The disclosure relates to an integrated circuit comprising a nonvolatile memory on a semiconductor substrate. The integrated circuit comprises a doped isolation layer implanted in the depth of the substrate, isolated conductive trenches reaching the isolation layer and forming gates of selection transistors of memory cells, isolation trenches perpendicular to the conductive trenches and reaching the isolation layer, and conductive lines parallel to the conductive trenches, extending on the substrate and forming control gates of charge accumulation transistors of memory cells. The isolation trenches and the isolated conductive trenches delimit a plurality of mini wells in the substrate, the mini wells electrically isolated from each other, each having a floating electrical potential and comprising two memory cells.