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.

A 4 Crystal Monochromator for High Resolution Rocking Curves

1987 ◽  
Vol 31 ◽  
pp. 403-408
Author(s):  
Robert W. Green
Keyword(s):  
Bragg Reflection ◽  
Thin Layers ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Lattice Constants ◽  
Monochromator Crystal ◽  
Parallel Configuration ◽  
Double Crystal Diffractometer

X-ray characterization of single crystal materials in the form of thin layers can be accomplished with the use of a double crystal diffractometer. The resultant rocking curve is a convolution of the Bragg reflection from both the first and second crystals. The width of the rocking curve at half-height is a measure of the crystal perfection of a materiel. Since the FWHM for the material being analyzed cannot be less than that of the first crystal (Monochromator), the first crystal should be of very good crystal quality. The problem that arises with the two crystal parallel configuration (Fig. 1) is that the monochromator crystal must be changed each time a material of different orientation or stoichiometry with different resultant lattice constants is analyzed. This requires changing the monochromator and re-aligning the double crystal diffractometer.

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.

X-Ray Double Crystal Diffraction Characterization of Epitaxial Magnetic Transiton Metal Difluorides

1990 ◽  
Vol 187 ◽  
Author(s):  
M. Lui ◽  
A. R. King ◽  
V. Jaccarino ◽  
R. F. C. Farrow ◽  
S. S. P. Parkins
Keyword(s):  
Lattice Mismatch ◽  
Magnetic Transition ◽  
Diffraction Theory ◽  
Epitaxial Films ◽  
Structural Quality ◽  
Double Crystal ◽  
Lattice Match ◽  
Rocking Curve ◽  
X Ray ◽  
Quality Material

AbstractEpitaxial films of a variety of magnetic transition metal difluoride films have been grown by molecular beam epitaxy techniques. The structural quality of these films have been characterized using X-ray double crystal rocking curve analysis. The observed rocking curve linewidths were compared to their intrinsic values as calculated by dynamical diffraction theory. The degree of crystalline perfection as judge by the rocking curves have been correlated with the amount of lattice mismatch between the various epitaxial films and substrates. In the well lattice match case (Δa/a < 0.2%) of epitaxial films of FeF2 and CoF2 grown on (001) ZnF2 substrates, the rocking curve line widths approached their intrinsic limit indicative of extremely high quality material. This work represents some of the best epitaxial magnetic insulating films grown to date.

Subsurface Micro-Lattice Strain Mapping

1986 ◽  
Vol 90 ◽  
Author(s):  
T. S. Ananthanarayanan ◽  
R. G. Rosemeier ◽  
W. E. Mayo ◽  
P. Becla
Keyword(s):  
Diffraction Method ◽  
Epitaxial Films ◽  
Depth Of Penetration ◽  
Ir Detector ◽  
Strain Mapping ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Microplastic Strain ◽  
Invaluable Tool

SYNOPSISDefect morphology and distribution up to depths of 20um have been shown to be critical to device performance in micro-electronic applications. A unique and novel x-ray diffraction method called DARC (Digital Automated Rocking Curve) topography has been effectively utilized to map crystalline micro-lattice strains in various substrates and epitaxial films. The spatial resolution of this technique is in the the order of 100um and the analysis time for a 2cm2 area is about 10 secs. DARC topography incorporates state-ofthe- art 1-dimensional and 2-dimensional X-ray detectors to modify a conventional Double Crystal Diffractometer to obtain color x-ray rocking curve topographs.This technique, being non-destructive and non-intrusive in nature, is an invaluable tool in materials’ quality control for IR detector fabrication. The DARC topographs clearly delineate areas of microplastic strain inhomogeniety. Materials analyzed using this technique include HgMnTe, HgCdTe, BaF2, PbSe, PbS both substrates and epitaxial films. By varying the incident x-ray beam wavelength the depth of penetration can be adjusted from a 1–2 micron up to 15–20um. This can easily be achieved in a synchrotron.

Fine-rotation attachment to standard goniometers

2004 ◽  
Vol 37 (1) ◽  
pp. 62-66 ◽  
Author(s):  
P. Suortti ◽  
J. Keyriläinen ◽  
M. Fernández
Keyword(s):  
Torsion Angle ◽  
Rotation Angle ◽  
Linear Actuator ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Fine Focus ◽  
New Type ◽  
Rotation Stage ◽  
Double Crystal Diffractometer

A new type of fine-rotation stage has been constructed and tested. It can be attached to standard goniometers used in X-ray and neutron crystallography. The device consists of a shaft and a bar that is fitted tightly to a hole traversing the shaft. The diameter of the shaft is 5 to 10 times larger than the diameter of the bar and the length of the bar is about 5 times larger than the height of the shaft. The bottom of the shaft is attached to the top plate of the goniometer and a goniometer head can be fitted to the other end of the shaft. The free end of the bar is pushed tangentially by a linear actuator to produce a torsion moment at the shaft. The dimensions and materials of the prototype were chosen such that a 1 mm bend of the bar corresponded to a torsion angle of the shaft of about 20 µrad. The rotation angle was measured using a double-crystal diffractometer in the non-dispersive setting, with MoKα1radiation from a fine-focus X-ray tube. Accurately known angular deviations were produced by refraction in a prism and the shifts in the rocking-curve position were measured. The measured torsion angle agreed within 4% with the value calculated from the elastic constants and dimensions of the device. The repeatability of the angle was ±20 nrad (0.004 arcsec).

Characterization of Epitaxial Films by X-Ray Diffraction

1985 ◽  
Vol 29 ◽  
pp. 353-366 ◽  
Author(s):  
Armin Segmüller
Keyword(s):  
Strain Tensor ◽  
Grazing Incidence ◽  
Epitaxial Films ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
X Ray ◽  
Structural Details ◽  
Composition Profiles

AbstractIn this paper, the application of recently developed x-ray diffraction techniques to the characterization of thin epitaxial films will be discussed. The double-crystal diffractometer, with high resolution in the non-dispersive arrangement, enables the materials scientist to study epitaxial systems having a very small mismatch with high precision. A key part of the characterization of an epitaxial film is the determination of the strain tensor by measuring lattice spacing! in various directions The determination of strain and composition profiles in ion-implanted films, epitaxial layers and superlattices by rocking-curve analysis will also be reviewed. Grazingincidence diffraction, an emerging new technique, can be used to obtain structural details parallel to the interface on films with thicknesses ranging down to a few atomic layers. The synchroton has now become increasingly available as a powerful source of x radiation which will facilitate the application of conventional and grazing-incidence diffraction to ultra-thin films.

Strain Mapping in InGaAsP Epitaxial Films by An X-Ray Diffraction Technique

1985 ◽  
Vol 54 ◽  
Author(s):  
Jharna Chaudhuri ◽  
William E. Mayo ◽  
Sigmund Weissmann
Keyword(s):  
Electronic Materials ◽  
Strain Tensor ◽  
Diffraction Method ◽  
Epitaxial Films ◽  
X Ray Diffraction ◽  
Strain Mapping ◽  
Rocking Curve ◽  
X Ray ◽  
Inp Substrate ◽  
Elastic Strain Tensor

ABSTRACTA new x-ray diffraction method is developed to determine the full elastic strain tensor and its distribution about a strain center in single crystal materials. It is based on the recently developed Computer Aided Rocking Curve Analyzer and is particularly well suited for analysis of thin film structures common to electronic materials. This technique will be described in detail, and its application in measuring the non-uniform strains in InGaAsP epitaxial film on InP substrate will be presented. Also, possibility of using this method to measure the uniformity of film thickness will be discussed.

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.

Thermal Strain Study of Almost Lattice-Matched Epitaxial InuGa1-uAs1-vP1-v Films on InP(100) Substrates

1989 ◽  
Vol 160 ◽  
Author(s):  
G. Bai ◽  
M-A. Nicolet ◽  
S.-J. Kim ◽  
R.G. Sobers ◽  
J.W. Lee ◽  
...  
Keyword(s):  
Room Temperature ◽  
Epitaxial Film ◽  
Lattice Mismatch ◽  
Thermal Strain ◽  
Growth Direction ◽  
Epitaxial Films ◽  
Double Crystal ◽  
X Ray ◽  
Lattice Matched ◽  
Coherent Interfaces

AbstractSingle layers of ~ 0.5µm thick InuGa1-uAs1-vPv (0.52 < u < 0.63 and 0.03 < v < 0.16) were grown epitaxially on InP(100) substrates by liquid phase epitaxy at ~ 630°C. The compositions of the films were chosen to yield a constant banndgap of ~ 0.8 eV (λ = 1.55 µm) at room temperature. The lattice mismatch at room temperature between the epitaxial film and the substrate varies from - 4 × 10-3 to + 4 × 10-3. The strain in the films was characterized in air by x-ray double crystal diffractometry with a controllable heating stage from 23°C to ~ 700°C. All the samples have an almost coherent interfaces from 23°C to about ~ 330°C with the lattice mismatch accomodated mainly by the tetragonal distortion of the epitaxial films. In this temperature range, the x-ray strain in the growth direction increases linearly with temperature at a rate of (2.0 ± 0.4) × 10-6/°C and the strain state of the films is reversible. Once the samples are heated above ~ 300°C, a significant irreversible deterioration of the epitaxial films sets in.

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