Regensburg 1998 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 21: Quantendr
ähte

HL 21.12: Vortrag

Dienstag, 24. März 1998, 18:45–19:00, H1

Non-uniform strain in epitaxial surface gratings: beyound the ordinary elastic description — •tilo Baumbach — Fraunhofer Institut Zerstoerungsfreie Pruefverfahren Dresden, Fraunhofer Institut Zerstoerungsfreie Pruefverfahren Dresden, actual address: ESRF, BP 220, F-38043 Grenoble, France

A generalized elastic description of non-uniform strain in layered epitaxial surface gratings is presented. The functional of the total free energy of the system is described including a surface term responsible for the interaction energy density contribution. The variational calculus for the functional of the free energy is developed. The equilibrium equations are solved numerically for strong anchoring energy. The lattice displacement field and the strain field in the grating structures is calculated for multilayer surface gratings and buried gratings of the material system GaInAsP. We discuss the influence of the grating shape, the composition and the layer thicknesses on the elastic relaxation bahaviour in the wires. Further we describe the effect of grating induced periodic lattice distortion in the planar layers above and below the grating and in the substrate.