A novel high-performance junctionless 4H-SiC trench MOSFET with improved switching characteristics

Abstract

A high-performance novel 4H-SiC trench power MOSFET employing the junctionless concept is proposed in this work. The presented design is modeled and investigated numerically by Devedit and Atlas TCAD tools, where the advantages of the junctionless concept are used to maximize the performance of the trench structure. This new structure helps lowering the input and reverse transfer capacitances of the trench power MOSFET compared to the conventional structures. The proposed device shows a lower high frequency (HF) Figure of Merits (FoM) value of 1078 mΩ.pF as compared to the conventional counterpart (4600 mΩ.pF), with a relative improvement of 76.5%. Moreover, a superior agreement between the breakdown voltage and the specific on-resistance has been revealed by a higher FoM (BV2/Ron = 2580 MV/mΩ.cm−2) in comparison to the conventional power MOSFET (860 MV/mΩ.cm−2). In addition, the proposed design proves to support a higher critical electric field at the gate edge (E = 3.93 MV/cm) in comparison to that of its conventional counterpart (E = 3.7 MV/cm). The substantial outcomes of this study pairing improvements in switching, blocking and conducting electrical performances, forcefully suggest this cost-effective design as a potential candidate in developing low-cost and high-performance 4H-SiC power MOSFETS.