Patent ID: 6210770
Filing Date: 2001-04-03
Classification: G11B,Y10S,Y10T

Abstract:
An optical recording medium comprising a recording layer of a phase-change material switchable between a crystalline state and an amorphous state in response to signal-wise illumination by light focused onto the recording layer to change the phase thereof from crystalline to amorphous, thereby writing an information signal onto the recording layer, said phase-change material comprising a GeSbTe alloy and said recording layer being formed by sputtering in an Ar gas atmosphere comprising N.sub.2, O.sub.2 or both N.sub.2 and O.sub.2, wherein:the recording layer is formed at a speed X (nm/s) in an Ar gas atmosphere containing N.sub.2 and O.sub.2 gases of which the mixing ratio (N.sub.2 and O.sub.2)/Ar among the N.sub.2, O.sub.2 and Ar gases is Y(%) and the mixing ratio O.sub.2 /(N.sub.2 +O.sub.2) of O.sub.2 gas with the mixture of N.sub.2 and O.sub.2 gases is Z(%), the parameters X, Y and Z meeting the following relations (1) to (3):Y.gtoreq.2.3X+1.0 (1)Y.ltoreq.12.8X+16.7 (2)10.ltoreq.Z.ltoreq.60 (3).