Evolution of Ge/Si(001) islands during Si capping at high temperature

Journal Article · Thu Dec 15 04:00:00 EST 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2141652· OSTI ID:20787732

Capellini, G; De Seta, M; Di Gaspare, L; Evangelisti, F; D'Acapito, F ^[1]

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1. Universita Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy)

We discuss the effect of the deposition of a Si cap layer on the composition and morphological properties of Ge(Si)/Si(001) self-assembled islands deposited by chemical vapor deposition at 750 deg. C. The morphological evolution of the island shape was investigated by means of atomic force microscopy and the actual island composition has been measured by means of x-ray photoemission spectroscopy and x-ray absorption spectroscopy techniques. At an early stage of Si capping, Si atoms are incorporated in the island layer. As a consequence, we observe a reverse Stranski-Krastanov growth dynamics in agreement with the volume-composition stability diagram proposed for domes, pyramids, and prepyramids in the Ge{sub x}Si{sub 1-x}/Si(100) system. We find that the island burying begins when the Ge average composition reaches the value x=0.28. Once the islands are buried under a thin silicon layer their composition is unaffected by subsequent silicon deposition. We conclude that strain relief, rather than thermal diffusion, is the main driving force for the observed Ge-Si alloying.

• OSTI ID: 20787732
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 98; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
ATOMIC FORCE MICROSCOPY
CHEMICAL VAPOR DEPOSITION
CRYSTAL GROWTH
GERMANIUM
GERMANIUM ALLOYS
LAYERS
MAGNETIC ISLANDS
MORPHOLOGY
PHOTOEMISSION
SEMICONDUCTOR MATERIALS
SILICON
SILICON ALLOYS
TEMPERATURE RANGE 1000-4000 K
THERMAL DIFFUSION
X-RAY PHOTOELECTRON SPECTROSCOPY
X-RAY SPECTRA
X-RAY SPECTROSCOPY