Patent ID: 7300725

Claim:
A method for determining and correcting reticle variations, comprising: comparing one or more measured features of a reticle to one or more reference features; determining a reticle global variation based on the comparison, wherein the reticle global variation indicates how a parameter of the reticle varies across the reticle; identifying one or more reticle regions for dose correction based on the determined reticle global variation and associating one or more levels of dose correction with the one or more identified reticle regions; and applying dose correction to the one or more identified reticle regions according to the associated one or more levels of dose correction so as to minimize the reticle global variation, wherein the operation of applying dose correction comprises embedding scattering centers into the reticle at the identified one or more reticle regions using an optical beam so as to alter a transmission level through such identified one or more reticle regions.