This paper reports the fabrication of indium gallium tin oxide (IGTO) thin-film transistors (TFTs) with ultraviolet (UV)-treated PVP-co-PMMA-based hybrid gate insulators at an extremely low temperature (≤150 °C). Synergetic hafnia loading and UV treatment were used to tailor the mechanical softness and hydroxyl fraction in the polymer dielectric film. The UV-treated hybrid dielectric film had a low hydroxyl concentration, a smoother surface, and a denser packing nature, which can be explained by the high ionicity of hafnium oxide and photon-assisted improvement in the cohesion between organic and inorganic materials. Suitability of the UV-treated hybrid dielectric film as a gate insulator was evaluated by fabricating bottom gate TFTs with sputtered IGTO films as a channel layer, which showed high carrier mobility at a low temperature. The resulting IGTO TFTs with a UV-treated hybrid gate insulator exhibited a remarkable high field-effect mobility of 25.9 cm2/(V s), a threshold voltage of −0.2 V, a subthreshold gate swing of 0.4 V/decade, and an I ON/OFF ratio of >107 even at a low annealing temperature of 150 °C. The fabricated IGTO TFTs with the UV-treated hybrid dielectric film on the plastic substrate were shown to withstand the 100 times mechanical bending stress even under an extremely small curvature radius of 1 mm due to the intrinsic stretchability of the hybrid dielectric film.

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Stretchable electronic devices should be enabled by the smart design of materials and architectures because their commercialization is limited by the tradeoff between stretchability and electrical performance limits. In this study, thin‐film transistors are fabricated using strategies that combine the unit process of a novel hybrid gate insulator and low‐temperature indium gallium tin oxide (IGTO) channel layer and a stress‐relief substrate structure. Novel hybrid dielectric films are synthesized and their molecular structural configurations are analyzed. These films consist of a polymer [poly(4‐vinylphenol‐co‐methylmethacrylate)], cross‐linkers having different binding structures [1,6‐bis(trimethoxysilyl)hexane (BTMSH), dodecyltrimethoxysilane, and poly(melamine‐co‐formaldehyde)], and an inorganic zirconia component (ZrOx). The hybrid film with BTMSH cross‐linker and 0.2 M ZrOx exhibits excellent insulating properties as well as mechanical stretchability. IGTO transistors fabricated on polyimide‐coated glass substrates are transferred to the rubber substrate to offer stretchability of the transistor pixelated thin‐film transistors. IGTO transistors fabricated on stretchable substrates using these strategies show promising electrical performance and mechanical durability. After 200 stretchability test cycles under uniaxial elongation of approximately 300%, the IGTO transistor still retains a high carrier mobility of 21.7 cm2 V−1 s−1, a low sub‐threshold gate swing of 0.68 V decade−1 and a high ION/OFF ratio of 2.0 × 107.

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We report the growth behavior of oxide nanostructures according to physical properties such as work function, electrical and thermal conductivities, and roughness for high resolution nanostructure fabrication. Among these factors, threshold voltages, in particular, which induced the formation of a water meniscus and driving voltage, which drive oxyanions for oxidation, decreased as the mobility of electrons increased by the increasing electrical conductivity. Oxide growth increased as the diffusion of OH radical increased by the increasing conductivity of thermal energy. The high electrical and thermal conductivities imply that the reaction of the OH radical and surface was more easily activated over a wide reaction region ͑in the parallel direction of substrate͒ by the conductivity of the generated thermal energy at a low driving voltage. On the basis of these conductivity effects, the Cr film, which is the most sensitive to electron transport and conductivities, had hill-shaped nanostructures and could be applied as a candidate for high-speed atomic force microscope lithography at the lowest driving voltage. In addition, Ta and Ti, which are less sensitive, can be used to fabricate nanostructures with a high aspect ratio ͑spike shape͒.