Patent ID: 7307336

Claim:
A bipolar transistor having a base and self-positioned active emitter, characterized in that the base is formed from a first substantially monocrystalline epitaxial region ( 1 ) which is arranged in parallel relationship to the surface of the semiconductor substrate ( 2 ) and a second substantially polycrystalline and highly doped region ( 3 ) of the same conductivity type which is arranged in perpendicular relationship to the substrate surface and encloses the first region at all sides and that said second region, at least at one side, is conductingly connected to a third high temperature-resistant polycrystalline layer ( 4 ) which is arranged in parallel relationship to the surface of the semiconductor substrate and forms or includes the outer base contact to a metallic conductor track system, and further characterized in that between the self-positioned active emitter ( 5 ) and the highly doped polycrystalline region ( 3 ) arranged in perpendicular relationship to the surface of the semiconductor substrate ( 2 ) is spacing defined by a spacer ( 3 a ) arranged at the perpendicular region and comprising one or more insulating layers ( 9 , 10 ) and at least one high temperature-resistant, good-conducting polycrystalline layer ( 6 ), wherein the latter is conductingly connected to the active emitter.