1. Institute
of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea
2. Department
of Material Science and Engineering, Yonsei University, Seoul 120-749, Korea
3. School
Department of Material Science and Engineering, Sungkyunkwan University, Suwon 440-746, Korea
4. Analysis
and Research Division, Korea Basic Science Institute, Daejeon 305-806, Korea
5. Process Development Team, Semiconductor R&D Center, Samsung Electronics Co., Ltd., Yongin 446-711, Korea