Mask blank, method for manufacturing phase shift mask, and method for manufacturing semiconductor device

Patent metadata

Field	Value
Publication number	US-10915016-B2
Application number	US-201615769116-A
Country	US
Kind code	B2
Filing date	Oct 26, 2016
Priority date	Nov 6, 2015
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

The mask blank (100) in which a phase shift film (2) made of a material containing silicon, a light shielding film (3) made of a material containing chromium, oxygen, and carbon, and a hard mask film (4) made of a material containing one or more elements selected from silicon and tantalum are provided in this order on a transparent substrate (1) is characterized in that the light shielding film (3) is a single layer film having a composition gradient portion with an increased oxygen content at a surface on the hard mask film (4) side and in a region close thereto, the light shielding film (3) has a maximum peak of N1s narrow spectrum obtained by analysis of X-ray photoelectron spectroscopy of lower detection limit or less, and a part of the light shielding film (3) excluding the composition gradient portion has a chromium content of 50 atom % or more and has a maximum peak of Cr2p narrow spectrum obtained by analysis of X-ray photoelectron spectroscopy at binding energy of 574 eV or less.

First claim

The invention claimed is:

1. A mask blank comprising:
a transparent substrate;
a phase shift film on the transparent substrate;
a light shielding film on the phase shift film; and
a hard mask film on the light shielding film,
wherein the phase shift film contains silicon, and
wherein the light shielding film is a single layer film having a composition gradient portion with increased oxygen content, and
wherein the light shielding film contains chromium, oxygen, and carbon and has a first surface that is farthest from the phase shift film in a film thickness direction of the light shielding film, and
wherein the composition gradient portion extends from the first surface of the light shielding film to a depth of less than 5 nm, and the oxygen content of the composition gradient portion varies and is highest at the first surface, and
wherein the light shielding film, excluding the composition gradient portion, has chromium content of 50 atom % or more, and
wherein the light shielding film has a maximum peak of Nls narrow spectrum, obtained by analysis of X-ray photoelectron spectroscopy, of lower detection limit or less, and
wherein the light shielding film, excluding the composition gradient portion, has a maximum peak of Cr2p narrow spectrum, obtained by analysis of X-ray photoelectron spectroscopy, at binding energy of 574 eV or less.

2. The mask blank according to claim 1 , wherein ratio of carbon content [atom %] divided by total content [atom %] of chromium, carbon, and oxygen of the light shielding film, excluding the composition gradient portion, is 0.1 or more.

3. The mask blank according to claim 1 , wherein the composition gradient portion of the light shielding film has a maximum peak of Cr2p narrow spectrum obtained by analysis of X-ray photoelectron spectroscopy at binding energy of 576 eV or more.

4. The mask blank according to claim 1 , wherein the light shielding film has a maximum peak of Si2p narrow spectrum obtained by analysis of X-ray photoelectron spectroscopy of lower detection limit or less.

5. The mask blank according to claim 1 , wherein the light shielding film, excluding the composition gradient portion, has chromium content of 80 atom % or less.

6. The mask blank according to claim 1 , wherein the light shielding film, excluding the composition gradient portion, has carbon content of at least 10 atom % and not more than 20 atom %.

7. The mask blank according to claim 1 , wherein the light shielding film, excluding the composition gradient portion, has oxygen content of at least 10 atom % and not more than 35 atom %.

8. The mask blank according to claim 1 , wherein the light shielding film, excluding the composition gradient portion, has difference in content of each constituent element in thickness direction that is less than 10 atom %.

9. The mask blank according to claim 1 , wherein an optical density, to ArF excimer laser exposure light, of a layered structure consisting of the phase shift film and the light shielding film is greater than 2.0.

10. The mask blank according to claim 1 , wherein the light shielding film has a thickness of 60 nm or less.

11. A method of manufacturing a phase shift mask using the mask blank according to claim 1 , comprising:
forming a phase shift pattern on the hard mask film through dry etching using fluorine-based gas with a resist film having a phase shift pattern formed on the hard mask film as a mask;
forming a phase shift pattern on the light shielding film through dry etching using a mixed gas of chlorine-based gas and oxygen gas with the hard mask film having the phase shift pattern formed thereon as a mask;
forming a phase shift pattern on the phase shift film through dry etching using fluorine-based gas with the light shielding film having the phase shift pattern formed thereon as a mask; and
forming a light shielding pattern on the light shielding film through dry etching using a gaseous mixture of chlorine-based gas and oxygen gas with a resist film having the light shielding pattern formed on the light shielding film as a mask.

12. A method of manufacturing a semiconductor device comprising exposure-transferring a transfer pattern on a resist film on a semiconductor substrate, using the phase shift mask manufactured by the method of manufacturing a phase shift mask of claim 11 .

13. The method of manufacturing a semiconductor device according to claim 12 , wherein the hard mask film contains one or more elements selected from silicon and tantalum.

14. The method of manufacturing a semiconductor device according to claim 12 , wherein the oxygen content of the composition gradient portion decreases as distance from the first surface increases.

15. The method of manufacturing a phase shift mask according to claim 11 , wherein the hard mask film contains one or more elements selected from silicon and tantalum.

16. The method of manufacturing a phase shift mask according to claim 11 , wherein the oxygen content of the composition gradient portion decreases as distance from the first surface increases.

17. The mask blank according to claim 1 , wherein a thickness of the light shielding film is greater than 15 nm.

18. The mask blank according to claim 1 , the composition gradient portion has oxygen content of 40 atom % or more.

19. The mask blank according to claim 1 , wherein the hard mask film contains one or more elements selected from silicon and tantalum.

20. The mask blank according to claim 1 , wherein the oxygen content of the composition gradient portion decreases as distance from the first surface increases.

Assignees

• Hoya Corp

Inventors

• Nozawa Osamu
• Ohkubo Ryo
• Shishido Hiroaki

Classifications

• H10P76/4085

  characterised by the processes involved to create the masks · CPC title

• G03F1/80

  Etching · CPC title

• G03F1/54

  Absorbers, e.g. of opaque materials · CPC title

• G03F1/26 Primary

  Phase shift masks [PSM]; PSM blanks; Preparation thereof · CPC title

• G03F1/38

  Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof · CPC title