Impact of Trapped-Charge Variations on Scaled Ferroelectric FET Nonvolatile Memories
You-Sheng Liu, Pin Su
Abstract
This article investigates the impact of interface trapped-charge variations on the dimensional scaling of the ferroelectric field-effect transistor (FeFET) nonvolatile memory (NVM) under two scenarios: a uniform ferroelectric and random ferroelectric-dielectric (FE-DE) phase distribution. Our study indicates that both memory window (MW) and read margin decrease with increasing trap density ( ), and the MW of FeFET devices with scaled channel width can be more vulnerable to the trapped-charge variations than that with scaled gate length. Under the presence of the FE-DE phase variation, for low , the impact of trapped charges is mainly on the MW degradation for the high MW instances. As the continues to rise, the trapped charges can further worsen the worst case MW significantly. Besides, when down-scaling the interfacial layer thickness of the FeFET device to increase the MW, the increased σMW due to the random interface trapped charges may also need to be considered. Our study may provide insights for device design with advanced FeFET NVMs.