Abstract: The invention proposes a bipolar transistor comprising a substrate, emitter, base, and collector layers and, if appropriate, contact layers. The base layer is formed from a GaAsSb material. The transistor also has at least one transition layer formed from a GaInP material between the emitter layer and the base layer. The presence and composition of the transition layer allows the profile of the conduction band of the transistor to be shaped to optimize performance. Further, the composition of the transition layer facilitates fabrication of the transistor by selective etching. The invention also relates to a circuit comprising a bipolar transistor of the invention. The invention also proposes a method of fabricating a transistor in accordance with the invention.

Abstract: A monolithic integrated optical component includes a control transistor connected to an electro-optical component including an active waveguide and at least one input waveguide and one output waveguide. The transistor is a heterojunction bipolar transistor including at least one sub-collector layer that is common to a confinement layer of the electro-optical component. The active waveguide of the electro-optical component includes a widened structure under a contact area of the heterojunction bipolar transistor and having substantially the same surface area as the transistor.

Abstract: The invention relates to a method of manufacturing a double heterojunction bipolar transistor (1) comprising successively at least one sub-collector layer, a collector layer, a base layer and a metallic layer (10) deposited on the said base layer; the said metallic layer (10) being extended towards a contact pad (110) of the base by an underetched metallic “air bridge” (100), characterized in that producing the said “air bridge” (100) includes the following steps: effecting a first localized etching under the said bridge, this first etching being selective so as to etch the sub-collector layer laterally; and effecting a second localized etching under the said bridge, this second etching being selective so as to vertically etch at least the collector layer.

Abstract: A monolithic integrated optical component includes a control transistor connected to an electro-optical component including an active waveguide and at least one input waveguide and one output waveguide. The transistor is a heterojunction bipolar transistor including at least one sub-collector layer that is common to a confinement layer of the electro-optical component. The active waveguide of the electro-optical component includes a widened structure under a contact area of the heterojunction bipolar transistor and having substantially the same surface area as the transistor.

Abstract: The invention relates to a method of manufacturing a double heterojunction bipolar transistor (1) comprising successively at least one sub-collector layer, a collector layer, a base layer and a metallic layer (10) deposited on the said base layer; the said metallic layer (10) being extended towards a contact pad (110) of the base by an underetched metallic “air bridge” (100), characterized in that producing the said “air bridge” (100) includes the following steps: