Investigation on the mechanism of instability for step morphology during 3C-SiC (111) vicinal surface epitaxial growth

In the step flow growth of SiC, the morphological instability will significantly affect the crystal quality. Exploring and mastering the intrinsic mechanism of crystal morphology instability from a microscopic point of view can provide theoretical references for practical production. The lattice kinetic Monte Carlo method is used to investigate the mechanism of step morphology instability during the epitaxial growth of 3C-SiC. Si and C are considered as independent atoms, and the Ehrlich-Schwoebel barrier and the diffusion barrier parallel to the step edge are all considered. The differences in atomic diffusion are mainly discussed, and the microscopic evolution of 3C-SiC crystals is simulated from the intrinsic properties and external factors affecting their morphology. And the relevant parameters measuring the morphology stability are calculated. The results show that the growth temperature mainly affects the atoms diffusion, which is a key external factor leading to the instability of step morphology. The difference in step crystal orientation can lead to morphological differences through the bonding energy at the edges of the step. The different diffusion barriers parallel to the step edge can lead to energy imbalance in the substrate, resulting in nucleation phenomenon, which is a potential factor for the instability of crystal morphology.