Patent ID: 10101650

Abstract:
A mask blank is provided, by which an alignment mark can be formed between a transparent substrate and a laminated structure of a light semitransmissive film, etching stopper film, and light shielding film during manufacture of a transfer mask. The mask blank 100 comprises a structure in which the light semitransmissive film 2, etching stopper film 3, light shielding film 4, and etching mask film 5 are laminated in said order on the transparent substrate 1; the light semitransmissive film 2 and light shielding film 3 are made of a material which can be dry etched with a fluorine-based gas; the etching stopper film and etching mask film are made of a material containing chromium; and when a thickness of the etching stopper film is Ds, an etching rate of the etching stopper film with respect to an oxygen-containing chlorine-based gas is Vs, a thickness of the etching mask film is Dm, and an etching rate of the etching mask film with respect to the oxygen-containing chlorine-based gas is Vm, a relationship: (Dm/Vm)>(Ds/Vs) is satisfied.