Processing Effect on Via Extrusion for TSVs in Three-Dimensional Interconnects: A Comparative Study

A comparative study has been performed to investigate the processing effects on via extrusion for through-silicon vias (TSVs) in 3-D integration. This paper is focused on three TSV structures with identical geometry but different processing conditions. The thermomechanical behavior, microstructure, via extrusion, and additives incorporated during electroplating are examined by various techniques, including the electron backscatter diffraction and the time-of-flight secondary ion mass spectroscopy. By comparing the stress, material, and via extrusion behaviors of the TSV structures, the effect of processing conditions, particularly electroplating and postplating annealing, on via extrusion are discussed.