Carbon nanotube via interconnect technologies: Size-classified catalyst nanoparticles and low-resistance ohmic contact formation

We propose a new approach to fabricating carbon nanotube (CNT) via interconnects for future LSIs, which uses preformed catalyst nanoparticles to grow the CNTs. A newly designed impactor provided size-classified catalyst particles. For the new approach, we employ a TiN contact layer which is more resistant to oxidation and enables us to form a lower resistance ohmic contact between CNTs and wiring layers. The resultant CNT-via resistance was 0.59 Ω for 2-μm vias, which is the smallest ever reported. We also study the CNT nucleation process using molecular dynamics and discuss how to remove amorphous carbon from the nucleation process.