An embodiment of a semiconductor device includes a semiconductor mesa in an active device area. The semiconductor mesa includes source regions arranged along a longitudinal direction of the semiconductor mesa and separated from one another along the longitudinal direction. The semiconductor device further includes an electrode trench structure including a dielectric and an electrode. The electrode trench structure adjoins a side of the semiconductor mesa. The semiconductor device further includes an isolation trench structure filled with one or more insulating materials. The isolation trench structure extends through the semiconductor mesa and into or through the electrode trench structure along a first lateral direction.