Realization of a high capacitance density in Bi2Mg2∕3Nb4∕3O7 pyrochlore thin films deposited directly on polymer substrates for embedded capacitor applications

Bi 2 Mg 2 ∕ 3 Nb 4 ∕ 3 O 7 (BMN) thin films were deposited on copper clad laminate substrates at temperatures below 150°C for embedded capacitor applications by pulsed laser deposition. The BMN films deposited at temperatures below 150°C showed smooth surface morphologies having root mean square roughness of approximately 3.0nm. 130-nm-thick films deposited at 150°C exhibit a dielectric constant of 47, a capacitance density of approximately 302nF∕cm2, and breakdown strength of 0.7MV∕cm. The origin exhibiting high dielectric constant in BMN films deposited at low temperatures was attributed to the nanocrystallines having grain sizes of approximately 4.0nm in the films. The low temperature processed-BMN films are suitable candidate for capacitor applications embodied directly on printed circuit board substrates.