Study On The Electrical Properties Of The Super Barrier Rectifier

With the rapidly increasing demands pertaining to high voltage applications,semiconductor power devices have become widely used in today’s electronic systems.Because of its improved performance,the super barrier rectifier(SBR)concept is more and more favored,where a super barrier is an adjustable potential barrier under MOS structure for a majority carrier operation without an unreliable Schottky contact.The elimination of the junction type field effect transistor region allows a significant reduction of the overall specific on-resistance for the trench gate type SBR(TSBR)not only because its resistance is excluded but more importantly because the cell pitch can be made much smaller than that of the SBR.Furthermore,the charge coupling effect plays an important role in determining the breakdown voltage of the power TSBR.However,there is no intensive study on this point and the electrical properties related theory.In this paper,the forward conduction characteristics in the MOS channel are explained.Base on the simulation results with Sentaurus TCAD,the formula of channel current-voltage proved successful.The trench field-plate mode and analytical model have been discussed to demonstrate two-dimensional charge coupling within power TSBR structures,and some advisable formulas are proposed on the base of simulation results.Then,we performed the key parameters optimization,including 60 V TSBR and 280 V TSBR,which can provide significant guidance for the SBR/TSBR design.In addition,a novel TSBR with the stepped oxide(SO-TSBR)is proposed.Similar to,yet different from,the structure for the dual trench MOSFET or the power charge coupling MOSFET,the stepped oxide structure equips TSBRs with enhanced the voltage-blocking capability.Compared to the conventional TSBR,simulation results show that SO-TSBRs decrease the forward voltage drop by 26.6%with almost the same leakage current.Deep trench SO-TSBR(DT-SO-TSBR),as a improved mode of SO-TSBRs,decreases the forward voltage drop by 11%than that of SO-TSBRs.The simulations in this paper are combined with theory analysis all the time.The simulation data and the analysis results will be helpful in designing SBRs used in modern electronic systems.