Power device protection chip and preparation method thereof

Abstract

The invention provides a power device protection chip, which includes a substrate; an epitaxial layer formed on the substrate; a rectification region formed in the epitaxial layer at intervals, and the rectification region includes a first groove formed from the upper surface of the epitaxial layer into the epitaxial layer groove, a second groove formed from the bottom of the first groove into the epitaxial layer, and a third groove formed from the bottom of the second groove into the epitaxial layer, the first groove, the second groove and the third The grooves are connected and the widths are successively reduced. The first metal layer is filled in the first groove, the second groove and the third groove, and the first metal layer in the first groove, the second groove and the third groove The height of the Schottky barrier between the epitaxial layer and the epitaxial layer decreases in turn; the isolation region extending from the upper surface of the epitaxial layer to the substrate between the two rectification regions, the isolation region includes the fourth trench and fills the fourth The trench is in ohmic contact with the substrate on the second metal layer. The invention also provides a preparation method for the protection chip of the power device, which enhances the stability, reduces the encapsulation area and reduces 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 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...

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