NUMERICAL-ANALYSIS OF EXCIMER-LASER-INDUCED MELTING AND SOLIDIFICATION OF THIN SI FILMS

We have developed an efficient two-dimensional numerical model, based on the finite difference method and utilizing the alternate-direction explicit scheme, that can simulate excimer laser melting and solidific ation of thin Si films on SiO2. The model takes into account important aspects of the process such as undercooling and the temperature-depen dent velocity of the solidifying interface, supercooling of liquid Si, and the inert nature of the underlying oxide interface. We demonstrat e the unique capability of the model by simulating spatially confined beam-induced localized complete melting of the irradiated portion of t he film, and the ensuing lateral solidification, which initiates from the unmelted regions of the film into the completely molten area. (C) 1997 American Institute of Physics.