Progress in instrumentation,data reduction,and depth profiles in Auger electron spectroscopy

Progress in the use of Auger electron spectroscopy is discussed. Specifically limits to spatial resolution in the scanning Auger microprobe resulting from backscattered electrons is illustrated. Determination of chemical state by peak shapes and energies are discussed along with the use of correction factors in quantitating Auger electron data. Finally, the use of inverse Laplace transforms of angle-resolved electron spectroscopy data to generate composition depth profiles of sputtered GaAs is illustrated. It is concluded that Gibbsian surface segregation during sputtering caused depletion of As near the surface of GaAs.     

The application of deconvolution methods in electron spectroscopy — a review

In this review of the application of deconvolution in electron spectroscopy the operations of convolution and deconvolution are first defined. The theoretical background to direct methods, Fourier Transform techniques and iterative approaches to deconvolution is given. The use of smoothing techniques, the removal of secondary electron background and the determination of broadening functions are then considered. Examples of deconvolution in electron spectroscopy are discussed. These include valence and core levels in XPS, gas-phase UPS studies and resolution enhancement in Auger spectroscopy. Deconvolution of Auger spectra to yield density of states curves is examined. The likely future status of deconvolution in electron spectroscopy is considered.     

超高真空俄歇电子能谱原位加热和GaN热效应研究

建立一套基于超高真空俄歇电子能谱的原位加热系统,对GaN薄膜进行热效应研究．随着温度的增加,Ga LMM和Ga MVV的动能减小．利用第一性原理计算,获得理论的GaMVV俄歇谱.加热过程由于晶格热膨胀以及表面原子再构引起价电子态密度发生变化,从而导致价带俄歇谱负移．     

Energy and angular distributions of electrons emitted by direct double auger decay

We have observed the direct L(2,3)MMM double Auger transition after photoionization of the 2p shell of argon by angle-resolved electron-electron coincidence spectroscopy. The process is responsible for about 20% of the observed Auger electron intensity. In contrast to the normal Auger lines, the spectra in double Auger decay show a continuous intensity distribution. The energy and angular distributions of the emitted electrons allow one to obtain information on the electron correlations giving rise to the double Auger process as well as the symmetry of the associated two-electron continuum state.     

On the satellite in the Auger electron spectrum

The satellite line profile in the C–VV Auger electron spectroscopy spectrum depends upon how the initial core hole state and the final multiple hole state are created. Even if the numbers of the holes in the satellite states are the same, the Auger electron spectroscopy spectral profiles of the final multiple hole states are different. The localization of the three hole satellite state is discussed.     

Auger and direct electron spectra in X-ray photoelectron studies of zinc,zinc oxide,gallium and gallium oxide

Auger and direct electron spectra from Zn, ZnO, Ga and Ga₂O₃ have been studied with X-ray photoelectron spectroscopy (ESCA). The chemical shift between zinc electron binding energies in Zn and ZnO is very small, whereas the zinc Auger electron signals are separated by 4.3 eV. In gallium, the oxide and metal signals are separated by 1.9 eV, but the Auger electron energy shift is three times as large. Thus the Auger signals are more sensitive to the chemical environment than the direct electron signals, which is the same relation as earlier observed for copper and copper oxides.     

Quantitative Auger electron spectroscopy analysis of binary alloys with separate matrix correction factors for bulk and surface

A new method which takes into account the separate matrix correction factors for bulk and surface has been tried out for quantitative Auger electron spectroscopy analysis of binary alloys. The calculations use an iteration scheme. It has been applied to the Fe-Cr alloys studied at this Centre and the Auger electron spectroscopy data for the other alloy systems available in literature. The results are now more compatible with the expectation that the surface composition is different from the bulk.     

Beobachtung von Elektronen-Channeling-Diagrammen im Augerelektronen-Spektrometer mit Rasterzusatz

In the scanning electron microscope the electron channeling patterns allow us to determine the orientation and quality of single crystal objects. If the Auger spectrometer is equipped with a scanning sample positioner, the electron channeling patterns can be observed with primary energies used in Auger spectroscopy, i.e. 0.5–5 keV.     

Multielectron spectroscopy: the xenon 4d hole double auger decay

A magnetic bottle spectrometer of the type recently developed by Eland et al. [Phys. Rev. Lett. 90, 053003 (2003).] has been implemented for use with synchrotron radiation, allowing multidimensional electron spectroscopy. Its application to the Xe 4d double Auger decay reveals all the energy pathways involved. The dominant path is a cascade process with a rapid (6 fs) ejection of a first Auger electron followed by the slower (>23 fs) emission of a second Auger electron. Weaker processes implying 3 electron processes are also revealed, namely, direct double Auger and associated Rydberg series.     

Specific features of the formation of ytterbium films on the Si(111) surface at room temperature

The processes accompanying the formation of ytterbium films on the Si(111) surface at room temperature are investigated by the contact potential difference method, Auger electron spectroscopy, low-energy electron diffraction, and thermal desorption spectroscopy. It is shown that the grown metal films are uniform in thickness and that Si atoms virtually do not dissolve in the films. The atoms of the silicon substrate can diffuse in limited amounts into the Yb metal film only when the surface is bombarded by high-energy primary electron beams employed in Auger electron spectroscopy. The results obtained permit the conclusion that the previously observed oscillations of the work function in Yb-Si(111) thin-film structures cannot originate from dissolution of silicon atoms in the ytterbium film.     

On the restoration of Auger line shapes

A simple and efficient method to deduce the true Auger spectrum from the raw data is presented. This method is an application to Auger spectroscopy derived from signal processing procedures employed in different fields. It appears particularly promising when complex spectra are analyzed as it avoids spurious information to be introduced. The method is also compared with the more-standard van Cittert's approach. An experimental check of the common assumption that an Auger electron experiences almost the same energy-loss mechanisms as a nearly elastically reflected primary electron at the same energy is given.     

Bone calcium, phosphorus detection by Auger electron spectroscopy

Auger electron spectroscopy was used to detect calcium and phosphorus of cortical bone from rat femoral neck and rear tibia. Spectra were taken from bone pieces as well as from disks prepared from grinded bone material. Experimental conditions were found whereby the samples could be analyzed without conductive coatings. The results of this preliminary investigation demonstrate that Auger electron spectroscopy can be used to study bone mineral elements.     

Electron spectroscopic study of the iron surface and its interaction with oxygen and nitrogen

The interaction of oxygen and nitrogen with a clean polycrystalline iron surface was investigated using Auger electron spectroscopy, photoelectron spectroscopy and electron energy loss spectroscopy. Further evidence for the dissociative nature of adsorbed nitrogen on iron is shown by the photoelectron spectroscopy data in conjunction with preliminary thermal desorption work. The first electron energy loss data for the nitrided iron surface is presented and shown to be very similar to that for the clean and oxidized surfaces.     

Surface segregation in an Ir-2%Pt alloy studied using Auger electron spectroscopy

The surface segregation in an Ir-2%Pt alloy has been studied using Auger electron spectroscopy. The variation of the probing depth with Auger electron energy was utilized for estimating the in-depth segregation profile. After annealing at 950°C and cooling to room temperature, Auger spectra were recorded in five different kinetic energy regions. The quantitative analysis of four of these spectra was performed using computer added spectra from pure Ir and Pt. A strong segregation of Pt to the surface layer was observed.     

Crystallographic incident beam effects in quantitative Auger electron spectroscopy

Auger electron spectroscopic studies of cylindrical copper single crystals show large variations with surface orientation in Auger yield from both the clean surface and oxygen adsorbed to saturation on the surface which can be attributed to incident beam effects and “inverse Kikuchi” phenomena. Ways are discussed of minimising the effect of these anisotropies to obtain true comparative surface coverages from Auger electron spectroscopy of different crystal surface orientations.     

Emploi quantitatif de la spectroscopie Auger; Étalonnage de la méthode

A calibration is presented for the measurement, by Auger electron spectroscopy, of sulphur adsorbed on nickel. The Auger emission from the metal is used as a reference. The use of radioactive sulphur permits a direct measurement of the quantity of adsorbed sulphur.     

Modification of the Surface Properties of Free Si–Cu Films by Implantation of Active Metal Ions

Technical Physics - Using the methods of Auger electron spectroscopy, electron energy loss spectroscopy, and UV photoelectron spectroscopy, the influence of Ba+ ion implantation on the...     

Structures and chemistry of the annealed SrTiO3(001) surface

Surface structures and chemistry of the annealed SrTiO₃(001) have been studied by scanning tunneling microscopy and Auger electron spectroscopy. Our STM results show that islands arc formed on an originally smooth surface after annealing in ultra high vacuum at a temperature of 1300°C. Tunneling spectra show that the islands exhibit a different electronic structure than that of SrTiO₃, with an apparent bandgap of 6 eV rather than 3.2 eV. Auger electron spectroscopy indicates that annealing yields strontium enrichment at the surface. The nature of the islands and change of surface chemistry are discussed in terms of correlation of the STM and Auger results.     

Study of multigraphene films prepared by sublimation on the sic surface

Graphene films were prepared by sublimation epitaxy of SiC under vacuum. The films were studied by Auger electron spectroscopy, reflection high-energy electron diffraction, atomic force microscopy, and Raman spectroscopy. It is concluded that the films prepared are polycrystalline and consist of graphene single crystals about 50 nm in size.     

Mobility and surface recombination processes of primary electrons in dielectric systems during Auger electron spectroscopy

The time evolution of the surface electric field in a dielectric system during Auger electron spectroscopy is calculated. It is shown that steady electric fields are very quickly attained. Their steady value is connected to primary electron mobility.