1. Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
2. National Synchrotron Radiation Research Center, Hsinchu 300092, Taiwan
3. Department of Electrical Engineering, Tatung University, Taipei 104327, Taiwan
4. Corporate Research, Taiwan Semiconductor Manufacturing Company (TSMC), Hsinchu 300096, Taiwan
5. International College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan