WRITE-ONECE-READ-MANY OPTICAL RECORDING MEDIUM AND SPUTTERING TARGET THEREOF

摘要

A write-once-read-many optical recording medium enabling excellent recording and reproducing properties at a wavelength of blue-laser wavelengths or shorter, i.e. 500nm or less, particularly at wavelengths of near 405nm and high density recording. To this end, a write-once-read-many optical recording medium of the invention comprises a recording layer using a material represented by BiOx (0< x < 1.5), in which a recorded mark comprises crystal of Bi and/or crystal of a Bi oxide. Another write-once-read-many optical recording medium comprises a recording layer which comprises Bi, oxygen, and M (M represents at least one element selected from Mg, Al, Cr, Mn, Co, Fe, Cu, Zn, Li, Si, Ge, Zr, Ti, Hf, Sn, Mo, V, Nb, Y, and Ta), in which a recorded mark comprises crystal of the elements contained in the recording layer and crystal of an oxide of the elements.