# US 12,111,566 B2 · Reflective mask blank, reflective mask and manufacturing method thereof, and semiconductor device manufacturing method

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- Number: US 12,111,566 B2
- Document ID: US12111566B2
- Status: Granted
- Kind: B2
- Application number: 18/483,453
- Filed: 2023-10-09
- Published: 2024-02-01
- Granted: 2024-10-08
- Earliest claimed: 2018-05-25
- Assignees: Hoya Corporation
- Applicants: Hoya Corporation
- Inventors: Yohei Ikebe; Tsutomu Shoki
- Web page: https://patentgrep.com/patent/US12111566B2

## CPC

- G03F 1/32: Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof
- G03F 1/24: Reflection masks; Preparation thereof
- G03F 7/2004: {characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light}
- 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

Provided is a reflective mask blank with which it is possible to further reduce the shadowing effect of a reflective mask, and also possible to form a fine and highly accurate phase-shift pattern. A reflective mask blank having, in the following order on a substrate, a multilayer reflective film and a phase-shift film that shifts the phase of EUV light, said reflective mask blank characterized in that the phase-shift film has a thin film comprising a metal-containing material that contains: ruthenium (Ru); and at least one element from among chromium (Cr), nickel (Ni), (Co), aluminum (Al), silicon (Si), titanium (Ti), vanadium (V), germanium (Ge), niobium (Nb), molybdenum (Mo), tin (Sn), tellurium (Te), hafnium (Hf), tungsten (W), and rhenium (Re).

## Claims

### Claim 1

A reflective mask blank comprising:
a substrate;
a multilayer reflective film on the substrate; and
a phase shift film on the multilayer reflective film,
wherein
the phase shift film comprises ruthenium (Ru) and at least one selected from chromium (Cr), nickel (Ni), cobalt (Co), aluminum (Al), silicon (Si), titanium (Ti), vanadium (V), germanium (Ge), niobium (Nb), molybdenum (Mo), tin (Sn), tellurium (Te), hafnium (Hf), tungsten (W) and rhenium (Re),
the phase difference of the phase shift film is 130 degrees to 160 degrees or 200 degrees to 230 degrees,
the refractive index n to EUV light is 0.860 to 0.950 and the extinction coefficient k to EUV light is 0.009 to 0.095 when the phase difference of the phase shift film is 130 degrees to 160 degrees, and
the refractive index n to EUV light is 0.860 to 0.940 and the extinction coefficient k to EUV light is 0.008 to 0.057 when the phase difference of the phase shift film is 200 degrees to 230 degrees.

### Claim 2 (depends on 1)

The reflective mask blank according to claim 1, wherein the relative reflectance of the phase shift film is 10% to 40%.

### Claim 3 (depends on 1)

The reflective mask blank according to claim 1, wherein the thickness of the phase shift film is 60 nm or less.

### Claim 4 (depends on 1)

The reflective mask blank according to claim 1, wherein the crystal structure of the phase shift film is amorphous.

### Claim 5 (depends on 1)

The reflective mask blank according to claim 1, wherein the phase shift film further comprises at least one selected from nitrogen (N), oxygen (O), carbon (C) and boron (B).

### Claim 6 (depends on 1)

The reflective mask blank according to claim 1, further comprising an etching mask film on the phase shift film, wherein
the etching mask film comprises tantalum (Ta) and at least one selected from oxygen (O), nitrogen (N), carbon (C), boron (B) and hydrogen (H).

### Claim 7 (depends on 1)

The reflective mask blank according to claim 1, further comprising an etching mask film on the phase shift film, wherein
the etching mask film comprises chromium (Cr) and at least one selected from nitrogen (N), oxygen (O), carbon (C) and hydrogen (H).

### Claim 8 (depends on 1)

The reflective mask blank according to claim 1, further comprising a protective film between the multilayer reflective film and the phase shift film.

### Claim 9

A reflective mask comprising:
a substrate;
a multilayer reflective film on the substrate; and
a phase shift film with a pattern on the multilayer reflective film, wherein
the phase shift film comprises ruthenium (Ru) and at least one selected from chromium (Cr), nickel (Ni), cobalt (Co), aluminum (Al), silicon (Si), titanium (Ti), vanadium (V), germanium (Ge), niobium (Nb), molybdenum (Mo), tin (Sn), tellurium (Te), hafnium (Hf), tungsten (W) and rhenium (Re),
the phase difference of the phase shift film is 130 degrees to 160 degrees or 200 degrees to 230 degrees,
the refractive index n to EUV light is 0.860 to 0.950 and the extinction coefficient k to EUV light is 0.009 to 0.095 when the phase difference of the phase shift film is 130 degrees to 160 degrees, and
the refractive index n to EUV light is 0.860 to 0.940 and the extinction coefficient k to EUV light is 0.008 to 0.057 when the phase difference of the phase shift film is 200 degrees to 230 degrees.

### Claim 10 (depends on 9)

The reflective mask according to claim 9, wherein the relative reflectance of the phase shift film is 10% to 40%.

### Claim 11 (depends on 9)

The reflective mask according to claim 9, wherein the thickness of the phase shift film is 60 nm or less.

### Claim 12 (depends on 9)

The reflective mask according to claim 9, wherein the crystal structure of the phase shift film is amorphous.

### Claim 13 (depends on 9)

The reflective mask according to claim 9, wherein the phase shift film further comprises at least one selected from nitrogen (N), oxygen (O), carbon (C) and boron (B).

### Claim 14 (depends on 9)

The reflective mask according to claim 9, further comprising a protective film between the multilayer reflective film and the phase shift film.

### Claim 15 (depends on 1)

A method of manufacturing a reflective mask, the method comprising that a phase shift pattern is formed by patterning the phase shift film of the reflective mask blank according to claim 1, by a dry etching gas comprising a chlorine-based gas and an oxygen gas.

### Claim 16 (depends on 9)

A method of manufacturing a semiconductor device, the method comprising placing the reflective mask according to claim 9 in an exposure apparatus comprising an exposure light source that emits EUV light, and transferring a transfer pattern to a resist film formed on a transferred substrate.