Channel/ferroelectric interface modification in ZnO non-volatile memory TFT with P(VDF-TrFE) polymer

Abstract

We report on the fabrication of ZnO non-volatile memory thin-film transistors (NVM-TFTs) with 200 nm-thick poly(vinylidene fluoride/trifluoroethylene)[P(VDF-TrFE)] ferroelectric layer. The NVM-TFTs have been tested for the most optimum properties in respect of their memory windows and memory retention properties, as prepared with the modified channel/ferroelectric interfaces inserted by respective thin buffer layers: 1, 3, 5, 10, and 20 nm-thin Al2O3, or 1 nm-thin inorganic-organic hybrid dielectrics of a AlOx-(or TiOx-) self assembled monolayer (SAM). All our NVM-TFTs operated on glass substrates under the low-voltage WR-ER pulses of +/- 20 V with a maximum field effect mobility of similar to 1 cm(2)/V s and memory window of 12 similar to 16 V. Among all the NVM-TFTs, the device with the 5 nm-thin Al2O3 buffer demonstrated the longest retention time of more than 104 s without much reduction of write-to-erase (WR/ER) current ratio, keeping a good memory window of similar to 16 V and WR/ER ratio of similar to 40.