Reflective photomask substrate, manufacturing method of reflective photomask substrate, reflective photomask, manufacturing method of reflective photomask

Abstract

This invention provides a reflective photomask substrate with a relatively high etching rate for the absorber film compared to the etching rate for the protective film. The reflective photomask substrate of this invention sequentially comprises a substrate, a multilayer reflective film for reflecting EUV light, a protective film, and an absorber film. The absorber film contains platinum, the oxygen content of the absorber film is less than 20% of the total atoms of the absorber film, and the rhodium content in the outermost layer of the protective film on the absorber film side is 50% or more of the total atoms of the outermost layer.

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