Platinum additive impacts on vapor-liquid-solid growth chemical interface for high-quality SiC single crystal films

Pt additive to Si-based flux in the vapor-liquid-solid (VLS) process for 4H–SiC epitaxial films has been successful in suppressing the step bunching as well as in promoting the step-flow growth mode at growth temperatures much lower than 2000 °C, as evidenced by in situ laser microscope observation of a model solution growth chemical interface. As a result, the SiC film surface became remarkably flat, exhibiting well-regulated step-and-terrace structures with narrow terrace widths and straight step lines; the polytype of 4H–SiC was much more stabilized in the grown SiC films even at a growth temperature of 1250 °C. Furthermore, there is little concern about incorporation of Pt atoms as an impurity into the grown SiC films so that their Schottky junction properties are almost as excellent as those of 4H–SiC single crystals.