Efficient high-pass filtering with practical, high-yield X-ray transmission mirror optics

2020 ◽  
Vol 35 (S1) ◽  
pp. S3-S7
Author(s):  
David N. Agyeman-Budu ◽  
Joel D. Brock ◽  
Arthur R. Woll
Keyword(s):  
Thin Film ◽  
High Yield ◽  
Silicon Substrates ◽  
Transmitted Beam ◽  
X Ray ◽  
Silicon Nitride Membrane ◽  
Novel Approach ◽  
Potential Applications ◽  
High Pass ◽  
Thin Film Membrane

Although the concept, first demonstration, and potential applications of X-ray transmission mirrors (XTMs) were initially described over 30 years ago, only a few implementations exist in the literature. This is attributed to the unsolved challenge of a thick frame supporting a thin, reflecting membrane which does not itself block the transmitted beam. Here, we introduce a novel approach to solve this problem by employing silicon microfabrication. A robust XTM frame has been fabricated by using a novel two-step etch process, which secures the thin-film membrane without blocking the transmitted beam. Specifically, we have fabricated delicate XTM optics with 90% yield, which consist of 280-nm-thick low-stress silicon nitride membrane windows that are 1.5 mm wide and 125 mm long on silicon substrates. The XTM optics have been demonstrated to be a more efficient high-pass X-ray filter; for example, when configured for 40% transmission of 11.3 keV photons, we measure the reduction of 8.4 keV photons by a factor of 56.

A new approach to characterization of the transition temperatures of thin film NiTi shape memory alloys

2004 ◽  
Vol 19 (6) ◽  
pp. 1762-1767
Author(s):  
Nicholas W. Botterill ◽  
David M. Grant ◽  
Jianxin Zhang ◽  
Clive J. Roberts
Keyword(s):  
Thin Film ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Transition Temperatures ◽  
New Approach ◽  
Novel Approach ◽  
Potential Applications ◽  
Niti Shape Memory Alloys

A novel approach in determining the transition temperatures of NiTi shape memory alloys was investigated and compared with conventional techniques. The technique is based on microthemal analysis using a scanning thermal microscope (SThM). In particular, this method has the potential to allow the transformation temperatures of thin films to be investigated in situ. Thin film shape memory alloys have potential applications, such as microactuators, where conventional analysis techniques are either not directly applicable to such samples or are difficult to perform.

Identification of the Failure Mechanism of a Thin Film on a Thick Substrate by Means of Synchrotron X-Ray Topography Combined with Transmission Electron Microscopy

1987 ◽  
Vol 108 ◽  
Author(s):  
D. Goyal ◽  
W. Ng ◽  
A. H. King ◽  
J. C. Bilello
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Film Thickness ◽  
Film Stress ◽  
Silicon Substrates ◽  
X Ray ◽  
Transmission Electron ◽  
Thick Substrate

ABSTRACTWe have used synchrotron x-ray topographic techniques to study the stresses in thin films formed upon silicon substrates either by evaporation or sputtering. It is found that the film stress generally decreases with increasing film thickness for evaporated films, but film delamination occurs at a well defined film thickness. Transmission electron microscope studies have been performed on the same specimens in order to reveal what mechanisms are involved with the delamination of the films.

Wide-range three-dimensional reciprocal-space mapping: a novel approach applied to organic monodomain thin films

2007 ◽  
Vol 40 (3) ◽  
pp. 580-582 ◽  
Author(s):  
R. Resel ◽  
O. Lengyel ◽  
T. Haber ◽  
O. Werzer ◽  
W. Hardeman ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Three Dimensional ◽  
Reciprocal Space ◽  
Ray Method ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Novel Approach ◽  
Wide Range ◽  
Thin Film Characterization

An X-ray method is presented to characterize thin films with unknown crystal structure with specific crystal orientations. The method maps large volumes of the reciprocal space by a series of pole-figure measurements using a standard texture goniometer. The data can be used for lattice indexing and texture evaluation and in subsequent steps for a complete structural thin-film characterization. The application of the method is demonstrated on an organic monodomain thin film consisting of uniaxially aligned crystallites.

Microstructure and Mechanical Properties of Combinatorially Prepared Thin Film Aluminum-Silicon Nanocomposites

2006 ◽  
Vol 977 ◽  
Author(s):  
Charles H. Olk ◽  
Michael Lukitsch ◽  
Daad B Haddad
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Structural Phase ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystallite Sizes ◽  
Amorphous Si ◽  
Sputter Deposited ◽  
Combinatorial Methods

Abstracte have undertaken the exploration of the AlxSi1-x systems to discover new alloys with enhanced properties. We describe the mechanical properties of thin film AlxSi1-x alloys determined through indentation experiments. Combinatorial methods were used to systematically control thin film microstructure through variations in composition and growth temperature. Discrete libraries of compositionally graded films have been sputter deposited onto silicon substrates to produce two structural phase regions: amorphous Al-Si and amorphous Si plus crystalline Al. The mechanical properties of the thin films were determined by analyzing the load-displacement traces based on the Oliver-Pharr method. X-ray diffraction was used to investigate the microstructures and determine the crystallite sizes.

scholarly journals Coatings for FEL optics: preparation and characterization of B4C and Pt

2018 ◽  
Vol 25 (1) ◽  
pp. 116-122 ◽  
Author(s):  
Michael Störmer ◽  
Frank Siewert ◽  
Christian Horstmann ◽  
Jana Buchheim ◽  
Grzegorz Gwalt
Keyword(s):  
Thin Film ◽  
Layer Thickness ◽  
Single Layer ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Surface Finishing ◽  
Silicon Substrates ◽  
Shape Error ◽  
X Ray ◽  
Efficient Delivery

Large X-ray mirrors are required for beam transport at both present-day and future free-electron lasers (FELs) and synchrotron sources worldwide. The demand for large mirrors with lengths up to 1 m single layers consisting of light or heavy elements has increased during the last few decades. Accordingly, surface finishing technology is now able to produce large substrate lengths with micro-roughness on the sub-nanometer scale. At the Helmholtz-Zentrum Geesthacht (HZG), a 4.5 m-long sputtering facility enables us to deposit a desired single-layer material some tens of nanometers thick. For the European XFEL project, the shape error should be less than 2 nm over the whole 1 m X-ray mirror length to ensure the safe and efficient delivery of X-ray beams to the scientific instruments. The challenge is to achieve thin-film deposition on silicon substrates, benders and gratings without any change in mirror shape. Thin films of boron carbide and platinum with a thickness in the range 30–100 nm were manufactured using the HZG sputtering facility. This setup is able to cover areas of up to 1500 mm × 120 mm in one step using rectangular sputtering sources. The coatings produced were characterized using various thin-film methods. It was possible to improve the coating process to achieve a very high uniformity of the layer thickness. The movement of the substrate in front of the sputtering source has been optimized. A variation in B4C layer thickness below 1 nm (peak-to-valley) was achieved at a mean thickness of 51.8 nm over a deposition length of 1.5 m. In the case of Pt, reflectometry and micro-roughness measurements were performed. The uniformity in layer thickness was about 1 nm (peak-to-valley). The micro-roughness of the Pt layers showed no significant change in the coated state for layer thicknesses of 32 nm and 102 nm compared with the uncoated substrate state. The experimental results achieved will be discussed with regard to current restrictions and future developments.

Characterization of Y-Ba-Cu-O films grown on silicon substrates by sequential evaporation

1988 ◽  
Vol 46 ◽  
pp. 866-867
Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
L. G. Turner ◽  
N. Lewis
Keyword(s):  
Thin Film ◽  
Thin Film Deposition ◽  
Superconducting Films ◽  
Electron Beam Evaporation ◽  
Film Deposition ◽  
Silicon Substrates ◽  
Superconducting Properties ◽  
Sequential Electron ◽  
Thin Superconducting Films

There is great interest in the growth of thin superconducting films of YBa2Cu3Ox on silicon, since this is a necessary first step in the use of this superconductor in a variety of possible electronic applications including interconnects and hybrid semiconductor/superconductor devices. However, initial experiments in this area showed that drastic interdiffusion of Si into the superconductor occurred during annealing if the Y-Ba-Cu-O was deposited direcdy on Si or SiO2, and this interdiffusion destroyed the superconducting properties. This paper describes the results of the use of a zirconia buffer layer as a diffusion barrier in the growth of thin YBa2Cu3Ox films on Si. A more complete description of the growth and characterization of these films will be published elsewhere.Thin film deposition was carried out by sequential electron beam evaporation in vacuum onto clean or oxidized single crystal Si wafers. The first layer evaporated was 0.4 μm of zirconia.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

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.

Problems in Thin-Film X-ray Quantification

1990 ◽  
Vol 48 (2) ◽  
pp. 458-459
Author(s):  
J N Chapman ◽  
W A P Nicholson
Keyword(s):  
Thin Film ◽  
Specimen Thickness ◽  
X Rays ◽  
Characteristic Peak ◽  
Local Composition ◽  
X Ray ◽  
Measured Ratio ◽  
Path Lengths ◽  
Composition Changes

Energy dispersive x-ray microanalysis (EDX) is widely used for the quantitative determination of local composition in thin film specimens. Extraction of quantitative data is usually accomplished by relating the ratio of the number of atoms of two species A and B in the volume excited by the electron beam (nA/nB) to the corresponding ratio of detected characteristic photons (NA/NB) through the use of a k-factor. This leads to an expression of the form nA/nB = kAB NA/NB where kAB is a measure of the relative efficiency with which x-rays are generated and detected from the two species.Errors in thin film x-ray quantification can arise from uncertainties in both NA/NB and kAB. In addition to the inevitable statistical errors, particularly severe problems arise in accurately determining the former if (i) mass loss occurs during spectrum acquisition so that the composition changes as irradiation proceeds, (ii) the characteristic peak from one of the minority components of interest is overlapped by the much larger peak from a majority component, (iii) the measured ratio varies significantly with specimen thickness as a result of electron channeling, or (iv) varying absorption corrections are required due to photons generated at different points having to traverse different path lengths through specimens of irregular and unknown topography on their way to the detector.

Electron diffraction detection of ordliking in annealed PbTe thin film

1990 ◽  
Vol 48 (4) ◽  
pp. 1018-1019
Author(s):  
Karimat El-Sayed
Keyword(s):  
Thin Film ◽  
Electron Diffraction ◽  
Lead Telluride ◽  
Structural Basis ◽  
Face Centered Cubic ◽  
X Ray ◽  
Polycrystalline Thin Films ◽  
Stage Process ◽  
Diffraction Patterns ◽  
Face Centered

Lead telluride is an important semiconductor of many applications. Many Investigators showed that there are anamolous descripancies in most of the electrophysical properties of PbTe polycrystalline thin films on annealing. X-Ray and electron diffraction studies are being undertaken in the present work in order to explain the cause of this anamolous behaviour.Figures 1-3 show the electron diffraction of the unheated, heated in air at 100°C and heated in air at 250°C respectively of a 300°A polycrystalline PbTe thin film. It can be seen that Fig. 1 is a typical [100] projection of a face centered cubic with unmixed (hkl) indices. Fig. 2 shows the appearance of faint superlattice reflections having mixed (hkl) indices. Fig. 3 shows the disappearance of thf superlattice reflections and the appearance of polycrystalline PbO phase superimposed on the [l00] PbTe diffraction patterns. The mechanism of this three stage process can be explained on structural basis as follows :

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