Fourier Transformation of X-Ray Rocking Curves from Interferometer Structures

1993 ◽  
Vol 37 ◽  
pp. 135-144
Author(s):  
J. M. Hudson ◽  
B. K. Tanner ◽  
R. Blunt
Keyword(s):  
Layer Thickness ◽  
Bragg Peak ◽  
Noisy Data ◽  
X Ray Diffraction ◽  
Interference Structure ◽  
X Ray ◽  
Auto Correlation ◽  
Interference Fringes ◽  
Spline Fitting ◽  
Cubic Spline Fitting

AbstractWe discuss the use of Fourier transform techniques to extract layer thickness from the interference fringes observed in high resolution X-ray diffraction rocking curves of pseudomorphic HEMT structures. The interference structure is extracted by cubic spline fitting to the extrema of the data, thereby obtaining a background envelope which is used to normalise the data. The resulting constant background is subtracted from the data and the residual Fourier transformed. Auto correlation of the residual significantly improves the result from noisy data. Satisfactory results are obtained only when the Bragg peak from the substrate is windowed out. With a limited dynamic and angular range, there is often insufficient data to separate the two closely spaced periods arising from the total layer thickness and that excluding the quantum well. The result then corresponds to the average of these two thicknesses.

scholarly journals Irregular Electrodeposition of Cu-Sn Alloy Coatings in [EMIM]Cl Outside the Glove Box with Large Layer Thickness

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 310
Author(s):  
Lars Lehmann ◽  
Dominik Höhlich ◽  
Thomas Mehner ◽  
Thomas Lampke
Keyword(s):  
Layer Thickness ◽  
Alloy System ◽  
Liquid Solution ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
X Ray ◽  
Argon Stream ◽  
Ionic Liquid Solution ◽  
The Relationship ◽  
Layer Composition

Thick Cu−Sn alloy layers were produced in an [EMIM]Cl ionic-liquid solution from CuCl2 and SnCl2 in different ratios. All work, including the electrodeposition, took place outside the glovebox with a continuous argon stream over the electrolyte at 95 °C. The layer composition and layer thickness can be adjusted by the variation of the metal-salts content in the electrolyte. A layer with a thickness of up to 15 µm and a copper content of up to ωCu = 0.86 was obtained. The phase composition was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF). Furthermore, it was found that the relationship between the alloy composition and the concentration of the ions in the electrolyte is described as an irregular alloy system as according to Brenner. Brenner described such systems only for aqueous electrolytes containing complexing agents such as cyanide. In this work, it was confirmed that irregular alloy depositions also occur in [EMIM]Cl.

High Resolution X-ray Diffraction for the Characterization of Semiconducting Materials

1989 ◽  
Vol 33 ◽  
pp. 1-11 ◽  
Author(s):  
B. K. Tanner
Keyword(s):  
Bragg Peak ◽  
Thin Layers ◽  
X Ray Diffraction ◽  
Semiconducting Materials ◽  
Multiple Reflections ◽  
X Ray ◽  
Analyzer Crystal ◽  
Glancing Angle ◽  
Heteroepitaxial Layers

AbstractUse of a reference crystal to condition the beam in the double-axis diffractometer permits the Bragg peak width to be reduced to the correlation of the two crystal reflecting ranges. Some recent applications of double axis diffractometry to the study of heteroepitaxial layers are discussed. The advantages of multiple reflections for beam conditioning and the four reflection DuMond monochromator are examined. Glancing incidence and exit diffractometry permits the study of very thin layers, down to a few tens of nanometres in thickness and both synchrotron radiation and skew reflections can be used to tune the glancing angle close to the critical angle. Recent applications of triple-axis diffraction, where an analyzer crystal is used after the specimen, to the study of very thin single epitaxial layers and multiquantum well structures are reviewed.

X-Ray Interference Measurements of Ultrathin Semiconductor Layers

1989 ◽  
Vol 145 ◽  
Author(s):  
C.R. Wie
Keyword(s):  
X Ray Diffraction ◽  
Nondestructive Technique ◽  
Interference Structure ◽  
Rocking Curve ◽  
X Ray ◽  
Double Heterojunction ◽  
Strained Quantum Well ◽  
Interference Measurements ◽  
Strained Layer Superlattices

AbstractWe present various x-ray diffraction phenomena from semiconductor hetero-epitaxial layers. Each of these phenomena gives useful information on the layers. Knowing what to look for in the x-ray rocking curve (XRC) can make this nondestructive technique a very powerful tool for characterization of a few A-several g.tm thick layers We discuss the use of individual Bragg peak, diffraction fringe, and interference structure to obtain layer information. We particularly emphasize the use of x-ray interference in studying buried strained quantum well or quantum barrier layers. We present experimental rocking curves of an AlGaAs/GaAs double heterojunction laser structure and GaInAs/GaAs strained layer superlattices in both <001> and <111> orientations.

Properties of Boride Layer on Boridesae 1035 Steel by Molten Salt

2013 ◽  
Vol 467 ◽  
pp. 116-121 ◽  
Author(s):  
Alaeddine Kaouka ◽  
Omar Allaoui ◽  
Mourad Keddam
Keyword(s):  
Layer Thickness ◽  
Steel Substrate ◽  
Kinetic Studies ◽  
Salt Bath ◽  
Boride Layer ◽  
Process Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Parabolic Relationship ◽  
Borided Steel

Properties of borided SAE 1035 steel have been investigated during boriding treatment, which was carried out in slurry salt bath at temperature range from1073 to 1273K for 2, 4 and 8 h. The presence of both FeB and Fe2B phases formed on the surface of steel substrate was confirmed by X-ray diffraction. Scanning electron microscopy (SEM) and optical microscopy examinations showed that boride layers have saw-tooth and columnar morphology. It has been shown that the thickness of boride layers increased when the time and temperature process increased, its value ranged from 20 to 387 μm. The hardness value of the boride layer was about 1760±200 HV0.1, while the hardness of un-borided steel was about 225±20 HV0.1. The kinetic studies showed a parabolic relationship between layer thickness and process time. Depending on temperature and layer thickness.

Evaluation of strain balancing layer thickness for InAs/GaAs quantum dot arrays using high resolution x-ray diffraction and photoluminescence

2009 ◽  
Vol 95 (20) ◽  
pp. 203110 ◽  
Author(s):  
Christopher G. Bailey ◽  
Seth M. Hubbard ◽  
David V. Forbes ◽  
Ryne P. Raffaelle
Keyword(s):  
High Resolution ◽  
Quantum Dot ◽  
Layer Thickness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gaas Quantum Dot

scholarly journals Characterization of individual stacking faults in a wurtzite GaAs nanowire by nanobeam X-ray diffraction

2017 ◽  
Vol 24 (5) ◽  
pp. 981-990 ◽  
Author(s):  
Arman Davtyan ◽  
Sebastian Lehmann ◽  
Dominik Kriegner ◽  
Reza R. Zamani ◽  
Kimberly A. Dick ◽  
...  
Keyword(s):  
Bragg Peak ◽  
Stacking Faults ◽  
Growth Direction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Patterson Function ◽  
Transmission Electron ◽  
Gaas Nanowires ◽  
Gaas Nanowire

Coherent X-ray diffraction was used to measure the type, quantity and the relative distances between stacking faults along the growth direction of two individual wurtzite GaAs nanowires grown by metalorganic vapour epitaxy. The presented approach is based on the general property of the Patterson function, which is the autocorrelation of the electron density as well as the Fourier transformation of the diffracted intensity distribution of an object. Partial Patterson functions were extracted from the diffracted intensity measured along the [000\bar{1}] direction in the vicinity of the wurtzite 00\bar{1}\bar{5} Bragg peak. The maxima of the Patterson function encode both the distances between the fault planes and the type of the fault planes with the sensitivity of a single atomic bilayer. The positions of the fault planes are deduced from the positions and shapes of the maxima of the Patterson function and they are in excellent agreement with the positions found with transmission electron microscopy of the same nanowire.

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