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

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 an 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.