Mask blank, phase shift mask, and production method thereof

Patent metadata

Field	Value
Publication number	US-9971238-B2
Application number	US-201515301900-A
Country	US
Kind code	B2
Filing date	Jan 29, 2015
Priority date	Aug 20, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The present invention provides a mask blank including: a transparent substrate, a half-transparent layer for controlling a phase and a transmittance of the exposure light, formed on the transparent substrate, a middle layer formed on the half-transparent layer, and a light-shielding layer formed on the middle layer, wherein the light-shielding layer is constituted with a single metal material not including a transition metal; a film thickness of the light-shielding layer is 40 nm or less; and an optical density of a laminated body, in which three kinds of layers: the half-transparent layer, the middle layer, and the light-shielding layer are laminated, with respect to the exposure light is a value to the extent that the laminated body functions as a light-shielding region or more; the mask blank is used for producing a half tone type phase shift mask, and suitable for a lithography technique on a wafer from 40 nm half pitch and on for its high light-shielding property even thinning the light-shielding pattern film, capability of decreasing the value of EMF bias, and excellency in pattern processability, light-shielding property and chemical resistance.

First claim

The invention claimed is:

1. A mask blank to be used for producing a half tone type phase shift mask which applies an ArF excimer laser exposure light, comprising:
a transparent substrate,
a half-transparent layer for controlling a phase and a transmittance of the exposure light, formed on the transparent substrate,
a middle layer formed on the half-transparent layer, and
a light-shielding layer formed on the middle layer,
wherein the light-shielding layer is comprised of a single metal material not including a transition metal,
a film thickness of the light-shielding layer is 40 nm or less, and
an optical density of a laminated body, in which three kinds of layers: the half-transparent layer, the middle layer, and the light-shielding layer are laminated, with respect to the exposure light is a value to the extent that the laminated body functions as a light-shielding region or more.

2. The mask blank according to claim 1 , wherein the laminated body, in which three kinds of layers: the half-transparent layer, the middle layer, and the light-shielding layer are laminated, is adjusted so as to have an optical density with respect to the exposure light being 2.8 or more.

3. The mask blank according to claim 1 , wherein a relation between a transmittance T with respect to the exposure light of the half-transparent layer and a film thickness “d” of the light-shielding layer is:
in the range of 23 nm≤d≤27 nm when T=6%,
in the range of 31 nm≤d≤35 nm when T=20%,
in the range of 33 nm≤d≤37 nm when T=30%.

4. The mask blank according to claim 1 , wherein the light-shielding layer is comprised of the single metal material with a refractive index “n” being 1.0 or less and an extinction coefficient “k” being 2.0 or more.

5. The mask blank according to claim 1 , wherein the single metal material is silicone.

6. The mask blank according to claim 1 , wherein the half-transparent layer is comprised of Si x O 1-x-y N y (“x” and “y” satisfy 0<x<1, 0<y<1, and 0<x+y≤1).

7. The mask blank according to claim 1 , wherein the middle layer is comprised of a material with resistance to a dry etching using fluorine-based gas.

8. The mask blank according to claim 1 , wherein the middle layer is comprised of a chrome-based material containing chrome (Cr), and a film thickness of the middle layer is in the range of 2 nm to 5 nm.

9. The mask blank according to claim 1 , wherein a hard mask layer comprised of a material with resistance to a dry etching using fluorine-based gas is provided on the light-shielding layer.

10. A half tone type phase shift mask which applies an ArF excimer laser exposure light, comprising:
a transparent substrate,
a half-transparent pattern film for controlling a phase and a transmittance of the exposure light, formed on the transparent substrate,
a middle pattern film formed on the half-transparent pattern film, and
a light-shielding pattern film formed on the middle pattern film,
wherein the light-shielding pattern film is comprised of a single metal material not including a transition metal,
a film thickness of the light-shielding pattern film is 40 nm or less, and
an optical density of a laminated body, in which three kinds of films: the half-transparent pattern film, the middle pattern film, and the light-shielding pattern film are laminated, with respect to the exposure light is a value to the extent that the laminated body functions as a light-shielding region or more.

11. The phase shift mask according to claim 10 , wherein the laminated body, in which three kinds of films: the half-transparent pattern film, the middle pattern film, and the light-shielding pattern film are laminated, is adjusted so as to have an optical density with respect to the exposure light being 2.8 or more.

12. The phase shift mask according to claim 10 , wherein a relation between a transmittance T with respect to the exposure light of the half-transparent pattern film and a film thickness “d” of the light-shielding pattern film is:
in the range of 23 nm≤d≤27 nm when T=6%,
in the range of 31 nm≤d≤35 nm when T=20%,
in the range of 33 nm≤d≤37 nm when T=30%.

13. The phase shift mask according to claim 10 , wherein the light-shielding pattern film is comprised of the single metal material with a reflective index “n” being 1.0 or less and an extinction coefficient “k” being 2.0 or more.

14. The phase shift mask according to claim 10 , wherein the single metal material is silicone.

15. The phase shift mask according to claim 10 , wherein the half-transparent pattern film is comprised of Si x O 1-x-y N y (“x” and “y” satisfy 0<x<1, 0<y<1, and 0<x+y≤1).

16. The phase shift mask according to claim 10 , wherein the middle pattern film is comprised of a material with resistance to a dry etching using fluorine-based gas.

17. The phase shift mask according to claim 10 , wherein the middle pattern film is comprised of a chrome-based material containing chrome (Cr), and a film thickness of the middle pattern film is in the range of 2 nm to 5 nm.

18. A producing method for a phase shift mask, the method comprising steps of:
preparing a mask blank with a hard mask layer comprising a transparent substrate, a half-transparent layer for controlling a phase and a transmittance of the exposure light, formed on the transparent substrate, a middle layer formed on the half-transparent layer, and a light-shielding layer formed on the middle layer, in which a hard mask layer is formed on the light-shielding layer of the mask blank, the light-shielding layer is comprised of a single metal material not including a transition metal;
forming a first resist pattern film on the hard mask layer;
forming a first form of a hard mask pattern film by etching the hard mask layer exposed from the first resist pattern film;
forming a first form of a light-shielding pattern film by etching the light-shielding layer exposed from the first form of a hard mask pattern film by using the middle layer as an etch stopping layer;
removing the first resist pattern film;
forming a second resist pattern film that covers a desired region of the first form of a hard mask pattern film and a desired region of the middle layer exposed from the first form of a light-shielding pattern film;
forming a second form of a hard mask pattern film and a first form of a middle pattern film by etching the first form of a hard mask pattern film exposed from the second resist pattern film and the middle layer exposed from the second resist pattern film and the first form of a light-shielding pattern film;
removing the second resist pattern film;
forming a second form of a light-shielding pattern film and a half-transparent pattern film by etching the first form of a light-shielding pattern film exposed from the second form of a hard mask pattern film and the half-transparent layer exposed from the first form of a middle pattern film; and
forming a second form of a middle pattern film by etching the second form of a hard mask pattern film and the first form of a middle pattern film exposed from the second form of a light-shielding pattern film, while removing the second form of a hard mask pattern film;
in this order.

19. A producing method for a phase shift mask, the method comprising steps of:
preparing a mask blank with a hard mask layer comprising a transparent substrate, a half-transparent layer for controlling a phase and a transmittance of the exposure light, formed on the transparent substrate, a middle layer formed on the half-transparent layer, and a light-shielding layer formed on

Assignees

• Dainippon Printing Co Ltd

Inventors

• Watanabe Hiroshi
• Hayano Katsuya
• Takamizawa Hideyoshi
• Ohkawa Youhei
• Adachi Takashi
• Tani Ayako
• Miura Yoichi

Classifications

• G03F1/32 Primary

  Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof · CPC title

• G03F1/54

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