicon. Using a movable Langmuir probe, the profiles of the plasma potential and ion density were measured along an axis perpendicularly to the cathode and in front of the so-called race-track. The deposition rate of silicon, under different conditions of pressure and input power, has been found to compare well with those determined with the relations derived.

  20. Stress analysis, structure and magnetic properties of sputter deposited Ni-Mn-Ga ferromagnetic shape memory thin films

    NASA Astrophysics Data System (ADS)

    Annadurai, A.; Manivel Raja, M.; Prabahar, K.; Kumar, Atul; Kannan, M. D.; Jayakumar, S.

    2011-11-01

    The residual stress instituted in Ni-Mn-Ga thin films during deposition is a key parameter influencing their shape memory applications by affecting its structural and magnetic properties. A series of Ni-Mn-Ga thin films were prepared by dc magnetron sputtering on Si(1 0 0) and glass substrates at four different sputtering powers of 25, 45, 75 and 100 W for systematic investigation of the residual stress and its effect on structure and magnetic properties. The residual stresses in thin films were characterized by a laser scanning technique. The as-deposited films were annealed at 600 °C for 1 h in vacuum for structural and magnetic ordering. The compressive stresses observed in as-deposited films transformed into tensile stresses upon annealing. The annealed films were found to be crystalline and possess mixed phases of both austenite and martensite, exhibiting good soft magnetic properties. It was found that the increase of sputtering power induced coarsening in thin films. Typical saturation magnetization and coercivity values were found to be 330 emu/cm 3 and 215 Oe, respectively. The films deposited at 75 and 100 W display both structural and magnetic transitions above room temperature.

  1. Sputter deposition of ZnS:Mn/SrS:Ce multilayer stacks for use as white phosphor thin film electroluminscent panels

    SciTech Connect

    Ruffner, J.A.; Tuenge, R.T.; Sun, Sey-Shing

    1995-07-01

    Sputter deposition of ZnS:Mn/SrS:Ce multilayered broad-band ``white`` emission thin film electroluminescent (TFEL) stacks has been investigated. To date, deposition of these multilayers has been limited to vacuum evaporation techniques and atomic layer epitaxy, both of which require two different substrate temperatures for growth of high quality ZnS and SrS. This repeated thermal cycling during multilayer deposition can induce stress, defects, and interdiffusion with adversely affect EL performance. Sputter deposition of ZnS and SrS produces high quality TFELs for a wider range of substrate temperatures. Both materials can be sputter deposited at a common temperature (300-350{degrees}C) which eliminates the need for thermal cycling and increases manufacturability. Luminance outputs from sputter deposited ZnS and SrS thin films are comparable to those from evaporated films, making sputtering an attractive alternative deposition technique for these materials. We report on the effects of sputter deposition parameters including chamber pressure, substrate temperature, and H2S process gas partial pressure on the resultant composition and morphology of ZnS:Mn and SrS:Ce thin films and multilayers. Their EL performance was evaluated and correlated to composition and morphology.

  2. Fabrication and characterization of the electrical and optical properties of n-type thin film transparent conducting oxides deposited by neutralized ion beam sputtering and pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Vanderford, John D.

    Transparent conducting oxides have become a fundamental electronic material for numerous current technologies and are optimally deposited as a uniform thin film with low electrical resistivity and high optical transmission. The purpose of this study is to characterize the electrical and optical characteristics of three TCO: Indium Tin Oxide (ITO) (95%, 5%), Zinc Oxide (ZnO), and Aluminum doped Zinc Oxide (AZO) (98%, 2%). The deposition techniques of neutralized ion beam sputtering and pulsed laser deposition will be investigated. ITO will be deposited from commercially available sintered targets whereas ZnO and AZO will be deposited from powder pressed targets. The results have shown that AZO deposit AZO from a powder pressed target with comparable electrical and optical properties to that of ITO deposited from a sintered target.

  3. Co-sputter deposited nickel-copper bimetallic nanoalloy embedded carbon films for electrocatalytic biomarker detection

    NASA Astrophysics Data System (ADS)

    Shiba, Shunsuke; Kato, Dai; Kamata, Tomoyuki; Niwa, Osamu

    2016-06-01

    -mannitol, which should be detected with a low detection limit in urine samples for the diagnosis of severe intestinal diseases. With a Ni/Cu ratio of around 64/36, the electrocatalytic current per metal area was 3.4 times larger than that of an alloy film electrode with a similar composition (~70/30). This improved electrocatalytic activity realized higher stability (n = 60, relative standard deviation (RSD): 4.6%) than the alloy film (RSD: 32.2%) as demonstrated by continuous measurements of d-mannitol. Electronic supplementary information (ESI) available: The concept of UBM co-sputtering for fabricating nanoalloy embedded carbon films. HRTEM images of the NiNP and Ni32Cu68 nanoalloy embedded carbon films. The experimental conditions for sputter deposition, HRTEM, HAADF-STEM, STEM-EDS measurements and continuous flow injection analysis. XPS analysis of the nanoalloy embedded carbon film. Repeated CVs of both the nanoalloy embedded carbon film and the alloy film. Amperometric detection of d-mannitol in the presence of chloride ions. See DOI: 10.1039/c6nr02287a

  4. Development of sputtering process to deposit stoichiometric zirconia coatings for the inside wall of regeneratively cooled rocket thrust chambers

    NASA Technical Reports Server (NTRS)

    Busch, R.

    1978-01-01

    Thermal barrier coatings of yttria stabilized zirconia and zirconia-ceria mixtures were deposited by RF reactive sputtering. Coatings were 1-2 mils thick, and were deposited on copper cylinders intended to simulate the inner wall of a regeneratively cooled thrust chamber. Coating stoichiometry and adherence were investigated as functions of deposition parameters. Modest deposition rates (approximately 0.15 mil/hr) and subambient sustrate temperatures (-80 C) resulted in nearly stoichiometric coatings which remained adherent through thermal cycles between -196 and 400 C. Coatings deposited at higher rates or substrates temperatures exhibited greater oxygen deficiences, while coatings deposited at lower temperatures were not adherent. Substrate bias resulted in structural changes in the coating and high krypton contents; no clear effect on stoichiometry was observed.

  5. Surface/interface analysis and optical properties of RF sputter-deposited nanocrystalline titanium nitride thin films

    NASA Astrophysics Data System (ADS)

    White, N.; Campbell, A. L.; Grant, J. T.; Pachter, R.; Eyink, K.; Jakubiak, R.; Martinez, G.; Ramana, C. V.

    2014-02-01

    Titanium nitride (TiNx) thin films were grown by radio-frequency (RF) magnetron sputter deposition by varying the nitrogen content in the reactive gas mixture over a wide range. The effect of nitrogen gas flow rate on the surface and interface morphology, chemical composition and optical properties of TiN thin films was studied employing atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Analysis of the optical properties probed with SE has shown that films deposited at low (0-5 sccm) nitrogen flow rates have the highest absorption at energies <2 eV. It was also shown that Lorentz oscillators with energy positions lower than 2 eV can be distinguished from the Drude oscillator function during parameter fitting. AFM imaging analysis indicates that the roughness decreases and plateaus at approximately 1.5 nm with the introduction of a small N2 flow rate, remaining consistent thereafter. SEM cross-sectional imaging analysis indicates the dense, columnar structure for the films grown at lower nitrogen flow rates. XPS analysis of atomic composition and the chemical states indicate that the atomic composition remained nearly constant while the chemical states varied significantly among the samples as a function of N2 flow rate. XPS analyses confirm the presence of TiNx, TiO2 and TiOxNy. These process-property relationships derived could be useful for defining and expanding the range of optical and electronic applications of titanium nitrides and (oxy)nitrides.

  6. Tribological and structural properties of titanium nitride and titanium aluminum nitride coatings deposited with modulated pulsed power magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Ward, Logan

    The demand for economical high-performance materials has brought attention to the development of advanced coatings. Recent advances in high power magnetron sputtering (HPPMS) have shown to improve tribological properties of coatings. These coatings offer increased wear and oxidation resistance, which may facilitate the use of more economical materials in harsh applications. This study demonstrates the use of novel forms of HPPMS, namely modulated pulsed-power magnetron sputtering (MPPMS) and deep oscillation magnetron sputtering (DOMS), for depositing TiN and Ti1-xAlxN tribological coatings on commonly used alloys, such as Ti-6Al-4V and Inconel 718. Both technologies have been shown to offer unique plasma characteristics in the physical vapor deposition (PVD) process. High power pulses lead to a high degree of ionization compared to traditional direct-current magnetron sputtering (DCMS) and pulsed magnetron sputtering (PMS). Such a high degree of ionization was previously only achievable by cathodic arc deposition (CAD); however, CAD can lead to increased macroparticles that are unfavorable in high friction and corrosive environments. MPPMS, DOMS, and other HPPMS techniques offer unique plasma characteristics and have been shown to produce coatings with refined grain structure, improved density, hardness, adhesion, and wear resistance. Using DOMS and MPPMS, TiN and Ti1-xAlxN coatings were deposited using PMS to compare microstructures and tribological performance. For Ti1-xAlxN, two sputtering target compositions, Ti 0.5Al0.5 and Ti0.3Al0.7, were used to evaluate the effects of MPPMS on the coating's composition and tribological properties. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to characterize microstructure and crystallographic texture. Several tribological properties were evaluated including: wear rate, coefficient of friction, adhesion, and nanohardness. Results show that substrate

  7. Composition and structure variation for magnetron sputtered tantalum oxynitride thin films, as function of deposition parameters

    NASA Astrophysics Data System (ADS)

    Cristea, D.; Pătru, M.; Crisan, A.; Munteanu, D.; Crăciun, D.; Barradas, N. P.; Alves, E.; Apreutesei, M.; Moura, C.; Cunha, L.

    2015-12-01

    Tantalum oxynitride thin films were produced by magnetron sputtering. The films were deposited using a pure Ta target and a working atmosphere with a constant N2/O2 ratio. The choice of this constant ratio limits the study concerning the influence of each reactive gas, but allows a deeper understanding of the aspects related to the affinity of Ta to the non-metallic elements and it is economically advantageous. This work begins by analysing the data obtained directly from the film deposition stage, followed by the analysis of the morphology, composition and structure. For a better understanding regarding the influence of the deposition parameters, the analyses are presented by using the following criterion: the films were divided into two sets, one of them produced with grounded substrate holder and the other with a polarization of -50 V. Each one of these sets was produced with different partial pressure of the reactive gases P(N2 + O2). All the films exhibited a O/N ratio higher than the N/O ratio in the deposition chamber atmosphere. In the case of the films produced with grounded substrate holder, a strong increase of the O content is observed, associated to the strong decrease of the N content, when P(N2 + O2) is higher than 0.13 Pa. The higher Ta affinity for O strongly influences the structural evolution of the films. Grazing incidence X-ray diffraction showed that the lower partial pressure films were crystalline, while X-ray reflectivity studies found out that the density of the films depended on the deposition conditions: the higher the gas pressure, the lower the density. Firstly, a dominant β-Ta structure is observed, for low P(N2 + O2); secondly a fcc-Ta(N,O) structure, for intermediate P(N2 + O2); thirdly, the films are amorphous for the highest partial pressures. The comparison of the characteristics of both sets of produced TaNxOy films are explained, with detail, in the text.

  8. Sputtering of amorphous silicon nitride irradiated with energetic C60 ions: Preferential sputtering and synergy effect between electronic and collisional sputtering

    NASA Astrophysics Data System (ADS)

    Kitayama, T.; Morita, Y.; Nakajima, K.; Narumi, K.; Saitoh, Y.; Matsuda, M.; Sataka, M.; Toulemonde, M.; Kimura, K.

    2015-12-01

    Amorphous silicon nitride films (thickness 30 nm) deposited on Si(0 0 1) were irradiated with 30-1080 keV C60 and 100 MeV Xe ions to fluences ranging from 2 × 1011 to 1 × 1014 ions/cm2. The composition depth profiles of the irradiated samples were measured using high-resolution Rutherford backscattering spectrometry. The sputtering yields were estimated from the derived composition profiles. Pronounced preferential sputtering of nitrogen was observed in the electronic energy loss regime. In addition, a large synergy effect between the electronic and collisional sputtering was also observed. The sputtering yields were calculated using the unified thermal spike model to understand the observed results. Although the calculated results reproduced the observed total sputtering yields with a lowered sublimation energy, the observed preferential sputtering of nitrogen could not be explained. The present results suggest an additional sputtering mechanism related to the electronic energy loss.

  9. Sputtering of SiC with low energy He and Ar ions under grazing incidence

    NASA Astrophysics Data System (ADS)

    Kosiba, R.; Ecke, G.; Ambacher, O.; Menyhard, M.

    2003-10-01

    The effect of low energy sputtering under grazing incidence upon the surface composition of SiC was investigated by Auger electron spectroscopy. The energy of the sputtering projectiles (He, Ar) varied from 200 to 1500 eV. Peak shifts to the higher energies with increasing argon ion energy were observed for all silicon and carbon Auger transitions. These shifts were explained by enhanced damage of the surface region within the sampling depth of the Auger electrons. The insensitivity of the Auger peak position to the energy of helium ions indicates that the damage state in the surface region does not change with the increasing energy of helium ions. An increase of the carbon concentration with the decrease of the argon energy was observed. The experiments were accompanied by dynamic Monte Carlo simulations by the TRIDYN code.

  10. Antibacterial and Bioactive Coatings Based on Radio Frequency Co-Sputtering of Silver Nanocluster-Silica Coatings on PEEK/Bioactive Glass Layers Obtained by Electrophoretic Deposition.

    PubMed

    Ur Rehman, Muhammad Atiq; Ferraris, Sara; Goldmann, Wolfgang H; Perero, Sergio; Bastan, Fatih Erdem; Nawaz, Qaisar; Confiengo, G Gautier di; Ferraris, Monica; Boccaccini, Aldo R

    2017-09-27

    Bioactive and antibacterial coatings on stainless steel substrates were developed and characterized in this study. Silver nanocluster-silica composite coatings of 60-150 nm thickness were deposited using radio frequency (RF) co-sputtering on PEEK/bioactive glass (BG) layers (of 80-90 μm thickness) which had been electrophoretically deposited onto stainless steel. Two sputtering conditions were used by varying the deposition time (15 and 40 min); the resulting microstructure, composition, adhesion strength, in vitro bioactivity, and antibacterial activity were investigated. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDX) confirmed the presence of silver nanoclusters, which were homogeneously embedded in the silica matrix. The isoelectric point of the coatings and their charge at physiological pH were determined by zeta potential measurements. The presence of BG particles in the PEEK/BG layer allows the coatings to form apatite-like crystals upon immersion in simulated body fluid (SBF). Moreover, silver nanoclusters embedded in the silica matrix as a top layer provided an antibacterial effect against Escherichia coli and Staphylococcus carnosus.

  11. Growing LaAlO{sub 3}/SrTiO{sub 3} interfaces by sputter deposition

    SciTech Connect

    Dildar, I. M.; Neklyudova, M.; Xu, Q.; Zandbergen, H. W.; Harkema, S.; Boltje, D.; Aarts, J.

    2015-06-15

    Sputter deposition of oxide materials in a high-pressure oxygen atmosphere is a well-known technique to produce thin films of perovskite oxides in particular. Also interfaces can be fabricated, which we demonstrated recently by growing LaAlO{sub 3} on SrTiO{sub 3} substrates and showing that the interface showed the same high degree of epitaxy and atomic order as is made by pulsed laser deposition. However, the high pressure sputtering of oxides is not trivial and number of parameters are needed to be optimized for epitaxial growth. Here we elaborate on the earlier work to show that only a relatively small parameter window exists with respect to oxygen pressure, growth temperature, radiofrequency power supply and target to substrate distance. In particular the sensitivity to oxygen pressure makes it more difficult to vary the oxygen stoichiometry at the interface, yielding it insulating rather than conducting.

  12. Structural and optical characterization of terbium doped ZnGa2O4 thin films deposited by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Somasundaram, K.; Girija, K. G.; Sudarsan, V.; Selvin, P. Christopher; Vatsa, R. K.

    2016-05-01

    Tb3+ doped ZnGa2O4 nanophosphor (21 nm) has been synthesized via low temperature polyol route and subsequently thin films of the same were deposited on glass and ITO substrates by RF magnetron sputtering. The films were characterized by X-ray Diffraction and luminescence measurements. The XRD pattern showed that Tb3+ doped ZnGa2O4 nanophosphor has a cubic spinel phase. Luminescence behavior of the nanophosphor and as deposited sputtered film was investigated. The PL emission spectra of nanophosphor gave a broad ZnGa2O4 host emission band along with a strong terbium emission and the thin films showed only broad host emission band and there was no terbium ion emission.

  13. Plasma damage-free deposition of Al cathode on organic light-emitting devices by using mirror shape target sputtering

    SciTech Connect

    Kim, Han-Ki; Kim, D.-G.; Lee, K.-S.; Huh, M.-S.; Jeong, S.H.; Kim, K.I.; Kim, H.; Han, D.W.; Kwon, J.H.

    2004-11-08

    We report on the fabrication of plasma damage-free organic light-emitting devices (OLEDs) by using a mirror shape target sputtering (MSTS) technique. It is shown that OLEDs with Al cathode deposited by the MSTS show much lower leakage current (1x10{sup -5} mA/cm{sup 2}) at reverse bias of -6 V, compared to that (1x10{sup -1}-{approx}10{sup -2} mA/cm{sup 2} at -6 V) of OLEDs with Al cathodes grown by conventional dc magnetron sputtering. This indicates that there is no plasma damage, which is caused by the bombardment of energetic particles. This suggests that MSTS could be a useful plasma damage-free and low-temperature deposition technique for both top- and bottom-emitting OLEDs and flexible displays.

  14. Comparison of Stress Relief Mechanisms of Metal Films Deposited on Liquid Substrates by Thermal Evaporating and Sputtering

    NASA Astrophysics Data System (ADS)

    Yu, Sen-Jiang; Zhang, Yong-Ju; Chen, Miao-Gen

    Various metal film systems, deposited on liquid (silicone oil) substrates by thermal evaporating and DC-magnetron sputtering methods, have been successfully fabricated and the stress relief mechanisms are systematically studied by analyzing the characteristic surface morphologies. The experiment shows that the evaporating metal films can move on silicone oil surfaces freely due to the nearly zero adhesion of solid-liquid interface, which results in spontaneous formation of ordered surface patterns with a characteristic sandwiched structure driven by the internal stress. For the sputtering metal film system, however, the top surface of silicone oil can be modified to form an elastomeric polymer layer on the liquid substrate during deposition. Subsequent cooling of the system creates a higher compressive stress in the film, which is relieved by buckling of the film to form periodic wavy structures because the adhesion of solid-elastomer interface is quite strong.

  15. On performance limitations and property correlations of Al-doped ZnO deposited by radio-frequency sputtering

    NASA Astrophysics Data System (ADS)

    Crovetto, Andrea; Sand Ottsen, Tobias; Stamate, Eugen; Kjær, Daniel; Schou, Jørgen; Hansen, Ole

    2016-07-01

    The electrical properties of RF-sputtered Al-doped ZnO are often spatially inhomogeneous and strongly dependent on deposition parameters. In this work, we study the mechanisms that limit the minimum resistivity achievable under different deposition regimes. In a low- and intermediate-pressure regime, we find a generalized dependence of the electrical properties, grain size, texture, and Al content on compressive stress, regardless of sputtering pressure or position on the substrate. In a high-pressure regime, a porous microstructure limits the achievable resistivity and causes it to increase over time as well. The primary cause of inhomogeneity in the electrical properties is identified as energetic particle bombardment. Inhomogeneity in oxygen content is also observed, but its effect on the electrical properties is small and limited to the carrier mobility.

  16. Lithium phosphorus oxynitride solid-state thin-film electrolyte deposited and modified by bias sputtering and low temperature annealing

    SciTech Connect

    Chiu, K.-F.; Chen, C. C.; Lin, K. M.; Lo, C. C.; Lin, H. C.; Ho, W.-H.; Jiang, C. S.

    2010-07-15

    Amorphous lithium phosphorus oxynitride (LiPON) solid-state thin-film electrolyte has been deposited and characterized. The thin films were prepared by rf magnetron sputtering under various substrate biases. By fabricating under different substrate biases and applying low temperature annealing (473 K), the properties of the LiPON thin-film electrolytes and the electrolyte/cathode interfaces were modified. The ionic conductivity as high as 9.4x10{sup -4} S m{sup -1} can be obtained by depositing at optimal bias. The performances of the consequently fabricated SnO{sub 2}/LiPON/LiMn{sub 2}O{sub 4} all-solid-state lithium ion thin-film batteries were improved using the bias sputtering technique, due to the enhanced the ionic conductivity and uniform interface.

  17. Photocatalytic Properties of TiO2 Thin Films Modified with Ag and Pt Nanoparticles Deposited by Gas Flow Sputtering.

    PubMed

    Maicu, M; Glöss, D; Frach, Peter; Hecker, D; Gerlach, G; Córdoba, José M

    2015-09-01

    In this work, a gas flow sputtering (GFS) process which allows the production and deposition of metal nanoparticles (NPs) in a vacuum environment is described. Aim of the study is to prove the potential of this technology for the fabrication of new TiO2 films with enhanced photocatalytic properties. For this purpose, Ag and Pt NPs have been produced and deposited on photocatalytic float glass coated with TiO2 thin films by magnetron sputtering. The influence of the process parameters and of the metal amount on the final properties of the particles (quantity, size, size distribution, oxidation state etc.,) was widely investigated. Moreover, the effect of the NPs on the photocatalytic activity of the resulting materials was evaluated for the case of the decomposition of stearic acid (SA) during UV-A irradiation. The reduction of the water contact angle (WCA) during the irradiation period was measured in order to test the photo-induced super-hydrophilicity (PSH).

  18. Improving the growth of Ge/Si islands by modulating the spacing between screen and accelerator grids in ion beam sputtering deposition system

    NASA Astrophysics Data System (ADS)

    Yang, Jie; Zhao, Bo; Wang, Chong; Qiu, Feng; Wang, Rongfei; Yang, Yu

    2016-11-01

    Ge islands were fabricated on Si buffer layer by ion beam sputtering deposition with a spacing between the screen and accelerator grids of either 1 mm or 2 mm. The Si buffer layer exhibits mixed-phase microcrystallinity for samples grown with 1 mm spacing and crystallinity for those with 2 mm spacing. Ge islands are larger and less dense than those grown on the crystalline buffer because of the selective growth mechanism on the microcrystalline buffer. Moreover, the nucleation site of Ge islands formed on the crystalline Si buffer is random. Ge islands grown at different grid-to-grid gaps are characterized by two key factors, namely, divergence half angle of ion beam and crystallinity of buffer layer. High grid-to-grid spacing results in small divergence half angle, thereby enhancing the sputtering energy and redistribution of sputtered atoms. The crystalline volume fraction of the microcrystalline Si buffer was obtained based on the integrated intensity ratio of Raman peaks. The islands show decreased density with decreasing crystalline volume fraction and are difficult to observe at crystalline volume fractions lower than 72%.

  19. Low-Energy Sputtering Studies of Boron Nitride with Xenon Ions

    NASA Technical Reports Server (NTRS)

    Ray, P. K.; Shutthanandan, V.

    1999-01-01

    Sputtering of boron nitride with xenon ions was investigated using secondary ion (SIMS) and secondary neutral (SNMS) mass spectrometry. The ions generated from the ion gun were incident on the target at an angle of 50' with respect to the surface'normal. The energy of ions ranged from 100 eV to 3 keV. A flood electron gun was used to neutralize the positive charge build-up on the target surface. The intensities of sputtered neutral and charged particles, including single atoms, molecules, and clusters, were measured as a function of ion energy. Positive SIMS spectra were dominated by the two boron isotopes whereas BN- and B- were the two major constituents of the negative SIMS spectra. Nitrogen could be detected only in the SNMS spectra. The intensity-energy curves of the sputtered particles were similar in shape. The knees in P-SIMS and SNMS intensity-energy curves appear at around I keV which is significantly higher that 100 to 200 eV energy range at which knees appear in the sputtering of medium and heavy elements by ions of argon and xenon. This difference in the position of the sputter yield knee between boron nitride and heavier targets is due to the reduced ion energy differences. The isotopic composition of secondary ions of boron were measured by bombarding boron nitride with xenon ions at energies ranging from 100 eV to 1.5 keV using a quadrupole mass spectrometer. An ion gun was used to generate the ion beam. A flood electron gun was used to neutralize the positive charge buildup on the target surface. The secondary ion flux was found to be enriched in heavy isotopes at lower incident ion energies. The heavy isotope enrichment was observed to decrease with increasing primary ion energy. Beyond 350 eV, light isotopes were sputtered preferentially with the enrichment increasing to an asymptotic value of 1.27 at 1.5 keV. The trend is similar to that of the isotopic enrichment observed earlier when copper was sputtered with xenon ions in the same energy

  20. Combinatorial study of WInZnO films deposited by rf magnetron co-sputtering

    SciTech Connect

    Oh, Byeong-Yun; Park, Jae-Cheol; Lee, Young-Jun; Cha, Sang-Jun; Kim, Joo-Hyung; Kim, Kwang-Young; Kim, Tae-Won; Heo, Gi-Seok

    2011-09-15

    The compositional dependence of co-sputtered tungsten indium zinc oxide (WInZnO) film properties was first investigated by means of a combinatorial technique. Indium zinc oxide (IZO) and WO{sub 3} targets were used with different target power. W composition ratio [W/(In+Zn+W)] was varied between 3 and 30 at% and film thickness was reduced as the sample position moved toward WO{sub 3} target. Furthermore, the optical bandgap energy increased gradually, which might be affected by the reduction in film thickness. All the WInZnO films showed an amorphous phase regardless of the W/(In+Zn+W) ratio. As the W/(In+Zn+W) ratio in WInZnO films increased, the carrier concentration was restricted, causing the increase in electrical resistivity. W cations worked as oxygen binders in determining the electronic properties, resulting in suppressing the formation of oxygen vacancies. Consequentially, W metal cations were effectively incorporated into the WInZnO films as a suppressor against the oxygen vacancies and the carrier generation by employing the combinatorial technique. - Graphical abstract: The film thickness and the sheet resistance (R{sub s}) with respect to the sample position of WInZnO films, which is compositionally graded by rf power for each target, are exhibited. Highlights: > The compositional dependence of co-sputtered WInZnO film properties is first investigated. > W cations work as oxygen binders in determining the electronic properties. > All the WInZnO films show an amorphous phase regardless of the W/(In+Zn+W) ratio. > W metal cations are effectively incorporated into the WInZnO films by the combinatorial technique.

  1. Optoelectronic properties of delafossite structure CuCr0.93Mg0.07O2 sputter deposited coatings

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Arab Pour Yazdi, Mohammad; Sanchette, Frederic; Billard, Alain

    2016-05-01

    CuCr0.93Mg0.07O2 thin films with improved optoelectronic properties were deposited by reactive magnetron sputtering on fused quartz substrates. The influence of annealing temperature under vacuum on optoelectronic properties of the films was investigated. The amorphous films annealed under vacuum at temperatures higher than 923 K are single-phased delafossite structure, while impurity phases like CuCr2O4 that affect the optoelectronic properties of the films are detected below 873 K. c-axis orientation is observed for CuCr0.93Mg0.07O2 layers and the annealing temperature window in which the films are single-phased delafossite is much larger with Mg doping (923 K  →  1073 K) than that for undoped films (~953 K). The optical and electrical behaviours of the films are enhanced by Mg substitution and their direct band gap energy of about 3.12-3.14 eV is measured. The film possesses the optimum properties after annealing under vacuum at about 1023 K its average transmittance in the visible region can reach 54.23% while the film’s conductivity is about 0.27 S cm-1.

  2. Protection of p(+)-n-Si Photoanodes by Sputter-Deposited Ir/IrOx Thin Films.

    PubMed

    Mei, Bastian; Seger, Brian; Pedersen, Thomas; Malizia, Mauro; Hansen, Ole; Chorkendorff, Ib; Vesborg, Peter C K

    2014-06-05

    Sputter deposition of Ir/IrOx on p(+)-n-Si without interfacial corrosion protection layers yielded photoanodes capable of efficient water oxidation (OER) in acidic media (1 M H2SO4). Stability of at least 18 h was shown by chronoamperomety at 1.23 V versus RHE (reversible hydrogen electrode) under 38.6 mW/cm(2) simulated sunlight irradiation (λ > 635 nm, AM 1.5G) and measurements with quartz crystal microbalances. Films exceeding a thickness of 4 nm were shown to be highly active though metastable due to an amorphous character. By contrast, 2 nm IrOx films were stable, enabling OER at a current density of 1 mA/cm(2) at 1.05 V vs. RHE. Further improvement by heat treatment resulted in a cathodic shift of 40 mV and enabled a current density of 10 mA/cm(2) (requirements for a 10% efficient tandem device) at 1.12 V vs. RHS under irradiation. Thus, the simple IrOx/Ir/p(+)-n-Si structures not only provide the necessary overpotential for OER at realistic device current, but also harvest ∼100 mV of free energy (voltage) which makes them among the best-performing Si-based photoanodes in low-pH media.

  3. Experimental investigation of the energy and temperature dependence of beryllium self sputtering

    SciTech Connect

    Korshunov, S.N.; Guseva, M.I.; Stolijarova, V.G.

    1995-09-01

    The low-Z metal beryllium is considered as plasma facing material (PFM) for the ITER. It is expected that operation temperature range of beryllium PFM will be (670 - 1070) K. While experimental Be-sputtering data bases exist for H{sup +}, D{sup +} and He{sup +}-ions, the self-sputtering yields of Be have only been estimated by computer simulation. In this paper we report the experimental results on the energy and temperature dependence of the beryllium self-sputtering yield (S). The energy dependence of S{sup s} in the energy range (0.5 - 10.0) keV was measured at 670 K. The self-sputtering yield of Be attains its maximal value at the ion energy of 1.5 keV, being equal to 0.32 {+-} at./ion. Comparison of the experimental results and theoretical prediction shows a good agreement for energy dependence of S{sup s}. The temperature dependence of S{sup s} in the temperature range (370-1070)K was obtained for 0.9keV Be{sup +}-ions. The value of S{sup s} is not changed up to 870 K. It sharply increases at the temperatures above 870 attaining the value of 0.75 at./ion at 1070 K.

  4. Photocatalytic efficiency of reusable ZnO thin films deposited by sputtering technique

    NASA Astrophysics Data System (ADS)

    Ahumada-Lazo, R.; Torres-Martínez, L. M.; Ruíz-Gómez, M. A.; Vega-Becerra, O. E.; Figueroa-Torres, M. Z.

    2014-12-01

    The photocatalytic activity of ZnO thin films with different physicochemical characteristics deposited by RF magnetron sputtering on glass substrate was tested for the decolorization of orange G dye aqueous solution (OG). The crystalline phase, surface morphology, surface roughness and the optical properties of these ZnO films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-visible spectroscopy (UV-Vis), respectively. The dye photodecolorization process was studied at acid, neutral and basic pH media under UV irradiation of 365 nm. Results showed that ZnO films grow with an orientation along the c-axis of the substrate and exhibit a wurtzite crystal structure with a (002) preferential crystalline orientation. A clear relationship between surface morphology and photocatalytic activity was observed for ZnO films. Additionally, the recycling photocatalytic abilities of the films were also evaluated. A promising photocatalytic performance has been found with a very low variation of the decolorization degree after five consecutive cycles at a wide range of pH media.

  5. Optical, structural and electrochromic properties of sputter- deposited W-Mo oxide thin films

    NASA Astrophysics Data System (ADS)

    Gesheva, K.; Arvizu, M. A.; Bodurov, G.; Ivanova, T.; Niklasson, G. A.; Iliev, M.; Vlakhov, T.; Terzijska, P.; Popkirov, G.; Abrashev, M.; Boyadjiev, S.; Jágerszki, G.; Szilágyi, I. M.; Marinov, Y.

    2016-10-01

    Thin metal oxide films were investigated by a series of characterization techniques including impedance spectroscopy, spectroscopic ellipsometry, Raman spectroscopy, and Atomic Force Microscopy. Thin film deposition by reactive DC magnetron sputtering was performed at the Ångström Laboratory. W and Mo targets (5 cm diameter) and various oxygen gas flows were employed to prepare samples with different properties, whereas the gas pressure was kept constant at about 30 mTorr. The substrates were 5×5 cm2 plates of unheated glass pre-coated with ITO having a resistance of 40 ohm/sq. Film thicknesses were around 300 nm as determined by surface profilometry. Newly acquired equipment was used to study optical spectra, optoelectronic properties, and film structure. Films of WO3 and of mixed W- Mo oxide with three compositions showed coloring and bleaching under the application of a small voltage. Cyclic voltammograms were recorded with a scan rate of 5 mV s-1. Ellipsometric data for the optical constants show dependence on the amount of MoOx in the chemical composition. Single MoOx film, and the mixed one with only 8% MoOx have the highest value of refractive index, and similar dispersion in the visible spectral range. Raman spectra displayed strong lines at wavenumbers between 780 cm-1 and 950 cm-1 related to stretching vibrations of WO3, and MoO3. AFM gave evidence for domains of different composition in mixed W-Mo oxide films.

  6. Temperature dependent structural, optical and hydrophobic properties of sputtered deposited HfO{sub 2} films

    SciTech Connect

    Dave, V.; Dubey, P.; Chandra, R.; Gupta, H. O.

    2014-01-28

    Hafnium oxide being high-k dielectric has been successfully utilized in electronic and optical applications. Being thermodynamically stable and having good mechanical strength, it can be used as a protective coating for outdoor HV insulators which are suffering from surface flashover problem due to contamination. In this paper, we are investigating the effect of substrate temperature on structural, optical and hydrophobic properties of hafnium oxide coating deposited over glass insulators by DC magnetron sputtering. X-ray diffraction is applied to determine the crystalline phase and crystallite size of the film. The morphology of the samples is examined using atomic force microscopy. The optical properties are studied using UV-vis-NIR spectrophotometer. The wettability of the film is investigated using contact angle meter. The thickness is measured using surface profilometer and verified through optical data. The relationship between substrate temperature with grain size, roughness, refractive index, and hydrophobicity is manifested. The maximum contact angle for HfO{sub 2} film was found to be 106° at 400°C.

  7. Growth dynamics of reactive-sputtering-deposited AlN films

    SciTech Connect

    Auger, M.A.; Vazquez, L.; Sanchez, O.; Jergel, M.; Cuerno, R.; Castro, M.

    2005-06-15

    We have studied the surface kinetic roughening of AlN films grown on Si(100) substrates by dc reactive sputtering within the framework of the dynamic scaling theory. Films deposited under the same experimental conditions for different growth times were analyzed by atomic force microscopy and x-ray diffraction. The AlN films display a (002) preferred orientation. We have found two growth regimes with a crossover time of 36 min. In the first regime, the growth dynamics is unstable and the films present two types of textured domains, well textured and randomly oriented, respectively. In contrast, in the second regime the films are homogeneous and well textured, leading to a relative stabilization of the surface roughness characterized by a growth exponent {beta}=0.37{+-}0.03. In this regime a superrough scaling behavior is found with the following exponents: (i) Global exponents: roughness exponent {alpha}=1.2{+-}0.2 and {beta}=0.37{+-}0.03 and coarsening exponent 1/z=0.32{+-}0.05; (ii) local exponents: {alpha}{sub loc}=1, {beta}{sub loc}=0.32{+-}0.01. The differences between the growth modes are found to be related to the different main growth mechanisms dominating their growth dynamics: sticking anisotropy and shadowing, respectively.

  8. Electronic and photo-electronic transport in sputter deposited MoS2 film

    NASA Astrophysics Data System (ADS)

    Wasala, Milinda; Ghosh, Sujoy; Zhang, Jie; Richie, Julianna; Mazumdar, Dipanjan; Kar, Swastik; Talapatra, Saikat

    2015-03-01

    Here we report on the electrical transport as well as photo response of large area sputter deposited few-layers of thin MoS2. Temperature dependent (55 K -275K) electronic conductivity measured on these samples show evidence of 2D Variable Range Hopping (2D-VRH) mechanism within 100K-275K. Photoconductivity measurements investigated using a continuous laser of λ = 658nm (E =1.88eV), over a broad range of illuminating laser intensity, P (0.19 μW

  9. Cell adhesion on NiTi thin film sputter-deposited meshes.

    PubMed

    Loger, K; Engel, A; Haupt, J; Li, Q; Lima de Miranda, R; Quandt, E; Lutter, G; Selhuber-Unkel, C

    2016-02-01

    Scaffolds for tissue engineering enable the possibility to fabricate and form biomedical implants in vitro, which fulfill special functionality in vivo. In this study, free-standing Nickel–Titanium(NiTi) thin film mesheswere produced by means of magnetron sputter deposition.Meshes contained precisely defined rhombic holes in the size of 440 to 1309 μm2 and a strut width ranging from 5.3 to 9.2 μm. The effective mechanical properties of the microstructured superelastic NiTi thin film were examined by tensile testing. These results will be adapted for the design of the holes in the film. The influence of hole and strut dimensions on the adhesion of sheep autologous cells (CD133+) was studied after 24 h and after seven days of incubation. Optical analysis using fluorescence microscopy and scanning electron microscopy showed that cell adhesion depends on the structural parameters of the mesh. After 7 days in cell culture a large part of the mesh was covered with aligned fibrous material. Cell adhesion is particularly facilitated on meshes with small rhombic holes of 440 μm2 and a strut width of 5.3 μm. Our results demonstrate that free-standing NiTi thin film meshes have a promising potential for applicationsin cardiovascular tissue engineering, particularly for the fabrication of heart valves.

  10. Microstructure and tribological properties of Ti-contained amorphous carbon film deposited by DC magnetron sputtering

    SciTech Connect

    Li, R. L.; Tu, J. P.; Hong, C. F.; Liu, D. G.; Zhou, D. H.; Sun, H. L.

    2009-12-15

    Pure amorphous carbon (a-C) film and that with a small amount of Ti were deposited on high speed steel (W18Cr4V) substrates by means of dc closed field unbalanced magnetron sputtering. The chemical composition and microstructure of the a-C films were performed using x-ray photoelectron spectroscopy, x-ray diffraction, Raman spectra, and transmission electron microscopy. The mechanical and tribological properties were evaluated using a nanoindentor, Rockwell and scratch tests, and a conventional ball-on-disk tribometer, respectively. The pure a-C film showed the high hardness (53 GPa), elastic modulus (289 GPa), but the poor adhesive strength. When adding a small amount of Ti to the a-C film, both the adhesive strength and the tribological properties were improved. The Ti contained a-C film had the low wear rate (1.9x10{sup -17} m{sup 3} N{sup -1} m{sup -1}) and friction coefficient in humid air.

  11. Continued improvment of large area, in situ sputter deposition of superconducting YBCO thin films

    NASA Technical Reports Server (NTRS)

    Truman, J. K.; White, W. R.; Ballentine, P. H.; Mallory, D. S.; Kadin, A. M.

    1993-01-01

    The deposition of thin films of superconducting YBa2Cu3O7-x onto substrates of up to 3-in diameter by an integrated off-axis sputtering is reported. The substrate is located above the center of an 8-in-diameter YBCO planar target, and, in conjunction with a negative ion shield, negative ion effects are avoided. A large radiant heater provides backside, noncontact heating of the bare substrates. YBCO films have been grown on polished 1-cm2 MgO and LaAlO3 substrates with Tc = 90 K or greater, Jc = 2.5 x 10 exp 6 A/sq cm or greater at 77 K, and microwave surface resistance Rs less than 0.4 micro-ohm at 77 K and 10 GHz. The films have a very smooth surface morphology. Uniformity data for LaAlO3 substrates are less than +/-5 percent in Rs. Thickness uniformity results for 3-in substrates indicate less than 10 percent variation. The growth of epitaxial insulating films for use with YBCO films and application of the YBCO films in microwave devices are briefly discussed.

  12. Sputter deposition of thin film MIM capacitors on LTCC substrates for RF bypass and filtering applications

    SciTech Connect

    Murray, Jack; O'Keefe, Matthew J.; Wilder, Kristina; Eatinger, Ryan; Kuhn, William; Krueger, Daniel S.; Wolf, J. Ambrose

    2011-08-31

    Thin film capacitors for RF bypass and filtering applications were sputter deposited onto low temperature co-fired ceramic (LTCC) substrates. The capacitors were configured in a metal-insulator-metal (MIM) design featuring 200 nm thick Al electrodes and a 300 nm thick Al{sub 2}O{sub 3} dielectric layer, with dimensions varied between ~150x150 μm and ~750x750 μm. DC current-voltage measurements (E ≤ 5 MV/cm) coupled with impedance analysis (≤15 MHz) was used to characterize the resulting devices. More than 90% of the devices functioned as capacitors with high DC resistance (>20 MΩ) and low loss (tan δ <0.1). A second set of capacitors were made under the same experimental conditions with device geometries optimized for high frequency (≥200 MHz) applications. These capacitors featured temperature coefficient of capacitance (TCC) values between 500 and 1000 ppm/°C as well as low loss and high self-resonant frequency performance (ESR <0.6 Ohms at self-resonance of 5.7 GHz for 82 pF). Capacitance and loss values were comparable between the capacitor structures of similar areas at the different frequency regimes.

  13. Structure-related antibacterial activity of a titanium nanostructured surface fabricated by glancing angle sputter deposition

    NASA Astrophysics Data System (ADS)

    Sengstock, Christina; Lopian, Michael; Motemani, Yahya; Borgmann, Anna; Khare, Chinmay; Buenconsejo, Pio John S.; Schildhauer, Thomas A.; Ludwig, Alfred; Köller, Manfred

    2014-05-01

    The aim of this study was to reproduce the physico-mechanical antibacterial effect of the nanocolumnar cicada wing surface for metallic biomaterials by fabrication of titanium (Ti) nanocolumnar surfaces using glancing angle sputter deposition (GLAD). Nanocolumnar Ti thin films were fabricated by GLAD on silicon substrates. S. aureus as well as E. coli were incubated with nanostructured or reference dense Ti thin film test samples for one or three hours at 37 °C. Bacterial adherence, morphology, and viability were analyzed by fluorescence staining and scanning electron microscopy and compared to human mesenchymal stem cells (hMSCs). Bacterial adherence was not significantly different after short (1 h) incubation on the dense or the nanostructured Ti surface. In contrast to S. aureus the viability of E. coli was significantly decreased after 3 h on the nanostructured film compared to the dense film and was accompanied by an irregular morphology and a cell wall deformation. Cell adherence, spreading and viability of hMSCs were not altered on the nanostructured surface. The results show that the selective antibacterial effect of the cicada wing could be transferred to a nanostructured metallic biomaterial by mimicking the natural nanocolumnar topography.

  14. Intermediate crystalline states produced by isothermal annealing of sputter-deposited a-Si films

    NASA Astrophysics Data System (ADS)

    Akazawa, Housei

    2005-02-01

    The crystalline states produced by isothermally annealing sputter-deposited hydrogen-free amorphous-Si (a-Si) films greatly differ from those of a-Si :H films. Strained network and numerous vacancies in the a-Si film are indicated by the ⟨ɛ2⟩ spectrum. Annealing the sample at temperatures between 300 and 550°C relaxes the strained network due to local exchanges of Si-Si bond while maintaining the amorphous state. Self-assembly of hemispherical grains of microcrystalline Si on the film surface occurs during the onset of crystallization (600°C ). At a slightly elevated temperature of 690°C, the cohesion of Si atoms in the film creates nanocrystalline Si (2-nm diameter), which directly corresponds to the emergence of the absorption peak feature below 3eV in the ⟨ɛ2⟩ spectrum. Dense voids at the interfacial region severely limit the range of solid phase epitaxy, thus facilitating preferential nucleation in the film.

  15. Study of magnetic thin films deposited by closed-field unbalanced magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Ormston, M. W.; Petford-Long, A. K.; Teer, D. G.

    1999-04-01

    Closed-field unbalanced magnetron sputtering, developed by TEER Coatings Ltd., uses a novel plasma confinement system, which allows controllable high-rate deposition from a wide range of target materials. We report the first use of this technique using ferromagnetic target materials to grow films of nanometer thickness. A study was carried out on a series of Py/Cu/Py and Py/Au/Py magnetic multilayer films, with and without underlayers of Ti or Ta. High-resolution electron microscopy showed that 5 nm of Ti or 15 nm of Ta did not change the structure of the trilayers. The use of Au as a spacer layer induced a texture in the upper Py layer, which decreased its saturation field by half. In situ experiments to observe the effects of an applied field on the domain structure of the films were carried out using Lorentz transmission electron microscopy. Variations in the switching field of the Py layers and of the coupling strength between the Py layers were observed when the thicknesses of the three layers were varied. Double domain wall structures with different wall intensities were observed in some cases. The roughness of the interfaces were increased by ion bombardment; this increased the saturation field of the Py layers.

  16. Turnover of texture in low rate sputter-deposited nanocrystalline molybdenum films

    SciTech Connect

    Druesedau, T.P.; Klabunde, F.; Loehmann, M.; Hempel, T.; Blaesing, J.

    1997-07-01

    The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 {angstrom}/s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 {micro}m, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture. In the early state of growth (20 nm thickness) the development of dome-like structures on the surface is observed. The number of these structures increases with film thickness, whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neutrals resulting from backscattering at the target under oblique angle and causing resputtering. Due to the narrow angular distribution of the reflected argon, bombardment of the substrate plane is inhomogeneous and only significant for regions close to the erosion zone of the magnetron.

  17. Structure-related antibacterial activity of a titanium nanostructured surface fabricated by glancing angle sputter deposition.

    PubMed

    Sengstock, Christina; Lopian, Michael; Motemani, Yahya; Borgmann, Anna; Khare, Chinmay; Buenconsejo, Pio John S; Schildhauer, Thomas A; Ludwig, Alfred; Köller, Manfred

    2014-05-16

    The aim of this study was to reproduce the physico-mechanical antibacterial effect of the nanocolumnar cicada wing surface for metallic biomaterials by fabrication of titanium (Ti) nanocolumnar surfaces using glancing angle sputter deposition (GLAD). Nanocolumnar Ti thin films were fabricated by GLAD on silicon substrates. S. aureus as well as E. coli were incubated with nanostructured or reference dense Ti thin film test samples for one or three hours at 37 °C. Bacterial adherence, morphology, and viability were analyzed by fluorescence staining and scanning electron microscopy and compared to human mesenchymal stem cells (hMSCs).Bacterial adherence was not significantly different after short (1 h) incubation on the dense or the nanostructured Ti surface. In contrast to S. aureus the viability of E. coli was significantly decreased after 3 h on the nanostructured film compared to the dense film and was accompanied by an irregular morphology and a cell wall deformation. Cell adherence, spreading and viability of hMSCs were not altered on the nanostructured surface. The results show that the selective antibacterial effect of the cicada wing could be transferred to a nanostructured metallic biomaterial by mimicking the natural nanocolumnar topography.

  18. Sputter-deposited TiN electrode coatings for superior sensing and pacing performance.

    PubMed

    Schaldach, M; Hubmann, M; Weikl, A; Hardt, R

    1990-12-01

    The sensing and pacing performance of pacemaker electrodes is characterized by the electrochemical properties of the electrode/tissue interface affecting tissue reactions and the kinetics of the ionic exchange. The usually smooth metallic electrode surface results in a high pass filter characteristic. To better match the electrode's filter characteristic to the spectral content of the depolarization signal, various combinations of electrode shape, material and surface structure have been researched. The electrode with sputter-deposited TiN coating presented in this report has been designed to meet the demand for low acute as well as chronic thresholds and superior sensing performance not only with respect to spontaneous activity but also regarding the detection of the evoked response. The clinical results obtained with this electrode prove the excellent pacing and sensing properties resulting from minimized polarization losses and optimized filtering of the signal to be detected, respectively. The acute and chronic clinical advantages over previous concepts are attributed mainly to the biocompatibility of the material used and the microcrystalline surface structure achieved by the coating process. The design concept of the new electrode is presented together with the clinical results obtained. While the advancements in microelectronics and battery technology have certainly formed the basis for the development of pulse generators featuring an ever increasing versatility of functions at the same or even smaller pacemaker dimensions, from a point of view of pacing system performance the development of improved electrode concepts as the one presented must be regarded as equally indispensable.

  19. Structure of anodized Al-Zr sputter deposited coatings and effect on optical appearance

    NASA Astrophysics Data System (ADS)

    Gudla, Visweswara Chakravarthy; Canulescu, Stela; Shabadi, Rajashekhara; Rechendorff, Kristian; Dirscherl, Kai; Ambat, Rajan

    2014-10-01

    The mechanism of interaction of light with the microstructure of anodized layer giving specific optical appearance is investigated using Al-Zr sputter deposited coating as a model system on an AA6060 substrate. Differences in the oxidative nature of various microstructural components result in the evolution of typical features in the anodized layer, which are investigated as a function of microstructure and correlated with its optical appearance. The Zr concentration in the coating was varied from 6 wt.% to 23 wt.%. Heat treatment of the coated samples was carried out at 550 °C for 4 h in order to evolve Al-Zr based second phase precipitates in the microstructure. Anodizing was performed using 20 wt.% sulphuric acid at 18 °C with an intention to study the effect of anodizing on the Al-Zr based precipitates in the coating. Detailed microstructural characterization of the coating and anodized layer was carried out using high resolution scanning and transmission electron microscopy, grazing incidence X-ray diffraction analysis, glow discharge optical emission spectroscopy, and optical appearance using spectrophotometry. The evolution of microstructure in the anodized layer as a function of anodizing parameters and their influence on the interaction of light is investigated and the results in general are applicable to discolouration of anodized layer on recycled aluminium alloys due to intermetallics.

  20. Defects, stoichiometry, and electronic transport in SrTiO3-δ epilayers: A high pressure oxygen sputter deposition study

    NASA Astrophysics Data System (ADS)

    Ambwani, P.; Xu, P.; Haugstad, G.; Jeong, J. S.; Deng, R.; Mkhoyan, K. A.; Jalan, B.; Leighton, C.

    2016-08-01

    SrTiO3 is not only of enduring interest due to its unique dielectric, structural, and lattice dynamical properties, but is also the archetypal perovskite oxide semiconductor and a foundational material in oxide heterostructures and electronics. This has naturally focused attention on growth, stoichiometry, and defects in SrTiO3, one exciting recent development being such precisely stoichiometric defect-managed thin films that electron mobilities have finally exceeded bulk crystals. This has been achieved only by molecular beam epitaxy, however (and to a somewhat lesser extent pulsed laser deposition (PLD)), and numerous open questions remain. Here, we present a study of the stoichiometry, defects, and structure in SrTiO3 synthesized by a different method, high pressure oxygen sputtering, relating the results to electronic transport. We find that this form of sputter deposition is also capable of homoepitaxy of precisely stoichiometric SrTiO3, but only provided that substrate and target preparation, temperature, pressure, and deposition rate are carefully controlled. Even under these conditions, oxygen-vacancy-doped heteroepitaxial SrTiO3 films are found to have carrier density, mobility, and conductivity significantly lower than bulk. While surface depletion plays a role, it is argued from particle-induced X-ray emission (PIXE) measurements of trace impurities in commercial sputtering targets that this is also due to deep acceptors such as Fe at 100's of parts-per-million levels. Comparisons of PIXE from SrTiO3 crystals and polycrystalline targets are shown to be of general interest, with clear implications for sputter and PLD deposition of this important material.

  1. Effects of Microstructure and Adhesion on Performance of Sputter-Deposited MoS2 Solid Lubricant Coatings

    DTIC Science & Technology

    1990-01-15

    signatures of missile plumes, sensor out-of-fied-of-view rejection, applied laser spectroscopy, laser chemistry, laser optoelectronics, solar cell ...using atmospheric radiation; solar physics, infrared astronomy, infrared signature analysis; effects of solar activity, magnetic storms and nuclear...and Adhesion on Performance of Sputter-Deposited MoS2 Solid Lubricant Coatings 12. PERSONAL AUTHOR(S) Fleischauer, Paul D.; Hilton, Michael R.; and

  2. Synthesis of Large-Sized Single-Crystal Hexagonal Boron Nitride Domains on Nickel Foils by Ion Beam Sputtering Deposition.

    PubMed

    Wang, Haolin; Zhang, Xingwang; Liu, Heng; Yin, Zhigang; Meng, Junhua; Xia, Jing; Meng, Xiang-Min; Wu, Jinliang; You, Jingbi

    2015-12-22

    Large-sized single-crystal h-BN domains with a lateral size up to 100 μm are synthesized on Ni foils by ion-beam sputtering deposition. The nucleation density of h-BN is dramatically decreased by reducing the concentrations of both active sites and species on the Ni surface through a brief in situ pretreatment of the substrate and optimization of the growth parameters, enabling the growth of large-sized domains.

  3. Modeling of substrate bias effect on the compositional variations in sputtered-deposited TiB{sub 2+x} diffusion barrier thin films

    SciTech Connect

    Sinder, M.; Sade, G.; Pelleg, J.

    1998-12-31

    Sputter-deposited titanium boride diffusion barrier layers have been found to be boron enriched when r.f. substrate bias was applied. In the present experiments titanium boride was deposited by co-sputtering from Ti and B pure targets in Ar discharge and the voltage of r.f. self-bias was in the range of 100--250 V. Films deposited were found by Auger electron spectroscopy to be B enriched with increasing bias voltage at constant Ti and B sputtering rates. A model of the sputter-deposition conditions was developed to predict the composition and the thickness of the growing film. The model explains the experimental results indicating that B enrichment is mainly a result of differential resputtering of the components from the growing film by energetic Ar ions capture from the r.f. discharge.

  4. Structural, morphological and electrical properties of nickel oxide thin films deposited by reactive sputtering

    NASA Astrophysics Data System (ADS)

    Keraudy, J.; García Molleja, J.; Ferrec, A.; Corraze, B.; Richard-Plouet, M.; Goullet, A.; Jouan, P.-Y.

    2015-12-01

    This paper is devoted to the study of the influence of oxygen content in the nickel oxide films on the film structural, morphological and electrical properties. Nickel oxide films have been synthesized by reactive DC magnetron sputtering discharge by varying the oxygen flow rate (1.9 < Q(O2) < 3.6 sccm) for various deposition time. XRD analyses revealed the polycrystalline nature of the as-deposited films and also a phase transition from nickel oxide (1 1 1) to nickel oxide (2 0 0) associated with nickel non-stoichiometry in the NiO structure. The polycrystalline films presented an average crystallite size of 15-30 nm and a surface roughness of 1-10 nm. In-plane stress measurements have established the correlation between crystallite size and intrinsic compressive stress and also the ion-penning effect of negative oxygen ions during the film growth. A maximum stress of 10 GPa was found for lower film thickness (10 nm). By adjusting the oxygen concentration, conductive AFM (C-AFM) and resistivity measurements by the four point method have revealed at room temperature an electrical transition from insulating to conductive state. C-AFM and four point measurements showed respectively an increase in the collected current and an abrupt decrease of the mean resistivity from 107 to 10 Ω cm when the stoichiometry varies from NiO0.96 to NiO1.14. This transition is related to the non-stoichiometry attributed to nickel vacancies. Finally, low-temperature (290-100 K) electrical conduction measurements confirmed the weak dependence of Ni-deficient nickel oxide films with film thickness and showed that charge carrier conduction is a thermal-activated process.

  5. Measurement and simulation of the momentum transferred to a surface by deposition of sputtered atoms*

    NASA Astrophysics Data System (ADS)

    Spethmann, Alexander; Trottenberg, Thomas; Kersten, Holger

    2016-11-01

    Forces on a small plane measurement target caused by sputtered atomic particles originated at plane sputter targets by a beam of argon particles are investigated. The rotatable sputter targets are centrally mounted in front of the ion source and allow a variation of the angle of incidence. The measurement surface of the force probe is arranged laterally beside the sputter target; it collects the particles released perpendicularly to the beam direction. Sputter targets of silver, copper, aluminum, titanium, and carbon are studied. The measurements are compared with a model that traces the trajectories of the argon ions and the sputtered target atoms between the ion source, the sputter target, and the force probe. The sputtering is calculated with the popular SRIM code based on binary collision cascades. The measured forces are found to be in general greater than the simulated forces. The dependence on the angle of incidence is similar in case of the elements heavier than the ions. In case of the lighter elements, only the simulation exhibits a pronounced maximum at angles between 65° and 70°. Contribution to the Topical Issue "Physics of Ion Beam Sources", edited by Holger Kersten and Horst Neumann.

  6. Effect of sputter deposited YSZ thin films on the fracture behavior of dental bioceramics

    NASA Astrophysics Data System (ADS)

    Teixeira, Erica Cappelletto Nogueira

    The fracture behavior of dental bioceramic materials was evaluated under physiologic conditions when modified by yttria stabilized zirconia (YSZ) thin film deposition. It was hypothesized that changing the YSZ thin film properties will produce a significant enhancement in the strength of bioceramic materials, ultimately promoting a more fatigue resistant construct. Porcelain, alumina, and zirconia were evaluated in terms of dynamic fatigue for an initial characterization of their fracture behavior. Data showed that strength degradation occurred in all three materials, most drastically in porcelain. Initial strength measurements, focused on depositing YSZ thin films on three unique substrates; porcelain, alumina, and zirconia, were carried out. A significant increase in strength was observed for alumina and porcelain. Since strength alone is not enough to characterize the fracture behavior of brittle materials, coated specimens of porcelain and zirconia were subjected to dynamic fatigue and Weibull analysis. Coated YSZ porcelain specimens showed a significant increase in strength at all tested stressing rates. YSZ coated zirconia specimens showed similar strength values at all stressing rates. The effect of film thickness on porcelain was also evaluated. Data demonstrated that film thickness alone does not appear to control increases in the flexural strength of a modified substrate. It is expected that deposition induced stress in YSZ sputtered films does not change with film thickness. However, a thicker film will generate a larger force at the film/substrate interface, contributing to delamination of the film. It was clear that in order to have a significant improvement in the fracture behavior of porcelain, changing the thickness of the film is not enough. The columnar structure of the YSZ films developed seems to favor an easy path for crack propagation limiting the benefits expected by the coating. The effect of a multilayered film, composed by brittle

  7. Selective deposition of a crystalline Si film by a chemical sputtering process in a high pressure hydrogen plasma

    NASA Astrophysics Data System (ADS)

    Ohmi, Hiromasa; Kakiuchi, Hiroaki; Yasutake, Kiyoshi

    2015-07-01

    The selective deposition of Si films was demonstrated using a chemical sputtering process induced by a high pressure hydrogen plasma at 52.6 kPa (400 Torr). In this chemical sputtering process, the initial deposition rate (Rd) is dependent upon the substrate type. At the initial stage of Si film formation, Rd on glass substrates increased with elapsed time and reached to a constant value. In contrast, Rd on Si substrates remained constant during the deposition. The selective deposition of Si films can be achieved by adjusting the substrate temperature (Tsub) and hydrogen concentration (CH2) in the process atmosphere. For any given deposition time, it was found that an optimum CH2 exists for a given Tsub to realize the selective deposition of a Si film, and the optimum Tsub value tends to increase with decreasing CH2. According to electron diffraction patterns obtained from the samples, the selectively prepared Si films showed epitaxial-like growth, although the Si films contained many defects. It was revealed by Raman scattering spectroscopy that some of the defects in the Si films were platelet defects induced by excess hydrogen incorporated during Si film formation. Raman spectrum also suggested that Si related radicals (SiH2, SiH, Si) with high reactivity contribute to the Si film formation. Simple model was derived as the guideline for achieving the selective growth.

  8. Microstructure and chemical wet etching characteristics of AlN films deposited by ac reactive magnetron sputtering

    SciTech Connect

    Tanner, S. M.; Felmetsger, V. V.

    2010-01-15

    The influence of the surface morphology of a molybdenum underlayer on the crystallinity and etchability of reactively sputtered c-axis oriented aluminum nitride thin films was investigated. Atomic force microscopy, scanning electron microscopy, transmission electron microscopy, high resolution x-ray diffraction, and defect selective chemical etching were used to characterize the microstructure of the Mo and AlN films. 1000 nm thick films of AlN with a full width at half maximum (FWHM) of the x-ray rocking curve ranging from 1.1 deg. to 1.9 deg. were deposited on 300 nm thick Mo underlayers with a FWHM of around 1.5 deg. The Ar pressure during the Mo deposition had a critical effect on the Mo film surface morphology, affecting the structure of the subsequently deposited AlN films and, hence, their wet etching characteristics. AlN films deposited on Mo sputtered at a relatively high pressure could not be etched completely, while AlN films deposited on low pressure Mo etched more easily. Postdeposition etching of the Mo surface in Ar rf discharge prior to deposition of the AlN film was found to influence the formation of AlN residuals that were difficult to etch. Optimal rf plasma etching conditions were found, which minimized the formation of these residuals.

  9. Observing Planets and Small Bodies in Sputtered High Energy Atom (SHEA) Fluxes

    NASA Technical Reports Server (NTRS)

    Milillo, A.; Orsini, S.; Hsieh, K. C.; Baragiola, R.; Fama, M.; Johnson, R.; Mura, A.; Plainaki, Ch.; Sarantos, M.; Cassidy, T. A.; DeAngelis, E; Desai, M.; Goldstein, R.; Lp, W.-H.; Killen, R.; Livi, S.

    2012-01-01

    The evolution of the surfaces of bodies unprotected by either strong magnetic fields or thick atmospheres in the Solar System is caused by various processes, induced by photons, energetic ions and micrometeoroids. Among these processes, the continuous bombardment of the solar wind or energetic magnetospheric ions onto the bodies may significantly affect their surfaces, with implications for their evolution. Ion precipitation produces neutral atom releases into the exosphere through ion sputtering, with velocity distribution extending well above the particle escape limits. We refer to this component of the surface ejecta as sputtered high-energy atoms (SHEA). The use of ion sputtering emission for studying the interaction of exposed bodies (EB) with ion environments is described here. Remote sensing in SHEA in the vicinity of EB can provide mapping of the bodies exposed to ion sputtering action with temporal and mass resolution. This paper speculates on the possibility of performing remote sensing of exposed bodies using SHEA The evolution of the surfaces of bodies unprotected by either strong magnetic fields or thick atmospheres in the Solar System is caused by various processes, induced by photons, energetic ions and micrometeoroids. Among these processes, the continuous bombardment of the solar wind or energetic magnetospheric ions onto the bodies may significantly affect their surfaces, with implications for their evolution. Ion precipitation produces neutral atom releases into the exosphere through ion sputtering, with velocity distribution extending well above the particle escape limits. We refer to this component of the surface ejecta as sputtered high-energy atoms (SHEA). The use of ion sputtering emission for studying the interaction of exposed bodies (EB) with ion environments is described here. Remote sensing in SHEA in the vicinity of EB can provide mapping of the bodies exposed to ion sputtering action with temporal and mass resolution. This paper

  10. On the electron energy in the high power impulse magnetron sputtering discharge

    SciTech Connect

    Gudmundsson, J. T.; Sigurjonsson, P.; Larsson, P.; Lundin, D.; Helmersson, U.

    2009-06-15

    The temporal variation of the electron energy distribution function (EEDF) was measured with a Langmuir probe in a high power impulse magnetron sputtering (HiPIMS) discharge at 3 and 20 mTorr pressures. In the HiPIMS discharge a high power pulse is applied to a planar magnetron giving a high electron density and highly ionized sputtered vapor. The measured EEDF is Maxwellian-like during the pulse; it is broader for lower discharge pressure and it becomes narrower as the pulse progresses. This indicates that the plasma cools as the pulse progresses, probably due to high metal content of the discharge.

  11. Influence of nitrogen admixture to argon on the ion energy distribution in reactive high power pulsed magnetron sputtering of chromium

    NASA Astrophysics Data System (ADS)

    Breilmann, W.; Maszl, C.; Hecimovic, A.; von Keudell, A.

    2017-04-01

    Reactive high power impulse magnetron sputtering (HiPIMS) of metals is of paramount importance for the deposition of various oxides, nitrides and carbides. The addition of a reactive gas such as nitrogen to an argon HiPIMS plasma with a metal target allows the formation of the corresponding metal nitride on the substrate. The addition of a reactive gas introduces new dynamics into the plasma process, such as hysteresis, target poisoning and the rarefaction of two different plasma gases. We investigate the dynamics for the deposition of chromium nitride by a reactive HiPIMS plasma using energy- and time-resolved ion mass spectrometry, fast camera measurements and temporal and spatially resolved optical emission spectroscopy. It is shown that the addition of nitrogen to the argon plasma gas significantly changes the appearance of the localized ionization zones, the so-called spokes, in HiPIMS plasmas. In addition, a very strong modulation of the metal ion flux within each HiPIMS pulse is observed, with the metal ion flux being strongly suppressed and the nitrogen molecular ion flux being strongly enhanced in the high current phase of the pulse. This behavior is explained by a stronger return effect of the sputtered metal ions in the dense plasma above the racetrack. This is best observed in a pure nitrogen plasma, because the ionization zones are mostly confined, implying a very high local plasma density and consequently also an efficient scattering process.

  12. Molecular dynamics study on low-energy sputtering properties of MgO surfaces

    SciTech Connect

    Ahn, Hyo-Shin; Kim, Tae-Eun; Cho, Eunae; Ji, Miran; Lee, Choong-Ki; Han, Seungwu; Cho, Youngmi; Kim, Changwook

    2008-04-01

    In an effort to understand microscopic processes occurring between MgO protective layers and impinging plasma ions in a discharge cell of plasma-display panel, sputtering properties of MgO(100) surface by He, Ne, and Xe atoms are studied with molecular dynamics simulations. Interatomic potentials between constituent atoms are fitted to first-principles data sets for representative configurations. Various incident directions of ions are considered with kinetic energies under 100 eV. It is found that sputtering yields for the Ne atom are largest among tested noble gases. The angle dependence of sputtering yields indicates that (111)-oriented MgO films are much more vulnerable to ion attacks than (100)-oriented layers. A surface model including the monolayer step is also studied and it is found that the yields increase substantially for grazing-angle incidence.

  13. Towards an electro-magnetic field separation of deposited material implemented in an ion beam sputter process

    SciTech Connect

    Malobabic, Sina; Jupe, Marco; Ristau, Detlev

    2013-06-03

    Nowadays, Ion Beam Sputter (IBS) processes are very well optimized on an empirical basis. To achieve further progresses, a modification of the IBS process by guiding the coating material using an axial magnetic field and an additional electrical field has been studied. The electro-magnetic (EM) field leads to a significant change in plasma properties and deposition rate distributions, whereas an increase in deposition rate along the centerline of the axial EM field around 150% was observed. These fundamental studies on the prototype are the basis for the development of an applicable and workable design of a separation device.

  14. Growth and Characterization of CIS Thin Films Prepared by Ion Beam Sputtering Deposition

    NASA Astrophysics Data System (ADS)

    Fan, Ping; Liang, Guang-Xing; Zheng, Zhuang-Hao; Cai, Xing-Min; Zhang, Dong-Ping

    2010-04-01

    Copper indium diselenide (CuInSe2) thin films were prepared by ion beam sputtering Cu, In and Se targets continuously on BK7 glass substrates and the three-layer film was then annealed in the same vacuum chamber. X-ray diffraction shows that the CuInSe2 thin films have a single chalcopyrite structure with preferential (112) orientation. Scanning electron microscopy reveals that the CIS thin films consist of uniform and densely packed grain clusters. Energy dispersive x-ray spectroscopy demonstrates that the elemental composition of CIS films approaches the stochiometric composition ratios of 1:1:2. Raman measurement shows that the main peak is at about 174 cm-1 and this peak is identified as the A1 vibrational mode from chalcopyrite ordered CuInSe2. Optical transmission and absorption spectroscopy measurement reveal an energy band gap of about 1.05eV and an absorption coefficient of 105 cm-1. The film resistivity is about 0.01 Ωcm.

  15. Formation of (Ti,Al)N/Ti{sub 2}AlN multilayers after annealing of TiN/TiAl(N) multilayers deposited by ion beam sputtering

    SciTech Connect

    Dolique, V.; Jaouen, M.; Cabioc'h, T.; Pailloux, F.; Guerin, Ph.; Pelosin, V.

    2008-04-15

    By using ion beam sputtering, TiN/TiAl(N) multilayers of various modulation wavelengths ({lambda}=8, 13, and 32 nm) were deposited onto silicon substrates at room temperature. After annealing at 600 deg. C in vacuum, one obtains for {lambda}=13 nm a (Ti,Al)N/Ti{sub 2}AlN multilayer as it is evidenced from x-ray diffraction, high resolution transmission electron microscopy, and energy filtered electron imaging experiments. X-ray photoelectron spectroscopy (XPS) experiments show that the as-deposited TiAl sublayers contain a noticeable amount of nitrogen atoms which mean concentration varies with the period {lambda}. They also evidenced the diffusion of aluminum into TiN sublayers after annealing. Deduced from these observations, we propose a model to explain why this solid-state phase transformation depends on the period {lambda} of the multilayer.

  16. Deposition and parametric analysis of RF sputtered ZnO:Al thin films with very low resistivity

    NASA Astrophysics Data System (ADS)

    Jahed, N. M. S.; Mahmoudysepehr, M.; Sivoththaman, S.

    2016-11-01

    RF sputtered, aluminum-doped zinc oxide (ZnO:Al or AZO) is an attractive candidate material as transparent conductive oxides in the fabrication of opto-electronic devices. High electrical conductivity and optical transparency are two key requirements in such applications. This paper reports on the formation of AZO films on glass substrates in an RF-sputtering chamber modified to facilitate in situ heating during deposition. The influence of chamber pressure, RF power, and deposition temperature has been systematically studied and the electrical parameters such as film resistivity, carrier concentration, carrier mobility as well as optical transmission have been analyzed. Film deposition at 250 °C and a low chamber pressure of 0.5 mT resulted in a very low resistivity of 2.94 × 10-4 ohm cm. The structural properties of the films with the lowest resistivity have been further analyzed by x-ray diffraction (XRD) and PL measurements and are compared with the film deposited at room temperature. The XRD results show dominant peaks along (103) orientation for the AZO films with slightly improved crystal quality at higher temperature. Evolution of near band edge and deep level emission photoluminescence peaks also indicate improvement in crystal structure with increased deposition temperature.

  17. Formation of polyhedral N/sub 2/ bubbles during reactive sputter deposition of epitaxial TiN(100) films

    SciTech Connect

    Hultman, L.; Sundgren, J.; Greene, J. E.

    1989-07-15

    Cross-sectional transmission electron microscopy has been used to investigate the formation of polyhedral N/sub 2/ bubbles in single-crystal TiN(100). Thin TiN films were deposited on MgO(100) substrates by reactive magnetron sputtering in pure N/sub 2/ atmospheres at growth temperatures /ital T//sub /ital s// between 550 and 800 /degree/C and negative substrate biases /ital V//sub /ital s// between 0 and 500 V resulting in a deposition rate between 0.35 and 0.33 nm s/sup /minus/1/. The energy per incident nitrogen was /similar to//ital eV//sub /ital s///2 and the irradiation fluxes were less than or equal to2.5/times/10/sup 15/ N/sup +//sub 2/ cm/sup /minus/2/ s/sup /minus/1/. Nitrogen bubbles were observed in films grown at 550less than or equal to/ital T//sub /ital s///lt/800 /degree/C with /ital V//sub /ital s///gt/300 V. In as-deposited films grown at /ital T//sub /ital s//=650 /degree/C with /ital V//sub /ital s//=500 V, the bubbles were distributed in two shapes and size distributions. The largest bubbles were orthorhombohedra, i.e., cubes elongated along (100) directions normal to the growth direction, with 5--20 nm faces on /l brace/100/r brace/ planes most of which exhibited /l brace/110/r brace/ and /l brace/111/r brace/ faceting. Small (less than or equal to5 nm) octahedral bubbles with /l brace/111/r brace/ faces were also observed. /ital/ In situ annealing experiments in the transmission electron microscope showed that the bubbles transformed from orthorhombohedra to octahedra at /ital T//sub /ital s//=350 /degree/C and then returned to orthorhombohedral shape with either continued heating to /ital T//sub /ital s//=600 /degree/C or upon cooling to room temperature. Assuming quasiequilibrium conditions, the surface energy ..gamma.. of N/sub 2/ bubbles in TiN was found to be anisotropic and to vary as ..gamma../sub 100//lt//gamma110//lt//gamma111/.

  18. Nanopatterning of mica surface under low energy ion beam sputtering

    SciTech Connect

    Metya, A.; Ghose, D.; Mollick, S. A.; Majumdar, A.

    2012-04-01

    Irradiation of crystalline muscovite mica samples by 500 eV Ar{sup +} ions at different incident angles can induce significant surface morphological variations. A periodic ripple pattern of nano-dimensions forms in the angle window 47 deg. -70 deg. . On the other hand, tilted conical protrusions develop on the surface at grazing incidence angles around 80 deg. . From the derivative of the topographic images the distribution of the side-facet slopes in the ion incidence plane are measured, which is found to be strongly related to the pattern morphology. Additionally, it has been shown that, for the ripple structures, the base angles can be tuned by changing the ion fluence. An asymmetric sawtooth profile of the ripples obtained at low fluence is transformed to a symmetrical triangular profile at high fluence. As the slopes are found to be small, the pattern formation is not provoked by the gradient-dependent erosion mechanism rather it is the general effect of the curvature-dependent sputtering phenomena.

  19. Low-energy nitrogen-ion implantation: relevance to reactive compound sputtering

    SciTech Connect

    Springer, R.W.; Hosford, C.D.; Rachocki, K.D.

    1982-01-01

    Reactive sputtering is a tool widely used to produce compound coatings. The details of the target physics and compound formation are not well understood. Among several factors, the low-energy ion-implant range in a target could well affect the stoichiometry of the resultant film. Thin films of aluminum, chromium, and tantalum were bombarded with low-energy nitrogen (approx. .5 - approx. .5 keV) and the subsequent implant profiles analyzed. Low-energy-argon depth profiling combined with Auger Electron Spectroscopy was employed to obtain the profiles. The profiles are compared with the computed range distribution obtained from low-energy LSS theory. The agreement between the computed and measured distributions is very good. Comparisons between sputtered-film stoichiometry and range profiles are made.

  20. Influence of microstructure and chemical composition of sputter deposited TiO2 thin films on in vitro bioactivity.

    PubMed

    Lilja, Mirjam; Genvad, Axel; Astrand, Maria; Strømme, Maria; Enqvist, Håkan

    2011-12-01

    Functionalisation of biomedical implants via surface modifications for tailored tissue response is a growing field of research. Crystalline TiO(2) has been proven to be a bone bioactive, non-resorbable material. In contact with body fluids a hydroxyapaptite (HA) layer forms on its surface facilitating the bone contact. Thus, the path of improving biomedical implants via deposition of crystalline TiO(2) on the surface is interesting to follow. In this study we have evaluated the influence of microstructure and chemical composition of sputter deposited titanium oxide thin films on the in vitro bioactivity. We find that both substrate bias, topography and the flow ratio of the gases used during sputtering affect the HA layer formed on the films after immersion in simulated body fluid at 37°C. A random distribution of anatase and rutile crystals, formed at negative substrate bias and low Ar to O(2) gas flow ratios, are shown to favor the growth of flat HA crystal structures whereas higher flow ratios and positive substrate bias induced growth of more spherical HA structures. These findings should provide valuable information when optimizing the bioactivity of titanium oxide coatings as well as for tailoring process parameters for sputtered-based production of bioactive titanium oxide implant surfaces.