Method for manufacturing trench power metal-oxide semiconductor field-effect transistor

Abstract

A method for manufacturing a trench power metal-oxide semiconductor field-effect transistor includes forming a pattern layer on a substrate; etching the substrate via the pattern layer to form a gate trench in the substrate; forming a first oxide layer in the gate trench in an oxidation manner to increase the width of the gate trench; forming a gate oxide layer on the inner surface of the gate trench after the first oxide layer is removed; etching the bottom of the gate trench via the pattern layer to form an opening penetrating through the gate oxide layer; then forming a thick oxide layer in the opening; and forming two first heavily doped regions on two sides of the thick oxide layer in an ion implantation mode to prevent a body region from being diffused to the bottom of the gate trench. The method has the advantages that the thickness of an insulating layer between a gate electrode and a drain electrode can be increased, accordingly, capacitance of the gate electrode to the drain electrode is reduced, and switching loss is decreased.

Description

technical field [0001] The invention relates to a method for manufacturing a trench-type power metal-oxygen-semiconductor field-effect transistor, in particular to a method for manufacturing a trench-type power metal-oxygen-semiconductor field-effect transistor that can reduce the switching loss of the metal-oxygen-semiconductor field-effect transistor. Background technique [0002] Power MOSFETs are widely used in switching elements of power devices, such as power supplies, rectifiers, or low-voltage motor controllers. Today's power MOS field effect transistors mostly adopt a vertical structure design to increase device density. It utilizes the backside of the chip as the drain, and manufactures the sources and gates of multiple transistor elements on the front side of the chip. Since the drains of each transistor element are connected in parallel, their withstand current can be increased. [0003] The operating loss of power MOSFETs can be divided into two categories: sw...

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Problems solved by technology

Among them, the switching loss caused by the input capacitor Ciss will increase with the increase of operating frequency

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