Abstract: Semiconductor devices, one having a planar bipolar high-voltage semiconductor circuit element comprising an island-shaped region of one conductivity type. On its lower side the island-shaped region is bounded by a first pn junction having a comparatively high breakdown voltage, and laterally by a second pn junction having a comparatively low breakdown voltage. The doping and the thickness of the island-shaped region are so small that the region is entirely depleted before breakdown occurs.The second semiconductor device having a field effect transistor of the lateral or vertical type with an island-shaped region having a contact region and bounded at the bottom by a pn junction having a comparatively high breakdown voltage and laterally by a second pn junction having a comparatively low breakdown voltage.

Abstract: A field effect transistor of the V-MOST type in which the channel region comprises a more highly doped part which adjoins the source zone and a lower doped part which surrounds said region, said channel region adjoining the surface and surrounded by an insulation diffusion. The lower-doped part is depleted from the pn junction with the low-doped drain region up to the surface at a voltage which is lower than the breakdown voltage.

Abstract: A semiconductor device includes a body comprising two planar complementary transistor structures preferably but not exclusively with dielectric insulation. Both complementary transistor structures comprise parts of two epitaxial layers of opposite conductivity types present one on top of the other, the first layer forming the base zone of the first transistor and the second layer forming the collector zone of the second transistor, the emitter zone of the first transistor and the base zone of the second transistor being formed by parts of the second layer.