Ferroelectric Field Effect Transistors-Based Content-Addressable Storage-Class Memory: A Study on the Impact of Device Variation and High-Temperature Compatibility

Hafnium oxide (HfO2)-based ferroelectric field effect transistors (FeFETs) revolutionize the emerging nonvolatile memory area, especially with the potential to replace flash memories for several applications. In this article, the suitability of FeFET memories is investigated, especially FeFET-based content addressable memory (CAM) cells, as storage-class memory under junction temperature variations. FeFETs with silicon oxynitride interfacial layer are fabricated and characterized at various temperatures, varying from room temperature to 120 °C. Although the memory window, numbers of programmable states, and endurance deteriorate at high temperatures, FeFETs show excellent robustness in data retention, write latency, and read stability at all temperatures, especially for binary operation. Finally, system-level simulations using a Simulation Program with Integrated Circuit Emphasis software using experimental data are conducted to gauge the robustness of the data-search operation using the CAM array under different temperatures. Despite temperature-variation-induced changes in FeFET devices, it is observed that binary CAM cells perform robust and unerring search operations for storing and searching data at temperatures up to 120 °C.