主权项 |
1. A mask blank, comprising:
a transparent substrate having a main surface; and a thin film for forming a transfer pattern on the main surface of the transparent substrate; wherein the thin film is made of a material composed of silicon and nitrogen or a material composed of silicon and nitrogen and one or more elements selected from semi-metal elements, non-metal elements, and rare gases; wherein the thin film has as a surface layer an oxide layer having an oxygen content higher than an oxygen content of the thin film of a region excluding the surface layer, wherein the thin film is formed so that a thickness of an outer peripheral portion is greater than a thickness of a central portion on a side of the main surface, and wherein the oxide layer is formed so that a thickness of the outer peripheral portion is greater than a thickness of the central portion on the side of the main surface. |