In situ relaxed Si[sub 1−x]Ge[sub x] epitaxial layers with low threading dislocation densities grown on compliant Si-on-insulator substrates

1998 ◽  
Vol 16 (3) ◽  
pp. 1489 ◽  
Author(s):  
Z. Yang
Keyword(s):  
Epitaxial Layers ◽  
Threading Dislocation ◽  
Dislocation Densities

Residual Strain and Defect Analysis in as Grown and Annealed SiGe Layers

1991 ◽  
Vol 220 ◽  
Author(s):  
A. R. Powell ◽  
R. A. Kubiak ◽  
T. E. Whall ◽  
E. H. C. Parker ◽  
D. K. Bowen
Keyword(s):  
Residual Strain ◽  
Buffer Layers ◽  
Limited Area ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
High Temperature Anneal ◽  
Dislocation Densities ◽  
Acceptable Quality ◽  
Strained Sige

ABSTRACTIn this paper we address the problem of producing SiGe buffer layers of acceptable quality for the growth of symmetrically strained SiGe structures. Initially we consider SiGe layers grown to well beyond the metastable critical thickness and examine the degree of residual strain both as - grown and post anneal. The defect levels in metastable SiGe layers following high temperature anneal were also studied. A buffer layer was grown consisting of stacked metastable SiGe layers each of which is annealed in situ prior to the growth of the next layer and terminating with a 0.45 SiGe alloy. This produces nearly fully relaxed 1.15pim thick structures with threading dislocation densities of 4 × 106cm−2. Limited area growth on Si suggests that elastically relaxed material free of both threading and misfit dislocations can be produced.

SiH4 exposure of GaN surfaces: A useful tool for highlighting dislocations

2005 ◽  
Vol 892 ◽  
Author(s):  
Rachel Oliver ◽  
Menno J. Kappers ◽  
Joy Sumner ◽  
Ranjan Datta ◽  
Colin J. Humphreys
Keyword(s):  
Atomic Force Microscopy ◽  
Vapour Phase ◽  
Threading Dislocation ◽  
Vapour Phase Epitaxy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dislocation Densities ◽  
Metal Organic ◽  
Organic Vapour

AbstractFast-turnaround, accurate methods for the assessment of threading dislocation densities in GaN are an essential research tool. Here, we present an in-situ surface treatment for use in MOVPE (metal-organic vapour phase epitaxy) growth, in which GaN is exposed to a SiH4 flux at 860 °C in the presence of NH3. Subsequent characterisation by atomic force microscopy shows that the treatment is effective in increasing edge and mixed/screw dislocation pit sizes on both n- and p-type material, and on partially coalesced GaN layers.

TEM characterization of dislocation reduction processes in GaAs/Si

1989 ◽  
Vol 47 ◽  
pp. 590-591
Author(s):  
R.A. Herring ◽  
P.N. Uppal ◽  
S.P. Svensson ◽  
J.S. Ahearn
Keyword(s):  
Lattice Mismatch ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Growth Interface ◽  
Dislocation Reduction ◽  
Dislocation Densities ◽  
Threading Dislocation Density ◽  
Interfacial Dislocations ◽  
Strained Layer Superlattices

A high density of interfacial dislocations are needed at the GaAs/Si interface to alleviate the 4% lattice mismatch between GaAs and Si. Some remnant dislocations thread through the epilayer and follow the growth interface. Current growth methods are not able to obtain acceptable threading dislocation densities (104 – 105) for devices. Many methods can be used to reduce the number of threading dislocations which include misorienting the substrate to enhance the slip of dislocations on specific [110]{111} planes, annealing during and after growth, and adding strained layer superlattices (SLS's) to block dislocations. Conventional TEM (CTEM), performed using a JEM 100c, has been used to characterize threading dislocations in the epilayer of a GaAs/Si material where in situ thermal annealing and SLS's force dislocation reactions and thereby reduce the threading dislocation density. Using TEM we have viewed dislocations under many two-beam diffraction conditions and with the help of a stereogram have determined their Burgers vectors (b), line directions (u) and habit planes (R).

X-Ray Diffraction Analysis of GaN and AlGaN

2002 ◽  
Vol 743 ◽  
Author(s):  
H. Kang ◽  
N. Spencer ◽  
D. Nicol ◽  
Z. C. Feng ◽  
I. Ferguson ◽  
...  
Keyword(s):  
Tilt Angle ◽  
Coherence Length ◽  
Twist Angle ◽  
Columnar Structure ◽  
Epitaxial Layers ◽  
Threading Dislocation ◽  
Reciprocal Space Mapping ◽  
Nucleation Layer ◽  
X Ray ◽  
Dislocation Densities

ABSTRACTIn this paper, threading dislocation densities in GaN and AlGaN epitaxial layers have been evaluated using two different X-ray analysis techniques; a Williamson Hall (WH) plot and reciprocal space mapping (RSM). GaN and AlGaN have crystalline growth composed of columnar structures that can be estimated by coherence length and angular misorientation measured by X-ray. A WH plot can provide information about coherence length and tilt angle from a linear fit to the linewidth of the triple axis rocking curve (000l) symmetric reflections. RSM is typically used to obtain this data, but it is more involved in technique. The two dominant components of threading dislocation densities (screw and edge types) in the GaN and AlGaN epitaxial layers were found to be similar by both techniques. The treading dislocation density correlates to the size of columnar structure as determined by coherence length, tilt angle, and twist angle. The effect of Al composition in AlGaN alloys on these dislocation densities was investigated and found to depend on strongly on the type of nucleation layer, GaN or AlN.

scholarly journals Dislocation densities in a low-carbon steel during martensite transformation determined by in situ high energy X-Ray diffraction

2021 ◽  
Vol 800 ◽  
pp. 140249
Author(s):  
Juan Macchi ◽  
Steve Gaudez ◽  
Guillaume Geandier ◽  
Julien Teixeira ◽  
Sabine Denis ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Martensite Transformation ◽  
Low Carbon Steel ◽  
High Energy ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dislocation Densities

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.

A Pictorial Tracking of Basal Plane Dislocations in SiC Epitaxy

2010 ◽  
Vol 645-648 ◽  
pp. 271-276 ◽  
Author(s):  
Robert E. Stahlbush ◽  
Rachael L. Myers-Ward ◽  
Brenda L. VanMil ◽  
D. Kurt Gaskill ◽  
Charles R. Eddy
Keyword(s):  
Epitaxial Growth ◽  
Basal Plane ◽  
Reduction Process ◽  
Epitaxial Layers ◽  
In Situ Growth ◽  
Half Loop ◽  
Insight Into

The recently developed technique of UVPL imaging has been used to track the path of basal plane dislocations (BPDs) in SiC epitaxial layers. The glide of BPDs during epitaxial growth has been observed and the role of this glide in forming half-loop arrays has been examined. The ability to track the path of BPDs through the epitaxy has made it possible to develop a BPD reduction process for epitaxy grown on 8° offcut wafers, which uses an in situ growth interrupt and has achieved a BPD reduction of > 98%. The images also provide insight into the strong BPD reduction that typically occurs in epitaxy grown on 4° offcut wafers.

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
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