Atomic layer deposition of SrTiO3 thin films from a novel strontium precursor-strontium-bis(tri-isopropylcyclopentadienyl)

Strontium titanate thin films were grown by atomic layer deposition (ALD) a t 250-325 degreesC from the novel strontium compound, strontium bis(tri-iso propyl cyclopentadienyl), titanium tetraisopropoxide, and water. Though com pletely self-limiting,. deposition of strontium could not be achieved becau se of some minor decomposition of the strontium compound. This decompositio n was slow enough to ensure that good control of film stoichiometry was obt ained by controlling either the (Sr-O)/(Ti-O) pulsing ratio, or the stronti um precursor exposure time. The films were polycrystalline and strongly ori ented in the (100) direction. After annealing at 500 degreesC in air, the f ilms with the optimal composition were found to have measured permittivity values of around 180.