Patent ID: 7138212
Filing Date: 2006-11-21
Classification: G03F

Abstract:
1. A method of generating complementary masks for use in a multiple-exposure lithographic imaging process, said method comprising the steps of: generating a model defining the imaging performance of said multiple-exposure lithographic imaging process, identifying a target pattern having a plurality of features, said plurality of features comprising horizontal and vertical edges, generating a horizontal mask based on said target pattern, generating a vertical mask based on said target pattern, and performing a shielding step in which at least one of the vertical edges of the plurality of features in the target pattern is replaced by a shield in the horizontal mask, and in which at least one of the horizontal edges of the plurality of features in the target pattern is replaced by a shield in the vertical mask, said shields having a width which is greater that the width of the corresponding feature in the target pattern, wherein the amount of shielding to be applied in said shielding step is determined utilizing said model.