Method For Forming Arbitrary Lithographic Wavefronts Using Standard Mask Technology

摘要

A desired set of diffracted waves using mask features whose transmissions are chosen from a set of supported values are generated. A representation of the mask as a set of polygonal elements is created. Constraints which require that the ratio of the spatial frequencies in the representation take on the amplitude ratios of the desired set of diffracted waves are defined. An optimization algorithm is used to adjust the transmission discontinuities at the edges of the polygons to substantial equality with the discontinuity values allowed by the set of supported transmissions while maintaining the constraints.