Patent ID: 6775815
Filing Date: 2004-08-10
Classification: G03F

Abstract:
An exposure method for correcting pattern line width variation occurring during a development process in fabricating a photomask, the method comprising:calculating a standard deviation &sgr; of a pattern line width variation &Dgr;CD(r) by dividing a photomask substrate into meshes and assuming that a distribution of the pattern line width variation &Dgr;CD(r) for each mesh, which is separated from a reference mesh at the center of the photomask substrate by a distance r, is a Gaussian distribution expressed by the following equation Î”&it;â€ƒ&it;CD&it;(r)=A+B&CenterDot;exp&af;[-r2Ïƒ2],wherein A and B are constants;combining the calculated standard deviation &sgr; with the above equation and estimating a pattern line width variation &Dgr;CD(x) at an arbitrary point, separated from the reference mesh by a distance x on the photomask substrate, from the above equation; correcting pattern line width data with respect to each point on the photomask substrate such that a pattern line width increases in an area where the estimated pattern line width variation &Dgr;CD(x) is negative, and a pattern line width decreases in an area where the estimated pattern line width variation &Dgr;CD(x) is positive; and applying the pattern line width data corrected with respect to each point on the photomask substrate to an exposure apparatus.