1. Division of Materials Science and Engineering; Hanyang University; Seoul 133-791 Korea
2. Department of Nano-scale Semiconductor Engineering; Hanyang University; Seoul 133-791 Korea
3. FAB Manufacturing Division; SK Hynix, Inc., 2091, Gyeongchung-daero, Bubal-eub, Icheon-si Gyeonggi-Do 167-701 Korea
4. Department of Materials Science and Engineering and Department of Energy Systems Research; Ajou University; Suwon 443-749 Korea
5. Department of Chemistry; University of Helsinki; P.O. Box 55 00014 Helsinki Finland