摘要
A Ga wetting layer was used to modify the surface structure of sapphire (0001) substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 30 rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated by in situ reflection high energy electron diffraction, ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron microscopy. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.
A Ga wetting layer was used to modify the surface structure of sapphire (0001) substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 30° rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated byin situ reflection high energy electron diffraction,ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron microscopy. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.
作者
ZENG Zhaoquan1,3, WANG Yong2, DU Xiaolong1, MEI Zengxia1, KONG Xianghe3, JIA Jinfeng1, XUE Qikun1 & ZHANG Ze2, 4 1. State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
2. Laboratory of Electron Microscopy, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
3. College of Physics and Engineering, Qufu Normal University, Qufu 273165, China
4. Beijing University of Technology, Beijing 100022, China
基金
The authors would like to thank Prof.Zhou Junming for the technical assistance.This work was supported by the National Natural Science Foundation of China(Grant Nos.60376004,10174089,and 60021403)
the Nation Key Basic Research and Development Programme of China(Grant No.2002CB613502).
