Gate Work Function Engineering for Nanotube-Based Circuits

The impact of different work function metal gates on the performance of individual nanotube transistors and ultimately an entire nano-circuit is presented. The use of an Al-gate, in the case of a carbon nanotube device, translates directly into a threshold-voltage shift relative to a Pd-gated FET, corresponding to the work function difference between the two metal gates. In this way, a CMOS-type 5-stage ring oscillator on an individual carbon nanotube, is realized without the use of dopants.