Process and material for preventing deleterious expansion of high aspect ratio copper filled through silicon vias (tsvs)

Abstract

Techniques are disclosed for forming through-silicon vias (TSVs) implementing a negative thermal expansion (NTE) material such as zirconium tungstate (ZrWO) or hafnium tungstate (HfWO). In some cases, the NTE material is disposed between the substrate and conductive core material of the TSV and serves to offset, at least in part, the coefficient of thermal expansion (CTE) mismatch there between, thus reducing heat-induced stresses and/or protrusion (pumping) of the conductive core material. The NTE material also may protect against leakage, voltage breakdown, and/or diffusion of the conductive core material. Furthermore, the NTE material may reduce radial stresses in high-aspect-ratio TSVs. In some cases, techniques disclosed herein may improve TSV reliability, enhance three-dimensional integration, and/or enhance performance in three-dimensional integrated circuits and/or other three-dimensional packages. Other embodiments which can employ techniques described herein will be apparent in light of this disclosure.