A semiconductor device having trenches and method for manufacturing a semiconductor device

A semiconductor body (1001) includes a first transistor cell (110) having a first gate electrode (122) in a first trench (120). The semiconductor device (1001) further includes a second transistor cell (130) having a second gate electrode (142) in a second trench (140), said first and second gate electrodes (122, 142) are electrically connected. The semiconductor device further includes a third trench (160) between the first and second trenches (120, 140), said third trench (160) deeper into a semiconductor body (105) from a first side (107) of the semiconductor body (105) as the first and second trenches (120, 140). The semiconductor device (1001) further comprises a dielectric (165) in the third trench (160) having a bottom side and walls of the third trench (160) covered.