OPTICAL RECORDING MEDIUM AND PREPARATION THEREOF

摘要

PURPOSE:To enhance the repeated characteristics of recording and erasure by forming a material prepared by adding nitrogen to a mixture of GeTe-Sb2 Te3-Sb on a substrate. CONSTITUTION:The first protective layer 2 composed of ZnS-SiO2 excellent in heat resistance is preliminarily formed to a substrate 1. A recording layer 3 is a membrane wherein nitrogen is mixed with GeTe, Sb2Te3 and Sb and the second protective layer 4 is composed of the same material as the first protective layer 2. A reflecting layer 5 is composed of an Al alloy and a protective plate 6 is bonded to the substrate 1 by an adhesive 7. The recording layer 3 has such a composition that the mol ratio (g) of GeTe/Sb2Te3 is 0.5 <= g <=2.3 and the mol ratio (b) of Sb/Sb2Te3 is 0 <= b <= 1.0. The recording layer is formed by a sputtering method using a gaseous mixture of argon and nitrogen gas. At this time, nitrogen partial pressure is set to 10<-5> - 1.0 X 10<-4>Torr. The second protective layer 4 is made thinner than the first protective layer 2 and the thickness thereof is set to 30nm or less.