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 $hbox{m}Omegacdothbox{cm}^{2}$ was achieved with a gate bias of 16 V, corresponding to a forward voltage drop of 5.3 V at 100 $ hbox{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 $hbox{3}times$ 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 $(sim !!hbox{140} hbox{A/cm}^{2})$ for the p-IGBTs, and a turn-on time of 40 ns and a turn-off time of $sim !!hbox{2.8} muhbox{s}$ were measured.