Influence of Nitrogen Concentrations on the Lattice Constants and Resistivities of n-Type 4H-SiC Single Crystals

4H-SiC single crystals with different nitrogen doping concentrations were grown by sublimation method. After processing, the standard 4H-SiC substrates were obtained. The carrier and nitrogen concentrations in 4H-SiC single crystals were measured by Raman spectroscopy and secondary ion mass spectrometry, respectively. The resistivities of 4H-SiC single crystals were measured by a noncontact resistivity testing system. The influence of nitrogen concentration on the resistivity of 4H-SiC single crystal was assessed. In addition, the structural qualities of 4H-SiC single crystals were investigated by high resolution X-ray diffractometry. The 004, 008 symmetric reflection rocking curves and 102, 204 skew symmetric reflection rocking curves of 4H-SiC single crystals were measured and the lattice constants of 4H-SiC single crystals were accurately determined. The effect of nitrogen concentration on the lattice constants was discussed.