フレキシブル基板上に形成した酸化亜鉛薄膜トランジスタの曲げ耐性評価

抄録

We report the fabrication and characterization of zinc oxide (ZnO) thin-film transistors (TFTs) on flexible cyclo-olefin polymer (COP) substrates. The bending durability and the rupture mechanisms for the fabricated devices were also investigated. For two-terminal devices and TFTs, the electrical resistance increased sharply at a radius of curvature of about 7 mm, suggesting that stretching deformation occurred in the ZnO film due to fracture of the underlying SiO₂ buffer layer. However, it was found that this problem could be avoided by considering the surface strain and reducing the thickness of the substrate. Using a 25-µm-thick COP substrate, a flexible device could be fabricated that functioned at a curvature radius of less than 5 mm. Such flexible oxide-based electronic devices are promising for use as wearable biological sensors and other advanced sensing applications.