Patent ID: 7367010
Filing Date: 2008-04-29
Classification: G03F

Abstract:
1. A device for designing a phase shift mask, said phase shift mask having a substrate with a transparent property and an opaque layer having an opaque property formed on the substrate, wherein a plurality of rectangular apertures are formed in said opaque layer, a two-dimensional layout pattern is formed by opaque parts comprising regions at which said opaque layer is formed and transparent parts comprising regions at which said apertures are formed, and for a pair of adjacently disposed apertures, a trench having a predetermined depth and an outline greater than an outline of an aperture is formed at a portion of the substrate at which a first aperture is formed so that a phase of light transmitted through the first aperture will be shifted by 180 degrees with respect to a phase of light transmitted through a second aperture: said phase shift mask designing device comprising; a two-dimensional layout pattern designing tool which, based on instructions from an operator, designs a two-dimensional layout pattern wherein a plurality of apertures are disposed on an X-Y plane having an X-axis and a Y-axis defined on a surface of said substrate, and determines for each aperture whether or not phase shifting is to be performed; an optimal function database, which stores a predetermined optimal function for each of a plurality of two-dimensional dimension conditions M for determining specific dimension values for a width Wx in the X-axis direction and a width Wy in the Y-axis direction of each aperture and a width Ws of each opaque part; an optimal function extracting tool, which, based on instructions from the operator, selects two-dimensional dimension condition M that can be applied to the two-dimensional layout pattern designed by said two-dimensional layout pattern designing tool and extracts an optimal function for the selected two-dimensional dimension condition M from said optimal function database; an undercut amount/bias correction amount determining tool, which, based on the extracted optimal function, determines an undercut amount Uc that indicates a distance between a position of an outline of the trench and a position of an outline of the aperture and a bias correction amount δ that indicates an amount of increase or decrease of a width of an aperture on the two-dimensional layout pattern designed by said two-dimensional layout pattern designing tool; a three-dimensional structure determining tool, which, based on the undercut amount Uc that is determined by said undercut amount/bias correction amount determining tool and a trench depth d that is determined based on a predetermined exposure condition, determines a three-dimensional structure concerning an aperture with which phase shifting is to be performed; and a two-dimensional layout pattern correcting tool, which, based on the bias correction amount δ determined by said undercut amount/bias correction amount determining tool, corrects the two-dimensional layout pattern designed by said two-dimensional layout pattern designing tool; wherein in said optimal function database, a function indicating optimal values of the bias correction amount δ with respect to undercut amounts Uc within a predetermined range is stored as an optimal function for each two-dimensional dimension condition M.