MANUFACTURE OF BIPOLAR TRANSISTOR

PURPOSE:To obtain a bipolar transistor having small capacity between a base and a collector and floating capacity by forming intrinsic base region and an emitter region on the exposed epitaxial layer surface and forming a base electrode connecting to a sidewall and an emitter electrode connecting to an emitter region. CONSTITUTION:In the formation of the intrinsic base and emitter regions, directly after the etching removal of an oxide film a polysilicon film for an emitter electrode covers the whole surface. Next, in order to form intrinsic base region 12, boron is ion-implanted as base impurities on condition that it does not penetrate the polysilicon film so as to perform thermal diffusion for being connected to an outer region formed in advance. Further, arsenic is ion-implanted as emitter impurities so as to form an emitter region 13. Patterning of a polysilicon film is performed by a usual photolithography method so as to form an emitter electrode 11. The polysilicon film 24 connected to a collector electrode is separated followed by a usual manufacturing method.