High-Performance Split-Gate Enhanced UMOSFET With p-Pillar Structure

In this paper, a split-gate resurf stepped oxide (RSO) vertical UMOSFET with p-pillar under the p⁺ plug region structure is proposed. The p-pillar could modulate the electric field of the drift region with the split-gate in 3-D and simultaneously brings electric field peaks at the sidewall junction between p-pillar and n-drift region. Thus the split-gate enhanced with p-pillar (SGEP) UMOS could increase the drift region doping concentration, reduce the on-state-specific resistance, and maintains the breakdown voltage as compared with the super junction and split-gate RSO UMOSs. Numerical simulation results show that the charge imbalance endurance of SGEP is also largely increased.