Comparison of carrier lifetime measurements and mapping using time resolved photoluminescence and µ-PCD

Carrier lifetime measurements and wafer mappings have been done on several different 4H-SiC epiwafers to compare two different measurement techniques, time-resolved photoluminescence and microwave-detected photoconductivity decay. The absolute values of the decay time differ by a factor of two, as expected from recombination and measurement theory. Variations within each wafer are comparable with the two techniques. Both techniques are shown to be sensitive to substrate quality and distribution of extended defects.