Patent ID: 7736819
Filing Date: 2010-06-15
Classification: G03F

Abstract:
1. A method for compensating for critical dimension (CD) variations of pattern lines of a wafer, by correcting the CD of a corresponding photomask used in manufacturing the pattern lines on the wafer, the photomask comprising a transparent substrate having two substantially opposite surfaces, a first back surface and a second front surface on which front surface an absorbing coating is provided, on which the pattern lines were formed by removing the coating at the pattern lines, the method comprising: mapping CD variations across regions of a wafer exposure field relating to the photomask; and using laser radiation providing Shading Elements within the substrate of the photomask in regions which correlate to regions of the wafer exposure field where CD variations greater than a predetermined target value were determined, the shading elements forming correction patterns across the correlating regions wherein the shading elements include arrays of pixels, each array extending across one of the regions; thereby having the shading elements attenuate light passing through the regions, so as to compensate for the CD variations.