A new silicon controlled rectifier type esd protection structure and its realization method

Abstract

The invention discloses a novel silicon controlled rectifier-type ESD (Electro-Static Discharge) protection structure and a realization method thereof. The structure comprises a semiconductor substrate (80), an N well (60) and a P well (70) generated on the semiconductor substrate, high-concentration P-type doping (20) and high-concentration N-type doping (28) placed at the upper part of the N well (60), high-concentration N-type doping (24) and high-concentration P-type doping (26) placed at the upper part of the P well (70), high-concentration N-type doping (22) placed above the boundary between the N well (60) and the P well (70), and an N-type gate (50) placed above between the high-concentration N-type doping (22) and the high-concentration N-type doping (24), wherein the high-concentration P-type doping (20), the N well (60) and the P well (70) form an equivalent PNP triode structure; and the N well (60), the substrate (80) and the high-concentration N-type doping (24) form an equivalent NPN triode structure. Thus, the maintenance voltage of hysteresis effects of the ESD protection structure can be increased.

Description

technical field [0001] The invention relates to the technical field of semiconductor integrated circuits, in particular to a novel silicon-controlled rectifier type ESD protection structure with low trigger voltage and high sustain voltage and its realization method. Background technique [0002] In the field of electrostatic (ESD, Electro-Static Discharge) protection design, Silicon Controlled Rectifier (SCR, Silicon Controlled Rectifier) ​​has been widely valued because of its strong ESD discharge capability and small parasitic capacitance. Serious defects limit its application: the first defect is that the trigger voltage of the hysteresis effect is very high, because its trigger voltage is mainly determined by the high reverse breakdown voltage between the N well and the P well; the second defect is that the hysteresis effect The holding voltage of the hysteresis effect is very low, which can easily lead to latch-up effect. [0003] Aiming at the defect of high trigger ...

AI Technical Summary

Problems solved by technology

Because the N-type doping (N+) 24 between the N well (N-Well) 50 and the P well (P-Well) 60 interface in the novel silicon controlled rectifier is directly connected with the anode A, so the hysteresis of the novel silicon controlled rectifier The trigger voltage of the effect is directly determined by the breakdown voltage of the N-type doping (N+) 24 / P well (P-Well) 60 and is greatly reduced. In addition, the N-type doping (N+) 24 is applied because it is directly connected to the anode A The positive pressure will reduce the probability of holes from P-type doping (P+) 22 incident to N well (N-Well) 50 / P well (P-Well) 60 interface, so the silicon controlled rectifier type ESD protection structure The current gain of the parasitic transistor P-type doping (P+) 22 / N-well (N-Well) 50 / P-well (P-Well) 60 will be reduced, so the holding voltage of the new silicon controlled rectifier hysteresis effect will also increase

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