CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-148377, filed on Aug. 13, 2019, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a method for producing a photomask, a method for producing a semiconductor device, a method for forming a pattern, and a photomask.

BACKGROUND

A method for forming a fine-line pattern in a process of producing a semiconductor device includes a pattern transfer using a photomask (for example, a phase-shift mask) including a halftone film or the like. When such a photomask is produced, after a transfer pattern is formed in a halftone film, a light-shielding frame pattern surrounding the periphery of the pattern, for example, is formed with a light-shielding film. This requires multiple lithography steps to achieve.

