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AssigneeShin-Etsu Chemical Co., Ltd.
InventorsSatoshi WATANABE, Ryuji Koitabashi, Shinichi Igarashi, Yoshio Kawai, Shozo Shirai
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A photomask blank is provided comprising a transparent substrate, a single or multi-layer film including an outermost layer composed of chromium base material, and an etching mask film. The etching mask film is a silicon oxide base material film formed of a composition comprising a hydrolytic condensate of a hydrolyzable silane, a crosslink promoter, and an organic solvent and having a thickness of 1-10 nm. The etching mask film has high resistance to chlorine dry etching, ensuring high-accuracy processing of the photomask blank.
A photomask blank comprising a transparent substrate, a film formed thereon, the film comprising one or more layers including an outermost layer composed of a chromium base material, and an etching mask film on the outermost layer serving as a mask upon dry etching,
A method for etching a film formed on a transparent substrate, the film comprising one or more layers including an outermost layer composed of a chromium base material, said method comprising chlorine dry etching using a silicon oxide base material film as an etching mask,
Dependencies are inferred from the claim text.