Patent ID: 11022875

Abstract:
Provided is a mask blank for a phase shift mask including an etching stopper film. A mask blank has a structure where a transparent substrate has layered thereon an etching stopper film and a phase shift film in this order, in which the phase shift film contains silicon and oxygen, in which the phase shift film has a refractive index n1 of 1.5 or more for light of 193 nm wavelength and an extinction coefficient k1 of 0.1 or less for light of 193 nm wavelength, in which the etching stopper film has a refractive index n2 of 2.6 or more for light of 193 nm wavelength and an extinction coefficient k2 of 0.4 or less for light of 193 nm wavelength, and the refractive index n2 and the extinction coefficient k2 satisfy at least one of k2≤[(−0.188×n2)+0.879] and k2≤[(2.75×n2)−6.945].