Dislocations in MBE-grown ZnSe/GaAs(001) epitaxial layers Article

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Overview

abstract

• We report on dislocation densities in MBE grown ZnSe/GaAs/GaAs heterostructures of different epilayer thickness determined by high-resolution X-ray diffraction (HRXD), transmission electron microscopy (TEM) and etch-pit density (EPD) direct determination. We observed three regimes of dislocation generation. The first regime is present for samples of sub-critical thickness, where only stacking faults (SF) are present. SF formation depends on the conditions of substrate preparation and initial growth conditions. The second regime exists for samples with layer thickness greater than the critical thickness and thinner than a threshold thickness ht ≅ 0.3 μm, where a large amount of misfit (MF) dislocations are generated as consequence of SF reactions. We observe by TEM that the formation onset of MF dislocations starts at a critical thickness hc approx. 0.12 μm. The third regime, starts for layer thickness greater than ht. In this regime the formation of dislocations is substantially slowed down and the dislocation density follows a 1/h dependence as predicted by the glide model.

authors

• Constantino M.E.
• Hernández-Calderón I.
• López-López M.
• Navarro Contreras Hugo Ricardo
• Salazar-Hernández B.
• Vidal Borbolla Miguel Angel
• Yonezu H.

publication date

• 1999-01-01

published in

• Diffusion and Defect Data. Pt A Defect and Diffusion Forum  Journal

Research

keywords

• Density (specific gravity); Dislocations (crystals); Molecular beam epitaxy; Semiconducting gallium arsenide; Semiconducting zinc compounds; Stacking faults; Substrates; Transmission electron microscopy; X ray diffraction; Epilayer thickness; Epitaxial layers; Etch pit density; High resolution X ray diffraction; Subcritical thickness; Heterojunctions

Additional Document Info

start page

• 31

end page

• 46

volume

• 173