COMPOSITIONAL INFORMATION FROM AMORPHOUS SI-CE MULTILAYERS USING HIGH-RESOLUTION ELECTRON-MICROSCOPY IMAGING AND DIRECT DIGITAL RECORDING

A simple method for extracting compositional information from high-res olution electron microscopy images of an amorphous two-element system using a slow-scan CCD camera has been developed. The method has been e valuated on amorphous Si/Ge multilayers. The characterisation of the m ultilayers provided information about thickness of the layers, maximum concentrations within the layers and elemental profiles across the bo undaries. It was shown that the intensity profiles could be corrected for the wedge shape of the specimen and that the derived compositional profile was independent of average sample thickness variation within the range of the cross-section sample thickness. The results have been compared to analysis performed by Auger electron spectroscopy depth p rofiling on as-prepared multilayers as well as by energy-dispersive X- ray analysis and electron energy filtered images of cross-sections. Th e proposed HREM image contrast evaluation method gave spatial resoluti on in chemical analysis across the thin layers comparable in accuracy to the other methods, whereas the oscillation amplitude for the concen tration is slightly less due to specimen preparation artifacts.