Abstract: A complementary BiCMOS semiconductor device comprises a substrate of a first conductivity type and a number of active regions which are provided therein and which are delimited in the lateral direction by shallow field insulation regions, in which vertical npn-bipolar transistors with an epitaxial base are arranged in a first subnumber of the active regions and vertical pnp-bipolar transistors with an epitaxial base are arranged in a second subnumber of the active regions, wherein either one transistor type or both transistor types have both a collector region and also a collector contact region in one and the same respective active region. To improve the high-frequency properties exclusively in a first transistor type in which the conductivity type of the substrate is identical to that of the collector region, an insulation doping region is provided between the collector region and the substrate.