Charge-Trapping Phenomena in HfO2-Based FeFET-Type Nonvolatile Memories

Ferroelectric field effect transistors (FeFETs) based on ferroelectric hafnium oxide (HfO2) thin films show high potential for future embedded nonvolatile memory applications. However, HfO2 films besides their recently discovered ferroelectric behavior are also prone to undesired charge trapping effects. Therefore, the scope of this paper is to verify the possibility of the charge trapping during standard operation of the HfO2-based FeFET memories. The kinetics of the charge trapping and its interplay with the ferroelectric polarization switching are analyzed in detail using the single-pulse I-D-V-G technique. Furthermore, the impact of the charge trapping on the important memory characteristics such as retention and endurance is investigated.