CORRELATION BETWEEN FOURIER-TRANSFORM-INFRARED (FTIR) SPECTRA AND TEMPERATURE-DEPENDENCE OF DIELECTRIC-PROPERTIES OF SRTIO3 THIN-FILMS

SrTiO3 (STO) thin films were grown on (111)Pt/(100)MgO substrates at several deposition temperatures T(D) (350-710-degrees-C) and characterized. Deposition temperatures T(D) greater-than-or-equal-to 540-degrees-C yielded epitaxial (100)STO films but they strongly affected both the optical and dielectric properties of films. The LO (longitudinal optical phonon) absorption spectra and partial derivative epsilon/partial derivative T (temperature coefficient of the dielectric constant) showed similar dependence on T(D), and optimization was achieved at T(D) = 665-degrees-C. However, the highest value of the room temperature epsilon( = 313epsilon0, where epsilon0 is the vacuum dielectric costant) was obtained from the film grown at T(D) = 540-degrees-C.