Amorphous IGZO Nonvolatile Memory Thin Film Transistors Using Ta<sub>2</sub>O<sub>5</sub> Gate Dielectric

Abstract

A nonvolatile memory thin-film transistor (MTFT) using an amorphous indium gallium zinc oxide (a-IGZO) semiconducting channel and a Ta2O5 gate insulator is proposed. The high-dielectric-constant material Ta2O5 was deposited by e-beaming and used for the charge storage layer, i.e., a metal-oxide-semiconductor (MOS) capacitor. We obtained memory windows (ΔVth = 2 V) at 3-V gate voltage and realized reliable memory operations. Therefore, a-IGZO TFT with Ta2O5 can be employed in integrated high-performance nonvolatile memory devices for applications to transparent displays and flexible electronic devices.