Eco-Friendly, Water-Induced In2O3 Thin Films for High-Performance Thin-Film Transistors and Inverters

Li Zhu,Gang He,Bing Yang,Yuting Long,Jianguo Lv

doi:10.1109/ted.2018.2824336

Abstract

Solution-driven metal–oxide semiconductors have recently received much attention as a viable option for low-cost, flexible electronic devices. In this paper, a simple, environmentally friendly aqueous solution method has been adopted to deposit an ultrathin In 2 O 3 semiconductor layer with a thickness of about 7 nm at low temperature. Then, in combination with the advantages of atomic layer deposition (ALD) technology, an ultrathin aluminum oxide dielectric layer of about 20 nm was prepared to fabricate high-performance In 2 O 3 /Al 2 O 3 thin-film transistor (TFT) devices. The device with optimized annealing temperature of 280 °C has demonstrated an excellent electrical performance, including a high saturation mobility of 11.85 cm 2 · V −1 · s −1 , a large ON/OFF current ratio of 10 6 , a low threshold voltage of 0.12 V, a small hysteresis voltage of 0.05 V, and a small density of interface state of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textsf {1.97} \times \textsf {10}^{\textsf {12}}$ </tex-math></inline-formula> cm −2 , respectively. To demonstrate the potential of In 2 O 3 /AlO x TFT toward more complex logic applications, the unipolar inverter was further constructed and exhibited a high gain of 5. Importantly, all these device parameters were obtained at an ultralow operating voltage of 2.5 V. As a result, it can be inferred that the water-induced In 2 O 3 TFTs based on ALD-derived Al 2 O 3 dielectrics have a potential application as a promising alternative for low-cost, low-power consumption, and large-area environmentally friendly oxide flexible electronics.

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