Thin high-k dielectric Y2O3 and ZrO2 films were grown directly on Si by the pulsed laser deposition (PLD) technique. The interfacial layer formed between the Si and the deposited oxide film was characterized. Since this layer has a detrimental effect on the MOS capacitance of the films, an attempt to modify its characteristics was performed through UV-assisted low-temperature nitridation of the surface to create a barrier layer that suppresses Si diffusion through the interface. It was confirmed by structural characterization that this surface pretreatment results in a thinner interfacial layer. (C) 2002 Elsevier Science B.V. All rights reserved.