2D-composition mapping in InGaN without electron beam induced clustering of indium by STEM HAADF Z-contrast imaging
Rosenauer, Andreas; Mehrtens, Thorsten; Müller, Knut; Gries, Katharina; Schowalter, Marco; Bley, Stephanie; Satyam, Parlapalli Venkata; Avramescu, Adrian; Engl, Karl; Lutgen, Stephan; Rosenauer, Andreas; University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany;; Mehrtens, Thorsten; University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany; Müller, Knut; University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany; Gries, Katharina; University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany; Schowalter, Marco; University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany; Bley, Stephanie; University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany; Satyam, Parlapalli Venkata; University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany; Avramescu, Adrian; OSRAM Opto Semiconductors GmbH, D-93055 Regensburg, Germany; Engl, Karl; OSRAM Opto Semiconductors GmbH, D-93055 Regensburg, Germany; Lutgen, Stephan; OSRAM Opto Semiconductors GmbH, D-93055 Regensburg, Germany
Журнал:
Journal of Physics: Conference Series
Дата:
2011-11-09
Аннотация:
Investigation of composition in InGaN quantum wells and quantum dots by TEM is hampered by formation of electron beam induced agglomeration of indium, which occurs if the specimen is exposed to the electron beam for a few minutes. In this contribution we demonstrate that compositional analysis of InGaN nanostructures is possible without this artifact if STEM Z-contrast imaging is applied instead of parallel beam illumination. The suggested method for composition analysis in InGaN is based on a comparison of intensity normalized with respect to the incident electron beam with simulated image intensity. Simulations are performed with the STEMsim program using the frozen lattice multislice approximation for which static atomic displacements were taken into account.
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