Highly conformal and adhesive electroless barrier and Cu seed formation using nanoparticle catalyst for realizing a high aspect ratio cu-filled TSV

A conformal diffusion barrier was formed in a high aspect ratio through-silicon via (TSV) using electroless plating. Dense adsorption of Pd nanoparticle catalyst on SiO₂ assisted the formation of a thin electroless CoWB layer, on which an electroless Cu seed layer could be deposited. The adhesion strength of the CoWB layer was improved with addition of adequate amount of saccharine and conformal deposition property was obtained with addition of SPS.