Patent ID: 10571797

Abstract:
A mask blank is provided, which makes it possible to form a fine transfer pattern in a light-semitransmissive film with high accuracy even if the light-semitransmissive film is made of a material containing silicon and a light shielding film is made of a material containing chromium.The mask blank 100 has a structure in which the light-semitransmissive film 2, etching mask film 3, and light shielding film 4 are laminated in this order on the transparent substrate 1. It is featured in that the light-semitransmissive film 2 is made of the material containing silicon, the etching mask film 3 is made of the material containing chromium, the light shielding film 4 is made of a material containing chromium and oxygen, and a ratio of the etching rate of the light shielding film 4 to the etching rate of the etching mask film 3 in the dry etching with an oxygen-containing chlorine-based gas is not less than 3 and not more than 12.