Effect of Co-Reactants on Interfacial Oxidation in Atomic Layer Deposition of Oxides on Metal Surfaces.

We have examined the atomic layer deposition (ALD) of AlO using TMA as the precursor and -BuOH and HO as the co-reactants, focusing on the effects of the latter on both the ALD process and the possible modification of the underlying substrate. We employed a quartz crystal microbalance (QCM) to monitor ALD and in real time, and the deposited thin films have been characterized using X-ray photoelectron spectroscopy, spectroscopic ellipsometry, X-ray reflectivity, and atomic force microscopy. Growth of thin films of AlO using TMA and either -BuOH or HO as the co-reactant at = 285 °C produces thin films of similar physical properties (density, stoichiometry, minimal carbon incorporation), and the growth rate per cycle is similar for the two co-reactants at this temperature.