Transformation of the Crystalline Structure of an ALD TiO2 Film on a Ru Electrode by O3 Pretreatment

The influence of the thin RuO 2 surface layer, formed by oxidation of a Ru electrode using O 3 (250°C for 15 s), on the phase formation and dielectric properties of TiO 2 thin films grown by atomic layer deposition (ALD) is investigated. TiO 2 films grown on the as-received Ru electrode (no O 3 pretreatment) have an anatase structure and the dielectric constant is ∼30. However, the crystalline structure of the TiO 2 film grown on an O 3 pretreated Ru electrode is rutile, and the dielectric constant is >60. This is attributed to a structural compatibility between rutile TiO 2 and RuO 2 .