High aspect ratio TSVs fabricated by magnetic self-assembly of gold-coated nickel wires

Three-dimensional (3D) integration is an emerging technology that vertically interconnects stacked dies of electronics and/or MEMS-based transducers using through silicon vias (TSVs). TSVs enable the realization of devices with shorter signal lengths, smaller packages and lower parasitic capacitances, which can result in higher performance and lower costs of the system. In this paper we demonstrate a new manufacturing technology for high-aspect ratio (>;8) through silicon metal vias using magnetic self-assembly of gold-coated nickel rods inside etched through-silicon-via holes. The presented TSV fabrication technique enables through-wafer vias with high aspect ratios and superior electrical characteristics. This technique eliminates common issues in TSV fabrication using conventional approaches, such as the metal deposition and via insulation and hence it has the potential to reduce significantly the production costs of high-aspect ratio state-of-the-art TSVs for e.g. interposer, MEMS and RF applications.