Process for fabricating a self aligned double polysilicon bipolar transistor with heterojunction base and transistor fabricated by this processs

摘要

A method for the fabrication of a bipolar transistor consists of forming, using non-selective epitaxy, a semiconductor region with a silicon-germanium heterojunction (1) extending over an active region (ZA) of a semiconductor substrate and an insulating region (STI) delimiting the active region, and incorporating the region of the intrinsic base of the transistor; an emitter region (8) situated above the active region and coming into contact with the upper surface of the heterojunction semiconductor region (1); a layer of polysilicon (30) forming the region of the extrinsic base of the transistor, situated either side of the emitter region (8) and separated from the heterojunction semiconductor region by a separation layer incorporating an electrical liaison conductor (74) part situated in the external neighbourhood of the emitter region, this liaison part assuring an electrical contact between the extrinsic base and the intrinsic base. An Independent claim is included for such a bipolar transistor.