Asymmetrical, bidirectional triggering ESD structure

摘要

An ESD protection structure which includes, preferably a single semiconductor chip, a forward SCR for coupling across a source of potential and a reverse SCR for coupling across the same source of potential which is non-symmetrical to the forward SCR. The breakdown voltage of the forward SCR is different from the breakdown voltage of the reverse SCR. Each of the SCRs has a separate triggering mechanism. None of the anode, cathode and triggering elements of the forward SCR are common to the reverse SCR. A unidirectional device, preferably a Schottky diode, is disposed in the body of semiconductor material between the forward and reverse SCRs to prevent conduction from the body of semiconductor material when the source of potential across the SCRs is reversed.