Enabling Energy-Efficient Nonvolatile Computing With Negative Capacitance FET

Negative capacitance FETs (NCFETs) have attracted significant interest due to their steep-switching capability at a low voltage and the associated benefits for implementing energy-efficient Boolean logic. While most existing works aim to avoid theID–VGhysteresis in NCFETs, this paper exploits this hysteresis feature for logic-memory synergy and presents a custom-designed nonvolatile NCFET D flip-flop (DFF) that maintains its state during power outages. This paper also presents an NCFET fabricated for this purpose, showingRDSratio between the two polarization states. With a device-circuit codesign that takes advantage of the embedded nonvolatility and the highRDSratio, the proposed DFF consumes negligible static current in backup and restore operations, and remains robust even with significant global and local ferroelectric material variations across a wide 0.3–0.8 V supply voltage range. Therefore, the proposed DFF achieves energy-efficient and low-latency backup and restore operations. Furthermore, it has an ultralow energy-delay overhead, below 2.1% in normal operations, and operates using the same voltage supply as the Boolean logic elements with which it connects. This promises energy-efficient nonvolatile computing in energy-harvesting and power-gating applications.