Improving Switching Characteristics of 4H-SiC Junction Rectifiers Using Epitaxial and Implanted Anodes with Epitaxial Refill

The on-state and switching performance of high voltage 4H-SiC junction rectifiers are compared using numerical simulations and experimental characterization. Epitaxial and implanted anode PiN diodes as well as novel, advanced rectifiers have been fabricated in 4H-SiC using 110μm thick drift layers. The relatively low forward voltage drop of these epi-anode diodes (4.2V @ 100A/cm2) indicates moderate conductivity modulation, while the superior switching performance of the “MPS-like” rectifiers is demonstrated with reverse recovery characteristics at various temperatures and forward current densities.