ABSTRACT

Following the correction of the spherical aberration, the size of the objective aperture is then increased to allow improved resolution. For constant source demagnification, this results in a corresponding increase in probe current, improving signal to noise ratios and Electron Energy Loss Spectroscopy (EELS) analysis. This is slightly off-set by the need to increase the demagnification of the source to improve the resolution, but will still allow far more current in a probe of any given size than in an uncorrected STEM (Dellby et al, 2001).