Floating Islands and Thick Bottom Oxide Trench Gate MOSFET (FITMOS) with Passive Hole Gate -60V Ultra Low On-Resistance Novel MOSFET-

A MOSFET structure called a FITMOS has been successfully developed that exhibits record-low loss in the 60V breakdown voltage range (Kasakian and Perrault, 2001). The device has a body diode with superior reverse recovery characteristics and exhibits an extremely small value for RonQgd. The distinctive features of this device are the use of floating P islands formed by self-alignment and trench gates with a thick oxide layer at the bottom. However, during AC operation, the charges in the floating P islands become greater, increasing the on-resistance due to the JFET effect. This issue was solved by forming passive hole gates in the end walls of the trenches. The on-resistance under AC operation is equivalent to the on-resistance under DC operation