bluuebunny/crossref_metadata_2025_split huggingface dataset:
Instrumental effects in the analysis of non‐homogeneous specimens in XPS
Authors: Koening M. F. , Grant J. T. 
Published: December 2004

AbstractThe effects of specimen non‐homogeneity on XPS spectra have been studied for a Kratos ES300 x‐ray photoelectron spectrometer. This instrument was equipped with a real‐time imaging system to permit accurate specimen positioning. It was found that, for a correctly positioned specimen, both the measured kinetic energy and intensity of a photoelectron peak depended on the position on the specimen from which the signal arose. The variation in measured kinetic energy across the width of the entrance slit was found to be ∼1.7 eV for the widest entrance slit and highest pass energy of our spectrometer (FAT mode, 130 eV pass energy, 5 mm wide slit). The intensity of the photoelectron peaks was found to vary by a factor of ∼2 across the analyzer acceptance area for the widest (5 mm) slit, which corresponds to the inverse square of the distance from the X‐ray source. These studies show that significant shifts in kinetic energy are possible due solely to specimen non‐homogeneity (as opposed to chemical shifts) as well as misleading intensity variations. Therfore, data obtained from non‐homogeneous specimens should be carefully examined for these artifacts when using large‐ area XPS analysis.
Interpretation of the fragmentation patterns in static SIMS analysis of polymers. Part I. Simple aliphatic hydrocarbons
Authors: Van Ooij W. J. , Brinkhuis R. H. G. 
Published: December 2004

AbstractA number of simple aliphatic hydrocarbon polymers have been studied by static SIMS. The low‐mass positive spectra reflect structural differences in the polymeric structure, which result in characteristic fingerprint spectra. Unsaturation and differences in branching lead to very distinct spectral features which show promise for the application of SIMS as an analytical technique in polymer‐related areas. An attempt is made to interpret the spectra in terms of molecular structure, fragmentation mechanisms and ion stabilities. The chemical nature of ion beam damage in PE and PP was studied to some extent.
Studies of the UV/Ozone oxidation of GaAs using angle‐resolved x‐ray photoelectron spectroscopy
Authors: Flinn B. J. , McIntyre N. S. 
Published: December 2004

AbstractAngle‐resolved x‐ray photoelectron spectroscopy (ARXPS) has been used to study the composition of oxides grown on 〈110〉 and 〈100〉 GaAs during exposure to UV/ozone. The effects of substrate treatments on oxide growth were compared on 〈100〉 surfaces exposed to an HF treatment and thermal desorption of the oxide and 〈110〉 surfaces prepared by in situ cleaving. Short‐term (10 min) oxidation of 〈110〉 cleaved surfaces resulted in a mixture of Ga and As stoichiometric oxides, with arsenic depletion of the underlying GaAs substrate. Less arsenic depletion of the substrate occurs for acid‐etched 〈100〉 GaAs oxidized under the same conditions. Extended UV/ozone oxidation (60 min) of these substrates yields oxide films that are less stoichiometric, with an arsenic oxide phase segregating nearer to the surface. Cleaved 〈110〉 substrates are again depleted in arsenic just below the interface. UV/ozone oxidation of 〈100〉 GaAs surfaces prepared by thermal desorption produced oxide films of uneven thickness, which yielded poor ARXPS profile results. The Laplace Transform model of Bussing and Holloway was modified to allow the use of different electron inelastic mean free path (λ) values for surface oxide and substrate. The range of values used to test the modified equation did not cause significant changes of the depth profile.
Static SIMS study of miscible blends of polystyrene and poly(vinyl methyl ether)
Authors: Bhatia Qamar S. , Burrell Michael C. 
Published: December 2004

AbstractStatic secondary ion mass spectroscopy (SSIMS) is applied to study the surface of the miscible polystyrene (PS)/poly(vinyl methyl ether) (PVME) blend. The blend surface is enriched with PVME and the enrichment is shown to depend on the composition and molecular weight of the blend constituents. A semi‐quantitative analysis of SSIMS intensities to obtain surface compositions gives good qualitative agreement with previous x‐ray photoelectron spectroscopy (XPS) results.
Analysis of AlGaAs/GaAs superlattices by means of sputter‐assisted AES, SEM and TEM
Authors: Kajiwara K. , Kawai H. 
Published: December 2004

AbstractThis paper reports the developments of evaluation methods on epitaxially grown superlattices by means of sputterassisted Auger electron spectroscopy (AES), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). AlGaAs/GaAs semiconductor superlattics were grown epitaxially by metal–organic chemical vapour deposition (MOCVD). The layer thickness of the superlattices ranged from a few to ten nanometers.Firstly, developments of Auger depth profiling were tried by using: (1) a differential pumping‐type ion gun instead of a static pressure type to reduce the oxygen adsorbates on the AlGaAs layer; (2) low‐energy Auger signals instead of high‐energy ones to shorten the escape depth; and (3) the lowest ion etching energy of 0.2 keV instead of 1 keV to reduce the surface roughening effects. It is shown that the depth resolution of sputter‐assisted AES is attainable to 1.5 nm.Secondly, high‐resolution SEM can be used as an easy evaluation method by observing the cleaved surface of superlattices, since the layers can be distinguished by signal contrast. Also, TEM can be used as an evaluation method by observing the (110) cross‐section thinned sample. The dark field image has a high contrast between AlGaAs and GaAs using the (002) diffraction.It is confirmed from these AES, SEM and TEM evaluations that the hetero‐interface abruptness of AlGaAs/GaAs superlattices grown by MOCVD is of the order of one monoatomic layer.
Surface investigation of copper in the printed circuit board
Authors: Manara A. , Sirtori V. 
Published: December 2004

AbstractThe aim of the study was to determine both the oxidation rate of copper in the printed circuit board and the degradation of an organic compound (ENTEK) present on its surface during the different phases of circuit assembling.A large number of samples stripped from electronic cards have been measured by XPS and Auger techniques ‘as received’ in order to have a statistical indication of surface composition. Other samples were heated at 220°C in a vapour‐phase atmosphere.A very thin layer (∼20 Å) is present on the copper of the printed circuit board. This layer comprises carbon, oxygen and nitrogen. After vapour‐phase treatment at 220°C, the layer on the copper surface increases up to ∼100 Å and its composition changes: carbon decreases, oxygen appears more in the ‘lattice form’ than as hydroxide and nitrogen is present in two valence states.
Temperature influences on surface energetic parameters evaluated at solid–liquid interfaces
Authors: McGuire Joseph , Lee Euisang , Sproull Robert D. 
Published: December 2004

AbstractThe adhesive events experienced by a solid material upon contact with a biofluid are related to measurable surface properties of the solid; consequently, surface properties have been suggested to provide direction for the prediction and control of biofluid behavior at interfaces. With respect to biofilm formation at elevated temperatures, knowledge of temperature influences on such properties would serve to assist the development of predictive models that incorporate a surface‐related influence. In this work, surface energetic parameters for a variety of engineering materials were determined at temperatures of 7–80°C using contact angle analysis with a modified sessile drop technique. Specifically, a linear relationship between the polar component of the work of adhesion and the polar component of liquid surface tension, observed for each material, was characterized by its slope and intercept at each temperature. The value of the slope was observed to decrease linearly with temperature. The negative values of the ordinate intercept were observed to increase in magnitude with temperature for low‐energy surfaces, but did not change uniformly for solids of higher surface energy. The polar component of the work required to remove water from a surface, observed to decrease with decreasing polar character of a solid at a given temperature, was observed to decrease with increasing temperature. The observed temperature effects indicate a need to account for this influence in the development of models describing biofluid–contact surface interactions at temperatures outside of the ambient range.
Analysis of polymer surfaces by SIMS. Part 14. Aliphatic hydrocarbons revisited
Authors: Briggs D. 
Published: December 2004

AbstractA series of saturated and unsaturated aliphatic hydrocarbon polymers previously studied by van Ooij and co‐workers has been re‐examined by static SIMS. Significant differences in the positive ion spectra have been found in several cases, particularly for the unsaturated polymers. This has important consequences for both spectral interpretation and for assessing the analytical capability of SIMS within this class of polymers. Possible reasons for these differences are discussed and ion beam damage effects are shown to be the likely cause in the case of the unsaturated polymers. A systematic comparison of negative ion spectra is reported for the first time.
Application of Tougaard background subtraction to Auger spectra. I: Silicon, SiO2 and Si3N4
Authors: Bender H. 
Published: December 2004

AbstractThe inelastic background subtraction algorithm that was proposed by Tougaard for x‐ray photoelectron spectroscopy is applied to Auger electron spectra of Si, SiO2 and Si3N4. The influence of the different parameters, the cascade fitting and the use of calculated λ(E)K(E, T) functions or of the ‘Universal Cross‐section’ are examined in detail. It is shown that the method can be applied quite successfully for quantitative analysis when matrix corrections are considered.
The characteristics of resonant laser ablation for surface analysis
Authors: Ledingham K. W. D. , Borthwick I. S. , Singhal R. P. 
Published: December 2004

AbstractResonant laser ablation (RLA) is a technique in which a pulsed tunable laser beam is directed at grazing incidence to the surface of a sample, such that neutral atoms are first ablated and then resonantly ionized by the same pulse. In this short communication the important characterstics of RLA are presented. From the results already obtained, detection levels of a few parts per million for aluminium in steel samples have been determined. The potential of RLA as a surface analysis technique is assessed.
Backscattering method possibilities for precise determination of the oxygen profile in oxide films by the use of the elastic resonance in reaction 16O(4He, 4He)16O at 3.045 MeV of 4He
Authors: Chernenko L. P. , Kobzev A. P. , Korneev D. A. , Shirokov D. M. 
Published: December 2004

AbstractElastic resonant backscattering can be used as a highly sensitive probe for the measurement of oxygen concentration for different oxides. This method of near‐surface analysis is absolute, non‐destructive and does not need calibration with the aid of standard samples. Our experimental results concern the investigation of the method possibilities for very precise determination of the concentration profile of oxygen for thin monocrystalline films of high‐temperature superconducting materials. An accuracy of better than 1.5 relative per cent (rel.%) for a 30 nm depth resolution and 0.6 rel.% for total oxygen content determination has been reached, which is an uncommon level of precision for the backscattering method. Our results are important for those application in which oxygen profiling is essential.
The structure of the PET m/z 152 ion and implications for ion formation mechanisms in static SIMS
Authors: Leggett Graham J. , Vickerman John C. 
Published: December 2004

AbstractWe discuss results of SIMS studies of isotopically labelled poly(ethylene terephthalate) (PET) and compare the results obtained with results obtained from tandem SIMS studies in the case of the m/z 152 ion. We suggest that a biphenylene structure is plausible for this ion. We discuss some mechanistic problems associated with the structures of some of the minor ions in the PET SIMS spectrum, and respond to the previosly published suggestion that only a recombinative emission process is capable of explaining the observation of these ions.
Low‐energy Ar neutral beam etching method for x‐ray photoelectron spectroscopy
Authors: Iijima Yoshitoki , Yamada Takahisa , Matsumoto Shigeo , Hiraoka Kenzo 
Published: December 2004

AbstractA simple Ar neutral beam gun capable of providing low‐energy Ar atoms has been developed for surface cleaning and depth profile analysis in x‐ray photoelectron spectroscopy, Auger electron spectroscopy, etc. Characterization of the Ar neutral beam gun is described. The effect of neutral beam bombardment was investigated for an Si(100) wafer and a polyethylene terephthalate (PET) film in order to reduce chemical damage by sputter etching in XPS. The neutral beam etching gun was composed of a Kaufman‐type ion source, a gas collision chamber and an electrostatic deflector. This gun can work also as an ion gun by a simple operation mode change. Neutral and ion beam fluxes were measured using an absorption current plate made of stainless steel. Experimental results showed that the probability of neutralization in a charge exchange chamber was ∼80% of the maximum between 1 x 10−1 Pa and 2 x 10−1 Pa, and the sputtering rate for SiO2 at 600 eV was 14 nm min−1, which is ∼30% lower than with a Kaufman‐type ion gun. The bombardment process for an Si wafer was essentially the same for the Ar ion beam and the Ar neutral beam. However, it was observed that radiation damage to the PET film surface etched by the neutral beam was remarkably diminished as compared with that by the ion etching method. This can be ascribed to the fact that the effect of electronic damage etching due to Ar0 is less than that due to Ar+.
Boumans' equation revisited. Part I: Characteristics of the glow discharge lamp
Authors: Payling Richard 
Published: December 2004

AbstractIn Part I, an equation is presented that describes the general current–voltage–pressure relationship in a hollow anode glow discharge lamp. The equation shows that no current flows until the applied voltage exceeds a turn‐on voltage of about 235 V. Comparison with Suzuki's ion energy data shows that it is only the voltage in excess of this turn‐on voltage that is effective in providing energy for sputtering. Hence, the threshold voltage constant, V0, in Boumans' sputtering equation is shown to be the sum of the turn‐on voltage and the minimum voltage required for sputtering. Other published sputtering equations are considered and shown simply to be various ways of expressing the same current–voltage–pressure relationship of the lamp.
Scanning force microscopy analysis of the surface of ion‐irradiated diamond
Authors: Demanet C. M. , Shrivastava S. , Sellschop J. P. F. 
Published: December 2004

AbstractThe surface of a natural diamond substrate, a chemical vapour‐deposited diamond epilayer and ion‐irradiated regions are compared using scanning force microscopy. Differences are reported in terms of microtopography, force modulation, lateral force and electric field gradient images.
Accuracy of the correction for a hydrocarbon contamination layer in routine quantitative XPS analysis of oxygen‐inert samples
Authors: Zagorenko A. , Beccat P. , Huiban Y. , Lynch J. 
Published: December 2004

AbstractA procedure for determination of the reduced thickness of the contamination layer for oxygen‐inert samples was implemented. The correction algorithm is valid for the reduced thickness of a contamination layer x ≥ 0.3 (x is expressed as the ratio of the layer thickness to the electron attenuation length in the contamination layer at energy 1 keV). It is shown that the linear background subtraction method traditionally used in XPS generally does not provide correct results. Application of an advanced experimental data treatment method with correction for the presence of a contamination layer to quantitative surface analysis of Al2O3, SiO2, GeO2, Fe2O3, NiO, CuO and NaF resulted in a decrease of the mean error of analysis from 27% using the elemental sensitivity factors approach to 5%.
Effect of ion incidence angle on surface concentrations in Ar+‐bombarded Co2Si, studied by AES
Authors: Zaporozchenko V. I. , Stepanova M. G. , Vojtusik S. S. 
Published: December 2004

AbstractThe surface concentration ratios CCo/CSi in Co2Si sputtered by 4 keV Ar+ at angles of incidence of 0–60° were measured by AES using Co MVV, Si LVV, Co LMM and Si KLL Auger lines at normal and oblique take‐off angles. Relying on comparison of the experimental data with results of model calculations, it is concluded that ion bombardment gives rise to a maximum of Co concentration at a depth of 5–10 nm in Co2Si.
Static SIMS investigation of metal/polymer interfaces
Authors: Travaly Y. , Bertrand P. 
Published: December 2004

AbstractThe formation of the interface between thermally evaporated metals (aluminium, copper) and polymers [poly(ethylene terephthalate) (PET), poly(methyl methacrylate) (PMMA)] has been investigated by static SIMS. Two generations of instrument have been used. The first one, using a quadrupole mass spectrometer directly connected to the same ultrahigh vacuum environment as the metallization chamber, has allowed an in situ characterization of the interface formation after each metal deposition in the submonolayer regime. The second system, using a time‐of‐flight (ToF) mass spectrometer, has allowed ex situ analyses of Al/PET, Cu/PET, Al/PMMA and Cu/PMMA interfaces. The high mass resolution of the ToF spectrometer led to the unambiguous identification of the molecular fragments that are characteristic of polymer–metal interaction. The results show that Al atoms react with the oxygenated parts of PET and PMMA. This interaction limits the lateral diffusion of Al atoms on the polymer surface and, consequently, induces a two‐dimensional growth of the Al film on these polymer substrates. In the Cu deposition case, a weaker metal–polymer interaction is observed. This leads to Cu clustering and a three‐dimensional growth. Time‐of‐flight SIMS molecular imaging clearly reveals Cu clusters on the PMMA surface.
Electronic structures of N2+ and O2+ ion‐implanted Si(100)
Authors: Yamamoto Hiroyuki , Baba Yuji , Sasaki Teikichi A. 
Published: December 2004

AbstractElectronic structures of N2+ and O2+ ion‐implanted Si(100) (SiNx, SiOx) have been investigated by means of x‐ray photoelectron spectroscopy (XPS), x‐ray‐induced Auger electron spectroscopy (XAES) and x‐ray absorption near‐edge structures (XANES). For the O2+ ion irradiation, the binding energies of Si 2p and SiKLL Auger lines for SiOx at x > 0.4 show that SiO2 is predominantly produced. The XANES spectra of SiOx (x > 0.2) at the Si 2p edge are similar to those of bulk SiO2. However, other oxides such as SiO are scarcely observed in these spectra. These observations indicate that the SiOx layer consists of a mixture of Si and SiO2 islands. On the other hand, chemical shift of the Si 2p and SiKLL Auger lines for SiNx becomes larger gradually with the implantation. Thus, it is considered that such changes are due to the stepwise replacement of the SiSi bond with the SiN bond. It implies that SiNx has several chemical states of nitride.
Friction studies at steps with friction force microscopy
Authors: Weilandt E. , Menck A. , Marti O. 
Published: December 2004

AbstractIn this study we investigated the contrast of lateral force at highly oriented pyrolytic graphite steps in an electrolytic environment with a scanning force and friction microscope. A characteristic enhancement of lateral force was visible. Steps were imaged with and without electrochemical potential control whereby a change of friction with potential could be observed. The behaviour of lateral force at the steps indicated that the observed contrast enhancement must be a real friction effect and is not caused solely by the topography.
Intercomparison of algorithms for background correction in XPS
Authors: Jansson C. , Tougaard S. , Beamson G. , Briggs D. , Davies S. F. , Rossi A. , Hauert R. , Hobi G. , Brown N. M. D. , Meenan B. J. , Anderson C. A. , Repoux M. , Malitesta C. , Sabbatini L. 
Published: December 2004

AbstractIn the present interlaboratory comparison, the consistency and validity of the Shirley, straight‐line and Tougaard methods for determination of peak intensities from measured XPS spectra have been studied by analysis of data on Au and Ni taken at eight laboratories. The reproducibility of the individual measuring systems was determined to be 2–6%. The RMS scatter around their mean values of the ratio of the peak intensity to the Au 4d peak intensity was 6% for the Tougaard method, 9–10% for the Shirley method and 8–9% for the straight‐line method. The increase in root mean square (RMS) scatter of data due to data being recorded in different laboratories amounts to 3–4%, independent of the method applied for background correction. The RMS deviation from theory of intensity ratios of peaks from Ni and Au to the Au 4d peak intensity is 14% for the Tougaard method, 33% for the Shirley method and 31% for the straight‐line method. The absolute accuracy of the methods cannot be established to better than the accuracy on the theoretical peak intensity ratios and the uncertainty in the energy dependence of the analyser response function. It is, however, reasonable to expect the combined uncertainty of these factors to be at least 10–15%. The peak intensity ratios obtained with the Tougaard method then falls within the expected accuracy of the theoretical ratios.
Chemical modifications of vinyl chloride polymers
Authors: Lambla Morand 
Published: December 2004

AbstractPoly(vinyl chloride) could be considered as an ideal basis for chemical modifications, due to its chemical structure, which contains the repeating unitCH2CHCl. Presumably, the chlorine may react as in other chlorine‐containing aliphatic compounds, but secondary degradation reactions will occur at the same time, due to irregularities in the polymer structure and consequential lowering of the intrinsic reactivity site. Nevertheless, various functional modification reactions (grafting and crosslinking), were carried out in solution and in the condensed state, in order to improve specific properties of the polymer, leading to a larger scale of applications. Furthermore, it is also important to note the potential of PVC for the manufacture of flexible products, by introduction of plasticizers, generally characterized by a good solubility in the polymer and low volatility. In order to improve the aging properties of these products, recent developments were made in the field of oligomeric and polymeric plasticizers, which may or may not be reactive. The success of this new direction depends on larger developments in reactive processing.
Some recent developments in the processing of poly(vinyl chloride)
Authors: Stephenson Richard C. 
Published: December 2004

AbstractPoly(Vinyl chloride) is the basic material for a huge number of products which are fabricated using very many different techniques. Established processing techniques continue to be improved, leading to additional benefits in process efficiency and product quality. New processes are also being introduced which are intended to increase the efficiency of material usage and to open up new application areas. These include: molecular orientation, foaming, and cross‐linking. Developments are also occurring in the use of PVC in conjunction with other materials as micro‐ or macro‐composites. Processing techniques include coextrusion and lamination. Many processing methods are likely to benefit from the microelectronics revolution in process control and monitoring.