Nonvolatile memory performance improvements for solution-processed thin-film transistors with composition-modified In-Zn-Ti-0 active channel and ferroelectric copolymer gate insulator

摘要

The nonvolatile memory thin-film transistors (M-TFTs) using a solution-processed indium-zinc-titanium oxide (IZTiO) active channel and a poly(vinylidene fluoride-trifluoroethyl-ene) ferroelectric gate insulator were fabricated and characterized to elucidate the relationships between the IZTiO channel composition and the memory performances such as program speed and data retention. The compositions of the spin-coated IZTiO layers were modified with different Ti amounts of 0, 2, 5, and 10 mol%. The carrier concentration of IZTiO channel layer was effectively modulated by the incorporated Ti amounts and the defect densities within the channel were effectively reduced by Ti incorporation. The M-TFT fabricated with IZTiO channel with 2-mol% Ti composition exhibited the best overall device performances, in which the μ_(EF) SS, MW, and programmed I_(on/off) were obtained to be 23.6 cm~2 V~(-1) s~(-1) 701 mV/decade, 11.8 V, and 1.2 × 10~5, respectively. Furthermore, thanks to the suitable amounts of Ti incorporation into the IZO, the improved program speed and data retention properties were successfully confirmed.