Patent ID: 7514751

Claim:
An electrostatic discharge (ESD) protection circuit comprising: a semiconductor structure having: a substrate of a first conductivity type; a buried layer of a second conductivity type that touches the substrate; a surface region of the second conductivity type that touches the buried layer and a top surface of the semiconductor structure, the surface region having a dopant concentration that is lower than a dopant concentration of the buried layer; and an isolation region that extends down from the top surface of the semiconductor structure; spaced-apart first and second regions of the first conductivity type that lie on the top surface of the semiconductor structure and touch the isolation region; spaced-apart third and fourth regions of the second conductivity type that lie on and touch the first and second regions, respectively; spaced-apart first and second contacts electrically connected to the first and third regions, respectively, and to a first pad; and spaced-apart third and fourth contacts electrically connected to the second and fourth regions, respectively, and to a second pad.