SCR (Silicon Controlled Rectifier) structure for providing ESD ( Electro-Static discharge) protection for I/O (Input/Output) port of integrated circuit under all modes

Abstract

The invention provides an SCR (Silicon Controlled Rectifier) structure for providing ESD (Electro-Static discharge) protection for an I / O (Input / Output) port of an integrated circuit under all modes, belonging to the technical field of electronics. The SCR structure comprises a P well region on the surface of a substrate, two N well regions, three P+ regions and five N+ regions. The P well region is sandwiched between the two N well regions; the first N+ region and the first P+ region are located in the first N well region and are connected with the I / O port of an external chip; the second N+ region and the second P+ region are located in the second N well region and are connected with a VDD (Voltage Drain Drain) track of a power source of the external chip; the third N+ region and the third P+ region are located in the P well region and are connected with a VSS (Voltage Series Series) track of the power source of the external chip; the fourth N+ region is located at the joint area of the first N well region and the top of the P well region; the fifth N+ region is located at the joint area of the P well region and the top of the second N well region; and a first and a second polysilicon regions are located on the surface of the P well region and are connected with the VSS track of the power source of the external chip. According to the invention, one single device is utilized to provide ESD protection for the I / O port under all modes, the occupying area of the protected device in the chip is effectively reduced and the parasitic capacitance is effectively reduced.

Description

technical field [0001] The invention belongs to the field of electronic technology, and relates to an electrostatic discharge (ElectroStatic Discharge, referred to as ESD) protection circuit design technology for semiconductor integrated circuit chips, especially a kind of SCR that provides full-mode ESD protection for integrated circuit input and output (I / O) ports (Silicon Controlled Rectifier) ​​structure. Background technique [0002] Electrostatic Discharge (ESD) phenomenon is the most important reliability problem that causes the failure of integrated circuit products. Studies have shown that 30% of integrated circuit failure products are caused by electrostatic discharge. Therefore, it is necessary to improve the protection of integrated circuits against electrostatic discharge. The reliability of the product has a non-negligible effect on improving the product yield and promoting the economic development of the industry. Electrostatic discharge will occur in a serie...

AI Technical Summary

Problems solved by technology

The disadvantage of this structure is that the series structure will increase the primary breakdown voltage of the device and increase the total on-resistance, which means increased power consumption and may lead to a decrease in ESD resistance

At the same time, a large on-resistance will lead to an increase in the voltage across the internal circuit connected in parallel with the protection structure under the same ESD current, making it difficult to provide better ESD protection for the internal circuit.

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