Nanoscale Research Letters · 2013 · 67 citations · 12 references
EngineeringElectrical EngineeringMaterials ScienceElectronic MaterialsSemiconductor MaterialsThin FilmsMetal-oxide-semiconductor Field-effect TransistorsOxide SemiconductorsSemiconductor Device MaterialsSemiconductor Thin FilmsThin Film Electrical PropertiesThin-film TransistorsAmorphous Indium Gallium Zinc OxideGate DielectricsOxygen VacanciesSemiconductor Oxide Thin FilmsSubthreshold SwingThin Oxide FilmsThreshold VoltageVoltage Stress Reliability
In this letter, we investigated the structural and electrical characteristics of high-κ Er2O3 and Er2TiO5 gate dielectrics on the amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) devices. Compared with the Er2O3 dielectric, the a-IGZO TFT device incorporating an Er2TiO5 gate dielectric exhibited a low threshold voltage of 0.39 V, a high field-effect mobility of 8.8 cm2/Vs, a small subthreshold swing of 143 mV/decade, and a high Ion/Ioff current ratio of 4.23 × 107, presumably because of the reduction in the oxygen vacancies and the formation of the smooth surface roughness as a result of the incorporation of Ti into the Er2TiO5 film. Furthermore, the reliability of voltage stress can be improved using an Er2TiO5 gate dielectric.
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