LASER ANNEALING OF SRTIO3 THIN-FILMS DEPOSITED DIRECTLY ON SI SUBSTRATES AT LOW-TEMPERATURE

SrTiO3 films sputter deposited directly on a Si substrate at 200-degrees-C were annealed at a scanning cw Ar laser beam at a substrate temperature of 200-degrees-C. The laser annealing improved the crystallinity of the SrTiO3 films and minimized the formation of a SiO2 layer between SrTiO3 and Si. These results are confirmed by x-ray diffraction analysis and secondary ion mass spectrometry. The dielectric constant of the SrTiO3 films increased monotonically with laser power up to 1.2 W. The dielectric constant was improved from the as-grown value of 26-118 for a 160-nm-thick SrTiO3 film annealed at a 1.2 W laser power. At 1.0 W laser power, the annealed dielectric constant varied from 55 to 101 with increasing film thickness from 110 to 3 80 nm. From the film thickness dependence constant, it is shown that the intrinsic dielectric constant for the SrTiO3 films is about 150.