PHASE SHIFT MASK BLANK AND ITS MANUFACTURING METHOD, AND METHOD FOR MANUFACTURING PHASE SHIFT MASK

摘要

Provided are a phase shift mask blank which can pattern a phase shift film to have a cross section which can sufficiently exhibit a phase shift effect by wet etching process, a manufacturing method thereof, and a manufacturing method of a phase shift mask which has a phase shift film patterns capable of sufficiently exhibiting a phase shift effect. The phase shift mask blank (1) has a phase shift film (3) which contains metal, silicon, oxygen, and/or nitrogen on a transparent substrate (2). The phase shift film (3) has a main layer (3a) and a top surface layer (3b) which are constituted of same material as the phase shift film. The refractive index of the upper part of the main layer on the side of the top surface layer (3b) under a wavelength of 365 nm is smaller than the refractive index of the bottom part of the main layer on the side of the transparent substrate (2) under a wavelength of 365 nm.