Effect of cobalt addition to Si–Cr solvent in top-seeded solution growth

Top-seeded solution growth (TSSG) has received considerable attention as a promising growth method for obtaining high-quality silicon carbide (SiC) single crystals. However, low carbon solubility in the TSSG method prevents rapid growth of bulk SiC single crystals. In this study, we propose cobalt (Co), for the first-ever use in this method, with the aim of improving the SiC growth rate and crystal quality realized through the TSSG method with a Si0.6Cr0.4 solvent. The surface morphology of crystals grown with the Si0.6Cr0.4 solvent was characterized by significant step bunching. However, the growth surface generated by a Si0.56Cr0.4Co0.04 solvent was characterized by a smooth surface with step-flow growth, and the crystal grown with this solvent contained almost no Co. Furthermore, the growth rate in the Si0.56Cr0.4Co0.04 solvent was three times higher than that in the Si0.6Cr0.4 solvent. Based on the aforementioned results, Si0.56Cr0.4Co0.04 represents a promising solvent that can be used to enhance the growth rate and improve the quality of SiC single crystals.