Bidirectional transient voltage suppressor and manufacture method thereof

Abstract

The invention provides a bidirectional transient voltage suppressor and a manufacture method thereof. The manufacture method comprises steps of providing a substrate of a second conductive type, etching the substrate so as to form a ditch, forming a second epitaxial layer and a third epitaxial layer of the second conductive type on the side wall of the ditch, forming a forth epitaxial layer of a first conductive type on the upper surface of the substrate, forming a fifth epitaxial layer of the first conductive type on the lower surface of the substrate, forming a first metal layer on the uppersurface of the fourth epitaxial layer, and forming a second metal layer on the lower surface of the fifth epitaxial layer. The anti-breakdown voltage capability of the bidirectional transient voltagesuppressor is improved through multiple groups of PN junctions; the bidirectional transient voltage suppressor has a multi-path bidirectional function so as to protect multiple circuits simultaneously in use, and application cost of the power device is lowered. The bidirectional transient voltage suppressor requires etching for only once, so that the manufacture cost is lowered.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a bidirectional transient voltage suppressor and a manufacturing method thereof. Background technique [0002] Electrostatic discharge, as well as other random voltage transients in the form of voltage surges, are commonly found in a variety of electronic devices. As semiconductor devices become increasingly miniaturized, dense, and multifunctional, electronic devices are increasingly susceptible to potentially fatal voltage surges, which can induce transients in everything from electrostatic discharge to lightning current spikes. [0003] Transient voltage suppressor 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 High reliability and other advantages, so it has been widely used in voltage transi...

AI Technical Summary

Problems solved by technology

[0004] Currently commonly used trench transient voltage suppressors can only achieve unidirectional protection. If bidirectional protection is required, multiple transient voltage suppressors need to be connected in series or in parallel, which increases the device area and manufacturing cost.

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