Vertical bipolar transistor device

Abstract

A vertical bipolar transistor device includes a heavily-doped semiconductor substrate, a first semiconductor epitaxial layer, at least one doped well, an isolation structure, and an external conductor. The heavily-doped semiconductor substrate and the doped well have a first conductivity type, and the first semiconductor epitaxial layer has a second conductivity type. The first semiconductor epitaxial layer is formed on the heavily-doped semiconductor substrate. The doped well is formed in the first semiconductor epitaxial layer. The isolation structure, formed in the heavily-doped semiconductor substrate and the first semiconductor epitaxial layer, surrounds the first semiconductor epitaxial layer and the at least one doped well. The external conductor is arranged outside the first semiconductor epitaxial layer and the doped well and electrically connected to the first semiconductor epitaxial layer and the doped well.

Dependencies are inferred from the claim text.