Abstract: The invention provides a variable capacity diode with a plane structure so that it may be formed in an integrated circuit, this diode has, on the substrate, three coplanar regions. The first and second uniformly doped regions support the contact making metallizations. The transition region has a variation of doping level, low at one end and high at the other end. This variation is obtained by implantation by means of a focused ion beam, with constant energy and sweeping at increasing doses, which allows a hyperabrupt profile to be obtained. The diode is a p-n junction of Schottky contact diode.