Correlation between the violet luminescence intensity and defect density in AlN epilayers grown by ammonia-source molecular beam epitaxy

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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Homo- and Hetero-Epitaxial Gallium Nitride Grown by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-537-g4.11 ◽

1998 ◽

Vol 537 ◽

Author(s):

C.T. Foxon ◽

T.S. Cheng ◽

D. Korakakis ◽

S.V. Novikov ◽

R.P. Campion ◽

...

Keyword(s):

High Temperature ◽

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Defect Density ◽

Boundary Structure ◽

Quantum Well Structures ◽

Flat Surfaces ◽

Grain Boundary Structure ◽

Bulk Gan ◽

Atomically Flat

AbstractVarious methods have been used to initiate growth by Molecular Beam Epitaxy (MBE) of GaN on sapphire, or other substrates, but there is always a problem with morphology and with a high defect density which results in the formation of a sub-grain boundary structure. We show that by using, homo-epitaxial growth on properly prepared bulk GaN substrates, combined with high temperature growth, we obtain a significant improvement in surface morphology. Growth at sufficiently high temperature leads to a rapid smoothing of the surface and to almost atomically flat surfaces over relatively large areas. Multi-Quantum Well structures grown on such GaN epitaxial films are dislocation free with abrupt interfaces.

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GaSb layers with low defect density deposited on (001) GaAs substrate in two-dimensional growth mode using molecular beam epitaxy

Current Applied Physics ◽

10.1016/j.cap.2019.02.012 ◽

2019 ◽

Vol 19 (4) ◽

pp. 542-547

Author(s):

Agata Jasik ◽

Iwona Sankowska ◽

Andrzej Wawro ◽

Jacek Ratajczak ◽

Dariusz Smoczyński ◽

...

Keyword(s):

Molecular Beam Epitaxy ◽

Gaas Substrate ◽

Molecular Beam ◽

Defect Density ◽

Growth Mode ◽

Two Dimensional ◽

Dimensional Growth

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Ferromagnetism in lightly Gd doped GaN: The role of defects

MRS Proceedings ◽

10.1557/opl.2011.177 ◽

2011 ◽

Vol 1290 ◽

Cited By ~ 2

Author(s):

J. K. Mishra ◽

S. Dhar ◽

M. A. Khaderabad ◽

O. Brandt

Keyword(s):

Magnetic Properties ◽

Molecular Beam Epitaxy ◽

Saturation Magnetization ◽

Magnetic Moment ◽

Molecular Beam ◽

Defect Density ◽

Defect Cluster ◽

Clear Correlation ◽

Defect Band

ABSTRACTGd:GaN layers grown with different Gd concentrations by molecular beam epitaxy (MBE) are studied using photoconductivity and photo-thermoelectric power spectroscopy. Our study reveals that the incorporation of Gd produces a large concentration of acceptor-like defects in the GaN lattice. The defect band is found to be located ~450meV above the valence band. Moreover, the concentration of defects is found to increase with the Gd concentration. The effect of annealing on the structural and the magnetic properties of GaN implanted with Gd is also investigated. A clear correlation between the saturation magnetization and the defect density is observed in implanted samples. The colossal magnetic moment per Gd ion and the ferromagnetism observed in this material is explained in terms of the formation of giant defect cluster around each Gd ion.

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Growth of (110) GaAs/GaAs by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-46-391 ◽

1985 ◽

Vol 46 ◽

Cited By ~ 2

Author(s):

L.T. Parechanian ◽

E.R. Weber ◽

T.L. Hierl

Keyword(s):

Molecular Beam Epitaxy ◽

Substrate Temperature ◽

Hall Effect ◽

Room Temperature ◽

Molecular Beam ◽

Defect Density ◽

Temperature Dependent ◽

Mbe Growth ◽

Order Of Magnitude ◽

Hall Effect Measurements

AbstractThe simultaneous molecular beam epitaxy (MBE) growth of (100) and (110) GaAs/GaAsintentionally doped with Si(∼lE16/cm^3) was studied as a function of substrate temperature, arsenic overpressure, and epitaxial growth rate. The films wereanalyzed by scanning electron and optical microscopy, liquid helium photoluminescence (PL), and electronic characterization.For the (110) epitaxal layers, an increase in morphological defect density and degradation of PL signal was observed with a lowering of the substrate temperature from 570C. Capacitance-voltage (CV) and Hall Effect measurements yield room temperature donor concentrations for the (100) films of n∼l5/cm^3 while the (110) layers exhibit electron concentrations of n∼2El7/cm^3. Hall measurements at 77K on the (100) films show the expected mobility enhancement of Si donors, whereas the (110) epi layers become insulating or greatly compensated. This behavior suggests that room temperature conduction in the (110) films is due to a deeper donor partially compensated by an acceptor level whose concentration is of the same order of magnitude as that of any electrically active Si. Temperature dependent Hall effect indicates that the activation energy of the deeper donor level lies ∼290 meV from the conduction band. PL and Hall effect indicate that the better quality (110) material is grown by increasingthe arsenic flux during MBE growth. The nature of the defects involved with the growth process will be discussed.

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Molecular beam epitaxy of low defect density (⩽1×104 cm−2) ZnSSe on GaAs

Applied Physics Letters ◽

10.1063/1.116338 ◽

1996 ◽

Vol 68 (20) ◽

pp. 2828-2830 ◽

Cited By ~ 46

Author(s):

B. J. Wu ◽

G. M. Haugen ◽

J. M. DePuydt ◽

L. H. Kuo ◽

L. Salamanca‐Riba

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Defect Density

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Algan/Gan High-Electron-Mobility Transistors Grown By Ammonia Source Molecular Beam Epitaxy

Gallium Nitride (GaN) ◽

10.4324/b19387-2 ◽

2017 ◽

pp. 45-61

Author(s):

Yvon Cordier

Keyword(s):

Molecular Beam Epitaxy ◽

Electron Mobility ◽

Molecular Beam ◽

High Electron Mobility Transistors ◽

High Electron ◽

High Electron Mobility ◽

Electron Mobility Transistors ◽

Ammonia Source

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Quality and uniformity assessment of AlGaN/GaN quantum wells and HEMT heterostructures grown by molecular beam epitaxy with ammonia source

physica status solidi (c) ◽

10.1002/pssc.200565423 ◽

2006 ◽

Vol 3 (6) ◽

pp. 2325-2328 ◽

Cited By ~ 12

Author(s):

Y. Cordier ◽

F. Pruvost ◽

F. Semond ◽

J. Massies ◽

M. Leroux ◽

...

Keyword(s):

Molecular Beam Epitaxy ◽

Quantum Wells ◽

Molecular Beam ◽

Ammonia Source

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Trapping of Oxygen at Homoepitaxial Si-Si Interfaces Grown by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-59-317 ◽

1985 ◽

Vol 59 ◽

Author(s):

R. Hull ◽

M. E. Twigg ◽

J. C. Bean ◽

J. M. Gibson ◽

D. C. Joy

Keyword(s):

Molecular Beam Epitaxy ◽

Thermal Annealing ◽

Molecular Beam ◽

Defect Density ◽

High Density ◽

Buffer Layers ◽

Si Substrates ◽

Preparation Conditions ◽

Primary Model ◽

Post Deposition

ABSTRACTInterfaces between Si substrates and epitaxial Si buffer layers grown by Molecular Beam Epitaxy (MBE) are shown to contain a high density of SiOx pockets for certain sustrate preparation conditions. It is also shown that post-deposition thermal annealing of these structures grown upon Czochralski wafers can lead to a greatly increased defect density at the interface. The primary model proposed for this increase is trapping of background oxygen diffusing from the bulk of the Czochralski substrate wafers.

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Homo- and Hetero-Epitaxial Gallium Nitride Grown by Molecular Beam Epitaxy

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300002933 ◽

1999 ◽

Vol 4 (S1) ◽

pp. 484-489 ◽

Cited By ~ 2

Author(s):

C.T. Foxon ◽

T.S. Cheng ◽

D. Korakakis ◽

S.V. Novikov ◽

R.P. Campion ◽

...

Keyword(s):

High Temperature ◽

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Defect Density ◽

Boundary Structure ◽

Quantum Well Structures ◽

Flat Surfaces ◽

Grain Boundary Structure ◽

Bulk Gan ◽

Atomically Flat

Various methods have been used to initiate growth by Molecular Beam Epitaxy (MBE) of GaN on sapphire, or other substrates, but there is always a problem with morphology and with a high defect density which results in the formation of a sub-grain boundary structure. We show that by using, homo-epitaxial growth on properly prepared bulk GaN substrates, combined with high temperature growth, we obtain a significant improvement in surface morphology. Growth at sufficiently high temperature leads to a rapid smoothing of the surface and to almost atomically flat surfaces over relatively large areas. Multi-Quantum Well structures grown on such GaN epitaxial films are dislocation free with abrupt interfaces.

Download Full-text