1. Division of Materials Science and Engineering, Hanyang University, Seoul 04763, South Korea and Memory Division Thin film Technology Team, Samsung Electronics, Hwasung 18448, South Korea
2. Division of Materials Science and Engineering, Hanyang University, Seoul 04763, South Korea
3. Division of Nanoscale Semiconductor Engineering, Hanyang University, Seoul 04763, South Korea
4. Memory Division Thin film Technology Team, Samsung Electronics, Hwasung 18448, South Korea
5. Division of Materials Science and Engineering, Hanyang University, Seoul 04763, South Korea and Division of Nanoscale Semiconductor Engineering, Hanyang University, Seoul 04763, South Korea