Method for producing a through semiconductor via connection

Abstract

The disclosed technology relates to methods for producing an interconnect structure on the back side of an integrated circuit chip. According to a first aspect, a via opening is etched in a top semiconductor layer, and filled with a sacrificial material, thereby forming a sacrificial pillar. Then front and back end of line portions are processed and the substrate is thinned. The etch stop layer and the sacrificial pillar are removed, and replaced an electrically conductive material forming a through semiconductor via. According to a second aspect, the sacrificial pillar is etched through the opening of a trench that intersects the pillar. Filling the trench with a conductive material also fills the cavity created by etching back the pillar resulting in an integral conductive pad and interconnect rail structure. The pillar can be removed and replaced by a conductive material, thereby creating the TSV connection.