In one embodiment, a wafer includes a number of die areas each including a semiconductor device and dedicated to become a separate die. The die areas are disposed on a first face of the wafer and wherein adjacent die areas are distanced from one another. A first trench and a second trench are formed on the first face between adjacent die areas. The first trench and the second trench are spaced apart from one another by a ridge. A third trench is disposed above the ridge on a second face of the wafer.