[1] New Technology Development Section, Tokyo Ohka Kogyo Co., Ltd., 1590 Tabata, Samukawa-machi, Koza-gun, Kanagawa 253-0114, Japan
[2] ULSI Research Department, Central Research Laboratory, Hitachi, Ltd., 1-280, Higashi-koigakubo, Kokubunji, Tokyo 185-8601, Japan