Occurrence of Polytype Transformation during Nitrogen Doping of SiC Bulk Wafer

Abstract

The polytype structural variations of a set of SiC bulk wafers with different Nitrogen (N) doping levels, prepared by Physical Vapore Deposition (PVD), are studied. The initial growth conditions were used to produce 6H-polytype SiC, which has been approved for the undoped and lightly doped materials. However, when extreme high N-dopants were applied, the obtained wafer was found with 4H- and 15R-polytype features. Our experimental results of HR-TEM and Raman scattering have revealed clearly the polytype transformation, indicating that the inducement of N in the reactor leads to the polytype transformation of the resulted SiC crystal.

Polytype switching identification in 4H-SiC single crystal grown by PVT

“…But due to the small region, we could not probe the ion beam in the 15R region accurately in SIMS experiment. Chen et al also explained the polytype transformation during the nitrogen doping in SiC bulk crystal prepared by physical vapour deposition [36]. They explained lightly doped nitrogen in SiC crystal was found to be 6H-SiC polytype, while applying high nitrogen doping in SiC was found to be 4H-and 15R-SiC polytypes.…”

Polytype inclusions and polytype stability in silicon-carbide crystals

“…Furthermore, high concentrations of nitrogen (>10 19 cm -3 ) give rise to the appearance of 4H inclusions in 6H-SiC ingots [38,39]. Stabilization of the 4H polytype can be related to a number of factors.…”