| 摘要 |
A P_STSCR structure includes a P-type substrate, an N-well in the P-type substrate, a first N+ diffusion region located in the P-type substrate connected to the cathode, a second P+ diffusion region located in the N-well connected to the anode, and a third P+ diffusion region as a trigger node located in the P-type substrate and between the first N+ diffusion region and the second P+ diffusion region. A lateral SCR device including the second P+ diffusion region, the N-well, the P-type substrate and the first N+ diffusion region is thereby formed. When a current flows from the trigger node into the P-type substrate, the lateral SCR device is triggered on into its latch state to discharge ESD current. Since the present invention utilizes a substrate-triggered current Itrig flowing into or flowing out from the P-type substrate or the N-well through the inserted trigger node, a much lower switching voltage in the SCR device is obtained.With such a lower switching voltage in the SCR device, the total layout area of the ESD protection circuit can be reduced, and the turn-on speed of SCR device is further improved to quickly discharge ESD current.ESD current flowing through surface channels, and heat dissipation issues, are avoided, while presenting no increase to the overall complexity and difficulty of CMOS IC manufacturing.
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