Simultaneous Quantification of Indium and Nitrogen Concentration in InGaNAs Using HAADF-STEM

Tim Grieb (1) , Knut Müller (1) , Emmanuel Cadel (2) , Andreas Beyer (3) , Marco Schowalter (1) , Etienne Talbot (2) , Kerstin Volz (3) , Andreas Rosenauer (1)

1 University of Bremen
2 GPM - Groupe de physique des matériaux
3 Fachbereich Physik [Marburg]

To unambiguously evaluate the indium and nitrogen concentrations in In x Ga 1 − x N y As 1 − y , two independent sources of information must be obtained experimentally. Based on high-resolution scanning transmission electron microscopy (STEM) images taken with a high-angle annular dark-field (HAADF) detector the strain state of the InGaNAs quantum well is determined as well as its characteristic HAADF-scattering intensity. The strain state is evaluated by applying elasticity theory and the HAADF intensity is used for a comparison with multislice simulations. The combination of both allows for determination of the chemical composition where the results are in accordance with X-ray diffraction measurements, three-dimensional atom probe tomography, and further transmission electron microscopy analysis. The HAADF-STEM evaluation was used to investigate the influence of As-stabilized annealing on the InGaNAs/GaAs sample. Photoluminescence measurements show an annealing-induced blue shift of the emission wavelength. The chemical analysis precludes an elemental diffusion as origin of the energy shift-instead the results are in agreement with a model based on an annealing-induced redistribution of the atomic next-neighbor configuration.

Mots clés: InGaNAs; HAADF; STEM; annealing; atom probe tomography

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Tim Grieb, Knut Müller, Emmanuel Cadel, Andreas Beyer, Marco Schowalter, et al.. Simultaneous Quantification of Indium and Nitrogen Concentration in InGaNAs Using HAADF-STEM. Microscopy and Microanalysis, 2014, 20 (06), pp.1740 - 1752. ⟨10.1017/S1431927614013051⟩. ⟨hal-01633486⟩