Patent ID: 7812367

Claim:
An ESD device comprising: a semiconductor substrate of a first conductivity type and having a first doping concentration, the semiconductor substrate having first and second surfaces; a first semiconductor layer of a second conductivity type on the first surface of the semiconductor substrate, the first semiconductor layer having a first surface that is opposite to the first surface of the semiconductor substrate and having a second doping concentration; a second semiconductor layer of the first conductivity type on the first surface of the first semiconductor layer having a first surface that is opposite to the first surface of the first semiconductor layer and having a third doping concentration; a third semiconductor layer of the second conductivity type on the first surface of the second semiconductor layer, the third semiconductor layer having a first surface that is opposite to the first surface of the second semiconductor layer and having a fourth doping concentration; a first semiconductor region of the second conductivity type positioned between a first portion of the third semiconductor layer and the first surface of the second semiconductor layer, the first semiconductor region forming a zener diode with dopants of the second semiconductor layer; a first isolation trench formed as a first multiply-connected domain having a periphery and extending from the first surface of the third semiconductor layer into the semiconductor substrate wherein the periphery surrounds at least a first portion of the third semiconductor layer; and a plurality of diodes formed in the first portion of the third semiconductor layer.