Static dielectric constant of Al nanocrystal/Al2O3 nanocomposite thin films determined by the capacitance-voltage reconstruction technique

Abstract

Al nanocrystal (nc-Al)/Al2O3 nanocomposite thin films were synthesized by radio-frequency magnetron sputtering. The static dielectric constant (εr) of the nanocomposite thin films was determined by the capacitance-voltage reconstruction technique which was able to correct for the influence of high current conduction in the thin films. In contrast to pure Al2O3, the nanocomposite has a much higher εr and its εr exhibits strong temperature dependence also. The higher εr is attributed to the dipole effect of the Al–O dangling bonds due to the presence of nc-Al in the Al2O3 matrix. However, the dipole effect degrades at a higher temperature, which explains the observed decrease in εr with increasing temperature.