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Sample records for complementary metal-oxide-semiconductor biosensor

  1. Real-time, multiplexed electrochemical DNA detection using an active complementary metal-oxide-semiconductor biosensor array with integrated sensor electronics.

    PubMed

    Levine, Peter M; Gong, Ping; Levicky, Rastislav; Shepard, Kenneth L

    2009-03-15

    Optical biosensing based on fluorescence detection has arguably become the standard technique for quantifying extents of hybridization between surface-immobilized probes and fluorophore-labeled analyte targets in DNA microarrays. However, electrochemical detection techniques are emerging which could eliminate the need for physically bulky optical instrumentation, enabling the design of portable devices for point-of-care applications. Unlike fluorescence detection, which can function well using a passive substrate (one without integrated electronics), multiplexed electrochemical detection requires an electronically active substrate to analyze each array site and benefits from the addition of integrated electronic instrumentation to further reduce platform size and eliminate the electromagnetic interference that can result from bringing non-amplified signals off chip. We report on an active electrochemical biosensor array, constructed with a standard complementary metal-oxide-semiconductor (CMOS) technology, to perform quantitative DNA hybridization detection on chip using targets conjugated with ferrocene redox labels. A 4 x 4 array of gold working electrodes and integrated potentiostat electronics, consisting of control amplifiers and current-input analog-to-digital converters, on a custom-designed 5 mm x 3 mm CMOS chip drive redox reactions using cyclic voltammetry, sense DNA binding, and transmit digital data off chip for analysis. We demonstrate multiplexed and specific detection of DNA targets as well as real-time monitoring of hybridization, a task that is difficult, if not impossible, with traditional fluorescence-based microarrays.

  2. Real-time, multiplexed electrochemical DNA detection using an active complementary metal-oxide-semiconductor biosensor array with integrated sensor electronics

    PubMed Central

    Levine, Peter M.; Gong, Ping; Levicky, Rastislav; Shepard, Kenneth L.

    2009-01-01

    Optical biosensing based on fluorescence detection has arguably become the standard technique for quantifying extents of hybridization between surface-immobilized probes and fluorophore-labeled analyte targets in DNA microarrays. However, electrochemical detection techniques are emerging which could eliminate the need for physically bulky optical instrumentation, enabling the design of portable devices for point-of-care applications. Unlike fluorescence detection, which can function well using a passive substrate (one without integrated electronics), multiplexed electrochemical detection requires an electronically-active substrate to analyze each array site and benefits from the addition of integrated electronic instrumentation to further reduce platform size and eliminate the electromagnetic interference that can result from bringing non-amplified signals off chip. We report on an active electrochemical biosensor array, constructed with a standard complementary metal-oxide-semiconductor (CMOS) technology, to perform quantitative DNA hybridization detection on chip using targets conjugated with ferrocene redox labels. A 4×4 array of gold working electrodes and integrated potentiostat electronics, consisting of control amplifiers and current-input analog-to-digital converters, on a custom-designed 5×3 mm2 CMOS chip drive redox reactions using cyclic voltammetry, sense DNA binding, and transmit digital data off chip for analysis. We demonstrate multiplexed and specific detection of DNA targets as well as real-time monitoring of hybridization, a task that is difficult, if not impossible, with traditional fluorescence-based microarrays. PMID:19054661

  3. High-temperature Complementary Metal Oxide Semiconductors (CMOS)

    NASA Technical Reports Server (NTRS)

    Mcbrayer, J. D.

    1981-01-01

    The results of an investigation into the possibility of using complementary metal oxide semiconductor (CMOS) technology for high temperature electronics are presented. A CMOS test chip was specifically developed as the test bed. This test chip incorporates CMOS transistors that have no gate protection diodes; these diodes are the major cause of leakage in commercial devices.

  4. The MSFC complementary metal oxide semiconductor (including multilevel interconnect metallization) process handbook

    NASA Technical Reports Server (NTRS)

    Bouldin, D. L.; Eastes, R. W.; Feltner, W. R.; Hollis, B. R.; Routh, D. E.

    1979-01-01

    The fabrication techniques for creation of complementary metal oxide semiconductor integrated circuits at George C. Marshall Space Flight Center are described. Examples of C-MOS integrated circuits manufactured at MSFC are presented with functional descriptions of each. Typical electrical characteristics of both p-channel metal oxide semiconductor and n-channel metal oxide semiconductor discrete devices under given conditions are provided. Procedures design, mask making, packaging, and testing are included.

  5. Single-photon imaging in complementary metal oxide semiconductor processes

    PubMed Central

    Charbon, E.

    2014-01-01

    This paper describes the basics of single-photon counting in complementary metal oxide semiconductors, through single-photon avalanche diodes (SPADs), and the making of miniaturized pixels with photon-counting capability based on SPADs. Some applications, which may take advantage of SPAD image sensors, are outlined, such as fluorescence-based microscopy, three-dimensional time-of-flight imaging and biomedical imaging, to name just a few. The paper focuses on architectures that are best suited to those applications and the trade-offs they generate. In this context, architectures are described that efficiently collect the output of single pixels when designed in large arrays. Off-chip readout circuit requirements are described for a variety of applications in physics, medicine and the life sciences. Owing to the dynamic nature of SPADs, designs featuring a large number of SPADs require careful analysis of the target application for an optimal use of silicon real estate and of limited readout bandwidth. The paper also describes the main trade-offs involved in architecting such chips and the solutions adopted with focus on scalability and miniaturization. PMID:24567470

  6. Extended-Gate Metal Oxide Semiconductor Field Effect Transistor-Based Biosensor for Detection of Deoxynivalenol

    NASA Astrophysics Data System (ADS)

    Kwon, Insu; Lee, Hee-Ho; Choi, Jinhyeon; Shin, Jang-Kyoo; Seo, Sang-Ho; Choi, Sung-Wook; Chun, Hyang Sook

    2011-06-01

    In this work, we present an extended-gate metal oxide semiconductor field effect transistor (MOSFET)-based biosensor for the detection of deoxynivalenol using a null-balancing circuit. An extended-gate MOSFET-based biosensor was fabricated by a standard complementary metal oxide semiconductor (CMOS) process and its characteristics were measured. A null-balancing circuit was used to measure the output voltage of the sensor directly, instead of measuring the drain current of the sensor. Au was used as the gate metal, which has a chemical affinity with thiol, which leads to the immobilization of a self-assembled monolayer (SAM) of mercaptohexadecanoic acid (MHDA). The SAM was used to immobilize the anti-deoxynivalenol antibody. The carboxyl group of the SAM was bound to the anti-deoxynivalenol antibody. The anti-deoxynivalenol antibody and deoxynivalenol were bound by their antigen-antibody reaction. The measurements were performed in phosphate buffered saline (PBS; pH 7.4) solution. A standard Ag/AgCl electrode was employed as a reference electrode. The bindings of a SAM, anti-deoxynivalenol antibody, and deoxynivalenol caused a variation in the output voltage of the extended-gate MOSFET-based biosensor. Surface plasmon resonance (SPR) measurement was performed to verify the interaction among the SAM, deoxynivalenol-antibody, and deoxynivalenol.

  7. Printable Ultrathin Metal Oxide Semiconductor-Based Conformal Biosensors.

    PubMed

    Rim, You Seung; Bae, Sang-Hoon; Chen, Huajun; Yang, Jonathan L; Kim, Jaemyung; Andrews, Anne M; Weiss, Paul S; Yang, Yang; Tseng, Hsian-Rong

    2015-12-22

    Conformal bioelectronics enable wearable, noninvasive, and health-monitoring platforms. We demonstrate a simple and straightforward method for producing thin, sensitive In2O3-based conformal biosensors based on field-effect transistors using facile solution-based processing. One-step coating via aqueous In2O3 solution resulted in ultrathin (3.5 nm), high-density, uniform films over large areas. Conformal In2O3-based biosensors on ultrathin polyimide films displayed good device performance, low mechanical stress, and highly conformal contact determined using polydimethylsiloxane artificial skin having complex curvilinear surfaces or an artificial eye. Immobilized In2O3 field-effect transistors with self-assembled monolayers of NH2-terminated silanes functioned as pH sensors. Functionalization with glucose oxidase enabled d-glucose detection at physiologically relevant levels. The conformal ultrathin field-effect transistor biosensors developed here offer new opportunities for future wearable human technologies.

  8. DNA detection using a complementary metal-oxide semiconductor ring oscillator circuit

    NASA Astrophysics Data System (ADS)

    Kocanda, Martin; Abdel-Motaleb, Ibrahim

    2010-10-01

    A DNA detection scheme has been implemented that utilizes a simple complementary metal-oxide semiconductor (CMOS) ring oscillator circuit. The detector oscillates at a fundamental frequency when using a nonhybridized single-strand DNA probe layer. Upon hybridization with a complimentary DNA strand, the oscillator output exhibits an increased frequency shift, indicating a genetic match. The probe assembly consists of a p-GaAs substrate containing a pulsed laser deposition-applied barium strontium titanate layer and an overlying sodium dodecyl sulfate lipid layer that serves to anchor a functionalized oligonucleotide probe. The oscillator circuit consisting of cascaded discrete complimentary n-channel and p-channel metal-oxide-semiconductor field-effect transistors was implemented using passive components arranged in a T-network to provide the associated fundamental time constant.

  9. Ultrasensitive mass sensor fully integrated with complementary metal-oxide-semiconductor circuitry

    NASA Astrophysics Data System (ADS)

    Forsen, E.; Abadal, G.; Ghatnekar-Nilsson, S.; Teva, J.; Verd, J.; Sandberg, R.; Svendsen, W.; Perez-Murano, F.; Esteve, J.; Figueras, E.; Campabadal, F.; Montelius, L.; Barniol, N.; Boisen, A.

    2005-07-01

    Nanomechanical resonators have been monolithically integrated on preprocessed complementary metal-oxide-semiconductor (CMOS) chips. Fabricated resonator systems have been designed to have resonance frequencies up to 1.5 MHz. The systems have been characterized in ambient air and vacuum conditions and display ultrasensitive mass detection in air. A mass sensitivity of 4ag/Hz has been determined in air by placing a single glycerine drop, having a measured weight of 57 fg, at the apex of a cantilever and subsequently measuring a frequency shift of 14.8 kHz. CMOS integration enables electrostatic excitation, capacitive detection, and amplification of the resonance signal directly on the chip.

  10. Radiation induced failures of complementary metal oxide semiconductor containing pacemakers: a potentially lethal complication

    SciTech Connect

    Lewin, A.A.; Serago, C.F.; Schwade, J.G.; Abitbol, A.A.; Margolis, S.C.

    1984-10-01

    New multi-programmable pacemakers frequently employ complementary metal oxide semiconductors (CMOS). This circuitry appears more sensitive to the effects of ionizing radiation when compared to the semiconductor circuits used in older pacemakers. A case of radiation induced runaway pacemaker in a CMOS device is described. Because of this and other recent reports of radiation therapy-induced CMOS type pacemaker failure, these pacemakers should not be irradiated. If necessary, the pacemaker can be shielded or moved to a site which can be shielded before institution of radiation therapy. This is done to prevent damage to the CMOS circuit and the life threatening arrythmias which may result from such damage.

  11. Implementation of Surface Acoustic Wave Vapor Sensor Using Complementary Metal-Oxide-Semiconductor Amplifiers

    NASA Astrophysics Data System (ADS)

    Chiu, Chia-Sung; Chang, Ching-Chun; Ku, Chia-Lin; Peng, Kang-Ming; Jeng, Erik S.; Chen, Wen-Lin; Huang, Guo-Wei; Wu, Lin-Kun

    2009-04-01

    A surface acoustic wave (SAW) vapor sensor is presented in this work. A SAW delay line oscillator on quartz substrate with the high gain complementary metal-oxide-semiconductor (CMOS) amplifier using a two-poly-two-metal (2P2M) 0.35 µm process was designed. The gain of the CMOS amplifier and its total power consumption are 20 dB and 70 mW, respectively. The achieved phase noise of this SAW oscillator is -150 dBc/Hz at 100 kHz offset. The sensing is successfully demonstrated by a thin poly(epichlorohydrin) (PECH) polymer film on a SAW oscillator with alcohol vapor. This two-in-one sensor unit includes the SAW device and the CMOS amplifier provides designers with comprehensive model for using these components for sensor circuit fabrication. Furthermore it will be promising for future chemical and biological sensing applications.

  12. Dimensional optimization of nanowire--complementary metal oxide--semiconductor inverter.

    PubMed

    Hashim, Yasir; Sidek, Othman

    2013-01-01

    This study is the first to demonstrate dimensional optimization of nanowire-complementary metal-oxide-semiconductor inverter. Noise margins and inflection voltage of transfer characteristics are used as limiting factors in this optimization. Results indicate that optimization depends on both dimensions ratio and digital voltage level (Vdd). Diameter optimization reveals that when Vdd increases, the optimized value of (Dp/Dn) decreases. Channel length optimization results show that when Vdd increases, the optimized value of Ln decreases and that of (Lp/Ln) increases. Dimension ratio optimization reveals that when Vdd increases, the optimized value of Kp/Kn decreases, and silicon nanowire transistor with suitable dimensions (higher Dp and Ln with lower Lp and Dn) can be fabricated.

  13. Flexible complementary metal oxide semiconductor microelectrode arrays with applications in single cell characterization

    NASA Astrophysics Data System (ADS)

    Pajouhi, H.; Jou, A. Y.; Jain, R.; Ziabari, A.; Shakouri, A.; Savran, C. A.; Mohammadi, S.

    2015-11-01

    A highly flexible microelectrode array with an embedded complementary metal oxide semiconductor (CMOS) instrumentation amplifier suitable for sensing surfaces of biological entities is developed. The array is based on ultrathin CMOS islands that are thermally isolated from each other and are interconnected by meandered nano-scale wires that can adapt to cellular surfaces with micro-scale curvatures. CMOS temperature sensors are placed in the islands and are optimally biased to have high temperature sensitivity. While no live cell thermometry is conducted, a measured temperature sensitivity of 0.15 °C in the temperature range of 35 to 40 °C is achieved by utilizing a low noise CMOS lock-in amplifier implemented in the same technology. The monolithic nature of CMOS sensors and amplifier circuits and their versatile flexible interconnecting wires overcome the sensitivity and yield limitations of microelectrode arrays fabricated in competing technologies.

  14. Modeling boron dose loss in sidewall spacer stacks of complementary metal oxide semiconductor transistors

    NASA Astrophysics Data System (ADS)

    Essa, Z.; Pelletier, B.; Morin, P.; Boulenc, P.; Pakfar, A.; Tavernier, C.; Wacquant, F.; Zechner, C.; Juhel, M.; Autran, J. L.; Cristiano, F.

    2016-12-01

    The presence of capping materials during annealing (activation for example) can substantially impact the silicon junction profiles of Complementary Metal Oxide Semiconductor Field Effect Transistors (CMOSFET), depending on the nature of these layers. In this paper we specifically investigated the boron out-diffusion from a silicon junction into the silicon oxide in presence of a silicon oxide/silicon nitride capping bi-layer similar to the stacks used to form sidewall spacers. After 120 s anneal we observed with secondary ion mass spectrometry (SIMS) substantial boron dose loss in silicon and segregation at the silicon oxide interface related to oxide and nitride material properties, in particular to the hydrogen concentration. We then modeled the boron profiles in both silicon and oxide as a function of the hydrogen static and dynamic in the materials. The exponential-like boron diffusion profiles observed in oxide are reproduced by introducing a long hop mechanism mediated with hydrogen-related defects (HRDs).

  15. Laser Doppler blood flow complementary metal oxide semiconductor imaging sensor with analog on-chip processing.

    PubMed

    Gu, Quan; Hayes-Gill, Barrie R; Morgan, Stephen P

    2008-04-20

    A 4 x 4 pixel array with analog on-chip processing has been fabricated within a 0.35 mum complementary metal oxide semiconductor process as a prototype sensor for laser Doppler blood flow imaging. At each pixel the bandpass and frequency weighted filters necessary for processing laser Doppler blood flow signals have been designed and fabricated. Because of the space constraints of implementing an accurate omega(0.5) filter at the pixel level, this has been approximated using the "roll off" of a high-pass filter with a cutoff frequency set at 10 kHz. The sensor has been characterized using a modulated laser source. Fixed pattern noise is present that is demonstrated to be repeatable across the array and can be calibrated. Preliminary blood flow results on a finger before and after occlusion demonstrate that the sensor array provides the potential for a system that can be scaled to a larger number of pixels for blood flow imaging.

  16. Laser Doppler blood flow complementary metal oxide semiconductor imaging sensor with analog on-chip processing

    SciTech Connect

    Gu Quan; Hayes-Gill, Barrie R.; Morgan, Stephen P

    2008-04-20

    A 4x4 pixel array with analog on-chip processing has been fabricated within a 0.35 {mu}m complementary metal oxide semiconductor process as a prototype sensor for laser Doppler blood flow imaging. At each pixel the bandpass and frequency weighted filters necessary for processing laser Doppler blood flow signals have been designed and fabricated. Because of the space constraints of implementing an accurate {omega}{sup 0.5} filter at the pixel level, this has been approximated using the ''roll off'' of a high-pass filter with a cutoff frequency set at 10 kHz. The sensor has been characterized using a modulated laser source. Fixed pattern noise is present that is demonstrated to be repeatable across the array and can be calibrated. Preliminary blood flow results on a finger before and after occlusion demonstrate that the sensor array provides the potential for a system that can be scaled to a larger number of pixels for blood flow imaging.

  17. Polycrystalline silicon ring resonator photodiodes in a bulk complementary metal-oxide-semiconductor process.

    PubMed

    Mehta, Karan K; Orcutt, Jason S; Shainline, Jeffrey M; Tehar-Zahav, Ofer; Sternberg, Zvi; Meade, Roy; Popović, Miloš A; Ram, Rajeev J

    2014-02-15

    We present measurements on resonant photodetectors utilizing sub-bandgap absorption in polycrystalline silicon ring resonators, in which light is localized in the intrinsic region of a p+/p/i/n/n+ diode. The devices, operating both at λ=1280 and λ=1550  nm and fabricated in a complementary metal-oxide-semiconductor (CMOS) dynamic random-access memory emulation process, exhibit detection quantum efficiencies around 20% and few-gigahertz response bandwidths. We observe this performance at low reverse biases in the range of a few volts and in devices with dark currents below 50 pA at 10 V. These results demonstrate that such photodetector behavior, previously reported by Preston et al. [Opt. Lett. 36, 52 (2011)], is achievable in bulk CMOS processes, with significant improvements with respect to the previous work in quantum efficiency, dark current, linearity, bandwidth, and operating bias due to additional midlevel doping implants and different material deposition. The present work thus offers a robust realization of a fully CMOS-fabricated all-silicon photodetector functional across a wide wavelength range.

  18. Silicon-on-insulator-based complementary metal oxide semiconductor integrated optoelectronic platform for biomedical applications

    NASA Astrophysics Data System (ADS)

    Mujeeb-U-Rahman, Muhammad; Scherer, Axel

    2016-12-01

    Microscale optical devices enabled by wireless power harvesting and telemetry facilitate manipulation and testing of localized biological environments (e.g., neural recording and stimulation, targeted delivery to cancer cells). Design of integrated microsystems utilizing optical power harvesting and telemetry will enable complex in vivo applications like actuating a single nerve, without the difficult requirement of extreme optical focusing or use of nanoparticles. Silicon-on-insulator (SOI)-based platforms provide a very powerful architecture for such miniaturized platforms as these can be used to fabricate both optoelectronic and microelectronic devices on the same substrate. Near-infrared biomedical optics can be effectively utilized for optical power harvesting to generate optimal results compared with other methods (e.g., RF and acoustic) at submillimeter size scales intended for such designs. We present design and integration techniques of optical power harvesting structures with complementary metal oxide semiconductor platforms using SOI technologies along with monolithically integrated electronics. Such platforms can become the basis of optoelectronic biomedical systems including implants and lab-on-chip systems.

  19. Transport properties of silicon complementary-metal-oxide semiconductor quantum well field-effect transistors

    NASA Astrophysics Data System (ADS)

    Naquin, Clint Alan

    Introducing explicit quantum transport into silicon (Si) transistors in a manner compatible with industrial fabrication has proven challenging, yet has the potential to transform the performance horizons of large scale integrated Si devices and circuits. Explicit quantum transport as evidenced by negative differential transconductances (NDTCs) has been observed in a set of quantum well (QW) n-channel metal-oxide-semiconductor (NMOS) transistors fabricated using industrial silicon complementary MOS processing. The QW potential was formed via lateral ion implantation doping on a commercial 45 nm technology node process line, and measurements of the transfer characteristics show NDTCs up to room temperature. Detailed gate length and temperature dependence characteristics of the NDTCs in these devices have been measured. Gate length dependence of NDTCs shows a correlation of the interface channel length with the number of NDTCs formed as well as with the gate voltage (VG) spacing between NDTCs. The VG spacing between multiple NDTCs suggests a quasi-parabolic QW potential profile. The temperature dependence is consistent with partial freeze-out of carrier concentration against a degenerately doped background. A folding amplifier frequency multiplier circuit using a single QW NMOS transistor to generate a folded current-voltage transfer function via a NDTC was demonstrated. Time domain data shows frequency doubling in the kHz range at room temperature, and Fourier analysis confirms that the output is dominated by the second harmonic of the input. De-embedding the circuit response characteristics from parasitic cable and contact impedances suggests that in the absence of parasitics the doubling bandwidth could be as high as 10 GHz in a monolithic integrated circuit, limited by the transresistance magnitude of the QW NMOS. This is the first example of a QW device fabricated by mainstream Si CMOS technology being used in a circuit application and establishes the feasibility

  20. Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector.

    PubMed

    Smith, Richard J; Light, Roger A; Sharples, Steve D; Johnston, Nicholas S; Pitter, Mark C; Somekh, Mike G

    2010-02-01

    This paper presents a multichannel, time-resolved picosecond laser ultrasound system that uses a custom complementary metal-oxide-semiconductor linear array detector. This novel sensor allows parallel phase-sensitive detection of very low contrast modulated signals with performance in each channel comparable to that of a discrete photodiode and a lock-in amplifier. Application of the instrument is demonstrated by parallelizing spatial measurements to produce two-dimensional thickness maps on a layered sample, and spectroscopic parallelization is demonstrated by presenting the measured Brillouin oscillations from a gallium arsenide wafer. This paper demonstrates the significant advantages of our approach to pump probe systems, especially picosecond ultrasonics.

  1. Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector

    SciTech Connect

    Smith, Richard J.; Light, Roger A.; Johnston, Nicholas S.; Pitter, Mark C.; Somekh, Mike G.; Sharples, Steve D.

    2010-02-15

    This paper presents a multichannel, time-resolved picosecond laser ultrasound system that uses a custom complementary metal-oxide-semiconductor linear array detector. This novel sensor allows parallel phase-sensitive detection of very low contrast modulated signals with performance in each channel comparable to that of a discrete photodiode and a lock-in amplifier. Application of the instrument is demonstrated by parallelizing spatial measurements to produce two-dimensional thickness maps on a layered sample, and spectroscopic parallelization is demonstrated by presenting the measured Brillouin oscillations from a gallium arsenide wafer. This paper demonstrates the significant advantages of our approach to pump probe systems, especially picosecond ultrasonics.

  2. Improved Radio Frequency Power Characteristics of Complementary Metal-Oxide-Semiconductor-Compatible Asymmetric-Lightly-Doped-Drain Metal-Oxide-Semiconductor Transistor

    NASA Astrophysics Data System (ADS)

    Chang, Tsu; Kao, Hsuan-ling; Chen, Y. J.; Chin, Albert

    2010-03-01

    We have characterized and modeled the radio frequency (RF) power performance of a 0.18 µm asymmetric-lightly-doped-drain metal-oxide-semiconductor field-effect transistor (LDD MOSFET). In comparison with the conventional 0.18 µm MOSFET, this asymmetric-LDD device shows a larger power density of 0.54 W/mm, and 8 dB better adjacent channel power ratio (ACPR) linearity at 2.4 GHz from the improved twice DC breakdown voltage of 6.9 V. These significant improvements of RF power performance in the asymmetric-LDD transistor are important for the medium RF power amplifier application.

  3. Improved Radio Frequency Power Characteristics of Complementary Metal-Oxide-Semiconductor-Compatible Asymmetric-Lightly-Doped-Drain Metal-Oxide-Semiconductor Transistor

    NASA Astrophysics Data System (ADS)

    Tsu Chang,; Hsuan-ling Kao,; Y. J. Chen,; Albert Chin,

    2010-03-01

    We have characterized and modeled the radio frequency (RF) power performance of a 0.18 μm asymmetric-lightly-doped-drain metal-oxide-semiconductor field-effect transistor (LDD MOSFET). In comparison with the conventional 0.18 μm MOSFET, this asymmetric-LDD device shows a larger power density of 0.54 W/mm, and 8 dB better adjacent channel power ratio (ACPR) linearity at 2.4 GHz from the improved twice DC breakdown voltage of 6.9 V. These significant improvements of RF power performance in the asymmetric-LDD transistor are important for the medium RF power amplifier application.

  4. Ratiometric, filter-free optical sensor based on a complementary metal oxide semiconductor buried double junction photodiode.

    PubMed

    Yung, Ka Yi; Zhan, Zhiyong; Titus, Albert H; Baker, Gary A; Bright, Frank V

    2015-07-16

    We report a complementary metal oxide semiconductor integrated circuit (CMOS IC) with a buried double junction (BDJ) photodiode that (i) provides a real-time output signal that is related to the intensity ratio at two emission wavelengths and (ii) simultaneously eliminates the need for an optical filter to block Rayleigh scatter. We demonstrate the BDJ platform performance for gaseous NH3 and aqueous pH detection. We also compare the BDJ performance to parallel results obtained by using a slew scanned fluorimeter (SSF). The BDJ results are functionally equivalent to the SSF results without the need for any wavelength filtering or monochromators and the BDJ platform is not prone to errors associated with source intensity fluctuations or sensor signal drift.

  5. Characterization of a complementary metal-oxide semiconductor operational amplifier from 300 to 4.2 K

    NASA Astrophysics Data System (ADS)

    Hastings, J. Todd; Ng, K.-W.

    1995-06-01

    We report the first operation of a commercially available complementary metal-oxide semiconductor operational amplifier, at liquid helium temperature. In addition, we have characterized several factors important to the practical application of such a circuit from room temperature down to 4.2 K. The temperature dependence and measurement techniques for open-loop gain, input offset voltage, input referred noise voltage, and quiescent current are presented. We will discuss our observations of low temperature behavior of the opamp with respect to others' previous results. This work represents an advancement over earlier studies which only reported opamp operation down to 77 or 30 K with measurements taken only at a limited number of temperatures instead of a broad range. Our data suggest that under special operating conditions the opamps can be effectively used with careful consideration of noise and gain performance. Input offset voltage levels and quiescent current (including power consumption) resemble normal room temperature operation.

  6. 32×32 pixel array complementary metal-oxide semiconductor imaging sensor for laser Doppler blood-flow measurement

    NASA Astrophysics Data System (ADS)

    He, Diwei; Kongsavatsak, Chayut; Hayes-Gill, Barrie R.; Crowe, John A.; Morgan, Stephen P.

    2011-05-01

    A 32×32 pixel array has been fabricated in a 0.35-μm complementary metal-oxide semiconductor process with the aim of producing two-dimensional laser Doppler blood-flow images. In the design, each pixel contains five basic elements: a photodiode, a front-end consisting of a current to voltage converter, voltage amplifier, antialiasing filter, and buffer. The analog design is optimized for the detection of laser Doppler blood-flow signals and thus offers advantages over conventional sensors. The analog outputs are passed through an on-chip multiplexer and digitized by an external analog-to-digital converter. The sensor has been fully characterized electrically and optically using modulated electrical and optical signals. A calibration process for fixed pattern noise reduces the standard deviation of the ac gain by a factor of 2. The imaging response is tested by imaging a vibrating test structure and a rotating diffuser. Blood-flow measurements on a finger before and after occlusion demonstrate that the sensor array is capable of detecting blood-flow signals from tissue. The knowledge gained from the characterization of the design can be used to develop a fully integrated laser Doppler blood-flow sensors with a higher number of pixels.

  7. Photosystem I Bio-Photosensor Integrated with Complementary Metal-Oxide-Semiconductor Source-Drain Follower on a Chip

    NASA Astrophysics Data System (ADS)

    Tsukada, Junichi; Ozawa, Hiroaki; Uno, Shigeyasu; Nakazato, Kazuo; Terasaki, Nao; Yamamoto, Noritaka; Hiraga, Takashi; Iwai, Masako; Konno, Masae; Ito, Kohsuke; Inoue, Yasunori

    2010-01-01

    A new bio-photosensor where photons are converted to electrons by photosystem I (PSI) of Thermosynechococcus elongatus is described; in this bio-photosensor, the converted electronic charge is sensed by a complementary metal-oxide-semiconductor (CMOS) source-drain follower circuit fabricated by the 1.2 µm standard CMOS process. Thin Au/Ti films are deposited and patterned with a 4.255×4.255 µm2 extended-gate electrode, and an SU-8 layer is formed, with the exception of the electrode, to reduce the light-induced drift of silicon nitride. As a result, only the Au electrode and the SU-8 layer come into contact with the electrolyte. The PSI is immobilized on the electrode, and the photoresponse due to the photovoltaic effect of PSI is measured as the output voltage of the CMOS source-drain follower. The action spectrum from the light source is consistent with the PSI absorption spectrum. In addition, the selectivity of the photoresponse between two adjacent sensor cells is confirmed, which is promising for ultrasensitive bioimage sensing.

  8. Ultrasonic fingerprint sensor using a piezoelectric micromachined ultrasonic transducer array integrated with complementary metal oxide semiconductor electronics

    NASA Astrophysics Data System (ADS)

    Lu, Y.; Tang, H.; Fung, S.; Wang, Q.; Tsai, J. M.; Daneman, M.; Boser, B. E.; Horsley, D. A.

    2015-06-01

    This paper presents an ultrasonic fingerprint sensor based on a 24 × 8 array of 22 MHz piezoelectric micromachined ultrasonic transducers (PMUTs) with 100 μm pitch, fully integrated with 180 nm complementary metal oxide semiconductor (CMOS) circuitry through eutectic wafer bonding. Each PMUT is directly bonded to a dedicated CMOS receive amplifier, minimizing electrical parasitics and eliminating the need for through-silicon vias. The array frequency response and vibration mode-shape were characterized using laser Doppler vibrometry and verified via finite element method simulation. The array's acoustic output was measured using a hydrophone to be ˜14 kPa with a 28 V input, in reasonable agreement with predication from analytical calculation. Pulse-echo imaging of a 1D steel grating is demonstrated using electronic scanning of a 20 × 8 sub-array, resulting in 300 mV maximum received amplitude and 5:1 contrast ratio. Because the small size of this array limits the maximum image size, mechanical scanning was used to image a 2D polydimethylsiloxane fingerprint phantom (10 mm × 8 mm) at a 1.2 mm distance from the array.

  9. An optical relay approach to very low cost hybrid polymer-complementary metal-oxide semiconductor electrophoresis instrumentation.

    PubMed

    Hall, Gordon H; Sloan, David L; Ma, Tianchi; Couse, Madeline H; Martel, Stephane; Elliott, Duncan G; Glerum, D Moira; Backhouse, Christopher J

    2014-07-04

    Electrophoresis is an integral part of many molecular diagnostics protocols and an inexpensive implementation would greatly facilitate point-of-care (POC) applications. However, the high instrumentation cost presents a substantial barrier, much of it associated with fluorescence detection. The cost of such systems could be substantially reduced by placing the fluidic channel and photodiode directly above the detector in order to collect a larger portion of the fluorescent light. In future, this could be achieved through the integration and monolithic fabrication of photoresist microchannels on complementary metal-oxide semiconductor microelectronics (CMOS). However, the development of such a device is expensive due to high non-recurring engineering costs. To facilitate that development, we present a system that utilises an optical relay to integrate low-cost polymeric microfluidics with a CMOS chip that provides a photodiode, analog-digital conversion and a standard serial communication interface. This system embodies an intermediate level of microelectronic integration, and significantly decreases development costs. With a limit of detection of 1.3±0.4nM of fluorescently end-labeled deoxyribonucleic acid (DNA), it is suitable for diagnostic applications.

  10. A Three-Stage Inverter-Based Stacked Power Amplifier in 65 nm Complementary Metal Oxide Semiconductor Process

    NASA Astrophysics Data System (ADS)

    Kiumarsi, Hamid; Mizuochi, Yutaka; Ito, Hiroyuki; Ishihara, Noboru; Masu, Kazuya

    2012-02-01

    A three-stage inverter-based stacked power amplifier (PA) in complementary metal oxide semiconductor (CMOS) process is proposed to overcome low breakdown voltage problem of scaled CMOS technologies. Unlike previous reported stacked PAs which radio frequency choke (RFC) was inevitable, we proposed stacked nMOS and pMOS transistors which effectively eliminates use of RFC. By properly setting self-biased circuits' and transistors' parameters, output impedance could reach up to 50 Ω which together with not employing the RFC makes this topology very appealing for the scalable PA realization. As a proof of concept, a three-stage PA using 65 nm CMOS technology is implemented. With a 6 V power supply for the third stage, the fabricated PA shows a small-signal gain of 36 dB, a saturated output power of 16 dBm and a maximum power added efficiency of 10% at 1 GHz. Using a 7.5 V of power supply, saturated output power reaches 18 dBm. To the best of our knowledge, this is the first reported inverter-based stacked PA.

  11. Ultrasonic fingerprint sensor using a piezoelectric micromachined ultrasonic transducer array integrated with complementary metal oxide semiconductor electronics

    SciTech Connect

    Lu, Y.; Fung, S.; Wang, Q.; Horsley, D. A.; Tang, H.; Boser, B. E.; Tsai, J. M.; Daneman, M.

    2015-06-29

    This paper presents an ultrasonic fingerprint sensor based on a 24 × 8 array of 22 MHz piezoelectric micromachined ultrasonic transducers (PMUTs) with 100 μm pitch, fully integrated with 180 nm complementary metal oxide semiconductor (CMOS) circuitry through eutectic wafer bonding. Each PMUT is directly bonded to a dedicated CMOS receive amplifier, minimizing electrical parasitics and eliminating the need for through-silicon vias. The array frequency response and vibration mode-shape were characterized using laser Doppler vibrometry and verified via finite element method simulation. The array's acoustic output was measured using a hydrophone to be ∼14 kPa with a 28 V input, in reasonable agreement with predication from analytical calculation. Pulse-echo imaging of a 1D steel grating is demonstrated using electronic scanning of a 20 × 8 sub-array, resulting in 300 mV maximum received amplitude and 5:1 contrast ratio. Because the small size of this array limits the maximum image size, mechanical scanning was used to image a 2D polydimethylsiloxane fingerprint phantom (10 mm × 8 mm) at a 1.2 mm distance from the array.

  12. Chemistry integrated circuit: chemical system on a complementary metal oxide semiconductor integrated circuit.

    PubMed

    Nakazato, Kazuo

    2014-03-28

    By integrating chemical reactions on a large-scale integration (LSI) chip, new types of device can be created. For biomedical applications, monolithically integrated sensor arrays for potentiometric, amperometric and impedimetric sensing of biomolecules have been developed. The potentiometric sensor array detects pH and redox reaction as a statistical distribution of fluctuations in time and space. For the amperometric sensor array, a microelectrode structure for measuring multiple currents at high speed has been proposed. The impedimetric sensor array is designed to measure impedance up to 10 MHz. The multimodal sensor array will enable synthetic analysis and make it possible to standardize biosensor chips. Another approach is to create new functional devices by integrating molecular systems with LSI chips, for example image sensors that incorporate biological materials with a sensor array. The quantum yield of the photoelectric conversion of photosynthesis is 100%, which is extremely difficult to achieve by artificial means. In a recently developed process, a molecular wire is plugged directly into a biological photosynthetic system to efficiently conduct electrons to a gold electrode. A single photon can be detected at room temperature using such a system combined with a molecular single-electron transistor.

  13. Chemistry integrated circuit: chemical system on a complementary metal oxide semiconductor integrated circuit

    PubMed Central

    Nakazato, Kazuo

    2014-01-01

    By integrating chemical reactions on a large-scale integration (LSI) chip, new types of device can be created. For biomedical applications, monolithically integrated sensor arrays for potentiometric, amperometric and impedimetric sensing of biomolecules have been developed. The potentiometric sensor array detects pH and redox reaction as a statistical distribution of fluctuations in time and space. For the amperometric sensor array, a microelectrode structure for measuring multiple currents at high speed has been proposed. The impedimetric sensor array is designed to measure impedance up to 10 MHz. The multimodal sensor array will enable synthetic analysis and make it possible to standardize biosensor chips. Another approach is to create new functional devices by integrating molecular systems with LSI chips, for example image sensors that incorporate biological materials with a sensor array. The quantum yield of the photoelectric conversion of photosynthesis is 100%, which is extremely difficult to achieve by artificial means. In a recently developed process, a molecular wire is plugged directly into a biological photosynthetic system to efficiently conduct electrons to a gold electrode. A single photon can be detected at room temperature using such a system combined with a molecular single-electron transistor. PMID:24567475

  14. Transistor sizing in the design of high-speed CMOS (complementary-symmetry metal-oxide-semiconductor) super buffers. Master's thesis

    SciTech Connect

    Steele, G.R.

    1988-03-01

    An algorithm for sizing transistors for static Complementary-symmetry Metal-Oxide-Semiconductor (CMOS) integrated-circuit logic design using silicon-gate enhancement-mode Field-Effect Transistors (FET) is derived and implemented in software. The algorithm is applied to the mask-level hardware design of a three-micron-minimum feature-size p-well high-speed super buffer. A software representation of the super buffer can be used for the automated design of custom Very-Large-Scale Integrated (VLSI) circuits.

  15. Self-aligned silicides for Ohmic contacts in complementary metal-oxide-semiconductor technology: TiSi2, CoSi2, and NiSi

    NASA Astrophysics Data System (ADS)

    Zhang, S.-L.; Smith, U.

    2004-07-01

    Metal silicides continue to play an indispensable role during the remarkable development of microelectronics. Along with several other technological innovations, the implementation of the self-aligned silicide technology paved the way for a rapid and successful miniaturization of device dimensions for metal-oxide-semiconductor field-effect transistors (MOSFETs) in pace with the Moore's law. The use of silicides has also evolved from creating reliable contacts for diodes, to generating high-conductivity current paths for local wiring, and lately to forming low-resistivity electrical contacts for MOSFETs. With respect to the choice of silicides for complementary metal-oxide-semiconductor (CMOS) technology, a convergence has become clear with the self-alignment technology using only a limited number of silicides, namely TiSi2, CoSi2, and NiSi. The present work discusses the advantages and limitations of TiSi2, CoSi2, and NiSi using the development trend of CMOS technology as a measure. Specifically, the reactive diffusion and phase formation of these silicides in the three terminals of a MOSFET, i.e., gate, source, and drain, are analyzed. This work ends with a brief discussion about future trends of metal silicides in micro/nanoelectronics with reference to potential material aspects and device structures outlined in the International Technology Roadmap for Semiconductors. .

  16. Analysis, Design, and Optimization of Matched-Impedance Wide-Band Amplifiers With Multiple Feedback Loops Using 0.18 μm Complementary Metal Oxide Semiconductor Technology

    NASA Astrophysics Data System (ADS)

    Lin, Yo-Sheng; Lee, Tai-Hsing

    2004-10-01

    The realization of matched-impedance wide-band amplifier fabricated by 0.18 μm complementary metal oxide semiconductor (CMOS) process is reported. The technique of multiple feedback loops was used in the amplifier for terminal impedance matching and wide bandwidth simultaneously. The experimental results show that 3-dB bandwidth of 3 GHz and a gain of 10.7 dB with in-band input/output return loss more than 10 dB are obtained. These values agree well with those predicted from the analytic expressions derived for voltage gain, trans-impedance gain, bandwidth, and input/output return loss and impedance. In addition, the use of source capacitive peaking technique can improve the intrinsic over-damped characteristic of this amplifier.

  17. Mechanical stress effects on Pb(Zr,Ti)O3 thin-film ferroelectric capacitors embedded in a standard complementary metal-oxide-semiconductor process

    NASA Astrophysics Data System (ADS)

    Acosta, Antonio G.; Rodriguez, John A.; Nishida, Toshikazu

    2014-06-01

    We report experimental investigations of externally applied mechanical stress on 70 nm Pb(Zr,Ti)O3 ferroelectric capacitors embedded within a 130 nm complementary metal-oxide-semiconductor manufacturing process. An average increase in the remnant polarization of 3.37% per 100 MPa compressive uniaxial stress was observed. The maximum polarization increased by 2.68% per 100 MPa, while the cycling endurance was not affected by stress. The significant difference between experiment and the lattice distortion model suggests that two mechanisms are responsible for the polarization change. These results indicate that stress engineering may be used to enhance the signal margin in ferroelectric random access memory and enable technology scaling.

  18. A 3.5-4.5 GHz Complementary Metal-Oxide-Semiconductor Ultrawideband Receiver Frontend Low-Noise Amplifier with On-Chip Integrated Antenna for Interchip Communication

    NASA Astrophysics Data System (ADS)

    Azhari, Afreen; Kimoto, Kentaro; Sasaki, Nobuo; Kikkawa, Takamaro

    2010-04-01

    Chip-to-chip ultrawideband (UWB) wireless interconnections are essential for reducing resistance capacitance (RC) delay in wired interconnections and three-dimensional (3D) highly integrated packaging. In this study, we demonstrated a wireless interchip signal transmission between two on-chip meander antennas on printed circuit board (PCB) for 1 to 20 mm transmission distances where the low power gain of each antenna due to a lossy Si substrate has been amplified by a low-noise amplifier (LNA). The measured result shows that the LNA produces 26 dB of improvement in antenna power gain at 4.5 GHz on a lossy Si substrate. Moreover, a Gaussian monocycle pulse with a center frequency of 2.75 GHz was also received by an on-chip antenna and amplified by the LNA. The LNA was integrated with an on-chip antenna on a Si substrate with a resistivity of 10 Ω·cm using 180 nm complementary metal-oxide-semiconductor (CMOS) technology. The investigated system is required for future single chip transceiver front ends, integrated with an on-chip antenna for 3D mounting on a printed circuit (PC) board.

  19. Real time in vivo imaging and measurement of serine protease activity in the mouse hippocampus using a dedicated complementary metal-oxide semiconductor imaging device.

    PubMed

    Ng, David C; Tamura, Hideki; Tokuda, Takashi; Yamamoto, Akio; Matsuo, Masamichi; Nunoshita, Masahiro; Ishikawa, Yasuyuki; Shiosaka, Sadao; Ohta, Jun

    2006-09-30

    The aim of the present study is to demonstrate the application of complementary metal-oxide semiconductor (CMOS) imaging technology for studying the mouse brain. By using a dedicated CMOS image sensor, we have successfully imaged and measured brain serine protease activity in vivo, in real-time, and for an extended period of time. We have developed a biofluorescence imaging device by packaging the CMOS image sensor which enabled on-chip imaging configuration. In this configuration, no optics are required whereby an excitation filter is applied onto the sensor to replace the filter cube block found in conventional fluorescence microscopes. The fully packaged device measures 350 microm thick x 2.7 mm wide, consists of an array of 176 x 144 pixels, and is small enough for measurement inside a single hemisphere of the mouse brain, while still providing sufficient imaging resolution. In the experiment, intraperitoneally injected kainic acid induced upregulation of serine protease activity in the brain. These events were captured in real time by imaging and measuring the fluorescence from a fluorogenic substrate that detected this activity. The entire device, which weighs less than 1% of the body weight of the mouse, holds promise for studying freely moving animals.

  20. Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers

    NASA Astrophysics Data System (ADS)

    Hoidn, Oliver R.; Seidler, Gerald T.

    2015-08-01

    We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2-6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ˜20% quantum efficiency at 2.6 keV with ˜190 eV resolution and a 100 kHz maximum detection rate. The detector platform's useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry.

  1. Three-Dimensional Flexible Complementary Metal-Oxide-Semiconductor Logic Circuits Based On Two-Layer Stacks of Single-Walled Carbon Nanotube Networks.

    PubMed

    Zhao, Yudan; Li, Qunqing; Xiao, Xiaoyang; Li, Guanhong; Jin, Yuanhao; Jiang, Kaili; Wang, Jiaping; Fan, Shoushan

    2016-02-23

    We have proposed and fabricated stable and repeatable, flexible, single-walled carbon nanotube (SWCNT) thin film transistor (TFT) complementary metal-oxide-semiconductor (CMOS) integrated circuits based on a three-dimensional (3D) structure. Two layers of SWCNT-TFT devices were stacked, where one layer served as n-type devices and the other one served as p-type devices. On the basis of this method, it is able to save at least half of the area required to construct an inverter and make large-scale and high-density integrated CMOS circuits easier to design and manufacture. The 3D flexible CMOS inverter gain can be as high as 40, and the total noise margin is more than 95%. Moreover, the input and output voltage of the inverter are exactly matched for cascading. 3D flexible CMOS NOR, NAND logic gates, and 15-stage ring oscillators were fabricated on PI substrates with high performance as well. Stable electrical properties of these circuits can be obtained with bending radii as small as 3.16 mm, which shows that such a 3D structure is a reliable architecture and suitable for carbon nanotube electrical applications in complex flexible and wearable electronic devices.

  2. 2 Gbit/s 0.5 μm complementary metal-oxide semiconductor optical transceiver with event-driven dynamic power-on capability

    NASA Astrophysics Data System (ADS)

    Wang, Xingle; Kiamilev, Fouad; Gui, Ping; Wang, Xiaoqing; Ekman, Jeremy; Zuo, Yongrong; Blankenberg, Jason; Haney, Michael

    2006-06-01

    A 2 Gb/s0.5 μm complementary metal-oxide semiconductor optical transceiver designed for board- or backplane level power-efficient interconnections is presented. The transceiver supports optical wake-on-link (OWL), an event-driven dynamic power-on technique. Depending on external events, the transceiver resides in either the active mode or the sleep mode and switches accordingly. The active-to-sleep transition shuts off the normal, gigabit link and turns on dedicated circuits to establish a low-power (~1.8 mW), low data rate (less than 100 Mbits/s) link. In contrast the normal, gigabit link consumes over 100 mW. Similarly the sleep-to-active transition shuts off the low-power link and turns on the normal, gigabit link. The low-power link, sharing the same optical channel with the normal, gigabit link, is used to achieve transmitter/receiver pair power-on synchronization and greatly reduces the power consumption of the transceiver. A free-space optical platform was built to evaluate the transceiver performance. The experiment successfully demonstrated the event-driven dynamic power-on operation. To our knowledge, this is the first time a dynamic power-on scheme has been implemented for optical interconnects. The areas of the circuits that implement the low-power link are approximately one-tenth of the areas of the gigabit link circuits.

  3. Potentiometric Dye Imaging for Pheochromocytoma and Cortical Neurons with a Novel Measurement System Using an Integrated Complementary Metal-Oxide-Semiconductor Imaging Device

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takuma; Tagawa, Ayato; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Hatanaka, Yumiko; Tamura, Hideki; Ishikawa, Yasuyuki; Shiosaka, Sadao; Ohta, Jun

    2010-11-01

    The combination of optical imaging with voltage-sensitive dyes is a powerful tool for studying the spatiotemporal patterns of neural activity and understanding the neural networks of the brain. To visualize the potential status of multiple neurons simultaneously using a compact instrument with high density and a wide range, we present a novel measurement system using an implantable biomedical photonic LSI device with a red absorptive light filter for voltage-sensitive dye imaging (BpLSI-red). The BpLSI-red was developed for sensing fluorescence by the on-chip LSI, which was designed by using complementary metal-oxide-semiconductor (CMOS) technology. A micro-electro-mechanical system (MEMS) microfabrication technique was used to postprocess the CMOS sensor chip; light-emitting diodes (LEDs) were integrated for illumination and to enable long-term cell culture. Using the device, we succeeded in visualizing the membrane potential of 2000-3000 cells and the process of depolarization of pheochromocytoma cells (PC12 cells) and mouse cerebral cortical neurons in a primary culture with cellular resolution. Therefore, our measurement application enables the detection of multiple neural activities simultaneously.

  4. Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers.

    PubMed

    Hoidn, Oliver R; Seidler, Gerald T

    2015-08-01

    We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2-6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ∼20% quantum efficiency at 2.6 keV with ∼190 eV resolution and a 100 kHz maximum detection rate. The detector platform's useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry.

  5. Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers

    SciTech Connect

    Hoidn, Oliver R.; Seidler, Gerald T.

    2015-08-15

    We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2–6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ∼20% quantum efficiency at 2.6 keV with ∼190 eV resolution and a 100 kHz maximum detection rate. The detector platform’s useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry.

  6. Integration of crystalline orientated γ-Al2O3 films and complementary metal-oxide-semiconductor circuits on Si(1 0 0) substrate

    NASA Astrophysics Data System (ADS)

    Oishi, Koji; Akai, Daisuke; Ishida, Makoto

    2015-01-01

    In this paper, integration of crystalline orientated γ-Al2O3 films and complementary metal-oxide-semiconductor (CMOS) circuits on Si(1 0 0) substrate was reported. In this integration processes, crystalline γ-Al2O3 films need to be preserved their crystallinity during high temperature annealing processes of CMOS fabrication in order to prevent surface condition changes. The γ-Al2O3 films grown on Si substrates are annealed in the CMOS fabrication process conditions, drive-in annealing at 1150 °C in O2 atmosphere and wet annealing 1000 °C in H2O vapor atmosphere. Reflection high energy electron diffraction (RHEED) and x-ray diffraction (XRD) were used to characterize the crystallinity of γ-Al2O3 films after the annealing processes. Surface conditions of the films are analyzed and observed with X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). As a result, RHEED patterns of the γ-Al2O3 films indicated that wet oxidation annealing was a critical process severally inferior surface condition of crystalline γ-Al2O3 films. XRD, XPS, and SEM investigation unveiled further details of the crystallinity changes on γ-Al2O3 films for each process. These results indicated passivation films were required to integrate γ-Al2O3 films with CMOS fabrication process. Therefore we proposed and introduced Si3N4/TEOS passivation films on γ-Al2O3 films in CMOS fabrication processes. At last, MOSFETs on γ-Al2O3 integrated Si(1 0 0) substrate were fabricated and characterized. The designed characteristics of MOSFETs were obtained on γ-Al2O3 integrated Si substrate.

  7. Fluorescence-suppressed time-resolved Raman spectroscopy of pharmaceuticals using complementary metal-oxide semiconductor (CMOS) single-photon avalanche diode (SPAD) detector.

    PubMed

    Rojalin, Tatu; Kurki, Lauri; Laaksonen, Timo; Viitala, Tapani; Kostamovaara, Juha; Gordon, Keith C; Galvis, Leonardo; Wachsmann-Hogiu, Sebastian; Strachan, Clare J; Yliperttula, Marjo

    2016-01-01

    In this work, we utilize a short-wavelength, 532-nm picosecond pulsed laser coupled with a time-gated complementary metal-oxide semiconductor (CMOS) single-photon avalanche diode (SPAD) detector to acquire Raman spectra of several drugs of interest. With this approach, we are able to reveal previously unseen Raman features and suppress the fluorescence background of these drugs. Compared to traditional Raman setups, the present time-resolved technique has two major improvements. First, it is possible to overcome the strong fluorescence background that usually interferes with the much weaker Raman spectra. Second, using the high photon energy excitation light source, we are able to generate a stronger Raman signal compared to traditional instruments. In addition, observations in the time domain can be performed, thus enabling new capabilities in the field of Raman and fluorescence spectroscopy. With this system, we demonstrate for the first time the possibility of recording fluorescence-suppressed Raman spectra of solid, amorphous and crystalline, and non-photoluminescent and photoluminescent drugs such as caffeine, ranitidine hydrochloride, and indomethacin (amorphous and crystalline forms). The raw data acquired by utilizing only the picosecond pulsed laser and a CMOS SPAD detector could be used for identifying the compounds directly without any data processing. Moreover, to validate the accuracy of this time-resolved technique, we present density functional theory (DFT) calculations for a widely used gastric acid inhibitor, ranitidine hydrochloride. The obtained time-resolved Raman peaks were identified based on the calculations and existing literature. Raman spectra using non-time-resolved setups with continuous-wave 785- and 532-nm excitation lasers were used as reference data. Overall, this demonstration of time-resolved Raman and fluorescence measurements with a CMOS SPAD detector shows promise in diverse areas, including fundamental chemical research, the

  8. Dual Metal/High-k Gate-Last Complementary Metal-Oxide-Semiconductor Field-Effect Transistor with SiBN Film and Characteristic Behavior In Sub-1-nm Equivalent Oxide Thickness

    NASA Astrophysics Data System (ADS)

    Kikuchi, Yoshiaki; Wakabayashi, Hitoshi; Tsukamoto, Masanori; Nagashima, Naoki

    2011-08-01

    For the first time, dual metal/high-k gate-last complementary metal-oxide-semiconductor field-effect transistors (CMOSFETs) with low-dielectric-constant-material offset spacers and several gate oxide thicknesses were fabricated to improve CMOSFETs characteristics. Improvements of 23 aF/µm in parasitic capacitances were confirmed with a low-dielectric-constant material, and drive current improvements were also achieved with a thin gate oxide. The drive currents at 100 nA/µm off leakages in n-type metal-oxide-semiconductor (NMOS) were improved from 830 to 950 µA/µm and that in p-type metal-oxide-semiconductor (PMOS) were from 405 to 450 µA/µm with a reduction in gate oxide thickness. The thin gate oxide in PMOS was thinner than that in NMOS and the gate leakage was increased. However the gate leakage did not affect the off leakage below a gate length of about 44 nm. On the basis of this result, in these gate-last CMOSFETs, it is concluded that the transistors have potential for further reduction of the equivalent oxide thickness without an increase in off leakages at short gate lengths for high off leakage CMOSFETs. For low off leakage CMOSFETs, the optimization of wet process condition is needed to prevent the reduction of the 2 nm HfO2 thickness in PMOS during a wet process.

  9. Metal oxide semiconductor thin-film transistors for flexible electronics

    NASA Astrophysics Data System (ADS)

    Petti, Luisa; Münzenrieder, Niko; Vogt, Christian; Faber, Hendrik; Büthe, Lars; Cantarella, Giuseppe; Bottacchi, Francesca; Anthopoulos, Thomas D.; Tröster, Gerhard

    2016-06-01

    The field of flexible electronics has rapidly expanded over the last decades, pioneering novel applications, such as wearable and textile integrated devices, seamless and embedded patch-like systems, soft electronic skins, as well as imperceptible and transient implants. The possibility to revolutionize our daily life with such disruptive appliances has fueled the quest for electronic devices which yield good electrical and mechanical performance and are at the same time light-weight, transparent, conformable, stretchable, and even biodegradable. Flexible metal oxide semiconductor thin-film transistors (TFTs) can fulfill all these requirements and are therefore considered the most promising technology for tomorrow's electronics. This review reflects the establishment of flexible metal oxide semiconductor TFTs, from the development of single devices, large-area circuits, up to entirely integrated systems. First, an introduction on metal oxide semiconductor TFTs is given, where the history of the field is revisited, the TFT configurations and operating principles are presented, and the main issues and technological challenges faced in the area are analyzed. Then, the recent advances achieved for flexible n-type metal oxide semiconductor TFTs manufactured by physical vapor deposition methods and solution-processing techniques are summarized. In particular, the ability of flexible metal oxide semiconductor TFTs to combine low temperature fabrication, high carrier mobility, large frequency operation, extreme mechanical bendability, together with transparency, conformability, stretchability, and water dissolubility is shown. Afterward, a detailed analysis of the most promising metal oxide semiconducting materials developed to realize the state-of-the-art flexible p-type TFTs is given. Next, the recent progresses obtained for flexible metal oxide semiconductor-based electronic circuits, realized with both unipolar and complementary technology, are reported. In particular

  10. Selective Conversion from p-Type to n-Type of Printed Bottom-Gate Carbon Nanotube Thin-Film Transistors and Application in Complementary Metal-Oxide-Semiconductor Inverters.

    PubMed

    Xu, Qiqi; Zhao, Jianwen; Pecunia, Vincenzo; Xu, Wenya; Zhou, Chunshan; Dou, Junyan; Gu, Weibing; Lin, Jian; Mo, Lixin; Zhao, Yanfei; Cui, Zheng

    2017-04-12

    The fabrication of printed high-performance and environmentally stable n-type single-walled carbon nanotube (SWCNT) transistors and their integration into complementary (i.e., complementary metal-oxide-semiconductor, CMOS) circuits are widely recognized as key to achieving the full potential of carbon nanotube electronics. Here, we report a simple, efficient, and robust method to convert the polarity of SWCNT thin-film transistors (TFTs) using cheap and readily available ethanolamine as an electron doping agent. Printed p-type bottom-gate SWCNT TFTs can be selectively converted into n-type by deposition of ethanolamine inks on the transistor active region via aerosol jet printing. Resulted n-type TFTs show excellent electrical properties with an on/off ratio of 10(6), effective mobility up to 30 cm(2) V(-1) s(-1), small hysteresis, and small subthreshold swing (90-140 mV dec(-1)), which are superior compared to the original p-type SWCNT devices. The n-type SWCNT TFTs also show good stability in air, and any deterioration of performance due to shelf storage can be fully recovered by a short low-temperature annealing. The easy polarity conversion process allows construction of CMOS circuitry. As an example, CMOS inverters were fabricated using printed p-type and n-type TFTs and exhibited a large noise margin (50 and 103% of 1/2 Vdd = 1 V) and a voltage gain as high as 30 (at Vdd = 1 V). Additionally, the CMOS inverters show full rail-to-rail output voltage swing and low power dissipation (0.1 μW at Vdd = 1 V). The new method paves the way to construct fully functional complex CMOS circuitry by printed TFTs.

  11. Demonstration of Y1Ba2Cu3O(7-delta) and complementary metal-oxide-semiconductor device fabrication on the same sapphire substrate

    NASA Technical Reports Server (NTRS)

    Burns, M. J.; De La Houssaye, P. R.; Russell, S. D.; Garcia, G. A.; Clayton, S. R.; Ruby, W. S.; Lee, L. P.

    1993-01-01

    We report the first fabrication of active semiconductor and high-temperature superconducting devices on the same substrate. Test structures of complementary MOS transistors were fabricated on the same sapphire substrate as test structures of Y1Ba2Cu3O(7-delta) flux-flow transistors, and separately, Y1Ba2Cu3O(7-delta) superconducting quantum interference devices utilizing both biepitaxial and step-edge Josephson junctions. Both semiconductor and superconductor devices were operated at 77 K. The cofabrication of devices using these disparate yet complementary electronic technologies on the same substrate opens the door for the fabrication of true semiconductive/superconductive hybrid integrated circuits capable of exploiting the best features of each of these technologies.

  12. Complementary Metal Oxide Semiconductor-Compatible, High-Mobility, ⟨111⟩-Oriented GaSb Nanowires Enabled by Vapor-Solid-Solid Chemical Vapor Deposition.

    PubMed

    Yang, Zai-Xing; Liu, Lizhe; Yip, SenPo; Li, Dapan; Shen, Lifan; Zhou, Ziyao; Han, Ning; Hung, Tak Fu; Pun, Edwin Yue-Bun; Wu, Xinglong; Song, Aimin; Ho, Johnny C

    2017-04-05

    Using CMOS-compatible Pd catalysts, we demonstrated the formation of high-mobility ⟨111⟩-oriented GaSb nanowires (NWs) via vapor-solid-solid (VSS) growth by surfactant-assisted chemical vapor deposition through a complementary experimental and theoretical approach. In contrast to NWs formed by the conventional vapor-liquid-solid (VLS) mechanism, cylindrical-shaped Pd5Ga4 catalytic seeds were present in our Pd-catalyzed VSS-NWs. As solid catalysts, stoichiometric Pd5Ga4 was found to have the lowest crystal surface energy and thus giving rise to a minimal surface diffusion as well as an optimal in-plane interface orientation at the seed/NW interface for efficient epitaxial NW nucleation. These VSS characteristics led to the growth of slender NWs with diameters down to 26.9 ± 3.5 nm. Over 95% high crystalline quality NWs were grown in ⟨111⟩ orientation for a wide diameter range of between 10 and 70 nm. Back-gated field-effect transistors (FETs) fabricated using the Pd-catalyzed GaSb NWs exhibit a superior peak hole mobility of ∼330 cm(2) V(-1) s(-1), close to the mobility limit for a NW channel diameter of ∼30 nm with a free carrier concentration of ∼10(18) cm(-3). This suggests that the NWs have excellent homogeneity in phase purity, growth orientation, surface morphology and electrical characteristics. Contact printing process was also used to fabricate large-scale assembly of Pd-catalyzed GaSb NW parallel arrays, confirming the potential constructions and applications of these high-performance electronic devices.

  13. Nanoscale Metal Oxide Semiconductors for Gas Sensing

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Evans, Laura; Xu, Jennifer C.; VanderWal, Randy L.; Berger, Gordon M.; Kulis, Michael J.

    2011-01-01

    A report describes the fabrication and testing of nanoscale metal oxide semiconductors (MOSs) for gas and chemical sensing. This document examines the relationship between processing approaches and resulting sensor behavior. This is a core question related to a range of applications of nanotechnology and a number of different synthesis methods are discussed: thermal evaporation- condensation (TEC), controlled oxidation, and electrospinning. Advantages and limitations of each technique are listed, providing a processing overview to developers of nanotechnology- based systems. The results of a significant amount of testing and comparison are also described. A comparison is made between SnO2, ZnO, and TiO2 single-crystal nanowires and SnO2 polycrystalline nanofibers for gas sensing. The TECsynthesized single-crystal nanowires offer uniform crystal surfaces, resistance to sintering, and their synthesis may be done apart from the substrate. The TECproduced nanowire response is very low, even at the operating temperature of 200 C. In contrast, the electrospun polycrystalline nanofiber response is high, suggesting that junction potentials are superior to a continuous surface depletion layer as a transduction mechanism for chemisorption. Using a catalyst deposited upon the surface in the form of nanoparticles yields dramatic gains in sensitivity for both nanostructured, one-dimensional forms. For the nanowire materials, the response magnitude and response rate uniformly increase with increasing operating temperature. Such changes are interpreted in terms of accelerated surface diffusional processes, yielding greater access to chemisorbed oxygen species and faster dissociative chemisorption, respectively. Regardless of operating temperature, sensitivity of the nanofibers is a factor of 10 to 100 greater than that of nanowires with the same catalyst for the same test condition. In summary, nanostructure appears critical to governing the reactivity, as measured by electrical

  14. Silicon Metal-Oxide-Semiconductor Quantum Devices

    NASA Astrophysics Data System (ADS)

    Nordberg, Eric

    This thesis presents stable quantum dots in a double gated silicon metal-oxide-semiconductor (MOS) system with an open-lateral geometry. In recent years, semiconductor lateral quantum dots have emerged as an appealing approach to quantum computing. Silicon offers the potential for very long electron spin decoherence times in these dots. Several important steps toward a functioning silicon-based electron spin qubit are presented, including stable Coulomb blockade within a quantum dot, a tunable double quantum dot, and integrated charge sensing. A fabrication process has been created to make low-disorder constrictions on relatively high mobility Si-MOS material and to facilitate essentially arbitrary gate geometries. Within this process, changes in mobility and charge defect densities are measured for critical process steps. This data was used to guide the fabrication of devices culminating, in this work, with a clean, stable quantum dot in a double-gated MOS system. Stable Coulomb-blockade behavior showing single-period conductance oscillations was observed in MOS quantum dots. Measured capacitances within each device and capacitances calculated via modeling are compared, showing that the measured Coulomb-blockade is consistent with a lithographically defined quantum dot, as opposed to a disorder dot within a single constriction. A tunable double dot is also observed. Laterally coupled charge sensing of quantum dots is highly desirable because it enables measurement even when conduction through the quantum dot itself is suppressed. Such charge sensing is demonstrated in this system. The current through a point contact constriction located near a quantum dot shows sharp 2% changes corresponding to charge transitions between the dot and a nearby lead. The coupling capacitance between the charge sensor and the quantum dot is extracted and agrees well with a capacitance model of the integrated sensor and quantum dot system.

  15. Integrated photo-responsive metal oxide semiconductor circuit

    NASA Technical Reports Server (NTRS)

    Jhabvala, Murzban D. (Inventor); Dargo, David R. (Inventor); Lyons, John C. (Inventor)

    1987-01-01

    An infrared photoresponsive element (RD) is monolithically integrated into a source follower circuit of a metal oxide semiconductor device by depositing a layer of a lead chalcogenide as a photoresistive element forming an ohmic bridge between two metallization strips serving as electrodes of the circuit. Voltage from the circuit varies in response to illumination of the layer by infrared radiation.

  16. Positron studies of metal-oxide-semiconductor structures

    SciTech Connect

    Au, H.L.; Asoka-Kumar, P.; Nielsen, B.; Lynn, K.G. )

    1993-03-15

    Positron annihilation spectroscopy provides a new probe to study the properties of interface traps in metal-oxide semiconductors (MOS). Using positrons, we have examined the behavior of the interface traps as a function of gate bias. We propose a simple model to explain the positron annihilation spectra from the interface region of a MOS capacitor.

  17. Multilevel metallization method for fabricating a metal oxide semiconductor device

    NASA Technical Reports Server (NTRS)

    Hollis, B. R., Jr.; Feltner, W. R.; Bouldin, D. L.; Routh, D. E. (Inventor)

    1978-01-01

    An improved method is described of constructing a metal oxide semiconductor device having multiple layers of metal deposited by dc magnetron sputtering at low dc voltages and low substrate temperatures. The method provides multilevel interconnections and cross over between individual circuit elements in integrated circuits without significantly reducing the reliability or seriously affecting the yield.

  18. CMOS array design automation techniques. [metal oxide semiconductors

    NASA Technical Reports Server (NTRS)

    Ramondetta, P.; Feller, A.; Noto, R.; Lombardi, T.

    1975-01-01

    A low cost, quick turnaround technique for generating custom metal oxide semiconductor arrays using the standard cell approach was developed, implemented, tested and validated. Basic cell design topology and guidelines are defined based on an extensive analysis that includes circuit, layout, process, array topology and required performance considerations particularly high circuit speed.

  19. New Performance Indicators of Metal-Oxide-Semiconductor Field-Effect Transistors for High-Frequency Power-Conscious Design

    NASA Astrophysics Data System (ADS)

    Katayama, Kosuke; Fujishima, Minoru

    2012-02-01

    With the progress of complementary metal-oxide-semiconductor (CMOS) process technology, it is possible to apply CMOS devices to millimeter-wave amplifier design. However, the power consumption of the system becomes higher in proportion to its target frequency. Moreover, CMOS devices are biased at a point where the device achieves the highest gain and consumes much power. In order to reduce the power consumption without any compromise, we introduce two types of indicator. One works towards achieving the highest gain with the lowest power consumption. The other works towards achieving the highest linearity with consideration of the power consumption. In this work, we have shown the effectiveness of those indicators by applying measured data of the fabricated metal-oxide-semiconductor field-effect transistors (MOSFETs) to cascade common-source amplifiers.

  20. Bistability in a complementary metal oxide semiconductor inverter circuit.

    PubMed

    Carroll, Thomas L

    2005-09-01

    Radiofrequency signals can disrupt the operation of low frequency circuits. A digital inverter circuit would seem to be immune to such disruption, because its output state usually jumps abruptly between 0 and 5 V. Nevertheless, when driven with a high frequency signal, the inverter can have two coexisting stable states (which are not at 0 and 5 V). Slow switching between these states (by changing the rf signal) will produce a low frequency signal. I demonstrate the bistability in a circuit experiment and in a simple model of the circuit.

  1. NO2 sensitive Au gate metal-oxide-semiconductor capacitors

    NASA Astrophysics Data System (ADS)

    Filippini, D.; Aragón, R.; Weimar, U.

    2001-08-01

    Au gate metal-oxide-semiconductor capacitors are sensitive to NO2 in air up to 200 ppm, depending on operating temperature (100 °C to 200 °C), gate thickness (50 to 900 nm), and morphology. In the absence of catalytic properties or lattice diffusivity, a model invoking molecular surface adsorption and grain boundary diffusion is proposed, which quantitatively describes the transient and steady state response of the devices. Sensitivity is given by the arrival of the diffusing species to the gate-dielectric interface, where capacitive coupling of the adsorbed molecules induces work function changes, which shift the flat band voltage positively, opposite that observed for H2 with Pd gates, consistently with an oxidizing, rather than reducing, character.

  2. Waveguide biosensor with integrated detector array for tuberculosis testing

    NASA Astrophysics Data System (ADS)

    Yan, Rongjin; Lynn, N. Scott; Kingry, Luke C.; Yi, Zhangjing; Slayden, Richard A.; Dandy, David S.; Lear, Kevin L.

    2011-01-01

    A label-free immunoassay using a local evanescent array coupled (LEAC) biosensor is reported. Complementary metal oxide semiconductor chips with integrated photoconductor arrays are used to detect an antibody to a M. tuberculosis protein antigen, HspX. The metrology limits of the LEAC sensor using dc and ac measurement systems correspond to average film thicknesses of 28 and 14 pm, respectively. Limits of detection are 87 and 108 pm, respectively, for mouse immunoglobulin G antibody patterning and antigen detection.

  3. Effect of edge roughness on electronic transport in graphene nanoribbon channel metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Basu, D.; Gilbert, M. J.; Register, L. F.; Banerjee, S. K.; MacDonald, A. H.

    2008-01-01

    Results of quantum mechanical simulations of the influence of edge disorder on transport in graphene nanoribbon metal-oxide-semiconductor field-effect transistors (MOSFETs) are reported. The addition of edge disorder significantly reduces ON-state currents and increases OFF-state currents, and introduces wide variability across devices. These effects decrease as ribbon widths increase and as edges become smoother. However, the band gap decreases with increasing width, thereby increasing the band-to-band tunneling mediated subthreshold leakage current even with perfect nanoribbons. These results suggest that without atomically precise edge control during fabrication, MOSFET performance gains through use of graphene will be difficult to achieve in complementary MOS applications.

  4. Plasmonic nanostructured metal-oxide-semiconductor reflection modulators.

    PubMed

    Olivieri, Anthony; Chen, Chengkun; Hassan, Sa'ad; Lisicka-Skrzek, Ewa; Tait, R Niall; Berini, Pierre

    2015-04-08

    We propose a plasmonic surface that produces an electrically controlled reflectance as a high-speed intensity modulator. The device is conceived as a metal-oxide-semiconductor capacitor on silicon with its metal structured as a thin patch bearing a contiguous nanoscale grating. The metal structure serves multiple functions as a driving electrode and as a grating coupler for perpendicularly incident p-polarized light to surface plasmons supported by the patch. Modulation is produced by charging and discharging the capacitor and exploiting the carrier refraction effect in silicon along with the high sensitivity of strongly confined surface plasmons to index perturbations. The area of the modulator is set by the area of the incident beam, leading to a very compact device for a strongly focused beam (∼2.5 μm in diameter). Theoretically, the modulator can operate over a broad electrical bandwidth (tens of gigahertz) with a modulation depth of 3 to 6%, a loss of 3 to 4 dB, and an optical bandwidth of about 50 nm. About 1000 modulators can be integrated over a 50 mm(2) area producing an aggregate electro-optic modulation rate in excess of 1 Tb/s. We demonstrate experimentally modulators operating at telecommunications wavelengths, fabricated as nanostructured Au/HfO2/p-Si capacitors. The modulators break conceptually from waveguide-based devices and belong to the same class of devices as surface photodetectors and vertical cavity surface-emitting lasers.

  5. A comparison of imaging methods for use in an array biosensor.

    PubMed

    Golden, Joel P; Ligler, Frances S

    2002-09-01

    An array biosensor has been developed which uses an actively-cooled, charge-coupled device (CCD) imager. In an effort to save money and space, a complementary metal-oxide semiconductor (CMOS) camera and photodiode were tested as replacements for the cooled CCD imager. Different concentrations of CY5 fluorescent dye in glycerol were imaged using the three different detection systems with the same imaging optics. Signal discrimination above noise was compared for each of the three systems.

  6. A comparison of imaging methods for use in an array biosensor

    NASA Technical Reports Server (NTRS)

    Golden, Joel P.; Ligler, Frances S.

    2002-01-01

    An array biosensor has been developed which uses an actively-cooled, charge-coupled device (CCD) imager. In an effort to save money and space, a complementary metal-oxide semiconductor (CMOS) camera and photodiode were tested as replacements for the cooled CCD imager. Different concentrations of CY5 fluorescent dye in glycerol were imaged using the three different detection systems with the same imaging optics. Signal discrimination above noise was compared for each of the three systems.

  7. A biristor based on a floating-body silicon nanowire for biosensor applications

    NASA Astrophysics Data System (ADS)

    Moon, Dong-Il; Peycelon, Maxime; Kim, Jee-Yeon; Ahn, Jae-Hyuk; Jung Park, Tae; Choi, Yang-Kyu

    2013-01-01

    A silicon nanowire (SiNW), which has been named "biristor" (bistable resistor), is demonstrated for biosensor applications. The SiNW is composed of three segments: n-type (source), p-type (floating-body), and n-type (drain). Its structure is based on a metal-oxide-semiconductor field-effect transistor without a gate. The biristor uses the uncovered floating-body as a sensing site, and it is triggered by impact ionization. A charge effect arising from biomolecules influences the triggering voltage, which is a sensing metric and changes the resistance of the SiNW. The biristor can be a promising candidate for biosensors in terms of complementary metal-oxide-semiconductor compatibility, low-cost, and compact density.

  8. Challenges of Electrical Measurements of Advanced Gate Dielectrics in Metal-Oxide-Semiconductor Devices

    NASA Astrophysics Data System (ADS)

    Vogel, Eric M.; Brown, George A.

    2003-09-01

    Experimental measurements and simulations are used to provide an overview of key issues with the electrical characterization of metal-oxide-semiconductor (MOS) devices with ultra-thin oxide and alternate gate dielectrics. Experimental issues associated with the most common electrical characterization method, capacitance-voltage (C-V), are first described. Issues associated with equivalent oxide thickness extraction and comparison, interface state measurement, extrinsic defects, and defect generation are then overviewed.

  9. High temperature behavior of multi-region direct current current-voltage spectroscopy and relationship with shallow-trench-isolation-based high-voltage laterally diffused metal-oxide-semiconductor field-effect-transistors reliability

    NASA Astrophysics Data System (ADS)

    He, Yandong; Zhang, Ganggang; Zhang, Xing

    2014-01-01

    With the process compatibility with the mainstream standard complementary metal-oxide-semiconductor (CMOS), shallow trench isolation (STI) based laterally diffused metal-oxide-semiconductor (LDMOS) devices have become popular for its better tradeoff between breakdown voltage and performance, especially for smart power applications. A multi-region direct current current-voltage (MR-DCIV) technique with spectroscopic features was demonstrated to map the interface state generation in the channel, accumulation and STI drift regions. High temperature behavior of MR-DCIV spectroscopy was analyzed and a physical model was verified. Degradation of STI-based LDMOS transistors under high temperature reverse bias (HTRB) stress is experimentally studied by MR-DCIV spectroscopy. The impact of interface state location on device electrical characteristics was investigated. Our results show that the major contribution to HTRB degradation, in term of the on-resistance degradation, was attributed to interface state generation under STI drift region.

  10. CMOS Electrochemical Instrumentation for Biosensor Microsystems: A Review.

    PubMed

    Li, Haitao; Liu, Xiaowen; Li, Lin; Mu, Xiaoyi; Genov, Roman; Mason, Andrew J

    2016-12-31

    Modern biosensors play a critical role in healthcare and have a quickly growing commercial market. Compared to traditional optical-based sensing, electrochemical biosensors are attractive due to superior performance in response time, cost, complexity and potential for miniaturization. To address the shortcomings of traditional benchtop electrochemical instruments, in recent years, many complementary metal oxide semiconductor (CMOS) instrumentation circuits have been reported for electrochemical biosensors. This paper provides a review and analysis of CMOS electrochemical instrumentation circuits. First, important concepts in electrochemical sensing are presented from an instrumentation point of view. Then, electrochemical instrumentation circuits are organized into functional classes, and reported CMOS circuits are reviewed and analyzed to illuminate design options and performance tradeoffs. Finally, recent trends and challenges toward on-CMOS sensor integration that could enable highly miniaturized electrochemical biosensor microsystems are discussed. The information in the paper can guide next generation electrochemical sensor design.

  11. CMOS Electrochemical Instrumentation for Biosensor Microsystems: A Review

    PubMed Central

    Li, Haitao; Liu, Xiaowen; Li, Lin; Mu, Xiaoyi; Genov, Roman; Mason, Andrew J.

    2016-01-01

    Modern biosensors play a critical role in healthcare and have a quickly growing commercial market. Compared to traditional optical-based sensing, electrochemical biosensors are attractive due to superior performance in response time, cost, complexity and potential for miniaturization. To address the shortcomings of traditional benchtop electrochemical instruments, in recent years, many complementary metal oxide semiconductor (CMOS) instrumentation circuits have been reported for electrochemical biosensors. This paper provides a review and analysis of CMOS electrochemical instrumentation circuits. First, important concepts in electrochemical sensing are presented from an instrumentation point of view. Then, electrochemical instrumentation circuits are organized into functional classes, and reported CMOS circuits are reviewed and analyzed to illuminate design options and performance tradeoffs. Finally, recent trends and challenges toward on-CMOS sensor integration that could enable highly miniaturized electrochemical biosensor microsystems are discussed. The information in the paper can guide next generation electrochemical sensor design. PMID:28042860

  12. Positron annihilation studies in the field induced depletion regions of metal-oxide-semiconductor structures

    SciTech Connect

    Asoka-Kumar, P.; Leung, T.C.; Lynn, K.G.; Nielsen, B.; Forcier, M.P. ); Weinberg, Z.A.; Rubloff, G.W. )

    1992-06-01

    The centroid shifts of positron annihilation spectra are reported from the depletion regions of metal-oxide-semiconductor (MOS) capacitors at room temperature and at 35 K. The centroid shift measurement can be explained using the variation of the electric field strength and depletion layer thickness as a function of the applied gate bias. An estimate for the relevant MOS quantities is obtained by fitting the centroid shift versus beam energy data with a steady-state diffusion-annihilation equation and a derivative-gaussian positron implantation profile. Inadequacy of the present analysis scheme is evident from the derived quantities and alternate methods are required for better predictions.

  13. Anomalous quantum efficiency for photoconduction and its power dependence in metal oxide semiconductor nanowires.

    PubMed

    Chen, R S; Wang, W C; Lu, M L; Chen, Y F; Lin, H C; Chen, K H; Chen, L C

    2013-08-07

    The quantum efficiency and carrier lifetime that decide the photoconduction (PC) efficiencies in the metal oxide semiconductor nanowires (NWs) have been investigated. The experimental result surprisingly shows that the SnO2, TiO2, WO3, and ZnO NWs reveal extraordinary quantum efficiencies in common, which are over one to three orders of magnitude lower than the theoretical expectation. The surface depletion region (SDR)-controlled photoconductivity is proposed to explain the anomalous quantum efficiency and its power dependence. The inherent difference between the metal oxide nanostructures such as carrier lifetime, carrier concentration, and dielectric constant leading to the distinct PC performance and behavior are also discussed.

  14. Metal-oxide-semiconductor field effect transistor humidity sensor using surface conductance

    NASA Astrophysics Data System (ADS)

    Song, Seok-Ho; Yang, Hyun-Ho; Han, Chang-Hoon; Ko, Seung-Deok; Lee, Seok-Hee; Yoon, Jun-Bo

    2012-03-01

    This letter presents a metal-oxide-semiconductor field effect transistor based humidity sensor which does not use any specific materials to sense the relative humidity. We simply make use of the low pressure chemical vapor deposited (LPCVD) silicon dioxide's surface conductance change. When the gate is biased and then floated, the electrical charge in the gate is dissipated through the LPCVD silicon dioxide's surface to the surrounding ground with a time constant depending on the surface conductance which, in turn, varies with humidity. With this method, extremely high sensitivity was achieved—the charge dissipation speed increased thousand times as the relative humidity increased.

  15. Anomalous quantum efficiency for photoconduction and its power dependence in metal oxide semiconductor nanowires

    NASA Astrophysics Data System (ADS)

    Chen, R. S.; Wang, W. C.; Lu, M. L.; Chen, Y. F.; Lin, H. C.; Chen, K. H.; Chen, L. C.

    2013-07-01

    The quantum efficiency and carrier lifetime that decide the photoconduction (PC) efficiencies in the metal oxide semiconductor nanowires (NWs) have been investigated. The experimental result surprisingly shows that the SnO2, TiO2, WO3, and ZnO NWs reveal extraordinary quantum efficiencies in common, which are over one to three orders of magnitude lower than the theoretical expectation. The surface depletion region (SDR)-controlled photoconductivity is proposed to explain the anomalous quantum efficiency and its power dependence. The inherent difference between the metal oxide nanostructures such as carrier lifetime, carrier concentration, and dielectric constant leading to the distinct PC performance and behavior are also discussed.The quantum efficiency and carrier lifetime that decide the photoconduction (PC) efficiencies in the metal oxide semiconductor nanowires (NWs) have been investigated. The experimental result surprisingly shows that the SnO2, TiO2, WO3, and ZnO NWs reveal extraordinary quantum efficiencies in common, which are over one to three orders of magnitude lower than the theoretical expectation. The surface depletion region (SDR)-controlled photoconductivity is proposed to explain the anomalous quantum efficiency and its power dependence. The inherent difference between the metal oxide nanostructures such as carrier lifetime, carrier concentration, and dielectric constant leading to the distinct PC performance and behavior are also discussed. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr01635h

  16. Fabrication and characterization of spiral interdigitated electrodes based biosensor for salivary glucose detection

    NASA Astrophysics Data System (ADS)

    Adelyn, P. Y. P.; Hashim, U.; Arshad, M. K. Md; Voon, C. H.; Liu, Wei-Wen; Kahar, S. M.; Huda, A. R. N.; Lee, H. Cheun

    2017-03-01

    This work introduces the non-invasive glucose monitoring technique by using the Complementary Metal Oxide Semiconductor (CMOS) technologically fabricated spiral Interdigitated Electrodes (IDE) based biosensor. Scanning Electron Microscopy (SEM) image explores the morphology of spiral IDE while Energy Dispersive X-Ray (EDX) determines the elements induced in spiral IDE. Oral saliva of two patients are collected and tested on the spiral IDE sensor with electrical characterization as glucose detection results. However, both patients exhibit their glucose level characteristics inconsistently. Therefore, this work could be extended and enhanced by adding Glutaraldehyde in between 3-Aminoproply)triethoxysilane (APTES) modified and glucose oxidase (GOD) enzyme immobilized layer with FTIR validation for bonding attachment.

  17. Influence of extrinsic factors on accuracy of mobility extraction in graphene metal-oxide-semiconductor field effect transistors

    NASA Astrophysics Data System (ADS)

    Gon Lee, Young; Ji Kim, Yun; Goo Kang, Chang; Cho, Chunhum; Lee, Sangchul; Jun Hwang, Hyeon; Jung, Ukjin; Hun Lee, Byoung

    2013-03-01

    Graphene has attracted attention because of its extraordinarily high mobility. However, procedures to extract mobility from graphene metal-oxide semiconductor transistors have not been systematically established because the accuracy of mobility value is affected by many extrinsic parameters. In this work, the influence of extrinsic parameters, such as contact resistance, transient charging effect, measurement temperature, and ambient on mobility are examined in order to provide a protocol capable of accurately assessing the mobility of graphene metal-oxide-semiconductor field effect transistors. Using a well controlled test protocol, the mobility of graphene is found to be temperature independent up to 450 K.

  18. CMOS biosensors for in vitro diagnosis - transducing mechanisms and applications.

    PubMed

    Lei, Ka-Meng; Mak, Pui-In; Law, Man-Kay; Martins, Rui P

    2016-09-21

    Complementary metal oxide semiconductor (CMOS) technology enables low-cost and large-scale integration of transistors and physical sensing materials on tiny chips (e.g., <1 cm(2)), seamlessly combining the two key functions of biosensors: transducing and signal processing. Recent CMOS biosensors unified different transducing mechanisms (impedance, fluorescence, and nuclear spin) and readout electronics have demonstrated competitive sensitivity for in vitro diagnosis, such as detection of DNA (down to 10 aM), protein (down to 10 fM), or bacteria/cells (single cell). Herein, we detail the recent advances in CMOS biosensors, centering on their key principles, requisites, and applications. Together, these may contribute to the advancement of our healthcare system, which should be decentralized by broadly utilizing point-of-care diagnostic tools.

  19. Note: Complementary metal-oxide-semiconductor high voltage pulse generation circuits.

    PubMed

    Sun, Jiwei; Wang, Pingshan

    2013-10-01

    We present two types of on-chip pulse generation circuits. The first is based on CMOS pulse-forming-lines (PFLs). It includes a four-stage charge pump, a four-stacked-MOSFET switch and a 5 mm long PFL. The circuit is implemented in a 0.13 μm CMOS process. Pulses of ~1.8 V amplitude with ~135 ps duration on a 50 Ω load are obtained. The obtained voltage is higher than 1.6 V, the rated operating voltage of the process. The second is a high-voltage Marx generator which also uses stacked MOSFETs as high voltage switches. The output voltage is 11.68 V, which is higher than the highest breakdown voltage (~10 V) of the CMOS process. These results significantly extend high-voltage pulse generation capabilities of CMOS technologies.

  20. Metal oxide-based monolithic complementary metal oxide semiconductor gas sensor microsystem.

    PubMed

    Graf, Markus; Barrettino, Diego; Taschini, Stefano; Hagleitner, Christoph; Hierlemann, Andreas; Baltes, Henry

    2004-08-01

    A fully integrated gas sensor microsystem is presented, which comprises for the first time a micro hot plate as well as advanced analog and digital circuitry on a single chip. The micro hot plate is coated with a nanocrystalline SnO2 thick film. The sensor chip is produced in an industrial 0.8-microm CMOS process with subsequent micromachining steps. A novel circular micro hot plate, which is 500 x 500 microm(2) in size, features an excellent temperature homogeneity of +/-2% over the heated area (300-microm diameter) and a high thermal efficiency of 6.0 degrees C/mW. A robust prototype package was developed, which relies on standard microelectronic packaging methods. Apart from a microcontroller board for managing chip communication and providing power supply and reference signals, no additional measurement equipment is needed. The on-chip digital temperature controller can accurately adjust the membrane temperature between 170 and 300 degrees C with an error of +/-2 degrees C. The on-chip logarithmic converter covers a wide measurement range between 1 kOmega and 10 MOmega. CO concentrations in the sub-parts-per-million range are detectable, and a resolution of +/-0.1 ppm CO was achieved, which renders the sensor capable of measuring CO concentrations at threshold levels.

  1. Note: Complementary metal-oxide-semiconductor high voltage pulse generation circuits

    NASA Astrophysics Data System (ADS)

    Sun, Jiwei; Wang, Pingshan

    2013-10-01

    We present two types of on-chip pulse generation circuits. The first is based on CMOS pulse-forming-lines (PFLs). It includes a four-stage charge pump, a four-stacked-MOSFET switch and a 5 mm long PFL. The circuit is implemented in a 0.13 μm CMOS process. Pulses of ˜1.8 V amplitude with ˜135 ps duration on a 50 Ω load are obtained. The obtained voltage is higher than 1.6 V, the rated operating voltage of the process. The second is a high-voltage Marx generator which also uses stacked MOSFETs as high voltage switches. The output voltage is 11.68 V, which is higher than the highest breakdown voltage (˜10 V) of the CMOS process. These results significantly extend high-voltage pulse generation capabilities of CMOS technologies.

  2. Low Temperature Processed Complementary Metal Oxide Semiconductor (CMOS) Device by Oxidation Effect from Capping Layer

    PubMed Central

    Wang, Zhenwei; Al-Jawhari, Hala A.; Nayak, Pradipta K.; Caraveo-Frescas, J. A.; Wei, Nini; Hedhili, M. N.; Alshareef, H. N.

    2015-01-01

    In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190°C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field. PMID:25892711

  3. Photoconduction efficiencies of metal oxide semiconductor nanowires: The material's inherent properties

    NASA Astrophysics Data System (ADS)

    Chen, R. S.; Wang, W. C.; Chan, C. H.; Lu, M. L.; Chen, Y. F.; Lin, H. C.; Chen, K. H.; Chen, L. C.

    2013-11-01

    The photoconduction (PC) efficiencies of various single-crystalline metal oxide semiconductor nanowires (NWs) have been investigated and compared based on the materials' inherent properties. The defined PC efficiency (normalized gain) of SnO2 NWs is over one to five orders of magnitude higher than that of its highly efficient counterparts such as ZnO, TiO2, WO3, and GaN. The inherent property of the material allowed the photoconductive gain of an SnO2 single-NW photodetector to easily reach 8 × 108 at a low bias of 3.0 V and a low light intensity of 0.05 Wm-2, which is the optimal reported value so far for the single-NW photodetectors. The probable physical origins, such as charged surface state density and surface band bending, that caused the differences in PC efficiencies and carrier lifetimes are also discussed.

  4. A novel lateral diffused metal oxide semiconductor (LDMOS) by attracting the electric field Lines

    NASA Astrophysics Data System (ADS)

    Orouji, Ali A.; Hanaei, Mahsa

    2015-11-01

    In this paper, a novel silicon on insulator (SOI) lateral diffused metal oxide semiconductor (LDMOS) transistor with high voltage and high frequency performance is presented. In this work we try to reduce the electric field crowding in the drift region. The proposed structure consists of a metal in the buried oxide and also connected to the source. The inserted metal attracts the electric field lines in the buried oxide. It causes 67% improvement in the breakdown voltage in comparison with a conventional SOI-LDMOS (C-LDMOS). Our simulations with two dimensional ATLAS simulator show that the gate-drain capacitance improves in the proposed structure. The unilateral power gain also enhances. So, the proposed structure is suitable for high voltage and high frequency applications.

  5. Metal-oxide-semiconductor capacitors on GaAs with germanium nitride passivation layer

    NASA Astrophysics Data System (ADS)

    Zhao, Han; Kim, Hyoung-Sub; Zhu, Feng; Zhang, Manhong; OK, Injo; Park, Sung Il; Yum, Jung Hwan; Lee, Jack C.

    2007-10-01

    We present gallium arsenide (GaAs) metal-oxide-semiconductor capacitors (MOSCAPs) with a thin HfO2 gate dielectric and a thin germanium nitride (GexNy) interfacial passivation layer (IPL). TaN /HfO2/GexNy/GaAs MOSCAPs show a low interface state density and a thin equivalent oxide thickness (1.6nm). Compared to GaAs MOSCAPs with germanium (Ge) IPL, the GexNy IPL has a smaller slow trap density, which is confirmed by improved C-V characteristics without humps near the flatband voltage. The lower rate of flatband voltage shift and gate leakage decreasing under constant gate voltage stress were also demonstrated in GaAs MOSCAPs with GexNy IPL than the Ge IPL.

  6. Effect of Temperature on GaGdO/GaN Metal Oxide Semiconductor Field Effect Transistors

    SciTech Connect

    Abernathy, C.R.; Baca, A.; Chu, S.N.G.; Hong, M.; Lothian, J.R.; Marcus, M.A.; Pearton, S.J.; Ren, F.; Schurman, M.J.

    1998-10-14

    GaGdO was deposited on GaN for use as a gate dielectric in order to fabricate a depletion metal oxide semiconductor field effect transistor (MOSFET). This is the fmt demonstration of such a device in the III-Nitride system. Analysis of the effect of temperature on the device shows that gate leakage is significantly reduced at elevated temperature relative to a conventional metal semiconductor field effeet transistor (MESFET) fabricated on the same GaN layer. MOSFET device operation in fact improved upon heating to 400 C. Modeling of the effeet of temperature on contact resistance suggests that the improvement is due to a reduction in the parasitic resistances present in the device.

  7. Field-induced activation of metal oxide semiconductor for low temperature flexible transparent electronic device applications

    NASA Astrophysics Data System (ADS)

    Pudasaini, Pushpa Raj; Noh, Joo Hyon; Wong, Anthony; Haglund, Amada; Ward, Thomas Zac; Mandrus, David; Rack, Philip

    Amorphous metal-oxide semiconductors have been extensively studied as an active channel material in thin film transistors due to their high carrier mobility, and excellent large-area uniformity. Here, we report the athermal activation of amorphous indium gallium zinc oxide semiconductor channels by an electric field-induced oxygen migration via gating through an ionic liquid. Using field-induced activation, a transparent flexible thin film transistor is demonstrated on a polyamide substrate with transistor characteristics having a current ON-OFF ratio exceeding 108, and saturation field effect mobility of 8.32 cm2/(V.s) without a post-deposition thermal treatment. This study demonstrates the potential of field-induced activation as an athermal alternative to traditional post-deposition thermal annealing for metal oxide electronic devices suitable for transparent and flexible polymer substrates. Materials Science and Technology Division, ORBL, Oak Ridge, TN 37831, USA.

  8. High and low threshold P-channel metal oxide semiconductor process and description of microelectronics facility

    NASA Technical Reports Server (NTRS)

    Bouldin, D. L.; Feltner, W. R.; Hollis, B. R.; Routh, D. E.

    1976-01-01

    The fabrication techniques and detail procedures for creating P-channel Metal-Oxide-Semiconductor (P-MOS) integrated circuits at George C. Marshall Space Flight Center (MSFC) are described. Examples of P-MOS integrated circuits fabricated at MSFC together with functional descriptions of each are given. Typical electrical characteristics of high and low threshold P-MOS discrete devices under given conditions are provided. A general description of MSFC design, mask making, packaging, and testing procedures is included. The capabilities described in this report are being utilized in: (1) research and development of new technology, (2) education of individuals in the various disciplines and technologies of the field of microelectronics, and (3) fabrication of many types of specially designed integrated circuits which are not commercially feasible in small quantities for in-house research and development programs.

  9. Modeling of n-InAs metal oxide semiconductor capacitors with high-κ gate dielectric

    SciTech Connect

    Babadi, A. S. Lind, E.; Wernersson, L. E.

    2014-12-07

    A qualitative analysis on capacitance-voltage and conductance data for high-κ/InAs capacitors is presented. Our measured data were evaluated with a full equivalent circuit model, including both majority and minority carriers, as well as interface and border traps, formulated for narrow band gap metal-oxide-semiconductor capacitors. By careful determination of interface trap densities, distribution of border traps across the oxide thickness, and taking into account the bulk semiconductor response, it is shown that the trap response has a strong effect on the measured capacitances. Due to the narrow bandgap of InAs, there can be a large surface concentration of electrons and holes even in depletion, so a full charge treatment is necessary.

  10. Charge sensed Pauli blockade in a metal-oxide-semiconductor lateral double quantum dot.

    PubMed

    Nguyen, Khoi T; Lilly, Michael P; Nielsen, Erik; Bishop, Nathan; Rahman, Rajib; Young, Ralph; Wendt, Joel; Dominguez, Jason; Pluym, Tammy; Stevens, Jeffery; Lu, Tzu-Ming; Muller, Richard; Carroll, Malcolm S

    2013-01-01

    We report Pauli blockade in a multielectron silicon metal-oxide-semiconductor double quantum dot with an integrated charge sensor. The current is rectified up to a blockade energy of 0.18 ± 0.03 meV. The blockade energy is analogous to singlet-triplet splitting in a two electron double quantum dot. Built-in imbalances of tunnel rates in the MOS DQD obfuscate some edges of the bias triangles. A method to extract the bias triangles is described, and a numeric rate-equation simulation is used to understand the effect of tunneling imbalances and finite temperature on charge stability (honeycomb) diagram, in particular the identification of missing and shifting edges. A bound on relaxation time of the triplet-like state is also obtained from this measurement.

  11. Gate tunneling current and quantum capacitance in metal-oxide-semiconductor devices with graphene gate electrodes

    NASA Astrophysics Data System (ADS)

    An, Yanbin; Shekhawat, Aniruddh; Behnam, Ashkan; Pop, Eric; Ural, Ant

    2016-11-01

    Metal-oxide-semiconductor (MOS) devices with graphene as the metal gate electrode, silicon dioxide with thicknesses ranging from 5 to 20 nm as the dielectric, and p-type silicon as the semiconductor are fabricated and characterized. It is found that Fowler-Nordheim (F-N) tunneling dominates the gate tunneling current in these devices for oxide thicknesses of 10 nm and larger, whereas for devices with 5 nm oxide, direct tunneling starts to play a role in determining the total gate current. Furthermore, the temperature dependences of the F-N tunneling current for the 10 nm devices are characterized in the temperature range 77-300 K. The F-N coefficients and the effective tunneling barrier height are extracted as a function of temperature. It is found that the effective barrier height decreases with increasing temperature, which is in agreement with the results previously reported for conventional MOS devices with polysilicon or metal gate electrodes. In addition, high frequency capacitance-voltage measurements of these MOS devices are performed, which depict a local capacitance minimum under accumulation for thin oxides. By analyzing the data using numerical calculations based on the modified density of states of graphene in the presence of charged impurities, it is shown that this local minimum is due to the contribution of the quantum capacitance of graphene. Finally, the workfunction of the graphene gate electrode is extracted by determining the flat-band voltage as a function of oxide thickness. These results show that graphene is a promising candidate as the gate electrode in metal-oxide-semiconductor devices.

  12. Characterization of Interface State in Silicon Carbide Metal Oxide Semiconductor Capacitors

    NASA Astrophysics Data System (ADS)

    Kao, Wei-Chieh

    Silicon carbide (SiC) has always been considered as an excellent material for high temperature and high power devices. Since SiC is the only compound semiconductor whose native oxide is silicon dioxide (SiO2), it puts SiC in a unique position. Although SiC metal oxide semiconductor (MOS) technology has made significant progress in recent years, there are still a number of issues to be overcome before more commercial SiC devices can enter the market. The prevailing issues surrounding SiC MOSFET devices are the low channel mobility, the low quality of the oxide layer and the high interface state density at the SiC/SiO2 interface. Consequently, there is a need for research to be performed in order to have a better understanding of the factors causing the poor SiC/SiO2 interface properties. In this work, we investigated the generation lifetime in SiC materials by using the pulsed metal oxide semiconductor (MOS) capacitor method and measured the interface state density distribution at the SiC/SiO2 interface by using the conductance measurement and the high-low frequency capacitance technique. These measurement techniques have been performed on n-type and p-type SiC MOS capacitors. In the course of our investigation, we observed fast interface states at semiconductor-dielectric interfaces in SiC MOS capacitors that underwent three different interface passivation processes, such states were detected in the nitrided samples but not observed in PSG-passivated samples. This result indicate that the lack of fast states at PSG-passivated interface is one of the main reasons for higher channel mobility in PSG MOSFETs. In addition, the effect of mobile ions in the oxide on the response time of interface states has been investigated. In the last chapter we propose additional methods of investigation that can help elucidate the origin of the particular interface states, enabling a more complete understanding of the SiC/SiO2 material system.

  13. Rapid Bacterial Detection via an All-Electronic CMOS Biosensor

    PubMed Central

    Nikkhoo, Nasim; Cumby, Nichole; Gulak, P. Glenn; Maxwell, Karen L.

    2016-01-01

    The timely and accurate diagnosis of infectious diseases is one of the greatest challenges currently facing modern medicine. The development of innovative techniques for the rapid and accurate identification of bacterial pathogens in point-of-care facilities using low-cost, portable instruments is essential. We have developed a novel all-electronic biosensor that is able to identify bacteria in less than ten minutes. This technology exploits bacteriocins, protein toxins naturally produced by bacteria, as the selective biological detection element. The bacteriocins are integrated with an array of potassium-selective sensors in Complementary Metal Oxide Semiconductor technology to provide an inexpensive bacterial biosensor. An electronic platform connects the CMOS sensor to a computer for processing and real-time visualization. We have used this technology to successfully identify both Gram-positive and Gram-negative bacteria commonly found in human infections. PMID:27618185

  14. Study of SiO[sub 2]-Si and metal-oxide-semiconductor structures using positrons

    SciTech Connect

    Leung, T.C.; Asoka-Kumar, P.; Nielsen, B.; Lynn, K.G. )

    1993-01-01

    Studies of SiO[sub 2]-Si and metal-oxide-semiconductor (MOS) structures using positrons are summarized and a concise picture of the present understanding of positrons in these systems is provided. Positron annihilation line-shape [ital S] data are presented as a function of the positron incident energy, gate voltage, and annealing, and are described with a diffusion-annihilation equation for positrons. The data are compared with electrical measurements. Distinct annihilation characteristics were observed at the SiO[sub 2]-Si interface and have been studied as a function of bias voltage and annealing conditions. The shift of the centroid (peak) of [gamma]-ray energy distributions in the depletion region of the MOS structures was studied as a function of positron energy and gate voltage, and the shifts are explained by the corresponding variations in the strength of the electric field and thickness of the depletion layer. The potential role of the positron annihilation technique as a noncontact, nondestructive, and depth-sensitive characterization tool for the technologically important, deeply buried interface is shown.

  15. Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

    PubMed Central

    Rossi, Alessandro; Tanttu, Tuomo; Hudson, Fay E.; Sun, Yuxin; Möttönen, Mikko; Dzurak, Andrew S.

    2015-01-01

    As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by quantum mechanical effects such as tunneling through single dopants, scattering via interface defects, and discrete trap charge states. However, progress in silicon technology has shown that these phenomena can be harnessed and exploited for a new class of quantum-based electronics. Among others, multi-layer-gated silicon metal-oxide-semiconductor (MOS) technology can be used to control single charge or spin confined in electrostatically-defined quantum dots (QD). These QD-based devices are an excellent platform for quantum computing applications and, recently, it has been demonstrated that they can also be used as single-electron pumps, which are accurate sources of quantized current for metrological purposes. Here, we discuss in detail the fabrication protocol for silicon MOS QDs which is relevant to both quantum computing and quantum metrology applications. Moreover, we describe characterization methods to test the integrity of the devices after fabrication. Finally, we give a brief description of the measurement set-up used for charge pumping experiments and show representative results of electric current quantization. PMID:26067215

  16. Metal oxide semiconductors for dye- and quantum-dot-sensitized solar cells.

    PubMed

    Concina, Isabella; Vomiero, Alberto

    2015-04-17

    This Review provides a brief summary of the most recent research developments in the synthesis and application of nanostructured metal oxide semiconductors for dye sensitized and quantum dot sensitized solar cells. In these devices, the wide bandgap semiconducting oxide acts as the photoanode, which provides the scaffold for light harvesters (either dye molecules or quantum dots) and electron collection. For this reason, proper tailoring of the optical and electronic properties of the photoanode can significantly boost the functionalities of the operating device. Optimization of the functional properties relies with modulation of the shape and structure of the photoanode, as well as on application of different materials (TiO2, ZnO, SnO2) and/or composite systems, which allow fine tuning of electronic band structure. This aspect is critical because it determines exciton and charge dynamics in the photoelectrochemical system and is strictly connected to the photoconversion efficiency of the solar cell. The different strategies for increasing light harvesting and charge collection, inhibiting charge losses due to recombination phenomena, are reviewed thoroughly, highlighting the benefits of proper photoanode preparation, and its crucial role in the development of high efficiency dye sensitized and quantum dot sensitized solar cells.

  17. Real-space electron transfer in III-nitride metal-oxide-semiconductor-heterojunction structures

    NASA Astrophysics Data System (ADS)

    Saygi, S.; Koudymov, A.; Adivarahan, V.; Yang, J.; Simin, G.; Khan, M. Asif; Deng, J.; Gaska, R.; Shur, M. S.

    2005-07-01

    The real-space transfer effect in a SiO2/AlGaN /GaN metal-oxide-semiconductor heterostructure (MOSH) from the two-dimensional (2D) electron gas at the heterointerface to the oxide-semiconductor interface has been demonstrated and explained. The effect occurs at high positive gate bias and manifests itself as an additional step in the capacitance-voltage (C-V) characteristic. The real-space transfer effect limits the achievable maximum 2D electron gas density in the device channel. We show that in MOSH structures the maximum electron gas density exceeds up to two times that at the equilibrium (zero bias) condition. Correspondingly, a significant increase in the maximum channel current (up to two times compared to conventional Schottky-gate structures) can be achieved. The real-space charge transfer effect in MOSH structures also opens up a way to design novel devices such as variable capacitors, multistate switches, memory cells, etc.

  18. Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping.

    PubMed

    Rossi, Alessandro; Tanttu, Tuomo; Hudson, Fay E; Sun, Yuxin; Möttönen, Mikko; Dzurak, Andrew S

    2015-06-03

    As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by quantum mechanical effects such as tunneling through single dopants, scattering via interface defects, and discrete trap charge states. However, progress in silicon technology has shown that these phenomena can be harnessed and exploited for a new class of quantum-based electronics. Among others, multi-layer-gated silicon metal-oxide-semiconductor (MOS) technology can be used to control single charge or spin confined in electrostatically-defined quantum dots (QD). These QD-based devices are an excellent platform for quantum computing applications and, recently, it has been demonstrated that they can also be used as single-electron pumps, which are accurate sources of quantized current for metrological purposes. Here, we discuss in detail the fabrication protocol for silicon MOS QDs which is relevant to both quantum computing and quantum metrology applications. Moreover, we describe characterization methods to test the integrity of the devices after fabrication. Finally, we give a brief description of the measurement set-up used for charge pumping experiments and show representative results of electric current quantization.

  19. High-resolution electrohydrodynamic inkjet printing of stretchable metal oxide semiconductor transistors with high performance.

    PubMed

    Kim, S-Y; Kim, K; Hwang, Y H; Park, J; Jang, J; Nam, Y; Kang, Y; Kim, M; Park, H J; Lee, Z; Choi, J; Kim, Y; Jeong, S; Bae, B-S; Park, J-U

    2016-10-06

    As demands for high pixel densities and wearable forms of displays increase, high-resolution printing technologies to achieve high performance transistors beyond current amorphous silicon levels and to allow low-temperature solution processability for plastic substrates have been explored as key processes in emerging flexible electronics. This study describes electrohydrodynamic inkjet (e-jet) technology for direct printing of oxide semiconductor thin film transistors (TFTs) with high resolution (minimum line width: 2 μm) and superb performance, including high mobility (∼230 cm(2) V(-1) s(-1)). Logic operations of the amplifier circuits composed of these e-jet-printed metal oxide semiconductor (MOS) TFTs demonstrate their high performance. Printed In2O TFTs with e-jet printing-assisted high-resolution S/D electrodes were prepared, and the direct printing of passivation layers on these channels enhanced their gate-bias stabilities significantly. Moreover, low process temperatures (<250 °C) enable the use of thin plastic substrates; highly flexible and stretchable TFT arrays have been demonstrated, suggesting promise for next-generation printed electronics.

  20. Analysis of Interface Charge Densities for High-k Dielectric Materials based Metal Oxide Semiconductor Devices

    NASA Astrophysics Data System (ADS)

    Maity, N. P.; Thakur, R. R.; Maity, Reshmi; Thapa, R. K.; Baishya, S.

    2016-10-01

    In this paper, the interface charge densities (Dit) are studied and analyzed for ultra thin dielectric metal oxide semiconductor (MOS) devices using different high-k dielectric materials such as Al2O3, ZrO2 and HfO2. The Dit have been calculated by a new approach using conductance method and it indicates that by reducing the thickness of the oxide, the Dit increases and similar increase is also found by replacing SiO2 with high-k. For the same oxide thickness, SiO2 has the lowest Dit and found to be the order of 1011cm-2eV-1. Linear increase in Dit has been observed as the dielectric constant of the oxide increases. The Dit is found to be in good agreement with published fabrication results at p-type doping level of 1×1017cm-3. Numerical calculations and solutions are performed by MATLAB and device simulation is done by ATLAS.

  1. Ionic Liquid Activation of Amorphous Metal-Oxide Semiconductors for Flexible Transparent Electronic Devices

    DOE PAGES

    Pudasaini, Pushpa Raj; Noh, Joo Hyon; Wong, Anthony T.; ...

    2016-02-09

    To begin this abstract, amorphous metal-oxide semiconductors offer the high carrier mobilities and excellent large-area uniformity required for high performance, transparent, flexible electronic devices; however, a critical bottleneck to their widespread implementation is the need to activate these materials at high temperatures which are not compatible with flexible polymer substrates. The highly controllable activation of amorphous indium gallium zinc oxide semiconductor channels using ionic liquid gating at room temperature is reported. Activation is controlled by electric field-induced oxygen migration across the ionic liquid-semiconductor interface. In addition to activation of unannealed devices, it is shown that threshold voltages of a transistormore » can be linearly tuned between the enhancement and depletion modes. Finally, the first ever example of transparent flexible thin film metal oxide transistor on a polyamide substrate created using this simple technique is demonstrated. Finally, this study demonstrates the potential of field-induced activation as a promising alternative to traditional postdeposition thermal annealing which opens the door to wide scale implementation into flexible electronic applications.« less

  2. Experimental characterization of a metal-oxide-semiconductor field-effect transistor-based Coulter counter

    PubMed Central

    Sridhar, Manoj; Xu, Dongyan; Kang, Yuejun; Hmelo, Anthony B.; Feldman, Leonard C.; Li, Dongqing; Li, Deyu

    2008-01-01

    We report the detailed characterization of an ultrasensitive microfluidic device used to detect the translocation of small particles through a sensing microchannel. The device connects a fluidic circuit to the gate of a metal-oxide-semiconductor field-effect transistor (MOSFET) and detects particles by monitoring the MOSFET drain current modulation instead of the modulation in the ionic current through the sensing channel. The minimum volume ratio of the particle to the sensing channel detected is 0.006%, which is about ten times smaller than the lowest detected volume ratio previously reported in the literature. This volume ratio is detected at a noise level of about 0.6% of the baseline MOSFET drain current, clearly showing the amplification effects from the fluidic circuits and the MOSFETs. We characterize the device sensitivity as a function of the MOSFET gate potential and show that its sensitivity is higher when the MOSFET is operating below its threshold gate voltage than when it is operating above the threshold voltage. In addition, we demonstrate that the device sensitivity linearly increases with the applied electrical bias across the fluidic circuit. Finally, we show that polystyrene beads and glass beads with similar sizes can be distinguished from each other based on their different translocation times, and the size distribution of microbeads can be obtained with accuracy comparable to that of direct scanning electron microscopy measurements. PMID:19479001

  3. Inversion channel diamond metal-oxide-semiconductor field-effect transistor with normally off characteristics

    NASA Astrophysics Data System (ADS)

    Matsumoto, Tsubasa; Kato, Hiromitsu; Oyama, Kazuhiro; Makino, Toshiharu; Ogura, Masahiko; Takeuchi, Daisuke; Inokuma, Takao; Tokuda, Norio; Yamasaki, Satoshi

    2016-08-01

    We fabricated inversion channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) with normally off characteristics. At present, Si MOSFETs and insulated gate bipolar transistors (IGBTs) with inversion channels are widely used because of their high controllability of electric power and high tolerance. Although a diamond semiconductor is considered to be a material with a strong potential for application in next-generation power devices, diamond MOSFETs with an inversion channel have not yet been reported. We precisely controlled the MOS interface for diamond by wet annealing and fabricated p-channel and planar-type MOSFETs with phosphorus-doped n-type body on diamond (111) substrate. The gate oxide of Al2O3 was deposited onto the n-type diamond body by atomic layer deposition at 300 °C. The drain current was controlled by the negative gate voltage, indicating that an inversion channel with a p-type character was formed at a high-quality n-type diamond body/Al2O3 interface. The maximum drain current density and the field-effect mobility of a diamond MOSFET with a gate electrode length of 5 μm were 1.6 mA/mm and 8.0 cm2/Vs, respectively, at room temperature.

  4. Inversion channel diamond metal-oxide-semiconductor field-effect transistor with normally off characteristics.

    PubMed

    Matsumoto, Tsubasa; Kato, Hiromitsu; Oyama, Kazuhiro; Makino, Toshiharu; Ogura, Masahiko; Takeuchi, Daisuke; Inokuma, Takao; Tokuda, Norio; Yamasaki, Satoshi

    2016-08-22

    We fabricated inversion channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) with normally off characteristics. At present, Si MOSFETs and insulated gate bipolar transistors (IGBTs) with inversion channels are widely used because of their high controllability of electric power and high tolerance. Although a diamond semiconductor is considered to be a material with a strong potential for application in next-generation power devices, diamond MOSFETs with an inversion channel have not yet been reported. We precisely controlled the MOS interface for diamond by wet annealing and fabricated p-channel and planar-type MOSFETs with phosphorus-doped n-type body on diamond (111) substrate. The gate oxide of Al2O3 was deposited onto the n-type diamond body by atomic layer deposition at 300 °C. The drain current was controlled by the negative gate voltage, indicating that an inversion channel with a p-type character was formed at a high-quality n-type diamond body/Al2O3 interface. The maximum drain current density and the field-effect mobility of a diamond MOSFET with a gate electrode length of 5 μm were 1.6 mA/mm and 8.0 cm(2)/Vs, respectively, at room temperature.

  5. Inversion channel diamond metal-oxide-semiconductor field-effect transistor with normally off characteristics

    PubMed Central

    Matsumoto, Tsubasa; Kato, Hiromitsu; Oyama, Kazuhiro; Makino, Toshiharu; Ogura, Masahiko; Takeuchi, Daisuke; Inokuma, Takao; Tokuda, Norio; Yamasaki, Satoshi

    2016-01-01

    We fabricated inversion channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) with normally off characteristics. At present, Si MOSFETs and insulated gate bipolar transistors (IGBTs) with inversion channels are widely used because of their high controllability of electric power and high tolerance. Although a diamond semiconductor is considered to be a material with a strong potential for application in next-generation power devices, diamond MOSFETs with an inversion channel have not yet been reported. We precisely controlled the MOS interface for diamond by wet annealing and fabricated p-channel and planar-type MOSFETs with phosphorus-doped n-type body on diamond (111) substrate. The gate oxide of Al2O3 was deposited onto the n-type diamond body by atomic layer deposition at 300 °C. The drain current was controlled by the negative gate voltage, indicating that an inversion channel with a p-type character was formed at a high-quality n-type diamond body/Al2O3 interface. The maximum drain current density and the field-effect mobility of a diamond MOSFET with a gate electrode length of 5 μm were 1.6 mA/mm and 8.0 cm2/Vs, respectively, at room temperature. PMID:27545201

  6. Core/shell nano-structuring of metal oxide semiconductors and their photocatalytic studies

    NASA Astrophysics Data System (ADS)

    Balakumar, S.; Rakkesh, R. Ajay

    2013-02-01

    Core/Shell Nanostructures of Metal Oxide Semiconductors (MOS) have attracted much attention because of their most fascinating tunable applications. These core shell morphologies can be easily engineered to enhance the unique properties of the metal-oxide nanostructures, which make them suitable as photocatalyst due to their high catalytic activity, substantial stability, and brilliant perspective in applications. This paper provides an overview on our work on the synthesis of some interesting core/ shell nanostructures of MOS such as ZnO-TiO2, ZnO-MoO3, and V2O5-TiO2 using a low temperature wet chemical route and hydrothermal techniques and their photocatalytic properties from the aspects of different shell materials and shell thicknesses. The effect of process parameters such as pH, temperature, and ratio of core and shell materials, was systematically studied. Here the evidence for the core shell formation with different shell thicknesses came from the X-ray diffraction peak intensities. The shell thickness variation was also confirmed by Transmission Electron Microscopic studies. Effect of shell thickness on optical band gap of the core shell fabricated was also investigated using DRS UV-Visible spectroscopy. A comprehensive study was carried out for the photocatalytic efficiency of core shell nanostructures by evaluating the photo-degradation of Acridine Orange (AO) dye in aqueous solution under visible and solar light irradiations. These results offered simple approaches to the nanoscale engineering and synthesis of MOS hybrid systems to serve as better photocatalytic materials.

  7. Metal-oxide-semiconductor capacitors and Schottky diodes studied with scanning microwave microscopy at 18 GHz

    NASA Astrophysics Data System (ADS)

    Kasper, M.; Gramse, G.; Hoffmann, J.; Gaquiere, C.; Feger, R.; Stelzer, A.; Smoliner, J.; Kienberger, F.

    2014-11-01

    We measured the DC and RF impedance characteristics of micrometric metal-oxide-semiconductor (MOS) capacitors and Schottky diodes using scanning microwave microscopy (SMM). The SMM consisting of an atomic force microscopy (AFM) interfaced with a vector network analyser (VNA) was used to measure the reflection S11 coefficient of the metallic MOS and Schottky contact pads at 18 GHz as a function of the tip bias voltage. By controlling the SMM biasing conditions, the AFM tip was used to bias the Schottky contacts between reverse and forward mode. In reverse bias direction, the Schottky contacts showed mostly a change in the imaginary part of the admittance while in forward bias direction the change was mostly in the real part of the admittance. Reference MOS capacitors which are next to the Schottky diodes on the same sample were used to calibrate the SMM S11 data and convert it into capacitance values. Calibrated capacitance between 1-10 fF and 1/C2 spectroscopy curves were acquired on the different Schottky diodes as a function of the DC bias voltage following a linear behavior. Additionally, measurements were done directly with the AFM-tip in contact with the silicon substrate forming a nanoscale Schottky contact. Similar capacitance-voltage curves were obtained but with smaller values (30-300 aF) due to the corresponding smaller AFM-tip diameter. Calibrated capacitance images of both the MOS and Schottky contacts were acquired with nanoscale resolution at different tip-bias voltages.

  8. Silicon carbide: A unique platform for metal-oxide-semiconductor physics

    NASA Astrophysics Data System (ADS)

    Liu, Gang; Tuttle, Blair R.; Dhar, Sarit

    2015-06-01

    A sustainable energy future requires power electronics that can enable significantly higher efficiencies in the generation, distribution, and usage of electrical energy. Silicon carbide (4H-SiC) is one of the most technologically advanced wide bandgap semiconductor that can outperform conventional silicon in terms of power handling, maximum operating temperature, and power conversion efficiency in power modules. While SiC Schottky diode is a mature technology, SiC power Metal Oxide Semiconductor Field Effect Transistors are relatively novel and there is large room for performance improvement. Specifically, major initiatives are under way to improve the inversion channel mobility and gate oxide stability in order to further reduce the on-resistance and enhance the gate reliability. Both problems relate to the defects near the SiO2/SiC interface, which have been the focus of intensive studies for more than a decade. Here we review research on the SiC MOS physics and technology, including its brief history, the state-of-art, and the latest progress in this field. We focus on the two main scientific problems, namely, low channel mobility and bias temperature instability. The possible mechanisms behind these issues are discussed at the device physics level as well as the atomic scale, with the support of published physical analysis and theoretical studies results. Some of the most exciting recent progress in interface engineering for improving the channel mobility and fundamental understanding of channel transport is reviewed.

  9. Ionic Liquid Activation of Amorphous Metal-Oxide Semiconductors for Flexible Transparent Electronic Devices

    SciTech Connect

    Pudasaini, Pushpa Raj; Noh, Joo Hyon; Wong, Anthony T.; Ovchinnikova, Olga S.; Haglund, Amanda V.; Dai, Sheng; Ward, Thomas Zac; Mandrus, David; Rack, Philip D.

    2016-02-09

    To begin this abstract, amorphous metal-oxide semiconductors offer the high carrier mobilities and excellent large-area uniformity required for high performance, transparent, flexible electronic devices; however, a critical bottleneck to their widespread implementation is the need to activate these materials at high temperatures which are not compatible with flexible polymer substrates. The highly controllable activation of amorphous indium gallium zinc oxide semiconductor channels using ionic liquid gating at room temperature is reported. Activation is controlled by electric field-induced oxygen migration across the ionic liquid-semiconductor interface. In addition to activation of unannealed devices, it is shown that threshold voltages of a transistor can be linearly tuned between the enhancement and depletion modes. Finally, the first ever example of transparent flexible thin film metal oxide transistor on a polyamide substrate created using this simple technique is demonstrated. Finally, this study demonstrates the potential of field-induced activation as a promising alternative to traditional postdeposition thermal annealing which opens the door to wide scale implementation into flexible electronic applications.

  10. Centroid shift of. gamma. rays from positron annihilation in the depletion region of metal-oxide-semiconductor structures

    SciTech Connect

    Leung, T.C.; Kong, Y.; Lynn, K.G.; Nielsen, B. ); Weinberg, Z.A.; Rubloff, G.W. )

    1991-01-07

    Using metal-oxide-semiconductor (MOS) structures, the shift of centroid (peak) of {gamma}-ray energy distributions emitted from positron annihilation has been measured as a function of incident positron energy. The Doppler centroid shift was found to be consistent with the positron motion in the MOS depletion region. The results are described by a one-dimensional positron diffusion model, and provide information on effective'' positron diffusion length under applied field.

  11. Metal-oxide-semiconductor based gas sensors: screening, preparation, and integration.

    PubMed

    Zhang, Jian; Qin, Ziyu; Zeng, Dawen; Xie, Changsheng

    2017-03-01

    Metal-oxide-semiconductor (MOS) based gas sensors have been considered a promising candidate for gas detection over the past few years. However, the sensing properties of MOS-based gas sensors also need to be further enhanced to satisfy the higher requirements for specific applications, such as medical diagnosis based on human breath, gas detection in harsh environments, etc. In these fields, excellent selectivity, low power consumption, a fast response/recovery rate, low humidity dependence and a low limit of detection concentration should be fulfilled simultaneously, which pose great challenges to the MOS-based gas sensors. Recently, in order to improve the sensing performances of MOS-based gas sensors, more and more researchers have carried out extensive research from theory to practice. For a similar purpose, on the basis of the whole fabrication process of gas sensors, this review gives a presentation of the important role of screening and the recent developments in high throughput screening. Subsequently, together with the sensing mechanism, the factors influencing the sensing properties of MOSs involved in material preparation processes were also discussed in detail. It was concluded that the sensing properties of MOSs not only depend on the morphological structure (particle size, morphology, pore size, etc.), but also rely on the defect structure and heterointerface structure (grain boundaries, heterointerfaces, defect concentrations, etc.). Therefore, the material-sensor integration was also introduced to maintain the structural stability in the sensor fabrication process, ensuring the sensing stability of MOS-based gas sensors. Finally, the perspectives of the MOS-based gas sensors in the aspects of fundamental research and the improvements in the sensing properties are pointed out.

  12. Infrared rectification in a nanoantenna-coupled metal-oxide-semiconductor tunnel diode.

    PubMed

    Davids, Paul S; Jarecki, Robert L; Starbuck, Andrew; Burckel, D Bruce; Kadlec, Emil A; Ribaudo, Troy; Shaner, Eric A; Peters, David W

    2015-12-01

    Direct rectification of electromagnetic radiation is a well-established method for wireless power conversion in the microwave region of the spectrum, for which conversion efficiencies in excess of 84% have been demonstrated. Scaling to the infrared or optical part of the spectrum requires ultrafast rectification that can only be obtained by direct tunnelling. Many research groups have looked to plasmonics to overcome antenna-scaling limits and to increase the confinement. Recently, surface plasmons on heavily doped Si surfaces were investigated as a way of extending surface-mode confinement to the thermal infrared region. Here we combine a nanostructured metallic surface with a heavily doped Si infrared-reflective ground plane designed to confine infrared radiation in an active electronic direct-conversion device. The interplay of strong infrared photon-phonon coupling and electromagnetic confinement in nanoscale devices is demonstrated to have a large impact on ultrafast electronic tunnelling in metal-oxide-semiconductor (MOS) structures. Infrared dispersion of SiO2 near a longitudinal optical (LO) phonon mode gives large transverse-field confinement in a nanometre-scale oxide-tunnel gap as the wavelength-dependent permittivity changes from 1 to 0, which leads to enhanced electromagnetic fields at material interfaces and a rectified displacement current that provides a direct conversion of infrared radiation into electric current. The spectral and electrical signatures of the nanoantenna-coupled tunnel diodes are examined under broadband blackbody and quantum-cascade laser (QCL) illumination. In the region near the LO phonon resonance, we obtained a measured photoresponsivity of 2.7 mA W(-1) cm(-2) at -0.1 V.

  13. Effects of oxide traps, interface traps, and border traps'' on metal-oxide-semiconductor devices

    SciTech Connect

    Fleetwood, D.M.; Winokur, P.S.; Reber, R.A. Jr.; Meisenheimer, T.L.; Schwank, J.R.; Shaneyfelt, M.R.; Riewe, L.C. )

    1993-05-15

    We have identified several features of the 1/[ital f] noise and radiation response of metal-oxide-semiconductor (MOS) devices that are difficult to explain with standard defect models. To address this issue, and in response to ambiguities in the literature, we have developed a revised nomenclature for defects in MOS devices that clearly distinguishes the language used to describe the physical location of defects from that used to describe their electrical response. In this nomenclature, oxide traps'' are simply defects in the SiO[sub 2] layer of the MOS structure, and interface traps'' are defects at the Si/SiO[sub 2] interface. Nothing is presumed about how either type of defect communicates with the underlying Si. Electrically, fixed states'' are defined as trap levels that do not communicate with the Si on the time scale of the measurements, but switching states'' can exchange charge with the Si. Fixed states presumably are oxide traps in most types of measurements, but switching states can either be interface traps or near-interfacial oxide traps that can communicate with the Si, i.e., border traps'' [D. M. Fleetwood, IEEE Trans. Nucl. Sci. [bold NS]-[bold 39], 269 (1992)]. The effective density of border traps depends on the time scale and bias conditions of the measurements. We show the revised nomenclature can provide focus to discussions of the buildup and annealing of radiation-induced charge in non-radiation-hardened MOS transistors, and to changes in the 1/[ital f] noise of MOS devices through irradiation and elevated-temperature annealing.

  14. Scanning internal photoemission studies of sodium-contaminated metal-oxide-semiconductor capacitors

    NASA Astrophysics Data System (ADS)

    Bouthillier, T. M.; Young, L.; Tsoi, H. Y.

    1983-02-01

    Following DiStefano and also Williams and Woods we have used scanning internal photoemission to map barrier inhomogeneities in sodium-contaminated Al/SiO2/Si Metal-Oxide-Semiconductor capacitors. A computer controlled system was used with a He/Cd laser. A well-known and striking result of the previous work is that peaks tend to be found in the internal photoemission. In some cases these peaks have been attributed to the segregation of an initially uniform sodium ion distribution into clusters of a few μm diameter. This clustering occurred during a low temperature anneal under positive gate bias. The mechanism for the supposed segregation is of considerable interest. One possibility is that the segregation maps pre-existing inhomogeneities either in the silicon substrate or in the oxide. Another mechanism, proposed by Williams and Woods, involves the image force lowering of the potential energy of the sodium ions. The lowering is increased as the induced electron charge density in the silicon increases with progressive clustering. This positive feedback was proposed to lead to instability. A thermodynamic development of the model by Wojtowcz led to the concept of two-dimensional phase transitions in the sodium distribution. In the present work we report the result that peaks can be produced by a low temperature anneal with the sodium either at the Al/SiO2 interface or drifted to the Si/SiO2 interface. In the first case, the sodium must be drifted to the silicon side before the peaks appear. This may show that nucleation centers are produced by the anneal and mapped by the sodium. Alternatively, if un-nucleated segregation occurs it must be a function of sodium in SiO2 rather than of sodium near the Si/SiO2 interface. Correlation with weak spot breakdown was again observed and the effects of using HCl oxides were studied.

  15. Gate length and temperature dependence of negative differential transconductance in silicon quantum well metal-oxide-semiconductor field-effect transistors

    SciTech Connect

    Naquin, Clint; Lee, Mark; Edwards, Hal; Mathur, Guru; Chatterjee, Tathagata; Maggio, Ken

    2015-09-28

    Introducing quantum transport into silicon transistors in a manner compatible with industrial fabrication has the potential to transform the performance horizons of large scale integrated silicon devices and circuits. Explicit quantum transport as evidenced by negative differential transconductances (NDTCs) has been observed in a set of quantum well (QW) transistors fabricated using industrial silicon complementary metal-oxide-semiconductor processing. Detailed gate length and temperature dependence characteristics of the NDTCs in these devices have been measured. The QW potential was formed via lateral ion implantation doping on a commercial 45 nm technology node process line, and measurements of the transfer characteristics show NDTCs up to room temperature. Gate length dependence of NDTCs shows a correlation of the interface channel length with the number of NDTCs formed as well as with the gate voltage (V{sub G}) spacing between NDTCs. The V{sub G} spacing between multiple NDTCs suggests a quasi-parabolic QW potential profile. The temperature dependence is consistent with partial freeze-out of carrier concentration against a degenerately doped background.

  16. Gate length and temperature dependence of negative differential transconductance in silicon quantum well metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Naquin, Clint; Lee, Mark; Edwards, Hal; Mathur, Guru; Chatterjee, Tathagata; Maggio, Ken

    2015-09-01

    Introducing quantum transport into silicon transistors in a manner compatible with industrial fabrication has the potential to transform the performance horizons of large scale integrated silicon devices and circuits. Explicit quantum transport as evidenced by negative differential transconductances (NDTCs) has been observed in a set of quantum well (QW) transistors fabricated using industrial silicon complementary metal-oxide-semiconductor processing. Detailed gate length and temperature dependence characteristics of the NDTCs in these devices have been measured. The QW potential was formed via lateral ion implantation doping on a commercial 45 nm technology node process line, and measurements of the transfer characteristics show NDTCs up to room temperature. Gate length dependence of NDTCs shows a correlation of the interface channel length with the number of NDTCs formed as well as with the gate voltage (VG) spacing between NDTCs. The VG spacing between multiple NDTCs suggests a quasi-parabolic QW potential profile. The temperature dependence is consistent with partial freeze-out of carrier concentration against a degenerately doped background.

  17. Nondestructive measurement of thermal contact resistance for the power vertical double-diffused metal-oxide-semiconductor

    NASA Astrophysics Data System (ADS)

    Li, Rui; Guo, Chun-Sheng; Feng, Shi-Wei; Shi, Lei; Zhu, Hui; Wang, Lin

    2015-07-01

    To obtain thermal contact resistance (TCR) between the vertical double-diffused metal-oxide-semiconductor (VDMOS) and the heat sink, we derived the relationship between the total thermal resistance and the contact force imposed on the VDMOS. The total thermal resistance from the chip to the heat sink is measured under different contact forces, and the TCR can be extracted nondestructively from the derived relationship. Finally, the experimental results are compared with the simulation results. Project supported by the National Natural Science Foundation of China (Grant No. 61204081).

  18. Reliability properties of metal-oxide-semiconductor capacitors using LaAlO3 high-k dielectric

    NASA Astrophysics Data System (ADS)

    Yeh, Lingyen; Chang, Ingram Yin-Ku; Chen, Chun-Heng; Lee, Joseph Ya-Min

    2009-10-01

    In this study, metal-oxide-semiconductor (MOS) capacitors with high dielectric constant LaAlO3 film were fabricated. Furthermore, the characteristic time-to-breakdown, TBD, of the MOS capacitors was investigated. The TBD was measured and the corresponding Weibull slopes, β, of the MOS capacitors with various LaAlO3 thicknesses were calculated. In addition, a modified percolation model was proposed to consider the extrinsic factors of breakdown. These extrinsic factors were described by an equivalent reduction of the path-to-breakdown, tex, in the model. Using this model, the calculated tex of the MOS capacitor was 5.8 nm.

  19. Models of second-order effects in metal-oxide-semiconductor field-effect transistors for computer applications

    NASA Technical Reports Server (NTRS)

    Benumof, Reuben; Zoutendyk, John; Coss, James

    1988-01-01

    Second-order effects in metal-oxide-semiconductor field-effect transistors (MOSFETs) are important for devices with dimensions of 2 microns or less. The short and narrow channel effects and drain-induced barrier lowering primarily affect threshold voltage, but formulas for drain current must also take these effects into account. In addition, the drain current is sensitive to channel length modulation due to pinch-off or velocity saturation and is diminished by electron mobility degradation due to normal and lateral electric fields in the channel. A model of a MOSFET including these considerations and emphasizing charge conservation is discussed.

  20. Plasmonic nanohole arrays on Si-Ge heterostructures: an approach for integrated biosensors

    NASA Astrophysics Data System (ADS)

    Augel, L.; Fischer, I. A.; Dunbar, L. A.; Bechler, S.; Berrier, A.; Etezadi, D.; Hornung, F.; Kostecki, K.; Ozdemir, C. I.; Soler, M.; Altug, H.; Schulze, J.

    2016-03-01

    Nanohole array surface plasmon resonance (SPR) sensors offer a promising platform for high-throughput label-free biosensing. Integrating nanohole arrays with group-IV semiconductor photodetectors could enable low-cost and disposable biosensors compatible to Si-based complementary metal oxide semiconductor (CMOS) technology that can be combined with integrated circuitry for continuous monitoring of biosamples and fast sensor data processing. Such an integrated biosensor could be realized by structuring a nanohole array in the contact metal layer of a photodetector. We used Fouriertransform infrared spectroscopy to investigate nanohole arrays in a 100 nm Al film deposited on top of a vertical Si-Ge photodiode structure grown by molecular beam epitaxy (MBE). We find that the presence of a protein bilayer, constitute of protein AG and Immunoglobulin G (IgG), leads to a wavelength-dependent absorptance enhancement of ~ 8 %.

  1. CMOS capacitive biosensors for highly sensitive biosensing applications.

    PubMed

    Chang, An-Yu; Lu, Michael S-C

    2013-01-01

    Magnetic microbeads are widely used in biotechnology and biomedical research for manipulation and detection of cells and biomolecules. Most lab-on-chip systems capable of performing manipulation and detection require external instruments to perform one of the functions, leading to increased size and cost. This work aims at developing an integrated platform to perform these two functions by implementing electromagnetic microcoils and capacitive biosensors on a CMOS (complementary metal oxide semiconductor) chip. Compared to most magnetic-type sensors, our detection method requires no externally applied magnetic fields and the associated fabrication is less complicated. In our experiment, microbeads coated with streptavidin were driven to the sensors located in the center of microcoils with functionalized anti-streptavidin antibody. Detection of a single microbead was successfully demonstrated using a capacitance-to-frequency readout. The average capacitance changes for the experimental and control groups were -5.3 fF and -0.2 fF, respectively.

  2. Anomalous degradation of low-field mobility in short-channel metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Natori, Kenji; Iwai, Hiroshi; Kakushima, Kuniyuki

    2015-12-01

    The anomalous degradation of the low-field mobility observed in short-channel metal-oxide-semiconductor field-effect transistors is analyzed by collating various reported data in experiments and simulations. It is inferred that the degradation is not caused by the channel scattering of the carriers. The origin is proposed to be the backscattering of channel carriers on injection into the drain. The expression of the low-field mobility, including the backscattering effect, is derived. The inverse of the low-field mobility is a linear function of the inverse of channel length, the expression of which reproduces that empirically derived by Bidal's group. By fitting the expression to simulated as well as experimental data, we can estimate the value of parameters related to the channel scattering and also to the backscattering from the drain. We find that these values are in reasonable magnitude.

  3. Hydrogen-terminated diamond vertical-type metal oxide semiconductor field-effect transistors with a trench gate

    NASA Astrophysics Data System (ADS)

    Inaba, Masafumi; Muta, Tsubasa; Kobayashi, Mikinori; Saito, Toshiki; Shibata, Masanobu; Matsumura, Daisuke; Kudo, Takuya; Hiraiwa, Atsushi; Kawarada, Hiroshi

    2016-07-01

    The hydrogen-terminated diamond surface (C-H diamond) has a two-dimensional hole gas (2DHG) layer independent of the crystal orientation. A 2DHG layer is ubiquitously formed on the C-H diamond surface covered by atomic-layer-deposited-Al2O3. Using Al2O3 as a gate oxide, C-H diamond metal oxide semiconductor field-effect transistors (MOSFETs) operate in a trench gate structure where the diamond side-wall acts as a channel. MOSFETs with a side-wall channel exhibit equivalent performance to the lateral C-H diamond MOSFET without a side-wall channel. Here, a vertical-type MOSFET with a drain on the bottom is demonstrated in diamond with channel current modulation by the gate and pinch off.

  4. Semi-classical noise investigation for sub-40nm metal-oxide-semiconductor field-effect transistors

    SciTech Connect

    Spathis, C. Birbas, A.; Georgakopoulou, K.

    2015-08-15

    Device white noise levels in short channel Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) dictate the performance and reliability of high-frequency circuits ranging from high-speed microprocessors to Low-Noise Amplifiers (LNAs) and microwave circuits. Recent experimental noise measurements with very short devices demonstrate the existence of suppressed shot noise, contrary to the predictions of classical channel thermal noise models. In this work we show that, as the dimensions continue to shrink, shot noise has to be considered when the channel resistance becomes comparable to the barrier resistance at the source-channel junction. By adopting a semi-classical approach and taking retrospectively into account transport, short-channel and quantum effects, we investigate the partitioning between shot and thermal noise, and formulate a predictive model that describes the noise characteristics of modern devices.

  5. Impedance analysis of Al{sub 2}O{sub 3}/H-terminated diamond metal-oxide-semiconductor structures

    SciTech Connect

    Liao, Meiyong; Liu, Jiangwei; Imura, Masataka; Koide, Yasuo; Sang, Liwen; Coathup, David; Li, Jiangling; Ye, Haitao

    2015-02-23

    Impedance spectroscopy (IS) analysis is carried out to investigate the electrical properties of the metal-oxide-semiconductor (MOS) structure fabricated on hydrogen-terminated single crystal diamond. The low-temperature atomic layer deposition Al{sub 2}O{sub 3} is employed as the insulator in the MOS structure. By numerically analysing the impedance of the MOS structure at various biases, the equivalent circuit of the diamond MOS structure is derived, which is composed of two parallel capacitive and resistance pairs, in series connection with both resistance and inductance. The two capacitive components are resulted from the insulator, the hydrogenated-diamond surface, and their interface. The physical parameters such as the insulator capacitance are obtained, circumventing the series resistance and inductance effect. By comparing the IS and capacitance-voltage measurements, the frequency dispersion of the capacitance-voltage characteristic is discussed.

  6. Nanowire Metal-Oxide-Semiconductor Field-Effect Transistors with Small Subthreshold Swing Driven by Body-Bias Effect

    NASA Astrophysics Data System (ADS)

    Nishiguchi, Katsuhiko; Fujiwara, Akira

    2012-08-01

    We demonstrate metal-oxide-semiconductor field-effect transistors (MOSFETs) with small subthreshold swing (SS). The MOSFETs have a nanowire channel and three gates. A parasitic bipolar transistor formed in a fully depleted silicon-on-insulator MOSFET applies body bias to the MOSFET's channel and thus reduces the SS. Additionally, triple-gate operation makes the drain voltage smaller and provides current characteristics with a high on/off ratio and small hysteresis. As a result, SSs of the n- and p-type MOSFETs reach 6.6 and 5.2 mV/dec, respectively, in the range of current of six orders of magnitude. These features promise MOSFETs with low power consumption.

  7. SOI metal-oxide-semiconductor field-effect transistor photon detector based on single-hole counting.

    PubMed

    Du, Wei; Inokawa, Hiroshi; Satoh, Hiroaki; Ono, Atsushi

    2011-08-01

    In this Letter, a scaled-down silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) is characterized as a photon detector, where photogenerated individual holes are trapped below the negatively biased gate and modulate stepwise the electron current flowing in the bottom channel induced by the positive substrate bias. The output waveforms exhibit clear separation of current levels corresponding to different numbers of trapped holes. Considering this capability of single-hole counting, a small dark count of less than 0.02 s(-1) at room temperature, and low operation voltage of 1 V, SOI MOSFET could be a unique photon-number-resolving detector if the small quantum efficiency were improved.

  8. A compact quantum correction model for symmetric double gate metal-oxide-semiconductor field-effect transistor

    SciTech Connect

    Cho, Edward Namkyu; Shin, Yong Hyeon; Yun, Ilgu

    2014-11-07

    A compact quantum correction model for a symmetric double gate (DG) metal-oxide-semiconductor field-effect transistor (MOSFET) is investigated. The compact quantum correction model is proposed from the concepts of the threshold voltage shift (ΔV{sub TH}{sup QM}) and the gate capacitance (C{sub g}) degradation. First of all, ΔV{sub TH}{sup QM} induced by quantum mechanical (QM) effects is modeled. The C{sub g} degradation is then modeled by introducing the inversion layer centroid. With ΔV{sub TH}{sup QM} and the C{sub g} degradation, the QM effects are implemented in previously reported classical model and a comparison between the proposed quantum correction model and numerical simulation results is presented. Based on the results, the proposed quantum correction model can be applicable to the compact model of DG MOSFET.

  9. Modeling of graphene metal-oxide-semiconductor field-effect transistors with gapless large-area graphene channels

    NASA Astrophysics Data System (ADS)

    Thiele, S. A.; Schaefer, J. A.; Schwierz, F.

    2010-05-01

    A quasianalytical modeling approach for graphene metal-oxide-semiconductor field-effect transistors (MOSFETs) with gapless large-area graphene channels is presented. The model allows the calculation of the I-V characteristics, the small-signal behavior, and the cutoff frequency of graphene MOSFETs. It applies a correct formulation of the density of states in large-area graphene to calculate the carrier-density-dependent quantum capacitance, a steady-state velocity-field characteristics with soft saturation to describe the carrier transport, and takes the source/drain series resistances into account. The modeled drain currents and transconductances show very good agreement with experimental data taken from the literature {Meric et al., [Nat. Nanotechnol. 3, 654 (2008)] and Kedzierski et al., [IEEE Electron Device Lett. 30, 745 (2009)]}. In particular, the model properly reproduces the peculiar saturation behavior of graphene MOSFETs with gapless channels.

  10. Ultraviolet-visible electroluminescence from metal-oxide-semiconductor devices with CeO{sub 2} films on silicon

    SciTech Connect

    Lv, Chunyan; Zhu, Chen; Wang, Canxing; Li, Dongsheng; Ma, Xiangyang Yang, Deren

    2015-03-15

    We report on ultraviolet-visible (UV-Vis) electroluminescence (EL) from metal-oxide-semiconductor (MOS) devices with the CeO{sub 2} films annealed at low temperatures. At the same injection current, the UV-Vis EL from the MOS device with the 550 °C-annealed CeO{sub 2} film is much stronger than that from the counterpart with the 450 °C-annealed CeO{sub 2} film. This is due to that the 550 °C-annealed CeO{sub 2} film contains more Ce{sup 3+} ions and oxygen vacancies. It is tentatively proposed that the recombination of the electrons in multiple oxygen-vacancy–related energy levels with the holes in Ce 4f{sup 1} energy band pertaining to Ce{sup 3+} ions leads to the UV-Vis EL.

  11. Nonvolatile Memory Effect in Indium Gallium Arsenide-Based Metal-Oxide-Semiconductor Devices Using II-VI Tunnel Insulators

    NASA Astrophysics Data System (ADS)

    Chan, P.-Y.; Gogna, M.; Suarez, E.; Karmakar, S.; Al-Amoody, F.; Miller, B. I.; Jain, F. C.

    2011-08-01

    This paper reports the successful use of ZnSe/ZnS/ZnMgS/ZnS/ZnSe as a gate insulator stack for an InGaAs-based metal-oxide-semiconductor (MOS) device, and demonstrates the threshold voltage shift required in nonvolatile memory devices using a floating gate quantum dot layer. An InGaAs-based nonvolatile memory MOS device was fabricated using a high- κ II-VI tunnel insulator stack and self-assembled GeO x -cladded Ge quantum dots as the charge storage units. A Si3N4 layer was used as the control gate insulator. Capacitance-voltage data showed that, after applying a positive voltage to the gate of a MOS device, charges were being stored in the quantum dots. This was shown by the shift in the flat-band/threshold voltage, simulating the write process of a nonvolatile memory device.

  12. Drift region doping effects on characteristics and reliability of high-voltage n-type metal-oxide-semiconductor transistors

    NASA Astrophysics Data System (ADS)

    Chen, Jone F.; Chang, Chun-Po; Liu, Yu Ming; Tsai, Yan-Lin; Hsu, Hao-Tang; Chen, Chih-Yuan; Hwang, Hann-Ping

    2016-01-01

    In this study, off-state breakdown voltage (VBD) and hot-carrier-induced degradation in high-voltage n-type metal-oxide-semiconductor transistors with various BF2 implantation doses in the n- drift region are investigated. Results show that a higher BF2 implantation dose results in a higher VBD but leads to a greater hot-carrier-induced device degradation. Experimental data and technology computer-aided design simulations suggest that the higher VBD is due to the suppression of gate-induced drain current. On the other hand, the greater hot-carrier-induced device degradation can be explained by a lower net donor concentration and a different current-flow path, which is closer to the Si-SiO2 interface.

  13. Monolithic integration of GaN-based light-emitting diodes and metal-oxide-semiconductor field-effect transistors.

    PubMed

    Lee, Ya-Ju; Yang, Zu-Po; Chen, Pin-Guang; Hsieh, Yung-An; Yao, Yung-Chi; Liao, Ming-Han; Lee, Min-Hung; Wang, Mei-Tan; Hwang, Jung-Min

    2014-10-20

    In this study, we report a novel monolithically integrated GaN-based light-emitting diode (LED) with metal-oxide-semiconductor field-effect transistor (MOSFET). Without additionally introducing complicated epitaxial structures for transistors, the MOSFET is directly fabricated on the exposed n-type GaN layer of the LED after dry etching, and serially connected to the LED through standard semiconductor-manufacturing technologies. Such monolithically integrated LED/MOSFET device is able to circumvent undesirable issues that might be faced by other kinds of integration schemes by growing a transistor on an LED or vice versa. For the performances of resulting device, our monolithically integrated LED/MOSFET device exhibits good characteristics in the modulation of gate voltage and good capability of driving injected current, which are essential for the important applications such as smart lighting, interconnection, and optical communication.

  14. Experimental study on vertical scaling of InAs-on-insulator metal-oxide-semiconductor field-effect transistors

    SciTech Connect

    Kim, SangHyeon E-mail: sh-kim@kist.re.kr; Yokoyama, Masafumi; Nakane, Ryosho; Takenaka, Mitsuru; Takagi, Shinichi; Ichikawa, Osamu; Osada, Takenori; Hata, Masahiko

    2014-06-30

    We have investigated effects of the vertical scaling on electrical properties in extremely thin-body InAs-on-insulator (-OI) metal-oxide-semiconductor field-effect transistors (MOSFETs). It is found that the body thickness (T{sub body}) scaling provides better short channel effect (SCE) control, whereas the T{sub body} scaling also causes the reduction of the mobility limited by channel thickness fluctuation (δT{sub body}) scattering (μ{sub fluctuation}). Also, in order to achieve better SCEs control, the thickness of InAs channel layer (T{sub channel}) scaling is more favorable than the thickness of MOS interface buffer layer (T{sub buffer}) scaling from a viewpoint of a balance between SCEs control and μ{sub fluctuation} reduction. These results indicate necessity of quantum well channel structure in InAs-OI MOSFETs and these should be considered in future transistor design.

  15. Interface states and internal photoemission in p-type GaAs metal-oxide-semiconductor surfaces

    NASA Technical Reports Server (NTRS)

    Kashkarov, P. K.; Kazior, T. E.; Lagowski, J.; Gatos, H. C.

    1983-01-01

    An interface photodischarge study of p-type GaAs metal-oxide-semiconductor (MOS) structures revealed the presence of deep interface states and shallow donors and acceptors which were previously observed in n-type GaAs MOS through sub-band-gap photoionization transitions. For higher photon energies, internal photoemission was observed, i.e., injection of electrons to the conduction band of the oxide from either the metal (Au) or from the GaAs valence band; the threshold energies were found to be 3.25 and 3.7 + or - 0.1 eV, respectively. The measured photoemission current exhibited a thermal activation energy of about 0.06 eV, which is consistent with a hopping mechanism of electron transport in the oxide.

  16. Metallic precipitate contribution to carrier generation in metal-oxide-semiconductor capacitors due to the Schottky effect

    NASA Astrophysics Data System (ADS)

    Negoita, M. D.; Tan, T. Y.

    2004-01-01

    The contribution of metallic precipitates to carrier generation has been modeled for metal-oxide-semiconductor (MOS) capacitor devices fabricated using Si, with the precipitate located in the depletion region of the device. The physical mechanism responsible for the electrical activity of the metallic precipitate is attributed to the Schottky junction property between the precipitate and the Si matrix materials. The precipitate serves as a highly effective carrier generation center when the capacitor is switched from the accumulation mode to the deep depletion mode. As a practical case, the electrical activity of the Cu3Si precipitate is investigated and the impact of the precipitate located at different positions within the depleted region of the MOS capacitor on the device performance degradation is analyzed.

  17. Semi-classical noise investigation for sub-40nm metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Spathis, C.; Birbas, A.; Georgakopoulou, K.

    2015-08-01

    Device white noise levels in short channel Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) dictate the performance and reliability of high-frequency circuits ranging from high-speed microprocessors to Low-Noise Amplifiers (LNAs) and microwave circuits. Recent experimental noise measurements with very short devices demonstrate the existence of suppressed shot noise, contrary to the predictions of classical channel thermal noise models. In this work we show that, as the dimensions continue to shrink, shot noise has to be considered when the channel resistance becomes comparable to the barrier resistance at the source-channel junction. By adopting a semi-classical approach and taking retrospectively into account transport, short-channel and quantum effects, we investigate the partitioning between shot and thermal noise, and formulate a predictive model that describes the noise characteristics of modern devices.

  18. Modeling the dark current histogram induced by gold contamination in complementary-metal-oxide-semiconductor image sensors

    SciTech Connect

    Domengie, F. Morin, P.; Bauza, D.

    2015-07-14

    We propose a model for dark current induced by metallic contamination in a CMOS image sensor. Based on Shockley-Read-Hall kinetics, the expression of dark current proposed accounts for the electric field enhanced emission factor due to the Poole-Frenkel barrier lowering and phonon-assisted tunneling mechanisms. To that aim, we considered the distribution of the electric field magnitude and metal atoms in the depth of the pixel. Poisson statistics were used to estimate the random distribution of metal atoms in each pixel for a given contamination dose. Then, we performed a Monte-Carlo-based simulation for each pixel to set the number of metal atoms the pixel contained and the enhancement factor each atom underwent, and obtained a histogram of the number of pixels versus dark current for the full sensor. Excellent agreement with the dark current histogram measured on an ion-implanted gold-contaminated imager has been achieved, in particular, for the description of the distribution tails due to the pixel regions in which the contaminant atoms undergo a large electric field. The agreement remains very good when increasing the temperature by 15 °C. We demonstrated that the amplification of the dark current generated for the typical electric fields encountered in the CMOS image sensors, which depends on the nature of the metal contaminant, may become very large at high electric field. The electron and hole emissions and the resulting enhancement factor are described as a function of the trap characteristics, electric field, and temperature.

  19. Transistor Sizing in the Design of High-Speed CMOS (Complementary-Symmetry Metal-Oxide-Semiconductor) Super Buffers

    DTIC Science & Technology

    1988-03-01

    MOSFET flows from drain to source. This is illustrated in Figure 2.7.a. In a p channel enhancement MOSFET it flows from source to drain [ Sedra and Smith ... Sedra and Smith : "A critical aspect of the design of any logic device, particularly those using LSI (Large-Scale Integration) and VLSI (Very-Large...VLSI circuits is a challenging problem, involving control of signals that are both large in amplitude and in rate of rise." [ Sedra and Smith , 1982, p

  20. Characterization of near-terahertz complementary metal-oxide semiconductor circuits using a Fourier-transform interferometer

    DOE PAGES

    Arenas, D. J.; Shim, Dongha; Koukis, D. I.; ...

    2011-10-24

    Optical methods for measuring of the emission spectra of oscillator circuits operating in the 400-600 GHz range are described. The emitted power from patch antennas included in the circuits is measured by placing the circuit in the source chamber of a Fourier-transform interferometric spectrometer. The results show that this optical technique is useful for measuring circuits pushing the frontier in operating frequency. The technique also allows the characterization of the circuit by measuring the power radiated in the fundamental and in the harmonics. This capability is useful for oscillator architectures designed to cancel the fundamental and use higher harmonics. Themore » radiated power was measured using two techniques: direct measurement of the power by placing the device in front of a bolometer of known responsivity, and by comparison to the estimated power from blackbody sources. The latter technique showed that these circuits have higher emission than blackbody sources at the operating frequencies, and, therefore, offer potential spectroscopy applications.« less

  1. A Programmable Difference-of-Gaussian Analog Complementary Metal Oxide Semiconductor Image Sensor Operating in the Subthreshold Regime

    NASA Astrophysics Data System (ADS)

    Wang, Zheye; Shibata, Tadashi

    2013-04-01

    A difference-of-Gaussian (DoG) analog CMOS image sensor architecture in which the kernel size and shape are made arbitrarily programmable has been developed based on the MOS subthreshold characteristics. The variability of MOS transistor threshold voltage causes a serious problem in the circuits operating in the subthreshold regime because the current varies exponentially depending on the threshold voltage. The problem has been alleviated by introducing a cancellation scheme employing a switched floating-gate MOS (neuMOS) circuitry. A proof-of-concept chip was designed in a 0.18-µm CMOS technology. The operation of the designed circuits was investigated by SPICE (simulation program with integrated circuit emphasis) simulation and their basic functions were demonstrated. A part of the core function, i.e., the generation of the Gaussian function profile, was confirmed by the measurement of a fabricated test circuit.

  2. Characterization of near-terahertz complementary metal-oxide semiconductor circuits using a Fourier-transform interferometer

    SciTech Connect

    Arenas, D. J.; Shim, Dongha; Koukis, D. I.; Seok, Eunyoung; Tanner, D. B.; O, Kenneth K.

    2011-10-24

    Optical methods for measuring of the emission spectra of oscillator circuits operating in the 400-600 GHz range are described. The emitted power from patch antennas included in the circuits is measured by placing the circuit in the source chamber of a Fourier-transform interferometric spectrometer. The results show that this optical technique is useful for measuring circuits pushing the frontier in operating frequency. The technique also allows the characterization of the circuit by measuring the power radiated in the fundamental and in the harmonics. This capability is useful for oscillator architectures designed to cancel the fundamental and use higher harmonics. The radiated power was measured using two techniques: direct measurement of the power by placing the device in front of a bolometer of known responsivity, and by comparison to the estimated power from blackbody sources. The latter technique showed that these circuits have higher emission than blackbody sources at the operating frequencies, and, therefore, offer potential spectroscopy applications.

  3. An ultrasensitive method of real time pH monitoring with complementary metal oxide semiconductor image sensor.

    PubMed

    Devadhasan, Jasmine Pramila; Kim, Sanghyo

    2015-02-09

    CMOS sensors are becoming a powerful tool in the biological and chemical field. In this work, we introduce a new approach on quantifying various pH solutions with a CMOS image sensor. The CMOS image sensor based pH measurement produces high-accuracy analysis, making it a truly portable and user friendly system. pH indicator blended hydrogel matrix was fabricated as a thin film to the accurate color development. A distinct color change of red, green and blue (RGB) develops in the hydrogel film by applying various pH solutions (pH 1-14). The semi-quantitative pH evolution was acquired by visual read out. Further, CMOS image sensor absorbs the RGB color intensity of the film and hue value converted into digital numbers with the aid of an analog-to-digital converter (ADC) to determine the pH ranges of solutions. Chromaticity diagram and Euclidean distance represent the RGB color space and differentiation of pH ranges, respectively. This technique is applicable to sense the various toxic chemicals and chemical vapors by situ sensing. Ultimately, the entire approach can be integrated into smartphone and operable with the user friendly manner.

  4. A hybrid magnetic/complementary metal oxide semiconductor three-context memory bit cell for non-volatile circuit design

    SciTech Connect

    Jovanović, B. E-mail: lionel.torres@lirmm.fr; Brum, R. M.; Torres, L.

    2014-04-07

    After decades of continued scaling to the beat of Moore's law, it now appears that conventional silicon based devices are approaching their physical limits. In today's deep-submicron nodes, a number of short-channel and quantum effects are emerging that affect the manufacturing process, as well as, the functionality of the microelectronic systems-on-chip. Spintronics devices that exploit both the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, are promising solutions to circumvent these scaling threats. Being compatible with the CMOS technology, such devices offer a promising synergy of radiation immunity, infinite endurance, non-volatility, increased density, etc. In this paper, we present a hybrid (magnetic/CMOS) cell that is able to store and process data both electrically and magnetically. The cell is based on perpendicular spin-transfer torque magnetic tunnel junctions (STT-MTJs) and is suitable for use in magnetic random access memories and reprogrammable computing (non-volatile registers, processor cache memories, magnetic field-programmable gate arrays, etc). To demonstrate the potential our hybrid cell, we physically implemented a small hybrid memory block using 45 nm × 45 nm round MTJs for the magnetic part and 28 nm fully depleted silicon on insulator (FD-SOI) technology for the CMOS part. We also report the cells measured performances in terms of area, robustness, read/write speed and energy consumption.

  5. Image stacking approach to increase sensitivity of fluorescence detection using a low cost complementary metal-oxide-semiconductor (CMOS) webcam

    PubMed Central

    Balsam, Joshua; Bruck, Hugh Alan; Kostov, Yordan; Rasooly, Avraham

    2013-01-01

    Optical technologies are important for biological analysis. Current biomedical optical analyses rely on high-cost, high-sensitivity optical detectors such as photomultipliers, avalanched photodiodes or cooled CCD cameras. In contrast, Webcams, mobile phones and other popular consumer electronics use lower-sensitivity, lower-cost optical components such as photodiodes or CMOS sensors. In order for consumer electronics devices, such as webcams, to be useful for biomedical analysis, they must have increased sensitivity. We combined two strategies to increase the sensitivity of CMOS-based fluorescence detector. We captured hundreds of low sensitivity images using a Webcam in video mode, instead of a single image typically used in cooled CCD devices.We then used a computational approach consisting of an image stacking algorithm to remove the noise by combining all of the images into a single image. While video mode is widely used for dynamic scene imaging (e.g. movies or time-lapse photography), it is not used to capture a single static image, which removes noise and increases sensitivity by more than thirty fold. The portable, battery-operated Webcam-based fluorometer system developed here consists of five modules: (1) a low cost CMOS Webcam to monitor light emission, (2) a plate to perform assays, (3) filters and multi-wavelength LED illuminator for fluorophore excitation, (4) a portable computer to acquire and analyze images, and (5) image stacking software for image enhancement. The samples consisted of various concentrations of fluorescein, ranging from 30 μM to 1000 μM, in a 36-well miniature plate. In the single frame mode, the fluorometer's limit-of-detection (LOD) for fluorescein is ∼1000 μM, which is relatively insensitive. However, when used in video mode combined with image stacking enhancement, the LOD is dramatically reduced to 30 μM, sensitivity which is similar to that of state-of-the-art ELISA plate photomultiplier-based readers. Numerous medical diagnostics assays rely on optical and fluorescence readers. Our novel combination of detection technologies, which is new to biodetection may enable the development of new low cost optical detectors based on an inexpensive Webcam (<$10). It has the potential to form the basis for high sensitivity, low cost medical diagnostics in resource-poor settings. PMID:23990697

  6. Fabrication and characterization on width of spiral interdigitated electrodes based biosensors

    NASA Astrophysics Data System (ADS)

    Adelyn, P. Y. P.; Hashim, U.; Arshad, M. K. Md; Ruslinda, A. R.; Voon, C. H.; Ayub, R. M.; Gopinath, Subash C. B.; Liu, Wei-Wen; Kahar, S. M.; Huda, A. R. N.; Lee, H. Cheun

    2017-03-01

    Simple and inexpensive mask layout design on a transparency film were demonstrated using the conventional complementary metal oxide semiconductor (CMOS) technique to produce interdigitated electrodes (IDEs) for biomedical biosensors applications. Lift-off techniques were implemented during photolithography process in order to pattern an electrode widths of 200µm, 300µm, 400µm and 500µm, respectively with a standardized 400µm gap spacing spiral IDEs. Due to the effect of the transparent mask, a fabrication of these spiral IDEs resulted in shrinkage of electrode width and increment of the gap spacing. Among these electrode sizes, the conductance of 300µm, 400µm and 500µm electrode width were successfully examined as compared to 200µm.

  7. Biodegradable elastomers and silicon nanomembranes/nanoribbons for stretchable, transient electronics, and biosensors.

    PubMed

    Hwang, Suk-Won; Lee, Chi Hwan; Cheng, Huanyu; Jeong, Jae-Woong; Kang, Seung-Kyun; Kim, Jae-Hwan; Shin, Jiho; Yang, Jian; Liu, Zhuangjian; Ameer, Guillermo A; Huang, Yonggang; Rogers, John A

    2015-05-13

    Transient electronics represents an emerging class of technology that exploits materials and/or device constructs that are capable of physically disappearing or disintegrating in a controlled manner at programmed rates or times. Inorganic semiconductor nanomaterials such as silicon nanomembranes/nanoribbons provide attractive choices for active elements in transistors, diodes and other essential components of overall systems that dissolve completely by hydrolysis in biofluids or groundwater. We describe here materials, mechanics, and design layouts to achieve this type of technology in stretchable configurations with biodegradable elastomers for substrate/encapsulation layers. Experimental and theoretical results illuminate the mechanical properties under large strain deformation. Circuit characterization of complementary metal-oxide-semiconductor inverters and individual transistors under various levels of applied loads validates the design strategies. Examples of biosensors demonstrate possibilities for stretchable, transient devices in biomedical applications.

  8. A Customized Metal Oxide Semiconductor-Based Gas Sensor Array for Onion Quality Evaluation: System Development and Characterization

    PubMed Central

    Konduru, Tharun; Rains, Glen C.; Li, Changying

    2015-01-01

    A gas sensor array, consisting of seven Metal Oxide Semiconductor (MOS) sensors that are sensitive to a wide range of organic volatile compounds was developed to detect rotten onions during storage. These MOS sensors were enclosed in a specially designed Teflon chamber equipped with a gas delivery system to pump volatiles from the onion samples into the chamber. The electronic circuit mainly comprised a microcontroller, non-volatile memory chip, and trickle-charge real time clock chip, serial communication chip, and parallel LCD panel. User preferences are communicated with the on-board microcontroller through a graphical user interface developed using LabVIEW. The developed gas sensor array was characterized and the discrimination potential was tested by exposing it to three different concentrations of acetone (ketone), acetonitrile (nitrile), ethyl acetate (ester), and ethanol (alcohol). The gas sensor array could differentiate the four chemicals of same concentrations and different concentrations within the chemical with significant difference. Experiment results also showed that the system was able to discriminate two concentrations (196 and 1964 ppm) of methlypropyl sulfide and two concentrations (145 and 1452 ppm) of 2-nonanone, two key volatile compounds emitted by rotten onions. As a proof of concept, the gas sensor array was able to achieve 89% correct classification of sour skin infected onions. The customized low-cost gas sensor array could be a useful tool to detect onion postharvest diseases in storage. PMID:25587975

  9. Functional integrity of flexible n-channel metal-oxide-semiconductor field-effect transistors on a reversibly bistable platform

    NASA Astrophysics Data System (ADS)

    Alfaraj, Nasir; Hussain, Aftab M.; Torres Sevilla, Galo A.; Ghoneim, Mohamed T.; Rojas, Jhonathan P.; Aljedaani, Abdulrahman B.; Hussain, Muhammad M.

    2015-10-01

    Flexibility can bring a new dimension to state-of-the-art electronics, such as rollable displays and integrated circuit systems being transformed into more powerful resources. Flexible electronics are typically hosted on polymeric substrates. Such substrates can be bent and rolled up, but cannot be independently fixed at the rigid perpendicular position necessary to realize rollable display-integrated gadgets and electronics. A reversibly bistable material can assume two stable states in a reversible way: flexibly rolled state and independently unbent state. Such materials are used in cycling and biking safety wristbands and a variety of ankle bracelets for orthopedic healthcare. They are often wrapped around an object with high impulsive force loading. Here, we study the effects of cumulative impulsive force loading on thinned (25 μm) flexible silicon-based n-channel metal-oxide-semiconductor field-effect transistor devices housed on a reversibly bistable flexible platform. We found that the transistors have maintained their high performance level up to an accumulated 180 kN of impact force loading. The gate dielectric layers have maintained their reliability, which is evidenced by the low leakage current densities. Also, we observed low variation in the effective electron mobility values, which manifests that the device channels have maintained their carrier transport properties.

  10. Anomalous wear-out phenomena of europium-implanted light emitters based on a metal-oxide-semiconductor structure

    NASA Astrophysics Data System (ADS)

    Rebohle, L.; Lehmann, J.; Prucnal, S.; Nazarov, A.; Tyagulskii, I.; Tyagulskii, S.; Kanjilal, A.; Voelskow, M.; Grambole, D.; Skorupa, W.; Helm, M.

    2009-12-01

    The anomalous wear-out phenomena of Eu-implanted metal-oxide-semiconductor devices were investigated. It will be shown that in contrast to other rare earth elements the electroluminescence (EL) intensity of Eu-implanted SiO2 layers can rise under constant current injection before the known EL quenching will start. Under certain circumstances, this rise may amount up to two orders of magnitude. The EL behavior will be correlated with the microstructural and electrical properties of the devices. Transmission electron microscopy and Rutherford backscattering spectroscopy were applied to trace the development of Eu/Eu oxide clusters and the diffusion of Eu to the interfaces of the gate oxide layer. The hydrogen profile within the SiO2-SiON interface region was determined by nuclear reaction analysis. Current-voltage characteristics, EL decay times, and the progression of the voltage and the EL spectrum with increasing charge injection were measured to study charge and trapping phenomena in the oxide layer to reveal details of the EL excitation mechanism. A first qualitative model for the anomalous life time behavior is proposed.

  11. Theoretical Study of Triboelectric-Potential Gated/Driven Metal-Oxide-Semiconductor Field-Effect Transistor.

    PubMed

    Peng, Wenbo; Yu, Ruomeng; He, Yongning; Wang, Zhong Lin

    2016-04-26

    Triboelectric nanogenerator has drawn considerable attentions as a potential candidate for harvesting mechanical energies in our daily life. By utilizing the triboelectric potential generated through the coupling of contact electrification and electrostatic induction, the "tribotronics" has been introduced to tune/control the charge carrier transport behavior of silicon-based metal-oxide-semiconductor field-effect transistor (MOSFET). Here, we perform a theoretical study of the performances of tribotronic MOSFET gated by triboelectric potential in two working modes through finite element analysis. The drain-source current dependence on contact-electrification generated triboelectric charges, gap separation distance, and externally applied bias are investigated. The in-depth physical mechanism of the tribotronic MOSFET operations is thoroughly illustrated by calculating and analyzing the charge transfer process, voltage relationship to gap separation distance, and electric potential distribution. Moreover, a tribotronic MOSFET working concept is proposed, simulated and studied for performing self-powered FET and logic operations. This work provides a deep understanding of working mechanisms and design guidance of tribotronic MOSFET for potential applications in micro/nanoelectromechanical systems (MEMS/NEMS), human-machine interface, flexible electronics, and self-powered active sensors.

  12. Electroluminescence from metal-oxide-semiconductor devices with erbium-doped CeO{sub 2} films on silicon

    SciTech Connect

    Lv, Chunyan; Zhu, Chen; Wang, Canxing; Gao, Yuhan; Ma, Xiangyang Yang, Deren

    2015-04-06

    We report on erbium (Er)-related electroluminescence (EL) in the visible and near-infrared (NIR) from metal-oxide-semiconductor (MOS) devices with Er-doped CeO{sub 2} (CeO{sub 2}:Er) films on silicon. The onset voltage of such EL under either forward or reverse bias is smaller than 10 V. Moreover, the EL quenching can be avoidable for the CeO{sub 2}:Er-based MOS devices. Analysis on the current-voltage characteristic of the device indicates that the electron transportation at the EL-enabling voltages under either forward or reverse bias is dominated by trap-assisted tunneling mechanism. Namely, electrons in n{sup +}-Si/ITO can tunnel into the conduction band of CeO{sub 2} host via defect states at sufficiently high forward/reverse bias voltages. Then, a fraction of such electrons are accelerated by electric field to become hot electrons, which impact-excite the Er{sup 3+} ions, thus leading to characteristic emissions. It is believed that this work has laid the foundation for developing viable silicon-based emitters using CeO{sub 2}:Er films.

  13. A customized metal oxide semiconductor-based gas sensor array for onion quality evaluation: system development and characterization.

    PubMed

    Konduru, Tharun; Rains, Glen C; Li, Changying

    2015-01-12

    A gas sensor array, consisting of seven Metal Oxide Semiconductor (MOS) sensors that are sensitive to a wide range of organic volatile compounds was developed to detect rotten onions during storage. These MOS sensors were enclosed in a specially designed Teflon chamber equipped with a gas delivery system to pump volatiles from the onion samples into the chamber. The electronic circuit mainly comprised a microcontroller, non-volatile memory chip, and trickle-charge real time clock chip, serial communication chip, and parallel LCD panel. User preferences are communicated with the on-board microcontroller through a graphical user interface developed using LabVIEW. The developed gas sensor array was characterized and the discrimination potential was tested by exposing it to three different concentrations of acetone (ketone), acetonitrile (nitrile), ethyl acetate (ester), and ethanol (alcohol). The gas sensor array could differentiate the four chemicals of same concentrations and different concentrations within the chemical with significant difference. Experiment results also showed that the system was able to discriminate two concentrations (196 and 1964 ppm) of methlypropyl sulfide and two concentrations (145 and 1452 ppm) of 2-nonanone, two key volatile compounds emitted by rotten onions. As a proof of concept, the gas sensor array was able to achieve 89% correct classification of sour skin infected onions. The customized low-cost gas sensor array could be a useful tool to detect onion postharvest diseases in storage.

  14. Proposal of Trench-Oxide Metal-Oxide-Semiconductor Structure and Computer Simulation of Silicon Quantum-Wire Characteristics

    NASA Astrophysics Data System (ADS)

    Tsukui, Tetsuya; Oda, Shunri

    1993-12-01

    We propose “trench-oxide metal-oxide-semiconductor (MOS)” structures as a novel formation method of silicon-based low-dimensional quantum structures, which are considered to be basic elements of future ultrahigh-speed and ultralarge-scale integrated devices. In this method, the applied gate voltage forms the potential well confined in an additional direction defined by ultrafine “trenches” on the oxide layer of the MOS structure. We characterize “trench-oxide MOS” quantum wire structures by two-dimensional numerical calculation of the shape of the potential well, the subband energy levels and the electron density, and investigate the possibility of the experimental observation of quantized density of states peculiar to quantum wires, by measuring capacitance-gate voltage (C-V) characteristics of “trench-oxide MOS capacitors.” We also have successfully fabricated “trench-oxide MOS” quantum wires with the width of 16 nm using electron beam (EB) lithography and electron cyclotron resonance reactive ion etching (ECR-RIE).

  15. Single-electron regime and Pauli spin blockade in a silicon metal-oxide-semiconductor double quantum dot

    NASA Astrophysics Data System (ADS)

    Rochette, Sophie; Ten Eyck, Gregory A.; Pluym, Tammy; Lilly, Michael P.; Carroll, Malcolm S.; Pioro-Ladrière, Michel

    2015-03-01

    Silicon quantum dots are promising candidates for quantum information processing as spin qubits with long coherence time. We present electrical transport measurements on a silicon metal-oxide-semiconductor (MOS) double quantum dot (DQD). First, Coulomb diamonds measurements demonstrate the one-electron regime at a relatively high temperature of 1.5 K. Then, the 8 mK stability diagram shows Pauli spin blockade with a large singlet-triplet separation of approximatively 0.40 meV, pointing towards a strong lifting of the valley degeneracy. Finally, numerical simulations indicate that by integrating a micro-magnet to those devices, we could achieve fast spin rotations of the order of 30 ns. Those results are part of the recent body of work demonstrating the potential of Si MOS DQD as reliable and long-lived spin qubits that could be ultimately integrated into modern electronic facilities. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  16. Study of Strain Induction for Metal-Oxide-Semiconductor Field-Effect Transistors using Transparent Dummy Gates and Stress Liners

    NASA Astrophysics Data System (ADS)

    Kosemura, Daisuke; Takei, Munehisa; Nagata, Kohki; Akamatsu, Hiroaki; Kohno, Masayuki; Nishita, Tatsuo; Nakanishi, Toshio; Ogura, Atsushi

    2009-06-01

    Strain induction was studied on a sample that had a dummy gate tetraethyl orthosilicate-silicon dioxide (TEOS-SiO2) and SiN film by UV-Raman spectroscopy with high spatial and high wave-number resolution. The UV laser penetrated through the dummy gate that was transparent to UV light, which enabled us to evaluate strain in the channel of the metal-oxide-semiconductor field-effect transistor (MOSFET) model. Furthermore, we compared stress profiles obtained by finite element (FE) calculations with those obtained by UV-Raman measurements. There was a difference between the stress profiles in the line-and-space pattern sample and in the dummy-gate sample; large compressive (tensile) strains were concentrated at the channel edges in the dummy-gate sample with the compressive (tensile) stress liner, although both tensile and compressive strains existed at the channel edge in the line-and-space pattern sample. The results from UV-Raman spectroscopy were consistent with those obtained by the FE calculation.

  17. Nonvolatile and tunable switching of lateral photo-voltage triggered by laser and electric pulse in metal dusted metal-oxide-semiconductor structures

    PubMed Central

    Zhou, Peiqi; Gan, Zhikai; Huang, Xu; Mei, Chunlian; Huang, Meizhen; Xia, Yuxing; Wang, Hui

    2016-01-01

    Owing to the innate stabilization of built-in potential in p–n junction or metal-oxide-semiconductor structure, the sensitivity and linearity of most lateral photovoltaic effect (LPE) devices is always fixed after fabrication. Here we report a nonvolatile and tunable switching effect of lateral photo-voltage (LPV) in Cu dusted ultrathin metal-oxide-semiconductor structure. With the stimulation of electric pulse and local illumination, the sensitivity and linearity of LPV can be adjusted up and down in a nonvolatile manner. This phenomenon is attributed to a controllable change of the Schottky barrier formed between the metal layer and silicon substrate, including the consequent change of film resistivity. This work may widely improve the performance of existing LPE-based devices and suggest new applications for LPE in other areas. PMID:27535351

  18. Degradation mechanisms of electron mobility in metal-oxide-semiconductor field-effect transistors with LaAlO{sub 3} gate dielectric

    SciTech Connect

    Chang, Ingram Yin-ku; You Shengwen; Chen Maingwo; Chen Chunheng; Lee, Joseph Yamin; Juan, Pichun

    2009-05-15

    LaAlO{sub 3} is a promising candidate of gate dielectric for future very large scale integration devices. In this work, metal-oxide-semiconductor capacitors and transistors with LaAlO{sub 3} gate dielectric were fabricated and the electron mobility degradation mechanisms were studied. The LaAlO{sub 3} films were deposited by radio frequency magnetron sputtering. The LaAlO{sub 3} films were examined by x-ray diffraction, secondary ion mass spectroscopy, and x-ray photoelectron spectroscopy. The temperature dependence of metal-oxide-semiconductor field-effect transistors characteristics was studied from 11 K to 400 K. The rate of threshold voltage change with temperature (DELTAV{sub T}/DELTAT) is -1.51 mV/K. The electron mobility limited by surface roughness is proportional to E{sub eff}{sup -0.66} in the electric field of 0.93 MV/cmmetal-oxide-semiconductor field-effect transistors.

  19. Real-time, continuous, fluorescence sensing in a freely-moving subject with an implanted hybrid VCSEL/CMOS biosensor

    PubMed Central

    O’Sullivan, Thomas D.; Heitz, Roxana T.; Parashurama, Natesh; Barkin, David B.; Wooley, Bruce A.; Gambhir, Sanjiv S.; Harris, James S.; Levi, Ofer

    2013-01-01

    Performance improvements in instrumentation for optical imaging have contributed greatly to molecular imaging in living subjects. In order to advance molecular imaging in freely moving, untethered subjects, we designed a miniature vertical-cavity surface-emitting laser (VCSEL)-based biosensor measuring 1cm3 and weighing 0.7g that accurately detects both fluorophore and tumor-targeted molecular probes in small animals. We integrated a critical enabling component, a complementary metal-oxide semiconductor (CMOS) read-out integrated circuit, which digitized the fluorescence signal to achieve autofluorescence-limited sensitivity. After surgical implantation of the lightweight sensor for two weeks, we obtained continuous and dynamic fluorophore measurements while the subject was un-anesthetized and mobile. The technology demonstrated here represents a critical step in the path toward untethered optical sensing using an integrated optoelectronic implant. PMID:24009996

  20. Metal-oxide-semiconductor diodes containing C60 fullerenes for non-volatile memory applications

    NASA Astrophysics Data System (ADS)

    Beckmeier, Daniel; Baumgärtner, Hermann

    2013-01-01

    For non-volatile memories, silicon-oxide-nitride-oxide-silicon or floating gate structures are used to store information by charging and discharging electronic states reversibly. In this article, we propose to replace the floating gate by C60 molecules. This would allow more defined programming voltages because of the discrete molecular energy levels and a higher resistance to tunneling oxide defects because of the weak electrical connection between the single molecules. Such C60 MOS diode structures are produced and their electrical properties are analyzed regarding current transport and charging mechanism of the molecules. To create the MOS structures, C60 molecules (5% of a monolayer) are evaporated onto a part of a clean silicon wafer and covered by amorphous silicon in situ in an ultra high vacuum system. Then the wafer is oxidized in wet atmosphere at just 710 °C through the C60 layer. The goal is to produce a clean oxide above and under the molecules without destroying them. Aluminum gate contacts are defined on top of these layers to perform complementary capacitance voltage (CV) and current voltage (IV) measurements. First, the gate voltage is swept to analyze the injection current, then CV measurements are performed after each sweep to analyze the charge state of the C60 layer and the oxide quality. Reference diodes without C60 on the same wafer show an identical Fowler-Nordheim (FN) tunneling behavior for currents injected from silicon or from aluminum, respectively. In the CV curves, no pronounced flatband voltage shift is observable. In diodes with C60, for negative gate voltages, a classical FN tunneling is observed and compared to theory. The electron injection from silicon shows a different tunneling current behavior. It starts at a lower electric field and has a smaller slope then a FN current would have. It is identified as a trap-assisted tunneling (TAT) current caused by oxidation-induced traps under the C60 layer. It is modeled by an

  1. Study of Si/Si, Si/SiO sub 2 , and metal-oxide-semiconductor (MOS) using positrons

    SciTech Connect

    Leung, To Chi.

    1991-01-01

    A variable-energy positron beam is used to study Si/Si, Si/SiO{sub 2}, and metal-oxide-semiconductor (MOS) structures. The capability of depth resolution and the remarkable sensitivity to defects have made the positron annihilation technique a unique tool in detecting open-volume defects in the newly innovated low temperature (300C) molecular-beam-epitaxy (MBE) Si/Si. These two features of the positron beam have further shown its potential role in the study of the Si/SiO{sub 2}. Distinct annihilation characteristics has been observed at the interface and has been studied as a function of the sample growth conditions, annealing (in vacuum), and hydrogen exposure. The MOS structure provides an effective way to study the electrical properties of the Si/SiO{sub 2} interface as a function of applied bias voltage. The annihilation characteristics show a large change as the device condition is changed from accumulation to inversion. The effect of forming gas (FG) anneal is studied using positron annihilation and the result is compared with capacitance-voltage (C-V) measurements. The reduction in the number of interface states is found correlated with the changes in the positron spectra. The present study shows the importance of the positron annihilation technique as a non-contact, non-destructive, and depth-sensitive characterization tool to study the Si-related systems, in particular, the Si/SiO{sub 2} interface which is of crucial importance in semiconductor technology, and fundamental understanding of the defects responsible for degradation of the electrical properties.

  2. Design of nanophotonic, hot-electron solar-blind ultraviolet detectors with a metal-oxide-semiconductor structure

    NASA Astrophysics Data System (ADS)

    Wang, Zhiyuan; Wang, Xiaoxin; Liu, Jifeng

    2014-12-01

    Solar-blind ultraviolet (UV) detection refers to photon detection specifically in the wavelength range of 200 nm-320 nm. Without background noises from solar radiation, it has broad applications from homeland security to environmental monitoring. The most commonly used solid state devices for this application are wide band gap (WBG) semiconductor photodetectors (Eg > 3.5 eV). However, WBG semiconductors are difficult to grow and integrate with Si readout integrated circuits (ROICs). In this paper, we design a nanophotonic metal-oxide-semiconductor structure on Si for solar-blind UV detectors. Instead of using semiconductors as the active absorber, we use Sn nano-grating structures to absorb UV photons and generate hot electrons for internal photoemission across the Sn/SiO2 interfacial barrier, thereby generating photocurrent between the metal and the n-type Si region upon UV excitation. Moreover, the transported hot electron has an excess kinetic energy >3 eV, large enough to induce impact ionization and generate another free electron in the conduction band of n-Si. This process doubles the quantum efficiency. On the other hand, the large metal/oxide interfacial energy barrier (>3.5 eV) also enables solar-blind UV detection by blocking the less energetic electrons excited by visible photons. With optimized design, ˜75% UV absorption and hot electron excitation can be achieved within the mean free path of ˜20 nm from the metal/oxide interface. This feature greatly enhances hot electron transport across the interfacial barrier to generate photocurrent. The simple geometry of the Sn nano-gratings and the MOS structure make it easy to fabricate and integrate with Si ROICs compared to existing solar-blind UV detection schemes. The presented device structure also breaks through the conventional notion that photon absorption by metal is always a loss in solid-state photodetectors, and it can potentially be extended to other active metal photonic devices.

  3. Verification of the plan dosimetry for high dose rate brachytherapy using metal-oxide-semiconductor field effect transistor detectors

    SciTech Connect

    Qi Zhenyu; Deng Xiaowu; Huang Shaomin; Lu Jie; Lerch, Michael; Cutajar, Dean; Rosenfeld, Anatoly

    2007-06-15

    The feasibility of a recently designed metal-oxide-semiconductor field effect transistor (MOSFET) dosimetry system for dose verification of high dose rate (HDR) brachytherapy treatment planning was investigated. MOSFET detectors were calibrated with a 0.6 cm{sup 3} NE-2571 Farmer-type ionization chamber in water. Key characteristics of the MOSFET detectors, such as the energy dependence, that will affect phantom measurements with HDR {sup 192}Ir sources were measured. The MOSFET detector was then applied to verify the dosimetric accuracy of HDR brachytherapy treatments in a custom-made water phantom. Three MOSFET detectors were calibrated independently, with the calibration factors ranging from 0.187 to 0.215 cGy/mV. A distance dependent energy response was observed, significant within 2 cm from the source. The new MOSFET detector has a good reproducibility (<3%), small angular effect (<2%), and good dose linearity (R{sup 2}=1). It was observed that the MOSFET detectors had a linear response to dose until the threshold voltage reached approximately 24 V for {sup 192}Ir source measurements. Further comparison of phantom measurements using MOSFET detectors with dose calculations by a commercial treatment planning system for computed tomography-based brachytherapy treatment plans showed that the mean relative deviation was 2.2{+-}0.2% for dose points 1 cm away from the source and 2.0{+-}0.1% for dose points located 2 cm away. The percentage deviations between the measured doses and the planned doses were below 5% for all the measurements. The MOSFET detector, with its advantages of small physical size and ease of use, is a reliable tool for quality assurance of HDR brachytherapy. The phantom verification method described here is universal and can be applied to other HDR brachytherapy treatments.

  4. Are dangling bond centers important interface traps in 4H-SiC metal oxide semiconductor field effect transistors?

    NASA Astrophysics Data System (ADS)

    Anders, M. A.; Lenahan, P. M.; Lelis, A. J.

    2016-10-01

    Silicon carbide (SiC) based metal-oxide-semiconductor field-effect transistors (MOSFETs) have great promise in high power and high temperature applications. Unfortunately, effective channel mobilities remain disappointingly low, typically about 30 cm2/Vs. A major contributor to the disappointing effective channel mobilities is the presence of substantial densities of interface traps at the SiC/SiO2 interface. Many investigators have invoked silicon or carbon dangling bonds to be the dominating source of these interface defects, but very little, if any, direct experimental evidence exists to support this assumption in the SiC/SiO2 system. Cantin et al. [Phys. Rev. Lett. 92, 1 (2004)] have used conventional electron paramagnetic resonance measurements on porous oxidized SiC structures to measure the g tensor for the SiC/SiO2 interface carbon dangling bond. These results provide a particularly straightforward means to search for the presence of carbon dangling bonds in fully processed SiC MOSFETs using electrically detected magnetic resonance. Additionally, simple theory provides guidance to search for silicon dangling bond defects. In this study, we utilize K band electrically detected magnetic resonance via spin dependent charge pumping measurements in which almost all of the SiC band gap at the SiC/SiO2 interface is accessed. Although quite high signal to noise measurements are achieved, we are unable to detect any trace of the carbon dangling bond spectra. However, in very poor quality p-channel devices, we observe a spectrum which could be consistent with silicon dangling bonds. Other defect centers are clearly present and we conclude that these other centers dominate the interface trap density of states.

  5. Metal-oxide-semiconductor capacitors and Schottky diodes studied with scanning microwave microscopy at 18 GHz

    SciTech Connect

    Kasper, M.; Gramse, G.; Hoffmann, J.; Gaquiere, C.; Feger, R.; Stelzer, A.; Smoliner, J.; Kienberger, F.

    2014-11-14

    We measured the DC and RF impedance characteristics of micrometric metal-oxide-semiconductor (MOS) capacitors and Schottky diodes using scanning microwave microscopy (SMM). The SMM consisting of an atomic force microscopy (AFM) interfaced with a vector network analyser (VNA) was used to measure the reflection S11 coefficient of the metallic MOS and Schottky contact pads at 18 GHz as a function of the tip bias voltage. By controlling the SMM biasing conditions, the AFM tip was used to bias the Schottky contacts between reverse and forward mode. In reverse bias direction, the Schottky contacts showed mostly a change in the imaginary part of the admittance while in forward bias direction the change was mostly in the real part of the admittance. Reference MOS capacitors which are next to the Schottky diodes on the same sample were used to calibrate the SMM S11 data and convert it into capacitance values. Calibrated capacitance between 1–10 fF and 1/C{sup 2} spectroscopy curves were acquired on the different Schottky diodes as a function of the DC bias voltage following a linear behavior. Additionally, measurements were done directly with the AFM-tip in contact with the silicon substrate forming a nanoscale Schottky contact. Similar capacitance-voltage curves were obtained but with smaller values (30–300 aF) due to the corresponding smaller AFM-tip diameter. Calibrated capacitance images of both the MOS and Schottky contacts were acquired with nanoscale resolution at different tip-bias voltages.

  6. Effects of buffered HF cleaning on metal-oxide-semiconductor interface properties of Al2O3/InAs/GaSb structures

    NASA Astrophysics Data System (ADS)

    Nishi, Koichi; Yokoyama, Masafumi; Yokoyama, Haruki; Hoshi, Takuya; Sugiyama, Hiroki; Takenaka, Mitsuru; Takagi, Shinichi

    2015-06-01

    We studied the impact of buffered HF (BHF) cleaning on the interface properties of Al2O3/InAs/GaSb metal-oxide-semiconductor (MOS) structures fabricated by the ex-situ surface cleaning process. The Al2O3/InAs/GaSb MOS structures fabricated with BHF cleaning exhibited lower Dit values than those fabricated with sulfur passivation. In addition, the Al2O3/InAs/GaSb MOS structures fabricated with BHF cleaning were robust with respect to the MOS field-effect transistor fabrication process by using W gate metal with PMA in the 250-300 °C range.

  7. High resolution imaging in cross-section of a metal-oxide-semiconductor field-effect-transistor using super-higher-order nonlinear dielectric microscopy

    NASA Astrophysics Data System (ADS)

    Chinone, N.; Yamasue, K.; Honda, K.; Cho, Y.

    2013-11-01

    Scanning nonlinear dielectric microscopy (SNDM) can evaluate carrier or charge distribution in semiconductor devices. High sensitivity to capacitance variation enables SNDM to measure the super-high-order (higher than 3rd) derivative of local capacitance-voltage (C-V) characteristics directly under the tip (dnC/dVn,n = 3, 4, ...). We demonstrate improvement of carrier density resolution by measurement of dnC/dVn,n = 1, 2, 3, 4 (super-higher-order method) in the cross-sectional observation of metal-oxide-semiconductor field-effect-transistor.

  8. Detailed investigation of InSb p-channel metal-oxide-semiconductor field effect transistor prepared by photo-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Liu, Biing-Der; Lee, Si-Chen; Sun, Tai-Ping; Yang, Sheng-Jenn

    1995-05-01

    The InSb metal-oxide-semiconductor field effect transistor (MOSFET) with three different channel lengths 5, 15, and 30 micron were fabricated successfully. The SiO2 prepared by photo-enhanced chemical vapor deposition was used both as the gate insulator and the source/drain passivation layer to reduce the source/drain pn junction surface leakage current. The common-source current-voltage characteristics show a breakdown voltage exceeding 2 V indicating an excellent pn junction reverse characteristics. The capacitance-voltage and the transferred current versus gate voltage characteristics are discussed in detail to explain the geometry effect on the device performance.

  9. Stress Characterization of 4H-SiC Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) using Raman Spectroscopy and the Finite Element Method.

    PubMed

    Yoshikawa, Masanobu; Kosaka, Kenichi; Seki, Hirohumi; Kimoto, Tsunenobu

    2016-07-01

    We measured the depolarized and polarized Raman spectra of a 4H-SiC metal-oxide-semiconductor field-effect transistor (MOSFET) and found that compressive stress of approximately 20 MPa occurs under the source and gate electrodes and tensile stress of approximately 10 MPa occurs between the source and gate electrodes. The experimental result was in close agreement with the result obtained by calculation using the finite element method (FEM). A combination of Raman spectroscopy and FEM provides much data on the stresses in 4H-SiC MOSFET.

  10. Anomalous output characteristic shift for the n-type lateral diffused metal-oxide-semiconductor transistor with floating P-top layer

    SciTech Connect

    Liu, Siyang; Zhang, Chunwei; Sun, Weifeng; Su, Wei; Wang, Shaorong; Ma, Shulang; Huang, Yu

    2014-04-14

    Anomalous output characteristic shift of the n-type lateral diffused metal-oxide-semiconductor transistor with floating P-top layer is investigated. It shows that the linear drain current has obvious decrease when the output characteristic of fresh device is measured for two consecutive times. The charge pumping experiments demonstrate that the decrease is not from hot-carrier degradation. The reduction of cross section area for the current flowing, which results from the squeezing of the depletion region surrounding the P-top layer, is responsible for the shift. Consequently, the current capability of this special device should be evaluated by the second measured output characteristic.

  11. Ballistic performance comparison of monolayer transition metal dichalcogenide MX{sub 2} (M = Mo, W; X = S, Se, Te) metal-oxide-semiconductor field effect transistors

    SciTech Connect

    Chang, Jiwon; Register, Leonard F.; Banerjee, Sanjay K.

    2014-02-28

    We study the transport properties of monolayer MX{sub 2} (M = Mo, W; X = S, Se, Te) n- and p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) using full-band ballistic non-equilibrium Green's function simulations with an atomistic tight-binding Hamiltonian with hopping potentials obtained from density functional theory. We discuss the subthreshold slope, drain-induced barrier lowering (DIBL), as well as gate-induced drain leakage (GIDL) for different monolayer MX{sub 2} MOSFETs. We also report the possibility of negative differential resistance behavior in the output characteristics of nanoscale monolayer MX{sub 2} MOSFETs.

  12. Flatband voltage control in p-metal gate metal-oxide-semiconductor field effect transistor by insertion of TiO2 layer

    NASA Astrophysics Data System (ADS)

    Maeng, W. J.; Kim, Woo-Hee; Koo, Ja Hoon; Lim, S. J.; Lee, Chang-Soo; Lee, Taeyoon; Kim, Hyungjun

    2010-02-01

    Titanium oxide (TiO2) layer was used to control the flatband voltage (VFB) of p-type metal-oxide-semiconductor field effect transistors. TiO2 was deposited by plasma enhanced atomic layer deposition (PE-ALD) on hafnium oxide (HfO2) gate dielectrics. Comparative studies between TiO2 and Al2O3 as capping layer have shown that improved device properties with lower capacitance equivalent thickness (CET), interface state density (Dit), and flatband voltage (VFB) shift were achieved by PE-ALD TiO2 capping layer.

  13. A Novel Gate Electrode Structure for Reduction of Gate Resistance of Sub-0.1 µm RF/Mixed-Signal Metal Oxide Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Nagase, Hirokazu; Tanabe, Akira; Umeda, Kyoko; Watanabe, Takashi; Hayashi, Yoshihiro

    2009-04-01

    To reduce noise and enhance gain for scaled-down metal oxide semiconductor field-effect transistors (MOSFETs), a novel gate electrode structure “direct finger contact (DFC)” is proposed. The DFC structure reduces the gate electrode resistance by 40%. NF50 (noise figure when the input impedance is 50 Ω) is reduced by 4% with the gate length L = 48 nm, the gate width Wfinger =1 µm, and the number of finger N =20. This structure is suitable for low-noise sub-0.1 µm RF/mixed-signal system on chips (SoCs).

  14. Determination of Fowler-Nordheim tunneling parameters in Metal-Oxide-Semiconductor structure including oxide field correction using a vertical optimization method

    NASA Astrophysics Data System (ADS)

    Toumi, S.; Ouennoughi, Z.; Strenger, K. C.; Frey, L.

    2016-08-01

    Current conduction mechanisms through a Metal-Oxide-Semiconductor structure are characterized via Fowler-Nordheim (FN) plots. The extraction of the FN parameters like the electron/hole effective mass in oxide mox and in semiconductor msc, the barrier height at the semiconductor-oxide interface ϕB, and the correction oxide voltage Vcorr for a MOS structure is made using a vertical optimization process on the current density without any assumption about ϕB or mox. An excellent agreement is obtained between the FN plots calculated with the FN parameters extracted using a vertical optimization process with the experimental one.

  15. Evaluation of Interface Property and DC Characteristics Enhancement in Nanoscale n-Channel Metal-Oxide-Semiconductor Field-Effect Transistor Using Stress Memorization Technique

    NASA Astrophysics Data System (ADS)

    Huang, Po Chin; Lein Wu, San; Jinn Chang, Shoou; Huang, Yao Tsung; Kuo, Cheng Wen; Chang, Ching Yao; Cheng, Yao Chin; Cheng, Osbert

    2010-09-01

    In this letter, the advanced 40 nm technology n-channel metal-oxide-semiconductor field-effect transistor devices using the stress memorization technique (SMT) are presented. We demonstrate that SMT process would not affect the electrical characteristics of devices and can introduce higher tensile stress on channels, which enhances drive current. Through charge pumping measurement, it can be verified that SMT does not affect Si/SiO2 interface quality. Moreover, SMT-induced higher tensile stress decreases not only scattering coefficient but also tunneling attenuation length, resulting in smaller input-referred noise, which represents an intrinsic advantage of low-frequency noise performance.

  16. Improvement of charge-pumping electrically detected magnetic resonance and its application to silicon metal-oxide-semiconductor field-effect transistor

    NASA Astrophysics Data System (ADS)

    Hori, Masahiro; Tsuchiya, Toshiaki; Ono, Yukinori

    2017-01-01

    Charge-pumping electrically detected magnetic resonance (CP EDMR), or EDMR in the CP mode, is improved and applied to a silicon metal-oxide-semiconductor field-effect transistor (MOSFET). Real-time monitoring of the CP process reveals that high-frequency transient currents are an obstacle to signal amplification for EDMR. Therefore, we introduce cutoff circuitry, leading to a detection limit for the number of spins as low as 103 for Si MOS interface defects. With this improved method, we demonstrate that CP EDMR inherits one of the most important features of the CP method: the gate control of the energy window of the detectable interface defects for spectroscopy.

  17. Electron spectroscopic analysis of the SiO2/Si system and correlation with metal-oxide-semiconductor device characteristics

    NASA Astrophysics Data System (ADS)

    Iwata, Seiichi; Ishizaka, Akitoshi

    1996-05-01

    ESCA (electron spectroscopy for chemical analysis) measurement results on thin SiO2/Si samples are examined comprehensively, critically, and in detail to show that it is possible to correlate these results with MOS (metal-oxide-semiconductor) device characteristics such as flatband (threshold) voltage, oxide breakdown field, mobile-ion density, hole and electron trap density, and hot-carrier lifetime. Up to now, much effort has been made to detect SiOx phases at SiO2/Si interfaces since they are thought to have a significant effect on MOS device characteristics. However, correlating the SiOx phases with device characteristics is difficult and involves overcoming two problems. First, the chemical state is difficult to determine exactly due to x-ray irradiation effects. Second, the amount of defects and impurities which influence device characteristics is usually below the ESCA detection limit (1012-1013 cm-2) in device-quality SiO2/Si samples. Investigation of the first problem led to the conclusion that it is possible to correct for these effects from the x-ray intensity or oxide thickness dependence of the chemical shift. However, accurate (better than ±0.2 eV) chemical state determination is not easy. It is therefore necessary to approach this detection problem from a different viewpoint. Our first attempt involves measuring the ESCA thickness, which decreases when oxide defects like unoxidized Si or uneven thickness (or pinholes) are present, resulting in breakdown field degradation. Our second attempt started while we were studying how to interpret the measured chemical shift. The photoelectron peaks of the SiO2 and the Si can be observed to shift due to small amounts of charged defects and impurities, although they cannot be detected as peaks. This method is considered to be especially useful for characterizing ultrathin (a few nm thick) SiO2/Si samples which are difficult to characterize using conventional C-V (capacitance-voltage) measurements because of

  18. Interface states in Al2O3/AlGaN/GaN metal-oxide-semiconductor structure by frequency dependent conductance technique

    NASA Astrophysics Data System (ADS)

    Liao, Xue-Yang; Zhang, Kai; Zeng, Chang; Zheng, Xue-Feng; En, Yun-Fei; Lai, Ping; Hao, Yue

    2014-05-01

    Frequency dependent conductance measurements are implemented to investigate the interface states in Al2O3/AlGaN/GaN metal-oxide-semiconductor (MOS) structures. Two types of device structures, namely, the recessed gate structure (RGS) and the normal gate structure (NGS), are studied in the experiment. Interface trap parameters including trap density Dit, trap time constant τit, and trap state energy ET in both devices have been determined. Furthermore, the obtained results demonstrate that the gate recess process can induce extra traps with shallower energy levels at the Al2O3/AlGaN interface due to the damage on the surface of the AlGaN barrier layer resulting from reactive ion etching (RIE).

  19. Investigation on edge fringing effect and oxide thickness dependence of inversion current in metal-oxide-semiconductor tunneling diodes with comb-shaped electrodes

    NASA Astrophysics Data System (ADS)

    Lin, Chien-Chih; Hsu, Pei-Lun; Lin, Li; Hwu, Jenn-Gwo

    2014-03-01

    A particular edge-dependent inversion current behavior of metal-oxide-semiconductor (MOS) tunneling diodes was investigated utilizing square and comb-shaped electrodes. The inversion tunneling current exhibits the strong dependence on the tooth size of comb-shaped electrodes and oxide thickness. Detailed illustrations of current conduction mechanism are developed by simulation and experimental measurement results. It is found that the electron diffusion current and Schottky barrier height lowering for hole tunneling current both contribute on inversion current conduction. In MOS tunneling photodiode applications, the photoresponse can be improved by decreasing SiO2 thickness and using comb-shaped electrodes with smaller tooth spacing. Meantime, the high and steady photosensitivity can also be approached by introducing HfO2 into dielectric stacks.

  20. Interface trap density and mobility extraction in InGaAs buried quantum well metal-oxide-semiconductor field-effect-transistors by gated Hall method

    SciTech Connect

    Chidambaram, Thenappan; Madisetti, Shailesh; Greene, Andrew; Yakimov, Michael; Tokranov, Vadim; Oktyabrsky, Serge; Veksler, Dmitry; Hill, Richard

    2014-03-31

    In this work, we are using a gated Hall method for measurement of free carrier density and electron mobility in buried InGaAs quantum well metal-oxide-semiconductor field-effect-transistor channels. At room temperature, mobility over 8000 cm{sup 2}/Vs is observed at ∼1.4 × 10{sup 12} cm{sup −2}. Temperature dependence of the electron mobility gives the evidence that remote Coulomb scattering dominates at electron density <2 × 10{sup 11} cm{sup −2}. Spectrum of the interface/border traps is quantified from comparison of Hall data with capacitance-voltage measurements or electrostatic modeling. Above the threshold voltage, gate control is strongly limited by fast traps that cannot be distinguished from free channel carriers just by capacitance-based methods and can be the reason for significant overestimation of channel density and underestimation of carrier mobility from transistor measurements.

  1. III-V-on-nothing metal-oxide-semiconductor field-effect transistors enabled by top-down nanowire release process: Experiment and simulation

    NASA Astrophysics Data System (ADS)

    Gu, J. J.; Koybasi, O.; Wu, Y. Q.; Ye, P. D.

    2011-09-01

    III-V-on-nothing (III-VON) metal-oxide-semiconductor field-effect transistors (MOSFETs) are experimentally demonstrated with In0.53Ga0.47As as channel and atomic layer deposited Al2O3 as gate dielectric. A hydrochloric acid based release process has been developed to create an air gap beneath the InGaAs channel layer, forming the nanowire channel with width down to 40 nm. III-VON MOSFETs with channel lengths down to 50 nm are fabricated and show promising improvement in drain-induced barrier lowering, due to suppressed short-channel effects. The top-down processing technique provides a viable pathway towards fully gate-all-around III-V MOSFETs.

  2. Achieving low parasitic resistance in Ge p-channel metal-oxide-semiconductor field-effect transistors by ion implantation after germanidation

    NASA Astrophysics Data System (ADS)

    Hsin Chang, Wen; Ota, Hiroyuki; Maeda, Tatsuro

    2015-05-01

    The parasitic resistance (Rpara) of Ge p-channel metal-oxide-semiconductor field-effect transistors (p-MOSFETs) fabricated by ion implantation after germanidation (IAG) has been investigated by varying the drive-in annealing temperature. The lowest Rpara of 835 Ω µm was achieved after 450 °C drive-in annealing for 1 min. Boron segregation between NiGe and Ge induced by drive-in annealing has advantages in forming an abrupt metallic source/drain (S/D) junction and contributes to the decrease in Rpara. The appropriate process window for fabricating Ge p-MOSFETs by IAG was also given. IAG, a pathway for introducing a Ge channel into CMOS technology beyond the 10 nm node, was proved to be effective for reducing Rpara.

  3. Device and Circuit Codesign Strategy for Application to Low-Noise Amplifier Based on Silicon Nanowire Metal-Oxide-Semiconductor Field Effect Transistors

    NASA Astrophysics Data System (ADS)

    Seongjae Cho,; Hee-Sauk Jhon,; Jung Hoon Lee,; Se Hwan Park,; Hyungcheol Shin,; Byung-Gook Park,

    2010-04-01

    In this study, a full-range approach from device level to circuit level design is performed for RF application of silicon nanowire (SNW) metal-oxide-semiconductor field effect transistors (MOSFETs). Both DC and AC analyses have been conducted to confirm the advantages of an SNW MOSFET over the conventional planar (CPL) MOSFET device having dimensional equivalence. Besides the intrinsic characteristic parameters, the extrinsic resistance and capacitance caused by wiring components are extracted from each device. On the basis of these intrinsic and extrinsic parameters, a multi-fingered 5.8 GHz low-noise amplifier (LNA) design adopting SNW MOSFETs has been achieved, which shows an improved gain of 17.5 dB and a noise figure of 3.1 dB over a CPL MOSFET LNA.

  4. Effects of stress annealing in nitrogen on the index of refraction of silicon dioxide layers in metal-oxide-semiconductor devices

    NASA Astrophysics Data System (ADS)

    Massoud, Hisham Z.; Przewlocki, Henryk M.

    2002-08-01

    In this article, we report the results of a study of the effects of high-temperature stress annealing in nitrogen on the index of refraction of SiO2 layers in metal/oxide/semiconductor (MOS) devices. In this study, we have experimentally characterized the dependence of mechanical stress in the Si-SiO2 system on the oxidation and annealing conditions and correlated such properties with the dependence of the index of refraction on processing conditions and oxide thickness. We consider the contributions of the thermal-relaxation and nitrogen-incorporation processes in determining changes in the index of refraction with annealing time. This description is consistent with other annealing studies carried out in argon where only the thermal-relaxation process is present. Correlations of these experimental observations with the electrical properties of the same MOS devices are presented in a companion article.

  5. Spin-dependent transport properties of a GaMnAs-based vertical spin metal-oxide-semiconductor field-effect transistor structure

    SciTech Connect

    Kanaki, Toshiki Asahara, Hirokatsu; Ohya, Shinobu Tanaka, Masaaki

    2015-12-14

    We fabricate a vertical spin metal-oxide-semiconductor field-effect transistor (spin-MOSFET) structure, which is composed of an epitaxial single-crystal heterostructure with a ferromagnetic-semiconductor GaMnAs source/drain, and investigate its spin-dependent transport properties. We modulate the drain-source current I{sub DS} by ∼±0.5% with a gate-source voltage of ±10.8 V and also modulate I{sub DS} by up to 60% with changing the magnetization configuration of the GaMnAs source/drain at 3.5 K. The magnetoresistance ratio is more than two orders of magnitude higher than that obtained in the previous studies on spin MOSFETs. Our result shows that a vertical structure is one of the hopeful candidates for spin MOSFET when the device size is reduced to a sub-micron or nanometer scale.

  6. Quasi-two-dimensional threshold voltage model for junctionless cylindrical surrounding gate metal-oxide-semiconductor field-effect transistor with dual-material gate

    NASA Astrophysics Data System (ADS)

    Li, Cong; Zhuang, Yi-Qi; Zhang, Li; Jin, Gang

    2014-01-01

    Based on the quasi-two-dimensional (2D) solution of Poisson's equation in two continuous channel regions, an analytical threshold voltage model for short-channel junctionless dual-material cylindrical surrounding-gate (JLDMCSG) metal-oxide-semiconductor field-effect transistor (MOSFET) is developed. Using the derived model, channel potential distribution, horizontal electrical field distribution, and threshold voltage roll-off of JLDMCSG MOSFET are investigated. Compared with junctionless single-material CSG (JLSGCSG) MOSFET, JLDMCSG MOSFET can effectively suppress short-channel effects and simultaneously improve carrier transport efficiency. It is also revealed that threshold voltage roll-off of JLDMCSG can be significantly reduced by adopting both a small oxide thickness and a small silicon channel radius. The model is verified by comparing its calculated results with that obtained from three-dimensional (3D) numerical device simulator ISE.

  7. Direct x-ray imaging system using an amplified metal-oxide-semiconductor imager in the 4-13-nm wavelength region

    NASA Astrophysics Data System (ADS)

    Haga, Tsuneyuki; Kinoshita, Hiroo

    1995-10-01

    We describe a direct x-ray imaging system that uses an amplified metal-oxide-semiconductor imager to detect soft x rays directly for real-time imaging. From the absolute sensitivity of this system as measured through the use of a monochromatic synchrotron radiation beam and a GaAsP Schottky-type photodiode, the minimum sensitivity at a wavelength of 13 nm was estimated to be greater than 108 photons mm-2. This is sufficient to detect soft x rays directly for real-time imaging. Onion cell observations at wavelengths of 4.3 and 4.6 nm indicate that x-ray absorption by the carbon in the cells was detected. This is a promising imaging system for the soft x-ray region in which conventional CCD's are difficult to use.

  8. Multi-frequency inversion-charge pumping for charge separation and mobility analysis in high-k/InGaAs metal-oxide-semiconductor field-effect transistors

    SciTech Connect

    Djara, V.; Cherkaoui, K.; Negara, M. A.; Hurley, P. K.

    2015-11-28

    An alternative multi-frequency inversion-charge pumping (MFICP) technique was developed to directly separate the inversion charge density (N{sub inv}) from the trapped charge density in high-k/InGaAs metal-oxide-semiconductor field-effect transistors (MOSFETs). This approach relies on the fitting of the frequency response of border traps, obtained from inversion-charge pumping measurements performed over a wide range of frequencies at room temperature on a single MOSFET, using a modified charge trapping model. The obtained model yielded the capture time constant and density of border traps located at energy levels aligned with the InGaAs conduction band. Moreover, the combination of MFICP and pulsed I{sub d}-V{sub g} measurements enabled an accurate effective mobility vs N{sub inv} extraction and analysis. The data obtained using the MFICP approach are consistent with the most recent reports on high-k/InGaAs.

  9. Impact of drift gap, N-layer, and deep N+ sinker on breakdown voltage and saturation current of lateral double-diffused metal oxide semiconductor transistor.

    PubMed

    Sung, Kunsik; Won, Taeyoung

    2011-08-01

    In this paper, we discuss on the optimal design of a High-Side n-channel Lateral Double-diffused Metal Oxide Semiconductor Field Effect Transistor (LDMOSFET) whose breakdown voltage is over 100 V with 0.35 microm Bipolar-CMOS-DMOS (BCD) process. The proposed nLDMOSFET has been fabricated and tested in order to confirm the features of a deep N+ sinker and a gap of between the drift region (DEEP N-WELL) and the center of the source. The surface is implanted by the N-layer for high breakdown voltage and simultaneously the low specific on-resistance. The computer simulation of the proposed High-Side LDMOS exhibits BVdss of 115 V and Ron,sp of as low as 2.20 m ohms cm2, which is consistent with the experimental results.

  10. Direct observation of both contact and remote oxygen scavenging of GeO{sub 2} in a metal-oxide-semiconductor stack

    SciTech Connect

    Fadida, S. Shekhter, P.; Eizenberg, M.; Cvetko, D.; Floreano, L.; Verdini, A.; Kymissis, I.

    2014-10-28

    In the path to incorporating Ge based metal-oxide-semiconductor into modern nano-electronics, one of the main issues is the oxide-semiconductor interface quality. Here, the reactivity of Ti on Ge stacks and the scavenging effect of Ti were studied using synchrotron X-ray photoelectron spectroscopy measurements, with an in-situ metal deposition and high resolution transmission electron microscopy imaging. Oxygen removal from the Ge surface was observed both in direct contact as well as remotely through an Al{sub 2}O{sub 3} layer. The scavenging effect was studied in situ at room temperature and after annealing. We find that the reactivity of Ti can be utilized for improved scaling of Ge based devices.

  11. Effect of nitrogen incorporation into Al-based gate insulators in AlON/AlGaN/GaN metal-oxide-semiconductor structures

    NASA Astrophysics Data System (ADS)

    Asahara, Ryohei; Nozaki, Mikito; Yamada, Takahiro; Ito, Joyo; Nakazawa, Satoshi; Ishida, Masahiro; Ueda, Tetsuzo; Yoshigoe, Akitaka; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

    2016-10-01

    The superior physical and electrical properties of aluminum oxynitride (AlON) gate dielectrics on AlGaN/GaN substrates in terms of thermal stability, reliability, and interface quality were demonstrated by direct AlON deposition and subsequent annealing. Nitrogen incorporation into alumina was proven to be beneficial both for suppressing intermixing at the insulator/AlGaN interface and reducing the number of electrical defects in Al2O3 films. Consequently, we achieved high-quality AlON/AlGaN/GaN metal-oxide-semiconductor capacitors with improved stability against charge injection and a reduced interface state density as low as 1.2 × 1011 cm-2 eV-1. The impact of nitrogen incorporation into the insulator will be discussed on the basis of experimental findings.

  12. INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Quantum-Mechanical Study on Surrounding-Gate Metal-Oxide-Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Hu, Guang-Xi; Wang, Ling-Li; Liu, Ran; Tang, Ting-Ao; Qiu, Zhi-Jun

    2010-10-01

    As the channel length of metal-oxide-semiconductor field-effect transistors (MOSFETs) scales into the nanometer regime, quantum mechanical effects are becoming more and more significant. In this work, a model for the surrounding-gate (SG) nMOSFET is developed. The Schrödinger equation is solved analytically. Some of the solutions are verified via results obtained from simulations. It is found that the percentage of the electrons with lighter conductivity mass increases as the silicon body radius decreases, or as the gate voltage reduces, or as the temperature decreases. The centroid of inversion-layer is driven away from the silicon-oxide interface towards the silicon body, therefore the carriers will suffer less scattering from the interface and the electrons effective mobility of the SG nMOSFETs will be enhanced.

  13. Electrical characteristics and thermal stability of HfO{sub 2} metal-oxide-semiconductor capacitors fabricated on clean reconstructed GaSb surfaces

    SciTech Connect

    Miyata, Noriyuki Mori, Takahiro; Yasuda, Tetsuji; Ohtake, Akihiro; Ichikawa, Masakazu

    2014-06-09

    HfO{sub 2}/GaSb interfaces fabricated by high-vacuum HfO{sub 2} deposition on clean reconstructed GaSb surfaces were examined to explore a thermally stable GaSb metal-oxide-semiconductor structure with low interface-state density (D{sub it}). Interface Sb-O bonds were electrically and thermally unstable, and post-metallization annealing at temperatures higher than 200 °C was required to stabilize the HfO{sub 2}/GaSb interfaces. However, the annealing led to large D{sub it} in the upper-half band gap. We propose that the decomposition products that are associated with elemental Sb atoms act as interface states, since a clear correlation between the D{sub it} and the Sb coverage on the initial GaSb surfaces was observed.

  14. Improvement in C-V characteristics of Ge metal-oxide semiconductor capacitor by H2O2 incorporated HCl pretreatment

    NASA Astrophysics Data System (ADS)

    Kamata, Yoshiki; Ino, Tsunehiro; Koyama, Masato; Nishiyama, Akira

    2008-02-01

    Electrical characteristics of high-κ /Ge metal-oxide semiconductor (MOS) capacitors pretreated with HCl or HF solutions are investigated, including the effect of H2O2 incorporation. HCl treatment is more effective than HF treatment for decreasing equivalent oxide thickness. H2O2 incorporation into HCl solution leads to dramatic decrease in the capacitance at inversion side. We have confirmed that residual metal impurities are reduced below 1010atoms/cm2 on the Ge surface after pretreatment with mixed solution of HCl and H2O2. We conclude that decrease in metal impurities at Ge surface is responsible for the superior C-V characteristic of Ge MOS capacitor.

  15. Evaluation of a gate-first process for AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors with low ohmic annealing temperature

    NASA Astrophysics Data System (ADS)

    Liuan, Li; Jiaqi, Zhang; Yang, Liu; Jin-Ping, Ao

    2016-03-01

    In this paper, TiN/AlOx gated AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors (MOS-HFETs) were fabricated for gate-first process evaluation. By employing a low temperature ohmic process, ohmic contact can be obtained by annealing at 600 °C with the contact resistance approximately 1.6 Ω·mm. The ohmic annealing process also acts as a post-deposition annealing on the oxide film, resulting in good device performance. Those results demonstrated that the TiN/AlOx gated MOS-HFETs with low temperature ohmic process can be applied for self-aligned gate AlGaN/GaN MOS-HFETs. Project supported by the International Science and Technology Collaboration Program of China (Grant No. 2012DFG52260).

  16. Origin of the performances degradation of two-dimensional-based metal-oxide-semiconductor field effect transistors in the sub-10 nm regime: A first-principles study

    NASA Astrophysics Data System (ADS)

    Lu, Anh Khoa Augustin; Pourtois, Geoffrey; Agarwal, Tarun; Afzalian, Aryan; Radu, Iuliana P.; Houssa, Michel

    2016-01-01

    The impact of the scaling of the channel length on the performances of metal-oxide-semiconductor field effect transistors, based on two-dimensional (2D) channel materials, is theoretically investigated, using density functional theory combined with the non-equilibrium Green's function method. It is found that the scaling of the channel length below 10 nm leads to strong device performance degradations. Our simulations reveal that this degradation is essentially due to the tunneling current flowing between the source and the drain in these aggressively scaled devices. It is shown that this electron tunneling process is modulated by the effective mass of the 2D channel material, and sets the limit of the scaling in future transistor designs.

  17. Magnetically modulated laser-induced resistance effect observed in Metal-Oxide-Semiconductor structure of Cr/SiO(2)/Si.

    PubMed

    Xie, Xin; Liu, Shuai; Huang, Meizhen; Wang, Hui

    2015-09-21

    In this study, we report our finding of laser-induced resistance effect in metal-oxide-semiconductor (MOS) structure of Cr/SiO(2)/Si. Under the irradiation of a laser beam, the effect shows a large linear resistance change ratio of 92% with a spatial sensitivity of 0.79 MΩ/mm. In particular, by the application of an external magnetic field perpendicular to the Cr film, the resistance change ratio is increased to 110%. This effect is attributed to the Lorentz force acting on the photo-generated carriers in the inversion layer of MOS structures. The work suggests an approach for the development of new type magnetically modulated photoelectric devices.

  18. 0.5 μm Silicon-on-Sapphire Metal Oxide Semiconductor Field Effect Transistor for RF Power Amplifier Applications

    NASA Astrophysics Data System (ADS)

    Tsui, Kenneth; Chen, Kevin J.; Lam, Sang; Chan, Mansun

    2003-08-01

    0.5 μm thin-film silicon-on-sapphire (SOS) metal oxide semiconductor field effect transistors (MOSFETs) are investigated for applications in RF power amplifiers. Detailed static and pulsed I-V characteristics are measured to distinguish between fully depleted and partially depleted SOS MOSFETs. We have performed the first detailed large-signal load-pull characterization of SOS MOSFETs at 2 GHz with a Maury load-pull system with automated tuners. The maximum output power (Pout) of 18 dBm, maximum gain (G) of 12.5 dB and maximum power-added efficiency (PAE) of 55% were achieved. Third-order intermodulation (IM3) and adjacent channel power ratio (ACPR) were measured to characterize the linearity of an SOS MOSFET power amplifier. For the optimum design of RF power amplifiers, impedance matching information is essential as revealed by the large-signal load-pull measurements.

  19. Electrical hysteresis in p-GaN metal-oxide-semiconductor capacitor with atomic-layer-deposited Al2O3 as gate dielectric

    NASA Astrophysics Data System (ADS)

    Zhang, Kexiong; Liao, Meiyong; Imura, Masataka; Nabatame, Toshihide; Ohi, Akihiko; Sumiya, Masatomo; Koide, Yasuo; Sang, Liwen

    2016-12-01

    The electrical hysteresis in current-voltage (I-V) and capacitance-voltage characteristics was observed in an atomic-layer-deposited Al2O3/p-GaN metal-oxide-semiconductor capacitor (PMOSCAP). The absolute minimum leakage currents of the PMOSCAP for forward and backward I-V scans occurred not at 0 V but at -4.4 and +4.4 V, respectively. A negative flat-band voltage shift of 5.5 V was acquired with a capacitance step from +4.4 to +6.1 V during the forward scan. Mg surface accumulation on p-GaN was demonstrated to induce an Mg-Ga-Al-O oxidized layer with a trap density on the order of 1013 cm-2. The electrical hysteresis is attributed to the hole trapping and detrapping process in the traps of the Mg-Ga-Al-O layer via the Poole-Frenkel mechanism.

  20. Influence of interface traps inside the conduction band on the capacitance-voltage characteristics of InGaAs metal-oxide-semiconductor capacitors

    NASA Astrophysics Data System (ADS)

    Taoka, Noriyuki; Yokoyama, Masafumi; Kim, Sang Hyeon; Suzuki, Rena; Iida, Ryo; Takenaka, Mitsuru; Takagi, Shinichi

    2016-11-01

    We investigated the influences of the AC response with interface/bulk-oxide traps near the conduction band (CB) and a low effective density of states (DOS) on the accumulation capacitance C acc of an n-type InGaAs metal-oxide-semiconductor (MOS) capacitor. We found that the capacitance associated with the interface traps inside the CB significantly increases C acc compared to the C acc value constrained by a low DOS. These results indicate that accurate characterization inside the CB and considering the capacitance due to the interface traps inside the CB in the MOS capacitance-voltage curves are indispensable for accurate characterization of InGaAs MOS interface properties.

  1. Radio Frequency Performance Improvement with Drain Bias and Limiting Factors of 65-nm-Node Radio Frequency Metal-Oxide-Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Kao, Hsuan-ling; Lu, Chia-Ling; Chang, Yung-Cheng

    2009-01-01

    With the continuous down scaling of radio frequency metal-oxide-semiconductor field-effect transistors (RF MOSFETs) into a 65 nm node, the RF performance of unity-gain cutoff frequency ( fT), the maximum frequency of oscillation ( fmax), and the minimum noise figure (NFmin) show much smaller dependences on short-channel effects due to increases in drain current and transconductance (gm), which originate from the short-channel effects. We have studied the effect of drain bias on the RF performance of 65-nm-node MOSFETs. Both the fT and NFmin improve linearly with increasing drain voltage, in contrast with their independence on drain bias in longer-channel devices. Additionally, although fT improves continuously in sub-65-nm node devices, fmax and NFmin deteriorate more in 65-nm-node transistors than in 90-nm-node devices owing to a limiting parasitic effect.

  2. Investigation of Stress Memorization Process on Low-Frequency Noise Performance for Strained Si n-Type Metal-Oxide-Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Kuo, Cheng-Wen; Wu, San-Lein; Lin, Hau-Yu; Huang, Yao-Tsung; Chang, Shoou-Jinn; Hong, De-Gong; Wu, Chung-Yi; Cheng, Yao-Chin; Cheng, Osbert

    2011-04-01

    The use of low-frequency (1/f) noise to evaluate low-cost stress-memorization technique (SMT) induced-stress in n-type metal-oxide-semiconductor field-effect transistors has been investigated. As compared to device without SMT process, the comparable 1/f noise level obtained for strained Si devices with the low-cost SMT process indicates that adding the low-cost SMT process will not affect the Si/SiO2 interface quality. Moreover, through observing experiment result and Hooge's parameter αH, the mechanism of 1/f noise in the both devices can be properly interpreted by the carrier number fluctuations correlated mobility fluctuations (unified model).

  3. Temperature-independent switching rates for a random telegraph signal in a silicon metal-oxide-semiconductor field-effect transistor at low temperatures

    SciTech Connect

    Scofield, John H.; Borland, Nick; Fleetwood, D. M.

    2000-05-29

    We have observed discrete random telegraph signals (RTSs) in the drain voltages of three, nominally 1.25 {mu}mx1.25 {mu}m, enhancement-mode p-channel metal-oxide-semiconductor transistors operated in strong inversion in their linear regimes with constant drain-current and gate-voltage bias, for temperatures ranging from 4.2 to 300 K. The switching rates for all RTSs observed above 30 K were thermally activated. The switching rate for the only RTS observed below 30 K was thermally activated above 30 K but temperature independent below 10 K. This response is consistent with a crossover from thermal activation to tunneling at low temperatures. Implications are discussed for models of change exchange between the Si and the near-interfacial SiO{sub 2}. (c) 2000 American Institute of Physics.

  4. The influence of electron energy quantization in a space-charge region on the accumulation capacitance of InAs metal-oxide-semiconductor capacitors

    SciTech Connect

    Kovchavtsev, A. P. Tsarenko, A. V.; Guzev, A. A.; Polovinkin, V. G.; Nastovjak, A. E.; Valisheva, N. A.; Aksenov, M. S.

    2015-09-28

    The influence of electron energy quantization in a space-charge region on the accumulation capacitance of the InAs-based metal-oxide-semiconductor capacitors (MOSCAPs) has been investigated by modeling and comparison with the experimental data from Au/anodic layer(4-20 nm)/n-InAs(111)A MOSCAPs. The accumulation capacitance for MOSCAPs has been calculated by the solution of Poisson equation with different assumptions and the self-consistent solution of Schrödinger and Poisson equations with quantization taken into account. It was shown that the quantization during the MOSCAPs accumulation capacitance calculations should be taken into consideration for the correct interface states density determination by Terman method and the evaluation of gate dielectric thickness from capacitance-voltage measurements.

  5. Commercialisation of CMOS Integrated Circuit Technology in Multi-Electrode Arrays for Neuroscience and Cell-Based Biosensors

    PubMed Central

    Graham, Anthony H. D.; Robbins, Jon; Bowen, Chris R.; Taylor, John

    2011-01-01

    The adaptation of standard integrated circuit (IC) technology as a transducer in cell-based biosensors in drug discovery pharmacology, neural interface systems and electrophysiology requires electrodes that are electrochemically stable, biocompatible and affordable. Unfortunately, the ubiquitous Complementary Metal Oxide Semiconductor (CMOS) IC technology does not meet the first of these requirements. For devices intended only for research, modification of CMOS by post-processing using cleanroom facilities has been achieved. However, to enable adoption of CMOS as a basis for commercial biosensors, the economies of scale of CMOS fabrication must be maintained by using only low-cost post-processing techniques. This review highlights the methodologies employed in cell-based biosensor design where CMOS-based integrated circuits (ICs) form an integral part of the transducer system. Particular emphasis will be placed on the application of multi-electrode arrays for in vitro neuroscience applications. Identifying suitable IC packaging methods presents further significant challenges when considering specific applications. The various challenges and difficulties are reviewed and some potential solutions are presented. PMID:22163884

  6. Commercialisation of CMOS integrated circuit technology in multi-electrode arrays for neuroscience and cell-based biosensors.

    PubMed

    Graham, Anthony H D; Robbins, Jon; Bowen, Chris R; Taylor, John

    2011-01-01

    The adaptation of standard integrated circuit (IC) technology as a transducer in cell-based biosensors in drug discovery pharmacology, neural interface systems and electrophysiology requires electrodes that are electrochemically stable, biocompatible and affordable. Unfortunately, the ubiquitous Complementary Metal Oxide Semiconductor (CMOS) IC technology does not meet the first of these requirements. For devices intended only for research, modification of CMOS by post-processing using cleanroom facilities has been achieved. However, to enable adoption of CMOS as a basis for commercial biosensors, the economies of scale of CMOS fabrication must be maintained by using only low-cost post-processing techniques. This review highlights the methodologies employed in cell-based biosensor design where CMOS-based integrated circuits (ICs) form an integral part of the transducer system. Particular emphasis will be placed on the application of multi-electrode arrays for in vitro neuroscience applications. Identifying suitable IC packaging methods presents further significant challenges when considering specific applications. The various challenges and difficulties are reviewed and some potential solutions are presented.

  7. Spectroscopic analysis on metal-oxide-semiconductor light-emitting diodes with buried Si nanocrystals and nano-pyramids in SiO(x) film.

    PubMed

    Lin, Gong-Ru

    2008-03-01

    The difference between the white and near-infrared electroluminescence of metal-oxide-semiconductor light-emitting diodes fabricated on 1,100 degrees C-annealed Si-rich SiO(x)/p-Si substrate with interfacial pyramidal Si dots (Si nano-pyramids) was characterized. By changing the substrate temperature and induced coupled plasma power during the plasma enhanced chemical vapor deposition of Si-rich SiO(x) films, the effects of the growth conditions on the defect- and Si nano-pyramid-related carrier transport and Si nanocrystal-related electroluminescence spectroscopy were also investigated. The annealed Si-rich SiO(x)/p-Si films grown at higher synthesized substrate temperate (350 degrees C) show the larger Si nano-pyramids precipitating near the Si/SiO2 interface. The indium tin oxide/Si-rich SiO(x)/p-Si/Al metal-oxide-semiconductor light-emitting diodes with Si-rich SiO(x) films exhibit different white-light electroluminescence spectra at wavelengths from 400 to 650 nm. The Si nanocrystal-related electroluminescence spectra at 650-850 nm are confirmed, whereas the electroluminescence spectra are shorter wavelengths is attributed to oxygen related defects. These defects become an electron-preferred transporting path within the Si-rich SiO(x) film, whose densities are decreased by increasing the substrate temperature or reducing the induced coupled plasma power. Defect-related white-light electroluminescence emits power for a relatively short lifetime. The lifetime can be lengthened and the electroluminescence power can be raised simultaneously by increasing deposition temperature to 350 degrees C and adjusting the induced coupled plasma power to a threshold of 30 W, which effectively increases the densities of Si nanocrystals and nano-pyramids in the Si-rich SiO(x) film with Si concentration of up to 40 at%. A nearly defect-free Si-rich SiO(x) sample can be grown under such conditions, which contributes to the most stable and largest near-infrared electroluminescence

  8. Biosensors.

    ERIC Educational Resources Information Center

    Rechnitz, Garry A.

    1988-01-01

    Describes theory and principles behind biosensors that incorporate biological components as part of a sensor or probe. Projects major applications in medicine and veterinary medicine, biotechnology, food and agriculture, environmental studies, and the military. Surveys current use of biosensors. (ML)

  9. P-Channel InGaN/GaN heterostructure metal-oxide-semiconductor field effect transistor based on polarization-induced two-dimensional hole gas

    PubMed Central

    Zhang, Kexiong; Sumiya, Masatomo; Liao, Meiyong; Koide, Yasuo; Sang, Liwen

    2016-01-01

    The concept of p-channel InGaN/GaN heterostructure field effect transistor (FET) using a two-dimensional hole gas (2DHG) induced by polarization effect is demonstrated. The existence of 2DHG near the lower interface of InGaN/GaN heterostructure is verified by theoretical simulation and capacitance-voltage profiling. The metal-oxide-semiconductor FET (MOSFET) with Al2O3 gate dielectric shows a drain-source current density of 0.51 mA/mm at the gate voltage of −2 V and drain bias of −15 V, an ON/OFF ratio of two orders of magnitude and effective hole mobility of 10 cm2/Vs at room temperature. The normal operation of MOSFET without freeze-out at 8 K further proves that the p-channel behavior is originated from the polarization-induced 2DHG. PMID:27021054

  10. Impact of oxygen plasma postoxidation process on Al2O3/n-In0.53Ga0.47As metal-oxide-semiconductor capacitors

    NASA Astrophysics Data System (ADS)

    Lechaux, Y.; Fadjie-Djomkam, A. B.; Bollaert, S.; Wichmann, N.

    2016-09-01

    Capacitance-voltage (C-V) measurements and x-ray photoelectron spectroscopy (XPS) analysis were performed in order to investigate the effect of a oxygen (O2) plasma after oxide deposition on the Al2O3/n-In0.53Ga0.47As metal-oxide-semiconductor structure passivated with ammonia NH4OH solution. From C-V measurements, an improvement of charge control is observed using the O2 plasma postoxidation process on In0.53Ga0.47As, while the minimum of interface trap density remains at a good value lower than 1 × 1012 cm-2 eV-1. From XPS measurements, we found that NH4OH passivation removes drastically the Ga and As native oxides on the In0.53Ga0.47As surface and the O2 plasma postoxidation process enables the reduction of interface re-oxidation after post deposition annealing (PDA) of the oxide. The advanced hypothesis is the formation of interfacial barrier between Al2O3 and In0.53Ga0.47As which prevents the diffusion of oxygen species into the semiconductor surface during PDA.

  11. Effects of substrate voltage on noise characteristics and hole lifetime in SOI metal-oxide-semiconductor field-effect transistor photon detector.

    PubMed

    Putranto, Dedy Septono Catur; Priambodo, Purnomo Sidi; Hartanto, Djoko; Du, Wei; Satoh, Hiroaki; Ono, Atsushi; Inokawa, Hiroshi

    2014-09-08

    Low-frequency noise and hole lifetime in silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFETs) are analyzed, considering their use in photon detection based on single-hole counting. The noise becomes minimum at around the transition point between front- and back-channel operations when the substrate voltage is varied, and increases largely on both negative and positive sides of the substrate voltage showing peculiar Lorentzian (generation-recombination) noise spectra. Hole lifetime is evaluated by the analysis of drain current histogram at different substrate voltages. It is found that the peaks in the histogram corresponding to the larger number of stored holes become higher as the substrate bias becomes larger. This can be attributed to the prolonged lifetime caused by the higher electric field inside the body of SOI MOSFET. It can be concluded that, once the inversion channel is induced for detection of the photo-generated holes, the small absolute substrate bias is favorable for short lifetime and low noise, leading to high-speed operation.

  12. Improved interface properties of GaN metal-oxide-semiconductor device with non-polar plane and AlN passivation layer

    NASA Astrophysics Data System (ADS)

    Wu, Xian; Liang, Renrong; Guo, Lei; Liu, Lei; Xiao, Lei; Shen, Shanshan; Xu, Jun; Wang, Jing

    2016-12-01

    Utilizing a non-polar plane substrate and an ultra-thin AlN passivation layer results in significantly improved interface properties of a GaN metal-oxide-semiconductor (MOS) device. After depositing an Al2O3 gate dielectric layer on GaN substrates with polar c-plane and non-polar m-plane surfaces, it is found that the devices on the non-polar surface show much better interface properties than those on the polar surface. To further improve the interface properties, an amorphous ultra-thin AlN layer is deposited on the substrate before the Al2O3 deposition. The interface properties of both devices on the c-plane and m-plane are dramatically improved by the AlN passivation layer. The interface trap density of the Al/Al2O3/AlN/GaN MOS capacitor on the non-polar surface is reduced by two orders of magnitude compared to that on the polar surface.

  13. Passivation of oxide traps and interface states in GaAs metal-oxide-semiconductor capacitor by LaTaON passivation layer and fluorine incorporation

    SciTech Connect

    Liu, L. N.; Choi, H. W.; Lai, P. T.; Xu, J. P.

    2015-11-23

    GaAs metal-oxide-semiconductor capacitor with TaYON/LaTaON gate-oxide stack and fluorine-plasma treatment is fabricated and compared with its counterparts without the LaTaON passivation interlayer or the fluorine treatment. Experimental results show that the sample exhibits better characteristics: low interface-state density (8 × 10{sup 11 }cm{sup −2}/eV), small flatband voltage (0.69 V), good capacitance-voltage behavior, small frequency dispersion, and small gate leakage current (6.35 × 10{sup −6} A/cm{sup 2} at V{sub fb} + 1 V). These should be attributed to the suppressed growth of unstable Ga and As oxides on the GaAs surface during gate-oxide annealing by the LaTaON interlayer and fluorine incorporation, and the passivating effects of fluorine atoms on the acceptor-like interface and near-interface traps.

  14. GaAs metal-oxide-semiconductor based non-volatile flash memory devices with InAs quantum dots as charge storage nodes

    SciTech Connect

    Islam, Sk Masiul Chowdhury, Sisir; Sarkar, Krishnendu; Nagabhushan, B.; Banerji, P.; Chakraborty, S.

    2015-06-24

    Ultra-thin InP passivated GaAs metal-oxide-semiconductor based non-volatile flash memory devices were fabricated using InAs quantum dots (QDs) as charge storing elements by metal organic chemical vapor deposition technique to study the efficacy of the QDs as charge storage elements. The grown QDs were embedded between two high-k dielectric such as HfO{sub 2} and ZrO{sub 2}, which were used for tunneling and control oxide layers, respectively. The size and density of the QDs were found to be 5 nm and 1.8×10{sup 11} cm{sup −2}, respectively. The device with a structure Metal/ZrO{sub 2}/InAs QDs/HfO{sub 2}/GaAs/Metal shows maximum memory window equivalent to 6.87 V. The device also exhibits low leakage current density of the order of 10{sup −6} A/cm{sup 2} and reasonably good charge retention characteristics. The low value of leakage current in the fabricated memory device is attributed to the Coulomb blockade effect influenced by quantum confinement as well as reduction of interface trap states by ultra-thin InP passivation on GaAs prior to HfO{sub 2} deposition.

  15. AlGaN/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistor with Polarized P(VDF-TrFE) Ferroelectric Polymer Gating

    PubMed Central

    Liu, Xinke; Lu, Youming; Yu, Wenjie; Wu, Jing; He, Jiazhu; Tang, Dan; Liu, Zhihong; Somasuntharam, Pannirselvam; Zhu, Deliang; Liu, Wenjun; Cao, Peijiang; Han, Sun; Chen, Shaojun; Seow Tan, Leng

    2015-01-01

    Effect of a polarized P(VDF-TrFE) ferroelectric polymer gating on AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) was investigated. The P(VDF-TrFE) gating in the source/drain access regions of AlGaN/GaN MOS-HEMTs was positively polarized (i.e., partially positively charged hydrogen were aligned to the AlGaN surface) by an applied electric field, resulting in a shift-down of the conduction band at the AlGaN/GaN interface. This increases the 2-dimensional electron gas (2-DEG) density in the source/drain access region of the AlGaN/GaN heterostructure, and thereby reduces the source/drain series resistance. Detailed material characterization of the P(VDF-TrFE) ferroelectric film was also carried out using the atomic force microscopy (AFM), X-ray Diffraction (XRD), and ferroelectric hysteresis loop measurement. PMID:26364872

  16. AlGaN/GaN metal oxide semiconductor heterostructure field-effect transistors with 4 nm thick Al2O3 gate oxide

    NASA Astrophysics Data System (ADS)

    Gregušová, D.; Stoklas, R.; Čičo, K.; Lalinský, T.; Kordoš, P.

    2007-08-01

    AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors (MOSHFETs) with 4 nm thick Al2O3 gate oxide were prepared and their performance was compared with that of AlGaN/GaN HFETs. The MOSHFETs yielded ~40% increase of the saturation drain current compared with the HFETs, which is larger than expected due to the gate oxide passivation. Despite a larger gate-channel separation in the MOSHFETs, a higher extrinsic transconductance than that of the HFETs was measured. The drift mobility of the MOSHFETs, evaluated on large-gate FET structures, was significantly higher than that of the HFETs. The zero-bias mobility for MOSHFETs and HFETs was 1950 cm2 V-1 s-1 and 1630 cm2 V-1 s-1, respectively. These features indicate an increase of the drift velocity and/or a decrease of the parasitic series resistance in the MOSHFETs. The current collapse, evaluated from pulsed I-V measurements, was highly suppressed in the MOSHFETs with 4 nm thick Al2O3 gate oxide. This result, together with the suppressed frequency dispersion of the capacitance, indicates that the density of traps in the Al2O3/AlGaN/GaN MOSHFETs was significantly reduced.

  17. Studies of Electron Beam Evaporated SiO2/AlGaN/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistors

    NASA Astrophysics Data System (ADS)

    Arulkumaran, Subramaniam; Egawa, Takashi; Ishikawa, Hiroyasu

    2005-06-01

    The metal-oxide-semiconductor high-electron-mobility transistors (MOSHEMTs) have been demonstrated and its dc characteristics were examined and compared with the conventional AlGaN/GaN HEMTs. The electron beam (EB) evaporated SiO2 layers were used as a gate-insulator. Capacitance-voltage plot of MOS contacts revealed the existence of injection type complete accumulation up to +4.0 V. The fabricated MOSHEMTs have exhibited better dc characteristics when compared with the conventional AlGaN/GaN HEMTs. The MOSHEMTs could operate at positive gate-biases as high as +4.0 V. The 2.0-μm-gate-length EB-SiO2 MOSHEMTs exhibited higher drain current density and extrinsic transconductance of 856 mA/mm and 145 mS/mm when compared to the conventional AlGaN/GaN HEMTs. The gate leakage current (IgLeak) was three orders of magnitude lower than that of the conventional AlGaN/GaN HEMTs. The stable device operations at high operating voltages with low IgLeak and high gmmax values leads to the occurrence of low trap density at EB-SiO2/AlGaN interface.

  18. Achievement of low parasitic resistance in Ge n-channel metal-oxide-semiconductor field-effect transistor using an embedded TiN-source/drain structure

    NASA Astrophysics Data System (ADS)

    Nagatomi, Y.; Tateyama, T.; Tanaka, S.; Yamamoto, K.; Wang, D.; Nakashima, H.

    2017-03-01

    We investigated the source/drain (S/D) parasitic resistance (R P) of a Ge n-channel metal-oxide-semiconductor field-effect transistor (n-MOSFET) with TiN-S/D. The R P was as high as ∼1400 Ω, which is attributed to a very thin amorphous interlayer (a-IL) at a TiN/Ge interface. To solve this problem, n-MOSFETs with an embedded S/D structure were fabricated, of which the S/D was formed by the etching of a Ge layer using 0.03%-H2O2 solution followed by TiN sputter deposition. The electrical performances were investigated for devices with etching depths in the range of 2–22 nm. The devices with etching depths of 2–5 nm did not work. The devices with etching depths of 12–15 nm showed a quite normal transistor operation, and the R P was as low as ∼130 Ω, which is comparable to that of a p-MOSFET with PtGe-S/D. However, R Ps of the devices with etching depths of ∼22 nm was considerably high. The reason for these results is discussed on the basis of an a-IL formation at the sidewall of the engraved S/D region.

  19. Ultrathin body GaSb-on-insulator p-channel metal-oxide-semiconductor field-effect transistors on Si fabricated by direct wafer bonding

    SciTech Connect

    Yokoyama, Masafumi Takenaka, Mitsuru; Takagi, Shinichi; Yokoyama, Haruki

    2015-02-16

    We have realized ultrathin body GaSb-on-insulator (GaSb-OI) on Si wafers by direct wafer bonding technology using atomic-layer deposition (ALD) Al{sub 2}O{sub 3} and have demonstrated GaSb-OI p-channel metal-oxide-semiconductor field-effect transistors (p-MOSFETs) on Si. A 23-nm-thick GaSb-OI p-MOSFET exhibits the peak effective mobility of ∼76 cm{sup 2}/V s. We have found that the effective hole mobility of the thin-body GaSb-OI p-MOSFETs decreases with a decrease in the GaSb-OI thickness or with an increase in Al{sub 2}O{sub 3} ALD temperature. The InAs passivation of GaSb-OI MOS interfaces can enhance the peak effective mobility up to 159 cm{sup 2}/V s for GaSb-OI p-MOSFETs with the 20-nm-thick GaSb layer.

  20. Light-Induced Carrier Transfer in NiSi-Nanodots/Si-Quantum-Dots Hybrid Floating Gate in Metal-Oxide-Semiconductor Structures

    NASA Astrophysics Data System (ADS)

    Morisawa, Naoya; Ikeda, Mitsuhisa; Nakanishi, Sho; Kawanami, Akira; Makihara, Katsunori; Miyazaki, Seiichi

    2010-04-01

    We have fabricated a metal-oxide-semiconductor (MOS) capacitor with a hybrid floating gate stack consisting of silicon quantum dots (Si-QDs) and NiSi Nanodots (NiSi-NDs) with a 3-nm-thick interlayer SiO2, and studied the effect of 1310 nm light irradiation on charge distribution in a hybrid floating gate. The light irradiation resulted in a reduced flat-band voltage shift due to the charging of the hybrid floating gate under the application of gate biases in comparison to the shift in the dark. This result can be interpreted in terms of the shift of the charge centroid toward the gate side in the hybrid floating gate caused by the photoexcitation of electrons in NiSi-NDs and the subsequent electron tunneling to Si-QDs. When the light irradiation was turned off, the transferred charges moved back from the Si-QDs to the NiSi-NDs without being emitted to the Si substrate.

  1. Optimization of Vertical Double-Diffused Metal-Oxide Semiconductor (VDMOS) Power Transistor Structure for Use in High Frequencies and Medical Devices

    PubMed Central

    Farhadi, Rozita; Farhadi, Bita

    2014-01-01

    Power transistors, such as the vertical, double-diffused, metal-oxide semiconductor (VDMOS), are used extensively in the amplifier circuits of medical devices. The aim of this research was to construct a VDMOS power transistor with an optimized structure to enhance the operation of medical devices. First, boron was implanted in silicon by implanting unclamped inductive switching (UIS) and a Faraday shield. The Faraday shield was implanted in order to replace the gate-field parasitic capacitor on the entry part of the device. Also, implanting the UIS was used in order to decrease the effect of parasitic bipolar junction transistor (BJT) of the VDMOS power transistor. The research tool used in this study was Silvaco software. By decreasing the transistor entry resistance in the optimized VDMOS structure, power losses and noise at the entry of the transistor were decreased, and, by increasing the breakdown voltage, the lifetime of the VDMOS transistor lifetime was increased, which resulted in increasing drain flow and decreasing Ron. This consequently resulted in enhancing the operation of high-frequency medical devices that use transistors, such as Radio Frequency (RF) and electrocardiograph machines. PMID:25763152

  2. Experimental Study of Floating-Gate-Type Metal-Oxide-Semiconductor Capacitors with Nanosize Triangular Cross-Sectional Tunnel Areas for Low Operating Voltage Flash Memory Application

    NASA Astrophysics Data System (ADS)

    Liu, Yongxun; Guo, Ruofeng; Kamei, Takahiro; Matsukawa, Takashi; Endo, Kazuhiko; O'uchi, Shinichi; Tsukada, Junichi; Yamauchi, Hiromi; Ishikawa, Yuki; Hayashida, Tetsuro; Sakamoto, Kunihiro; Ogura, Atsushi; Masahara, Meishoku

    2012-06-01

    The floating-gate (FG)-type metal-oxide-semiconductor (MOS) capacitors with planar (planar-MOS) and three-dimensional (3D) nanosize triangular cross-sectional tunnel areas (3D-MOS) have successfully been fabricated by introducing rapid thermal oxidation (RTO) and postdeposition annealing (PDA), and their electrical characteristics between the control gate (CG) and FG have been systematically compared. It was experimentally found in both planar- and 3D-MOS capacitors that the uniform and higher breakdown voltages are obtained by introducing RTO owing to the high-quality thermal oxide formation on the surface and etched edge regions of the n+ polycrystalline silicon (poly-Si) FG, and the leakage current is highly suppressed after PDA owing to the improved quality of the tetraethylorthosilicate (TEOS) silicon dioxide (SiO2) between CG and FG. Moreover, a lower breakdown voltage between CG and FG was obtained in the fabricated 3D-MOS capacitors as compared with that of planar-MOS capacitors thanks to the enhanced local electric field at the tips of triangular tunnel areas. The developed nanosize triangular cross-sectional tunnel area is useful for the fabrication of low operating voltage flash memories.

  3. Interface States and Trapping Effects in Al2O3- and ZrO2/InAlN/AlN/GaN Metal-Oxide-Semiconductor Heterostructures

    NASA Astrophysics Data System (ADS)

    Ťapajna, Milan; Kuzmík, Jan; Čičo, Karol; Pogany, Dionyz; Pozzovivo, Gianmauro; Strasser, Gottfried; Abermann, Stephan; Bertagnolli, Emmerich; Carlin, Jean-François; Grandjean, Nicolas; Fröhlich, Karol

    2009-09-01

    We investigate Al2O3- and ZrO2/InAlN/GaN metal-oxide-semiconductor heterostructures (MOS-H) using capacitance-time transients in the temperature range of 25-300 °C. A deep-level transient spectroscopy based analysis revealed the maximum interface state density distributions Dit(E) up to 3×1013 and 1×1013 eV-1 cm-2 for the Al2O3/InAlN and ZrO2/InAlN interface, respectively. The integral densities of interface states correlate well with the trapping-related gate-lag effect in corresponding InAlN/GaN MOS high electron mobility transistors (HEMTs). This explains the strongly reduced lag effect in ZrO2 MOS HEMTs. We assume hole trapping at oxide/InAlN interface to be a dominant effect responsible for the gate-lag effect in InAlN/GaN MOS HEMTs.

  4. Interface States and Trapping Effects in Al2O3- and ZrO2/InAlN/AlN/GaN Metal-Oxide-Semiconductor Heterostructures

    NASA Astrophysics Data System (ADS)

    Ťapajna, Milan; Kuzmík, Jan; Čičo, Karol; Pogany, Dionyz; Pozzovivo, Gianmauro; Strasser, Gottfried; Abermann, Stephan; Bertagnolli, Emmerich; Carlin, Jean-François; Grandjean, Nicolas; Fröhlich, Karol

    2009-09-01

    We investigate Al2O3- and ZrO2/InAlN/GaN metal-oxide-semiconductor heterostructures (MOS-H) using capacitance-time transients in the temperature range of 25-300 °C. A deep-level transient spectroscopy based analysis revealed the maximum interface state density distributions Dit(E) up to 3× 1013 and 1× 1013 eV-1 cm-2 for the Al2O3/InAlN and ZrO2/InAlN interface, respectively. The integral densities of interface states correlate well with the trapping-related gate-lag effect in corresponding InAlN/GaN MOS high electron mobility transistors (HEMTs). This explains the strongly reduced lag effect in ZrO2 MOS HEMTs. We assume hole trapping at oxide/InAlN interface to be a dominant effect responsible for the gate-lag effect in InAlN/GaN MOS HEMTs.

  5. In Situ XPS Chemical Analysis of MnSiO3 Copper Diffusion Barrier Layer Formation and Simultaneous Fabrication of Metal Oxide Semiconductor Electrical Test MOS Structures.

    PubMed

    Byrne, Conor; Brennan, Barry; McCoy, Anthony P; Bogan, Justin; Brady, Anita; Hughes, Greg

    2016-02-03

    Copper/SiO2/Si metal-oxide-semiconductor (MOS) devices both with and without a MnSiO3 barrier layer at the Cu/SiO2 interface have been fabricated in an ultrahigh vacuum X-ray photoelectron spectroscopy (XPS) system, which allows interface chemical characterization of the barrier formation process to be directly correlated with electrical testing of barrier layer effectiveness. Capacitance voltage (CV) analysis, before and after tube furnace anneals of the fabricated MOS structures showed that the presence of the MnSiO3 barrier layer significantly improved electric stability of the device structures. Evidence of improved adhesion of the deposited copper layer to the MnSiO3 surface compared to the clean SiO2 surface was apparent both from tape tests and while probing the samples during electrical testing. Secondary ion mass spectroscopy (SIMS) depth profiling measurements of the MOS test structures reveal distinct differences of copper diffusion into the SiO2 dielectric layers following the thermal anneal depending on the presence of the MnSiO3 barrier layer.

  6. Tunneling-injection-induced turnaround behavior of threshold voltage in thermally nitrided oxide n-channel metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Ma, Z. J.; Lai, P. T.; Liu, Z. H.; Fleischer, S.; Cheng, Y. C.

    1990-12-01

    The threshold voltage (VT) degradation metal-oxide-semiconductor field-effect transistors (MOSFETs) with thermally nitrided oxide or pure oxide as gate dielectric was determined under Fowler-Nordheim (FN) stressing. A typical VT turnaround behavior was observed for both kinds of devices. The VT for nitrided oxide MOSFETs shifts more negatively than that for pure oxide MOSFETs during the initial period of FN stressing whereas the opposite is true for the positive shift after the critical time at turnaround point. The discovery that the shift of substrate current peak exhibits similar turnaround behavior reinforces the above results. In the meantime, the field-effect electron mobility and the maximum transconductance in the channel for nitrided oxide MOSFETs are only slightly degraded by stressing as compared to that for pure oxide MOSFETs. The VT turnaround behavior can be explained as follows: Net trapped charges in the oxide are initially positive (due to hole traps in the oxide) and result in the negative shift of VT. With increasing injection time, trapped electrons in the oxide as well as acceptortype interface states increase. This results in the positive shift in VT. It is revealed that VT degradation in MOSFETs is dominated by the generation of acceptortype interface states rather than electron trapping in the oxide after the critical time.

  7. Mechanical Stress Evaluation of Si Metal-Oxide-Semiconductor Field-Effect Transistor Structure Using Polarized Ultraviolet Raman Spectroscopy Measurements and Calibrated Technology-Computer-Aided-Design Simulations

    NASA Astrophysics Data System (ADS)

    Satoh, Akira; Tada, Tetsuya; Poborchii, Vladimir; Kanayama, Toshihiko; Satoh, Shigeo; Arimoto, Hiroshi

    2012-01-01

    The mechanical stresses in Si metal-oxide-semiconductor field-effect transistors (MOSFETs) were evaluated by polarized UV Raman spectroscopy measurements and stress simulations. To calibrate stress parameters of the materials used in the Si MOSFETs, we compared measured and simulated Raman frequency shifts on the cleaved Si(110) surfaces of the MOSFETs. Consequently, we extracted intrinsic stress values of -400 MPa for a SiO2, -200 MPa for polycrystalline Si (poly-Si), 700 MPa for Ni silicide, 1250 MPa for a SiN tensile stress liner, and -3500 MPa for a SiN compressive stress liner by finding good agreement between the measured and simulated Raman shift distributions. To verify our stress simulation, we investigated the source/drain width dependences of Raman frequency shifts near the channel regions of Si MOSFETs by top-view Raman measurements. The calculated Raman frequency shifts agreed well with the results of polarized Raman measurements in terms of not only relative tendencies but also absolute Raman shift values.

  8. Low- and high-resistivity silicon substrate characterization using the Al/silicon-rich oxide/Si structure with comparison to the metal oxide semiconductor technique

    NASA Astrophysics Data System (ADS)

    Luna-López, A.; Aceves-Mijares, M.; Malik, O.; Glaenzer, R.

    2005-05-01

    High-resistivity silicon substrates (HRS, NB<1014 cm-3) are commonly used, especially in optoelectronic integrated circuits. However, standard metal oxide semiconductor (MOS) characterization methods fail to predict correctly the dopant concentration and lifetime. This is due to the high resistance in series with the MOS capacitor, which causes an erroneous capacitance measurement at high frequency. To overcome this restriction, a different characterization method is proposed, using the electronic transport property of silicon-rich oxide (SRO) films, with aluminum/silicon-rich oxide (Al/SRO/Si) devices and using capacitance-voltage (C-V) and current-voltage (I-V) characteristics, the dopant concentration and lifetime can be estimated with these method. In addition, using low/high-frequency C-V measurements in MOS structure on HRS can be used to determine the dopant concentration. In this work, low-resistivity silicon and HRS substrates are characterized. The results for both type of substrates and for the different methods are compared. It is shown that the results are similar and any of these methods produce reliable results, but the Al/SRO/Si structure has the advantage that the generation lifetime is easily obtained.

  9. Optimization of Vertical Double-Diffused Metal-Oxide Semiconductor (VDMOS) Power Transistor Structure for Use in High Frequencies and Medical Devices.

    PubMed

    Farhadi, Rozita; Farhadi, Bita

    2014-01-01

    Power transistors, such as the vertical, double-diffused, metal-oxide semiconductor (VDMOS), are used extensively in the amplifier circuits of medical devices. The aim of this research was to construct a VDMOS power transistor with an optimized structure to enhance the operation of medical devices. First, boron was implanted in silicon by implanting unclamped inductive switching (UIS) and a Faraday shield. The Faraday shield was implanted in order to replace the gate-field parasitic capacitor on the entry part of the device. Also, implanting the UIS was used in order to decrease the effect of parasitic bipolar junction transistor (BJT) of the VDMOS power transistor. The research tool used in this study was Silvaco software. By decreasing the transistor entry resistance in the optimized VDMOS structure, power losses and noise at the entry of the transistor were decreased, and, by increasing the breakdown voltage, the lifetime of the VDMOS transistor lifetime was increased, which resulted in increasing drain flow and decreasing Ron. This consequently resulted in enhancing the operation of high-frequency medical devices that use transistors, such as Radio Frequency (RF) and electrocardiograph machines.

  10. High quality HfO{sub 2}/p-GaSb(001) metal-oxide-semiconductor capacitors with 0.8 nm equivalent oxide thickness

    SciTech Connect

    Barth, Michael; Datta, Suman; Bruce Rayner, G.; McDonnell, Stephen; Wallace, Robert M.; Bennett, Brian R.; Engel-Herbert, Roman

    2014-12-01

    We investigate in-situ cleaning of GaSb surfaces and its effect on the electrical performance of p-type GaSb metal-oxide-semiconductor capacitor (MOSCAP) using a remote hydrogen plasma. Ultrathin HfO{sub 2} films grown by atomic layer deposition were used as a high permittivity gate dielectric. Compared to conventional ex-situ chemical cleaning methods, the in-situ GaSb surface treatment resulted in a drastic improvement in the impedance characteristics of the MOSCAPs, directly evidencing a much lower interface trap density and enhanced Fermi level movement efficiency. We demonstrate that by using a combination of ex-situ and in-situ surface cleaning steps, aggressively scaled HfO{sub 2}/p-GaSb MOSCAP structures with a low equivalent oxide thickness of 0.8 nm and efficient gate modulation of the surface potential are achieved, allowing to push the Fermi level far away from the valence band edge high up into the band gap of GaSb.

  11. Improved interface properties of Ge metal-oxide-semiconductor capacitor with TaTiO gate dielectric by using in situ TaON passivation interlayer

    NASA Astrophysics Data System (ADS)

    Ji, F.; Xu, J. P.; Liu, J. G.; Li, C. X.; Lai, P. T.

    2011-05-01

    TaON is in situ formed as a passivating interlayer in Ge metal-oxide-semiconductor (MOS) capacitors with high-k TaTiO gate dielectric fabricated simply by alternate sputtering of Ta and Ti. Also, postdeposition annealing is performed in wet N2 to suppress the growth of unstable GeOx at the Ge surface. As a result, excellent electrical properties of the Ge MOS devices are demonstrated, such as high equivalent dielectric constant (22.1), low interface-state density (7.3×1011 cm-2 eV), small gate leakage current (8.6×10-4 A cm-2 at Vg-Vfb=1 V), and high device reliability. Transmission electron microscopy and x-ray photoelectron spectroscopy support that all these should be attributed to the fact that the nitrogen barrier in the TaON interlayer can effectively block the interdiffusions of Ge and Ta, and the wet-N2 anneal can significantly suppress the growth of unstable low-k GeOx.

  12. Pattern dependency in selective epitaxy of B-doped SiGe layers for advanced metal oxide semiconductor field effect transistors

    NASA Astrophysics Data System (ADS)

    Hâllstedt, J.; Kolahdouz, M.; Ghandi, R.; Radamson, H. H.; Wise, R.

    2008-03-01

    This study presents investigations about the physical mechanisms, origin, and methods to control the pattern dependency in selective epitaxial growth of Si1-xGex (x=0.14-0.32) layers. It is shown with a comprehensive experimental study that the local Si coverage of individual chips on patterned wafers is the main parameter for the layer profile in the epitaxial growth. This was explained by the gas depletion of the growth species in the low velocity boundary layer over the wafer. The gas depletion radius around each oxide opening was in the centimeter range which is related to the boundary layer thickness. The results from these experiments were applied to grow Si0.75Ge0.25 layers with B concentration of 4×1020cm-3 selectively for elevated source and drains in fully depleted ultrathin body silicon on insulator p metal oxide semiconductor field effect transistor (p-MOSFET) devices. The epitaxy control was maintained over a wide range of device sizes by optimized process parameters in combination with a wafer pattern design consisting of dummy features causing a uniform gas depletion over the chips on the wafer.

  13. Control of Subthreshold Characteristics of Narrow-Channel Silicon-on-Insulator n-Type Metal-Oxide-Semiconductor Transistor with Additional Side Gate Electrodes

    NASA Astrophysics Data System (ADS)

    Okuyama, Kiyoshi; Yoshikawa, Koji; Sunami, Hideo

    2007-04-01

    A silicon-on-insulator (SOI) n-type metal-oxide-semiconductor (MOS) transistor with additional side gate electrodes is fabricated and its subthreshold characteristics are discussed. Since its device structure provides independent biasing to gates, flexible device-characteristic control for the respective device is expected. The key fabrication process is the formation of transistor gates. Additional side gate electrodes are formed by reactive ion etching (RIE) with a SiO2-covered top gate as an etching mask. Subthreshold characteristics are improved by negative side-gate biasing. In addition, the side-gate voltage VSG required to decrease off-leakage current by one decade is around 100 mV. Since the sidewall oxide thickness is chosen to be 5 nm, which is the same as the top-oxide thickness, rather sensitive subthreshold-characteristic control compared with that of biasing through a thick buried-oxide layer is achieved in response to performance requirement. In the viewpoint of stand-by-power suppression, these provide a certain controllability to a circuit operation.

  14. Anomalous Increase in Effective Channel Mobility on Gamma-Irradiated p-Channel SiC Metal-Oxide-Semiconductor Field-Effect Transistors Containing Step Bunching

    NASA Astrophysics Data System (ADS)

    Lee, Kin Kiong; Ohshima, Takeshi; Ohi, Akihiko; Itoh, Hisayoshi; Pensl, Gerhard

    2006-09-01

    The influence of gamma-radiation on the electrical characteristics of 6H-SiC p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) containing step bunching is reported. The formation of step bunching perpendicular to the channel inhibited the current flow, whereas such an effect was not seen in devices with step bunching formed parallel to the channel. The effective channel mobility in the latter devices increases with gamma-radiation. This improvement of the hole mobility is attributed partially to the positively trapped charges screened the holes from approaching too close to the surface and partially to the effect of position of these charges, resulting in a reduction of scattering and capture of holes. No enhancement in the effective channel mobility was observed for devices with no step bunching or with root mean square roughness in the channel region less than 4 nm. Further irradiation leads to a decrease in the effective channel mobility due to both the formation of latent interface traps and electrostatics repulsion of holes.

  15. Investigation of Device Performance and Negative Bias Temperature Instability of Plasma Nitrided Oxide in Nanoscale p-Channel Metal-Oxide-Semiconductor Field-Effect Transistor's

    NASA Astrophysics Data System (ADS)

    Han, In-Shik; Ji, Hee-Hwan; Goo, Tae-Gyu; Yoo, Ook-Sang; Choi, Won-Ho; Na, Min-Ki; Kim, Yong-Goo; Park, Sung-Hyung; Lee, Heui-Seung; Kang, Young-Seok; Kim, Dae-Byung; Lee, Hi-Deok

    2008-04-01

    In this paper, we investigated the device performance and negative bias temperature instability (NBTI) degradation for thermally nitrided oxide (TNO) and plasma nitrided oxide (PNO) in nanoscale p-channel metal oxide semiconductor field effect transistor (PMOSFET). PNOs show the improvement of dielectric performance compared to TNO with no change of the device performance. PNOs also show the improvement of NBTI immunity than TNO at low temperature stress, whereas NBTI immunity of PNO with high N concentration can be worse than TNO at high temperature stress. Recovery effect of NBTI degradation of PNO is lower than that of TNO and it is increased as the N concentration is increased in PNO because the dissociated Si dangling bonds and generated positive oxide charges are repassivated and neutralized, respectively. Moreover, complete recovery of ΔVth is dominated by neutralization of positive oxide charges. Therefore, N contents at polycrystalline Si/SiO2 interface as well as N contents at Si/SiO2 interface can affect significantly on NBTI degradation and recovery effect.

  16. Temperature dependence of frequency dispersion in III–V metal-oxide-semiconductor C-V and the capture/emission process of border traps

    SciTech Connect

    Vais, Abhitosh Martens, Koen; DeMeyer, Kristin; Lin, Han-Chung; Ivanov, Tsvetan; Collaert, Nadine; Thean, Aaron; Dou, Chunmeng; Xie, Qi; Maes, Jan; Tang, Fu; Givens, Michael; Raskin, Jean-Pierre

    2015-08-03

    This paper presents a detailed investigation of the temperature dependence of frequency dispersion observed in capacitance-voltage (C-V) measurements of III-V metal-oxide-semiconductor (MOS) devices. The dispersion in the accumulation region of the capacitance data is found to change from 4%–9% (per decade frequency) to ∼0% when the temperature is reduced from 300 K to 4 K in a wide range of MOS capacitors with different gate dielectrics and III-V substrates. We show that such significant temperature dependence of C-V frequency dispersion cannot be due to the temperature dependence of channel electrostatics, i.e., carrier density and surface potential. We also show that the temperature dependence of frequency dispersion, and hence, the capture/emission process of border traps can be modeled by a combination of tunneling and a “temperature-activated” process described by a non-radiative multi-phonon model, instead of a widely believed single-step elastic tunneling process.

  17. Impacts of Ti on electrical properties of Ge metal-oxide-semiconductor capacitors with ultrathin high- k LaTiON gate dielectric

    NASA Astrophysics Data System (ADS)

    Xu, H. X.; Xu, J. P.; Li, C. X.; Chan, C. L.; Lai, P. T.

    2010-06-01

    Ge Metal-Oxide-Semiconductor (MOS) capacitors with LaON gate dielectric incorporating different Ti contents are fabricated and their electrical properties are measured and compared. It is found that Ti incorporation can increase the dielectric permittivity, and the higher the Ti content, the larger is the permittivity. However, the interfacial and gate-leakage properties become poorer as the Ti content increases. Therefore, optimization of Ti content is important in order to obtain a good trade-off among the electrical properties of the device. For the studied range of the Ti/La2O3 ratio, a suitable Ti/La2O3 ratio of 14.7% results in a high relative permittivity of 24.6, low interface-state density of 3.1×1011 eV-1 cm-2, and relatively low gate-leakage current density of 2.0×10-3 A cm-2 at a gate voltage of 1 V.

  18. High-performance GaAs metal-oxide-semiconductor capacitor by using NbAlON as high-k gate dielectric

    NASA Astrophysics Data System (ADS)

    Liu, L. N.; Choi, H. W.; Xu, J. P.; Lai, P. T.

    2017-03-01

    A GaAs metal-oxide-semiconductor (MOS) capacitor using NbAlON as a gate dielectric with different Nb contents is fabricated. Experimental results show that the k value and crystallization temperature of the AlON dielectric can be improved by Nb incorporation, together with reduction in negative oxide charges. However, the interface quality and gate leakage become poorer as the Nb content increases, as confirmed by TEM and X-ray photoelectron spectroscopy results. Therefore, through comprehensively considering the advantages and disadvantages, the sample with a Nb/(Al+Nb) atomic ratio of 62.5% exhibits the best characteristics: high k value (23.3), low interface-state density (2.7 × 1012 cm-2/eV), small hysteresis (55 mV), small frequency dispersion, and low gate leakage current (2.66 × 10-5A/cm2 at Vfb + 1 V). By comparing with reported GaAs MOS devices with different high-k gate dielectrics, it can be suggested that NbAlON is a promising gate dielectric material to achieve excellent electrical performance for GaAs MOS devices.

  19. Role of fringing field on the electrical characteristics of metal-oxide-semiconductor capacitors with co-planar and edge-removed oxides

    NASA Astrophysics Data System (ADS)

    Yang, Chang-Feng; Hwu, Jenn-Gwo

    2016-12-01

    Due to the simplicity of the fabrication process, the ultra-thin oxide metal-oxide-semiconductor capacitors (MOSCAPs) can be a promising device for sensing, memory, and transconductance applications. The investigation of the fundamental electrical characteristics of ultra-thin oxide MOSCAPs is still of importance. In this work, the influence of the removal of the surrounded gate oxide was studied to know the role of fringing field. For edge-removed oxide, the tunneling saturation current shows no oxide thickness dependency and exhibits a low current level of 9.4×10-11 at 2V (dox=2.3 nm). Also, its deep depletion occurs earlier when biasing. In contrast, for the device without oxide removing, i.e., co-planar oxide, the saturation current is strongly related to the oxide thickness and exhibits a high current level of 3.5×10-6 at 2V (dox=2.3 nm) due to regular oxide voltage drop modulation effect on effective Schottky barrier height. For the thick oxide of 4.2 nm the inversion capacitances are frequency dependant for CP-OX but are independent for ER-OX MOSCAPs. These characteristics are mainly caused by the different fringing fields and the defect densities at device edge between two structures.

  20. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO2 by capacitance voltage measurement on inverted metal oxide semiconductor structure

    NASA Astrophysics Data System (ADS)

    Zhang, Tian; Puthen-Veettil, Binesh; Wu, Lingfeng; Jia, Xuguang; Lin, Ziyun; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan

    2015-10-01

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO2. The ncSi thin films with high resistivity (200-400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO2/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 1018-1019 cm-3 despite their high resistivity. The saturation of doping at about 1.4 × 1019 cm-3 and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10-3 cm2/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.

  1. Analytical modeling to design the vertically aligned Si-nanowire metal-oxide-semiconductor photosensors for direct color sensing with high spectral resolution

    NASA Astrophysics Data System (ADS)

    Sikdar, Subhrajit; Chowdhury, Basudev Nag; Ghosh, Ajay; Chattopadhyay, Sanatan

    2017-03-01

    In the current work, an analytical model for the design of vertically aligned silicon (Si) nanowire metal-oxide-semiconductor (MOS) capacitor based multi-color photodetectors has been developed for the detection of entire visible spectrum with high spectral resolution. The photogeneration phenomena within the nanostructures are analyzed in detail by developing a quantum field model associated with second quantization electron-photon field operators. The non-equilibrium Green's function (NEGF) formalism is employed to solve the relevant equations. The study shows that the proposed device with specified design of diameter-voltage combinations is capable of detecting 64 spectral bands of the entire visible spectrum (380 nm to700 nm) directly with a very high resolution of 5 nm wavelength. Such direct sensing of each wavelength is observed to be independent of the fluctuations of illumination intensity. The device is designed to obtain a full-width-at-half-maximum (FWHM) smaller than the spectral resolution (5 nm) for each wavelength of the visible range, which indicates a very high quality digital imaging/sensing method. Such devices may be a potential alternative for the future nanoelectronics based photodevices for superior sensing/imaging applications.

  2. The role of the substrate on the dispersion in accumulation in III-V compound semiconductor based metal-oxide-semiconductor gate stacks

    SciTech Connect

    Krylov, Igor; Ritter, Dan; Eizenberg, Moshe

    2015-09-07

    Dispersion in accumulation is a widely observed phenomenon in metal-oxide-semiconductor gate stacks based on III-V compound semiconductors. The physical origin of this phenomenon is attributed to border traps located in the dielectric material adjacent to the semiconductor. Here, we study the role of the semiconductor substrate on the electrical quality of the first layers at atomic layer deposited (ALD) dielectrics. For this purpose, either Al{sub 2}O{sub 3} or HfO{sub 2} dielectrics with variable thicknesses were deposited simultaneously on two technology important semiconductors—InGaAs and InP. Significantly larger dispersion was observed in InP based gate stacks compared to those based on InGaAs. The observed difference is attributed to a higher border trap density in dielectrics deposited on InP compared to those deposited on InGaAs. We therefore conclude that the substrate plays an important role in the determination of the electrical quality of the first dielectric monolayers deposited by ALD. An additional observation is that larger dispersion was obtained in HfO{sub 2} based capacitors compared to Al{sub 2}O{sub 3} based capacitors, deposited on the same semiconductor. This phenomenon is attributed to the lower conduction band offset rather than to a higher border trap density.

  3. Oxide-free InAs(111)A interface in metal-oxide-semiconductor structure with very low density of states prepared by anodic oxidation

    SciTech Connect

    Valisheva, N. A. Aksenov, M. S.; Golyashov, V. A.; Levtsova, T. A.; Kovchavtsev, A. P.; Gutakovskii, A. K.; Tereshchenko, O. E.; Khandarkhaeva, S. E.; Kalinkin, A. V.; Prosvirin, I. P.; Bukhtiyarov, V. I.

    2014-10-20

    In this letter, we present structural, compositional, and electrical characteristics of anodic oxide layer-based metal-oxide-semiconductor (MOS) capacitors on n-type InAs(111)A, along with the effect of a thin fluorinated interfacial passivation layer. Electrochemical oxidation in acid electrolyte with addition of fluorine (NH{sub 4}F) led to the formation of oxygen free well-ordered wide gap fluorinated interfacial layer at InAs(111)A with the fixed charge (Q{sub fix}) and density of interface states (D{sub it}) in the range of (4–6) × 10{sup 10 }cm{sup −2} and (2–12) × 10{sup 10 }eV{sup −1 }cm{sup −2}, respectively. We found that MOS capacitors showed excellent capacitance-voltage characteristics with very small frequency dispersion (<1% and <15 mV). Fluorinated interfacial layer consists of crystalline isostructural compound with the InAs substrate, which remains intact with the atomic smoothness and sharpness that explain unpinned behavior of the Fermi level.

  4. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO{sub 2} by capacitance voltage measurement on inverted metal oxide semiconductor structure

    SciTech Connect

    Zhang, Tian Puthen-Veettil, Binesh; Wu, Lingfeng; Jia, Xuguang; Lin, Ziyun; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan

    2015-10-21

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO{sub 2}. The ncSi thin films with high resistivity (200–400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO{sub 2}/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 10{sup 18}–10{sup 19 }cm{sup −3} despite their high resistivity. The saturation of doping at about 1.4 × 10{sup 19 }cm{sup −3} and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10{sup −3} cm{sup 2}/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.

  5. Impact of GaN cap on charges in Al₂O₃/(GaN/)AlGaN/GaN metal-oxide-semiconductor heterostructures analyzed by means of capacitance measurements and simulations

    SciTech Connect

    Ťapajna, M. Jurkovič, M.; Válik, L.; Haščík, Š.; Gregušová, D.; Kuzmík, J.; Brunner, F.; Cho, E.-M.; Hashizume, T.

    2014-09-14

    Oxide/semiconductor interface trap density (D{sub it}) and net charge of Al₂O₃/(GaN)/AlGaN/GaN metal-oxide-semiconductor high-electron mobility transistor (MOS-HEMT) structures with and without GaN cap were comparatively analyzed using comprehensive capacitance measurements and simulations. D{sub it} distribution was determined in full band gap of the barrier using combination of three complementary capacitance techniques. A remarkably higher D{sub it} (∼5–8 × 10¹²eV⁻¹ cm⁻²) was found at trap energies ranging from EC-0.5 to 1 eV for structure with GaN cap compared to that (D{sub it} ∼ 2–3 × 10¹²eV⁻¹ cm⁻²) where the GaN cap was selectively etched away. D{sub it} distributions were then used for simulation of capacitance-voltage characteristics. A good agreement between experimental and simulated capacitance-voltage characteristics affected by interface traps suggests (i) that very high D{sub it} (>10¹³eV⁻¹ cm⁻²) close to the barrier conduction band edge hampers accumulation of free electron in the barrier layer and (ii) the higher D{sub it} centered about EC-0.6 eV can solely account for the increased C-V hysteresis observed for MOS-HEMT structure with GaN cap. Analysis of the threshold voltage dependence on Al₂O₃ thickness for both MOS-HEMT structures suggests that (i) positive charge, which compensates the surface polarization, is not necessarily formed during the growth of III-N heterostructure, and (ii) its density is similar to the total surface polarization charge of the GaN/AlGaN barrier, rather than surface polarization of the top GaN layer only. Some constraints for the positive surface compensating charge are discussed.

  6. A novel way to improve the quantum efficiency of silicon light-emitting diode in a standard silicon complementary metal-oxide-semiconductor technology

    NASA Astrophysics Data System (ADS)

    Xu, Kaikai; Li, G. P.

    2013-03-01

    Silicon diode at avalanche breakdown has visible light emission in the depletion region. It is believed that this optical radiation comes from the kinetic energy loss of carriers generated by impact ionization colliding with immobile charge centers in the avalanche region. A theoretical model is presented to show the correlation of the hot carrier effect with the related photonic emission in high field. Meanwhile, a PMOSFET-like silicon light source device fabricated completely in the standard silicon CMOS process technology is measured to demonstrate that avalanching current is linearly proportional to optical emission power whether this light source acts as a two-terminal device (i.e., diode, the "p+ Source/Drain to n-Substrate junction" with floating the gate) or acts as a three-terminal device (i.e., gate-diode, the "p+ Source/Drain to n-Substrate junction" in the course of varying the gate voltage). Such linearity implies that control of the increasing current is a significant way to enhance the quantum efficiency of this light source device no matter what the physical structure (i.e., two terminals or three terminals) of this device is. For the first time, it has been discovered that, at the same avalanching current, the optical output power in gate-diode structure is higher than the optical output power in diode structure. In other words, for this PMOSFET-like device, the three-terminal operating mode is more efficient than the two-terminal operating mode.

  7. Novel High-Performance Analog Devices for Advanced Low-Power High-k Metal Gate Complementary Metal-Oxide-Semiconductor Technology

    NASA Astrophysics Data System (ADS)

    Han, Jin-Ping; Shimizu, Takashi; Pan, Li-Hong; Voelker, Moritz; Bernicot, Christophe; Arnaud, Franck; Mocuta, Anda; Stahrenberg, Knut; Azuma, Atsushi; Eller, Manfred; Yang, Guoyong; Jaeger, Daniel; Zhuang, Haoren; Miyashita, Katsura; Stein, Kenneth; Nair, Deleep; Hoo Park, Jae; Kohler, Sabrina; Hamaguchi, Masafumi; Li, Weipeng; Kim, Kisang; Chanemougame, Daniel; Kim, Nam Sung; Uchimura, Sadaharu; Tsutsui, Gen; Wiedholz, Christian; Miyake, Shinich; van Meer, Hans; Liang, Jewel; Ostermayr, Martin; Lian, Jenny; Celik, Muhsin; Donaton, Ricardo; Barla, Kathy; Na, MyungHee; Goto, Yoshiro; Sherony, Melanie; Johnson, Frank S.; Wachnik, Richard; Sudijono, John; Kaste, Ed; Sampson, Ron; Ku, Ja-Hum; Steegen, An; Neumueller, Walter

    2011-04-01

    High performance analog (HPA) devices in high-k metal gate (HKMG) scheme with innovative halo engineering have been successfully demonstrated to produce superior analog and digital performance for low power applications. HPA device was processed “freely” with no extra mask, no extra litho, and no extra process step. This paper details a comprehensive study of the analog and digital characteristics of these HPA devices in comparison with analog control (conventional digital devices with matched geometry). Analog properties such as output voltage gain (also called self-gain), trans-conductance Gm, conductance Gds, Gm/Id, mismatching (MM) behavior, flicker noise (1/f noise) and current linearity have clearly reflected the advantage of HPA devices over analog control, while DC performance (e.g., Ion-Ioff, Ioff-Vtsat, DIBL, Cjswg) and reliability (HCI) have also shown the comparability of HPA devices over control.

  8. Ultra-low power high temperature and radiation hard complementary metal-oxide-semiconductor (CMOS) silicon-on-insulator (SOI) voltage reference.

    PubMed

    Boufouss, El Hafed; Francis, Laurent A; Kilchytska, Valeriya; Gérard, Pierre; Simon, Pascal; Flandre, Denis

    2013-12-13

    This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40-200 °C and for different process corners. Robustness to radiation was simulated using custom model parameters including TID effects, such as mobilities and threshold voltages degradation. The proposed circuit has been tested up to high total radiation dose, i.e., 1 Mrad (Si) performed at three different temperatures (room temperature, 100 °C and 200 °C). The maximum drift of the reference voltage V(REF) depends on the considered temperature and on radiation dose; however, it remains lower than 10% of the mean value of 1.5 V. The typical power dissipation at 2.5 V supply voltage is about 20 μW at room temperature and only 75 μW at a high temperature of 200 °C. To understand the effects caused by the combination of high total ionizing dose and temperature on such voltage reference, the threshold voltages of the used SOI MOSFETs were extracted under different conditions. The evolution of V(REF) and power consumption with temperature and radiation dose can then be explained in terms of the different balance between fixed oxide charge and interface states build-up. The total occupied area including pad-ring is less than 0.09 mm2.

  9. A hybrid magnetic/complementary metal oxide semiconductor process design kit for the design of low-power non-volatile logic circuits

    NASA Astrophysics Data System (ADS)

    Di Pendina, G.; Prenat, G.; Dieny, B.; Torki, K.

    2012-04-01

    Since the advent of the MOS transistor, the performance of microelectronic circuits has followed Moore's law, stating that their speed and density would double every 18 months. Today, this trend tends to get out of breath: the continuously decreasing size of devices and increasing operation frequency result in power consumption and heating issues. Among the solutions investigated to circumvent these limitations, the use of non-volatile devices appears particularly promising. It allows easing, for example, the power gating technique, which consists in cutting-off the power supply of inactive blocks without losing information, drastically reducing the standby power consumption. In this approach, the advantages of magnetic tunnel junctions (MTJs) compared with other non-volatile devices allow one to design hybrid CMOS/magnetic circuits with high performance and new functionalities. Designing such circuits requires integrating MTJs in standard microelectronics design suites. This is performed by means of a process design kit (PDK) for the hybrid CMOS/magnetic technology. We present here a full magnetic PDK, which contains a compact model of the MTJ for electrical simulation, technology files for layout and physical verifications, and standard cells for the design of complex logic circuits and which is compatible with standard design suites. This PDK allows designers to accurately and comfortably design high-performance hybrid CMOS/magnetic logic circuits in the same way as standard CMOS circuits.

  10. A 94GHz Temperature Compensated Low Noise Amplifier in 45nm Silicon-on-Insulator Complementary Metal-Oxide Semiconductor (SOI CMOS)

    DTIC Science & Technology

    2014-01-01

    discovering techniques to build wide temperature range electronics for millimeter wave imaging applications. Realization of this plan has resulted in a...State Circuits. 41.12 (December 2006): 2992-2997. 8. De Vida , G., and G. Iannaccone. “An Ultra-Low Power, Temperature Compensated Voltage

  11. Ultra-Low Power High Temperature and Radiation Hard Complementary Metal-Oxide-Semiconductor (CMOS) Silicon-on-Insulator (SOI) Voltage Reference

    PubMed Central

    Boufouss, El Hafed; Francis, Laurent A.; Kilchytska, Valeriya; Gérard, Pierre; Simon, Pascal; Flandre, Denis

    2013-01-01

    This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of −40–200 °C and for different process corners. Robustness to radiation was simulated using custom model parameters including TID effects, such as mobilities and threshold voltages degradation. The proposed circuit has been tested up to high total radiation dose, i.e., 1 Mrad (Si) performed at three different temperatures (room temperature, 100 °C and 200 °C). The maximum drift of the reference voltage VREF depends on the considered temperature and on radiation dose; however, it remains lower than 10% of the mean value of 1.5 V. The typical power dissipation at 2.5 V supply voltage is about 20 μW at room temperature and only 75 μW at a high temperature of 200 °C. To understand the effects caused by the combination of high total ionizing dose and temperature on such voltage reference, the threshold voltages of the used SOI MOSFETs were extracted under different conditions. The evolution of VREF and power consumption with temperature and radiation dose can then be explained in terms of the different balance between fixed oxide charge and interface states build-up. The total occupied area including pad-ring is less than 0.09 mm2. PMID:24351635

  12. WE-G-204-04: Focal Spot Deblurring For High Resolution Amorphous Selenium (aSe) Complementary Metal Oxide Semiconductor (CMOS) X-Ray Detector

    SciTech Connect

    Nagesh, S Setlur; Rana, R; Russ, M; Ionita, C; Bednarek, D; Rudin, S

    2015-06-15

    Purpose: CMOS-based aSe detectors compared to CsI-TFT-based flat panels have the advantages of higher spatial sampling due to smaller pixel size and decreased blurring characteristic of direct rather than indirect detection. For systems with such detectors, the limiting factor degrading image resolution then becomes the focal-spot geometric unsharpness. This effect can seriously limit the use of such detectors in areas such as cone beam computed tomography, clinical fluoroscopy and angiography. In this work a technique to remove the effect of focal-spot blur is presented for a simulated aSe detector. Method: To simulate images from an aSe detector affected with focal-spot blur, first a set of high-resolution images of a stent (FRED from Microvention, Inc.) were acquired using a 75µm pixel size Dexela-Perkin-Elmer detector and averaged to reduce quantum noise. Then the averaged image was blurred with a known Gaussian blur at two different magnifications to simulate an idealized focal spot. The blurred images were then deconvolved with a set of different Gaussian blurs to remove the effect of focal-spot blurring using a threshold-based, inverse-filtering method. Results: The blur was removed by deconvolving the images using a set of Gaussian functions for both magnifications. Selecting the correct function resulted in an image close to the original; however, selection of too wide a function would cause severe artifacts. Conclusion: Experimentally, focal-spot blur at different magnifications can be measured using a pin hole with a high resolution detector. This spread function can be used to deblur the input images that are acquired at corresponding magnifications to correct for the focal spot blur. For CBCT applications, the magnification of specific objects can be obtained using initial reconstructions then corrected for focal-spot blurring to improve resolution. Similarly, if object magnification can be determined such correction may be applied in fluoroscopy and angiography.

  13. Effective passivation and high-performance metal-oxide-semiconductor devices using ultra-high-vacuum deposited high- κ dielectrics on Ge without interfacial layers

    NASA Astrophysics Data System (ADS)

    Chu, L. K.; Chu, R. L.; Lin, T. D.; Lee, W. C.; Lin, C. A.; Huang, M. L.; Lee, Y. J.; Kwo, J.; Hong, M.

    2010-09-01

    Without using any interfacial passivation layers, high- κ dielectric Y 2O 3, HfO 2, and Ga 2O 3(Gd 2O 3) [GGO], by electron beam evaporation in ultra-high-vacuum (UHV), have been directly deposited on Ge substrate. Comprehensive investigations have been carried out to study the oxide/Ge interfaces chemically, structurally, and electronically: hetero-structures of all the studied oxides on Ge are highly thermally stable with annealing to 500 °C, and their interfaces remain atomically sharp. The electrical analyses have been conducted on metal-oxide-semiconductor (MOS) devices, i.e. MOS capacitors (MOSCAPs) and MOS field-effect-transistors (MOSFETs). Dielectrics constants of the Y 2O 3, HfO 2, and GGO have been extracted to be ˜17, 20, and 13-15, respectively, indicating no interfacial layer formation with 500 °C annealing. A low interfacial density of states ( Dits), as low as 3 × 10 11 cm -2 eV -1, has been achieved for GGO/Ge near mid-gap along with a high Fermi-level movement efficiency as high as 80%. The GGO/Ge pMOSFETs with TiN as the metal gate have yielded very high-performances, in terms of 496 μA/μm, 178 μS/μm, and 389 cm 2/V s in saturation drain current density, maximum transconductance, and effective hole mobility, respectively. The gate width and gate length of the MOSFET are 10 μm and 1 μm.

  14. Sample size requirements for estimating effective dose from computed tomography using solid-state metal-oxide-semiconductor field-effect transistor dosimetry

    SciTech Connect

    Trattner, Sigal; Cheng, Bin; Pieniazek, Radoslaw L.; Hoffmann, Udo; Douglas, Pamela S.; Einstein, Andrew J.

    2014-04-15

    Purpose: Effective dose (ED) is a widely used metric for comparing ionizing radiation burden between different imaging modalities, scanners, and scan protocols. In computed tomography (CT), ED can be estimated by performing scans on an anthropomorphic phantom in which metal-oxide-semiconductor field-effect transistor (MOSFET) solid-state dosimeters have been placed to enable organ dose measurements. Here a statistical framework is established to determine the sample size (number of scans) needed for estimating ED to a desired precision and confidence, for a particular scanner and scan protocol, subject to practical limitations. Methods: The statistical scheme involves solving equations which minimize the sample size required for estimating ED to desired precision and confidence. It is subject to a constrained variation of the estimated ED and solved using the Lagrange multiplier method. The scheme incorporates measurement variation introduced both by MOSFET calibration, and by variation in MOSFET readings between repeated CT scans. Sample size requirements are illustrated on cardiac, chest, and abdomen–pelvis CT scans performed on a 320-row scanner and chest CT performed on a 16-row scanner. Results: Sample sizes for estimating ED vary considerably between scanners and protocols. Sample size increases as the required precision or confidence is higher and also as the anticipated ED is lower. For example, for a helical chest protocol, for 95% confidence and 5% precision for the ED, 30 measurements are required on the 320-row scanner and 11 on the 16-row scanner when the anticipated ED is 4 mSv; these sample sizes are 5 and 2, respectively, when the anticipated ED is 10 mSv. Conclusions: Applying the suggested scheme, it was found that even at modest sample sizes, it is feasible to estimate ED with high precision and a high degree of confidence. As CT technology develops enabling ED to be lowered, more MOSFET measurements are needed to estimate ED with the same

  15. Comparison of modification strategies towards enhanced charge carrier separation and photocatalytic degradation activity of metal oxide semiconductors (TiO2, WO3 and ZnO)

    NASA Astrophysics Data System (ADS)

    Kumar, S. Girish; Rao, K. S. R. Koteswara

    2017-01-01

    Metal oxide semiconductors (TiO2, WO3 and ZnO) finds unparalleled opportunity in wastewater purification under UV/visible light, largely encouraged by their divergent admirable features like stability, non-toxicity, ease of preparation, suitable band edge positions and facile generation of active oxygen species in the aqueous medium. However, the perennial failings of these photocatalysts emanates from the stumbling blocks like rapid charge carrier recombination and meager visible light response. In this review, tailoring the surface-bulk electronic structure through the calibrated and veritable approaches such as impurity doping, deposition with noble metals, sensitizing with other compounds (dyes, polymers, inorganic complexes and simple chelating ligands), hydrogenation process (annealing under hydrogen atmosphere), electronic integration with other semiconductors, modifying with carbon nanostructures, designing with exposed facets and tailoring with hierarchical morphologies to overcome their critical drawbacks are summarized. Taking into account the materials intrinsic properties, the pros and cons together with similarities and striking differences for each strategy in specific to TiO2, WO3 & ZnO are highlighted. These subtlety enunciates the primacy for improving the structure-electronic properties of metal oxides and credence to its fore in the practical applications. Future research must focus on comparing the performances of ZnO, TiO2 and WO3 in parallel to get insight into their photocatalytic behaviors. Such comparisons not only reveal the changed surface-electronic structure upon various modifications, but also shed light on charge carrier dynamics, free radical generation, structural stability and compatibility for photocatalytic reactions. It is envisioned that these cardinal tactics have profound implications and can be replicated to other semiconductor photocatalysts like CeO2, In2O3, Bi2O3, Fe2O3, BiVO4, AgX, BiOX (X = Cl, Br & I), Bi2WO6, Bi2MoO6

  16. Ultra-low specific on-resistance high-voltage vertical double diffusion metal-oxide-semiconductor field-effect transistor with continuous electron accumulation layer

    NASA Astrophysics Data System (ADS)

    Da, Ma; Xiao-Rong, Luo; Jie, Wei; Qiao, Tan; Kun, Zhou; Jun-Feng, Wu

    2016-04-01

    A new ultra-low specific on-resistance (R on,sp) vertical double diffusion metal-oxide-semiconductor field-effect transistor (VDMOS) with continuous electron accumulation (CEA) layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the R on,sp but also makes the R on,sp almost independent of the n-pillar doping concentration (N n). In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the N n, and further reduces the R on,sp. Especially, the two PN junctions within the trench gate support a high gate-drain voltage in the off-state and on-state, respectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the R on,sp by 80% compared with the conventional super-junction VDMOS (CSJ-VDMOS) at the same high breakdown voltage (BV). Project supported by the National Natural Science Foundation of China (Grant Nos. 61176069 and 61376079) and the Fundamental Research Funds for the Central Universities, China (Grant No. ZYGX2014Z006).

  17. Fabrication and characterization of the normally-off N-channel lateral 4H-SiC metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Qing-Wen, Song; Xiao-Yan, Tang; Yan-Jing, He; Guan-Nan, Tang; Yue-Hu, Wang; Yi-Meng, Zhang; Hui, Guo; Ren-Xu, Jia; Hong-Liang, Lv; Yi-Men, Zhang; Yu-Ming, Zhang

    2016-03-01

    In this paper, the normally-off N-channel lateral 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFFETs) have been fabricated and characterized. A sandwich- (nitridation-oxidation-nitridation) type process was used to grow the gate dielectric film to obtain high channel mobility. The interface properties of 4H-SiC/SiO2 were examined by the measurement of HF I-V, G-V, and C-V over a range of frequencies. The ideal C-V curve with little hysteresis and the frequency dispersion were observed. As a result, the interface state density near the conduction band edge of 4H-SiC was reduced to 2 × 1011 eV-1·cm-2, the breakdown field of the grown oxides was about 9.8 MV/cm, the median peak field-effect mobility is about 32.5 cm2·V-1·s-1, and the maximum peak field-effect mobility of 38 cm2·V-1·s-1 was achieved in fabricated lateral 4H-SiC MOSFFETs. Projcet supported by the National Natural Science Foundation of China (Grant Nos. 61404098, 61176070, and 61274079), the Doctoral Fund of Ministry of Education of China (Grant Nos. 20110203110010 and 20130203120017), the National Key Basic Research Program of China (Grant No. 2015CB759600), and the Key Specific Projects of Ministry of Education of China (Grant No. 625010101).

  18. Effect of proton irradiation dose on InAlN/GaN metal-oxide semiconductor high electron mobility transistors with Al2O3 gate oxide

    DOE PAGES

    Ahn, Shihyun; Kim, Byung -Jae; Lin, Yi -Hsuan; ...

    2016-07-26

    The effects of proton irradiation on the dc performance of InAlN/GaN metal-oxide-semiconductor high electron mobility transistors (MOSHEMTs) with Al2O3 as the gate oxide were investigated. The InAlN/GaN MOSHEMTs were irradiated with doses ranging from 1×1013 to 1×1015cm–2 at a fixed energy of 5MeV. There was minimal damage induced in the two dimensional electron gas at the lowest irradiation dose with no measurable increase in sheet resistance, whereas a 9.7% increase of the sheet resistance was observed at the highest irradiation dose. By sharp contrast, all irradiation doses created more severe degradation in the Ohmic metal contacts, with increases of specificmore » contact resistance from 54% to 114% over the range of doses investigated. These resulted in source-drain current–voltage decreases ranging from 96 to 242 mA/mm over this dose range. The trap density determined from temperature dependent drain current subthreshold swing measurements increased from 1.6 × 1013 cm–2 V–1 for the reference MOSHEMTs to 6.7 × 1013 cm–2 V–1 for devices irradiated with the highest dose. In conclusion, the carrier removal rate was 1287 ± 64 cm–1, higher than the authors previously observed in AlGaN/GaN MOSHEMTs for the same proton energy and consistent with the lower average bond energy of the InAlN.« less

  19. Effect of NO annealing on charge traps in oxide insulator and transition layer for 4H-SiC metal-oxide-semiconductor devices

    NASA Astrophysics Data System (ADS)

    Jia, Yifan; Lv, Hongliang; Niu, Yingxi; Li, Ling; Song, Qingwen; Tang, Xiaoyan; Li, Chengzhan; Zhao, Yanli; Xiao, Li; Wang, Liangyong; Tang, Guangming; Zhang, Yimen; Zhang, Yuming

    2016-09-01

    The effect of nitric oxide (NO) annealing on charge traps in the oxide insulator and transition layer in n-type 4H-SiC metal-oxide-semiconductor (MOS) devices has been investigated using the time-dependent bias stress (TDBS), capacitance-voltage (C-V), and secondary ion mass spectroscopy (SIMS). It is revealed that two main categories of charge traps, near interface oxide traps (Nniot) and oxide traps (Not), have different responses to the TDBS and C-V characteristics in NO-annealed and Ar-annealed samples. The Nniot are mainly responsible for the hysteresis occurring in the bidirectional C-V characteristics, which are very close to the semiconductor interface and can readily exchange charges with the inner semiconductor. However, Not is mainly responsible for the TDBS induced C-V shifts. Electrons tunneling into the Not are hardly released quickly when suffering TDBS, resulting in the problem of the threshold voltage stability. Compared with the Ar-annealed sample, Nniot can be significantly suppressed by the NO annealing, but there is little improvement of Not. SIMS results demonstrate that the Nniot are distributed within the transition layer, which correlated with the existence of the excess silicon. During the NO annealing process, the excess Si atoms incorporate into nitrogen in the transition layer, allowing better relaxation of the interface strain and effectively reducing the width of the transition layer and the density of Nniot. Project supported by the National Natural Science Foundation of China (Grant Nos. 61404098 and 61274079), the Doctoral Fund of Ministry of Education of China (Grant No. 20130203120017), the National Key Basic Research Program of China (Grant No. 2015CB759600), the National Grid Science & Technology Project, China (Grant No. SGRI-WD-71-14-018), and the Key Specific Project in the National Science & Technology Program, China (Grant Nos. 2013ZX02305002-002 and 2015CB759600).

  20. Highly strained channel with low-resistivity carbon-doped source/drain formed by cascade C7Hx implantation followed by rapid solid-phase epitaxy and laser annealing for n-channel metal-oxide-semiconductor field-effect transistor

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Tadashi; Kawasaki, Yoji; Yamashita, Tomohiro; Nishida, Yukio; Mizuo, Mariko; Maekawa, Kazuyoshi; Fujisawa, Masahiko

    2015-03-01

    We show the systematical investigation results of the effects of the implanted ion dose of P or As under various solid-phase epitaxy (SPE) conditions on the local stress in channel regions in metal-oxide-semiconductor field-effect transistor (MOSFET) structures, and on sheet resistance and strain in carbon-doped source/drain (Si:C-S/D) layers. P or As substitution is in conflict with C substitution in Si:C layers during SPE. Furthermore, the amount of P incorporated instead of C into the Si lattice site is larger than that of As incorporated instead of C. Therefore, low-resistivity Si:C layers with low stress in the case of using P and high-resistivity Si:C layers with high stress in the case of using As are formed by single-step C7Hx implantation with rapid thermal annealing and nonmelt laser annealing, respectively. As a countermeasure, we demonstrate that cascade C7Hx implantation to control the C profiles in Si:C layers is effective for achieving high-strain channels and low-resistivity Si:C-S/D layers. Control of C profiles is a key technology for state-of-the-art complementary MOS devices with Si:C-S/D.

  1. Interfacial band configuration and electrical properties of LaAlO3/Al2O3/hydrogenated-diamond metal-oxide-semiconductor field effect transistors

    NASA Astrophysics Data System (ADS)

    Liu, J. W.; Liao, M. Y.; Imura, M.; Oosato, H.; Watanabe, E.; Tanaka, A.; Iwai, H.; Koide, Y.

    2013-08-01

    In order to search a gate dielectric with high permittivity on hydrogenated-diamond (H-diamond), LaAlO3 films with thin Al2O3 buffer layers are fabricated on the H-diamond epilayers by sputtering-deposition (SD) and atomic layer deposition (ALD) techniques, respectively. Interfacial band configuration and electrical properties of the SD-LaAlO3/ALD-Al2O3/H-diamond metal-oxide-semiconductor field effect transistors (MOSFETs) with gate lengths of 10, 20, and 30 μm have been investigated. The valence and conduction band offsets of the SD-LaAlO3/ALD-Al2O3 structure are measured by X-ray photoelectron spectroscopy to be 1.1 ± 0.2 and 1.6 ± 0.2 eV, respectively. The valence band discontinuity between H-diamond and LaAlO3 is evaluated to be 4.0 ± 0.2 eV, showing that the MOS structure acts as the gate which controls a hole carrier density. The leakage current density of the SD-LaAlO3/ALD-Al2O3/H-diamond MOS diode is smaller than 10-8 A cm-2 at gate bias from -4 to 2 V. The capacitance-voltage curve in the depletion mode shows sharp dependence, small flat band voltage, and small hysteresis shift, which implies low positive and trapped charge densities. The MOSFETs show p-type channel and complete normally off characteristics with threshold voltages changing from -3.6 ± 0.1 to -5.0 ± 0.1 V dependent on the gate length. The drain current maximum and the extrinsic transconductance of the MOSFET with gate length of 10 μm are -7.5 mA mm-1 and 2.3 ± 0.1 mS mm-1, respectively. The enhancement mode SD-LaAlO3/ALD-Al2O3/H-diamond MOSFET is concluded to be suitable for the applications of high power and high frequency electrical devices.

  2. Ultraviolet-assisted oxidation and nitridation of hafnium and hafnium aluminum alloys as potential gate dielectrics for metal oxide semiconductor applications

    NASA Astrophysics Data System (ADS)

    Essary, Chad Robert

    The continued miniaturization of silicon-based complimentary metal oxide semiconductor (CMOS) devices is pushing the limits of the silicon dioxide (SiO2) gate dielectric. As the channel widths are decreased to increase packing densities and functionality of new chips, proportional vertical scaling of the dielectric must be maintained to keep constant capacitances. Silicon dioxide is approaching its fundamental limit in which it can be used as the gate dielectric due to high leakage currents resulting from direct tunneling through the layer. In order for the continued use of current CMOS gate design, an alternative material with a higher dielectric constant must be found. Several materials have been proposed but are still not providing the electrical characteristics favorable for use in the devices due to problems with excessive leakage and hysteresis resulting from the quality of the film and oxygen defects. The goal of this study is to create higher quality films at lower processing temperatures with low leakage and less hysteresis than has been achieved with hafnium oxide films. This study first examines the formation of the interfacial layer in pulsed laser deposited hafnium oxide films to understand the kinetics behind its formation. The second section focuses on the oxidation of pulsed laser deposited (PLD) hafnium metal thin films using ultraviolet (UV) assisted post-deposition annealing. Another set of samples was deposited in an ammonia atmosphere in order to incorporate nitrogen into the films. Comparisons of microstructure and stoichiometry of oxidized hafnium and oxy-nitride films were made using x-ray photospectroscopy, variable angle spectroscopic ellipsometry, glancing angle x-ray spectroscopy, x-ray reflectivity, and atomic force microscopy. Analysis of the interface between the films and the silicon substrate was carried out using x-ray reflectivity. The electrical characteristics of the films were characterized using capacitance-voltage and current

  3. Temperature-Independent Switching Rates for a Random Telegraph Signal in a Silicon Metal-Oxide-Semiconductor Field-Effect Transistor at Low Temperatures

    SciTech Connect

    Borland, Nick; Fleetwood, D.M.; Scofield, John H.

    1999-07-19

    We have observed discrete random telegraph signals (RTS'S) in the drain voltages of three, observed above 30 K were thermally activated. The switching rate for the only RTS observed below 30 K was thermally activated above 30 K but temperature-independent below 10 K. To our knowledge, this cross-over from thermal activation to tunneling behavior has not been previously observed for RTS's Metal-oxide-semiconductor field-effect transistors (MCEWETS) often exhibit relatively large levels of low-frequency (1/fl noise) [1,2]. Much evidence suggests that this noise is related to the capture all cases, switching rates have been thermally activated, often with different activation energies for capture and/or emission is accompanied by lattice relaxation. Though thermally activated behavior has sufficiently low temperatures [7,9]. While not observed in MOSFETS, cross-over from thermal activation to configurational tunneling has been observed for RTS's in junctions [13]. drain voltage was observed to randomly switch between two discrete levels, designated as Vup and Vdn, similar to RTS's reported by others [2,7'- 11 ]. We have characterized six RTS `S for temperatures above 30 K where thermally activated switching rates are observed. The properties of five of these have been the trap, i.e., the mean time a captured charge carrier spends in the trap before it is emitted. Similarly, we identify the mean time in the low resistance state ( trup in state Vup) as the capture time rc. F@ure 1 shows a typical time trace of the drain-voltage fluctuation &d(t)= Vd(t)+Vd>. This indicate that both the mean capture and emission times become independent of Tat low temperatures and where a= capture or emission, is temperature independent. The solid curve in Figure 3(a) (mean capture time) was obtained using a weighted nonlinear charge carriers are not in thermal equilibrium with the lattice, i.e., that while the lattice is being cooled Instead, we believe that the transition from thermally

  4. Additional-Body Effects in a Self-Aligned Deca-Nanometer Ultrathin-Body and Buried Oxide Silicon-on-Insulator Metal-Oxide-Semiconductor Field-Effect Transistor: A Three-Dimensional Simulation Study

    NASA Astrophysics Data System (ADS)

    Lin, Jyi-Tsong; Eng, Yi-Chuen; Chen, Cheng-Hsin; Fan, Yi-Hsuan

    2011-11-01

    In this paper, we numerically investigate the additional-body effects (ABEs) created by the isolation-last fabrication process of a self-aligned deca-nanometer ultrathin-body and buried oxide (UTBB) silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET). The reasons for the device's new electrical characteristics are also explained in detail. The additional silicon body volumes of the UTBB SOI MOSFET are found to improve the subthreshold swing and the on/off current ratio. The additional body has a negative effect, however, upon both the gate leakage current and the total gate capacitance, when compared with a standard UTBB SOI MOSFET.

  5. Charge trapping induced drain-induced-barrier-lowering in HfO2/TiN p-channel metal-oxide-semiconductor-field-effect-transistors under hot carrier stress

    NASA Astrophysics Data System (ADS)

    Lo, Wen-Hung; Chang, Ting-Chang; Tsai, Jyun-Yu; Dai, Chih-Hao; Chen, Ching-En; Ho, Szu-Han; Chen, Hua-Mao; Cheng, Osbert; Huang, Cheng-Tung

    2012-04-01

    This letter studies the channel hot carrier stress (CHCS) behaviors on high dielectric constant insulator and metal gate HfO2/TiN p-channel metal-oxide-semiconductor field effect transistors. It can be found that the degradation is associated with electron trapping, resulting in Gm decrease and positive Vth shift. However, Vth under saturation region shows an insignificant degradation during stress. To compare that, the CHC-induced electron trapping induced DIBL is proposed to demonstrate the different behavior of Vth between linear and saturation region. The devices with different channel length are used to evidence the trapping-induced DIBL behavior.

  6. Study of gate oxide traps in HfO2/AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors by use of ac transconductance method

    NASA Astrophysics Data System (ADS)

    Sun, X.; Saadat, O. I.; Chang-Liao, K. S.; Palacios, T.; Cui, S.; Ma, T. P.

    2013-03-01

    We introduce an ac-transconductance method to profile the gate oxide traps in a HfO2 gated AlGaN/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistors (MOS-HEMTs) that can exchange carriers with metal gates, which in turn causes changes in analog and pulsed channel currents. The method extracts energy and spacial distributions of the oxide and interface traps under the gate from the frequency dependence of ac transconductance. We demonstrate the method using MOS-HEMTs with gate oxides that were annealed at different temperatures.

  7. Design, experimental verification, and analysis of a 1.8-V-input-range voltage-to-current converter using source degeneration for low-noise multimodal CMOS biosensor array

    NASA Astrophysics Data System (ADS)

    Niitsu, Kiichi; Ikeda, Kei; Muto, Keita; Nakazato, Kazuo

    2017-01-01

    A multimodal complementary metal-oxide semiconductor (CMOS) biosensor array manufactured using measurement methods such as potentiometry, amperometry, and impedimetry improves its cost competitiveness and measurement accuracy. In addition, it provides a wider range of application because it can obtain signals from multiple aspects. To develop high-signal-to-noise ratio (SNR) multimodal biosensor arrays, time-domain current integration was proposed in the literature and found to be effective. In addition to amperometry and impedimetry, it is possible to perform current integration using the potentiometry output by employing a voltage-to-current converter (VCC). However, a conventional VCC with a fixed transconductance mode does not provide a sufficient input range (<0.6 V) and its noise property has not been investigated. In this work, we investigate the design and noise property of a newly proposed VCC with source degeneration that enhances the input range. For evaluating the proposed method, a test chip was fabricated in a 0.6 µm CMOS. The measured results successfully demonstrate that the input range was enhanced from 0.6 to 1.8 V. Autonomous current limitation was also confirmed. The measured total input-referred noise was 0.445 mV (from 10 Hz to 10 kHz, assuming current integration at every 1 ms).

  8. Damage free Ar ion plasma surface treatment on In{sub 0.53}Ga{sub 0.47}As-on-silicon metal-oxide-semiconductor device

    SciTech Connect

    Koh, Donghyi; Shin, Seung Heon; Ahn, Jaehyun; Sonde, Sushant; Banerjee, Sanjay K.; Kwon, Hyuk-Min; Orzali, Tommaso; Kim, Tae-Woo; Kim, Dae-Hyun

    2015-11-02

    In this paper, we investigated the effect of in-situ Ar ion plasma surface pre-treatment in order to improve the interface properties of In{sub 0.53}Ga{sub 0.47}As for high-κ top-gate oxide deposition. X-ray photoelectron spectroscopy (XPS) and metal-oxide-semiconductor capacitors (MOSCAPs) demonstrate that Ar ion treatment removes the native oxide on In{sub 0.53}Ga{sub 0.47}As. The XPS spectra of Ar treated In{sub 0.53}Ga{sub 0.47}As show a decrease in the AsO{sub x} and GaO{sub x} signal intensities, and the MOSCAPs show higher accumulation capacitance (C{sub acc}), along with reduced frequency dispersion. In addition, Ar treatment is found to suppress the interface trap density (D{sub it}), which thereby led to a reduction in the threshold voltage (V{sub th}) degradation during constant voltage stress and relaxation. These results outline the potential of surface treatment for III-V channel metal-oxide-semiconductor devices and application to non-planar device process.

  9. Near infrared biosensor based on Classical Electromagnetically Induced Reflectance (Cl-EIR) in a planar complementary metamaterial

    NASA Astrophysics Data System (ADS)

    Vafapour, Zohreh

    2017-03-01

    In the field of plasmonic metamaterials (MMs), the sub-wavelength metallic structures play a role similar to atoms in nature. Classical electromagnetically induced reflectance (Cl-EIR) is a classical phenomenon which is analogue to the EIR quantum phenomenon in atomic systems. A sensitive control of the Cl-EIR is crucial to a range of potential applications such as slowing light and biosensor. Here we report on our three-dimensional nanophotonic complementary planar metamaterial consisting of an array of three slot strips plasmonic that exhibits Cl-EIR phenomenon with magnetic and electric dipolar and quadruplar interaction between the plasmonic molecules. Simply by introducing symmetry broken of the proposed MM, the Cl-EIR can be dynamically tuned. We further demonstrate using a numerical simulation that the coupling between the plasmonic modes in one asymmetric case with changing the dielectric surrounding of the nano-structure to prove our design has a great potential for near-infrared localized surface plasmon resonance (LSPR) sensing applications. The changing of the used metal in thin-film was also proposed to explain the coupling effects between the bright and dark modes of the Cl-EIR electromagnetic spectra on sensitivity of our proposed nano-structure in plasmonic sensing. This work paves a promising approach to achieve plasmonic sensing devices. Actually, the reflection of more than 97% is observed which is very high for the EIR effect. Furthermore, the figure of merit (FOM) of 17.3 and the group index of 413 are obtained. These mentioned characteristics make the proposed metamaterial with potential to apply for ultrafast switches, bio-sensors, and slow-light devices.

  10. Inversion in the In0.53Ga0.47As metal-oxide-semiconductor system: Impact of the In0.53Ga0.47As doping concentration

    NASA Astrophysics Data System (ADS)

    O'Connor, É.; Cherkaoui, K.; Monaghan, S.; Sheehan, B.; Povey, I. M.; Hurley, P. K.

    2017-01-01

    In0.53Ga0.47As metal-oxide-semiconductor (MOS) capacitors with an Al2O3 gate oxide and a range of n and p-type In0.53Ga0.47As epitaxial concentrations were examined. Multi-frequency capacitance-voltage and conductance-voltage characterization exhibited minority carrier responses consistent with surface inversion. The measured minimum capacitance at high frequency (1 MHz) was in excellent agreement with the theoretical minimum capacitance calculated assuming an inverted surface. Minority carrier generation lifetimes, τg, extracted from experimentally measured transition frequencies, ωm, using physics based a.c. simulations, demonstrated a reduction in τg with increasing epitaxial doping concentration. The frequency scaled conductance, G/ω, in strong inversion allowed the estimation of accurate Cox values for these MOS devices.

  11. Fabricating metal-oxide-semiconductor field-effect transistors on a polyethylene terephthalate substrate by applying low-temperature layer transfer of a single-crystalline silicon layer by meniscus force

    SciTech Connect

    Sakaike, Kohei; Akazawa, Muneki; Nakamura, Shogo; Higashi, Seiichiro

    2013-12-02

    A low-temperature local-layer technique for transferring a single-crystalline silicon (c-Si) film by using a meniscus force was proposed, and an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) was fabricated on polyethylene terephthalate (PET) substrate. It was demonstrated that it is possible to transfer and form c-Si films in the required shape at the required position on PET substrates at extremely low temperatures by utilizing a meniscus force. The proposed technique for layer transfer was applied for fabricating high-performance c-Si MOSFETs on a PET substrate. The fabricated MOSFET showed a high on/off ratio of more than 10{sup 8} and a high field-effect mobility of 609 cm{sup 2} V{sup −1} s{sup −1}.

  12. Tinv Scaling and Gate Leakage Reduction for n-Type Metal Oxide Semiconductor Field Effect Transistor with HfSix/HfO2 Gate Stack by Interfacial Layer Formation Using Ozone-Water-Last Treatment

    NASA Astrophysics Data System (ADS)

    Oshiyama, Itaru; Tai, Kaori; Hirano, Tomoyuki; Yamaguchi, Shinpei; Tanaka, Kazuaki; Hagimoto, Yoshiya; Uemura, Takayuki; Ando, Takashi; Watanabe, Koji; Yamamoto, Ryo; Kanda, Saori; Wang, Junli; Tateshita, Yasushi; Wakabayashi, Hitoshi; Tagawa, Yukio; Tsukamoto, Masanori; Iwamoto, Hayato; Saito, Masaki; Oshima, Masaharu; Toyoda, Satoshi; Nagashima, Naoki; Kadomura, Shingo

    2008-04-01

    In this paper, we demonstrate a wet treatment for the HfSix/HfO2 gate stack of n-type metal oxide semiconductor field effect transistor (nMOSFET) fabricated by a gate-last process in order to scale down the electrical thickness at inversion state Tinv value and reduce the gate leakage Jg. As a result, we succeeded in scaling down Tinv to 1.41 nm without mobility or Jg degradation by ozone-water-last treatment. We found that a high-density interfacial layer (IFL) is formed owing to the ozone-water-last treatment, and Hf diffusion to the IFL is suppressed, which was analyzed by high-resolution angle-resolved spectroscopy.

  13. Effects of stress annealing in nitrogen on the effective contact-potential difference, charges, and traps at the Si/SiO2 interface of metal-oxide-semiconductor devices

    NASA Astrophysics Data System (ADS)

    Przewlocki, Henryk M.; Massoud, Hisham Z.

    2002-08-01

    In this article, we report the results of a study of the effects of high-temperature stress annealing in nitrogen on the electrical properties of metal/oxide/semiconductor devices. In this study, we have experimentally characterized the dependence of the reduced effective contact-potential difference, the effective oxide charge (Neff), and the midgap interface trap density (Dit) on the annealing conditions in nitrogen. We have correlated such properties with the dependence of the index of refraction and oxide stress on the annealing conditions and oxide thickness in a companion article. We consider the contributions of the thermal-relaxation and nitrogen-incorporation processes in determining changes in the electrical properties with annealing time. This model description is consistent with other annealing studies carried out in argon where only the thermal-relaxation process is present.

  14. Investigation of trap properties in high-k/metal gate p-type metal-oxide-semiconductor field-effect-transistors with aluminum ion implantation using random telegraph noise analysis

    SciTech Connect

    Kao, Tsung-Hsien; Chang, Shoou-Jinn Fang, Yean-Kuen; Huang, Po-Chin; Wu, Chung-Yi; Wu, San-Lein

    2014-08-11

    In this study, the impact of aluminum ion implantation (Al I/I) on random telegraph noise (RTN) in high-k/metal gate (HK/MG) p-type metal-oxide-semiconductor field-effect-transistors (pMOSFETs) was investigated. The trap parameters of HK/MG pMOSFETs with Al I/I, such as trap energy level, capture time and emission time, activation energies for capture and emission, and trap location in the gate dielectric, were determined. The configuration coordinate diagram was also established. It was observed that the implanted Al could fill defects and form a thin Al{sub 2}O{sub 3} layer and thus increase the tunneling barrier height for holes. It was also observed that the trap position in the Al I/I samples was lower due to the Al I/I-induced dipole at the HfO{sub 2}/SiO{sub 2} interface.

  15. Investigation of an anomalous hump in gate current after negative-bias temperature-instability in HfO2/metal gate p-channel metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Ho, Szu-Han; Chang, Ting-Chang; Wu, Chi-Wei; Lo, Wen-Hung; Chen, Ching-En; Tsai, Jyun-Yu; Liu, Guan-Ru; Chen, Hua-Mao; Lu, Ying-Shin; Wang, Bin-Wei; Tseng, Tseung-Yuen; Cheng, Osbert; Huang, Cheng-Tung; Sze, Simon M.

    2013-01-01

    This Letter investigates a hump in gate current after negative-bias temperature-instability (NBTI) in HfO2/metal gate p-channel metal-oxide-semiconductor field-effect transistors. Measuring gate current at initial through body floating and source/drain floating shows that hole current flows from source/drain. The fitting of gate current (Ig)-gate voltage (Vg) characteristic curves demonstrates that the Frenkel-Poole mechanism dominates the conduction. Next, by fitting the gate current after NBTI, in the order of Frenkel-Poole then tunneling, the Frenkel-Poole mechanism can be confirmed. These phenomena can be attributed to hole trapping in high-k bulk and the electric field formula Ehigh-k ɛhigh-k = Q + Esio2ɛsio2.

  16. Analysis of an anomalous hump in gate current after dynamic negative bias stress in HfxZr1-xO2/metal gate p-channel metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Ho, Szu-Han; Chang, Ting-Chang; Wu, Chi-Wei; Lo, Wen-Hung; Chen, Ching-En; Tsai, Jyun-Yu; Luo, Hung-Ping; Tseng, Tseung-Yuen; Cheng, Osbert; Huang, Cheng-Tung; Sze, Simon M.

    2012-07-01

    This letter investigates a hump in gate current after dynamic negative bias stress (NBS) in HfxZr1-xO2/metal gate p-channel metal-oxide-semiconductor field-effect transistors. By measuring gate current under initial through body floating and source/drain floating, it shows that hole current flows from source/drain. The fitting of gate current-gate voltage characteristic curve demonstrates that Frenkel-Poole mechanism dominates the conduction. Next, by fitting the gate current after dynamic NBS, in the order of Frenkel-Poole then tunneling, the Frenkel-Poole mechanism can be confirmed. These phenomena can be attributed to hole trapping in high-k bulk and the electric field formula Ehigh-k ɛhigh-k = Q + Esio2ɛsio2.

  17. The influences of surface treatment and gas annealing conditions on the inversion behaviors of the atomic-layer-deposition Al2O3/n-In0.53Ga0.47As metal-oxide-semiconductor capacitor

    NASA Astrophysics Data System (ADS)

    Trinh, H. D.; Chang, E. Y.; Wu, P. W.; Wong, Y. Y.; Chang, C. T.; Hsieh, Y. F.; Yu, C. C.; Nguyen, H. Q.; Lin, Y. C.; Lin, K. L.; Hudait, M. K.

    2010-07-01

    The inversion behaviors of atomic-layer-deposition Al2O3/n-In0.53Ga0.47As metal-oxide-semiconductor capacitors are studied by various surface treatments and postdeposition annealing using different gases. By using the combination of wet sulfide and dry trimethyl aluminum surface treatment along with pure hydrogen annealing, a strong inversion capacitance-voltage (C-V) response is observed, indicating a remarkable reduction in interface trap state density (Dit) at lower half-part of In0.53Ga0.47As band gap. This low Dit was confirmed by the temperature independent C-V stretch-out and horizontal C-V curves. The x-ray photoelectron spectroscopy spectra further confirm the effectiveness of hydrogen annealing on the reduction of native oxides.

  18. Bulk and interface trap generation under negative bias temperature instability stress of p-channel metal-oxide-semiconductor field-effect transistors with nitrogen and silicon incorporated HfO2 gate dielectrics

    NASA Astrophysics Data System (ADS)

    Choi, Changhwan; Lee, Jack C.

    2011-02-01

    Negative bias temperature instabilities (NBTIs) of p-channel metal-oxide-semiconductor field-effect-transistor with HfO2, HfOxNy, and HfSiON were investigated. Higher bulk trap generation (ΔNot) is mainly attributed to threshold voltage shift rather than interface trap generation (ΔNit). ΔNit, ΔNot, activation energy (Ea), and lifetime were exacerbated with incorporated nitrogen while improved with adding Si into gate dielectrics. Compared to HfO2, HfOxNy showed worse NBTI due to nitrogen pile-up at Si interface. However, adding Si into HfOxNy placed nitrogen peak profile away from Si/oxide interface and NBTI was reduced. This improvement is ascribed to reduced ΔNot and ΔNit, resulting from less nitrogen at Si interface.

  19. Comparison between chemical vapor deposited and physical vapor deposited WSi{sub 2} metal gate for InGaAs n-metal-oxide-semiconductor field-effect transistors

    SciTech Connect

    Ong, B. S.; Pey, K. L.; Ong, C. Y.; Tan, C. S.; Antoniadis, D. A.; Fitzgerald, E. A.

    2011-05-02

    We compare chemical vapor deposition (CVD) and physical vapor deposition (PVD) WSi{sub 2} metal gate process for In{sub 0.53}Ga{sub 0.47}As n-metal-oxide-semiconductor field-effect transistors using 10 and 6.5 nm Al{sub 2}O{sub 3} as dielectric layer. The CVD-processed metal gate device with 6.5 nm Al{sub 2}O{sub 3} shows enhanced transistor performance such as drive current, maximum transconductance and maximum effective mobility. These values are relatively better than the PVD-processed counterpart device with improvement of 51.8%, 46.4%, and 47.8%, respectively. The improvement for the performance of the CVD-processed metal gate device is due to the fluorine passivation at the oxide/semiconductor interface and a nondestructive deposition process.

  20. Origin of the performances degradation of two-dimensional-based metal-oxide-semiconductor field effect transistors in the sub-10 nm regime: A first-principles study

    SciTech Connect

    Lu, Anh Khoa Augustin; Pourtois, Geoffrey; Agarwal, Tarun; Afzalian, Aryan; Radu, Iuliana P.; Houssa, Michel

    2016-01-25

    The impact of the scaling of the channel length on the performances of metal-oxide-semiconductor field effect transistors, based on two-dimensional (2D) channel materials, is theoretically investigated, using density functional theory combined with the non-equilibrium Green's function method. It is found that the scaling of the channel length below 10 nm leads to strong device performance degradations. Our simulations reveal that this degradation is essentially due to the tunneling current flowing between the source and the drain in these aggressively scaled devices. It is shown that this electron tunneling process is modulated by the effective mass of the 2D channel material, and sets the limit of the scaling in future transistor designs.

  1. Improved electrical properties of Ge metal-oxide-semiconductor capacitors with high-k HfO2 gate dielectric by using La2O3 interlayer sputtered with/without N2 ambient

    NASA Astrophysics Data System (ADS)

    Xu, H. X.; Xu, J. P.; Li, C. X.; Lai, P. T.

    2010-07-01

    The electrical properties of n-Ge metal-oxide-semiconductor (MOS) capacitors with HfO2/LaON or HfO2/La2O3 stacked gate dielectric (LaON or La2O3 as interlayer) are investigated. It is found that better electrical performances, including lower interface-state density, smaller gate leakage current, smaller capacitance equivalent thickness, larger k value, and negligible C-V frequency dispersion, can be achieved for the MOS device with LaON interlayer. The involved mechanism lies in that the LaON interlayer can effectively block the interdiffusions of Ge, O, and Hf, thus suppressing the growth of unstable GeOx interlayer and improving the dielectric/Ge interface quality.

  2. Near interface traps in SiO2/4H-SiC metal-oxide-semiconductor field effect transistors monitored by temperature dependent gate current transient measurements

    NASA Astrophysics Data System (ADS)

    Fiorenza, Patrick; La Magna, Antonino; Vivona, Marilena; Roccaforte, Fabrizio

    2016-07-01

    This letter reports on the impact of gate oxide trapping states on the conduction mechanisms in SiO2/4H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs). The phenomena were studied by gate current transient measurements, performed on n-channel MOSFETs operated in "gate-controlled-diode" configuration. The measurements revealed an anomalous non-steady conduction under negative bias (VG > |20 V|) through the SiO2/4H-SiC interface. The phenomenon was explained by the coexistence of a electron variable range hopping and a hole Fowler-Nordheim (FN) tunnelling. A semi-empirical modified FN model with a time-depended electric field is used to estimate the near interface traps in the gate oxide (Ntrap ˜ 2 × 1011 cm-2).

  3. A comparison between HfO2/Al2O3 nano-laminates and ternary HfxAlyO compound as the dielectric material in InGaAs based metal-oxide-semiconductor (MOS) capacitors

    NASA Astrophysics Data System (ADS)

    Krylov, Igor; Pokroy, Boaz; Eizenberg, Moshe; Ritter, Dan

    2016-09-01

    We compare the electrical properties of HfO2/Al2O3 nano-laminates with those of the ternary HfxAlyO compound in metal oxide semiconductor (MOS) capacitors. The dielectrics were deposited by atomic layer deposition on InGaAs. Water, ozone, and oxygen plasma were tested as oxygen precursors, and best results were obtained using water. The total dielectric thickness was kept constant in our experiments. It was found that the effective dielectric constant increased and the leakage current decreased with the number of periods. Best results were obtained for the ternary compound. The effect of the sublayer thicknesses on the electrical properties of the interface was carefully investigated, as well as the role of post-metallization annealing. Possible explanations for the observed trends are provided. We conclude that the ternary HfxAlyO compound is more favorable than the nano-laminates approach for InGaAs based MOS transistor applications.

  4. High-performance, mechanically flexible, and vertically integrated 3D carbon nanotube and InGaZnO complementary circuits with a temperature sensor.

    PubMed

    Honda, Wataru; Harada, Shingo; Ishida, Shohei; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

    2015-08-26

    A vertically integrated inorganic-based flexible complementary metal-oxide-semiconductor (CMOS) inverter with a temperature sensor with a high inverter gain of ≈50 and a low power consumption of <7 nW mm(-1) is demonstrated using a layer-by-layer assembly process. In addition, the negligible influence of the mechanical flexibility on the performance of the CMOS inverter and the temperature dependence of the CMOS inverter characteristics are discussed.

  5. Low Threshold Voltage and High Mobility N-Channel Metal-Oxide-Semiconductor Field-Effect Transistor Using Hf-Si/HfO2 Gate Stack Fabricated by Gate-Last Process

    NASA Astrophysics Data System (ADS)

    Ando, Takashi; Hirano, Tomoyuki; Tai, Kaori; Yamaguchi, Shinpei; Yoshida, Shinichi; Iwamoto, Hayato; Kadomura, Shingo; Watanabe, Heiji

    2010-01-01

    Systematic characterization of Hf-Si/HfO2 gate stacks revealed two mobility degradation modes. One is carrier scattering by fixed charges and/or trapped charges induced by the crystallization in the thick HfO2 case (inversion oxide thickness, Tinv> 1.6 nm). The other is the Hf penetration into the interfacial layer with the Si substrate in the thin HfO2 case (Tinv< 1.6 nm) for the Hf-rich electrode. It was demonstrated that careful optimization of the HfO2 thickness and the Hf-Si composition can suppress both modes. As a result, a high electron mobility equivalent to that of n+polycrystalline silicon (poly-Si)/SiO2 (248 cm2 V-1 s-1 at Eeff=1 MV/cm) was obtained at Tinv of 1.47 nm. Moreover, the effective work function of the optimized Hf-Si/HfO2 gate stack is located within 50 mV from the Si band edge (Ec). An extremely high Ion of 1165 µA/µm (at Ioff = 81 nA/µm) at Vdd=1.0 V was demonstrated for a 45 nm gate n-channel metal-oxide-semiconductor field-effect transistor (n-MOSFET) without strain enhanced technology.

  6. High quality PECVD SiO2 process for recessed MOS-gate of AlGaN/GaN-on-Si metal-oxide-semiconductor heterostructure field-effect transistors

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Gil; Kim, Hyun-Seop; Seo, Kwang-Seok; Cho, Chun-Hyung; Cha, Ho-Young

    2016-08-01

    A high quality SiO2 deposition process using a plasma enhanced chemical vapor deposition system has been developed for the gate insulator process of normally-off recessed-gate AlGaN/GaN metal-oxide-semiconductor-heterostructure field-effect transistors (MOS-HFETs). SiO2 films were deposited by using SiH4 and N2O mixtures as reactant gases. The breakdown field increased with increasing the N2O flow rate. The optimum SiH4/N2O ratio was 0.05, which resulted in a maximum breakdown field of 11 MV/cm for the SiO2 film deposited on recessed GaN surface. The deposition conditions were optimized as follows; a gas flow rate of SiH4/N2O (=27/540 sccm), a source RF power of 100 W, a pressure of 2 Torr, and a deposition temperature of 350 °C. A fabricated normally-off MOS-HFET exhibited a threshold voltage of 3.2 V, a specific on-resistance of 4.46 mΩ cm2, and a breakdown voltage of 810 V.

  7. Measurement of n-type Dry Thermally Oxidized 6H-SiC Metal-oxide Semiconductor Diodes by Quasistatic and High-Frequency Capacitance Versus Voltage and Capacitance Transient Techniques

    NASA Technical Reports Server (NTRS)

    Neudeck, P.; Kang, S.; Petit, J.; Tabib-Azar, M.

    1994-01-01

    Dry-oxidized n-type 6H-SiC metal-oxide-semiconductor capacitors are investigated using quasistatic capacitance versus voltage (C-V), high-frequency C-V, and pulsed high-frequency capacitance transient (C-t) analysis over the temperature range from 297 to 573 K. The quasistatic C - V characteristics presented are the first reported for 6H-SiC MOS capacitors, and exhibit startling nonidealities due to nonequilibrium conditions that arise from the fact that the recombination/generation process in 6H-SiC is extraordinarily slow even at the highest measurement temperature employed. The high-frequency dark C-V characteristics all showed deep depletion with no observable hysteresis. The recovery of the high-frequency capacitance from deep depletion to inversion was used to characterize the minority-carrier generation process as a function of temperature. Zerbst analysis conducted on the resulting C-t transients, which were longer than 1000 s at 573 K, showed a generation lifetime thermal activation energy of 0.49 eV.

  8. Ultra-low temperature radio-frequency performance of partially depleted silicon-on-insulator n-type metal-oxide-semiconductor field-effect transistors with tunnel diode body contact structures

    NASA Astrophysics Data System (ADS)

    Lu, Kai; Chen, Jing; Huang, Yuping; Liu, Jun; Luo, Jiexin; Wang, Xi

    2016-11-01

    Radio-frequency (RF) characteristics under ultra-low temperature of multi-finger partially depleted silicon-on-insulator (PD SOI) n-type metal-oxide-semiconductor field-effect transistors (nMOSFETs) with tunnel diode body-contact (TDBC) structure and T-gate body-contact (TB) structure are investigated in this paper. When operating at 77 K, TDBC device suppresses floating-body effect (FBE) as well as the TB device. For TB device and TDBC device, cut-off frequency (f T) improves as the temperature decreases to liquid-helium temperature (77 K) while that of the maximum oscillation frequency (f MAX) is opposite due to the decrease of the unilateral power gain. While operating under 77 K, f T and f MAX of TDBC device reach to 125 GHz and 77 GHz, representing 8% and 15% improvements compared with those of TB device, respectively, which is mainly due to the lower parasitic resistances and capacitances. The results indicate that TDBC SOI MOSFETs could be considered as promising candidates for analog and RF applications over a wide range of temperatures and there is immense potential for the development of RF CMOS integrated circuits for cryogenic applications.

  9. Post-Annealing Effects on Fixed Charge and Slow/Fast Interface States of TiN/Al2O3/p-Si Metal-Oxide-Semiconductor Capacitor

    NASA Astrophysics Data System (ADS)

    Jeon, In Sang; Park, Jaehoo; Eom, Dail; Hwang, Cheol Seong; Kim, Hyeong Joon; Park, Chan Jin; Cho, Hoon Young; Lee, Jong-Ho; Lee, Nae-In; Kang, Ho-Kyu

    2003-03-01

    The fixed charges (Nf) and the “slow” (Nsi) and “fast” (Dit) interface states of TiN/Al2O3/p-Si metal-oxide-semiconductor (MOS) capacitors were investigated by the capacitance-voltage and deep level transient spectroscopy (DLTS) method. In addition, small pulse DLTS (SP-DLTS) analysis was performed for a more precise estimation of energies and capture cross sections of the interface states. The variations in the Nf, Nsi and Dit with various post-annealing conditions were evaluated. Annealing under a H2 atmosphere effectively reduced the Nf, Nsi, and Dit. The Dit at an energy of 0.35 eV from the valence band decreased from 1× 1012 cm-2eV-1 at the as-fabricated state to 4× 1011 cm-2eV-1 after annealing at 450°C. A large peak related to minority carrier capture was detected in the high temperature region of the DLTS results. The peak intensity also decreased after hydrogen annealing. This suggests that the interface states in the upper half of the Si band-gap decrease with H2 annealing.

  10. Effect of barrier recess on transport and electrostatic interface properties of GaN-based normally-off and normally-on metal oxide semiconductor heterostructure field effect transistors

    NASA Astrophysics Data System (ADS)

    Capriotti, M.; Bahat Treidel, E.; Fleury, C.; Bethge, O.; Ostermaier, C.; Rigato, M.; Lancaster, S. L. C.; Brunner, F.; Detz, H.; Hilt, O.; Würfl, J.; Pogany, D.; Strasser, G.

    2016-11-01

    We perform a comprehensive electrical transport and physical characterization of metal oxide semiconductor heterostructure field effect transistors with ZrO2 gate dielectrics, having partially (referred here as MOS-HFET) and fully (here called true-MOS-FET) recessed GaN/AlGaN/GaN barrier, giving normally-on and normally-off behavior, respectively. The mobility of the MOS-HFETs decreases with the proximity of the Coulomb scattering centers, situated at the ZrO2/AlGaN interface. The effect of the etching procedure and ZrO2 deposition on the formation of the interfacial charges, Nint, is evaluated by X-ray Photoelectron Spectroscopy and by fitting the threshold voltage values to numerical model. For the both device types, the extracted value of Nint lies within 15% around 2.8 × 1013 cm-2, which is of the order of polarization charge, showing that our low-damage three step etching procedure does not introduce extra interface states.

  11. Systematical Study of Reliability Issues in Plasma-Nitrided and Thermally Nitrided Oxides for Advanced Dual-Gate Oxide p-Channel Metal-Oxide-Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Lo, Wen-Cheng; Wu, Shien-Yang; Chang, Sun-Jay; Chiang, Mu-Chi; Lin, Chih-Yung; Chao, Tien-Sheng; Chang, Chun-Yen

    2007-03-01

    In this study, we compared the effects of negative-bias temperature instability (NBTI) and hot-carrier injection (HCI) on the core and input/output (I/O) p-channel metal-oxide-semiconductor field-effect transistor (PMOSFET) fabricated using the different gate dielectrics of plasma nitrided oxide (PNO) and thermally nitrided oxide (TNO). The mobility and constant overdrive current of the PMOSFETs fabricated using PNO as a gate oxide material are about 30 and 23% higher than those of the devices fabricated using TNO, respectively. The core PMOSFETs fabricated using PNO show a better NBTI and HCI immunity than those fabricated using TNO owing to the lower nitrogen concentration at the SiO2/Si-substrate interface. However, the I/O PMOSFETs fabricated using PNO show a higher HCI-induced degradation rate because of a higher oxide bulk trap density but a better NBTI than the devices fabricated using TNO at a normal stressed bias due to a low interface trap density.

  12. Nitride passivation reduces interfacial traps in atomic-layer-deposited Al{sub 2}O{sub 3}/GaAs (001) metal-oxide-semiconductor capacitors using atmospheric metal-organic chemical vapor deposition

    SciTech Connect

    Aoki, T. Fukuhara, N.; Osada, T.; Sazawa, H.; Hata, M.; Inoue, T.

    2014-07-21

    Using an atmospheric metal-organic chemical vapor deposition system, we passivated GaAs with AlN prior to atomic layer deposition of Al{sub 2}O{sub 3}. This AlN passivation incorporated nitrogen at the Al{sub 2}O{sub 3}/GaAs interface, improving the capacitance-voltage (C–V) characteristics of the resultant metal-oxide-semiconductor capacitors (MOSCAPs). The C–V curves of these devices showed a remarkable reduction in the frequency dispersion of the accumulation capacitance. Using the conductance method at various temperatures, we extracted the interfacial density of states (D{sub it}). The D{sub it} was reduced over the entire GaAs band gap. In particular, these devices exhibited D{sub it} around the midgap of less than 4 × 10{sup 12} cm{sup −2}eV{sup −1}, showing that AlN passivation effectively reduced interfacial traps in the MOS structure.

  13. Effect of proton irradiation dose on InAlN/GaN metal-oxide semiconductor high electron mobility transistors with Al2O3 gate oxide

    SciTech Connect

    Ahn, Shihyun; Kim, Byung -Jae; Lin, Yi -Hsuan; Ren, Fan; Pearton, Stephen J.; Yang, Gwangseok; Kim, Jihyun; Kravchenko, Ivan I.

    2016-07-26

    The effects of proton irradiation on the dc performance of InAlN/GaN metal-oxide-semiconductor high electron mobility transistors (MOSHEMTs) with Al2O3 as the gate oxide were investigated. The InAlN/GaN MOSHEMTs were irradiated with doses ranging from 1×1013 to 1×1015cm–2 at a fixed energy of 5MeV. There was minimal damage induced in the two dimensional electron gas at the lowest irradiation dose with no measurable increase in sheet resistance, whereas a 9.7% increase of the sheet resistance was observed at the highest irradiation dose. By sharp contrast, all irradiation doses created more severe degradation in the Ohmic metal contacts, with increases of specific contact resistance from 54% to 114% over the range of doses investigated. These resulted in source-drain current–voltage decreases ranging from 96 to 242 mA/mm over this dose range. The trap density determined from temperature dependent drain current subthreshold swing measurements increased from 1.6 × 1013 cm–2 V–1 for the reference MOSHEMTs to 6.7 × 1013 cm–2 V–1 for devices irradiated with the highest dose. In conclusion, the carrier removal rate was 1287 ± 64 cm–1, higher than the authors previously observed in AlGaN/GaN MOSHEMTs for the same proton energy and consistent with the lower average bond energy of the InAlN.

  14. Phosphorus and boron diffusion paths in polycrystalline silicon gate of a trench-type three-dimensional metal-oxide-semiconductor field effect transistor investigated by atom probe tomography

    SciTech Connect

    Han, Bin Takamizawa, Hisashi Shimizu, Yasuo; Inoue, Koji; Nagai, Yasuyoshi; Yano, Fumiko; Kunimune, Yorinobu; Inoue, Masao; Nishida, Akio

    2015-07-13

    The dopant (P and B) diffusion path in n- and p-types polycrystalline-Si gates of trench-type three-dimensional (3D) metal-oxide-semiconductor field-effect transistors (MOSFETs) were investigated using atom probe tomography, based on the annealing time dependence of the dopant distribution at 900 °C. Remarkable differences were observed between P and B diffusion behavior. In the initial stage of diffusion, P atoms diffuse into deeper regions from the implanted region along grain boundaries in the n-type polycrystalline-Si gate. With longer annealing times, segregation of P on the grain boundaries was observed; however, few P atoms were observed within the large grains or on the gate/gate oxide interface distant from grain boundaries. These results indicate that P atoms diffuse along grain boundaries much faster than through the bulk or along the gate/gate oxide interface. On the other hand, in the p-type polycrystalline-Si gate, segregation of B was observed only at the initial stage of diffusion. After further annealing, the B atoms became uniformly distributed, and no clear segregation of B was observed. Therefore, B atoms diffuse not only along the grain boundary but also through the bulk. Furthermore, B atoms diffused deeper than P atoms along the grain boundaries under the same annealing conditions. This information on the diffusion behavior of P and B is essential for optimizing annealing conditions in order to control the P and B distributions in the polycrystalline-Si gates of trench-type 3D MOSFETs.

  15. Reduction in the interface-states density of metal-oxide-semiconductor field-effect transistors fabricated on high-index Si (114) surfaces by using an external magnetic field

    SciTech Connect

    Molina, J. De La Hidalga, J.; Gutierrez, E.

    2014-08-14

    After fabrication of Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) devices on high-index silicon (114) surfaces, their threshold voltage (Vth) and interface-states density (Dit) characteristics were measured under the influence of an externally applied magnetic field of B = 6 μT at room temperature. The electron flow of the MOSFET's channel presents high anisotropy on Si (114), and this effect is enhanced by using an external magnetic field B, applied parallel to the Si (114) surface but perpendicular to the electron flow direction. This special configuration results in the channel electrons experiencing a Lorentzian force which pushes the electrons closer to the Si (114)-SiO{sub 2} interface and therefore to the special morphology of the Si (114) surface. Interestingly, Dit evaluation of n-type MOSFETs fabricated on Si (114) surfaces shows that the Si (114)-SiO{sub 2} interface is of high quality so that Dit as low as ∼10{sup 10 }cm{sup −2}·eV{sup −1} are obtained for MOSFETs with channels aligned at specific orientations. Additionally, using both a small positive Vds ≤ 100 mV and B = 6 μT, the former Dit is reduced by 35% in MOSFETs whose channels are aligned parallel to row-like nanostructures formed atop Si (114) surfaces (channels having a 90° rotation), whereas Dit is increased by 25% in MOSFETs whose channels are aligned perpendicular to these nanostructures (channels having a 0° rotation). From these results, the special morphology of a high-index Si (114) plane having nanochannels on its surface opens the possibility to reduce the electron-trapping characteristics of MOSFET devices having deep-submicron features and operating at very high frequencies.

  16. High-performance self-aligned inversion-channel In0.53Ga0.47As metal-oxide-semiconductor field-effect-transistors by in-situ atomic-layer-deposited HfO2

    NASA Astrophysics Data System (ADS)

    Lin, T. D.; Chang, W. H.; Chu, R. L.; Chang, Y. C.; Chang, Y. H.; Lee, M. Y.; Hong, P. F.; Chen, Min-Cheng; Kwo, J.; Hong, M.

    2013-12-01

    Self-aligned inversion-channel In0.53Ga0.47As metal-oxide-semiconductor field-effect-transistors (MOSFETs) have been fabricated using the gate dielectrics of in-situ directly atomic-layer-deposited (ALD) HfO2 followed by ALD-Al2O3. There were no surface pretreatments and no interfacial passivation/barrier layers prior to the ALD. TiN/Al2O3 (4 nm)/HfO2 (1 nm)/In0.53Ga0.47As/InP MOS capacitors exhibited well-behaved capacitance-voltage characteristics with true inversion behavior, low leakage current densities of ˜10-8 A/cm2 at ±1 MV/cm, and thermodynamic stability at high temperatures. Al2O3 (3 nm)/HfO2 (1 nm)/In0.53Ga0.47As MOSFETs of 1 μm gate length, with 700 °C-800 °C rapid thermal annealing in source/drain activation, have exhibited high extrinsic drain current (ID) of 1.5 mA/μm, transconductance (Gm) of 0.84 mS/μm, ION/IOFF of ˜104, low sub-threshold swing of 103 mV/decade, and field-effect electron mobility of 1100 cm2/V . s. The devices have also achieved very high intrinsic ID and Gm of 2 mA/μm and 1.2 mS/μm, respectively.

  17. Electrical properties of GaAs metal-oxide-semiconductor structure comprising Al2O3 gate oxide and AlN passivation layer fabricated in situ using a metal-organic vapor deposition/atomic layer deposition hybrid system

    NASA Astrophysics Data System (ADS)

    Aoki, Takeshi; Fukuhara, Noboru; Osada, Takenori; Sazawa, Hiroyuki; Hata, Masahiko; Inoue, Takayuki

    2015-08-01

    This paper presents a compressive study on the fabrication and optimization of GaAs metal-oxide-semiconductor (MOS) structures comprising a Al2O3 gate oxide, deposited via atomic layer deposition (ALD), with an AlN interfacial passivation layer prepared in situ via metal-organic chemical vapor deposition (MOCVD). The established protocol afforded self-limiting growth of Al2O3 in the atmospheric MOCVD reactor. Consequently, this enabled successive growth of MOCVD-formed AlN and ALD-formed Al2O3 layers on the GaAs substrate. The effects of AlN thickness, post-deposition anneal (PDA) conditions, and crystal orientation of the GaAs substrate on the electrical properties of the resulting MOS capacitors were investigated. Thin AlN passivation layers afforded incorporation of optimum amounts of nitrogen, leading to good capacitance-voltage (C-V) characteristics with reduced frequency dispersion. In contrast, excessively thick AlN passivation layers degraded the interface, thereby increasing the interfacial density of states (Dit) near the midgap and reducing the conduction band offset. To further improve the interface with the thin AlN passivation layers, the PDA conditions were optimized. Using wet nitrogen at 600 °C was effective to reduce Dit to below 2 × 1012 cm-2 eV-1. Using a (111)A substrate was also effective in reducing the frequency dispersion of accumulation capacitance, thus suggesting the suppression of traps in GaAs located near the dielectric/GaAs interface. The current findings suggest that using an atmosphere ALD process with in situ AlN passivation using the current MOCVD system could be an efficient solution to improving GaAs MOS interfaces.

  18. Blue/pink/purple electroluminescence from metal-oxide-semiconductor devices fabricated by spin-coating of [tantalum:(gadolinium/praseodymium)] and (praseodymium:cerium) organic compounds on silicon

    NASA Astrophysics Data System (ADS)

    Ohzone, Takashi; Matsuda, Toshihiro; Fukuoka, Ryouhei; Hattori, Fumihiro; Iwata, Hideyuki

    2016-08-01

    Blue/pink/purple electroluminescence (EL) from metal-oxide-semiconductor (MOS) devices with an indium tin oxide (ITO)/[Gd/(Ta + Gd/Pr)/(Pr + Ce)-Si-O] insulator layer/n+-Si substrate surface is reported. The insulator layers were fabricated from organic liquid sources of Gd or (Ta + Gd/Pr)/(Pr + Ce) mixtures, which were spin-coated on the n+-Si substrate and annealed at 950 °C for 30 min in air. The EL emission could be observed by the naked eye in the dark in the Fowler-Nordheim (FN) tunnel current regions. Peak wavelengths in the measured EL spectra were independent of the positive current. The EL intensity ratio of ultraviolet (UV) to the visible range varied with the composition ratio of the (Ta + Gd) liquids, and an optimum Ta to Gd ratio existed for the strongest blue emission, which could be attributed to the Ta-related oxide/silicate. The pink EL of the device fabricated with the (\\text{Ta}:\\text{Pr} = 6:4) mixture ratio can be explained by EL emission peaks related to the Pr3+ ions. The purple EL observed from the (\\text{Pr}:\\text{Ce} = 6:4) device corresponds to the strong and broad emission profile near the 357 nm peak, which cannot be assigned to Ce3+ ions. The results suggest that the EL can be attributed to the double-layer oxides with different compositions in the MOS devices. The upper layer consists of various Ta-, Gd-, Pr-, and Ce-related oxides and their silicates, while the lower SiO x -rich layer contributes to the FN current due to the high electric field, and thus the various EL colors.

  19. Enhanced two dimensional electron gas transport characteristics in Al{sub 2}O{sub 3}/AlInN/GaN metal-oxide-semiconductor high-electron-mobility transistors on Si substrate

    SciTech Connect

    Freedsman, J. J. Watanabe, A.; Urayama, Y.; Egawa, T.

    2015-09-07

    The authors report on Al{sub 2}O{sub 3}/Al{sub 0.85}In{sub 0.15}N/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistor (MOS-HEMT) on Si fabricated by using atomic layer deposited Al{sub 2}O{sub 3} as gate insulator and passivation layer. The MOS-HEMT with the gate length of 2 μm exhibits excellent direct-current (dc) characteristics with a drain current maximum of 1270 mA/mm at a gate bias of 3 V and an off-state breakdown voltage of 180 V for a gate-drain spacing of 4 μm. Also, the 1 μm-gate MOS-HEMT shows good radio-frequency (rf) response such as current gain and maximum oscillation cut-off frequencies of 10 and 34 GHz, respectively. The capacitance-voltage characteristics at 1 MHz revealed significant increase in two-dimensional electron gas (2DEG) density for the MOS-HEMT compared to conventional Schottky barrier HEMTs. Analyses using drain-source conductivity measurements showed improvements in 2DEG transport characteristics for the MOS-HEMT. The enhancements in dc and rf performances of the Al{sub 2}O{sub 3}/Al{sub 0.85}In{sub 0.15}N/GaN MOS-HEMT are attributed to the improvements in 2DEG characteristics.

  20. Ultraviolet GaN photodetectors on Si via oxide buffer heterostructures with integrated short period oxide-based distributed Bragg reflectors and leakage suppressing metal-oxide-semiconductor contacts

    SciTech Connect

    Szyszka, A. E-mail: adam.szyszka@pwr.wroc.pl; Haeberlen, M.; Storck, P.; Thapa, S. B.; Schroeder, T.

    2014-08-28

    Based on a novel double step oxide buffer heterostructure approach for GaN integration on Si, we present an optimized Metal-Semiconductor-Metal (MSM)-based Ultraviolet (UV) GaN photodetector system with integrated short-period (oxide/Si) Distributed Bragg Reflector (DBR) and leakage suppressing Metal-Oxide-Semiconductor (MOS) electrode contacts. In terms of structural properties, it is demonstrated by in-situ reflection high energy electron diffraction and transmission electron microscopy-energy dispersive x-ray studies that the DBR heterostructure layers grow with high thickness homogeneity and sharp interface structures sufficient for UV applications; only minor Si diffusion into the Y{sub 2}O{sub 3} films is detected under the applied thermal growth budget. As revealed by comparative high resolution x-ray diffraction studies on GaN/oxide buffer/Si systems with and without DBR systems, the final GaN layer structure quality is not significantly influenced by the growth of the integrated DBR heterostructure. In terms of optoelectronic properties, it is demonstrated that—with respect to the basic GaN/oxide/Si system without DBR—the insertion of (a) the DBR heterostructures and (b) dark current suppressing MOS contacts enhances the photoresponsivity below the GaN band-gap related UV cut-off energy by almost up to two orders of magnitude. Given the in-situ oxide passivation capability of grown GaN surfaces and the one order of magnitude lower number of superlattice layers in case of higher refractive index contrast (oxide/Si) systems with respect to classical III-N DBR superlattices, virtual GaN substrates on Si via functional oxide buffer systems are thus a promising robust approach for future GaN-based UV detector technologies.

  1. Ge{sub 0.83}Sn{sub 0.17} p-channel metal-oxide-semiconductor field-effect transistors: Impact of sulfur passivation on gate stack quality

    SciTech Connect

    Lei, Dian; Wang, Wei; Gong, Xiao E-mail: yeo@ieee.org; Liang, Gengchiau; Yeo, Yee-Chia E-mail: yeo@ieee.org; Zhang, Zheng; Pan, Jisheng; Tok, Eng-Soon

    2016-01-14

    The effect of room temperature sulfur passivation of the surface of Ge{sub 0.83}Sn{sub 0.17} prior to high-k dielectric (HfO{sub 2}) deposition is investigated. X-ray photoelectron spectroscopy (XPS) was used to examine the chemical bonding at the interface of HfO{sub 2} and Ge{sub 0.83}Sn{sub 0.17}. Sulfur passivation is found to be effective in suppressing the formation of both Ge oxides and Sn oxides. A comparison of XPS results for sulfur-passivated and non-passivated Ge{sub 0.83}Sn{sub 0.17} samples shows that sulfur passivation of the GeSn surface could also suppress the surface segregation of Sn atoms. In addition, sulfur passivation reduces the interface trap density D{sub it} at the high-k dielectric/Ge{sub 0.83}Sn{sub 0.17} interface from the valence band edge to the midgap of Ge{sub 0.83}Sn{sub 0.17}, as compared with a non-passivated control. The impact of the improved D{sub it} is demonstrated in Ge{sub 0.83}Sn{sub 0.17} p-channel metal-oxide-semiconductor field-effect transistors (p-MOSFETs). Ge{sub 0.83}Sn{sub 0.17} p-MOSFETs with sulfur passivation show improved subthreshold swing S, intrinsic transconductance G{sub m,int}, and effective hole mobility μ{sub eff} as compared with the non-passivated control. At a high inversion carrier density N{sub inv} of 1 × 10{sup 13 }cm{sup −2}, sulfur passivation increases μ{sub eff} by 25% in Ge{sub 0.83}Sn{sub 0.17} p-MOSFETs.

  2. A molybdenum disulfide/carbon nanotube heterogeneous complementary inverter.

    PubMed

    Huang, Jun; Somu, Sivasubramanian; Busnaina, Ahmed

    2012-08-24

    We report a simple, bottom-up/top-down approach for integrating drastically different nanoscale building blocks to form a heterogeneous complementary inverter circuit based on layered molybdenum disulfide and carbon nanotube (CNT) bundles. The fabricated CNT/MoS(2) inverter is composed of n-type molybdenum disulfide (MOS(2)) and p-type CNT transistors, with a high voltage gain of 1.3. The CNT channels are fabricated using directed assembly while the layered molybdenum disulfide channels are fabricated by mechanical exfoliation. This bottom-up fabrication approach for integrating various nanoscale elements with unique characteristics provides an alternative cost-effective methodology to complementary metal-oxide-semiconductors, laying the foundation for the realization of high performance logic circuits.

  3. Subnanowatt carbon nanotube complementary logic enabled by threshold voltage control.

    PubMed

    Geier, Michael L; Prabhumirashi, Pradyumna L; McMorrow, Julian J; Xu, Weichao; Seo, Jung-Woo T; Everaerts, Ken; Kim, Chris H; Marks, Tobin J; Hersam, Mark C

    2013-10-09

    In this Letter, we demonstrate thin-film single-walled carbon nanotube (SWCNT) complementary metal-oxide-semiconductor (CMOS) logic devices with subnanowatt static power consumption and full rail-to-rail voltage transfer characteristics as is required for logic gate cascading. These results are enabled by a local metal gate structure that achieves enhancement-mode p-type and n-type SWCNT thin-film transistors (TFTs) with widely separated and symmetric threshold voltages. These complementary SWCNT TFTs are integrated to demonstrate CMOS inverter, NAND, and NOR logic gates at supply voltages as low as 0.8 V with ideal rail-to-rail operation, subnanowatt static power consumption, high gain, and excellent noise immunity. This work provides a direct pathway for solution processable, large area, power efficient SWCNT advanced logic circuits and systems.

  4. Parasitic analysis and π-type Butterworth-Van Dyke model for complementary-metal-oxide-semiconductor Lamb wave resonator with accurate two-port Y-parameter characterizations

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Goh, Wang Ling; Chai, Kevin T.-C.; Mu, Xiaojing; Hong, Yan; Kropelnicki, Piotr; Je, Minkyu

    2016-04-01

    The parasitic effects from electromechanical resonance, coupling, and substrate losses were collected to derive a new two-port equivalent-circuit model for Lamb wave resonators, especially for those fabricated on silicon technology. The proposed model is a hybrid π-type Butterworth-Van Dyke (PiBVD) model that accounts for the above mentioned parasitic effects which are commonly observed in Lamb-wave resonators. It is a combination of interdigital capacitor of both plate capacitance and fringe capacitance, interdigital resistance, Ohmic losses in substrate, and the acoustic motional behavior of typical Modified Butterworth-Van Dyke (MBVD) model. In the case studies presented in this paper using two-port Y-parameters, the PiBVD model fitted significantly better than the typical MBVD model, strengthening the capability on characterizing both magnitude and phase of either Y11 or Y21. The accurate modelling on two-port Y-parameters makes the PiBVD model beneficial in the characterization of Lamb-wave resonators, providing accurate simulation to Lamb-wave resonators and oscillators.

  5. Metal oxide semiconductors for dye degradation

    SciTech Connect

    Adhikari, Sangeeta; Sarkar, Debasish

    2015-12-15

    Highlights: • Hydrothermal synthesis of monoclinic and hexagonal WO{sub 3} nanostructures. • Nanocuboid and nanofiber growth using different structure directing agents. • WO{sub 3}–ZnO nanocomposites for dye degradation under UV and visible light. • High photocatalytic efficiency is achieved by 10 wt% monoclinic WO{sub 3}. • WO{sub 3} assists to trap hole in UV and arrests electron in visible light irradiation. - Abstract: Organic contaminants are a growing threat to the environment that widely demands their degradation by high efficient photocatalysts. Thus, the proposed research work primely focuses on the efficient degradation of methyl orange using designed WO{sub 3}–ZnO photocatalysts under both UV and visible light irradiation. Two different sets of WO{sub 3} nanostructures namely, monoclinic WO{sub 3} (m-WO{sub 3}) and hexagonal WO{sub 3} (h-WO{sub 3}) synthesizes in presence of a different structure directing agents. A specific dispersion technique allows the intimate contact of as-synthesized WO{sub 3} and ultra-violet active commercial ZnO photocatalyst in different weight variations. ZnO nanocrystal in presence of an optimum 10 wt% m-WO{sub 3} shows a high degree of photocatalytic activity under both UV and visible light irradiation compared to counterpart h-WO{sub 3}. Symmetrical monoclinic WO{sub 3} assists to trap hole in UV, but electron arresting mechanism predominates in visible irradiation. Coupling of monoclinic nanocuboid WO{sub 3} with ZnO proves to be a promising photocatalyst in both wavelengths.

  6. Gate-Leakage and Carrier-Transport Mechanisms for Plasma-PH3 Passivated InGaAs N-Channel Metal-Oxide-Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Azzah Bte Suleiman, Sumarlina; Lee, Sungjoo

    2012-02-01

    Gate leakage mechanism of the HfAlO plasma-PH3 passivated and non-passivated In0.53Ga0.47As N-channel metal-oxide-semiconductor field-effect transistors (N-MOSFETs) have been evaluated, in order to correlate the quality of the oxide deposited with the gate leakage mechanisms observed. At temperatures higher than 300 K, trap-free space charge limited conduction (SCLC) mechanism dominates the gate leakage of passivated device but non-passivated device consists of exponentially distributed SCLC mechanism at low electric field and Frenkel-Poole emission at high electric field. This Frenkel-Poole emission is associated with energy trap levels of ˜0.95 to 1.3 eV and is responsible for the increased gate leakage of non-passivated device. In addition, the electrical properties of the non-passivated device has also been extracted from the SCLC mechanism, with the average trap concentration of the shallow traps given as 1.3×1019 cm-3 and the average activation energy given as ˜0.22 to 0.27 eV. The existence of these defect levels in non-passivated device can be attributed to the interdiffusion of Ga/As/O elements across the HfAlO/In0.53Ga0.47As interface. On the other hand, passivated device does not contain Frenkel-Poole emission nor exponentially distributed SCLC mechanism, indicating a reduction in traps in the bulk of the oxide. In addition, the temperature dependent characteristics of off-state leakage have also been evaluated to provide insight into the off-state mechanism. The off-state leakage of both passivated and non-passivated device is determined by junction leakage, with Shockley-Read-Hall mechanism being its main contributor, and has activation energy of 0.38 eV for passivated device and 0.4 eV for non-passivated device. From Id∝T-0.37 observed for passivated device, in comparison to Id∝T-0.18 for non-passivated device, we have further confirmed the phonon scattering dominance of the passivated device at high electric field.

  7. Gate-Leakage and Carrier-Transport Mechanisms for Plasma-PH3 Passivated InGaAs N-Channel Metal--Oxide--Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Suleiman, Sumarlina Azzah Bte; Lee, Sungjoo

    2012-02-01

    Gate leakage mechanism of the HfAlO plasma-PH3 passivated and non-passivated In0.53Ga0.47As N-channel metal--oxide--semiconductor field-effect transistors (N-MOSFETs) have been evaluated, in order to correlate the quality of the oxide deposited with the gate leakage mechanisms observed. At temperatures higher than 300 K, trap-free space charge limited conduction (SCLC) mechanism dominates the gate leakage of passivated device but non-passivated device consists of exponentially distributed SCLC mechanism at low electric field and Frenkel--Poole emission at high electric field. This Frenkel--Poole emission is associated with energy trap levels of ˜0.95 to 1.3 eV and is responsible for the increased gate leakage of non-passivated device. In addition, the electrical properties of the non-passivated device has also been extracted from the SCLC mechanism, with the average trap concentration of the shallow traps given as 1.3× 1019 cm-3 and the average activation energy given as ˜0.22 to 0.27 eV. The existence of these defect levels in non-passivated device can be attributed to the interdiffusion of Ga/As/O elements across the HfAlO/In0.53Ga0.47As interface. On the other hand, passivated device does not contain Frenkel--Poole emission nor exponentially distributed SCLC mechanism, indicating a reduction in traps in the bulk of the oxide. In addition, the temperature dependent characteristics of off-state leakage have also been evaluated to provide insight into the off-state mechanism. The off-state leakage of both passivated and non-passivated device is determined by junction leakage, with Shockley--Read--Hall mechanism being its main contributor, and has activation energy of 0.38 eV for passivated device and 0.4 eV for non-passivated device. From Id\\propto T-0.37 observed for passivated device, in comparison to Id\\propto T-0.18 for non-passivated device, we have further confirmed the phonon scattering dominance of the passivated device at high electric field.

  8. Interfacial band configuration and electrical properties of LaAlO{sub 3}/Al{sub 2}O{sub 3}/hydrogenated-diamond metal-oxide-semiconductor field effect transistors

    SciTech Connect

    Liu, J. W.; Liao, M. Y.; Imura, M.; Oosato, H.; Watanabe, E.; Tanaka, A.; Iwai, H.; Koide, Y.

    2013-08-28

    In order to search a gate dielectric with high permittivity on hydrogenated-diamond (H-diamond), LaAlO{sub 3} films with thin Al{sub 2}O{sub 3} buffer layers are fabricated on the H-diamond epilayers by sputtering-deposition (SD) and atomic layer deposition (ALD) techniques, respectively. Interfacial band configuration and electrical properties of the SD-LaAlO{sub 3}/ALD-Al{sub 2}O{sub 3}/H-diamond metal-oxide-semiconductor field effect transistors (MOSFETs) with gate lengths of 10, 20, and 30 μm have been investigated. The valence and conduction band offsets of the SD-LaAlO{sub 3}/ALD-Al{sub 2}O{sub 3} structure are measured by X-ray photoelectron spectroscopy to be 1.1 ± 0.2 and 1.6 ± 0.2 eV, respectively. The valence band discontinuity between H-diamond and LaAlO{sub 3} is evaluated to be 4.0 ± 0.2 eV, showing that the MOS structure acts as the gate which controls a hole carrier density. The leakage current density of the SD-LaAlO{sub 3}/ALD-Al{sub 2}O{sub 3}/H-diamond MOS diode is smaller than 10{sup −8} A cm{sup −2} at gate bias from −4 to 2 V. The capacitance-voltage curve in the depletion mode shows sharp dependence, small flat band voltage, and small hysteresis shift, which implies low positive and trapped charge densities. The MOSFETs show p-type channel and complete normally off characteristics with threshold voltages changing from −3.6 ± 0.1 to −5.0 ± 0.1 V dependent on the gate length. The drain current maximum and the extrinsic transconductance of the MOSFET with gate length of 10 μm are −7.5 mA mm{sup −1} and 2.3 ± 0.1 mS mm{sup −1}, respectively. The enhancement mode SD-LaAlO{sub 3}/ALD-Al{sub 2}O{sub 3}/H-diamond MOSFET is concluded to be suitable for the applications of high power and high frequency electrical devices.

  9. Functionalization and Characterization of Nanomaterial Gated Field-Effect Transistor-Based Biosensors and the Design of a Multi-Analyte Implantable Biosensing Platform

    NASA Astrophysics Data System (ADS)

    Croce, Robert A., Jr.

    Advances in semiconductor research and complementary-metal-oxide semiconductor fabrication allow for the design and implementation of miniaturized metabolic monitoring systems, as well as advanced biosensor design. The first part of this dissertation will focus on the design and fabrication of nanomaterial (single-walled carbon nanotube and quantum dot) gated field-effect transistors configured as protein sensors. These novel device structures have been functionalized with single-stranded DNA aptamers, and have shown sensor operation towards the protein Thrombin. Such advanced transistor-based sensing schemes present considerable advantages over traditional sensing methodologies in view of its miniaturization, low cost, and facile fabrication, paving the way for the ultimate realization of a multi-analyte lab-on-chip. The second part of this dissertation focuses on the design and fabrication of a needle-implantable glucose sensing platform which is based solely on photovoltaic powering and optical communication. By employing these powering and communication schemes, this design negates the need for bulky on-chip RF-based transmitters and batteries in an effort to attain extreme miniaturization required for needle-implantable/extractable applications. A complete single-sensor system coupled with a miniaturized amperometric glucose sensor has been demonstrated to exhibit reality of this technology. Furthermore, an optical selection scheme of multiple potentiostats for four different analytes (glucose, lactate, O 2 and CO2) as well as the optical transmission of sensor data has been designed for multi-analyte applications. The last part of this dissertation will focus on the development of a computational model for the amperometric glucose sensors employed in the aforementioned implantable platform. This model has been applied to single-layer single-enzyme systems, as well as multi-layer (single enzyme) systems utilizing glucose flux limiting layer-by-layer assembled

  10. Scaling carbon nanotube complementary transistors to 5-nm gate lengths

    NASA Astrophysics Data System (ADS)

    Qiu, Chenguang; Zhang, Zhiyong; Xiao, Mengmeng; Yang, Yingjun; Zhong, Donglai; Peng, Lian-Mao

    2017-01-01

    High-performance top-gated carbon nanotube field-effect transistors (CNT FETs) with a gate length of 5 nanometers can be fabricated that perform better than silicon complementary metal-oxide semiconductor (CMOS) FETs at the same scale. A scaling trend study revealed that the scaled CNT-based devices, which use graphene contacts, can operate much faster and at much lower supply voltage (0.4 versus 0.7 volts) and with much smaller subthreshold slope (typically 73 millivolts per decade). The 5-nanometer CNT FETs approached the quantum limit of FETs by using only one electron per switching operation. In addition, the contact length of the CNT CMOS devices was also scaled down to 25 nanometers, and a CMOS inverter with a total pitch size of 240 nanometers was also demonstrated.

  11. Random depth access full-field heterodyne low-coherence interferometry utilizing acousto-optic modulation and a complementary metaloxide semiconductor camera.

    PubMed

    Egan, Patrick; Connelly, Michael J; Lakestani, Fereydoun; Whelan, Maurice P

    2006-04-01

    With analog scanning, time-domain low-coherence interferometry lacks precise depth information, and optical carrier generation demands a linear scanning speed. Full-field heterodyne low-coherence interferometry that uses a logarithmic complementary metal-oxide semiconductor camera, acousto-optic modulation, and digital depth stepping is reported, with which random regions of interest, lateral and axial, can be accessed. Furthermore, nanometer profilometry is possible through heterodyne phase retrieval of the interference signal. The approach demonstrates inexpensive yet high-precision functional machine vision offering true digital random access in three dimensions.

  12. Investigation of dielectric modulated (DM) double gate (DG) junctionless MOSFETs for application as a biosensors

    NASA Astrophysics Data System (ADS)

    Ajay; Narang, Rakhi; Saxena, Manoj; Gupta, Mridula

    2015-09-01

    In this paper, an analytical model for Junctionless (JL) Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) based biosensor for label free electrical detection of biomolecules like enzyme, cell, DNA etc. using the Dielectric Modulation (DM) technique has been developed. The analytical results are validated with the help of "Sentaurus" device simulation software. For the biomolecule immobilization, nanogap cavity is formed in the JL MOSFET by etching gate oxide layer from both source as well as drain end of the channel. As a result, the surface potential in the channel underneath the nanogap cavity region is affected by the neutral and charged biomolecules that binds to SiO2 adhesion layer in the cavity. The surface potential solution is obtained by solving a 2-D Poisson's equation assuming parabolic potential profile in the channel. The shift in threshold voltage and drain current of the device has been considered as the sensing metric for detection of biomolecules under dry environment condition.

  13. L{sub g} = 100 nm In{sub 0.7}Ga{sub 0.3}As quantum well metal-oxide semiconductor field-effect transistors with atomic layer deposited beryllium oxide as interfacial layer

    SciTech Connect

    Koh, D. E-mail: Taewoo.Kim@sematech.org; Kwon, H. M.; Kim, T.-W. E-mail: Taewoo.Kim@sematech.org; Veksler, D.; Gilmer, D.; Kirsch, P. D.; Kim, D.-H.; Hudnall, Todd W.; Bielawski, Christopher W.; Maszara, W.; Banerjee, S. K.

    2014-04-21

    In this study, we have fabricated nanometer-scale channel length quantum-well (QW) metal-oxide-semiconductor field effect transistors (MOSFETs) incorporating beryllium oxide (BeO) as an interfacial layer. BeO has high thermal stability, excellent electrical insulating characteristics, and a large band-gap, which make it an attractive candidate for use as a gate dielectric in making MOSFETs. BeO can also act as a good diffusion barrier to oxygen owing to its small atomic bonding length. In this work, we have fabricated In{sub 0.53}Ga{sub 0.47}As MOS capacitors with BeO and Al{sub 2}O{sub 3} and compared their electrical characteristics. As interface passivation layer, BeO/HfO{sub 2} bilayer gate stack presented effective oxide thickness less 1 nm. Furthermore, we have demonstrated In{sub 0.7}Ga{sub 0.3}As QW MOSFETs with a BeO/HfO{sub 2} dielectric, showing a sub-threshold slope of 100 mV/dec, and a transconductance (g{sub m,max}) of 1.1 mS/μm, while displaying low values of gate leakage current. These results highlight the potential of atomic layer deposited BeO for use as a gate dielectric or interface passivation layer for III–V MOSFETs at the 7 nm technology node and/or beyond.

  14. Passivation of GaSb using molecular beam epitaxy Y{sub 2}O{sub 3} to achieve low interfacial trap density and high-performance self-aligned inversion-channel p-metal-oxide-semiconductor field-effect-transistors

    SciTech Connect

    Chu, R. L.; Chiang, T. H.; Hsueh, W. J.; Chyi, J. I.; Chen, K. H.; Lin, K. Y.; Hong, M. E-mail: mhong@phys.ntu.edu.tw; Brown, G. J.; Kwo, J. E-mail: mhong@phys.ntu.edu.tw

    2014-11-03

    Molecular beam epitaxy deposited rare-earth oxide of Y{sub 2}O{sub 3} has effectively passivated GaSb, leading to low interfacial trap densities of (1–4) × 10{sup 12 }cm{sup −2} eV{sup −1} across the energy bandgap of GaSb. A high saturation drain current density of 130 μA/μm, a peak transconductance of 90 μS/μm, a low subthreshold slope of 147 mV/decade, and a peak field-effect hole mobility of 200 cm{sup 2}/V-s were obtained in 1 μm-gate-length self-aligned inversion-channel GaSb p-Metal-Oxide-Semiconductor Field-Effect-Transistors (MOSFETs). In this work, high-κ/GaSb interfacial properties were better in samples with a high substrate temperature of 200 °C than in those with high κ's deposited at room temperature, in terms of the interfacial electrical properties, particularly, the reduction of interfacial trap densities near the conduction band and the MOSFET device performance.

  15. High-performance carbon-nanotube-based complementary field-effect-transistors and integrated circuits with yttrium oxide

    SciTech Connect

    Liang, Shibo; Zhang, Zhiyong Si, Jia; Zhong, Donglai; Peng, Lian-Mao

    2014-08-11

    High-performance p-type carbon nanotube (CNT) transistors utilizing yttrium oxide as gate dielectric are presented by optimizing oxidization and annealing processes. Complementary metal-oxide-semiconductor (CMOS) field-effect-transistors (FETs) are then fabricated on CNTs, and the p- and n-type devices exhibit symmetrical high performances, especially with low threshold voltage near to zero. The corresponding CMOS CNT inverter is demonstrated to operate at an ultra-low supply voltage down to 0.2 V, while displaying sufficient voltage gain, high noise margin, and low power consumption. Yttrium oxide is proven to be a competitive gate dielectric for constructing high-performance CNT CMOS FETs and integrated circuits.

  16. A commercial MOSFET-based biosensor with a gold extended gate electrode

    NASA Astrophysics Data System (ADS)

    Lyu, Hong-Kun; Choi, Young-Sam; Shin, Jang-Kyoo; Kim, Jae-Hyun

    2009-05-01

    This paper presents a commercial metal-oxide-semiconductor field-effect transistor (MOSFET)-based biosensor with a gold extended-gate electrode for the electronic detection of C-reactive protein (CRP). From a component point of view, the commercial MOSFET-based biosensor consists of a commercial MOSFET with a socket for connecting the gold electrode which was fixed on a printed circuit board (PCB) and a reaction-vessel module which was assembled with the gold electrode and the Ag/AgCl reference electrode. The gold electrode with only one gold layer was fabricated on a glass substrate simply and it was used as the extended-gate metal to form a self-assembled monolayer (SAM). The binding of the CRP to anti-CRP was detected by measuring the electrical characteristics of the biosensor. Variation of the drain current before and after the interaction of CRP and anti-CRP was about 1.2mA on the measured IDS-VDS and real-time characteristics. The concentration of the CRP solution was adjusted to 10μg/ml by dissolving in PBS. The change of surface voltage of the gold extended-gate electrode was about 30mV by IDS-VGS characteristic curve of the commercial MOSFET. Therefore, it is confirmed that the detection of CRP is possible by measuring the drain current of the commercial MOSFET. The proposed biosensor might open up a new possibility for FET-based biosensors with lowcost and simple construction. It is expected that the commercial MOSFET-based biosensor with the gold extended-gate electrode could also be used for detecting various biomarkers by modifying the surface of the gold extended-gate electrode.

  17. Wireless Charge Based Capacitance Measurement Circuits with On-Chip Spiral Inductor for Radio Frequency Identification Biosensor

    NASA Astrophysics Data System (ADS)

    Kim, Boram; Uno, Shigeyasu; Nakazato, Kazuo

    2012-04-01

    A wireless measuring system of charge based capacitance measurement (CBCM) circuit has been designed and demonstrated for biomedical applications. The radio frequency identification (RFID) chip that includes on-chip spiral inductor tag antenna, and RFID circuit, and CBCM sensor chip are fabricated within standard complementary metal oxide semiconductor (CMOS) process. The capacitance change caused by DNA detection can be converted into the voltage output using capacitance-to-voltage conversion circuit. To confirm the transmission of the capacitance, the poly-capacitor of fixed capacitance and on-chip spiral inductor tag antenna were fabricated using 1.2 µm, 2-metal, 2-poly CMOS technology. As a result of measurement, three different capacitances (34, 141, 564 fF) were detected wirelessly.

  18. Biosensor commercialization strategy - a theoretical approach.

    PubMed

    Lin, Chin-Tsai; Wang, Su-Man

    2005-01-01

    Biosensors are analytical devices, which use biological interactions to provide either qualitative or quantitative results. They are extensively employed in many fields such as clinical diagnosis and biomedicine, military applications, anti-terrorism, farm, garden and veterinary analysis, process control, fermentation control and analysis, pharmaceutical and drug analysis, food and drink production and analysis, pollution control and monitoring, microbiology, bacterial and viral analysis, mining, and industrial and toxic gases. The biosensor market has significantly increased and will be mushrooming in the next decade. The total biosensor market is estimated to be 10.8 billion dollars by 2007. The emerging biosensor market presents both opportunities and obstacles to start-up biosensor entrepreneurs. The major challenge and threat for these entrepreneurs is how to predict the biosensor market and how to convert promising biosensor technology into commercialized biosensors. By adopting a simple commercialization strategy framework, we identify two key elements of biosensor commercialization strategy: excludability and complementary asset. We further divide biosensor commercialization environments into four distinct sub-environments: the Attacker's Advantage, Reputation-Based Idea Trading, Greenfield Competition and Ideas Factories. This paper explains how the interaction between these two key elements shapes biosensor commercialization strategy and biosensor industry dynamics. This paper also discusses alternative commercialization strategies for each specific commercialization environment and how to choose from these alternatives. The analysis of this study further provides a good reference for start-up biosensor entrepreneurs to formulate effective biosensor commercialization strategy.

  19. Self-aligned inversion n-channel In 0.2Ga 0.8As/GaAs metal-oxide-semiconductor field-effect-transistors with TiN gate and Ga 2O 3(Gd 2O 3) dielectric

    NASA Astrophysics Data System (ADS)

    Chen, C. P.; Lin, T. D.; Lee, Y. J.; Chang, Y. C.; Hong, M.; Kwo, J.

    2008-10-01

    A self-aligned process for fabricating inversion n-channel metal-oxide-semiconductor field-effect-transistors (MOSFET's) of strained In 0.2Ga 0.8As on GaAs using TiN as gate metal and Ga 2O 3(Gd 2O 3) as high κ gate dielectric has been developed. A MOSFET with a 4 μm gate length and a 100 μm gate width exhibits a drain current of 1.5 mA/mm at Vg = 4 V and Vd = 2 V, a low gate leakage of <10 -7 A/cm 2 at 1 MV/cm, an extrinsic transconductance of 1.7 mS/mm at Vg = 3 V, Vd = 2 V, and an on/off ratio of ˜10 5 in drain current. For comparison, a TiN/Ga 2O 3(Gd 2O 3)/In 0.2Ga 0.8As MOS diode after rapid thermal annealing (RTA) to high temperatures of 750 °C exhibits excellent electrical and structural performances: a low leakage current density of 10 -8-10 -9 A/cm 2, well-behaved capacitance-voltage ( C- V) characteristics giving a high dielectric constant of ˜16 and a low interfacial density of state of ˜(2˜6) × 10 11 cm -2 eV -1, and an atomically sharp smooth Ga 2O 3(Gd 2O 3)/In 0.2Ga 0.8As interface.

  20. Complimentary Metal Oxide Semiconductor (CMOS)-Memristor Hybrid Nanoelectronics

    DTIC Science & Technology

    2011-06-01

    N+ N+ M1M1 P+ N- P- P N+ N M1M1 (d) TEOS open (e) SiN open with TEOS as hardmask (f) Oxidation N-Well P-Well P P+ N N+ M1M1 P+ N-Well P-Well P N...N+ M1M1 P+ N- P- P N+ N M1M1 (d) TEOS open (e) SiN open with TEOS as hardmask (f) Oxidation N-Well P-Well P+ P+ N+ N+ M1M1 N-Well P-Well P+ P+ N

  1. Optical biosensors

    PubMed Central

    Damborský, Pavel; Švitel, Juraj

    2016-01-01

    Optical biosensors represent the most common type of biosensor. Here we provide a brief classification, a description of underlying principles of operation and their bioanalytical applications. The main focus is placed on the most widely used optical biosensors which are surface plasmon resonance (SPR)-based biosensors including SPR imaging and localized SPR. In addition, other optical biosensor systems are described, such as evanescent wave fluorescence and bioluminescent optical fibre biosensors, as well as interferometric, ellipsometric and reflectometric interference spectroscopy and surface-enhanced Raman scattering biosensors. The optical biosensors discussed here allow the sensitive and selective detection of a wide range of analytes including viruses, toxins, drugs, antibodies, tumour biomarkers and tumour cells. PMID:27365039

  2. A high-performance complementary inverter based on transition metal dichalcogenide field-effect transistors.

    PubMed

    Cho, Ah-Jin; Park, Kee Chan; Kwon, Jang-Yeon

    2015-01-01

    For several years, graphene has been the focus of much attention due to its peculiar characteristics, and it is now considered to be a representative 2-dimensional (2D) material. Even though many research groups have studied on the graphene, its intrinsic nature of a zero band-gap, limits its use in practical applications, particularly in logic circuits. Recently, transition metal dichalcogenides (TMDs), which are another type of 2D material, have drawn attention due to the advantage of having a sizable band-gap and a high mobility. Here, we report on the design of a complementary inverter, one of the most basic logic elements, which is based on a MoS2 n-type transistor and a WSe2 p-type transistor. The advantages provided by the complementary metal-oxide-semiconductor (CMOS) configuration and the high-performance TMD channels allow us to fabricate a TMD complementary inverter that has a high-gain of 13.7. This work demonstrates the operation of the MoS2 n-FET and WSe2 p-FET on the same substrate, and the electrical performance of the CMOS inverter, which is based on a different driving current, is also measured.

  3. Impact of La{sub 2}O{sub 3} interfacial layers on InGaAs metal-oxide-semiconductor interface properties in Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks deposited by atomic-layer-deposition

    SciTech Connect

    Chang, C.-Y. Takenaka, M.; Takagi, S.; Ichikawa, O.; Osada, T.; Hata, M.; Yamada, H.

    2015-08-28

    We examine the electrical properties of atomic layer deposition (ALD) La{sub 2}O{sub 3}/InGaAs and Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs metal-oxide-semiconductor (MOS) capacitors. It is found that the thick ALD La{sub 2}O{sub 3}/InGaAs interface provides low interface state density (D{sub it}) with the minimum value of ∼3 × 10{sup 11} cm{sup −2} eV{sup −1}, which is attributable to the excellent La{sub 2}O{sub 3} passivation effect for InGaAs surfaces. It is observed, on the other hand, that there are a large amount of slow traps and border traps in La{sub 2}O{sub 3}. In order to simultaneously satisfy low D{sub it} and small hysteresis, the effectiveness of Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks with ultrathin La{sub 2}O{sub 3} interfacial layers is in addition evaluated. The reduction of the La{sub 2}O{sub 3} thickness to 0.4 nm in Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks leads to the decrease in hysteresis. On the other hand, D{sub it} of the Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs interfaces becomes higher than that of the La{sub 2}O{sub 3}/InGaAs ones, attributable to the diffusion of Al{sub 2}O{sub 3} through La{sub 2}O{sub 3} into InGaAs and resulting modification of the La{sub 2}O{sub 3}/InGaAs interface structure. As a result of the effective passivation effect of La{sub 2}O{sub 3} on InGaAs, however, the Al{sub 2}O{sub 3}/10 cycle (0.4 nm) La{sub 2}O{sub 3}/InGaAs gate stacks can realize still lower D{sub it} with maintaining small hysteresis and low leakage current than the conventional Al{sub 2}O{sub 3}/InGaAs MOS interfaces.

  4. Complementary Treatment.

    PubMed

    Berlin, Joey

    2016-10-01

    As the debate over complementary and alternative medicine's place in medicine continues, Texas Medical Association policy recommends physicians stay on top of evidence-based studies of complementary and alternative therapies and routinely ask patients about their use of such therapies.

  5. Complementary actions.

    PubMed

    Sartori, Luisa; Betti, Sonia

    2015-01-01

    Complementary colors are color pairs which, when combined in the right proportions, produce white or black. Complementary actions refer here to forms of social interaction wherein individuals adapt their joint actions according to a common aim. Notably, complementary actions are incongruent actions. But being incongruent is not sufficient to be complementary (i.e., to complete the action of another person). Successful complementary interactions are founded on the abilities: (i) to simulate another person's movements, (ii) to predict another person's future action/s, (iii) to produce an appropriate incongruent response which differ, while interacting, with observed ones, and (iv) to complete the social interaction by integrating the predicted effects of one's own action with those of another person. This definition clearly alludes to the functional importance of complementary actions in the perception-action cycle and prompts us to scrutinize what is taking place behind the scenes. Preliminary data on this topic have been provided by recent cutting-edge studies utilizing different research methods. This mini-review aims to provide an up-to-date overview of the processes and the specific activations underlying complementary actions.

  6. Complementary actions

    PubMed Central

    Sartori, Luisa; Betti, Sonia

    2015-01-01

    Complementary colors are color pairs which, when combined in the right proportions, produce white or black. Complementary actions refer here to forms of social interaction wherein individuals adapt their joint actions according to a common aim. Notably, complementary actions are incongruent actions. But being incongruent is not sufficient to be complementary (i.e., to complete the action of another person). Successful complementary interactions are founded on the abilities: (i) to simulate another person’s movements, (ii) to predict another person’s future action/s, (iii) to produce an appropriate incongruent response which differ, while interacting, with observed ones, and (iv) to complete the social interaction by integrating the predicted effects of one’s own action with those of another person. This definition clearly alludes to the functional importance of complementary actions in the perception–action cycle and prompts us to scrutinize what is taking place behind the scenes. Preliminary data on this topic have been provided by recent cutting-edge studies utilizing different research methods. This mini-review aims to provide an up-to-date overview of the processes and the specific activations underlying complementary actions. PMID:25983717

  7. Ultralow power complementary inverter circuits using axially doped p- and n-channel Si nanowire field effect transistors

    NASA Astrophysics Data System (ADS)

    van, Ngoc Huynh; Lee, Jae-Hyun; Whang, Dongmok; Kang, Dae Joon

    2016-06-01

    We have successfully synthesized axially doped p- and n-type regions on a single Si nanowire (NW). Diodes and complementary metal-oxide-semiconductor (CMOS) inverter devices using single axial p- and n-channel Si NW field-effect transistors (FETs) were fabricated. We show that the threshold voltages of both p- and n-channel Si NW FETs can be lowered to nearly zero by effectively controlling the doping concentration. Because of the high performance of the p- and n-type Si NW channel FETs, especially with regard to the low threshold voltage, the fabricated NW CMOS inverters have a low operating voltage (<3 V) while maintaining a high voltage gain (~6) and ultralow static power dissipation (<=0.3 pW) at an input voltage of +/-3 V. This result offers a viable way for the fabrication of a high-performance high-density logic circuit using a low-temperature fabrication process, which makes it suitable for flexible electronics.We have successfully synthesized axially doped p- and n-type regions on a single Si nanowire (NW). Diodes and complementary metal-oxide-semiconductor (CMOS) inverter devices using single axial p- and n-channel Si NW field-effect transistors (FETs) were fabricated. We show that the threshold voltages of both p- and n-channel Si NW FETs can be lowered to nearly zero by effectively controlling the doping concentration. Because of the high performance of the p- and n-type Si NW channel FETs, especially with regard to the low threshold voltage, the fabricated NW CMOS inverters have a low operating voltage (<3 V) while maintaining a high voltage gain (~6) and ultralow static power dissipation (<=0.3 pW) at an input voltage of +/-3 V. This result offers a viable way for the fabrication of a high-performance high-density logic circuit using a low-temperature fabrication process, which makes it suitable for flexible electronics. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01040g

  8. Cantilever biosensors.

    PubMed

    Fritz, Jürgen

    2008-07-01

    This review will provide a general introduction to the field of cantilever biosensors by discussing the basic principles and the basic technical background necessary to understand and evaluate this class of sensors. Microfabricated cantilever sensors respond to changes in their environment or changes on their surface with a mechanical bending in the order of nanometers which can easily be detected. They are able to detect pH and temperature changes, the formation of self-assembled monolayers, DNA hybridization, antibody-antigen interactions, or the adsorption of bacteria. The review will focus on the surface stress mode of microfabricated cantilever arrays and their application as biosensors in molecular life science. A general background on biosensors, an overview of the different modes of operation of cantilever sensors and some details on sensor functionalization will be given. Finally, key experiments and current theoretical efforts to describe the surface stress mode of cantilever sensors will be discussed.

  9. Plasmonic Biosensors

    PubMed Central

    Hill, Ryan T.

    2015-01-01

    The unique optical properties of plasmon resonant nanostructures enable exploration of nanoscale environments using relatively simple optical characterization techniques. For this reason, the field of plasmonics continues to garner the attention of the biosensing community. Biosensors based on propagating surface plasmon resonances (SPRs) in films are the most well-recognized plasmonic biosensors, but there is great potential for the new, developing technologies to surpass the robustness and popularity of film-based SPR sensing. This review surveys the current plasmonic biosensor landscape with emphasis on the basic operating principles of each plasmonic sensing technique and the practical considerations when developing a sensing platform with the various techniques. The “gold standard” film SPR technique is reviewed briefly, but special emphasis is devoted to the up-and-coming LSPR-based and plasmonically coupled sensor technology. PMID:25377594

  10. Durability-enhanced two-dimensional hole gas of C-H diamond surface for complementary power inverter applications

    NASA Astrophysics Data System (ADS)

    Kawarada, Hiroshi; Yamada, Tetsuya; Xu, Dechen; Tsuboi, Hidetoshi; Kitabayashi, Yuya; Matsumura, Daisuke; Shibata, Masanobu; Kudo, Takuya; Inaba, Masafumi; Hiraiwa, Atsushi

    2017-02-01

    Complementary power field effect transistors (FETs) based on wide bandgap materials not only provide high-voltage switching capability with the reduction of on-resistance and switching losses, but also enable a smart inverter system by the dramatic simplification of external circuits. However, p-channel power FETs with equivalent performance to those of n-channel FETs are not obtained in any wide bandgap material other than diamond. Here we show that a breakdown voltage of more than 1600 V has been obtained in a diamond metal-oxide-semiconductor (MOS) FET with a p-channel based on a two-dimensional hole gas (2DHG). Atomic layer deposited (ALD) Al2O3 induces the 2DHG ubiquitously on a hydrogen-terminated (C-H) diamond surface and also acts as both gate insulator and passivation layer. The high voltage performance is equivalent to that of state-of-the-art SiC planar n-channel FETs and AlGaN/GaN FETs. The drain current density in the on-state is also comparable to that of these two FETs with similar device size and VB.

  11. Durability-enhanced two-dimensional hole gas of C-H diamond surface for complementary power inverter applications

    PubMed Central

    Kawarada, Hiroshi; Yamada, Tetsuya; Xu, Dechen; Tsuboi, Hidetoshi; Kitabayashi, Yuya; Matsumura, Daisuke; Shibata, Masanobu; Kudo, Takuya; Inaba, Masafumi; Hiraiwa, Atsushi

    2017-01-01

    Complementary power field effect transistors (FETs) based on wide bandgap materials not only provide high-voltage switching capability with the reduction of on-resistance and switching losses, but also enable a smart inverter system by the dramatic simplification of external circuits. However, p-channel power FETs with equivalent performance to those of n-channel FETs are not obtained in any wide bandgap material other than diamond. Here we show that a breakdown voltage of more than 1600 V has been obtained in a diamond metal-oxide-semiconductor (MOS) FET with a p-channel based on a two-dimensional hole gas (2DHG). Atomic layer deposited (ALD) Al2O3 induces the 2DHG ubiquitously on a hydrogen-terminated (C-H) diamond surface and also acts as both gate insulator and passivation layer. The high voltage performance is equivalent to that of state-of-the-art SiC planar n-channel FETs and AlGaN/GaN FETs. The drain current density in the on-state is also comparable to that of these two FETs with similar device size and VB. PMID:28218234

  12. Ultralow power complementary inverter circuits using axially doped p- and n-channel Si nanowire field effect transistors.

    PubMed

    Van, Ngoc Huynh; Lee, Jae-Hyun; Whang, Dongmok; Kang, Dae Joon

    2016-06-09

    We have successfully synthesized axially doped p- and n-type regions on a single Si nanowire (NW). Diodes and complementary metal-oxide-semiconductor (CMOS) inverter devices using single axial p- and n-channel Si NW field-effect transistors (FETs) were fabricated. We show that the threshold voltages of both p- and n-channel Si NW FETs can be lowered to nearly zero by effectively controlling the doping concentration. Because of the high performance of the p- and n-type Si NW channel FETs, especially with regard to the low threshold voltage, the fabricated NW CMOS inverters have a low operating voltage (<3 V) while maintaining a high voltage gain (∼6) and ultralow static power dissipation (≤0.3 pW) at an input voltage of ±3 V. This result offers a viable way for the fabrication of a high-performance high-density logic circuit using a low-temperature fabrication process, which makes it suitable for flexible electronics.

  13. Durability-enhanced two-dimensional hole gas of C-H diamond surface for complementary power inverter applications.

    PubMed

    Kawarada, Hiroshi; Yamada, Tetsuya; Xu, Dechen; Tsuboi, Hidetoshi; Kitabayashi, Yuya; Matsumura, Daisuke; Shibata, Masanobu; Kudo, Takuya; Inaba, Masafumi; Hiraiwa, Atsushi

    2017-02-20

    Complementary power field effect transistors (FETs) based on wide bandgap materials not only provide high-voltage switching capability with the reduction of on-resistance and switching losses, but also enable a smart inverter system by the dramatic simplification of external circuits. However, p-channel power FETs with equivalent performance to those of n-channel FETs are not obtained in any wide bandgap material other than diamond. Here we show that a breakdown voltage of more than 1600 V has been obtained in a diamond metal-oxide-semiconductor (MOS) FET with a p-channel based on a two-dimensional hole gas (2DHG). Atomic layer deposited (ALD) Al2O3 induces the 2DHG ubiquitously on a hydrogen-terminated (C-H) diamond surface and also acts as both gate insulator and passivation layer. The high voltage performance is equivalent to that of state-of-the-art SiC planar n-channel FETs and AlGaN/GaN FETs. The drain current density in the on-state is also comparable to that of these two FETs with similar device size and VB.

  14. High-Performance Complementary Transistors and Medium-Scale Integrated Circuits Based on Carbon Nanotube Thin Films.

    PubMed

    Yang, Yingjun; Ding, Li; Han, Jie; Zhang, Zhiyong; Peng, Lian-Mao

    2017-03-29

    Solution-derived carbon nanotube (CNT) network films with high semiconducting purity are suitable materials for the wafer-scale fabrication of field-effect transistors (FETs) and integrated circuits (ICs). However, it is challenging to realize high-performance complementary metal-oxide semiconductor (CMOS) FETs with high yield and stability on such CNT network films, and this difficulty hinders the development of CNT-film-based ICs. In this work, we developed a doping-free process for the fabrication of CMOS FETs based on solution-processed CNT network films, in which the polarity of the FETs was controlled using Sc or Pd as the source/drain contacts to selectively inject carriers into the channels. The fabricated top-gated CMOS FETs showed high symmetry between the characteristics of n- and p-type devices and exhibited high-performance uniformity and excellent scalability down to a gate length of 1 μm. Many common types of CMOS ICs, including typical logic gates, sequential circuits, and arithmetic units, were constructed based on CNT films, and the fabricated ICs exhibited rail-to-rail outputs because of the high noise margin of CMOS circuits. In particular, 4-bit full adders consisting of 132 CMOS FETs were realized with 100% yield, thereby demonstrating that this CMOS technology shows the potential to advance the development of medium-scale CNT-network-film-based ICs.

  15. Symmetric complementary logic inverter using integrated black phosphorus and MoS2 transistors

    NASA Astrophysics Data System (ADS)

    Su, Yang; Kshirsagar, Chaitanya U.; Robbins, Matthew C.; Haratipour, Nazila; Koester, Steven J.

    2016-03-01

    The operation of an integrated two-dimensional complementary metal-oxide-semiconductor inverter with well-matched input/output voltages is reported. The circuit combines a few-layer MoS2 n-MOSFET and a black phosphorus (BP) p-MOSFET fabricated using a common local backgate electrode with thin (20 nm) HfO2 gate dielectric. The constituent devices have linear threshold voltages of -0.8 V and +0.8 V and produce peak transconductances of 16 μS μm-1 and 41 μS μm-1 for the MoS2 n-MOSFET and BP p-MOSFET, respectively. The inverter shows a voltage gain of 3.5 at a supply voltage, V DD = 2.5 V, and has peak switching current of 108 μA and off-state current of 8.4 μA (2.4 μA) at V IN = 0 (V IN = 2.5 V). In addition, the inverter has voltage gain greater than unity for V DD ≥ 0.5 V, has open butterfly curves for V DD ≥ 1 V, and achieves static noise margin over 500 mV at V DD = 2.5 V. The voltage gain was found to be insensitive to temperature between 270 and 340 K, and AC large and small-signal operation was demonstrated at frequencies up to 100 kHz. The demonstration of a complementary 2D inverter which operates in a symmetric voltage window suitable for driving a subsequent logic stage is a significant step forward in developing practical applications for devices based upon 2D materials.

  16. Nanotechnology and biosensors.

    PubMed

    Jianrong, Chen; Yuqing, Miao; Nongyue, He; Xiaohua, Wu; Sijiao, Li

    2004-09-01

    Nanotechnology is playing an increasingly important role in the development of biosensors. The sensitivity and performance of biosensors is being improved by using nanomaterials for their construction. The use of these nanomaterials has allowed the introduction of many new signal transduction technologies in biosensors. Because of their submicron dimensions, nanosensors, nanoprobes and other nanosystems have allowed simple and rapid analyses in vivo. Portable instruments capable of analyzing multiple components are becoming available. This work reviews the status of the various nanostructure-based biosensors. Use of the self-assembly techniques and nano-electromechanical systems (NEMS) in biosensors is discussed.

  17. Photo-Patternable ZnO Thin Films Based on Cross-Linked Zinc Acrylate for Organic/Inorganic Hybrid Complementary Inverters.

    PubMed

    Jeong, Yong Jin; An, Tae Kyu; Yun, Dong-Jin; Kim, Lae Ho; Park, Seonuk; Kim, Yebyeol; Nam, Sooji; Lee, Keun Hyung; Kim, Se Hyun; Jang, Jaeyoung; Park, Chan Eon

    2016-03-02

    Complementary inverters consisting of p-type organic and n-type metal oxide semiconductors have received considerable attention as key elements for realizing low-cost and large-area future electronics. Solution-processed ZnO thin-film transistors (TFTs) have great potential for use in hybrid complementary inverters as n-type load transistors because of the low cost of their fabrication process and natural abundance of active materials. The integration of a single ZnO TFT into an inverter requires the development of a simple patterning method as an alternative to conventional time-consuming and complicated photolithography techniques. In this study, we used a photocurable polymer precursor, zinc acrylate (or zinc diacrylate, ZDA), to conveniently fabricate photopatternable ZnO thin films for use as the active layers of n-type ZnO TFTs. UV-irradiated ZDA thin films became insoluble in developing solvent as the acrylate moiety photo-cross-linked; therefore, we were able to successfully photopattern solution-processed ZDA thin films using UV light. We studied the effects of addition of a tiny amount of indium dopant on the transistor characteristics of the photopatterned ZnO thin films and demonstrated low-voltage operation of the ZnO TFTs within ±3 V by utilizing Al2O3/TiO2 laminate thin films or ion-gels as gate dielectrics. By combining the ZnO TFTs with p-type pentacene TFTs, we successfully fabricated organic/inorganic hybrid complementary inverters using solution-processed and photopatterned ZnO TFTs.

  18. CMOS Active-Pixel Image Sensor With Simple Floating Gates

    NASA Technical Reports Server (NTRS)

    Fossum, Eric R.; Nakamura, Junichi; Kemeny, Sabrina E.

    1996-01-01

    Experimental complementary metal-oxide/semiconductor (CMOS) active-pixel image sensor integrated circuit features simple floating-gate structure, with metal-oxide/semiconductor field-effect transistor (MOSFET) as active circuit element in each pixel. Provides flexibility of readout modes, no kTC noise, and relatively simple structure suitable for high-density arrays. Features desirable for "smart sensor" applications.

  19. Heat-Transfer Microstructures for Integrated Circuits

    DTIC Science & Technology

    2007-11-02

    fatigue failure curves for silicon mounted on molybdenum or copper (from Lang et a[ [75]). Microcapillary thermal interface concept. a) Tunnels...Coolant Figure of Merit Complementary Metal-Oxide-Semiconductor Emitter- Coupled Logic Integrated Circuit Metal-Oxide-Semiconductor Median Time to...nominally independent devices; for example, electromagnetic coupling (crosstalk) between adjacent long, parallel wires on an IC, especially when a ground

  20. Trends in tactile biosensors, smell-sensitive biosensors

    NASA Astrophysics Data System (ADS)

    Higuchi, K.; Kawana, Y.; Kimura, J.

    1986-03-01

    Biosensors, whch combine substances from living organisms such as enzymes with electrochemical transducers, are considered taste-sensitive biosensors. Touch sensors were analyzed using various pressure-sensitive elements, but no attempts were made to use substances from organisms. The sense of smell is a gase sensor for the body; there are numerous uncertainties about the meaning of smell-sensitive biosensors. Tactile biosensors and olfactor biosensors were examined. Biosensors include sensors directly apply materials extracted from organisms and sensors which copy sensors.

  1. DETECTION OF DNA DAMAGE USING A FIBEROPTIC BIOSENSOR

    EPA Science Inventory

    A rapid and sensitive fiber optic biosensor assay for radiation-induced DNA damage is reported. For this assay, a biotin-labeled capture oligonucleotide (38 mer) was immobilized to an avidin-coated quartz fiber. Hybridization of a dye-labeled complementary sequence was observed...

  2. Complementary Paired G4FETs as Voltage-Controlled NDR Device

    NASA Technical Reports Server (NTRS)

    Mojarradi, Mohammad; Chen, Suheng; Blalock, Ben; Britton, Chuck; Prothro, Ben; Vandersand, James; Schrimph, Ron; Cristoloveanu, Sorin; Akavardar, Kerem; Gentil, P.

    2009-01-01

    It is possible to synthesize a voltage-controlled negative-differential-resistance (NDR) device or circuit by use of a pair of complementary G4FETs (four-gate field-effect transistors). [For more information about G4FETs, please see the immediately preceding article]. As shown in Figure 1, the present voltage-controlled NDR device or circuit is an updated version of a prior NDR device or circuit, known as a lambda diode, that contains a pair of complementary junction field-effect transistors (JFETs). (The lambda diode is so named because its current-versus- voltage plot bears some resemblance to an upper-case lambda.) The present version can be derived from the prior version by substituting G4FETs for the JFETs and connecting both JFET gates of each G4FET together. The front gate terminals of the G4FETs constitute additional terminals (that is, terminals not available in the older JFET version) to which one can apply control voltages VN and VP. Circuits in which NDR devices have been used include (1) Schmitt triggers and (2) oscillators containing inductance/ capacitance (LC) resonant circuits. Figure 2 depicts such circuits containing G4FET NDR devices like that of Figure 1. In the Schmitt trigger shown here, the G4FET NDR is loaded with an ordinary inversion-mode, p-channel, metal oxide/semiconductor field-effect transistor (inversion-mode PMOSFET), the VN terminal of the G4FET NDR device is used as an input terminal, and the input terminals of the PMOSFET and the G4FET NDR device are connected. VP can be used as an extra control voltage (that is, a control voltage not available in a typical prior Schmitt trigger) for adjusting the pinch-off voltage of the p-channel G4FET and thereby adjusting the trigger-voltage window. In the oscillator, a G4FET NDR device is loaded with a conventional LC tank circuit. As in other LC NDR oscillators, oscillation occurs because the NDR counteracts the resistance in the tank circuit. The advantage of this G4FET-NDR LC oscillator

  3. Electrochemical application of DNA biosensors

    NASA Astrophysics Data System (ADS)

    Mascini, M.; Lucarelli, F.; Palchetti, I.; Marrazza, G.

    2001-09-01

    Disposable electrochemical DNA-based biosensors are reviewed; they have been used for the determination of low- molecular weight compounds with affinity for nucleic acids and for the detection of hybridization reaction. The first application is related to the molecular interaction between surface-linked DNA and pollutants or drugs, in order to develop a simple device for rapid screening of toxic compounds. The determination of such compounds was measured by their effect simple device for rapid screening of toxic compounds. The determination of such compounds was measured by their effect on the oxidation signal of the guanine peak of calf thymus DNA immobilized on the electrode surface and investigated by chronopotentiometric or voltammetric analysis. Applicability to river and wastewater sample is demonstrated. Moreover, disposable electrochemical sensors for the detection of a specific sequence of DNA were realized by immobilizing synthetic single-stranded oligonucleotides onto a graphite screen-printed electrode. The probes because hybridized with different concentrations of complementary sequences present in the sample. The hybrids formed on the electrode surface were evaluated by chronopotentiometric analysis using daunomycin as the indicator of the hybridization reaction. The hybridization was also performed using real samples. Application to apolipoprotein E is described, in this case samples have to be amplified by PCR and then analyzed by the DNA biosensor. The extension of such procedures to samples of environmental interest or to contamination of food is discussed.

  4. Complementary and Integrative Medicine

    MedlinePlus

    ... medical treatments that are not part of mainstream medicine. When you are using these types of care, it may be called complementary, integrative, or alternative medicine. Complementary medicine is used together with mainstream medical ...

  5. Charge transport and storage in ion implanted metal-oxide-semiconductor structures

    NASA Astrophysics Data System (ADS)

    Augulis, L.; Pranevičius, L.; Vosylius, J.

    A physical model that predicts charge accumulation in MOS structures with implanted SiO 2 is investigated theoretically and experimentally. It is shown that, to achieve memory effects, MOS structures have to include a SiO 2 layer with different conduction mechanism along its thickness. The sign of the flat-band voltage shift depends on the localization of traps in oxide created by ion implantation. The time characteristics of charge accumulation and discharging of implanted SiO 2 by the pulses of applied voltage are similar to those observed in MNOS structures.

  6. Electrosprayed Metal Oxide Semiconductor Films for Sensitive and Selective Detection of Hydrogen Sulfide

    PubMed Central

    Ghimbeu, Camelia Matei; Lumbreras, Martine; Schoonman, Joop; Siadat, Maryam

    2009-01-01

    Semiconductor metal oxide films of copper-doped tin oxide (Cu-SnO2), tungsten oxide (WO3) and indium oxide (In2O3) were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD). The morphology studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows porous homogeneous films comprising uniformly distributed aggregates of nano particles. The X-ray diffraction technique (XRD) proves the formation of crystalline phases with no impurities. Besides, the Raman cartographies provided information about the structural homogeneity. Some of the films are highly sensitive to low concentrations of H2S (10 ppm) at low operating temperatures (100 and 200 °C) and the best response in terms of Rair/Rgas is given by Cu-SnO2 films (2500) followed by WO3 (1200) and In2O3 (75). Moreover, all the films exhibit no cross-sensitivity to other reducing (SO2) or oxidizing (NO2) gases. PMID:22291557

  7. Metal oxide semiconductor gas sensors utilizing a Cr-zeolite catalytic layer for improved selectivity

    NASA Astrophysics Data System (ADS)

    Mann, D. P.; Paraskeva, T.; Pratt, K. F. E.; Parkin, I. P.; Williams, D. E.

    2005-05-01

    A novel method of improving the selectivity of metal oxide sensors has been developed. The addition of zeolites, catalytically modified with chromium, results in controlled selectivity to alkanes based on shape and size effects. The cracking patterns of n-alkanes over Cr-zeolite Y and Cr-zeolite β between 200 °C and 400 °C have been ascertained using a novel system involving a heated zeolite bed, thermal desorber and GC/MS. The findings correlate with discrimination shown when the respective zeolites are incorporated as a catalytic layer on chromium titanium oxide (CTO) gas sensors used in a proprietary sensor array system to ascertain their suitability for inclusion into an electronic nose.

  8. Technology of GaAs metal-oxide-semiconductor solar cells

    NASA Technical Reports Server (NTRS)

    Stirn, R. J.; Yeh, Y. C. M.

    1977-01-01

    The growth of an oxide interfacial layer was recently found to increase the open-circuit voltage (OCV) and efficiency by up to 60 per cent in GaAs metal-semiconductor solar cells. Details of oxidation techniques to provide the necessary oxide thickness and chemical structure and using ozone, water-vapor-saturated oxygen, or oxygen gas discharges are described, as well as apparent crystallographic orientation effects. Preliminary results of the oxide chemistry obtained from X-ray, photoelectron spectroscopy are given. Ratios of arsenic oxide to gallium oxide of unity or less seem to be preferable. Samples with the highest OVC predominantly have As(+3) in the arsenic oxide rather than As(+5). A major difficulty at this time is a reduction in OCV by 100-200 mV when the antireflection coating is vacuum deposited.

  9. Atomic origin of high-temperature electron trapping in metal-oxide-semiconductor devices

    SciTech Connect

    Shen, Xiao; Dhar, Sarit; Pantelides, Sokrates T.

    2015-04-06

    MOSFETs based on wide-band-gap semiconductors are suitable for operation at high temperature, at which additional atomic-scale processes that are benign at lower temperatures can get activated, resulting in device degradation. Recently, significant enhancement of electron trapping was observed under positive bias in SiC MOSFETs at temperatures higher than 150 °C. Here, we report first-principles calculations showing that the enhanced electron trapping is associated with thermally activated capturing of a second electron by an oxygen vacancy in SiO{sub 2} by which the vacancy transforms into a structure that comprises one Si dangling bond and a bond between a five-fold and a four-fold Si atoms. The results suggest a key role of oxygen vacancies and their structural reconfigurations in the reliability of high-temperature MOS devices.

  10. Electrosprayed metal oxide semiconductor films for sensitive and selective detection of hydrogen sulfide.

    PubMed

    Ghimbeu, Camelia Matei; Lumbreras, Martine; Schoonman, Joop; Siadat, Maryam

    2009-01-01

    Semiconductor metal oxide films of copper-doped tin oxide (Cu-SnO(2)), tungsten oxide (WO(3)) and indium oxide (In(2)O(3)) were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD). The morphology studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows porous homogeneous films comprising uniformly distributed aggregates of nano particles. The X-ray diffraction technique (XRD) proves the formation of crystalline phases with no impurities. Besides, the Raman cartographies provided information about the structural homogeneity. Some of the films are highly sensitive to low concentrations of H(2)S (10 ppm) at low operating temperatures (100 and 200 °C) and the best response in terms of R(air)/R(gas) is given by Cu-SnO(2) films (2500) followed by WO(3) (1200) and In(2)O(3) (75). Moreover, all the films exhibit no cross-sensitivity to other reducing (SO(2)) or oxidizing (NO(2)) gases.

  11. Single Event Effects (SEE) for Power Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs)

    NASA Technical Reports Server (NTRS)

    Lauenstein, Jean-Marie

    2011-01-01

    Single-event gate rupture (SEGR) continues to be a key failure mode in power MOSFETs. (1) SEGR is complex, making rate prediction difficult SEGR mechanism has two main components: (1) Oxide damage-- Reduces field required for rupture (2) Epilayer response -- Creates transient high field across the oxide.

  12. Theoretical Analyses of Oxide-Bypassed Superjunction Power Metal Oxide Semiconductor Field Effect Transistor Devices

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Liang, Yung C.; Samudra, Ganesh S.

    2005-02-01

    The performance merit of silicon unipolar power devices is best described by a trade-off relationship between specific on-state resistance (Ron,sp) and breakdown voltage (Vbr), which leads to the establishment of an ideal unipolar limit on device performance. Recently, engineering the electric field in the device drift region to break this unipolar silicon limit for superior performance has become an important research topic. The superjunction (SJ) structure achieves this by paralleling precisely matched higher doping alternate p--n layers to replace the typically low doping drift region. Alternatively, for fabrication simplicity in an oxide-bypassed (OB) structure, an oxide layer of predetermined thickness together with a polycontact is used to replace the p-column of the SJ structure to modulate the electric field. The further improved gradient OB (GOB) structure with slanted oxide sidewalls delivers a performance similar to ideal SJ devices. In this paper, detailed theoretical analyses in closed-form equations on OB and GOB devices are made for the first time to model the performance in various operating regions. The theoretical analyses were also carefully verified through two-dimensional numerical simulations.

  13. Defect-driven interfacial electronic structures at an organic/metal-oxide semiconductor heterojunction.

    PubMed

    Winget, Paul; Schirra, Laura K; Cornil, David; Li, Hong; Coropceanu, Veaceslav; Ndione, Paul F; Sigdel, Ajaya K; Ginley, David S; Berry, Joseph J; Shim, Jaewon; Kim, Hyungchui; Kippelen, Bernard; Brédas, Jean-Luc; Monti, Oliver L A

    2014-07-16

    The electronic structure of the hybrid interface between ZnO and the prototypical organic semiconductor PTCDI is investigated via a combination of ultraviolet and X-ray photoelectron spectroscopy (UPS/XPS) and density functional theory (DFT) calculations. The interfacial electronic interactions lead to a large interface dipole due to substantial charge transfer from ZnO to 3,4,9,10-perylenetetracarboxylicdiimide (PTCDI), which can be properly described only when accounting for surface defects that confer ZnO its n-type properties.

  14. Thin germanium carbon layers deposited directly on silicon for metal oxide semiconductor devices

    NASA Astrophysics Data System (ADS)

    Kelly, D. Q.; Wiedmann, I.; García-Gutierrez, D. I.; José-Yacamán, M.; Banerjee, S. K.

    2007-01-01

    We report the growth process and materials characterization of germanium-carbon alloys (Ge1-xCx) deposited directly on Si (1 0 0) substrates by ultra-high-vacuum chemical vapour deposition. The Ge1-xCx films are characterized by transmission electron microscopy, etch-pit density, x-ray diffraction, secondary ion mass spectrometry and electron energy loss spectroscopy. The results show that the films exhibit low threading dislocation densities despite significant strain relaxation. We also present evidence for carbon segregation in the Ge1-xCx and interpret these results as a strain relaxation mechanism.

  15. Synthesis Methods, Microscopy Characterization and Device Integration of Nanoscale Metal Oxide Semiconductors for Gas Sensing

    PubMed Central

    Vander Wal, Randy L.; Berger, Gordon M.; Kulis, Michael J.; Hunter, Gary W.; Xu, Jennifer C.; Evans, Laura

    2009-01-01

    A comparison is made between SnO2, ZnO, and TiO2 single-crystal nanowires and SnO2 polycrystalline nanofibers for gas sensing. Both nanostructures possess a one-dimensional morphology. Different synthesis methods are used to produce these materials: thermal evaporation-condensation (TEC), controlled oxidation, and electrospinning. Advantages and limitations of each technique are listed. Practical issues associated with harvesting, purification, and integration of these materials into sensing devices are detailed. For comparison to the nascent form, these sensing materials are surface coated with Pd and Pt nanoparticles. Gas sensing tests, with respect to H2, are conducted at ambient and elevated temperatures. Comparative normalized responses and time constants for the catalyst and noncatalyst systems provide a basis for identification of the superior metal-oxide nanostructure and catalyst combination. With temperature-dependent data, Arrhenius analyses are made to determine activation energies for the catalyst-assisted systems. PMID:22408484

  16. Π Band Dispersion along Conjugated Organic Nanowires Synthesized on a Metal Oxide Semiconductor

    PubMed Central

    2016-01-01

    Surface-confined dehalogenation reactions are versatile bottom-up approaches for the synthesis of carbon-based nanostructures with predefined chemical properties. However, for devices generally requiring low-conductivity substrates, potential applications are so far severely hampered by the necessity of a metallic surface to catalyze the reactions. In this work we report the synthesis of ordered arrays of poly(p-phenylene) chains on the surface of semiconducting TiO2(110) via a dehalogenative homocoupling of 4,4″-dibromoterphenyl precursors. The supramolecular phase is clearly distinguished from the polymeric one using low-energy electron diffraction and scanning tunneling microscopy as the substrate temperature used for deposition is varied. X-ray photoelectron spectroscopy of C 1s and Br 3d core levels traces the temperature of the onset of dehalogenation to around 475 K. Moreover, angle-resolved photoemission spectroscopy and tight-binding calculations identify a highly dispersive band characteristic of a substantial overlap between the precursor’s π states along the polymer, considered as the fingerprint of a successful polymerization. Thus, these results establish the first spectroscopic evidence that atomically precise carbon-based nanostructures can readily be synthesized on top of a transition-metal oxide surface, opening the prospect for the bottom-up production of novel molecule–semiconductor devices. PMID:27115554

  17. Development of a Silicon Metal-Oxide-Semiconductor-Based Qubit Using Spin Exchange Interactions Alone

    DTIC Science & Technology

    2016-03-31

    platform. The logic qubit is formed by three individual spins in electrostatically-defined quantum dots. The gate operations are carried out by spin...compatible with commercial Si CMOS technology. During the funding period, we have successfully developed an array of highly stable Si MOS triple quantum ...ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 quantum computing, Si qubits, Si MOS quantum dots, ESR

  18. Localized dielectric breakdown and antireflection coating in metal-oxide-semiconductor photoelectrodes

    NASA Astrophysics Data System (ADS)

    Ji, Li; Hsu, Hsien-Yi; Li, Xiaohan; Huang, Kai; Zhang, Ye; Lee, Jack C.; Bard, Allen J.; Yu, Edward T.

    2017-01-01

    Silicon-based photoelectrodes for solar fuel production have attracted great interest over the past decade, with the major challenge being silicon's vulnerability to corrosion. A metal-insulator-semiconductor architecture, in which an insulator film serves as a protection layer, can prevent corrosion but must also allow low-resistance carrier transport, generally leading to a trade-off between stability and efficiency. In this work, we propose and demonstrate a general method to decouple the two roles of the insulator by employing localized dielectric breakdown. This approach allows the insulator to be thick, which enhances stability, while enabling low-resistance carrier transport as required for efficiency. This method can be applied to various oxides, such as SiO2 and Al2O3. In addition, it is suitable for silicon, III-V compounds, and other optical absorbers for both photocathodes and photoanodes. Finally, the thick metal-oxide layer can serve as a thin-film antireflection coating, which increases light absorption efficiency.

  19. Modeling the Effects of Heavy Charged Particles on MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors).

    DTIC Science & Technology

    1988-03-01

    Prefareace.P.e... e.a...........................................................................5 Listol oflag vsg ...energies from 2-16 MeV. The angle between the proton track and the electric field was varied, and data collected for the cases of 0, 45, and 80...anomaly, the data was replotted in a different format, shown in Figures 5, 6, and 7. Figure 5 shows the change in threshold voltage as a function of

  20. Highly mobile and reactive state of hydrogen in metal oxide semiconductors at room temperature

    PubMed Central

    Chen, Wan Ping; He, Ke Feng; Wang, Yu; Chan, Helen Lai Wah; Yan, Zijie

    2013-01-01

    Hydrogen in metal oxides usually strongly associates with a neighboring oxygen ion through an O-H bond and thus displays a high stability. Here we report a novel state of hydrogen with unusually high mobility and reactivity in metal oxides at room temperature. We show that freshly doped hydrogen in Nb2O5 and WO3 polycrystals via electrochemical hydrogenation can reduce Cu2+ ions into Cu0 if the polycrystals are immersed in a CuSO4 solution, while this would not happen if the hydrogenated polycrystals have been placed in air for several hours before the immersion. Time-dependent studies of electrochemically hydrogenated rutile single crystals reveal two distinct states of hydrogen: one as protons covalently bonded to oxygen ions, while the other one is highly unstable with a lifetime of just a few hours. Observation of this mobile and reactive state of hydrogen will provide new insight into numerous moderate and low temperature interactions between metal oxides and hydrogen. PMID:24193143

  1. Permanent optical doping of amorphous metal oxide semiconductors by deep ultraviolet irradiation at room temperature

    SciTech Connect

    Seo, Hyungtak; Cho, Young-Je; Bobade, Santosh M.; Park, Kyoung-Youn; Choi, Duck-Kyun; Kim, Jinwoo; Lee, Jaegab

    2010-05-31

    We report an investigation of two photon ultraviolet (UV) irradiation induced permanent n-type doping of amorphous InGaZnO (a-IGZO) at room temperature. The photoinduced excess electrons were donated to change the Fermi-level to a conduction band edge under the UV irradiation, owing to the hole scavenging process at the oxide interface. The use of optically n-doped a-IGZO channel increased the carrier density to approx10{sup 18} cm{sup -3} from the background level of 10{sup 16} cm{sup -3}, as well as the comprehensive enhancement upon UV irradiation of a-IGZO thin film transistor parameters, such as an on-off current ratio at approx10{sup 8} and field-effect mobility at 22.7 cm{sup 2}/V s.

  2. Fast 1 kV metal-oxide-semiconductor field-effect transistor switch

    NASA Astrophysics Data System (ADS)

    Dedman, C. J.; Roberts, E. H.; Gibson, S. T.; Lewis, B. R.

    2001-09-01

    A fast, high-voltage switch based on cheap and readily available components is described. This simple circuit can switch 1 kV to ground with a fall time of ˜2.5 ns, and has proved a cost-effective means of driving electrostatic gating and rereferencing devices in pulsed ion-beam experiments.

  3. A novel RF-insensitive EED utilizing an integrated metal-oxide-semiconductor structure

    NASA Astrophysics Data System (ADS)

    Baginski, Thomas A.; Baginski, Michael E.

    1990-05-01

    The description and characterization of an electroexplosive device (EED) are presented. The structure is designed, using microelectric fabrication techniques, to be inherently immune to radio frequency (RF) radiation and also offers protection against stray signals associated with RF-induced arcing. A detailed discussion of the structure, which includes the fundamental mechanisms of operation, fabrication techniques, the device's frequency response and sensitivity to RF-induced arcing, and its compatibility with present fire control systems, is provided. Preliminary test results of the prototype device are discussed and show a significant improvement in the system's overall EMI immunity. These results include bench and field measurements of the structure's RF response for frequencies of 10-225 MHz and field measurements of the device's sensitivity to RF-induced arcing. The measurements indicate a significant reduction in real power dissipated by an EED employing the structure over an EED employing a conventional bridgewire (20 dB at 90 MHz).

  4. Biosensors for Cell Analysis.

    PubMed

    Zhou, Qing; Son, Kyungjin; Liu, Ying; Revzin, Alexander

    2015-01-01

    Biosensors first appeared several decades ago to address the need for monitoring physiological parameters such as oxygen or glucose in biological fluids such as blood. More recently, a new wave of biosensors has emerged in order to provide more nuanced and granular information about the composition and function of living cells. Such biosensors exist at the confluence of technology and medicine and often strive to connect cell phenotype or function to physiological or pathophysiological processes. Our review aims to describe some of the key technological aspects of biosensors being developed for cell analysis. The technological aspects covered in our review include biorecognition elements used for biosensor construction, methods for integrating cells with biosensors, approaches to single-cell analysis, and the use of nanostructured biosensors for cell analysis. Our hope is that the spectrum of possibilities for cell analysis described in this review may pique the interest of biomedical scientists and engineers and may spur new collaborations in the area of using biosensors for cell analysis.

  5. Photoelectrochemical enzymatic biosensors.

    PubMed

    Zhao, Wei-Wei; Xu, Jing-Juan; Chen, Hong-Yuan

    2017-06-15

    Enzymatic biosensors have been valuable bioanalytical devices for analysis of diverse targets in disease diagnosis, biological and biomedical research, etc. Photoelectrochemical (PEC) bioanalysis is a recently emerged method that promptly becoming a subject of new research interests due to its attractive potential for future bioanalysis with high sensitivity and specificity. PEC enzymatic biosensors integrate the inherent sensitivities of PEC bioanalysis and the selectivity of enzymes and thus share their both advantages. Currently, PEC enzymatic biosensors have become a hot topic of significant research and the recent impetus has grown rapidly as demonstrated by increased research papers. Given the pace of advances in this area, this review will make a thorough discussion and survey on the fundamentals, sensing strategies, applications and the state of the art in PEC enzymatic biosensors, followed by future prospects based on our own opinions. We hope this work could provide an accessible introduction to PEC enzymatic biosensors for any scientist.

  6. Genomagnetic Electrochemical Biosensors

    NASA Astrophysics Data System (ADS)

    Wang, Joseph; Erdem, Arzum

    The use of nucleic acid technologies has significantly improved preparation and diagnostic procedures in life sciences. Nucleic acid layers combined with electrochemical or optical transducers produce a new kind of affinity biosensors as DNA Biosensor for small molecular weight molecules. Electrochemical DNA biosensors are attractive devices for converting the hybridization event into an analytical signal for obtaining sequence-specific information in connection with clinical, environmental or forensic investigations. DNA hybridization biosensors, based on electrochemical transduction of hybridization, couple the high specificity of hybridization reactions with the excellent sensitivity and portability of electrochemical transducers. The main goal in all researches is to design DNA biosensors for preparing a basis for the future DNA microarray system. DNA chip has now become a powerful tool in biological research, however the real clinic assay is still under development. Recently, there has been a great interest to the magnetic beads and/or nanoparticles labelled with metals such as gold, cadmium, silver, etc. for designing of novel electrochemical DNA biosensor approaches resulting in efficient separation. The attractive features of this technology include simple approach, rapid results, multi-analyte detection, low-cost per measurument, stable, and non-hazardous reagents, and reduced waste handling. Some of these new approaches and applications of the electrochemical DNA biosensors based on magnetic beads and its combining with nanoparticles labelled with metals are described and discussed.

  7. Introduction to biosensors

    PubMed Central

    Bhalla, Nikhil; Jolly, Pawan; Formisano, Nello

    2016-01-01

    Biosensors are nowadays ubiquitous in biomedical diagnosis as well as a wide range of other areas such as point-of-care monitoring of treatment and disease progression, environmental monitoring, food control, drug discovery, forensics and biomedical research. A wide range of techniques can be used for the development of biosensors. Their coupling with high-affinity biomolecules allows the sensitive and selective detection of a range of analytes. We give a general introduction to biosensors and biosensing technologies, including a brief historical overview, introducing key developments in the field and illustrating the breadth of biomolecular sensing strategies and the expansion of nanotechnological approaches that are now available. PMID:27365030

  8. Biosensors in clinical chemistry.

    PubMed

    D'Orazio, Paul

    2003-08-01

    Biosensors are analytical devices composed of a recognition element of biological origin and a physico-chemical transducer. The biological element is capable of sensing the presence, activity or concentration of a chemical analyte in solution. The sensing takes place either as a binding event or a biocatalytical event. These interactions produce a measurable change in a solution property, which the transducer converts into a quantifiable electrical signal. Present-day applications of biosensors to clinical chemistry are reviewed, including basic and applied research, commercial applications and fabrication techniques. Recognition elements include enzymes as biocatalytic recognition elements and immunoagents and DNA segments as affinity ligand recognition elements, coupled to electrochemical and optical modes of transduction. The future will include biosensors based on synthetic recognition elements to allow broad applicability to different classes of analytes and modes of transduction extending lower limits of sensitivity. Microfabrication will permit biosensors to be constructed as arrays and incorporated into lab-on-a-chip devices.

  9. Biosensors Incorporating Bimetallic Nanoparticles

    PubMed Central

    Rick, John; Tsai, Meng-Che; Hwang, Bing Joe

    2015-01-01

    This article presents a review of electrochemical bio-sensing for target analytes based on the use of electrocatalytic bimetallic nanoparticles (NPs), which can improve both the sensitivity and selectivity of biosensors. The review moves quickly from an introduction to the field of bio-sensing, to the importance of biosensors in today’s society, the nature of the electrochemical methods employed and the attendant problems encountered. The role of electrocatalysts is introduced with reference to the three generations of biosensors. The contributions made by previous workers using bimetallic constructs, grouped by target analyte, are then examined in detail; following which, the synthesis and characterization of the catalytic particles is examined prior to a summary of the current state of endeavor. Finally, some perspectives for the future of bimetallic NPs in biosensors are given. PMID:28344262

  10. Triggered optical biosensor

    DOEpatents

    Song, Xuedong; Swanson, Basil I.

    2001-10-02

    An optical biosensor is provided for the detection of a multivalent target biomolecule, the biosensor including a substrate having a bilayer membrane thereon, a recognition molecule situated at the surface, the recognition molecule capable of binding with the multivalent target biomolecule, the recognition molecule further characterized as including a fluorescence label thereon and as being movable at the surface and a device for measuring a fluorescence change in response to binding between the recognition molecule and the multivalent target biomolecule.

  11. Complementary Health Approaches

    MedlinePlus

    ... on some complementary approaches, such as acupuncture and yoga, but there have been fewer studies on other approaches, so much less is known about them. The National Institutes of Health (NIH) is sponsoring research to learn more about ...

  12. Complementary and Integrative Therapies

    MedlinePlus

    ... correctly • Supplement is free of harmful contents like pesticides and heavy metals (such as lead, arsenic or ... 1-888-644-6226 http://nccam.nih.gov Natural Medicines Information on complementary therapies http://naturaldatabase.therapeuticresearch. ...

  13. Complementary and Alternative Medicine

    MedlinePlus

    ... use practices like acupuncture in medicine. But until recently, most Western hospitals didn't provide any alternative ... medicine is often used instead of conventional medical techniques. Complementary medicine is used in addition to conventional ...

  14. All-ion-implantation process for integrated circuits

    NASA Technical Reports Server (NTRS)

    Woo, D. S.

    1979-01-01

    Simpler than diffusion fabrication, ion bombardment produces complementary-metal-oxide-semiconductor / silicon-on-sapphire (CMOS/SOS) circuits that are one-third faster. Ion implantation simplifies the integrated circuit fabrication procedure and produces circuits with uniform characteristics.

  15. A liquid-crystal-based DNA biosensor for pathogen detection

    NASA Astrophysics Data System (ADS)

    Khan, Mashooq; Khan, Abdur Rahim; Shin, Jae-Ho; Park, Soo-Young

    2016-03-01

    A liquid-crystal (LC)-filled transmission electron microscopy (TEM) grid cell coated with the cationic surfactant dodecyltrimethylammonium bromide (DTAB), to which a single-stranded deoxyribonucleic acid probe (ssDNAprobe) was adsorbed at the LC/aqueous interface (TEMDTAB/DNA), was applied for the highly specific detection of target DNA molecules. The DTAB-coated E7 (used LC mixture) in the TEM grid (TEMDTAB) exhibited a homeotropic orientation, and changed to a planar orientation upon adsorption of the ssDNAprobe. The TEMDTAB/DNA was then exposed to complementary (target) ssDNA, which resulted in a planar-to-homeotropic configurational change of E7 that could be observed through a polarized optical microscope under crossed polarizers. The optimum adsorption density (2 μM) of ssDNAprobe enabled the detection of ≥0.05 nM complementary ssDNA. This TEMDTAB/DNA biosensor could differentiate complementary ssDNA from mismatched ssDNA as well as double-stranded DNA. It also successfully detected the genomic DNAs of the bacterium Erwinia carotovora and the fungi Rhazictonia solani. Owe to the high specificity, sensitivity, and label-free detection, this biosensor may broaden the applications of LC-based biosensors to pathogen detection.

  16. A liquid-crystal-based DNA biosensor for pathogen detection

    PubMed Central

    Khan, Mashooq; Khan, Abdur Rahim; Shin, Jae-Ho; Park, Soo-Young

    2016-01-01

    A liquid-crystal (LC)-filled transmission electron microscopy (TEM) grid cell coated with the cationic surfactant dodecyltrimethylammonium bromide (DTAB), to which a single-stranded deoxyribonucleic acid probe (ssDNAprobe) was adsorbed at the LC/aqueous interface (TEMDTAB/DNA), was applied for the highly specific detection of target DNA molecules. The DTAB-coated E7 (used LC mixture) in the TEM grid (TEMDTAB) exhibited a homeotropic orientation, and changed to a planar orientation upon adsorption of the ssDNAprobe. The TEMDTAB/DNA was then exposed to complementary (target) ssDNA, which resulted in a planar-to-homeotropic configurational change of E7 that could be observed through a polarized optical microscope under crossed polarizers. The optimum adsorption density (2 μM) of ssDNAprobe enabled the detection of ≥0.05 nM complementary ssDNA. This TEMDTAB/DNA biosensor could differentiate complementary ssDNA from mismatched ssDNA as well as double-stranded DNA. It also successfully detected the genomic DNAs of the bacterium Erwinia carotovora and the fungi Rhazictonia solani. Owe to the high specificity, sensitivity, and label-free detection, this biosensor may broaden the applications of LC-based biosensors to pathogen detection. PMID:26940532

  17. Biosensors: sense and sensibility.

    PubMed

    Turner, Anthony P F

    2013-04-21

    This review is based on the Theophilus Redwood Medal and Award lectures, delivered to Royal Society of Chemistry meetings in the UK and Ireland in 2012, and presents a personal overview of the field of biosensors. The biosensors industry is now worth billions of United States dollars, the topic attracts the attention of national initiatives across the world and tens of thousands of papers have been published in the area. This plethora of information is condensed into a concise account of the key achievements to date. The reasons for success are examined, some of the more exciting emerging technologies are highlighted and the author speculates on the importance of biosensors as a ubiquitous technology of the future for health and the maintenance of wellbeing.

  18. Biosensor development in Russia.

    PubMed

    Reshetilov, Anatoly N

    2007-07-01

    The review summarizes the current Russian research in the field of biological sensors for detection of carbohydrates, alcohols, medicines, enzyme inhibitors, toxicants, heavy metal ions, as well as viruses and microbial cells. Some of the presented works describe the analytical parameters of biosensors; other publications provide a basis for their development. The review covers mainly publications that have appeared over the past 10 years. As a whole, the collected material gives an idea of the main tendencies of biosensor development in Russia. The review is not meant to be comprehensive but highlights the major trends in this field in the last decade.

  19. Electrochemical biosensors for hormone analyses.

    PubMed

    Bahadır, Elif Burcu; Sezgintürk, Mustafa Kemal

    2015-06-15

    Electrochemical biosensors have a unique place in determination of hormones due to simplicity, sensitivity, portability and ease of operation. Unlike chromatographic techniques, electrochemical techniques used do not require pre-treatment. Electrochemical biosensors are based on amperometric, potentiometric, impedimetric, and conductometric principle. Amperometric technique is a commonly used one. Although electrochemical biosensors offer a great selectivity and sensitivity for early clinical analysis, the poor reproducible results, difficult regeneration steps remain primary challenges to the commercialization of these biosensors. This review summarizes electrochemical (amperometric, potentiometric, impedimetric and conductometric) biosensors for hormone detection for the first time in the literature. After a brief description of the hormones, the immobilization steps and analytical performance of these biosensors are summarized. Linear ranges, LODs, reproducibilities, regenerations of developed biosensors are compared. Future outlooks in this area are also discussed.

  20. Surface stress-based biosensors.

    PubMed

    Sang, Shengbo; Zhao, Yuan; Zhang, Wendong; Li, Pengwei; Hu, Jie; Li, Gang

    2014-01-15

    Surface stress-based biosensors, as one kind of label-free biosensors, have attracted lots of attention in the process of information gathering and measurement for the biological, chemical and medical application with the development of technology and society. This kind of biosensors offers many advantages such as short response time (less than milliseconds) and a typical sensitivity at nanogram, picoliter, femtojoule and attomolar level. Furthermore, it simplifies sample preparation and testing procedures. In this work, progress made towards the use of surface stress-based biosensors for achieving better performance is critically reviewed, including our recent achievement, the optimally circular membrane-based biosensors and biosensor array. The further scientific and technological challenges in this field are also summarized. Critical remark and future steps towards the ultimate surface stress-based biosensors are addressed.

  1. Biosensors for bioprocesses

    SciTech Connect

    Van Brunt, J.

    1987-05-01

    The advent of biosensors has been touted as the marriage of the century - a marriage of microelectronics and biotechnology. But exactly what is a biosensor. Actually, the term is used interchangeably for two sometimes very different classes of devices - those that measure biological molecules and particles and those that use biomolecules as part of the sensing mechanism. The basic conceptual design of a biosensor is simple: a biological receptor is coupled to an electronic tranducer in such a way that the transducer converts biochemical activity at one end into electrical activity at the other. The biological component is usually an enzyme (for selective chemical catalysis) or an antibody (for highly selective binding), although cell membrane receptors, tissue slices, and microbial cells are used as well. The electronic component measures voltage (potentiometric), current (amperometric), light, sound, temperaure, or mass (piezoelectric). Biosensors display several unique features that make them especially attractive. They are small. They are simple to use many procedures require one step, no additional reagents, and no radioactivity. They are portable. And they are inexpensive and perfect for data processing.

  2. Recent Trends in Biosensors

    NASA Astrophysics Data System (ADS)

    Karube, Isao

    The determination of organic compounds in foods is very important in food industries. A various compounds are contained in foods, selective determination methods are required for food processing and analysis. Electrochemical monitoring devices (biosensors) employing immobilized biocatalysts such as immobilized enzymes, organelles, microorganisms, and tissue have definite advantages. The enzyme Sensors consisted of immobilized enzymes and electrochemical devices. Enzyme sensors could be used for the determination of sugars, amino acids, organic acids, alcohols, lipids, nucleic acid derivatives, etc.. Furthermore, a multifunctional biosensor for the determination of several compounds has been developed for food processing. On the other hand, microbial sensors consisted of immobilized microorganisms and electrodes have been used for industrial and environmental analysis. Microbial sensors were applied for the determination of sugars, organic acids, alcohols, amino acids, mutagens, me thane, ammonia, and BOD. Furthermore, micro-biosensors using immobilized biocatalysts and ion sensitive field effect transistor or microelectrodes prepared by silicon fabrication technologies have been developed for medical ap. plication and food processing. This review summarizes the design and application of biosensors.

  3. High-sensitive label-free biosensors based on single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Maehashi, Kenzo; Matsumoto, Kazuhiko

    2006-02-01

    DNA hybridization has sensitively been detected using carbon nanotube field-effect transistors (CNTFETs) in real time. After full-complementary DNA introduction, the source-drain current gradually increased while monitoring in real time. Full-complementary DNA with concentration as low as 1 fmol/L solution could be effectively detected. Our CNTFET-based biochip is a promising candidate for the development of an integrated, high-throughput, multiplexed DNA biosensor for medical, forensic and environmental diagnostics.

  4. Complementary Coffee Cups

    ERIC Educational Resources Information Center

    Banchoff, Thomas

    2006-01-01

    What may have been the birth of a new calculus problem took place when the author noticed that two coffee cups, one convex and one concave, fit nicely together, and he wondered which held more coffee. The fact that their volumes were about equal led to the topic of this article: complementary surfaces of revolution with equal volumes.

  5. Mutually Exclusive, Complementary, or . . .

    ERIC Educational Resources Information Center

    Schloemer, Cathy G.

    2016-01-01

    Whether students are beginning their study of probability or are well into it, distinctions between complementary sets and mutually exclusive sets can be confusing. Cathy Schloemer writes in this article that for years she used typical classroom examples but was not happy with the student engagement or the level of understanding they produced.…

  6. A novel self-powered and sensitive label-free DNA biosensor in microbial fuel cell.

    PubMed

    Asghary, Maryam; Raoof, Jahan Bakhsh; Rahimnejad, Mostafa; Ojani, Reza

    2016-08-15

    In this work, a novel self-powered, sensitive, low-cost, and label-free DNA biosensor is reported by applying a two-chambered microbial fuel cell (MFC) as a power supply. A graphite electrode and an Au nanoparticles modified graphite electrode (AuNP/graphite electrode) were used as anode and cathode in the MFC system, respectively. The active biocatalyst in the anodic chamber was a mixed culture of microorganisms. The sensing element of the biosensor was fabricated by the well-known Au-thiol binding the ssDNA probe on the surface of an AuNP/graphite cathode. Electrons produced by microorganisms were transported from the anode to the cathode through an external circuit, which could be detected by the terminal multi-meter detector. The difference between power densities of the ssDNA probe modified cathode in the absence and presence of complementary sequence served as the detection signal of the DNA hybridization with detection limit of 3.1nM. Thereafter, this biosensor was employed for diagnosis and determination of complementary sequence in a human serum sample. The hybridization specificity studies further revealed that the developed DNA biosensor could distinguish fully complementary sequences from one-base mismatched and non-complementary sequences.

  7. Recent advances in phosphate biosensors.

    PubMed

    Upadhyay, Lata Sheo Bachan; Verma, Nishant

    2015-07-01

    A number of biosensors have been developed for phosphate analysis particularly, concerning its negative impact within the environmental and biological systems. Enzymatic biosensors comprising either a single or multiple enzymatic system have been extensively used for the direct and indirect analysis of phosphate ions. Furthermore, some non-enzymatic biosensors, such as affinity-based biosensors, provide an alternative analytical approach with a higher selectivity. This article reviews the recent advances in the field of biosensor developed for phosphate estimation in clinical and environmental samples, concerning the techniques involved, and the sensitivity toward phosphate ions. The biosensors have been classified and discussed on the basis of the number of enzymes used to develop the analytical system, and a comparative analysis has been performed.

  8. Thiol- and biotin-labeled probes for oligonucleotide quartz crystal microbalance biosensors of microalga alexandrium minutum.

    PubMed

    Lazerges, Mathieu; Perrot, Hubert; Rabehagasoa, Niriniony; Compère, Chantal

    2012-07-04

    Two quartz crystal microbalance oligonucleotide biosensors of a toxic microalga gene sequence (Alexandrium Minutum) have been designed. Grafting on a gold surface of 20-base thiol- or biotin-labeled probe, and selective hybridization with the complementary 20-base target, have been monitored in situ with a 27 MHz quartz crystal microbalance under controlled hydrodynamic conditions. The frequency of the set up is stable to within a few hertz, corresponding to the nanogram scale, for three hour experiments. DNA recognition by the two biosensors is efficient and selective. Hybridization kinetic curves indicate that the biosensor designed with the thiol-labeled probe is more sensitive, and that the biosensor designed with the biotin-labeled probe has a shorter time response and a higher hybridization efficiency.

  9. Thiol- and Biotin-Labeled Probes for Oligonucleotide Quartz Crystal Microbalance Biosensors of Microalga Alexandrium Minutum

    PubMed Central

    Lazerges, Mathieu; Perrot, Hubert; Rabehagasoa, Niriniony; Compère, Chantal

    2012-01-01

    Two quartz crystal microbalance oligonucleotide biosensors of a toxic microalga gene sequence (Alexandrium Minutum) have been designed. Grafting on a gold surface of 20-base thiol- or biotin-labeled probe, and selective hybridization with the complementary 20-base target, have been monitored in situ with a 27 MHz quartz crystal microbalance under controlled hydrodynamic conditions. The frequency of the set up is stable to within a few hertz, corresponding to the nanogram scale, for three hour experiments. DNA recognition by the two biosensors is efficient and selective. Hybridization kinetic curves indicate that the biosensor designed with the thiol-labeled probe is more sensitive, and that the biosensor designed with the biotin-labeled probe has a shorter time response and a higher hybridization efficiency. PMID:25585927

  10. Nanomaterial-Based Electrochemical Biosensors and Bioassays

    SciTech Connect

    Liu, Guodong; Mao, Xun; Gurung, Anant; Baloda, Meenu; Lin, Yuehe; He, Yuqing

    2010-08-31

    This book chapter summarizes the recent advance in nanomaterials for electrochemical biosensors and bioassays. Biofunctionalization of nanomaterials for biosensors fabrication and their biomedical applications are discussed.

  11. High-density fiber optic biosensor arrays

    NASA Astrophysics Data System (ADS)

    Epstein, Jason R.; Walt, David R.

    2002-02-01

    Novel approaches are required to coordinate the immense amounts of information derived from diverse genomes. This concept has influenced the expanded role of high-throughput DNA detection and analysis in the biological sciences. A high-density fiber optic DNA biosensor was developed consisting of oligonucleotide-functionalized, 3.1 mm diameter microspheres deposited into the etched wells on the distal face of a 500 micrometers imaging fiber bundle. Imaging fiber bundles containing thousands of optical fibers, each associated with a unique oligonucleotide probe sequence, were the foundation for an optically connected, individually addressable DNA detection platform. Different oligonucleotide-functionalized microspheres were combined in a stock solution, and randomly dispersed into the etched wells. Microsphere positions were registered from optical dyes incorporated onto the microspheres. The distribution process provided an inherent redundancy that increases the signal-to-noise ratio as the square root of the number of sensors examined. The representative amount of each probe-type in the array was dependent on their initial stock solution concentration, and as other sequences of interest arise, new microsphere elements can be added to arrays without altering the existing detection capabilities. The oligonucleotide probe sequences hybridize to fluorescently-labeled, complementary DNA target solutions. Fiber optic DNA microarray research has included DNA-protein interaction profiles, microbial strain differentiation, non-labeled target interrogation with molecular beacons, and single cell-based assays. This biosensor array is proficient in DNA detection linked to specific disease states, single nucleotide polymorphism (SNP's) discrimination, and gene expression analysis. This array platform permits multiple detection formats, provides smaller feature sizes, and enables sensor design flexibility. High-density fiber optic microarray biosensors provide a fast

  12. Complementary and Alternative Methods and Cancer

    MedlinePlus

    ... Effects Complementary and Alternative Medicine Complementary and Alternative Methods and Cancer Complementary and alternative are terms used ... with cancer here. What Are Complementary and Alternative Methods? How Are Complementary Methods Used to Manage Cancer? ...

  13. Carbon Nanotube Biosensors

    NASA Astrophysics Data System (ADS)

    Tilmaciu, Carmen-Mihaela; Morris, May

    2015-10-01

    Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular Carbon Nanotubes (CNTs) can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we will describe their structural and physical properties, discuss functionalization and cellular uptake, biocompatibility and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers.

  14. Carbon nanotube biosensors

    PubMed Central

    Tîlmaciu, Carmen-Mihaela; Morris, May C.

    2015-01-01

    Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular, carbon nanotubes (CNTs) can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical, and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites, or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we describe their structural and physical properties, functionalization and cellular uptake, biocompatibility, and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers. PMID:26579509

  15. Biosensors based on DNA-Functionalized Graphene

    NASA Astrophysics Data System (ADS)

    Vishnubhotla, Ramya; Ping, Jinglei; Vrudhula, Amey; Johnson, A. T. Charlie

    Since its discovery, graphene has been used for sensing applications due to its outstanding electrical properties and biocompatibility. Here, we demonstrate the capabilities of field effect transistors (FETs) based on CVD-grown graphene functionalized with commercially obtained DNA oligomers and aptamers for detection of various biomolecular targets (e.g., complementary DNA and small molecule drug targets). Graphene FETs were created with a scalable photolithography process that produces arrays consisting of 50-100 FETs with a layout suitable for multiplexed detection of four molecular targets. FETs were characterized via AFM to confirm the presence of the aptamer. From the measured electrical characteristics, it was determined that binding of molecular targets by the DNA chemical recognition element led to a reproducible, concentration-dependent shift in the Dirac voltage. This biosensor class is potentially suitable for applications in drug detection. This work is funded by NIH through the Center for AIDS Research at the University of Pennsylvania.

  16. Micro-algal biosensors.

    PubMed

    Brayner, Roberta; Couté, Alain; Livage, Jacques; Perrette, Catherine; Sicard, Clémence

    2011-08-01

    Fighting against water pollution requires the ability to detect pollutants for example herbicides or heavy metals. Micro-algae that live in marine and fresh water offer a versatile solution for the construction of novel biosensors. These photosynthetic microorganisms are very sensitive to changes in their environment, enabling the detection of traces of pollutants. Three groups of micro-algae are described in this paper: chlorophyta, cyanobacteria, and diatoms.

  17. Graphene-based biosensors

    NASA Astrophysics Data System (ADS)

    Lebedev, A. A.; Davydov, V. Yu.; Novikov, S. N.; Litvin, D. P.; Makarov, Yu. N.; Klimovich, V. B.; Samoilovich, M. P.

    2016-07-01

    Results of developing and testing graphene-based sensors capable of detecting protein molecules are presented. The biosensor operation was checked using an immunochemical system comprising fluorescein dye and monoclonal antifluorescein antibodies. The sensor detects fluorescein concentration on a level of 1-10 ng/mL and bovine serum albumin-fluorescein conjugate on a level of 1-5 ng/mL. The proposed device has good prospects for use for early diagnostics of various diseases.

  18. Symposium on Biosensors

    DTIC Science & Technology

    1989-11-01

    the same side of irreversible thermodynamic equation is the pyroelectric effect in which a thermal cradient induces a field and a measurable voltage...permit analysis of phosphate and bicarbonate, for example, and Li+ and Mg÷2 among the cations. Design of optical sensors has again lagged behind trial...make good enthatipetric biosensors for use in flow injectic analysis systems. First, a bimo:-ph is constructed by placing two sheets of the fiV face

  19. A portable array biosensor

    NASA Astrophysics Data System (ADS)

    Golden, Joel P.; Shriver-Lake, Lisa C.; Taitt, Chris R.; Fertig, Stephanie; Sapsford, Kim E.; Ligler, Fran S.

    2004-12-01

    An array biosensor developed for performing simultaneous analysis of multiple samples for multiple analytes has been miniaturized and fully automated. The biochemical component of the multi-analyte biosensor consists of a patterned array of biological recognition elements ("capture" antibodies) immobilized on the surface of a planar waveguide. A fluorescence assay is performed on the patterned surface, yielding an array of fluorescent spots, the locations of which are used to identify what analyte is present. Signal transduction is accomplished by means of a diode laser for fluorescence excitation, optical filters and a CCD camera for image capture. A laptop computer controls the miniaturized fluidics system and image capture. Data analysis software has been developed to locate each spot and quantify the fluorescent signal in each spot. The array biosensor is capable of detecting a variety of analytes including toxins, bacteria and viruses and shows minimal interference from complex physiological sample matrices such whole blood and blood components, fecal matter, saliva, nasal secretions, and urine. Some results from recent field trials are presented.

  20. Biosensors, antibiotics and food.

    PubMed

    Virolainen, Nina; Karp, Matti

    2014-01-01

    Antibiotics are medicine's leading asset for fighting microbial infection, which is one of the leading causes of death worldwide. However, the misuse of antibiotics has led to the rapid spread of antibiotic resistance among bacteria and the development of multiple resistant pathogens. Therefore, antibiotics are rapidly losing their antimicrobial value. The use of antibiotics in food production animals is strictly controlled by the European Union (EU). Veterinary use is regulated to prevent the spread of resistance. EU legislation establishes maximum residue limits for veterinary medicinal products in foodstuffs of animal origin and enforces the establishment and execution of national monitoring plans. Among samples selected for monitoring, suspected noncompliant samples are screened and then subjected to confirmatory analysis to establish the identity and concentration of the contaminant. Screening methods for antibiotic residues are typically based on microbiological growth inhibition, whereas physico-chemical methods are used for confirmatory analysis. This chapter discusses biosensors, especially whole-cell based biosensors, as emerging screening methods for antibiotic residues. Whole-cell biosensors can offer highly sensitive and specific detection of residues. Applications demonstrating quantitative analysis and specific analyte identification further improve their potential as screening methods.

  1. A sensitive DNA capacitive biosensor using interdigitated electrodes.

    PubMed

    Wang, Lei; Veselinovic, Milena; Yang, Lang; Geiss, Brian J; Dandy, David S; Chen, Tom

    2017-01-15

    This paper presents a label-free affinity-based capacitive biosensor using interdigitated electrodes. Using an optimized process of DNA probe preparation to minimize the effect of contaminants in commercial thiolated DNA probe, the electrode surface was functionalized with the 24-nucleotide DNA probes based on the West Nile virus sequence (Kunjin strain). The biosensor has the ability to detect complementary DNA fragments with a detection limit down to 20 DNA target molecules (1.5aM range), making it suitable for a practical point-of-care (POC) platform for low target count clinical applications without the need for amplification. The reproducibility of the biosensor detection was improved with efficient covalent immobilization of purified single-stranded DNA probe oligomers on cleaned gold microelectrodes. In addition to the low detection limit, the biosensor showed a dynamic range of detection from 1µL(-1) to 10(5)µL(-1) target molecules (20 to 2 million targets), making it suitable for sample analysis in a typical clinical application environment. The binding results presented in this paper were validated using fluorescent oligomers.

  2. Fabrication of an electrochemical DNA-based biosensor for Bacillus cereus detection in milk and infant formula.

    PubMed

    Izadi, Zahra; Sheikh-Zeinoddin, Mahmoud; Ensafi, Ali A; Soleimanian-Zad, Sabihe

    2016-06-15

    This paper describes fabrication of a DNA-based Au-nanoparticle modified pencil graphite electrode (PGE) biosensor for detection of Bacillus cereus, causative agent of two types of food-borne disease, i.e., emetic and diarrheal syndrome. The sensing element of the biosensor was comprised of gold nanoparticles (GNPs) self-assembled with single-stranded DNA (ssDNA) of nheA gene immobilized with thiol linker on the GNPs modified PGE. The size, shape and dispersion of the GNPs were characterized by field emission scanning electron microscope (FESEM). Detection of B. cereus was carried out based on an increase in the charge transfer resistance (Rct) of the biosensor due to hybridization of the ss-DNA with target DNA. An Atomic force microscope (AFM) was used to confirm the hybridization. The biosensor sensitivity in pure cultures of B. cereus was found to be 10(0) colony forming units per milliliter (CFU/mL) with a detection limit of 9.4 × 10(-12) mol L(-1). The biosensor could distinguish complementary from mismatch DNA sequence. The proposed biosensor exhibited a rapid detection, low cost, high sensitivity to bacterial contamination and could exclusively and specifically detect the target DNA sequence of B. cereus from other bacteria that can be found in dairy products. Moreover, the DNA biosensor exhibited high reproducibility and stability, thus it may be used as a suitable biosensor to detect B. cereus and to become a portable system for food quality control.

  3. Electrochemical biosensor for Mycobacterium tuberculosis DNA detection based on gold nanotubes array electrode platform.

    PubMed

    Torati, Sri Ramulu; Reddy, Venu; Yoon, Seok Soo; Kim, CheolGi

    2016-04-15

    The template assisted electrochemical deposition technique was used for the synthesis of gold nanotubes array (AuNTsA). The morphological structure of the synthesized AuNTsA was observed by scanning electron microscopy and found that the individual nanotubes are around 1.5 μm in length with a diameter of 200 nm. Nanotubes are vertically aligned to the Au thick film, which is formed during the synthesis process of nanotubes. The electrochemical performance of the AuNTsA was compared with the bare Au electrode and found that AuNTsA has better electron transfer surface than bare Au electrode which is due to the high surface area. Hence, the AuNTsA was used as an electrode for the fabrication of DNA hybridization biosensor for detection of Mycobacterium Tuberculosis DNA. The DNA hybridization biosensor constructed by AuNTsA electrode was characterized by cyclic voltammetry technique with Fe(CN)6(3-/4-) as an electrochemical redox indicator. The selectivity of the fabricated biosensor was illustrated by hybridization with complementary DNA and non-complementary DNA with probe DNA immobilized AuNTsA electrode using methylene blue as a hybridization indicator. The developed electrochemical DNA biosensor shows good linear range of complementary DNA concentration from 0.01 ng/μL to 100 ng/μL with high detection limit.

  4. [Nanobiotechnology and biosensor research].

    PubMed

    Reshetilov, A N; Bezborodov, A M

    2008-01-01

    Nanobiotechnology is defined as an interdisciplinary field of science that studies the application of fine-sized biological objects (of nanoscale, 1-100 nm) to design the devices and systems of the same size that utilize for new purposes the unusual, known, or previously unknown effects. Analysis demonstrates that the final goals, approaches, solution methods, and applications of nanostructures and biological sensors have much in common. This brief review attempts to systematize a number of the available data and pick out an organic connection of the new research direction with the field of biosensor technology, which have reached the level of sustainable development.

  5. A low cost color-based bacterial biosensor for measuring arsenic in groundwater.

    PubMed

    Huang, Chi-Wei; Wei, Chia-Cheng; Liao, Vivian Hsiu-Chuan

    2015-12-01

    Using arsenic (As) contaminated groundwater for drinking or irrigation has caused major health problems for humans around the world, raising a need to monitor As level efficiently and economically. This study developed a color-based bacterial biosensor which is easy-to-use and inexpensive for measuring As and could be complementary to current As detecting techniques. The arsR-lacZ recombinant gene cassette in nonpathogenic strain Escherichia coli DH5α was used in the color-based biosensor which could be observed by eyes or measured by spectrometer. The developed bacterial biosensor demonstrates a quantitative range from 10 to 500μgL(-1) of As in 3-h reaction time. Furthermore, the biosensor was able to successfully detect and estimate As concentration in groundwater sample by measuring optical density at 595nm (OD595). Among different storage methods used in this study, biosensor in liquid at 4°C showed the longest shelf life about 9d, and liquid storage at RT and cell pellet could also be stored for about 3-5d. In conclusion, this study showed that the As biosensor with reliable color signal and economical preservation methods is useful for rapid screening of As pollutant, providing the potential for large scale screening and better management strategies for environmental quality control.

  6. Field Friendly Tuberculosis Biosensor

    NASA Astrophysics Data System (ADS)

    Proper, N.; Scherman, M. S.; Jevsevar, K. L.; Stone, J.; McNeil, M. R.; Krapf, D.

    2009-10-01

    Tuberculosis (TB) is a fading threat in the United States, but in the developing world it is still a major health-care concern. Given the rising number of cases and lack of resources, there is a desperate need for an affordable, portable detection system. We are working towards the development of a field-friendly immunological biosensor that utilizes florescence microscopy to undertake this task. We observe fluorescently labeled antibodies/antigens as they bind to a glass slide treated with polyethylene glycol (PEG) in order to inhibit non-specific adsorption. Antibodies against the antigens of interest are bound to the PEGylated glass slides via biotin-streptavidin interactions. Then, fluorescently labeled antibodies are mixed with different concentrations of TB antigens and this solution is incubated on the treated glass slides for 30 minutes. The slides are thoroughly rinsed with water following the incubation period. The antigens are then detected by fluorescence using a low-cost biosensor. Our system includes a ``supermarket-scanner'' HeNe laser, home-built electronics, off-the-shelf optics and a Si photodiode. Work is underway to incorporate a flow-cell into the system, in a small portable box.

  7. Electrochemical biosensors and nanobiosensors

    PubMed Central

    Hammond, Jules L.; Formisano, Nello; Carrara, Sandro; Tkac, Jan

    2016-01-01

    Electrochemical techniques have great promise for low-cost miniaturised easy-to-use portable devices for a wide range of applications–in particular, medical diagnosis and environmental monitoring. Different techniques can be used for biosensing, with amperometric devices taking the central role due to their widespread application in glucose monitoring. In fact, glucose biosensing takes an approximately 70% share of the biosensor market due to the need for diabetic patients to monitor their sugar levels several times a day, making it an appealing commercial market. In this review, we present the basic principles of electrochemical biosensor devices. A description of the different generations of glucose sensors is used to describe in some detail the operation of amperometric sensors and how the introduction of mediators can enhance the performance of the sensors. Electrochemical impedance spectroscopy is a technique being increasingly used in devices due to its ability to detect variations in resistance and capacitance upon binding events. Novel advances in electrochemical sensors, due to the use of nanomaterials such as carbon nanotubes and graphene, are presented as well as future directions that the field is taking. PMID:27365037

  8. Improved Biosensors for Soils

    NASA Astrophysics Data System (ADS)

    Silberg, J. J.; Masiello, C. A.; Cheng, H. Y.

    2014-12-01

    Microbes drive processes in the Earth system far exceeding their physical scale, affecting crop yields, water quality, the mobilization of toxic materials, and fundamental aspects of soil biogeochemistry. The tools of synthetic biology have the potential to significantly improve our understanding of microbial Earth system processes: for example, synthetic microbes can be be programmed to report on environmental conditions that stimulate greenhouse gas production, metal oxidation, biofilm formation, pollutant degradation, and microbe-plant symbioses. However, these tools are only rarely deployed in the lab. This research gap arises because synthetically programmed microbes typically report on their environment by producing molecules that are detected optically (e.g., fluorescent proteins). Fluorescent reporters are ideal for petri-dish applications and have fundamentally changed how we study human health, but their usefulness is quite limited in soils where detecting fluorescence is challenging. Here we describe the construction of gas-reporting biosensors, which release nonpolar gases that can be detected in the headspace of incubation experiments. These constructs can be used to probe microbial processes within soils in real-time noninvasive lab experiments. These biosensors can be combined with traditional omics-based approaches to reveal processes controlling soil microbial behavior and lead to improved environmental management decisions.

  9. Assortativity of complementary graphs

    NASA Astrophysics Data System (ADS)

    Wang, H.; Winterbach, W.; van Mieghem, P.

    2011-09-01

    Newman's measure for (dis)assortativity, the linear degree correlationρD, is widely studied although analytic insight into the assortativity of an arbitrary network remains far from well understood. In this paper, we derive the general relation (2), (3) and Theorem 1 between the assortativity ρD(G) of a graph G and the assortativityρD(Gc) of its complement Gc. Both ρD(G) and ρD(Gc) are linearly related by the degree distribution in G. When the graph G(N,p) possesses a binomial degree distribution as in the Erdős-Rényi random graphs Gp(N), its complementary graph Gpc(N) = G1-p(N) follows a binomial degree distribution as in the Erdős-Rényi random graphs G1-p(N). We prove that the maximum and minimum assortativity of a class of graphs with a binomial distribution are asymptotically antisymmetric: ρmax(N,p) = -ρmin(N,p) for N → ∞. The general relation (3) nicely leads to (a) the relation (10) and (16) between the assortativity range ρmax(G)-ρmin(G) of a graph with a given degree distribution and the range ρmax(Gc)-ρmin(Gc) of its complementary graph and (b) new bounds (6) and (15) of the assortativity. These results together with our numerical experiments in over 30 real-world complex networks illustrate that the assortativity range ρmax-ρmin is generally large in sparse networks, which underlines the importance of assortativity as a network characterizer.

  10. Organic photodiodes for biosensor miniaturization.

    PubMed

    Wojciechowski, Jason R; Shriver-Lake, Lisa C; Yamaguchi, Mariko Y; Füreder, Erwin; Pieler, Roland; Schamesberger, Martin; Winder, Christoph; Prall, Hans Jürgen; Sonnleitner, Max; Ligler, Frances S

    2009-05-01

    Biosensors have successfully demonstrated the capability to detect multiple pathogens simultaneously at very low levels. Miniaturization of biosensors is essential for use in the field or at the point of care. While microfluidic systems reduce the footprint for biochemical processing devices and electronic components are continually becoming smaller, optical components suitable for integration--such as LEDs and CMOS chips--are generally still too expensive for disposable components. This paper describes the integration of polymer diodes onto a biosensor chip to create a disposable device that includes both the detector and the sensing surface coated with immobilized capture antibody. We performed a chemiluminescence immunoassay on the OPD substrate and measured the results using a hand-held reader attached to a laptop computer. The miniaturized biosensor with the disposable slide including the organic photodiode detected Staphylococcal enterotoxin B at concentrations as low as 0.5 ng/mL.

  11. Graphene electrochemistry: fabricating amperometric biosensors.

    PubMed

    Brownson, Dale A C; Banks, Craig E

    2011-05-21

    The electrochemical sensing of hydrogen peroxide is of substantial interest to the operation of oxidase-based amperometric biosensors. We explore the fabrication of a novel and highly sensitive electro-analytical biosensor using well characterised commercially available graphene and compare and contrast responses using Nafion -graphene and -graphite modified electrodes. Interestingly we observe that graphite exhibits a superior electrochemical response due to its enhanced percentage of edge plane sites when compared to graphene. However, when Nafion, routinely used in amperometric biosensors, is introduced onto graphene and graphite modified electrodes, re-orientation occurs in both cases which is beneficial in the former and detrimental in the latter; insights into this contrasting behaviour are consequently presented providing acuity into sensor design and development where graphene is utilised in biosensors.

  12. Theoretical comparison of Si, Ge, and GaAs ultrathin p-type double-gate metal oxide semiconductor transistors

    NASA Astrophysics Data System (ADS)

    Dib, Elias; Bescond, Marc; Cavassilas, Nicolas; Michelini, Fabienne; Raymond, Laurent; Lannoo, Michel

    2013-08-01

    Based on a self-consistent multi-band quantum transport code including hole-phonon scattering, we compare current characteristics of Si, Ge, and GaAs p-type double-gate transistors. Electronic properties are analyzed as a function of (i) transport orientation, (ii) channel material, and (iii) gate length. We first show that ⟨100⟩-oriented devices offer better characteristics than their ⟨110⟩-counterparts independently of the material choice. Our results also point out that the weaker impact of scattering in Ge produces better electrical performances in long devices, while the moderate tunneling effect makes Si more advantageous in ultimately scaled transistors. Moreover, GaAs-based devices are less advantageous for shorter lengths and do not offer a high enough ON current for longer gate lengths. According to our simulations, the performance switching between Si and Ge occurs for a gate length of 12 nm. The conclusions of the study invite then to consider ⟨100⟩-oriented double-gate devices with Si for gate length shorter than 12 nm and Ge otherwise.

  13. Study of the Physics of Insulating Films as Related to the Reliability of Metal-Oxide-Semiconductor (MOS) Devices

    DTIC Science & Technology

    1981-06-01

    Masouka, T. Sato, and M . Ishikawa, IEEE Trans. Electron Devices ED-23, 379 (1976). 23. M . Kikuchi, S. Ohya , and M . Yamagishi, Japan. J. App!. Phys. 17...34, at the Electrochemical Society Meeting, Minneapolis, Minnesota, May 10-15, 1981. 12. A. Reisman, J.M. Aitken, A.K. Ray, M . Berkenblit, C.J. Merz and...and Its Interfaces, ed. by S.T. Pantelides (Pergamon, New York, 1978), p. 160 and references contained therein. 5. M . Schutz, in Insulatinx Films on

  14. Theory of near-interface trap quenching by impurities in SiC-based metal-oxide-semiconductor devices

    NASA Astrophysics Data System (ADS)

    Tuttle, B. R.; Shen, X.; Pantelides, S. T.

    2013-03-01

    Oxidizing SiC in the presence of various impurities (e.g., sodium, potassium, nitrogen, and phosphorous) has been previously observed to result in a significant reduction of the electron traps in the gate oxide near the SiC-SiO2 interface. Here, we explore the electro-chemistry of the impurity elements involved using first-principles quantum mechanical calculations. Our results indicate that the observed reduction in the near interface traps (NITs) is not due to direct chemical passivation. Instead, we show that the quenching occurs because the NIT energy levels are lowered by the Coulombic tail of the positively charged impurities and thus become inaccessible to the experimental measurements. This new proposal explains a variety of experiments and leads to specific predictions.

  15. Performance analysis of boron nitride embedded armchair graphene nanoribbon metal-oxide-semiconductor field effect transistor with Stone Wales defects

    NASA Astrophysics Data System (ADS)

    Chanana, Anuja; Sengupta, Amretashis; Mahapatra, Santanu

    2014-01-01

    We study the performance of a hybrid Graphene-Boron Nitride armchair nanoribbon (a-GNR-BN) n-MOSFET at its ballistic transport limit. We consider three geometric configurations 3p, 3p + 1, and 3p + 2 of a-GNR-BN with BN atoms embedded on either side (2, 4, and 6 BN) on the GNR. Material properties like band gap, effective mass, and density of states of these H-passivated structures are evaluated using the Density Functional Theory. Using these material parameters, self-consistent Poisson-Schrodinger simulations are carried out under the Non Equilibrium Green's Function formalism to calculate the ballistic n-MOSFET device characteristics. For a hybrid nanoribbon of width ˜5 nm, the simulated ON current is found to be in the range of 265 μA-280 μA with an ON/OFF ratio 7.1 × 106-7.4 × 106 for a VDD = 0.68 V corresponding to 10 nm technology node. We further study the impact of randomly distributed Stone Wales (SW) defects in these hybrid structures and only 2.5% degradation of ON current is observed for SW defect density of 3.18%.

  16. Sustained hole inversion layer in a wide-bandgap metal-oxide semiconductor with enhanced tunnel current

    PubMed Central

    Shoute, Gem; Afshar, Amir; Muneshwar, Triratna; Cadien, Kenneth; Barlage, Douglas

    2016-01-01

    Wide-bandgap, metal-oxide thin-film transistors have been limited to low-power, n-type electronic applications because of the unipolar nature of these devices. Variations from the n-type field-effect transistor architecture have not been widely investigated as a result of the lack of available p-type wide-bandgap inorganic semiconductors. Here, we present a wide-bandgap metal-oxide n-type semiconductor that is able to sustain a strong p-type inversion layer using a high-dielectric-constant barrier dielectric when sourced with a heterogeneous p-type material. A demonstration of the utility of the inversion layer was also investigated and utilized as the controlling element in a unique tunnelling junction transistor. The resulting electrical performance of this prototype device exhibited among the highest reported current, power and transconductance densities. Further utilization of the p-type inversion layer is critical to unlocking the previously unexplored capability of metal-oxide thin-film transistors, such applications with next-generation display switches, sensors, radio frequency circuits and power converters. PMID:26842997

  17. Study of the relative performance of silicon and germanium nanoparticles embedded gate oxide in metal-oxide-semiconductor memory devices

    NASA Astrophysics Data System (ADS)

    Chakraborty, G.; Sengupta, A.; Requejo, F. G.; Sarkar, C. K.

    2011-03-01

    In the present work, we have investigated a comparative performance of the silicon (Si) and germanium (Ge) nanoparticles embedded SiO2 floating gate MOS memory devices. In such devices for low applied fields, the tunneling current is dominated by the direct tunneling mechanism, whereas for higher electric fields, the Fowler-Nordheim tunneling mechanism dominates. As the device dimensions get smaller, problem arises in the conventional MOS memory devices due to the leakage through the thin tunnel oxide. This leakage can be reduced via charge trapping by embedding nanoparticles in the gate dielectric of such devices. Here one objective is to prevent the leakage due to the direct tunneling mechanism and the other objective is to reduce the write voltage, by lowering the onset voltage of the Fowler-Nordheim tunneling mechanism. Our simulations for the current voltage characteristics covered both the low and the high applied field regions. Simulations showed that both the Si and the Ge nanoparticles embedded gate dielectrics offer reduction of the leakage current and a significant lowering of the writing or programming onset voltage, compared to the pure SiO2 gate dielectric. In terms of the comparative performance, the Germanium nanoparticles embedded gate dielectric showed better results compared to the silicon nanoparticles embedded one. The results of the simulations are discussed in the light of recent experimental results.

  18. Change in Ion Beam Induced Current from Si Metal-Oxide-Semiconductor Capacitors after Gamma-Ray Irradiation

    SciTech Connect

    Ohshima, T.; Onoda, S.; Hirao, T.; Takahashi, Y.; Vizkelethy, G.; Doyle, B. L.

    2009-03-10

    To investigate the effects of gamma-ray irradiation on transient current induced in MOS capacitors by heavy ion incidence, Si MOS capacitors were irradiated with gamma-rays up to 60.9 kGy(SiO2). The change in Transient Ion Beam Induced Current (TIBIC) signals due to gamma-ray irradiation was investigated using 15 MeV-oxygen ion microbeams. After gamma-ray irradiation, the peak current of the TIBIC signal vs. bias voltage curve shifted toward negative voltages. This shift can be interpreted in terms of the charge trapped in the oxide. In this dose range, no significant effects of the interface traps induced by gamma-ray irradiation on the TIBIC signals were observed.

  19. A Subthreshold Digital Library Using a Dynamic-Threshold Metal-Oxide Semiconductor (DTMOS) and Transmission Gate Logic

    DTIC Science & Technology

    2014-09-01

    electrocardiography (ECG), electromyography (EMG), and electroencephalography (EEG) applications that operate using thermoelectrically generated energy...semiconductor ECG electrocardiography EEG electroencephalography EMG electromyography FY15 fiscal year 2015 IC integrated circuit MOSFETs

  20. Charge noise analysis of metal oxide semiconductor dual-gate Si/SiGe quantum point contacts

    SciTech Connect

    Kamioka, J.; Oda, S.; Kodera, T.; Takeda, K.; Obata, T.; Tarucha, S.

    2014-05-28

    The frequency dependence of conductance noise through a gate-defined quantum point contact fabricated on a Si/SiGe modulation doped wafer is characterized. The 1/f{sup 2} noise, which is characteristic of random telegraph noise, is reduced by application of a negative bias on the global top gate to reduce the local gate voltage. Direct leakage from the large global gate voltage also causes random telegraph noise, and therefore, there is a suitable point to operate quantum dot measurement.

  1. Synthesis Methods, Microscopy Characterization and Device Integration of Nanoscale Metal Oxide Semiconductors for Gas Sensing in Aerospace Applications

    NASA Technical Reports Server (NTRS)

    VanderWal, Randy L.; Berger, Gordon M.; Kulis, Michael J.; Hunter, Gary W.; Xu, Jennifer C.; Evans, Laura J.

    2009-01-01

    A comparison is made between SnO2, ZnO, and TiO2 single-crystal nanowires and SnO2 polycrystalline nanofibers for gas sensing. Both nanostructures possess a one-dimensional morphology. Different synthesis methods are used to produce these materials: thermal evaporation-condensation (TEC), controlled oxidation, and electrospinning. Advantages and limitations of each technique are listed. Practical issues associated with harvesting, purification, and integration of these materials into sensing devices are detailed. For comparison to the nascent form, these sensing materials are surface coated with Pd and Pt nanoparticles. Gas sensing tests, with respect to H2, are conducted at ambient and elevated temperatures. Comparative normalized responses and time constants for the catalyst and noncatalyst systems provide a basis for identification of the superior metal-oxide nanostructure and catalyst combination. With temperature-dependent data, Arrhenius analyses are made to determine an activation energy for the catalyst-assisted systems.

  2. Study of the Physics of Insulating Films as Related to the Reliability of Metal-Oxide-Semiconductor (MOS) Devices

    DTIC Science & Technology

    1982-09-01

    Sponsored in part by Consejo Nacional de Ciench y Technologia (CONACyT) and Centro d Invstigaciones y Estudios Avanzados del I.P.N. (CIBAP, Mexico. - . - The...Sponsored in part by Consejo Nacional de Ciencia y Technologia (CONACyT) and Centro de Investigaciones y Estudios Avanzados del I.P.N. (CIEA), Mexico. 1. D.J...Centro de Investigaciones y Estudios Avanzados del I.P.N. (CIEA). Mexico. I. "Electroluminescence". Topics in Appl. Physics 17, ed. J.1. Pankove

  3. Study of the Physics of Insulating Films as Related to the Reliability of Metal-Oxide Semiconductor Devices

    DTIC Science & Technology

    1983-08-01

    W. Allen. AppI. Phys. Lett. 35. o I Nacional de Ciencia y Technologist (CONACyT) and Centro ( 19791. de Investigaciones y Estudios Avanzados del I.P.N...Sponsored in part by Consejo Nacional de Ciencia y Technologia (CONACyT) and Centro de Investigaciones y Estudios Avanzados del I.P.N. (CIEA). Mexico...Nacional de Ciencia y Technologia (CONACyT) and Centro de Investigaciones y Estudios Avanzados del I.P.N. (CIEA), Mexico. 1. C. Falcony, D.J. DiMaria

  4. Effect of Remote Oxygen Scavenging on Electrical Properties of Ge-Based Metal-Oxide-Semiconductor Capacitors

    NASA Astrophysics Data System (ADS)

    Fadida, Sivan; Nyns, Laura; Van Elshocht, Sven; Eizenberg, Moshe

    2017-01-01

    Remote oxygen scavenging has been studied in a metal/high- k dielectric/GeO2/Ge stack, where a thin Ti layer inserted into the metal/high- k dielectric interface serves as the scavenger. First, we established that remote oxygen scavenging indeed occurs specifically in the studied HfO2/Al2O3/GeO2/Ge stack. It was also established that the source for oxygen is decomposition of the GeO2 layer. Then, the effect of remote oxygen scavenging of the GeO2 layer on the electrical characteristics of the metal/oxide/Ge capacitors was investigated. The electrical properties were studied in comparison with identical gate stacks with a Pt electrode, before and after annealing. Although a decrease in effective oxide thickness was demonstrated as a result of this process, clear degradation of the interface electrical quality was observed after scavenging. Initiation of the scavenging process was witnessed upon deposition of Ti at room temperature, emphasizing that this process could not be controlled.

  5. Study of the Physics of Insulating Films as Related to the Reliability of Metal-Oxide Semiconductor Devices

    DTIC Science & Technology

    1980-05-01

    shorting problem with poly-Si can be understood from the oxidation results. Therefore, the present study deals firstly with descnb- ing the morphologial ...Poly-Si islands with curved surfaces facing the thermal SiO 2 layer will give field distortion and current enhance- ment. V. CONCLUSIONS Clearly, this...equivalent to that In ftg 19 which was stremd with V3 -8 V frm an intal umchargs virgi Mtat. Vo~ ag *ft indicate "peulte due to umistentional writ of W

  6. Study of the Physics of Insulating Films as Related to the Reliability of Metal-Oxide-Semiconductor (MOS) Devices

    DTIC Science & Technology

    1982-02-01

    and DEIS 112-13-20,21 were 4-port devices of the type illustrated in (c). AP . A, and A, were 7.7 x 10-7, 1.0 X 10". and 4.8 x 10-6 for Cl-21-. 1.6 x 10...sites after electron capture. 98 29 a -COULOMBIC ATTRACTIvE 1 Ec-E HOTk Figre7. chmatc eprsetatonof otntil nery istibtio fr () colobq atrcie b eurl n C

  7. Diagnosis and complementary examinations.

    PubMed

    Menghini, Moreno; Duncan, Jacque L

    2014-01-01

    Development of neuroprotective therapies requires an understanding of the mechanisms of retinal degeneration and a way to monitor response to treatment. With the increasing availability of genetic testing, precise characterization of the retinal degeneration phenotype is essential. This chapter covers standard and innovative diagnostic techniques and complementary examinations needed for the evaluation and treatment of retinal degenerative diseases. It aims to provide an overview of functional and structural diagnostic tools for the evaluation of retinal degenerative diseases, but is not intended as a comprehensive reference. Subjective assessment of visual function includes psychophysical tests, such as perimetry and microperimetry. Electrophysiology tests, such as the electroretinogram and electro-oculogram, are crucial in the assessment of retinal degenerative diseases and provide an objective assessment of global photoreceptor and retinal pigment epithelial cell function. Retinal structural measures are correlated with measures of retinal function to characterize the disease phenotype, including fundus photography using color, near-infrared, and autofluorescence imaging. Ocular perfusion can be assessed using fluorescein, indocyanine green, and noninvasive angiography. Optical coherence tomography provides information about retinal structure. Resolution of all images of retinal structure can be improved using adaptive optics, which permits visualization of individual photoreceptors and retinal pigment epithelial cells in the macula.

  8. The electrophotonic silicon biosensor

    PubMed Central

    Juan-Colás, José; Parkin, Alison; Dunn, Katherine E.; Scullion, Mark G.; Krauss, Thomas F.; Johnson, Steven D.

    2016-01-01

    The emergence of personalized and stratified medicine requires label-free, low-cost diagnostic technology capable of monitoring multiple disease biomarkers in parallel. Silicon photonic biosensors combine high-sensitivity analysis with scalable, low-cost manufacturing, but they tend to measure only a single biomarker and provide no information about their (bio)chemical activity. Here we introduce an electrochemical silicon photonic sensor capable of highly sensitive and multiparameter profiling of biomarkers. Our electrophotonic technology consists of microring resonators optimally n-doped to support high Q resonances alongside electrochemical processes in situ. The inclusion of electrochemical control enables site-selective immobilization of different biomolecules on individual microrings within a sensor array. The combination of photonic and electrochemical characterization also provides additional quantitative information and unique insight into chemical reactivity that is unavailable with photonic detection alone. By exploiting both the photonic and the electrical properties of silicon, the sensor opens new modalities for sensing on the microscale. PMID:27624590

  9. Glycan and lectin biosensors

    PubMed Central

    Belický, Štefan; Katrlík, Jaroslav

    2016-01-01

    A short description about the importance of glycan biorecognition in physiological (blood cell type) and pathological processes (infections by human and avian influenza viruses) is provided in this review. Glycans are described as much better information storage media, compared to proteins or DNA, due to the extensive variability of glycan structures. Techniques able to detect an exact glycan structure are briefly discussed with the main focus on the application of lectins (glycan-recognising proteins) in the specific analysis of glycans still attached to proteins or cells/viruses. Optical, electrochemical, piezoelectric and micromechanical biosensors with immobilised lectins or glycans able to detect a wide range of analytes including whole cells/viruses are also discussed. PMID:27365034

  10. The electrophotonic silicon biosensor

    NASA Astrophysics Data System (ADS)

    Juan-Colás, José; Parkin, Alison; Dunn, Katherine E.; Scullion, Mark G.; Krauss, Thomas F.; Johnson, Steven D.

    2016-09-01

    The emergence of personalized and stratified medicine requires label-free, low-cost diagnostic technology capable of monitoring multiple disease biomarkers in parallel. Silicon photonic biosensors combine high-sensitivity analysis with scalable, low-cost manufacturing, but they tend to measure only a single biomarker and provide no information about their (bio)chemical activity. Here we introduce an electrochemical silicon photonic sensor capable of highly sensitive and multiparameter profiling of biomarkers. Our electrophotonic technology consists of microring resonators optimally n-doped to support high Q resonances alongside electrochemical processes in situ. The inclusion of electrochemical control enables site-selective immobilization of different biomolecules on individual microrings within a sensor array. The combination of photonic and electrochemical characterization also provides additional quantitative information and unique insight into chemical reactivity that is unavailable with photonic detection alone. By exploiting both the photonic and the electrical properties of silicon, the sensor opens new modalities for sensing on the microscale.

  11. Noninvasive biosensor for hypoglycemia

    NASA Astrophysics Data System (ADS)

    Varadan, Vijay K.; Whitchurch, Ashwin K.; Sarukesi, Karunakaran

    2003-01-01

    Hypoglycemia-abnormal decrease in blood sugar- is a major obstacle in the management of diabetes and prevention of long-term complications, and it may impose serious effects on the brain, including impairment of memory and other cognitive functions. This is especially a concern in early childhood years when the nervous system is still developing. Hypoglycemic unawareness (in which the body"s normal ability to signal low blood sugar doesn"t work and an oncoming low blood sugar episode proceeds undetected) is a particularly frightening problem for many people with diabetes. Researchers have now uncovered evidence that repeated bouts of insulin-induced hypoglycemia can harm the brain over time, causing confusion, abnormal behavior, loss of consciousness, and seizures. Extreme cases have resulted in coma and death. In this paper, a non-invasive biosensor in a wrist watch along with a wireless data downloading system is proposed.

  12. Integrated optic biosensor

    NASA Astrophysics Data System (ADS)

    Boiarski, Anthony A.; Busch, James R.; Bhullar, Ballwant S.; Ridgway, Richard W.; Miller, Larry S.; Zulich, A. W.

    1993-05-01

    A micro-sized biosensor is formed using integrated-optic channel waveguides in a Mach- Zehnder interferometer configuration. The device measures refractive index changes on the waveguide surface, so it is called a biorefractometer. With an appropriate overlay or selective coating, the sensor can monitor proteins in blood or pollutants and bio-warfare agents in water. The waveguides are fabricated in a glass substrate using potassium ion exchange. A patterned glass buffer layer defines the interferometer's sensing and reference arms. A silicone-rubber cell arrangement brings sample analytes into contact with proteins immobilized on the integrated-optical waveguide surface. Data obtained for antigen-antibody binding of the proteins human Immunoglobulin-G and staph enterotoxin-B indicate that a 50 - 100 ng/ml concentration levels can be measured in less than ten minutes.

  13. DNA nanotechnology-enabled biosensors.

    PubMed

    Chao, Jie; Zhu, Dan; Zhang, Yinan; Wang, Lianhui; Fan, Chunhai

    2016-02-15

    Biosensors employ biological molecules to recognize the target and utilize output elements which can translate the biorecognition event into electrical, optical or mass-sensitive signals to determine the quantities of the target. DNA-based biosensors, as a sub-field to biosensor, utilize DNA strands with short oligonucleotides as probes for target recognition. Although DNA-based biosensors have offered a promising alternative for fast, simple and cheap detection of target molecules, there still exist key challenges including poor stability and reproducibility that hinder their competition with the current gold standard for DNA assays. By exploiting the self-recognition properties of DNA molecules, researchers have dedicated to make versatile DNA nanostructures in a highly rigid, controllable and functionalized manner, which offers unprecedented opportunities for developing DNA-based biosensors. In this review, we will briefly introduce the recent advances on design and fabrication of static and dynamic DNA nanostructures, and summarize their applications for fabrication and functionalization of DNA-based biosensors.

  14. 3D hydrogel scaffold doped with 2D graphene materials for biosensors and bioelectronics.

    PubMed

    Song, Hyun Seok; Kwon, Oh Seok; Kim, Jae-Hong; Conde, João; Artzi, Natalie

    2017-03-15

    Hydrogels consisting of three-dimensional (3D) polymeric networks have found a wide range of applications in biotechnology due to their large water capacity, high biocompatibility, and facile functional versatility. The hydrogels with stimulus-responsive swelling properties have been particularly instrumental to realizing signal transduction in biosensors and bioelectronics. Graphenes are two-dimensional (2D) nanomaterials with unprecedented physical, optical, and electronic properties and have also found many applications in biosensors and bioelectronics. These two classes of materials present complementary strengths and limitations which, when effectively coupled, can result in significant synergism in their electrical, mechanical, and biocompatible properties. This report reviews recent advances made with hydrogel and graphene materials for the development of high-performance bioelectronics devices. The report focuses on the interesting intersection of these materials wherein 2D graphenes are hybridized with 3D hydrogels to develop the next generation biosensors and bioelectronics.

  15. Electrochemical DNA biosensor based on avidin-biotin conjugation for influenza virus (type A) detection

    NASA Astrophysics Data System (ADS)

    Chung, Da-Jung; Kim, Ki-Chul; Choi, Seong-Ho

    2011-09-01

    An electrochemical DNA biosensor (E-DNA biosensor) was fabricated by avidin-biotin conjugation of a biotinylated probe DNA, 5'-biotin-ATG AGT CTT CTA ACC GAG GTC GAA-3', and an avidin-modified glassy carbon electrode (GCE) to detect the influenza virus (type A). An avidin-modified GCE was prepared by the reaction of avidin and a carboxylic acid-modified GCE, which was synthesized by the electrochemical reduction of 4-carboxyphenyl diazonium salt. The current value of the E-DNA biosensor was evaluated after hybridization of the probe DNA and target DNA using cyclic voltammetry (CV). The current value decreased after the hybridization of the probe DNA and target DNA. The DNA that was used follows: complementary target DNA, 5'-TTC GAC CTC GGT TAG AAG ACT CAT-3' and two-base mismatched DNA, 5'-TTC GAC AGC GGT TAT AAG ACT CAT-3'.

  16. Label-free DNA biosensor based on resistance change of platinum nanoparticles assemblies.

    PubMed

    Skotadis, Evangelos; Voutyras, Konstantinos; Chatzipetrou, Marianneza; Tsekenis, Georgios; Patsiouras, Lampros; Madianos, Leonidas; Chatzandroulis, Stavros; Zergioti, Ioanna; Tsoukalas, Dimitris

    2016-07-15

    A novel nanoparticle based biosensor for the fast and simple detection of DNA hybridization events is presented. The sensor utilizes hybridized DNA's charge transport properties, combining them with metallic nanoparticle networks that act as nano-gapped electrodes. The DNA hybridization events can be detected by a significant reduction in the sensor's resistance due to the conductive bridging offered by hybridized DNA. By modifying the nanoparticle surface coverage, which can be controlled experimentally being a function of deposition time, and the structural properties of the electrodes, an optimized biosensor for the in situ detection of DNA hybridization events is ultimately fabricated. The fabricated biosensor exhibits a wide response range, covering four orders of magnitude, a limit of detection of 1nM and can detect a single base pair mismatch between probe and complementary DNA.

  17. Complementary and alternative medicine

    PubMed Central

    Gaboury, Isabelle; Johnson, Noémie; Robin, Christine; Luc, Mireille; O’Connor, Daniel; Patenaude, Johane; Pélissier-Simard, Luce; Xhignesse, Marianne

    2016-01-01

    Abstract Objective To determine whether medical training prepares FPs to meet the requirements of the Collège des médecins du Québec for their role in advising patients on the use of complementary and alternative medicine (CAM). Design Secondary analysis of survey results. Setting Quebec. Participants Family physicians and GPs in active practice. Main outcome measures Perceptions of the role of the physician as an advisor on CAM; level of comfort responding to questions and advising patients on CAM; frequency with which patients ask their physicians about CAM; personal position on CAM; and desire for training on CAM. Results The response rate was 19.5% (195 respondents of 1000) and the sample appears to be representative of the target population. Most respondents (85.8%) reported being asked about CAM several times a month. A similar proportion (86.7%) believed it was their role to advise patients on CAM. However, of this group, only 33.1% reported being able to do so. There is an association between an urban practice and knowledge of the advisory role of physicians. More than three-quarters of respondents expressed interest in receiving additional training on CAM. Conclusion There is a gap between the training that Quebec physicians receive on CAM and their need to meet legal and ethical obligations designed to protect the public where CAM products and therapies are concerned. One solution might be more thorough training on CAM to help physicians meet the Collège des médecins du Québec requirements. PMID:27965354

  18. NANOSCALE BIOSENSORS IN ECOSYSTEM EXPOSURE RESEARCH

    EPA Science Inventory

    This powerpoint presentation presented information on nanoscale biosensors in ecosystem exposure research. The outline of the presentation is as follows: nanomaterials environmental exposure research; US agencies involved in nanosensor research; nanoscale LEDs in biosensors; nano...

  19. BIOSENSORS FOR ENVIRONMENTAL MONITORING: A REGULATORY PERSPECTIVE

    EPA Science Inventory

    Biosensors show the potential to complement laboratory-based analytical methods for environmental applications. Although biosensors for potential environmental-monitoring applications have been reported for a wide range of environmental pollutants, from a regulatory perspective, ...

  20. The potential of microelectrode arrays and microelectronics for biomedical research and diagnostics.

    PubMed

    Jones, Ian L; Livi, Paolo; Lewandowska, Marta K; Fiscella, Michele; Roscic, Branka; Hierlemann, Andreas

    2011-03-01

    Planar microelectrode arrays (MEAs) are devices that can be used in biomedical and basic in vitro research to provide extracellular electrophysiological information about biological systems at high spatial and temporal resolution. Complementary metal oxide semiconductor (CMOS) is a technology with which MEAs can be produced on a microscale featuring high spatial resolution and excellent signal-to-noise characteristics. CMOS MEAs are specialized for the analysis of complete electrogenic cellular networks at the cellular or subcellular level in dissociated cultures, organotypic cultures, and acute tissue slices; they can also function as biosensors to detect biochemical events. Models of disease or the response of cellular networks to pharmacological compounds can be studied in vitro, allowing one to investigate pathologies, such as cardiac arrhythmias, memory impairment due to Alzheimer's disease, or vision impairment caused by ganglion cell degeneration in the retina.

  1. An underlap field-effect transistor for electrical detection of influenza

    NASA Astrophysics Data System (ADS)

    Lee, Kwang-Won; Choi, Sung-Jin; Ahn, Jae-Hyuk; Moon, Dong-Il; Park, Tae Jung; Lee, Sang Yup; Choi, Yang-Kyu

    2010-01-01

    An underlap channel-embedded field-effect transistor (FET) is proposed for label-free biomolecule detection. Specifically, silica binding protein fused with avian influenza (AI) surface antigen and avian influenza antibody (anti-AI) were designed as a receptor molecule and a target material, respectively. The drain current was significantly decreased after the binding of negatively charged anti-AI on the underlap channel. A set of control experiments supports that only the biomolecules on the underlap channel effectively modulate the drain current. With the merits of a simple fabrication process, complementary metal-oxide-semiconductor compatibility, and enhanced sensitivity, the underlap FET could be a promising candidate for a chip-based biosensor.

  2. Graphene coated fiber optic surface plasmon resonance biosensor for the DNA hybridization detection: Simulation analysis

    NASA Astrophysics Data System (ADS)

    Shushama, Kamrun Nahar; Rana, Md. Masud; Inum, Reefat; Hossain, Md. Biplob

    2017-01-01

    In this paper, a graphene coated optical fiber surface plasmon resonance (SPR) biosensor is presented for the detection of DNA Hybridization. For the proposed sensor, a four layer model (fiber core /metal /sensing layer /sample) where a sheet of graphene (biomolecular recognition elements (BRE)) acting as a sensing layer is coated around the gold film because graphene enhances the sensitivity of fiber optic SPR biosensor. Numerical analysis shows the variation of resonance wavelength and spectrum of transmitted power for mismatched DNA strands and for complementary DNA strands. For mismatched DNA strands variation is negligible whereas for complementary DNA strands is considerably countable. Proposed sensor successfully distinguishes hybridization and single nucleotide polymorphisms (SNP) by observing the variation level of resonance wavelength and spectrum of transmitted power.

  3. [Complementary medicine--the facts].

    PubMed

    Grossman, Ehud

    2011-08-01

    The popularity of complementary medicine in the western world continues to grow. Complementary medicine has a wide scope of topics including acupuncture, hypnosis, meditation, chiropractic manipulation, tai chi, yoga, botanical and herbal supplements and many other undefined modalities such as copper bracelets, magnets, holy water etc. For most modalities the mechanism of action is unknown and the evidence of benefit is poor. Some modalities such as acupuncture, hypnosis and tai chi may improve pain and other subjective complains. It seems that most of the beneficial effects of complementary medicine are placebo effects. Complementary treatment may be associated with side effects and should not be an alternative to the conventional medicine. Complementary medicine can be used as an adjunct to the conventional medicine and should be used in full agreement with and under the supervision of the attending physician. Patients should be informed about the existing evidence and what to expect from complementary medicine. Further meticulous research should be conducted to expand our knowledge in complementary medicine.

  4. Biosensor for metal analysis and speciation

    DOEpatents

    Aiken, Abigail M.; Peyton, Brent M.; Apel, William A.; Petersen, James N.

    2007-01-30

    A biosensor for metal analysis and speciation is disclosed. The biosensor comprises an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode. The immobilized enzyme comprises an enzyme having biological activity inhibited by a metal to be detected by the biosensor.

  5. Aptamer-Based Fluorescent Biosensors

    PubMed Central

    Wang, Rongsheng E.; Zhang, Yin; Cai, Jianfeng; Cai, Weibo; Gao, Ting

    2011-01-01

    Selected from random pools of DNA or RNA molecules through systematic evolution of ligands by exponential enrichment (SELEX), aptamers can bind to target molecules with high affinity and specificity, which makes them ideal recognition elements in the development of biosensors. To date, aptamer-based biosensors have used a wide variety of detection techniques, which are briefly summarized in this article. The focus of this review is on the development of aptamer-based fluorescent biosensors, with emphasis on their design as well as properties such as sensitivity and specificity. These biosensors can be broadly divided into two categories: those using fluorescently-labeled aptamers and others that employ label-free aptamers. Within each category, they can be further divided into “signal-on” and “signal-off” sensors. A number of these aptamer-based fluorescent biosensors have shown promising results in biological samples such as urine and serum, suggesting their potential applications in biomedical research and disease diagnostics. PMID:21838688

  6. Porous silicon biosensor: current status.

    PubMed

    Dhanekar, Saakshi; Jain, Swati

    2013-03-15

    Biosensing technologies cater to modern day diagnostics and point of care multi-specialty clinics, hospitals and laboratories. Biosensors aggregate the sensitivity of detection methodologies and constitutional selectivity of biomolecules. Endeavors to develop highly sensitive, fast, stable and low cost biosensors have been made possible by extensive and arduous research. Immense research work is going on for detection of molecules using various materials as immobilization substrate and sensing elements. Amongst materials being used as bio-sensing substrates, nano-porous silicon (PS) has amassed attention and gained popularity in recent years. It has captivating and tunable features like ease of fabrication, special optico-physico properties, tailored morphological structure and versatile surface chemistry enhancing its prospects as transducer for fabricating biosensors. The present review describes the fabrication of PS and its biosensing capabilities for detection of various analytes including, but not limited to, glucose, DNA, antibodies, bacteria and viruses. Attention has been consecrated on the various methodologies such as electrical, electrochemical, optical and label free techniques along with the performances of these biosensors. It concludes with some future prospects and challenges of PS based biosensors.

  7. Reagentless optical biosensor

    NASA Astrophysics Data System (ADS)

    Grace, Karen M.; Goeller, Roy M.; Grace, W. K.; Kolar, Jerome D.; Morrison, Leeland J.; Sweet, Martin R.; Wiig, L. G.; Reed, Scott M.; Lauer, Sabine A.; Little, Kristin M.; Bustos, Gerrie L.; Anderson, Aaron S.; Swanson, Basil I.

    2004-03-01

    Critical to our ability to respond effectively to a biothreat attack is the development of sensitive and specific sensor systems that can easily be used for rapid screening of potential victims for infection due to biothreat agents and detection of pathogens in the environment. To help address these needs, we have developed a Reagentless Optical Biosensor (ROB) based on protein specific assays and waveguide-based evanescent fluorescence excitation. Modeled on host pathogen interactions, the sensor's membrane based assay provides rapid, sensitive detection without the addition of reagents. We report here the development of two waveguide based detection systems: a laboratory sensor test-bed system and a handheld, battery operated, prototype. Evanescent fluorescence excitation using planar optical waveguides provides spatial filtering of background auto-fluorescence found in many natural samples, thereby permitting direct analysis of complex environmental and medical samples. The waveguide based assay is fully self-contained in a small, exchangeable cartridge that is optically coupled to the sensor detection system making ROB simple to use and offering the possibility of inexpensive, disposable sensor elements. Using assays for cholera toxin we compare results using flourimetry of vesicle solutions against results for our waveguide based test-bed and prototype sensor systems.

  8. Biosensors for termite control

    NASA Astrophysics Data System (ADS)

    Farkhanda, M.

    2013-12-01

    Termites are major urban pests in Pakistan and cause damage to wooden structures and buildings. Termite management has two parts: prevention and control. The most difficult part of termite control is termite detection as most of them are subterranean in Pakistan and have tunneling habit.Throughout the world, chemical termiticides are going to be replaced by baits, microwave and sensor technology. Termite species are distinct biologically and have specific foraging behaviors. Termite Detection Radar, Moisture meter and Remote Thermal Sensor with Laser are available throughout the world. These can detect termites underground and use fewer chemicals than traditional methods. For wooden buildings, a termite sensor and an intrusion detection system for detecting termites are designed. A pair of electrodes is disposed inside the container. A pair of terminals is connected to these electrodes, these extend outside the container. Termites are detected by a change of conductivity between the electrodes, when termites are detected a warning device generates a warning signal. In Pakistan, there is dire need to develop such biosensoring devices locally, then apply control methods that would save money and protect the environment.

  9. Plants as Environmental Biosensors

    PubMed Central

    Ranatunga, Don Rufus A

    2006-01-01

    Plants are continuously exposed to a wide variety of perturbations including variation of temperature and/or light, mechanical forces, gravity, air and soil pollution, drought, deficiency or surplus of nutrients, attacks by insects and pathogens, etc., and hence, it is essential for all plants to have survival sensory mechanisms against such perturbations. Consequently, plants generate various types of intracellular and intercellular electrical signals mostly in the form of action and variation potentials in response to these environmental changes. However, over a long period, only certain plants with rapid and highly noticeable responses for environmental stresses have received much attention from plant scientists. Of particular interest to our recent studies on ultra fast action potential measurements in green plants, we discuss in this review the evidence supporting the foundation for utilizing green plants as fast biosensors for molecular recognition of the direction of light, monitoring the environment, and detecting the insect attacks as well as the effects of pesticides, defoliants, uncouplers, and heavy metal pollutants. PMID:19521490

  10. DNA biosensors that reason.

    PubMed

    Sainz de Murieta, Iñaki; Rodríguez-Patón, Alfonso

    2012-08-01

    Despite the many designs of devices operating with the DNA strand displacement, surprisingly none is explicitly devoted to the implementation of logical deductions. The present article introduces a new model of biosensor device that uses nucleic acid strands to encode simple rules such as "IF DNA_strand(1) is present THEN disease(A)" or "IF DNA_strand(1) AND DNA_strand(2) are present THEN disease(B)". Taking advantage of the strand displacement operation, our model makes these simple rules interact with input signals (either DNA or any type of RNA) to generate an output signal (in the form of nucleotide strands). This output signal represents a diagnosis, which either can be measured using FRET techniques, cascaded as the input of another logical deduction with different rules, or even be a drug that is administered in response to a set of symptoms. The encoding introduces an implicit error cancellation mechanism, which increases the system scalability enabling longer inference cascades with a bounded and controllable signal-noise relation. It also allows the same rule to be used in forward inference or backward inference, providing the option of validly outputting negated propositions (e.g. "diagnosis A excluded"). The models presented in this paper can be used to implement smart logical DNA devices that perform genetic diagnosis in vitro.

  11. A Note on Complementary Medicines

    MedlinePlus

    ... Photo: iStock Herbal supplements, meditation, chiropractic manipulation, and acupuncture are types of complementary and alternative medicine (CAM) ... effective. For example, NCCAM studies have shown that: Acupuncture can provide pain relief and improve function for ...

  12. Small sets of complementary observables

    NASA Astrophysics Data System (ADS)

    Grassl, M.; McNulty, D.; Mišta, L.; Paterek, T.

    2017-01-01

    Two observables are called complementary if preparing a physical object in an eigenstate of one of them yields a completely random result in a measurement of the other. We investigate small sets of complementary observables that cannot be extended by yet another complementary observable. We construct explicit examples of unextendible sets up to dimension 16 and conjecture certain small sets to be unextendible in higher dimensions. Our constructions provide three complementary measurements, only one observable away from the ultimate minimum of two. Almost all our examples in finite dimensions are useful for discriminating pure states from some mixed states, and they help to shed light on the complex topology of the Bloch space of higher-dimensional quantum systems.

  13. Electrochemical DNA biosensor based on the proximity-dependent surface hybridization assay.

    PubMed

    Zhang, Yanli; Wang, Ying; Wang, Haibo; Jiang, Jian-Hui; Shen, Guo-Li; Yu, Ru-Qin; Li, Jinghong

    2009-03-01

    This paper describes a novel electrochemical DNA (E-DNA) biosensor for simple, rapid, and specific detection of nucleic acids based on the proximity-dependent surface hybridization assay. This E-DNA biosensor was constructed by self-assembly of a 3' short thiolated capture probe on the gold electrode. DNA detection was realized by outputting a remarkable redox current of the 5' ferrocene (Fc) tail labeled probe. When the target DNA was introduced into the system, it was complementary to the 5' Fc labeled probe at the one-half-segment and complementary to the 3' short thiolated capture probe at the other half-segment, resulting in forming a stable duplex complex. As a result, the Fc probe was proximate to the electrode surface, and the Faradaic current was observed. This E-DNA biosensor was proved to have a low detection limit (1 fM) and a wide dynamic range (from 1 fM to 1 nM) due to the stable hybridization mode. In addition, the sensing system could discriminate the complementary sequence from mismatch sequences, with high sensitivity, stability, and reusability.

  14. A review on impedimetric biosensors.

    PubMed

    Bahadır, Elif Burcu; Sezgintürk, Mustafa Kemal

    2016-01-01

    Electrochemical impedance spectroscopy (EIS) is a sensitive technique for the analysis of the interfacial properties related to biorecognition events such as reactions catalyzed by enzymes, biomolecular recognition events of specific binding proteins, lectins, receptors, nucleic acids, whole cells, antibodies or antibody-related substances, occurring at the modified surface. Many studies on impedimetric biosensors are focused on immunosensors and aptasensors. In impedimetric immunosensors, antibodies and antigens are bound each other and thus immunocomplex is formed and the electrode is coated with a blocking layer. As a result of that electron transfer resistance increases. In impedimetric aptasensors, impedance changes following the binding of target sequences, conformational changes, or DNA damages. Impedimetric biosensors allow direct detection of biomolecular recognition events without using enzyme labels. In this paper, impedimetric biosensors are reviewed and the most interesting ones are discussed.

  15. A biosensor for ferric ion.

    PubMed

    Barrero, J M; Morino-Bondi, M C; Pérez-Conde, M C; Cámara, C

    1993-11-01

    A new biosensor for monitoring iron has been developed. The active solid phase is pyoverdin, a natural fluorescent pigment biosynthesized by Pseudomonas fluorescens immobilized on controlled pore glass (CPG) and packed in a quartz flow-through cell. The biosensor is very selective for iron(III) and can be easily regenerated in about 2 min by passing 1M HCl through the cell. The optimum conditions and analytical characteristics (detection limit, precision and linear range) for the new sensor in solution (DL = 10 ng/ml) and in immobilized form (DL = 3 ng/ml) are reported. The biosensor has good stability and can be used continuously over a period for at least 3 months (over 1000 determinations). The sensor was successfully applied to determine iron in different water samples. There were no significant differences between the new method and the Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) reference method at the 95% confidence level.

  16. Fluidics cube for biosensor miniaturization

    NASA Technical Reports Server (NTRS)

    Dodson, J. M.; Feldstein, M. J.; Leatzow, D. M.; Flack, L. K.; Golden, J. P.; Ligler, F. S.

    2001-01-01

    To create a small, portable, fully automated biosensor, a compact means of fluid handling is required. We designed, manufactured, and tested a "fluidics cube" for such a purpose. This cube, made of thermoplastic, contains reservoirs and channels for liquid samples and reagents and operates without the use of any internal valves or meters; it is a passive fluid circuit that relies on pressure relief vents to control fluid movement. We demonstrate the ability of pressure relief vents to control fluid movement and show how to simply manufacture or modify the cube. Combined with the planar array biosensor developed at the Naval Research Laboratory, it brings us one step closer to realizing our goal of a handheld biosensor capable of analyzing multiple samples for multiple analytes.

  17. Biosensors for hepatitis B virus detection

    PubMed Central

    Yao, Chun-Yan; Fu, Wei-Ling

    2014-01-01

    A biosensor is an analytical device used for the detection of analytes, which combines a biological component with a physicochemical detector. Recently, an increasing number of biosensors have been used in clinical research, for example, the blood glucose biosensor. This review focuses on the current state of biosensor research with respect to efficient, specific and rapid detection of hepatitis B virus (HBV). The biosensors developed based on different techniques, including optical methods (e.g., surface plasmon resonance), acoustic wave technologies (e.g., quartz crystal microbalance), electrochemistry (amperometry, voltammetry and impedance) and novel nanotechnology, are also discussed. PMID:25253948

  18. Complementary and Alternative Medicine for Patients

    MedlinePlus

    ... Ask about Your Treatment Research Complementary and Alternative Medicine for Patients Complementary and alternative medicine (CAM) is ... based on scientific evidence from research studies. Complementary medicine refers to treatments that are used with standard ...

  19. Biosensors and their applications – A review

    PubMed Central

    Mehrotra, Parikha

    2016-01-01

    The various types of biosensors such as enzyme-based, tissue-based, immunosensors, DNA biosensors, thermal and piezoelectric biosensors have been deliberated here to highlight their indispensable applications in multitudinous fields. Some of the popular fields implementing the use of biosensors are food industry to keep a check on its quality and safety, to help distinguish between the natural and artificial; in the fermentation industry and in the saccharification process to detect precise glucose concentrations; in metabolic engineering to enable in vivo monitoring of cellular metabolism. Biosensors and their role in medical science including early stage detection of human interleukin-10 causing heart diseases, rapid detection of human papilloma virus, etc. are important aspects. Fluorescent biosensors play a vital role in drug discovery and in cancer. Biosensor applications are prevalent in the plant biology sector to find out the missing links required in metabolic processes. Other applications are involved in defence, clinical sector, and for marine applications. PMID:27195214

  20. A luminescent nisin biosensor

    NASA Astrophysics Data System (ADS)

    Immonen, Nina; Karp, Matti

    2006-02-01

    Nisin is a lantibiotic, an antibacterial peptide produced by certain Lactococcus lactis strains that kills or inhibits the growth of other bacteria. Nisin is widely used as a food preservative, and its long-time use suggests that it can be generally regarded as safe. We have developed a method for determining the amount of nisin in food samples that is based on luminescent biosensor bacteria. Bacterial luciferase operon luxABCDE was inserted into plasmid pNZ8048, and the construct was transformed by electroporation into Lc. lactis strain NZ9800, whose ability to produce nisin has been erased by deletion of the gene nisA. The operon luxABCDE has been modified to be functional in gram-positive bacteria to confer a bioluminescent phenotype without the requirement of adding an exogenous substrate. In the plasmid pNZ8048, the operon was placed under control of the nisin-inducible nisA promoter. The chromosomal nisRK genes of Lc. lactis NZ9800 allow it to sense nisin in the environment and relay this signal via signal transduction proteins NisK and NisR to initiate transcription from nisA promoter. In the case of our sensor bacteria, this leads to production of luciferase and, thus, luminescence that can be directly measured from living bacteria. Luminescence can be detected as early as within minutes of induction. The nisin assay described here provides a detection limit in the sub-picogram level per ml, and a linear area between 1 - 1000 pg/ml. The sensitivity of this assay exceeds the performance of all previously published methods.

  1. Electrical percolation based biosensors.

    PubMed

    Bruck, Hugh Alan; Yang, Minghui; Kostov, Yordan; Rasooly, Avraham

    2013-10-01

    A new approach to label free biosensing has been developed based on the principle of "electrical percolation". In electrical percolation, long-range electrical connectivity is formed in randomly oriented and distributed systems of discrete elements. By applying this principle to biological interactions, it is possible to measure biological components both directly and electronically. The main element for electrical percolation biosensor is the biological semiconductor (BSC) which is a multi-layer 3-D carbon nanotube-antibody network. In the BSC, molecular interactions, such as binding of antigens to the antibodies, disrupt the network continuity causing increased resistance of the network. BSCs can be fabricated by immobilizing conducting elements, such as pre-functionalized single-walled carbon nanotubes (SWNTs)-antibody complex, directly onto a substrate, such as a Poly(methyl methacrylate) (PMMA) surface (also known as plexi-glass or Acrylic). BSCs have been demonstrated for direct (label-free) electronic measurements of antibody-antigen binding using SWNTs. If the concentration of the SWNT network is slightly above the electrical percolation threshold, then binding of a specific antigen to the pre-functionalized SWNT dramatically increases the electrical resistance due to changes in the tunneling between the SWNTs. Using anti-staphylococcal enterotoxin B (SEB) IgG as a "gate" and SEB as an "actuator", it was demonstrated that the BSC was able to detect SEB at concentrations of 1 ng/ml. Based on this concept, an automated configuration for BSCs is described here that enables real time continuous detection. The new BSC configuration may permit assembly of multiple sensors on the same chip to create "biological central processing units (CPUs)" with multiple biological elements, capable of processing and sorting out information on multiple analytes simultaneously.

  2. Fiber optic-based biosensor

    NASA Technical Reports Server (NTRS)

    Ligler, Frances S.

    1991-01-01

    The NRL fiber optic biosensor is a device which measures the formation of a fluorescent complex at the surface of an optical fiber. Antibodies and DNA binding proteins provide the mechanism for recognizing an analyze and immobilizing a fluorescent complex on the fiber surface. The fiber optic biosensor is fast, sensitive, and permits analysis of hazardous materials remote from the instrumentation. The fiber optic biosensor is described in terms of the device configuration, chemistry for protein immobilization, and assay development. A lab version is being used for assay development and performance characterization while a portable device is under development. Antibodies coated on the fiber are stable for up to two years of storage prior to use. The fiber optic biosensor was used to measure concentration of toxins in the parts per billion (ng/ml) range in under a minute. Immunoassays for small molecules and whole bacteria are under development. Assays using DNA probes as the detection element can also be used with the fiber optic sensor, which is currently being developed to detect biological warfare agents, explosives, pathogens, and toxic materials which pollute the environment.

  3. Improved Ion-Channel Biosensors

    NASA Technical Reports Server (NTRS)

    Nadeau, Jay; White, Victor; Dougherty, Dennis; Maurer, Joshua

    2004-01-01

    An effort is underway to develop improved biosensors of a type based on ion channels in biomimetic membranes. These sensors are microfabricated from silicon and other materials compatible with silicon. As described, these sensors offer a number of advantages over prior sensors of this type.

  4. A high content assay for biosensor validation and for examining stimuli that affect biosensor activity

    PubMed Central

    Slattery, Scott D.; Hahn, Klaus M.

    2015-01-01

    Biosensors are valuable tools used to monitor many different protein behaviors in vivo. Demand for new biosensors is high, but their development and characterization can be difficult. During biosensor design, it is necessary to evaluate the effects of different biosensor structures on specificity, brightness, and fluorescence responses. By co-expressing the biosensor with upstream proteins that either stimulate or inhibit the activity reported by the biosensor, one can determine the difference between the biosensor’s maximally activated and inactivated state, and examine response to specific proteins. This involves considerable labor and expense, as expression conditions must be optimized to saturate the biosensor with the regulator, and multiple replicates and controls are required. We describe here a protocol for biosensor validation in a 96-well plate format using an automated microscope. This protocol produces dose-response curves, enables efficient examination of many parameters, and unlike cell suspension assays allows visual inspection (eg for cell health and biosensor or regulator localization). Optimization of single chain and dual chain Rho GTPase biosensors is addressed, but the assay is applicable to any biosensor that can be expressed or otherwise loaded in adherent cells. The assay can also be used for purposes other than biosensor validation, using a well-characterized biosensor as a readout for variations in upstream molecules. PMID:25447074

  5. A High-Content Assay for Biosensor Validation and for Examining Stimuli that Affect Biosensor Activity.

    PubMed

    Slattery, Scott D; Hahn, Klaus M

    2014-12-01

    Biosensors are valuable tools used to monitor many different protein behaviors in vivo. Demand for new biosensors is high, but their development and characterization can be difficult. During biosensor design, it is necessary to evaluate the effects of different biosensor structures on specificity, brightness, and fluorescence responses. By co-expressing the biosensor with upstream proteins that either stimulate or inhibit the activity reported by the biosensor, one can determine the difference between the biosensor's maximally activated and inactivated state, and examine response to specific proteins. We describe here a method for biosensor validation in a 96-well plate format using an automated microscope. This protocol produces dose-response curves, enables efficient examination of many parameters, and unlike cell suspension assays, allows visual inspection (e.g., for cell health and biosensor or regulator localization). Optimization of single-chain and dual-chain Rho GTPase biosensors is addressed, but the assay is applicable to any biosensor that can be expressed or otherwise loaded in adherent cells. The assay can also be used for purposes other than biosensor validation, using a well-characterized biosensor as a readout for effects of upstream molecules.

  6. A label-free, PCR-free and signal-on electrochemical DNA biosensor for Leishmania major based on gold nanoleaves.

    PubMed

    Moradi, M; Sattarahmady, N; Rahi, A; Hatam, G R; Sorkhabadi, S M Rezayat; Heli, H

    2016-12-01

    Detection of leishmaniasis is important in clinical diagnoses. In the present study, identification of Leishmania parasites was performed by a label-free, PCR-free and signal-on ultrasensitive electrochemical DNA biosensor. Gold nanoleaves were firstly electrodeposited by an electrodeposition method using spermidine as a shape directing agent. The biosensor was fabricated by immobilization of a Leishmania major specific DNA probe onto gold nanoleaves, and methylene blue was employed as a marker. Hybridization of the complementary single stranded DNA sequence with the biosensor under the selected conditions was then investigated. The biosensor could detect a synthetic DNA target in a range of 1.0×10(-10) to 1.0×10(-19)molL(-1) with a limit of detection of 1.8×10(-20)molL(-1), and genomic DNA in a range of 0.5-20ngμL(-1) with a limit of detection of 0.07ngμL(-1). The biosensor could distinguish Leishmania major from a non-complementary-sequence oligonucleotide and the tropica species with a high selectivity. The biosensor was applicable to detect Leishmania major in patient samples.

  7. Fabrication of Ultrasensitive Field-Effect Transistor DNA Biosensors by a Directional Transfer Technique Based on CVD-Grown Graphene.

    PubMed

    Zheng, Chao; Huang, Le; Zhang, Hong; Sun, Zhongyue; Zhang, Zhiyong; Zhang, Guo-Jun

    2015-08-12

    Most graphene field-effect transistor (G-FET) biosensors are fabricated through a routine process, in which graphene is transferred onto a Si/SiO2 substrate and then devices are subsequently produced by micromanufacture processes. However, such a fabrication approach can introduce contamination onto the graphene surface during the lithographic process, resulting in interference for the subsequent biosensing. In this work, we have developed a novel directional transfer technique to fabricate G-FET biosensors based on chemical-vapor-deposition- (CVD-) grown single-layer graphene (SLG) and applied this biosensor for the sensitive detection of DNA. A FET device with six individual array sensors was first fabricated, and SLG obtained by the CVD-growth method was transferred onto the sensor surface in a directional manner. Afterward, peptide nucleic acid (PNA) was covalently immobilized on the graphene surface, and DNA detection was realized by applying specific target DNA to the PNA-functionalized G-FET biosensor. The developed G-FET biosensor was able to detect target DNA at concentrations as low as 10 fM, which is 1 order of magnitude lower than those reported in a previous work. In addition, the biosensor was capable of distinguishing the complementary DNA from one-base-mismatched DNA and noncomplementary DNA. The directional transfer technique for the fabrication of G-FET biosensors is simple, and the as-constructed G-FET DNA biosensor shows ultrasensitivity and high specificity, indicating its potential application in disease diagnostics as a point-of-care tool.

  8. Capacitive Biosensors and Molecularly Imprinted Electrodes

    PubMed Central

    Ertürk, Gizem; Mattiasson, Bo

    2017-01-01

    Capacitive biosensors belong to the group of affinity biosensors that operate by registering direct binding between the sensor surface and the target molecule. This type of biosensors measures the changes in dielectric properties and/or thickness of the dielectric layer at the electrolyte/electrode interface. Capacitive biosensors have so far been successfully used for detection of proteins, nucleotides, heavy metals, saccharides, small organic molecules and microbial cells. In recent years, the microcontact imprinting method has been used to create very sensitive and selective biorecognition cavities on surfaces of capacitive electrodes. This chapter summarizes the principle and different applications of capacitive biosensors with an emphasis on microcontact imprinting method with its recent capacitive biosensor applications. PMID:28218689

  9. Lipase and phospholipase biosensors: a review.

    PubMed

    Herrera-López, Enrique J

    2012-01-01

    Recent advances in the field of biology, electronics, and nanotechnology have improved the development of biosensors. A biosensor is a device composed of a biological recognition element and a sensor element. Biosensor applications are becoming increasingly important in areas such as biotechnology, pharmaceutics, food, and environment. Lipases and phospholipases are enzymes which have been used widely in food industry, oleochemical industry, biodegradable polymers, detergents, and other applications. In the medical industry, lipases and phospholipases are used as diagnostic tools to detect triglycerides, cholesterol, and phospholipids levels in blood samples. Therefore, the development of lipase and phospholipase biosensors is of paramount importance in the clinical area. This chapter introduces the reader into the preliminaries of biosensor and reviews recent developments of lipase and phospholipase biosensors.

  10. Capacitive Biosensors and Molecularly Imprinted Electrodes.

    PubMed

    Ertürk, Gizem; Mattiasson, Bo

    2017-02-17

    Capacitive biosensors belong to the group of affinity biosensors that operate by registering direct binding between the sensor surface and the target molecule. This type of biosensors measures the changes in dielectric properties and/or thickness of the dielectric layer at the electrolyte/electrode interface. Capacitive biosensors have so far been successfully used for detection of proteins, nucleotides, heavy metals, saccharides, small organic molecules and microbial cells. In recent years, the microcontact imprinting method has been used to create very sensitive and selective biorecognition cavities on surfaces of capacitive electrodes. This chapter summarizes the principle and different applications of capacitive biosensors with an emphasis on microcontact imprinting method with its recent capacitive biosensor applications.

  11. Integrating and Amplifying Signal from Riboswitch Biosensors

    DTIC Science & Technology

    2014-08-01

    AFRL-RH-WP-TR-2014-0108 INTEGRATING AND AMPLIFYING SIGNAL FROM RIBOSWITCH BIOSENSORS Michael S. Goodson Yaroslav G. Chushak UES...Amplifying Signal from Riboswitch Biosensors 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Michael...88ABW-2014-1997; Cleared 30 Apr 2014. 14. ABSTRACT Biosensors offer a built-in energy supply and inherent sensing machinery that when exploited

  12. Recent Development in Optical Fiber Biosensors

    PubMed Central

    Bosch, María Espinosa; Sánchez, Antonio Jesús Ruiz; Rojas, Fuensanta Sánchez; Ojeda, Catalina Bosch

    2007-01-01

    Remarkable developments can be seen in the field of optical fibre biosensors in the last decade. More sensors for specific analytes have been reported, novel sensing chemistries or transduction principles have been introduced, and applications in various analytical fields have been realised. This review consists of papers mainly reported in the last decade and presents about applications of optical fiber biosensors. Discussions on the trends in optical fiber biosensor applications in real samples are enumerated.

  13. Comparison of impedimetric detection of DNA hybridization on the various biosensors based on modified glassy carbon electrodes with PANHS and nanomaterials of RGO and MWCNTs.

    PubMed

    Benvidi, Ali; Tezerjani, Marzieh Dehghan; Jahanbani, Shahriar; Mazloum Ardakani, Mohammad; Moshtaghioun, Seyed Mohammad

    2016-01-15

    In this research, we have developed lable free DNA biosensors based on modified glassy carbon electrodes (GCE) with reduced graphene oxide (RGO) and carbon nanotubes (MWCNTs) for detection of DNA sequences. This paper compares the detection of BRCA1 5382insC mutation using independent glassy carbon electrodes (GCE) modified with RGO and MWCNTs. A probe (BRCA1 5382insC mutation detection (ssDNA)) was then immobilized on the modified electrodes for a specific time. The immobilization of the probe and its hybridization with the target DNA (Complementary DNA) were performed under optimum conditions using different electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed biosensors were used for determination of complementary DNA sequences. The non-modified DNA biosensor (1-pyrenebutyric acid-N- hydroxysuccinimide ester (PANHS)/GCE), revealed a linear relationship between ∆Rct and logarithm of the complementary target DNA concentration ranging from 1.0×10(-16)molL(-1) to 1.0×10(-10)mol L(-1) with a correlation coefficient of 0.992, for DNA biosensors modified with multi-wall carbon nanotubes (MWCNTs) and reduced graphene oxide (RGO) wider linear range and lower detection limit were obtained. For ssDNA/PANHS/MWCNTs/GCE a linear range 1.0×10(-17)mol L(-1)-1.0×10(-10)mol L(-1) with a correlation coefficient of 0.993 and for ssDNA/PANHS/RGO/GCE a linear range from 1.0×10(-18)mol L(-1) to 1.0×10(-10)mol L(-1) with a correlation coefficient of 0.985 were obtained. In addition, the mentioned biosensors were satisfactorily applied for discriminating of complementary sequences from noncomplementary sequences, so the mentioned biosensors can be used for the detection of BRCA1-associated breast cancer.

  14. Zinc oxide interdigitated electrode for biosensor application

    NASA Astrophysics Data System (ADS)

    Sin L., L.; Arshad, M. K. Md.; Fathil, M. F. M.; Adzhri, R.; M. Nuzaihan M., N.; Ruslinda, A. R.; Gopinath, Subash C. B.; Hashim, U.

    2016-07-01

    In biosensors, zinc oxide (ZnO) thin film plays a crucial role in term of stability, sensitivity, biocompatibility and low cost. Interdigitated electrode (IDE) design is one of the device architecture in biosensor for label free, stability and sensitivity. In this paper, we discuss the fabrication of zinc oxide deposited on the IDE as a transducer for sensing of biomolecule. The formation of APTES had increase the performance of the surface functionalization..Furthermore we extend the discuss on the surface functionalization process which is utilized for probe attachment onto the surface of biosensor through surface immobilization process, thus enables the sensing of biomolecules for biosensor application.

  15. Organic Photodiodes for Biosensor Miniaturization

    DTIC Science & Technology

    2009-01-01

    1 pW/mm2. Using this system, sandwich immunoassays were performed on the OPD substrate for detection of Staphylococcal enterotoxin B (SEB). Results...demonstrated the capability to detect multiple pathogens simultaneously at very low levels. Miniaturization of biosensors is essential for use in the field or...the sensing surface coated with immobilized capture antibody. We performed a chemiluminescence immunoassay on the OPD substrate and measured the results

  16. Biosensors for DNA sequence detection

    NASA Technical Reports Server (NTRS)

    Vercoutere, Wenonah; Akeson, Mark

    2002-01-01

    DNA biosensors are being developed as alternatives to conventional DNA microarrays. These devices couple signal transduction directly to sequence recognition. Some of the most sensitive and functional technologies use fibre optics or electrochemical sensors in combination with DNA hybridization. In a shift from sequence recognition by hybridization, two emerging single-molecule techniques read sequence composition using zero-mode waveguides or electrical impedance in nanoscale pores.

  17. An electrochemical DNA biosensor based on Oracet Blue as a label for detection of Helicobacter pylori.

    PubMed

    Hajihosseini, Saeedeh; Nasirizadeh, Navid; Hejazi, Mohammad Saeid; Yaghmaei, Parichereh

    2016-10-01

    An innovative method of a DNA electrochemical biosensor based on Oracet Blue (OB) as an electroactive label and gold electrode (AuE) for detection of Helicobacter pylori, was offered. A single-stranded DNA probe with a thiol modification was covalently immobilized on the surface of the AuE by forming an Au-S bond. Differential pulse voltammetry (DPV) was used to monitor DNA hybridization by measuring the electrochemical signals of reduction of the OB binding to double-stranded DNA (ds-DNA). Our results showed that OB-based DNA biosensor has a decent potential for detection of single-base mismatch in target DNA. Selectivity of the proposed DNA biosensor was further confirmed in the presence of non-complementary and complementary DNA strands. Under optimum conditions, the electrochemical signal had a linear relationship with the concentration of the target DNA ranging from 0.3nmolL(-1) to 240.0nmolL(-1), and the detection limit was 0.17nmolL(-1), whit a promising reproducibility and repeatability.

  18. Alginate cryogel based glucose biosensor

    NASA Astrophysics Data System (ADS)

    Fatoni, Amin; Windy Dwiasi, Dian; Hermawan, Dadan

    2016-02-01

    Cryogel is macroporous structure provides a large surface area for biomolecule immobilization. In this work, an alginate cryogel based biosensor was developed to detect glucose. The cryogel was prepared using alginate cross-linked by calcium chloride under sub-zero temperature. This porous structure was growth in a 100 μL micropipette tip with a glucose oxidase enzyme entrapped inside the cryogel. The glucose detection was based on the colour change of redox indicator, potassium permanganate, by the hydrogen peroxide resulted from the conversion of glucose. The result showed a porous structure of alginate cryogel with pores diameter of 20-50 μm. The developed glucose biosensor was showed a linear response in the glucose detection from 1.0 to 5.0 mM with a regression of y = 0.01x+0.02 and R2 of 0.994. Furthermore, the glucose biosensor was showed a high operational stability up to 10 times of uninterrupted glucose detections.

  19. Cholesterol self-powered biosensor.

    PubMed

    Sekretaryova, Alina N; Beni, Valerio; Eriksson, Mats; Karyakin, Arkady A; Turner, Anthony P F; Vagin, Mikhail Yu

    2014-10-07

    Monitoring the cholesterol level is of great importance, especially for people with high risk of developing heart disease. Here we report on reagentless cholesterol detection in human plasma with a novel single-enzyme, membrane-free, self-powered biosensor, in which both cathodic and anodic bioelectrocatalytic reactions are powered by the same substrate. Cholesterol oxidase was immobilized in a sol-gel matrix on both the cathode and the anode. Hydrogen peroxide, a product of the enzymatic conversion of cholesterol, was electrocatalytically reduced, by the use of Prussian blue, at the cathode. In parallel, cholesterol oxidation catalyzed by mediated cholesterol oxidase occurred at the anode. The analytical performance was assessed for both electrode systems separately. The combination of the two electrodes, formed on high surface-area carbon cloth electrodes, resulted in a self-powered biosensor with enhanced sensitivity (26.0 mA M(-1) cm(-2)), compared to either of the two individual electrodes, and a dynamic range up to 4.1 mM cholesterol. Reagentless cholesterol detection with both electrochemical systems and with the self-powered biosensor was performed and the results were compared with the standard method of colorimetric cholesterol quantification.

  20. Biosensor of endotoxin and sepsis

    NASA Astrophysics Data System (ADS)

    Shao, Yang; Wang, Xiang; Wu, Xi; Gao, Wei; He, Qing-hua; Cai, Shaoxi

    2001-09-01

    To investigate the relation between biosensor of endotoxin and endotoxin of plasma in sepsis. Method: biosensor of endotoxin was designed with technology of quartz crystal microbalance bioaffinity sensor ligand of endotoxin were immobilized by protein A conjugate. When a sample soliton of plasma containing endotoxin 0.01, 0.03, 0.06, 0.1, 0.5, 1.0Eu, treated with perchloric acid and injected into slot of quartz crystal surface respectively, the ligand was released from the surface of quartz crystal to form a more stable complex with endotoxin in solution. The endotoxin concentration corresponded to the weight change on the crystal surface, and caused change of frequency that occurred when desorbed. The result was biosensor of endotoxin might detect endotoxin of plasma in sepsis, measurements range between 0.05Eu and 0.5Eu in the stop flow mode, measurement range between 0.1Eu and 1Eu in the flow mode. The sensor of endotoxin could detect the endotoxin of plasm rapidly, and use for detection sepsis in clinically.

  1. Gold nanoparticles-decorated graphene field-effect transistor biosensor for femtomolar MicroRNA detection.

    PubMed

    Cai, Bingjie; Huang, Le; Zhang, Hong; Sun, Zhongyue; Zhang, Zhiyong; Zhang, Guo-Jun

    2015-12-15

    Early detection is proven to be the best chance for successful cancer treatment. MiRNAs, as ideal biomarkers, can identify cancer in the early stage. Therefore, development of highly sensitive and selective detection methods for miRNA is still anticipated. Here we report on a gold nanoparticles (AuNPs)-decorated graphene field-effect transistor (FET) biosensor for highly sensitive, selective and label-free detection of miRNA. The AuNPs-decorated graphene FET biosensor was fabricated by drop-casting the reduced graphene oxide (R-GO) suspension onto the sensor surface, and subsequently decorating AuNPs onto the surface of R-GO. After peptide nucleic acid (PNA) probe was immobilized on the AuNPs surface, miRNA detection was carried out via PNA-miRNA hybridization. It was found that the developed FET biosensor was able to achieve a detection limit as low as 10 fM. In addition, the biosensor enabled an accurate distinction of complementary miRNA from one-base mismatched miRNA and noncomplementary miRNA. What's more, this highly sensitive and selective assay was also applied to the detection of miRNA in serum samples, making it a potential method for diagnosis of gene-related diseases.

  2. Biosensors and their applications in detection of organophosphorus pesticides in the environment.

    PubMed

    Hassani, Shokoufeh; Momtaz, Saeideh; Vakhshiteh, Faezeh; Maghsoudi, Armin Salek; Ganjali, Mohammad Reza; Norouzi, Parviz; Abdollahi, Mohammad

    2017-01-01

    This review discusses the past and recent advancements of biosensors focusing on detection of organophosphorus pesticides (OPs) due to their exceptional use during the last decades. Apart from agricultural benefits, OPs also impose adverse toxicological effects on animal and human population. Conventional approaches such as chromatographic techniques used for pesticide detection are associated with several limitations. A biosensor technology is unique due to the detection sensitivity, selectivity, remarkable performance capabilities, simplicity and on-site operation, fabrication and incorporation with nanomaterials. This study also provided specifications of the most OPs biosensors reported until today based on their transducer system. In addition, we highlighted the application of advanced complementary materials and analysis techniques in OPs detection systems. The availability of these new materials associated with new sensing techniques has led to introduction of easy-to-use analytical tools of high sensitivity and specificity in the design and construction of OPs biosensors. In this review, we elaborated the achievements in sensing systems concerning innovative nanomaterials and analytical techniques with emphasis on OPs.

  3. Towards reliable multi-pathogen biosensors using high-dimensional encoding and decoding techniques

    NASA Astrophysics Data System (ADS)

    Chakrabartty, Shantanu; Liu, Yang

    2008-08-01

    Advances in micro-nano-biosensor fabrication are enabling technology that can integrate a large number of biological recognition elements within a single package. As a result, hundreds to millions of tests can be performed simultaneously and can facilitate rapid detection of multiple pathogens in a given sample. However, it is an open question as to how to exploit the high-dimensional nature of the multi-pathogen testing for improving the detection reliability a typical biosensor system. In this paper, we discuss two complementary high-dimensional encoding/decoding methods for improving the reliability of multi-pathogen detection. The first method uses a support vector machine (SVM) to learn the non-linear detection boundaries in the high-dimensional measurement space. The second method uses a forward error correcting (FEC) technique to synthetically introduce redundant patterns on the biosensor which can then be efficiently decoded. In this paper, experimental and simulation studies are based on a model conductimetric lateral flow immunoassay that uses antigen-antibody interaction in conjunction with a polyaniline transducer to detect presence or absence of pathogen in a given sample. Our results show that both SVM and FEC techniques can improve the detection performance by exploiting cross-reaction amongst multiple recognition sites on the biosensor. This is contrary to many existing methods used in pathogen detection technology where the main emphasis has been reducing the effects of cross-reaction and coupling instead of exploiting them as side information.

  4. Portable evanescent wave fiber biosensor for highly sensitive detection of Shigella

    NASA Astrophysics Data System (ADS)

    Xiao, Rui; Rong, Zhen; Long, Feng; Liu, Qiqi

    2014-11-01

    A portable evanescent wave fiber biosensor was developed to achieve the rapid and highly sensitive detection of Shigella. In this study, a DNA probe was covalently immobilized onto fiber-optic biosensors that can hybridize with a fluorescently labeled complementary DNA. The sensitivity of detection for synthesized oligonucleotides can reach 10-10 M. The surface of the sensor can be regenerated with 0.5% sodium dodecyl sulfate solution (pH 1.9) for over 30 times without significant deterioration of performance. The total analysis time for a single sample, including the time for measurement and surface regeneration, was less than 6 min. We employed real-time polymerase chain reaction (PCR) and compared the results of both methods to investigate the actual Shigella DNA detection capability of the fiber-optic biosensor. The fiber-optic biosensor could detect as low as 102 colony-forming unit/mL Shigella. This finding was comparable with that by real-time PCR, which suggests that this method is a potential alternative to existing detection methods.

  5. A Graphene-Based Biosensing Platform Based on Regulated Release of an Aptameric DNA Biosensor.

    PubMed

    Mao, Yu; Chen, Yongli; Li, Song; Lin, Shuo; Jiang, Yuyang

    2015-11-09

    A novel biosensing platform was developed by integrating an aptamer-based DNA biosensor with graphene oxide (GO) for rapid and facile detection of adenosine triphosphate (ATP, as a model target). The DNA biosensor, which is locked by GO, is designed to contain two sensing modules that include recognition site for ATP and self-replication track that yields the nicking domain for Nt.BbvCI. By taking advantage of the different binding affinity of single-stranded DNA, double-stranded DNA and aptamer-target complex toward GO, the DNA biosensor could be efficiently released from GO in the presence of target with the help of a complementary DNA strand (CPDNA) that partially hybridizes to the DNA biosensor. Then, the polymerization/nicking enzyme synergetic isothermal amplification could be triggered, leading to the synthesis of massive DNA amplicons, thus achieving an enhanced sensitivity with a wide linear dynamic response range of four orders of magnitude and good selectivity. This biosensing strategy expands the applications of GO-DNA nanobiointerfaces in biological sensing, showing great potential in fundamental research and biomedical diagnosis.

  6. Electrochemical Biosensors - Sensor Principles and Architectures

    PubMed Central

    Grieshaber, Dorothee; MacKenzie, Robert; Vörös, Janos; Reimhult, Erik

    2008-01-01

    Quantification of biological or biochemical processes are of utmost importance for medical, biological and biotechnological applications. However, converting the biological information to an easily processed electronic signal is challenging due to the complexity of connecting an electronic device directly to a biological environment. Electrochemical biosensors provide an attractive means to analyze the content of a biological sample due to the direct conversion of a biological event to an electronic signal. Over the past decades several sensing concepts and related devices have been developed. In this review, the most common traditional techniques, such as cyclic voltammetry, chronoamperometry, chronopotentiometry, impedance spectroscopy, and various field-effect transistor based methods are presented along with selected promising novel approaches, such as nanowire or magnetic nanoparticle-based biosensing. Additional measurement techniques, which have been shown useful in combination with electrochemical detection, are also summarized, such as the electrochemical versions of surface plasmon resonance, optical waveguide lightmode spectroscopy, ellipsometry, quartz crystal microbalance, and scanning probe microscopy. The signal transduction and the general performance of electrochemical sensors are often determined by the surface architectures that connect the sensing element to the biological sample at the nanometer scale. The most common surface modification techniques, the various electrochemical transduction mechanisms, and the choice of the recognition receptor molecules all influence the ultimate sensitivity of the sensor. New nanotechnology-based approaches, such as the use of engineered ion-channels in lipid bilayers, the encapsulation of enzymes into vesicles, polymersomes, or polyelectrolyte capsules provide additional possibilities for signal amplification. In particular, this review highlights the importance of the precise control over the delicate

  7. Selling Complementary Patents: Experimental Investigation

    SciTech Connect

    Bjornstad, David J; Santore, Rudy; McKee, Michael

    2010-02-01

    Production requiring licensing groups of complementary patents implements a coordination game among patent holders, who can price patents by choosing among combinations of fixed and royalty fees. Summed across patents, these fees become the total producer cost of the package of patents. Royalties, because they function as excise taxes, add to marginal costs, resulting in higher prices and reduced quantities of the downstream product and lower payoffs to the patent holders. Using fixed fees eliminates this inefficiency but yields a more complex coordination game in which there are multiple equilibria, which are very fragile in that small mistakes can lead the downstream firm to not license the technology, resulting in inefficient outcomes. We report on a laboratory market investigation of the efficiency effects of coordinated pricing of patents in a patent pool. We find that pool-like pricing agreements can yield fewer coordination failures in the pricing of complementary patents.

  8. A Drosophila complementary DNA resource

    SciTech Connect

    Rubin, Gerald M.; Hong, Ling; Brokstein, Peter; Evans-Holm, Martha; Frise, Erwin; Stapleton, Mark; Harvey, Damon A.

    2000-03-24

    Collections of nonredundant, full-length complementary DNA (cDNA) clones for each of the model organisms and humans will be important resources for studies of gene structure and function. We describe a general strategy for producing such collections and its implementation, which so far has generated a set of cDNAs corresponding to over 40% of the genes in the fruit fly Drosophila melanogaster.

  9. Ultrasensitive cDNA Detection of Dengue Virus RNA Using Electrochemical Nanoporous Membrane-Based Biosensor

    PubMed Central

    Rai, Varun; Hapuarachchi, Hapuarachchige C.; Ng, Lee Ching; Soh, Siew Hwa; Leo, Yee Sin; Toh, Chee-Seng

    2012-01-01

    A nanoporous alumina membrane-based ultrasensitive DNA biosensor is constructed using 5′-aminated DNA probes immobilized onto the alumina channel walls. Alumina nanoporous membrane-like structure is carved over platinum wire electrode of 76 µm diameter dimension by electrochemical anodization. The hybridization of complementary target DNA with probe DNA molecules attached inside the pores influences the pore size and ionic conductivity. The biosensor demonstrates linear range over 6 order of magnitude with ultrasensitive detection limit of 9.55×10−12 M for the quantification of ss-31 mer DNA sequence. Its applicability is challenged against real time cDNA PCR sample of dengue virus serotype1 derived from asymmetric PCR. Excellent specificity down to one nucleotide mismatch in target DNA sample of DENV3 is also demonstrated. PMID:22927927

  10. Label-free detection of DNA hybridization and single point mutations in a nano-gap biosensor.

    PubMed

    Zaffino, R L; Mir, M; Samitier, J

    2014-03-14

    We describe a conductance-based biosensor that exploits DNA-mediated long-range electron transport for the label-free and direct electrical detection of DNA hybridization. This biosensor platform comprises an array of vertical nano-gap biosensors made of gold and fabricated through standard photolithography combined with focused ion beam lithography. The nano-gap walls are covalently modified with short, anti-symmetric thiolated DNA probes, which are terminated by 19 bases complementary to both the ends of a target DNA strand. The nano-gaps are separated by a distance of 50 nm, which was adjusted to fit the length of the DNA target plus the DNA probes. The hybridization of the target DNA closes the gap circuit in a switch on/off fashion, in such a way that it is readily detected by an increase in the current after nano-gap closure. The nano-biosensor shows high specificity in the discrimination of base-pair mismatching and does not require signal indicators or enhancing molecules. The design of the biosensor platform is applicable for multiplexed detection in a straightforward manner. The platform is well-suited to mass production, point-of-care diagnostics, and wide-scale DNA analysis applications.

  11. Label-free detection of DNA hybridization and single point mutations in a nano-gap biosensor

    NASA Astrophysics Data System (ADS)

    Zaffino, R. L.; Mir, M.; Samitier, J.

    2014-03-01

    We describe a conductance-based biosensor that exploits DNA-mediated long-range electron transport for the label-free and direct electrical detection of DNA hybridization. This biosensor platform comprises an array of vertical nano-gap biosensors made of gold and fabricated through standard photolithography combined with focused ion beam lithography. The nano-gap walls are covalently modified with short, anti-symmetric thiolated DNA probes, which are terminated by 19 bases complementary to both the ends of a target DNA strand. The nano-gaps are separated by a distance of 50nm, which was adjusted to fit the length of the DNA target plus the DNA probes. The hybridization of the target DNA closes the gap circuit in a switch on/off fashion, in such a way that it is readily detected by an increase in the current after nano-gap closure. The nano-biosensor shows high specificity in the discrimination of base-pair mismatching and does not require signal indicators or enhancing molecules. The design of the biosensor platform is applicable for multiplexed detection in a straightforward manner. The platform is well-suited to mass production, point-of-care diagnostics, and wide-scale DNA analysis applications.

  12. Nanomaterials based biosensors for cancer biomarker detection

    NASA Astrophysics Data System (ADS)

    Malhotra, Bansi D.; Kumar, Saurabh; Mouli Pandey, Chandra

    2016-04-01

    Biosensors have enormous potential to contribute to the evolution of new molecular diagnostic techniques for patients suffering with cancerous diseases. A major obstacle preventing faster development of biosensors pertains to the fact that cancer is a highly complex set of diseases. The oncologists currently rely on a few biomarkers and histological characterization of tumors. Some of the signatures include epigenetic and genetic markers, protein profiles, changes in gene expression, and post-translational modifications of proteins. These molecular signatures offer new opportunities for development of biosensors for cancer detection. In this context, conducting paper has recently been found to play an important role towards the fabrication of a biosensor for cancer biomarker detection. In this paper we will focus on results of some of the recent studies obtained in our laboratories relating to fabrication and application of nanomaterial modified paper based biosensors for cancer biomarker detection.

  13. Water soluble nano-scale transient material germanium oxide for zero toxic waste based environmentally benign nano-manufacturing

    NASA Astrophysics Data System (ADS)

    Almuslem, A. S.; Hanna, A. N.; Yapici, T.; Wehbe, N.; Diallo, E. M.; Kutbee, A. T.; Bahabry, R. R.; Hussain, M. M.

    2017-02-01

    In the recent past, with the advent of transient electronics for mostly implantable and secured electronic applications, the whole field effect transistor structure has been dissolved in a variety of chemicals. Here, we show simple water soluble nano-scale (sub-10 nm) germanium oxide (GeO2) as the dissolvable component to remove the functional structures of metal oxide semiconductor devices and then reuse the expensive germanium substrate again for functional device fabrication. This way, in addition to transiency, we also show an environmentally friendly manufacturing process for a complementary metal oxide semiconductor (CMOS) technology. Every year, trillions of complementary metal oxide semiconductor (CMOS) electronics are manufactured and billions are disposed, which extend the harmful impact to our environment. Therefore, this is a key study to show a pragmatic approach for water soluble high performance electronics for environmentally friendly manufacturing and bioresorbable electronic applications.

  14. Complementary therapies for cancer pain.

    PubMed

    Cassileth, Barrie; Trevisan, Carrie; Gubili, Jyothirmai

    2007-08-01

    Pharmacologic treatment of pain does not always meet patients' needs and may produce difficult side effects. Complementary therapies, which are safe, noninvasive, and generally considered to be relatively free of toxicity, may be used adjunctively with standard pain management techniques to improve outcome and reduce the need for prescription medication. Approaches such as acupuncture, massage therapy, mind-body interventions, and music therapy effectively reduce pain, enhance quality of life, and provide patients with the opportunity to participate in their own care. Such therapies have an important role in modern pain management.

  15. Microfabricated silicon biosensors for microphysiometry

    NASA Technical Reports Server (NTRS)

    Bousse, L. J.; Libby, J. M.; Parce, J. W.

    1993-01-01

    Microphysiometers are biosensor devices that measure the metabolic rate of living cells by detecting the rate of extracellular acidification caused by a small number of cells. The cells are entrapped in a microvolume chamber, whose bottom surface is a silicon sensor chip. In a further miniaturization step, we have recently fabricated multichannel flow-through chips that will allow greater throughput and multiplicity. Microphysiometer technology can be applied to the detection of microorganisms. We describe the sensitive detection of bacteria and yeast. Further applications of microphysiometry to the characterization of microorganisms can be anticipated.

  16. Quantum dot-based microfluidic biosensor for cancer detection

    SciTech Connect

    Ghrera, Aditya Sharma; Pandey, Chandra Mouli; Ali, Md. Azahar; Malhotra, Bansi Dhar

    2015-05-11

    We report results of the studies relating to fabrication of an impedimetric microfluidic–based nucleic acid sensor for quantification of DNA sequences specific to chronic myelogenous leukemia (CML). The sensor chip is prepared by patterning an indium–tin–oxide (ITO) coated glass substrate via wet chemical etching method followed by sealing with polydimethylsiloxane (PDMS) microchannel for fluid control. The fabricated microfluidic chip comprising of a patterned ITO substrate is modified by depositing cadmium selenide quantum dots (QCdSe) via Langmuir–Blodgett technique. Further, the QCdSe surface has been functionalized with specific DNA probe for CML detection. The probe DNA functionalized QCdSe integrated miniaturized system has been used to monitor target complementary DNA concentration by measuring the interfacial charge transfer resistance via hybridization. The presence of complementary DNA in buffer solution significantly results in decreased electro-conductivity of the interface due to presence of a charge barrier for transport of the redox probe ions. The microfluidic DNA biosensor exhibits improved linearity in the concentration range of 10{sup −15} M to 10{sup −11} M.

  17. Quantum dot-based microfluidic biosensor for cancer detection

    NASA Astrophysics Data System (ADS)

    Ghrera, Aditya Sharma; Pandey, Chandra Mouli; Ali, Md. Azahar; Malhotra, Bansi Dhar

    2015-05-01

    We report results of the studies relating to fabrication of an impedimetric microfluidic-based nucleic acid sensor for quantification of DNA sequences specific to chronic myelogenous leukemia (CML). The sensor chip is prepared by patterning an indium-tin-oxide (ITO) coated glass substrate via wet chemical etching method followed by sealing with polydimethylsiloxane (PDMS) microchannel for fluid control. The fabricated microfluidic chip comprising of a patterned ITO substrate is modified by depositing cadmium selenide quantum dots (QCdSe) via Langmuir-Blodgett technique. Further, the QCdSe surface has been functionalized with specific DNA probe for CML detection. The probe DNA functionalized QCdSe integrated miniaturized system has been used to monitor target complementary DNA concentration by measuring the interfacial charge transfer resistance via hybridization. The presence of complementary DNA in buffer solution significantly results in decreased electro-conductivity of the interface due to presence of a charge barrier for transport of the redox probe ions. The microfluidic DNA biosensor exhibits improved linearity in the concentration range of 10-15 M to 10-11 M.

  18. Characterization of Textile-Insulated Capacitive Biosensors.

    PubMed

    Ng, Charn Loong; Reaz, Mamun Bin Ibne

    2017-03-12

    Capacitive biosensors are an emerging technology revolutionizing wearable sensing systems and personal healthcare devices. They are capable of continuously measuring bioelectrical signals from the human body while utilizing textiles as an insulator. Different textile types have their own unique properties that alter skin-electrode capacitance and the performance of capacitive biosensors. This paper aims to identify the best textile insulator to be used with capacitive biosensors by analysing the characteristics of 6 types of common textile materials (cotton, linen, rayon, nylon, polyester, and PVC-textile) while evaluating their impact on the performance of a capacitive biosensor. A textile-insulated capacitive (TEX-C) biosensor was developed and validated on 3 subjects. Experimental results revealed that higher skin-electrode capacitance of a TEX-C biosensor yields a lower noise floor and better signal quality. Natural fabric such as cotton and linen were the two best insulating materials to integrate with a capacitive biosensor. They yielded the lowest noise floor of 2 mV and achieved consistent electromyography (EMG) signals measurements throughout the performance test.

  19. Nanotubes, Nanowires, and Nanocantilevers in Biosensor Development

    SciTech Connect

    Wang, Jun; Liu, Guodong; Lin, Yuehe

    2007-03-08

    In this chapter, the reviews on biosensor development based on 1-D nanomaterials, CNTs, semiconducting nanowires, and some cantilevers will be introduced. The emphasis of this review will be placed on CNTs and electrochemical/electronic biosensor developments. Section 2 of this chapter gives a detailed description of carbon nanotubes-based biosensor development, from fabrication of carbon nanotubes, the strategies for construction of carbon nanotube based biosensors to their bioapplications. In the section of the applications of CNTs based biosensors, various detection principles, e. g. electrochemical, electronic, and optical method, and their applications are reviewed in detail. Section 3 introduces the method for synthesis of semiconducting nanowires, e.g. silicon nanowires, conducting polymer nanowires and metal oxide nanowires and their applications in DNA and proteins sensing. Section 4 simply describes the development for nanocantilevers based biosensors and their application in DNA and protein diagnosis. Each section starts from a brief introduction and then goes into details. Finally in the Conclusion section, the development of 1-D nanomaterials based biosensor development is summarized.

  20. Characterization of Textile-Insulated Capacitive Biosensors

    PubMed Central

    Ng, Charn Loong; Reaz, Mamun Bin Ibne

    2017-01-01

    Capacitive biosensors are an emerging technology revolutionizing wearable sensing systems and personal healthcare devices. They are capable of continuously measuring bioelectrical signals from the human body while utilizing textiles as an insulator. Different textile types have their own unique properties that alter skin-electrode capacitance and the performance of capacitive biosensors. This paper aims to identify the best textile insulator to be used with capacitive biosensors by analysing the characteristics of 6 types of common textile materials (cotton, linen, rayon, nylon, polyester, and PVC-textile) while evaluating their impact on the performance of a capacitive biosensor. A textile-insulated capacitive (TEX-C) biosensor was developed and validated on 3 subjects. Experimental results revealed that higher skin-electrode capacitance of a TEX-C biosensor yields a lower noise floor and better signal quality. Natural fabric such as cotton and linen were the two best insulating materials to integrate with a capacitive biosensor. They yielded the lowest noise floor of 2 mV and achieved consistent electromyography (EMG) signals measurements throughout the performance test. PMID:28287493