Synergistic Modulation of Polarization and Leakage Current in MPB-HZO Capacitors via TiO2 Interlayer

Abstract

To address critical reliability concerns in ferroelectric devices, the role of a TiO2 interlayer in modulating the electrical characteristics of HfxZr1-xO2 (HZO)-based metal-ferroelectric-metal (MFM) capacitors near the morphotropic phase boundary (MPB) is investigated. The TiO2 interlayer is inserted at the HZO interface to selectively modulate defect behavior while preserving the desired MPB phase composition. Electrical, structural, and spectroscopic analyses reveal that TiO2 integration enables 1) suppression of leakage pathways, 2) stabilization of polarization with enhanced dielectric response, 3) modulation of oxygen vacancy (VO) distribution, and 4) reduction of low-frequency noise (LFN) amplitude. These synergistic effects collectively improve the reliability and energy efficiency of MPB-HZO capacitors, offering a promising interface-engineering strategy for next-generation ferroelectric DRAM technologies.