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.

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.

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.

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.

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.

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.

Phase analysis of bulk samples using sample-tilting X-ray diffractometry

1992 ◽  
Vol 25 (5) ◽  
pp. 582-588 ◽  
Author(s):  
Q. Cong
Keyword(s):  
Phase Analysis ◽  
Diffraction Method ◽  
Sample Surface ◽  
Geometrical Optics ◽  
Crystal Plane ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
Depth Of Penetration ◽  
X Ray ◽  
Surface Reflection

In the Bragg–Brentano X-ray powder diffractometer, the sample-tilting X-ray diffraction (STD) technique probes a fixed depth of penetration from the sample surface. In this way, phase analysis can be carried out from the surface layers to the depth probed by the CBD (conventional Bragg–Brentano geometry X-ray diffraction) method. In the present paper, after derivation of the diffracted intensity and the observed crystal-plane azimuthal equations, attention is focused on investigations of the geometrical optics of X-ray surface reflection by comparing the STD and CBD methods. Some examples are given to illustrate the applications of the STD technique for solving phase analyses and related problems.

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.

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.

Characterization of epilayers by X-ray double crystal rocking curve peak profile analysis

1995 ◽  
Vol 148 (1-2) ◽  
pp. 31-34 ◽  
Author(s):  
Haiyan An ◽  
Ming Li ◽  
Shuren Yang ◽  
Zhenhong Mai ◽  
Shiyong Liu
Keyword(s):  
Profile Analysis ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray
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