Effect of the Extinction Distance in X-Ray Rocking Curve Analyses of II-VI Compounds

1990 ◽  
Vol 209 ◽  
Author(s):  
P.D. Moran ◽  
R.J. Matyi
Keyword(s):  
Single Crystal ◽  
Crystalline Perfection ◽  
Double Crystal ◽  
Rocking Curve ◽  
Dynamical Diffraction ◽  
X Ray ◽  
Extinction Length

ABSTRACTDouble crystal x-ray rocking curves from single crystal CdTe and CdZnTe of various degrees of crystalline perfection were recorded under diffraction conditions in which the extinction distance varied from under 10 microns to more than 100 microns. In crystals of intermediate quality the rocking curves recorded under conditions of long extinction length showed structure not evident in those recorded under conditions of short extinction length. Integrated reflectivity measurements were performed at both long and short extinction lengths. The results have been interpreted within the framework of a transition from kinematic to dynamical diffraction.

Buried Silicide Synthesis and Strain in Cobalt-Implanted Silicon

1987 ◽  
Vol 102 ◽  
Author(s):  
J.C. Barbour ◽  
S.T. Picraux ◽  
B.L. Doyle
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Silicide Formation ◽  
Critical Layer Thickness ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Ion Channeling ◽  
Single Crystal Layer

ABSTRACTSilicon (001) substrates were implaynted with 350 keV Co at room temperature and 450°C with fluence of from l×l017 Co/cm2 to 6×1017 Co/cm . All samples were annealed at 1000°C in order to form the CoSi2 phase Concentration profiles were determined with Rutherford backscattering spectrometry (RBS), and the associated strain profiles were analyzed with double-crystal X-ray rocking curve measurements. Ion channeling was also used to characterize the silicide formation and crystal quality. An implantation of 6×1017 Co/cm2 at 450°C forms a single-crystal CoSi2 layer while lower fluences do not. A continuous, buried CoSi2 single-crystal layer is formed for the 3×1017 Co/cm2 sample implanted at 450°C and annealed at 1000°C. The continous CoSi2 layer is thicker than the critical layer thickness for a fully coherent film, and therefore the layer partially relaxes. A relaxation of 50% of the fully coherent value is observed for this buried silicide system.

Buried Silicide Synthesis and Strain in Cobalt-Implanted Silicon

1987 ◽  
Vol 107 ◽  
Author(s):  
J.C. Barbour ◽  
S.T. Picraux ◽  
B.L. Doyle
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Concentration Profiles ◽  
Critical Layer Thickness ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Ion Channeling ◽  
Single Crystal Layer

AbstractSilicon (001) substrates were implanted with 350 keV co at room temperature and 450°C with fluence of from 1x1017 Co/cm2 to 6x10 Co/cm2. All samples were annealed at 1000°C in order to form the CoSi2 phase. Concentration profiles were determined with Rutherford backscattering spectrometry (RBS), and the associated strain profiles were analyzed with double-crystal X-ray rocking curve measurements. Ion channeling was also used to characterize.the suicide formation and crystal quality. An implantation of 6x1017 Co/cm2 at 450°C forms a single-crystal CoSi2 layer while lower fluences do not. A continuous, buried CoSi2 single-crystal layer is formed for the 3x1017 Co/cm2 sample implanted at 450°C and annealed at 1000°C. The continous CoSi2 layer is thicker than the critical layer thickness for a fully coherent film, and therefore the layer partially relaxes. A relaxation of 50% of the fully coherent value is observed for this buried suicide system.

Investigation on Large-Sized Sapphire Crystalline Perfection by X-Ray Double-Crystal Diffraction Method

2007 ◽  
Vol 353-358 ◽  
pp. 1521-1524 ◽  
Author(s):  
Gui Gen Wang ◽  
Ming Fu Zhang ◽  
Hong Bo Zuo ◽  
Xiao Dong He ◽  
Jie Cai Han ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Crystal Surface ◽  
Diffraction Method ◽  
Sapphire Crystal ◽  
Crystalline Perfection ◽  
Double Crystal ◽  
X Ray ◽  
Infrared Spectral ◽  
Growth Method ◽  
Small Temperature Gradient

The large-sized sapphire (Ø225×205 mm, 27.5 kg) was grown successfully by SAPMAC method (sapphire growth technique with micro-pulling and shoulder-expanding at cooled center). The surface quality of the specimens was characterized by micro-Raman spectroscopy, and double crystal X-ray diffractometry (DCD) was utilized to investigate its crystalline perfection. The measurement of rocking curves was performed on various specimens from different region of large sapphire boule. The experimental results showed that CMP (chemo-mechanical polishing) with subsequent suitable chemically etching can develop the best-quality sapphire crystal surface and the values of FWHM obtained by conventional DCD were in the range from 27” to 58”. The infrared spectral transmission (2.0-4.5 5m) of sapphire crystal exceeded 82%. It is confirmed of SAPMAC growth method characteristics with in-situ annealing, small temperature gradient and low residual stress level by numerical simulation analysis.

Fabrication of Ultrathin Bragg Beam Splitter by Plasma Chemical Vaporization Machining

2012 ◽  
Vol 523-524 ◽  
pp. 40-45 ◽  
Author(s):  
Taito Osaka ◽  
Makina Yabashi ◽  
Yasuhisa Sano ◽  
Kensuke Tono ◽  
Yuichi Inubushi ◽  
...  
Keyword(s):  
Beam Splitter ◽  
Bragg Reflection ◽  
Free Electron Lasers ◽  
Crystalline Perfection ◽  
Plasma Chemical ◽  
High Quality ◽  
Rocking Curve ◽  
Mechanical Process ◽  
X Ray ◽  
Beam Splitters

A novel fabrication process was proposed to produce high-quality Bragg beam splitters for hard X-ray free-electron lasers (XFELs), which should consist of thin, bend-free, and robust Bragg-case crystals without any defects. A combination of a mechanical process and plasma chemical vaporization machining was employed. High crystalline perfection of the fabricated Si(110) crystal was verified with X-ray topography and rocking curve measurements. In addition, the thickness was evaluated to be 4.4 μm from the fringe period of the measured rocking curve. The crystal can be employed in Bragg beam splitters using the (220) Bragg reflection for X-ray pump-X-ray probe experiments with XFEL sources.

Accurate Lattice Constant and Mismatch Measurements of SiC Heterostructures by X-Ray Multiple-Order Reflections

2002 ◽  
Vol 742 ◽  
Author(s):  
XianRong Huang ◽  
Michael Dudley ◽  
Philip G. Neudeck ◽  
J. Anthony Powell
Keyword(s):  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
Coherent Interface ◽  
Rocking Curve ◽  
X Ray ◽  
Lattice Planes ◽  
Atomically Flat

ABSTRACTHigh-resolution X-ray diffraction (HRXRD) combined with other diffraction techniques is applied to characterize 3C SiC epilayers hoteroepitaxially grown on atomically flat mesas on 4H and 6H SiC substrates. Small-beam rocking curve scan and reciprocal mapping show extremely high crystalline perfection and homogeneity of the ideally grown 3C-SiC epilayers. Accurate lattice measurements based on X-ray multiple-order reflections reveal that: 1) no misorientation between the (0001) lattice planes across the 4H/3C or 6H/3C interface is detected, confirming the 2D nucleation mechanism of the 3C epilayer from a flat coherent interface; 2) in-plane substrate/epilayer lattice mismatch always exists, but the 3C epilayers do not correspond to a completely relaxed cubic structure, indicating that the epilayers are partially strained; 3) lattice mismatch varies for different regions, implying a complicated strain relaxation mechanism of 3C epilayers on various mesas.

Crystallinity of YBa2Cu3O7−x single crystals grown by the pulling method

1996 ◽  
Vol 11 (4) ◽  
pp. 804-812 ◽  
Author(s):  
Y. Namikawa ◽  
M. Egami ◽  
S. Koyama ◽  
Y. Shiohara ◽  
H. Kutami
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Growth Direction ◽  
Annealed Sample ◽  
Seed Crystal ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Crystal Seed ◽  
Better Than

Large YBa2Cu3O7−x (Y123) single crystals (larger than 13 mm cubed) have been grown along the c-axis reproducibly by the modified pulling method. The crystallinity of Y123 single crystal was investigated by x-ray diffraction and x-ray topography. Crystals grown from an MgO single crystal seed had some low angle subgrain boundaries which tilted 0.1–0.8° from each other. These grain boundaries originated from the seed crystal, and the subgrains were extended along the growth direction from the seed crystal. Y123 single crystals with no marked subgrains in the whole area were obtained by using Y123 single subgrain crystal seeds. FWHM of the x-ray rocking curve for the crystal so produced was about 0.14°, which was much better than the spectrum consisting of several separated peaks obtained from the previous crystals. Tc onset of the annealed sample was about 93.6 K, and the transition width was about 0.9 K. The low angle subgrain boundaries did not seem to be effective pinning centers for the magnetic flux.

Defect structure analysis of polycrystalline materials by computer-controlled double-crystal diffractometer with position-sensitive detector

1983 ◽  
Vol 16 (1) ◽  
pp. 89-95 ◽  
Author(s):  
R. Yazici ◽  
W. Mayo ◽  
T. Takemoto ◽  
S. Weissmann
Keyword(s):  
Position Sensitive Detector ◽  
Polycrystalline Materials ◽  
Sensitive Detector ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Local Lattice ◽  
Position Sensitive ◽  
The Individual ◽  
Double Crystal Diffractometer

The method represents an extension of a previously developed X-ray double-crystal diffractometer method when a film was used to record the crystallite reflections, each reflecting crystallite being regarded as the second crystal of a double-crystal diffractometer. By utilizing a position-sensitive detector (PSD) with interactive computer controls, the tedious and limiting task of data acquisition and analysis is greatly simplified. The specimen is irradiated with crystal-monochromated radiation and the numerous microscopic spots emanating from the reflecting crystallites are recorded separately by the position-sensitive detector and its associated multichannel analyzer at each increment of specimen rotation. An on-line minicomputer simultaneously collects these data and applies the necessary corrections. This process is then automatically repeated through the full rocking-curve range. The computer carries out the rocking-curve analysis of the individual crystallite reflections as well as that of the entire reflecting crystallite population. The instrument is provided with a specimen translation device which permits analysis of large sections of solid specimens. Thus, sites of local lattice defects induced either mechanically, chemically or by radiation can rapidly be established and quantitatively determined in terms of rocking-curve parameters as well as imaged by X-ray topography, by inserting a film in front of the PSD. The versatility and usefulness of the method is demonstrated by examples given from studies of fracture, fatigue and stress-corrosion cracking of commercial alloys.

Digital X-Ray Rocking Curve Topography

1986 ◽  
Vol 82 ◽  
Author(s):  
T. S. Ananthanarayanan ◽  
R. G. Rosemeier ◽  
W. E. Mayo ◽  
J. H. Dinan
Keyword(s):  
Bragg Reflection ◽  
Strain Tensor ◽  
Epitaxial Films ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Density Maps ◽  
First Time ◽  
Considerable Body ◽  
Double Crystal Diffractometer

SUMMARYThere is a considerable body of work available illustrating the significance of X-ray rocking curve measurements in micro-electronic applications. For the first time a high resolution (100-150µm) 2-dimensional technique called DARC (Digital Autcmated Rocking Curve) topography has been implemented. This method is an enhancement of the conventional double crystal diffractometer using a real time 2-dimensional X-ray detector.Several materials have been successfully examined using DARC topography. Same of these include: Si, GaAs, AlGaAs, InGaAs, HgMnTe, Al, Inconel, steels, etc. By choosing the appropriate Bragg reflection multi-layered micro-electronic structures have been analyzed nondestructively. Several epitaxial films, including HgCdTe and ZnCdTe, grown by molecular beam epitaxy, have also been characterized using iARC topography. The rocking curve half width maps can be translated to dislocation density maps with relative ease. This technique also allows the deconvolution of the micro-plastic lattice strain ccaponent from the total strain tensor.

TEM Study of the Morphology Of GaN/SiC (0001) Grown at Various Temperatures by MBE

1999 ◽  
Vol 595 ◽  
Author(s):  
W.L. Sarney ◽  
L. Salamanca-Riba ◽  
V. Ramachandran ◽  
R.M Feenstra ◽  
D.W. Greve
Keyword(s):  
Low Temperatures ◽  
Stacking Faults ◽  
Full Width ◽  
X Ray Diffraction ◽  
High Quality ◽  
Double Crystal ◽  
Tem Analysis ◽  
Rocking Curve ◽  
X Ray ◽  
Substrate Temperatures

AbstractGaN films grown on SiC (0001) by MBE at various substrate temperatures (600° - 750° C) were characterized by RHEED, STM, x-ray diffraction, AFM and TEM. This work focuses on the TEM analysis of the films' features, such as stacking faults and dislocations, which are related to the substrate temperature. There are several basal plane stacking faults in the form of cubic inclusions for samples grown at low temperatures compared to those grown at high temperatures. The dislocation density is greatest for the film grown at 600°C, and it steadily decreases with increasing growth temperatures. Despite the presence of various defects, x-ray analysis shows that the GaN films are of high quality. The double crystal rocking curve full width at half maximum (FWHM) for the GaN (0002) peak is less than 2 arc-minutes for all of the films we measured and it decreases with increasing growth temperature.

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