Effect of cerium impurity on the stable growth of the 4H-SiC polytype by the physical vapour transport method

Effect of cerium impurity in the SiC source material on the 4H-SiC growth was investigated. 4H-SiC crystals were grown on 6H-SiC crystal seeds by physical vapor transport and using the open seed backside method. Cerium is the impurity used for promotion of the 4H polytype nucleation. The optimal amount of CeO2 for the growth of 4H-SiC with a good crystalline quality and without undesired 15R- and 6H-SiC inclusions was identified. The open seed backside method combined with the presence of cerium impurity in the growth chamber were more effective for the crystal growth process due to a lower degradation of the backside surface of the grown crystal.