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

• US 20030215598A1
• Filed: 06/10/2003
• Published: 11/20/2003
• Est. Priority Date: 06/22/1998
• Status: Active Grant

• Current Assignee: Target Technology Company LLC
• Original Assignee: Han H. Nee
• Inventors: Nee, Han H.
• Granted Patent: US 6,852,384 B2
• Time in Patent Office: Days
• US Class Current: 428/64.4
• 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, rethenium, osmium, platinum, plalladium, copper, silicon, cadmium, tin, lithium, nickel, cobalt, indium, chromium, antimony, gallium, boron, molybdenum, zirconium, beryllium, titanium, magnesium, and zinc. These alloys have moderate to high reflective 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 coating adjacent the first layer, said first coating includes a first metal alloy;

wherein the first metal alloy comprises;

silver; and

at least one other element, selected from the group consisting of copper, silicon, cadmium, tin, lithium, nickel, cobalt, indium, chromium, antimony, gallium, boron, molybdenum, zirconium, beryllium, titanium and magnesium, wherein said other elements are present from 0.01 a/o percent to 10.0 a/o percent of the amount of silver present.

2. The medium of claim 1, and wherein said at least one other elements are present in the amount of 0.1 a/o percent to 5.0 a/o percent.

3. The medium according to claim 1, wherein said first coating directly contacts said first metal alloy.

4. The medium of claim 1, further comprising:

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

a second coating adjacent said second layer.

5. The medium according to claim 1, further comprising:

a second layer having a pattern of features in at least one major surface, the second layer including a dielectric material;

a third layer having a pattern of features in at least one major surface, the third layer including an optically re-recordable material; and

a fourth layer having a pattern of features in at least one major surface, the fourth layer including a dielectric material.

6. The medium of claim 5, wherein said optically re-recordable material is a phase-changeable material.

7. The medium of claim 6, wherein said optically re-recordable material further comprises a phase changeable material selected from the group consisting of Ge—

Sb—

Te, As—

In—

Sb—

Te, Cr—

Ge—

Sb—

Te, As—

Te—

Ge, Te—

Ge—

Sn, Te—

Ge—

Sn—

O, Te—

Se, Sn—

Te—

Se, Te—

Ge—

Sn—

Au, Ge—

Sb—

Te, Sb—

Te—

Se, In—

Se—

Tl, In Sb, In—

Sb—

Se, In—

Se—

Tl—

Co, Bi—

Ge, Bi—

Ge—

Sb, Bi—

Ge—

Te, and Si—

Te—

Sn.

8. The medium of claim 5, wherein said optically re-recordable material is a magneto-optic material.

9. The medium of claim 8, wherein the optically re-recordable material further comprises a magneto-optic material selected from the group consisting of Tb—

Fe—

Co and Gd—

Tb—

Fe.

10. The medium of claim 1, wherein the first metal alloy comprises:

copper;

zinc; and

silver wherein copper is present from about 0.01 a/o percent to about 10.0 a/o percent, zinc is present from about 0.01 a/o percent to 10.0 a/o, and the remainder is silver.

11. The medium of claim 1, wherein said first metal alloy comprises:

copper;

titanium; and

silver, wherein copper is present in about 0.01 a/o percent to about 10.0 a/o percent of the amount of silver present, and titanium is present from about 0.01 a/o percent to about 5.0 a/o percent of the amount of silver present.

12. The medium of claim 1, wherein said first metal alloy comprises:

silver; and

at least one other metal selected from the group consisting of gold, rhodium, ruthenium, osmium, iridium, platinum and palladium and mixtures thereof, wherein said at least one metal is present from about 0.01 a/o percent to about 5.0 a/o percent of the amount of silver present.

13. The medium of claim 1, wherein said first metal alloy comprises:

silver;

copper; and

silicon wherein copper is present from about 0.01 a/o percent to about 10.0 a/o percent of the amount of silver present, and silicon is present from about 0.01 a/o percent to about 5.0 a/o percent of the amount of silver present.

14. An optical information recording medium, comprising:

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

a first recording layer adjacent the feature pattern; and

a first reflective layer adjacent to the first recording layer, said reflective layer including a first metal alloy;

wherein the first metal alloy comprises;

silver; and

at least one other element selected from the group consisting of copper, zinc, titanium, cadmium, lithium, nickel, cobalt, indium, aluminum, germanium, chromium, germanium, tin, beryllium, magnesium, manganese, antimony, gallium, silicon, boron, zirconium, molybdenum and mixtures thereof, wherein said other elements are present from 0.01 a/o percent to 10.0 a/o percent of the amount of silver present.

15. The medium of claim 14, wherein said other elements are present from 0.1 a/o percent to 5.0 a/o percent of the amount of silver present.

16. The medium of claim 14, wherein said first recording layer directly contacts said first metal alloy.

17. The medium of claim 14, further including:

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

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

18. The medium of claim 14, wherein the first metal alloy comprises:

silver;

copper; and

zinc wherein copper is from 0.01 a/o percent to 10.0 a/o percent of the amount of silver present and zinc is present from 0.01 a/o percent to 10.0 a/o percent of the amount of silver present.

19. The medium of claim 14, wherein said first metal alloy comprises:

silver; and

at least one element selected from the group consisting of gold, rhodium, ruthenium, osmium, iridium, platinum and palladium and mixtures thereof, wherein the said element is present from 0.01 a/o percent to 5.0 a/o percent of the amount of silver present.

20. An optical storage medium, comprising:

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

a semi-reflective layer adjacent said feature pattern, said semi-reflective layer including a metal alloy;

said metal alloy comprising;

silver; and

copper;

wherein the relationship between the amounts of silver and copper is defined by Ag_xCu_y where 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 high reflective layer adjacent the feature pattern of said second substrate; and

at least one spacer layer, located between said first and second substrates.

21. The medium of claim 20, wherein 0.95≦

x≦

0.999 and 0.001≦

y≦

0.050.

22. The medium of claim 20 wherein said semi-reflective layer directly contacts said first metal alloy.

23. The medium according to claim 20, further including:

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

a second reflective layer adjacent the second substrate.

24. The medium of claim 20, wherein said metal alloy further comprises at least one element selected from the group consisting of silicon, cadmium, tin, lithium, nickel, cobalt, indium, chromium, antimony, gallium, boron, molybdenum, zirconium, beryllium, titanium, magnesium and elements are present from 0.01 a/o percent to 10.0 a/o percent of the amount of silver present.

25. The medium according to claim 20, wherein said semi-reflective layer metal alloy includes manganese present from about 0.01 a/o percent to about 7.5 a/o percent of the amount of silver present.

26. The medium of claim 20, wherein semi-reflective layer metal alloy includes manganese present from about 0.01 a/o percent to about 5.0 a/o percent of the amount of silver present.

27. The medium of claim 20, wherein said high reflective layer metal alloy includes manganese present from about 0.01 a/o percent to about 5.0 a/o percent of the amount of silver present.

28. The medium of claim 20, wherein said semi-reflective layer metal alloy includes titanium present from about 0.01 a/o percent to about 5.0 a/o percent of the amount of silver present.

29. The medium of claim 20, wherein said semi-reflective layer metal alloy includes silicon present from about 0.01 a/o percent to about 5.0 a/o percent of the amount of silver present.

30. The medium of claim 20, wherein said high reflective layer metal alloy includes silicon present from about 0.01 a/o percent to about 5.0 a/o percent of the amount of silver present