Cellular Automaton Modeling of Silicon Facet Formation during Directional Solidification

Silicon facet formation during directional solidification is simulated by cellular automaton (CA) modeling in which anisotropic interfacial energy and kinetics are considered. Numerical simulations were performed with different anisotropy strengths of interfacial energy and they show good agreement with analytical equilibrium shapes obtained by the Gibbs-Thomson equation. We also compare our results of anisotropic kinetics with in situ observation experiments and the results of the phase model to verify the accuracy of our model. Simulation results of facet formation show that perturbation is promoted to the corner by the negative temperature gradient of the interface and the heat accumulation location leads to the disappearance of small corners.