New Improvement Results on 7.5 kV 4H-SiC p-IGBTs with Rdiff, on of 26 mΩ·cm2 at 25°C

A significant improvement in 4H-SiC p-IGBTs has been achieved. A differential on- resistance of ˜26 mΩ.cm₂ was demonstrated at a gate bias of -16 V at 25°C. A novel current suppressing layer (CSL) was adopted to eliminate the JFET effect and enhance conductivity modulation by suppressing the current conduction through the BJT section. A hole mobility in the inversion channel of 10 cm²/V.s with a threshold voltage of -7.6 V was achieved by optimizing the n⁺-well doping profile and gate oxidation process. Inductive switching characterization has been conducted, and results have shown that p-IGBTs exhibit a turn-off time of ˜1 μs at -4 kV collector voltage and 25°C. A turn-off trajectory shows a square reverse bias safe operating area (RBSOA) indicating p-IGBTs are suitable devices for high power, high frequency applications.