The invention relates to a bipolar non-punch-through power semiconductor device and a corresponding manufacturing method. The device comprises a semiconductor wafer and a first electrode formed on a first main side of the wafer and a second electrode formed on a second main side of the wafer opposite the first main side. The wafer comprises a pair of layers of different conductivity types, such as a drift layer of a first conductivity type, and a first layer of a second conductivity type arranged on the drift layer towards the first main side and contacting the first electrode.The wafer comprises an inner region wand an outer region surrounding the inner region. The drift layer has a thickness in the inner region greater or equal than a thickness in the outer region. A thickness of the first layer increases in a transition region between the inner region and the outer region from a thickness in the inner region to a maximum thickness in the outer region. The thickness of the first layer increases linearly over the transition region with a width of the transition region greater than 5 times a thickness of the first section of the first layer.