This paper describes the structural properties and electrical characteristics of thin Ho 2 O 3 gate dielectrics deposited on silicon substrates by means of reactive sputtering. The structural and morphological features of these films after postdeposition annealing were studied by X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy. It is found that Ho 2 O 3 dielectrics annealed at 700°C exhibit a thinner capacitance equivalent thickness and excellent electrical properties, including the interface trap density and the hysteresis in the capacitance–voltage curves. Under constant current stress, the Weibull slope of the charge-to-breakdown of the 700°C-annealed films is about 1.7. These results are attributed to the formation of well-crystallized Ho 2 O 3 structure and the reduction of the interfacial SiO 2 layer.