A transient voltage suppression (TVS) device and method of formation. A TVS device may include a first layer, disposed on a first surface of a substrate, comprising a first P+ layer; a second layer, disposed on a second surface of the substrate, opposite the first surface, comprising a second P+ layer; a third layer, disposed between the first P+ layer and the second P+ layer, comprising an N- layer; and an isolation diffusion region, comprising a P structure, connected to the second P+ layer, and extending along a perimeter of the N- layer.