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In this paper, we studied the enhancement of the breakdown voltage in the 4H–SiC MESFET–MOSFET (MES–MOSFET) structure which we have proposed in our previous work. We compared this structure with Conventional Bulk-MOSFET (CB-MOSFET) and Field plated Conventional Bulk-MOSFET (FCB-MOSFET) structures. The 4H–SiC MES–MOSFET structure consists of two additional schottky buried gates which behave like a Metal on Semiconductor (MES) at the interface of the active region and substrate. The motivation for this structure was to enhance the breakdown voltage by introducing a new technique of utilizing the reduced surface field (RESURF) concept. In our comparison and investigation we used a two-dimensional device simulator. Our simulation results show that the breakdown voltage of the proposed structure is 3.7 and 2.9 times larger than CB-MOSFET and FCB-MOSFET structures, respectively. We also showed that the threshold voltage and the slope of drain current ( I D ) as a function of drain–source voltage ( V DS ) for all the structures is the same. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, we employ the Reduced Surface Field technique in metal semiconductor field effect transistors (MESFETs) by a P-type region above the active layer near gate (PR-MESFET). Electric field distribution can be made more uniform by a new depletion region in the active layer of the proposed structure that is created by a P-type region. Therefore, the electric field peak at the gate edge decreases, and the breakdown voltage increases. On the basis of our simulation results, the breakdown voltage increases as compared with the conventional bulk 4H-SiC MESFET (CB-MESFET) and the spacer bulk 4H-SiC MESFET (SB-MESFET). Detailed numerical simulations demonstrate that for proposed structure due to decrease in parasitic gate-to-drain capacitor, maximum oscillation frequency increases with respect to SB-MESFET. Our simulation results show that output current slightly decreases in comparison with CB-MESFET. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we report a novel Super Junction Metal Semiconductor Field Effect Transistor (SJ-MESFET) where the drift region consists of a p-type pillar in order to improve breakdown voltage. We demonstrate that the depletion region in the drift region can be extended entirely by the p-type pillar leading to a uniform electric field. Therefore breakdown voltage significantly improves. Using two-dimensional and two-carrier device simulation, we have analyzed the various performance and design considerations of the SJ-MESFET. Also we have explained the reasons for improving the performance of the SJ-MESFET when compared to a Conventional Bulk MESFET (CB-MESFET). Detailed numerical simulations demonstrate that for the proposed structure due to decrease in parasitic gate-to-drain capacitor, maximum oscillation frequency increases with respect to CB-MESFET. [Copyright &y& Elsevier]