Contact resistance of low-temperature carbon nanotube vertical interconnects

The electrical contact resistance and length dependant resistance of vertically aligned carbon nanotubes (CNT) grown at 500 °C with high tube density (10
¹¹
cm
^-2
) are investigated by measuring samples with different CNT lengths. Cross-sectional imaging revealed that the CNT tips are well embedded over a length of several hundred nm. The determined contact resistance of 18 kΩ is low, which is attributed to a combination of CNT tip embedding and tip growth mechanism. When the CNT mean free path determined by Raman spectroscopy is compared with that obtained from the electrical measurements, it shows that multiple walls are conducting in parallel per CNT.