Photomask and pattern formation method

Abstract

A photomask includes: a transparent substrate; and first and second mask patterns located on the transparent substrate and at least partially facing each other with a space sandwiched therebetween. The first mask pattern includes a semi-light-shielding part which transmits part of light therethrough and a light-shielding part. In the first mask pattern, the semi-light-shielding part at least partially faces the space with the light-shielding part sandwiched therebetween. In a direction along which the first mask pattern and the second mask pattern face each other, the first mask pattern has a size greater than (0.7×λ/NA)×M, and the space has a size less than or equal to (0.5×λ/NA)×M where λ is a wavelength of exposure light, NA is a numerical aperture of a reduced projection optical system of an exposure device, and M is a magnification of the reduced projection optical system.

Dependencies are inferred from the claim text.