Structural and optical characterization of c-axis textured BaTiO3 thin films on MgO fabricated by RF magnetron sputtering

In this paper, BaTiO3 thin films were prepared by RF magnetron sputtering on MgO substrates and their properties such as the crystal structure and optical waveguide properties were investigated. The optimum deposition parameters, such as substrate temperature, deposition pressure, gas flow ratio, the RF power and the after annealing temperature, were obtained in order to get the best BaTiO3 film quality. The XRD results show that highly c-axis textured BaTiO3 thin films were successfully grown on MgO substrate. Films obtained under the optimum deposition parameters, substrate temperature of 650A degrees C, RF power of 50 W, deposition pressure 18 mTorr and gas flow ratio O-2/(Ar+ O-2) of 15% namely, reaches a full width at half maximum intensity (FWHM) of BaTiO3 (002) XRD peak of 0.25A degrees. The FWHM of BaTiO3 (002) XRD peak was further reduced to 0.24A degrees via post-treatment with furnace annealing (at 800A degrees C for 2 h) which indicates the film crystal quality is further improved. The bright and sharp TE modes measured by m-line spectroscopy of the BaTiO3 film were observed indicating its possible application in optical waveguide.