Design optimal built-in snubber in trench field plate power MOSFET for superior EMI and efficiency performance

A 40V field plate trench MOSFET with optimal built-in snubber has been evaluated in Sentaurus TCAD, showing superior EMI and efficiency performance in the application of power sync-buck and power brick. We developed an advanced TCAD mixed-mode simulation to simulate switching performance of the field plate trench MOSFET with different built-in snubber resistance. Simulation demonstrates Vds damping effects through different snubber designs and an optimal range has been indicated. Physical insight has also been obtained through simulation by visualizing electrical field propagation and current distribution. In-circuit efficiency simulation demonstrates that with an optimize snubber design one can maximize the self-damping without penalization on the switching power losses or the product cost.