A Magnetic Czochralski semiconductor wafer having opposing first and second sides arranged distant from one another in a first vertical direction is treated by implanting first particles into the semiconductor wafer via the second side to form crystal defects in the semiconductor wafer. The crystal defects have a maximum defect concentration at a first depth. The semiconductor wafer is heated in a first thermal process to form radiation induced donors. Implantation energy and dose are chosen such that the semiconductor wafer has, after the first thermal process, an n-doped semiconductor region arranged between the second side and first depth, and the n-doped semiconductor region has, in the first vertical direction, a local maximum of a net doping concentration between the first depth and second side and a local minimum of the net doping concentration between the first depth and first maximum.