ABSTRACT
Image resolution in both conventional transmission electron microscopy (CTEM) and scanning transmission electron microscopy (STEM) have asymptotically approached a value of between 0.1 and 0.2 nm. A field emission source is the key to the formation of the small probe which contains a sufficient number of electrons to produce a high quality image or a high resolution microanalysis. One of the fundamental limits to probe size is the spherical aberration coefficient of the probe-forming lens, Cs. The spectrum imaging concept is an extremely powerful one, where whole spectra are collected at each data point in a map, and advanced spectral processing software has been developed to produce chemical maps ‘off-line’. While beam damage is a nuisance if one is attempting to obtain a high resolution image or an accurate chemical analysis, the damage can be used to carry out micro-machining on the nanometre scale.
