Effect of the Introduction of a MBE Buffer Layer on the Morphology of InSb Almbe Layers Grown on InP Substrates

1995 ◽  
Vol 399 ◽  
Author(s):  
J.C. Ferrer ◽  
A. Cornet ◽  
F. Peiró ◽  
J.R. Morante ◽  
T. Utzmeier ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
Three Dimensional ◽  
Atomic Layer ◽  
Buffer Layers ◽  
Dislocation Network ◽  
Threading Dislocation ◽  
Large Lattice Mismatch ◽  
Inp Substrates

ABSTRACTIn this paper we report on the morphology of InSb layers grown by atomic layer molecular beam epitaxy (ALMBE) onto InP substrates at low temperatures (330<T<400°C), comparing the nature and densities of defects with those found in ALMBE InSb films grown over InSb/InP buffer layers grown by molecular beam epitaxy (MBE). The main types of defects for ALMBE direct layers are threading dislocations and stacking faults with similar defect densities along both á110ñ directions. The inclusion of the intermediate InSb/InP MBE grown buffer layers leads to lower threading dislocation densities but higher and anisotropic stacking fault distribution. Moreover, different types of three-dimensional defects appear, which are associated with pyramidal or truncated pyramidal hillocks on the surface. These defects, consisting in twins associations are originated at the InSb/InP MBE interface and they are induced by an anomalous growth of InSb layers. In all the cases, the strain caused by the large lattice mismatch is accommodated by means of a pure edge-type misfit dislocation network placed at the interface.

scholarly journals Selective Area Growth and Structural Characterization of GaN Nanostructures on Si(111) Substrates

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 366 ◽  
Author(s):  
Alexana Roshko ◽  
Matt Brubaker ◽  
Paul Blanchard ◽  
Todd Harvey ◽  
Kris Bertness
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
Buffer Layers ◽  
Selective Area Growth ◽  
Gan Nanowires ◽  
Selective Area ◽  
Area Growth ◽  
Eutectic Formation

Selective area growth (SAG) of GaN nanowires and nanowalls on Si(111) substrates with AlN and GaN buffer layers grown by plasma-assisted molecular beam epitaxy was studied. For N-polar samples filling of SAG features increased with decreasing lattice mismatch between the SAG and buffer. Defects related to Al–Si eutectic formation were observed in all samples, irrespective of lattice mismatch and buffer layer polarity. Eutectic related defects in the Si surface caused voids in N-polar samples, but not in metal-polar samples. Likewise, inversion domains were present in N-polar, but not metal-polar samples. The morphology of Ga-polar GaN SAG on nitride buffered Si(111) was similar to that of homoepitaxial GaN SAG.

scholarly journals Снижение плотности прорастающих дислокаций в темплейтах AlN/c-сапфир, выращенных методом плазменно-активированной молекулярно-пучковой эпитаксии

2020 ◽  
Vol 46 (8) ◽  
pp. 36
Author(s):  
В.В. Ратников ◽  
Д.В. Нечаев ◽  
А.В. Мясоедов ◽  
О.А. Кошелев ◽  
В.Н. Жмерик
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Flux Ratio ◽  
Buffer Layers ◽  
Stress Generation ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Regimes ◽  
Dislocation Densities

Multiple-crystal X-ray diffraction and a multi-beam optical stress sensor were used to study AlN/c-sapphire templates grown by plasma-assisted molecular beam epitaxy. The influence of the nucleation and buffer layers growth regimes, temperature, the ratio between Al and N* growth fluxes on the stress generation and the character of the dislocation structure were analyzed. Templates with the best crystal quality with screw and edge threading dislocation densities in a range of 4∙10^8 and 8∙10^9 cm-2, respectively, were obtained at the flux ratio of Al to N* close to 1 by using two-stage temperature regimes.

scholarly journals Microstructure of Pyramidal Defects in InSb Layers Grown by Atomic Layer Molecular Beam Epitaxy on InP Substrates

1997 ◽  
Vol 7 (12) ◽  
pp. 2317-2324 ◽  
Author(s):  
J. C. Ferrer ◽  
F. Peiró ◽  
A. Cornet ◽  
J. R. Morante ◽  
T. Utzmeier ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Inp Substrates

Transport in High-Mobility Si1−xGex Heterostructures Grown by Molecular-Beam Epitaxy

1992 ◽  
Vol 281 ◽  
Author(s):  
Don Monroe ◽  
Y.-H. Xie ◽  
E. A. Fitzgerald ◽  
P. J. Silverman
Keyword(s):  
Molecular Beam Epitaxy ◽  
Hall Effect ◽  
Molecular Beam ◽  
High Mobility ◽  
Interface Roughness ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Fractional Quantum Hall ◽  
Angle Scattering ◽  
Interface Roughness Scattering

ABSTRACTWe report Hall mobilities (at T = 4.2K) as high as 180,000cm2V−1 s−1 in modulation-doped Si layers in Si1−x Gex heterostructures grown by Molecular-Beam Epitaxy. These mobilities reflect dramatic improvements in the quality of relaxed Si1−xGex buffer layers (with x'30%) grown by gradual grading of composition at high temperature. The resulting moderate threading dislocation densities (< 106 cm−2 ) appear to cause no mobility degradation. The strong damping of Shubnikov de Haas oscillations, as well as the increase of mobility with carrier density, indicate predominantly small-angle scattering. This suggests that residual Coulomb scattering from background impurities limit the mobility, rather than interface-roughness scattering as for the Si/SiO2 interface. The reduced interfacial scattering, as well as the strain-induced splitting of the valley degeneracy to select the two low-effective-mass valleys, significantly enhance room-temperature transport as well, with μHall ' 2,100cm2 V−1 s−1. We also observe a small splitting of the remaining twofold valley degeneracy using the integral quantized Hall effect. As a further indication of the high sample quality, measurements to 17T at 0.3K show indications of the v = 2/3 fractional quantum Hall effect.

Growth and Characterization of InxGa1−xP(x≤0.38) on GaP(1OO) with a Linearly Graded Buffer Layer by Gas-Source Molecular Beam Epitaxy

1992 ◽  
Vol 281 ◽  
Author(s):  
T. P. Chin ◽  
J. C. P. Chang ◽  
K. L. Kavanagh ◽  
C. W. Tu ◽  
P. D. Kirchner ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
High Energy ◽  
Threading Dislocation ◽  
Dislocation Loops ◽  
Double Crystal ◽  
X Ray ◽  
Gas Source

ABSTRACTInxGa1−xP(x>0.27) grown on a GaP substrate has a large direct-bandgap, which is suitable for yellow light emission on a transparent substrate. Because of the large lattice mismatch, usually a thick (10–20 μm) graded buffer layer was required to reduce the threading dislocation density. In this work we report that a thin (1.2 μm for x≃0.35), linearly graded buffer layer can filter out dislocations effectively. The structures were grown by gas-source molecular beam epitaxy. Reflection high-energy electron diffraction (RHEED) intensity oscillations and X-ray double-crystal diffraction were used to control and determine the composition, respectively. Threading dislocations are well confined in the buffer layer, as shown under transmission electron microscopy. Dislocation loops injected into the substrate were observed, similar to those observed in the Six Ge1−x/Si system. X-ray analysis also shows that the 3% mismatched buffer layer is fully relaxed. This relaxed buffer layer then can serve as a substrate for further growth. Homojunction and heterojunction light emitting diodes were fabricated to demonstrate the material quality.

Molecular Beam Epitaxy of Single Crystal Colossal Magneto-Resistive Material

1995 ◽  
Vol 401 ◽  
Author(s):  
J. N. Eckstein ◽  
I. Bozovic ◽  
M. Rzchowski ◽  
J. O'donnell ◽  
B. Hinaus ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Growth Conditions ◽  
Dislocation Network ◽  
Layer By Layer ◽  
Flat Surfaces ◽  
Low Field ◽  
Resistive Material ◽  
Atomically Flat

AbstractWe have grown films of (LaSr)MnO3 (LSMO) and (LaCa)MnO3 (LCMO) using atomic layer-by-layer molecular beam epitaxy (ALL-MBE). Depending on growth conditions, substrate lattice constant and the exact cation stoichiometry, the films are either pseudomorphic or strain relaxed. The pseudomorphic films show atomically flat surfaces, with a unit cell terrace structure that is a replica of that observed on the slightly vicinal substrates, while the strain relaxed films show bumpy surfaces correlated with a dislocation network. All films show tetragonal structure and exhibit anisotropic magnetoresistance, with a low field response, (1/R)(dR/dH) as large as 5 T−1.

Morphology evolution of InSb island grown on InP substrates by atomic layer molecular beam epitaxy

1998 ◽  
Vol 43-44 ◽  
pp. 51-57 ◽  
Author(s):  
J.C Ferrer ◽  
F Peiró ◽  
A Cornet ◽  
J.R Morante ◽  
T Utzmeier ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Morphology Evolution ◽  
Inp Substrates

Thermal annealing effect on InAs/InGaAs quantum dots grown by atomic layer molecular beam epitaxy

2004 ◽  
Vol 269 (2-4) ◽  
pp. 181-186 ◽  
Author(s):  
G.X. Shi ◽  
P. Jin ◽  
B. Xu ◽  
C.M. Li ◽  
C.X. Cui ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Molecular Beam Epitaxy ◽  
Thermal Annealing ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Annealing Effect

Optical and structural prorerties of InAs epilayer on graded InGaAs

2001 ◽  
Vol 696 ◽  
Author(s):  
Gu Hyun Kim ◽  
Jung Bum Choi ◽  
Joo In Lee ◽  
Se-Kyung Kang ◽  
Seung Il Ban ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Residual Strain ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
Peak Position ◽  
Excitation Intensity ◽  
Total Thickness ◽  
Ingaas Layer ◽  
X Ray Diffraction ◽  
X Ray

AbstractWe have studied infrared photoluminescence (PL) and x-ray diffraction (XRD) of 400 nm and 1500 nm thick InAs epilayers on GaAs, and 4 nm thick InAs on graded InGaAs layer with total thickness of 300 nm grown by molecular beam epitaxy. The PL peak positions of 400 nm, 1500 nm and 4 nm InAs epilayer measured at 10 K are blue-shifted from that of InAs bulk by 6.5, 4.5, and 6 meV, respectively, which can be largely explained by the residual strain in the epilayer. The residual strain caused by the lattice mismatch between InAs and GaAs or graded InGaAs/GaAs was observed from XRD measurements. While the PL peak position of 400 nm thick InAs layer is linearly shifted toward higher energy with increase in excitation intensity ranging from 10 to 140 mW, those of 4 nm InAs epilayer on InGaAs and 1500 nm InAs layer on GaAs is gradually blue-shifted and then, saturated above a power of 75 mW. These results suggest that adopting a graded InGaAs layer between InAs and GaAs can efficiently reduce the strain due to lattice mismatch in the structure of InAs/GaAs.

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