SCR structure and ESD protection structure having same

Abstract

The invention discloses an SCR structure. A first P well, a second P well, a first N well and a second N well are alternately arranged on a substrate from left to right. A first P-type heavily doped region is arranged in the upper part of the first P well, a first N-type heavily doped region is arranged in the first P well on the right side of the first P-type heavily doped region, a second N-typeheavily doped region is arranged in the first P well on the right side of the first N-type heavily doped region, and a polysilicon gate is arranged above the first P well between the first and secondN-type heavily doped regions. A third N-type heavily doped region is arranged in the upper part of the first N well, and a second P-type heavily doped region is arranged in the first N well on the right side of the third N-type heavily doped region. A fourth N-type heavily doped region is arranged in the upper part of the second P well, and a third P-type heavily doped region is arranged in the second P well on the right side of the fourth N-type heavily doped region. A fourth P-type heavily doped region is arranged in the upper part of the second N well, and a fifth N-type heavily doped region is arranged in the second N well on the right side of the fourth P-type heavily doped region. The invention further provides an ESD protection structure having the SCR structure.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to an SCR structure. The invention also relates to an ESD protection structure with the SCR structure. Background technique [0002] Static electricity is an objective natural phenomenon, which can be produced in many ways, such as contact, friction, induction between electrical appliances, etc. Static electricity is characterized by long-term accumulation, high voltage, low power, small current and short action time. Static electricity causes serious harm in many fields. Friction electrification and human body static electricity are two major hazards in the electronics industry, which often cause unstable operation or even damage of electronic and electrical products. ESD is a discipline formed since the middle of the 20th century to study the generation, harm and protection of static electricity. It is customary in the world to refer to the equipment used for electrostatic protect...

AI Technical Summary

Problems solved by technology

[0003] The SCR structure (silicon controlled rectifier) ​​has two disadvantages as an ESD protection device: one is the high turn-on voltage, which is inconvenient to adjust; the other is the low maintenance voltage, which has a greater risk of latch-up

[0006] 2. In a high-temperature environment, the leakage current to the diode will increase significantly, increasing power consumption

[0007] 3. Unable to achieve two-way protection

Because the N well is not connected to the static terminal, the discharge from GND to the static terminal can only be discharged through the P-type heavily doped region (P-type heavily doped region) / N well reverse junction of the SCR, and the ESD protection capability is poor.

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