The Evolution of Strain Relaxation Close to The Critical Thickness

1993 ◽  
Vol 317 ◽  
Author(s):  
P. Kidd ◽  
P.F. Fewster
Keyword(s):  
Residual Strain ◽  
Strain Field ◽  
Critical Thickness ◽  
Strain Relaxation ◽  
Epitaxial Layers ◽  
X Ray Diffraction ◽  
Strain Fields ◽  
X Ray ◽  
Local Relaxation ◽  
Homogeneous Strain

ABSTRACTHigh resolution X-ray diffraction space mapping has been used to follow the change in the distribution of residual strain and localised relaxation in low mismatched epitaxial layers. Using this new technique, we have obtained a series of diffraction space maps of partially relaxed epitaxial layers of In.1Ga.9As on GaAs. The layers have different thicknesses and hence different degrees of strain relaxation. The diffuse scatter close to the Bragg peaks provides information about the imperfect and distorted regions in the structure and this has allowed us to examine the extent and distribution of residual strain close to the dislocations. We have followed the evolution of local relaxation, which is confined initially to regions around isolated dislocations, through to the case of overlapping dislocation strain fields, leading to a more homogeneous strain field distribution and microscopic and macroscopic tilting of the layers.

scholarly journals Quantitative Imaging of the Stress/Strain Fields and Generation of Macroscopic Cracks from Indents in Silicon

2017 ◽  
Author(s):  
Brian K. Tanner ◽  
David Allen ◽  
Jochen Wittge ◽  
Andreas N. Danilewsky ◽  
Jorge Garagorri ◽  
...  
Keyword(s):  
Strain Field ◽  
Strain Relaxation ◽  
Quantitative Imaging ◽  
Mechanical Damage ◽  
X Ray Diffraction ◽  
Strain Fields ◽  
X Ray ◽  
Diffraction Imaging ◽  
Bevel Edge ◽  
Contrast Feature

The crack geometry and associated strain field around Berkovich and Vickers indents on silicon have been studied by X-ray diffraction imaging and micro-Raman spectroscopy scanning. The techniques are complementary, the Raman data coming from within a few micrometers of the indentation, whereas the X-ray image probes the strain field at a distance of typically tens of micrometers. For example, Raman data provides an explanation for the central contrast feature in the X-ray images of an indent. Strain relaxation from breakout and high temperature annealing are examined and it is demonstrated that millimeter length cracks, similar to those produced by mechanical damage from misaligned handling tools, can be generated in a controlled fashion by indentation within 75 micrometers of the bevel edge of 200mm diameter wafers.

Epitaxial tilt of partially relaxed InGaAs layers grown on (100) GaAs substrates

1992 ◽  
Vol 70 (10-11) ◽  
pp. 838-842
Author(s):  
P. Maigné ◽  
A. P. Roth ◽  
C. Desruisseaux ◽  
D. Coulas
Keyword(s):  
Residual Strain ◽  
Gaas Substrate ◽  
Strain Relaxation ◽  
Azimuthal Angle ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Monoclinic Symmetry ◽  
X Ray ◽  
Mismatch Strain ◽  
Gaas Substrates

The structural properties of partially relaxed InxGa1−xAs layers grown on (100) GaAs substrates have been investigated, using high-resolution X-ray diffraction, in order to better understand the mechanisms responsible for the relaxation of the mismatch strain. From symmetric [400] reflections recorded as functions of the azimuthal angle [Formula: see text], the (100) InGaAs planes are found to be tilted with respect to the (100) GaAs substrate planes. The tilt magnitude is first seen to decrease then to increase with layer thickness. The direction of the tilt changes from [01-1] to [00-1] in the range of thickness investigated. From [422] asymmetric reflections, the average in-plane lattice parameter, the indium composition as well as the percentage of relaxation can be measured. Our values for relaxation are in qualitative agreement with the Dodson and Tsao model of strain relaxation (Appl. Phys. Lett. 51, 1710 (1987)). In addition, our data show an anisotropy in residual strain along <011> directions. This anisotropy increases with the amount of strain relieved and changes the crystal symmetry of the cell from tetragonal to monoclinic. This monoclinic symmetry can be characterized by an angle β that measures the angle between 90° and the inner angles of the new crystallographic cell. As for the anisotropy in residual strain, |3 increases with the amount of strain relieved. Correlations between tilt magnitude and tilt direction with the formation of 60° type dislocations are discussed.

Characterizations Of Zr/Si1-x-yGexCy After Rapid Thermal Annealing

1998 ◽  
Vol 533 ◽  
Author(s):  
V. Aubry-Fortuna ◽  
M. Barthula ◽  
F. Meyer ◽  
A. Eyal ◽  
C. Cytermann ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Schottky Barrier ◽  
Rapid Thermal Annealing ◽  
Residual Strain ◽  
Strain Relaxation ◽  
Small Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Heights ◽  
Final Compound

AbstractIn this work, we have investigated the reaction between Zr and SiGeC alloys after Rapid Thermal anneals performed at 800°C for 5 min. The interactions of the metal with the alloy have been investigated by X-Ray diffraction. Four crystal X-Ray diffraction was also performed to measure the residual strain in the epilayer. The final compound of the reaction is the C49- Zr(Si1-xGex)2 phase. The C49 film contains the same Ge concentration as in the as-deposited Si1-x-yGexCy layer. This suggests that no Ge-segregation occurs during annealing. Only a small strain relaxation is detected in the unreacted SiGe epilayer during the reaction. The addition of C in the epilayer prevents any strain relaxation. These results are in contrast with those observed in systems with Ti and Co, and show that the system Zr-Si-Ge is much more stable. Schottky barrier heights have been also measured: annealing leads to a slight decrease of the barrier without any degradation of the contact. The resistivity of the C49 film is about 80 μΩcm. These results indicate that Zr may be a good candidate for contacts on IV-IV alloys in term of thermal stability.

Mapping the Strain State of 3C-SiC/Si (001) Suspended Structures Using μ-XRD

2016 ◽  
Vol 858 ◽  
pp. 274-277 ◽  
Author(s):  
Gerard Colston ◽  
Stephen D. Rhead ◽  
Vishal Ajit Shah ◽  
Oliver J. Newell ◽  
Igor P. Dolbnya ◽  
...  
Keyword(s):  
Convenient Method ◽  
Residual Strain ◽  
Tensile Strain ◽  
Strain State ◽  
Strain Relaxation ◽  
Lattice Parameters ◽  
Raman Shift ◽  
X Ray Diffraction ◽  
X Ray ◽  
Direct Measurements

The residual strain has been mapped across suspended 3C-SiC membranes and wires using synchrotron based micro X-ray diffraction (μ-XRD). Residual tensile strain is observed to relax slightly upon suspension in both sets of structures. Similar maps were acquired by calculating the residual strain from the shift in 3C-SiC Raman peaks. Comparable trends in strain relaxation are observed by both methods, although the sensitivity of μ-XRD is higher using our measurement conditions. While Raman shift provides a fast and convenient method for mapping strain variations, it cannot give direct measurements of the lattice parameters that can be achieved with μ-XRD, making these techniques excellent complimentary methods of mapping residual strain in 3C-SiC.

Measurement of Elastic Strains in Crystal Surfaces by X-Ray Diffraction Topography

1967 ◽  
Vol 11 ◽  
pp. 385-393
Author(s):  
Brian R. Lawn
Keyword(s):  
Strain Field ◽  
Crystal Surface ◽  
Silicon Surfaces ◽  
X Ray Diffraction ◽  
Crystal Surfaces ◽  
Strain Fields ◽  
Diamond Surfaces ◽  
X Ray ◽  
Detailed Nature ◽  
Elastic Strains

AbstractThe use of X-ray topographic techniques for studying elastic strains in crystals deformed at their surfaces is becoming widespread, especially in the field of silicon semiconductor devices. Although the broad features of the phenomenological processes involved in producing the strain patterns on the X-ray micrographs are understood, little attention has been devoted to evaluating the detailed nature or range of the strain fields in the crystal. In this paper, an clastic model is proposed for cases in which a region of crystal surface is uniformly deformed over a thin layer. With this model, the associated strain field in the surrounding crystal, which is readily computed from elasticity theory, may be characterized by a single parameter. The model is in accord with observed strain patterns on topographs of abraded diamond surfaces and silicon surfaces onto which a strip of metal film has been evaporated. From the spatial range of the diffraction contrast, an estimate of the parameter characterizing the strain field may be made.

POSSIBLE ABNORMAL MECHANISM FOR LATTICE STRAIN RELAXATION IN La0.7Ca0.3MnO3 THIN FILM

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2415-2420 ◽  
Author(s):  
W. S. TAN ◽  
Q. J. JIA ◽  
J. GAO
Keyword(s):  
Critical Thickness ◽  
Lattice Strain ◽  
Strain Relaxation ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Radio Frequency Magnetron Sputtering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lcmo Film ◽  
Oriented Single Crystal

La 0.7 Ca 0.3 MnO 3(LCMO) thin films with the thickness of 50 nm were deposited on (001)-oriented single crystal SrTiO 3(STO), MgO and α- Al 2 O 3(ALO) by 90° off-axis radio frequency magnetron sputtering. Grazing incidence X-ray diffraction technique, associated with normal X-ray diffraction, was performed to measure the in-plane lattice parameter and investigate the lattice strain and strain relaxation in LCMO films. The results indicated that critical thickness of strain relaxation is very small, which may be related to large mismatch between film and substrate. The mechanism for strain relaxation in LCMO film is perhaps different from that for tetragonal distortion.

Homogeneous Strain Relaxation and Mosaic Spread in InGaAs/GaAs Heterostructures Using Triple Axis Diffractometry

1994 ◽  
Vol 38 ◽  
pp. 221-226
Author(s):  
M. S. Goorsky ◽  
K. M. Matney ◽  
G. Chu ◽  
R. S. Goldman ◽  
K. L. Kavanagh
Keyword(s):  
Strain Relaxation ◽  
Growth Direction ◽  
Indium Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mosaic Spread ◽  
Peak Broadening ◽  
High Indium Content ◽  
Crystallographic Tilt ◽  
Homogeneous Strain

Abstract We investigated strain relaxation in (001) InGaAs/GaAs structures using both double and triple axis high resolution x-ray diffraction techniques. We determined diat broadening which is observed in double axis scans stews pnmanly from mosaic spread and not from lattice constant variations in the layer, demonstrating that relaxation is uniform along the growth direction. These observations held for layers with both low and high indium content and extents of relaxation. Triple axis measurements showed that the peak broadening was due exclusively to mosaic spread for the low indium content samples and also confirmed earlier double axis measurements that a crystallographic tilt of the epitaxial layer was attributed to substrate miscut. The ability to distinguish the source of peak broadening and crystallographic tilts makes triple axis diffraction a powerful characterization technique for the study of mismatched epitaxial layers.

SURFACE AND INTERFACE STRAINS REVEALED BY X-RAY DIFFRACTION

1999 ◽  
Vol 06 (06) ◽  
pp. 963-966 ◽  
Author(s):  
KOICHI AKIMOTO ◽  
TAKASHI EMOTO ◽  
YUYA ISHIKAWA ◽  
AYAHIKO ICHIMIYA
Keyword(s):  
Silicon Substrate ◽  
Strain Field ◽  
Theoretical Calculations ◽  
Incident Angle ◽  
Experimental Results ◽  
Lattice Expansion ◽  
X Rays ◽  
X Ray Diffraction ◽  
Strain Fields ◽  
X Ray

We measured strain fields near semiconductor surface by X-ray diffraction. The diffraction geometry was using the extremely asymmetric Bragg-case bulk reflection of a small incident angle to the surface and a large angle exiting from the surface. The incident angle of the X-rays was set near critical angle of total reflection by tuning X-ray energy of synchrotron radiation. The X-ray intensity of the silicon substrate 311 reflection was measured to study a Si(111) surface in the ultrahigh vacuum chamber. A clean Si (111)-(7 × 7) surface was found to give a sharper X-ray diffraction peak than that of the native oxide/Si(111) system. By comparison of experimental results and theoretical calculations, it was concluded that the thin silicon oxide film itself gives strong strain fields to the silicon substrates of lattice expansion toward the [311] direction. The strain fields at the Al- and Ag- induced [Formula: see text] surface reconstruction on the Si(111) substrate were also measured. By comparison of experimental results and theoretical calculations, Al-induced reconstruction was suggested to give a strain field to the silicon substrate of lattice expansion toward the [311] direction, whereas Ag-induced reconstruction was suggested to give a strain field to the silicon substrate of lattice compression toward the [311] direction.

Influence of Growth Parameters on the Residual Strain in 3C-SiC Epitaxial Layers on (001) Silicon

2008 ◽  
Vol 600-603 ◽  
pp. 223-226 ◽  
Author(s):  
Günter Wagner ◽  
J. Schwarzkopf ◽  
M. Schmidbauer ◽  
R. Fornari
Keyword(s):  
Residual Strain ◽  
Deposition Temperature ◽  
Vapour Deposition ◽  
Growth Parameters ◽  
Chemical Vapour ◽  
Vapour Phase ◽  
Epitaxial Layers ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray

3C-SiC epitaxial layers were grown on on-axis Si (001) substrates by low-pressure hot-wall chemical vapour deposition. Depending on the growth parameters, the residual strain in the 3C-SiC layer was seen to be tensile or compressive. In this work, the influence of parameters, such as growth temperature and C/Si ratio in the vapour phase, on residual strain and macroscopic layer bow is investigated. We found that the wafer bow changes from convex, at a deposition temperature of 1270° C, to concave at 1370° C. High resolution x-ray diffraction data indicate that the crystal-line perfection of the layers is lower for decreasing deposition temperature and increasing compres-sive strain. No remarkable influence of the C/Si ratio in the gaseous atmosphere on the FWHM of the rocking curve was observed.

Optical and structural prorerties of InAs epilayer on graded InGaAs

2001 ◽  
Vol 696 ◽  
Author(s):  
Gu Hyun Kim ◽  
Jung Bum Choi ◽  
Joo In Lee ◽  
Se-Kyung Kang ◽  
Seung Il Ban ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Residual Strain ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
Peak Position ◽  
Excitation Intensity ◽  
Total Thickness ◽  
Ingaas Layer ◽  
X Ray Diffraction ◽  
X Ray

AbstractWe have studied infrared photoluminescence (PL) and x-ray diffraction (XRD) of 400 nm and 1500 nm thick InAs epilayers on GaAs, and 4 nm thick InAs on graded InGaAs layer with total thickness of 300 nm grown by molecular beam epitaxy. The PL peak positions of 400 nm, 1500 nm and 4 nm InAs epilayer measured at 10 K are blue-shifted from that of InAs bulk by 6.5, 4.5, and 6 meV, respectively, which can be largely explained by the residual strain in the epilayer. The residual strain caused by the lattice mismatch between InAs and GaAs or graded InGaAs/GaAs was observed from XRD measurements. While the PL peak position of 400 nm thick InAs layer is linearly shifted toward higher energy with increase in excitation intensity ranging from 10 to 140 mW, those of 4 nm InAs epilayer on InGaAs and 1500 nm InAs layer on GaAs is gradually blue-shifted and then, saturated above a power of 75 mW. These results suggest that adopting a graded InGaAs layer between InAs and GaAs can efficiently reduce the strain due to lattice mismatch in the structure of InAs/GaAs.

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