1. Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, Tainan City 701, Taiwan (R.O.C.)
2. Department of Engineering Science, National Cheng Kung University, Tainan City 701, Taiwan (R.O.C.)
3. Department of Microelectronics Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 807, Taiwan (R.O.C.)