Nucleation of misfit dislocations in strained-layer InGaAs on GaAs

Green, G. S.; Tanner, B. K.; Barnett, S. J.; Emeny, M. T.; Pitt, A. D.; Whitehouse, C. R.; Clark, Gregory

doi:10.1080/09500839008215049

Cited by 35 publications

(7 citation statements)

References 12 publications

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“…In 0.04 Ga 0.96 As epilayers, grown 60 • C below the transition temperature, showed extreme anisotropy of the initial relaxation. As in all our previous ex situ [6] and in situ [7] studies, the fast B(g) misfit dislocations lying along the [110] direction nucleated first (figure 4). The thickness at which the slow A(g) dislocations, lying in the [1 10] direction, were nucleated was approximately the thickness at which significant multiplication of the B(g) dislocations occurred.…”

Section: Resultssupporting

confidence: 84%

In situx-ray topography measurement of the growth temperature dependence of the critical thickness of epitaxial InGaAs on GaAs

Tanner

Parbrook

Whitehouse

et al. 2001

J. Phys. D: Appl. Phys.

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In situ high-resolution double-axis x-ray topography measurements have been made of the critical thickness at which misfit dislocations form in strained layers of InxG1-xAs grown epitaxially on (001) GaAs substrates. The critical thickness for formation of the initial fast B(g) misfit dislocations was found to be close to, but larger than the predictions of the Matthews-Blakeslee model. The discrepancy and the variation of the critical thickness with silicon doping have been modelled by inclusion of a Peierls stress in the force balance equation of misfit dislocation motion. Only a very small change was observed in the critical thickness as a function of growth temperature. Inclusion of a temperature-dependent term in the Matthews-Blakeslee model enabled an activation energy 0.3±0.2 eV to be determined.

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Section: Resultssupporting

confidence: 84%

In situx-ray topography measurement of the growth temperature dependence of the critical thickness of epitaxial InGaAs on GaAs

Tanner

Parbrook

Whitehouse

et al. 2001

J. Phys. D: Appl. Phys.

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“…Thus the larger the distance between two parallel dislocations, the bigger the critical thickness needed for the formation of interfacial dislocations and half-loop arrays. Observations also indicate that while any BPD screw segments which pierce the substrate surface are replicated into the epilayer it appears that only those which have Burgers vectors parallel to the offcut direction (screw type dislocations with Burgers vector [11][12][13][14][15][16][17][18][19][20]) could create HLAs. In addition HLAs were also observed to be generated from BPDs which were nucleated in the epilayer.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Critical Thickness for the Formation of Interfacial Dislocations and Half Loop Arrays in 4H-SiC Epilayer via X-Ray Topography

Wang

Dudley

et al. 2014

MSF

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Synchrotron X-ray Beam Topography (SWBXT) and KOH etching observations are presented of interfacial dislocations (IDs) and half-loop arrays (HLAs) which can form under certain growth conditions during homoepitaxy of 4H-SiC on off-cut substrates. The HLAs and IDs are observed to form from pairs of opposite sign basal plane dislocations in the substrate which intersect the substrate surface in screw orientation. These dislocations glide in opposite direction in the epilayer once critical thickness has been exceeded. Half-loop arrays are formed at the same time as the screw-type basal plane dislocations (BPDs) side-glide inside the epilayer. From knowledge of the formation mechanism of the HLAs [, if the line of the HLA is extended to intersect the original threading dislocation line direction, then the distance between this intersection point and the ID along the line direction of the original BPD provides a measure of the critical thickness. It is also calculated that the critical thickness in this case is largely determined by the mutual attractive force between the pairs of opposite sign threading BPDs in the substrate. In addition we observed both interfacial dislocations and HLAs generated from: (a) surface sources of BPDs; (b) micropipes; (c) 3C inclusions; and (d) substrate/epilayer interface scratches.

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“…The main feature of figure 1 is the deep drop in the curve, which starts at a nominal epilayer thickness of 0.2 µm. From this study and from our earlier in situ [12][13][14] and ex situ [16,17] synchrotron DCXRRT experiments, the critical thickness of misfit dislocation generation has been determined for an epitaxial layer of this particular composition to be 0.046 ± 0.005 µm. Figures 2(a), and 2(b) are double-crystal x-ray reflection topographs taken at an epilayer thickness of 0.050 ± 0.0025 µm, and 0.065 ± 0.0033 µm, respectively ‡.…”

Section: Resultsmentioning

confidence: 97%

“…Arrow g indicates the diffraction vector projected on to the image plane. The generation of a fast gliding α-type misfit dislocation with line direction [ 110] (see [8,17,28,32]) has already taken place at a threading dislocation. As the epilayer thickness increases, the misfit dislocation grows from 404±8 µm to 423 ± 4 µm length (from top to bottom on the topographs, i.e.…”

Section: Resultsmentioning

confidence: 99%

Determination of the critical thickness of misfit dislocation multiplication usingin situdouble-crystal x-ray diffraction

Möck

Tanner

et al. 1996

Semicond. Sci. Technol.

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Two different kinds of critical thicknesses in the relaxation process were determined by means of in situ synchrotron double-crystal x-ray reflection topography and in situ synchrotron double-crystal x-ray diffractometry during the growth of an In 0.066 Ga 0.934 As epilayer on a GaAs (001) substrate. The first critical thickness, derived from the in situ x-ray topographs, has been found to be in agreement with the Matthews and Blakeslee theory of misfit dislocation generation. We present measurements of the lattice constant perpendicular to the interface employing the rocking curves of the symmetric reflection and show that the deep drop in the plot of the lattice constant versus epilayer thickness may be related to misfit dislocation multiplication rather than to misfit dislocation generation processes. Our second critical thickness, derived from the in situ x-ray diffraction data has been found to be in reasonable agreement with recently published theories of misfit dislocation multiplication and substantial relaxation.

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Nucleation of misfit dislocations in strained-layer InGaAs on GaAs

Cited by 35 publications

References 12 publications

In situx-ray topography measurement of the growth temperature dependence of the critical thickness of epitaxial InGaAs on GaAs

In situx-ray topography measurement of the growth temperature dependence of the critical thickness of epitaxial InGaAs on GaAs

Measurement of Critical Thickness for the Formation of Interfacial Dislocations and Half Loop Arrays in 4H-SiC Epilayer via X-Ray Topography

Determination of the critical thickness of misfit dislocation multiplication usingin situdouble-crystal x-ray diffraction

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