Blankmask and photomask for EUV lithography with hard mask film containing chrome and niobium

Abstract

The blank mask for EUV lithography has a structure in which a reflective film, a capping film, an absorber film, and a hard mask film are sequentially stacked on a substrate. The hard mask film is formed of a material containing chromium (Cr), niobium (Nb), oxygen (O), and nitrogen (N), allowing sufficient etching speed to be obtained even using only chlorine-based etching gas without oxygen (O2). Accordingly, damage to the resist film caused by oxygen (O2) is prevented, and damage to the capping film is prevented since the capping film is not exposed to oxygen (O2) during the process of removing the hard mask film.

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