Hole-Trapping Mechanism and SILC of Dual-Layer nc-ITO Embedded ZrHfO High-k Nonvolatile Memories

Abstract

MOS capacitors containing singe- and dual-layer nc-ITO embedded ZrHfO high-k gate dielectric films were fabricated and characterized for nonvolatile memory functions and reliability. The addition of the second nc-ITO into the high-k dielectric enhanced the memory function of the devices, e.g., a larger memory window, more sensitive to the gate bias voltage, and longer charge retention time. From the SILC test, the dual-layer nc-ITO sample also showed more pronounced Coulomb blockade phenomena than the single nc-ITO embedded sample, which is consistent with the hole-trapping characteristics. The novel charge storage characteristics of the dual-layer nc-ITO embedded high-k make it suitable for future memory applications.