Exclusion zone model of islands spatial distribution in molecular beam epitaxy

Molecular-beam epitaxy (MBE) is potentially an extremely valuable tool for growing III-V compounds. The value of the technique results partly from the ease with which controlled layers of precisely determined composition can be grown, and partly from the ability that it provides for growing accurately doped layers.

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An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010648x ◽

1988 ◽

Vol 46 ◽

pp. 884-885

Author(s):

D. Loretto ◽

J. M. Gibson ◽

S. M. Yalisove ◽

R. T. Tung

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Defect Density ◽

High Vacuum ◽

Ultra High Vacuum ◽

Ex Situ ◽

Metal Base ◽

In Situ Experiments ◽

Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

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Near-Surface Aggregation of Sn In Heavily Sn-Doped GaAs Films Grown By Molecular Beam Epitaxy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118710 ◽

1985 ◽

Vol 43 ◽

pp. 368-369

Author(s):

S. H. Chen

Keyword(s):

Molecular Beam Epitaxy ◽

Cross Section ◽

Electron Spectroscopy ◽

Molecular Beam ◽

Surface Segregation ◽

Secondary Ion Mass Spectrometry ◽

Specimen Preparation ◽

Near Surface ◽

Gaas Films ◽

Secondary Ion

Sn has been used extensively as an n-type dopant in GaAs grown by molecular-beam epitaxy (MBE). The surface accumulation of Sn during the growth of Sn-doped GaAs has been observed by several investigators. It is still not clear whether the accumulation of Sn is a kinetically hindered process, as proposed first by Wood and Joyce, or surface segregation due to thermodynamic factors. The proposed donor-incorporation mechanisms were based on experimental results from such techniques as secondary ion mass spectrometry, Auger electron spectroscopy, and C-V measurements. In the present study, electron microscopy was used in combination with cross-section specimen preparation. The information on the morphology and microstructure of the surface accumulation can be obtained in a fine scale and may confirm several suggestions from indirect experimental evidence in the previous studies.

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The relaxation of compressive biaxial strains in SOS via microtwins

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155013 ◽

1989 ◽

Vol 47 ◽

pp. 608-609

Author(s):

M. E. Twigg ◽

E. D. Richmond ◽

J. G. Pellegrino

Keyword(s):

Thin Film ◽

Chemical Vapor Deposition ◽

Molecular Beam Epitaxy ◽

Compressive Stress ◽

Vapor Deposition ◽

Partial Dislocation ◽

Molecular Beam ◽

Volume Fraction ◽

Chemical Vapor ◽

Silicon Thin Film

For heteroepitaxial systems, such as silicon on sapphire (SOS), microtwins occur in significant numbers and are thought to contribute to strain relief in the silicon thin film. The size of this contribution can be assessed from TEM measurements, of the differential volume fraction of microtwins, dV/dν (the derivative of the microtwin volume V with respect to the film volume ν), for SOS grown by both chemical vapor deposition (CVD) and molecular beam epitaxy (MBE).In a (001) silicon thin film subjected to compressive stress along the [100] axis , this stress can be relieved by four twinning systems: a/6[211]/( lll), a/6(21l]/(l1l), a/6[21l] /( l1l), and a/6(2ll)/(1ll).3 For the a/6[211]/(1ll) system, the glide of a single a/6[2ll] twinning partial dislocation draws the two halves of the crystal, separated by the microtwin, closer together by a/3.

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