Extreme ultraviolet mask absorber materials
Extreme ultraviolet (EUV) mask blanks, methods for their manufacture and production systems therefor are disclosed. The EUV mask blanks comprise a substrate; a multilayer stack of reflective layers on the substrate; a capping layer on the multilayer stack of reflecting layers; and an absorber layer on the capping layer, the absorber layer made from tantalum and antimony.
1. A method of manufacturing an extreme ultraviolet (EUV) mask blank comprising:
forming on a substrate a multilayer stack which reflects EUV radiation, the multilayer stack comprising a plurality of reflective layer pairs;
forming a capping layer on the multilayer stack; and
forming an absorber layer on the capping layer, the absorber layer comprising an alloy of tantalum and antimony.
2. The method of claim 1 , wherein the alloy of tantalum and antimony comprises about 33.7 wt. % to about 57.8 wt. % tantalum and about 42.2 wt. % to about 63.3 wt. % antimony.
3. The method of claim 1 , wherein the alloy of tantalum and antimony comprises about 57.8 wt. % to about 78.2 wt. % tantalum and about 21.8 wt. % to about 42.2 wt. % antimony.
4. The method of claim 2 , wherein the alloy of tantalum and antimony comprises about 21.9 wt. % to about 33.7 wt. % tantalum and about 66.3 wt. % to about 78.1 wt. % antimony.
5. The method of claim 3 , wherein the alloy of tantalum and antimony is amorphous.
6. The method of claim 1 , wherein the alloy is formed by co-sputtering the tantalum and antimony with a gas selected from one or more of argon (Ar), oxygen (O 2 ), or nitrogen (N 2 ) to form the absorber layer.
7. The method of claim 1 , wherein the alloy is deposited layer by layer as a laminate of tantalum and antimony layers using a gas selected from one or more of argon (Ar), oxygen (O 2 ), or nitrogen (N 2 ) to form the absorber layer.
8. The method of claim 1 , wherein the alloy is deposited using a bulk target having the same composition as the alloy and is sputtered using a gas selected from one or more of argon (Ar), oxygen (O 2 ), or nitrogen (N 2 ) to form the absorber layer.
9. The method of claim 2 , wherein the alloy of tantalum and antimony is doped with one of more of nitrogen or oxygen in a range of from 0.1 wt. % to 5 wt. %.
10. The method of claim 3 , wherein the alloy of tantalum and antimony is doped with one of more of nitrogen or oxygen in a range of from about 0.1 wt. % to about 5 wt. %.
11. 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;
a capping layer on the multilayer stack of reflecting layers; and
an absorber layer comprising an alloy of tantalum and antimony.
12. The extreme ultraviolet (EUV) mask blank of claim 11 , wherein the alloy of tantalum and antimony comprises about 33.7 wt. % to about 57.8 wt. % tantalum and about 42.2 wt. % to about 63.3 wt. % antimony.
13. The extreme ultraviolet (EUV) mask blank of claim 11 , the alloy of tantalum and antimony comprises about 57.8 wt. % to about 78.2 wt. % tantalum and about 21.8 wt. % to about 42.2 wt. % antimony.
14. The extreme ultraviolet (EUV) mask blank of claim 12 , wherein the alloy of tantalum and antimony comprises about 21.9 wt. % to about 33.7 wt. % tantalum and about 66.3 wt. % to about 78.1 wt. % antimony.
15. The extreme ultraviolet (EUV) mask blank of claim 13 , wherein the alloy of tantalum and antimony is amorphous.
16. The extreme ultraviolet (EUV) mask blank of claim 11 , wherein the absorber layer has a thickness of less than 45 nm.
17. The extreme ultraviolet (EUV) mask blank of claim 11 , wherein the absorber layer further comprises a range of rom about 0.1 wt. % to about 5 wt. % of a dopant selected from one or more of nitrogen or oxygen.
18. The extreme ultraviolet (EUV) mask blank of claim 11 , wherein the absorber layer has a thickness of less than 45 nm.
19. The extreme ultraviolet (EUV) mask blank of claim 11 , wherein the absorber layer is etch selective relative to the capping layer.
20. 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 molybdenum (Mo) and silicon (Si);
a capping layer on the multilayer stack of reflecting layers; and
an absorber layer comprising an alloy of tantalum and antimony.