Defect Reduction in GaAs Epilayers on Si Substrates Using Strained Layer Superlattices

ABSTRACTInxGa11-xAs-GaAsl-yPy strained layer superlattice buffer layers have been used to reduce threading dislocations in GaAs grown on Si substrates. However, for an initially high density of dislocations, the strained layer superlattice is not an effective filtering system. Consequently, the emergence of dislocations from the SLS propagate upwards into the GaAs epilayer. However, by employing thermal annealing or rapid thermal annealing, the number of dislocation impinging on the SLS can be significantly reduced. Indeed, this treatment greatly enhances the efficiency and usefulness of the SLS in reducing the number of threading dislocations.

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Growth of (GaAs)1−x (Si2)x Metastable Alloys using Migration-Enhanced Epitaxy

MRS Proceedings ◽

10.1557/proc-222-151 ◽

1991 ◽

Vol 222 ◽

Cited By ~ 1

Author(s):

T. Sudersena Rao ◽

Y. Horikoshi

Keyword(s):

Buffer Layers ◽

Double Crystal ◽

Cross Sectional ◽

Strained Layer ◽

Si Substrates ◽

Migration Enhanced Epitaxy ◽

Strained Layer Superlattice ◽

Metastable Alloys ◽

Si Content ◽

Strained Layer Superlattices

ABSTRACTEpitaxial (GaAs)1−x (Si2)x metastable alloys have been grown on GaAs (100) substrates using Migration-Enhanced Epitaxy in the composition range of 0<x<0.25. The lattice constant a0 of the alloys was found to decrease with increasing Si content from 0.56543nm at x=0 to 0.5601nm at x=0.25. Double-crystal x-ray diffraction rocking curve measurements and cross-sectional transmission electron microscopy studies made on a 10 period (GaAs)1−x(Si2)x/GaAs strained layer superlattice indicated sharp and abrupt interfaces. High crystalline quality GaAs has been grown on Si substrates using (GaAs)0.80(Si2)0.20/GaAs strained layer superlattices as buffer layers.

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The Structure of GaAs/Si(211) Heteroepitaxial Layers

MRS Proceedings ◽

10.1557/proc-91-91 ◽

1987 ◽

Vol 91 ◽

Cited By ~ 10

Author(s):

Zuzanna Liliental-Weber ◽

E.R. Weber ◽

J. Washburn ◽

T.Y. Liu ◽

H. Kroemer

Keyword(s):

Buffer Layer ◽

Surface Preparation ◽

Gaas Layer ◽

Misfit Dislocations ◽

Strained Layer ◽

Si Substrates ◽

Density Of Dislocations ◽

Gaas Buffer Layer ◽

Graded Layers ◽

Strained Layer Superlattices

ABSTRACTGallium arsenide films grown on (211)Si by molecular-beam epitaxy have been investigated using transmission electron microscopy. The main defects observed in the alloy were of misfit dislocations, stacking faults, and microtwin lamellas. Silicon surface preparation was found to play an important role on the density of defects formed at the Si/GaAs interface.Two different types of strained-layer superlattices, InGaAs/InGaP and InGaAs/GaAs, were applied either directly to the Si substrate, to a graded layer (GaP-InGaP), or to a GaAs buffer layer to stop the defect propagation into the GaAs films. Applying InGaAs/GaAs instead of InGaAs/InGaP was found to be more effective in blocking defect propagation. In all cases of strained-layer superlattices investigated, dislocation propagation was stopped primarily at the top interface between the superlattice package and GaAs. Graded layers and unstrained AlGaAs/GaAs superlattices did not significantly block dislocations propagating from the interface with Si. Growing of a 50 nm GaAs buffer layer at 505°C followed by 10 strained-layer superlattices of InGaAs/GaAs (5 nm each) resulted in the lowest dislocation density in the GaAs layer (∼;5×l07/cm2) among the structures investigated. This value is comparable to the recently reported density of dislocations in the GaAs layers grown on (100)Si substrates [8]. Applying three sets of the same strained layersdecreased the density of dislocations an additional ∼2/3 times.

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Defect Reduction in Mocvd Grown Si/GaAs

MRS Proceedings ◽

10.1557/proc-116-141 ◽

1988 ◽

Vol 116 ◽

Cited By ~ 16

Author(s):

M.M. Al-Jassim ◽

Takashi Nishioka ◽

Yoshio Itoh ◽

Akio Yamamoto ◽

Masafumi Yamaguchi

Keyword(s):

Layer Thickness ◽

Threading Dislocations ◽

Defect Reduction ◽

Closed Loops ◽

Si Substrates ◽

Dislocation Densities ◽

Low Pressure Mocvd ◽

Strained Layer Superlattices ◽

Lattice Matched

AbstractThe effectiveness of thermal annealing and strained layer superlattices (SLS's) in defect reduction in Si/GaAs structures was studied. The GaAs layers were grown on (100) Si substrates by low pressure MOCVD. They were evaluated by TEM, HREM, EBIC and PL. As-grown layers contained dislocation densities in the 108-109 cm−2 range, depending on the layer thickness. Post-growth and in situ annealing were performed on a wide variety of these structures. TEM examination showed that in situ annealing was more effective as it resulted in confining a large portion of the threading dislocations to the interface region. Furthermore, the interaction of threading dislocations to form closed loops was evident. Additionally, the effect of GaAs/GaInAs and GaInAs/GaAsP SLS's on dislocation bending was investigated. The former SLS, although not lattice matched to GaAs, proved more effective.

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Rapid Thermal Annealing Effects in InxGal−xAs/GaAs Strained-Layer Superlattices

MRS Proceedings ◽

10.1557/proc-221-453 ◽

1991 ◽

Vol 221 ◽

Author(s):

J.A. Olsen ◽

E.L. Hu ◽

D.R. Myers ◽

J.F. Klem ◽

Andrew Skumanich

Keyword(s):

Thermal Annealing ◽

Rapid Thermal Annealing ◽

Strained Layer ◽

Annealing Effects ◽

Strained Layer Superlattices

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On the Existence of Multiple Equilibrium States in Strained-Layer Superlattices

MRS Proceedings ◽

10.1557/proc-103-61 ◽

1987 ◽

Vol 103 ◽

Cited By ~ 2

Author(s):

William C. Johnson

Keyword(s):

Free Energy ◽

Equilibrium State ◽

Stable Equilibrium ◽

Multiple Equilibrium ◽

Equilibrium Thermodynamic ◽

Relative Thickness ◽

Two Phase ◽

Strained Layer ◽

Strained Layer Superlattice ◽

Strained Layer Superlattices

ABSTRACTUsing recent results from the thermodynamics of stressed solids, two-phase coexistence in a simple binary strained-layer superlattice is examined. We show that for a given temperature and overall composition of the superlattice, there can exist more than one linearly stable, equilibrium thermodynamic state. That is, there may exist several combinations of relative thickness of the phases and corresponding phase compositions that minimize the free energy of the system. The equilibrium state observed experimentally can, therefore, be influenced by the processing path.

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Synthesis of Ge1−xSnx Alloy Thin Films by Rapid Thermal Annealing of Sputtered Ge/Sn/Ge Layers on Si Substrates

Materials ◽

10.3390/ma11112248 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2248 ◽

Cited By ~ 4

Author(s):

Hadi Mahmodi ◽

Md Hashim ◽

Tetsuo Soga ◽

Salman Alrokayan ◽

Haseeb Khan ◽

...

Keyword(s):

Thermal Annealing ◽

Rapid Thermal Annealing ◽

Near Infrared ◽

Annealing Temperature ◽

Solid Phase ◽

Infrared Region ◽

Alloy Formation ◽

Phase Mixing ◽

Si Substrates ◽

Msm Photodetector

In this work, nanocrystalline Ge1−xSnx alloy formation from a rapid thermal annealed Ge/Sn/Ge multilayer has been presented. The multilayer was magnetron sputtered onto the Silicon substrate. This was followed by annealing the layers by rapid thermal annealing, at temperatures of 300 °C, 350 °C, 400 °C, and 450 °C, for 10 s. Then, the effect of thermal annealing on the morphological, structural, and optical characteristics of the synthesized Ge1−xSnx alloys were investigated. The nanocrystalline Ge1−xSnx formation was revealed by high-resolution X-ray diffraction (HR-XRD) measurements, which showed the orientation of (111). Raman results showed that phonon intensities of the Ge-Ge vibrations were improved with an increase in the annealing temperature. The results evidently showed that raising the annealing temperature led to improvements in the crystalline quality of the layers. It was demonstrated that Ge-Sn solid-phase mixing had occurred at a low temperature of 400 °C, which led to the creation of a Ge1−xSnx alloy. In addition, spectral photo-responsivity of a fabricated Ge1−xSnx metal-semiconductor-metal (MSM) photodetector exhibited its extending wavelength into the near-infrared region (820 nm).

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Interdiffusion in MBE-Grown Symmetrically and Asymmetrically Strained Si/Si1−xGex Superlattices Investigated by Ion Scattering

MRS Proceedings ◽

10.1557/proc-263-255 ◽

1992 ◽

Vol 263 ◽

Author(s):

B. Holländer ◽

R. Butz ◽

S. Mantl

Keyword(s):

Thermal Annealing ◽

Rapid Thermal Annealing ◽

Rutherford Backscattering Spectrometry ◽

Buffer Layers ◽

Arrhenius Law ◽

Ion Scattering ◽

Strained Si ◽

The Individual ◽

Interdiffusion Coefficients ◽

Fourier Algorithm

ABSTRACTThe interdiffusion in MBE-grown Si/Si1−xGex superlattices was measured by Rutherford backscattering spectrometry. The superlattices consisted of 5 periods of 100 !A Si and 100 !A Si1−xGex layers with Ge concentrations, x, between 0.20 and 0.70. Both, asymmetrically strained superlattices, grown on Si(100), as well as symmetrically strained superlattices, grown on relaxed Si1−y.Gey buffer layers were investigated. Rapid thermal annealing in the temperature range between 900°C and 1125°C leads to significant interdiffusion between the individual layers, indicated by a decrease of the amplitudes of the backscattering spectra. Interdiffusion coefficients were deduced using a Fourier algorithm. The interdiffusion coefficients follow an Arrhenius law for a given Ge concentration. The interdiffusivity increases significantly with increasing Ge concentration.

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The Growth of InAsSb/InGaAs Strained-Layer Superlattices by Metal-Organic Chemical Vapor Deposition

MRS Proceedings ◽

10.1557/proc-325-493 ◽

1993 ◽

Vol 325 ◽

Cited By ~ 3

Author(s):

R. M. Biefeld ◽

K. C. Baucom ◽

S. R. Kurtz ◽

D. M. Follstaedt

Keyword(s):

Chemical Vapor Deposition ◽

Thermodynamic Model ◽

Vapor Deposition ◽

Chemical Vapor ◽

Organic Chemical ◽

Strained Layer ◽

Strained Layer Superlattice ◽

Metal Organic ◽

Strained Layer Superlattices ◽

Organic Chemical Vapor Deposition

AbstractWe have grown InAsl-xSbx/Inl-yGayAs strained-layer superlattice (SLS) semiconductors lattice matched to InAs using a variety of conditions by metal-organic chemical vapor deposition. The V/III ratio was varied from 2.5 to 10 at a temperature of 475 °C, at pressures of 200 to 660 torr and growth rates of 3 - 5 A/s and layer thicknesses ranging from 55 to 152 Å. The composition of the InAsSb ternary can be predicted from the input gas molar flow rates using a thermodynamic model. At lower temperatures, the thermodynamic model must be modified to take account of the incomplete decomposition of arsine and trimethylantimony. Diodes have been prepared using Zn as the p-type dopant and undoped SLS as the n-type material. The diode was found to emit at 3.56 μm. These layers have been characterized by optical microscopy, SIMS, x-ray diffraction, and transmission electron diffraction. The optical properties of these SLS's were determined by infrared photoluminescence and absorption measurements.

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