Raman imaging characterization of electric properties of SiC near a micropipe

Electrical and crystalline properties around micropipe defects have been studied in n-type 4H-SiC bulk crystals by using Raman imaging technique. We have observed clear decrease in carrier concentration and mobility in the vicinity of micropipe, indicating existence of carrier trapping centers. Experiments at high temperatures up to 1200 degreesC showed that thermal excitation of carriers was negligibly small. This suggests that the trap levels are relatively deep.