Polytype-controlled single-crystal growth of silicon carbide using 3C→6H solid-state phase transformation

The phase transformation from 3C-SiC to 6H-SiC at high temperature has been applied to crystal growth of SiC. Single-crystal growth of controlled polytype has been carried out on chemical-vapor-deposition-grown 3C-SiC(001) films by using a sublimation method. The polytype of grown layers was controlled as either cubic 3C-SiC or hexagonal 6H-SiC. The growth temperature was varied in the range of 1800–2400 °C. A growth rate up to several hundred micrometers per hour was achieved. The polytypes, crystallographic planes, and crystallinity of the grown layers were examined using photoluminescence, Raman spectroscopy, x-ray diffraction, reflection high-energy electron diffraction, and molten KOH (potassium hydroxide) etching. The polytype of the grown layers was changed from 3C-SiC to 6H-SiC with an increase in substrate temperature, and 6H-SiC(011̄4) planes were grown on 3C-SiC(001) at high temperatures. The crystallographic relationship between 6H-SiC(0114) and 3C-SiC(001) is described. The growth mechanism of 6H-SiC(011̄4) on 3C-SiC(001) is discussed based on experimental results on the thermal stability of 3C-SiC.