Direct Observation and Three Dimensional Structural Analysis for Threading Mixed Dislocation Inducing Current Leakage in 4h–sic IGBT

The Burgers vector and inclination angles for threading dislocations which induce current leakage have been investigated for SiC insulated gate bipolar transistors fabricated with a thickness of a drift layer as large as 100 μm on a 4H–SiC substrate. Direct analysis by convergent-beam electron diffraction to a threading mixed dislocation (TMD) inducing current leakage revealed that the Burgers vector was b = [ 1 ¯ 011 ], which has been theoretically predicted but had not been observed. Although a range of inclination zenith angles of TMDs from c-axis has been observed by non-destructive two-photon-excited photoluminescence as 12°–14°, which is in good agreement with theoretical values, their azimuthal angles on (0001) plane are significantly different from theoretical predictions.