Stretchable Polymer Gate Dielectric by UV-assisted Hafnium Oxide Doping at Low Temperature for High-performance Indium Gallium Tin Oxide Transistors.

Author(s) Hur, J.Seok; Kim, J.Oh; Kim, H.A.; Jeong, J.Kyeong
Journal ACS Appl Mater Interfaces
Date Published 2019 May 24

This letter reports the fabrication of indium gallium tin oxide (IGTO) thin-film transistors (TFTs) with 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 the 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-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. These TFTs 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 cm/V⸱s, a threshold voltage of -0.2 V, a subthreshold gate swing of 0.4 V/decade, and an I ratio > 10 even at a low annealing temperature of 150 °C. In addition, the intrinsic stretchability of the hybrid dielectric film was examined on the PDMS substrate, confirming the mechanical durability under stretching cycles with less than 10% strain.

DOI 10.1021/acsami.9b02935
ISSN 1944-8252
Citation ACS Appl Mater Interfaces. 2019.

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