Development of Structure-Property Relationships in Disordered Zirconia Thin Films for High Energy Density Mim Capacitors

Amorphous zirconium oxide thin films were prepared by reactive magnetron sputtering. The dielectric films were characterized by impedance spectroscopy with temperature. The effect of annealing on capacitor performance was studied. Annealing gold electroded thin films at 250°C greatly reduced the losses with little changes in crystallinity. Space charge relaxation started to appear at 190°C. The activation energy for the relaxation was 0.84 eV with a very low relaxation frequency at room temperature (0.23μHz). Electrode effects dominated at very low frequencies at all temperatures. AC conductivity followed the universality behavior for the AC charge transport showing that the films are highly disordered. No DC conductivity regime was observed indicating that DC conductivity is very low. DC conductivity of the films was of the order of 10−13 S/m, which is lesser than the comparable thickness high quality gate oxides.