X-Ray Reflectometry from Semiconductor Surfaces and Interfaces

1990 ◽  
Vol 208 ◽  
Author(s):  
Brian K Tanner ◽  
Simon J Miles ◽  
D Keith Bowen ◽  
Linda Hart ◽  
Neil Loxley

ABSTRACTX-ray reflectance measurements at grazing incidence provide non-destructively a measure of the thickness of thin layers, the electron density as a function of depth, and interface and surface roughness. We show that the effect of roughness at a buried interface is only to reduce the visibility of the interference fringes, whereas roughness at the top surface leads also to an overall increase in the rate of fall of intensity with angle (or energy). These two contributions can then be readily distinguished.Most work has been performed in monochromatic angular dispersive mode. We present here a preliminary study of the application of the high-energy, fixed-angle, energy dispersive mode for the study of thin epitaxial layers, Langmuir-Blodgett films, surface damage on silicon chemi-sol polished wafers and ion implanted silicon and aluminium. Data has been analysed using the theory of Parratt, which we have adapted for use in the energy dispersive method.

Langmuir ◽  
1998 ◽  
Vol 14 (20) ◽  
pp. 5896-5899 ◽  
Author(s):  
Deborah B. Hammond ◽  
Trevor Rayment ◽  
Damien Dunne ◽  
Philip Hodge ◽  
Ziad Ali-Adib ◽  
...  

Langmuir ◽  
2002 ◽  
Vol 18 (21) ◽  
pp. 8260-8262 ◽  
Author(s):  
Jeffrey T. Culp ◽  
Mark Davidson ◽  
Randolph S. Duran ◽  
Daniel R. Talham

2004 ◽  
Vol 19 (1) ◽  
pp. 45-48 ◽  
Author(s):  
B. K. Tanner ◽  
T. P. A. Hase ◽  
T. A. Lafford ◽  
M. S. Goorsky

The laboratory implementation of grazing incidence in-plane X-ray diffraction, using an unmodified commercial diffractometer, is described. Low resolution, high intensity measurements are illustrated in the study of the in-plane lattice parameters and texture of a thin polycrystalline ZnO film on glass, the in-plane order in Cd arachidate Langmuir–Blodgett films, and the depth dependence of the lattice parameter in graded Si–Ge epilayers. Use of an asymmetrically cut Ge crystal to compress and monochromate the beam provides a high resolution setting, appropriate to measurement of the in-plane mosaic of mismatched epilayers such as GaN on sapphire.


1991 ◽  
Vol 237 ◽  
Author(s):  
B. K. Tanner ◽  
D. K Bowen ◽  
M. C Petty ◽  
S. Swaminathan ◽  
F. Granfeld

ABSTRACTGrazing incidence X-ray reflectometry has been used to characterize Langmuir-Blodgett films of cadmium arachidate deposited on silicon substrates. The agreement between layer parameters deduced from the interference fringe period and low angle Bragg peak positions was excellent. Good agreement was found between experimental and simulated reflectivity profiles only when interface roughness and a varying molecular layer thickness was included. Inclusion of interface roughness alone results in a substantial enhancement in the intensity of the Bragg peaks. This effect is identified as being equivalent to the reduction in extinction found in classical X-ray diffraction due to crystal imperfections.


2004 ◽  
Vol 37 (6) ◽  
pp. 967-976 ◽  
Author(s):  
Andrew C. Jupe ◽  
Stuart R. Stock ◽  
Peter L. Lee ◽  
Nikhila N. Naik ◽  
Kimberly E. Kurtis ◽  
...  

Spatially resolved energy dispersive X-ray diffraction, using high-energy synchrotron radiation (∼35–80 keV), was used nondestructively to obtain phase composition profiles along the radii of cylindrical cement paste samples to characterize the progress of the chemical changes associated with sulfate attack on the cement. Phase distributions were acquired to depths of ∼4 mm below the specimen surface with sufficient spatial resolution to discern features less than 200 µm thick. The experimental and data analysis methods employed to obtain quantitative composition profiles are described. The spatial resolution that could be achieved is illustrated using data obtained from copper cylinders with a thin zinc coating. The measurements demonstrate that this approach is useful for nondestructively visualizing the sometimes complex transformations that take place during sulfate attack on cement-based materials. These transformations can be spatially related to microstructure as seen by computed microtomography.


2017 ◽  
Vol 50 (3) ◽  
pp. 830-839 ◽  
Author(s):  
S. M. Suturin ◽  
V. V. Fedorov ◽  
A. M. Korovin ◽  
N. S. Sokolov ◽  
A. V. Nashchekin ◽  
...  

The development of growth techniques aimed at the fabrication of nanoscale heterostructures with layers of ferroic 3dmetals on semiconductor substrates is very important for their potential usage in magnetic media recording applications. A structural study is presented of single-crystal nickel island ensembles grown epitaxially on top of CaF2/Si insulator-on-semiconductor heteroepitaxial substrates with (111), (110) and (001) fluorite surface orientations. The CaF2buffer layer in the studied multilayer system prevents the formation of nickel silicide, guides the nucleation of nickel islands and serves as an insulating layer in a potential tunneling spin injection device. The present study, employing both direct-space and reciprocal-space techniques, is a continuation of earlier research on ferromagnetic 3dtransition metals grown epitaxially on non-magnetic and magnetically ordered fluorides. It is demonstrated that arrays of stand-alone faceted nickel islands with a face-centered cubic lattice can be grown controllably on CaF2surfaces of (111), (110) and (001) orientations. The proposed two-stage nickel growth technique employs deposition of a thin seeding layer at low temperature followed by formation of the islands at high temperature. The application of an advanced three-dimensional mapping technique exploiting reflection high-energy electron diffraction (RHEED) has proved that the nickel islands tend to inherit the lattice orientation of the underlying fluorite layer, though they exhibit a certain amount of {111} twinning. As shown by scanning electron microscopy, grazing-incidence X-ray diffraction (GIXD) and grazing-incidence small-angle X-ray scattering (GISAXS), the islands are of similar shape, being faceted with {111} and {100} planes. The results obtained are compared with those from earlier studies of Co/CaF2epitaxial nanoparticles, with special attention paid to the peculiarities related to the differences in lattice structure of the deposited metals: the dual-phase hexagonal close-packed/face-centered cubic lattice structure of cobalt as opposed to the single-phase face-centered cubic lattice structure of nickel.


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