US Patent 10199482 Apparatus for electrostatic discharge protection

An apparatus includes an electrostatic discharge (ESD) protection device configured to protect a circuit from ESD conditions. The protection device includes an emitter region having a first diffusion polarity; a collector region laterally spaced apart from the emitter region, and having the first diffusion polarity; and a barrier region interposed laterally between the emitter region and the collector region while contacting the emitter region. The barrier region has a second diffusion polarity opposite from the first diffusion polarity. The device can further include a base region having the second diffusion polarity, and laterally surrounding and underlying the emitter region and the barrier region. The barrier region can have a higher dopant concentration than the base region, and block a lateral current flow between the collector and emitter regions, thus forming a vertical ESD device having enhanced ESD performance.