Carbon Nanotube Transistor Arrays for Multistage Complementary Logic and Ring Oscillators

This work demonstrates multistage complementary NOR, OR, NAND, and AND logic gates and ring oscillators (frequency ∼220 Hz) with arrays of p- and n-type nanotube field effect transistors (FETs). The demonstration is made possible by progress in three aspects of nanotube synthesis and integration. First, patterned growth leads to large numbers of nanotube FETs in an array, as up to 70% of individual nanotubes are semiconductors. Second, metal electrodes are successfully embedded underneath nanotubes and used as local gates. Third, complementary logic gates are made possible by converting p-type FETs in an array into n-type FETs by a local electrical manipulation and doping approach.