X-ray Analysis of Si/Ge/Si(001) Heterolayer Structures Grown by Surfactant Mediated Epitaxy.

2001 ◽  
Vol 696 ◽  
Author(s):  
Brad P. Tinkham ◽  
Duane M. Goodner ◽  
Donald A. Walko ◽  
Michael J. Bedzyk

AbstractX-ray diffraction and x-ray standing waves (XSW) have been used to investigate the quality of epitaxial ultra-thin Ge films grown on Si(001) with and without Te as a surfactant. The efficacy of Te as a surfactant in this application has been debated. We measured samples between 1 and 10 ML in thickness and our results clearly indicate that Ge films grown with Te are superior to those grown without Te. The coherent positions and coherent fract ons determined from XSW analysis agree well with those predicted by linear elasticity theory for Ge/Si(001). Furthermore, grazing incidence diffraction measurements (GIXD) suggests that 9 ML Ge grown on Si(001) with Te is strained in-plane while the same film grown without Te is relaxed.

2021 ◽  
Vol 54 (5) ◽  
pp. 1530-1534
Author(s):  
Sergey Stepanov

X-ray Server (https://x-server.gmca.aps.anl.gov) is a collection of programs for online modelling of X-ray diffraction and scattering. The dynamical diffraction program is the second most popular Server program, contributing 34% of total Server usage. It models dynamical X-ray diffraction from strained crystals and multilayers for any Bragg-case geometry including grazing incidence and exit. This paper reports on a revision of equations used by the program, which yields ten times faster calculations in most use cases, on implementing calculations of X-ray standing waves and on adding new options for modelling diffraction from monolayers.


Author(s):  
Chad E. Miller ◽  
Jaroslaw Majewski ◽  
Thomas Gog ◽  
Tonya L. Kuhl

AbstractUsing complementary X-ray reflectivity (XR) and grazing incidence X-ray diffraction (GIXD), we report structural studies of supported thin-organic layers in contact with water and air. Using a monochromatic synchrotron beam to penetrate 10 mm of liquid, we have characterized buried films composed of 12.5 repeating bilayers of arachidic acid (C


1991 ◽  
Vol 239 ◽  
Author(s):  
J. M. Hudson ◽  
A. R. Powell ◽  
D. K. Bowen ◽  
M. Wormington ◽  
B. K. Tanner ◽  
...  

ABSTRACTWe demonstrate the use of x-ray diffraction to provide accurate compositional information, together with grazing incidence reflectivity to provide information on layer thicknesses and surface and interface roughnesses, on Si/Si1-xGex superlattice structures of less than 200nm total thickness.The quality of SiGe interfaces has been investigated in superlattices where x varies from 0.1 to 0.5. At low Ge compositions the interfaces are shown to be smooth to a few angstroms. However, as the Ge composition in the SiGe layer approaches 50%, severe roughness is observed at the SiGe to Si interfaces, although the Si to SiGe interfaces remain relatively smooth.Upon annealing for one hour at 850°C the Ge diffuses outwards from the SiGe layers and can be closely modelled by inclusion of a (2.4±0.3)nm linearly graded layer either side of the SiGe layer into a simulation program. The long range roughness at the SiGe to Si interface is lost upon annealing leaving only a short range roughness of similar size to the Si to SiGe interface roughness.Reflectivity measurements have been shown to distinguish between interface roughness and interdiffusion for the annealed system.


2002 ◽  
Vol 35 (2) ◽  
pp. 163-167 ◽  
Author(s):  
F. Pfeiffer ◽  
U. Mennicke ◽  
T. Salditt

An X-ray diffraction experiment on multilamellar membranes incorporated into an X-ray waveguide structure is reported. In the device, the lipid bilayers are confined to one side by the silicon substrate and to the other side by an evaporated thin metal cap layer. Shining a highly brilliant X-ray beam onto the system, resonantly enhanced, precisely defined and clearly distinguishable standing-wavefield distributions (modes) are excited. The in-plane structure of the acyl chain ordering is then studied by grazing incidence diffraction under simultaneously excited modes. A significant gain in signal-to-noise ratio as well as enhanced spatial resolution can be obtained with such a setup.


1987 ◽  
Vol 31 ◽  
pp. 223-230
Author(s):  
L. T. Nguyen ◽  
I. C. Noyan

The results of an experimental study on residual stresses within the encapsulation layers of electronic components are described. For this study, silicon wafers were coated with a flexibilized cycloaliphatic formulation filled with 30 and 40 (vol.) % of Cu particles. The residual stresses were determined by measuring the radii of curvature of the encapsulated wafers. The stress in the Cu particles at the surface was also measured by X-Ray diffraction. It was seen that the stresses within the structure are primarily macro-stresses, with little stress present within the Cu particles. Comparison of the experimental values to those calculated from linear elasticity theory also indicate relaxation within the composite during curing.


2013 ◽  
Vol 772 ◽  
pp. 143-147
Author(s):  
Marianna Marciszko ◽  
Andrzej Stanisławczyk ◽  
Andrzej Baczmanski ◽  
Krzysztof Wierzbanowski ◽  
Wilfrid Seiler ◽  
...  

The geometry based on the multireflection grazing incidence X-ray diffraction (called the MGIXD method) can be applied to measure residual stresses. Using this method, it is possible to perform a non-destructive analysis of the heterogeneous stresses for different and well defined volumes below the surface of the sample (range of several mm). As the result the average values of stresses weighted by absorption of X-ray radiation are measured. In this work the stress profile as a function of depth for mechanically polished Ti and Al samples were calculated from MGIXD data using inverse Laplace transform.


1994 ◽  
Vol 375 ◽  
Author(s):  
J. L. Jordan-Sweet ◽  
P. M. Mooney ◽  
G. B. Stephenson

AbstractHigh-resolution x-ray diffraction is an excellent probe of strain relaxation in complex SiGe structures. The high flux provided by synchrotron sources enables us to make extensive reciprocal space map measurements and evaluate many samples. The diffraction peak positions of each layer in a step-graded structure, measured for two different reflections, yield quantitative values for the relaxation and alloy composition in the layer. Grazing-incidence diffraction allows us to determine the in-plane structure of very thin layers, which have thickness-broadened peaks at conventional diffraction geometries. We demonstrate the power of these techniques with two examples.


1993 ◽  
Vol 37 ◽  
pp. 189-196 ◽  
Author(s):  
B. L. Ballard ◽  
P. K. Predecki ◽  
D. N. Braski

AbstractIntrinsic stresses as a function of σ, the 1/e penetration depth were measured for a smooth, 1μm thick, fine grained, cylindrical post magnetron sputtered molybdenum film deposited on a vycor glass substrate in the dynamic deposition mode. Using grazing incidence diffraction and the Mo (321) reflection, lattice spacing profiles were determined for τ values from 200-4400 Å. The in-plane intrinsic stresses parallel and perpendicular to the post axis were determined employing the ϕ-integral method and assuming elastic isotropy. The results were related to the surface structure and composition profiles via atomic force microscopy (AFM) and auger electron spectroscopy (AES) respectively.


1986 ◽  
Vol 30 ◽  
pp. 457-464 ◽  
Author(s):  
S. S. Iyengar ◽  
M. W. Santana ◽  
H. Windischmann ◽  
P. Engler

Due to the current high interest in characterizing epitaxially deposited thin films required by the electronics industry as well as the increased attention in elucidating reactions between solid surfaces and the environment (e.g., corrosion), investigators have increased their efforts in developing X-ray procedures for analyzing films and surfaces less than 2 μm thick. For example, an entire session of the 1985 Denver Conference on Applications of X-ray Analysis was devoted to this subject and an excellent review of X-ray diffraction techniques for characterizing thin films was recently published by Segmuller (1). Specific techniques include grazing incidence diffraction (2, 3), double crystal diffraction (3), and the use of the Seemann-Bohlin focusing geometry (4, 5).


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