Patent Document ID: 20060141365
Application ID: 10497743
Patent Flag: 0

Claim One:
1. A method for designing a phase shift mask, having a substrate ( 200 ) with a transparent property, and an opaque layer ( 100 ) formed on said substrate and having an opaque property, wherein a plurality of rectangular apertures are formed in said opaque layer, a two-dimensional layout pattern is formed by opaque parts ( 120 ) comprising regions at which said opaque layer is formed, and transparent parts ( 110 ) comprising regions at which said apertures are formed, and for a pair of adjacently disposed apertures, so that a phase of light transmitted through one of said pair of adjacent apertures will be shifted by 180 degrees with respect to a phase of light transmitted through the other of said pair of adjacent apertures, a trench ( 220 ), having a predetermined depth and an outline greater than an outline of said one aperture, is formed on a portion of said substrate at which said one aperture is formed, said phase shift mask designing method comprising the steps of: a two-dimensional layout designing step (S 1 ) of defining an XY plane on a surface of said substrate, determining a width Wx in the X-axis direction and a width Wy in the Y-axis direction of an aperture and a width Ws of an opaque part, and positioning a plurality of apertures of the same size at least along the X-axis to thereby design a two-dimensional layout on said XY plane; a three-dimensional structure determination step (S 2 ) of determining, for each of said plurality of apertures, whether or not phase shifting is to be performed and determining, for the apertures with which phase shifting is to be performed, a trench depth d and an undercut amount Uc, which indicates a distance between a position of the outline of the trench and a position of the outline of the aperture, to thereby determine a three-dimensional structure; a three-dimensional analysis step (S 3 ) of using a three-dimensional structural body, which is defined by said two-dimensional layout and said three-dimensional structure, to determine a light intensity deviation D, which indicates, for a case where light is transmitted under same exposure conditions through a pair of adjacent apertures that have been designed to realize a phase shift of 180 degrees with respect to each other, a deviation in intensities of light transmitted through the respective apertures; a two-dimensional analysis step (S 4 ) of using a two-dimensional structural body, which is defined by said two-dimensional layout, to determine, in a case where, for said pair of adjacent apertures, a light transmittance of one aperture is set to 100% and a light transmittance of the other aperture is set to T%, a transmittance T such that a deviation in intensities of light transmitted through each of said pair of adjacent apertures will be equal to said light intensity deviation D; and a layout correction step (S 5 ) of correcting said two-dimensional layout based on said transmittance T.