Infrared Transmission and Reflectivity Measurements of 4H- and 6H-SiC Single Crystals

Room temperature infrared transmittance and reflectance spectra of 4H and 6H-SiC single crystals were measured by a NEXUS 670 Fourier Transform Infrared-Raman spectrometer. The transmittance and reflectance of non-doped, V-doped semi-insulating (SI), high purity semi-insulating, n-type and p-type SiC wafers have been compared and assessed. The effect of nitrogen and boron concentration on the transmittance is discussed. In addition, the carrier concentrations in 4H-SiC wafers were measured by Raman spectroscopy at room temperature. The influence of nitrogen concentration on the transmittance is also discussed.