| abstract |
A photomask substrate comprising: a transparent substrate; the first film is made of a material which can be etched by dry etching in a chlorine-oxygen system and has resistance in fluorine-based dry etching, and the second film is in contact with the first film. Formed by yttrium and oxygen, or yttrium and oxygen and nitrogen, having Si-Si bonding, consisting of a material that is not substantially etched in dry etching of oxychloride; the adhesion of the photoresist film is improved even by When the photoresist film is formed into a fine resist pattern, the resist pattern is not deteriorated, poured or peeled off, and can be stably maintained, and good shape and dimensional accuracy can be obtained in etching of the underlying film using the resist pattern. |