Determination of Crystal Structure and Cation Distribution in Thin Films

1991 ◽  
Vol 35 (A) ◽  
pp. 151-157
Author(s):  
G. Will ◽  
T. C. Huang ◽  
F. Sequeda

The structural characterization of thin films is important for research development and manufacturing of electronic, magnetic, optical, and other high-tech materials. The grazing incidence X-ray diffraction technique has bean used successfully for the determination of crystalline phases, structural-depth profiles, crystallite size, and strain, etc. of thin films with thickness's down to a few tens of Å, If the crystal structure, e.g. the distribution of atoms in the unit cell, or the crystallinity and texture (or preferred orientation) of a film is of interest, the conventional Bragg-Brentano diffractometer technique with the θ-2θ scanning geometry has been found to be appropriate.

1991 ◽  
Vol 35 (A) ◽  
pp. 143-150 ◽  
Author(s):  
T. C. Huang

AbstractGrazing-incidence X-ray analysis techniques which are commonly used for the nondestructive characterization of surfaces and thin films are reviewed. The X-ray reflectivity technicue is used to study surface uniformity and oxidation, layer thickness and density, interface roughness and diffusion, etc. The grazing-incidence in-plane diffraction technique is used to determine in-plane crystallography of epitaxial films. The grazing-incidence asymmetric-Bragg diffraction is used for surface phase identification and structural depth profiling determination of polycrystalline films. Typical examples to illustrate the types of information that can be obtained by the techniques are presented.


2013 ◽  
Vol 46 (6) ◽  
pp. 1749-1754 ◽  
Author(s):  
P. Wadley ◽  
A. Crespi ◽  
J. Gázquez ◽  
M.A. Roldán ◽  
P. García ◽  
...  

Determining atomic positions in thin films by X-ray diffraction is, at present, a task reserved for synchrotron facilities. Here an experimental method is presented which enables the determination of the structure factor amplitudes of thin films using laboratory-based equipment (Cu Kα radiation). This method was tested using an epitaxial 130 nm film of CuMnAs grown on top of a GaAs substrate, which unlike the orthorhombic bulk phase forms a crystal structure with tetragonal symmetry. From the set of structure factor moduli obtained by applying this method, the solution and refinement of the crystal structure of the film has been possible. The results are supported by consistent high-resolution scanning transmission electron microscopy and stoichiometry analyses.


2013 ◽  
Vol 53 (1S) ◽  
pp. 01AD01 ◽  
Author(s):  
Takeshi Watanabe ◽  
Tomoyuki Koganezawa ◽  
Mamoru Kikuchi ◽  
Christine Videlot-Ackermann ◽  
Jörg Ackermann ◽  
...  

2016 ◽  
Vol 23 (3) ◽  
pp. 729-734 ◽  
Author(s):  
Roland Resel ◽  
Markus Bainschab ◽  
Alexander Pichler ◽  
Theo Dingemans ◽  
Clemens Simbrunner ◽  
...  

Dynamical scattering effects are observed in grazing-incidence X-ray diffraction experiments using an organic thin film of 2,2′:6′,2′′-ternaphthalene grown on oxidized silicon as substrate. Here, a splitting of all Bragg peaks in the out-of-plane direction (z-direction) has been observed, the magnitude of which depends both on the incidence angle of the primary beam and the out-of-plane angle of the scattered beam. The incident angle was varied between 0.09° and 0.25° for synchrotron radiation of 10.5 keV. This study reveals comparable intensities of the split peaks with a maximum for incidence angles close to the critical angle of total external reflection of the substrate. This observation is rationalized by two different scattering pathways resulting in diffraction peaks at different positions at the detector. In order to minimize the splitting, the data suggest either using incident angles well below the critical angle of total reflection or angles well above, which sufficiently attenuates the contributions from the second scattering path. This study highlights that the refraction of X-rays in (organic) thin films has to be corrected accordingly to allow for the determination of peak positions with sufficient accuracy. Based thereon, a reliable determination of the lattice constants becomes feasible, which is required for crystallographic structure solutions from thin films.


2011 ◽  
Vol 64 (8) ◽  
pp. 1065 ◽  
Author(s):  
Vivek M. Prabhu ◽  
Shuhui Kang ◽  
R. Joseph Kline ◽  
Dean M. DeLongchamp ◽  
Daniel A. Fischer ◽  
...  

The ccc stereoisomer-purified tert-butoxycarbonyloxy-protected calix[4]resorcinarene molecular resists blended with photoacid generator exhibit a non-uniform photoacid-catalyzed reaction in thin films. The surface displays a reduced reaction extent, compared with the bulk, with average surface-layer thickness 7.0 ± 1.8 nm determined by neutron reflectivity with deuterium-labelled tert-butoxycarbonyloxy groups. Ambient impurities (amines and organic bases) are known to quench surface reactions and contribute, but grazing-incidence X-ray diffraction shows an additional effect that the protected molecular resists are preferentially oriented at the surface, whereas the bulk of the film displays diffuse scattering representative of amorphous packing. The surface deprotection reaction and presence of photoacid were quantified by near-edge X-ray absorption fine-structure measurements.


1993 ◽  
Vol 62 (12) ◽  
pp. 1353-1355 ◽  
Author(s):  
T. C. Huang ◽  
R. Savoy ◽  
R. F. C. Farrow ◽  
R. F. Marks

1985 ◽  
Vol 29 ◽  
pp. 353-366 ◽  
Author(s):  
Armin Segmüller

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.


2010 ◽  
Vol 93-94 ◽  
pp. 340-343 ◽  
Author(s):  
Adisorn Buranawong ◽  
Surasing Chaiyakhun ◽  
Pichet Limsuwan

Nanocrystalline aluminium titanium nitride (AlTi3N) thin films were deposited on Si (100) wafers and grids by reactive magnetron co-sputtering technique using titanium and aluminium targets. The films were sputtered in Ar and N2 mixture at a constant flow rate under different conditions of deposition time ranging from 15 to 60 minutes. The crystal structure was characterized by X-Ray diffraction (XRD) and microstructure was analyzed by transmission electron microscopy (TEM). The results indicated that the formation of polycrystalline AlTi3N with the orthorhombic structure and the development of crystal structure was observed by varied the deposition time. The microstructure of films was good according to the XRD results. On the other hand, after annealed the films at 500OC in the air for 1 hour, the crystal structure did not change that exposed the stable structure of AlTi3N films.


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