Multibit Ferroelectric HfZrO Memcapacitor for Non-Volatile Analogue Memory and Reconfigurable Electronics

Abstract

Tunable capacitors are essential for adaptive and reconfigurable electronics, yet most existing implementations rely on continuous biasing or mechanical actuation. In this context, ferroelectric memcapacitors have emerged as promising non-volatile tuning elements for analogue, RF, and neuromorphic computing applications. While multilevel capacitance has been demonstrated in recent reports, a systematic understanding of switching behavior, stability, and circuit-level implications remains limited. Here, we present a voltage-programmable ((Formula presented.) 3 V) ferroelectric memcapacitor based on a simple TiN/HfZrO/TiN stack that achieves more than eight stable capacitive states within a competitive memory window of (Formula presented.) 24 pF in compact (Formula presented.) devices, exhibiting synaptic-like switching behavior. The devices show endurance up to (Formula presented.) cycles and state retention beyond (Formula presented.) s without extrapolation. Systematic area scaling from (Formula presented.) to (Formula presented.) and frequency-dependent measurements from 5 kHz to 10 MHz further clarify the robustness and practical limits of the capacitive memory window. At the nanoscale, multistate charge retention and tunability are directly visualised using atomic force microscopy. Furthermore, circuit-level functionality is demonstrated by tuning the cutoff frequency of a high-pass filter by (Formula presented.) 4.4 kHz and the oscillation frequency of an RC relaxation oscillator by (Formula presented.) 6.5 kHz using a packaged memcapacitor.