On-chip bidirectional electrostatic protection apparatus for medium-voltage integrated circuit

Abstract

The invention provides an on-chip bidirectional electrostatic protection apparatus for a medium-voltage integrated circuit. The apparatus comprises more than one DDGCSCR device, the DDGCSCR represents a bidirectional symmetric SCR, each DDGCSCR device is in bilateral symmetry in structure, and when currents of the same magnitude flow into the DDGCSCR devices from an anodes and a cathode, the electrical characteristics are consistent. Each DDGCSCR device comprises a P-type substrate, a deep N well, a first P well, an N well and a second P well, wherein the deep N well is arranged on the P-type substrate, the first P well and the second P well are respectively adjacent to the N well, and a first P+ injection region, a first N+ injection region and a second N+ injection region are sequentially arranged in the first P well from left to right; a first gate oxide structure is arranged on the surface between the first N+ injection region and the second N+ injection region; and a first bridge-shaped P+ injection region is arranged between the N well and the first P well, and the second P well and the first P well are symmetrically arranged.

Description

Technical field [0001] The present invention relates to the field of electrostatic discharge protection semiconductor integrated circuit chip technology, and more particularly, high robustness, latch immunized bidirectionally conductive static protection (ESD) device structure having a relatively low trigger voltage. Background technique [0002] As the semiconductor industry technology continues to improve, the industry for product reliability evaluation of more stringent ESD protection integrated circuit reliability testing has become an important part of the evaluation process. Therefore, the reliability of the on-chip ESD protection unit, practicality, and the manufacturing cost of the entire IC industry will have far-reaching effects. To achieve full-chip ESD protection integrated circuit chip to be protected, all input / output (I / O), power and ground are required between a design may provide electrostatic current discharge path. [0003] Industry is currently widely used...

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Problems solved by technology

[0010] In order to solve the above-mentioned problems in the prior art, the present invention provides a bidirectional symmetrical SCR device (DDGCSCR) with low trigger and latch-up immunity characteristics. Its electrostatic protection capability per unit area is very high, which can make the entire circuit design area It is optimized; its bidirectional symmetrical structure can meet the bidirectional electrostatic protection requirements between two ports, further optimizing the product design area and development cost; the device has a very high sustain voltage, which overcomes the traditional SCR and bidirectional SCR devices The latch-up problem faced, but also avoids the phenomenon that the robustness of the device is greatly reduced due to the increase of the holding voltage

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