The influence of ions and photons during plasma-assited ALD of metal oxides

The influence of oxygen ions and photons during remote plasma atomic layer deposition (ALD) of metal oxide thin films was investigated for pressures of 0.5-3 Pa and plasma powers of 100-500 W. Ions have kinetic energies of ~15-35 eV and fluxes of ~10^13-10^14 cm^-2 s^-1 towards the substrate surface. The ion energy is low enough to prevent substantial ion-induced film damage, however the total energy flux provided to the substrate is sufficiently large to potentially stimulate the ALD surface reactions, e.g., through ligand desorption and adatom migration. Furthermore, it is demonstrated that the presence of VUV photons with energies of ~9.5 eV can deteriorate the electrical performance of electronic structures with ALD synthesized metal oxide films