Mesa contact for MOS controlled power semiconductor device

A power semiconductor device, comprising:

• a first load terminal at a first side, a second load terminal, and a semiconductor body coupled to the first load terminal and the second load terminal and configured to conduct a load current between the first load terminal and the second load terminal;
• a plurality of trenches at the first side and extending into the semiconductor body along a vertical direction, wherein each trench of the plurality of trenches includes a trench electrode insulated from the semiconductor body by a trench insulator, wherein two of the plurality of trenches are arranged laterally adjacent to each other and spatially confine a mesa portion;
• a first insulation layer formed above each trench electrode of the plurality of trenches;
• a semiconductor source region in the mesa portion;
• a semiconductor body region in the mesa portion;
• a contact plug extending from the first side into the mesa portion, wherein the contact plug is arranged:
• in contact with both the semiconductor source region and the semiconductor body region;
• in contact with the trench insulator of one of the two trenches that spatially confine the mesa portion;
• and
• spaced apart from the trench insulator of the other one of the two trenches that spatially confine the mesa portion,
• wherein both trenches that spatially confine the mesa portion are control trenches and the trench electrodes of both trenches that spatially confine the mesa portion are control electrodes insulated from the first load terminal and configured to control the load current in the mesa portion,
• wherein at least one of the two trenches that spatially confine the mesa portion is a multi-trench-electrode trench, and
• wherein an extension of overlap of the contact plug with the first insulation layer on a first side of the contact plug is different than an extension of overlap of the contact plug with the first insulation layer on a second, opposite side of the contact plug.