Patent ID: 6040066
Filing Date: 2000-03-21
Classification: G11B,Y10S,Y10T

Abstract:
An optical information medium for erasable high-speed recording by means of a laser-light beam, said medium comprising a substrate carrying a stack of layers, which stack comprises, in this order, a first dielectric layer, a recording layer of a phase-change material comprising a compound consisting of Ge, Sb, Te and O, a second dielectric layer and a metal mirror layer, characterized in thatthe compound has a composition (Ge.sub.a Sb.sub.b Te.sub.c).sub.1-d O.sub.d,wherein:a+b+c=10.0001.ltoreq.d.ltoreq.0.035the first dielectric layer having a thickness of 70 to (70+.lambda./2n) nm, wherein .lambda. is the wavelength of the laser-light beam, and n is the refractive index of this layer;the recording layer having a thickness of 10 to 35 nm;the second dielectric layer having a thickness of 10 to 50 mn;the metal mirror layer having a thickness of 60 to 160 nm.