1. School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro,
Yuseong-gu, Daejeon 34141, Republic of Korea
2. Department of Memory Business, Samsung Electronics, San 16 Banwol-Dong, Hwasung City, Gyeonggi-Do 18448, Republic of Korea
3. Department of Nano-Process, National Nanofab Center (NNFC), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea