1. Key Laboratory of Microelectronics Devices and Integrated Technology; Institute of Microelectronics; Chinese Academy of Sciences; No. 3, BeiTuCheng West Road ChaoYang District Beijing 100029 P. R. China
2. University of Chinese Academy of Sciences; Beijing 100049 China
3. Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM); Nanjing 210009 China