Preparation and characterization of BaTiO₃ thin films on MgO-buffered Si(100) substrates by RF sputtering

We report the results of a study on the deposition and characterization of partially oriented BaTiO₃ thin films on MgO-buffered Si(100) by radio-frequency magnetron sputtering. The structural and morphological characteristics of the MgO buffer layer were investigated as a function of substrate temperature. The x-ray θ-2θ, Φ scans, and observation of surface morphology revealed that MgO grew with a tendency of (001) orientation. Partially (00l) or (h00) textured BaTiO₃ thin films were obtained on Si(100) with the MgO buffer layer while randomly oriented BaTiO₃ thin films with large-scale cracks on the surface were made without the MgO layer. Pt/BaTiO₃/Pt multistructures were formed on Si(100), MgO/Si(100), and MgO(100) single crystal substrates to conduct preliminary electrical measurements for metal-insulator-metal type capacitor. Comparison of the crystallographic orientation, morphology, and electrical properties between the BaTiO₃ films on Si(100) with and without the MgO buffer layer supported the favorable role of the MgO layer as a buffer for the growth of BaTiO₃ films on Si(100).