# US 12,117,725 B2 · Pellicle for an EUV lithography mask and a method of manufacturing thereof

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- Number: US 12,117,725 B2
- Document ID: US12117725B2
- Status: Granted
- Kind: B2
- Application number: 17/498,543
- Filed: 2021-10-11
- Published: 2022-01-27
- Granted: 2024-10-15
- Earliest claimed: 2018-04-30
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Company, Ltd.
- Inventors: Yun-Yue Lin
- Web page: https://patentgrep.com/patent/US12117725B2

## CPC

- G03F 1/62: Pellicles, e.g. pellicle assemblies, e.g. having membrane on support frame; Preparation thereof
- G03F 7/70033: {by plasma extreme ultraviolet [EUV] sources}
- G03F 7/70983: {Optical system protection, e.g. pellicles or removable covers for protection of mask}
- 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 pellicle for an EUV photo mask includes a base membrane layer, a core layer disposed over the base membrane layer and one or more metallic layers disposed over the core layer.

## Claims

### Claim 1

A method of manufacturing a pellicle for an extreme ultraviolet (EUV) photo mask, the method comprising:
forming a base membrane layer over a front surface of a substrate;
forming a core layer over the base membrane layer;
forming a cover layer over the core layer;
forming a first protection layer over the cover layer;
forming a second protection layer over the first protection layer;
forming a hard mask layer on a back surface of the substrate;
forming a first opening in the hard mask by patterning the hard mask;
removing the second protection layer;
forming a third protection layer over the first protection layer;
forming a second opening in the substrate by etching the substrate through the first opening;
removing the third protection layer and the first protection layer; and
forming one or more metallic layers over the cover layer.

### Claim 2 (depends on 1)

The method of claim 1, wherein the base membrane layer is made of SiC or silicon nitride.

### Claim 3 (depends on 2)

The method of claim 2, wherein the core layer is a poly silicon layer.

### Claim 4 (depends on 3)

The method of claim 3, wherein the cover layer is formed by implanting impurities in the core layer.

### Claim 5 (depends on 1)

The method of claim 1, wherein the cover layer is a silicon nitride layer.

### Claim 6 (depends on 1)

The method of claim 1, wherein the one or more metallic layers includes a first metallic layer and a second metallic layer disposed over the first metallic layer.

### Claim 7 (depends on 6)

The method of claim 6, wherein the second metallic layer is a Ru layer.

### Claim 8 (depends on 7)

The method of claim 7, wherein the first metallic layer is a Mo layer.

### Claim 9 (depends on 7)

The method of claim 7, wherein the first metallic layer is a Zr layer.

### Claim 10 (depends on 1)

The method of claim 1, wherein the first protection layer is made of silicon oxide or silicon nitride.

### Claim 11 (depends on 10)

The method of claim 10, wherein the second protection layer is made of a different material than the first protection layer and includes metallic material.

### Claim 12 (depends on 11)

The method of claim 11, wherein the metallic material is AlCu.

### Claim 13 (depends on 10)

The method of claim 10, wherein the third protection layer includes a metallic material.

### Claim 14 (depends on 13)

The method of claim 13, wherein the metallic material for the third protection layer is Ni.

### Claim 15 (depends on 1)

The method of claim 1, wherein the hard mask layer is made of dielectric material.

### Claim 16

A method of manufacturing a pellicle for an EUV photo mask, the method comprising:
forming a base membrane layer over a front surface of a substrate;
forming a core layer over the base membrane layer;
forming a cover layer over the core layer;
forming a first metallic layer over the cover layer;
forming a second metallic layer over the first metallic layer;
forming a first protection layer over the second metallic layer;
forming a second protection layer over the first protection layer;
forming a hard mask layer on a back surface of the substrate;
forming a first opening in the hard mask by patterning the hard mask;
removing the second protection layer;
forming a third protection layer over the first protection layer;
forming a second opening in the substrate by etching the substrate through the first opening; and
removing the third protection layer and the first protection layer.

### Claim 17 (depends on 16)

The method of claim 16, wherein a thickness of the second metal layer is smaller than a thickness of the first metal layer.

### Claim 18 (depends on 16)

The method of claim 16, wherein a thickness of the cover layer is smaller than the thickness of the first metal layer and in a range from 0.5 nm to 10 nm.

### Claim 19

A method of manufacturing a pellicle for an EUV photo mask, the method comprising:
forming a base membrane layer over a front surface of a substrate;
forming a first metallic layer in contact with the base membrane layer;
forming a second metallic layer on the second metallic layer;
forming a first protection layer over the second metallic layer;
forming a second protection layer over the first protection layer;
forming a hard mask layer on a back surface of the substrate;
forming a first opening in the hard mask by patterning the hard mask;
removing the second protection layer;
forming a third protection layer over the first protection layer;
forming a second opening in the substrate by etching the substrate through the first opening; and
removing the third protection layer and the first protection layer.

### Claim 20 (depends on 19)

The method of claim 19, wherein:
the first metallic layer is a Mo layer or a Zr layer, and
the second metallic layer is a Ru layer.