12-kV p-channel IGBTs with low on-resistance in 4H-SiC

SiC bipolar devices are favored over SiC unipolar devices for applications requiring breakdown voltage in excess of 10 kV. We have designed and fabricated p-channel insulated-gate bipolar transistors (IGBTs) in 4H-SiC with 12-kV blocking voltage for high-power applications. A differential on-resistance of 18.6 m Omega center dot cm(2) was achieved with a gate bias of 16 V, corresponding, to a forward voltage drop of 5.3 V at 100 A/cm(2) indicating strong conductivity modulation in the p-type drift region. A moderately doped current enhancement layer grown on the lightly doped drift layer effectively reduces the JFET resistance while maintaining a high carrier lifetime for conductivity modulation. The p-channel IGBT (p-IGBT) exhibits a transconductance that is 3 x higher than that of the 12-kV n-channel SiC IGBTs. An inductive switching test was done at 1.5 kV and 0.55 A (similar to 140 A/cm(2)) for the p-IGBTs, and a turn-on time of 40 ns and a turn-off time of similar to 2.8 mu s were measured.