Polycrystalline HfO 2 thin film capacitors were prepared by anodizing sputter-deposited Hf films, and their capacitor and leakage current properties were studied. Electrical measurements were performed for the parallel-plate Hf anodized capacitors with an Al-HfO 2 -Hf (metal-insulator-metal) structure, and high capacitance density (0.6 "F/cm 2 ) and low dielectric loss (0.0095) were obtained for a very thin-oxide capacitor anodized at 10 V. In addition, the leakage current density of this capacitor was about 5 Â 10 À9 A/cm 2 at an applied voltage of 5 V. The leakage current density (J) of HfO 2 capacitors as a function of applied electric field (E) was investigated for several capacitors with different oxide thicknesses, by plotting lnðJÞ vs E 1=2 curves. As a result, it was revealed that the conduction mechanism is due to Schottky emission, irrespective of the oxide thickness.

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Microcrystalline ZrO2 and HfO2 thin film capacitors were prepared by anodizing sputter-deposited Zr and Hf films. The thermal degradation behavior of both anodized capacitors was clarified by the measurement of their capacitance properties and Auger depth profiles before and after heat treatment in air. As a result, it is confirmed that the heat-resistance property of the HfO2 anodized capacitor is superior to that of the ZrO2 capacitor. In addition, it is revealed that the thermal degradation of the ZrO2 anodized capacitor is caused by the diffusion of Zr atoms from the underlying layer into the ZrO2 anodized layer, while that of the HfO2 anodized capacitor is caused by the diffusion of oxygen atoms from the anodized layer into the underlying Hf layer.