Iridium Nanocrystal Thin-Film Transistor Nonvolatile Memory with Si3N4/SiO2 Stack of Asymmetric Tunnel Barrier

Abstract

Iridium nanocrystals (Ir-NCs) lying on the Si3N4/SiO2 tunneling layer have been demonstrated and Ir-NC-assisted thin-film transistor nonvolatile memory devices were successfully developed. Results show that Ir-NCs with a number density of similar to 6 x 10(11) cm(-2) and a particle diameter of 4 to 12 nm can successfully be fabricated as charge trapping centers. Owing to the asymmetric SiO2/Si3N4 tunneling layer that increases programming/erasing efficiency, a significant memory window of 5.5 V has potential to be applied to multibit memory devices. Furthermore, after 10(4) s, the memory window is still about 4.0 V in logic states. (C) 2011 The Japan Society of Applied Physics