1. Electronic
Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea
2. Department
of Materials Science and Engineering, Yonsei University, Seoul 120-749, Republic of Korea
3. Institute
for Research in Electronics and Applied Physics, University of Maryland, College
Park Maryland 20742, United States
4. Interface
Control Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea
5. Department
of Nanomaterials Science and Technology, Korea University of Science and Technology, Daejeon 305-333, Republic of Korea