Optical data storage media with enhanced contrast

• US 7,368,222 B2
• Filed: 05/11/2001
• Issued: 05/06/2008
• Est. Priority Date: 01/16/2001
• Status: Expired due to Fees

• Current Assignee: Enhanced Data Solutions LLC
• Original Assignee: DPHI Acquisitions, Inc.
• Inventors: Medower, Brian S., Redmond, Ian R., Davies, David H.
• Primary Examiner(s): ANGEBRANNDT, MARTIN J
• Application Number:
  US09/854,333
• Publication Number:
  US 20020094405A1
• Time in Patent Office: 2,552 Days
• Field of Search: 430/270.13, 430/945, 369/275.5, 369/275.2, 428/64.6
• US Class Current: 430/270.13
• CPC Class Codes: G11B 2007/24304 group 2 or 12 elements (e.g. Be, Ca, Mg, Zn, Cd)
• CPC Class Codes: G11B 2007/2431 group 13 elements (B, Al, Ga, In)
• 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 2007/25408 consisting essentially of inorganic materials
• CPC Class Codes: G11B 2007/2571 containing group 14 elements except carbon (Si, Ge, Sn, Pb)
• CPC Class Codes: G11B 2007/25713 containing nitrogen
• CPC Class Codes: G11B 2007/25715 containing oxygen
• CPC Class Codes: G11B 2220/216 Rewritable discs
• CPC Class Codes: G11B 7/00452 involving bubble or bump forming
• 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 7/2531 comprising glass
• CPC Class Codes: G11B 7/2534 polycarbonates [PC]
• CPC Class Codes: G11B 7/254 of protective topcoat layers
• CPC Class Codes: G11B 7/2542 consisting essentially of organic resins
• CPC Class Codes: G11B 7/257 of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
• CPC Class Codes: G11B 7/2572 consisting essentially of organic materials
• CPC Class Codes: G11B 7/258 of reflective layers
• CPC Class Codes: G11B 7/26 Apparatus or processes specially adapted for the manufacture of record carriers
• CPC Class Codes: Y10S 430/146 : Laser beam

Abstract

Disclosed is an optical data storage medium with enhanced contrast. The optical data storage medium includes a substrate having oppositely facing first and second surfaces. A first metal/alloy layer is formed overlaying the first surface of the substrate. The first metal/alloy layer is formed from tin, antimony and element selected from the group consisting of indium, germanium, aluminum, and zinc. After the first metal/alloy layer is formed, a first dielectric layer is formed overlaying the first metal/alloy layer. This dielectric layer is formed from silicon oxynitride. The first metal/alloy layer is positioned between the substrate and the first dielectric layer.

Claims

1. An optical data storage device comprising:

a substrate having oppositely facing first and second surfaces;

a first metal/alloy layer overlaying the first surface of the substrate, wherein the first metal/alloy layer comprises tin, antimony and an element selected from the group consisting of indium, germanium, aluminum, and zinc, and;

a first silicon oxynitride layer overlaying the first metal/alloy layer, wherein a thickness of the first silicon oxynitride layer and an index of refraction of the first silicon oxynitride layer are selected to substantially maximize an optical contrast between an amorphous state of the first metal/alloy layer and a crystalline state of the first metal/alloy layer, and wherein no further layers overlay the first silicon oxynitride layer.

2. The optical data storage device of claim 1 further comprising:

a second metal/alloy layer overlaying the second surface of the substrate, wherein the second metal/alloy layer comprises tin, antimony and an element selected from the group consisting of indium, germanium, aluminum, and zinc, and;

a second silicon oxynitride layer overlaying the second metal/alloy layer, wherein the second metal/alloy layer is positioned between the substrate and the second silicon oxynitride layer.

3. The optical data storage device of claim 1 wherein the first metal/alloy layer has a cross-sectional thickness between 40 nm and 125 nm.

4. The optical data storage device of claim 1 wherein the first silicon oxynitride layer has a cross-sectional thickness between 20 nm and 120 nm.

5. The optical data storage device of claim 1 wherein the first silicon oxynitride layer has a cross-sectional thickness of approximately 60 nm and the first metal/alloy layer has a cross-sectional thickness of approximately 85 nm.

6. The optical data storage device of claim 1 wherein the substrate comprises a rigid material.

7. The optical data storage device of claim 1 wherein the metal/alloy layer comprises Sb₇₀Sn₁₅In₁₅.

8. The optical data storage device of claim 1 wherein the first metal/alloy layer is formed using a sputtering technique.

9. The optical data storage device of claim 1 wherein the first metal/alloy layer is formed using a vapor deposition technique.

10. The optical data storage device of claim 1 wherein a real part of refractive index for the first silicon oxynitride layer is between 1.4 and 2.0.

11. The optical data storage device of claim 1 wherein the first surface of the substrate is grooved, wherein grooves of the first surface define raised surface portions, recessed surface portions, and side walls therebetween.

12. The optical data storage device of claim 1 wherein the first metal/alloy layer comprises a grooved surface, wherein grooves of the first metal/alloy layer define raised surface portions, recessed surface portions, and side walls therebetween, wherein the raised surface portions are configured to store optical data.

13. A method conspiring:

forming a first metal/alloy layer overlaying a first surface of a substrate wherein the first metal/alloy layer comprises tin, antimony and an element selected from the group consisting of indium, germanium, aluminum, and zinc, and;

forming a first silicon oxynitride layer overlaying the first metal/alloy layer, wherein the first silicon oxynitride layer has a thickness and an index of refraction substantially maximize selected to an optical contrast between an amorphous state of the first metal/alloy layer and a crystalline state of the first metal/alloy layer, and wherein the first metal/alloy layer is positioned between the substrate and the first silicon oxynitride layer and no further layers overlay the first silicon oxynitride layer.

14. The method of claim 13 further comprising:

forming a second metal/alloy layer overlaying a second surface of the substrate, wherein the second metal/alloy layer comprises tin, antimony and an element selected from the group consisting of indium, germanium, aluminum, and zinc, and;

forming a second silicon oxynitride layer overlaying the second metal/alloy layer, wherein the second metal/alloy layer is positioned between the substrate and the second silicon oxynitride layer.

15. The method of claim 13 wherein the first metal/alloy layer has a cross-sectional thickness between 40 nm and 125 nm.

16. The method of claim 13 wherein the first dielectric layer has a cross-sectional thickness between 20 nm and 120 nm.

17. The method of claim 13 wherein the substrate comprises a rigid material.

18. The method of claim 13 wherein the metal/alloy layer comprises Sb₇₀Sn₁₅In₁₅.

19. The method of claim 13 wherein the first metal/alloy layer is formed using a sputtering technique.

20. The method of claim 13 wherein a real part of refractive index for the first dielectric layer is between 1.4 and 2.0.