Read-Out Modulation Scheme for the Display Driving Circuits Composed of Nonvolatile Ferroelectric Memory and Oxide–Semiconductor Thin-Film Transistors for Low-Power Consumption

Abstract

New circuit architecture composed of nonvolatile memory thin-film transistors (M-TFTs) and oxide–semiconductor TFTs (Ox-TFTs) has been proposed to realize low-power consumption and compact size for dynamic driving circuit applications. In order to compensate the slow operation speed of the nonvolatile M-TFTs in the dynamic driving circuits, we proposed the read-out modulation (ROM) scheme. The device operation characteristics of the M-TFTs were confirmed under various specified conditions to effectively apply the ROM, in which a top-gate structure was fabricated to be ferroelectric poly(vinylidene fluoride-trifluoroethylene) gate insulator/Al2O3/In–Ga–ZnO active layers. Full fabrication processes for the M-TFTs were optimized, so that they can be integrated with Ox-TFTs on the same glass substrate. The memory device characteristics, including the current ratios between ON- and OFF-programmed drain current ( $I_{D}$ ) values ( $I_{p-\mathrm {\mathrm{\scriptscriptstyle ON}}}/I_{p-\mathrm {\mathrm{\scriptscriptstyle OFF}}})$ before and after the ROM, drain-bias dependence of the $I_{p-\mathrm {\mathrm{\scriptscriptstyle ON}}}/I_{p-\mathrm {\mathrm{\scriptscriptstyle OFF}}}$ , and the program $I_{D}$ scalability, were confirmed for the fabricated M-TFT. These results suggest the feasibility of a low-power display driver circuit embedded with the nonvolatile M-TFTs.