Simulation Study Of An Injection Enhanced SiC IGBT

Abstract

In this paper, a novel structure of an injection enhanced SiC IGBT have been investigated for the first time. In the new structure, a top surface Schottky contact is added to the p-base area as a holes barrier to enhance the conductivity modulation effect. And the P-P+-P (shaped like island structure) is formed by multiple ion implantation process steps. Especially the Schottky diode enhances the conductivity modulation while the turn-off loss does not increase. TCAD simulation shows that the new structure of SiC IGBT offers a total turn-on and turn-off loss (Eall) reduction of 18% when compared with a conventional IGBT structure on SiC substrate. Furthermore, the static and dynamic characteristics simulation shows that the Schottky barrier height (SB) and depth of P contact zone (Hpp) dramatically affect the performance of the device. To the best of our knowledge, the injection enhanced SiC IGBT is the only structure which exhibits a simultaneous drop in forward voltage drop and turn-off loss without complicating the fabrication process in comparison with the other conductivity modulation enhancement structures.