SiGe base bipolar technology with 74 GHz f/sub max/ and 11 ps gate delay

An epitaxial SiGe-base bipolar technology suited for very high performance mixed digital/analogue applications is presented. A key feature is the emitter/base process which is the obvious SiGe-base extension of the implanted base double-poly self-aligned emitter/base structure. The fabricated HBTs exhibit a maximum cut-off frequency f/sub T/ of 61 GHz, a maximum oscillation frequency f/sub max/ of 74 GHz and a record CML gate delay time of 11 ps.