Details

Autor(en) / Beteiligte

• WALTHER, T.

Titel

A new experimental procedure to quantify annular dark field images in scanning transmission electron microscopy

Ist Teil von

• Journal of microscopy (Oxford), 2006-02, Vol.221 (2), p.137-144

Ort / Verlag

Oxford, UK: Blackwell Publishing Ltd

Erscheinungsjahr

2006

Link zum Volltext

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Summary A new procedure to quantify the contrast in annular dark field images recorded without lattice resolution in a scanning transmission electron microscope is proposed. The method relies on the use of an in‐column energy filter prior to the annular dark field detector and the acquisition of a series of energy‐filtered images as a function of the inner detection angle. When the image contrast of an interface between two materials in such energy‐filtered annular dark field images is plotted vs. camera length and extrapolated to zero (i.e. infinite scattering angle), the contrast is shown to behave exactly as predicted by Rutherford's scattering formula (i.e. intensity scales ∝Z2). This can then be used to determine the local chemistry at and the effective chemical widths of interfaces or thin films without any additional spectroscopy method for calibration, provided the global chemical composition is known. As examples, the systems SiGe/Si and InGaAs/Ge are considered in detail.