A semiconductor device includes a semiconductor body, having a first surface, a gate electrode structure, which includes polycrystalline silicon, of an IGFET in a first trench extending from the first surface into the semiconductor body. The device also includes a semiconductor element, which is different from the gate electrode structure of the IGFET and includes polycrystalline silicon, in a second trench extending from the first surface into the semiconductor body, wherein the polycrystalline silicon of the IGFET and of the semiconductor element different therefrom ends below a top side of an insulation layer adjoining the first surface of the semiconductor body.