Patent ID: 9274416
Filing Date: 2016-03-01
CPC Classification: G03F

Claim Text:
1. A method for forming a photo-mask, comprising: providing a first photo-mask pattern relating to a first line, an original second photo-mask pattern relating to a first via plug, and a third photo-mask pattern relating to a second line, wherein the original second photo-mask pattern is defined only at an intersection of the first photo-mask pattern and the third photo-mask pattern, the first metal line, the first via plug and the second line are disposed in sequence in a semiconductor structure, and the first line extends along a first direction, the second line extends along a second direction, the first via plug is disposed at the intersection of the first line and the second line; performing a first optical proximity correction (OPC) process by using a computer, comprising a comparing step and/or a modification step for the original second photo-mask pattern; performing a second OPC process, comprising enlarging a width of the original second photo-mask pattern along the second direction, wherein after the first OPC process and the second OPC process, the original second photo-mask pattern becomes a revised second photo-resist pattern; after the second OPC process, performing a contour simulation process to make sure the revised second photo-mask pattern is larger or equal to the original second-mask pattern; and outputting the first photo-mask pattern to form a first photo-mask, outputting the revised second photo-mask pattern to form a second photo-mask, and outputting the third photo-mask pattern to form a third photo-mask.