Integrated circuit with a very small-sized reading diode

A method for fabricating a diode (DL) of small dimensions between two silicon electrodes deposited above a substrate, comprising the following steps:

• a) producing the two electrodes, separated by a gap, above the substrate;
• b) thermally oxidizing a part of a thickness of the electrodes, in height and in width, leaving a space remaining between the oxidized electrodes, the substrate being protected against oxidation in the space;
• c) exposing the surface of the substrate in the space,
• d) depositing a layer of doped polycrystalline silicon entering in contact with the substrate in the space in order to form one pole of the diode, the substrate forming another pole,
• e) partially removing the polycrystalline silicon while leaving a desired pattern remaining, the pattern covering at least the space left between the electrodes and also covering a region lying outside the space,
• f) depositing an insulating layer, and locally etching an opening into the insulating layer above the polycrystalline silicon outside the space lying between the electrodes, in order to form an offset contact zone, depositing a metal layer entering in contact with the polycrystalline silicon in the offset contact zone, and etching the metal layer according to a desired pattern of interconnections.