As a new dielectric layer for magneto-optical disks, we have developed AlGeN films prepared by the reactive sputtering method. The deposition rate, internal stress, and refractive index were investigated as functions of the sputtering parameters.AlGeN films were found to be superior in these points: high deposition rate, low internal stress (<1.5×109 dyne/cm2), and high refractive index (>2.4).
To evaluate dynamic characteristics and reliability, magneto-optical disks with TbFeCo double layer sandwiched by AlGeN layers were prepared on the polycarbonate substrate. Those disks had high carrier-to-noise ratio (C/N) even for 0.7 6 μm recording bit length. The acceleration test at a temperature of 60°C and a relative humidity of 90% was carried out. The defect error rate remained constant up to 2000 hours.
High reliability and good dynamic recording characteristics of the magneto-optical disk can be achieved by use of the AlGeN dielectric films.