The estimation of dislocation densities in metals from X-ray data

Gay, Peter; Hirsch, P. B.; Kelly, Anthony

doi:10.1016/0001-6160(53)90106-0

Cited by 497 publications

(194 citation statements)

References 8 publications

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“…2, the width of the ZnSe 004 profile increases monotonically as the dislocation density is increased from 0 cm À2 to 2 9 10 7 cm À2 . The observed FWHM values (60 arcsec, 74 arcsec, and 100 arcsec for dislocation densities of 0.6 9 10 7 cm À2 , 1 9 10 7 cm À2 , and 2 9 10 7 cm À2 , respectively) are in fair agreement (within 20%) with the square law expected from an approximate analysis of a uniform layer with uniform dislocation density as described by Gay et al 15 However, an important advantage of the present model is the ability to analyze structures with nonuniform dislocation a is the relaxed lattice constant, h B is the 004 Bragg angle for unstrained material, V is the unit cell volume used for the calculation of the structure factors, and F 0 , F H , and F H are the structure factors for the 000, 004, and 004 reflections, respectively. For mixed ZnS y Se 1Ày crystals, linear interpolation was used to estimate the relaxed lattice constant and atomic scattering factors for the calculation of the structure factors.…”

Section: Resultssupporting

confidence: 83%

Dynamical X-ray Diffraction from ZnS y Se1−y /GaAs (001) Multilayers and Superlattices with Dislocations

Rago

Suarez

Jain

et al. 2012

Journal of Elec Materi

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High-resolution x-ray diffraction is a valuable nondestructive tool for structural characterization of semiconductor heterostructures, and the diffraction profiles contain information on the depth profiles of strain, composition, and defect densities in device structures. Much of this information goes untapped because the lack of phase information prevents direct inversion of the diffraction profile. The current practice is to use dynamical simulations in conjunction with a curve-fitting procedure to indirectly extract the profiles of strain and composition. These dynamical simulations have been based on perfect, dislocation-free laminar crystals, rendering the analysis inapplicable to structures having dislocation densities greater than about 10 6 cm À2 . In this work we present a dynamical model for Bragg x-ray diffraction in semiconductor device structures with nonuniform composition, strain, and dislocation density, which is based on the Takagi-Taupin equation for distorted crystals and accounts for the angular and strain broadening of dislocations. We show that the x-ray diffraction profiles from ZnS y Se 1Ày multilayers and superlattices are strongly affected by the depth distribution of the dislocation density as well as the composition, suggesting that it should be possible to extract the profiles of composition, strain, and dislocation density by the analysis of measured diffraction profiles.

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Section: Resultssupporting

confidence: 83%

Dynamical X-ray Diffraction from ZnS y Se1−y /GaAs (001) Multilayers and Superlattices with Dislocations

Rago

Suarez

Jain

et al. 2012

Journal of Elec Materi

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“…If dislocations are piled up in small angle grain boundaries, Fig. 8 The edge, screw, and total dislocation density as a function of the nitridation time the edge dislocation density (D edge ), therefore, can be calculated according to [28,29],…”

Section: Resultsmentioning

confidence: 99%

The influence of nitridation time on the structural properties of GaN grown on Si (111) substrate

et al. 2008

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In the present paper, the effect of in-situ substrate nitridation time on crystalline quality of GaN films grown on Si (111) substrates by metal organic chemical vapor deposition (MOCVD) were investigated. A thin buffer layer of silicon nitride (SiN x ) with various thicknesses was achieved through the nitridation of substrate at different nitiridation times ranging from 0 to 660 s. The structural characteristics, such as dislocation densities, correlation lengths of columnar crystallites, the tilt and twist of the mosaic structure, and the angles of rotational disorder, were all studied in detail by using a planar and cross-sectional view of high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (HRXRD) performed at different scattering geometries. It was found that the dislocation densities, lateral coherence lengths, vertical coherence lengths, and the tilt and

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“…6,13 The resulting microstructure is described using a mosaic model and yields an increased angular width of x-ray reflections. 14 In addition, vacancies in STO result in a well-known lattice expansion. 15 At high ion doses there are sufficient atomic displacements to produce a transformation to an amorphous structure, either directly beneath or adjacent to the location of the ion beam.…”

mentioning

confidence: 99%

Fabrication and convergent X-ray nanobeam diffraction characterization of submicron-thickness SrTiO3 crystalline sheets

et al. 2016

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The creation of thin SrTiO3 crystals from (001)-oriented SrTiO3 bulk single crystals using focused ion beam milling techniques yields sheets with submicron thickness and arbitrary orientation within the (001) plane. Synchrotron x-ray nanodiffraction rocking curve widths of these SrTiO3 sheets are less than 0.02°, less than a factor of two larger than bulk SrTiO3, making these crystals suitable substrates for epitaxial thin film growth. The change in the rocking curve width is sufficiently small that we deduce that dislocations are not introduced into the SrTiO3 sheets. Observed lattice distortions are consistent with a low concentration of point defects.

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The estimation of dislocation densities in metals from X-ray data

Cited by 497 publications

References 8 publications

Dynamical X-ray Diffraction from ZnS y Se1−y /GaAs (001) Multilayers and Superlattices with Dislocations

Dynamical X-ray Diffraction from ZnS y Se1−y /GaAs (001) Multilayers and Superlattices with Dislocations

The influence of nitridation time on the structural properties of GaN grown on Si (111) substrate

Fabrication and convergent X-ray nanobeam diffraction characterization of submicron-thickness SrTiO3 crystalline sheets

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