Formation and Evaluation of Electroless-Plated Barrier Films for High-Aspect-Ratio Through-Si Vias

Abstract

Listen

Translate article

The formation of a diffusion barrier layer in a through-Si via (TSV) has been studied with a combination of nanoparticle catalyst and electroless plating (ELP). We used Au-nanoparticles (Au-NPs) or Pd-nanoparticles (Pd-NPs) as catalysts for ELP of Ni- and Co-alloy barrier layers. We studied deposition of Ni–B and Co–B films in high-aspect-ratio (AR) TSV. Then, we succeeded in controlling the deposition profile of Ni–B in a high-AR TSV by the addition of bis(3-sulfopropyl)-disulfide (SPS). SPS turned out to be an inhibitor of electroless plating of Ni–B. On the other hand, the Co–B film was deposited conformally without additive. The electrical resistivity of Cu after annealing Cu/barrier stacked structure suggests that Co–B has better thermal stability than Ni–B.