TRENCH GATE MOSFET AND METHOD OF FORMING THE SAME

摘要

A trench gate MOSFET is provided. An N-type epitaxial layer is disposed on an N-type substrate. An N-type source region is disposed in the N-type epitaxial layer. The N-type epitaxial layer has at least one trench therein. An insulating layer serving as a gate insulating layer is disposed in the trench. A conductive layer serving as a gate fills up the trench. Two isolation structures are disposed in the N-type source region beside the trench and contact the trench. Two conductive plugs are disposed in the N-type epitaxial layer beside the trench and penetrate through the N-type source region. A dielectric layer is disposed on the N-type epitaxial layer. A metal layer is disposed on the dielectric layer and electrically connected to the N-type source region.

主权项

1. A method of forming a trench gate MOSFET, comprising:
forming an epitaxial layer of a first conductivity type on a substrate of the first conductivity type; forming a source region of the first conductivity type in the epitaxial layer; faulting at least two first trenches in the source region; completely filling a plurality of first insulating layers in the first trenches to form a plurality of isolation structures, respectively; forming a second trench in the epitaxial layer, wherein the isolation structures are located beside the second trench and in contact with the second trench; forming a second insulating layer in the second trench; filling a first conductive layer in the second trench; forming two third trenches in the epitaxial layer beside the second trench; and filling a plurality of second conductive layers respectively in the third trenches.