KR-102963842-B1 - Reflective mask blank and reflective mask, and method for manufacturing a semiconductor device

KR102963842B1KR 102963842 B1KR102963842 B1KR 102963842B1KR-102963842-B1

Abstract

The present invention provides a reflective mask blank capable of providing a phase shift film that can further reduce crystallinity (can be further microcrystalline or amorphous) while satisfying the optical properties of the phase shift film. A reflective mask blank having a multilayer reflective film and a thin film for pattern formation in this order on the main surface of a substrate, wherein the thin film is formed as a single layer structure comprising a ruthenium-containing layer containing at least ruthenium, nitrogen, and oxygen, or as a multilayer structure including a ruthenium-containing layer, and an X-ray diffraction profile is obtained by performing an analysis by in-plane measurement of the X-ray diffraction method on the ruthenium-containing layer, and when the maximum value of the diffraction intensity within the range where the diffraction angle 2θ is 65 to 75 degrees is I_P1 and the average value of the diffraction intensity within the range where the diffraction angle 2θ is 55 to 65 degrees is I_avg, the reflective mask blank is characterized in that I_P1/I_avg is greater than 1.0 and less than 3.0.

Inventors

후카사와 이쿠야
이케베 요헤이

Assignees

호야 가부시키가이샤

Dates

Publication Date: 20260513
Application Date: 20210217
Priority Date: 20200310

Claims (15)

A reflective mask blank having a multilayer reflective film and a thin film for pattern formation in this order on the main surface of a substrate, The above thin film is a phase shift film having a single-layer structure comprising a ruthenium-containing layer containing at least ruthenium, nitrogen, and oxygen, or a multi-layer structure comprising said ruthenium-containing layer. The oxygen content of the ruthenium-containing layer is 2 atomic% or more and 30 atomic% or less, and the nitrogen content is 5 atomic% or more and 50 atomic% or less, and A reflective mask blank characterized by having an amorphous or microcrystalline structure in which I_P1/I_avg is greater than 1.0 and less than 3.0, where I_P1 is the maximum diffraction intensity within the range where the diffraction angle 2θ is 65 to 75 degrees and I_avg is the average diffraction intensity within the range where the diffraction angle 2θ is 55 to 65 degrees, and I_P1/I_avg is greater than 1.0 and less than 3.0.
In Article 1, A reflective mask blank characterized in that the above-mentioned ruthenium-containing layer has a nitrogen content greater than the oxygen content.
In Article 1 or Article 2, A reflective mask blank characterized in that the above-mentioned ruthenium-containing layer contains chromium.
In Article 1 or Article 2, A reflective mask blank characterized in that the element most abundantly contained in the above ruthenium-containing layer is ruthenium.
In Article 1 or Article 2, A reflective mask blank characterized in that the thin film is formed in a multilayer structure having an uppermost layer containing ruthenium on top of the ruthenium-containing layer.
In Article 5, A reflective mask blank characterized in that the element most abundantly contained in the uppermost layer is oxygen.
In Article 1 or Article 2, A reflective mask blank characterized by having a protective film between the above-mentioned multilayer reflective film and the above-mentioned thin film.
A reflective mask having a multilayer reflective film and a thin film having a transfer pattern formed thereon in this order on the main surface of a substrate, The above thin film is a phase shift film having a single-layer structure comprising a ruthenium-containing layer containing at least ruthenium, nitrogen, and oxygen, or a multi-layer structure comprising said ruthenium-containing layer. The oxygen content of the ruthenium-containing layer is 2 atomic% or more and 30 atomic% or less, and the nitrogen content is 5 atomic% or more and 50 atomic% or less, and A reflective mask characterized by having an amorphous or microcrystalline structure in which I_P1/I_avg is greater than 1.0 and less than 3.0, where I_P1 is the maximum diffraction intensity within the range where the diffraction angle 2θ is 65 to 75 degrees and I_avg is the average diffraction intensity within the range where the diffraction angle 2θ is 55 to 65 degrees, and I_P1/I_avg is greater than 1.0 and less than 3.0.
In Article 8, A reflective mask characterized in that the above-mentioned ruthenium-containing layer has a nitrogen content greater than the oxygen content.
In Article 8 or Article 9, A reflective mask characterized in that the above-mentioned ruthenium-containing layer contains chromium.
In Article 8 or Article 9, A reflective mask characterized in that the element most abundantly contained in the above ruthenium-containing layer is ruthenium.
In Article 8 or Article 9, A reflective mask characterized in that the thin film is formed as a multilayer structure having a top layer containing ruthenium on top of the ruthenium-containing layer.
In Article 12, A reflective mask characterized in that the element most abundantly contained in the uppermost layer is oxygen.
In Article 8 or Article 9, A reflective mask characterized by having a protective film between the above-mentioned multilayer reflective film and the above-mentioned thin film.
A method for manufacturing a semiconductor device characterized by comprising a process of photolithographically transferring a transfer pattern onto a resist film on a semiconductor substrate using a reflective mask described in claim 8 or 9.

Description

Reflective mask blank and reflective mask, and method for manufacturing a semiconductor device The present invention relates to a reflective mask blank and a reflective mask, which are plates for manufacturing an exposure mask used in the manufacture of semiconductor devices, and a method for manufacturing a semiconductor device. Photolithography equipment used in the manufacture of semiconductor devices has evolved by gradually shortening the wavelength of the light source. To realize finer pattern transfer, EUV lithography using extreme ultraviolet light (EUV; hereinafter referred to as EUV light) with a wavelength of approximately 13.5 nm has been developed. In EUV lithography, reflective masks are used because there are few materials that are transparent to EUV light. Representative reflective masks include reflective binary masks and reflective phase shift masks (reflective halftone phase shift masks). A reflective binary mask has a relatively thick absorber pattern that sufficiently absorbs EUV light. A reflective phase shift mask has a relatively thin absorber pattern (phase shift pattern) that reduces the light of EUV light through light absorption and also generates reflected light with a phase inverted at a desired angle with respect to the reflected light from a multilayer reflective film. The reflective phase shift mask can further improve resolution because high transfer optical contrast is obtained through the phase shift effect. In addition, since the film thickness of the absorber pattern (phase shift pattern) of the reflective phase shift mask is thin, a fine phase shift pattern with good precision can be formed. Technologies related to such reflective masks for EUV lithography and mask blanks for producing them are described in Patent Documents 1 and 2. Patent Document 1 describes a reflective exposure mask having a multilayer reflective film that becomes a high-reflection region with respect to exposure light, and an absorber pattern that absorbs the exposure light and simultaneously becomes a low-reflection region with respect to the exposure light. Furthermore, Patent Document 1 describes that the phase difference between the reflected light of the exposure light from the multilayer reflective film and the reflected light of the exposure light from the absorber pattern is within 180 degrees ± 10 degrees. Additionally, Patent Document 1 describes using, as the absorber pattern, a single-layer absorber pattern composed of a Ru film having Ru as the main component, or a multilayer absorber pattern composed of a stacked film of a Ru film and a Cr film having Cr as the main component, which is thinner than the Ru film. Furthermore, as the material for the Ru film having Ru as the main component, for example, a CrRu alloy and a CrRuN alloy are described. Patent Document 2 describes a halftone type EUV mask comprising a substrate, a high-reflection portion formed on the substrate, and a patterned low-reflection portion formed on the high-reflection portion. Additionally, Patent Document 2 describes that the low-reflection portion has a stacked structure comprising a first layer having Ta (tantalum) and a second layer having Ru (ruthenium). FIG. 1 is a schematic cross-sectional view of a main part to explain an example of the schematic configuration of a reflective mask blank of an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a main part to explain another example of the schematic configuration of a reflective mask blank of an embodiment of the present invention. Figure 3 is a process diagram showing a cross-sectional schematic of the main part of the process of manufacturing a reflective mask from a reflective mask blank. Figure 4 is a diagram showing the relationship between the diffraction angle and the diffraction intensity when a phase shift film using a material corresponding to the lower layer of Example 1 is measured by the in-plane measurement method of X-ray diffraction. Figure 5 is a diagram showing the relationship between the diffraction angle and the diffraction intensity when a phase shift film using a material corresponding to the lower layer of Example 2 is measured by the in-plane measurement method of X-ray diffraction. Figure 6 is a diagram showing the relationship between the diffraction angle and the diffraction intensity when a phase shift film using a material corresponding to the lower layer of Example 3 is measured by the in-plane measurement method of X-ray diffraction. Figure 7 is a diagram showing the relationship between the diffraction angle and the diffraction intensity when a phase shift film using a material corresponding to the lower layer of Comparative Example 1 is measured by the in-plane measurement method of X-ray diffraction. FIG. 8 is a diagram showing the relationship between the diffraction angle and the diffraction intensity when a phase shift film using a material corresponding to the lower layer of Comparative