Chemical surface passivation of HfO₂films in a ZnO nanowire transistor

The effects of different annealing atmospheres on the chemical surface structure of HfO 2 gate dielectric layers have been evaluated in terms of the improvement in the transconductance ( g m ), current on/off ratio ( I on / I off ), and carrier mobility (μ e ) of a back-gated ZnO nanowire field-effect transistor (FET). Compared to O 2 and N 2 annealed HfO 2 -gated transistors, the H 2 annealed HfO 2 -gated ZnO nanowire FET exhibited a higher transconductance of 1.77 × 10 −7 A V −1 , on/off current ratio of ∼1.2 × 10 4 , and electron mobility of 11.90 cm 2 V −1 s −1 .