Development of compact Cs corrector for desktop electron microscope

作者：Chang Wei Yu; Chen Fu Rong^*

来源：Ultramicroscopy, 2017, 179: 94-99.

DOI：10.1016/j.ultramic.2017.04.009

The desktop Electron Microscopes (desktop EMs) have been commercialized in the recent years, offering a spatial resolution around 1 nm in scanning-transmission mode in a routine operation. For the purpose of further improvement in spatial resolution and signal / noise, one may need an aberration corrector with a compact form in order to fit into a desktop EM. In this paper, the permanent magnets with tunable coil are implemented as a transfer lens doublet to realize a compact hexapole corrector for a desktop EM. It will be shown that, with a proper design of permanent magnet transfer lens doublet and hexapole lens, we can generate a negative Cs and avoid the second-order axial astigmatism to reduce the final spot size at the sample plane to be better than 0.5 nm for a field emission source. To fulfill with the required condition of a hexapole corrector, a tunable lens is implemented to adjust the magnetic field for compensating the practical error from the permanent magnet.

• 出版日期2017-8
• 单位清华大学