[15p-4E-1~23] 7.2 Applications and technologies of electron beams

△ [15p-4E-7] Development of electrostatic Cs-corrector with annular and circular electrodes (Simulations)

〇Yasuyuki Takai¹, Yuki Ogawa¹, Tadahiro Kawasaki^2,3, Takafumi Ishida³, Tetsuji Kodama¹, Takashi Ikuta⁴ (1.Meijo Univ., 2.JFCC, 3.EcoTopia Sci. Inst., Nagoya Univ, 4.Osaka Electro-Communication Univ)

Keywords:spherical-aberration-corrector,electrostatic lens,STEM

A simple spherical-aberration-corrector which consists of annular/ circular electrodes and a constant-voltage supply has been newly developed. Before constructing the apparatus, simulation has been done in advance to investigate appropriate parameters for correcting the aberration of a STEM optical system. In this study, aberration coefficient Cs which the corrector produces were examined by calculating three-dimensional electric field between two electrodes and electron beam trajectories in the field. The simulation results determine the voltage required for the residual aberration in the objective lens to be zero. In addition, desired accuracies for the electrodes in fabrication and assembling were evaluated.