Advanced hexagonal layout design for split-gate reduced surface field stepped oxide U-groove metal-oxide-semiconductor field-effect transistor

Split-gate reduced surface field (RESURF) stepped oxide (SGRSO) device with advanced hexagonal p-pillar (AHP) layout is investigated using three-dimensional simulations. The AHP layout can improve the on-state characteristics while not increasing the process difficulty. The p-pillar under the source electrode enhances the RESURF effect to the n-drift region, so that the n-drift region doping concentration could be substantially increased and the breakdown voltage is not reduced. Based on the SGRSO device, the AHP layout modifies the electric field distribution in the n-drift region, and reduces the R-SP as compared with the common hexagonal and mesa strip layout structures. The figure of merit of the AHP layout improves by 49.8% as compared with the other two types of layouts, and the AHP has superior characteristics within a wider N-D range.