Tracking defect type and strain relaxation in patterned Ge/Si(001) islands by x-ray forbidden reflection analysis

Journal Article · Mon Aug 15 04:00:00 EDT 2011 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.84.075314· OSTI ID:21596851

Richard, M -I ^[1]; Malachias, A ^[2]; Rouviere, J -L; Renaud, G ^[3]; Yoon, T -S ^[4]; Holmstroem, E; Nordlund, K ^[5]; Xie, Y -H ^[6]; Favre-Nicolin, V ^[3]; Holy, V ^[7]; Metzger, T -H ^[1]

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1. ID01/ESRF, 6 rue Jules Horowitz, BP220, FR-38043 Grenoble Cedex (France)
2. Laboratorio Nacional de Luz Sincrotron, C.P. 6192, Campinas, S.P. (Brazil)
3. CEA-UJF, INAC, SP2M, 17 rue des Martyrs, FR-38054 Grenoble Cedex 9 (France)
4. Department of Nano Science and Engineering, Myongji University, Yongin, Gyeonggi-do 449-728 (Korea, Republic of)
5. Helsinki Institute of Physics and Department of Physics, P.O. Box 43, FI-00014 University of Helsinki (Finland)
6. Department of Materials Science and Engineering, University of California at Los Angeles, California 90095-1595 Los Angeles (United States)
7. Faculty of Mathematics and Physics, Charles University Prague (Czech Republic)

Plastic relaxation and formation of defects are crucial issues in the epitaxial growth of nanoparticles and thin films. Indeed, defects generate local stress in the crystalline lattice, which affects their surroundings and may lead to undesired effects such as reduced charge-carrier lifetime or nonradiative recombinations. Here, we use a nondestructive method based on x-ray diffuse scattering close to forbidden reflections to identify the defect types with a high sensitivity and quantify their average size and strain field. Combined with transmission electron microscopy, it offers opportunities to track both ensemble average and single defects inside three-dimensional structures. These techniques have been applied to partially embedded and high-Ge-content (x{sub Ge}=0.87{+-}0.06) dots selectively grown in 20-nm-sized pits on Si(001) surfaces through openings in a SiO{sub 2} template. The stress in the 20-nm-wide Ge islands is relaxed not only by interfacial dislocations but also by microtwins and/or stacking faults located at the interface, proving the importance of {l_brace}111{r_brace} planes and twinning in the relaxation process of nanometer-size Ge dots.

• OSTI ID: 21596851
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 7 Vol. 84; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
DIFFRACTION
DIFFUSE SCATTERING
DISLOCATIONS
ELASTICITY
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
EPITAXY
FILMS
INTERFACES
IONIZING RADIATIONS
LIFETIME
LINE DEFECTS
MECHANICAL PROPERTIES
MICROSCOPY
NANOSTRUCTURES
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
RECOMBINATION
REFLECTION
RELAXATION
SCATTERING
SILICON COMPOUNDS
SILICON OXIDES
SPECTROSCOPY
STACKING FAULTS
STRAINS
STRESSES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION