Impact of interface controlling layer of Al2O3 for improving the retention behaviors of In–Ga–Zn oxide-based ferroelectric memory transistor

Abstract
We characterized the nonvolatile memory thin-film transistors, which was composed of an amorphous indium-gallium-zinc oxide ( α -IGZO ) active channel and a ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] gate insulator, and investigated the impact of an interface controlling layer. Excellent device performances, such as the field-effect mobility of 60.9 cm 2 V − 1 s − 1 , the subthreshold swing of 120 mV/dec, and the memory window of 6.4 V at ±12 V programming, were confirmed for the device without any interface layer. However, the memory retention time was very short. The retention behaviors could be dramatically improved when 4 nm thick Al 2 O 3 layer was introduced between the P(VDF-TrFE) and α -IGZO .