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

We characterized the nonvolatile memory thin-film transistors, which was composed of an amorphous indium-gallium-zinc oxide (alpha-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 Al2O3 layer was introduced between the P(VDF-TrFE) and alpha-IGZO. (C) 2010 American Institute of Physics. [doi:10.1063/1.3452339]