High frequency response of amorphous tantalum oxide thin films

Amorphous tantalum oxide films were deposited using a pulsed dc reactive magnetron sputtering technique at low temperature (/spl les/200/spl deg/C). A test vehicle (metal-insulator-metal structure) was designed and fabricated for the high frequency characterization of the dielectric thin film. The dielectric constant and loss tangent of the amorphous tantalum oxide thin film were measured using dc, time domain reflectometry (TDR), and network analyzer up to 10 GHz. The measured dielectric constant and loss tangent was 22 and 0.007, respectively from 1 KHz to 10 GHz. The high frequency properties of the amorphous tantalum oxide thin film show little dispersion up to 10 GHz. However, the resonance oscillation due to the parasitics is evident between 10 GHz and 40 GHz and depends on the capacitor area. Modeling of the equivalent circuits would allow us to identify the parasitic components and their effects on the measured scattering parameters.