X-ray and neutron reflectivity analysis of thin films and superlattices

1994 ◽  
Vol 58 (3) ◽  
pp. 159-168 ◽  
Author(s):  
H. Zabel
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.


Author(s):  
M. Tolan ◽  
W. Press

AbstractThe general concepts of x-ray and neutron reflectivity are outlined. Theoretical principles are discussed at the beginning where both, the optical treatment based on the solution of the Helmholtz equation and the kinematical scattering formalism are given. Afterwards experimental standard setups are presented, and a small fraction of the work that has been done in the past is discussed. The examples deal with scattering from liquid thin films and polymer films where x-ray and neutron reflectivity are almost unique probes to obtain structural information. This is in particular true for polymer/polymer interfaces where neutron reflectivity has one of its most prominent applications. Other examples show how oxidation processes can be monitored by x-ray reflectivity and how layer systems of technological importance, here CoSi


2015 ◽  
Vol 233-234 ◽  
pp. 666-669 ◽  
Author(s):  
Sergey Granovsky ◽  
Irina Gaidukova ◽  
Andrey Sokolov ◽  
Anton Devishvili ◽  
Vyacheslav Snegirev

We present the results of macroscopic measurements, X-ray diffraction and neutron reflectivity experiments on ≈ 25 nm thin films of Ni50Mn35In15 grown using Pulsed laser deposition technique on MgO single-crystalline substrate. Intrinsic magnetization of the film below Tc ≈ 290 K was confirmed. Structural measurements show the large temperature-dependent residual strain on the substrate with no indication of martensitic transition.


Author(s):  
R. M. Anderson

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.


Author(s):  
C. W. Price ◽  
E. F. Lindsey

Thickness measurements of thin films are performed by both energy-dispersive x-ray spectroscopy (EDS) and x-ray fluorescence (XRF). XRF can measure thicker films than EDS, and XRF measurements also have somewhat greater precision than EDS measurements. However, small components with curved or irregular shapes that are used for various applications in the the Inertial Confinement Fusion program at LLNL present geometrical problems that are not conducive to XRF analyses but may have only a minimal effect on EDS analyses. This work describes the development of an EDS technique to measure the thickness of electroless nickel deposits on gold substrates. Although elaborate correction techniques have been developed for thin-film measurements by x-ray analysis, the thickness of electroless nickel films can be dependent on the plating bath used. Therefore, standard calibration curves were established by correlating EDS data with thickness measurements that were obtained by contact profilometry.


Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.


Author(s):  
D J H Cockayne ◽  
D R McKenzie

The study of amorphous and polycrystalline materials by obtaining radial density functions G(r) from X-ray or neutron diffraction patterns is a well-developed technique. We have developed a method for carrying out the same technique using electron diffraction in a standard TEM. It has the advantage that studies can be made of thin films, and on regions of specimen too small for X-ray and neutron studies. As well, it can be used to obtain nearest neighbour distances and coordination numbers from the same region of specimen from which HREM, EDS and EELS data is obtained.The reduction of the scattered intensity I(s) (s = 2sinθ/λ ) to the radial density function, G(r), assumes single and elastic scattering. For good resolution in r, data must be collected to high s. Previous work in this field includes pioneering experiments by Grigson and by Graczyk and Moss. In our work, the electron diffraction pattern from an amorphous or polycrystalline thin film is scanned across the entrance aperture to a PEELS fitted to a conventional TEM, using a ramp applied to the post specimen scan coils. The elastically scattered intensity I(s) is obtained by selecting the elastically scattered electrons with the PEELS, and collecting directly into the MCA. Figure 1 shows examples of I(s) collected from two thin ZrN films, one polycrystalline and one amorphous, prepared by evaporation while under nitrogen ion bombardment.


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