Impact of Buffered Layer Growth Conditions on Grown-In Vacancy Concentrations in Molecular Beam Epitaxy Silicon Germanium

2004 ◽  
Vol 809 ◽  
Author(s):  
Kareem M. Shoukri ◽  
Yaser M. Haddara ◽  
Andrew P. Knights ◽  
Paul G. Coleman ◽  
Mohammad M. Rahman ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Point Defects ◽  
Growth Temperature ◽  
Silicon Germanium ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Layer Growth ◽  
Vacancy Clusters ◽  
Temperature And Growth

ABSTRACTSilicon-Germanium (SiGe) has become increasingly attractive to semiconductor manufacturers over the last decade for use in high performance devices. In order to produce thin layers of device grade SiGe with low concentrations of point defects and well-controlled doping profiles, advanced growth and deposition techniques such as molecular beam epitaxy (MBE) are used. One of the key issues in modeling dopant diffusion during subsequent processing is the concentration of grown-in point defects. The incorporation of vacancy clusters and vacancy point defects in 200nm SiGe/Si layers grown by molecular beam epitaxy over different buffer layers has been observed using beam-based positron annihilation spectroscopy. Variables included the type of buffer layer, the growth temperature and growth rate for the buffer, and the growth temperature and growth rate for the top layer. Different growth conditions resulted in different relaxation amounts in the top layer, but in all samples the dislocation density was below 106 cm−2. Preliminary results indicate a correlation between the size, type and concentration of vacancy defects and the buffer layer growth temperature. At high buffer layer growth temperature of 500°C the vacancy point defect concentration is below the PAS detectable limit of approximately 1015 cm−3. As the buffer layer growth is decreased to a minimum value of 300°C, large vacancy clusters are observed in the buffered layer and vacancy point defects are observed in the SiGe film. These results are relevant to the role played by point defects grown-in at temperatures below ∼350°C in modeling dopant diffusion during processing.

scholarly journals Processes of formation of epitaxial arrays of self-catalytic GaP nanowires on Si (111)

2021 ◽  
Vol 2103 (1) ◽  
pp. 012127
Author(s):  
S V Fedina ◽  
V V Fedorov ◽  
Yu S Berdnikov ◽  
G A Sapunov ◽  
I S Mukhin
Keyword(s):  
Molecular Beam Epitaxy ◽  
Growth Temperature ◽  
Surface Density ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Nanowire Arrays

Abstract This study is devoted to the investigation of the effect of growth conditions (growth temperature, values of molecular beam fluxes) on the formation of self-catalytic GaP NW on Si(111), namely surface density, orientation and NW morphology. Nanowire arrays were grown on Si (111) by the plasma-assisted molecular beam epitaxy. It was determined that an increase of the temperature and a decrease of the Ga flux, while maintaining the V/III ratio, reduces the inclined NWs and parasitic islands nucleation probability.

Study of Interface Properties of InN and InN-Based Heterostructures by Molecular Beam Epitaxy

2001 ◽  
Vol 693 ◽  
Author(s):  
Hai Lu ◽  
William J. Schaff ◽  
Lester F. Eastman ◽  
Colin Wood
Keyword(s):  
Molecular Beam Epitaxy ◽  
Film Thickness ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Growth Conditions ◽  
High Energy ◽  
Near Surface ◽  
Low Leakage ◽  
Sheet Charge ◽  
Aln Buffer

AbstractIn this work, we prepared epitaxial InN on (0001) sapphire with an AlN or GaN buffer layer by molecular beam epitaxy (MBE). A series of samples were grown with different thickness under the optimized growth conditions. Films were characterized by x-ray diffraction (XRD), reflective high-energy electron diffraction (RHEED), atomic-force microscopy (AFM), transmission electron microscopy (TEM) and Hall measurements. By extrapolating the fitted curve of sheet carrier density vs. film thickness to zero film thickness, a strong residual sheet charge was derived, which may be located at the interface between the buffer layer and the InN film, or at the near-surface. It was found that for InN film on AlN buffer, the residual sheet charge is about 4.3×1013 cm-2, while for InN films on GaN buffer, the residual sheet charge is about 2.5×1013 cm-2. At present, we tentatively believe that the residual charge is surface charge accumulation similar to what is observed at the InAs surface. InN samples with Hall mobility beyond 1300 cm2/Vs and carrier concentration below 2×1018 cm-3 were routinely achieved in this study.The first study on InN-based FET structures was performed. Amorphous AlN was used as the barrier material, which was prepared by migration enhanced epitaxy (MEE) at low growth temperature. It was found that the surface morphology is improved after an AlN barrier layer is added to InN. Hg was used as a back-to-back Schottky metallization. Very low leakage current and weak rectifying behavior were observed.

Effect of Aluminum Nitride Buffer Layer Temperature on Gallium Nitride Grown by OMVPE

1994 ◽  
Vol 339 ◽  
Author(s):  
L. B. Rowland ◽  
K. Doverspike ◽  
D. K. Gaskill ◽  
J. A. Freitas
Keyword(s):  
Gallium Nitride ◽  
Buffer Layer ◽  
Growth Temperature ◽  
Growth Conditions ◽  
Layer Growth ◽  
Buffer Layers ◽  
Double Crystal ◽  
Relative Crystallinity ◽  
Excitonic Emission ◽  
Aln Buffer

ABSTRACTGallium nitride layers were grown by organometallic vapor phase epitaxy on AlN buffer layers deposited in the range of 450–650°C. The GaN growth conditions were kept constant so that changes in film properties were due only to changes in the buffer layer growth temperature. A monotonie improvement in relative crystallinity as measured by double-crystal X-ray diffraction corresponded with a decrease in buffer layer growth temperature. Improvements in GaN electron transport at 300 and 77 K were also observed with decreasing AlN buffer layer temperature. Photoluminescence spectra for the lowest temperatures studied were dominated by sharp excitonic emission, with some broadening of the exciton linewidth observed as the buffer layer growth temperature was increased. The full width at half maximum of the excitonic emission was 2.7 meV for GaN grown on a 450°C buffer layer. These results indicate that minimizing AlN buffer layer temperature results in improvements in GaN film quality.

Investigation of GaSb/GaAs Quantum Dots Formation on Ge (001) Substrate and Effect of Anti-Phase Domains

MRS Advances ◽  
2016 ◽  
Vol 1 (23) ◽  
pp. 1729-1734 ◽  
Author(s):  
Zon ◽  
Thanavorn Poempool ◽  
Suwit Kiravittaya ◽  
Suwat Sopitpan ◽  
Supachok Thainoi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Buffer Layer ◽  
Growth Temperature ◽  
Molecular Beam ◽  
Sample Surface ◽  
Layer Growth ◽  
Group Iv ◽  
Optimum Conditions ◽  
Molecular Beam Epitaxial ◽  
Molecular Beam Epitaxial Growth

ABSTRACTThe effects of GaAs anti-phase domains (APDs) on the growth of GaSb quantum dots (QDs) are investigated by molecular beam epitaxial growth of GaAs on Ge (001) substrate. Ge is a group-IV element and GaAs is a polar III-V compound semiconductor. Due to polar/non polar interface, GaAs APDs are formed. Initial formation of APD relates to a non-uniform growth of high index GaAs surfaces. However, due to high sticking coefficient of Sb atoms at low substrate growth temperature, GaSb QDs can be formed on the whole surface of the sample without any effects from APD boundary. The buffer layer growth temperature is one of the key roles to control the APDs formation. Therefore we tried to adjust the optimum conditions such as buffer layer thickness and growth temperature to get nearly flat sample surface with large APDs for high QDs density (∼ 8×109 dots/cm2). Low-temperature photoluminescence is conducted and GaSb QDs peak is observed at the energy range of 1.0 eV-1.3 eV.

scholarly journals Нелегированный высокоомный буферный слой GaN для HEMT AlGaN/GaN

2019 ◽  
Vol 45 (15) ◽  
pp. 21
Author(s):  
Т.В. Малин ◽  
Д.С. Милахин ◽  
И.А. Александров ◽  
В.Е. Земляков ◽  
В.И. Егоркин ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Point Defects ◽  
High Resistance ◽  
Electron Mobility ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Buffer Layers ◽  
High Electron ◽  
High Electron Mobility ◽  
Background Impurity

In this paper the possibility of obtaining the intentionally undoped high resistance GaN buffer layers in AlGaN/GaN heterostructures with high electron mobility for transistors by ammonia molecular beam epitaxy was demonstrated. The growth conditions based on background impurity concentrations and point defects calculations for different gallium and ammonia flows ratios were optimized.

scholarly journals Damping of Oscillations in Layer-by-Layer Growth

1997 ◽  
Vol 11 (31) ◽  
pp. 3621-3634 ◽  
Author(s):  
H. Kallabis ◽  
L. Brendel ◽  
J. Krug ◽  
D. E. WOLF
Keyword(s):  
Molecular Beam Epitaxy ◽  
Computer Simulations ◽  
Power Law ◽  
Coherence Length ◽  
Molecular Beam ◽  
Diffusion Length ◽  
Growth Conditions ◽  
Layer Growth ◽  
Layer By Layer ◽  
Theoretical Results

We present a theory for the damping of layer-by-layer growth oscillations in molecular beam epitaxy. The surface becomes rough on distances larger than a layer coherence length which is substantially larger than the diffusion length. The damping time can be calculated by a comparison of the competing roughening and smoothening mechanisms. The dependence on the growth conditions, temperature and deposition rate, is characterized to be a power law. The theoretical results are confirmed by computer simulations.

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