We have investigated the physical and dielectric properties of the Zr-silicate interfacial layer of ZrO2 metal-insulator-semiconductor (MIS) structure fabricated by pulsed-laser ablation deposition. It was found that an ultrathin Zr-silicate interfacial layer is formed on a Si substrate as a result of the reaction between ZrO2 and Si. We showed that MIS capacitors consisting solely of the ultrathin Zr-silicate interfacial layer could be fabricated by selective etching of the ZrO2 layer. The Zr-silicate interfacial layer showed a small equivalent oxide thickness of 0.8 nm, a dielectric constant of 8-9, and low leakage less than 1 A/cm(2) at V-g of -1 V. (C) 2002 American Institute of Physics.