Dielectric properties of zirconium oxide grown by atomic layer deposition from iodide precursor

ZrO2 films were grown from ZrI4 and H2O-H2O2 on p-Si(100) substrates using the atomic layer deposition technique. The influence of deposition conditions on the dielectric properties of ZrO2 films was investigated. The breakdown field exceeded 2 MV/cm in the films grown at 325-500 degreesC. The relative permittivity measured at 10 kHz was 20-24 in the films deposited at 275-325 degreesC. The dissipation factor of these films was as low as 0.02-0.03. The relative permittivity decreased to 7 and the dissipation factor increased to 0.6 when the growth temperature was raised to 450-500 degreesC. Variation of the measurement frequency from 1 to 100 kHz had only a slight influence on the permittivity values. Hysteresis of the capacitance-voltage curves indicated that a considerable amount of deep levels at the oxide-semiconductor interface and/or in the oxide were recharged under dc bias. The density of rechargeable states increased with the deposition temperature, and the recharging mechanism also depended on the substrate temperature used for the ZrO2 growth. (C) 2001 The Electrochemical Society.