A semiconductor device includes a gate electrode adjacent to a body region in a semiconductor substrate. The semiconductor device further includes a field electrode in a field plate trench in the main surface, the field plate trench having an extension length in a first direction parallel to a main surface. The extension length is less than the double of an extension length in a second direction that is perpendicular to the first direction parallel to the main surface. The extension length in the first direction is more than half of the extension length in the second direction. The field electrode is insulated from an adjacent drift zone by means of a field dielectric layer. A field plate material of the field electrode has a resistivity in a range from 105 to 10−1 Ohm·cm.