bluuebunny/crossref_metadata_2025_split huggingface dataset:
ESCA study of the adhesion of Ag, Cu and Ni to polysiloxane resins used in the semiconductor industry
Authors: Torrisi A. , Marletta G. , Puglisi O. , Pignataro S. 
Published: December 2004

AbstractCommercial polysiloxane resins used in the semiconductor industry were moulded on Ag, Ni and Cu real surfaces. The samples were broken by using a pull test machine and the joint strength measured. The ‘resin’ and ‘metal’ faces obtained in the rupture process were analysed by ESCA. The chemical composition of the two faces was very different. The one from the resin side resembled that of the bulk. That from the metal side was rich in additives from the commercial resin. Some differences were found between the three metals, whilst the spiral flow of the resin in the range examined influenced the results in only a very limited way. The weak boundary layer in which the above additives accumulate seems responsible for the low adhesion level found. The Pb/Si concentration ratio at the fracture locus is correlated with the adhesive joint strength. The multifactorial nature of the adhesion in practical samples is discussed. It is suggested that the influence of the heavy elements present in the additive has to be explored in connection not only with the adhesion problem but also with the electrical reliability of the device.
Rutherford backscattering spectrometry as an experimental method to study the oxidation mechanism of NiAl3 alloy
Authors: Young E. W. A. , De Wit J. H. W. 
Published: December 2004

AbstractThe oxidation mechanism of NiAl3 alloy is investigated by means of Rutherford Backscattering Spectrometry (RBS), using 2.0 MeV He+ ions. In addition SEM and thermogravimetry experiments were performed. The oxidation characteristics of Ni–Al alloys are of interest because of their application as coating materials on high temperature alloys. It is found that during thermal oxidation at 973 K, an Al2O3 scale is formed on the alloy. The scale grows at a sub‐parabolic rate and does not spall‐off. These characteristics make NiAl3 a promising coating material.
Characterization of a high depth‐resolution tantalum pentoxide sputter profiling reference material
Authors: Hunt C. P. , Seah M. P. 
Published: December 2004

AbstractA major use of surface analysis instruments concerns composition depth profiling. In many instances poor depth resolution is obtained, one cause of which is poor ion beam alignment and uniformity. To enable instrument users to optimise instrument settings and know (1) the instrument contribution to depth resolution and (2) the ion etch rate, tantalum pentoxide reference materials have been developed with thicknesses of 30 nm and 100 nm and interface widths, measured by AES, of 1.5 and 1.7 nm respectively. The effects of argon ion beam energy, electron beam current density, sputtering geometry and gas purity effects on etch rate and interface width are measured and interpreted in terms of basic parameters, showing that the material is a well‐behaved model system that is robust and easily used. The precise shape of the interface and preferential sputtering effects are also analysed.
Advances in charge neutralization for XPS measurements of nonconducting materials
Authors: Barth G. , Linder R. , Bryson C. 
Published: December 2004

AbstractThe build‐up of a positive charge during the XPS measurement of nonconducting materials can severely affect the spectral resolution leading to line broadening and time‐dependent energy shifts. The use of a low kinetic energy electron flood gun in conjunction with a metal screen placed in close proximity to the sample surface permits the establishment of a uniform surface potential. The advantages of this approach are demonstrated with spectral data taken from a variety of organic materials. Spectral line widths of 0.9–1.3 eV are routinely obtainable for the C(1s) core level photoelctron signals. Further, the reproducibility obtained on line positions (±0.1 eV) allows the use of a calibration procedure to study the relative line positions between different samples. This combined with better resolution allows a more complete assignment of spectral features including some nearest neighbor effects. A shift between aromatic and aliphatic C(1s) lines is observed.
Characterization of polyamic acid/polyimide films in the nanometric thickness range from spin‐deposited polyamic acid
Authors: Russat Jean 
Published: December 2004

AbstractA dilute polyamic acid solution was spin‐deposited onto gold substrates and XPS analyses were performed after deposition. Evidence of the presence of organic films on the top surface of the substrates was found. A chemical characterization allowed us to identify these organic films as being polyamic acid after a 125°C curing and polyimide after a 240°C curing. From angle‐dependent data we have shown that the gold substrates were coated quasi‐uniformly by ultra‐thin films. This conclusion was confirmed by an Auger analysis. The computed thickness were found in a range of 1.3 to 2.9 nm depending on the sample preparation conditions. Adsorption was supposed to occur just after the deposition. Some possible mechanisms of the interfacial interaction between the polyamic acid and the surface were proposed. A thermally‐activated chain cleavage was supposed to occur at the interface or near the interface.
Depth analysis of metal coatings by glow discharge spectroscopy with emphasis on the interface problem
Authors: Teo W. B. , Hirokawa K. 
Published: December 2004

AbstractGrimm glow discharge spectrometry was used to analyze metal coatings on various metal substrates to determine the sputter broadening characteristics of the glow discharge lamp, especially at the interface. The sputter broadening characteristics are important when the depth profile is to be found. The samples of Cu/Ni, Ni/Cu, Sn/Ni, Ni/Sn, Fe/Ni, Ni/Fe metal coatings investigated, indicate that the poor depth resolution of glow discharge spectrometry is due to uneven profiling since the central portion of the sputtered surface is sputtered away faster than the edges. This depth resolution problem is fundamentally different from that of depth profiling in AES or SIMS. Besides being dependent on the usual sputtering parameters the depth profile is also dependent on the glow discharge characteristics of the coating metal and substrate metal combination. From the plots of plasma composition vs. fraction of metal coating sputtered, plasma composition vs. depth sputtered and fraction of metal coating sputtered vs. depth sputtered, the development of the crater profile can be followed and the cause of the depth resolution problem evaluated.
The precise determination of concentration distributions using depth‐sectioning methods
Authors: Katardjiev I. V. , Nobes M. J. , Carter G. 
Published: December 2004

AbstractConsideration of the continuity equation relating atomic fluxes entering and leaving a layer from the instantaneous surface to a fixed depth beyond the extent of any atomic relocation shows that measurements of total atomic exit flux, of a given species, the rate of change with time of the species concentration over the fixed depth, and sputtering speed, can yield initial depth distributions of the atomic species.
Surface reactions of copper films in O2/CF4/N2 plasmas
Authors: Coolbaugh D. D. , Matienzo L. J. , Egitto F. D. , Knoll A. R. 
Published: December 2004

AbstractCopper surfaces treated with O2/CF4 and O2/CF4/N2 plasmas have been characterized using x‐ray photoelectron and Auger electron spectroscopy. Deeper oxidation and fluorination result for oxygen‐rich mixtures than for CF4‐rich gas feeds. Film thicknesses increase with time of exposure. Copper oxidation is always deeper than fluorination for O2/CF4 mixtures. It appears that penetration of fluorine is more facile through the copper oxide matrix than through the metallic copper film. With addition of 5% N2, concentration of fluorine is enhanced relative to oxygen. These observations are discussed with respect to gas phase and surface reactions involving oxygen, fluorine and nitrogen.
The effects of excimer laser annealing and yttria on corrosion of an FeCrNi alloy at 700°C
Authors: Baer D. R. , Wright I. G. , Jervis T. R. 
Published: December 2004

AbstractSeveral surface and near‐surface analysis methods have been used to examine the effects of excimer (KrF, 248 nm) laser annealing and the addition of 2 wt.% Y2O3 on the early stages of corrosion of an Fe‐25Cr‐20Ni alloy at 700°C. Two specific questions were addressed experimentally: (1) Can excimer laser treatment improve the corrosion properties of the FeCrNi alloy in a mixed gas environment (containing oxygen and sulfur)?; (2) Does the Y2O3‐induced improvement of the corrosion behavior of the alloy result from prevention of S segregation to the surface or scale‐metal interface? Results show that laser annealing increased the Cr surface concentration of the treated alloy, but did not enhance the formation of a Cr‐rich oxide. However, the treated alloy was less susceptible to scale breakdown and sulfide formation. Surface segregation of S was not prevented by the Y2O3 addition. Differences between doped and undoped alloys may be attributable primarily to changes in microstructure.
Decomposition of 2p3/2 bands in XPS spectra of Fe, Co and Ni compounds
Authors: Stoch J. , Capecki A. 
Published: December 2004

AbstractA procedure is described for handling the XPS spectra of Fe, Co and Ni compounds. For background removal, a modified Shirley algorithm is used. The background line shape and position are determined from the spectrum by a procedure of successive iterations, which are repeated until the ratio of peak heights in the 2p doublet reaches a value approximately equal to the ratio of the photoelectron cross‐sections. An experimental value of 2.1 for the ratio is suggested.
Program for XPS spectrum conversion to VGS‐5000 format
Authors: Abel P. B. 
Published: December 2004

AbstractA FORTRAN program has been written for use on an IBM‐PC/XT/AT or compatible microcomputer (PC) that converts a column of ASCII‐format numbers into a binary‐format file suitable for interactive analysis on a Digital Equipment Corporation (DEC) computer running the VGS‐5000 Enhanced Data Processing (EDP) software package. The incompatible floating‐point number representations of the two computers were compared, and a subroutine was created to store correctly on the PC floating‐point numbers in a format that can be read directly by DEC computers. The data file header required by the EDP programs for an x‐ray photoelectron spectrum is also written to the file.
Quantitative analysis of SIMS spectra of mixtures of powders of FeSO4 and ZnSO4
Authors: Michaud Daniel , Baril Marcel , Adnot Alain 
Published: December 2004

AbstractBinary mixtures of powders of iron and zinc sulphate have been analysed with SIMS. The proportions of iron, used as representative species, were calculated with an empirical method based on the sensitivity factor. An accuracy of 7% relative has been obtained on these calculated proportions. Results obtained with two different SIMS instruments are compared, as well as results obtained by an XPS analysis.
X‐ray photoelectron spectroscopic studies of thin film oxides of cobalt and molybdenum
Authors: McIntyre N. S. , Johnston D. D. , Coatsworth L. L. , Davidson R. D. , Brown J. R. 
Published: December 2004

AbstractSurface oxidation reactions of cobalt, molybdenum and mixed cobalt–molybdenum metals have been investigated using x‐ray photoelectron spectroscopy (XPS). The oxide stoichiometries have been determined from XPS intensity measurements. Such quantification has been important in identifying oxide compositions with characteristic XPS spectra. A number of discrete binary molybdenum oxides have been characterized after reactions at 200°C and pressures ranging from 1 atm to 10−6 Pa. At the lowest pressure, the Mo 3d spectra and O/Mo ratios suggest the formation of a molybdenum–oxygen structure with a stoichiometry near unity. By contrast, at higher pressures, oxides that are predominantly MoO2 and MoO3 appear, but other intermediate oxide structures are also identified. Well‐defined binary oxides of cobalt can be prepared from cobalt metal after heating in oxygen at different pressures. New binary oxides of cobalt and molybdenum have been generated by the reaction on MoO3 or Co3O4 substrates. Oxidation of a thin film of molybdenum on a Co3O4 substrate has been shown to produce a nearly stoichiometric surface layer of CoMoO4. The procedure could be useful for the production of other ternary oxides of possible interest for use as XPS reference materials.
AES and RBS analyses of tokamak collector probes—experimental considerations
Authors: Paynter R. W. , Ross G. G. 
Published: December 2004

AbstractAnalyses by RBS and AES of beryllium collector samples exposed to discharges in the Tokamak de Varennes have been made. Good agreement for the total amounts and types of material deposited on collectors oriented in each of three ways was observed. However, analysis of the AES sputter‐depth profile indicated a peaking of the metal near the outer surface of the collectors. This can be explained by a simple model involving sputtering and redeposition during the tokamak discharge. Implications of this model are that the average amount of material deposited on the collectors may not be related directly to impurity concentrations in the plasma. Experimental analysis of material deposited on the collectors must be made with sufficient depth resolution to obtain information about sputter–redeposition activities during plasma discharges.
AES: Energy calibration of electron spectrometers. I—an absolute, traceable energy calibration and the provision of atomic reference line energies
Authors: Seah M. P. , Smith G. C. , Anthony M. T. 
Published: December 2004

AbstractExperiments have been made to provide calibrated kinetic energy values for AES peaks in order to calibrate Auger electron spectrometers of various resolving powers. The kinetic energies are measured using a VG Scientific ESCALAB II, which has power supplies appropriate for AES measurements in both the constant ΔE and constant ΔE/E modes. The absolute calibration of the energy scale is obtained by the development of a new measurement chain, which, in turn, is calibrated in terms of the post‐1990 representation of electron‐volts using XPS peaks with a traceable kinetic energy accuracy of 0.02 eV. The effects of instrumental and operating parameters, including the spectrometer dispersion and stray magnetic fields, are all assessed and contribute errors for three peaks not exceeding 0.06 eV and for two peaks not exceeding 0.03 eV. Calibrated positions in the direct spectrum are given for the Cu M2,3VV, Au N6,7VV, Ag M4NN, Cu L3VV and Au M5N6,7N6,7 transitions at 0.2 eV resolution, referred to both the Standard Vacuum Level and the Fermi level. For the differential spectrum, the positions of the negative excursions are derived numerically by computer from these data and are established with the same accuracy. Data are tabulated for the above peaks in both the direct and differentiated modes for the popular resolutions of 0.15%, 0.3% and 0.6% produced by Gaussian broadening of the high‐resolution spectra. Differentiations are effected by both sinusoidal modulation and Savitzky–Golay functions of 2 eV and 5 eV peak‐to‐peak.
Surface composition and chemical bonding of thermally reduced yttria as studied by XPS and SEXAFS: Influence of Zr doping
Authors: Thromat N. , Gautier M. , Jollet F. , Duraud J. P. , Le Gressus C. 
Published: December 2004

AbstractSurfaces of thermally reduced yttria, either pure (5 N) or doped with Zr, are studied by means of x‐ray absorption spectroscopy (surface‐extended x‐ray absorption fine structures), x‐ray‐induced Auger electron spectroscopy and x‐ray photoelectron spectroscopy. No Zr surface segregation is observed for the solid solutions considered, (100 − x) YO1.5 + xZrO2 (with x = 5.3 or 13), whatever the thermal treatment experienced.In pure and Zr‐doped yttria, the concentration of oxygen vacancies is estimated at the surface as a function of reduction time: while, in the early stages, oxygen deficiency appears to be spatially homogeneous, after a certain time the first atomic layers are much more oxygen‐depleted than the bulk. The introduction of oxygen vacancies in the lattice leads to a modification of the YO bond, which corresponds to a decrease of the local atomic charge on the remaining oxygen atoms, as observed from the Auger O KLL lineshape. This decrease in the ionic character of the bond causes an increase in the total polarizability and of the surface optical dielectric constant, as deduced from O and Y Auger parameter measurements. These variations are weaker in the doped samples, which could be due to a smaller static disorder compared to that of pure samples.
Monte carlo calculations of the X‐ray induced enhancement signal in electron probe microanalysis (EPMA) and Auger electron spectroscopy (AES) of stratified materials
Authors: Nassiopoulos A. G. , Valamontes E. 
Published: December 2004

AbstractWhen thin overlayers on a bulk material have to be analysed by EPMA (electron probe microanalysis) or AES (Auger electron spectroscopy), the signal obtained is enhanced by three factors: (i) back‐scattering, (ii) characteristic x‐rays induced in the bulk by the primary beam and (iii) continuous x‐rays (bremsstrahlung) created also in the bulk. The Monte Carlo techniques are applied in order to evaluate the above three enhancement factors when the primary energy is varied in the range 5–50 keV. It is shown that at high primary energies the second and third factors are no longer negligible and become significant in some cases. The approximation to ignore the third factor in EPMA and both the second and third factors in AES is not always valid and introduces an appreciable error. Results are shown for the case of thin films (Al, Au, Cu) on a bulk material (Au, Cu, Si, Ni, Pt).
Sputter depth profile analysis of marker layers
Authors: Peinador J. A. , Abril I. , Jiménez‐Rodríguez J. J. , Gras‐Marti A. 
Published: December 2004

AbstractWe study theoretically the distortion of marker layers embedded in homogeneous media due to energetic ion bombardment. For realistic relocation cross‐sections, we have solved the balance equation, first proposed by Sigmund and co‐workers, for the evolution of irradiated polyatomic targets. The collisional mixing operator accounts for recoil mixing, isotropic cascade mixing and surface barrier effects.Following the evolution with ion fluence of the marker concentration profiles, we can obtain the tracer yield, which is related directly to the as‐recorded intensity in a SIMS experiment. The influence of the surface barrier on signal broadening also will be discussed.
Evaluation of correction accuracy of several schemes for AES matrix effect corrections
Authors: Tanuma S. , Sekine T. , Yoshihara K. , Shimizu R. , Homma T. , Tokutaka H. , Goto K. , Uemura M. , Fujita D. , Kurokawa A. , Ichimura S. , Oshima C. , Kurahashi M. , Kudo M. , Hashiguchi Y. , Suzuki T. , Ohmura T. , Soeda F. , Tanaka K. , Tanaka A. , Shiokawa Y. , Hayashi T. 
Published: December 2004

AbstractA matrix effect correction is required to improve the accuracy of quantitative AES analysis. The correction includes terms involving the atomic density (n), electron back‐scattering factor (R) and electron escape depth (L). Many schemes have been proposed by various people for corrections of the R and L terms. However, up to now, there have been no systematic investigations of the correction accuracy of the proposed schemes. We have evaluated the correction accuracy, based on measured intensity data for AuCu alloys of different compositions. Comparison was made between the observed intensity ratio K (=Iunk/Istd) and the calculated intensity, ratio K′ (= C(nunk/nstd)(Runk/Rstd)(Lunk/Lstd)), where C and I represent the concentration and intensity, respectively. The superscripts ‘unk’ and ‘std’ denote that the parameters are for unknown and standard specimens, here the pure elements. If the correction works well, the error Er (= K′  K)/(K) will become smaller. Evaluations were carried out on three schemes for the R correction and on seven schemes for the L correction using the Au 239 eV, Au 2024 eV and Cu 920 eV transitions. The root mean square (RMS) of the calculated errors showed several per cent for the best case and 20–30% for the worst case. The RMS error varied a few per cent between schemes for the R correction but it varied ∼30% for the L correction.
Sputter reduction of oxides by ion bombardment during Auger depth profile analysis
Authors: Mitchell D. F. , Sproule G. I. , Graham M. J. 
Published: December 2004

AbstractQuantification of the magnitude of preferential sputtering of oxygen from metallic oxides has been examined for a large number of 30 nm thick amorphous oxides deposited onto polished silicon substrates. The method of analysis was derivative‐mode Auger analysis carried out in a cleaner vacuum system and with cleaner initial surfaces than has been the case usually for data found in the literature. Ion sputtering was primarily with 3 keV xenon ions but the effect of ion energy (1, 3 and 4.5 keV), ion mass (argon or xenon) and sputter rate was also examined. The magnitude of preferential sputtering at 20°C was generally much less than has been reported previously and was not a function of ion energy, mass or sputter rate over the range studied. The results separate into two groups: oxides that reduce appreciably and those that do not. The results agree well with the predictions from the theoretical model of Kelly.1 It must be concluded from the work that most of the data reported in literature are primarily the result of unrecognized and therefore unreported variables. Likely candidates are contaminants within the ion beam and background environment that contribute chemical effects to the sputter process, ion beam and electron beam heating of poorly conducting samples, or redeposition of sputtered material into the analysis area.
The characterization of doped and undoped states of conducting polypyrrole, poly‐3‐methylthiophene and poly(3‐thiopheneacetic acid) thin films on a platinum surface by specular‐reflectance Fourier transform infrared spectroscopy
Authors: Wang Jin Hai 
Published: December 2004

AbstractAn improved specular‐reflectance Fourier transform infrared spectroscopy (SRFTIRS) is applied in the characterization of several kinds of conducting polymer, which were synthesized electrochemically and coated on platinum electrodes. This technique allows the use of the same electrode as that used in electrochemical experiments as the optical reflectance substrate and requires no further sampling. Satisfactory spectra were obtained for a variety of film thicknesses. Both the conducting and insulating states of the polymer and the anion and cation dopants can be identified clearly. The technique is fast, very versatile and convenient. Furthermore, the results obtained indicate its potential application in the analysis and characterization of other conducting polymer films and/or other coatings on metal substrates.