School of Electrical Engineering, Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
School of Electrical Engineering, Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
Ultramicroscopy. 2018 Jun;189:46-53. doi: 10.1016/j.ultramic.2018.03.016. Epub 2018 Mar 27.
Nearly eighty years ago, Scherzer showed that rotationally symmetric, charge-free, static electron lenses are limited by an unavoidable, positive spherical aberration. Following a long struggle, a major breakthrough in the spatial resolution of electron microscopes was reached two decades ago by abandoning the first of these conditions, with the successful development of multipole aberration correctors. Here, we use a refractive silicon nitride thin film to tackle the second of Scherzer's constraints and demonstrate an alternative method for correcting spherical aberration in a scanning transmission electron microscope. We reveal features in Si and Cu samples that cannot be resolved in an uncorrected microscope. Our thin film corrector can be implemented as an immediate low cost upgrade to existing electron microscopes without re-engineering of the electron column or complicated operation protocols and can be extended to the correction of additional aberrations.
大约 80 年前，Scherzer 表明旋转对称、无电荷、静态电子透镜受到不可避免的正球差的限制。经过长期的努力，大约 20 年前，通过放弃这些条件中的第一个，成功开发了多极像差校正器，使电子显微镜的空间分辨率取得了重大突破。在这里，我们使用折射氮化硅薄膜来解决 Scherzer 的第二个限制，并展示了一种在扫描透射电子显微镜中校正球差的替代方法。我们揭示了在未经校正的显微镜中无法分辨的 Si 和 Cu 样品的特征。我们的薄膜校正器可以作为现有电子显微镜的低成本升级，无需对电子柱进行重新设计或复杂的操作协议，并且可以扩展到校正其他像差。
