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

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 (Y
2
O
x
) dielectrics exhibit n-type behavior with I
on
/I
off
of 10
⁶
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.