Metal alloys for the reflective or the semi-reflective layer of an optical storage medium

• US 6,852,384 B2
• Filed: 06/10/2003
• Issued: 02/08/2005
• Est. Priority Date: 06/22/1998
• Status: Expired due to Term

• Current Assignee: Target Technology Company LLC
• Original Assignee: Han H. Nee
• Inventors: Nee, Han H.
• Primary Examiner(s): MULVANEY, ELIZABETH EVANS
• Application Number:
  US10/457,935
• Publication Number:
  US 20030215598A1
• Time in Patent Office: 609 Days
• Field of Search: 428/64.1, 428/64.4, 428/457, 428/913, 430/270.12, 430/495.1, 430/945
• US Class Current: 428/64.1
• CPC Class Codes: G11B 2007/24306 transition metal elements of groups 3-10
• CPC Class Codes: G11B 2007/24312 group 14 elements (e.g. Si, Ge, Sn)
• CPC Class Codes: G11B 2007/24314 group 15 elements (e.g. Sb, Bi)
• CPC Class Codes: G11B 2007/24316 group 16 elements (i.e. chalcogenides, Se, Te)
• CPC Class Codes: G11B 7/00454 involving phase-change effects
• CPC Class Codes: G11B 7/24038 Multiple laminated recording layers
• CPC Class Codes: G11B 7/243 comprising inorganic materials only, e.g. ablative layers
• CPC Class Codes: G11B 7/2433 Metals or elements of Groups 13, 14, 15 or 16 of the Periodic Table, e.g. B, Si, Ge, As, Sb, Bi, Se or Te
• CPC Class Codes: G11B 7/246 containing dyes
• CPC Class Codes: G11B 7/2472 cyanine
• CPC Class Codes: G11B 7/2534 polycarbonates [PC]
• CPC Class Codes: G11B 7/258 of reflective layers
• CPC Class Codes: G11B 7/259 based on silver
• CPC Class Codes: G11B 7/2595 based on gold
• CPC Class Codes: G11B 7/26 Apparatus or processes specially adapted for the manufacture of record carriers
• CPC Class Codes: G11B 7/266 Sputtering or spin-coating layers sputtering in general C23C14/24; spin-coating in general B05D1/005
• CPC Class Codes: Y10T 428/21 Circular sheet or circular blank
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A silver-based alloy thin film is provided for the highly reflective or semi-reflective layer of optical discs. Alloy additions to silver include gold, rhodium, ruthenium, osmium, platinum, palladium, copper, silicon, cadmium, tin, lithium, nickel, cobalt, indium, chromium, antimony, gallium, boron, molybdenum, zirconium, beryllium, titanium, and zinc. These alloys have moderate to high reflectivity and reasonable corrosion resistance in the ambient environment.

Claims

1. An optical storage medium, comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the feature pattern, the first semi-reflective coating including a metal alloy, said metal alloy including silver; and

an element A, wherein element A is selected from the group consisting of, cadmium, lithium, cobalt, indium, chromium, antimony, gallium, boron, molybdenum, zirconium, and beryllium, and wherein the relationship between the amounts of silver and element A in the metal alloy is defined by Ag_xA_y, wherein 0.9<

x<

0.9999, and 0.0001<

y<

0.10.

2. The optical storage medium of claim 1, wherein 0.001<

y<

0.05.

3. The optical storage medium of claim 1, further comprising:

a second layer having a pattern of features in at least one major surface; and

a second reflective coating adjacent the feature pattern, the second reflective coating including a metal alloy.

6. The optical storage medium of claim 1, wherein

said metal alloy, further includes element B, wherein element B is selected from the group consisting of gold, rhodium, ruthenium, osmium, iridium, platinum and palladium and wherein the relationship between-the amounts of silver and element B in the metal alloy is defined by Ag_xyB_v wherein 0.95<

x<

0.9999 and 0.0001<

v<

0.05.

4. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the feature pattern, the first semi-reflective coating including a metal alloy, said metal alloy including silver, copper, and, zinc, and wherein the relationship between the amounts of silver, copper, and zinc in the metal alloy is defined by Ag_xCu_wZn_z where 0.8<

x<

0.9998,0.0001<

w<

0.1, 0.0001<

z<

0.1.

5. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the feature pattern, the first semi-reflective coating including a metal alloy, said metal alloy including silver, copper, and titanium, and wherein the relationship between the amounts of silver, copper and titanium in the metal alloy is defined by Ag_xCu_wTi_t wherein 0.85<

x0.9998, 0.0001<

w<

0.1, 0.0001<

t<

0.05.

7. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the feature pattern, the first semi-reflective coating including a metal alloy, said metal alloy including silver, copper, and silicon, and wherein the relationship between the amounts of silver, copper, and, silicon in the metal alloy is defined by Ag_xCu_wSi_s wherein 0.85<

x<

0.9998, 0.0001<

w<

0.1, 0.0001<

s<

0.05.

8. An optical information recording medium, comprising:

a first substrate;

a first recording layer adjacent said first substrate; and

a first semi-reflective coating adjacent the first recording layer, the first semi-reflective coating including a metal alloy;

said metal alloy including silver and element A, wherein element A is selected from the group consisting of copper, zinc, titanium, cadmium, lithium, nickel, cobalt, indium, aluminum, chromium, germanium, tin, beryllium, manganese, antimony, gallium, silicon, boron, zirconium, and molybdenum and, wherein the relationship between the amounts of silver and element A in the metal alloy is defined by Ag_xA_y wherein 0.9<

0.9999, and 0.0001<

y<

0.10.

9. The optical information recording medium of claim 8, wherein 0.001<

y<

0.05.

10. The optical information recording medium of claim 8, wherein said first recording layer directly contacts said first semi-reflective coating.

11. The optical information recording medium of claim 8, further including:

a second substrate having a pattern of features in at least one major surface; and

a spacer layer, located between the said first and said second substrate.

13. The optical information recording medium of claim 8, wherein

said metal alloy further includes element B, wherein element B is selected from the group consisting of gold, rhodium, ruthenium, osmium, iridium, platinum and palladium, and wherein the relationship between the amounts of silver and element B in the metal alloy is defined by Ag_xyB_y wherein 0.95<

x<

0.9999, and 0.0001<

v<

0.05.

12. An optical information recording medium comprising:

a first substrate;

a first recording layer adjacent said first substrate; and

a first semi-reflective coating adjacent the first recording layer, the first semi-reflective coating including a metal alloy, said metal alloy including silver, copper, and, zinc, and wherein the relationship between the amounts of silver, copper, and zinc in the metal alloy is defined by Ag_xCu_wZn_z wherein 0.8<

x<

0.9998, 0.0001<

w<

0.1, 0.0001<

z<

0.1.

14. An optical storage medium, comprising:

a first substrate having a pattern of features in at least one major surface;

a semi-reflective coating adjacent the feature pattern, the first semi-reflective coating including a metal alloy;

said metal alloy including silver and copper, and wherein the relationship between the amounts of silver and copper in the metal alloy is defined by Ag_xCu_y wherein 0.90<

x<

0.999, 0.001<

y<

0.10;

a second substrate having a pattern of features in at least one major surface;

a highly reflective layer adjacent the second feature pattern of said second substrate; and

at least one spacer layer, located between said semi-reflective coating and said highly reflective layer.

15. The optical storage medium of claim 14, wherein 0.95<

x<

0.999 and 0.001<

y<

0.050.

16. The optical storage medium of claim 14, further including:

a pattern of features in at least one said snacer layer.

17. The optical storage medium of claim 14, wherein said metal alloy further includes element A, wherein element A is selected from the group consisting of, cadmium, lithium, cobalt, indium, chromium, antimony, gallium, boron, molybdenum, zirconium, and beryllium, and wherein the relationship between the amounts of silver and element A in the metal alloy is defined by Ag_xA_y, wherein 0.9999<

x<

0.9, 0.0001<

y<

0.1.

18. The optical storage medium of claim 14, wherein said metal alloy includes manganese, and wherein the relationship between the amounts of silver and manganese in the metal alloy is defined by Ag_xM_nq wherein 0.09<

x<

0.999, and 0.0001<

m<

0.075.

19. The optical storage medium of claim 18, wherein 0.0001<

mq<

0.05.

20. The optical storage medium of claim 14, wherein said metal alloy further includes silicon, wherein the relationship between the amounts of silver and silicon in the metal alloy is defined by Ag_xSi_s wherein 0.895<

x<

0.9999, and 0.0001<

s<

0.05.

21. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the first layer, the first semi-reflective coating including a first metal alloy, said first metal alloy including silver and manganese, and wherein the relationship between the amounts of silver and manganese in said first metal alloy is defined by Ag_xMn_q where 0.90<

x<

0.9999 and 0.0001<

q <

0.10.

22. The medium of claim 21, and wherein 0.001<

q<

0.05.

23. The medium of claim 21, further including:

a second layer having a pattern of features in at least one major surface; and

a second coating adjacent the second layer.

24. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the first layer, the first semi-reflective coating including a first metal alloy, said first metal alloy including silver and zinc, and wherein the relationship between the amounts of silver and zinc in said first metal alloy is defined by Ag_xZn_z where 0.85<

x<

0.9999 and 0.0001<

z<

0.15.

25. The medium of claim 24, and wherein 0.001<

z<

0.10.

26. The medium of claim 24, further including:

a second layer having a pattern of features in at least one major surface; and

a second coating adjacent the second layer.

27. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the first layer, the first semi-reflective coating including a first metal alloy, said first metal alloy including silver and silicon, and wherein the relationship between the amounts of silver and silicon in said first metal alloy is defined by Ag_xSi_s where 0.90<

x<

0.9999 and 0.0001<

s<

0.10.

28. The medium of claim 27, and wherein 0.001<

s<

0.05.

29. The medium of claim 27, further including:

a second layer having a pattern of features in at least one major surface; and

a second coating adjacent the second layer.

30. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the first layer, the first semi-reflective coating including a first metal alloy, said first metal alloy including silver and tin, and wherein the relationship between the amounts of silver and tin in said first metal alloy is defined by Ag_xSn_q where 0.90<

x<

0.9999 and 0.0001<

p<

0.10.

31. The medium of claim 30, and wherein 0.001<

p<

0.05.

32. The medium of claim 30, further including:

a second layer having a pattern of features in at least one major surface; and

a second coating adjacent the second layer.

33. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the first layer, the first semi-reflective coating including a first metal alloy, said first metal alloy including silver and nickel, and wherein the relationship between the amounts of silver and nickel in said first metal alloy is defined by Ag_xNi_r where 0.90<

x<

0.9999 and 0.0001<

r<

0.10.

34. The medium of claim 33, and wherein 0.001<

r<

0.05.

35. The medium of claim 33, further including:

a second layer having a pattern of features in at least one major surface; and

a second coating adjacent the second layer.

36. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the first layer, the first semi-reflective coating including a first metal alloy, said first metal alloy including silver and titanium, and wherein the relationship between the amounts of silver and titanium in said first metal alloy is defined by Ag_xTi_p where 0.90<

x<

0.9999 and 0.0001<

p <

0.10.

37. The medium of claim 36, and wherein 0.001<

p<

0.05.

38. The medium of claim 36, further including:

a second layer having a pattern of features in at least one major surface; and

a second coating adjacent the second layer.

39. An optical storage medium comprising:

a first layer having a pattern of features in at least one major surface; and

a first semi-reflective coating adjacent the first layer, the first semi-reflective coating including a first metal alloy, said first metal alloy including silver and germanium, and wherein the relationship between the amounts of silver and germanium in said first metal alloy is defined by Ag_xGe_u where 0.90<

x<

0.9999 and 0.0001<

u<

0.10.

40. The medium of claim 39, and wherein 0.001<

u<

0.05.

41. The medium of claim 39, further including:

a second layer having a pattern of features in at least one major surface; and

a second coating adjacent the second layer.