Gate-commuted thyristor cell with a base region having a varying thickness

A power semiconductor device comprising a gate-commutated thyristor cell, a first main side and a second main side opposite to the first main side,

• wherein the gate-commutated thyristor cell comprises in an order from the first main side to the second main side:
• -a cathode electrode arranged on the first main side,
• a cathode region of a first conductivity type,
• a base layer of a second conductivity type different than the first conductivity type forming a first junction to the cathode region,
• a drift layer of the first conductivity type forming a second junction with the base layer,
• an anode layer of the second conductivity type, and
• an anode electrode arranged on the second main side,
• wherein the gate-commutated thyristor cell further comprises a gate electrode which is arranged lateral to the cathode region,
• wherein the base layer comprises:
• -a cathode base region located between the cathode region and the drift layer and having a first depth,
• a gate base region located between the gate electrode and the drift layer and having a second depth, and
• an intermediate base region located between the cathode base region and the gate base region and having at least two different values of a third depth, wherein the at least two values of the third depth are both larger than the first depth and smaller than the second depth,
• wherein a maximum doping concentration of the gate base region is higher than a maximum doping concentration of the intermediate base region,
• wherein the maximum doping concentration of the intermediate base region is higher than a maximum doping concentration of the cathode base region, and
• wherein a part of the second junction, which is located between the intermediate base region and the drift layer, includes a first base transition region forming a step and a second base transition region forming another step.