Composition evaluation by lattice fringe analysis

摘要: Abstract In this paper we present a compositional analysis, by high-resolution transmission electron microscopy of 2 nm InxGa1−xAs layer (nominal In-content 60%) which was deposited on GaAs ( 0 1 ) and capped with 10 nm GaAs. A three-beam condition close to the (1 0 0) zone axis is used. The lattice fringe images result from interference ), 4 2 beams latter centered optical axis. Due chemical sensitivity beam, obtained contrast patterns strongly depend x averaged along beam direction. We suggest simple analysis procedure that uses ratio A002/A004 reflections local image cell diffractograms, respectively, bijective function x. Furthermore, show suggested method does not require exact knowledge objective lens defocus sample thickness in order check reliability gained results, finite-element calculation strain state performed based evaluated In-concentration profile. results are compared an evaluation using atomic scale measurements. investigations showed overgrowth caused structural modification initial island structure transformed into rather homogeneous varies locally. Reasons for morphological transition discussed.