Dielectric Properties of Bismuth-Zinc-Niobium Thin Films for Embedded Capacitor

摘要

Dielectric properties of bismuth-zinc-niobium oxide (Bi1.5Zn1.0Nb1.5O7, BZN) thin films deposited by by RF magnetron sputtering have been investigated for embedded capacitor. Crystalline BZN has a pyrochlore structure in nature and shows a dielectric constant of～200 with very low leakage current when crystallized. Since the process temperature is limited to < 200?E due to an organic based substrate in printed circuit board, as-deposited BZN film was composed of an amorphous phase, confirmed by XRD analysis. However, it showed remarkably high dielectric constant of 113. It makes BZN to be a proper candidate as a decoupling embedded capacitor in power delivery circuits. Effects of post treatment such as oxygen plasma treatment and low temperature thermal annealing on dielectric properties of BZN thin films were studied. By optimizing deposition conditions, amorphous BZN thin film was well processed in the current printed circuit board (PCB) process and provided a capacitance density as high as 218 nF/cm~2 and leakage current less than 1 iA/§~2 at 3V.