Improved growth and electrical properties of atomic-layer-deposited metal-oxide film by discrete feeding method of metal precursor

Abstract

A new model for the growth behavior of saturated HfO2 films by atomic layer deposition (ALD) was suggested. The well-known ALD saturation of the growth rate with increasing precursor input was observed, but the full saturation required an extremely long feeding time. After the rapid increase in growth rate with increasing precursor feeding time, a pseudo-saturation region was observed where full saturation was hindered by the screening effect of the physisorbed precursor molecules or byproduct molecules on the chemisorbed species. The physisorbed precursor molecules screen the active adsorption sites for the following precursor. The discrete feeding method, which is the modified process recipe suggested in this study, provided improved growth behavior and electrical properties of the film. © 2011 American Chemical Society.