Numerical Simulations of a 4H-SiC BMFET Power Transistor with Normally-Off Characteristics

A numerical simulation study focused on an oxide-free 4H-SiC power device that is based on a normally-off Bipolar Mode Field Effect Transistor (BMFET) structure, and therefore on the principle of conductivity modulation from minority carrier injection, is presented. Starting from a n-/n+ 4H-SiC epi-wafer, with an epitaxial layer thickness of a few microns, and considering the presently available 4H-SiC ion implantation technology, a completely planar SiC-based BMFET has been designed. Such a device has interesting features in terms of static forward and blocking I V characteristics for high power applications. The 4H-SiC fundamental physical models, such as the doping incomplete ionization and the carrier recombination processes, were taken into account during the simulations.