Bulk crystal growth of cubic silicon carbide by sublimation epitaxy

摘要

Cubic silicon carbide has a potential for high power, high frequency and high temperature devices. Sublimation growth is an established technique to prepare silicon carbide wafers, due to the possibility to obtain high quality crystals with high growth rates. However, the sublimation growth of cubic silicon carbide has not been very successful owing to the poor temperature stability of the polytype. In this study, bulk crystal growth of cubic silicon carbide on hexagonal silicon carbide substrates was tried by sublimation epitaxy. In previous work, the (0001) basal plane of hexagonal silicon carbide have been used as substrate for cubic silicon carbide growth by the sublimation method. In this study, crystal growth was carried out not on the (0001) basal plane but on the off-axis (0001) plane tilted towards <1120>. This tilted plane was used in order to form step-free (0001) basal plane and to grow cubic silicon carbide on this step-free plane. A step-free surface was formed on the off-axis oriented seed crystal by limiting the growth area and single crystal cubic silicon carbide could be successfully grown. Cubic silicon carbide with a size of 4.0 mm x 4.0 mm and 2.0mm thick was obtained.