Silicon-carbide transistor device with a shielded gate

A SiC transistor device, comprising:

• a silicon-carbide semiconductor substrate having a plurality of first doped regions laterally spaced apart from one another and beneath a main surface of the substrate, a second doped region extending from the main surface to a third doped region that is above the first doped regions, and a plurality of fourth doped regions in the substrate extending from the main surface to the first doped regions, the second doped region having a first conductivity type, the first, third and fourth doped regions having a second conductivity type opposite the first conductivity type;
• a gate trench extending through the second and third doped regions, the gate trench having sidewalls, a bottom and rounded corners between the bottom and the sidewalls, and
• wherein a doping concentration of the first doped region increases with increasing distance from the main surface such that the doping concentration of the first doped region is higher at a bottom of the first doped region than at a top of the first doped region.