Effect of diffusion coating of Nd on the corrosion resistance of biodegradable Mg implants in simulated physiological electrolyte.

Sm2O3 gate dielectric on Si substrate

The authors report on the direct integration of high-dielectric constant (high-k) Ta2O5 films on p-type single crystal diamond for high-power electronic devices. Crystallized hexagonal phase δ-Ta2O5 film is achieved on diamond by annealing the amorphous Ta2O5 film deposited by a sputter-deposition technique. The electrical properties of the Ta2O5 thin films are investigated by fabricating metal-insulator-semiconductor (MIS) diodes. The leakage current of the MIS diode is as low as 10−8 A/cm2 for the as-deposited amorphous Ta2O5 film and 10−2 A/cm2 for the crystallized film, which is 108 and 102 times lower than that of the Schottky diode at a forward bias of −3 V, respectively. The dielectric constant of the amorphous Ta2O5 films is measured to be 16 and increases to 29 after annealing at 800  °C. Different current leakage mechanisms and charge trapping behaviors are proposed for the amorphous and crystallized Ta2O5 thin films.

Integration of high-dielectric constant Ta2O5 oxides on diamond for power devices

The effects of Ta incorporation in Y2O3 gate dielectric on the electrical characteristics of InGaZnO thin-film transistor are investigated. With an appropriate Ta content in the Y2O3 gate dielectric, the saturation mobility of the thin-film transistor can be significantly increased, about three times that of the control sample with Y2O3 gate dielectric. Accordingly, the sample with a Ta/Ta+Y ratio of 68.6% presents a high saturation mobility of 33.5 cm2 V−1 s−1, low threshold voltage of 2.0 V, large on/off current ratio of 2.8 × 107, and suppressed hysteresis. This can be attributed to the fact that the Ta incorporation can suppress the hygroscopicity of Y2O3 and thus reduces the Y2O3/InGaZnO interface roughness and also the traps at/near the interface, as supported by atomic force microscopy and low-frequency noise measurement, respectively. However, excessive Ta incorporation in the Y2O3 gate dielectric leads to degradation in device performance because Ta-related defects are generated.

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Effects of Ta incorporation in Y2O3 gate dielectric of InGaZnO thin-film transistor

Lanthanide rare earth oxide thin film as an alternative gate oxide

The high-k Ta2O5 films deposited on the polycrystalline silicon treated with different postrapid thermal annealing temperatures were formed as high-k interdielectrics. Physical and electrical characteristics of the Ta2O5 dielectrics were investigated with x-ray diffraction, x-ray photoelectron spectroscopy, atomic force microscopy, and electrical analysis. The annealing at 800 °C was found to be the optimal condition to reduce the defects and interface traps existed in the interface between the Ta2O5 dielectric and polysilicon to fabricate a well-crystallized film with higher breakdown field, lower leakage current and smaller charge trapping rate. This Ta2O5 dielectric shows promise for future generation of nonvolatile memory.

Kung Shao Chen

Papers

Physical and electrical characteristics of the high-k Ta2O5 "tantalum pentoxide… dielectric deposited on the polycrystalline silicon

Physical and electrical characteristics of the high-k Nd2O3 polyoxide deposited on polycrystalline silicon