Patent ID: 6586168
Filing Date: 2003-07-01
Classification: G03F

Abstract:
A multiple exposure method using plural masks, said method comprising:exposing a position where an image of a low-contrast pattern is to be formed on the basis of a mask, of the plural masks, having fine lines extending in different directions, with an image of a pattern of a mask having a phase difference of 180 degrees between adjacent patterns, whereby a contrast of an exposure amount distribution related to the pattern of the low contrast is increased; and making the exposure with the image of the pattern having the phase difference of 180 degrees while registering the boundaries of the pattern with the fine lines of the pattern, extending in different directions, where the fine lines or extensions thereof intersect with each other at a single point, wherein the boundaries having a phase difference of 180 degrees serve to divide a pattern region into zones of an even number regardless of whether the number of the fine lines is even or odd, and the fine lines are reproduced on the basis of the boundaries.