Patent ID: 6093598
Filing Date: 2000-07-25
Classification: G03F,H01L

Abstract:
A process for fabricating a semiconductor device, comprising the steps in sequence of:a) preparing a first semiconductor structure;b) spreading a photo-resist solution having sensitized characteristics represented by at least two plots having a periodicity in the presence of an optical standing wave and different in phase from each other over said first semiconductor structure so as to form a first photo-resist layer varied in thickness;c) exposing said first photo-resist layer to a first image carrying optical radiation varying said sensitized characteristics along one of said at least two plots so as to form a first latent image in said first photo-resist layer;d) developing said first latent image so that said first photo-resist layer is formed into a first photo-resist mask;e) carrying out a first predetermining operation on a first area of said first semiconductor structure by using said first photo-resist mask so that said first semiconductor structure is modified to a second semiconductor structure;f) spreading said photo-resist solution over said second semiconductor structure so as to form a second photo-resist layer varied in thickness and having a thickness different from the thickness of said first photo-resist layer by a value equivalent to at least a half of a period of said periodicity;g) exposing said second photo-resist layer to a second image carrying optical radiation varying said sensitized characteristics along another of said at least two plots so as to form a second latent image in said second photo-resist layer;h) developing said second latent image so that said second photo-resist layer is formed into a second photo-resist mask; andi) carrying out a second predetermining operation on a second area of said second semiconductor structure by using said second photo-resist mask, one of said first area and said second area being nested in the other of said first area and said second area.