Volume and interfacial dielectric properties of Al/Ho2O3/Al thin-film capacitors

Experimental characteristics of the complex capacitance and dielectric permittivity for holmium oxide-based thin-film capacitors with different insulator thickness are presented and discussed. It is shown that volume of the insulator film is responsible for the dielectric properties of Al/Ho2O3/Al structures at high frequencies and low temperatures. In this range ε′=10.8. Near-electrode regions decide on the dielectric properties at low frequencies and high temperatures. High values of the apparent “dielectric permittivity” (∼100–750) have been observed in this range. Thickness of the barrier regions and concentration of traps have been determined.