Silicon carbide epitaxial wafer, silicon carbide insulated gate bipolar transistor, and manufacturing method thereof

摘要

PROBLEM TO BE SOLVED: To provide a SiC-IGBT arranged so that the occurrence of expansion of a lamination defect attributed to excessive electron injection in the vicinity of a collector electrode can be suppressed effectively during a time when IGBT arranged by use of a self-supporting epitaxial film is in a forward operation.SOLUTION: An SiC-IGBT comprises: a p-type collector layer (p-type buffer layer 2); an ntype voltage sustaining layer 4 provided over the collector layer; p-type base regions (p-type second base regions 6a, 6b) provided over an ntype voltage sustaining layer 4; ntype emitter regions 8a, 8b provided over the p-type base regions; a gate insulative film 10 provided over the voltage sustaining layer 4; and a gate electrode 11 provided on the gate insulative film 10. The p-type buffer layer 2 has a thickness t1 of 5 μm or more and 20 μm or less, and is added with Al at an impurity concentration of 5×10cmor more and 5×10cmor less, and B at an impurity concentration equal to or more than 2×10cmand less than 5×10cm.SELECTED DRAWING: Figure 1