Insulating Block in a Semiconductor Trench

A method of producing a semiconductor device, the method comprising:

• providing a semiconductor body having a front side;
• forming a mask on the front side;
• creating at least one opening in the mask, the opening exposing the front side;
• creating, underneath the at least one opening, at least one trench extending into the semiconductor body, the trench having at least one side wall and a trench bottom;
• laterally recessing the mask from a rim of the trench by a distance;
• depositing an insulating layer that covers the mask, a part of the front side of the semiconductor body where the mask has been laterally recessed, the trench bottom, and the at least one side wall;
• depositing a spacer layer on the insulating layer, the spacer layer comprising a first electrode material;
• removing the spacer layer from at least a portion of the insulating layer that covers the trench bottom;
• filling at least a portion of the trench with an insulating material;
• removing only a part of the insulating material that is laterally confined by the spacer layer so as to leave an insulating block in the trench;
• and
• filling at least a portion of the trench with a second electrode material so as to form an electrode within the trench.

A semiconductor device, comprising:

• a semiconductor body having a front side and a back side;
• and
• a trench included in the semiconductor body, the trench extending into the semiconductor body along an extension direction that points from the front side to the back side, wherein the trench comprises an electrode structure and an insulation structure, the insulation structure insulating the electrode structure from the semiconductor body and the electrode structure being arranged for receiving an electric signal from external of the semiconductor device,
• wherein the electrode structure includes a first electrode and a second electrode in contact with the first electrode, the first electrode comprising a first electrode material and the second electrode comprising a second electrode material different from the first electrode material,
• wherein the first electrode extends further along the extension direction as compared to the second electrode.