N-type doping of carbon nanotube transistors using yttrium oxide (Y2Ox)

Abstract

We present a novel, VLSI compatible technique to fabricate n-type carbon nanotube (CNT) transistors using yttrium oxide as gate dielectric. Wafer-scale, aligned CNT transistors with yttrium oxide (Y₂O_x) dielectrics exhibit n-type behavior with I_on/I_off of 10⁶ and subthreshold slope of 95 mV/dec. Controlled, slow evaporation of yttrium (Y) forms a smooth oxide surface that has excellent wetting to CNTs which consistently gives rise to strong n-type behavior in CNT transistors.