Physical vapor deposition system and processes

Patent metadata

Field	Value
Publication number	US-11237473-B2
Application number	US-202016801642-A
Country	US
Kind code	B2
Filing date	Feb 26, 2020
Priority date	Mar 1, 2019
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A physical vapor deposition (PVD) chamber and a method of operation thereof are disclosed. Chambers and methods are described that provide a chamber comprising an upper shield with two holes that are positioned to permit alternate sputtering from two targets. A process for improving reflectivity from a multilayer stack is also disclosed.

First claim

What is claimed is:

1. An extreme ultraviolet (EUV) mask blank comprising:
a substrate;
a multilayer stack which reflects EUV radiation, the multilayer stack comprising a plurality of reflective layer pairs including a silicon layer and a molybdenum layer, and an interface layer between the silicon layer and the molybdenum layer, the interface layer comprising Si 3 N 4 ;
a capping layer on the multilayer stack of reflecting layers; and
an absorber layer on the capping layer.

2. The EUV mask blank of claim 1 , wherein the multilayer stack comprises 40 reflective layer pairs.

3. The EUV mask blank of claim 2 , wherein the capping layer comprises ruthenium.

4. The EUV mask blank of claim 3 , wherein the absorber layer comprises tantalum.

5. The EUV mask blank of claim 3 , wherein the multilayer stack exhibits a reflectivity of 13.5 nm light that is greater than a multilayer stack comprising a plurality of reflective layer pairs comprising silicon and molybdenum that does not include the Si 3 N 4 interface layer.

6. The EUV mask blank of claim 1 , the interface layer comprises a first interface layer on the silicon layer.

7. The EUV mask blank of claim 6 , further comprises a second interface layer on the molybdenum layer.

8. The EUV mask blank of claim 6 , wherein the second interface layer comprises Si 3 N 4 .

9. The EUV mask blank of claim 8 , wherein the multilayer stack comprises 40 reflective layer pairs.

10. The EUV mask blank of claim 9 , wherein the multilayer stack comprises a first interface layer on every silicon layer and a second interface layer on every molybdenum layer that has a silicon layer thereon.

11. The EUV mask blank of claim 8 , wherein each multilayer of the silicon layer, the interface layer and the molybdenum layer has a thickness in a range of 5-10 nm.

12. The EUV mask blank of claim 8 , wherein the thickness of the multilayer of the silicon layer, the interface layer and the molybdenum layer is 7 nm.

13. The EUV mask blank of claim 1 , wherein the multilayer stack exhibits a reflectivity of 13.5 nm light is greater than a multilayer stack that does not include the interface layer.

Assignees

• Applied Materials Inc

Inventors

• Jindal Vibhu
• Xiao Wen
• Bhat Sanjay

Classifications

• G03F1/24 Primary

  Reflection masks; Preparation thereof · CPC title

• C23C14/165

  by cathodic sputtering · CPC title

• G03F1/52

  Reflectors · CPC title

• C23C14/352 Primary

  using more than one target (C23C14/56 takes precedence) · CPC title

• C23C14/0036

  Reactive sputtering · CPC title