Patent ID: 8742455

Claim:
An apparatus comprising: an internal circuit electrically coupled between a first node and a second node; and a protection device electrically coupled between the first node and the second node, wherein the protection device is configured to protect the internal circuit from transient electrical events, the protection device comprising: a silicon-controlled rectifier (SCR) having an anode, a gate, and a cathode, wherein the anode is electrically coupled to the first node, and the cathode is electrically coupled to the second node, wherein the SCR comprises: a substrate having a doping of a first type; a first well disposed in a first upper portion of the substrate, and having a doping of a second type different from the first type; a second well disposed in a second upper portion of the substrate, and spaced apart laterally from the first well such that a third upper portion of the substrate is laterally interposed between the first and second wells, the second well having a doping of the second type, the third upper portion having a doping of the first type; a first region disposed in a top portion of the first well, and having a doping of the second type with a higher doping concentration than that of the first well, the first region being electrically coupled to the second node; a second region disposed in a top portion of the second well, and having a doping of the second type with a higher doping concentration than that of the second well; a third region disposed in the first well adjacent to the first region such that the third region is interposed laterally between the first region and the third upper portion of the substrate, the third region having a doping of the first type with a higher doping concentration than that of the substrate; a fourth region disposed in the second well adjacent to the second region such that the fourth region is interposed laterally between the second region and the third upper portion of the substrate, the fourth region having a doping of the first type with a higher doping concentration than that of the substrate, the fourth region being electrically coupled to the first node; and a gate contact disposed on the third upper portion of the substrate.