An approach to quantitative compositional profiling at near-atomic resolution using high-angle annular dark field imaging

Anderson, Stuart; Birkeland, Christophe R.; Anstis, G. R.; Cockayne, D. J. H.

doi:10.1016/s0304-3991(97)00041-7

Cited by 59 publications

(19 citation statements)

References 18 publications

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“…For example, CTEM studies of defects (dislocations, twins, stacking faults and cracks) and morphology helped to determine the strain relaxation mechanisms in SiGe/Si, InGaAsP/InP, GaAsN/GaAS films, which then facilitated optimization of growth methodology [2][3][4][5]. In recent years, annular dark field scanning transmission electron microscopy (ADF-STEM) has become a widely used and powerful technique for characterizing strained epitaxial layers due to the fact that ADF-STEM image contrast depends strongly on the atomic number Z of the scattering atoms in a simple Z n form (n¼1.6-1.9), which makes composition variation evident through a change in image intensity [6][7][8][9][10]. However, the existence of strain in the films and relaxation of strain at the surfaces of the TEM specimen make interpretation of the measured intensity profile less straightforward.…”

Section: Introductionmentioning

confidence: 99%

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si

Robertson

Kawasaki

et al. 2012

Ultramicroscopy

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The effects of specimen tilt and probe convergence angle on annular dark field (ADF) image contrast of Si 0.8 Ge 0.2 heteroepitaxial strained layers on (100) Si were investigated in a 200 kV scanning transmission electron microscope (STEM) for a TEM specimen thickness of 195 nm. With 0.5 degrees of specimen tilt away from the exact /011S zone-axis orientation, the signal-to-noise level of atomic columns was significantly reduced for both Si 0.8 Ge 0.2 and Si in high resolution ADF-STEM lattice images. When the specimen was tilted 0.5 degrees around the /011S axis, or the STEM probe convergence semiangle was reduced from 14.3 to 3.6 mrad, the ADF-STEM image intensity profiles across the Si 0.8 Ge 0.2 and Si layers changed significantly as compared to those obtained at the exact /011S zone axis orientation, and no longer reflected the composition changes occurring across the layer structure. Multislice image simulation results revealed that the misfit strain between the Si 0.8 Ge 0.2 and Si layers, and strain relaxation near the surface of the TEM specimen, were responsible for the observed changes in image intensity.Crown

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Section: Introductionmentioning

confidence: 99%

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si

Robertson

Kawasaki

et al. 2012

Ultramicroscopy

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“…Therefore, special care needs to be taken in beam alignment for quantitative HAADF STEM applications such as the determination of crystallographic polarity or the compositional analysis of impurity atoms. From these investigations we concluded that it is still worth while illustrating how HAADF STEM images are influenced by optical conditions, although some simulation experiments have been reported so far [4,5,9,14,22,23].…”

Section: Introductionmentioning

confidence: 91%

Effect of incident probe on HAADF STEM images

Watanabe

Nakanishi

Yamazaki

et al. 2002

Physica Status Solidi (b)

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Atomic-resolution incoherent high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images of [011]-oriented Si have been recorded using different incident beam probes, and analysed by means of dynamical image calculation based on the Bloch wave description. It is shown how atomic-resolution images are influenced by the semiangle of the probe and the spherical aberration and defocus of the probe-forming lens. The resolution of an incoherent HAADF STEM image can be simply perceived by the contrast transfer function of incoherent imaging which is the Fourier transform of the incident probe intensity.

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“…However, given the strong Z-dependence of intensity in HAADF STEM images, extracting quantitative chemical information from images has been a topic of great interest. Both phenomenological methods and methods based on comparison with simulations have been applied to extract quantitative composition maps from images Anderson et al, 1997;Klenov and Stemmer, 2006;Rosenauer et al, 2009;Van Aert et al, 2009). One of the challenges in quantitative interpretation of Z-contrast images has been relating the simulated and experimental images.…”

Section: Quantitative High Resolution Stem Imaging Of Qwrs and Qdsmentioning

confidence: 98%

High resolution STEM of quantum dots and quantum wires

Kadkhodazadeh

2013

Micron

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An approach to quantitative compositional profiling at near-atomic resolution using high-angle annular dark field imaging

Cited by 59 publications

References 18 publications

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si

Effect of incident probe on HAADF STEM images

High resolution STEM of quantum dots and quantum wires

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