Reconfigurable Sequential-Logic-in-Memory Implementation Utilizing Ferroelectric Field-Effect Transistors.

In modern digital systems, sequential logic circuits store and process information over time, whereas combinational logic circuits process only the current inputs. Conventional sequential systems, however, are complex and energy-inefficient due to the separation of volatile and nonvolatile memory components. This study proposes a compact, nonvolatile, and reconfigurable van der Waals (vdW) ferroelectric field-effect transistor (FeFET)-based sequential logic-in-memory (S-LiM) unit that performs sequential logic operations in two nonvolatile states. Unlike conventional edge computing systems that require separate combinational logic circuits, sequential logic circuits (such as latches for short-term data storage), and nonvolatile memory for long-term data storage, this innovative S-LiM unit integrates logic and memory into a single nonvolatile vdW FeFET device. The nonvolatile ferroelectric elements directly replace both sequential logic and memory in conventional systems, eliminating frequent data transfers, reducing static power, and increasing the storage density. Six distinct logic operations are implemented in a single vdW FeFET through voltage-controlled ferroelectric polarization, highlighting the unit's reconfigurability. The device shows significant potential for low-power edge computing, especially where frequent power cycling is necessary. Its nonvolatile polarization retains the state without the need for storing processes, enabling rapid recovery at startup, even after extended power-off periods of tens of minutes. These features make the vdW FeFET-based S-LiM unit ideal for energy-efficient, high-density, and low-power edge computing, especially in remote operations with unstable power supplies. This innovation contributes to the development of next-generation, low-power electronics with enhanced efficiency and storage density.