For electron microscopes, the spherical aberration of the electron lenses has long been an obstacle in the way of improving resolution. Finally, in the mid-1990s, a system for correcting spherical aberration was developed. However, there were many technical challenges for implementing it in a high voltage STEM/TEM. In coope-ration with CEOS GmbH which had been developing a spherical aberration corrector (Cs-corrector) for practical use, Hitachi, Ltd. and Hitachi High-Technologies Corpo-ration developed a 200 kV STEM and a 300 kV TEM that implement spherical aberration correctors, and achieved a significant improvement in resolution. In addition, the companies succeeded in incorporating a Cs-corrector into a 1.2 MV atomic-resolution holography electron microscope. This made a great contribution to achieving world-leading resolution. In the development of these instruments, in addition to the development of spherical aberration correctors that support high-voltage and ultra-high-voltage, the electron microscope itself required a significant improvement in stability. Through close cooperation, the companies have solved these technical issues one by one. In this paper, Prof. Dr. Max. Haider, who founded CEOS and has led the development of spherical aberration correctors, summarizes the development CEOS carried out in cooperation with Hitachi, Ltd. and Hitachi High-Technologies Corporation.
Co-founder of CEOS GmbH, former Managing Director of CEOS GmbH, and today Senior Advisor and authorised officer, Honorary Professor at KIT (Karlsruhe Institute of Technology), Germany.
Managing Director, CEOS GmbH. He is currently involved in theoretical studies of advanced charged particle systems and the project management of several projects.
