XPS Studies of the Si/SiO2 Interface With Synchrotron Radiation

1999 ◽  
Vol 592 ◽  
Author(s):  
F. Rochet ◽  
F. Jolly ◽  
G. Dufour ◽  
C. Grupp ◽  
A. Taleb-Ibrahimi
Keyword(s):  
Synchrotron Radiation ◽  
High Surface ◽  
High Energy ◽  
High Energy Resolution ◽  
Surface Sensitivity ◽  
Thin Oxide Films ◽  
Very High Energy ◽  
Recent Debate ◽  
Spectroscopy Studies ◽  
Very High

ABSTRACTSi 2p core-level spectroscopy is a unique tool to determine the chemical composition and spatial extension of the suboxide layer present at the Si/SiO2 interface. In the case of ultra-thin oxide films (thickness <10 Å), the high surface sensitivity provided by the tunability of synchrotron radiation allows the observation of four energetically well-separated oxidation states, generally attributed to a silicon atom with an increasing number of oxygen first neighbors, and hence often denoted Sin+(with n=1,…,4). After a brief review of two decades of XPS studies on the Si/SiO2 interface, we give an account of the recent debate concerning the possible contribution of the second oxygen neighbor shell to the chemical shift, which, if effective, would modify the picture of the interface. Then, we examine the benefit derived from the use of very high energy resolution (70 meV at hv=130 eV), and we try to determine, for this system, what are the limits of this spectroscopy. To illustrate the latter point, among various case studies (thermal oxides, room temperature adsorption etc.), we treat in more detail the case of the H-terminated Si(1 11) surface oxidized by atomic oxygen, and discuss our data in the light of previous XPS and vibrational spectroscopy studies.

High-energy resolution in X-ray scattering with the spectrometer INELAX. I. The principles and the test instrument

1991 ◽  
Vol 24 (6) ◽  
pp. 1042-1050 ◽  
Author(s):  
E. Burkel ◽  
B. Dorner ◽  
Th. Illini ◽  
J. Peisl
Keyword(s):  
Energy Resolution ◽  
High Energy ◽  
Bragg Angle ◽  
High Energy Resolution ◽  
X Rays ◽  
Test Results ◽  
X Ray Scattering ◽  
Radiation Sources ◽  
Very High Energy ◽  
Very High

Very high-energy resolution measurements using X-rays can be achieved by extreme backreflection (Bragg angle close to 90°) from perfect crystals. This technique, combined with the high intensity of X-rays emitted by synchrotron-radiation sources, allowed the development of the instrument INELAX for inelastic scattering experiments. The principles and test results are discussed.

Low-temperature high-Z gamma-detectors with very high energy resolution

2001 ◽  
Author(s):  
Carlos Pobes ◽  
Chiara Brofferio ◽  
Carlo Bucci ◽  
Oliviero Cremonesi ◽  
Ettore Fiorini ◽  
...  
Keyword(s):  
Low Temperature ◽  
Energy Resolution ◽  
High Energy ◽  
High Energy Resolution ◽  
Very High Energy ◽  
Very High ◽  
Gamma Detectors

scholarly journals Focusing X-Ray Optics for Astronomy

2010 ◽  
Vol 2010 ◽  
pp. 1-19 ◽  
Author(s):  
Paul Gorenstein
Keyword(s):  
Angular Resolution ◽  
Effective Area ◽  
High Energy ◽  
High Energy Resolution ◽  
Physical Optics ◽  
Long Distance ◽  
Modest Improvement ◽  
X Ray ◽  
Very High Energy ◽  
Very High

Focusing X-ray telescopes have been the most important factor in X-ray astronomy’s ascent to equality with optical and radio astronomy. They are the prime tool for studying thermal emission from very high temperature regions, non-thermal synchrotron radiation from very high energy particles in magnetic fields and inverse Compton scattering of lower energy photons into the X-ray band. Four missions with focusing grazing incidence X-ray telescopes based upon the Wolter 1 geometry are currently operating in space within the 0.2 to 10 keV band. Two observatory class missions have been operating since 1999 with both imaging capability and high resolution dispersive spectrometers. They are NASA’s Chandra X-ray Observatory, which has an angular resolution of 0.5 arc seconds and an area of 0.1 m2 and ESA’s XMM-Newton which has 3 co-aligned telescopes with a combined effective area of 0.43 m2 and a resolution of 15 arc seconds. The two others are Japan’s Suzaku with lower spatial resolution and non-dispersive spectroscopy and the XRT of Swift which observes and precisely positions the X-ray afterglows of gamma-ray bursts. New missions include focusing telescopes with much broader bandwidth and telescopes that will perform a new sky survey. NASA, ESA, and Japan’s space agency are collaborating in developing an observatory with very large effective area for very high energy resolution dispersive and non-dispersive spectroscopy. New technologies are required to improve upon the angular resolution of Chandra. Adaptive optics should provide modest improvement. However, orders of magnitude improvement can be achieved only by employing physical optics. Transmitting diffractive-refractive lenses are capable theoretically of achieving sub-milli arc second resolution. X-ray interferometry could in theory achieve 0.1 micro arc second resolution, which is sufficient to image the event horizon of super massive black holes at the center of nearby active galaxies. However, the physical optics systems have focal lengths in the range 103 to 104 km and cannot be realized until the technology for accurately positioned long distance formation flying between optics and detector is developed.

Experiments with Very High Energy Synchrotron Radiation

1998 ◽  
Vol 5 (3) ◽  
pp. 286-292 ◽  
Author(s):  
Th. Tschentscher ◽  
P. Suortti
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
High Energy ◽  
Future Research ◽  
High Electron ◽  
Magnetic Systems ◽  
Research Areas ◽  
Insertion Device ◽  
Very High Energy ◽  
Very High

The use of synchrotron radiation with very high photon energies has become possible only with the latest generation of storage rings. All high-electron-energy synchrotron sources will have a dedicated program for the use of very high photon energies. The high-energy beamline ID15 at the ESRF was the first beamline built and dedicated to this purpose, and it has now been in user operation for more than three years. The useful energy range of this beamline is 30–1000 keV and the superconducting insertion device for producing the highest attainable photon energies is described in detail. The techniques most often used today are diffraction and Compton scattering; an overview of the most important experiments is given. Both techniques have been used in the investigation of magnetic systems, and, additionally, the high resolution in reciprocal space, which can be achieved in diffraction, has led to a series of applications. Other fields of research are addressed, and attempts to indicate possible future research areas of high-energy synchrotron radiation are made.

Fano Factor Determination For CZT

1997 ◽  
Vol 487 ◽  
Author(s):  
R. H. Redus ◽  
J. A. Pantazis ◽  
A. C. Huber ◽  
V. T. Jordanov ◽  
J. F. Butler ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Fano Factor ◽  
High Energy ◽  
High Resolution Spectroscopy ◽  
High Energy Resolution ◽  
X Rays ◽  
A Value ◽  
Very High Energy ◽  
Gamma Ray Detector ◽  
Very High

AbstractContinued improvements in the manufacturing of Cd1−xZnxTe (CZT) material have resulted in a practical thermoelectrically cooled X-ray and gamma-ray detector of very high energy resolution. A high resolution spectroscopy system was used to measure the Fano factor in CZT at temperatures down to -40°C. The best resolution of the 5.9 keV 55Fe peak was measured to be 188 eV FWHM, while the best resolution of the 59.5 keV 241Am peak was measured to be 482 eV FWHM. The minimum measured Fano factor was 0.082, with several measurements yielding a value of 0.089±0.005. With a resolution of 4.2 keV FWHM for the 662 keV peak of 137Cs, these detectors demonstrate excellent performance in detecting X-rays and gamma rays.

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