Composition analysis of ternary semiconductors by combined application of conventional TEM and HRTEM

✍ Scribed by Häusler, I. ;Kirmse, H. ;Neumann, W.

• Book ID: 105364946
• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 487 KB
• Volume: 205
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200780205

✦ Synopsis

Abstract

The chemical composition of ternary material systems can be determined by a combined analysis of dark‐field imaging and quantitative high‐resolution transmission electron microscopy (qHRTEM). This method is restricted to material systems where on the one hand chemically sensitive reflections occur and on the other hand the material surrounding the nanostructure contains only those atomic species which are also present in the nanostructure. In the developed procedure the dark‐field image intensity is calculated as a function of chemical composition. Additionally, it is taken into consideration that the strained state of the system leads to a change of the symmetry. For analysing the chemically sensitive dark‐field images the composition must be normalized by a known concentration value. The method will be demonstrated for the following system: GaSb~x~As~1–x~ quantum dots (QDs) grown by metal‐organic chemical vapour phase deposition (MOCVD) on GaAs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)