Patent ID: 6278684
Filing Date: 2001-08-21
Classification: G11B

Abstract:
A rewritable optical information recording medium of the phase-change type, comprising:a substrate;a first dielectric layer formed on said substrate;a recording layer formed on said first dielectric layer and made of a Te--Ge--Sb--B quaternary alloy, wherein said Te--Ge--Sb--B guaternary alloy is defined by a formula Te.sub.a Ge.sub.b Sb.sub.c B.sub.d, where a, b, c, and d are atomic percentages ranging from 45 to 57, 33 to 45, 5 to 15, and 0.1 to 2, respectively, such that said recording layer exhibits an optical contrast greater than 35% between an amorphous state and a crystalline state at a wavelength range between 350 nm and 800 nm;a second dielectric layer formed on said recording layer;a reflective layer formed on said second dielectric layer; anda protective layer formed on said reflective layer.