Bi-directional transient voltage suppression device and forming method thereof

A bidirectional transient voltage suppression device is disclosed. The bi-directional transient voltage suppression device comprises a semiconductor die. The semiconductor die has a multi-layer structure comprising a semiconductor substrate of a first conductivity type, a buried layer of a second conductivity type, an epitaxial layer, and five diffused regions. The buried layer and the semiconductor substrate form a first semiconductor junction. The first diffused region of the second conductivity type and the semiconductor substrate form a second semiconductor junction. The fourth diffused region of the first conductivity type and the third diffused region of the second conductivity type form a third semiconductor junction. The fifth diffused region of the first conductivity type and the second diffused region of the second conductivity type form a fourth semiconductor junction.