Layer by layer deposition of zirconium oxide onto silicon

Zirconium oxide films have been produced by sequential adsorption of diluted zirconium alkoxide solutions onto a silicon wafer. After 100 deposition cycles, the film thickness increases quasi linearly with the alkoxide concentration. However, the film density decreases. Analysis of these results demonstrates that the amount of zirconium grafted at each cycle follows a Freundlich-type adsorption law, characterizing a disordered adsorption with condensation between adsorbates. Although an average monolayer can be adsorbed at each cycle, it is not dense. The resulting films are highly homogeneous and remain amorphous up to 600 °C. Despite of the low film density, the static dielectric constant measured at 1 kHz in capacitance-voltage geometry is around 15 for the films heat-treated at 300 °C in air as compared to 22 for the bulk ZrO2.