Molecular-Beam Epitaxial Growth of GaAs on Si(321)

1988 ◽  
Vol 116 ◽  
Author(s):  
P.N. Uppal ◽  
J.S. Ahearn ◽  
S.W. Duncan
Keyword(s):  
Molecular Beam ◽  
Strain Relaxation ◽  
Stacking Faults ◽  
Dislocation Glide ◽  
Molecular Beam Epitaxial ◽  
Charged Interface ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Gaas Films ◽  
Molecular Beam Epitaxial Growth

AbstractMaterial properties of GaAs films grown on Si(321) substrates using molecular beam epitaxy (MBE) were evaluated and compared to films grown on Si(100) and Si(211). Dislocation densities in the GaAs(321) films, determined using transmission electron microscopy (TEM), were lower than those observed in GaAs(100) and GaAs(211), and the density of stacking faults in GaAs(321) also was quantitatively lower than in GaAs(211). Low-temperature (4.2 K) photoluminescence spectroscopy (PL) indicated that the tensile stress on the GaAs(321) films was greater than that on GaAs(100). These differences are attributed to changes in the strain-relaxation process caused by variations in the number of geometric arrangement of active-dislocation glide systems with different orientations. In addition, Si uptake near the GaAs/Si interface was less than 1/100 of a monolayer in GaAs(321) and 1/4 of a monolayer in GaAs(100). This difference is attributed to the presence of a non-polar (neutral) interface in the (321), whereas the (100) has a polar (charged) interface. MODFET devices with a I-)m gate length exhibited a transconductance of 180–200 ms/mm, comparable to devices on homoepitaxial GaAs(100).

Molecular Beam Epitaxial Growth and Characterization of GaAs Films on Thin Si Substrates

1998 ◽  
Vol 37 (Part 1, No. 1) ◽  
pp. 39-44 ◽  
Author(s):  
Kenzo Maehashi ◽  
Hisao Nakashima ◽  
Frank Bertram ◽  
Peter Veit ◽  
Jürgen Christen
Keyword(s):  
Epitaxial Growth ◽  
Molecular Beam ◽  
Si Substrates ◽  
Molecular Beam Epitaxial ◽  
Gaas Films ◽  
Molecular Beam Epitaxial Growth

Molecular Beam Epitaxial Growth of (Al,Ga)As Tilted Superlattices on Vicinal GaAs (110)

1991 ◽  
Vol 237 ◽  
Author(s):  
Mohan Krishnamurthy ◽  
M. Wassermeier ◽  
H. Weman ◽  
J. L. Merz ◽  
P. M. Petroffa
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Vicinal Surface ◽  
Vicinal Surfaces ◽  
Island Growth ◽  
Quantum Well Structures ◽  
Molecular Beam Epitaxial ◽  
Transmission Electron ◽  
Molecular Beam Epitaxial Growth

ABSTRACTA study of the molecular beam epitaxial (MBE) growth on singular and vicinal (110) surfaces of GaAs is presented. Quantum well structures and tilted superlattices (TSL) were grown on substrates misoriented 0.5°-2° towards the nearest [010] and [111]A azimuths at growth temperatures ranging from 450° C to 600° C under different growth conditions. The structures were characterized by Nomarski optical microscopy, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy.Two types of faceting were observed on the surfaces. The structures grown at temperatures above 540°C and As beam fluxes below l×10-5 torr showed V-shaped facets pointing in the [001] direction and are attributed to As deficient island growth. Lower temperatures and higher As beam fluxes lead to surfaces with microfacets that are elongated along the respective step directions on the vicinal surface and are due to step bunching during growth. Their density and height decrease with decreasing vicinal angle and they disappear on the singular (110) surface. The photoluminescence of the GaAs quantum wells grown on these samples is redshifted with respect to that of the quantum wells grown on the flat surface. This is being ascribed to the fact that on the vicinal surface, the recombination takes place at the facets where the quantum wells are wider.The contrast in the TEM images of the TSL show for the samples misoriented towards [010] that the lateral segregation to the step edges on this surface is appreciable. The TSL spacing and the tilt however show that during growth the vicinal surfaces tend towards a surface with smaller miscut.

Molecular Beam Epitaxial Growth of Cdl-xznxTe Matched to HgCdTe Alloys

1986 ◽  
Vol 90 ◽  
Author(s):  
N. Magnea ◽  
F. Dal'bo ◽  
J. L. Pautrat ◽  
A. Million ◽  
L. Di Cioccio ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Bulk Material ◽  
Strained Layers ◽  
Molecular Beam Epitaxial ◽  
Transmission Electron ◽  
Molecular Beam Epitaxial Growth ◽  
Thick Layers

ABSTRACTCD1−xZnxTe alloys of various composition have been grown by the Molecular Beam Epitaxy Technique and characterized by Transmission Electron Microscopy. C(V) measurements and photoluminescence spectroscopy techniques. The quality of the thick layers is comparable to that of bulk material. Thin strained layers have also been grown whose interfaces are structurally good. The recombination within a CdTe well confined between Cd1−xZnxTe barriers is dominated by intrinsic processes.

A Study on the Strain and Microstructure in SiGe Film Grown on Si(001) Substrate by MBE

1994 ◽  
Vol 356 ◽  
Author(s):  
Kyoung-Ik Cho ◽  
Sahn Nahm ◽  
Sang-Gi Kim ◽  
Seung-Chang Lee ◽  
Kyung-Soo Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam ◽  
Large Strain ◽  
Strain Relaxation ◽  
Stacking Faults ◽  
Double Crystal ◽  
Crystalline Layer ◽  
X Ray ◽  
Transmission Electron ◽  
Plain Strain

AbstractSi/Si0.8Ge0.2/Si(001) structures were grown at various growth temperatures (250 ∼ 760 °C) using molecular beam epitaxy, and the variation of strain and microstructure of the film was investigated using double crystal X-ray diffractometry and transmission electron microscopy. SiGe films with good single crystallinity were obtained at the growth temperatures of 440 ∼ 600 °C. For the samples grown below 350 °C, an amorphous SiGe film was developed over the SiGe single crystalline layer with a jagged amorphous/crystalline (a/c) interface, and many defects such as stacking faults and microtwins were formed below the a/c interface. Dislocations were developed through out the films for the samples grown above 680 °C. In addition, for the samples grown below 680 °C, the amount of in-plane strain of the SiGe film was found to be about − 8×l0−3 without strain relaxation. However, the SiGe films grown at 760 °C have small in-plain strain of − 4×l0−3 and large strain relaxation of 50%.

Molecular Beam Epitaxial Growth of Gaas on Silicon with Buried Implanted Oxides

1987 ◽  
Vol 107 ◽  
Author(s):  
K. Das ◽  
T.P. Humphreys ◽  
J.B. Posthill ◽  
N. Parikh ◽  
J. Tarn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam ◽  
Antiphase Domain ◽  
Molecular Beam Epitaxial ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
First Results ◽  
Direct Growth ◽  
Molecular Beam Epitaxial Growth ◽  
Microscopy Techniques

AbstractWe report the first results of direct growth of GaAs by molecular beam epitaxy on nominally (100) oriented silicon with buried implanted oxides. Rutherford backscattering and transmission electron microscopy techniques have been used to characterize these layers. The formation of hillocks and a uniform layer of GaAs in the intervening regions between hillocks have been observed. Microtwins, dislocations and antiphase domain boundaries are the predominant defects observed in these layers.

Reduction of Defect Density in Heteroepitaxial GexSi1-x Grown on Patterned Si Substrates

1989 ◽  
Vol 160 ◽  
Author(s):  
E.A. Fitzgerald ◽  
Y.-H. Xie ◽  
J. Michel ◽  
P.E. Freeland ◽  
B.E. Weir
Keyword(s):  
Defect Density ◽  
Threading Dislocation ◽  
Patterned Substrate ◽  
Si Substrates ◽  
Molecular Beam Epitaxial ◽  
Etch Pit ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Electron Beam Induced Current ◽  
Molecular Beam Epitaxial Growth

AbstractWe have investigated the molecular beam epitaxial growth of GexSi1-x on small growth areas patterned in Si substrates. Electron beam induced current, etch-pit density measurements, transmission electron microscopy, and photoluminescence were used to compare dislocation densities in GexSi1-x on patterned and unpattemed substrates. We find a dramatic reduction in both misfit and threading dislocation densities for the patterned substrate growth. Our results also show that dislocation introduction is dominated by heterogeneous nucleation.

Growth of Metamorphic InGaP for Wide-Bandgap Photovoltaic Junction by MBE

2010 ◽  
Vol 1268 ◽  
Author(s):  
John Simon ◽  
Stephanie Tomasulo ◽  
Paul Simmonds ◽  
Manuel J Romero ◽  
Minjoo Larry Lee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Strain Relaxation ◽  
Wide Bandgap ◽  
Threading Dislocation ◽  
Step Size ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Substrate Temperatures

AbstractMetamorphic triple-junction solar cells can currently attain efficiencies as high as 41.1%. Using additional junctions could lead to efficiencies above 50%, but require the development of a wide bandgap (2.0-2.2eV) material to act as the top layer. In this work we demonstrate wide bandgap InyGa1-yP grown on GaAsxP1-x via solid source molecular beam epitaxy. Unoptimized tensile GaAsxP1-x buffers grown on GaAs exhibit asymmetric strain relaxation, along with formation of faceted trenches 100-300 nm deep in the [01-1] direction. Smaller grading step size and higher substrate temperatures minimizes the facet trench density and results in symmetric strain relaxation. In comparison, compressively-strained graded GaAsxP1-x buffers on GaP show nearly-complete strain relaxation of the top layers and no evidence of trenches. We subsequently grew InyGa1-yP layers on the GaAsxP1-x buffers. Photoluminescence and transmission electron microscopy measurements show no indication of phase separation or CuPt ordering. Taken in combination with the low threading dislocation densities obtained, MBE-grown InyGa1-yP layers are promising candidates for future use as the top junction of a multi-junction solar cell.

Molecular Beam Epitaxial Growth and Characterization of GaAs on Sapphire and Silicon-on-Sapphire Substrates

1988 ◽  
Vol 144 ◽  
Author(s):  
T. P. Humphreys ◽  
C. J. Miner ◽  
N. R. Parikh ◽  
K. Das ◽  
M. K. Summerville ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam ◽  
Optical Analysis ◽  
Molecular Beam Epitaxial ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Current Voltage ◽  
Semiconductor Contacts ◽  
Molecular Beam Epitaxial Growth

ABSTRACTEpitaxial GaAs layers have been grown by molecular beam epitaxy on (1012) sapphire and silicon-on-sapphire substrates. The grown layers were characterized by optical and transmission electron microscopy; Rutherford backscattering/channeling of 2.1 MeV He+ ions; Raman spectroscopy; Hall mobility measurements; photoluminescence spectroscopy and current-voltage measurements from metal-semiconductor contacts. The extensive microstructural, electrical and optical analysis of the GaAs layers indicates that the films deposited on silicon-on-sapphire are superior to those grown directly on (1012) sapphire substrates.

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