Annealing Effects of Schottky Contacts on the Characteristics of 4H-SiC Schottky Barrier Diodes

1999 ◽  
Vol 572 ◽  
Author(s):  
S. C. Kang ◽  
B. H. Kum ◽  
S. J. Do ◽  
J. H. Je ◽  
M. W. SHIN
Keyword(s):  
Schottky Barrier ◽  
Schottky Barrier Diodes ◽  
X Ray ◽  
Annealing Temperatures ◽  
X Ray Scattering ◽  
Different Temperatures ◽  
Annealing Effects ◽  
Evolution Of Microstructure ◽  
The Relationship ◽  
Ray Scattering

ABSTRACTThis paper reports on the relationship between the microstructure and the device performance of Pt/4H-SiC schottky barrier diodes ( SBDs ). The evolution of microstructure in the metal/SiC interfaces annealed at different temperatures was characterized using X-ray scattering techniques. The reverse characteristics of the devices were degraded with annealing temperatures. The maximum breakdown voltages of as-deposited devices and 850 °C annealed devices are 1300 V and 626 V, respectively. However, the forward characteristics of the devices were found out to improve with annealing temperatures. X-ray scattering analysis showed that Pt-silicides were formed by annealing performed at or higher than 650 °C. The formation of silicides was shown to increase the roughness of the Pt/SiC interface. It is believed that the forward characteristics of the SBDs be strongly dependent on the crystallity of silicides formed in the Pt/SiC interface during the annealing process.

Fundamentals of Kinematical X-Ray Scattering Theory

2014 ◽  
pp. 1-14
Keyword(s):  
Scattering Theory ◽  
Profile Analysis ◽  
Reciprocal Lattice ◽  
Line Profile Analysis ◽  
X Ray ◽  
X Ray Scattering ◽  
Basic Concepts ◽  
Lattice Planes ◽  
The Relationship ◽  
Ray Scattering

The broadening of X-ray line profiles is usually described by the kinematical scattering theory. In this chapter, the basic concepts and equations of the kinematical X-ray scattering are presented in order to better understand the theory of line profile analysis. The correlation between the crystal structure and the diffracted intensity distribution is shown. The scattering angles of the diffracted peak maxima are given by the Ewald construction in the reciprocal space. The correspondence between the reciprocal lattice vectors and the lattice planes is also presented, and the relationship between the scattering angle and the lattice plane spacing is given by Bragg’s law.

Small-angle X-ray scattering of two-phase systems: significance of polydispersity

2010 ◽  
Vol 43 (5) ◽  
pp. 998-1004 ◽  
Author(s):  
Wilhelm Ruland
Keyword(s):  
Size Distribution ◽  
Small Angle ◽  
Two Phase ◽  
X Ray ◽  
X Ray Scattering ◽  
Phase Systems ◽  
Two Phases ◽  
The Relationship ◽  
Ray Scattering

Evaluation of the small-angle X-ray scattering of two-phase systems leads to the determination of the Porod lengthlpand the correlation lengthlc. In dilute systems, the parameter κl=lc/lp− 1 is a measure of the polydispersity of the chord lengthslwithin the dilute phase, which depends on the size distribution and the shape of the particles forming this phase. As an example, the change of κlwith the size distribution is calculated for spheres and spheroids. For dense two-phase systems, κldepends not only on the polydispersities of the chord lengthsl1andl2of the two phases but also on the spatial order in the system. This is demonstrated by examples related to microemulsions. The appendix contains a short discussion on the relationship between chord-length distributions and Bertrand's paradox.

Phase separation in gel-derived materials, separation and crystallization of SnO2 within an amorphous SiO2 matrix

1992 ◽  
Vol 7 (2) ◽  
pp. 435-443 ◽  
Author(s):  
R. Dal Maschio ◽  
S. Dirè ◽  
G. Carturan ◽  
S. Enzo ◽  
L. Battezzati
Keyword(s):  
Surface Segregation ◽  
Primary Crystallization ◽  
Amorphous Sio2 ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Two Phases ◽  
Average Size ◽  
Ray Scattering

On heating a gel of composition 33.5SnO2−66.5SiO2 (wt. %) up to 1050 °C, SnO2 crystallization occurred with different mechanisms according to thermal treatments. Thermal analysis, SAXS (Small Angle X-Ray Scattering), WAXS (Wide Angle X-Ray Scattering), and TEM (Transmission Electron Microscopy) results obtained for samples treated at different temperatures demonstrated that the SnO2 load is divided into two moieties, one composed of isolated SnO2 particles suitable for primary crystallization yielding crystallites with 4.0 nm of average size; the other, being dissolved in SiO2, remains in the amorphous SiO2/SnO2 solid solution up to the highest temperature. The presence of these two phases accounts for SnO2 surface segregation at the expense of the SnO2 concentration of neighboring outer layers and the independence of apparent density on temperature.

An insight into real and average structure from diffuse X-ray scattering – a case study

2016 ◽  
Vol 72 (4) ◽  
pp. 571-583 ◽  
Author(s):  
Michał Leszek Chodkiewicz ◽  
Anna Makal ◽  
Roman Gajda ◽  
Dragoslav Vidovic ◽  
Krzysztof Woźniak
Keyword(s):  
Diffuse Scattering ◽  
Organic Salt ◽  
X Ray ◽  
Average Structure ◽  
X Ray Scattering ◽  
The Difference ◽  
The Relationship ◽  
Insight Into ◽  
Ray Scattering

Two-dimensional diffuse X-ray scattering from an organic salt [N-(3-(2,6-dimethylanilino)-1-methylbut-2-enylidene)-2,6-dimethylanilinium chloride, C21H27N2+Cl−] was interpreted with the help of an analytical model of diffuse scattering. An analysis of the relationship between symmetry and diffuse scattering for the studied system has been undertaken. The symmetry of the system explains the extinction pattern, taking the form of curves, on the diffuse scattering planes. We have also tested the relationship between the average structure model and scattering intensities. Two models, differing in their representation of overlapping atoms, were used. In the case of diffuse scattering the difference between resulting intensities is immense, while for the Bragg intensities it is much smaller. This sensitivity of diffuse scattering could potentially be used to improve the description of the average structure.

Temperature evolution of microstructure of turbostratic high melting coal-tar synthetic pitch studied using wide-angle X-ray scattering method

Carbon ◽  
2015 ◽  
Vol 81 ◽  
pp. 272-283 ◽  
Author(s):  
Milan Dopita ◽  
Marcus Emmel ◽  
Anton Salomon ◽  
Martin Rudolph ◽  
Zdeněk Matěj ◽  
...  
Keyword(s):  
Coal Tar ◽  
Temperature Evolution ◽  
Scattering Method ◽  
Wide Angle ◽  
High Melting ◽  
X Ray ◽  
X Ray Scattering ◽  
Evolution Of Microstructure ◽  
Ray Scattering

Exotic X-ray back-diffraction: a path toward a soft inelastic X-ray scattering spectrometer

2014 ◽  
Vol 47 (5) ◽  
pp. 1658-1665 ◽  
Author(s):  
Marcelo Goncalves Hönnicke ◽  
Raymond Conley ◽  
Cesar Cusatis ◽  
Edson Massayuki Kakuno ◽  
Juan Zhou ◽  
...  
Keyword(s):  
Dynamical Theory ◽  
Extreme Condition ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Magnetic Imaging ◽  
X Ray Scattering ◽  
Low Energies ◽  
Different Temperatures ◽  
Ray Scattering

In this work, soft X-ray back-diffraction (XBD; X-ray diffraction at angles near and exactly equal to 90°) is explored. The experiment was conducted at the SXS beamline at Laboratorio Nacional de Luz Sincrotron, Brazil, at ∼3.2 keV. A high-resolution Si(220) multi-bounce back-diffraction monochromator was designed and constructed for this experiment. An ultra-thin Si(220) crystal (5 µm thick) was used as the sample. This ultra-thin crystal was characterized by profilometry, rocking-curve measurements and X-ray topography prior to the XBD measurements. It is shown that the measured forward-diffracted beam (o-beam) profiles, taken at different temperatures, are in close agreement with profiles predicted by the extended dynamical theory of X-ray diffraction, with the absence of multiple-beam diffraction (MBD). This is an important result for future studies on the basic properties of back-diffracted X-ray beams at energies slightly above the exact XBD condition (extreme condition where XBD is almost extinguished). Also, the results presented here indicate that stressed crystals behave like ideal strain-free crystals when used for low-energy XBD. This is mainly due to the large widths of XBD profiles, which lead to a low strain sensitivity in the detection of defects. This result opens up new possibilities for mounting spherical analyzers without degrading the energy resolution, at least for low energies. This is a path that may be used to construct a soft inelastic X-ray scattering spectrometer where different applications such as element-specific magnetic imaging tools could be explored.

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