High frequency characteristics of mim capacitors with nanostructured anodic oxide dielectrics

MIM capacitors have been prepared with three types of nanostructured thin film dielectrics made of anodic oxides of Al (99,99 %), AlSi (1 %) alloy and Al (99,99 %)/Ta metal bilayer. High breakdown voltages, low leakage currents and dielectric losses have been achieved. A weak dispersion of dielectric constant, from 7,3 to 6,7, and the features of temperature and frequency dependencies of dielectric losses in the range of 10³ to 3 10⁸ Hz are the signature of ion-relaxation polarization with the characteristic times ranging 10^-4 to 10^-5 depending on the dielectric type. The nanostructured oxide dielectrics are promising for radio frequency applications.