| abstract |
An ESD-protection device includes a gate electrode formed on a substrate; a first diffusion region of a first conductivity type formed in the substrate at a first side of the gate electrode, a second diffusion region of the first conductivity type formed in the substrate at a second side of the gate electrode, and a third diffusion region of a second conductivity type formed in the substrate underneath the second diffusion region in contact with the second diffusion region. Thereby, the impurity concentration level of the third diffusion region is set to be larger than the impurity concentration level of the region of the substrate located at the same depth right underneath the gate electrode. |