Solution-processed high-k magnesium oxide dielectrics for low-voltage oxide thin-film transistors

TitleSolution-processed high-k magnesium oxide dielectrics for low-voltage oxide thin-film transistors
Publication TypeJournal Article
Year of Publication2016
Authorsb c Jiang G a, b c Liu A a, b c Liu G a, b c Zhu C a, b c Meng Y a, Shin B d, Fortunato E e, Martins R e, b c Shan F a
JournalApplied Physics Letters
KeywordsAnnealing temperatures, Atomic force microscopy, Dielectric films, Dielectric materials, Electrical measurement, Gate dielectrics, High dielectric constants, High-k dielectric, Insulating properties, Low-power consumption, Magnesia, Metal oxide thin films, Metals, Oxide films, Oxide thin-film transistors, Thermogravimetric analysis, Thin film circuits, Thin film transistors, Thin films, Thin-film transistor (TFTs), X ray diffraction, X ray photoelectron spectroscopy

Solution-processed metal-oxide thin films with high dielectric constants (k) have been extensively studied for low-cost and high-performance thin-film transistors (TFTs). In this report, MgO dielectric films were fabricated using the spin-coating method. The MgO dielectric films annealed at various temperatures (300, 400, 500, and 600 °C) were characterized by using thermogravimetric analysis, optical spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and atomic-force microscopy. The electrical measurements indicate that the insulating properties of MgO thin films are improved with an increase in annealing temperature. In order to clarify the potential application of MgO thin films as gate dielectrics in TFTs, solution-derived In2O3 channel layers were separately fabricated on various MgO dielectric layers. The optimized In2O3/MgO TFT exhibited an electron mobility of 5.48 cm2/V s, an on/off current ratio of 107, and a subthreshold swing of 0.33 V/dec at a low operation voltage of 6 V. This work represents a great step toward the development of portable and low-power consumption electronics. © 2016 Author(s).