An integrated circuit device includes a semiconductor substrate having a top surface; at least one insulation region extending from the top surface into the semiconductor substrate; a plurality of base contacts of a first conductivity type electrically interconnected to each other; and a plurality of emitters and a plurality of collectors of a second conductivity type opposite the first conductivity type. Each of the plurality of emitters, the plurality of collectors, and the plurality of base contacts is laterally spaced apart from each other by the at least one insulation region. The integrated circuit device further includes a buried layer of the second conductivity type in the semiconductor substrate, wherein the buried layer has an upper surface adjoining bottom surfaces of the plurality of collectors.