A 50–60 V Class Ultralow Specific on-Resistance Trench Power MOSFET

A 50–60 V class ultralow specific on-resistance (R_on,sp) trench power MOSFET is proposed. The structure is characterized by an n⁺-layer which is buried on the top surface of the p-substrate and connected to the drain n⁺-region. The low-resistance n⁺-layer shortens the motion-path in high-resistance n^? drift region for the carriers, and therefore, reduces the R_on,sp in the on-state. Electrical characteristics for the proposed power MOSFET are analyzed and discussed. The 50–60 V class breakdown voltages (V_B) with R_on,sp less than 0.35 mΩ?cm² are obtained. Compared with several power MOSFETs, the proposed power MOSFET has a significantly optimized dependence of R_on,sp on V_B.