Patent ID: 7070907

Claim:
A processing method of a character/symbol section in a substrate having the character/symbol section to be recognized as a character, symbol or both in addition to a phase-shift section on a surface of the same substrate, wherein said substrate having the character/symbol section is a chromeless phase-shift mask having no substrate-engraving-type light shielding layer or a phase mask for fiber Bragg grating fabrication, and said resist arranging step is conducted by simultaneously carrying out, after providing a light shielding film over an entire surface of the transparent substrate and arranging an electron-beam-sensitive resist over said entire surface of the light shielding film, a step for forming the character/symbol section and a step for forming the shifter section, comprising (A) a resist image forming sub-step of selectively exposing the resist to electron beam, and developing the resist, thereby forming a resist image opening at portions for forming the character/symbol section and a portion for forming a shifter section; (B) an etching sub-step of etching a light shielding film opening at portions for forming the character/symbol section and a portion for forming the shifter section; (C) a substrate engraving sub-step of engraving the portions of the substrate exposed from the openings of the resist and the light shielding film by etching; and (D) a sub-step of removing remaining resist and light shielding film.