Patent ID: 7370313
Filing Date: 2008-05-06
Classification: G03F

Abstract:
1. A method for making a photolithographic mask, the method comprising: providing a desired layout pattern, said desired layout pattern comprising at least one structural feature; providing an imaging model of a photolithographic apparatus, said imaging model comprising an illumination source parameter of an illumination source of said photolithographic apparatus and a lens aperture; providing at least one optimized reference diffraction coefficient based on said desired layout pattern and said illumination source parameter of said illumination source for imaging relevant diffraction orders of said illumination source passing said lens aperture; providing an initial mask geometry, said initial mask geometry being parameterized having polygon-shaped structures; providing at least one initial diffraction coefficient based on said initial mask geometry; determining a difference based on said optimized reference diffraction coefficient and said initial diffraction coefficient; optimizing said initial mask geometry by modifying said polygon-shaped structures so as to form an optimized mask pattern by minimizing said difference; providing a photolithographic mask, said photolithographic mask having a translucent substrate and being capable to accommodate at least one structural element being light-attenuating and phase-shifting when illuminated by said illumination source; and providing the at least one light-attenuating phase-shifting structural element on said photolithographic mask in accordance with said optimized mask pattern.