Almost perfectly symmetric SWCNT-based CMOS devices and scaling.

Symmetric n- and p-type field-effect transistors (FETs) have been fabricated on the same undoped single-walled carbon nanotube (SWCNT). The polarity of the FET is defined by controlled injection of electrons (n-type, via Sc electrodes) or holes (p-type, via Pd electrodes) into the SWCNT, instead of via chemically doping the SWCNT. The SWCNT-based FETs with different channel lengths show a clear trend of performance improvement for channel length scaling. Taking full advantage of the perfect symmetric band structure of the semiconductor SWCNT, a perfect SWCNT-based CMOS inverter is demonstrated, which gives a voltage gain of over 160, and for the two adjacent n- and p-type FETs fabricated on the same SWCNT, high field mobility is realized simultaneously for electrons (3000 cm(2)/V.s) and holes (3300 cm(2)/V.s).