Patent ID: 6621133
Filing Date: 2003-09-16
Classification: H01L

Abstract:
An electrostatic discharge (ESD) protection device, comprising:a substrate; a first parasitic bipolar transistor within the substrate, wherein the first parasitic bipolar transistor includes a first emitter terminal, a first collector terminal and a first base terminal; a second parasitic bipolar transistor within the substrate, wherein the second parasitic bipolar transistor includes a second emitter terminal, a second collector terminal and a second base terminal, and the second collector terminal is adjacent to the first collector terminal; a first longitudinal doped region between the first collector terminal and the second collector terminal; a third parasitic bipolar transistor within the substrate, wherein the third parasitic bipolar transistor includes a third emitter, a third collector and a third base, and the third emitter and the second emitter are connected; a fourth parasitic bipolar transistor within the substrate, wherein the fourth parasitic bipolar transistor includes a fourth emitter, a fourth collector and a fourth base, and the fourth collector is adjacent to the third collector; a second longitudinal doped region between the fourth collector and the third collector; a guard ring circumscribing the substrate; and an isolation region inside the guard ring for isolating the first/second/third/fourth parasitic bipolar transistor from the guard ring, the first collector, the first longitudinal doped region and the second collector from each other as well as the third collector, the second longitudinal doped region and the fourth collector from each other.