Optical recording medium

Abstract

An optical recording medium formed from a transparent substrate, an enhancement layer formed on the substrate, a guide layer, an interference layer, a recording layer, a protective layer, and a reflective layer. A recording region is formed on the guide layer by etching to a predetermined spiral or a coaxial circular pattern. Because the enhancement layer is formed from a compound of aluminum such as Al.sub.2 O.sub.3, it is not etched during plasma etching using a gas mixture of carbon tetrachloride and oxygen. Therefore, the recording region remains smooth and noise generated by roughness between layers can be prevented. By making the thickness of the guide layer 20 nm or more, light which passes through the guide layer and which generates multi-layer interference between the recording layer and the reflective layer is reduced and the amount of reflective light is increased, Therefore, fluctuations in the pushpull signal by the fluctuations in the thickness of the guide layer is reduced. By making the guide layer 40 nm or less thick, noise from the guide layer can be reduced.

Dependencies are inferred from the claim text.