Self-aligned 40 nm channel carbon nanotube field-effect transistors with subthreshold swings down to 70mV/decade

Abstract

The fabrication of highly scaled single-walled carbon nanotube (SWNT) field effect transistors (FET) and the performance limit of carbon nanotube FETs was investigated. Fabrication of SWNT FETs was performed with patterned chemical vapor deposition (CVD) of nanotubes on SiO2(thickness ∼ 500 nm)/Si substrates. Nearly ballistic p-channel SWNT FETs were fabricated with 40 nm channel lengths, self aligned source (S), drain (D) and gate electrodes, palladium S and D contacts with low contact resistance and HfO2 high-k dielectric gas insulators. It was also found that using Pd S/D contacts, SWNTs with d similar to 1.5 nm can afford high performance FETs with high ON/OFF ratios without large compromise on Imax.