Reflective mask blank, reflective mask, method of manufacturing reflective mask, and method of manufacturing semiconductor device
Provided is a reflective mask blank with which it is possible to further reduce the shadowing effect of a reflective mask, and also possible to form a fine and highly accurate phase-shift pattern. A reflective mask blank having, in the following order on a substrate, a multilayer reflective film and a phase-shift film that shifts the phase of EUV light, said reflective mask blank characterized in that: the phase-shift film has a first layer and a second layer; the first layer comprises a material that contains at least one element from among tantalum (Ta) and chromium (Cr); and the second layer comprises a metal-containing material that contains ruthenium (Ru) and at least one element from among chromium (Cr), nickel (Ni), cobalt (Co), vanadium (V), niobium (Nb), molybdenum (Mo), tungsten (W), and rhenium (Re).
1. A reflective mask blank comprising:
a substrate;
a multilayer reflective film on the substrate; and
a phase shift film on the multilayer reflective film,
wherein
the phase shift film comprises a first layer and a second layer,
the first layer comprises at least one selected from tantalum (Ta) and chromium (Cr), and
the second layer comprises ruthenium (Ru),
the phase difference of the phase shift film is 130 degrees to 160 degrees or 200 degrees to 230 degrees,
the refractive index n to EUV light is 0.930 to 0.960 and the extinction coefficient k to EUV light is 0.025 to 0.046 when the phase difference of the phase shift film is 130 degrees to 160 degrees, and
the refractive index n to EUV light is 0.930 to 0.960 and the extinction coefficient k to EUV light is 0.015 to 0.036 when the phase difference of the phase shift film is 200 degrees to 230 degrees.
2. The reflective mask blank according to claim 1 , wherein the relative reflectance of the phase shift film is 10% to 40%.
3. The reflective mask blank according to claim 1 , wherein the second layer comprises the ruthenium (Ru) and at least one selected from chromium (Cr), nickel (Ni), cobalt (Co), vanadium (V), niobium (Nb), molybdenum (Mo), tungsten (W), and rhenium (Re).
4. The reflective mask blank according to claim 1 , wherein the thickness of the first layer is 2 to 55 nm.
5. The reflective mask blank according to claim 1 , wherein the first layer comprises the tantalum (Ta) and at least one selected from oxygen (O), nitrogen (N), carbon (C), boron (B) and hydrogen (H).
6. The reflective mask blank according to claim 1 , wherein the first layer comprises the tantalum (Ta) and nitrogen (N), and an atomic ratio of the tantalum (Ta) and the nitrogen (N) (Ta:N) is 3:1 to 20:1.
7. The reflective mask blank according to claim 1 , wherein the first layer comprises the chromium (Cr) and at least one selected from oxygen (O), nitrogen (N), carbon (C), boron (B) and hydrogen (H).
8. The reflective mask blank according to claim 1 , wherein the first layer is formed between the multilayer reflective film and the second layer.
9. The reflective mask blank according to claim 1 , further comprising a protective film between the multilayer reflective film and the phase shift film, wherein the protective film comprises ruthenium (Ru).
10. The reflective mask blank according to claim 1 , further comprising an etching mask film on the phase shift film, wherein
the etching mask film comprises tantalum (Ta) and at least one selected from oxygen (O), nitrogen (N), carbon (C), boron (B) and hydrogen (H).
11. The reflective mask blank according to claim 1 , further comprises an etching mask film on the phase shift film, wherein
the etching mask film comprises chromium (Cr) and at least one selected from nitrogen (N), oxygen (O), carbon (C) and hydrogen (H).
12. A reflective mask comprising:
a substrate;
a multilayer reflective film on the substrate; and
a phase shift film with a pattern on the multilayer reflective film, wherein
the phase shift film comprises a first layer and a second layer,
the first layer comprises at least one selected from tantalum (Ta) and chromium (Cr), and
the second layer comprises ruthenium (Ru),
the phase difference of the phase shift film is 130 degrees to 160 degrees or 200 degrees to 230 degrees,
the refractive index n to EUV light is 0.930 to 0.960 and the extinction coefficient k to EUV light is 0.025 to 0.046 when the phase difference of the phase shift film is 130 degrees to 160 degrees, and
the refractive index n to EUV light is 0.930 to 0.960 and the extinction coefficient k to EUV light is 0.015 to 0.036 when the phase difference of the phase shift film is 200 degrees to 230 degrees.
13. The reflective mask according to claim 12 , wherein the relative reflectance of the phase shift film is 10% to 40%.
14. The reflective mask according to claim 12 , wherein the second layer comprises the ruthenium (Ru) and at least one selected from chromium (Cr), nickel (Ni), cobalt (Co), vanadium (V), niobium (Nb), molybdenum (Mo), tungsten (W), and rhenium (Re).
15. The reflective mask according to claim 12 , wherein the thickness of the first layer is 2 to 55 nm.
16. The reflective mask according to claim 12 , wherein the first layer comprises the tantalum (Ta) and at least one selected from oxygen (O), nitrogen (N), carbon (C), boron (B) and hydrogen (H).
17. The reflective mask according to claim 12 , wherein the first layer comprises the tantalum (Ta) and nitrogen (N), and an atomic ratio of the tantalum (Ta) and the nitrogen (N) (Ta:N) is 3:1 to 20:1.
18. The reflective mask according to claim 12 , wherein the first layer comprises the chromium (Cr) and at least one selected from oxygen (O), nitrogen (N), carbon (C), boron (B) and hydrogen (H).
19. The reflective mask according to claim 12 , wherein the first layer is formed between the multilayer reflective film and the second layer.
20. The reflective mask according to claim 12 , further comprising a protective film between the multilayer reflective film and the phase shift film, wherein the protective film comprises ruthenium (Ru).