Patent ID: 8107203
Filing Date: 2012-01-31
Classification: H01L

Abstract:
1. An electrostatic discharge protection circuit, comprising: a first bipolar transistor including one terminal connected with a first power supply terminal, another terminal connected with an input/output terminal, and a control terminal connected with a second power supply terminal; and a thyristor including one terminal connected with the input/output terminal, another terminal connected with the second power supply terminal, and a control terminal connected with the first power supply terminal, wherein the first bipolar transistor is formed in a first conductivity type well, and a region of the other terminal of the first bipolar transistor, which is connected with the input/output terminal includes a second-conductivity-type first diffusion region, and a second-conductivity-type second diffusion region formed entirely below the second-conductivity-type first diffusion region, the second conductivity-type second diffusion region having an impurity concentration less than an impurity concentration of the second-conductivity-type first diffusion region.