Semiconductor device of the bipolar transistor type has heterojunction

摘要

Semiconductor device of the heterojunction bipolar transistor type comprising, on a substrate, a layer for forming the collector and a layer for forming the base, these layers being of a group III-V material, furthermore comprising a layer for forming the emitter, this emitter layer being on the one hand composed of materials whose energy band width is greater than that of the base layer and on the other hand composed of several layers having concentrations of impurities which differ, characterised in that: - the various emitter layers comprise on the one hand thin layers of a group III-V material and on the other hand, surmounting these latter, a thicker layer of germanium Ge; - electrical contact on the emitter layer is produced by means of non-alloyed metal layers. Application: heterojunction bipolar transistor synergistically manufactured with group III-V semiconductor devices. IMAGE