Low-trigger voltage bidirectional SCR device based on buried layer trigger

Abstract

The invention belongs to the technical field of electronics, and provides a low-trigger voltage bidirectional SCR device based on buried layer trigger for lowering the trigger voltage of the bidirectional SCR device. The bidirectional SCR device is composed of one main device, n trigger devices and m trigger devices at two sides of the main device; the trigger device is a diode device, and the adjacent trigger devices are connected in series; a first conductive type heavily-doped region is respectively arranged in each of the first conductive type well region A and the first conductive type well region C in the bidirectional SCR structure through the main device, a closed first conductive type heavily-doped buried layer only with the isolation effect in the basic bidirectional SCR is connected with the trigger diode strings out of two sides to form a low-voltage trigger channel with the buried layer and the diode strings, thereby lowering the trigger voltage of the bidirectional SCR device; and meanwhile, the trigger voltage is adjustable through the adjustment of the number of the trigger device; the starting speed of the device is effectively improved.

Description

Technical field [0001] The present invention belongs to the field of electronic technology, relates to the design of an electrostatic discharge (ESD: Electro-Static discharge) protection circuit, and specifically relates to a horizontal silicon controlled rectifier SCR (Silicon Controlled Rectifier for short SCR). Background technique [0002] Electro-Static Discharg (ESD for short) refers to the flow of current between two objects with different electrostatic potential energies. Generally speaking, ESD refers to rapid current flow. In people's daily life, ESD phenomenon can be seen everywhere. For integrated circuits, from production to transportation, system integration and user use, all processes may produce electrostatic discharge on the pins of the integrated circuit. The instantaneous large current and high power generated during the ESD process can cause a series of thermal damage to the semiconductor device, which will burn down the semiconductor and metal interconnectio...

AI Technical Summary

Problems solved by technology

[0007] With the continuous advancement of integrated circuit technology, the gate oxide layer of MOS devices is further thinned, which will cause the gate oxide breakdown voltage B Vox to continue to decrease. The trigger voltage of traditional bidirectional SCR devices that rely on pn junction avalanche breakdown to trigger is much higher. Due to the gate oxide breakdown voltage of the protection circuit, the SCR cannot play the role of voltage clamping and cannot achieve effective ESD protection

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