Halftone phase shift mask blank, halftone phase shift mask, and pattern exposure method
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsTakuro Kosaka, Yukio Inazuki
Life of this patent
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Abstract
In a halftone phase shift mask blank comprising a transparent substrate and a halftone phase shift film thereon, the halftone phase shift film is composed of a silicon base material consisting of silicon, nitrogen and 0-6 at % of oxygen, has a refractive index n of at least 2.4, an extinction coefficient k of 0.4-0.7, and a thickness of 40-67 nm. The halftone phase shift film is thin enough to be advantageous for photomask pattern formation, has chemical resistance against chemical cleaning, and maintains a necessary phase shift for phase shift function and a necessary transmittance for halftone function.
Claims5
A halftone phase shift mask blank comprising a transparent substrate and a halftone phase shift film thereon having a phase shift of 150 to 200° and a transmittance of 3 to 12% with respect to light of wavelength up to 200 nm, wherein
- said halftone phase shift film is a single layer composed of a silicon base material consisting of silicon and nitrogen or a silicon base material consisting of silicon, nitrogen and oxygen, with an oxygen content being up to 6 at %, the single layer having a refractive index n of at least 2.4 and an extinction coefficient k of 0.4 to 0.7, or a multilayer film including at least one layer composed of a silicon base material consisting of silicon and nitrogen or a silicon base material consisting of silicon, nitrogen and oxygen, with an oxygen content being up to 6 at %, the at least one layer having a refractive index n of at least 2.4 and an extinction coefficient k of 0.4 to 0.7, and said halftone phase shift film has a thickness of up to 67 nm, wherein
- said halftone phase shift film is a single layer composed of a silicon base material consisting of silicon and nitrogen, or a multilayer film including at least one layer composed of a silicon base material consisting of silicon and nitrogen and at least one layer composed of a silicon base material consisting of silicon, nitrogen and oxygen.
A halftone phase shift mask comprising a transparent substrate and a pattern of halftone phase shift film thereon having a phase shift of 150 to 200° and a transmittance of 3 to 12% with respect to light of wavelength up to 200 nm, wherein
- said halftone phase shift film is a single layer composed of a silicon base material consisting of silicon and nitrogen or a silicon base material consisting of silicon, nitrogen and oxygen, with an oxygen content being up to 6 at %, the single layer having a refractive index n of at least 2.4 and an extinction coefficient k of 0.4 to 0.7, or a multilayer film including at least one layer composed of a silicon base material consisting of silicon and nitrogen or a silicon base material consisting of silicon, nitrogen and oxygen, with an oxygen content being up to 6 at %, the at least one layer having a refractive index n of at least 2.4 and an extinction coefficient k of 0.4 to 0.7, and said halftone phase shift film has a thickness of up to 67 nm, wherein
- said halftone phase shift film is a single layer composed of a silicon base material consisting of silicon and nitrogen, or a multilayer film including at least one layer composed of a silicon base material consisting of silicon and nitrogen and at least one layer composed of a silicon base material consisting of silicon, nitrogen and oxygen.
A method of exposing a photoresist film on a processable substrate to light of wavelength up to 200 nm through a mask for pattern transfer, the method being a photolithography for forming a pattern with a half pitch of up to 50 nm on the processable substrate, wherein
- said mask is a halftone phase shift mask comprising a transparent substrate and a pattern of halftone phase shift film thereon having a phase shift of 150 to 200° and a transmittance of 3 to 12% with respect to light of wavelength up to 200 nm,
- said halftone phase shift film is a single layer composed of a silicon base material consisting of silicon and nitrogen or a silicon base material consisting of silicon, nitrogen and oxygen, with an oxygen content being up to 6 at %, the single layer having a refractive index n of at least 2.4 and an extinction coefficient k of 0.4 to 0.7, or a multilayer film including at least one layer composed of a silicon base material consisting of silicon and nitrogen or a silicon base material consisting of silicon, nitrogen and oxygen, with an oxygen content being up to 6 at %, the at least one layer having a refractive index n of at least 2.4 and an extinction coefficient k of 0.4 to 0.7, and said halftone phase shift film has a thickness of up to 67 nm, wherein
- said halftone phase shift film is a single layer composed of a silicon base material consisting of silicon and nitrogen, or a multilayer film including at least one layer composed of a silicon base material consisting of silicon and nitrogen and at least one layer composed of a silicon base material consisting of silicon, nitrogen and oxygen.
Dependencies are inferred from the claim text.