Strain-induced changes in epitaxial layer morphology of highly-strained III/V-semiconductor heterostructures

✍ Scribed by T. Marschner; S. Lutgen; M. Volk; W. Stolz; E.O. Göbel; N.Y. Jin-Phillipp; F. Phillipp

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 220 KB
• Volume: 15
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1994.1037

✦ Synopsis

We present a study of changes in the layer morphology of symmetrically strained (GaIn)As/ (\mathrm{Ga}(\mathrm{PAs})) superlattices as a function of strain and off-orientation of substrates. The samples were deposited by metal-organic vapour-phase epitaxy (MOVPE). For samples grown on exactly oriented (100) GaAs substrates sharp 2dimensional interfaces are observed up to a lattice mismatch ((\Delta d / d)^{\perp}=2.4 \cdot 10^{-2}). The use of off-oriented (100) substrates leads to a strain induced surface roughening (3-dimensional growth mode) and the formation of laterally ordered thickness modulations during further growth. The surface steps due to the substrate offorientation are regarded as a cause for this effect. We discuss the structural properties of the samples investigated by transmission electron microscopy (TEM) and high-resolution X-ray diffraction (XRD) as a function of the strain in the individual layers for samples grown on ( 100 ) GaAs substrates exactly oriented, (2^{\circ}) off towards ([110]) and (1.7^{\circ}) off towards [011], respectively.