A new Schottky-gate Bipolar Mode Field Effect Transistor (SBMFET) is proposed and verified by two-dimensional simulation. Unlike in the case of conventional BMFET, which uses deep diffused p + -regions as the gate, the proposed device uses the Schottky gate formed on the silicon planar surface for injecting minority carriers into the drift region. The SBMFET is demonstrated to have improved current gain, identical breakdown voltage and ON-voltage drop when compared to the conventional BMFET. Since the fabrication of the SBMFET is much simpler and obliterates the need for deep thermal diffusion of P+-gates, the SBMFET is expected to be of great practical importance in medium-power high-current switching applications.

The Bipolar Mode Field Effect Transistors (BMFETs) using P+ gates on N-type Silicon substrate are the most commonly used power devices for high-current mediumpower switching applications and as optically controlled switches 11,21. These are dual gate devices with deep P+ gate junctions, which require large thermal cycles for diffusion. In this paper, we propose a novel Schottky-gate BMFET (SBMFET) using Ptype 4H Silicon-Carbide 13,41, a wide bandgap material, in which the PN junction gates are replaced by the Schottky gates. We have studied the characteristics of this device using twodimensional numerical simulation 1[1. Our results demonstrate for the first time that the P-SiC Schottky-gate BMFET has very low ON voltage drop, good output characteristics, a reasonable current gain and a blocking voltage greater than 1000 V.

No abstract