Vanadium-Doped Hafnium Oxide: A High-Endurance Ferroelectric Thin Film with Demonstrated Negative Capacitance
Ehsan Ansari, Niccolò Martinolli, Emeric Hartmann, Anna Varini, Igor Stolichnov, Adrian Ionescu
Abstract
High Resolution Image Download MS PowerPoint Slide This study proposes and validates a novel CMOS-compatible ferroelectric thin-film insulator made of vanadium-doped hafnium oxide (V:HfO 2 ) by using an optimized atomic layer deposition (ALD) process. Comparative electrical performance analysis of metal–ferroelectric–metal capacitors with varying V-doping concentrations, along with advanced material characterizations, confirmed the ferroelectric behavior and reliability of V:HfO 2 . With remnant polarization ( P r ) values up to 20 μC/cm 2, a coercive field ( E c ) of 1.5 MV/cm, excellent endurance (>10 11 cycles without failure, extrapolated to 10 12 cycles), projected 10-year nonvolatile retention (>100 days measured), and large grain sizes of ∼180 nm, V:HfO 2 emerges as a promising robust candidate for nonvolatile memory and neuromorphic applications. Importantly, negative capacitance (NC) effects were observed and analyzed in V:HfO 2 through pulsed measurements, demonstrating its potential for NC applications. Finally, this novel ferroelectric shows potential as a gating insulator for future 3-terminal vanadium dioxide Mott-insulator devices and sensors, achieved through an all-ALD process.