SOI process silicon controlled rectifier electrostatic discharge protection structure with adjustable maintaining voltage

Abstract

The invention relates to the technical field of silicon controlled rectifier electrostatic protection, and particularly relates to an SOI process silicon controlled rectifier electrostatic discharge protection structure with adjustable maintaining voltage. The structure comprises polycrystalline silicon, an N-type well region, a P-type well region, a silicon film layer, a buried oxide layer and asilicon substrate layer which are stacked, wherein an N-type well region and a P-type well region are adjacently arranged in the silicon film layer along the left-right direction; the top of the N-type well region and the top of the P-type well region are in contact with the bottom of the polycrystalline silicon; a first N-type heavily doped region, a first P-type heavily doped region and an ultra-shallow trench isolation region are sequentially arranged at the upper part of the N-type well region from left to right; and a second N-type heavily doped region and a second P-type heavily doped region are sequentially arranged at the upper part of the P-type well region from left to right. According to the invention, the ultra-shallow trench isolation region is arranged above the N-type well region, and the equivalent resistance on the path from the positive electrode to the negative electrode in the SCR is increased by utilizing the insulation capability of the ultra-shallow trench isolation region, so that the purpose of improving the maintaining voltage of the SCR is achieved, and the electric leakage risk of the SCR is effectively reduced.

Description

technical field [0001] The invention relates to the technical field of thyristor electrostatic protection, in particular to an electrostatic discharge protection structure of SOI process thyristor with adjustable sustain voltage. Background technique [0002] Static electricity exists all the time in nature. When the external environment of the chip or the static charge accumulated inside the chip flows into or out of the chip through the pins of the chip, the instantaneous current (peak value can reach several amperes) or voltage will damage the integrated circuit. disable the function of the chip. Effective ESD (Electron Static Discharge, electrostatic discharge) enables the protective device to quickly open and discharge ampere-level current in an electrostatic event, and at the same time, the voltage between the clamp port or the power supply / ground is below the breakdown voltage of the core circuit to achieve protection The core circuit is not damaged by static electri...

AI Technical Summary

Problems solved by technology

Therefore, the thyristor SCR is an ideal electrostatic protection device, but due to its own characteristics, the device still has imperfections such as high turn-on voltage and low maintenance voltage.

Images