Vertical oriented semiconductor device in which well regions are created in a semiconductor body, and a method of manufacturing the same

A vertical oriented semiconductor device comprising a semiconductor body having a first major surface, the semiconductor device comprising:

• a current-accommodating region of a first conductivity type, wherein the current-accommodating region is adjoining the first major surface;
• well regions of a second conductivity type, at or near the first major surface, the second conductivity type opposite to the first conductivity type, the well regions being laterally adjacent sides of the current-accommodating region, the well regions having a first depth into the semiconductor body;
• a substrate region provided at a second major surface vertically opposite to the first major surface, the substrate region being of the first conductivity type;
• wherein at least one of the well regions has:
• a first lateral doping gradient with a monotonic decreasing doping concentration, from a first higher doping concentration at a first lateral end of the well region towards a first lower doping concentration at a second, opposite lateral end thereof facing the current-accommodating region;
• and
• a second lateral doping gradient with a monotonic decreasing doping concentration, from a second higher doping concentration at the first lateral end of the well region towards a second lower doping concentration at the second opposite, lateral end thereof facing the current-accommodating region;
• wherein the second lateral doping gradient is deeper inside the semiconductor body compared to the first lateral doping gradient, and wherein the first lateral doping gradient differs from the second lateral doping gradient;
• wherein the current-accommodating region has a doping gradient in a depth direction so that a doping concentration increases with increasing depth.