The growth of carbon nanotubes on electrically conductive ZrN support layers for through-silicon vias

• Carbon nanotube bundles were grown on electrically conductive ZrN support layers.
• Aspect ratios of 30 were achieved.
• Low surface energy of ZrN likely the cause of good de-wetting of the catalyst
• Electrical measurements on CNT TSV were performed.
• First results of CNT TSV contacted on both sides by metal thin-films.

State-of-the-art Cu-based through-silicon vias (TSVs) suffer from filling difficulties and reliability concerns. Carbon nanotubes (CNTs) are an attractive alternative filler material for TSV due to their high aspect ratio, attractive mechanical and thermal properties and high current carrying capability. However, so far tall enough CNT could only be grown on electrically insulating layers, limiting their electrical applications. In this work we demonstrate and investigate the growth of CNT with aspect ratios up to 30 on electrically conductive ZrN layers. This was used to fabricate the first CNT TSV devices which are contacted on both sides of the bundle by metal thin-films, instead of probe needles, which were subsequently electrically characterised.

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