Investigation of Accumulative Switching in Ferroelectric FETs: Enabling Universal Modeling of the Switching Behavior

Accumulative switching (AS) in ferroelectric field-effect transistors (FeFETs), which takes place under a train of subcritical voltage pulses, represents not only a concern in terms of disturbs for classical nonvolatile memory but also a source of novel opportunities for neuromorphic applications. Here, we report a detailed experimental investigation of AS for large-area and scaled devices and compare it with the conventional one-shot switching. We show that both of them obey the same exponential dependence between the switching time and voltage, irrespective of the pulse polarity, the investigated interval duration between the pulses, and the device size. This unified physical picture sheds new light on the FeFET operation and holds promise to considerably simplify the modeling of both memory and neuromorphic functionalities in these devices.