BICMOS integrated circuit having a shallow trench bipolar transistor with vertical base contacts

摘要

An improved bipolar transistor of a BiCMOS integrated circuit (9) is fabricated by utilizing a shallow trench (64) structure. The shallow trench (64) defines an active base (67) and a self-aligned emitter (69). The base resistance of the transistor is reduced because a vertical, rather than lateral, link base, which connects an extrinsic base (51) to the active base (67), is formed. In addition, the overall area is reduced, which provides for a lower collector to base capacitance.