A novel trench gate floating islands power MOSFET (TG-FLIMOSFET): Two-dimensional simulation study

Abstract

Novel trench gate floating islands MOSFET (TG-FLIMOSFET) designed using the concept of “Opposite Doped Buried Regions” (ODBR) and floating islands (FLI) along with trench gate technology is proposed and verified using two-dimensional simulations. The conventional FLIMOSFET experimentally demonstrated recently, although offers lowest on-resistance in the low voltage range, however, suffers from quasi-saturation effect like any other power MOSFETs. The proposed TG-FLIMOSFET demonstrated to obtain about 30% reduction in peak electric field in drift region of the proposed device. TG-FLIMOSFET also demonstrates quasi-saturation free forward and transconductance characteristics, improved synchronous rectifying characteristics, identical breakdown voltage, reduced on-resistance and increased transconductance ‘gm’ when compared with the conventional FLIMOSFET for various trench geometries. The proposed device breaks the limit set by the conventional FLIMOSFET approximately by a factor of 10. A possible process flow sequence to fabricate the proposed device commercially by integrating multi-epitaxial process with trench gate technology is also presented.