In this letter, we reported a high-k gadolinium oxide (Gd2O3) gate dielectric formed by reactive rf sputtering. It is found that the Gd2O3 gate dielectric film exhibits excellent electrical properties such as low leakage current density, high breakdown voltage, and almost no hysteresis and frequency dispersion in C-V curves comparable to that of HfO2 film. This indicates that postprocessing treatments can reduce a large amount of interface trap and can passivate a large amount of trapped charge at defect sites.

We report on the physical properties and electrical characteristics of Y 2 O 3 gate oxides grown on silicon substrates with NH 3 plasma treatment by reactive radio-frequency sputtering. The interfacial chemistry of the high-k gate dielectric Y 2 O 3 has been investigated on nitrided and un-nitrided Si using X-ray photoelectron spectroscopy. We found that the Y 2 O 3 gate film having NH 3 -based interface layer is very effective in reducing equivalent oxide thickness and leakage current as well as improving film qualities. This NH 3 -nitrided layer is suggested to minimize interfacial YSi x O y formation by limiting the amount of Si available to interact with the Y 2 O 3 layer. These Y 2 O 3 gate dielectrics exhibit excellent frequency dependence and weak temperature dependence of leakage current. They also show negligible charge trapping at high electric field stress.

Optical, electrical, and structural characteristics of yttrium oxide films deposited on plasma etched silicon substrates J.The structural properties and electrical characteristics of thin Nd 2 O 3 gate oxides were deposited on silicon substrates by reactive rf sputtering. The structural and morphological features of these films were studied, as a function of the growth conditions ͑three various argon-to-oxygen flow ratios: 20/ 5, 15/ 10, and 12.5/ 12.5 and temperature from 600 to 800°C͒, by x-ray diffraction, atomic force microscopy, and x-ray photoelectron spectroscopy. It is found that Nd 2 O 3 dielectrics with a 12.5/ 12.5 ratio condition annealed at 700°C exhibit a thinner capacitance equivalent thickness and excellent electrical properties, including the electric breakdown field, the interface trap density, the hysteresis, and frequency dispersion in the capacitance-voltage curves. This condition is suggested to the reduction of the interfacial SiO 2 and silicate formation, and the small of surface roughness due to the optimization of oxygen in the metal oxide film.

This paper describes the physical properties and electrical characteristics of thin Y 2 O 3 gate oxides grown on silicon substrates through reactive radiofrequency (RF) sputtering. The structural and morphological features of these films were studied using X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy. We found that the Y 2 O 3 gate film prepared under an argon-to-oxygen flow ratio of 25:5 and annealed at 700°C exhibited a reduced equivalent oxide thickness, gate leakage current, interfacial density of states, and hysteresis voltage; it also showed an increased breakdown voltage. We attribute this behavior to (1) the optimum oxygen content in the metal oxide film preventing amorphous silica or silicate from forming at the Y 2 O 3 /Si interface and (2) the low surface roughness. These materials also exhibit negligible degrees of charge trapping at high electric field stress.

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