A Novel Trench MOS Barrier Schottky Contact Super Barrier Rectifier

Abstract

In this paper, a novel trench MOS barrier Schottky contact super barrier rectifier (TMB-SSBR) is proposed by combining the advantages of vertical SSBR and conventional TMBS. The operation mechanism and simulation verification are presented. TMB-SSBR consists of MOS trenches with a vertical SSBR grid which replaces the Schottky diode in the mesa of a TMBS. Due to the presence of top p-n junction in the proposed TMB-SSBR, the image force barrier lowering effect is eliminated, the pinching off electric field effect by MOS trenches is weakened, so that the mesa surface electric field is much larger than that in conventional TMBS. Therefore, the mesa width is enlarged and the n-drift concentration is slightly increased, which results in a low specific on-resistance and a good tradeoff between reverse leakage currents and forward voltages. Compared to a conventional TMBS, simulation results show that, with the same breakdown voltage of 124 V and the same reverse leakage current at room temperature, TMB-SSBR increases the figure of merit (FOM, equates to V2B/Ron,sp) by 25.5%, and decreases the reverse leakage by 33.3% at the temperature of 423 K. Just like the development from SBD to TMBS, from TMBS to TMB-SSBR also brings obvious improvement of performance.