A competitive lattice model Monte Carlo method for simulation competitive growth of different polytypes in close-packed crystals: 4H and 6H silicon carbide

Abstract

A competitive lattice model Kinetic Monte Carlo method has been developed and implemented to simulate the SiC crystals growth by physical vapor transport method. The model is an advancement with respect to standard Monte Carlo algorithms, allowing to simulate polytypes competitive growth and defective evolution. The model can simulate the formation and evolution of threading screw dislocations in SiC as well. Kinetics processes with surface energy and bond energy, including deposition, evaporation and diffusion processes are considered in physical criterion in our model. Periodic boundary conditions and non-periodic boundary conditions are carried out. The competitive growth between 4H- and 6H-SiC polytypes suggests that retaining the step growth mode is an important factor to maintain a stable single 4H polytype during SiC growth. The threading screw dislocations simulation indicates that screw dislocations drive the growth of SiC. The evolution of surface morphologies demonstrates that fast surface diffusion rate and low growth rate may be one way to grow high quality, low-roughness 4H-SiC crystals.