High-angle annular dark-field imaging on a TEM/STEM system.

The technique of high-angle annular dark-field (HAADF) imaging, which is highly sensitive to atomic-number contrast, can be performed on TEM/STEM systems using the standard annular dark-field detector. For optimum HAADF imaging, the TEM/STEM must have a high maximum diffraction angle, small minimum camera length, and a descanning facility. The sensitivity of the technique is demonstrated to be about 10(5) to 10(6) times higher than energy-dispersive X-ray spectroscopy. Examples are shown from semiconductor, catalysis, ceramics, and particle analysis applications.