Transistor-injected silicon-controlled rectifier (scr) with perpendicular trigger and discharge paths

Abstract

An Electro-Static-Discharge (ESD) protection circuit has a Silicon-Controlled Rectifier (SCR) with a discharge current path in a first direction. A triggering transistor has a trigger current flowing in a second direction that is perpendicular to the first direction. Triggering transistors can be Fin Field-Effect Transistor (FinFET) transistors with current flowing along the long direction of the fins. The trigger current flows into a connecting N+ drain and into an N-Well under a center portion of the connecting N+ drain to inject carriers into the N-base of a PNPN SCR. The injected current flows through the base to generate a voltage gradient that turns on the PN junction in a P+ emitter that is parallel to but spaced apart from the FinFET transistors, causing a discharge current to flow perpendicular to the fins. The perpendicular discharge current flows through the substrate which can handle a larger current than the small fins.