In this work, thin epitaxial layers of dielectric barium titanate (BaTiO3 or BTO) were grown on Nb-doped strontium titanate (001) substrates using either molecular beam epitaxy or atomic layer deposition and then electrically stressed to the point of breakdown. The BTO layer thicknesses were in the range of 20–60 nm, and typical breakdown fields were in the range of 1.5–3.0 MV/cm. Electron microscopy and electron energy-loss spectroscopy (EELS) were used to provide information about the degradation mechanism. High-resolution imaging revealed widespread structural damage in the BTO films after breakdown had occurred, with substantial polycrystallinity as well as amorphous regions. EELS analysis of the stressed films showed characteristic signatures of valence change in the Ti L23 EELS spectra associated with the accumulation of oxygen vacancies. Stressed heterostructures that had been patterned by electron lithography showed similar trends, including degraded crystallinity as well as oxygen loss.

中文翻译：

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外延 BaTiO3 薄膜的介电击穿

在这项工作中，使用分子束外延或原子层沉积在 Nb 掺杂的钛酸锶 (001) 衬底上生长薄的介电钛酸钡（BaTiO3 或 BTO）外延层，然后施加电应力至击穿点。BTO 层厚度在 20-60 nm 范围内，典型击穿场在 1.5-3.0 MV/cm 范围内。电子显微镜和电子能量损失光谱 (EELS) 用于提供有关降解机制的信息。高分辨率成像显示 BTO 膜发生击穿后广泛的结构损坏，具有大量的多晶和非晶区域。应力薄膜的 EELS 分析显示了与氧空位积累相关的 Ti L23 EELS 光谱中价态变化的特征特征。