Microstructure and Electrical Properties of Amorphous $\hbox {Bi}_{5}\hbox {Nb}_{3}\hbox {O}_{15}$ Films Grown on Cu/Ti/ $\hbox {SiO}_{2}$

Amorphous Bi₅Nb₃O₁₅ (BNO) films were grown at room temperature (RT) on a Cu/Ti/SiO₂ /Si substrate using radio frequency magnetron sputtering. All the films were well formed on the Cu electrode with a sharp interface between the film and the electrode. The dielectric constant of the amorphous BNO film grown under 25 W was 46, with a low dissipation factor of 2.7% at 100 kHz. This film exhibited a low leakage current density of 5.5 × 10^-8 A/cm² at 4.5 V and a large breakdown voltage of 7.2 V. However, the electrical properties deteriorated as the sputtering power and the growth temperature increased due to the increased surface roughness; this was because a film with a rough surface generally has a larger surface area, and there can be electric field intensification at surface asperity, which degrade the electrical properties of the film. In addition, the electrical properties were not influenced by the oxygen partial pressure (OPP) because the variation of OPP during the growth of the films did not affect their surface roughness. The amorphous BNO film grown on the Cu/Ti/SiO₂/Si substrate at RT under 25 W may be a good candidate material for an embedded capacitor.