A low forward drop high voltage trench MOS barrier Schottky rectifier with linearly graded doping profile

Abstract

A novel high voltage Schottky rectifier, called the graded doped trench MOS barrier Schottky (GD-TMBS) rectifier, is described in this paper. A linearly graded drift region doping profile is shown to result in a uniform electric field in the drift region, resulting in the ability to support blocking voltages proportional to the trench depth. Two-dimensional device simulations have shown that breakdown voltages of up to 200 V can be achieved with a very low forward drop of 0.54 V. The measured on-state drop of fabricated 60 V and 100 V GD-TMBS are about 30% less than those of conventional Schottky rectifiers. The reverse leakage currents of the GD-TMBS rectifiers are two orders of magnitude less when compared to the conventional Schottky barrier diode.