Self-Assembled In-Plane Gate Oxide-Based Homojunction Thin-Film Transistors

In-plane gate homojunction thin-film transistors (TFTs) with patterned channel are self-assembled on SiO₂-based solid electrolytes with only one nickel shadow mask. All indium-tin oxide channel and electrodes (source, drain, and gate) are deposited simultaneously by one-step magnetron sputtering, and no alignment is necessary. Such TFTs exhibited a good performance with a low operation voltage of 2.0 V, a large field-effect mobility of 28.7 cm²/V·s, a low subthreshold swing of 125 mV/decade, and a large on-off ratio of 1.3 × 10⁶, respectively. A two-serial-capacitor model for the low-voltage operation mechanism is proposed and discussed.