Numerical Study of p-n-Doped Poly-Silicon Shield Gate Trench MOSFET With Reduced Output Capacitance

This letter proposes a new shield gate (SG) trench MOSFET structure, which utilizes a p-n-doped polysilicon refill as the SG electrode to minimize the total output capacitance or charge. TCAD simulation is carried out to compare the proposed and conventional device structures. It is shown that the proposed structure offers 30% lower Q
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and 18.2% reduction of inductive switching loss while retaining other attractive characteristics of the SG trench MOSFET.