Fabrication of STO buffer films on MgO substrates by the MOD method

We fabricated SrTiO₃ (STO) thin films, which are expected to be used as buffer layers on MgO substrates, by the metal-organic decomposition (MOD) method, and evaluated the properties of the films. By introducing a 2-step heat treatment and optimizing the precursor temperature, we could improve the full width at half maximum (FWHM) values of the rocking curves up to 1.81 deg in the X-ray diffraction (XRD) measurements of the STO films on MgO substrates. The minimum FWMH value of the in-plane rocking curves of the films was 2.60 deg and the films had a cube-on-cube structure on the MgO substrates. Furthermore, the root mean square (rms) roughness values of the surfaces of the STO thin films derived from atomic force microscopy (AFM) were 2.11–5.37 nm.