Three-dimensional analysis of overwritable phase-change optical disks

Three-dimensional computer calculations which analyze time-transient behavior of heat conduction and phase-change kinetics in an InSbTe overwritable disk were made. To improve the calculation accuracy, thermal conductivities of thin-film materials and critical cooling rate for crystallizing the recording film were estimated. For realization of high-performance overwrite, it was found that the cooling conditions of writing and erasing processes should be controlled to match the critical cooling rate in a given linear velocity range. This could be achieved by optimal design of the disk structure.