Reflective mask blank, reflective mask and method of manufacturing semiconductor device

• US 10,394,113 B2
• Filed: 12/15/2015
• Issued: 08/27/2019
• Est. Priority Date: 12/24/2014
• Status: Active Grant

• Current Assignee: Hoya Corporation
• Original Assignee: Hoya Corporation
• Inventors: Hamamoto, Kazuhiro, Ikebe, Yohei
• Primary Examiner(s): Young, Christopher G
• Application Number:
  US15/539,263
• Publication Number:
  US 20180329285A1
• Time in Patent Office: 1,351 Days
• Field of Search: 430 5
• CPC Class Codes: C03C 15/00 Surface treatment of glass, not in the form of fibres or filaments, by etching etching or surface-brightening compositions, in general C09K13/00
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3441 comprising carbon, a carbide or oxycarbide
• CPC Class Codes: C03C 17/3636 one layer at least containing silicon, hydrogenated silicon or a silicide
• CPC Class Codes: C03C 2204/08 Glass having a rough surface
• CPC Class Codes: C03C 23/0075 Cleaning of glass specially adapted to plate glass B08B11/00
• CPC Class Codes: C03C 3/06 with more than 90% silica by weight, e.g. quartz C03C3/045 takes precedence
• CPC Class Codes: G03F 1/24 Reflection masks; Preparation thereof
• CPC Class Codes: G03F 1/32 Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof
• CPC Class Codes: G03F 1/48 Protective coatings

Abstract

An object of the present invention is to obtain a reflective mask blank capable of obtaining high contrast at the edges of a phase shift film pattern. Provided is a reflective mask blank comprising a multilayer reflective film and a phase shift film that shifts the phase of EUV light formed in that order on a substrate, wherein root mean square roughness (Rms), obtained by measuring a 1 μm×1 μm region on the surface of the phase shift film with an atomic force microscope, is not more than 0.50 nm, and power spectrum density at a spatial frequency of 10 to 100 μm⁻¹ is not more than 17 nm⁴.

Claims

1. A reflective mask blank comprising:

a multilayer reflective film; and

a phase shift film that shifts the phase of EUV light formed in that order on a substrate;

wherein,

root mean square roughness (Rms), obtained by measuring a 1 μ

m×

1 μ

m region on the surface of the phase shift film with an atomic force microscope, is not more than 0.50 nm, and power spectrum density at a spatial frequency of 10 to 100 μ

m<sup>−

1</sup> is not more than 17 nm⁴.

2. The reflective mask blank according to claim 1, wherein a protective film is formed on the multilayer reflective film.

3. The reflective mask blank according to claim 1, wherein the phase shift film has a tantalum-based material layer comprising tantalum and nitrogen and a chromium-based material layer comprising chromium and nitrogen on the tantalum-based material layer.

4. The reflective mask blank according to claim 3, wherein the film thickness of the chromium-based material layer is 5 to 30 nm.

5. The reflective mask blank according to claim 2, wherein the phase shift film has a tantalum-based material layer comprising tantalum and nitrogen and a chromium-based material layer comprising chromium and nitrogen on the tantalum-based material layer.

6. The reflective mask blank according to claim 5, wherein the film thickness of the chromium-based material layer is 5 to 30 nm.

7. A reflective mask comprising:

a multilayer reflective film; and

a phase shift film pattern that shifts the phase of EUV light formed in that order on a substrate;

wherein,

root mean square roughness (Rms), obtained by measuring a 1 μ

m×

1 μ

m region on the surface of the phase shift film pattern with an atomic force microscope, is not more than 0.50 nm, and power spectrum density at a spatial frequency of 10 to 100 μ

m<sup>−

1</sup> is not more than 17 nm⁴.

8. The reflective mask according to claim 7, wherein a protective film is formed on the multilayer reflective film.

9. The reflective mask according to claim 7, wherein root mean square roughness (Rms), obtained by measuring a 1 μ

m×

1 μ

m region on the surface of the multilayer reflective film with an atomic force microscope, is not more than 0.15 nm, and power spectrum density at a spatial frequency of 10 to 100 μ

m<sup>−

1</sup> is not more than 7 nm⁴.

10. The reflective mask according to claim 7, wherein the difference between the power spectrum density on the surface of the phase shift film pattern and power spectrum density on the surface of the multilayer reflective film is not more than 10 nm⁴.

11. The reflective mask according to claim 8, wherein root mean square roughness (Rms), obtained by measuring a 1 μ

m×

1 μ

m region on the surface of the protective film with an atomic force microscope, is not more than 0.15 nm, and power spectrum density at a spatial frequency of 10 to 100 μ

m<sup>−

1</sup> is not more than 7 nm⁴.

12. The reflective mask according to claim 8, wherein the difference between the power spectrum density on the surface of the phase shift film pattern and power spectrum density on the surface of the protective film is not more than 10 nm⁴.

13. The reflective mask according to claim 8, wherein root mean square roughness (Rms), obtained by measuring a 1 μ

m×

1 μ

m region on the surface of the multilayer reflective film with an atomic force microscope, is not more than 0.15 nm, and power spectrum density at a spatial frequency of 10 to 100 μ

m<sup>−

1</sup> is not more than 7 nm⁴.

14. The reflective mask according to claim 8, wherein the difference between the power spectrum density on the surface of the phase shift film pattern and power spectrum density on the surface of the multilayer reflective film is not more than 10 nm⁴.

15. The reflective mask according to claim 9, wherein the difference between the power spectrum density on the surface of the phase shift film pattern and power spectrum density on the surface of the multilayer reflective film is not more than 10 nm⁴.

16. A method of manufacturing a semiconductor device comprising:

carrying out a lithography process using an exposure device using a reflective mask to form a transfer pattern on a transferred substrate, the reflective mask comprising;

a multilayer reflective film; and

a phase shift film pattern that shifts the phase of EUV light formed in that order on a substrate;

wherein,

root mean square roughness (Rms), obtained by measuring a 1 μ

m×

1 μ

m region on the surface of the phase shift film pattern with an atomic force microscope, is not more than 0.50 nm, and power spectrum density at a spatial frequency of 10 to 100 μ

m<sup>−

1</sup> is not more than 17 nm⁴.

17. The method of claim 16, wherein a protective film is formed on the multilayer reflective film.

18. The method of claim 16, wherein root mean square roughness (Rms), obtained by measuring a 1 μ

m×

1 μ

m region on the surface of the multilayer reflective film with an atomic force microscope, is not more than 0.15 nm, and power spectrum density at a spatial frequency of 10 to 100 μ

m<sup>−

1</sup> is not more than 7 nm⁴.

19. The method of claim 16, wherein the difference between the power spectrum density on the surface of the phase shift film pattern and power spectrum density on the surface of the multilayer reflective film is not more than 10 nm⁴.