Trench type MOSFET and manufacturing method thereof

Abstract

The invention discloses a trench type MOSFET and a method for manufacturing the trench type MOSFET. The method comprises the following steps of forming a trench extending from the upper surface to theinterior of a semiconductor substrate in the semiconductor substrate; forming a first insulating layer and a shielding conductor in the trench, covering the side wall and the bottom of the trench bythe first insulating layer and separating the shielding conductor from the semiconductor substrate; forming openings at the two sides of the shielding conductor in the trench, separating the openingsfrom the shielding conductor through the first insulating layer, and enabling the openings to extend into the trench from the upper surface of the semiconductor substrate; and forming a gate dielectric layer and a gate conductor in the opening, wherein the side wall of the opening is at least covered by the gate dielectric layer, and forming a body region, a source region and a drain electrode. According to the method provided by the invention, the process steps for forming the trench type MOSFET in the prior art are simplified, and the process errors are reduced.

Description

technical field [0001] The present invention relates to semiconductor technology, and more particularly, to a trench MOSFET and a method for manufacturing the trench MOSFET. Background technique [0002] Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) have been widely used as power semiconductor devices, for example as switches in power converters. [0003] In the past, the semiconductor industry has used various device structures and methods to form MOSFETs. Among them, the advantage of the shielded gate trench MOSFET over the traditional MOSFET is that it has a shielding conductor that helps reduce the gate-to-drain capacitance of the transistor, reducing The gate-drain capacitance is increased, and the cut-off voltage of the transistor is increased. The gate electrode and the shield electrode are insulated from each other by a dielectric layer, which is also called an interelectrode dielectric or IED. The IED must be of sufficient mass and thickness to supp...

AI Technical Summary

Problems solved by technology

[0004] In the prior art, to ensure sufficient strength and sufficient reliable high-quality IED to provide the required electrical characteristics, the process of forming the IED layer between the gate electrode and the shielding electrode is very cumbersome, the operation is complicated, the process error is large, and the production high cost

Images