Patent ID: 8781212

Claim:
A defect estimation device comprising: a first acquiring part which obtains a reference image and an optical image of a pattern formed on a mask; a first estimation part which utilizes the images obtained in the first acquiring part, and estimates first images of first transfer patterns obtained by transferring the optical and reference images onto a substrate by a first lithography process; a first comparison part which compares the first images with each other and when a difference exceeds at least one of a plurality of threshold values, determines that there is a defect in the optical image of the pattern formed on the mask; a simulation repair part which simulates a repair to the optical image of the pattern at a portion determined as defective by the first comparison part; a second estimation part which utilizes the reference image and the image obtained in the simulation repair part, and estimates second images of second transfer patterns obtained by transferring the images onto a substrate by a second lithography process, wherein the second lithography process is the same or more advanced than the first lithography process; and a second comparison part which compares the second images with each other and confirms whether or not the defect is eliminated by the simulation repair.