Cathodeluminescence Characterization of AlGaN Film Grown by MOCVD

2010 ◽  
Vol 143-144 ◽  
pp. 966-970
Author(s):  
Lian Jia Wang ◽  
You Zhang Zhu ◽  
Hong Xia Wang ◽  
Ben Li Liu ◽  
Jin She Yuan

Recent achievements in III-nitride semiconductor structures growth have allowed ultraviolet (UV) photo-detectors based on these compounds to be well established today. In this article, AlGaN film of 1-μm thickness was grown on Al2O3 substrate by metal-organic chemical vapor deposition (MOCVD). The AFM was used to analyze the surface morphology of the AlGaN film; X-ray diffraction measurements were used to study the quality of the film’ crystal structure; Cathode-ray luminescence(CL) was employed to study the luminescence properties of the AlGaN film. The result shows that there is a single atom layer on the AlGaN film’surface, and it shows that a low-defect-density AlGaN film with good surface morphology and single crystal Hexagonal structure has been obtained. It is found that there is some relationship between the film’crystal structure , dislocations and the luminescence properties . PACS: 73.61.

2012 ◽  
Vol 442 ◽  
pp. 16-20
Author(s):  
Yong Wang ◽  
Nai Sen Yu ◽  
Ming Li ◽  
Kei May Lau

The continuous 1.0 µm GaN epilayers with and without partially Mg-doped were grown on Si (111) substrates by metal organic chemical vapor deposition (MOCVD). The DC current-voltage (I-V), time-of-flying secondary ion mass spectrometer (ToF-SIMS) and atomic force microscope (AFM) measurements were employed for comparison to characterize surface morphology and resistivity of GaN buffer layer with and without partially Mg-doped. The sample of 1.0 µm GaN epilayer with partially Mg-doped shows much higher resistivity than sample without Mg-doped, which indicates the partially Mg doping in 1.0 µm GaN epilayer can effectively increase the resistivity of GaN grown on Si (111) substrates. As a result, the high resistivity GaN buffer layer with good surface morphology is achieved in the partially Mg-doped GaN buffer layer.


2018 ◽  
Vol 667 ◽  
pp. 48-54
Author(s):  
Adreen Azman ◽  
Ahmad Shuhaimi ◽  
Al-Zuhairi Omar ◽  
Anas Kamarundzaman ◽  
Muhammad Imran Mustafa Abdul Khudus ◽  
...  

2019 ◽  
Vol 25 (6) ◽  
pp. 1383-1393
Author(s):  
Sabyasachi Saha ◽  
Deepak Kumar ◽  
Chandan K. Sharma ◽  
Vikash K. Singh ◽  
Samartha Channagiri ◽  
...  

AbstractGaN films have been grown on SiC substrates with an AlN nucleation layer by using a metal organic chemical vapor deposition technique. Micro-cracking of the GaN films has been observed in some of the grown samples. In order to investigate the micro-cracking and microstructure, the samples have been studied using various characterization techniques such as optical microscopy, atomic force microscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM). The surface morphology of the AlN nucleation layer is related to the stress evolution in subsequent overgrown GaN epilayers. It is determined via TEM evidence that, if the AlN nucleation layer has a rough surface morphology, this leads to tensile stresses in the GaN films, which finally results in cracking. Raman spectroscopy results also suggest this, by showing the existence of considerable tensile residual stress in the AlN nucleation layer. Based on these various observations and results, conclusions or propositions relating to the microstructure are presented.


Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1364
Author(s):  
Ryan C. White ◽  
Hongjian Li ◽  
Michel Khoury ◽  
Cheyenne Lynsky ◽  
Michael Iza ◽  
...  

In this paper, we report the successful demonstration of bright InGaN-based microLED devices emitting in the red spectral regime grown by metal organic chemical vapor deposition (MOCVD) on c-plane semi-relaxed InGaN substrates on sapphire. Through application of an InGaN/GaN base layer scheme to ameliorate high defect density and maintain appropriate lattice constant throughout the growth, high-In quantum wells (QWs) can be grown with improved crystal quality. Improvement to the design of the growth scheme also yields higher power output resulting in an increase to the external quantum efficiency (EQE). Combined, these two improvements allow for an 80 × 80 μm2 microLED device emitting at 609 nm to achieve 0.83% EQE. Furthermore, the true In content of the QW is measured using atomic probe tomography (APT) to confirm the improved In incorporation during high temperature active region growth. These developments represent advancement toward the realization of bright, highly efficient red III-nitride LEDs to be used in RGB applications under one material system.


2013 ◽  
Vol 275-277 ◽  
pp. 2023-2026 ◽  
Author(s):  
Ai Hua Jiang ◽  
Hao Yu Jiang ◽  
Hang Zhao ◽  
Jian Rong Xiao

Gallium nitride (GaN) thin films samples were grown by metal-organic chemical vapor deposition (MOCVD) with ammonia and trimethyl-gallium, and the samples were annealed rapidly at different temperature. The scanning electron microscope (SEM) analysis was employed to study the surface morphology and lattice defects of the GaN thin films. The surface morphology of the thin films prepared at different condition was uniform and smoothly. The relationship of the films defects and the annealed temperature were summarized.


1992 ◽  
Vol 282 ◽  
Author(s):  
R. M. Biefeld

ABSTRACTIn metal organic chemical vapor deposition (MOCVD), the most commonly used sources are the trimethyls of Al, Ga, In, and Sb, and PH3 and ASH3. New organometallic sources are being developed as the understanding of the deposition process improvesand allows for the determination of the effects of source type and growth condition on the properties of the grown films. These new sources are safer and allow for the growth of higher purity materials using more favorable growth conditions. InSb and AlSb prepared using these trimethyl-sources are not of high enough quality to be used in many current device applications. Alternate organometallic Sb sources are being investigated to improve the materials characteristics of InSb grown by MOCVD.InSb grown using trimethylindium (TMIn) and trimethylantimony (TMSb) or triethylantimony (TESb) yielded similar quality materials under similar growth conditions. InSb grown using triethylindium (TEIn) and TESb under similar growth conditions yielded very poor quality n-type material. Three new organometallic Sb sources, triisopropylantimony (TIPSb), tris(dimethylamino)antimony (TDMASb), and tertiarybutyldimethylantimony (TBDMSb) are being investigated. The growth of InSb using TIPSb, TDMASb, or TBDMSb and TMIn was investigated over a temperature range of 350 to 475 °C. InSb grown from TDMASb had similar properties to InSb grown from TMIn and TMSbwhen using a similar temperature and V/III ratio range. The growth rates of InSb using TMIn and either TIPSb or TBDMSb at temperatures <= 425 °C were proportional to both the TMIn flow rate and the temperature. The surface morphology of InSb grown using eitherTIPSb or TBDMSb was very rough for growth temperatures <=425 °C. This may be due to the complex decomposition mechanisms involved and the presence of methyl groups on the surface. The InSb with the highest mobility was grown at 400 °C and a V/III ratioof 3 using TIPSb. It was n-type with a carrier concentration of 2.5 × 1015 cm−3 and a mobility of 78,160 cm2/Vs at 77 K. Both n- and p-type InSb were grown using TBDMSb with mobilities up to 67,530 and 7773 cm2/Vs, respectively at 77 K. The mobility for InSb using either TIPSb or TBDMSb was optimized by going to lower temperatures, pressures and V/III ratios. The opposite was truefor surface morphology which improved with higher temperature, pressure, and V/III ratio. The growth of high mobility InSb with smooth surfaces at T<=425 °C was not achieved with TIPSb or TBDMSb and TMIn under the conditions investigated in this work.


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