A semiconductor device is produced by: creating an opening in a mask formed on a semiconductor body; creating, underneath the opening, a trench in the semiconductor body which has a side wall and a trench bottom; creating, while the mask is on the semiconductor body, an insulating layer covering the trench bottom and the side wall; depositing a spacer layer including a first electrode material on the insulating layer; 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 the part of the insulating material 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.