MANOS performance dependence on ALD Al2O3 oxidation source

The electrical and chemical properties of atomic layer deposited (ALD) Al2O3 layers and their dependence on the oxygen source (water or oxygen plasma) are examined. Oxygen plasma ALD leads to Al2O3 layers with lower hydrogen contamination. The alumina layers were used as control oxides in MANOS (metal-alumina-nitride-oxide-silicon) memory capacitors. Memory functionality was observed only after post deposition annealing (PDA) performed in inert ambient at 850°C for 15min. No significant differences in electrical properties and memory performance were observed between the ANO stacks with Al2O3 layers formed by water or oxygen plasma ALD. This unexpected result is discussed with respect to the additional hydrogen contamination introduced during the post-ALD processing steps. Display Omitted Al2O3 layers were formed by ALD using H2O and oxygen plasma as oxidation agent.Al2O3 layers were used as blocking oxides in charge trapping memory capacitors.As-deposited stacks suffer from strong gate electron induced leakage current.Post-deposition annealing delivers functional memory stacks.Hydrogen contamination depends both on oxidation agent and thermal processes.