Photomask and next-generation lithography mask technology XIII : 18-20 April, 2006, Yokohama, Japan Morihisa Hoga, editor ; sponsored by PMJ--Photomask Japan, BACUS--the international technical group of SPIE dedicated to the advancement of photomask technology, [and] SPIE--the International Society for Optical Engineering ; cooperating organizations, the Japan Society of Applied Physics ... (et al.) ; supported by Yokohama City (Japan)