Transistor device, semiconductor package and method of fabricating a transistor device

A method of fabricating a transistor device, the method comprising

• providing a semiconductor substrate comprising a first conductivity type and a first major surface, a plurality of columnar field plate trenches extending into the first major surface, the columnar field trenches each comprising a field plate and a gate trench structure comprising an elongate gate trench having a length, the elongate gate trench extending into the first major surface of the semiconductor substrate and comprising a gate electrode;
• implanting dopants of a second conductivity type into the first major surface of the semiconductor substrate to form a body region in the semiconductor substrate, wherein the second conductivity type opposes the first conductivity type;
• in a first area of the first major surface only, implanting dopants of the second conductivity type into at least one subregion of the first major surface of the semiconductor substrate within the first area so that at least one of a depth and a doping level of the body region is increased in the at least one subregion and so that at least one of the depth and the doping level of the body region varies laterally within the first area;
• implanting dopants of the first conductivity type into the first major surface of the semiconductor substrate and forming a source region on the body region;
• and
• forming a metallization structure on the first major surface and that provides a contact pad for wire bonding vertically above the first area.