# US 11,112,690 B2 · Mask blank, transfer mask, and method for manufacturing semiconductor device

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- Number: US 11,112,690 B2
- Document ID: US11112690B2
- Status: Granted
- Kind: B2
- Application number: 16/327,172
- Filed: 2017-08-02
- Published: 2019-07-04
- Granted: 2021-09-07
- Earliest claimed: 2016-08-26
- Assignees: Hoya Corporation
- Applicants: Hoya Corporation
- Inventors: Hiroaki Shishido
- Web page: https://patentgrep.com/patent/US11112690B2

## CPC

- G03F 1/26: Phase shift masks [PSM]; PSM blanks; Preparation thereof
- G03F 1/50: Mask blanks not covered by G03F1/20 - G03F1/34; Preparation thereof
- G03F 1/54: Absorbers, e.g. of opaque materials
- G03F 7/20: Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00)
- G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G)

## Abstract

A mask blank including a light shielding film pattern having high ArF light fastness. The light shielding film is on a transparent substrate. In the mask blank, the light shielding film is a single layer film formed of a material containing silicon and nitrogen, and the light shielding film has an optical density to an ArF excimer laser exposure light of 2.5 or more, a surface reflectance to the exposure light of 40% or less, a back-surface reflectance to the exposure light of 40% or less, a transmittance to a light having a wavelength of 900 nm of 50% or less, an extinction coefficient to a light having a wavelength of 900 nm of 0.04 or more, and a thickness of 60 nm or less.

## Claims

### Claim 1

A mask blank comprising:
a transparent substrate; and
a light shielding film on the transparent substrate;
wherein the light shielding film is a single layer film formed of a material containing silicon and nitrogen;
wherein the light shielding film has an optical density to an ArF excimer laser exposure light of 2.5 or more;
wherein a surface reflectance of the light shielding film to the exposure light is 40% or less;
wherein a back-surface reflectance of the light shielding film to the exposure light is 40% or less;
wherein a transmittance of the light shielding film to a light having a wavelength of 900 nm is 50% or less;
wherein an extinction coefficient k of the light shielding film to a light having a wavelength of 900 nm is 0.04 or more; and
wherein a thickness of the light shielding film is 60 nm or less.

### Claim 2 (depends on 1)

The mask blank according to claim 1, wherein the light shielding film is formed of a material consisting of silicon and nitrogen, or a material consisting of silicon, nitrogen, and one or more elements selected from a semimetal element and a non-metal element.

### Claim 3 (depends on 1)

The mask blank according to claim 1,
wherein the light shielding film includes a composition gradient portion at a side opposite to the transparent substrate,
wherein an oxygen content of the composition gradient portion increases toward a surface opposite to the transparent substrate, and
wherein the light shielding film except for the surface layer is formed of a material consisting of silicon and nitrogen, or a material consisting of silicon, nitrogen, and one or more elements selected from a semimetal element and a non-metal element.

### Claim 4 (depends on 1)

The mask blank according to claim 1, comprising on the light shielding film a hard mask film made of a material containing chromium.

### Claim 5

A transfer mask comprising:
a transparent substrate; and
a light shielding film including a transfer pattern on the transparent substrate;
wherein the light shielding film is a single layer film formed of a material containing silicon and nitrogen;
wherein the light shielding film has an optical density to an ArF excimer laser exposure light of 2.5 or more;
wherein a surface reflectance of the light shielding film to the exposure light is 40% or less;
wherein a back surface reflectance of the light shielding film to the exposure light is 40% or less;
wherein a transmittance of the light shielding film to a light having a wavelength of 900 nm is 50% or less;
wherein an extinction coefficient k of the light shielding film to a light having a wavelength of 900 nm is 0.04 or more; and
wherein a thickness of the light shielding film is 60 nm or less.

### Claim 6 (depends on 5)

The transfer mask according to claim 5, wherein the light shielding film is formed of a material consisting of silicon and nitrogen, or a material consisting of silicon, nitrogen, and one or more elements selected from a semimetal element and a non-metal element.

### Claim 7 (depends on 5)

The transfer mask according to claim 5,
wherein the light shielding film includes a composition gradient portion at a side opposite to the transparent substrate,
wherein an oxygen content of the composition gradient portion increases toward a surface opposite to the transparent substrate, and
wherein the light shielding film except for the surface layer is formed of a material consisting of silicon and nitrogen, or a material consisting of silicon, nitrogen, and one or more elements selected from a semimetal element and a non-metal element.

### Claim 8 (depends on 5)

A method of manufacturing a semiconductor device, the method comprising the step of exposure-transferring the transfer pattern on a resist film on a semiconductor substrate using the transfer mask according to claim 5.