Effect of Oxygen Pressure on the Electrical Properties of $\hbox {Bi}_{5} \hbox {Nb}_{3}\hbox {O}_{15}$ Films Grown by RF Magnetron Sputtering

Bi₅Nb₃O₁₅ (B₅N₃) films grown under a low oxygen partial pressure (OP) of 1.7 mtorr showed a high leakage current density of 0.1 A/cm² at 1.0 MV/cm. However, the leakage current density decreased with increasing OP to a minimum of 5.8 times 10^-9 A/cm² for the film grown under 5.1 mtorr due to the decreased number of oxygen vacancies. This film also showed an improved breakdown field of 2.2 MV/cm and a large capacitance density of 24.9 fF /mum². The electrical properties of the film, however, deteriorated with a further increase in OP, which is probably due to the formation of oxygen interstitial ions. Therefore, superior electrical properties for the B₅N₃ film can be obtained by careful control of OP.