Bidirectional thyristor device based on capacitor-assisted trigger

Abstract

The invention discloses a bidirectional thyristor device based on capacitor-assisted trigger, comprising a P substrate layer; a first N trap, a P trap and a second N trap arranged on the P substrate layer; a first N + active injection zone, a first P + active injection zone and a second N + active injection zone arranged on the first N trap; a third N + active injection zone, a second P + active injection zone and a fourth N + active injection zone arranged on the second N trap, wherein the third N + active injection zone is connected with a first capacitor, the other end of the first capacitor is connected with a first metal electrode, the second N + active injection zone is connected with a second capacitor and the other end of the second capacitor is connected with a second metal electrode. The thyristor device uses the capacitor as an auxiliary trigger unit, thus the device has adjustable and relatively lower forward and reverse breakdown voltage and the device can be suitable for on-chip ESD (electronic static discharge) protection under the deep sub-micron technology, particularly suitable for ESD protection application among a plurality of mixed voltage interface circuits or different power domains.

Description

technical field [0001] The invention belongs to the technical field of electrostatic protection for integrated circuits, and in particular relates to a bidirectional thyristor device based on capacitance-assisted triggering. Background technique [0002] The phenomenon of electrostatic discharge (ESD) in nature poses a serious threat to the reliability of integrated circuits. In the industry, 30% of the failures of integrated circuit products are caused by electrostatic discharge, and the increasingly smaller process size and thinner gate oxide thickness greatly increase the probability of integrated circuit damage by electrostatic discharge. Therefore, improving the reliability of integrated circuit electrostatic discharge protection has a non-negligible effect on improving the yield of products. [0003] The modes of electrostatic discharge phenomena are usually divided into four types: HBM (Human Body Model), MM (Machine Discharge Model), CDM (Component Charge Discharge ...

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Problems solved by technology

[0006] figure 1 It is a unidirectional SCR structure under the CMOS process. The trigger voltage of the unidirectional SCR is high in one direction, and it is a parasitic diode structure in the other direction. The trigger voltage is very low and cannot be adjusted. Therefore, the structure is very It is difficult to directly apply on-chip ESD protection, especially in some mixed voltage domain interface circuits that require bidirectional trigger voltage adjustable and low ESD protection

[0007] figure 2 It is a bidirectional SCR structure under the CMOS process. Compared with the unidirectional SCR structure, this structure has the same trigger voltage in both directions, but the trigger voltage value is also too high and cannot be adjusted. In the deep submicron process, it is difficult to Protect the fragile gate oxide

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