Schottky field-effect transistor

A Schottky field-effect transistor (SFET) is described. The SFET is a three-terminal trench-gated device with a Schottky interface between a metal layer and the top surface of the semiconductor substrate. The gate electrodes are doped with material of the same conductivity type as the substrate, and the mesas between the trenches are relatively narrow. As a result, the electric fields produced by the gate electrodes generate depletion regions which merge at the center of the mesa to pinch off current flow. The SFET is turned on by applying a voltage opposite to the doping of the gate and substrate, creating accumulation regions along the walls o the trenches. In this condition the SFET exhibits a very low forward voltage drop across the Schottky interface. A SFET can be turned on or off with a relatively small swing in the gate voltage (e.g., +/-1 V), and it is therefore an ideal power switch for use with supply voltages of less than 3 V.