The graded doped trench MOS Barrier Schottky rectifier: a low forward drophigh voltage rectifier

A novel high voltage Schottky rectifier, called the Graded Doped Trench MOS Barrier Schottky (GD-TMBS) rectifier, is described in this paper. It is sh own to have very low forward drop with excellent reverse blocking character istics through device simulation and electrical characterization of fabrica ted devices. A linearly graded drift region doping profile is shown to resu lt in an uniform electric field in the drift region resulting in the abilit y to support blocking voltages proportional to the trench depth. Two-dimens ional device simulations have shown that breakdown voltages of upto 200 V c an be achieved with a very low forward drop of 0.54 V. The measured on-stat e drop of fabricated 60 and 100V GD-TMBS are about half those of convention al Schottky rectifiers. Power dissipation analysis indicates higher operati ng temperatures (150 degrees C) with reduced heat sink sizes when compared to conventional Schottky barrier diodes. (C) 1998 Elsevier Science Ltd. All rights reserved.