A systematical investigation of layer growth rate, impurity level and morphology evolution in TiO2 thin films grown by ALD between 100 and 300 °C

TiO2 thin films prepared by atomic layer deposition (ALD) have attracted great attention due to the widespread application of the oxide as a promising charge storage material for lithium or proton batteries. In this work, we study TiO2 film grown on Si substrates by atomic layer deposition with tetrakis (dimethylamino) titanium as metal precursor (TDMAT) and water vapour as an oxidant. The chemical composition and impurity content of the film as a function of growth temperature is studied by Ion Beam Analysis (IBA). D2O (99.8%) was used as oxidant to study the film growth to distinguish between hydrogen atoms originating from the water oxidant or the metal precursor. Combining ellipsometry with Rutherford Backscattering Spectrometry (RBS), Nuclear Reaction Analysis (NRA) and Elastic Recoil Detection Analysis (ERDA) reveals film density as a function of growth temperature. Atomic force microscopy (AFM) was used to characterize the film surface structure. By investigating the structural and compositional range of ALD TiO2 films will open the new opportunities of application. In this work, we study TiO2 film grown on Si substrates and bare Cu by atomic layer deposition with tetrakis (dimethylamino) titanium as metal precursor and water vapour as oxidant. The chemical composition and impurity content of the film as a function of growth temperature is studied by Ion Beam Analysis (IBA). D2O (99.8%) was used as oxidant to study the film growth to distinguish between hydrogen atoms originating from the water oxidant or the metal precursor. Combining ellipsometry with RBS, NRA, and ERDA reveals the film density as a function of growth temperature. Atomic force microscopy (AFM) was used to characterize the film surface structure.According to the composition and structure study, we here deposited ALD TiO2 films on the copper as a function of deposition temperature, the Tafel polarization and electrochemical impedance spectroscopy (EIS) were used to study the anti-corrosion properties of ALD TiO2 film coated on the copper in the 3.5% (0.6 M) NaCl solution. We proposed the H atoms in the TiO2 films (100 °C) and the rough structure (225 and 300 °C) determine the corrosion behaviors. [Display omitted] •We explored the impurity content and in particular the carbon, nitrogen and hydrogen areal density in ALD TiO2 film.•Isotope labelling confirmed that the vast majority of H atoms originated from the metal precursor.•The H atoms in the TiO2 films (100 °C) could alleviate t