Phase shift blankmask and photomask for EUV lithography

1. A blankmask for extreme ultraviolet lithography, comprising:

a substrate;

a reflective layer formed on the substrate; and

a phase shift layer formed on the reflective layer,

wherein the phase shift layer contains niobium (Nb) and tantalum (Ta),

wherein a content of tantalum (Ta) in the phase shift layer is 30 to 70 at %, and

wherein the phase shift layer has a relative reflectance of greater than 5% and lower than 20% with respect to the reflective layer in extreme ultraviolet exposure light having a wavelength of 13.5 nm.

2. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer is made of a material further containing at least one of molybdenum (Mo), ruthenium (Ru), silicon (Si), boron (B), and titanium (Ti).

3. The blankmask for extreme ultraviolet lithography of claim 2 ,

wherein a content of boron (B) in the phase shift layer increases downward.

4. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer is made of a material further containing nitrogen (N), and a content of nitrogen (N) is 1 to 30 at %.

5. The blankmask for extreme ultraviolet lithography of claim 4 ,

wherein the content of nitrogen (N) in the phase shift layer increases downward.

6. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer is made of a material further containing oxygen (O).

7. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer has a multi-layer structure of two or more layers, and

wherein an uppermost layer of the phase shift layer is made of a material further containing oxygen (O), a content of oxygen (O) is 1 to 40 at %, and a layer under the uppermost layer is made of a material not containing oxygen (O).

8. The blankmask for extreme ultraviolet lithography of claim 7 ,

wherein the uppermost layer further contains nitrogen (N).

9. The blankmask for extreme ultraviolet lithography of claim 8 ,

wherein a total content of nitrogen (N) and oxygen (O) in the uppermost layer is 1 to 40 at %.

10. The blankmask for extreme ultraviolet lithography of claim 8 ,

wherein the lower layer further contains nitrogen (N), and a content of nitrogen (N) is 1 to 40 at %.

11. The blankmask for extreme ultraviolet lithography of claim 7 ,

wherein the uppermost layer has a thickness of 2 to 10 nm.

12. The blankmask for extreme ultraviolet lithography of claim 11 ,

wherein the lower layer has a thickness of 30 to 70 nm.

13. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer has a phase shift amount of 170 to 230°.

14. A photomask manufactured using the blankmask for extreme ultraviolet lithography of claim 1 .

15. A blankmask for extreme ultraviolet lithography, comprising:

a substrate;

a reflective layer formed on the substrate; and

a phase shift layer formed on the reflective laver,

wherein the phase shift layer contains niobium (Nb), chrome (Cr), and nitrogen (N),

wherein the phase shift layer has a relative reflectance of 9 to 15% with respect to the reflective layer in extreme ultraviolet exposure light having a wavelength of 13.5 nm,

wherein the phase shift layer includes a first layer and a second layer on the first layer,

wherein the first layer is configured to have a constitution ratio of Cr:Nb:N=30 to 40 at %:20 to 50 at %:10 to 50 at % and

wherein the second layer is made of a material further containing oxygen (O) of 1 to 50 at %, and has a thickness of 5 nm or less.

16. The blankmask for extreme ultraviolet lithography of claim 15 ,

wherein a content of Nb in the phase shift layer is 0.6 to 2.0 times that of Cr.

17. The blankmask for extreme ultraviolet lithography of claim 16 ,

wherein the phase shift layer has a relative reflectance of 14 to 15%, and the content of Nb is equal to or higher than that of Cr.

18. The blankmask for extreme ultraviolet lithography of claim 16 ,

wherein the phase shift layer has a relative reflectance of 9 to 10%, and the content of Nb is equal to or lower than the content of Cr.

19. The blankmask for extreme ultraviolet lithography of claim 15 ,

wherein the content of nitrogen (N) in the phase shift layer increases downward.

20. The blankmask for extreme ultraviolet lithography of claim 15 ,

wherein the phase shift layer is made of a material further containing at least one of molybdenum (Mo), tantalum (Ta), ruthenium (Ru), silicon (Si), and titanium (Ti).

21. The blankmask for extreme ultraviolet lithography of claim 15 ,

wherein the phase shift layer further contains boron (B).

22. The blankmask for extreme ultraviolet lithography of claim 15 ,

wherein the phase shift layer includes a first layer and a lowermost layer on the first layer, and

wherein the lowermost layer is made of a material containing tantalum (Ta).

23. The blankmask for extreme ultraviolet lithography of claim 22 ,

wherein the lowermost layer is made of a material further containing at least one of boron (B), niobium (Nb), titanium (Ti), molybdenum (Mo), and chromium (Cr).

24. The blankmask for extreme ultraviolet lithography of claim 22 ,

wherein the lowermost layer is made of a material further containing at least one of nitrogen, carbon, and oxygen, and has a thickness of 7 nm or less.

25. The blankmask for extreme ultraviolet lithography of claim 15 ,

wherein the phase shift layer has a phase shift amount of 170 to 230°.

26. A photomask manufactured using the blankmask for extreme ultraviolet lithography of claim 15 .

27. A blankmask for extreme ultraviolet lithography, comprising:

a substrate;

a reflective layer formed on the substrate; and

a phase shift layer formed on the reflective layer,

wherein the phase shift layer contains niobium (Nb) and ruthenium (Ru),

wherein the phase shift layer has a content of Ru of 50 at % or more,

wherein the phase shift layer has a relative reflectance greater than 20% with respect to the reflective layer in extreme ultraviolet exposure light having a wavelength of 13.5 nm.

28. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer further contains at least one of molybdenum (Mo), tantalum (Ta), silicon (Si), and titanium (Ti).

29. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer is made of a material further containing nitrogen (N), and a content of nitrogen (N) is 50 at % or less.

30. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer further contains boron (B), and a content of boron is 5 to 50 at %.

31. The blankmask for extreme ultraviolet lithography of claim 1 ,

wherein the phase shift layer includes a first layer and a second layer on the first layer,

wherein the first layer is made of a material containing tantalum, and

wherein the second layer is made of a material containing ruthenium (Ru) and niobium (Nb).

32. The blankmask for extreme ultraviolet lithography of claim 31 ,

wherein the first layer is made of a material further containing at least one of boron (B), niobium (Nb), titanium (Ti), molybdenum (Mo), and chromium (Cr).

33. The blankmask for extreme ultraviolet lithography of claim 31 ,

wherein the first layer is made of a material further containing at least one of nitrogen, carbon, and oxygen.

34. The blankmask for extreme ultraviolet lithography of claim 33 ,

wherein the first layer has a content of nitrogen of 50 at % or less.

35. The blankmask for extreme ultraviolet lithography of claim 31 ,

wherein the first layer has a content of Ta of 50 at % or more.

36. The blankmask for extreme ultraviolet lithography of claim 31 ,

wherein the first layer has a thickness of 7 nm or less.

37. The blankmask for extreme ultraviolet lithography of claim 27 ,

wherein the phase shift layer has a phase shift amount of 170 to 230°.

38. A photomask manufactured using the blankmask for extreme ultraviolet lithography of claim 27 .