Carbon nanotubes for interconnects in future integrated circuits: The challenge of the density

A CVD process with a high density of CNTs has been developed on doped silicon material thanks to plasma pre-treatment of the catalyst. With this process small diameter double and triple wall CNTs with an average diameter of 3.8 nm have been grown. The density of the best materials on blanket substrate is larger than 1012 cm− 2. These materials have been successfully integrated in via holes with a diameter ranging between 1 µm and 0.3 µm with an equivalent density. In 140 nm hole diameter large 70 nm bundle formations have been observed. In these bundles a density of CNT walls close to 1013 cm− 2 has been estimated.