an igfet device includes : — a semiconductor body having a major surface , — a source region of first conductivity type abutting the surface , — a drain region of the first conductivity - type abutting the surface and spaced from the source region with a channel therefrom , — an active gate overlying the channel and insulated from the channel by a first dielectric material forming the gate oxide of the igfet device , — a dummy gate positioned between the active gate and the drain and insulated from the active gate by a second dielectric material so that a capacitance is formed between the active gate and the dummy gate , and insulated from the drain region by the gate oxide , wherein the active gate and the dummy gate are forming the electrodes of the capacitance substantially perpendicular to the surface .