Details

Autor(en) / Beteiligte

• Walther, T
• Cullis, A G
• Norris, D J
• Hopkinson, M

Titel

Nature of the Stranski-Krastanow transition during epitaxy of InGaAs on GaAs

Ist Teil von

• Physical review letters, 2001-03, Vol.86 (11), p.2381-2384

Ort / Verlag

United States

Erscheinungsjahr

2001

Quelle

PROLA - Physical Review Online Archive

Beschreibungen/Notizen

• We report first quantitative measurements by energy-selected imaging in a transmission electron microscope of In segregation within an uncapped islanded In0.25Ga0.75As layer grown epitaxially on GaAs. This layer has the lowest In concentration at which islanding occurs and, then, only after a flat approximately 3 nm alloy layer has been formed. In buildup by segregation at the surface of this initial flat layer is considered the driving force for islanding and, importantly, the segregation process introduces the characteristic delay seen before the Stranski-Krastanow transition. We observe strong inhomogeneous In enrichment within the islands (up to x(In) approximately 0.6 at the apex) and a simultaneous In depletion in the remaining flat layer.