Crystallizing mechanism and recording properties of In3SbTe2 phase-change optical disks

The crystallization mechanism and its application to improvement of the carrier-to-noise ratio (CNR) for In3SbTe2 phase-change optical disks were examined by that transmission electron microscopy (TEM). The TEM images indicated: (1) mark shapes were distorted when the interval between laser irradiations was short; (2) following dc laser irradiation onto the marks, crystallization proceeded only along the periphery of the amorphous phase; and (3) mark shapes were varied corresponding to the dc laser power. We assumed that the crystallization mechanism for In3SbTe2 was dominated by crystalline growth rather than nucleation. Then we simulated the mark shapes after dc irradiation. By controlling the thermal distribution on the marks, the CNR was improved promoted. We found that dc irradiation was a simple way of improving recording properties.