Patent ID: 7189495
Filing Date: 2007-03-13
Classification: G03F

Abstract:
1. A method of forming a photoresist layer free from a side-lobe by exposing a mask, comprising: providing a mask blank that is originally all dark having a transmittance of 0% and etching said mask blank to form a partial-clear region and a dark region located around said partial-clear region; etching said mask blank within said partial-clear region to form a patterned clear region, an intermediate partial-clear region and a side-lobe region, and leaving the dark region without etching, wherein said patterned clear region is located at corners of a rectangle defined within said partial-clear region, said side-lobe region is at a center of said rectangle, and said side-lobe region and said patterned clear region are spaced by said intermediate partial-clear region; and setting the transmittance of said side-lobe region lower than the transmittance of said intermediate partial-clear region so that the side-lobe region has a light intensity lower than the threshold required to trigger a photoreaction of a material for said photoresist layer.