Highly Ordered Ga Nanodroplets on a GaAs Surface Formed by a Focused Ion Beam

Journal Article · Fri Feb 22 00:00:00 EST 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.100.076103· OSTI ID:21024798

Qiangmin, Wei ^[1]; Jie, Lian ^[2]; Wei, Lu ^[3]; Lumin, Wang ^[1]

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1. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
2. Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)
3. Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

The morphological evolution of a GaAs surface induced by a focused ion beam (FIB) has been investigated by in situ electron microscopy. Under off-normal bombardment without sample rotation, Ga droplets with sizes from 70 to 25 nm in diameter on the GaAs surface can self-assemble into a highly ordered hexagonal pattern instead of Ostwald ripening or coalescence. The mechanism relies on a balance between anisotropic loss of atoms on the surface of droplets due to sputtering and an anisotropic supply of atoms on the substrate surface due to preferential sputtering of As. The ratio of wavelength to the droplet diameter predicted by this model is in excellent agreement with experimental observations.

• OSTI ID: 21024798
• Journal Information: Physical Review Letters, Vol. 100, Issue 7; Other Information: DOI: 10.1103/PhysRevLett.100.076103; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
COALESCENCE
DROPLETS
ELECTRON MICROSCOPY
EVOLUTION
GALLIUM ARSENIDES
ION BEAMS
NANOSTRUCTURES
SPUTTERING
SUBSTRATES
SURFACE PROPERTIES