New Algorithms for Rapid Full-Wafer Mapping by High Resolution Double Axis X-Ray Diffraction

1993 ◽  
Vol 324 ◽  
Author(s):  
N Loxley ◽  
S Cockerton ◽  
L M Cooke ◽  
T Gray ◽  
B K Tanner ◽  
...  
Keyword(s):  
High Resolution ◽  
Bragg Peak ◽  
Curve Shape ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Incidence Plane ◽  
Symmetric Geometry ◽  
The Mean ◽  
New Algorithms

AbstractWe describe successful algorithms for rapid alignment of the Bragg planes normal to the incidence plane in a high resolution X-ray diffraction experiment. One is appropriate to the surface symmetric geometry and uses a technique of rotation about the specimen normal.From an experimental study of the rocking curve shape as a function of tilt, we have developed a new algorithm which uses tilting about an axis formed by the intersection of the specimen and incidence planes. This has been shown to be reliable for rapid optimization of the diffraction conditions for wafers cut up to 15° off the (001) plane and for asymmetric reflections. Additionally algorithms are outlined which permit rapid location of the maximum of the Bragg peak and deduction of the mean wafer curvature from the X-ray data

The structures of marialite (Me6) and meionite (Me93) in space groups P42/n and I4/m, and the absence of phase transitions in the scapolite series

2011 ◽  
Vol 26 (2) ◽  
pp. 119-125 ◽  
Author(s):  
Sytle M. Antao ◽  
Ishmael Hassan
Keyword(s):  
Phase Transitions ◽  
High Resolution ◽  
Crystal Structures ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Space Groups ◽  
Cell Parameters ◽  
The Mean

The crystal structures of marialite (Me6) from Badakhshan, Afghanistan and meionite (Me93) from Mt. Vesuvius, Italy were obtained using synchrotron high-resolution powder X-ray diffraction (HRPXRD) data and Rietveld structure refinements. Their structures were refined in space groups I4/m and P42/n, and similar results were obtained. The Me6 sample has a formula Ca0.24Na3.37K0.24[Al3.16Si8.84O24]Cl0.84(CO3)0.15, and its unit-cell parameters are a=12.047555(7), c=7.563210(6) Å, and V=1097.751(1) Å3. The average ⟨T1-O⟩ distances are 1.599(1) Å in I4/m and 1.600(2) Å in P42/n, indicating that the T1 site contains only Si atoms. In P42/n, the average distances of ⟨T2-O⟩=1.655(2) and ⟨T3-O⟩=1.664(2) Å are distinct and are not equal to each other. However, the mean ⟨T2,3-O⟩=1.659(2) Å in P42/n and is identical to the ⟨T2′-O⟩=1.659(1) Å in I4/m. The ⟨M-O⟩ [7]=2.754(1) Å (M site is coordinated to seven framework O atoms) and M-A=2.914(1) Å; these distances are identical in both space groups. The Me93 sample has a formula of Na0.29Ca3.76[Al5.54Si6.46O24]Cl0.05(SO4)0.02(CO3)0.93, and its unit-cell parameters are a=12.19882(1), c=7.576954(8) Å, and V=1127.535(2) Å3. A similar examination of the Me93 sample also shows that both space groups give similar results; however, the C–O distance is more reasonable in P42/n than in I4/m. Refining the scapolite structure near Me0 or Me100 in I4/m forces the T2 and T3 sites (both with multiplicity 8 in P42/n) to be equivalent and form the T2′ site (with multiplicity 16 in I4/m), but ⟨T2-O⟩ is not equal to ⟨T3-O⟩ in P42/n. Using different space groups for different regions across the series implies phase transitions, which do not occur in the scapolite series.

scholarly journals Irreversible Structural Transformation of five fold i-AlPdMn Quasicrystals after Ion Bombardment and Annealing

2000 ◽  
Vol 643 ◽  
Author(s):  
F. Schmithüsen ◽  
G. Cappello ◽  
S. Decossas ◽  
G. Torricelli ◽  
T.-L. Lee ◽  
...  
Keyword(s):  
High Resolution ◽  
Structural Transformation ◽  
Bragg Peak ◽  
Normal Incidence ◽  
Ion Bombardment ◽  
Sample Surface ◽  
Bulk Sample ◽  
X Ray Diffraction ◽  
Energy Position ◽  
X Ray

AbstractFive fold i-AlPdMn surface prepared under UHV by ion bombardment and annealing was so far considered to be bulk terminated. This result was substantially based on a quantitative LEED analyses [1]. Analysis of the specular rod in a X ray diffraction experiment at grazing incidence supported this result [2]. We present a new study of this surface by high resolution X ray diffraction at normal incidence. In this Bragg configuration the diffraction peak 18 – 29 for instance is at a photon energy of 2.873keV, the 72 – 116 reflection at 5.725keV. This results in an analyzed thickness of the sample surface of a few micrometers.The surface was cleaned by ion bombardment. During annealing (T≅880K), we clearly observed the progressive disappearance of the initial Bragg peak characteristic of the as cast bulk sample. Conversely a new Bragg peak grows at an energy position shifted by 1eV compared to the position of the original Bragg peak. This is a clear signature for an irreversible structural transformation which takes place on at least the micron thickness. On the transformed surface, both, a LEED pattern and a RHEED pattern, characteristic for a five fold surface were easily obtained.This high resolution experiment (the relative Bragg peak shift is 3ׁ10−4) was reproduced on samples from different initial compositions. This shows that five fold i-AlPdMn surface changes after preparation by ion bombardment and annealing at 900K on a micrometer thickness. This is not consistent with the conclusion that the surface is simply terminated by a cut of the original bulk. We conclude that a reorganization process of the quasicrystalline structure during annealing proceeds in the surface vicinity (probed depth is close to a few microns).

Characterization of lattice mosaic ofa-plane GaN grown onr-plane sapphire by metalorganic vapor-phase epitaxy

2005 ◽  
Vol 892 ◽  
Author(s):  
Kazuhide Kusakabe ◽  
Shizutoshi Ando ◽  
Kazuhiro Ohkawa
Keyword(s):  
High Resolution ◽  
Vapor Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Morphological Transition ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Sapphire Substrates

AbstractNonpolara-plane GaN films were grown on r-plane sapphire substrates by atmospheric metalorganic vapor-phase epitaxy. The as-grown layers were studied by high-resolution x-ray diffraction. Thea-plane GaN lattice mosaic is orientation dependent as determined by x-ray rocking curve (XRC) measurements. The tilt mosaic measured with the c-axis within the scattering plane (c-mosaic) was greater than the mosaic measured with the m-axis within the scattering plane (m-mosaic). The mosaic along both azimuths decreased and thec-mosaic/m-mosaic ratio was increased with increase of growth temperature from 1050 °C to 1080 °C. The morphological transition was correlated to change in thea-plane GaN tilt mosaic measured by XRC.

Combined Room Temperature Photoluminescence And High Resolution X-Ray Diffraction Mapping Of Semiconductor Wafers

1995 ◽  
Vol 406 ◽  
Author(s):  
S Cockerton ◽  
M L Cooke ◽  
D K Bowen ◽  
B K Tanner
Keyword(s):  
High Resolution ◽  
Room Temperature ◽  
Poisson Ratio ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition Variation ◽  
Line Context ◽  
And Performance

AbstractWe describe the characteristics and performance of a combined desk-side high resolution X-ray diffractometer and room temperature photoluminescence spectrometer designed for rapid mapping of compound semiconductors in a production line context. The combined data for AIGaAs on GaAs suggest that recent measurements of the lattice constant and the Poisson ratio of AlAs may be more reliable than earlier published values. We illustrate the instrument performance in showing that for lattice matched ternary GaInP on GaAs systems, the X-ray rocking curve maps are much more sensitive to composition variation than the photoluminescence spectra.

X-ray diffraction characterization of MOVPE ZnSe films deposited on (100) GaAs using conventional and high-resolution diffractometers

2009 ◽  
Vol 24 (2) ◽  
pp. 78-81 ◽  
Author(s):  
T. N. Blanton ◽  
C. L. Barnes ◽  
M. Holland ◽  
K. B. Kahen ◽  
S. K. Gupta ◽  
...  
Keyword(s):  
High Resolution ◽  
Phase Identification ◽  
Pin Diode ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Sample Throughput ◽  
Gaas Substrates ◽  
Deposition Parameters

ZnSe-based heterostructures grown on GaAs substrates have been investigated for use in pin-diode LED applications. In this study, a conventional Bragg-Brentano diffractometer (BBD) has been used to screen samples for phase identification, crystallite size, presence of polycrystalline ZnSe, and initial rocking curve (RC) analysis. A limitation of the conventional diffractometer is that the smallest RC full width at half maximum (FWHM) that can be achieved is 500 to 600 arc sec. As deposition parameters are optimized and the RC limit of the conventional diffractometer is reached, analysis is moved to a four-bounce high-resolution diffractometer (HRD). Although more time for analysis is required, using the HRD has a RC resolution advantage, where RCs of <20 arc sec are obtained for neat GaAs wafers. Combining the BBD and HRD instruments for analysis of ZnSe films grown on GaAs substrates allows for an efficient means of high sample throughput combined with an accurate measurement of film alignment.

High-resolution X-ray diffraction analysis of the Bragg peak integrated intensity in highly mismatched III-N epilayers

2003 ◽  
Vol 250 (3-4) ◽  
pp. 354-358 ◽  
Author(s):  
G. Feng ◽  
X.M. Shen ◽  
J.J. Zhu ◽  
B.S. Zhang ◽  
D.G. Zhao ◽  
...  
Keyword(s):  
High Resolution ◽  
Diffraction Analysis ◽  
Bragg Peak ◽  
X Ray Diffraction ◽  
X Ray ◽  
Integrated Intensity

Compositional and Structural Characterization of Heterostructure InGaN-Based Light-Emitting Diode by High Resolution X-Ray Diffraction

2012 ◽  
Vol 620 ◽  
pp. 22-27 ◽  
Author(s):  
Ahmad Hadi Ali ◽  
Ahmad Shuhaimi ◽  
Hassan Zainuriah ◽  
Yushamdan Yusof
Keyword(s):  
High Resolution ◽  
Dislocation Density ◽  
Structural Characterization ◽  
Light Emitting Diode ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Light Emitting ◽  
X Ray ◽  
Multi Quantum Well

This paper focuses on the compositional and structural characterization of InGaN-based light-emitting diode (LED) using high resolution x-ray diffraction (HRXRD) system. The LED was epitaxially grown on Si (111) substrate that comprises of In0.11Ga0.89N multi-quantum-well (MQW) active layer. Phase analysis 2θ-scan proved the composition of GaN (0002) and (0004) at 34.63oand 72.98o, respectively. Rocking curveφ-scan showed six significant peaks of the hexagonal GaN structures with consistent angular gaps of ~60o. From x-ray rocking curve (XRC)ω-scan, screw and mix dislocation density is found as 2.85 × 109cm-2, while pure edge dislocation density is found as 2.23 × 1011cm-2.

High resolution x‐ray diffraction study of the Bragg peak width in highly mismatched III–V heterostructures

1996 ◽  
Vol 69 (27) ◽  
pp. 4233-4235 ◽  
Author(s):  
C. Ferrari ◽  
L. Francesio ◽  
P. Franzosi ◽  
S. Gennari
Keyword(s):  
High Resolution ◽  
Diffraction Study ◽  
Bragg Peak ◽  
Peak Width ◽  
X Ray Diffraction ◽  
X Ray

High-resolution X-ray diffraction study of highly mismatched III–V heterostructures by analysis of the layer Bragg peak width

1997 ◽  
Vol 19 (2-4) ◽  
pp. 277-284
Author(s):  
C. Ferrari ◽  
L. Francesio ◽  
P. Franzosi ◽  
S. Gennari
Keyword(s):  
High Resolution ◽  
Diffraction Study ◽  
Bragg Peak ◽  
Peak Width ◽  
X Ray Diffraction ◽  
X Ray
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