# US 2010/0304281 A1 · Exposure mask and method for manufacturing same and method for manufacturing semiconductor device

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- Number: US 2010/0304281 A1
- Document ID: US20100304281A1
- Status: Published application
- Kind: A1
- Application number: 12/727,652
- Filed: 2010-03-19
- Published: 2010-12-02
- Earliest claimed: 2009-05-29
- Assignees: Kabushiki Kaisha Toshiba
- Inventors: Tomotaka HIGAKI
- Web page: https://patentgrep.com/patent/US20100304281A1

## CPC

- G03F 1/36: Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes
- G03F 1/50: Mask blanks not covered by G03F1/20 - G03F1/34; Preparation thereof
- 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

An exposure mask used to transfer a pattern defined by exposure onto a wafer, includes: a substrate; a pattern formation region provided on the substrate, and having pattern elements formed therein, the pattern elements having a size not smaller than a resolution limit after being transferred onto the wafer; and a sub-pattern formation region provided on the substrate and having sub-pattern elements formed therein. The sub-pattern element has a size smaller than the resolution limit after being transferred onto the wafer, and the sub-pattern formation region is spaced from the pattern formation region by a distance having no optical proximity effect on the pattern.

## Claims

### Claim 1

An exposure mask used to transfer a pattern defined by exposure onto a wafer, comprising:
a substrate;
a pattern formation region provided on the substrate, and having pattern elements formed therein, the pattern elements having a size not smaller than a resolution limit after being transferred onto the wafer; and
a sub-pattern formation region provided on the substrate and having sub-pattern elements formed therein, the sub-pattern element having a size smaller than the resolution limit after being transferred onto the wafer,
the sub-pattern formation region being spaced from the pattern formation region by a distance having no optical proximity effect on the pattern.

### Claim 2 (depends on 1)

The mask according to claim 1, further comprising:
a light shielding film provided in a peripheral section of the exposure mask.

### Claim 3 (depends on 1)

The exposure mask according to claim 1, wherein at least a portion of the sub-pattern elements extend in a direction intersecting a direction in which pattern elements arranged at a smallest pitch of the pattern elements extend.

### Claim 4 (depends on 3)

The exposure mask according to claim 3, wherein the portion of the sub-pattern elements extend in a direction perpendicular to the direction in which the pattern elements arranged at the smallest pitch extend.

### Claim 5 (depends on 1)

The mask according to claim 1, wherein the sub-pattern formation region surrounds the pattern formation region.

### Claim 6 (depends on 1)

The mask according to claim 1, wherein a distance between an edge of the sub-pattern formation region on a side of the pattern formation region and an edge of the sub-pattern formation region on an opposite side of the pattern formation region is not less than a width of a peripheral portion of the pattern formation region in which a width of the pattern elements varies with respect to a width of pattern elements provided in a central portion of the pattern formation region if the sub-pattern formation region is not provided.

### Claim 7 (depends on 1)

The mask according to claim 1, wherein the pattern formation region is provided in plurality and the plurality of the pattern formation regions are spaced apart from one another.

### Claim 8 (depends on 1)

The mask according to claim 1, wherein assuming that R is one-half of a pitch of images of the sub-pattern elements after being projected onto the wafer, NA is a numerical aperture of a lens used for the exposure, and λ is a wavelength of a light used for the exposure, a following relationship is satisfied:
R<0.25×λ/NA

### Claim 9 (depends on 1)

The mask according to claim 1, wherein the substrate transmits the light used for the exposure.

### Claim 10 (depends on 1)

The mask according to claim 1, wherein the substrate reflects the light used for the exposure.

### Claim 11

A method for manufacturing an exposure mask used to transfer a pattern defined by exposure onto a wafer, comprising:
forming a resist film on a structure having a pattern forming film formed on a substrate;
exposing the resist film;
developing the resist film after the exposure to selectively remove the resist film; and
selectively removing the pattern forming film by etching using the selectively removed resist film as a mask,
the exposing the resist film including drawing pattern elements in a pattern formation region, the pattern elements having a size not smaller than a resolution limit after being transferred onto the wafer, and drawing sub-pattern elements in a sub-pattern formation region, the sub-pattern elements having a size smaller than the resolution limit after being transferred onto the wafer, the sub-pattern formation region being spaced from the pattern formation region by a distance having no optical proximity effect on the pattern.

### Claim 12 (depends on 11)

The method according to claim 11, further comprising:
removing a light shielding film disposed in the pattern formation region, the light shielding film being formed on the pattern forming film of the structure,
the selectively removing the pattern forming film including leaving the pattern forming film and the light shielding film in a peripheral section of the exposure mask.

### Claim 13 (depends on 11)

The method according to claim 11, wherein the exposing the resist film includes drawing at least a portion of the sub-pattern elements to extend in a direction intersecting a direction in which pattern elements arranged at a smallest pitch of the pattern elements extend.

### Claim 14 (depends on 13)

The method according to claim 13, wherein the exposing the resist film includes drawing the portion of the sub-pattern elements extending in a direction perpendicular to the direction in which the pattern elements arranged at the smallest pitch extend.

### Claim 15 (depends on 11)

The method according to claim 11, wherein the sub-pattern formation region is disposed to surround the pattern formation region.

### Claim 16

A method for manufacturing a semiconductor device, comprising:
forming a resist film on a wafer; and
exposing the resist film using an exposure mask,
a mask including a pattern formation region having a pattern formed and an sub-pattern formation region having a sub-pattern formed on a substrate being implemented as the exposure mask, the sub-pattern formation region being spaced from the pattern formation region by a distance having no optical proximity effect on the pattern,
the exposing including transferring the pattern onto the wafer and not transferring the sub-pattern onto the wafer.

### Claim 17 (depends on 16)

The method according to claim 16, wherein
the pattern includes a plurality of pattern elements and the sub-pattern includes a plurality of sub-pattern elements,
a size of the pattern elements is set to be not smaller than a resolution limit after being transferred onto the wafer and a size of the sub-pattern elements is set to be smaller than the resolution limit after being transferred onto the wafer.

### Claim 18 (depends on 16)

The method according to claim 16, wherein at least a portion of the sub-pattern elements extend in a direction intersecting a direction in which pattern elements arranged at a smallest pitch of the pattern elements extend,
the exposing including using a light polarized in a direction in which the pattern elements arranged at the smallest pitch extend.

### Claim 19 (depends on 18)

The exposure mask according to claim 18, wherein the portion of the sub-pattern elements extend in a direction perpendicular to the direction in which the pattern elements arranged at the smallest pitch extend.

### Claim 20 (depends on 16)

The mask according to claim 16, wherein assuming that R is one-half of a pitch of images of the sub-pattern elements after being projected onto the wafer, NA is a numerical aperture of a lens used for the exposure, and λ is a wavelength of a light used for the exposure, a following relationship is satisfied:
R<0.25×λ/NA