低電壓同調電子顯微鏡光學系統的設計

Design of optical columns for low-voltage coherent electron microscopy.

楊宗于(Yang Zong-Yu)

指導教授 ： 傅祖怡 ； 黃英碩

國立臺灣師範大學/理學院/物理學系/碩士(2019年)

https://doi.org/10.6345/NTNU201900479

摘要

由於高成像對比度和低輻射損傷，開發低電壓電子顯微鏡已成為普遍趨勢。最近，已經證明了電壓低至15-40kV的原子分辨透射電子顯微鏡。然而，在低於10kV的電壓下實現原子解析度是非常困難的。獲得高解析度圖像的另一種方法是同調繞射成像（CDI）。已經開發出低電壓同調電子顯微鏡以滿足CDI的取樣要求並調節光束能量。在這項工作中，我們分析了由發射器所構建的電子源光學系統的配置和操作條件。並獲得了最佳幾何形狀，我們將使用幾何結構為我們的低電壓同調電子顯微鏡製造光學系統。

關鍵字

同調繞射成像術 ； 靜電透鏡 ； 單原子針 ； 電子顯微鏡 ； 低能量電子束

並列摘要

Developing low-voltage electron microscopes has been a general trend due to high imaging contrast and low radiation damage. Recently, atom-resolved transmission electron microscopes with voltages as low as 15-40 kV have been demonstrated. However, achieving atomic resolution at voltages lower than 10 kV is extremely difficult. An alternative approach to obtaining high resolution images is coherent diffraction imaging (CDI). A low-voltage coherent electron microscope has been being developed to fulfill oversampling requirement of CDI and adjust beam energies. In this work, we analyzed configurations and operating conditions of optical columns of electron sources built from a nano-emitter. An optimal geometry was obtained and we will use the geometry to manufacture an optical column for our low-voltage coherent electron microscope.

並列關鍵字

coherent diffractive imaging ； electrostatic lens ； single-atom electron sources ； electron microscopy ； low-energy electron beams

參考文獻

1. E. Ruska, M. Knoll, “Die magnetische Sammelspule fuer schnelle Elektronenstrahlen”, Z. Techn. Physik 12 389 (1931).

2. O. Scherzer, “Über einige Fehler von Elektronenlinsen” Z. Phys. 101 593 (1936).

3. M. Haider, S. Uhlemann, E. Schwan, H. Rose, B. Kabius, K. Urban, “Electron microscopy image enhanced”, Nature 392 768 (1998).

4. O.L. Krivanek, N. Dellby, A.J. Spence, R.A. Camps, L.M. Brown, “Aberration correction in the STEM”, Inst. Phys. Conf. Ser. 153 35 (1997).

5. C. Kisielowski, B. Freitag, M. Bischoff, H. van Lin, S. Lazar, G. Knippels, P. Tiemeijer, M. van der Stam, S. von Harrach, M. Stekelenburg, M. Haider, S. Uhlemann, H. Müller, P. Hartel, B. Kabius, D. Miller, I. Petrov, E.A. Olson, T. Donchev, E.A. Kenik, A.R. Lupini, J. Bentley, S.J. Pennycook, I.M. Anderson,