Characterization of Nitrogen-Boron doped 4H-SiC substrates

Abstract

Nitrogen-Boron doped 4H-SiC single crystal was prepared by physical vapor transport method and the doping concentration was determined by secondary ion mass spectroscopy. The resistivity of 4H-SiC substrate was measured by contactless method. It was found that the resistivity decreased from center to edge of the substrates. Carrier concentration distribution on 4H-SiC was simulated based on Raman spectra mapping. From center to edge, the carrier concentration decreased gradually. Photoluminescence spectra of 4H-SiC showed a peak wavelength of about 538 nm with full with half maximum (FWHM) about 104 nm. The emission intensity is enhanced with the Nitrogen concentration increasing and then suppressed because of the free carrier absorption enhancement.