Abstract
This work presents a novel TaN-Al 2 O 3 -Si 3 N 4 -SiO 2 -Silicon (TANOS) nonvolatile memory (NVM) with a structure that comprises Pi-gate (p-gate) nanowires (NWs) structure. The Pi-gate structure in this TANOS NVM increases on current (I on ), decreases the threshold voltage (V th ) and the subthreshold slope (SS), and enlarges the memory window (δV th ). Furthermore, the use of high-k Al 2 O 3 and a metal gate TaN structure enhances the program/erase efficiency and reliability. This NVM device has a high fast program/erase (P/E) speed; A 3 V memory window can be achieved by applying 18 V for only in 10 μs. With respect to endurance and high-temperature retention characteristics, the 70 % and 60 % of the initial memory window was maintained after 10 4 P/E-cycle stress, and ten years of data storage, respectively. Two-bit operation is achieved and retention characteristics are favorable because of the localized charge trapping in the nitride layer. © 2012 by ESG.