Extreme ultraviolet mask and method of manufacturing the same
View Patent ↗A method of manufacturing an extreme ultraviolet mask, including forming a multilayer Mo/Si stack including alternating Mo and Si layers over a first major surface of a mask substrate, and forming a capping layer over the multilayer Mo/Si stack. An absorber layer is formed on the capping layer, and a hard mask layer is formed over the absorber layer. The hard mask layer is patterned to form a hard mask layer pattern. The hard mask layer pattern is extended into the absorber layer to expose the capping layer and form a mask pattern. A border pattern is formed around the mask pattern. The border pattern is extended through the multilayer Mo/Si stack to expose the mask substrate and form a trench surrounding the mask pattern. A passivation layer is formed along sidewalls of the trench.
1. A method of manufacturing an extreme ultraviolet mask, comprising:
forming a multilayer Mo/Si stack comprising alternating Mo and Si layers over a first major surface of a mask substrate made of a glass material;
forming a capping layer over the multilayer Mo/Si stack;
forming an absorber layer on the capping layer;
forming a hard mask layer over the absorber layer;
patterning the hard mask layer to form a hard mask layer pattern;
extending the hard mask layer pattern into the absorber layer to expose the capping layer and forming a mask pattern;
forming a border pattern around the mask pattern;
extending the border pattern through the multilayer Mo/Si stack to expose the first major surface of the mask substrate and forming a trench surrounding the mask pattern; and
forming a passivation layer along sidewalls of the trench and in direct contact with the first major surface of the mask substrate.
2. The method according to claim 1 , further comprising forming a conductive backside coating layer over a second major surface of the mask substrate opposing the first major surface.
3. The method according to claim 1 , further comprising forming an anti-reflection layer over the absorber layer.
4. The method according to claim 1 , further comprising removing the hard mask layer after forming the mask pattern.
5. The method according to claim 1 , further comprising forming a first photoresist layer over the hard mask layer.
6. The method according to claim 5 , further comprising forming a second photoresist layer over the absorber layer and the mask pattern.
7. The method according to claim 1 , wherein the forming a passivation layer comprises exposing the sidewalls of the trench to a nitrogen-based gas selected from the group consisting of N 2 , NH 3 , N 2 H 2 , and NO 2 .
8. A method of manufacturing an extreme ultraviolet mask, comprising:
patterning an absorber layer disposed over a multilayer Mo/Si stack comprising alternating Mo and Si layers disposed over a first major surface of a mask substrate made of a glass material to form a mask pattern;
forming a border pattern around the mask pattern;
extending the border pattern through the multilayer Mo/Si stack to expose the first major surface of the mask substrate and forming a trench surrounding the mask pattern; and
forming a passivation layer over the mask pattern, along sidewalls of the trench, and in direct contact with the first major surface of the mask substrate.
9. The method according to claim 8 , further comprising forming a capping layer over the Mo/Si stack.
10. The method according to claim 9 , further comprising forming a hard mask layer over the absorber layer;
patterning the hard mask layer to form a hard mask layer pattern; and
extending the hard mask layer pattern into the absorber layer to form the mask pattern.
11. The method according to claim 10 , further comprising forming a photoresist layer over the absorber layer and the mask pattern.
12. The method according to claim 11 , further comprising removing the photoresist layer before forming the passivation layer.
13. The method according to claim 11 , wherein the passivation layer is formed over the photoresist layer.
14. The method according to claim 8 , wherein the forming the passivation layer comprises exposing the sidewalls of the trench and the mask pattern to a nitrogen-based gas selected from the group consisting of N 2 , NH 3 , N 2 H 2 , and NO 2 .
15. An extreme ultraviolet mask, comprising:
a multilayer Mo/Si stack comprising alternating Mo and Si layers disposed over a first major surface of a mask substrate made of a glass material;
a capping layer disposed over the Mo/Si stack;
an absorber layer disposed over the capping layer;
a mask pattern formed in the absorber layer;
a trench formed in the multilayer Mo/Si stack surrounding the mask pattern, the trench exposing the first major surface of the mask substrate; and
a passivation layer disposed along sidewalls of the trench and in direct contact with the first major surface of the mask substrate.
16. The extreme ultraviolet mask according to claim 15 , further comprising an anti-reflection layer disposed over the absorber layer.
17. The extreme ultraviolet mask according to claim 15 , wherein the passivation layer is made of a silicon nitride, a silicon oxynitride, a metal doped silicon nitride, or a composite including at least one of metal silicide, metal nitride and metal oxide.
18. The extreme ultraviolet mask according to claim 15 , wherein the passivation layer has a thickness of less than about 10 nm.
19. The extreme ultraviolet mask according to claim 15 , wherein the passivation layer comprises a high-k material.
20. The extreme ultraviolet mask according to claim 15 , wherein the passivation layer comprises nickel or cobalt.