Electric characteristics of normally-off type 5 kV class 4H-SiC JFET, "SEJEET"

Abstract

A normally-off type 5.3 kV 4H-SiC JFET with low specific on-resistance, called SEJFET (Static Expansion channel JFET), has been fabricated. Its normally-off operation was realized by a thin regrown epitaxial channel layer and using the buried p+ regions as a gate in addition to the top p+ regions. The achieved blocking voltage is the highest class BV among the reported SiC JFET. In a 5.3 kV 4H-SiC SEJFET, the lowest specific on resistance of 69 mΩcm 2 .Furthermore, the highest current capability among SiC JFET of 3.3 A is achieved. In all reported FETs, the SEJFET has the best trade-off between RonS and blocking voltage (BV), which is about 1/230 th lower than theoretical limit of a Si FET. Furthermore, the figure of merit (BV 2 /RonS) is 407 MW/cm 2 , and this value is the highest among reported normally off SiC FETs.SiC JFET SEJFET