US Patent 10186587 Power semiconductor device

A power semiconductor device has a semiconductor body configured to conduct a load current in parallel to an extension direction between first and second load terminals of the power semiconductor device. The semiconductor body includes a doped contact region electrically connected to the second load terminal, a doped drift region having a dopant concentration that is smaller than a dopant concentration of the contact region, and an epitaxially grown doped transition region separated from the second load terminal by the contact region and that couples the contact region to the drift region. An upper subregion of the transition region is in contact with the drift region, and a lower subregion of the transition region is in contact with the contact region. The transition region has a dopant concentration of at least 0.5*1015 cm−3 for at least 5% of the total extension of the transition region in the extension direction.