Non-polar a-plane (112�0) GaN thin films were grown on r-plane (11�02) sapphire substrates by metal-organic chemical vapor deposition. In order to obtain a-plane GaN films with better crystal quality and surface morphology, detailed comparisons between different growth ...
NASA Astrophysics Data System (ADS)
Generalized infrared spectroscopic ellipsometry was applied to study the vibrational properties of anisotropically strained a-plane GaN films with different thicknesses. We have established a correlation between the phonon mode parameters and the strain, which allows the determination of the deformation potentials and strain-free ...
Non-polar a-plane (11bar 20) GaN films have been grown on r-plane (1bar 102) sapphire substrates by metal organic chemical vapour deposition. The influences of V/III ratio on the species diffusion anisotropy of a-plane GaN films were investigated by scanning electron microscopy, ...
This paper reports the growth by molecular beam epitaxy of AlN and GaN thin films on R-plane sapphire substrates. Contrary to previous findings that GaN grows with its (1120) A-plane parallel to the (1102) R-plane of sapphire, our results indicate that the crystallographic orientation of the III-nitride ...
Energy Citations Database
Conventional c-plane (Al, In, Ga)N optoelectronic devices suffer from deleterious polarization effects. These polarization effects can be eliminated by growing devices on alternative orientations of GaN crystals, such as {11�00} m-plane or {112�0} a-plane films. Previous attempts to grow nonpolar ...
We report the room temperature photoluminescence properties of AlGaN/AlGaN multiple quantum well (MQW) structures grown on high-quality a-plane GaN pillars oriented along the m-axis. The non-coalesced thick GaN films were laterally overgrown on r-plane sapphire at 900 �C using pulsed metalorganic chemical vapor ...
Non-polar a-plane GaN films grown by hydride vapor phase epitaxy were studied by means of transmission electron microscopy in order to elucidate defect formation mechanisms. The typical defects found were I1 basal plane stacking faults and Frank-Shockley partials. Moreover, prismatic stacking faults could be identified, which were ...
In this work, a-plane GaN/ r-sapphire templates have been used to grow nonpolar a-plane ZnO films by pulsed laser deposition. The ZnO film growth temperature was varied in the range of 400�C to 600�C, and the effect of growth temperature on the properties of the ZnO thin ...
Nonpolar a-plane (1 bar 2 0) GaN films have been grown on r-plane (1 bar 1 02) sapphire by metal-organic chemical vapor deposition (MOCVD) under different growth pressures. The as-grown films are investigated by optical microscopy, high-resolution X-ray diffraction (HRXRD) and Raman scattering. As growth pressure ...
It was critical to optimize V/III ratio for growing high quality GaN epilayers, because a suitable V/III ratio can promote the two-dimensional growth mode and decrease the crystalline anisotropy. In this paper, in order to investigate the influence of the V/III ratio on the surface morphology and the crystal quality of nonpolar a-GaN, a-plane ...
Growth and electrical characteristics of Mg-doped p-type nonpolar (1120) a-plane GaN films, grown on (1102) r-plane sapphire substrates via metalorganic chemical vapor deposition, were investigated as a function of growth rate, the ammonia to trimethylgallium flow ratio (V/III ratio), and the growth temperature. The electrical ...
The family of III-V nitrides are wide band-gap semiconductors with a broad range of opto-electronic applications in LEDs, laser diodes, UV detectors as well as high temperature/high frequency devices. Due to the lack of good quality native substrates, GaN is grown on foreign substrates that have a lattice and thermal mismatch with GaN. This results in a ...
The electrical properties of Mg-doped a-plane Ga1-xInxN (0films on undoped GaN grown by sidewall-epitaxial-lateral overgrowth on +0.5�-off r-plane sapphire substrates by metalorganic vapor phase epitaxy were systematically investigated. The activation energy of Mg acceptors in a-plane Ga0.83In0.17N was as small as 48 ...
The properties of nonpolar a-plane InGaN/GaN multiple-quantum wells (MQWs), grown simultaneously on lateral epitaxially overgrown (LEO) a-plane GaN and planar a-plane GaN, were studied. High-resolution x-ray diffraction analysis revealed that the In mol fraction in the MQWs grown on LEO-GaN was ...
The I1 intrinsic basal stacking faults (BSFs) are acknowledged as the principal defects observed on {1120} (a-plane) and {1100} (m-plane) grown GaN. Their importance is established by recent experimental results, which correlate the partial dislocations (PDs) bounding I1 BSFs to the luminescence characteristics of GaN. PDs are also ...
Gallium Nitride (GaN) Nanowires (NWs) have successfully been grown via a chemical beam epitaxy method. Source gases of Trimethylgallium (TMGa) and Ammonia (NH3) are impinged directly onto a hot growth substrate (�800 C) in high vacuum (�1x10-8 torr, base; �1x10-5 torr, growth). A thin metal film acts as catalyst, but NWs were also grown without ...
... Title : TRANSPARENT AND CONDUCTIVE IMPURITY-DOPED GAN THIN FILMS PREPARED BY AN ELECTRON CYCLOTRON RESONANCE ...
DTIC Science & Technology
We report on the growth and fabrication of nonpolar a-plane light emitting diodes with an in-situ SiNx interlayer grown between the undoped a-plane GaN buffer and Si-doped GaN layer. X-ray diffraction shows that the crystalline quality of the GaN buffer layer is greatly improved with the ...
We report on the reduction of defect densities in non-polar a-plane GaN films over r-plane sapphire achieved by epitaxial laterally overgrowth (ELOG) approach. A mask pattern was used to produce ELOG GaN with wing region width of about 30 ?m. Based on transmission electron microscopy (TEM) results, the window ...
Properties of nonpolar a-plane InGaN/GaN multiple quantum wells grown on lateral epitaxially-plane InGaN/GaN multiple-quantum wells MQWs , grown simultaneously on lateral epitaxially overgrown LEO a the absence of polarization-induced electric field in the quantum wells.7 Growth of high quality nonpolar InGaN/GaN
E-print Network
We demonstrate that formation of p-n junction in gallium nitride (GaN) can be directly visualized on cleavage surfaces in a cross-sectional geometry, where the focused synchrotron radiation (soft x-ray) images the different doping layers on the nonpolar a-plane surface perpendicular to the polar growth direction. In contrast to the as-grown ...
... precise control of the reactants for atomic layer epitaxy. ... Growth of high quality films is expected ... Thin films of gallium nitride (GaN) will be grown on Si ...
... Accession Number : ADA530485. Title : Study of Defect States in GaN Films by Photoconductivity Measurement. Descriptive Note : Journal article. ...
Page 1. 1 MAGNETIC AND OPTICAL PROPERTIES OF MN-DOPED GAN THIN FILMS AND PIN DEVICES ML Reed*, MO ...
Sep 18, 2007 ... The primary objective of this SBIR is to develop epitaxial GaN films with ... in strong photoluminescent emission at room temperature. ...
NASA Website
... an ensemble Monte Carlo simulation of the electron transport in gallium nitride (GaN). ... show that the 30 A AIN film is slightly relaxed, the 60 A film ...
In this paper, we report a detailed study on the evolution of surface morphology and microstructure of nonpolar a-plane GaN (a-GaN) through controlled growth interruptions. Microscopy imaging shows that the two-step a-GaN growth went through a roughening-recovery process. The first-step growth (under high V/III and high pressure) produced a rough surface ...
We report theoretical and experimental studies of radiative recombination of carriers in GaN quantum wells grown on low defect a-plane GaN templates fabricated by lateral epitaxial overgrowth. The radiative rates are presented as functions of temperature and well width.
Growth of GaN Thin Films on Silicon Using Single Source Precursors and Development of New We have grown the GaN thin films on silicon substrates using the newly developed single source precursors by thermal MOCVD method. Highly oriented GaN thin films in the [002] direction ...
... The results of GaN film deposition in ... GENERAL), PHOTOLUMINESCENCE, STRUCTURES, FILMS, EPITAXIAL GROWTH, MOLECULAR BEAMS ...
... those on Si(111) for both GaN and AlN ... the films were grown by atomic layer epitaxy than with ... of the reactants enhances significantly the growth rates ...
... Rectangular cross-sectional epitaxial stripes have been prepared by controlling the vertical growth rate ... the stripes, where the underlying GaN film is ...
Conventional state-of-the-art wurtzite nitrides based light-emitters, grown along the polar c-direction, are characterized by the presence of polarization-induced electrostatic fields in the quantum wells. These built-in fields are detrimental to the performance of optoelectronic devices. Growth of light-emitters along nonpolar and semipolar directions is an effective means to circumvent the ...
The technologies of fabrication of thin film phosphors based on gallium nitride using rf-magnetron sputtering are developed and structural properties of films are studied. Luminescence and electron spin resonance (ESR) spectra of GaN and GaN-Mn thin films have been studied. The correlation between ...
Journal of Crystal Growth 276 (2005) 407�414 Buffer-layer-free growth of high-quality epitaxial GaN conditions for GaN epitaxial growth on a sapphire substrate [8]. However, a continuous GaN film E. This means that the buffer GaN film on 4H-SiC has an adverse effect on ...
used substrate for GaN epitaxial growth.5,6 However, it is difficult to grow high qual- ity GaN thin quality GaN films were grown epitaxially in the 0002 direction at the growth temperature of 750 �CGrowth of single crystalline GaN thin films on Si,,111... substrates by ...
We investigated Si doping effect on GaN nanowires and GaN films grown by metal-organic chemical vapor deposition (MOCVD). Si as n-type dopant is incorporated to GaN nanowires and GaN films controlled by SiH4 flow rate (0, 1, 5, 8, and 10 sccm). The charge concentration and ...
PubMed
Exposure of wurtzite GaN films grown on Si-polar 6H-SiC(0001) to magnesium during molecular beam epitaxy (MBE) has been studied. In the nitrogen rich regime of MBE growth, GaN films are known to grow with rough morphology. The authors observe on GaN(0001) that small doses of Mg act as a ...
Conventional and high resolution electron microscopy havebeen applied for studying lattice defects in nonpolar a-plane GaN grownon a 4H-SiC substrate with an AlN buffer layer. Samples in plan-view andcross-section configurations have been investigated. Basal and prismaticstacking faults together with Frank and Shockley partial dislocationswere found to be ...
... Accession Number : ADA457942. Title : New Spectroscopic Data of Erbium Ions in GaN Thin Films. Descriptive Note : Journal article. ...
Sep 18, 2007 ... High quality GaN epitaxial films are key to current efforts for ... high linearity power amplifiers with excellent thermal stability and ...
Oct 23, 2008 ... High quality GaN epitaxial films are one of the keys to current efforts for development of both high-power/high-speed electronic devices and ...
... [26] J. Heikenfeld and AJ Steckl, "Rare-earth-doped GaN switchable color ... stableGaN-based phosphor and thick-film dielectric layer," IEEE Trans. ...
... Joint Staff and other US Military (ie, Army, Navy, Air Force) service ... Title : Injection Laser Using Rare Earth Doped GaN Thin Films for Visible and ...
... Title : Growth of Low Defect Density Gallium Nitride (GaN) Films on Novel Tantalum Carbide (TaC) Substrates for Improved Device Performance. ...
1 Growth of GaN on porous SiC and GaN substrates C. K. Inoki1 , T. S. Kuan1 , Ashutosh Sagar2 , C, Albuquerque, NM 87185 4 Beckman Institute, University of Illinois, Urbana, IL 61801 GaN films were grown on porous SiC and GaN templates using both plasma-assisted molecular beam epitaxy (PAMBE) ...
for the epitaxial growth of GaN NW arrays. In this study, 3-fold symmetrically distributed GaN NW arrays the epitaxial relationship between the GaN NW and the substrate. So far, Si,24,25,27 GaN,26 sapphire,22 preparation, 2-�m-thick wurtzite structured (0001) GaN film was ...
to grow epitaxially on GaN 0001 surfaces with Al 21�1� GaN 21�1�0 . For growth at 15 and 150 �C that epitaxial growth of Al occurs with 21�1�0 GaN 21�1� Al and 11�00 GaN 011� Al . As shown in Fig. 2-dimensional growth mode. AFM studies indicate that the initial GaN surface ...
Research conducted at Tuskegee University concentrates on electrical contacts to GaN films and their
NASA Technical Reports Server (NTRS)
A unique characteristic of every semiconductor is the amount of energy required to break an electron
A metalorganic molecular beam epitaxy (MOMBE) system equipped with a radio frequency plasma cell was employed to grow GaN films at a low temperature of 650�C. The structural and optical properties of GaN films were studied by X-ray diffraction, scanning electron microscope, and photoluminescence (PL). The ...
A remote plasma chemical vapour deposition (RPCVD) system for the growth of gallium nitride (GaN) thin films is investigated using optical emission spectroscopy (OES). The intensities of the various excited species in pure nitrogen as well as nitrogen/hydrogen plasmas are correlated with GaN film growth ...
Specular, planar semipolar gallium nitride films were grown by hydride vapor phase epitaxy. This is the first report of high quality semipolar GaN films that could be used for device growth. Planar films of (10\\bar{1}\\bar{1})GaN have been grown on (100)MgAl2O4 spinel, and planar ...
Nonpolar (1120) a-plane InGaN/GaN multiple-quantum-well light-emitting diodes were grown by metalorganic chemical vapor deposition on reduced-defect density hydride-vapor-phase-epitaxy lateral epitaxially overgrown a-plane GaN templates. Direct current output power of 240 ?W was measured at 20 mA for a 300�300 ?m2 device, and dc ...
The stress and wafer bending of (1120) a-plane GaN layers of different thicknesses grown on (1102) r-plane sapphire substrates by hydride vapor phase epitaxy were studied by high-resolution x-ray diffraction and photoluminescence and photoreflectance spectroscopies. The layers are found to be under compression in the growth plane and under tension in the ...
In the growth of nonpolar (1120) a-plane GaN on r-plane (1102) sapphire by plasma-assisted molecular beam epitaxy, misoriented crystallites are observed close to the substrate. They have average diameter {approx}10 nm and are oriented with the (0001){sub GaN} plane approximately parallel to the (2113){sub sapph.} plane and [0110]{sub ...
The remarkable progress in III-nitride semiconductors has enabled widespread development of high power and high efficiency optoelectronic devices. Conventionally the polar c-axis is the common orientation for the deposition of III-N film and heterostructures even though the performance of these devices suffers from strong polarization-related electric fields along the ...
Journal of Crystal Growth 274 (2005) 38�46 Influence of polarity on GaN thermal stability M November 2004 Abstract A comparative study of the stability of Ga- and N-polar GaN films was made interest in the column III- nitrides. The thermal and chemical stability of GaN and related materials
On GaN films ICP etched at low power did not differ from unetched GaN. Leakage currents for the low power and unetched GaN were similar to -10V (less than -1nA). The forward and reverse characteristics for 100 micrometer diameter Pt contacts on GaN etched...
National Technical Information Service (NTIS)
... and Film Growth Inputs for GaN Device Development Program. ... LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE. ...
... energy on growth kinetics and morphology of GaN films. Descriptors : *THIN FILMS, *EPITAXIAL GROWTH, ELECTRON MICROSCOPY, SILICON ...
... p-type and n-type doping of GaN during deposition ... THIN FILMS, FILMS, DIAMONDS, SINGLE CRYSTALS, EPITAXIAL GROWTH, SUBSTRATES. ...
In the epitaxial lateral overgrowth (ELO) of (11{bar 2}0) a-plane GaN, the uneven growth rates of two opposing wings, Ga- and N-wings, makes the coalescence of two neighboring wings more difficult than that in c-plane GaN. We report a two-stage growth method to get uniformly coalesced epitaxial lateral overgrown ...
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Nonpolar Si-doped a-plane GaN layers were grown using metal organic chemical vapor deposition (MOCVD) with different silane (SiH4) flow rates. The on-axis full width at half maximum (FWHM) of X-ray rocking curves (XRCs) along the c- and m-axis directions showed that Si doping barely affected the anisotropy of a-plane GaN. A decrease in ...
We fabricated and characterized nonpolar a-plane AlGaN/GaN heterostructure field-effect transistors (HFETs) grown on an a-plane freestanding GaN substrate. By optimizing the growth conditions, the unintentionally doped oxygen concentration was much reduced in the a-plane GaN buffer layer. As a result, the low leakage current in the ...
A high-quality a-plane GaN layer with a pit-free, mirror-like surface was grown on a hemispherical patterned r-plane sapphire substrate (PSS) by metal--organic chemical vapor deposition. The use of the r-plane PSS reduced the density of defects such as basal plane staking faults and threading dislocations of the a-plane GaN. The ...
AlGaN and GaN films were grown on (112�0) Al2O3 substrates at elevated temperatures by alternate supply of trimethylgallium (TMG) with (or without) trimethylaluminum (TMA) in group III flow and NH3 in group V stream. The optical characteristics of GaN films deposited on (112�0) Al2O3 substrates were found to be ...
There are three sources of strain in heteroepitaxial growth, lattice misfit; thermal misfit; and growth related defects. The primary aim of the present work was to do a fundamental study of strain and mechanisms for strain relaxation in epitaxial growth of polar-GaN and polar and nonpolar-ZnO thin films grown on sapphire substrates. We have shown that through the paradigm of ...
... were grown on (0 0 0 1) (C-plane) and (1 1 2 0) (A-plane) oriented sapphire substrates by the reduction of sol-gel derived vanadium oxide films. ...
To potentially improve device performance, we attempted to grow gallium nitride (GaN) films with better crystalline quality (fewer mismatch dislocations) using a tantalum carbide (TaC) substrate, which is more closely lattice matched to GaN than currently...
-step growth GaN Nucleation Layer V/III: 2500 Tg: ~600�C t: ~20 nm GaN Epitaxial Film V/III: 300 � 1300 Tg Lateral Epitaxial Overgrowth #12;Polarity Effects GaN polarity strongly affects lateral growth rate � Ga down ... #12;Epitaxial Relationship � a-GaN (1120) growth surface � GaN ...
Direct measurement of the thermochemical properties of GaN has proven difficult, and differences in reported values remain. We present a technique for direct measurement of the free energy of formation of GaN by finding the partial pressures of ammonia gas in hydrogen for spontaneous formation and elimination of a GaN ...
A novel lanthanon seed was employed as the catalyst for the growth of GaN nanowires. Large-scale GaN nanowires have been synthesized successfully through ammoniating Ga2O3/Tb films sputtered on Si(111) substrates. Scanning electron microscopy, x-ray diffraction, high-resolution transmission electron microscopy, and Fourier transform ...
We have studied phonons in two types of anisotropically strained GaN films: c-plane GaN films grown on a-plane sapphire and a-plane GaN films grown on r-plane sapphire. The anisotropic strain in the films is determined by high-resolution X-ray ...
Nanopore arrays with pore diameters of approximately 75 nm were fabricated in GaN films by inductively coupled plasma etching using anodic aluminum oxide (AAO) films as etch masks. Nanoporous AAO films were formed on the GaN surface by evaporating an Al film onto a ...
Nonpolar a-plane GaN epilayers are grown on several r-plane sapphire substrates by metal organic chemical vapour deposition using different nucleation layers: (A) a GaN nucleation layer deposited at low temperature (LT); (B) an AlN nucleation layer deposited at high temperature; or (C) an LT thin AlN nucleation layer with an AlN layer ...
... During the conventional GaN epitaxial growth a threading dislocation in the planar (0001) GaN film propagates along the [0001] direction because ...
Mn:doped GaN films, a dilute magnetic semiconductor material, are grown on (0001) sapphire substrates by metal organic vapor deposition. Optical properties are investigated by transmission measurements and two absorption bands are found to be dominating t...
Sep 18, 2009 ... This SBIR proposal addresses the liquid phase epitaxy (LPE) of gallium nitride ( GaN) films using nitrogen-enriched metal solutions. Growth ...
A 1.5 ?m thick crack-free GaN film is successfully grown on periodic grooved Si(111) substrate. Two low temperature (LT) interlayers are used in the epitaxial film to compensate tensile stress induced by thermal mismatch between GaN and Si. The width of parallel trenches etched in the substrate along the Si110 is 1 ...
Thin GaN films were grown on GaAs(111) substrates by radical-beam gettering epitaxy. The structural quality of the films was studied by high-resolution x-ray diffraction. The chemical composition of the GaAs surface and GaN film was studied by x-ray photoelectron spectroscopy. It is shown that ...
). It was found that epitaxial growth of Hf is possible even at room temperature. GaN films varying in thickness. EXPERIMENTAL GaN(000�1) films were grown on c-plane sapphire by molecular beam epitaxy (MBE) using a Ga K.6-1.8 micron were grown. RHEED was used to determine the Ga con- densation temperature and ...
1 Growth of GaN on SiC(0001) by Molecular Beam Epitaxy C. D. LEE (a), ASHUTOSH SAGAR (a), R. M Hill, NJ 07974 USA (Submitted June 21, 2001) Subject classification: 68.55.Jk; S7.14 GaN films dislocations are achieved in GaN films of 1 mm thickness grown under optimal conditions. Reverse leakage
InGaN alloys and MQWs constitute the active region of light emitting diodes (LEDs) and lasers emitting in the visible part of the spectrum. In spite of the significant progress over the past several years, the physics related to the growth, structure and optical properties of these alloys is poorly understood. This has prevented the development of efficient emitters in the blue and green part of ...
GaN thin films were deposited on Si (111) substrates using ZnO buffer layers by pulsed laser deposition of a GaN target in a nitrogen atmosphere. High-quality GaN thin films were obtained after annealing at 950 �C for 15 min in a NH3 atmosphere. The crystalline quality, composition, and ...
We report on the surface stoichiometry of Ga-polar GaN films grown by metalorganic chemical vapor deposition as studied by x-ray photoelectron spectroscopy. GaN film surfaces are found to be Ga-rich, with Ga:N ratios ranging from 1.3:1 to 3.2:1. In vacuo ion-beam sputter/annealing studies show ...
Defects in GaN films can be revealed by wet etching in hot H3PO4 and molten potassium hydroxide or by photoelectrochemical (PEC) etching. GaN film was irradiated by 500 keV Au ions with ion fluences in the range from 1 � 109/cm2 to 5 � 1015/cm2. Afterwards, AZ-400 K photoresist developer and aqueous KOH were ...
The metalorganic chemical vapor deposition of AlN and GaN on C-face 6H-SiC was investigated. Similar to the procedure on Si-face SiC, GaN films were fabricated in a two-step process, where first a thin AlN base layer was deposited prior to the growth of the main GaN layer. Polarity conversion from the expected ...
GaN films were grown on patterned-Si(1 1 1) substrates by metal organic chemical vapor deposition (MOCVD). Arrays of rectangular stripes and squares, with a 3.5-?m height and different lateral dimensions were patterned and etched on Si substrates using inductively coupled plasma reactive ion etching. A low temperature 24-nm-thick AlN (grown at 720 �C) ...
We report the growth of high-quality GaN epilayers on an ordered nanoporous GaN template by metalorganic chemical vapor deposition. The nanopores in GaN template were created by inductively coupled plasma etching using anodic aluminum oxide film as an etch mask. The average pore diameter and interpore distance is ...
Gallium nitride films have been grown on 6H-SiC substrates employing a new form of selective lateral epitaxy, namely pendeo-epitaxy. This technique forces regrowth to start exclusively on sidewalls of GaN seed structures. Both discrete pendeo-epitaxial microstructures and coalesced single crystal layers of GaN have been achieved. ...
We summarize structural properties of thick HVPE GaN templates from the point of view of their application as substrates for growth of nitride layers. This is followed by the results of optical and structural studies, mostly transmission electron microscopy, of nitride layers grown by MOCVD on top of the HVPE substrates. The results indicate high structural quality of these ...
GaN films have been grown on highly thermally conducting Ag(111) substrates by using pulsed laser deposition. GaN(0001) grows epitaxially on Ag(111) with an in-plane epitaxial relationship of GaN[1120]?Ag[110] when low temperature AlN buffer layers are used. The heterointerfaces in the AlN/Ag structure are ...
As one of the most mature techniques for manufacturing free-standing GaN substrates, hydride vapor phase epitaxy (HVPE) always encounters problems associated with residue thermal stress, such as GaN bending and cracking during and after growth. This work presents a patterning approach and a non-patterning approach to reduce stress in thick ...
The GaN thin film is successfully grown on the sample of ZnO/Si by dual ion beams deposition (DIBD) system. The thin film GaN/ZnO/Si is characterized by the in-situ X-ray photoelectron spectroscopy (XPS). It is shown that after a thin GaN film grown on the Zn/Si, the peaks of the Zn and O are ...
The transient thermoelastic stress fields of GaN films is analyzed by the finite element method for the laser lift-off (LLO) technique. Stress distributions in GaN films irradiated by pulse laser with different energy densities as functions of time and depth are simulated. The results show that the high ...
Piezoelectric films of AlN and GaN were grown on sapphire substrates for use in the generation, propagation, and processing of surface acoustic waves. The films were grown by CVD heteroepitaxy using the metal-organic reactants trimethyl aluminum or trimet...
by molecular-beam epitaxy MBE , hydride vapor-phase epitaxy, and metalorganic chemical-vapor deposition. After GaN films as in the in situ Pr-doped GaN films grown by MBE. � 1999 American Institute of Physics. S,7 PL and electroluminescence8,9 have been achieved by solid source molecular-beam epitaxy MBE
The homoepitaxial growth of GaN(0001) layers was studied in situ and in real time using the low-energy electron microscope and ex situ using atomic force microscopy and transmission electron microscopy. The growth was conducted on substrates of GaN(0001) ...
GaN films as filters. � 2001 American Vacuum Society. DOI: 10.1116/1.1415508 I. INTRODUCTION Gallium nitride GaN , indium gallium nitride InGaN , and aluminum gallium nitride AlGaN have electrical, opti- cal etching techniques to form group III-nitride material into MEMS were not avail- able. Due
The optical properties of homoepitaxial GaN layers deposited by organometallic vapor phase epitaxy on stripe-patterned GaN films on 6H-SiC substrates have been investigated. Analysis of the spatially resolved Raman scattering spectra indicate an improveme...
In summary, a new process is being developed to obtain free standing, large area, near single crystal quality GaN flake (highly oriented GaN films) promising as native substrates for homoepitaxial growth of device quality, low- defect density GaN layers. ...
Pendeo-epitaxial lateral growth (PE) of GaN epilayers on (0001) 6H- silicon carbide and (111) Si substrates has been achieved. Growth on the latter substrate was accomplished through the use of a 3C-SiC transition layer. The coalesced PE GaN epilayers wer...
are thought to be correlated with improved growth conditions for obtaining high quality epitaxial GaN layers reconstructions observed after epitaxial growth. A comparison of wurtzite GaN films grown directly on sapphire GaN on (0 0 0 1) sapphire by RF plasma-assisted molecular beam epitaxy Kyeong K. Leea, *, ...
:5) crystalline thin films have been epitaxially grown on wurtzite GaN(0001) surfaces using rf N-plasma molecular) orientation. The in-plane epitaxial relationship to GaN is nearly ideal with 110MnGa k 1100GaN and 112MnGa k or by growing a fresh 50-nm layer of GaN. N-plasma ...
The authors report the results of nondegenerate optical pump-probe absorption experiments performed on GaN and InGAN thin films and quantum wells under the conditions of strong optical band to band excitation. The evolution of the band edge in these materials was monitored as the number of photoexcited free carriers was increased ...
Electrical properties of arsenic and silicon-doped GaN films grown on sapphire substrates by low metalorganic chemical vapor deposition have been investigated using temperature dependent Hall-effect measurements. The Hall data measured from the GaN layers shows that the concentration decreases with arsine flow (4, 40, and 400 sccm) at ...
spectroscopy is applied to state-of-the-art thin film heterostructures of group-III nitrides on sapphire and Si properties of thin GaN and AlGaN films grown on both sapphire and Si substrates. We report and structural details of bulk-like crystals and layered systems. In optically thick material the strong
In this paper, we describe the growth and characterization of high-quality GaN heteroepitaxial films grown on basal-plane sapphire substrates using metalorganic chemical vapor deposition. The quality of these films is analyzed by a variety of methods, inc...
- emitting diodes.`$ GaN films have been grown with a wide range of growth techniques,223such as chemical films exposedto low-energy electronbeam irradiation after their growth.' Zinc blende GaN(@-GaN), which expansioncoefficient,it is rather difficult to epitaxially grow GaN on Si substrate. Early attempts have ...
Results demonstrating the ability of EBIC and CL methods for ELOG GaN films characterization are presented. It is shown that EBIC measurements allow us to estimate not only the lateral distribution of diffusion length but also the donor distribution in such films. Donor concentration is found to be different in slit and wing regions. A ...
Two preliminary experiments are reviewed and seeded growth of GaN is updated in this paper. In a mineralizer study, it was shown that basic mineralizers promoted synthesis of wurtzite GaN. Through a dissolution study of polycrystalline GaN in basic supercritical ammonia, it was confirmed that GaN has retrograde ...
The photocatalytic activity of GaN nanowires was investigated for the use of GaN nanowires as photocatalysts in harsh environments. GaN nanowires with diameters of 20-50 nm and lengths of 4-6 microm were prepared by Ni catalyst-assisted metal-organic chemical vapor deposition. Comparisons of GaN nanowires with ...
The fabrication of a blue m-plane GaInN light emitting diode (LED) grown on an m-plane GaN layer grown on a 3-in. patterned sapphire substrate is reported. The output power of the LED was approximately 3 mW at the wavelength of 461 nm, a driving current of 20 mA, and a forward voltage of 3.5 V. This is the first report of nonpolar or semipolar blue LEDs grown on ...
Development VIII. Recommendations #12;WBD/JLP I. CANDIDATE INFORMATION � Name � SPEC title � SPEC grade � CJC factors related to each job responsibility � Unit specific factor(s), if appropriate � Professional Development Form #12;WBD/JLP VIII. RECOMMENDATIONS Upon completion of the dossier, the candidate will forward
The properties and structure of the ZnO material are similar to those of the GaN. Since an excitonic
... chemisorption of NH3 on GaN(0001) of approximately 0.5 eV. Descriptors : *THIN FILMS, *EPITAXIAL GROWTH, *ELECTRON MICROSCOPY ...
... of GaN on OMVPE-grown GaN/AIN/SiC ... Descriptors : *ALUMINUM COMPOUNDS, *THIN FILMS, *EPITAXIAL GROWTH, *NITRIDES, *ELECTRON ...
... the N/Ga ratio at the growth surface approached ... of AlN films and subsequently deposited GaN layers grown ... showed the latter to be epitaxial with a ...
... Characterization of UV Detectors and Cold Cathode Devices. ... Personal Author(s) : Davis, RF ; Carlson, E ... Pendeo-epitaxial growth of GaN films has ...
... from Combinations of AlN, GaN and Selected ... PLASMAS(PHYSICS), STRUCTURES, THIN FILMS, EPITAXIAL GROWTH, ROOM TEMPERATURE ...
... The quantum efficiency of the infrared emission was esti- mated by comparison with the results obtained for a fluoride glass using the same phonon ...
We report the growth by molecular beam epitaxy and the optical characterization of GaN films nucleated on a Si(111) surface that has been patterned by dry etching an ordered array of nanometer-scale pores prior to the growth. The etching is performed using an anodized aluminum oxide membrane as a mask. The nanopore array surface with the pore diameter of ...
... We have grown " thin films by laser ablation of powdered PIN compressed into a pellet. ... pellet, but for some later runs the substrate was placed ...
... Title : Large Area Lateral Epitaxial Overgrowth (LEO) of Gallium Nitride (GaN) Thin Films on Silicon Substrates and Their Characterization. ...
... flow rates, ICP and RF bias power ... Films of GaN were ion ... PHOTOLUMINES CENCE, *SEMICONDUCTOR DEVICES, COUPLING(INTERACTION ...
... has been achieved on single crystal wafers of ... of GaN on sapphire followed the ... Descriptors : *THIN FILMS, *CRYSTALS, ABLATION, CONTRAST ...
... Continuous crystalline GaN films were grown on (0001 ... X RAY DIFFRACTION, FABRICATION, EPITAXIAL GROWTH, SUBSTRATES, CRYSTALS ...
... on Novel Tantalum Carbide (TaC) Substrates for Improved Device Performance ... on Novel Tantalum Carbide (TaC) Substrates ...
... RIE processing of GaN was developed and ... METALS, MAGNESIUM, ANNEALING, MOBILITY, EPITAXIAL GROWTH, SUBSTRATES, QUALITY ...
Single-crystalline Gallium Nitride (GaN) thin films were fabricated and grown by metal organic chemical vapor deposition (MOCVD) method on c-plane sapphire substrates and then characterized by high resolution-X-ray diffraction (HR-XRD) and photoluminescence (PL) measurements. The photocatalytic decomposition of Sulforhodamine B (SRB) molecules on ...
... presented by a thin insulating layer of AIN ... depletion region on the other side of the AIN ... characterization of piezoelectric layered semiconductor films ...
This paper addresses the formation of freestanding GaN substrates by a natural separation mechanism, effectively eliminating the need for post-growth processes such as laser liftoff, chemical etching or mechanical lapping to form freestanding GaN substrates. A number of GaN thick films were grown onto sapphire ...
The authors report on an improved quality of thick HVPE-Gan grown on MOCVD-GaN template layers compared to the material grown directly on sapphire. The film-substrate interface revealed by cathodoluminescence measurements shows an absence of highly doped columnar structures which are typically present in thick HVPE-Gan ...
The growth of epitaxial GaN films on (0 0 0 1)-sapphire has been investigated using X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED). In order to investigate the mechanism of the growth in detail, we have focused on the nitridation of pre-deposited Ga layers (droplets) using ion beam-assisted molecular beam epitaxy ...
The energy gap of GaN : Mg films with various Mg concentrations was studied by contactless electroreflectance (CER) spectroscopy at room temperature. A clear and well-defined CER resonance was observed for all GaN : Mg layers. This resonance has been attributed to band-to-band absorption without any excitonic contributions. Analysing ...
In this paper we report on the mechanism of efficient incorporation of Mg in GaN films during growth by plasma-assisted molecular beam epitaxy. It is found that Mg incorporates more efficiently during growth of GaN films at high temperatures (770 deg. C) under extreme Ga-rich conditions. We propose that this result ...
Lithium gallate (LiGaO2) has an orthorhombic crystal structure that can be described as a wurtzite-like structure. The M-plane basis of GaN wurtzite structure is nearly matched to the selected lattice axes of pseudo-hexagonal LiGaO2. M-plane GaN thin films have been grown on ?-LiGaO2 (100) substrates by plasma-assisted molecular-beam ...
Inlustra Technologies with subcontractor U.C. Santa Barbara conducted a project with the principle goal of demonstrating high internal quantum efficiency blue (430 nm) and green (540nm) light emitting diodes (LEDs) on low-defect density non-polar GaN wafers. Inlustra pursued the fabrication of smooth thick a-plane and m-plane GaN ...
Properties of GaN grown at high rates on sapphire and on 6H�SiC S. Fischer,a) C. Wetzel,b) W. L on 0001 sapphire and on 0001 6H�SiC were compared in terms of their structural and optical properties to deliver thick GaN films of high quality.5 Currently, bulk GaN crystals with dimensions of only a few
by gas-source molecular-beam epitaxy. GaN growth using thermal ammonia and Ga C2H5 3 exhibited a rapidly The ion-current density at the sample is 3 1014 cm 2 s 1 . All GaN films are deposited with excess ammonia with ions followed by growth from ammonia and TEG. FIG. 4. Comparison of deposited GaN versus time for ...
on the sapphire TABLE I. Physical properties of GaN and ZnO. Properties Molecular weight Density (mg/cm3) Crystal analogous with those of GaN. With a ZnO buffer layer, the reproducibility of growing GaN single crystal tempera- ture,' it is extremely difficult to grow a large-scale "bulk" single crystal of GaN. ...
Deposition of CVD diamond onto GaN P.W. May a,*, H.Y. Tsai b , W.N. Wang c , J.A. Smith a a School performed to deposit continuous layers of CVD diamond onto epitaxial GaN films. Such diamond coatings would be useful to enhance the light extraction and heat dissipation in GaN LEDs. A hot filament CVD reactor
We report the growth conditions necessary for highly oriented wurtzite GaN films on (111) GaAs, and single crystal GaN films on (111) GaAs using AlN buffer layers. The GaN films and AlN buffers are grown using rf reactive magnetron sputter deposition. Oriented basal plane ...
The microstructural and luminescent properties of sputtered GaN thin films preiiradiated and ?-ray irradiated were systematically investigated. Analytical results revealed that the increasing doses of ? rays could enhance the occurrence of more nitrogen vacancies, which not only created a prominent deep level luminescence but also destroyed the ...
Although it is known that GaN tend to decompose in hydrogen environments, there has been few investigations in hydrogen etch of GaN. This study performs a systematic research on hydrogen etch of GaN under various pressures. It is observed that hydrogen atoms initially etch into GaN to form pinholes. Dislocations ...
Microphotoluminescence spectroscopy is used to investigate local strain in GaN films grown on c-sapphire with CrN buffer, where the CrN buffer is partly etched. Biaxial compressive strain dominates GaN films grown on CrN buffer/c-plane sapphire. The emission energies of D0X, FXA, and FXA-1LO emission lines shift ...
The availability of reliable and quick methods to determine defect density and polarity in GaN films is of great interest.Photoelectrochemical (PEC) and hot wet etching using both H3PO4 and molten KOH have been used to estimate the defect density in GaN by producing at the surface defect sites free standing whiskers and hexagonal pits, ...
The GaN material has good semiconductor and peizoelectric nature. It is used to realize various electronic, optical and surface acoustic wave (SAW) devices with high power and high frequency. In this paper, we study basic characteristics of a GaN ultraviolet (UV) sensor based on effect of acoustic wave charge transfer on GaN epitaxial ...
TiO2 and GaN thin film were successfully fabricated on Si substrate by a sol-gel method. However, thin films did not show crystallinity structure without any treatment. To increase the crystallinity of thin films, TiO2 thin films were annealed while GaN was annealed under ...
Thin film bulk acoustic wave resonators (FBAR) using piezoelectric AlN, ZnO and GaN thin films have attracted extensive research activities in the past years. Highly c-axis oriented (normal-plane orientation) binary semiconductor piezoelectric thin films ...
Photocurrent decay in GaN thin films was studied in the time span from a few seconds to several days. The persistent photoconductivity (PPC) behavior was observed not only in Mg-doped {ital p}-type GaN films but also in undoped {ital n}-type GaN films. The photoconductivity ...
Single-phase hexangonal wurtzite GaN nanoparticles and GaN thin film were prepared by the sol-gel techniqiue.using Ga(NO3)3. For GaN thin films, Ga(NO3)3 was hydrolyzed with ethanol and acetic acid and aged for one day. GaO(OH) thin layer was fabricated with spin-coating and heating at 200 ...
Our experimental results using reactive magnetron sputtering, combined with earlier literature, are used to understand the thermodynamic and kinetic processes involved in GaN film growth and the limiting factors involved in the incorporation of nitrogen during the growth process. We show that GaN films fabricated ...
In organometallic vapor phase epitaxial growth of Gail on sapphire, the role of the low- temperature-deposited interlayers inserted between high-temperature-grown GaN layers was investigated by in situ stress measurement, X-ray diffraction, and transmission electron microscopy. Insertion of a series of low temperature GaN interlayers reduces the ...
GaN films on sapphire substrates are obtained using the metal-organic chemical vapor deposition growth technique. We present two methods to reduce the GaN wafer bowing caused by the mismatch of the thermal expansion coefficients (TECs) between the film and the substrate. The first method is to use coating materials ...
Thick GaN films were grown on sapphire in a home-made vertical HVPE reactor. Effect of nucleation treatments on the properties of GaN films was investigated, including the nitridation of sapphire, low temperature GaN buffer and MOCVD-template. Various material characterization techniques, ...
Visible and near-infrared (NIR) light-emitting thin-film electroluminescent gallium nitride (GaN) doped with rare earth (RE) elements was studied. The rare-earth-doped GaN thin films were prepared by radio frequency (RF) planar magnetron co-sputtering of separate targets consisting of a GaN ...
A unique apparatus incorporating four independent supersonic jets and a substrate transfer mechanism for the growth of thin films in an ultrahigh vacuum chamber is under construction. The four jets are the continuous flow type and can be turned on and off with computer control allowing precise control of the reactants for atomic layer epitaxy. The supersonic jet configuration ...
. Zinc oxide (ZnO) and gallium nitride (GaN) are wide bandgap semi conductors applicable to light emitting diodes (LEDs) and laser diodes (LDs) with wavelengths ranging from ultraviolet to blue light. Now ZnO and GaN are key ma terials for optoelectronic device applications and their applications are being rapidly expanded to lots of other technology ...
Intermittent gas supplies for hot-mesh chemical vapor deposition (CVD) for the epitaxial growth of gallium nitride (GaN) films were investigated to improve film crystallinity and optical properties. The GaN films were deposited on SiC/Si(111) substrates using an alternating-source gas supply or ...
Doping characteristics of Mg and Be in GaN films grown using a new single GaN precursor via molecular beam epitaxy were investigated. X-ray diffraction analysis confirmed that the GaN lattice expands or contracts with Mg or Be doping due to their differences in the size with respect to Ga. The c-axis oriented ...
The nucleation of GaN thin films on GaAs is investigated for growth at 620 "C. An rf plasma cell is used to generate chemically active nitrogen from N2. An arsenic flux is used in the first eight monolayer of nitride growth to enhance nucleation of the cubic phase. Subsequent growth does not require an As flux to preserve the cubic phase. The nucleation of ...
The mechanical properties of GaN are examined by microcompression. The Young's modulus and compressive yield stress in microscale are directly measured to be ~226 and 10 GPa, comparable to the modulus (~272 GPa) and hardness (15 GPa) measured by nanoindentation. The Raman spectrum measurements and transmission electron microscopy observations reveal that the residual stress in ...
The use of AlN epitaxial films deposited on vicinal Si(111) as templates for the growth of GaN quantum dots is investigated by transmission electron microscopy and atomic force microscopy. It is found that the substrate vicinality induces both a slight tilt of the AlN (0001) direction with respect to the [111] direction and a step bunching mechanism. As a ...
GaN is a promising material not only for electronic devices but also for photocatalysts. Synthesis of GaN nanocrystal is a key issue to improve performance for these applications. In the present study, GaN nanocrystallites have been synthesized by pulsed laser ablation (PLA), where safe and inactive pure N2 gases were used as reactive ...
The results of comparative studies of the growth kinetics of the GaN layers of different polarity during ammonia molecular beam epitaxy and plasma-assisted molecular beam epitaxy (PA MBE) of nitrogen with the use of sapphire substrates and GaN(0001-bar)/c-Al{sub 2}O{sub 3} templates grown by gas-phase epitaxy from metalorganic compounds are presented. The ...
We report here a double-sided process for the fabrication of a comb-drive GaN micro-mirror on a GaN-on-silicon platform. A silicon substrate is first patterned from the backside and removed by deep reactive ion etching, resulting in totally suspended GaN slabs. GaN microstructures including the torsion bars, movable combs and mirror ...
This paper presents method for facets passivation of high power lasers GaAl As using thin films of AIN and GaN formed by reactive sputtering at low temperature. GaN has been chosen due to its exceptional stability at high temperatures and resistance against attack. GaN is insoluble in acids. Layers of ...
GaN grown by metal-organic chemical vapor deposition was coimplanted with Gd+ ions with energy of 155 keV and dose of 2.75�1010 cm-2 and Si4+ ions with energies of 5 and 40 keV and corresponding doses of 8�1011 and 3.6�1012 cm-2. The implanted samples were not annealed before characterization. X-ray diffraction measurements revealed that the implanted ...
The dependence of polar direction of GaN film on growth conditions has been investigated by changing either the group-V/group-III ratio (V/III ratio) in supplying the source gas or the deposition rate. GaN films were deposited on a nitrided sapphire by two-step metalorganic chemical vapor deposition. The surface ...
N HEMTs are good candidates for high power microwave and millimeter wave applications. Si GaAs InP 4HUNIVERSITY OF CALIFORNIA Santa Barbara MMICs using GaN HEMTs and Thin-Film BST Capacitors ____________________________________________ Robert A. York, Committee Chair September 2005 #12;MMICs using GaN HEMTs and ...
DC blocking capacitors. We developed a valid method of integration BST film in active GaN HEMT) GaN HEMT oscillator using BST DC blocking capacitors. #12; circuit [2]. The oscillator, based on AlGaN/GaN HEMT, delivers 20.7 dBm output power at 5 GHz with phase
.38 . These coordinates correspond to Planck emission at a temperature of 3000 K and a color rendering index of 85Three-color integration on rare-earth-doped GaN electroluminescent thin films Y. Q. Wang and A. J June 2002; accepted 25 November 2002 We have realized full color integration on rare-earth-doped thin
Epitaxial growth GaN films at reasonable rates and at grazing incidence and using conditions similar to those employed for growth in a low energy electron microscope (LEEM) have been achieved. Preliminary phtoluminescence studies showed near band edge lum...
GaN films were doped with Eu to a concentration of0.12 at. % during growth at 800 C by molecular beam epitaxy, with the Eu cell temperature held constant at 470 C. All samples were postannealed at 675 C. The films exhibited strong photoluminescence PL in ...
Gallium nitride films have been grown on 6H-SiC substrates employing a new form of selective lateral epitaxy, namely pendeo-epitaxy. This technique forces regrowth to start exclusively on sidewalls of GaN seed structures. Both discrete pendeo-epitaxial mi...
Single-crystal GaN films grown on AlN buffer layers previously deposited on 6H-SiC(0001) were studied for radiation damage and its recovery using Rutherford backscattering/channeling, photoluminescence, and cross-sectional TEM. The highest fluence of (1e1...
. Generally, GaN:RE films are grown by molecular beam epitaxy (MBE) using metallic sources for the REs improvements have been reported in the MBE growth of GaAs15) and GaN16) with the equivalent techniqueN by interrupted growth MBE. Recently, a similar MBE pulsed growth technique -- metal modulated epitaxy (MME
Plain-view bright-field transmission electron microscopy and cathodoluminescence are used to study the defect structure of GaN films grown by hydride vapor-phase epitaxy on porous and nonporous SiC substrates. It is shown that the use of porous substrate reduces the mosaic structure of the films. This finding supports the compliance of ...
mechanisms of 0001 wurtzite GaN films from thermalized atomic gallium and nitrogen fluxes. The crystallinity and stoichiometry of the deposited wurtzite lattice struc- tures were determined as a function of growth temperature on wurtzite phase promoting substrates. The atomic assembly mechanisms responsible for these effects have been
The authors report the growth kinetics of GaN thin films using the single source precursor bisazido dimethylaminopropyl gallium (BAZIGA) in a cold wall reactor. Transparent, smooth, epitaxial (FWHM of the {alpha}-GaN 0002 rocking curve = 129.6 arcsec) and stoichiometric GaN films were grown on c-plane Al{sub ...
... hydrogen in Mg-doped films after their growth. ... we investigate the RIE of GaN in various ... Gallium nitride, Molecular beam epitaxy, Electron cyclotron ...
GaN exists in both wurtzite and zinc-blende phases and the growths of the two on its (0001) or (111) surfaces are achieved by choosing proper deposition conditions of molecular-beam epitaxy (MBE). At low substrate temperatures but high gallium fluxes, metastable zinc-blende GaN films are obtained, whereas at high temperatures and/or ...
A characterization of the Si impurity in GaN is performed by Raman spectroscopy. Applying hydrostatic pressure up to 25 GPa the authors study the behavior of the LO phonon-plasmon mode in a series of high mobility Si doped GaN films. In contrast to earlier results on unintentionally doped bulk GaN crystals no ...
Selective area epitaxy (SAE) of InGaN quantum wells on GaN micropyramids were grown by using metalorganic chemical vapor deposition (MOCVD). The pattern prepared for the SAE was fabricated by the deposition of 300 nm SiO2 film on n-type GaN substrate by using plasma enhanced chemical vapor deposition (PECVD) and followed by ...
The synthesis and characterization of GaN thick layers are reported in this paper. The layers were prepared by sublimation sandwich method (SSM). Powder of GaN was used as the source of gallium and ammonia was used as the source of nitrogen. Sapphire with 3 ?m GaN thin film grown by MOCVD was used as the substrate. ...
The paper reports on plasma-assisted MBE growth of good quality N-face GaN layers directly on c-Al2O3 substrates. Growth kinetics under different growth conditions (substrate temperature, Ga to activated nitrogen flux ratio, etc.) during deposition of GaN(0001) and GaN(000bar1) both by the ammonia-based MBE or plasma-assisted MBE was ...
The influence of the composition of the low-temperature GaN buffer layer on the structural, electrical, and optical properties of the subsequently grown GaN epilayer by molecular beam epitaxy is investigated. It is found that decreasing the N/Ga flux ratio during the buffer layer growth yields excess Ga in the buffer layer. GaN ...
GaN films have been deposited by reactive sputtering in nitrogen gas at pressures from 0.08 to 2.70 Pa with and without the addition of hydrogen gas. X-ray diffraction (XRD), Fourier transform infrared (FTIR), optical absorption, and photoluminescence (PL) spectroscopy have been used to characterize the sputter-deposited GaN ...
We have compared epitaxial growth of GaN films on 6H-SiC(0001)-({radical}(3)x{radical}(3))R30 deg. -Ga and on (0001)-sapphire. Predeposited Ga layers were nitrided by ion beam assisted molecular beam epitaxy. Whereas on SiC the initially deposited Ga covers the substrate surface completely, on sapphire only Ga droplets are present. The different ...
We report a unique low-temperature growth method for epitaxial GaN on Si(111) substrates via a ZrB{sub 2}(0001) buffer layer. The method utilizes the decomposition of a single gas-source precursor (D{sub 2}GaN{sub 3}){sub 3} on the substrate surface to form GaN. The film growth process is further promoted by irradiation of ultraviolet ...
nitride GaN thin films with a wurtzite structure were grown on fused silica FS substrates by pulsed laser ablation of a liquid gallium target in the presence of ammonia gas. X-ray diffraction measurement shows a single c-axis orientation for the GaN film grown with a thin 1000 � zinc oxide ZnO ...
Typical perovskite oxides SrTiO? (STO) and PbZr?.??Ti?.??O? (PZT) were fabricated on GaN semiconductor substrates by pulsed laser deposition. STO and PZT films were deposited on bare GaN, TiO?, and MgO-buffered GaN. The effects of TiO? and MgO buffer-layers on the orientations and electric properties of the ...
Low-temperature interlayer InN was used to fabricate GaN thin film on Si (1 1 1) substrate by molecular beam epitaxy method. Surface scanning electron microscopy image shows a uniform polycrystalline structure. Transmission electron microscopy and high-angle annular detector dark-field scanning transmission electron microscopy images indicate column ...
GaN is one of the most important targets among the wide-band-gap materials used in optical devices. In 1993 the first high brightness blue light emitting diodes and violet lasers diodes were developed based on III-V nitride. Those devices were a result of the successful growth of GaN of sufficient quality onto a sapphire substrate. Si(111) is considered to ...
