Optimizing Reliability: Suppressing Wake-Up Effects in Morphotropic Phase Boundary-Engineered Hf x Zr1-x O2 Ferroelectrics

초록

We investigated structural modulation strategies to suppress the wake-up effects in Hf x Zr1-x O2 (HZO)-based metal-ferroelectric-metal capacitors exhibiting morphotropic phase boundary characteristics. Three configurations were analyzed: Al-doped, nanolaminated, and heterostructured HZOs. Depth-profile X-ray photoelectron spectroscopy and atomic force microscopy analyses revealed distinct differences in oxygen vacancy (VO) ratios and grain sizes among the configurations, correlating with their wake-up behaviors. Heterostructured HZO exhibited the lowest VO concentrations (2.49%) and the largest average grain size (7.5 nm), in contrast to Al:HZO (5.2%, 6.2 nm) and laminated HZO (3.3%, 4.8 nm). Owing to its optimized defect profile and enhanced grain morphology, the heterostructured HZO maintains a stable phase composition even after 104 cycles, with minimal degradation in crystallinity and dielectric properties. These results highlight its potential for reliable, high-capacitance dynamic random-access memory (DRAM) applications.

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