bluuebunny/crossref_metadata_2025 huggingface dataset:
On the silicon dioxide/polycrystalline silicon interface width measurement
Authors: Queirolo G. , Manzini S. , Meda L. , Anderle M. , Canteri R. , Armigliato A. , Frabboni S.
Published: May 2005

The apparent width of the SiO2Si interface was evaluated with Auger electron spectrometry, secondary ions mass spectrometry and transmission electron microscopy for thin silicon dioxide films grown at temperature ranging from 900 to 1100°C, both on single‐ and poly‐crystalline silicon (polysilicon), with the aim of finding the meaning of this kind of measurement for this particular system. The width of the transition between SiO2and polysilicon was found to depend on both the oxidation temperature and polysilicon doping method, being lower for ion implanted than for gas phase (POCl3) doped samples and for oxides grown at higher temperature. The possible causes for the differences in the interface width are discussed and attributed, in the present case, to the oxide thickness non‐uniformity. This is due, in turn, to the lower oxide growth rate, particularly for the lower oxidation temperature, on the silicon grains protruding out of the surface.
New approach for correction of distortions in spectral line profiles in Auger electron spectroscopy
Authors: Sasse A. G. B. M. , Wormeester H. , Van Silfhout A.
Published: May 2005

A new deconvolution method for Auger electron spectroscopy is presented. This method is based on a non‐linear least squares minimizing routine (Levenberg–Marquardt) and global approximation using splines, solving many of the drawbacks inherent to the Van Cittert and Fourier transform based deconvolution methods. The deconvolution routine can be run on a personal computer. The application of this method goes beyond the electron spectroscopies and can be considered as a general deconvolution method.
Depth analysis of metal coatings by glow discharge spectrometry with an argon—helium gas mixture
Authors: Teo W. B. , Hirokawa K.
Published: May 2005

Depth profiles of Cu/Ni, Zn/Fe and Ni/Fe metal coatings obtained with a Grimm glow discharge lamp using an argon—helium gas mixture and pure argon gas were compared. Copper and zinc showed a large increase in intensity for the argon‐helium gas mixture, but Ni showed a small decrease. The sputter time for all three coating metals almost doubled, indicating a smaller sputtering rate for the argon—helium gas mixture. A broadened interface due to the different manner in which the surface was eroded was also observed for the argon—helium sputtered profiles. Intensity enhancement in Cu and Zn was explained by the higher excitation and ionization potential of helium and the simple energy levels (simple spectra) of these elements. On the other hand, the dense energy levels of the Ni atom (complex spectra) does not lead to intensity enhancement.
Surfaces of carbon fibres characterized by inverse gas chromatography
Authors: Grenier‐Loustalot Marie‐Florence , Borthomieu Yannick , Grenier Philippe
Published: May 2005

The surface properties of oxidized and sized (epoxy and epoxy‐polyester) carbon fibres have been determined with inverse phase gas chromatography. Using a column developed in the laboratory we have shown that it is possible to use non‐aggressive solvents (alkanes, alcohols, aromatic derivatives and water) for a highly detailed differentiation of sizing and of the treatments undergone by the fibre by the use of partition coefficient (K°) values (at a given temperature), excess enthalpy values of the mixture and excess entropy values.

We propose a classification of fibres according to their degree of sizing and treatment.
Surface oxides of boron and B12O2as determined by XPS
Authors: Moddeman W. E. , Burke A. R. , Bowling W. C. , Foose D. S.
Published: May 2005

Mound Laboratoires has been investigating pyrotechnic materials for several years. Prior studies on the mechanism of ignition have been performed on Ti/KCIO4and Ti/2B mixtures. These studies have shown the importance of the surface oxides of these materials in determining the mechanism of ignition. In the present study, XPS spectra of fused metal, oxidized fused boron and boron metal powder have been recorded. The spectra are interpeted by including the presence of a continuous boron suboxide layer. The results presented here are different from those previosuly reported, which suggests that the formation of boron oxide occurs in islets. The predominant suboxide will be shown to be BxOy, wherex/y= 3. This oxide was found to be present independent of the degree of oxidation. Including this oxide in thickness calculations shows the oxidation of powders to be five layers or so thick, and also aids in understanding Ti/2B ignition.
Quantitative determination of alkaline sizes on paper surfaces by ESCA part I. HABI [N,N,O‐tris(octadecylcarbamoyl)hydroxylamine]
Authors: Brinen J. S. , Calbick J. C. , Cody R. D.
Published: May 2005

ESCA has been used to monitor the presence of HABI, an experimental alkaline size, on a paper surface at levels normally used in commercial application. A linear relationship between the amount of HABI [N,N,O‐tris(octadecylcarbamoyl)hydroxylamine] applied and the amount detected by ESCA was found, suggesting ‘islanding’ of the sizing agent. Extraction experiments show that HABI is not chemically bound to the paper surface.
Measurement of narrow Si dopant distributions in GaAs by SIMS
Authors: Clegg J. B. , Beall R. B.
Published: May 2005

There is a developing interest in the use of atomic plane or δ‐doping to produce narrow dopant spikes in molecular beam epitaxy GaAs. It is of importance to measure the dopant profile and to determine the growth conditions that minimize dopant spreading. We have used SIMS with low‐energy oxygen bombardment to study the incorporation of silicon in such layers. To aid the optimization of the SIMS depth resolution, a special δ‐doped layered structure has been produced by growth at 400°C. A critical evaluation of the SIMS data for these spikes shows that the profiles are broadened entirely by sputter‐induced relocation effects rather than by thermal diffusion processes. The form of these δ‐spike profiles therefore represents the SIMS resolution function with our specific experimental conditions. The absolute depth resolution (ΔZ) is found to be essentially constant for eroded depths up to ∼500 nm. With the lowest probe energy (0.7 keV per atom), giving a ΔZ of 2.7 nm, at least 68% of the Si is contained within nine atomic planes. Using appropriate sample handling, a detection limit of 1 × 1016 cm−3 Si is obtained after the erosion of only ∼ 15 nm. Analysis of structures grown at normal molecular beam epitaxy temperatures indicates that significant dopant spreading takes place during growth. It is shown that a knowledge of the resolution function enables the inherent SIMS broadening errors to be removed from these measurements. Thus, when the layer growth time is deliberately increased, the Si migrational process is dominated by Fickian diffusion, with the diffusion coefficient being equal to 3.8 × 10−17 cm2 s−1 at 553°C.
Photoelectron diffraction and surface crystallography
Authors: Grenet G. , Jugnet Y. , Homberg S. , Poon H. C. , Duc Tran Minh
Published: May 2005

We report here the state of development of photoemission diffraction from core levels as a tool for the investigation of surfaces. Experimental procedures for performing reproducible and accurate photoemission diffraction curves are formulated. To this end, the merit and the limitations in the choice of different parameters, such as photoelectron kinetic energy or detection angles, are discussed in view of various applications. The discussion is largely exemplified from our experiences, as well as from those in the literature.
Regularization: A stable and accurate method for generating depth profiles from angle‐dependent XPS data
Authors: Tyler B. J. , Castner D. G. , Ratner B. D.
Published: May 2005

An algorithm for generating depth profiles from angle‐dependent XPS data has been developed. The algorithm uses the regularization method with non‐negativity constraints. Four criteria for determining the optimal amount of solution smoothing have been investigated. A criterion that uses the least‐squared error in the regenerated data set proved most effective for selecting the optimal smoothing. Simulated data for a two‐layer sample were used to investigate the effects of the number of data points, where each data point consisted of the spectra acquired at a take‐off angle. Simulated data were also used to investigate the effect of random error on the calculated depth profiles. Increasing the number of data points improved the resolution at the interface. Greater than 10% error could be added to the data without affecting the stability of the algorithm. The algorithm has also been tested on actual angle‐dependent XPS data sets from a thin polyurethane film on gold, a thin silicon oxide film on silicon, and a thick polyetherurethane film on glass. Performance of the regularization algorithm has been compared to an algorithm that uses a singular value decomposition of angle‐dependent XPS data to generate depth profiles. The regularization algorithm demonstrates significantly improved stability and accuracy with roughly equal computational difficulty. Using the regularization algorithm, a quantitative estimate of the depth profile in the upper 100 Å region of a sample can be calculated using data with > 10% error and using as few as three data points.
Improvement of crater‐edge profiling for the characterization of superlattice structures
Authors: Sobue S. , Tanemura M. , Okuyama F.
Published: May 2005

An Auger crater‐edge technique is proposed to measure the interfacial sharpness in superlattices grown by molecular beam epitaxy. The basis of the technique was to linearly raster the primary Xe+ ion beam to form a crater with elongated edges. The SEM images of the crater walls so produced on Al0.25Ga0.75As/GaAs samples resembled closely the X‐TEM images of the superlattice, thus allowing one to determine the lateral and vertical inhomogeneities in layer stacking. The ion beam was then rastered in a zigzag pattern at lower beam energy, exposing the superlattice layers with better‐resolved interfaces, which gave rise to line profiles as low as 30 Å in apparent depth resolution. This may assure that the technique can compete with X‐TEM, with respect to the superlattice characterization in non‐atomic dimensions.
XPS studies of the fluoride ion‐selective electrode membrane LaF3: Ion interferences
Authors: De Marco R. , Cattrall R. W. , Liesegang J. , Nyberg G. L. , Hamilton I. C.
Published: May 2005

XPS has been used to investigate ion‐exchange processes occurring at the surface of the fluoride ion‐selective electrode membrane. It is shown that ion exchange occurs to a depth much greater than that of the outermost solid surface monolayer. The effect of hydroxide ion interference on the response of the electrode has been studied, and a mechanism for its action is proposed. Studies of electrode membranes exposed to carbonate and phosphate ions show that interferences on the response of the electrode cannot be interpreted by solubility product considerations alone.
Evidence for surface titanium hydride on activated TiFe by hydrogen‐induced AES line‐shape effects
Authors: Jungblut B. , Sicking G.
Published: May 2005

The surface segregational processes taking place during the activation of the hydrogen storage material TiFe were studied by Auger electron spectroscopy (AES). In situ treatment of TiFe with 2 × 10−5 mbar hydrogen at 870 K results in the formation of an overlayer, with Ti as the only metallic component. To understand the catalytic mechanism of the hydrogen uptake it is of major importance to gain knowledge about the chemical state of this Ti overlayer. Recent work demonstrates that, in the case of Ti, it is possible to identify not only titanium oxides but also titanium hydrides by line‐shape effects, which act on the Ti L3M23V Auger signal. By comparison with Ti reference spectra measured before and after gas exposure, it becomes clear that the overlayer consists of titanium hydride. In order to emphasize the line‐shape effects, deconvolved spectra are shown. Since Fe was not detectable on the surface of the material after hydrogen treatment, it is concluded that the titanium hydride must catalyse the hydrogen uptake of activated TiFe.
New developments in surface characterization techniques for the semiconductor industry
Authors: Shaffner T. J.
Published: May 2005

Development of diagnostic techniques in the semiconductor industry continues to be measured against requirements for increased material purity and smaller device dimension. Progressive shrinking of very‐large‐scale integrated circuits into the submicron regime and the emergence of quantum structures on the nanometer scale now require accurate and timely analyses of killing defects, which can be an order of magnitude smaller than minimum geometry.

The approach of this article is to review new characterization technique developments which typify our search for an optimum compromise between x–y spatial resolution, depth of analysis and sensitivity of trace metals and dopants. Orders‐of‐magnitude improvement in detectability have been achieved using accelerator mass spectrometry (AMS), laser‐assisted SIMS and Fourier transform photoluminescence. Defects normally elusive at the partsper‐billion atomic level have been studied with sensitive spectroscopies based on positron annihilation and thermal desorption. Deconvolution of high‐resolution x‐ray rocking curves offers capability for in‐depth strain profiling of boron implants. Applications of high‐resolution electron microscopy to heteroepitaxial GaAs on Si and scanning tunneling microscopy to routine grain size measurement are also discussed. Ballistic electron microscopy holds promise as an important new tool for non‐destructive probing on a nanometer scale of the electrical properties of subsurface Schottky interfaces. Statistics are presented in context of the severe sampling problem which inevitably accompanies trace element analysis and single‐atom detection.
Surface kinetic aspects of Si incorporation in molecular beam epitaxial growth of GaAs
Authors: Lee B. , Szafranek I. , Stillman G. E. , Arai K. , Nashimoto Y. , Shimizu K. , Iwata N. , Sakuma I.
Published: May 2005

The incorporation and amphoteric behavior of Si impurities in Si‐doped (100) oriented molecular beam epitaxial (MBE) GaAs layers grown under different As4/Ga flux ratios but with a fixed Si flux have been studied using Hall effect measurements, photothermal ionization spectroscopy and photoluminescence. The Si donor concentration increases substantially with increasing As4/Ga flux ratio, while the Si acceptor concentration remains less than ∼ 1013 cm−3, regardless of the variation of As4/Ga flux ratio. The observed increase of carrier concentration with increasing V/III ratio is not due to a change of site preference of Si impurities from Ga to As sublattice sites as previously supposed, but is due to the increase in incorporation of Si donor. This result can be explained by the kinetic effects associated with surface reaction processes involved in Si impurity incorporation. From these results it is clear that the sticking coefficient of Si is less than unity, and varies with the growth conditions.
Auger electron spectroscopy from elemental standards. II. Peak height and area
Authors: Batchelor D. R. , Bishop H. E. , Venables J. A.
Published: May 2005

Auger electron signals from bulk samples of Si, Cu, Ag and W have been measured using three different machines (V.G. HB50, MA500 and ESCALAB), as a function of primary beam energy E0 (3–30 keV) and angle of incidence θ0 (0–80°). Relative peak‐height data are compared with the calculations of cross‐sections and back‐scattering correction factors presented in Paper I of this series, and with other data and calculations in the literature. The relative cross‐sections agree with experiment within 5% for Si‐K and Ag M5, whereas this agreement worsens to 20% for Cu L3 and W M5. Angular‐dependent experiments reflect the machine geometries and back‐scattering. Values of back‐scattering factors R(θ0) for Si K and W M5 relative to Cu L3 are in good agreement with transport equation calculations. Absolute (peak area) Auger yields have been analysed for one machine, leading to a common effective detector sensitivity (0.35 ± 0.03) for the three elements Si, Cu and Ag.
Determination of the angle of incidence in a Cameca IMS‐4f SIMS instrument
Authors: Meuris M. , De Bisschop P. , Leclair J. F. , Vandervorst W.
Published: May 2005

An improved model for the calculation of the angle of incidence of primary ions is presented for describing secondary ion mass spectrometry (SIMS) measurements in the low primary energy region (<7.5 keV) of a Cameca IMS‐4f with positive primary ions and a positive secondary detection mode. The model explains some of the inconsistencies observed between experiment and the approximative model used so far. Our improvement takes into account the effect of the deflection plates for beam positioning, which leads to a change in the angle of the primary ion with respect to the optical axis of the primary column. A comparison with experimental results is accomplished, showing the improvement of the new model. This new model also explains the slope of the crater bottom in the x‐direction at low primary ion energies, owing to a different sputter yield from one side to the other of the crater bottom.
SIMS/AES characterization of the initial oxidation of an iron—chromium—molybdenum alloy and its base metals at room temperature
Authors: Mathieu H. J. , Landolt D.
Published: May 2005

Low‐temperature oxidation of a FeCrMo alloy and their base metals was investigated by static and dynamic positive and negative SIMS combined with AES Ar+ sputter profiling at 5 keV primary beam energy. In situ oxidation was carried out for 0.3–10000 Langmuir (L) oxygen exposure after sputter cleanning. Static SIMS revealed oxidation of chromium at the outer surface at very low exposures (<0.5 L). With increasing exposures, mainly Fe2O3 was formed at the surface. Dynamic SIMS and AES concentration profiles revealed a multilayer structure with an outer Fe2O3 layer followed by a layer rich in chromium oxide. Oxidized molybdenum was found throughout the film and at the oxide/metal interface.
Quantitative predictions of sputtering phenomena
Authors: Eckstein W.
Published: May 2005

Computer simulation is used extensively in studying sputtering. The different approaches are briefly discussed to show the main advantages of the methods applied. The basic assumptions in the calculations will be considered critically. The main topic will be the discussion of the comparison between calculated and experimental data to demonstrate the agreement achieved.
On the role of water in the photoinduced oxidation of amorphous Ge—Se films
Authors: Schroeter B. , Abraham M. , Broese E. , Weissbrodt P. , Melcher N.
Published: May 2005

The photoinduced oxidation of sputtered amorphous Ge—Se films is investigated by AES, XPS and XAES. By variation of the composition of the oxidizing atmosphere, the dominant role of water in the oxidation process is established. The tendency for oxide formation is found to be strongly correlated with the composition of the oxidizing atmosphere and of the Ge—Se film.
Applications of tandem quadrupole mass spectrometry in SIMS
Authors: Leggett G. J. , Vickerman J. C. , Briggs D.
Published: May 2005

Tandem SIMS studies have been carried out for three polymers—PET, PTFE and LDPE. A variety of collision target gases has been compared and their effectiveness in the construction of fragmentation patterns is considered. For PTFE clusters, xenon provided the most extensive fragmentation patterns, whilst for LPDE clusters, oxygen was preferred. Oxygen and sulphur hexafluoride proved quite reactive when employed with PTFE cluster ions. Using daughter ion and neutral loss data, extensive fragmentation patterns could be constructed.
Microanalysis of inclusion/matrix interfaces in weld metals
Authors: Es‐Souni M. , Beaven P. A.
Published: May 2005

The effects of non‐metallic inclusions on the microstructure of as‐deposited C–Mn weld metals have been investigated in a series of welds produced using different electrode coatings to obtain inclusions of different chemical compositions. The inclusions were analysed on carbon extraction replicas or in thin foils in a 120 kV (scanning) transmission electron microscope (TEM (STEM)) equipped with energy dispersive x‐ray microanalysis facilities. Both x‐ray microanalysis and convergent beam diffraction techniques, with probe sizes down to 10 nm, were used to characterize the inclusions and the inclusion/matrix interfaces.

It was found that the ‘cores’ of the inclusions were mainly oxides, such as MnSiO3 or MnAl2O4. The surfaces of the inclusions were either coated with thin layers of copper sulphide, or mixtures of copper sulphide and titanium carbonitride when both copper and titanium were present as impurities in the welds. Effects of non‐metallic inclusions on weld metal microstructure are discussed with respect to the above‐mentioned coatings and the heterogeneous nucleation of the fine acicular ferrite microconstituent.
The reliability of quantitative analysis with AES
Authors: Yoshihara K. , Shimizu R. , Homma T. , Tokutaka H. , Goto K. , Fujita D. , Kurokawa A. , Ichimura S. , Kurahashi M. , Kudo M. , Hashiguchi Y. , Suzuki T. , Ohmura T. , Soeda F. , Tanaka K. , Tanaka A. , Sekine T. , Shiokawa Y. , Hayashi T.
Published: May 2005

The Japanese VAMAS‐SCA working group is composed of 19 institutes. Three kind of AuCu alloys (Au 75 at.‐%–Cu 25 at.‐%, Au 50 at.‐%–Cu 50 at.‐%, Au 25 at.‐%–Cu 75 at.‐%) were prepared, and these specimens, pure Au and pure Cu were distributed to the members of the VAMAS‐SCA working group. The surface concentrations of these alloys were calculated from the Auger peak amplitudes in two ways. One method used the published relative sensitivity factors, and the other used pure Au and Pure Cu as the standard materials. The mean values of the surface concentrations calculated with the published relative sensitivity factors were almost the same as those calculated with the standard materials. This means that the published relative sensitivity factors are reliable to some extent. The error of the surface concentration calculated with pure Au and pure Cu as the standard materials lay between about 3% and 10%, and that with the relative sensitivity factors lay between about 7% and 20%. The calculated surface concentrations of Au were larger than the bulk concentrations of Au when the matrix effect was neglected.
Influence of the inelastic background on the accuracy of factor analysis of electron spectra
Authors: Jansson C. , Tougaard S.
Published: May 2005

The role of the inelastic background in factor analysis of electron spectra is investigated. Ten sets of model spectra originating from different types of in‐depth profiles were considered. Since the background depends on the in‐depth concentration profile, it will normally vary strongly within a set of spectra. In spite of this, it is shown that the background does not give rise to any additional components in factor analysis because it does not vary as a linear spectral component. The inelastic background thus will be projected on the secondary factors in the same way as spectral noise. This and the fact that the background is a smooth function of energy explains why differentiation is an acceptable procedure for background removal when factor analysis is used to identify the relative components of spectral features. Background subtraction is found to be superior to spectral differentiation for those depth profiles where valid algorithms for background subtraction have been developed.
An XPS study of Cs2Te photocathode materials
Authors: Soriano L. , Galan L. , Rueda F.
Published: May 2005

The caesiation of a clean Te metal film during the formation process of a Cs2Te photocathode has been studied by X‐ray photoelectron and Auger electron spectroscopies. Cs2Te is essentially an ionic compound that is stable with a large Cs excess. The ionicity increases with Cs content up to the stoichiometric composition. The Cs excess, which affects the photoemissive spectral response, cannot be reversed by Te deposition since very stable elemental Te clusters seem to be formed. CsTe has been found also during the formation process.
XPS and UPS examinations of Fe53Ni and Fe10Ni in 1 M NaOH and 0.005 M H2SO4
Authors: Hoppe H.‐W. , Strehblow H.‐H.
Published: May 2005

The formation of passive films as a function of time and potential on Fe53Ni in 1 M NaOH in 0.005 M H2SO4 + 0.495 M K2SO4 and on Fe10Ni in 1 M NaOH was studied by XPS. In order to avoid air oxidation and to minimize contamination of the samples, an electrochemical specimen preparation and transsfer system attached to the ultrahigh vacuum (UHV) system was used. Quantitative evaluation of the data yields the total thickness and the composition of passive layers. Characteristic changes of the spectra in the transpassive range for Fe53Ni in the alkaline electrolyte, which include a shift of the peaks of the oxide components to lower binding energies, are observed. They are interpreted as a decrease of the Fermi level towards the valence bend as the result of the oxidation of Ni (OH)2 to NiOOH. This is supported by UPS measurements in dependence of the passivation potential of the specimen, which show an increase in work function corresponding to the Fermi level shift.
The kinetics of oxide film growth on Maraging steel as described by space‐charge effects
Authors: Greyling C. J. , Kotzé I. A. , Viljoen P. E.
Published: May 2005

The oxidation kinetics of a grade 300 maraging steel in air at temperatures ranging from 300 to 600 °C have been determined using Auger electron spectroscopy in conjunction with argon ion sputtering. A limited‐thickness type of growth was observed up to the relatively high temperature of 480 °C. Above 480 °C, the kinetics were parabolic.

A thin gold layer sputtered onto the surface before oxidation resulted to a change in the kinetics from limited‐thickness to approximately parabolic growth at temperatures below 480 °C, while it remained parabolic above 480°C.

The limited‐thickness oxide growth is described in terms of space‐charge effects, as outlined by the theory of Formhold. The insulating properties of a thin mixed spinel oxide present at the metaloxide interface is critical in bringing about the space charge in the oxide. A change in the electrical conductivity of the mixed spinel is associated with a change in the oxidation kinetics.
AES depth profiling of passive overlayers formed on nickel alloys
Authors: Lorang G. , Jallerat N. , Quang K. Vu , Langeron J.‐P.
Published: May 2005

Depth profiling analysis of passive films grown on the surface of two nickel‐based alloys (Inconel 600 and Hastelloy C4) in NaCl media was carried out using Auger electron spectroscopy (AES) and ion sputtering. Improvement to the sequential sputtering model of Hofmann (1976) should be performed when preferential sputtering occurs, especially in Mo‐containing alloys. In this way, the kinetic model of preferential sputtering of Ho et al. (1976) was extended to the case of ternary alloys. However, concentration gradients created by the electrochemical treatment in the metallic layers below the oxidized film make it unsuitable. Passive layers (5–11 monolayers) mainly consist of chromium oxide, always located at the film–alloy interface. A layered depth distribution of oxidized species is generally observed: in Inconel, chromium oxide is successively covered with iron and nickel oxides; in Hastelloy, chromium oxide is covered with nickel oxide (only very few molybdenum atoms are depicted in these films). Increasing the passivation potential, the temperature or the NaCl concentration slightly enhances the nickel oxide amounts in the film, its thickness and the external chloride contents.
Surface characterization of Cux/2Cd1−xIn2+x/2S4 model catalysts
Authors: Moretti G. , Anichini A. , Fierro G. , Lo Jacono M. , Porta P.
Published: May 2005

The sulphospinels reported in the title, with x ranging from 0 to 1.0, were characterized by bulk and surface techniques (XRD, magnetic susceptibility, reflectance spectroscopy and XPS, including x‐ray induced Auger spectroscopy).

Homogeneous spinel solid solutions are formed up to x = 0.4, whereas for the other compositions the CuInS2 phase also was indentified by XRD.

Only monovalent copper was found in all the samples, in the bulk as well as on the surface.

The surface of the sulphospinels is stable to air; on the contrary, the surface of CuS is transformed to Cu2SO4.

Making use of the Wagner Auger parameter and of a simple approximation of the shifts observed in the core electron binding energies, we estimate the charge distribution and the electronic environment of the indium ions in the different sites of the spinel structure.
Surface analysis and adhesion of polypropylene after low‐pressure plasma treatment
Authors: Nowak S. , Haerri H.‐P. , Schlapbach L. , Vogt J.
Published: May 2005

We have used XPS core‐level spectroscopy to study the nature of polypropylene surfaces that were exposed to an rf‐induced low‐pressure plasma. This treatment resulted in enhanced oxidation of the polymer surface, which can be attributed to CO functionalities. This modification of the polymer surface allowed the proparation of adhesive joints with improved strength of the polymerepoxy interface. Langmuir probe techniques were used to characterize the plasma. X‐ray degradation of the plasma‐modified polymer surfaces was observed.
ESCA and SIMS studies of plasma treatments of intraocular lenses
Authors: Brinen J. S. , Greenhouse S. , Pinatti L.
Published: May 2005

The surfaces of polymethylmethacrylate (PMMA) intraocular lenses (IOL) modified by treatment in a plasma containing various fluorine‐containing gases were studied by surface analytical techniques. The hydrophobicity imparted to the lens surface was monitored by water contact angle measurements and the degree of fluorination was determined by XPS measurements.

The fluorine chemistry on the surface, monitored by XPS and SIMS, was function of the gas mixture employed in the plasma. SIMS imaging was used to monitor coating homogeneity and demonstrated the fragile nature of the coated surface.
The effect of orientation on ion beam erosion rates in ionic crystals measured by SIMS depth profiling
Authors: Kilner A. M. C. , Kilner J. A. , Elliott J. C. , Cressey G. , Littlewood S. D.
Published: May 2005

There are reports in the literature that crystal orientation is a major source of variation in sputter yields when examining biomineralized tissue material. To examine this further, single crystals of fluorapatite and calcite, both mineralogical analogues, were examined with two different SIMS machines, an Atomika 2000 and a Cameca IMSA4F. Craters were eroded on planes parallel to (0001) and (1010) of both samples for different lengths of time, at different angles and with different primary ion beams. Instruments were operated at a voltge of 10 or 15 kV for Cs+ and O2+, respectively, and a primary beam current of 200 nA. The erosion times were such that all sites were exposed to high fluences of 1018 ions cm−2. For a given experimental geometry and primary ion beam, there wee no discernible differences in erosion rates due to crystal orientation. It is believed that this is due to amorphization of the crystal surface at the target site by site by ion bombardment at high fluences. Therefore, we conclude that crystal orientation is not a significant factor in variation of sputter yield in the materials investigated, and suggest that in biomineralized tissue material the development of surface topography is due to other factors.
The effect of carbonate contaminations on the XPS O 1s band structure in metal oxides
Authors: Stoch J. , Gablankowska‐Kukucz J.
Published: May 2005

The aim of the paper is to give examples of XPS analysis, showing how O 1s bands can be affected by surface carbonates. A proper peak assignment (e.g. to O− OH− species) needs the preliminary determination of a carbonate contribution. Although the samples examined represent Co and La compounds only, the principal conclusions can be extended also to other oxide systems.
Ellipsometric analysis of gallium arsenide surfaces
Authors: Ohlídal Invan , Líbezný Milan
Published: May 2005

In this paper the methods of immersion ellipsometry and multiple angle of incidence ellipsometry are used for analyzing gallium arsenide single crystals covered with very thin oxide layers growing under normal laboratory conditions. The values of all the optical parameters of the system mentioned, i.e. the values of the refractive index and the extinction coefficient of gallium arsenide and the refractive index and the thickness of the native oxide layer, can be determined with good accuracy if the experimental data corresponding to several samples of this system are interpreted together. The thicknesses of the native oxide layers corresponding to these samples analysed together must be mutually different. The method is applied at a wavelength of 632.8nm.
Correction of backscattering effects in the quantification of Auger depth profiles
Authors: Barkshire I. R. , Prutton M. , Skinner D. K.
Published: May 2005

The calculation of surface composition form Auger peak heights requires a knowledge of the matrix effects. These are modifications to the yield of Auger electrons arising from inelastic mean free paths, the Auger backscattering factor and sample density effects. A method for approximating the Auger backscattering factor for films of any thickness and atomic number is described. The method is based upon the assumption that the contribution of backscattered primary electrons to the Auger yield will change in proportion to the change in the electron backscattering coefficient of the film with thickness. The auger backscattering factor so calculated varies smoothly from the value corresponding to the bulk material of the film to that of the substrate. Using known generic equations for bulk backscattering coefficients and factors, a simple algebraic expression is obtained. Comparison with experimental data obtained form both high and low atomic number films yields good agreement for various primary beam energies and angles of incidence.
SIMS study on the composition of FeCr and FeCrMo oxide films
Authors: Mathieu H. J. , Vogel A. , Mischler S. , Landolt D.
Published: May 2005

Dynamic SIMS (secondary ion mass spectroscopy) has been applied to the study of Fe24Cr and Fe24Cr11Mo model alloys subjected to different polarization conditions in the cathodic and in the passive potential region in a sulphate electrolyte. Positive and negative SIMS was performed with a 5 KeV Ar+ primary ion beam using a quadrupole mass analyzer. Measured depth profiles were evaluated by calculating the signal intensity ratios or different species. The data suggest that the concentration in the surface oxide films is a function of depth. The maximum concentration of chromium oxide is found at a depth of the order of 1 nm. Hydroxide is found at the outer surface only. Comparison with mass spectra measured on FeO and Fe3O4 single crystals suggests that no divalent iron ions are present in the passive films. The usefulness and limits of using SIMS for the analysis of passive films are discussed.
TOF‐SIMS satudies of carbon‐fibre surfaces and carbon‐fibre composite fracture surfaces
Authors: Hearn M. J. , Briggs D.
Published: May 2005

The application of time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) to the investigation of interface interactions in carbon‐fibre composites is discussed. Surface analysis of carbon fibres before and after electrochemical oxidation reveals the dominating effect of molecular contamination of the fibre surface (and hence the importance of processing/handling memory effects) on the spectra obtained. High‐resolution SIMS imaging of carbon fibres is particularly useful for contamination identification and clarification of SEM information. Progress in the development of fractography using TOF‐SIMS imaging is also discussed; the important experimental parameters are defined whilst illustrating their effect with a real‐life example.
The effect of silanes on paint adhesion and sites of failure
Authors: Walker P.
Published: May 2005

It is shown that the exposure of organic coatings to high humidity or water immersion causes a rapid loss of adhesion. The use of organofunctional silanes of the general formula R1—Si(OR)3, where R1 is an amino, epoxide, mercapto, methacryloxy or vinyl group, can materially improve the initial, wet and recovered adhesion of epoxide, urethane and alkyd coatings to mild steel and aluminium substrates when used as pretreatment primers and additives.

XPS work on the locus of failure of surface coatings on aluminium substrates indicated that although some local loss of adhesion to the substrate may occur, the predominant mode of failure is cohesive within the paint film. These findings are discussed in the light of current theories.
A simple analysis of local wetting hysteresis on a Wilhelmy plate
Authors: Shanahan M. E. R.
Published: May 2005

Wetting measurements involving evaluation of the contact angle at the triple line of a solid/liquid/fluid system constitute a valuable means of characterizing solid surfaces. In principle, a given three‐phase system possesses a unique contact angle value but, in practice, hysteresis effects often lead to a range of accessible values. Although this inherent range renders estimation of the mean value more difficult, it is suggested here that knowledge of the intrinsic magnitudes and spatial distribution of heterogeneities on the solid leading to hysteresis may be used to characterize the surface more completely. The Wilhelmy plate technique used in dynamic mode (at low speed) effectively leads to a scan of the solid because of the moving triple line. Slight oscillations or ripples on the average measured force are attributed to locally changing populations of weak heterogeneities. A simple mathematical analysis of the behaviour is presented and applied to model arrays of inhomogeneities. Although the models are too simple for direct application to most real surfaces, it is believed that the basic ideas may be refined for use on practical systems.
Depth profile analysis of an electrodeposited multilayer structure with non‐uniform thickness distribution by glow discharge optical spectroscopy
Authors: Weiss Zdeněk
Published: May 2005

An electrodeposited multiplayer structure consisting of nine alternating layers of copper and nickel was depth profiled by glow discharge emission spectroscopy using a Grimm lamp with an anode tube of internal diameter 4 mm. Depth profiled of the non‐uniform region near the sample edge are reported. Thickness inhomogeneity causes the erosion crater bottom to penetrate through individual layers obliquely, which is the reason for signal response distortion. The dependence of signal response on the thickness gradient is discussed and a formula for the thickness gradient estimation from the depth profiles is proposed.
Effect of short‐chain xanthate on electrostatic interactions and equilibrium thickness of foam films from aqueous solutions of non‐ionic frother
Authors: Manev E. D. , Pugh R. J.
Published: May 2005

The equilibrium thickness of free thin films produced from aqueous solutions of C12(EO)5 surfactant (a model frother) with potassium ethylxanthate—KEX (a model collector)—was studied in a wide range of concentrations (from 10−7 M to 2 × 10−2 M C12(EO)5; up to 10−2 M xanthate).

The xanthate was found to behave in a similar way to common electrolytes and upon its addition the equilibrium film thickness was reduced, apparently due to the suppression of the electrostatic repulsion. However, at higher C12(EO)5 concentrations (≥10−5 M) the equilibrium thickness of the film increased relative to the thickness established with simple inorganic electrolytes at the same ionic strenght. This was explained by the negatively charged xanthate interacting with the non‐ionic frother at the interface and causing a build‐up of charge.

Higher frother concentrations were necessary to produce non‐rupturing films upon increasing the KEX content. This ‘antifoaming’ effect of the xanthate compliments its influence on the electrostatic interactions in the film.
A new approach for curve‐resolving photoemission peaks in XPS
Authors: Mattogno Giulia , Righini Guido
Published: May 2005

A new approach for obtaining photoemission peak areas from XPS spectra at the analytical level is proposed. In standard data handling, background removal is necessary for determining the peak areas in order to obtain the atomic fraction of the elements present on outer layers. It is possible to associate an analytical function to the inelastic scattering background. This new approach uses this analytical function during curve‐fitting proicedures on the first derivative of the raw derivative of the raw spectrum.

The systems studied are metallic Pd and PdO in powder form and grown over metallic palladium. The results are in good agreement with theoretical hypothesis.
Composition and structure of ion‐bombardment‐induced growth cones on InP
Authors: Malherbe J. B. , Lakner H. , Gries W. H.
Published: May 2005

The previously reported1,2 effect of low‐energy (several keV) ion bombardment on the surface topography of InP was investigated by scanning transmission electron microscopy. Convergent beam electron diffraction patterns of the surface growth ‘cones’ induced by argon ion bombardment of (100) InP between 7 and 10 keV proved the cones to consist of crystalline InP (and not metallic indium, as has sometimes been claimed). The investigation showed that the irradiated surface region is not rendered completely amorphous but that it recrystallizes from the crystalline/amorphous interface in a columnar growth pattern, often terminating in growth cones protruding above the surface. Weak beam investigations revealed that the overwhelming majority of the cones have the orientation of the substrate. These phenomena were observed at all dose densities from 7 × 1015 to 2 × 1017 cm−2.
Quantitative Auger electron spectroscopy of silicides by extended matrix correction using dN(E)/dE spectra
Authors: Wirth Th.
Published: May 2005

An extended matrix correction procedure is proposed which considers effects created by different atomic densities, electron backscattering, electron attenuation and peak shapes. Asymmetry factors are introduced that reflect line shape changes of signals in compounds or alloys very well. From asymmetry factors a peak shape correction factor is determined. To overcome the uncertainties in correction for changing electron attenuation, a new method for calculation of λ is presented. The results are compared with experimental values and tested in matrix correction. The concentration ratios obtained are compared with results using inelastic mean free path lengths or attenuation depths determined by the methods of Penn. Tanuma et al., Tokutaka et al. and Seah and Dench in matrix correction. For the determination of concentration ratios from samples of unknown composition, an iteration procedure is introduced. The extended matrix correction is applied on silicides such as VSi2, V5Si3, V3Si, CrSi2, Cr3Si, MoSi2, Pd2Si and PtSi, yielding results which are accurate to 7%. The weight of the individual correction factors in the extended matrix correction procedure is discussed, dependent on experimental conditions and sample constituents. Without correction for matrix effects, erroneous results up to 30% can occur.
An investigation of the surface chemistry of poly(ether etherketone). I. The effect of oxygen plasma treatment on surface structure
Authors: Pawson D. J. , Ameen A. P. , Short R. D. , Denison P. , Jones F. R.
Published: May 2005

Time‐of‐flight secondary ion mass spectroscopy (ToF‐SIMS) and x‐ray photoelectron spectroscopy (XPS) have been employed to study the plasma surface oxidation of poly(ether etherketone) (PEEK). The positive and negative ion ToF‐SIM spectra obtained from a cleaned PEEK surface were easily interpreted using conventional mass spectrometry rules. Plasma oxidatio of PEEK was found to produce complex positive and negative ion spectra. In these spectra, ions diagnostic of the PEEK repeat unit were much reduced in intensity, and new ions diagnostic of plasma treatment were introduced. However, a thorough interpretation of these spectra was not attempted. The corresponding XP C 1s and O 1s core‐level spectra were run. In the C 1s core level, surface oxidation produces a number of new carbon–oxygen environments and an increase in the number of oxidized carbons. In both the C 1s and O 1s core levels, the increased full width at half‐maximum (FWHM) required to fit these spectra is suggestive of several environments being contained within each of the peaks fitted. The plasma‐treated polymer surface was rinsed with methanol. In the ToF‐SIM spectra, rinsing removes or reduces the intensities of the ions introduced by plasma treatment and enhances the intensities of some ions not previously noted; but rinsing does not restore the original PEEK spectra. In the C 1s core‐level spectrum, rinsing was found to reduce the number of oxidized carbons and, in particular, the concentration of the environments introduced by plasma treatment. Further, it proved possible to fit the C 1s core level with a FWHM comparable to that employed for the clean PEEK: this may be indicative of a reduction in the variety of carbon–oxygen environments.
Characterization of interfaces in ceramic composites by SIMS, AES and EPMA
Authors: Mischler S. , Bishop H. E. , Davies J. J. R.
Published: May 2005

Fracture surfaces and polished cross‐sections of aligned SiC fibre–cordierite matrix composites have been studies using SIMS, AES and electron probe x‐ray microanalysis (EPMA). It has been shown that, during fabrication, interface reactions resulting in penetration of the fibres by matrix cations take place. Titanium diffusion out from the fibres together with segregation of matrix elements to the interface is also observed. A correlation is found between interface composition and mechanical properties of the composites. The relative merits of SIMS, AES and EPMA in the determination of the nature of the fibre‐matrix interface are discussed. SIMS using a microfocused Ga ion beam is shown to be a powerful new tool in the investigation of interfaces.
Optical ellipsometry and electron spectroscopy studies of copper oxidation related to copper on printed circuit boards
Authors: Manara A. , Sirtori V. , Mammarella L.
Published: May 2005

The aim of the present work was to investigate the oxidation of pure copper samples and of those cut out from circuit boards by using optical ellipsometry XPS and AES, in order to establish whether ellipsometry alone could be used as a simple, economical means for routine analysis at the wiring line of circuit boards.

Samples of pure copper, with a polished surface or after treatment in an ENTEK solution, were oxidized for different lengths of time at 180°C, the temperature at which circuit boards are heated before the soldering and wiring process. The oxide growth rate is constant for thicknesses of the oxide layer up to ∼ 100 Å. The thicknesses measured by XPS/AES depth profiles agree well with those measured by ellipsometry provided that two oxide films, Cu2O and CuO, are present for oxidation, while CuO begins to form at later stages.

An empirical correlation between the experimental ellipsometric and Auger spectroscopy data on 50 samples cut out from circuit boards, before and after the wiring process, permitted the oxide thickness and the quality of the copper surface of the circuit boards to be estblished by ellipsometry alone. An ellipsometer was installed on the assembly line of the circuit boards and is used for routine analysis of the copper surface of the boards.