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•Development of a special X-ray scattering setup for real-time monitoring of thin film growth in a CVD chamber.•In-situ tracking of phase changes during sulfurization of ...MoO3.•Determination of crystallographic orientations of MoO3 and MoO2 phases during growth.•Estimation of activation energies from crystallization kinetics parameters.
Chemical vapor deposition (CVD) is commonly used for the large-scale synthesis of the films of two-dimensional (2D) transition metal dichalcogenide (TMD) materials, including MoS2 thin films, which have potential applications in optoelectronics, catalysis, and nanoelectronics. As far as thin film of MoS2 is concerned, the influence of deposition parameters on the chemical reactions in the growth process via CVD synthesis has not yet been exhaustively studied. Here we present a comprehensive, time-resolved, in-situ study of the growth of MoS2 thin film from MoO3 by sulfurization using the grazing-incidence wide-angle X-ray scattering (GIWAXS) in laboratory conditions. We tracked the basic chemical reactions during the sulfurization process in real time by monitoring the phase transformations of MoO3 to MoO2 and MoO2 to MoS2 via a MoOS2 transient phase, although it was not possible to observe it directly. Preferential crystallographic orientation of MoO3, and MoO2 phases during the growth was confirmed. In addition, their activation energies were determined from the crystallization kinetics parameters. The present work highlights the importance of understanding the basic chemical reactions inside the CVD reactor as a prerequisite for optimizing the properties of the final 2D TMD films.
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Parasitic scattering caused by apertures is a well-known problem in X-ray analytics, which forces users and manufacturers to adapt their experimental setup to this unwanted phenomenon. ...Increased measurement times due to lower photon fluxes, a lower resolution caused by an enlarged beam stop, a larger beam defining pinhole-to-sample distance due to the integration of an antiscatter guard and generally a lower signal-to-noise ratio leads to a loss in data quality. In this presentation we will explain how the lately developed scatterless pinholes called SCATEX overcome the aforementioned problems. SCATEX pinholes are either made of Germanium or of Tantalum and momentarily have a minimum diameter of 30µm. Thus, these novel apertures are applicable to a wide range of different applications and X-ray energies. We will show measurements which were performed either at home-lab small angle X-ray scattering (SAXS) systems such as the NANOSTAR of Bruker AXS or at synchrotron beamlines. At the PTB four-crystal monochromator beamline at BESSY II data was collected for a comparison of conventional pinholes, scatterless Germanium slit systems and SCATEX pinholes. At the Nanofocus Endstation P03 beamline at PETRA III we compared the performance of our SCATEX apertures with conventional Tungsten slit systems under high flux density conditions.
A high‐performance W/B4C multilayer mirror with 80 periods of nominally 1.37 nm was measured by grazing‐incidence small‐angle X ray scattering (GISAXS) in order to analyse the lateral and vertical ...correlations of the interface roughness within the framework of a scaling concept of multilayer growth. A dynamic growth exponent z = 2.19 (7) was derived, which is close to the value predicted by the Edwards–Wilkinson growth model. The effective number of correlated periods indicates a partial replication of the low interface roughness frequencies. A simulation of the GISAXS pattern based on the Born approximation suggests a zero Hurst fractal parameter H and a logarithmic type of autocorrelation function. The as‐deposited mirror layers are amorphous and exhibit excellent thermal stability up to 1248 K in a 120 s rapid thermal vacuum annealing process. At higher temperatures, the B4C layers decompose and poorly developed crystallites of a boron‐rich W–B hexagonal phase are formed, and yet multilayer collapse is not complete even at 1273 K. Ozone treatment for 3000 s in a reactor with an ozone concentration of 150 mg m−3 results in the formation of an oxidized near‐surface region of a thickness approaching ∼10% of the total multilayer thickness, with a tendency to saturation.
A high-performance W/B
4
C multilayer mirror with 80 periods of nominally 1.37 nm was measured by grazing-incidence small-angle X ray scattering (GISAXS) in order to analyse the lateral and vertical ...correlations of the interface roughness within the framework of a scaling concept of multilayer growth. A dynamic growth exponent
z
= 2.19 (7) was derived, which is close to the value predicted by the Edwards–Wilkinson growth model. The effective number of correlated periods indicates a partial replication of the low interface roughness frequencies. A simulation of the GISAXS pattern based on the Born approximation suggests a zero Hurst fractal parameter
H
and a logarithmic type of autocorrelation function. The as-deposited mirror layers are amorphous and exhibit excellent thermal stability up to 1248 K in a 120 s rapid thermal vacuum annealing process. At higher temperatures, the B
4
C layers decompose and poorly developed crystallites of a boron-rich W–B hexagonal phase are formed, and yet multilayer collapse is not complete even at 1273 K. Ozone treatment for 3000 s in a reactor with an ozone concentration of 150 mg m
−3
results in the formation of an oxidized near-surface region of a thickness approaching ∼10% of the total multilayer thickness, with a tendency to saturation.
Incoatec develops and produces multilayer X‐ray optics with single layers of a few nanometers thickness. These optics are used in X‐ray diffractometers (XRD), X‐ray fluorescence spectrometers (XRF), ...single crystal diffraction (SCD) applications and at synchrotron sources. In this contribution, details of the production of multilayer X‐ray optics with sputter deposition methods are described.
Results from a new type of stationary microfocusing sealed tube X‐ray source will be presented here. Measurements obtained with the new low maintenance, high brilliance microfocus source IμS™ ...equipped with different 2‐dimensional beam shaping multilayer optics are shown. A comparison of the IμS source with typical sealed tube fine focus systems shows data of outstanding quality achieved in diffractometry applications using a 2‐dimensional detector. A large improvement in intensity (by a factor of about 16) was observed. Very promising results were achieved when measuring powders in transmission geometry using the IμS. With this way of focusing on the detector, better crystallite statistics and better resolution were provided. Intensity gain factors in the range of 100 were possible with some applications. For small angle scattering a factor of five was observed when using an IμS with optics for a parallel beam in comparison to a typical sealed tube instrument.
Results from a new type of stationary microfocusing sealed tube X‐ray source are presented here and compared to results from classical systems and an improvement in intensity by a factor of 5 to 100 is demonstrated. Applications for crystallite and powder XRD as well as Small Angle Scattering are discussed thoroughly.
Multilayer X‐ray optics with single layers of a few nanometers thickness can be obtained nowadays. These optics are used in X‐ray diffractometers (XRD), X‐ray fluorescence spectrometers (XRF) and at ...synchrotron sources. A detailed description of the production of multilayer X‐ray optics using sputter deposition methods is presented and the simulation of X‐ray optics and characterization with X‐ray analytical measurements are explained. Finally, the advantages of multilayer X‐ray optics in typical X‐ray analytical applications are summarized.
Multilayer X‐ray optics with single layers of a few nanometers thickness can be obtained and are used in X‐ray diffractometers (XRD), X‐ray fluorescence spectrometers (XRF) and at synchrotron sources. A detailed description of the production using sputter deposition methods is presented. Finally, the advantages of multilayer X‐ray optics in typical X‐ray analytical applications are summarized.
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