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

Abstract

Metal alloy thin films are provided for use in the highly reflective and semi-reflective layers of optical discs. Alloys include silver alloyed with gold, palladium, copper, rhodium, ruthenium, osmium, iridium, and platinum. Other alloys include copper alloys with silver, magnesium, cadmium, aluminum, nickel, beryllium, zirconium and zinc. These alloys have moderate to high reflectivity and reasonable corrosion resistance in the ambient environment.

1 . An optical storage medium, comprising:
 a first layer having a first pattern of features in at least one major surface;   a semi-reflective layer, said semi-reflective layer including a metal alloy, said metal alloy including silver and copper, wherein the relationship between the amounts of silver and copper in the metal alloy is defined by Ag x Cu y  where 0.95<x<0.9999 and 0.0001<y<0.05;   a second layer having a second pattern of features in at least one major surface; and   a high reflective layer.   
     
     
         2 . The optical storage medium of  claim 1 , further comprising an optically recordable dye layer adjacent to said semi-reflective layer. 
     
     
         3 . The optical storage medium of  claim 2 , wherein the first pattern of features includes a spiral groove. 
     
     
         4 . The optical storage medium of  claim 1 , wherein 0.001<y<0.03. 
     
     
         5 . The optical storage medium of  claim 1 , further comprising:
 a third layer adjacent to said semi-reflective layer, said third layer including a dielectric material;   a fourth layer, said fourth layer including an optically re-recordable material; and   a fifth layer, said fifth layer including a dielectric material.   
     
     
         6 . The optical storage medium of  claim 5 , wherein the first pattern of features includes a spiral groove. 
     
     
         7 . The optical storage medium of  claim 5 , wherein said optically re-recordable material is a phase-changeable material. 
     
     
         8 . The optical storage medium of  claim 7 , 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. 
     
     
         9 . The optical storage medium of  claim 5 , wherein said optically re-recordable material is a magneto-optic material. 
     
     
         10 . The optical storage medium of  claim 9 , wherein said optically re-recordable material further comprises a magneto-optic material selected from the group consisting of Tb—Fe—Co and Gd—Tb—Fe.