3-D crystallization simulation in phase change recording media

The technique of phase change optical recording has been developing very rapidly over past few years. More complicated recording techniques are being studied to apply to phase change recording, including multi-level recording and multi-layer recording (H.D. Shieh et al, 2001; L. Shi et al, 2000; T. Akiyama et al, 2001). They require precise control of laser power and pulse duration to obtain optimal disk performance (writing and erasing). Therefore a better understanding of the kinetics of the crystallization of the recording material is needed. Considerable effort has been put into simulation of crystallization process in phase change optical recording. Mansuripur et al (Applied Optics, vol. 39, no. 35, pp. 6695-6701) studied transient nucleation effects, Sheila et al (Proc. SPIE, vol. 4090, pp. 116-121) modeled the jitter due to the statistical nature of the crystal nucleation and growth. Both of their simulations are based on the 2D crystallization model. However, in order to understand some crystallization phenomena, such as the effects of recording layer thickness and the effects of dielectric layer interfaces (heterogeneous nucleation), we must study the crystallization in thin films in three dimensions. In this paper, we set up an isothermal model to explain the recording layer thickness effects. Based on the isothermal model, we developed a method to simulate the crystallization process of phase change recording material in 3D.