Abstract: The invention concerns a variable capacitance capacitor comprising a periodic structure of raised zones (5) separated by recesses (6) formed in a type N semiconductor substrate (1). The walls of the raised zones and the base of the recesses are coated with a conductive layer (9, 10). The substrate is connected to a first terminal (A) of the capacitor and the conductive layer to a second terminal (B) of the capacitor. At least the base of the recesses or the side of the raised zones comprises type P regions (8), the pitch of the raised parts being selected so that the space charging zones linked to the type P regions are joined when the voltage difference between said terminals exceeds a predetermined threshold. The zones not comprising type P regions are coated with an insulant (7) and a highly doped N region (10) is formed beneath the insulant.

Abstract: The invention concerns a variable capacitance capacitor comprising a periodic structure of raised zones (5) separated by recesses (6) formed in a type N semiconductor substrate (1). The walls of the raised zones and the base of the recesses are coated with a conductive layer (9, 10). The substrate is connected to a first terminal (A) of the capacitor and the conductive layer to a second terminal (B) of the capacitor. At least the base of the recesses or the side of the raised zones comprises type P regions (8), the pitch of the raised parts being selected so that the space charging zones linked to the type P regions are joined when the voltage difference between said terminals exceeds a predetermined threshold. The zones not comprising type P regions are coated with an insulant (7) and a highly doped N region (10) is formed beneath the insulant.