Bidirectional diode, manufacturing method thereof, and overvoltage protection device

Abstract

The embodiment of the invention discloses a bidirectional diode, a manufacturing method thereof and an overvoltage protection device. The bidirectional diode comprises a semiconductor substrate, an epitaxial layer of a first conductivity type located on one side of the semiconductor substrate, at least two separated trenches at one side of the epitaxial layer away from the semiconductor substrate,diffusion regions which extend into the epitaxial layer along any trench and are in one-to-one correspondence with the trenches, conductive mediums arranged in the trenches, and two electrodes whichare electrically connected to the conductive mediums in the different trenches, wherein the depth of the trenches is smaller than the thickness of the epitaxial layer in a direction perpendicular to the semiconductor substrate, the conductivity type of the diffusion regions are a second conductivity type different from the first conductivity type, any two adjacent diffusion regions are separated by a portion of the epitaxial layer, the diffusion regions are separated from the semiconductor substrate by a portion of the epitaxial layer. The technical solution provided by the embodiment of the invention can improve the flow capacity of the device and reduce the volume of the device.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a bidirectional diode, a manufacturing method thereof, and an overvoltage protection device. Background technique [0002] Transient Voltage Suppressor (TVS) is an overvoltage protection device that can be connected in parallel with the protected device to protect the system from various forms of transient high voltage and surge. When its two ends are subjected to an instantaneous high-energy impact, the transient voltage suppression diode quickly changes from cut-off to conduction, from a high-impedance state to a low-impedance state, and a large surge current can flow, and the transient voltage suppression diode The voltage at both ends of the diode will be clamped within a relatively small voltage range to prevent the back-end protected devices from being damaged by overvoltage. When the high-energy impact disappears, the amplitude of the normal operating voltage is lo...

AI Technical Summary

Problems solved by technology

[0003] The bidirectional TVS structure has the function of surge protection in both positive and negative directions. The traditional bidirectional transient voltage suppressor diode is a vertical structure. To achieve the required flow capacity, the volume of the device required to be manufactured is relatively large.

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