The influence of pressure on the growth of a-plane GaN on r-plane sapphire substrates by MOCVD  

作　　者：HE Tao LI Hui DAI LongGui WANG XiaoLi CHEN Yao MA ZiGuang XU PeiQiang JIANG Yang WANG Lu JIA HaiQiang WANG WenXin CHEN Hong 

机构地区：[1]Beijing National Laboratory of Condensed Matter, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2011年第3期446-449,共4页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 60890192 and 50872146)

摘　　要：Nonpolar a-plane （1120） GaN films have been grown on r-plane （1102） sapphire by metal-organic chemical vapor deposition （MOCVD） under different growth pressures. The as-grown films are investigated by optical microscopy, high-resolution X-ray diffraction （HRXRD） and Raman scattering. As growth pressure rises from 100 mbar to 400 mbar, the surface gets rougher, and the in-plane XRD full width at half maximum （FWHM） along the c-axis [0001] increases while that along the m-axis [1100] decreases. Meanwhile, residential stresses are reduced along both the c-axis and the m-axis. The structural anisotropy feature under 400 mbar is inverted with respect to 100 mbar, and the weakened anisotropy is achieved under a moderate pressure of 200 mbar, probably due to the suppressed Ga atomic migration along the c-axis under a larger pressure. We propose that pressure can affect a-plane growth through the V/III ratio.Nonpolar a-plane (110) GaN films have been grown on r-plane (102) sapphire by metal-organic chemical vapor deposition (MOCVD) under different growth pressures. The as-grown films are investigated by optical microscopy, high-resolution X-ray diffraction (HRXRD) and Raman scattering. As growth pressure rises from 100 mbar to 400 mbar, the surface gets rougher, and the in-plane XRD full width at half maximum (FWHM) along the c-axis [0001] increases while that along the m-axis [100] decreases. Meanwhile, residential stresses are reduced along both the c-axis and the m-axis. The structural anisotropy feature under 400 mbar is inverted with respect to 100 mbar, and the weakened anisotropy is achieved under a moderate pressure of 200 mbar, probably due to the suppressed Ga atomic migration along the c-axis under a larger pressure. We propose that pressure can affect a-plane growth through the V/III ratio.

关 键 词：GaN anisotropy XRD growth pressure MOCVD 

分 类 号：O484.1[理学—固体物理] TN304.23[理学—物理]