Free carrier distribution profiling of 4H-SiC substrates using a commercial optical scanner

Presented here is an explanation for the use of a commercial optical scanner for the mapping of doping density (ND) within SiC substrates and as a local probe for ND variations. This method provides a fast and cost effective method for determining ND homogeneity, examining local electrical characteristics, and recognizing defect sites including areas of different polytypes or polycrystallinity. Hall effect and micro-Raman spectroscopy were used to calibrate the transmission amplitude, integrated area and scanner red, green, blue (RGB) luminance values with ND. It is shown that features presented in the calculated ND maps strongly correlate to those observed in Lehighton resistivity maps.