Patent ID: 8056021
Filing Date: 2011-11-08
Classification: G03F

Abstract:
1. A computer-program product for use in conjunction with a computer system, the computer-program product comprising a non-transitory computer-readable storage medium and a computer-program mechanism embedded therein for determining a mask pattern to be used on a photo-mask in a photolithographic process, wherein the photo-mask has a plurality of distinct types of regions having distinct optical properties, the computer-program mechanism including: instructions for providing a first mask pattern that includes a plurality of distinct types of regions corresponding to the distinct types of regions of the photo-mask; instructions for calculating a gradient of a function, wherein the function depends on the first mask pattern and an estimate of a wafer pattern that results from the photolithographic process utilizing at least a portion of the first mask pattern, and wherein the gradient is calculated in accordance with a formula obtained by taking a derivative of the function; and instructions for generating a second mask pattern based, at least in part, on the gradient of the function.