A semiconductor device in a semiconductor substrate having a first main surface includes a transistor array and a termination region. The transistor array includes a source region, a drain region, a body region, a drift zone, and a gate electrode at the body region. The gate electrode is configured to control a conductivity of a channel in the body region. The body region and the drift zone are disposed along a first horizontal direction between the source region and the drain region. The transistor array further includes first field plate trenches in the drift zone. A longitudinal axis of the first field plate trenches extends in the first horizontal direction. The semiconductor device further includes a second field plate trench, a longitudinal axis of the second field plate trench extending in a second horizontal direction perpendicular to the first direction.