초록

and wherein the layer thickness d.sub.3 of said recording layer ranges between 25 and 35 nm. Such a medium is suitable for high speed recording (i.e. at least twice the CD-speed), and has a large cyclability of at least 10.sup.5 direct overwrite cycles.

대표청구항 ▼

[ We claim:] [1.] An optical information medium for erasable high-speed recording by means of a laser-light beam, said medium comprising:a substrate and;a stack of layers on the substrate; which stack includes:a first dielectric layer;a recording layer of a phase-change material including an alloy o

[ We claim:] [1.] An optical information medium for erasable high-speed recording by means of a laser-light beam, said medium comprising:a substrate and;a stack of layers on the substrate; which stack includes:a first dielectric layer;a recording layer of a phase-change material including an alloy of Ge, Sb and Te;a second dielectric layer; anda metal mirror layer; and wherein:the alloy has a composition defined by the formula Ge.sub.50x Sb.sub.40-40x Te.sub.60-10x in atomic percentage, where 0.166.ltoreq.x.ltoreq.0.444 and additional Sb to increase the recording sensitivity;the recording layer has a thickness of 25 to 35 nm;the second dielectric layer has a thickness of 15 to 50 nm; andthe metal mirror layer has a thickness of 60 to 160 nm.