Fabrication method of a double polysilicon bipolar transistor with heterojunction base and corresponding transistor

摘要

A method for the fabrication of a bipolar transistor of double polysilicon type with a hetero-junction consists of: (a) forming by non-selective epitaxy, a semiconducting layer with a silicon-germanium heterojunction (2) on an active region (ZA) of a semiconducting substrate and an insulating region (STI) surrounding the active region; (b) forming on the heterojunction semiconducting layer above a part of the active region, at least one engraving stoppage layer (3); (c) forming on the heterojunction semiconducting layer and on a part of the engraving stoppage layer a layer of polysilicon (5) and an upper insulating layer (6) such that an emitting window (7) is left free; (d) forming by epitaxy an emitter region (9) in the emitting window resting partially on the upper insulating layer and in contact with the heterojunction semiconducting layer. An Independent claim is also included for a bipolar transistor of the double-polysilicon with a heterojunction type.