Effect of Contact Improvement on the FET Characteristics of an Individual Single Walled Carbon Nanotube

Abstract

We report that the enhancement in the contact resistance after pulse annealing using the electric‐current‐induced joule heating in Pd electrode make an effect on the field effect transistor (FET) characteristics consisted of an individual single walled carbon nanotube (SWNT). The SWNTs are deposited onto Pd electrode patterned on SiO2/Si substrate, through which the electrical currents flow for microseconds to achieve a low contact resistance by meting the Pd electrode for an instant. Here, the transport measurement was performed to an identical SWNT before and after the pulse annealing at various temperatures from room temperature to 4K. From the results, a decrease of barrier height was observed after applying the pulse annealing, but much smaller than the value estimated from an increase of source/drain current. Therefore, we suggest that the enhancement in the contact resistance after the pulse annealing results from an increase of the effective contact length, causing a higher transmission probability, rather than a decrease of the barrier height between SWNT and metal electrode.