Synthesis of GaN Nanostructures at Low Temperatures by Chemical Vapor Deposition

2008 ◽  
Vol 1080 ◽  
Author(s):  
Christopher Y. Chow ◽  
Balaji Raghothamachar ◽  
Joan J. Carvajal ◽  
Hui Chen ◽  
Michael Dudley
Keyword(s):  
Gallium Nitride ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Synthesis Process ◽  
Metal Catalyst ◽  
Ni Catalyst ◽  
Tem Analysis ◽  
Gas Molecules

ABSTRACTIn this study, we report on the synthesis of gallium nitride (GaN) nanopowders on boron nitride (BN) substrates both with and without the use of metal catalyst by chemical vapor deposition (CVD). The synthesis process is based on the reaction between gallium (Ga) atoms from the decomposition of gallium acetylacetonate and ammonia (NH3) gas molecules. Using this process, gallium nitride (GaN) nanopowders have been synthesized at temperatures as low as 400°C, lower than previously reported. The grown nanopowders were characterized by SEM, EDX and TEM. Analysis reveals that higher yields were obtained by treating the BN substrates with Ni catalyst. Experiments to study the effect of growth conditions on the morphology of the nanopowders and analyze the growth mechanism are ongoing.

SiC Nanowires Grown on 4H-SiC Substrates by Chemical Vapor Deposition

2010 ◽  
Vol 645-648 ◽  
pp. 187-190 ◽  
Author(s):  
Bharat Krishnan ◽  
Siva Prasad Kotamraju ◽  
Siddarth G. Sundaresan ◽  
Yaroslav Koshka
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Metal Catalyst ◽  
X Ray Diffraction ◽  
Sic Nanowires ◽  
Vls Growth ◽  
Growth Experiments

Growth of SiC nanowires on commercial 4H-SiC substrates by chemical vapor deposition is reported. The main objective was to explore a possibility of reproducing the substrate polytype in order to obtain SiC NWs specifically composed of the hexagonal 4H-SiC polytype. The growth experiments were conducted in a hot-wall CVD reactor with H2 as the carrier gas, SiCl4 as the silicon source, and CH3Cl as the carbon source. Vapor-liquid-solid (VLS) growth mode was enabled by using metal nano-particle on the surface of the 4H-SiC substrates. Formation of nanowires or bigger nano-cones was achieved depending on the temperature and the metal catalyst used. Only SiC phase with no presence of Si was confirmed by X-ray diffraction for the growth temperatures down to 1050°C. The low temperature photoluminescence spectra measured on as-grown NWs showed clear 4H-SiC nitrogen bound excitons in some of the samples, particularly when in-situ N2 doping was used. The density of stacking faults detected by TEM strongly depended on the growth conditions.

Fabrication Gallium Nitride (GaN) Nanowires by Thermal Chemical Vapor Deposition (TCVD) Technique

2014 ◽  
Vol 925 ◽  
pp. 450-454 ◽  
Author(s):  
Qahtan Nofan Abdullah ◽  
Fong Kwong Yam ◽  
Yushamdan Yusof ◽  
Hassan Zainuriah
Keyword(s):  
Gallium Nitride ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Metal Catalyst ◽  
Thermal Chemical Vapor Deposition ◽  
Gan Nanowires ◽  
Diffraction Peaks ◽  
Low Dimensional ◽  
Plane Diffraction

In this paper, low-dimensional gallium nitride (GaN) nanowires have been successfully grown on silicon substrate through thermal chemical vapor deposition (TCVD); no metal catalyst was used to assist growth of nanostructure. A high purity of gallium nitride powder was used as a starting material, evaporated at 1150OC for 2 hour and then annealing at temperature 1000OC under stable flow of ammonia (NH3) gas in horizontal quartz tube. The morphological investigation and crystalline and orientations growth of GaN nanostructure were carried out by employing scanning electron microscopy (SEM), high resolution X-ray diffractmeter (HRXRD). A room temperature micro-Raman spectrum were employed to study the optical properties and crystalline defects. XRD shows the diffraction peaks located at 2θ= 32.43, 34.57, 36.89, 48.05, 57.83, 63.62, 69.02, and 70.470corresponding to the (100 ), (002), (101), (102), (110) , (103),(112 ) and (201) plane diffraction of GaN structure. These results revealed that the diffraction peaks can be attributed to hexagonal GaN phase with lattice constant of a = 3.190 A° and c = 5.1890 A°. Here we report on the growth of GaN nanowires on Si (111) substrate by CVD . This technique is much simpler and cheaper than such techniques as MBE, MOCVD and HVPE.

scholarly journals Laser‐Assisted Metal–Organic Chemical Vapor Deposition of Gallium Nitride

2021 ◽  
Vol 15 (6) ◽  
pp. 2170024
Author(s):  
Yuxuan Zhang ◽  
Zhaoying Chen ◽  
Kaitian Zhang ◽  
Zixuan Feng ◽  
Hongping Zhao
Keyword(s):  
Gallium Nitride ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Experimental Study of the Effect of Precursor Composition On the Microstructure of Gallium Nitride Thin Films Grown by the MOCVD Process

2021 ◽  
Author(s):  
Omar D. Jumaah ◽  
Yogesh Jaluria
Keyword(s):  
Thin Films ◽  
Gallium Nitride ◽  
Chemical Vapor Deposition ◽  
Deposition Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Transport Processes ◽  
Carrier Gas ◽  
Precursor Composition

Abstract Chemical vapor deposition (CVD) is a widely used manufacturing process for obtaining thin films of materials like silicon, silicon carbide, graphene and gallium nitride that are employed in the fabrication of electronic and optical devices. Gallium nitride (GaN) thin films are attractive materials for manufacturing optoelectronic device applications due to their wide band gap and superb optoelectronic performance. The reliability and durability of the devices depend on the quality of the thin films. The metal-organic chemical vapor deposition (MOCVD) process is a common technique used to fabricate high-quality GaN thin films. The deposition rate and uniformity of thin films are determined by the thermal transport processes and chemical reactions occurring in the reactor, and are manipulated by controlling the operating conditions and the reactor geometrical configuration. In this study, the epitaxial growth of GaN thin films on sapphire (AL2O3) substrates is carried out in two commercial MOCVD systems. This paper focuses on the composition of the precursor and the carrier gases, since earlier studies have shown the importance of precursor composition. The results show that the flow rate of trimethylgallium (TMG), which is the main ingredient in the process, has a significant effect on the deposition rate and uniformity of the films. Also the carrier gas plays an important role in deposition rate and uniformity. Thus, the use of an appropriate mixture of hydrogen and nitrogen as the carrier gas can improve the deposition rate and quality of GaN thin films.

scholarly journals Catalytic Growth of Gallium Nitride Nanowires on Wet Chemically Etched Substrates by Chemical Vapor Deposition

ACS Omega ◽  
2019 ◽  
Vol 4 (12) ◽  
pp. 14772-14779 ◽  
Author(s):  
Sanjay Sankaranarayanan ◽  
Prabakaran Kandasamy ◽  
Baskar Krishnan
Keyword(s):  
Gallium Nitride ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Catalytic Growth

Variation of Size and Alignment in Carbon Nanotubes by Changes of Growth Condition

2001 ◽  
Vol 7 (S2) ◽  
pp. 428-429
Author(s):  
Paula P. Provencio ◽  
Michael P. Siegal ◽  
Donald L. Overmyer
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Dwell Time ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Nitrogen Atmosphere ◽  
Ni Catalyst ◽  
Multiwall Carbon Nanotube ◽  
Catalyst Layers

Carbon nanotubes have previously been grown on Ni coated glass, aligned vertical to the substrate over a multi-centimeter square area1. Under vacuum, the aligned nanotubes were grown below 666° C (strain point of the best display glass) by plasma-enhanced hot filament, chemical vapor deposition. It was found, the size and alignment of the nanotubes could be varied by changing the dwell time and the thickness of the catalytic Ni layer by plasma etching. in more recent, ongoing studies, the size of carbon nanotubes is varied by changing the growth temperature and dwell time under acetylene/nitrogen atmosphere using chemical vapor deposition onto W and Ni coated Si.Multiwall carbon nanotube films are grown using a thermally-activated chemical vapor deposition process. Thin Ni catalyst layers are sputtered onto W-coated Si(100) and reduced in a 600°C CO anneal. Nanotubes then grow at temperatures ranging from 630 - 790°C in an acetylene/nitrogen mixture.

scholarly journals Optimization of Carbon Nanotube-Coated Monolith by Direct Liquid Injection Chemical Vapor Deposition Based on Taguchi Method

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 67 ◽  
Author(s):  
Omar Qistina ◽  
Ali Salmiaton ◽  
Thomas S.Y. Choong ◽  
Yun Hin Taufiq-Yap ◽  
Shamsul Izhar
Keyword(s):  
Chemical Vapor Deposition ◽  
Optimum Condition ◽  
Taguchi Method ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Ni Catalyst ◽  
Carbon Yield ◽  
X Ray ◽  
Liquid Injection ◽  
Direct Liquid Injection

Carbon nanotubes (CNTs) have the potential to act as a catalyst support in many sciences and engineering fields due to their outstanding properties. The CNT-coated monolith was synthesized over a highly active Ni catalyst using direct liquid injection chemical vapor deposition (CVD). The aim was to study the optimum condition for synthesizing CNT-coated monoliths. The Taguchi method with L9 (34) orthogonal array design was employed to optimize the experimental conditions of CNT-coated monoliths. The design response was the percentage of carbon yield expressed by the signal-to-noise (S/N) value. The parameters including the mass ratio of Ni to citric acid (Ni:CA) (A), the injection rate of carbon source (B), time of reaction (C), and operating temperature (D) were selected at three levels. The results showed that the optimum conditions for CNT-coated monolith were established at A1B2C1D2 and the most influential parameter was D followed by B, C, and A. The ANOVA analysis showed the design was significant with R-squared and standard deviation of the factorial model equal to 0.9982 and 0.22, respectively. A confirmation test was conducted to confirm the optimum condition with the actual values of the average percentage of carbon yield deviated 1.4% from the predicted ones. The CNT-coated monoliths were characterized by various techniques such as field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Raman spectroscopy.

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