According to an embodiment of a semiconductor device, the device includes first and second trenches formed in a semiconductor body and an electrode disposed in each of the trenches. One of the electrodes is a gate electrode, and the other electrode is electrically disconnected from the gate electrode. The semiconductor device further includes a semiconductor mesa between the trenches. The semiconductor mesa includes a separation region and at least one of a source region and a body region located in the semiconductor mesa. A drift zone is provided below the at least one of the source region and the body region. In the separation region, at least one of (i) a capacitive coupling between the gate electrode and the semiconductor mesa and (ii) a conductivity of majority charge carriers of the drift zone is lower than outside of the separation region.