Strain-Free GexSi1−x Layers with Low Threading Dislocation Densities Grown on Si Substrates

1991 ◽  
Vol 220 ◽  
Author(s):  
E. A. Fitzgerald ◽  
Y. H. Xie ◽  
M. L. Green ◽  
D. Brasen ◽  
A. R. Kortan ◽  
...  
Keyword(s):  
Threading Dislocation ◽  
Plan View ◽  
Light Emitting ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Electron Beam Induced Current ◽  
Current Densities ◽  
Dimensional Electron Gas ◽  
Compositional Grading

ABSTRACTWe have grown linearly compositionally graded GexSi1−x structures at high temperatures (700–900°C) on Si substrates to form a surface which resembles a GexSi1−x substrate. We have obtained completely relaxed structures with x≤0.50 and threading dislocation densities in the 105cm−2 - 106cm−2 range. Because of the very low threading dislocation densities, the structures appear dislocation free in conventional transmission electron microscopy (TEM) cross-section and plan view. Employing the electron beam induced current technique (EBIC), we were able to consistently measure these low threading dislocation densities. A direct comparison of two x=0.35 films, one graded in Ge content and one uniform in Ge content, shows that compositional grading decreases the dislocation density by a factor of 100–1000. These. higher quality graded buffers have been used as templates for the subsequent growth of InGaP light emitting diodes (LED) and GexSi1−x/Si two-dimensional electron gas (2DEG) structures. Room temperature operation of orange-red LEDs were obtained at current densities of =600A/cm, and mobilities as high as 96,000 cm2/V-s were achieved at 4.2K in the 2DEG structures.

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.

Strategies For Direct Monolithic Integration of AlxGa(1−x)As/InxGa(1−x)As LEDS and Lasers On Ge/GeSi/Si Substrates Via Relaxed Graded GexSi(1−x) Buffer Layers

2001 ◽  
Vol 692 ◽  
Author(s):  
Michael E. Groenert ◽  
Christopher W. Leitz ◽  
Arthur J. Pitera ◽  
Vicky K. Yang ◽  
Harry Lee ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Threshold Current ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Carrier Lifetimes ◽  
Si Substrates ◽  
Dislocation Densities ◽  
Minority Carrier Lifetimes ◽  
Current Densities ◽  
High Series

AbstractAlxGa(1−x)As/GaAs quantum well lasers have been demonstrated via organometallic chemical vapor deposition (OMCVD) on relaxed graded GexSi(1−x) virtual substrates on Si. Despite unoptimized laser structures with high series resistance and large threshold current densities, surface threading dislocation densities as low as 2×106 cm−2 enabled cw room-temperature lasing at a wavelength of 858nm. The laser structures are oxide-stripe gain-guided devices with differential quantum efficiencies of 0.16 and threshold current densities of 1550A/cm2. Identical devices grown on commercial GaAs substrates showed differential quantum efficiencies of 0.14 and threshold current densities of 1700A/cm2. This comparative data agrees with our previous measurements of near-bulk minority carrier lifetimes in GaAs grown on Ge/GeSi/Si substrates. A number of GaAs/Ge/Si integration issues including thermal expansion mismatch and Ge autodoping behavior in GaAs were overcome.

High Power 330 nm AlInGaN UV LEDs in the High Injection Regime

2003 ◽  
Vol 798 ◽  
Author(s):  
M. Gherasimova ◽  
J. Su ◽  
G. Cui ◽  
J. Han ◽  
H. Peng ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Threading Dislocation ◽  
Light Emitting ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dimensional Growth ◽  
Uv Leds

ABSTRACTWe report on the growth and testing of the light emitting diode structures incorporating quaternary AlInGaN active region with an emission wavelength of 330 nm. Small area circular devices were fabricated, yielding the output power of 110 μW measured with a bare-chip configuration in a high current injection regime (8 kA/cm2 for a 20 μm diameter device). Structural properties of the constituent epitaxial layers were evaluated by atomic force microscopy and transmission electron microscopy, resulting in the observation of two-dimensional growth morphologies of AlN and AlGaN, and the estimate of threading dislocation densities in the low 109 cm-2 range in the structures grown on sapphire substrates.

Threading Dislocation Densities in GaAs Grown on Reduced Area Si Substrates

1993 ◽  
Vol 308 ◽  
Author(s):  
J. Knall ◽  
L.T. Romano ◽  
D.K. Biegelsen ◽  
R.D. Bringans
Keyword(s):  
Side Wall ◽  
Heat Treatments ◽  
Threading Dislocation ◽  
Large Area ◽  
Plan View ◽  
Si Substrates ◽  
Gaas On Si ◽  
Dislocation Densities ◽  
Side Walls ◽  
Wall Growth

ABSTRACTWe have studied the possibilities of reducing the threading dislocation (TD) density in GaAs on Si using free side wall growth on patterned Si substrates and/or using a soft ZnSe interlayer in combination with post growth annealing procedures. TD densities were accurately determined using large area plan view TEM and were found to be unaffected by proximity to free side walls and by the ZnSe interlayer. Post growth heat treatments led to a factor of ∼2 reduction in TD density and to bunching of dislocations throughout the thickness of the film.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

Defect-Engineered Graded GexSi1-x Buffers on Si (001) with Extreme Low Threading Dislocation Density

1995 ◽  
Vol 378 ◽  
Author(s):  
G. Kissinger ◽  
T. Morgenstern ◽  
G. Morgenstern ◽  
H. B. Erzgräber ◽  
H. Richter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Threading Dislocation Density

AbstractStepwise equilibrated graded GexSii-x (x≤0.2) buffers with threading dislocation densities between 102 and 103 cm−2 on the whole area of 4 inch silicon wafers were grown and studied by transmission electron microscopy, defect etching, atomic force microscopy and photoluminescence spectroscopy.

Totally relaxed GexSi1−xlayers with low threading dislocation densities grown on Si substrates

1991 ◽  
Vol 59 (7) ◽  
pp. 811-813 ◽  
Author(s):  
E. A. Fitzgerald ◽  
Y.‐H. Xie ◽  
M. L. Green ◽  
D. Brasen ◽  
A. R. Kortan ◽  
...  
Keyword(s):  
Threading Dislocation ◽  
Si Substrates ◽  
Dislocation Densities

High Quality AlN Layer Grown on Patterned Sapphire Substrates by Hydride Vapor-Phase Epitaxy: A Route for Cost Efficient AlN Templates for Deep Ultraviolet Light Devices

2021 ◽  
Vol 21 (9) ◽  
pp. 4881-4885
Author(s):  
Seung-Jae Lee ◽  
Seong-Ran Jeon ◽  
Young Ho Song ◽  
Young-Jun Choi ◽  
Hae-Gon Oh ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Threading Dislocation ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Order Of Magnitude ◽  
Cost Efficient ◽  
Patterned Sapphire Substrates

We report the characteristics of AlN epilayers grown directly on cylindrical-patterned sapphire substrates (CPSS) by hydride vapor-phase epitaxy (HVPE). To evaluate the effect of CPSS, we analyzed the threading dislocation densities (TDDs) of AlN films grown simultaneously on CPSS and flat sapphire substrate (FSS) by transmission electron microscopy (TEM). The corresponding TDD is measured to be 5.69 x 108 cm−2 for the AlN sample grown on the CPSS that is almost an order of magnitude lower than the value of 3.43 × 109 cm−2 on the FSS. The CPSS contributes to reduce the TDs originated from the AlN/sapphire interface via bending the TDs by lateral growth during the coalescence process. In addition, the reduction of direct interface area between AlN and sapphire by CPSS reduce the generation of TDs.

Direct Deposition Reactions Between Nickel and Silicon Substrates

1993 ◽  
Vol 311 ◽  
Author(s):  
Lin Zhang ◽  
Douglas G. Ivey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Substrates ◽  
Silicide Formation ◽  
Cross Sectional ◽  
Deposition Rates ◽  
Plan View ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTSilicide formation through deposition of Ni onto hot Si substrates has been investigated. Ni was deposited onto <100> oriented Si wafers, which were heated up to 300°C, by e-beam evaporation under a vacuum of <2x10-6 Torr. The deposition rates were varied from 0.1 nm/s to 6 nm/s. The samples were then examined by both cross sectional and plan view transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy and electron diffraction. The experimental results are discussed in terms of a new kinetic model.

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