Patent ID: 8217461

Claim:
An electrostatic discharge (ESD) protection structure comprising: a substrate having a first conductivity type; a MOS transistor comprising a plurality of gate fingers on the substrate and source and drain regions formed in the substrate between the gate fingers, the gate fingers having first and second ends; a deep well underneath the MOS transistor, the deep well having a second conductivity type; a first ohmic contact to the deep well, the contact surrounding the MOS transistor and being substantially rectangular in shape with first and second sides that extend in a first direction and third and fourth sides that extend in a second direction; a second ohmic contact to the substrate, the second ohmic contact extending in the second direction and being located between the first ends of the gate fingers and one of the sides of the first ohmic contact that extend in the second direction; and a floating well extending in the second direction and located between the second ohmic contact and the first ends of the gate fingers, the floating well having the second conductivity type.