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US 7,622,228 B2Granted
Halftone phase shift mask blank, and method of manufacture
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsSatoshi Okazaki, Toshinobu Ishihara
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Abstract
A halftone phase shift mask blank has a phase shifter film on a transparent substrate. The phase shifter film is composed of a metal silicide compound containing Mo, at least one metal selected from Ta, Zr, Cr and W, and at least one element selected from O, N and C. The halftone phase shift mask blank has improved processability and high resistance to chemicals, especially to alkaline chemicals.
Claims5
A method of manufacturing a halftone phase shift mask blank, comprising the steps of:
- using molybdenum silicide as a first target and at least one metal silicide selected from the group consisting of tantalum silicide, zirconium silicide, chromium silicide, and tungsten silicide as a second target, and
- carrying out reactive sputtering in the presence of at least one reactive gas containing at least one element selected from the group consisting of oxygen, nitrogen, and carbon, while applying an electric power to the first and second targets at the same time, thereby forming a phase shifter film of a metal silicide compound on a transparent substrate.
Dependencies are inferred from the claim text.