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Effect of strain on surface diffusion in semiconductor heteroepitaxy

Evgeni Penev·Peter Kratzer·Matthias Scheffler
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Abstract

We present a first-principles analysis of the strain renormalization of the cation diffusivity on the GaAs(001) surface. For the example of In/GaAs(001)-c(4x4) it is shown that the binding of In is increased when the substrate lattice is expanded. The diffusion barrier ΔE(e) has a non-monotonic strain dependence with a maximum at compressive strain values (e < 0), while being a decreasing function for any tensile strain (e > 0) studied. We discuss the consequences of spatial variations of both the binding energy and the diffusion barrier of an adatom caused by the strain field around a heteroepitaxial island. For a simplified geometry, we evaluate the speed of growth of two coherently strained islands on the GaAs(001) surface and identify a growth regime where island sizes tend to equalize during growth due to the strain dependence of surface diffusion.

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Evgeni Penev, Peter Kratzer, Matthias Scheffler. 2001-05-21. Effect of strain on surface diffusion in semiconductor heteroepitaxy. https://doi.org/10.1103/physrevb.64.085401

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