Semiconductor device including a field stop region

A semiconductor device, comprising:

• an n-doped drift region arranged between a first surface and a second surface of a semiconductor body;
• a p-doped first region arranged at the second surface;
• an n-doped field stop region arranged between the n-doped drift region and the p-doped first region, wherein the n-doped field stop region comprises:
• a first sub-region and a second sub-region, wherein a p-n junction separates the p-doped first region and the first sub-region;
• and
• hydrogen related donors in the first sub-region and in the second sub-region,
• wherein a concentration of the hydrogen related donors, along a first vertical extent of the first sub-region, steadily increases from the pn-junction to a maximum value in the first sub-region, and steadily decreases from the maximum value in the first sub-region to a reference value at a first transition between the first sub-region to the second sub-region,
• wherein a second vertical extent of the second sub-region ends at a second transition to the n-doped drift region where the concentration of the hydrogen related donors equals 10% of the reference value,
• wherein a maximum value of a vertical gradient of a log-linear graph in which the ordinate is a non-linear logarithmic scale of the concentration of the hydrogen related donors and the abscissa is a linear scale of a depth along a vertical direction, is at least three times larger in the first sub-region than in the second sub-region, and
• wherein a ratio of the maximum value in the first sub-region to a maximum concentration value of the hydrogen related donors in the second sub-region ranges from 2 to 50.