发表机构
Centre for Nano Science and Engineering, Indian Institute of Science（印度科学学院纳米科学与工程中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过操作原子力显微镜等探针揭示氧化铪铁电器件可靠性变异性的电化学起源，提出简单工艺修改抑制竞争电化学路径，实现100%铁电器件。
AI 中文摘要
器件间和样品间的变异性仍然是基于氧化铪的铁电器件可靠实施的主要障碍，即使在相似加工条件下制备的名义上相同的结构中也是如此。这凸显了对操作诊断探针的需求，以提供超越传统结构相分析的工艺相关反馈。在此，我们证明操作纳米尺度表面测量可作为氧化铪铁电器件中控制可靠性的局部电化学过程的敏感探针。使用生长在La0.67Sr0.33MnO3 (LSMO)缓冲的SrTiO3上的外延菱方相Y:HfO2薄膜作为模型系统，我们结合操作原子力显微镜、导电AFM、压电力响应显微镜和关联STEM-EELS，直接将表面演化与界面电化学联系起来。表现出唤醒效应的器件显示表面高度的空间均匀增加，源于LSMO电极的均匀氧化，随后在极化切换过程中氧迁移进入铁电层。相比之下，漏电器件表现出明显的表面粗糙化和气泡形成，源于原始LSMO电极中空间不均匀的氧化态，促进了LSMO/Y:HfO2界面处竞争性析氧反应。伴随的电子产生导致瞬态漏电。在这些机理见解的指导下，我们引入了加工条件的简单修改，在不改变优化的铁电相的情况下，抑制了竞争性电化学路径，并可重复地获得100%的铁电器件。更广泛地说，这项工作确立了操作表面演化作为隐藏电化学过程的强大纳米尺度诊断工具，并为提高基于氧化铪的铁电器件的可靠性和可重复性提供了实用途径。
英文摘要
Device-to-device and sample-to-sample variability remains a major obstacle to the reliable implementation of hafnia-based ferroelectrics, even in nominally identical structures fabricated under similar processing conditions. This highlights the need for operando diagnostic probes that provide process-relevant feedback beyond conventional structural phase analysis. Here, we demonstrate that operando nanoscale surface measurements serve as sensitive probe of the local electrochemical processes governing reliability in hafnia ferroelectric devices. Using epitaxial rhombohedral Y:HfO2 films grown on La0.67Sr0.33MnO3 (LSMO)-buffered SrTiO3 as a model system, we combine operando atomic force microscopy, conductive AFM, piezoresponse force microscopy, and correlative STEM-EELS to directly link surface evolution with interfacial electrochemistry. Devices exhibiting wake-up show a spatially uniform increase in surface height, arising from homogeneous oxidation of the LSMO electrode followed by oxygen migration into the ferroelectric layer during polarization switching. In contrast, leaky devices display pronounced surface roughening and blister formation, originating from spatially inhomogeneous oxidation states in the pristine LSMO electrode that promote competing oxygen evolution reactions at the LSMO/Y:HfO2 interface. The accompanying electron generation produces leakage which is transient. Guided by these mechanistic insights, we introduce simple modifications to the processing conditions, without altering the optimized ferroelectric phase, that suppress the competing electrochemical pathways and reproducibly yield 100% ferroelectric devices. More broadly, this work establishes operando surface evolution as a powerful nanoscale diagnostic of hidden electrochemical processes and provides a practical route for improving the reliability and reproducibility of hafnia-based ferroelectric devices.
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