Abstract: A method of manufacturing a hetero-junction bipolar transistor, especially of gallium arsenide, comprising the step of forming superimposed epitaxial layers for forming a collector layer (1) of the n.sup.+ type, an emitter layer (3) of the n-type, the formation of localized implantations of the p.sup.+ type to obtain the base regions (31,30) or of the n.sup.+ type to obtain collector contact islands (20). This method also includes the formation by a controlled etching into a germanium layer (50) formed at the surface of these layers, of pads having a profile such that their tips define with a very high precision openings (E.sub.1), of which the distance (E.sub.0) between the edges defines the emitter contact region, while their edges have a concavity turned towards the exterior of the device.Application integrated circuits on gallium arsenide.

Abstract: A method of manufacturing a hetero-junction bipolar transistor especially of gallium arsenide comprising the formation of epitaxial layers superimposed to obtain a collector layer (1) of the n.sup.+ type, an emitter layer (3) of the n-type, the formation of localized implantations of the p.sup.+ type to obtain the base region (31, 30) or of the n.sup.+ type to form collector contact islands (20). This method also including the formation of base contacts B (70) having the dimensions B.sub.0 and located at a relative distance of E.sub.1, then covering the metallization (70) of pads (81) of silica (Si.sub.3 N.sub.4) having edges perpendicular to the plane of the layers on which bear spacers of silicon nitride (Si.sub.3 N.sub.4) (52) having dimensions h.sub.1 defining with a high precision the dimension E.sub.0 =B.sub.1 -2h of the emitter contact E and the distances between the different collector (90), base (70) and emitter (90) contacts C, B and E, respectively.