EUV masks to prevent carbon contamination
An extreme ultra-violet mask includes a substrate, a multi-layered mirror layer, a capping layer, a first tantalum-containing oxide layer, a tantalum-containing nitride layer, and a second tantalum-containing oxide layer. The multi-layered mirror layer is over the substrate. The capping layer is over the multi-layered mirror layer. The first tantalum-containing oxide layer is over the capping layer. The tantalum-containing nitride layer is over the first tantalum-containing oxide layer. The second tantalum-containing oxide layer is over the tantalum-containing nitride layer.
1. An extreme ultra-violet (EUV) mask, comprising:
a substrate;
a multi-layered mirror layer over the substrate;
a capping layer over the multi-layered mirror layer;
a first tantalum-containing oxide layer over the capping layer;
a tantalum-containing nitride layer over the first tantalum-containing oxide layer; and
a second tantalum-containing oxide layer over the tantalum-containing nitride layer.
2. The EUV mask of claim 1 , wherein the tantalum-containing nitride layer and the second tantalum-containing oxide layer have a same chemical element besides tantalum.
3. The EUV mask of claim 1 , wherein the tantalum-containing nitride layer comprises boron.
4. The EUV mask of claim 1 , wherein the second tantalum-containing oxide layer comprises boron.
5. The EUV mask of claim 1 , wherein the capping layer comprises ruthenium.
6. The EUV mask of claim 1 , wherein the second tantalum-containing oxide layer has a same thickness as the first tantalum-containing oxide layer.
7. The EUV mask of claim 1 , wherein the second tantalum-containing oxide layer has a thinner thickness than the tantalum-containing nitride layer.
8. The EUV mask of claim 1 , further comprising a tantalum boron layer, the substrate sandwiched between the tantalum boron layer and the multi-layered mirror layer.
9. An extreme ultra-violet (EUV) mask, comprising:
a substrate;
a multi-layered mirror layer over the substrate; and
a multi-layered absorber layer over the multi-layered mirror layer and comprising:
a first metal oxide layer;
a metal nitride layer over the first metal oxide layer, a first metal element of the first metal oxide layer being different than a second metal element of the metal nitride layer; and
a second metal oxide layer over the metal nitride layer and having the second metal element of the metal nitride layer.
10. The EUV mask of claim 9 , wherein the first metal element comprises ruthenium.
11. The EUV mask of claim 9 , wherein the second metal element comprises tantalum.
12. The EUV mask of claim 9 , wherein the metal nitride layer is free of the second metal element.
13. The EUV mask of claim 9 , wherein the second metal oxide layer is free of the first metal element.
14. The EUV mask of claim 9 , wherein the second metal oxide layer has a thinner thickness than the first metal oxide layer.
15. An extreme ultra-violet (EUV) mask, comprising:
a substrate;
a multi-layered mirror layer over the substrate;
a metal oxide layer over the multi-layered mirror layer;
a metal nitride layer over the metal oxide layer and having a thicker thickness than the metal oxide layer; and
a tantalum boron-oxide layer over the metal nitride layer and having a thinner thickness than the metal nitride layer.
16. The EUV mask of claim 15 , wherein the metal oxide layer is made of a same material as the tantalum boron-oxide layer.
17. The EUV mask of claim 15 , wherein the metal oxide layer is made of a different material than the tantalum boron-oxide layer.
18. The EUV mask of claim 15 , wherein the metal nitride layer is made of tantalum boron-nitride.
19. The EUV mask of claim 15 , further comprising a ruthenium oxide layer sandwiched between the multi-layered mirror layer and the metal oxide layer.
20. The EUV mask of claim 15 , further comprising a chromium nitride layer, the substrate sandwiched between the chromium nitride layer and the multi-layered mirror layer.