Affiliation: | a Information and Electronic Material Research Laboratory, Department of Metallurgical Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemun-Gu, Seoul 120-749, South Korea b Semiconductor Engineering Laboratory, Department of Electrical and Electronic Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemun-Gu, Seoul 120-749, South Korea |