Nonvolatile memory properties in ZnO-based thin-film transistors with polymer ferroelectric and thin buffer layer

We report the fabrication of ZnO non-volatile memory thin-film transistors (NVM-TFTs) with thin poly(vinylidene fluoride/trifluoroethylene)[P(VDF-TrFE)] ferroelectric layer and thin Al₂O₃ buffer layers. When our memory TFT has a thin Al₂O₃ layer inserted between P(VDF-TrFE) and ZnO channel: 5 nm, 10 nm and 20 nm. Our NVM-TFT operates on glass substrates under low voltage write-erase (WR-ER) pulse of ±20 V with high field effect mobilities of 0.6-1 cm²/Vs. The device with the Al₂O₃ layer shows much longer retention properties over 10⁴ s than the other without buffer. Depending on the thickness of buffer, our NVMTFT displays maximum memory window of ~20 V and also exhibits WR-ER current ratio of 4×10².