1. Department of Materials Science and Engineering and Inter‐University Semiconductor Research Center College of Engineering Seoul National University Seoul 08826 Republic of Korea
2. R&D Division SK Hynix Semiconductor, Inc. Icheon Gyeonggi 17336 Republic of Korea
3. IPIT and Department of Physics Jeonbuk National University Jeonju 54896 Republic of Korea
4. Department of Materials Science and Engineering Pusan National University Busan 46241 Republic of Korea