Image Process Method to Improve Mask Inspection Performance

摘要

The present disclosure relates to a method of inspecting a photomask to decrease false defects, which uses a plurality of image rendering models with varying emphasis on different design aspects, and an associated apparatus. In some embodiments, the method is performed by forming an integrated circuit (IC) design comprising a graphical representation of an integrated circuit. A first image rendering simulation is performed on the IC design using an initial image rendering model to determine a plurality of initial mask defects. A second image rendering simulation is performed on the IC design using a modified image rendering model that emphasizes a design aspect to determine a plurality of modified mask defects. By comparing the plurality of initial mask defects with the plurality of modified mask defects, falsely identified mask defects can be detected and eliminated.

主权项

1. A method of inspecting a photomask, comprising:
forming an integrated circuit (IC) design comprising a graphical representation of an integrated circuit layout; using an initial image rendering model to determine a plurality of initial mask defects comprising defects in a photomask formed from the IC design; performing a plurality of modified image rendering simulations on the IC design using a plurality of modified image rendering models that respectively emphasize different types of lithography errors to determine a plurality of modified mask defects; and comparing the plurality of initial mask defects with the plurality of modified mask defects to determine falsely identified mask defects associated with one of the different types of lithography errors; wherein a computer is used to form the IC design, to determine the plurality of initial mask defects, to perform the plurality of modified image rendering simulations, or to compare the plurality of initial mask defects with the plurality of modified mask defects.