Characterization of Nonvolatile Memory Behaviors of Al/Poly(vinylidene fluoride-trifluoroethylene)/Al2O3/ZnO Thin-Film Transistors

Abstract

The combination of a ferroelectric polymer and an oxide semiconductor is a very promising solution to realize embeddable nonvolatile memory thin-film transistors (TFTs) for novel electronic devices. Memory TFTs with a gate structure of Al/80 nm-poly(vinylidene fluoride-trifluoroethylene)[P(VDF-TrFE)]/4nm Al2O3/5nm ZnO were fabricated and their programming characteristics were investigated. Good performances in memory and transistor behaviors were successfully confirmed. When the voltage pulses of +/- 15 V and 990 ms were employed, a memory on/off ratio of 4400 was obtained. It was found that the initial memory on/off ratio was closely related to the applied programming conditions such as pulse amplitude and width of programming voltage signals. Retention behaviors were also sensitively affected by the programming conditions. The initial memory on/off ratio of approximately 300 decreased to 3.4 after a lapse of 10(4) s when the programming voltage, pulse duration, and gate bias during the retention period were set to be +/- 18 V, 500 ms, and open, respectively. (C) 2010 The Japan Society of Applied Physics