在ZnO缓冲的Si(111)衬底上生长的GaN薄膜的微观结构和成分特性

Microstructural and compositional characteristics of GaN films grown on a ZnO-buffered Si (111) wafer.

作者信息

Luo X H, Wang R M, Zhang X P, Zhang H Z, Yu D P, Luo M C

机构信息

Electron Microscopy Laboratory and State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.

出版信息

Micron. 2004;35(6):475-80. doi: 10.1016/j.micron.2004.01.010.

DOI:10.1016/j.micron.2004.01.010

PMID:15120133

Abstract

Polycrystalline GaN thin films have been deposited epitaxially on a ZnO-buffered (111)-oriented Si substrate by molecular beam epitaxy. The microstructural and compositional characteristics of the films were studied by analytical transmission electron microscopy (TEM). A SiO(2) amorphous layer about 3.5 nm in thickness between the Si/ZnO interface has been identified by means of spatially resolved electron energy loss spectroscopy. Cross-sectional and plan-view TEM investigations reveal (GaN/ZnO/SiO(2)/Si) layers exhibiting definite a crystallographic relationship: 111//111//0001 along the epitaxy direction. GaN films are polycrystalline with nanoscale grains ( approximately 100 nm in size) grown along [0001] direction with about 20 degrees between the (1l00) planes of adjacent grains. A three-dimensional growth mode for the buffer layer and the film is proposed to explain the formation of the as-grown polycrystalline GaN films and the functionality of the buffer layer.

摘要

通过分子束外延在ZnO缓冲的（111）取向Si衬底上外延生长了多晶GaN薄膜。利用分析型透射电子显微镜（TEM）研究了薄膜的微观结构和成分特征。借助空间分辨电子能量损失谱确定了Si/ZnO界面之间约3.5nm厚的SiO₂非晶层。横截面和平面视图TEM研究表明（GaN/ZnO/SiO₂/Si）层呈现确定的晶体学关系：沿外延方向111//111//0001。GaN薄膜是多晶的，具有沿[0001]方向生长的纳米级晶粒（尺寸约为100nm），相邻晶粒的（1l00）平面之间夹角约为20度。提出了缓冲层和薄膜的三维生长模式来解释生长态多晶GaN薄膜的形成以及缓冲层的功能。