ABSTRACT
The authors would like to thank their colleagues at Sony Shiroishi Semiconductor Inc. and Sony Corporation for technical support and helpful discussion. Special thanks are extended toT. Asano, T. Tojyo, T. Hino, S.Kijima, K. Shibuya and S. Tomiya for their contribution. The authors also thank S. Tanemo and Dr. 0. Kumagai for their encouragement during this work.
