SPATIALLY-RESOLVED MICROANALYSIS OF THIN-FILMS IN THE TRANSMISSION ELECTRON-MICROSCOPE

Electron energy-loss spectrometry (EELS) is an important technique for microanalysis of thin films in the transmission electron microscope. Absolute quantification of elements on a scale of less than 10 nm is f easible when the chromatic aberration of the post-specimen electron le nses is properly corrected. The accuracy of the quantification is infl uenced by several effects. We present a method for the compensation of the chromatic error using a defocus series and a correction of the ch romatic image shift. Experiments using specimens with an edge-like con centration function (planar interface, abrupt thickness variation) wer e performed on a parallel-detection EELS system (GATAN 666 PEELS) and on an energy-selecting imaging filter. Comparison of these results sug gests that for accurate quantification on selected positions of the sp ecimen the PEELS should be used, whereas the imaging filter is better suited for a fast overview of the elemental distribution in a larger a rea. The influence of Bragg scattering on the results of the quantific ation for both systems is discussed.