Metal alloys for the reflective or the semi-reflective layer of an optical storage medium
View Patent ↗A silver-based alloy thin film is provided for the highly reflective or semi-reflective coating layer of optical discs. Elements that can be added to silver to produce useful silver alloys include zinc, aluminum, copper, manganese, germanium, yttrium, bismuth, scandium, and cobalt. These alloys have moderate to high reflectivity and reasonable corrosion resistance in the ambient environment.
1. An optical storage medium, comprising:
a first layer having a pattern of features in at least one major surface;
a reflective coating;
said reflective coating including a metal alloy, said metal alloy including silver and yttrium, wherein the relationship between the amounts of silver and yttrium in the metal alloy is defined by Ag x Y w where 0.9500<x<0.9999 and 0.0001<w<0.05, wherein said reflective coating is about 60 nanometers thick or less.
2. The optical storage medium of claim 1 , wherein 0.001<w<0.03.
3. The optical storage medium of claim 1 , wherein said reflective coating is about 40 nanometers thick or less.
4. The optical storage medium of claim 1 , wherein said reflective coating is about 30 nanometers thick or less.
5. The optical storage medium of claim 1 , wherein said first layer is about 1.1 mm thick.
6. The optical storage medium of claim 1 , wherein said pattern of features includes a spiral groove.
7. The optical storage medium of claim 3 , wherein said pattern of features includes a spiral groove.
8. An optical storage medium, comprising:
a first layer having a pattern of features in at least one major surface;
a reflective coating;
said reflective coating including a metal alloy, said metal alloy including silver and scandium, wherein the relationship between the amounts of silver and scandium in the metal alloy is defined by Ag x Sc w where 0.9500<x<0.9999 and 0.0001<w<0.05, wherein said reflective coating is about 60 nanometers thick or less.
9. The optical storage medium of claim 8 , wherein 0.001<w<0.03.
10. The optical storage medium of claim 8 , wherein said reflective coating is about 40 nanometers thick or less.
11. The optical storage medium of claim 8 , wherein said reflective coating is about 30 nanometers thick or less.
12. The optical storage medium of claim 8 , wherein said first layer is about 1.1 mm thick.
13. The optical storage medium of claim 8 , wherein said pattern of features includes a spiral groove.
14. The optical storage medium of claim 10 , wherein said pattern of features includes a spiral groove.
15. An optical storage medium, comprising:
a first layer having a pattern of features in at least one major surface;
a reflective coating;
said reflective coating including a metal alloy, said metal alloy including silver and bismuth, wherein the relationship between the amounts of silver and bismuth in the metal alloy is defined by Ag x Bi w where 0.9500<x<0.9999 and 0.0001<w<0.05, wherein said reflective coating is about 60 nanometers thick or less.
16. The optical storage medium of claim 15 , wherein 0.001<w<0.03.
17. The optical storage medium of claim 15 , wherein said reflective coating is about 40 nanometers thick or less.
18. The optical storage medium of claim 15 , wherein said reflective coating is about 30 nanometers thick or less.
19. The optical storage medium of claim 15 , wherein said first layer is about 1.1 mm thick.
20. The optical storage medium of claim 15 , wherein said pattern of features includes a spiral groove.
21. The optical storage medium of claim 17 , wherein said pattern of features includes a spiral groove.
22. An optical storage medium, comprising:
a first layer having a pattern of features in at least one major surface;
a reflective coating;
said reflective coating including a said metal alloy including silver, copper, and element A, where A is selected from the group of elements consisting of yttrium, scandium, or bismuth, wherein the relationship between the amounts of silver, copper, and element A in the metal alloy is defined by Ag x Cu z A w where 0.85<x<0.9998, 0.0001<z<0.10, and 0.0001<w<0.05, wherein said reflective coating is about 60 nanometers thick a less.
23. The optical storage medium of claim 22 , wherein 0.001<w<0.03.
24. The optical storage medium of claim 22 , wherein said reflective coating is about 40 nanometers thick or less.
25. The optical storage medium of claim 22 , wherein said reflective coating is about 30 nanometers thick or less.
26. The optical storage medium of claim 22 , wherein said first layer is about 1.1 nm thick.
27. The optical storage medium of claim 22 , wherein said pattern of features includes a spiral groove.
28. The optical storage medium of claim 24 , wherein said pattern of features includes a spiral groove.
29. An optical storage medium, comprising:
a first layer having a pattern of features in at least one major surface;
a reflective coating;
said reflective coating including a metal alloy, said metal alloy including silver, copper, and magnesium, wherein the relationship between the amounts of silver, copper, and magnesium in the metal alloy is defined by Ag x Cu z Mg w where 0.85<x<0.9998, 0.0001<z<0.10, and 0.0001<w<0.05, wherein said reflective coating is about 60 nanometers thick or less.
30. The optical storage medium of claim 29 , wherein 0.001<w<0.03.
31. The optical storage medium of claim 29 , wherein said reflective coating is about 40 nanometers thick or less.
32. The optical storage medium of claim 29 , wherein said reflective coating is about 30 nanometers thick or less.
33. The optical storage medium of claim 29 , wherein said first layer is about 1.1 mm thick.
34. The optical storage medium of claim 29 , wherein said pattern of features includes a spiral groove.
35. The optical storage medium of claim 31 , wherein said pattern of features includes a spiral groove.
36. An optical storage medium, comprising:
a first layer having a pattern of features in at least one major surface;
a reflective coating;
said reflective coating including a metal alloy, said metal alloy including silver, copper, and cobalt, wherein the relationship between the amounts of silver, copper, and cobalt in the metal alloy is defined by Ag x Cu z Co w where 0.85<x<0.9998, 0.0001<z<0.10, and 0.0001 <w<0.05, wherein said reflective coating is about 60 nanometers thick or less.
37. The optical storage medium of claim 36 , wherein 0.001<w<0.03.
38. The optical storage medium of claim 36 , wherein said reflective coating is about 40 nanometers thick or less.
39. The optical storage medium of claim 36 , wherein said reflective coating is about 30 nanometers thick or less.
40. The optical storage medium of claim 36 , wherein said first layer is about 1.1 mm thick.
41. The optical storage medium of claim 36 , wherein said pattern of features includes a spiral groove.
42. The optical storage medium of claim 38 , wherein said pattern of features includes a spiral groove.
43. An optical storage medium, comprising:
a first layer having a pattern of features in at least one major surface;
a reflective coating;
said reflective coating including a metal alloy, said metal alloy including silver, zinc, and magnesium wherein the relationship between the amounts of silver, zinc, and magnesium in the metal alloy is defined by Ag x Zn y Mg w where 0.8000<x<0.9998, 0.0001<y<0.15, and 0.0001<w<0.05, wherein said reflective coating is about 60 nanometers thick or less.
44. The optical storage medium of claim 43 , wherein 0.001<w<0.03.
45. The optical storage medium of claim 43 , wherein said reflective coating is about 40 nanometers thick or less.
46. The optical storage medium of claim 43 , wherein said reflective coating is about 30 nanometers thick or less.
47. The optical storage medium of claim 43 , wherein said first layer is about 1.1 mm thick.
48. The optical storage medium of claim 43 , wherein said pattern of features includes a spiral groove.
49. The optical storage medium of claim 45 , wherein said pattern of features includes a spiral groove.
50. An optical storage medium, comprising:
a first layer having a pattern of features in at least one major surface;
a reflective coating;
said reflective coating including a metal alloy, said metal alloy including silver, zinc, and cobalt, wherein, the relationship between the amounts of silver, zinc, and cobalt in the metal alloy is defined by Ag x Zn y Co w where 0.8000<x<0.9998, 0.0001<y<0.15, and 0.0001<w<0.05, wherein said reflective coating is about 60 nanometers thick or less.
51. The optical storage medium of claim 50 , wherein 0.001<w<0.03.
52. The optical storage medium of claim 50 , wherein said reflective coating is about 40 nanometers thick or less.
53. The optical storage medium of claim 50 , wherein said reflective coating is about 30 nanometers thick or less.
54. The optical storage medium of claim 50 , wherein said first layer is about 1.1 mm thick.
55. The optical storage medium of claim 50 , wherein said pattern of features includes a spiral groove.
56. The optical storage medium of claim 52 , wherein said pattern of features includes a spiral groove.