Power device protective chip and preparation method thereof

Abstract

The invention provides a power device protective chip which comprises a substrate, a first epitaxial layer formed on the substrate, rectification areas formed in the first epitaxial layer separately,and an isolation area positioned between the two rectification areas and extending from the upper surface of the first epitaxial layer to the substrate; each rectification area comprises a first trench formed from the upper surface of the first epitaxial layer to the first epitaxial layer, a second trench formed from the bottom of the first trench to the first epitaxial layer, and a third trench formed the bottom of the second trench to the first epitaxial layer, the first, second and third trenches are communicated, the widths of the first, second and third trenches are decreased successively, and Schottky barrier heights between metal layers in the first, second and third trenches and the first epitaxial layer are reduced successively; and the isolation area comprises a fourth trench, aninjection region positioned in the bottom of the fourth trench and a second epitaxial layer formed in the fourth trench. The invention also provides a preparation method of the power device protective chip. The reliability is improved, the packaging area is reduced, and the cost is reduced.

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 become increasingly smaller, denser, and more versatile, electronic devices are increasingly susceptible to voltage surges, which can induce transient current spikes in everything from electrostatic discharge to lightning. Electrostatic discharge (ESD) and other random voltage transients in the form of voltage surges exist in a variety of 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 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. Based on different a...

AI Technical Summary

Problems solved by technology

In high-frequency circuits, because the surge protection chip also has parasitic capacitance, the signal attenuation of the circuit is relatively large, and even the stability of the entire circuit is affected.

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