Integrated circuit in silicon on insulator technology comprising a field effect transistor

An integrated circuit comprising at least one field effect transistor having a source (42) and a drain (44) in the upper part (16) of a semiconductor island (18), obtained by the local introduction of impurities of a first conductivity type, a gate (35, 33) located on the island between the source and the drain and electrically insulated therefrom, a buried electrical insulating layer (4) supporting the island, an electrode (12, 17) buried in the island and in contact with the insulating layer, said electrode having a second conductivity, different from the first, a zone (36) diffused into at least one edge (18a) of the island from a conductive material (29) covering the said edge, said conductive material being doped with impurities of the second conductivity type, the diffused zone of the second conductivity type being electrically insulated from the source and drain and ensuring the electrical contacting of the electrode and the conductive material which constitutes the electrical contact of the electrode, while the source, drain (50) and gate (31) contacts are electrically insulated from one another and from the electrode contact.