Trench MOS Barrier Schottky (TMBS) rectifier: A Schottky rectifier with higher than parallel plane breakdown voltage

Abstract

A new rectifier structure, called Trench MOS Barrier Schottky (TMBS) rectifier, is proposed and demonstrated by modeling and fabrication to have excellent characteristics. Two-dimensional numerical simulations have demonstrated coupling between the charge in the N − drift region and the metal on the trench sidewalls resulting in an improved electric field distribution. For epitaxial layer doping of 1 × 10 17cm −3, simulations show that break-down voltages of three times the plane parallel breakdown can be achieved with low leakage current. The measured on-state voltage drops for the devices fabricated using 0.5 μm technology at 60 and 300 A/cm 2 were 0.2 and 0.28 V, respectively. Due to smaller drift region resistances, TMBS rectifiers can be operated at large current densities (∼ 300 A/cm 2) resulting in small evice sizes.