Preparation and Properties of High Capacitance Density and Low Loss Thin Film Capacitors

In this paper, thin film capacitors were prepared on 99.6% alumina substrate. The dielectric layer was Ta
2
O
5
, which was fabricated by anodic oxidation of tantalum. When the applied anodic oxidation voltage was 120V, the capacitance density was more than 960 pF/mm
²
, and the withstand voltage was more than 50V. The insertion loss was about 0.2dB in the frequency range of 10GHz~50GHz. The loss factor and quality factor of prepared thin film capacitors were better than ceramic chip capacitor that had the same capacitance value. The high capacitance density and low loss thin film capacitors demonstrated good prospects in microwave hybrid integrated circuits.