Influence of reactive surface groups on the deposition of oxides thin film by atomic layer deposition

- Polar groups of CO has a strongly contribution to facilitate initial ALD growth.
- Surface roughness able to evaluate the ALD normal growth on the polymer substrate.
- The Al2O3 ALD layer can be a buffer layer as pre-treatment-like to provide OH groups.
- Ligand number in precursor molecules affect the resulted water compatible functional OH groups.

In this study, polyethylene terephthalate (PET) substrate was successfully coated Al2O3 and TiO2 films by atomic layer deposition (ALD). The experiment results demonstrate that the Al2O3 can be deposited more efficiently than TiO2 on PET substrates. Further characterization on the coated substrates reveals that the density of hydroxyl OH groups play a significant role on the growth of the oxides ALD film. Chemical composition of the coated substrates is characterized by X-ray photoelectron spectroscopy, which shows that the CO elements are replaced by the Al - related elements in the Al2O3 - coated PET and the Ti - related elements in the TiO2 - coated PET. The results demonstrate that the CO has a strongly contribution to facilitate the initial ALD growth of the oxides thin films.