Stabilized negative capacitance for near-theoretical efficiency and high reliability in charge trap flash memory

Abstract

Negative capacitance (NC) in ferroelectric heterostructures offers a promising pathway to internal voltage application for energy-efficient electronics. However, its adoption in non-volatile memory has been hindered by instability and limited endurance. Here, we demonstrate a stabilized NC-enhanced charge trap flash (NC-CTF) memory that simultaneously achieves high programming efficiency, long retention, and robust cycling endurance through dual interfacial engineering. An ultrathin Al₂O₃ interlayer in Hf_0.5Zr_0.5O₂ (HZO) modulates domain configurations and promotes energy redistribution into depolarization energy, reinforcing the NC effect. Simultaneously, a TiO₂ layer between the charge trap layer (CTL) and blocking oxide (BO) increases the conduction band offset, suppressing parasitic charge injection and degradation. As a result, the NC-CTF device achieves a near-ideal incremental step pulse programming (ISPP) slope of ∼0.95, a 13.4 V memory window enabling quad-level cell (QLC) operation, and endurance exceeding 10⁴ program/erase cycles. The integration of NC physics with flash memory architecture offers a scalable and CMOS-compatible platform for ultra-low-power memory and neuromorphic computing, contributing to the advancement of energy-efficient and intelligent nano-electronic systems.