Semiconductor structure with esd protection structure and manufacturing method thereof

Abstract

The invention discloses a semiconductor structure having an ESD protection structure and a manufacturing method thereof. The manufacturing method comprises: a semiconductor substrate is provided; an epitaxial layer is formed on the semiconductor substrate; a silicon oxynitride layer is formed on the epitaxial layer to obtain a first semiconductor structure; the silicon oxynitride layer and the part of epitaxial layer in a preset first region in the first semiconductor structure are etched; local thermal oxidation is carried out on the first region after etching to generate a field oxide layer; the silicon oxynitride layer at the surface of the epitaxial layer at a preset second region in the first semiconductor structure is removed; a cellular structure is formed at the second region; an ESD polycrystalline layer is formed at the field oxide layer; and an ESD polycrystalline diode structure is formed in the ESD polycrystalline layer, ESD contact holes are formed in the two sides of the ESD polycrystalline diode structure respectively, and at least one cellular structure contact hole is formed in the cellular structure in the second region. Occurrence of a blind hole can be reduced or eliminated by reducing or eliminating a height error between an ESD structure region contact hole and a cellular structure contact hole; and the yield of the device can increase.

Description

technical field [0001] The invention relates to the technical field of semiconductor design and manufacture, in particular to a semiconductor structure with an ESD protection structure and a manufacturing method thereof. Background technique [0002] Electrostatic discharge (ESD) is the transfer of electrostatic charge between two objects of different electrostatic potential caused by direct contact or induced by an electrostatic field. For semiconductor devices, due to the rapid discharge of voltage on a small resistance, the discharge current will be large, which may exceed 20 amps. If this discharge passes through a power MOSFET (metal oxide semiconductor field effect transistor) or other integrated Circuit, such a large current will cause serious damage to the device or circuit. According to statistics, among the failure mechanisms of all semiconductor devices, ESD failure accounts for almost 10%. [0003] Ordinary trench MOSFETs have little protection against ESD or o...

AI Technical Summary

Problems solved by technology

Blind holes will cause the source of individual cells not to be in contact with the source metal, and the source of a single cell will be suspended to cause abnormal breakdown voltage of the entire device

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