Authors: Zhen Huang Yuantao Zhang Baijun Zhao Fan Yang Junyan Jiang Gaoqiang Deng Baozhu Li Hongwei Liang Yuchun Chang Junfeng Song
Publish Date: 2015/10/28
Volume: 27, Issue: 2, Pages: 1738-1744
Abstract
In this study 15μmthick GaN films with AlN buffer were prepared on 6HSiC substrates by metalorganic chemical vapor deposition To determine the effects of growth conditions of AlN buffer on crystalline quality and stress state of GaN films two series of experiments were carried out By optimizing growth conditions of AlN buffer the full width at half maximum values of 0002 and 10bar12 rocking curves of GaN films were improved to 136 and 225 arcsec respectively A smooth surface was obtained with a small rootmeansquared roughness of 0332 nm and the excellent optical property was observed Simultaneously threading dislocation density and tensile stress in GaN films were reduced by increasing AlN buffer growth temperature and its thickness in some extent Besides stress values in GaN films were confirmed by Raman and lowtemperature photoluminescence spectra which indicated that the lower tensile stress in GaN film the higher the film crystallinityThis work was supported by the National Natural Science Foundation of China Nos 61106003 61274023 61223005 and 61376046 the Science and Technology Developing Project of Jilin Province 20130204032GX and 20150519004JH and the Program for New Century Excellent Talents in University NCET130254
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