Hybrid surface roughening modes during low-temperature heteroepitaxy: Growth of fully-strained metastable Ge12xSnx alloys on Ge„001...231
نویسندگان
چکیده
Fully-strained single-crystal metastable Ge12xSnx alloys were grown on Ge~001! up to their critical epitaxial thickness values tepi(x) in order to probe surface roughening pathways leading to heteroepitaxial breakdown during low-temperature molecular-beam epitaxy under large compressive strain. All films with x.0.09 have comparable roughnesses while films with x,0.09 are considerably rougher with larger lateral feature sizes. Roughening rates increase with increasing x for films with x.0.09 due to a new hybrid relaxation path which only becomes accessible under high strain as kinetic roughening provides surface oscillations on lateral length scales that allow bulk relaxation through strain-induced islanding at growth temperatures where it could not otherwise proceed. @S0163-1829~99!01247-3#
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