Development of a novel 1200-V-class 4H-SiC implantation-and-epitaxial trench MOSFET with low on-resistance

Abstract

In this paper, we present a newly developed 1200-V-class 4H-SiC implantation-and-epitaxial trench metal–oxide–semiconductor field-effect transistor (IETMOSFET). It uses high-quality p- and n-epitaxial layers for a channel and a trench current spreading layer (TCSL), respectively. It can enhance both channel mobility and bulk mobility for current spreading by avoiding damage and impurity variations caused by ion implantation. The ion implantation and epitaxial techniques developed for existing ion-implantation-and-epitaxial MOSFETs (IEMOSFETs) are herein utilized to protect the trench bottom and a relatively low-doped epitaxial channel layer with high mobility. By optimizing the geometry of p-base regions under a gate trench structure, we obtain a low specific on-resistance (RONA) of 1.8 mΩ cm2 with a breakdown voltage (BVDSS) above 1200 V.