Effect of SiC polytype inclusions on doping concentrations and electrical properties

This study investigated the effects of polytype inclusions on the doping concentrations and electrical properties of SiC substrates. Secondary ion mass spectrometry (SIMS) and glow discharge mass spectrometry (GDMS) were used to quantify the nitrogen doping concentrationsand metal impuritiesrespectively in the adjacent polytyperegions.Nitrogen doping concentrations show slight differences among polytypes, which can be attributed to the proportion of cubic carbon sites.and indicated that no polarity inversion during growth. All metal impurities were below the detection limit, confirming high crystal purity. Carrier concentrations derived from Raman LOPC mode and calculated resistivityagreed well with measured data. 6H-SiC had the highest resistivity due to the lowest electron mobility, whereas 15R-SiC showed the lowest because of its high carrier concentration-mobility product. This work clarifies the influence mechanism of SiC polytype inclusions and offers theoretical support for fabricating high-quality SiC substrates.