Experimental Demonstration of a Nonvolatile SRAM With Ferroelectric HfO2 Capacitor for Normally Off Application

In order to realize ultralow power Internet-of-Things (IoT) edge devices, standby leakage current must be suppressed because activity of IoT device is very small in an intermittent mode. One of the approaches for ultralow power consumption is normally off computing by utilizing nonvolatile memory. After the discovery of ferroelectricity in HfO₂ which is compatible to CMOS integration, ferroelectric nonvolatile memory has been revisited. In this paper, toward normally off computing, we have proposed, designed, and fabricated nonvolatile SRAM integrated with ferroelectric HfO₂ capacitor in a simple architecture with two capacitors. Fundamental store and recall operation have been demonstrated. This device technology will open a new path for ultralow power IoT application.