Comparisons of Performance and Reliability in 4H-SiC Tri-gate and Planar MOSFETs

In this work, a low-voltage tri-gate MOSFET in 4H-SiC is fabricated and measured to compare its performance with a planar gate MOSFET with the same channel length. The preliminary reliability of the devices is also studied. Experimental results show that the larger effective channel width enhances the current of the tri-gate contributed from the trench sidewall and the higher electron channel mobility on the a-face of 4H-SiC pm the sidewall, even though the gate voltage is limited at a lower value. PBTI, NBTI, and dynamic Ron are also measured and the results show that the reliability of both devices are comparable.