ISPSD ´07 Charitat Award; Split-Gate Resurf Stepped Oxide (RSO) MOSFETS for 25V Applications with Record Low Gate-to-Drain Charge

This paper presents a split-gate version of the Resurf Stepped Oxide (RSO) MOSFET. Splitting the gate enables a drastic reduction of the gate-to-drain capacitance intrinsic to the RSO device concept while keeping all the benefits of the RESURF effect. We achieved a record on-resistance of 3.8 m??mm² and gate-to-drain charge of 0.9 nCmm2 at a breakdown voltage of 35V for a pitch of 1.3 mm (0.8 mm trench width). The switching losses of our split-gate RSO MOSFET are 4 times better than the best published data in the same voltage range.