Vertical double-diffusion metal oxide semiconductor device and manufacturing method thereof

Abstract

The embodiments of the invention provide a vertical double-diffusion metal oxide semiconductor device and a manufacturing method thereof. The method comprises the steps of: providing a substrate of afirst conductive type; forming an epitaxial layer of the first conductive type on the substrate; forming a split gate structure on the epitaxial layer, a first split gate region and a second split gate region each comprising a first insulating layer and a polycrystalline silicon layer on the first insulating layer; forming a first doped region and a second doped region of a second conductive typeon the upper surface of the epitaxial layer; forming a second insulating layer on the epitaxial layer, the second insulating layer covering the first split gate region and the second split gate region; and removing the second insulating layer on the first doped region and the second doped region to expose the first doped region and the second doped region. The embodiments of the invention providea manufacturing method and a structure of a vertical double-diffusion metal oxide semiconductor device, which can reduce the reverse capacitance and the switching time of the device and improve the voltage endurance of the device.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a vertical double-diffused metal oxide semiconductor device and a preparation method thereof. Background technique [0002] Power semiconductor devices are essential core devices for realizing power conversion and control. With the establishment and promotion of the concept of energy saving, emission reduction and green environmental protection, the importance of power semiconductors is increasing day by day, and the application prospects are getting wider and wider. The country has made it an important strategic goal to promote the industrial development of new power electronic chips and devices. [0003] Vertical double-diffused metal oxide semiconductor (VDMOS) devices have the advantages of high input impedance, low driving power, fast switching speed, and good thermal stability, and have become the most widely used new power devices. Using VDMOS as a sw...

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Problems solved by technology

[0004] Due to the large gate coverage area of ​​conventional VDMOS devices, the reverse transmission capacitance is large, and the switching power consumption is large

At present, the common method to reduce the reverse transfer capacitance is to use a split gate structure, which is to etch away part of the silicon gate in the middle of the N-doped region on the conventional structure. The reverse transfer capacitance is much lower than the conventional structure, but due to the etching away The silicon gate on the surface will reduce the withstand voltage of the device

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