Optimization of Reverse Recovery Characteristics Based on Termination Structure for 700V Super-Junction VDMOS

In this work, we propose a 700V super-junction vertical double-diffused MOSFET (SJ VDMOS) with P-type lateral connection (LC) layer in the termination region. By changing the doping concentration of the LC layer, we can effectively adjust the reverse recovery characteristics. More internal holes remain near the depletion boundary for the termination structure with lower P-type LC layer doping concentration during the recovery period, leading to slower recovery current drop. However, the doping concentration of P-type LC layer does not affect the reverse period. Using this optimization method, we conduct experiments based on a multi-epitaxy/multi-implant platform. The experimental device realizes specific on-resistance of 12.09 m Ω.cm ² and breakdown voltage of 719 V. The experimental results are in good consistence with the simulated results. Both simulated and experimental results validate the effectiveness and feasibility of the proposed method.