Patent ID: 8566755
Filing Date: 2013-10-22
Classification: G03F

Abstract:
1. A method of correcting photomask patterns, comprising: providing measurement data of a plurality of photoresist patterns defined by patterns on a photomask that are arranged similar to the photomask patterns; providing a physical optical kernel and a mathematical load kernel, wherein the mathematical load kernel is a part of a first Gaussian distribution function or is a combined function including a part of a first Gaussian distribution function and an entire curve of a second Gaussian distribution function different from the first Gaussian distribution function; determining optimal values of parameters of the mathematical load kernel by fitting the measurement data with a simulation of the photoresist patterns, wherein the simulation uses graphic data of the patterns on the photomask, the physical optical kernel, and the mathematical load kernel; simulating photoresist patterns defined by the photomask patterns using graphic data of the photomask patterns, the physical optical kernel, and the mathematical load kernel with the optimal values of the parameters determined; and performing optical proximity correction (OPC) to modify the photomask patterns according to the simulated photoresist patterns.