Electrostatic protection circuit

Abstract

The invention discloses an electrostatic protection circuit. The electrostatic protection circuit comprises a P-type diode, an N-type diode and a clamping circuit. The P-type diode comprises a P-typesemiconductor substrate, an N-well, a first N+ diffusion region, a P+ diffusion region, and a second N+ diffusion region, wherein the first N+ diffusion region is arranged in the N well; the P+ diffusion region is arranged on the periphery of the first N+ diffusion region; and the second N+ diffusion region is arranged on the periphery of the P+ diffusion region. The N-type diode comprises a P-type semiconductor substrate, a first P+ diffusion region which is arranged in the P-type semiconductor substrate of the N-type diode, an N+ diffusion region which is arranged on the periphery of the first P+ diffusion region, and a second P+ diffusion region which is arranged on the periphery of the N+ diffusion region.

Description

technical field [0001] The invention relates to an electrostatic protection circuit, in particular to an electrostatic protection circuit with an innovative diode structure, which can have better electrostatic protection function and relatively low parasitic capacitance without increasing the area. Background technique [0002] figure 1 Shown is a simplified schematic diagram of a conventional electrostatic protection circuit 100, figure 2 shown as figure 1 A top view and a schematic cross-sectional view of an N-type diode in an electrostatic protection circuit 100 of FIG. Such as figure 1 As shown, the electrostatic protection circuit 100 includes: a P-type diode 110 coupled to a power supply terminal Power and an output-output terminal I / O; an N-type diode 120 coupled to a ground terminal GND and an output-output terminal I / O; and a clamping circuit 130 connected in parallel with the P-type diode 110 and the N-type diode 120 . Such as figure 2 As shown, the N-type ...

AI Technical Summary

Problems solved by technology

Therefore, the traditional ESD protection circuit 100 can only make the current flow from the P+ diffusion region 126 to the N+ diffusion region 124, that is, there is only one path, so if the traditional ESD protection circuit 100 wants to obtain a better ESD protection function, it must wait Increase the overall area of ​​the N-type diode 120 proportionally, but after the area increases, the parasitic capacitance will increase accordingly, which has a great impact on high-speed applications

Similarly, the P-type diode 110 also has a similar structure to the N-type diode 120, so it will cause the same problem

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