Benchmarking of Metal-to-Carbon Nanotube Side Contact Resistance

We report on side-contact resistances of four promising metal/multiwall-carbon-nanotube contacts utilizing transfer length method (TLM) test structures on densified carbon nanotube (CNT) strips formed from vertically-aligned CNT forests. Contact resistances of Ti/CNT, Pd/CNT, Ta/CNT, and W/CNT contacts with the same nominal contact area were extracted to be 40, 49, 108, and 160 Ω, respectively. Rapid thermal annealing at 400 °C for 5 min reduces the Ta/CNT and W/CNT contact resistances while increasing the Ti/CNT and Pd/CNT ones.