Abstract: A semiconductor device includes a silicon layer of a first conductivity type, which is disposed on a dielectric substrate and in which at least two zones of a semiconductor circuit element of a second opposite conductivity type and a contact zone having the same conductivity type as, but a higher doping concentration than the silicon layer are provided, which zones adjoin a surface of the silicon layer. According to the invention, the contact zone extends below the zones of the field effect transistor. This semiconductor device has the advantage that it can be manufactured in a very simple manner. In a method of manufacturing this device, in a silicon layer of a first conductivity type disposed on a dielectric substrate are formed a contact zone having the same conductivity type as, but a higher doping concentration than the silicon layer and at least two zones of a semiconductor circuit element of a second opposite conductivity type.