Surge protection chip and preparation method thereof

Abstract

The invention discloses a surge protection chip which comprises a substrate, a first epitaxial layer formed on the substrate, a first injection region on the first epitaxial layer, a second injection region on the first injection region, a second epitaxial layer on the second injection region, first grooves extending into the first epitaxial layer from the second epitaxial layer, and silicon oxide filled in the first groove, second grooves located between the first grooves and connected with the side walls of the first grooves, third epitaxial layer filled in the second grooves, a third injection region formed in the second grooves, a fourth injection region formed in the second epitaxial layer, a dielectric layer formed on the second epitaxial layer, the first grooves and the second grooves, a first contact hole formed in the dielectric layer and correspondingly formed in the third injection region, a second contact hole formed in the fourth injection region, a first metal layer arranged on the dielectric layer and filling the first contact hole and the second contact hole, and a second metal layer formed under the substrate. The invention further provides a preparation method of the surge protection chip, and the parasitic capacitance and high-frequency circuit signal attenuation are reduced.

Description

technical field [0001] The invention belongs to the technical field of semiconductor chip manufacturing technology, and in particular relates to a surge protection chip and a preparation method thereof. Background technique [0002] Surge protection chip is a solid-state semiconductor device specially designed to protect sensitive semiconductor devices from transient voltage surge damage. It has small clamping coefficient, small size, fast response, small leakage current and reliable High performance, so it has been widely used in voltage transient and surge protection. As semiconductor devices are increasingly miniaturized, high-density, and multi-functional, electronic devices are increasingly vulnerable to voltage surges, which can even cause fatal injuries. Various voltage surges from electrostatic discharge to lightning can induce transient current spikes, which makes it difficult for the surge discharge path of the surge protection chip and its own clamping voltage to...

AI Technical Summary

Problems solved by technology

Various voltage surges from electrostatic discharge to lightning can induce transient current spikes, which makes it difficult for the surge discharge path of the surge protection chip and its own clamping voltage to protect sensitive circuits from surges. Electrostatic discharge and other transient voltages that appear randomly in the form of voltage surges usually exist in the device, making high-frequency circuit signals susceptible to interference and reducing the performance of surge protection chips

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