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

• US 20030138591A1
• Filed: 01/15/2003
• Published: 07/24/2003
• Est. Priority Date: 06/22/1998
• Status: Active Grant

• Current Assignee: Target Technology Company LLC
• Original Assignee: Target Technology Company LLC
• Inventors: Nee, Han H.
• Granted Patent: US 6,790,503 B2
• Time in Patent Office: Days
• US Class Current: 428/64.4
• 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: 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, palladium, copper, rhodium, ruthenium, osmium, iridium, and platinum. These alloys have moderate to high reflectivity and reasonable corrosion resistance in the ambient environment.

Claims

1. An optical information recording medium, comprising:

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

a first reflective layer adjacent the feature pattern, the reflective layer including a metal alloy, said metal alloy including silver and copper wherein the relationship between the amount of silver and copper is defined by Ag_xCu_t where 0.90<

x<

0.999 and 0.0001<

t<

0.10.

2. The-medium of claim 1 and wherein 0.001<

t<

0.05.

3. The medium of claim 1, and further including:

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

a second reflective layer adjacent the second recording layer; and

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

4. The medium of claim 1, and further including:

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

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

5. An optical information recording medium, comprising:

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

a semi-reflective coating adjacent the first feature pattern;

said semi-reflective coating including a first metal alloy a second layer having a second pattern of features in at least one major surface;

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

a spacer layer located between the first and the second layer; and

said first metal alloy including silver and copper wherein the relationship between the amount of silver and copper is defined by Ag_xCu_t where 0.900<

x<

0.999 and 0.001<

t<

0.100.

6. The medium of claim 5, wherein 0.001<

t<

0.05.

7. The medium of claim 5, said second metal alloy including silver and copper wherein the relationship between the amounts of silver and copper is defined by Ag_xCu_t where 0.900<

x<

0.999 and 0.001<

t<

0.100.