Power device protection chip and preparation method thereof

Abstract

The invention provides a power device protection chip, which comprises a substrate; an epitaxial layer formed on the substrate; rectifying regions formed in the epitaxial layer and spaced apart from each other, the rectifying region includes a first trench formed from an upper surface of the epitaxial layer into the epitaxial layer, a second trench formed from the bottom of the first trench into the epitaxial layer and a third trench formed from the bottom of the second trench into the epitaxial layer, the first trench, the second trench and the third trench are communicated with each other and the width decreases in turn. the first trench, the second trench and the third trench are filled with the first metal layer, and the schottky barrier height between the first metal layer and the epitaxial layer in the first trench, the second trench and the third trench decreases in turn. the isolation region is located between that two rectify regions and extend from the upper surface of the epitaxial layer to the substrate, the isolation region including a fourth trench and a second metal layer filled with the fourth trench in ohmic contact with the substrate. The invention also provides apreparation method of a power device protection chip, which enhances the stability type, reduces the package area and the preparation cost.

Description

technical field [0001] The invention relates to the technical field of semiconductor chip manufacturing technology, in particular to a power device protection chip and a preparation method thereof. Background technique [0002] As semiconductor devices move toward miniaturization, high density, and multi-functionality, electronic devices are increasingly susceptible to voltage surges that can induce transient current spikes, ranging from electrostatic discharge to lightning. Electrostatic discharge (ESD) and other random voltage transients in the form of voltage surges are present in various electronic devices. [0003] Surge protection chip is a solid-state semiconductor device specially designed to protect sensitive semiconductor devices from transient voltage surge damage. It has the advantages of small clamping factor, small size, fast response, small leakage current and reliable It has the advantages of high performance, so it has been widely used in voltage transient ...

AI Technical Summary

Problems solved by technology

In high-frequency circuits, because the surge protection chip also has parasitic capacitance, the signal

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