| US 7,596,776 B2 | ||
| Light intensity distribution simulation method and computer program product | ||
| Satoshi Tanaka, Kawasaki (Japan); Shoji Mimotogi, Yokohama (Japan); Takashi Sato, Fujisawa (Japan); and Soichi Inoue, Yokohama (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Mar. 29, 2007, as Appl. No. 11/730,102. | ||
| Claims priority of application No. 2006-094847 (JP), filed on Mar. 30, 2006. | ||
| Prior Publication US 2007/0234269 A1, Oct. 04, 2007 | ||
| Int. Cl. G06F 17/50 (2006.01) | ||
| U.S. Cl. 716—21 [716/4; 716/20] | 18 Claims |
| 1. A light intensity distribution simulation method for predicting an intensity distribution of light on a substrate when
a photomask comprising a pattern is irradiated with light in which a shape distribution of an effective light source is defined,
by using an illumination optical system, and the light which passes through the photomask is projected on the substrate through
a projection optical system, the method comprising:
extracting a plurality of point light sources from the shape distribution of the effective light source;
entering light in the pattern of the photomask, the light being emitted from each of the plurality of point light sources;
calculating an effective shape for each of the plurality of point light sources by a CPU, the effective shape being a shape
obtained by excluding a part from a design shape of an aperture of the pattern, the part being failed to be irradiated with
the light directly due to a sidewall of a pattern film including the pattern; and
calculating a distribution of diffraction light generated in the pattern for each of the plurality of point light sources
by a CPU by using the effective shape calculated for each of the plurality of point light sources.
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