Effect of Heat Treatment on Structural and Optoelectronic Properties of GaN Epilayers

2010 ◽  
Vol 663-665 ◽  
pp. 1314-1317
Author(s):  
Jun Ping Mei ◽  
Xin Jian Xie ◽  
Qiu Yan Hao ◽  
Xin Liu ◽  
Jin Jin Xu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Annealing Temperature ◽  
Chemical Vapor ◽  
Xrd Analysis ◽  
Optoelectronic Properties ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Metal Organic ◽  
Hall Effect Measurements ◽  
Structural And Optoelectronic Properties

GaN epilayers were grown on sapphire by metal-organic chemical vapor deposition (MOCVD), and the samples were annealed with rapid thermal processor (RTP) at 650, 750, 850 and 950oC, respectively. The effect of heat treatment on structural and optoelectronic properties of GaN epilayers was investigated. X-ray diffraction (XRD) analysis shows that the full width at half maximum (FWHM) of the rocking curves becomes smaller as the annealing temperature increases. Photoluminescence (PL) spectra at room temperature demonstrate that the yellow band decreases with the increase of annealing temperature. Hall-effect measurements reveal that carrier concentration of the GaN epilayers raise with the increase of annealing temperature. The results suggest that the structural and optoelectronic properties of GaN epilayers could be significantly improved by heat treatment.

Epitaxial Growth and Characterization of Nonpolar A-Plane AlGaN-Based Multiple Quantum Wells

2018 ◽  
Vol 934 ◽  
pp. 8-12
Author(s):  
Jian Guo Zhao ◽  
Xiong Zhang ◽  
Jia Qi He ◽  
Shuai Chen ◽  
Zi Li Wu ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Chemical Vapor ◽  
Multiple Quantum Wells ◽  
Modulation Method ◽  
Duty Ratio ◽  
Organic Chemical ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Metal Organic

A serious of non-polar a-plane AlGaN-based multiple quantum wells (MQWs) were successfully grown on the semi-polar r-plane sapphire substrate with metal organic chemical vapor deposition technology. Intense MQWs-related emission peaks at an emission wavelength covered from 277-294 nm were observed based on the photoluminescence measurement. It was found that the employment of the trimethyl-aluminum (TMAl) flow duty-ratio modulation method which was developed based on the two-way pulsed-flows growth technique played a crucial role to control the Al composition of the non-polar a-plane AlGaN epi-layers. The non-polar a-plane AlGaN-based MQWs were deposited with the new developed TMAl flow duty-ratio modulation technique. Evident-3th order X-ray diffraction (XRD) satellite peak was observed from the high resolution-XRD measurement, proving the successful growth of non-polar a-plane AlGaN-based MQWs with abrupt hetero-interfaces.

Epitaxial Growth of InAlN/GaN Heterostructures on Silicon Substrates in a Single Wafer Rotating Disk MOCVD Reactor

MRS Advances ◽  
2017 ◽  
Vol 2 (5) ◽  
pp. 329-334 ◽  
Author(s):  
Jing Lu ◽  
Jie Su ◽  
Ronald Arif ◽  
George D. Papasouliotis ◽  
Ajit Paranjpe
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
Rotating Disk ◽  
High Electron Mobility Transistor ◽  
Xrd Analysis ◽  
Structural Quality ◽  
Organic Chemical ◽  
High Electron ◽  
Mocvd Reactor ◽  
Metal Organic

ABSTRACTInAlN films and InAlN/GaN high electron mobility transistor (HEMT) structures were demonstrated on 150mm <111> Si using Veeco’s Propel single wafer metal-organic chemical vapor deposition (MOCVD) system. Smooth surfaces with root mean square (rms) roughness of 0.68 nm were observed in a 5x5 μm2 atomic force microscope (AFM) scan. X-ray diffraction (XRD) analysis shows well-defined layer peaks and fringes, indicating good structural quality and abrupt layer interfaces. Thickness uniformity of InAlN is 0.87%, 1σ, for a 7-point XRD measurement across the 150 mm wafer. Secondary ion mass spectrometry (SIMS) analysis confirms the uniform indium depth profile and the presence of abrupt layer interfaces. Negligible Ga (< 100 ppm, atomic) incorporation was detected in the InAlN bulk film. Film sheet resistance of 230Ω/sq, charge of 2.1×1013/cm2, and mobility of 1270 cm2/V.s were measured on a prototypical InAlN/GaN HEMT structure comprising a 10 nm-thick, 17% indium, InAlN barrier.

Aluminizing for TiAl turbocharger rotor by reduced pressure metal-organic chemical vapor deposition (RPMOCVD) and the efficiency of its oxidation resistance

1994 ◽  
Vol 9 (8) ◽  
pp. 1984-1989 ◽  
Author(s):  
Takakazu Suzuki ◽  
Hiroyuki Umehara ◽  
Haruki Hino
Keyword(s):  
Heat Treatment ◽  
Chemical Vapor Deposition ◽  
Oxidation Resistance ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Turbine Rotor ◽  
Organic Chemical ◽  
Reduced Pressure ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

A complex-shaped TiAl turbine rotor has been uniformly aluminized by a metal-organic chemical vapor deposition under reduced pressure (RPMOCVD), and a thick TiAl3 layer, which affects the oxidation resistance, can be formed on the surface by subsequent heat treatment. The oxidation resistance has been studied with an oxidation test at 1173 K for 760 ks in static air. The microstructure has been investigated by SEM, EPMA, AES, and XRD. A heat treatment at above 933 K, which is the melting point of Al, is required to enhance the oxidation resistance of TiAl. With increasing the surface roughness of TiAl, the formation of TiAl3 increases, and consequently the oxidation resistance is more improved.

CRYSTAL STRUCTURE AND PROPERTIES OF CU-AL-O THIN FILMS

2002 ◽  
Vol 16 (01n02) ◽  
pp. 308-313 ◽  
Author(s):  
YUE WANG ◽  
HAO GONG ◽  
LING LIU
Keyword(s):  
Thin Films ◽  
Transparent Conducting Oxide ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Transparent Conducting ◽  
Potential Applications ◽  
Metal Organic ◽  
Hall Effect Measurements ◽  
Organic Precursors ◽  
P Type

P-type transparent conducting oxide thin films have attracted much attention due to their potential applications in novel transparent p-n junction devices. In this work, the transparent conducting Cu-Al-O thin films were prepared by the plasma enhanced chemical vapor deposition using metal organic precursors of Cu(acac) 2 and Al(acac) 3 (acac=acetylacetonate) while the substrate temperature was varied from 700 to 800°C. The x-ray diffraction and SEM results are analyzed to investigate the structure of the as-deposited and annealed films. The films contain metal copper and small grains of CuAlO 2. After annealing, metal copper turned into CuO . Hall effect measurements reveal that these films are p-type semiconductors and the film conductivity increased with the growth temperature.

scholarly journals Properties and Orientation of Antiferroelectric Lead Zirconate Thin Films Grown by MOCVD

1998 ◽  
Vol 541 ◽  
Author(s):  
Nan Chen ◽  
G. R. Bai ◽  
O. Auciello ◽  
R. E. Koritala ◽  
M. T. Lanagan
Keyword(s):  
Thin Films ◽  
Chemical Vapor ◽  
Lead Zirconate ◽  
Dielectric Constants ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Antiferroelectric Phase ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractSingle-phase polycrystalline PbZrO3 (PZ) thin films, 3000-6000 A thick, have been grown by metal-organic chemical vapor deposition (MOCVD) on (111)Pt/Ti/SiO2/Si substrates at ≍525°C. X-ray diffraction analysis indicated that the PZ films grown on (111)Pt/Ti/SiO2/Si (Pt/Tgi/Si) showed preferred pseudocubic (110) orientation. In contrast, PZ films grown on 150 A thick PbTiO3 (PT) template layers exhibited a pseudocubic (100) preferred orientation, and PZ films deposited on TiO2 template layers consisted of randomly oriented grains. The PZ films grown on Pt/Ti/Si with or without templates exhibited dielectric constants of 120-200 and loss tangents of 0.01-0.0. The PZ films with (110) orientation exhibited an electric-field-inducedtransformation from the antiferroelectric phase to the ferroelectric phase with a polarization of ≍34 µC/cm2, and the energy that was stored during switching was 7.1 J/cm3. The field needed to excite the ferroelectric state and that needed to revert to the antiferroelectric state were 50 and 250 kV/cm, respectively. Relationships between the MOCVD processing and the film microstructure and properties are discussed.

Investigation of Oxygen Vacancies in Micro-Patterned PZT Thin Films Using Raman Spectroscopy

2009 ◽  
Vol 421-422 ◽  
pp. 135-138
Author(s):  
Ken Nishida ◽  
Minoru Osada ◽  
Shintaro Yokoyama ◽  
Takafumi Kamo ◽  
Takashi Fujisawa ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Oxygen Vacancies ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Vapor Phase Deposition ◽  
Pzt Films ◽  
Metal Organic

Micro-patterned Pb(Zr,Ti)O3 (PZT) films with dot-pattern were grown by metal organic chemical vapor phase deposition (MOCVD). Micro-patterned Pb(Zr,Ti)O3 (PZT) films were formed on dot-patterned SrRuO3 (SRO) buffer layer that was prepared by MOCVD through the metal mask on (111)Pt/Ti/SiO2/Si substrate. The orientation of dot-patterned PZT films was ascertained by the micro-beam x-ray diffraction (XRD) and their crystallinity was characterized by Raman spectroscopy. It was found that PZT films were oriented to (111) on dot-pattern, while (100)/(001) out of dot-pattern and the amount of oxygen vacancies at the circumference of the dot-pattern were larger than that of center of dot-pattern.

Preparation and Characterization of High Mobility Nb-Doped SnO2 Transparent Conducting Films

2020 ◽  
Vol 993 ◽  
pp. 869-875
Author(s):  
Lin An He ◽  
Cai Na Luan ◽  
Di Wang ◽  
Yong Le ◽  
Jin Ma
Keyword(s):  
Hall Mobility ◽  
High Mobility ◽  
Chemical Vapor ◽  
Growth Direction ◽  
Light Transmittance ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Metal Organic ◽  
Good Transparency

Metal organic chemical vapor deposition (MOCVD) was employed for the preparation of niobium (Nb)-doped SnO2 films on SiO2 glass substrates. The structure, optical and electrical properties of the Nb-doped SnO2 films were systemically studied. The X-ray diffraction results indicated that the polycrystalline rutile SnO2 films were obtained with a preferred SnO2 [110] growth direction. Among which, the 5.4 at.% Nb-doped SnO2 film showed the lowest resistivity of 1.0×10-3 Ω∙cm and the highest Hall mobility of 74 cm2∙V-1∙s-1. The average visible light transmittance of the 5.4 at.% Nb-doped SnO2 sample was more than 79%. The obtained Nb-doped SnO2 films exhibited low resistivity, high Hall mobility and good transparency, which might have wide applications in electric and photoelectric devices.

CRYSTALLINE PHASE SEPARATION OF InGaN LAYER MATERIALS PREPARED BY METALORGANIC CHEMICAL VAPOR DEPOSITION

2002 ◽  
Vol 16 (01n02) ◽  
pp. 268-274
Author(s):  
ZHE CHUAN FENG ◽  
TZUEN RONG YANG ◽  
RONG LIU ◽  
ANDREW THYE SHEN WEE
Keyword(s):  
Chemical Vapor Deposition ◽  
Phase Separation ◽  
Vapor Deposition ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
Excitation Power ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Uniform Distributions ◽  
Metal Organic

Zn -doped InGaN thin films were epitaxied on the top of 1-2 micron thick GaN grown on sapphire by metal organic chemical vapor deposition, and studied by a combination of high resolution X-ray diffraction (HR-XRD), micro-photoluminescence (PL) and secondary ion mass spectrometry (SIMS). HRXRD exhibits a GaN band and a single band from InGaN for samples without phase separation, but two or more InGaN bands corresponding to different x(In) for samples with phase separation. PL emissions from InGaN spread over a wider energy ranges and were modulated by the interference effects. Excitation power dependence measurements reveal 2-sets of PL emissions for samples with phase separation, but only 1-set for samples without phase separation. SIMS data showed that phase separated InGaN:Zn films possess a high Zn concentration near the InGaN-GaN interface and non-uniform distributions of In and Zn contents, which are in contrast with data from InGaN:Zn films with no In -phase separation. These interesting results are correlated to the growth process and microstructural properties.

High-operating-temperature MWIR photodetector based on a InAs/GaSb superlattice grown by MOCVD

2022 ◽  
Vol 43 (1) ◽  
pp. 012303
Author(s):  
Xiujun Hao ◽  
Yan Teng ◽  
He Zhu ◽  
Jiafeng Liu ◽  
Hong Zhu ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Operating Temperature ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Cutoff Wavelength ◽  
X Ray Diffraction ◽  
High Crystalline Quality ◽  
High Operating Temperature ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Abstract We demonstrate a high-operating-temperature (HOT) mid-wavelength InAs/GaSb superlattice heterojunction infrared photodetector grown by metal–organic chemical vapor deposition. High crystalline quality and the near-zero lattice mismatch of a InAs/GaSb superlattice on an InAs substrate were evidenced by high-resolution X-ray diffraction. At a bias voltage of –0.1 V and an operating temperature of 200 K, the device exhibited a 50% cutoff wavelength of ~ 4.9 μm, a dark current density of 0.012 A/cm2, and a peak specific detectivity of 2.3 × 109 cm·Hz1/2 /W.

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