Reactive magnetron sputtering from a composite target for large area BaPbO3 thin film electrode

Radio frequency reactive magnetron sputtering from a composite target made of PbO pellets uniformly positioned on a metallic Ba disc has been utilized for BaPbO₃ electrode deposition on 150 mm Si wafers. The reactive sputtering process has been analyzed in relation to sputtering parameters for composite targets with different percentage of PbO coverage. The process optimization method for in situ crystallized BaPbO₃ thin film fabrication has been emphasized. The growth of BaPbO₃ films has been discussed from the viewpoint of the BaO-PbO phase diagram and thermodynamics of Ba_n + 1Pb_nO_3n + 1 (n = 1, 2, ∞) phase formation. The microstructure analysis of the deposited films has been performed with atomic force microscopy and wide-angle X-ray diffraction (XRD) techniques. The grazing angle XRD measurements reveal the formation of a Ba₂PbO₄ phase in the film fabricated at 450 °C. The Ba₂PbO₄ phase content decreases with decreasing substrate temperature. The BaPbO₃ film deposited at a substrate temperature of 430 °C on naturally oxidized (001) Si wafers shows an electrical resistivity of 1.13 mΩ·cm. The BaPbO₃ films deposited on SiO₂ (native oxide)/Si wafer do not exhibit a preferred orientation whereas use of (111) Pt/SiO₂/Si substrate results in highly (111)-oriented films.