Atomic layer deposition of aluminum oxide films on graphene

Seed-layer approach was studied to initiate atomic layer deposition (ALD) of Al₂O₃ films on graphene. Low-temperature ALD and electron beam evaporation (EBE) were applied for seed-layer preparation before deposition of the dielectric at 200 °C using trimethyl-aluminum and water or ozone as precursors. To characterize nucleation of the films and possible influence of the ALD processes on the quality of graphene, properties of graphene and Al₂O₃ films were investigated by Raman spectroscopy, X-ray fluorescence and X-ray photoelectron spectroscopy methods. The results suggest that seed layer formation by low-temperature ALD was more efficient in the O₃-based process than in the H₂O-based one while EBE seed layer provided fastest growth of Al₂O₃ together with minimum incubation period