Interface Roughness Determined by Diffuse Scattering and by Reflectivity of Hard X-Rays

1992 ◽  
Vol 280 ◽  
Author(s):  
B. Lengeler ◽  
M. Hüppauff
Keyword(s):  
Born Approximation ◽  
Diffuse Scattering ◽  
Interface Roughness ◽  
X Rays ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
X Ray ◽  
Non Destructive

ABSTRACTX-ray reflectivity and diffuse scattering are powerful techniques for the non-destructive determination of the vertical and lateral roughness of external and internal interfaces. The influence of roughness on the reflected and transmitted amplitudes is treated in terms of a model first described by Névot and Croce. The diffuse scattering is described by an improved distorted wave Born approximation. A few examples will demonstrate the possibilities of the techniques.

Interface Roughness in Strained Si/SiGe Multilayers

1996 ◽  
Vol 448 ◽  
Author(s):  
A. A. Darhuber ◽  
V. Holy ◽  
J. Stangl ◽  
G. Bauer ◽  
J. NÜtzel ◽  
...  
Keyword(s):  
Born Approximation ◽  
Interface Roughness ◽  
Interface Morphology ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Strained Si ◽  
X Ray ◽  
Level Model ◽  
Correlation Properties ◽  
Two Level Model

AbstractDiffuse x-ray reflection from a SiGe/Si multilayer grown pseudomorphically on slightly miscut Si(OOl) substrates has been studied theoretically and experimentally. In the framework of the Distorted-Wave Born Approximation (DWBA), we demonstrated that the distribution of the diffusely scattered intensity gives conclusive information on both the amount and the in-plane and inter-plane correlation properties of the interface roughness. The best model for the description of the interface-morphology was found to be a combination of a two-level model and a staircase model.

The Measurement of Elastic Constants for the Determination of Stresses by X-Rays

1983 ◽  
Vol 27 ◽  
pp. 159-170 ◽  
Author(s):  
K. Perry ◽  
I.C. Noyan ◽  
P.J. Rudnik ◽  
J.B. Cohen
Keyword(s):  
Interplanar Spacing ◽  
Measuring System ◽  
Laboratory System ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Measured Change ◽  
Non Destructive ◽  
Applied Stresses

Residual and applied stresses (σij) are often measured via X-ray diffraction, by calculating the resultant elastic strains (ϵij) from the measured change in interplanar spacing (“d”). This method is non-destructive, reasonably reproducible (typically ±14 MPa), can be carried out in the field, and is readily automated to give values to an operator-specified precision , Let Li represent the axes of the measuring system with L3 normal to the diffracting planes, and Pi represent the sample axes. These axes are illustrated in Figure 1. In what follows, primed stresses and strains are in the laboratory system, while unprimed values are in the sample system.

scholarly journals Interface Evolution in a W/Si Multilayer after Rapid Thermal Annealing Studied by X-ray Reflectivity and Diffuse Scattering

1997 ◽  
Vol 30 (5) ◽  
pp. 642-646 ◽  
Author(s):  
M. Jergel ◽  
V. Holý ◽  
E. Majková ◽  
S. Luby ◽  
R. Senderák
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Diffuse Scattering ◽  
Grazing Incidence ◽  
Interface Roughness ◽  
X Rays ◽  
Interface Evolution ◽  
X Ray ◽  
Scattering Measurements ◽  
Highly Correlated

An interface study of the effect of rapid thermal annealing (RTA) in the temperature range 523–1273 K for 5–40 s on a nominally [(50 Å Si/10 Å W) × 9] amorphous multilayer (ML) deposited on an Si(100) wafer was performed by X-ray reflectivity and diffuse-scattering measurements at grazing incidence. The results of the X-ray reflectivity and diffuse-scattering measurements were evaluated by Fresnel optical computational code and within the distorted-wave Born approximation, respectively. Up to the 773 K/5 s annealing step, the r.m.s. interface roughness decreases by 30%, which brings about a reflectivity increase of 20% on the first Bragg maximum. There is a small overall increase of the r.m.s. interface roughness across the ML in the as-deposited state and the interface profiles are highly correlated. From the very beginning of RTA, the fractal interface behaviour is gradually lost and the lateral correlation length increases, this process being accompanied by a decrease of the interface conformality. This tendency continues during the 773 K/20 s annealing; however, the r.m.s. roughness evolution is reversed. During the 1023 K/5 s annealing, the interfaces are no longer `seen' by the X-rays and, during the 1273 K/5 s annealing, a total collapse of the ML structure takes place.

scholarly journals What Can we Learn from off-Specular Neutron Reflection?

1994 ◽  
Vol 376 ◽  
Author(s):  
Roger Pynn
Keyword(s):  
Born Approximation ◽  
Diffuse Scattering ◽  
Organic Molecules ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Multilayer Systems ◽  
Remarkable Feature ◽  
Neutron Reflection ◽  
The Subject ◽  
Diffuse Neutron

ABSTRACTThis paper provides a brief introduction to the subject of off-specular neutron scattering by rough interfaces. Such scattering can be calculated using the distorted-wave Born approximation (DWBA) in which the neutron wavefunctions for a system with smooth interfaces are used as the basis for perturbation theory. Although it has been applied successfully to model the scattering from rough surfaces, the DWBA has several quantitative and qualitative limitations, some of which are described in this paper. When it is applied to multilayer systems, the DWBA correctly predicts a number of qualitative features of the diffuse scattering, including fringes of scattering that result from correlations between the roughnesses of neighbouring interfaces. A remarkable feature of diffuse neutron reflection is the range of length scales within a surface or interface that is probed. This is illustrated here by data obtained with a self-assembled multilayer of organic molecules where distances between 500 Å and 3 μm parallel to the layers are probed.

scholarly journals Non-Destructive Determination of Chemical Effects onFluorescence Yields and Vacancy Transfer Probabilities ofTin Compounds

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Ahmet Tursucu ◽  
Mehmet Haskul ◽  
Asaf Tolga Ulgen
Keyword(s):  
Gamma Rays ◽  
Chemical Effect ◽  
X Rays ◽  
Tin Compounds ◽  
X Ray ◽  
Chemical Effects ◽  
Fluorescence Efficiency ◽  
Non Destructive ◽  
Transfer Probability

In the current work, it was investigated to the K X-ray fluorescence efficiency and chemical effect on vacancy transfer probability for some tin compounds. We used Br2Tin, TinI2, SeTin, TinF2, TinSO4, TinCl2, TinO and TinS compounds for experimental study. The target samples were irradiated with 241Am annular radioactive source at the intensity of 5 Ci which emits gamma rays at wavelength of 0.2028 nm. The characteristic x-rays emitted because of the excitation are collected by a high-resolution HPGe semiconductor detector. It has been determined that the experimental calculations of the tin (Sn) element are compatible with the theoretical calculation. In addition, we have calculated the experimental intensity ratios, fluorescence yields and total vacancy transfer probabilitiesfor other Sn compounds. 

scholarly journals Non-Destructive Determination of Chemical Effects onFluorescence Yields and Vacancy Transfer Probabilities ofTin Compounds

2018 ◽  
Author(s):  
Ahmet Tursucu ◽  
Mehmet Haskul ◽  
Asaf Tolga Ulgen
Keyword(s):  
Gamma Rays ◽  
Chemical Effect ◽  
X Rays ◽  
Tin Compounds ◽  
X Ray ◽  
Chemical Effects ◽  
Fluorescence Efficiency ◽  
Non Destructive ◽  
Transfer Probability

In the current work, it was investigated to the K X-ray fluorescence efficiency and chemical effect on vacancy transfer probability for some tin compounds. We used Br2Tin, TinI2, SeTin, TinF2, TinSO4, TinCl2, TinO and TinS compounds for experimental study. The target samples were irradiated with 241Am annular radioactive source at the intensity of 5 Ci which emits gamma rays at wavelength of 0.2028 nm. The characteristic x-rays emitted because of the excitation are collected by a high-resolution HPGe semiconductor detector. It has been determined that the experimental calculations of the tin (Sn) element are compatible with the theoretical calculation. In addition, we have calculated the experimental intensity ratios, fluorescence yields and total vacancy transfer probabilitiesfor other Sn compounds. 

Grazing-incidence small-angle X-ray scattering from thin polymer films with lamellar structures – the scattering cross section in the distorted-wave Born approximation

2006 ◽  
Vol 39 (3) ◽  
pp. 433-442 ◽  
Author(s):  
P. Busch ◽  
M. Rauscher ◽  
D.-M. Smilgies ◽  
D. Posselt ◽  
C. M. Papadakis
Keyword(s):  
Thin Films ◽  
Polymer Films ◽  
Small Angle ◽  
Born Approximation ◽  
Grazing Incidence ◽  
Thin Polymer Films ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
X Ray ◽  
Thin Polymer

Grazing-incidence small-angle X-ray or neutron scattering of thin polymer films reveals information about the ordering and preferential orientations of the phase-separated microdomains within the films. The grazing-incidence geometry enhances the surface sensitivity; however, the scattering has to be treated within the framework of the distorted-wave Born approximation. In this work, the case of thin films with lamellar mesostructure is studied, where the orientation of the lamellae is either perpendicular or parallel to the film interfaces. For perpendicular lamellae, Bragg rods are found, which are extended along the film normal, whereas for parallel lamellae, peaks along the film normal appear. The positions of the maxima present in the latter case are explained by accounting for refraction at the film surface and reflection at the film–substrate interface. The results are relevant for thin films of lamellar diblock copolymers.

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