High-Temperature Retention Stability of Multibit Ferroelectric HfZrO₂ FinFET With SiGe/Si Superlattice Channel for Enhanced Speed and Memory Window

This research investigates multibit ferroelectric FinFET (Fe-FinFET) utilizing SiGe/Si heterostructure superlattice (SL) channel. The SiGe/Si SL multibit Fe-FinFET exhibits a significant memory window (MW) of 1.53 V with SiO ₂ for the interfacial layer (IL) and a rapid switching speed of 100 ns. A comparative analysis with the Si channel device was also conducted. Furthermore, the devices demonstrate the endurance of $10^{4}$ cycles, along with a retention duration surpassing $10^{4}$ s for each state, maintaining performance integrity over the equivalent of ten years of data retention at room temperature (RT) up to 85 °C. Additionally, basic physical analysis and simulations provide evidence that high mobility channels improve the MW and thermal stability. These results highlight the potential for low operating voltage in high-density 1T nonvolatile memory (NVM) applications.