FITMOS modeling and dynamic on-state characteristic evaluation

This paper presents a study of the detailed characteristics of the new Floating Island and Thick Bottom Oxide Trench Gate MOSFET (FITMOS) developed at Toyota. FITMOS has tremendous potential for automotive applications due to its low on-resistance, improved temperature coefficient of resistance and low gate charge. During the study, the key characteristics of this novel FITMOS were investigated; a behavioral model was developed in SPICE for simulation and optimization purposes, and their applications in the design of automotive power electronics was explored. In this study, we also identify a previously unrecognized phenomenon in the FITMOS MOSFET. In particular, we show that the on-state resistance of the device depends on both frequency and peak di/dt at a given frequency. This dynamic on-resistance variation can have a significant application impact.