1. Key Laboratory of Microelectronics Devices & Integration Technology Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029 China
2. School of Microelectronics University of Science and Technology of China Hefei Anhui 230026 China
3. Wuhan National Laboratory for Optoelectronics School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China