Role of electroless-Ni plating in high-aspect-ratio TSV fabrication for 3D integration and packaging

摘要

A feasibility study for the self-formed barrier cum seed Ni layer via electroless (EL) plating method for the low-cost, high-volume manufacturing of Si interposer containing high aspect-ratio through-silicon via (TSV) has been carried-out by optimizing the EL plating process parameters. The EL Ni plating bath was carefully adjusted in order to realize a conformal growth of Ni barrier cum seed layer along the high aspect-ratio TSV side wall. The reasonable resistance value of 36 mΩ per TSV with 10 μm-width and 100 μm-depth obtained from the Kelvin measurement of these Cu-TSV chain showed that as-formed EL Ni layer is as good as the conventionally formed seed layers for completely filling the high aspect ratio TSVs by Cu-electroplating.