# US 8,568,944 B2 · Reflective extreme ultraviolet mask and method of manufacturing the same

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- Number: US 8,568,944 B2
- Document ID: US8568944B2
- Status: Granted
- Kind: B2
- Application number: 13/422,206
- Filed: 2012-03-16
- Published: 2012-09-20
- Granted: 2013-10-29
- Earliest claimed: 2011-03-17
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Hoon Kim; Young-Su Sung; Young-Kuen Kim; Dong-Seok Nam
- Inventors: Hoon Kim; Young-Su Sung; Young-Kuen Kim; Dong-Seok Nam
- Web page: https://patentgrep.com/patent/US8568944B2

## CPC

- G03F 1/24: Reflection masks; Preparation thereof
- B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
- B82Y 40/00: Manufacture or treatment of nanostructures
- 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)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

A reflective EUV mask and a method of manufacturing the same, the reflective EUV mask including a mask substrate having an exposing region and a peripheral region, the mask substrate including a light scattering crystalline portion that scatters light incident to the peripheral region and that decreases reflectivity of the peripheral region; a reflective layer on an upper surface of the mask substrate, the reflective layer having a first opening that exposes the crystalline portion; and an absorbing layer pattern on an upper surface of the reflective layer, the absorbing layer pattern having a second opening in fluidic communication with the first opening.

## Claims

### Claim 1

A reflective EUV mask, comprising:
a mask substrate having an exposing region and a peripheral region, the mask substrate including a light scattering crystalline portion that scatters light incident to the peripheral region and that decreases reflectivity of the peripheral region;
a reflective layer on an upper surface of the mask substrate, the reflective layer having a first opening that exposes the crystalline portion; and
an absorbing layer pattern on an upper surface of the reflective layer, the absorbing layer pattern having a second opening in fluidic communication with the first opening.

### Claim 2 (depends on 1)

The reflective EUV mask as claimed in claim 1, wherein the crystalline portion has a crystalline facet substantially parallel with an incident direction of the light.

### Claim 3 (depends on 1)

The reflective EUV mask as claimed in claim 1, wherein the reflective layer includes an alternately stacked silicon layer and molybdenum layer.

### Claim 4 (depends on 1)

The reflective EUV mask as claimed in claim 1, wherein the absorbing layer pattern includes:
an EUV absorbing layer pattern on the upper surface of the reflective layer; and
a DUV absorbing layer pattern on an upper surface of the EUV absorbing layer pattern.

### Claim 5 (depends on 4)

The reflective EUV mask as claimed in claim 4, wherein the EUV absorbing layer pattern includes a tantalum boron nitride layer.

### Claim 6 (depends on 4)

The reflective EUV mask as claimed in claim 4, wherein the DUV absorbing layer pattern includes a tantalum boron oxide layer.

### Claim 7 (depends on 1)

The reflective EUV mask as claimed in claim 1, wherein the absorbing layer pattern includes an exposing pattern in the exposing region.

### Claim 8

A method of manufacturing a reflective EUV mask, the method comprising:
forming a reflective layer on an upper surface of a mask substrate, the substrate including an exposing region and a peripheral region;
forming an absorbing layer on an upper surface of the reflective layer;
etching the reflective layer and the absorbing layer in the peripheral region to form:
a first opening in the reflective layer, the first opening exposing the upper surface of the mask substrate, and
an absorbing layer pattern having a second opening in fluidic communication with the first opening; and
forming a crystalline portion at a portion of the upper surface of the mask substrate exposed through the first opening and the second opening such that the crystalline portion scatters light incident to the peripheral region and decreases reflectivity of the peripheral region.

### Claim 9 (depends on 8)

The method as claimed in claim 8, wherein forming the crystalline portion includes converting portions of the upper surface of the mask substrate in an amorphous state into a crystalline state.

### Claim 10 (depends on 9)

The method as claimed in claim 9, wherein converting the amorphous state into the crystalline state includes irradiating a laser to the upper surface of the mask substrate.

### Claim 11 (depends on 10)

The method as claimed in claim 10, wherein the laser is irradiated in a direction substantially parallel with an incident direction of the light and provides the crystalline portion with a crystalline facet substantially parallel with the incident direction of the light.

### Claim 12 (depends on 8)

The method as claimed in claim 8, wherein forming the absorbing layer includes:
forming an EUV absorbing layer on the upper surface of the reflective layer; and
forming a DUV absorbing layer on an upper surface of the EUV absorbing layer.

### Claim 13 (depends on 8)

The method as claimed in claim 8, wherein forming the absorbing layer pattern further includes etching the absorbing layer in the exposing region to form an exposing pattern.

### Claim 14 (depends on 13)

The method as claimed in claim 13, wherein the exposing pattern is formed simultaneously with the second opening.

### Claim 15

A reflective EUV mask, comprising:
a mask substrate having an exposing region and a peripheral region, the mask substrate including a light scattering crystalline portion in the peripheral region;
a reflective layer on an upper surface of the mask substrate, the reflective layer including a first opening therethrough, the first opening overlying the crystalline portion of the mask substrate; and
an absorbing layer pattern on an upper surface of the reflective layer, the absorbing layer pattern having a second opening therethrough, the second opening overlying the first opening.

### Claim 16 (depends on 15)

The reflective EUV mask as claimed in claim 15, wherein the crystalline portion has a crystalline facet that is substantially perpendicular to an upper surface of the mask substrate.

### Claim 17 (depends on 16)

The reflective EUV mask as claimed in claim 16, wherein the crystalline portion is configured to scatter light incident to the peripheral region and to decrease reflectivity of the peripheral region.

### Claim 18 (depends on 17)

The reflective EUV mask as claimed in claim 17, wherein the crystalline portion is configured to scatter light having a wavelength of about 100 nm to about 400 nm.