We investigated the microstructures and electrical properties of ZrO2 films
deposited by reactive dc magnetron sputtering on Si substrates for gate di
electrics applications. We observed that the refractive index value of the
ZrO2 films increased with an increase in deposition powers and annealing te
mperatures. The ZrO2 films deposited at elevated temperatures are polycryst
alline, and both the monoclinic and tetragonal phases exist in the films. F
ilms with higher density and improved crystallinity are obtained at higher
deposition temperatures. The interfacial oxide layer between ZrO2 films and
Si substrates grew upon annealing in the O-2 gas ambient, which is due to
the oxidation of Si substrates by the diffusion of oxidizing species from O
-2 gas ambient. The accumulation capacitance value increased upon annealing
in the N-2 gas ambient due to the densification of the films, while it dec
reased in O-2 gas ambient due to the growth of the interfacial oxide layer.
(C) 2001 American Vacuum Society.