Influences of different oxidants on characteristics of La₂O₃/Al₂O₃ nanolaminates deposited by atomic layer deposition

A comparative study of two kinds of oxidants (H₂O and O₃) with the combination of two metal precursors (TMA and La(ⁱPrCp)₃) for atomic layer deposition (ALD) La₂O₃/Al₂O₃ nanolaminates is carried out. The effects of different oxidants on the physical properties and electrical characteristics of La₂O₃/Al₂O₃ nanolaminates are studied. Initial testing results indicate that La₂O₃/Al₂O₃ nanolaminates could avoid moisture absorption in the air after thermal annealing. However, moisture absorption occurs in H₂O-based La₂O₃/Al₂O₃ nanolaminates due to the residue hydroxyl/hydrogen groups during annealing. As a result, roughness enhancement, band offset variation, low dielectric constant and poor electrical characteristics are measured because the properties of H₂O-based La₂O₃/Al₂O₃ nanolaminates are deteriorated. Addition thermal annealing effects on the properties of O₃-based La₂O₃/Al₂O₃ nanolaminates indicate that O₃ is a more appropriate oxidant to deposit La₂O₃/Al₂O₃ nanolaminates for electron devices application.