Patent ID: 7426711
Filing Date: 2008-09-16
Classification: G03F

Abstract:
1. A mask pattern data forming method for forming pattern data of a photomask to be used for projection exposure by double-pole illumination or quadrupole illumination in which a light source intensity is concentrated in a double pole or quadrupole form, the method comprising: arranging patterns with a minimum pitch in the pattern data in parallel or vertically in an X direction or a Y direction, where directions diagonally connected with respect to respective centers of gravity of the double-pole illumination or the quadrupole illumination are defined as the X direction and the Y direction; and arranging patterns or pattern groups whose exposure margins are smaller than that of the patterns with the minimum pitch in a direction deflected by 45° or 135° from the patterns with the minimum pitch, wherein a pitch p of the patterns or the pattern groups arranged in the direction deflected by 45° or 135° from the patterns with the minimum pitch satisfies a condition of: where λ is an exposure light wavelength of an exposure apparatus; NA is a numerical aperture of the exposure apparatus; and σ cb is a ratio of a distance between an optical axis and a point of center of a light source having a longest distance from the optical axis among a plurality of light sources which sprinkle in double-pole illumination or quadrupole illumination to numerical aperture NA.