Total pressure-controlled PVT SiC growth for polytype stability during using 2D nucleation theory

A total pressure-controlled physical vapor transport growth method that stabilizes SiC polytype is proposed. The supersaturation of carbon during SiC growth changed as a function of the growth time due to changes in the temperature difference between the surfaces of the source and the grown crystal. Supersaturation also varied as a function of the pressure inside the furnace. Therefore, modification of the pressure as a function of growth time allowed for constant supersaturation during growth. The supersaturation was calculated based on classical thermodynamic nucleation theory using data for heat and species of Si₂C and SiC₂ transfer in a furnace obtained from a global model. Based on this analysis, a method for polytype-stabilized SiC growth was proposed that involves decreasing the pressure as a function of growth time. The 4H-SiC prepared using this pressure-controlled method was more stable than that of 4H-SiC formed using the conventional constant-pressure method.