1. Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
2. Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
3. Department of Electrical Engineering, Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan
4. Institute of Pioneer Semiconductor Innovation, National Yang Ming Chiao Tung University, Hsinchu, Taiwan