Nano-scale chemistry of self-assembled nanostructures in epitaxial SiGe growth

Prabhu Balasubramanian, Jerrold A. Floro, Jennifer Lynn Gray, Robert Hull

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Epitaxial growth of SiGe alloy films under certain kinetically limiting conditions has previously been shown to lead to the self-assembly of nanostructures called Quantum Dot Molecules, QDMs. These QDMs consist of an assembly of pyramidal pits and elongated pyramidal islands, which exist at the edges of the pits. We investigate the nano-scale chemistry of QDMs in Si 0.7Ge0.3/Si (100) using Auger electron spectroscopy (AES). First, our AES analysis indicates that compressively strained QDM pit bases are most Ge rich regions in QDMs, consistent with previously reported observations. Second, our Auger analysis of the QDMs shows that Ge composition continuously increases from outside edges of the islands to the pit cusps. This results in asymmetric distribution of Ge about the apex of the islands. The segregation of Ge to the pit cusps is unexpected on the basis of strain energy minimization, and we propose that it is due to attachment of Ge to steps on the interiors of the QDMs. The continually varying Ge composition towards the pit cusps is also inconsistent with previous observations of islands in GeSi growth, where the composition is reported to be symmetric about the apex of islands.

Original languageEnglish (US)
Pages (from-to)15-20
Number of pages6
JournalJournal of Crystal Growth
Volume400
DOIs
StatePublished - Aug 15 2014

Fingerprint

Nanostructures
Auger electron spectroscopy
chemistry
Chemical analysis
cusps
Strain energy
Epitaxial growth
Self assembly
Semiconductor quantum dots
Auger spectroscopy
electron spectroscopy
apexes
Molecules
attachment
self assembly
assembly
quantum dots
optimization
molecules
Si-Ge alloys

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

Balasubramanian, Prabhu ; Floro, Jerrold A. ; Gray, Jennifer Lynn ; Hull, Robert. / Nano-scale chemistry of self-assembled nanostructures in epitaxial SiGe growth. In: Journal of Crystal Growth. 2014 ; Vol. 400. pp. 15-20.
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Nano-scale chemistry of self-assembled nanostructures in epitaxial SiGe growth. / Balasubramanian, Prabhu; Floro, Jerrold A.; Gray, Jennifer Lynn; Hull, Robert.

In: Journal of Crystal Growth, Vol. 400, 15.08.2014, p. 15-20.

Research output: Contribution to journalArticle

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