Mechanism for the Reduction of Threading Dislocation Densities in Si0.82Ge0.18 Films on Silicon on Insulator Substrates

2001 ◽  
Vol 673 ◽  
Author(s):  
E.M. Rehder ◽  
T.S. Kuan ◽  
T.F. Kuech
Keyword(s):  
Dislocation Density ◽  
Chemical Vapor ◽  
Dislocation Core ◽  
Extensive Study ◽  
Silicon On Insulator ◽  
Dislocation Dynamics ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Threading Dislocation Density ◽  
Soi Substrates

ABSTRACTWe have made an extensive study of Si0.82Ge0.18 film relaxation on silicon on insulator (SOI) substrates having a top Si layer 40, 70, 330nm, and 10[.proportional]m thick. SiGe films were deposited with a thickness up to 1.2[.proportional]m in an ultrahigh vacuum chemical vapor deposition system at 630°C. Following growth, films were characterized by X-ray diffraction and a dislocation revealing etch. The same level of relaxation is reached for each thickness of SiGe film independent of the substrate structure. Accompanying the film relaxation is the development of a tetragonal tensile strain in the thin Si layer of the SOI substrates. This strain reached 0.22% for the 1.2[.proportional]m film on the 40nm SOI and decreases with SOI thickness. The Si thickness of the SOI substrate also effected the threading dislocation density. For 85% relaxed films the density fell from 7×106 pits/cm2 on bulk Si to 103pits/cm2 for the 40, 70, and 330nm SOI substrates. The buried amorphous layer of the SOI substrate alters the dislocation dynamics by allowing dislocation core spreading or dislocation dissociation. The reduced strain field of these dislocations reduces dislocation interactions and the pinning that results. Without the dislocation pinning, the misfit dislocations can extend longer distances yielding a greatly reduced threading dislocation density.

Chemical-vapor-deposition growth and characterization of epitaxial 3C–SiC films on SOI substrates with thin silicon top layers

2001 ◽  
Vol 16 (1) ◽  
pp. 24-27 ◽  
Author(s):  
C. K. Moon ◽  
H. J. Song ◽  
J. K. Kim ◽  
J. H. Park ◽  
S. J. Jang ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Silicon On Insulator ◽  
Significant Shift ◽  
Misfit Dislocations ◽  
Chemical Vapor Deposition Growth ◽  
Hydrogen Flow ◽  
Soi Substrates ◽  
Sic Films

Epitaxial 3C–SiC films were grown by chemical vapor deposition on the silicon-on-insulator (SOI) substrates with 20–75-nm-thick Si top layers. A relatively low growth temperature of 1150 °C and a reduced hydrogen flow rate of 1 lpm during the precarbonization process was necessary to preserve the SOI structure and thereby obtain high-quality SiC films. The transmission electron microscopy observation of the SiC/SOI structures revealed high density of misfit dislocations in the SiC film, but no dislocation within the top Si layer. The x-ray-diffraction results did not show any significant shift of the (400) SiC peak position among the SiC/Si and the SiC/SOI samples. This strongly suggests that the Si top layer is not deformed during the SiC/SOI growth and the strain within the 3C–SiC layer is not critically affected by substituting the Si substrate with the SOI substrate, even when the Si top layer is as thin as 20 nm.

Reduction of Threading Dislocation Density in AlGaN by Indium Incorporation

2003 ◽  
Vol 798 ◽  
Author(s):  
H. Kang ◽  
Z. C. Feng ◽  
I. Ferguson ◽  
S. P. Guo ◽  
M. Pophristic
Keyword(s):  
Dislocation Density ◽  
Structural Properties ◽  
Coherence Length ◽  
Chemical Vapor ◽  
Columnar Structure ◽  
Organic Chemical ◽  
Threading Dislocation ◽  
Reciprocal Space Mapping ◽  
Threading Dislocation Density ◽  
Metal Organic

ABSTRACTThe addition of indium, even to small concentrations, to AlGaN has resulted in improved optical and doping properties for these materials. This paper is the first report of improved structural properties for indium containing AlGaN layers. A systematic series of the AlGaN layers with nominal concentration of 20% aluminum were grown by metal-organic chemical vapor deposition with traces amounts of indium incorporated into the layers (up to 0.15% indium). X-ray diffraction analysis of the layers was completed using Williamson Hall plots and reciprocal space mapping to investigate any change in the columnar structure of the initial AlGaN layers. It was found that the threading dislocation densities and lateral coherence length showed a systematic variation with indium incorporation. The threading dislocation density is lowered as indium composition increased with a corresponding increase in lateral coherence length. This indicates that even the incorporation of trace amounts of indium improves the structural properties of these epilayers.

Deep centers in GaN layers grown on epitaxial lateral overgrowth templates by metalorganic chemical vapor deposition

2006 ◽  
Vol 955 ◽  
Author(s):  
Serguei A Chevtchenko ◽  
J. Xie ◽  
Y. Fu ◽  
X. Ni ◽  
H. Morkoç
Keyword(s):  
Deep Level ◽  
Reference Sample ◽  
Chemical Vapor ◽  
Dislocation Core ◽  
Epitaxial Lateral Overgrowth ◽  
Threading Dislocation ◽  
Lateral Overgrowth ◽  
Threading Dislocation Density ◽  
Line Defects ◽  
Transient Spectroscopy

ABSTRACTThe dependence of traps and their concentration in GaN on the quality of templates, on which the layers are grown, has been studied by deep-level transient spectroscopy (DLTS). Thin GaN layers studied were grown on GaN templates employing conventional epitaxial lateral overgrowth (ELO) and nano-ELO with SiNx nanonetwork. The concentrations of traps found in these layers were compared with a reference sample grown on a standard GaN template not utilizing ELO. Two traps A (0.55 eV – 0.58 eV) and B (0.20 eV – 0.23 eV) were detected in the temperature range from 80 K to 400 K. A reduction of traps in layers grown on the ELO and nano-ELO templates was noted. We attribute this reduction to the reduction of threading dislocation density and as a result reduced capture of point defects and complexes as part of dislocation core structure and/or reduced formation of defects and complexes in the vicinity of line defects where the formation can be energetically favorable.

Engineering Dislocation Dynamics in Inx(AlyGa1−y)1−xP Graded Buffers Grown on Gap by Movpe

1998 ◽  
Vol 510 ◽  
Author(s):  
A.Y. Kim ◽  
E.A. Fitzgerald
Keyword(s):  
Surface Roughness ◽  
Dislocation Density ◽  
Growth Conditions ◽  
Dislocation Nucleation ◽  
Dislocation Dynamics ◽  
Threading Dislocation ◽  
High Quality ◽  
Movpe Growth ◽  
Threading Dislocation Density ◽  
Buffer Design

AbstractTo engineer high-quality Inx(AlyGa1−y)1−x P/Ga1−xP graded buffers, we have explored the effects of graded buffer design and MOVPE growth conditions on material quality. We demonstrate that surface roughness causes threading dislocation density (TDD) to increase with continued grading: dislocations and roughness interact in a recursive, escalating cycle to form pileups that cause increasing roughness and dislocation nucleation. Experiments show that V/III ratio, temperature, and grading rate can be used to control dislocation dynamics and surface roughness in InxGa1−xP graded buffers. Control of these parameters individually has resulted in x = 0.34 graded buffers with TDD = 5 × 106 cm−2and roughness = 15 nm and a simple optimization has resulted in TDD = 3 × 106 cm −2and roughness = 10 un. Our most recent work has focused on more sophisticated optimization and the incorporation of aluminum for x > 0.20 to keep the graded buffer completely transparent above 545 nm. Given our results, we expect to achieve transparent, device-quality Inx(AlyGa1−y)1−x P/GaP graded buffers with TDD < 106 cm−2

scholarly journals Epitaxial growth of low threading dislocation density InSb on GaAs using self-assembled periodic interfacial misfit dislocations

2015 ◽  
Vol 158 ◽  
pp. 258-261 ◽  
Author(s):  
Bo Wen Jia ◽  
Kian Hua Tan ◽  
Wan Khai Loke ◽  
Satrio Wicaksono ◽  
Soon Fatt Yoon
Keyword(s):  
Dislocation Density ◽  
Epitaxial Growth ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Threading Dislocation Density ◽  
Self Assembled

The use of ion implantation and annealing for the fabrication of strained silicon on thin SiGe virtual substrates

2004 ◽  
Vol 809 ◽  
Author(s):  
D. Buca ◽  
M.J. Mörschbächer ◽  
B. Holländer ◽  
M. Luysberg ◽  
R. Loo ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Rutherford Backscattering Spectrometry ◽  
Strain Relaxation ◽  
Chemical Vapor ◽  
Implantation Dose ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Dislocation Loops ◽  
Strained Si ◽  
Threading Dislocation Density

ABSTRACTStrain relaxed Si1−xGex layers are attractive virtual substrates for the epitaxial growth of strained Si. Tensile strained Si has attracted a lot of attention due its superior electronic properties. In this study, the strain relaxation of pseudomorphic Si1−xGex layers grown by chemical vapor deposition (CVD) on Si(100) substrates was investigated after He+ ion implantation and thermal annealing. The implantation induced defects underneath the SiGe/Si interface promote strain relaxation during annealing via preferred nucleation of dislocation loops which form misfit dislocations at the interface to the substrate. The amount of strain relaxation as well as the final threading dislocation density depend on the implantation dose and energy. Si1−xGex layers with thicknesses between 75 and 420 nm and Ge concentrations between 19 and 29 at% were investigated. The strain relaxation strongly depends on the layer thickness. Typically the structures show ≈70 % strain relaxation and threading dislocation densities in the low 106 cm−2 range. AFM investigations proved excellent surface morphology with an rms roughness of 0.6 nm. The samples were investigated by Rutherford backscattering spectrometry, ion channeling, transmission electron microscopy and atomic force microscopy.

Role of Dislocation Interactions in Decreasing Mobile Threading Dislocation Density and Limiting Strain Relaxation in Si1-xGex Heteroepitaxial Films

1994 ◽  
Vol 356 ◽  
Author(s):  
Veronique T Gillard ◽  
William D Nix
Keyword(s):  
Dislocation Density ◽  
Late Stage ◽  
Strain Relaxation ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Si Substrates ◽  
Good Account ◽  
Dislocation Interactions ◽  
Threading Dislocation Density ◽  
Residual Strains

AbstractIn situ substrate curvature measurements obtained during isothermal annealing of Si1-xGex films grown on (001) Si substrates allow determination of the evolution of strain versus time in these films. By coupling the strain relaxation measurements with previous measurements of dislocation velocities in this system, the mobile threading dislocation density and its evolution in the course of strain relaxation can be determined. The results indicate that in the late stage of strain relaxation, the mobile threading dislocation density decreases significantly. Results obtained with samples of two different sizes show that this decrease in mobile dislocation density is not primarily associated with dislocations running out at the edges of the film but with dislocation interactions impeding their further motion. Furthermore, for films thinner than 500 nm the residual strains after annealing are significantly higher than the values predicted by the equilibrium theory of misfit dislocations. The measured residual strains are compared with predictions based on Freund’s treatment of the blocking of a moving threading segment by an orthogonal misfit dislocation in its path. We find that the blocking criterion gives a very good account of the residual strain in Si1-xGex films and that blocking of threading dislocations by other misfit dislocations appears to play an important role in the late stage of strain relaxation.

Defect Reduction in GaAs Grown on Si by Using Saw-Tooth-Patterned Substrates

1992 ◽  
Vol 281 ◽  
Author(s):  
Jane G. Zhu ◽  
M. M. Al-Jassim ◽  
N. H. Karam ◽  
K. M. Jones
Keyword(s):  
Dislocation Density ◽  
Chemical Vapor ◽  
Growth Front ◽  
Organic Chemical ◽  
Threading Dislocation ◽  
Defect Reduction ◽  
Dislocation Configuration ◽  
Si Substrates ◽  
Transmission Electron ◽  
Threading Dislocation Density

ABSTRACTEpitaxial GaAs layers have been grown on saw-tooth-patterned (STP) Si substrates by metal-organic chemical vapor deposition and analyzed by transmission electron microscopy. The utilization of this special interface feature is effective in suppressing the formation of antiphase boundaries and reducing the threading dislocation density. The growth of GaAs has been studied with the epilayer thicknesses ranging from several hundred angstroms to several microns. Very flat growth front on (100) plane above the STP region is observed. The dislocation density decreases very rapidly in the area farther away from the interface. The dislocation configuration at this STP interface is very different from that at the extensively studied two-dimensional planar interface.

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