Carbon nanotube complementary logic based on Erbium contacts and self-assembled high purity solution tubes

Complementary logic gates based on chemically assisted directed assembly of solution carbon nanotubes with a high semiconducting purity (~91%) are demonstrated. Air stable, high quality carbon nanotube NFETs have been fabricated with low work function Erbium contacts, enabling an inverter gain of > 7 from transistors with 50 nm channel lengths. The substantial device yields of both NFET (~31%) and PFET (~44%) on the same chip allow us to construct and test a large number of CNT complementary logic gates for the first time. > 11% inverter yield from over 400 circuits tested along with fully functional NAND2 gates show promise of our fabrication scheme. This study points out several key directions for further yield enhancement, in which increasing the successful rate of CNT deposition into the trench plays a major role.