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

• US 7,291,374 B2
• Filed: 05/16/2006
• Issued: 11/06/2007
• Est. Priority Date: 06/22/1998
• Status: Expired due to Term

• Current Assignee: Target Technology Company LLC
• Original Assignee: Target Technology Company LLC
• Inventors: Nee, Han H.
• Primary Examiner(s): MULVANEY, ELIZABETH EVANS
• Application Number:
  US11/434,662
• Publication Number:
  US 20060204708A1
• Time in Patent Office: 539 Days
• Field of Search: 428/64.1, 428/64.4, 428/64.5, 428/64.6, 430/270.13
• 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, 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;

a semi-reflective layer adjacent the pattern of features in said first layer, the semi-reflective layer including a metal alloy, said metal alloy including silver, tin and indium, wherein the relationship between the amounts of silver, tin and indium in said metal alloy is defined by Ag_xSn_yIn_z, wherein 0.9<

x<

0.9998, 0.0001<

y<

0.5 and 0.0001<

z<

0.5;

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

a reflective layer adjacent the pattern of features in said second layer.