High-voltage integrated circuit with junction isolation

A high voltage integrated circuit with junction isolation, comprising at least one epitaxial region (2) having a first conductivity type and at least one junction isolation region (3) adjacent to the epitaxial region, having a second conductivity type opposite to the first and forming a reverse-biased junction with the epitaxial region. The epitaxial and isolation regions are covered by an electrically insulating layer (5) accommodating in its interior at least one shielding structure (9) of polycrystalline material overlying the junction. A shaped conducting layer (6) is furthermore superimposed on the insulating layer at the junction and has a high potential. In order to impart high breakdown voltages to the junction, at least one further region (15) having the second conductivity type extends from the isolation region towards the interior of the epitaxial region and has a lower level of doping impurities than the isolation region.