Shin-Etsu Chemical Co., Ltd.

Naoki Kawaura

Hideo Kaneko

Takuro Kosaka

Shigeo Irie

A photomask blank is provided comprising a transparent substrate, a first film of chromium-containing material on the substrate, and a second film of silicon/oxygen-containing material disposed contiguous to the first film. The second film includes a first layer contiguous to the first film and a second layer spaced apart from the first layer in film thickness direction. The oxygen content of the first layer is lower than the oxygen content of the second layer. During etching of the first film, this setting prevents an etching rate from ramping up at the interface between the first and second films.

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Joetsu, Japan

Naoki Kawaura