Growth and characterization of ultrathin zirconia dielectrics grown by ultraviolet ozone oxidation

In this letter, we report on the growth of ultrathin films of zirconia on s ilicon oxide and silicon oxynitride passivated (001) Si by ultraviolet ozon e oxidation of Zr metal precursor layers. The oxidation kinetics has been m easured using an accelerator-based nuclear reaction analysis. It was found that oxide films up to 55 Angstrom could be grown at room temperature by ox idation at 600 Torr while oxidation at 80 mTorr is self-limiting at 20 Angs trom. The interfaces between the dielectric and the substrate have been cha racterized by scanning transmission electron microscopy. The ZrO2 films wer e found to be crystalline as grown. Electrical measurements on capacitor st ructures with 30-Angstrom -thick ZrO2 films grown on native oxide on silico n show a capacitance-voltage hysteresis of 15 mV and a capacitance-based eq uivalent oxide thickness of 17 Angstrom at 100 kHz. (C) 2001 American Insti tute of Physics.