Photomask blank, photomask, and method of manufacture
First Claim
1. A phase shift mask blank, comprising:
- a substrate which is transparent to exposure light; and
a phase shift film disposed on the substrate, said phase shift film having one side contacting the substrate and a surface side remote therefrom, whereinsaid phase shift film consists of one of metal silicide oxide, metal silicide nitride and metal silicide oxynitride, andsaid phase shift film comprises a plurality of layers containing a metal and silicon in different compositional ratios which are stacked in such order that a layer having a higher etching rate is on the substrate side and a layer having a lower etching rate is on the surface side.
0 Assignments
0 Petitions
Accused Products
Abstract
A photomask blank comprising a multilayer film including at least four layers of different compositions, wherein the interface between the layers is moderately graded in composition; a phase shift mask blank comprising a phase shift film of at least two layers including a surface layer of a composition based on a zirconium silicide compound and a substrate adjacent layer of a composition based on a molybdenum silicide compound, and a further layer between one layer and another layer of a different composition, the further layer having a composition moderately graded from that of the one layer to that of the other layer; a phase shift mask blank comprising a phase shift film including a plurality of layers containing a metal and silicon in different compositional ratios which are stacked in such order that a layer having a higher etching rate is on the substrate side and a layer having a lower etching rate is on the surface side. The invention provides a photomask blank, typically a phase shift mask blank, which satisfies optical properties such as transmittance, reflectance and refractive index at an exposure wavelength of interest, and has an etched pattern with a minimal line edge roughness, and a photomask, typically a phase shift mask obtained therefrom.
-
Citations
11 Claims
-
1. A phase shift mask blank, comprising:
-
a substrate which is transparent to exposure light; and a phase shift film disposed on the substrate, said phase shift film having one side contacting the substrate and a surface side remote therefrom, wherein said phase shift film consists of one of metal silicide oxide, metal silicide nitride and metal silicide oxynitride, and said phase shift film comprises a plurality of layers containing a metal and silicon in different compositional ratios which are stacked in such order that a layer having a higher etching rate is on the substrate side and a layer having a lower etching rate is on the surface side. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification