Measurement of Microwave Dielectric Properties of (Sr,Ba)Nb₂O₆ Thin Films

Abstract

(001) oriented (Sr,Ba)Nb₂O₆ (SBN) thin films were deposited on MgO (001) single crystal substrates by the pulsed laser deposition method. Structural properties of SBN films were investigated using X-ray diffractometer. The microwave dielectric properties of SBN films were examined by calculating the scattering parameter obtained using a HP 8510C vector network analyzer with the frequency range 0.5–20 GHz at room temperature under the dc bias field of 0–80 kV/cm for interdigital capacitors (IDT) and coplanar waveguide (CPW) device based on SBN/MgO layer structure. Thick metal electrode patterns were fabricated by dc sputtering deposition, photolithography and etching process. The IDT device based on (001) oriented SBN films exhibited about 40% capacitance tunability with an electric field change of 80 kV/cm at room temperature, and the dielectric quality factor was about 20 at 12 GHz with no dc bias.

Keywords:

• (Sr,Ba)Nb₂O₆ (SBN)
• interdigital capacitor (IDT)
• capacitance tunability
• dielectric quality factor

ACKNOWLEDGEMENTS

This work was supported by the Minster of Information and Communications Department of Korea.