Floating Island and Thick Bottom Oxide Trench Gate MOSFET (FITMOS) Ultra-Low On-Resistance Power MOSFET for Automotive Applications

Abstract

This paper proposes a new structure for the power MOSFET called FITMOStrade, which is capable of realizing an ultra-low on-resistance that exceeds the unipolar limit in the automotive breakdown voltage range (50 to 100 V). In the past, FITMOS was developed for use as a 60 V breakdown voltage element. However, the demand for high-output devices for vehicle system applications has been growing in recent years, and a high breakdown voltage element is needed to meet this demand. The authors therefore utilized an efficient design of experiment, the D-optimal design, in an attempt to simultaneously optimize the complexly linked multiple characteristics and factors of FITMOS. As a result, the authors verified conditions for obtaining characteristics for excellent breakdown voltage (BVds = 74.0 V), on-resistance (RonmiddotA = 36.4 mOmegamm2 @ Vg = 15 V, excluding substrate resistance), and threshold voltage (Vth = 3.0 V).