Probing the composition of Ge dots and Si/Si{sub 1-x}Ge{sub x} island superlattices

Journal Article · Mon May 15 04:00:00 EDT 2006 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.2186658· OSTI ID:20777192

Baribeau, J -M; Wu, X; Lockwood, D J ^[1]

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1. Institute for Microstructural Sciences, National Research Council Canada, Ottawa, Ontario K1A 0R6 (Canada)

We use analytical transmission electron microscopy to map the composition of Ge dot and Si/Si{sub 1-x}Ge{sub x} island structures grown on (001) Si by molecular beam epitaxy or ultrahigh vacuum chemical vapor deposition. Energy-dispersive x-ray spectroscopy reveals that nominally pure Ge dots grown by molecular beam epitaxy at 650 deg. C exhibit considerable intermixing with the average Ge composition typically increasing from nearly zero at the base to about 50% at the top of the dot. In pyramid shaped dots, the Ge composition increases linearly up to the top of the dot, while for dome dots, a saturation of the incorporation rate is seen beyond a distance of 7 nm from the substrate interface. Probing of Si/Si{sub 1-x}Ge{sub x} island superlattices also reveals large Si/Ge intermixing with a Ge accumulation at the crest and Ge depletion at the troughs of the islands. These results are corroborated by x-ray diffraction and Raman scattering measurements.

• OSTI ID: 20777192
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 3 Vol. 24; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL ANALYSIS
CHEMICAL VAPOR DEPOSITION
GERMANIUM
GERMANIUM ALLOYS
MOLECULAR BEAM EPITAXY
QUANTUM DOTS
SEMICONDUCTOR MATERIALS
SILICON
SILICON ALLOYS
SUPERLATTICES
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY