Transient voltage suppressor and preparation method thereof

Abstract

A transient voltage suppressor includes a substrate, a plurality of trench regions formed on an upper surface of the substrate at intervals and extending into the substrate, each trench region includes a first trench and a second trench spaced apart, the first trench is filled with a first polysilicon layer, the second trench is filled with a second polysilicon layer, a third polysilicon layer formed on the upper surface of the substrate and covering the trench region, a first metal layer formed on an upper surface of the third polysilicon layer, a plurality of first implantation regions formed on a lower surface of the substrate at intervals and extending into the substrate, A plurality of first injection regions and a plurality of trench regions are disposed in a one-to-one manner, a plurality of second injection regions of a second conductivity type are formed between the plurality of first injection regions, and a second metal layer formed on the lower surface of the substrate andcovering the lower surfaces of the first injection region and the second injection region. The invention also provides a preparation method of the transient voltage suppressor, which improves the surge prevention ability and the working power of the transient voltage suppressor.

Description

technical field [0001] The invention relates to the technical field of semiconductor device manufacturing, in particular to a transient voltage suppressor and a preparation method thereof. Background technique [0002] A transient voltage suppressor (Transient Voltage Suppressor, TVS) is a clamp overvoltage protection device, which can fix the surge voltage at a relatively low voltage level in a short period of time, so that the back-end circuit is protected from overvoltage It is mainly used in various interface circuits, such as mobile phones, tablets, TVs, and computer hosts, where there are a large number of transient voltage suppressors. At present, with the continuous development of electronic products, especially in the field of high-power power supply and power management chips, correspondingly higher technical requirements are put forward for transient voltage suppressors, which not only require transient voltage suppressors to be able to withstand up to several tho...

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Problems solved by technology

This method has obvious limitations, because when the area of ​​the PN junction continues to increase, it means that the area of ​​the device becomes larger, and the package shell used in the package will also increase accordingly, which is different from the miniaturization of the device in electronic products. The requirements are contrary to the requirements, and the size of the device is too large to be soldered on the circuit board with high-density electronic components, which may even affect the normal use of the device on the circuit board

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