PHOTOMASK BLANK, PHOTOMASK AND METHOD FOR PRODUCING THOSE

摘要

A metal film is formed on one major surface of a photomask substrate (11) as a light-blocking layer (12). This metal film is not substantially etched by oxygen-containing chlorine-based dry etching ((Cl + O)-type dry etching), but can be etched by non-oxygen containing chlorine-based dry etching (Cl-type dry etching) and fluorine-based dry etching (F-type dry etching). A metal compound film is formed on the light-blocking layer (12) as an antireflective layer (13). This metal compound film is not substantially etched by non-oxygen containing chlorine-based dry etching (Cl-type), but can be etched by at least one of oxygen-containing chlorine-based dry etching ((Cl + O)-type) and fluorine-based dry etching (F-type).