Mesa Contact for a Power Semiconductor Device and Method of Producing a Power Semiconductor Device

A method of producing a power semiconductor device that includes, in a semiconductor body, a drift region of a first conductivity type, a plurality of trenches, wherein two adjacent trenches laterally confine a mesa of the semiconductor body, wherein each trench extends from a semiconductor body surface into the semiconductor body along a vertical direction and comprises a trench electrode isolated from the semiconductor body by a trench insulator, wherein each trench has a trench width along a first lateral direction and a trench length along a second lateral direction perpendicular to the first lateral direction, the trench length amounting to at least five times the trench width, and a semiconductor body region of a second conductivity type in the mesa, the method comprising:

• forming a source region of the first conductivity type in the mesa, the source region being arranged above the semiconductor body region;
• forming an insulation layer above and/or on the source region;
• providing a mask, wherein the mask includes at least one mask bridge covering a first portion of the source region and at least one mask opening exposing second portions of the source region in the mesa and below the insulation layer, wherein the first portion of the source region separates two adjacent ones of second portions of the source region along the second lateral direction in the mesa;
• in a region exposed by the at least one mask opening, removing a portion of the insulation layer and the second portions of the source region such that the remaining first portion of the source region forms an elevated source bridge between the two adjacent trenches in the mesa;
• depositing an electrically conductive material for forming a contact plug that extends at least from an upper surface of the insulation layer along the vertical direction so as to contact the first portion of the source region at a sidewall portion thereof.