Nonvolatile Memory Performances of Transparent and/or Flexible Memory Thin-Film Transistors Using IGZO Channel and ZnO Charge-Trap Layers

We proposed a transparent and/or flexible charge-trap-type memory thin film transistors (CTM-TFTs) with a top-gate structure composed of zinc-oxide (ZnO) charge-trap and In-Ga-Zn-O (IGZO) active channel layers. The memory on/off ratio higher than 7-orders-of magnitude was obtained for the fully transparent CTM-TFTs fabricated on glass substrates when the width and amplitude of program pulses were set as 500 ns and +/- 20 V, respectively. The nonvolatile memory behaviors was successfully confirmed for the memory window to be as wide as 25.8 V. Furthermore, the highly stable memory performance was also guaranteed even under the light illumination conditions using various wavelength in the visible range. The memory operations of the flexible CTM-TFTs prepared on plastic polyethylene naphthalate substrates will also be discussed at presentation.