Liquid phase silicon at the front of crystallization during SiC PVT growth

Formation mechanism of Type 2 micropipe defects in 4H–SiC crystals

“…32,33 As a result, the composition of the gas phase is strongly Si rich at the beginning of the growth. It is generally accepted [34][35][36][37] that Si droplets will appear on the surface of the growth crystal by the following reaction:…”

“…The critical value of the temperature difference required for liquid silicon formation was found to be a function of the evaporation temperature of the powder source as described in ref. 34. A larger axial temperature gradient will accelerate the formation of Si droplets on the growing surface.…”

Growth of Silicon Carbide

“…The value T S must be optimized since a high rate of growth ( 1.0 mm h −1 ) leads to defect generation due to the formation of essential thermal stress. Moreover, when the temperature difference T S ≥ 100 K the supersaturation becomes large enough to initiate silicon second-phase condensation [39] and planar-defect formation [40].…”

“…The planars lie parallel to the basal plane, typically a few micrometers in thickness, with trench-like depressions at the edges, and often associated with the formation of dislocations and micropipes. It was shown that the nonstoichiometry of the vapor, the large supersaturation, and high volatility of residual carbon species are the primary factors that determine the formation of planar defects and second-phase inclusions [39,40,61].…”

Self-congruent process of SiC growth by physical vapor transport

“…In fact, an excessive lowering of the sublimation temperature T V o2600 K would drastically shift the vapor stoichiometry towards Si abundance [8]. At the same time, even if T V is suitably high but T C is inadequately low, liquid silicon second phase from the vapor will condense at the growth front [11]. This eventually leads to the formation of heterogeneous inclusions, voids, vacancies and micropipes within the growing boule.…”