Preparation and characterization of Ba(ZrxTi1?x)O3 thin films for high-frequency applications

Ba(ZrxTi1−x)O3 (BZT) thin films were deposited on a (100)MgO substrate by RF-magnetron reactive sputtering using metal targets. In this paper, a model of the reactive sputtering process using a metal composite target at different reactive gas flow rates is presented. 500-nm-thick BZT thin (x = 0.26) films for high frequency performance showed a single perovskite phase and a high crystallinity on the MgO substrate with only a (001)/(100) orientation at an optimum reactive gas flow rate in Ar + O2. The BZT films had a stoichiometric Ba/Ti ratio and epitaxially grew on the MgO substrate. They showed a dense microstructure without cracks or voids. Their low capacitance and loss tangent showed little dispersion at 1–18 GHz. These results indicated that we succeeded in depositing high-quality and potentially tunable ferroelectric BZT films for high-frequency applications by RF-magnetron reactive sputtering using metal targets.