Recent Advances in Huang Diffuse Scattering

1984 ◽  
Vol 41 ◽  
Author(s):  
P. Ehrhart
Keyword(s):  
Point Defects ◽  
Diffuse Scattering ◽  
Reciprocal Lattice ◽  
Theoretical Background ◽  
Dislocation Loops ◽  
Short Introduction ◽  
X Ray ◽  
Different Types ◽  
Isolated Point ◽  
Influence Of Impurities

AbstractMeasurements of the diffuse X-ray (or neutron) scattering allow the detailed investigation of point defects in crystalline solids. The method can be applied for defect sizes ranging from isolated point defects up to large dislocation loops. The diffuse scattering intensity close to the Bragg reflections, Huang Diffuse Scattering and Asymptotic Diffuse Scattering, is of special interest as the intensities from lattice distorting defects are high and the scattering theory is most straightforward for this region of the reciprocal lattice. After a short introduction to the theoretical background and to the experimental techniques the capabilities and limitations of the method will be demonstrated with examples of experimental results. i) The structure of interstitial atoms has been investigated for low temperature irradiated crystals and for metals with interstitially dissolved solute atoms. ii) The mobility and growth of interstitial agglomerates during annealing stage II of irradiated metals is discussed. The influence of impurities on the cluster growth is demonstrated for the example of Nibase alloys. iii) Defect clusters and defect distributions within cascades as observed after different types of irradiations are discussed.

scholarly journals Capabilities of X-ray diffuse scattering method for study of microdefects in semiconductor crystals

2018 ◽  
Vol 4 (4) ◽  
pp. 125-134
Author(s):  
Vladimir T. Bublik ◽  
Marina I. Voronova ◽  
Kirill D. Shcherbachev
Keyword(s):  
Diffuse Scattering ◽  
Reciprocal Lattice ◽  
Lattice Parameter ◽  
Formation Mechanisms ◽  
Scattering Method ◽  
X Ray ◽  
Semiconductor Crystals ◽  
The Matrix ◽  
Decomposition Stages ◽  
Defects Analysis

The capabilities of X-ray diffuse scattering (XRDS) method for the study of microdefects in semiconductor crystals have been overviewed. Analysis of the results has shown that the XRDS method is a highly sensitive and information valuable tool for studying early stages of solid solution decomposition in semiconductors. A review of the results relating to the methodological aspect has shown that the most consistent approach is a combination of XRDS with precision lattice parameter measurements. It allows one to detect decomposition stages that cannot be visualized using transmission electron microscopy (TEM) and moreover to draw conclusions as to microdefect formation mechanisms. TEM-invisible defects that are coherent with the matrix and have smeared boundaries with low displacement field gradients may form due to transmutation doping as a result of neutron irradiation and relaxation of disordered regions accompanied by redistribution of point defects and annihilation of interstitial defects and vacancies. For GaP and InP examples, a structural microdefect formation mechanism has been revealed associated with the interaction of defects forming during the decomposition and residual intrinsic defects. Analysis of XRDS intensity distribution around the reciprocal lattice site and the related evolution of lattice constant allows detecting different decomposition stages: first, the formation of a solution of Frenkel pairs in which concentration fluctuations develop, then the formation of matrix-coherent microdefects and finally coherency violation and the formation of defects with sharp boundaries. Fundamentally, the latter defects can be precipitating particles. Study of the evolution of diffuse scattering iso-intensity curves in GaP, GaAs(Si) and Si(O) has allowed tracing the evolution of microdefects from matrix-coherent ones to microdefects with smeared coherency resulting from microdefect growth during the decomposition of non-stoichiometric solid solutions heavily supersaturated with intrinsic (or impurity) components.

scholarly journals Hardening in AlN Induced by Point Defects

1991 ◽  
Vol 235 ◽  
Author(s):  
H. Suematsu ◽  
T. E. Mitchell ◽  
T. Iseki ◽  
T. Yano
Keyword(s):  
Point Defects ◽  
Defect Density ◽  
Single Point ◽  
Length Change ◽  
Dislocation Loops ◽  
Three Samples ◽  
Different Temperatures ◽  
Hardness Change ◽  
Isolated Point ◽  
Small Clusters

ABSTRACTPressureless-sintered AlN was neutron irradiated and the hardness change was examined by Vickers indentation. The hardness was increased by irradiation. When the samples were annealed at high temperature, the hardness gradually decreased. Length was also found to increase and to change in the same way as the hardness. A considerable density of dislocation loops still remained, even after the hardness completely recovered to the value of the unirradiated sample. Thus, it is concluded that the hardening in AlN is caused by isolated point defects and small clusters of point defects, rather than by dislocation loops.Hardness was found to increase in proportion to the length change. If the length change is assumed to be proportional to the point defect density, then the curve could be fitted qualitatively to that predicted by models of solution hardening in metals. Furthermore, the curves for three samples irradiated at different temperatures and fluences are identical. There should be different kinds of defect clusters in samples irradiated at different conditions, e.g, the fraction of single point defects is the highest in the sample irradiated at the lowest temperature. Thus, hardening is insensitive to the kind of defects remaining in the sample and is influenced only by those which contribute to length change.

X-Ray Diffuse Scattering Investigation of Defects in Ion Implanted and Annealed Silicon

1998 ◽  
Vol 524 ◽  
Author(s):  
C. H. Chang ◽  
U. Beck ◽  
T. H. Metzger ◽  
J. R. Patel
Keyword(s):  
Ion Implantation ◽  
Point Defect ◽  
Point Defects ◽  
Diffuse Scattering ◽  
Grazing Incidence ◽  
X Rays ◽  
Scattered Intensity ◽  
X Ray ◽  
Defect Clusters ◽  
Point Defect Clusters

ABSTRACTTo characterize the point defects and point defect clusters introduced by ion implantation and annealing, we have used grazing incidence x-rays to measure the diffuse scattering in the tails of Bragg peaks (Huang Scattering). An analysis of the diffuse scattered intensity will allow us to characterize the nature of point defects or defect clusters introduced by ion implantation. We have also observed unexpected satellite peaks in the diffuse scattered tails. Possible causes for the occurrence of the peaks will be discussed.

Characterization of Reactive Ion Etch Damage in GaAs by Triple Crystal X-Ray Diffraction

1993 ◽  
Vol 324 ◽  
Author(s):  
Victor S. Wang ◽  
Richard J. Matyi ◽  
Karen J. Nordheden
Keyword(s):  
Bias Voltage ◽  
Diffuse Scattering ◽  
Reciprocal Lattice ◽  
Surface Region ◽  
Perfect Crystal ◽  
X Ray Diffraction ◽  
Reciprocal Lattice Point ◽  
Near Surface ◽  
X Ray ◽  
Imperfect Crystal

AbstractTriple crystal x-ray diffraction (TCXD) is a non-destructive structural characterization tool capable of the separation and direct observation of the dynamic (perfect crystal) and the kinematic (imperfect crystal) components of the total intensity diffracted by a crystal. Specifically, TCXD can be used to measure the magnitude of the diffuse scattering arising from defects in the crystal structure in the immediate vicinity of a reciprocal lattice point. In this study, the effects of BC13 reactive ion etching (RIE) on the near-surface region of GaAs were investigated by analyzing the changes in the diffuse scattering using both the symmetric 004 reflection as well as the highly asymmetric and more surface sensitive 113 reflection. While the results from the 004 reflections revealed little difference between the unetched and the BC13-etched samples, maps of the diffracted intensity around the 113 reflections showed an unexpected and reproducible decrease in the extent of the diffuse scattering in the transverse direction (perpendicular to the < 113 > direction) as the RIE bias voltage was increased. This decrease suggests that the degree of etch damage induced in the GaAs near-surface region is reduced with increasing bias voltage and ion energy. Additionally, the symmetry and orientation of the kinematic scattering was altered. Possible mechanisms for these results willbe discussed.

Dislocations around scratches and indents on ±(111) surface of gallium arsenide

1989 ◽  
Vol 22 (6) ◽  
pp. 606-612 ◽  
Author(s):  
M. R. Surowiec ◽  
H. S. Leipner ◽  
J. Schreiber
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Point Defects ◽  
Nucleation Mechanism ◽  
Dislocation Loops ◽  
X Ray ◽  
Transmission Electron ◽  
Double Kink ◽  
Slip Planes ◽  
Scanning Electron

The dislocation configurations around microscratches and indents on ±(111) surfaces of GaAs single crystals were studied by X-ray transmission topography, scanning electron microscopy in cathodoluminescence mode and high-voltage transmission electron microscopy. Most of the dislocations generated are loops of screw – B(g) or screw –B(g) – screw character gliding on {111} slip planes parallel or inclined to the surface. The irregular shape of the extended loops gliding parallel to the B surface is due to interaction with other loops and apparent motion involving a double kink nucleation mechanism. The exhibited configuration of dislocation loops suggests a cross-slip orientation of the dissociated screw segments. The direction of propagation of dislocations does not depend on the sense of scratching. Grown-in dislocations are surrounded by a cloud of point defects and they are immobile in contrast to dislocations introduced by indentation.

Layer-disordered wurtzite (ZnS-2H): diffuse X-ray scattering recorded by c-axis precession photography

1987 ◽  
Vol 20 (3) ◽  
pp. 191-194 ◽  
Author(s):  
M. E. Fleet
Keyword(s):  
Diffraction Pattern ◽  
Diffuse Scattering ◽  
Reciprocal Lattice ◽  
X Ray Diffraction ◽  
Closed Loops ◽  
X Ray ◽  
X Ray Scattering ◽  
Precession Cycle ◽  
Dimensional Parameters ◽  
Disordered Crystal

A novel type of X-ray diffraction pattern results when a layer-disordered crystal is photographed by X-ray precession using the stacking direction as the precession axis and no layer-line screen. The 10l, 20l, 21l and symmetry-equivalent rows of diffuse scattering of layer-disordered wurtzite (ZnS-2H) are represented by compound loops superimposed on the zero-level hk0 diffraction pattern. Closed loops result because the reciprocal-lattice rows associated with diffuse scattering remain in contact with the sphere of reflection during the precession cycle. Formulae for dimensional parameters of the compound loops of diffuse scattering are derived from the sphere-of-reflection construction.

scholarly journals Boron Precipitates in Ion Implanted Silicon

1975 ◽  
Vol 33 ◽  
pp. 256-257
Author(s):  
Wei-Kuo Wu ◽  
Jack Washburn
Keyword(s):  
Recent Work ◽  
Point Defects ◽  
Room Temperature ◽  
Dislocation Loops ◽  
Diffraction Contrast ◽  
Alternative Method ◽  
Different Types ◽  
Long Rod ◽  
Post Implantation ◽  
Ion Implanted

Long rod-like defects are observed in ion implanted silicon when boron is present either as a prior dopant addition or as the implanted species. For many years, these rods have been described variously as precipitates, lines of point defects, dislocation dipoles, or elongated dislocation loops. The diffraction contrast from the defects has been difficult to interpret unambiguously because of their very narrow spacing. Our recent work indicates that they have the characteristics of narrow extrinsic dipoles or elongated dislocation loops and that there are two different types along each of the six <110> directions.In this paper, an alternative method, annealing kinetics, has been used to identify the nature of these defects formed during post-implantation annealing in boron ion (100 keV) implanted silicon irradiated at room temperature to a dose of 2x1014/cm2.

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