TRENCH POWER MOSFET AND MANUFACTURING METHOD THEREOF

摘要

A trench power MOSFET and a manufacturing method thereof are provided. The gate of the trench power MOSFET includes an upper doped region and a lower doped region which have different types of doping to form a PN junction. As such, when the trench power MOSFET is in operation, a junction capacitance formed at the PN junction is in series with the intrinsic gate-to-drain capacitance. Accordingly, the effective capacitance between the gate and the drain may be reduced.

主权项

1. A trench power MOSFET comprising:
a substrate; an epitaxial layer formed on the substrate; and a plurality of trench transistor units formed in the epitaxial layer, wherein each of the trench transistor units includes a trench gate structure comprising:
a trench formed in the epitaxial layer, wherein an insulating layer is formed on an inner wall of the trench; anda gate filled in the trench, wherein the gate includes an upper doped region and a lower doped region to form a PN junction.