20 kV-Class Ultra-High Voltage 4H-SiC n-IE-IGBTs

Abstract

We demonstrate 20 kV-class 4H-SiC n-channel implantation and epitaxial (IE)-IGBTs having both low on-state voltage and high blocking characteristics. We fabricated n-IE-IGBTs on a (0001) silicon face with free-standing epitaxial layers. Effective carrier lifetime increased significantly from 0.9 μs to 9.6 μs by a lifetime enhancement process. We used the IE structure to suppress an increase of the surface p+-well concentration, reduce implantation damage at the p+-well, and reduce junction field effect transistor (JFET) region resistance by ion implantation as a counter doping. The n-IE-IGBT at 100 A/cm2 on-state voltage and specific differential on-resistance was 8.2 V and 36.9 mΩcm2, respectively, at room temperature with a 30 V gate voltage. The blocking voltage was 26.8 kV at 45.7 μA.