Method for producing a connection structure and semiconductor device

A method of manufacturing a connection structure, wherein the method comprises:

• forming an opening in a first main surface of a first substrate;
• forming a galvanic seed layer over a first main surface of a carrier substrate;
• forming a first insulating connection layer over the first main surface of the first substrate and over sidewalls of the opening;
• applying a second connection layer over the galvanic seed layer,
• connecting the first substrate to the carrier substrate, such that the galvanic seed layer is arranged between the first main surface of the first substrate and the first main surface of the carrier substrate and the first main surface of the first substrate is arranged between a second main surface of the first substrate and the carrier substrate;
• wherein the galvanic seed layer is formed over the first main surface of the carrier substrate before the first substrate is connected to the carrier substrate;
• thinning the first substrate such that the opening in the first substrate is opened on the second main surface of the first substrate facing away from the carrier substrate;
• removing the second connection layer from the surface of the opening facing the carrier substrate after the first substrate and the carrier substrate have been joined together such that part of the galvanic seed layer is exposed,
• galvanically forming a conductive material over the galvanic seed layer;
• and
• removing the carrier substrate after the second main surface of the first substrate has been connected to the second semiconductor substrate, wherein after removing the carrier substrate portions of the second connection layer are arranged over portions of the first substrate adjacent to the conductive material.