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.
!!!All Science Journal Classification (ASJC) codes
- 化学 (全般)