发光学报2013，Vol.34Issue(6)：776-781,6.DOI:10.3788/fgxb20133406.0776
H2载气流量对AlN缓冲层生长的影响
Influence of H2 Carrier Gas on Epitaxy of AlN Buffer Layer
摘要
Abstract
AlN buffer and GaN epitaxial layer were prepared by MOCVD on Si (111) substrate.The effect of H2 carrier gas flow for AlN buffer epitaxy on GaN was investigated by high resolution X-ray diffraction,ellipsometer and atomic force microscope.It is found that AlN thickness increases (i.e.the increasing of A1N growth rate) with the increasing of H2 flow.The surface roughness of A1N also tends to increase.The change in surface roughness is attributed to the enhancement of island-growth mode.The increasing of AlN buffer thickness contributes to the increasing of tensile stress which promotes AlN island growth mode.The higher density of islands with bad orientation was observed by AFM on A1N buffer layer which was grown with higher H2 flow.ω scan of (0002) and (1012)show that the increasing of H2 flow leads to the increasing in FWHM of GaN (i.e.the increasing in density of screw threading dislocation and edge threading dislocation).Because the three-dimensional growth of GaN starts on the top of AlN islands,the A1N buffer layer with high density of islands contributes to rapid coalescence of GaN islands that will lead high density of edge threading dislocation.The bad orientation of AlN islands on buffer layer will lead to GaN thin film with high density of screw threading dislocation.The obtained data demonstrate that the H2 carrier gas flow plays an important role in improving the crystal quality of GaN.关键词
氮化镓(GaN)/AlN缓冲层/H2载气/Si衬底/金属有机化学气相沉积Key words
GaN/ A1N buffer/ H2 carrier gas/ Si substrate/ MOCVD分类
数理科学引用本文复制引用
邓旭光,韩军,邢艳辉,汪加兴,崔明,陈翔,范亚明,朱建军,张宝顺..H2载气流量对AlN缓冲层生长的影响[J].发光学报,2013,34(6):776-781,6.基金项目
国家自然科学基金(N61176126,61006084,61204011) （N61176126,61006084,61204011）
国家杰出青年科学基金(60925017) （60925017）
北京市自然科学基金(4102003,4112006)资助项目 （4102003,4112006）
