Enhancing the retention properties of ZnO memory transistor by modifying the channel/ferroelectric polymer interface

We report on the fabrication of ZnO nonvolatile memory thin-film transistors (NVM-TFTs) with thin poly(vinylidene fluoride/trifluoroethylene) [P(VDF-TrFE)] ferroelectric layer. Our NVM-TFT operates on glass substrates under low voltage write-erase (WR-ER) pulse of ±20 V with a maximum field effect mobility of ∼1 cm2/V s, maximum memory window of ∼20 V, and WR-ER current ratio of 4×102. When the NVM-TFT has a modified channel/ferroelectric interface with an inserted thin Al2O3 buffer layer, our device shows long retention time of more than 104 s, which is much enhanced compared to that of the other device without the buffer. The dynamic response of our devices with or without the buffer was clear enough to distinguish the WR and ER states as performed with 300 ms pulse.