Role of gallium wetting layer in high-quality ZnO growth on sapphire (0001) substrates

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 

作者机构：1. State Key Laboratory for Surface Physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 2. College of Physics and Engineering Qufu Normal University 273165 Qufu China 3. Laboratory of Electron Microscopy Institute of Physics Chinese Academy of Sciences 100080 Beijing China 4. Beijing University of Technology 100022 Beijing China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2004年第47卷第5期

页      面：612-620页

核心收录：

学科分类：08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

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) 

主　　题：Ga wetting layer, sapphire, polarity, defect density, zinc oxide, rf-MBE, RHEED, HRXRD, TEM, CBED. 

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.