Optical information recording medium and method for manufacturing the same

1. An information recording medium for recording and/or reproducing information by applying light or electric energy, comprising:

a material layer containing a material which includes Sn and Ga, and at least one element selected from a group GL consisting of Ta and Y, and oxygen, wherein

the material is defined by the following formula: M h1 O i1 L i1 ,

wherein in the formula M denotes Sn and Ga, L denotes the at least one element selected from the group GL, and h 1 , i 1 , and j 1 are expressed on the basis of at % and satisfy the following: 5≦h 1 ≦40, 40≦i 1 ≦70, 0<j 1 ≦35, and h 1 +i 1 +j 1 =100.

2. The information recording medium according to claim 1 , wherein L in the formula denotes Y.

3. The information recording medium according to claim 1 , wherein the material layer contains oxides of Sn and Ga and an oxide of the at least one element selected from the group GL.

4. The information recording medium according to claim 3 , wherein the material layer contains a material defined by the following formula:

D x A 100-x ,

wherein D denotes SnO 2 and Ga 2 O 3 , A denotes at least one oxide selected from Ta 2 O 5 and Y 2 O 3 , and x is expressed on the basis of mol % and satisfies 30≦x≦95.

5. The information recording medium according to claim 1 , further comprising a phase-change type recording layer.

6. The information recording medium according to claim 5 , wherein the material layer is in contact with at least one face of the recording layer.

7. The information recording medium according to claim 5 , wherein the recording layer contains at least one material selected from Ge—Sb—Te, Ge—Sn—Sb—Te, Ge—Bi—Te, Ge—Sn—Bi—Te, Ge—Sb—Bi—Te, Ge—In—Bi—Te, Ag—In—Sb—Te, and Sb—Te.

8. The information recording medium according to claim 5 , wherein the recording layer has a thickness of 15 nm or thinner.

9. A method for manufacturing an information recording medium that records and/or reproduces information by applying light or electric energy, the method comprising

forming a material layer containing Sn and Ga, at least one element selected from the group GL consisting of Ta and Y, and oxygen by a sputtering using a sputtering target containing Sn and Ga, at least one element selected from the group GL consisting of Ta and Y, and oxygen,

wherein the sputtering target contains a material defined by the following formula:

M h2 O i2 L j2

wherein M denotes Sn and Ga, L denotes at least one element selected from the group GL, and h 2 , i 2 , and j 2 are expressed on the basis of at % and satisfy the following: 5≦h 2 ≦40, 40≦i 2 ≦70, 0<j 2 ≦35, and h 2 +i 2 +j 2 =100.

10. The method for manufacturing the information recording medium according to claim 9 , wherein L of the sputtering target contains Y.

11. The method for manufacturing the information recording medium according to claim 9 , wherein the sputtering target contains oxides of Sn and Ga and an oxide of at least one element selected from the group GL.

12. The method for manufacturing the information recording medium according to claim 11 , wherein a combined concentration of oxides of Sn and Ga is 30 mol % or more in the sputtering target.

13. The method for manufacturing the information recording medium according to claim 9 , wherein the sputtering target contains a material defined by the following formula:

(D) x (A) 100-x ,

wherein D denotes SnO 2 and Ga 2 O 3 , A denotes at least one oxide selected from Ta 2 O 5 and Y 2 O 3 , and x is expressed on the basis of mol % and satisfies 30≦x≦95.

14. An information recording medium for recording and/or reproducing information by applying light or electric energy, comprising:

a material layer containing a material which includes Sn, Y, and oxygen, wherein the material defined is by the following formula:

Sn h1 O i1 Y j1 ,

wherein h 1 , i 1 , and j 1 are expressed on the basis of at % and satisfy the following; 5≦h 1 ≦40, 40≦i 1 ≦70, 0<j 1 ≦35, and h 1 +i 1 +j 1 =100.

15. The information recording medium according to claim 14 , wherein the material layer contains oxides of Sn and Y.

16. The information recording medium according to claim 15 , wherein the material layer contains a material defined by the following formula:

D x A 100-x,

wherein D denotes SnO 2 , A denotes Y 2 O 3 , and x is expressed on the basis of mol % and satisfies 30≦x≦95.

17. The information recording medium according to claim 14 , wherein the material layer further contains Ta, and a combined concentration of Ta and Y is 35 at % or less in the material layer.

18. The information recording medium according to claim 16 , wherein the material layer further contains Ta 2 O 5 , and a combined concentration of Ta 2 O 5 and Y 2 O 3 is not more than 70 mol % but not less than 5 mol % in the material layer.

19. The information recording medium according to claim 14 , further comprising a phase-change type recording layer.

20. The information recording medium according to claim 19 , wherein the material layer is in contact with at least one face of the recording layer.

21. The information recording medium according to claim 19 , wherein the recording layer contains at least one material selected from Ge—Sb—Te, Ge—Sn—Sb—Te, Ge—Bi—Te, Ge—Sn—Bi—Te, Ge—Sb—Bi—Te, Ge—Sn—Sb—Bi—Te, Ag—In—Sb—Te, and Sb—Te.

22. The information recording medium according to claim 19 , wherein the recording layer has a thickness of 15 nm or thinner.

23. A method for manufacturing an information recording medium that records and/or reproduces information by applying light or electric energy, the method comprising

forming a material layer containing Sn, Y, and oxygen by sputtering using a sputtering target containing Sn, Y, and oxygen,

wherein the sputtering target contains a material defined by the following formula:

Sn h2 O i2 Y j2 ,

wherein h 2 , i 2 , and j 2 are expressed on the basis of at % and satisfy the following: 5≦h 2 ≦40, 40≦i 2 ≦70, 0<j 2 ≦35, and h 2 +i 2 +j 2 =100.

24. The method for manufacturing the information recording medium according to claim 23 , wherein the sputtering target contains oxides of Sn and Y.

25. The method for manufacturing the information recording medium according to claim 24 , wherein a concentration of oxides of Sn is 30 mol % or more in the sputtering target.

26. The method for manufacturing the information recording medium according to claim 23 , wherein the sputtering target contains a material defined by the following formula:

(SnO 2 ) x (Y 2 O 3 ) 100-x ,

wherein x is expressed on the basis of mol % and satisfies 30≦x≦95.

27. The method for manufacturing the information recording medium according to claim 23 , wherein the sputtering target further contains Ta, and a combined concentration of Ta and Y is 35 at % or less in the sputtering target.

28. The method for manufacturing the information recording medium according to claim 26 , wherein the sputtering target further contains Ta 2 O 5 , and a combined concentration of Ta 2 O 5 and Y 2 O 3 is not more than 70 mol % but not less than 5 mol % in the sputtering target.

29. An information recording medium for recording and/or reproducing information by applying light or electric energy, comprising:

a material layer containing a material which includes Ga, Ta, Y, and oxygen, wherein the material is defined by the following formula:

Ga h1 O i1 L j1 ,

wherein L denotes Ta and Y, h 1 , i 1 , and j 1 are expressed on the basis of at % and satisfy the following; 5≦h 1 ≦40, 40≦i 1 ≦70, 0<j 1 ≦35, and h 1 +i 1 +j 1 =100.

30. The information recording medium according to claim 29 , wherein the material layer contains oxides of Ga, Ta and Y.

31. The information recording medium according to claim 30 , wherein the material layer contains a material defined by the following formula:

D x A 100-x ,

wherein D denotes Ga 2 O 3 , A denotes Ta 2 O 5 and Y 2 O 3 , and x is expressed on the basis of mol % and satisfies 30≦x≦95.

32. The information recording medium according to claim 29 , further comprising a phase-change type recording layer.

33. The information recording medium according to claim 32 , wherein the material layer is in contact with at least one face of the recording layer.

34. The information recording medium according to claim 32 , wherein the recording layer contains at least one material selected from Ge—Sb—Te, Ge—Sn—Sb—Te, Ge—Bi—Te, Ge—Sn—Bi—Te, Ge—Sb—Bi—Te, Ge—In—Bi—Te, Ag—In—Sb—Te, and Sb—Te.

35. The information recording medium according to claim 32 , wherein the recording layer has a thickness of 15 nm or thinner.

36. A method for manufacturing an information recording medium that records and/or reproduces information by applying light or electric energy, the method comprising

forming a material layer containing Ga, Ta, Y, and oxygen by a sputtering method using a sputtering target containing Ga, Ta, Y, and oxygen,

wherein the sputtering target contains a material defined by the following formula:

Ga h2 O i2 L j2 ,

wherein L denotes Ta and Y, and h 2 , i 2 , and j 2 are expressed on the basis of at % and satisfy the following: 5≦h 2 ≦40, 40≦i 2 ≦70, 0<j 2 ≦35, and h 2 +i 2 +j 2 =100.

37. The method for manufacturing the information recording medium according to claim 36 , wherein the sputtering target contains oxides of Ga, Ta and Y.

38. The method for manufacturing the information recording medium according to claim 37 , wherein a concentration of oxides of Ga is 30 mol % or more in the sputtering target.

39. The method for manufacturing the information recording medium according to claim 36 , wherein the sputtering target contains a material defined by the following formula:

(D) x (A) 100-x ,

wherein D denotes Ga 2 O 3 ; A denotes Ta 2 O 5 and Y 2 O 3 , and x is expressed on the basis of mol % and satisfies 30≦x≦95.