1. High-Frequency High-Voltage Devices and ICs R&D Center, Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
3. Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029, China
4. Research Center for Carbon-Based Electronics, School of Electronics, Peking University, Beijing 100871, China