Structural and electrical properties of Bi5 Nb3 O15 thin films for MIM capacitors with low processing temperatures

Bi5 Nb3 O15 (B5 N3) thin films were well formed on a Pt/Ti/ SiO2 /Si substrate using radio-frequency magnetron sputtering. The crystalline B5 N3 phase was developed for the films grown at temperatures above 450°C, but it decomposed into the BiNbO3 phase when the growth temperature exceeded 550°C, probably due to the evaporation of Bi2 O3. The dielectric constant (k) of the B5 N3 film grown at room temperature was approximately 42 and increased with increasing growth temperature, reaching a maximum value of 160 for the film grown at 550°C. In particular, the B5 N3 films grown in the temperature range of 200-300°C showed a high k value of 70 with a low dissipation factor (<1.0%), and their leakage current density was very low with a high breakdown voltage. Therefore, B5 N3 films grown at low temperatures (≤300°C) can be a good candidate material for metal-insulator-metal (MIM) capacitors which require low processing temperatures.