1. Center for Reliability Sciences & Technologies; Chang Gung University; 259, Wen-Hua 1st Road Kwei-Shan Tao-Yuan Taiwan 33302 Republic of China
2. Center for Reliability Sciences & Technologies; Department of Electronic Engineering; Chang Gung University; 259, Wen-Hua 1st Road Kwei-Shan Tao-Yuan Taiwan 33302 Republic of China
3. Electronic Materials Growth and Interface Characterization (eMaGIC) Laboratory; Department of Physics; National University of Singapore; 2 Science Drive 3 Singapore 117551 Singapore