bluuebunny/crossref_metadata_2025_split huggingface dataset:
SAM analysis of fracture surfaces of ceramics
Authors: Hamminger R. 
Published: May 2005

AbstractThe application of high resolution scanning Auger electron spectroscopy on non‐conductive ceramic materials has been demonstrated. Advanced ceramics, e.g. SiC, ZrO2, AIN and Si3N4, have been analysed at a low beam voltage and a low beam current of typically 3 kV and 20 nA. Ion conductive materials were analysed at elevated temperatures up to 550°C. The application on interfacial details of advanced ceramic materials was found to be restricted only in the case of very fine‐grained materials, due to the unsufficient lateral resolution when very weak primary conditions were used to reduce charging.
XPS characterization of ultrafine Si3N4 powders
Authors: Bertóti I. , Varsányi G. , Mink G. , Székely T. , Vaivads J. , Millers T. , Grabis J. 
Published: May 2005

AbstractThe mechanical properties of Si3N4 based ceramic bodies are largely controlled by the phases formed on the grain boundaries during sintering. For this reason determination of the state and the chemical composition of the surface of the starting Si3N4 powder is of prime theoretial and practical importance, especially in the cases when advanced ultrafine powders are used. In this work an ultrafine Si3N4 powder, obtained by high temperature plasma nitridation of silicon, has been characterized by XPS. Oxygen, carbon and also a small amount of potassium were detected as surface impurities. The Si 2p and Si (KLL) spectral lines could be decomposed into two components corresponding to silicon in Si3N4 and SiO2 phases. From angle‐resolved and Ar‐ion depth‐profiling experiments a layer model, consisting of a Si3N4 core covered by a relatively thick SiO2 layer and a carbon contaminant overlayer, could be elucidated.
Determination of the grain boundary diffusion coefficient of oxygen in Cr2O3
Authors: Sockel H. G. , Saal B. , Heilmaier M. 
Published: May 2005

AbstractThe penetration of tracers into polycrystals is described by the solution of the corresponding differential equation by Suzuoka.1 A direct determination of DGB δ (DGB: grain boundary diffusion coefficient, 2δ: grain boundary thickness) by this complex solution is not possible. Therefore, so far, an approximate solution for intermediate times t and large penetration depths y derived from the Suzuoka solution has been used to obtain DGB δ by a graphical method. For very small DGB the penetration profiles of stable isotopes in polycrystals can be measured by SIMS. Under these conditions the graphical method cannot be applied. For this reason, a new numerical method based on the exact solution of Suzuoka had to be developed. It is applied and verified in the determination of DGB for oxygen in Cr2O3.
ESCA Studies of MoO2 and MoO3
Authors: Brox B. , Olefjord I. 
Published: May 2005

AbstractThe metallic and the oxide states of Mo were analysed by ESCA. A pure Mo metal sample was ion‐etched and analysed. MoO3 was formed by oxidation of Mo in oxygen. The four‐valent MoO2 was prepared by oxidation of Mo in a H2O/H2 gas mixture and by reduction of MoO3 in hydrogen.The binding energies of the Mo 3d5/2 and Mo 3d3/2 signals representing the metallic state are 227.9 and 231.0 eV, respectively. The chemical shift of the Mo 3d signals recorded for MoO3 is 4.8 eV.Each of the Mo 3d spin–orbit components recorded from MoO2 consists of two peaks. The area ratio between the low and high intensity peaks are 1:2. The shift of the low intensity peak is 3.2 eV corresponding to the value expected by linear interpolation between the four and six valent states. The high intensity peak is positioned at 1.6 eV higher binding energy than the metallic state. It is suggested that the low energy shift is due to the structure of MoO2; the MoMo distance in the structure is either 2.5 or 3.1 Å. Interaction between metal atoms gives a partly filled σ‐bond which screens the core electron and thereby the shift becomes lower. The chemical shift of the Mo4+ signal recorded from molybdenum oxyhydroxide is 3.2 eV. It is the same as for the low intensity peak in MoO2 representing the ionic character of the Mo atoms in the oxide.
Implantation of 29Si into GaAs {100}: Surface analysis and modelling of the dopant distribution
Authors: Hill I. R. , Lau W. M. , North R. A. 
Published: May 2005

AbstractSIMS concentration profiles have been measured for 29Si ions implanted into GaAs {100} in the energy range of 30 to 400 keV and at doses from 5 × 1012 to 5 × 1014 cm−2. It was found that these profiles could be fitted successfully to Pearson IV distributions enabling the establishment of projected range statistics for modelling purposes. The Si concentration profiles were found to be a function of not only implantation energy but also of the tilt and twist angles of the substrate wafer and of the implant dose. Raman spectroscopy was used to monitor the disorder induced in the GaAs substrate by the Si implantation. The SIMS profiles are discussed in terms of planar channelling of the Si ions and the Raman data are used in interpreting the dose dependence of the profiles.
Test of algorithm for background correction in XPS under variation of XPS peak energy
Authors: Tougaard S. , Braun W. , Holub‐Krappe E. , Saalfeld H. 
Published: May 2005

AbstractThe consistency of a recently proposed algorithm for background correction in XPS is studied, under variation of the XPS peak energy, by use of synchrotron radiation. Two approximations for the inelastic scattering properties of the solid are investigated. Both algorithms are found to account well for the variation in the inelastic scattering properties of the solid when the Au 4f XPS peak energy is varied. Small differences can be ascribed to the influence of surface excitations which are not included in the algorithm.
An XPS and SIMS analysis of biodegradable biomedical polyesters
Authors: Davies M. C. , Short R. D. , Khan M. A. , Watts J. F. , Brown A. , Eccles A. J. , Humphrey P. , Vickerman J. C. , Vert M. 
Published: May 2005

AbstractThe polymer surface compositions of some polyesters of importance in biomaterial science and advanced drug delivery have been examined by x‐ray photoelectron spectroscopy (XPS) and static secondary ion mass spectrometry (SSIMS). The XPS results show good quantitative stoichiometric correlation with the known chemical composition of the polyesters. The SIMS spectra show systematic fragmentation patterns in both positive and negative ion modes for the series of structurally related polymers. Evidence for the presence of radical cation formation in SIMS is presented. Comparison between the SIMS spectra of poly‐glycolic acid and poly‐lactic acid and the pyrolysis mass spectra of these polymers are made, and conclusions drawn on the different mechanisms of fragmentation. The combined application of SSIMS and XPS is shown to give a highly detailed analysis of these polyesters.
He(I) photoelectron studies of lidocaine films on liquid surfaces
Authors: Ballard R. E. , Jones Jimmy , Read Derek , Inchley Andrew , Cranmer Martin 
Published: May 2005

AbstractThe He(I) photoelectron spectra are reported of lidocaine (ω‐diethylamino‐2,6‐dimethylacetanilide) in the form of the free base, the hydrochloride, the ω‐N‐methyl halides and the ω‐N‐methyl hydrogen sulphate as surface films on liquid solutions.
Experiments on imaging X‐ray analytical methods
Authors: Gurker N. , Ebel M. F. , Ebel H. , Hedrich H. , Bavdaz M. , Giefing G. 
Published: May 2005

AbstractX‐ray induced analysis of matter offers solutions to a great variety of analyst's questions in various disciplines. Based on the physical nature of primary interaction (photoelectric absorption, elastic/inelastic scattering) and on the secondary specimen response (modulated primary radiation, fluorescent radiation, photoelectrons, Auger electrons), a powerful family of different analytical techniques has evolved. This paper emphasizes the methods of x‐ray photoeletron spectrometry (XPS) and x‐ray fluorescence analysis (XRF), covering depth information ranging from ca. 1 nm (XPS) to > 10 μm (XRF). Scanning schemes to extract spatial resolution of the specific analytical signal are presented. These methods operate in (hardware‐based) line‐selection modes during data acquisition and are essentially based on computer‐(software‐)aided data decoding to achieve point information (element map). Operating principles, alternative concepts, experimental set ups, results and some future trends are summarized.
Redistribution of boron during thermal oxidation of silicon studied by SIMS using Ar+ bombardment and the MISR method. Part I: Methodology
Authors: Michiels F. , Butaye L. , Adams F. 
Published: May 2005

AbstractQuantitative depth profiling of boron through SiO2/Si interfaces, when profiling with Ar+, is complicated by the matrix effects. The presence of oxygen affects the sensitivity of boron by three orders of magnitude and accurate determination of the distribution of the distribution coefficient of boron at the interface is only possible when the matrix effects can be elminated or taken into account in the quantification. By using matrix‐sensitive correlation factors, a sensitivity curve of boron at different primary ion current densitites was established. This relation shows a good long‐term reproducibility. Moreover, a physical interpretation of the shape of the sensitivity curve of boron is given by comparison with pure Si and SiO2. Tentative explanations for the behaviour of different SixOyz+ species in conditions of varying primary ion current density and oxygen backfill are given. The influence of the oxygen backfill pressure on the sputter rate of silicon was investigated and problems arising in the profilation of boron in SiO2/Si interfaces were addressed. Practical applications of the described methodology are discussed in Part II of this series.
Redistribution of boron during thermal oxidation of silicon studied by SIMS using Ar+ bombardment and the MISR method. Part II: Applications
Authors: Michiels F. , Butaye L. , Adams F. 
Published: May 2005

AbstractBoron‐implanted silicon samples were oxidized (± 1100°C, 20–140 min) in an oxygen ambient to study the redistribution during thermal treatment. The use of matrix‐sensitive correlation factors, to account for the matrix effect when profiling boron through a SiO2/Si interface under Ar+ bombardment, was evaluated. A correction procedure based on the calibration curve of Part I of this series was applied for this purpose. The internal precision of the procedure as estimated from several tens of profiles is of the order of 25%. The accuracy was assessed by comparison of the quantified SIMS profiles with boron profiles determined with sputtered neutrals mass spectrometry (SNMS). SIMS data indicate an enrichment in the SiO2 phase of a factor of 2–3. SNMS data surpass the SIMS data by a factor of three and indicate a distribution coefficient of 9. The segregation coefficient is independent of the oxidation time. Samples with a high concentration of boron showed an anomalous diffusion behaviour, which can be attributed to the formation of boron precipitates which could be visualized by spatially resolved depth profiling with ion‐sensitive imaging.
An altered layer model for sputter‐profiling
Authors: Carter G. , Katardjiev I. V. , Nobes M. J. 
Published: May 2005

AbstractAn altered layer model is developed, consisting of an outer surface or sputtering layer from which atoms are ejected by ion bombardment and an adjacent deeper layer in which atomic constituents are spatially homogenised by bombardment‐induced mixing processes and between which layers atomic constituents are again intermixed. The model is applied to the case of sputtering erosion through an interface, and broadening effects are examined. It is shown that the model relaxes, on the one hand, to earlier treatments of non‐distinguishable sputtering and altered layers and, on the other hand, by assuming multiple altered layers, to earlier continuum (non‐discretized layer) models. Suggestions for controlled experimental studies for model verification are made.
Selective XPS technique for analysis of submicrometer metal line sidewalls on semiconductor devices
Authors: White Eric J. 
Published: May 2005

AbstractThe sidewalls of the metal connection lines used in semiconductor devices have different process histories from that of the top of the metal film. A new technique has been developed to analyze sidewall surfaces on product wafers using x‐ray photoelectron spectroscopy (XPS). This tecniques allows selective analysis of the sidewall region, providing specfic information on the chemical state of the sidewall, including residual contamination or etch by‐products remaining after line formation and the effects of further processing on this material.
Ion sputter rates of CrMnFe spinel oxides
Authors: Wild R. K. 
Published: May 2005

AbstractThe oxide which forms on stainless steel is duplex in nature, with an outer spinel covering an inner rhombohedral Cr2O3. The thickness of the oxide is only a few micrometers, even after many thousands of hours of oxidation at high temperatures, and hence surface analytical techniques are required to characterize the oxide. In particular, depth analysis is obtained using the scanning Auger microprobe in conjunction with argon ion bombardment. The etch rates are at present assumed to be the same as that measured using a tantalum oxide standard. To obtain a more accurate measure of sputter rates on the spinel oxides 20%Cr/25%Ni/TiN‐strengthened steel has been oxidized and the thickness determined by independent means. These data have then been used to determine the etch rates, which are compared with that on tantalum pentoxide.
Composition of TiN diffusion barriers in contact holes of advanced integrated circuits: A challenge for quantitative Auger spectroscopy
Authors: Pamler W. , Kohlhase A. 
Published: May 2005

AbstractTiN is used in advanced integrated circuits as a diffusion barrier between Al metallization and Si substrate. Quantitative analysis of the TiN composition in contact holes of submicron devices is a particular challege for Auger spectroscopy owing to the contact hole geometry and topography (low signal‐to‐noise ratio, shadowing effects, scattering of primary electrons) and owing to material‐related problems (peak overlapping and lineshape changes, preferential sputtering, crystalline effects). It will be shown how methods of sample preparation and data evaluation can be used to advantage in solving these difficulties. The analysis reveals that the sputter‐deposited barrier layer is depleted in nitrogen at the contact hole wall.
Computer‐Aided quantification of AES and XPS spectra
Authors: Moir P. A. , Fitzgerald A. G. , Storey B. E. 
Published: May 2005

AbstractThe uses of a computer‐accessed database of elemental information relevant to quantitative interpretation of Auger electron and x‐ray photoelectron spectra will be described. Such a database has been compiled containing data on some 70 elements for access via UCSD Pascal computer programs implemented on IBM‐compatible microcomputers, Basic information required for the calculation of AES and XPS matrix factors is present in the database and routines for easy updating and extending of the information present are available. Programs for rapid calculation of the matrix factors needed for accurate quantification have also been developed to run in tandem with these library files. The simple data correction procedures present in these programs provide the analyst with a rapid method for obtaining an estimate of surface composition. Use of programs of this type help to prevent error by relying on the computer‐accessed library files for elemental information, help to prevent duplication of effort, and are of use in introducing the new surface analyst to the theoretical background to quantification. Some simple examples of uses of the programs are given.
Minimum detectable dimension, resolving power and quantification of scanning Auger microscopy at high lateral resolution
Authors: Cazaux J. 
Published: May 2005

AbstractUsing a two‐Gaussian model for the radial distribution of the emitted Auger electrons, it is shown that the resolving power (point‐to‐point resolution) is governed by the incident probe diameter d, while the minimum detectable dimension dm may be less than d. The convolution/deconvolution problem of Auger profiles is also considered with the transfer function of scanning Auger microscopy (SAM).Auger profiles across various flat distributions (single stripe, i.e. single quantum well; isolated rectangular details; stripe arrays; i.e. superlattices; and linear concentrations at non‐abrupt interfaces) are estimated showing the distortion of the experimental profiles by the radial distribution of Auger electrons.For small details, the apparent concentration looks very different from the true one and a two‐point analysis procedure is suggested for improving the quantification of SAM at high lateral resolution as an alternative to deconvolution of the Auger profiles.The same analysis may be applied to other analytical microscopies particularly to electron probe microanalysis of a specimen having a surface compsition different from that of the bulk.
Surface composition analyses of Co–Ni alloys under Ar+ ion bombardment by AES and ISS: A possible standard sample for surface chemical analysis
Authors: Kurokawa A. , Shimizu R. , Kubota Y. , Kang H. J. 
Published: May 2005

AbstractThe change in surface composition of Co(50.4 at.%)–Ni alloy under Ar+ ion bombardment was investigated by Auger electron spectroscopy (AES) and ion scattering spectroscopy (ISS). The surface concentrations were estimated by employing a spectrum synthesis method, since the Co and Ni signals in both AES and ISS spectra overlap each other. The results based on the quantifications by AES and ISS have indicated that the composition of the Co–Ni alloy surface under Ar+ ion bombardment is the same as the bulk composition within the accuracy in quantification, leading to the conclusion that ion bombardment does not cause surface composition change in the Co–Ni alloy. This supports the proposal that the Co–Ni alloy system is an appropriate reference material for surface chemical analysis.
Quantitative Auger electron spectroscopy of binary systems. Matrix correction
Authors: Zagorenko A. I. , Zaporozchenko V. I. 
Published: May 2005

AbstractThe matrix correction factor, M, has been determined for 1953 binary systems. The calculated M values are in the range 0.3–2.6. The probable error, with no account being taken of the matrix effect, is 30%. A study has been made of the effect on M of different methods of calculation, the experimental conditions of the analysis, the choice of the Auger lines and the concentration of the system analysed. The greatest effect on M values is the choice of equations used for calculating the escape depth of the Auger electrons. Measurements of concentrations were carried out on scribed samples of cobalt, vanadium, iron and copper silicides, and lead telluride. On the basis of a comparison of the known bulk concentrations and the calculated values, an expression has been chosen for calculating the escape depth of the Auger electrons that gives the best results.
Angular resolved sputtering yields of noble metals and an Au–Ag alloy
Authors: Huang W. 
Published: May 2005

AbstractSputtering of noble metals and an Au–Ag alloy with low keV ion bombardment is investigated by means of measuring angular distribution of sputter‐deposited material and by analysing the bombarded target with low energy. Auger electron spectroscopy (LEAES). The measurement provides information on the angular‐resolved sputtering yields and the compositional variation of the bombarded surface. The angular distributions of the sputtered particles vary with the measurement conditions: the energy and the type of bombarding ions, the crystallity of the bombarded surface and the vacuum conditions during sputtering. The measurement gives evidence of ion bombardment induced surface segregation on sputtering of the Au–Ag alloy.
Effect of temperature on chromium segregation to CoO(100) and NiO(100) surfaces
Authors: Hirschwald W. , Sikora I. , Stolze F. , Oblakowski J. 
Published: May 2005

AbstractSurface concentrations of chromium in CoOCr2O3 and NiOCr2O3 single crystals in dependence on bulk concentration and annealing temperature were determined by means of SIMS and XPS. From the temperature dependence, the heat of segregation ΔHs was calculated. Its value changed with bulk Cr concentration in the CoOCr2O3 system, whereas for the NiOCr2O3 system ΔHs was found to be constant in the whole range of bulk concentrations and temperatures studied.
On the theory of quantitative in‐depth composition information in X‐ray photoelectron spectroscopy
Authors: Tofterup Arne L. 
Published: May 2005

AbstractThe x‐ray photolectron spectroscopy (XPS) peak shape has previously been described by a single parameter D, which is the ratio of the peak area to the increase in background signal 30 eV below the peak energy. The aim was to extract in‐depth composition information from spectra. The influnce of elastic scattering on that background signal has been investigated for homogeneous and inhomogeneous transition and noble metals. Accurate, analytic expressions for D were derived, based upon a second‐order calculation of the inelastic scattering events and a so‐called P1 approximation of the elastic scattering. The background signal, and therefore D appears to depend strongly on elastic scattering in pronounced inhomogeneous solids but only weakly in the more homogeneous solids.
Surface analysis by sputtered neutral mass spectrometry with electron‐beam‐excited plasma
Authors: Hashiguchi Y. , Hayashi S. , Ohtsubo T. , Kato S. , Hamagaki H. , Hara T. , Aoyagi K. , Namba S. 
Published: May 2005

AbstractA new type of sputtered neutral mass spectrometer, named SNART (Sputtered Neutral Analysis—Riken Type), was evaluated. SNART uses an argon plasma that is driven by an electron beam. The plasma is used for both sputtering of the sample and post‐ionizing the sputtered neutral atoms. A depth profile of multilayered Ge/Si was taken by SNART to evaluate depth resolution. The quantitativeness of SNART was also checked using a stainless‐steel sample. The results were compared with those by conventional SIMS and glow discharge optical emission spectrometry. The following features of SNART were confirmed: (1) high post‐ionization efficiency; (2) high depth resolution; (3) high sputtering rate; (4) no matrix effect on post‐ionization efficiency; and (5) high quantitativeness.
High spectral and angular resolution studies of sputtered zirconium atoms
Authors: Cullin D. Wm. , Moryl J. E. , Jones P. L. 
Published: May 2005

AbstractWe present the first results from a new apparatus for high spectral and angular resolution studies of sputtered neutral species. The sputtering experiments employ laser‐induced fluorescence and a compact fiber‐optic‐based detection system to yield state‐specific angular distributions for the sputtered atom flux. The angular resolution is of the order of 3° and a 260 MHz residual Doppler shift is estimated for the observed atomic transitions. The angular distribution for ground‐state zirconium atoms shows clear deviations from the cosine dependence expected from linear cascade theory when sputtered by 1.5 keV Ar+ ions incident at 60° from the surface normal. The peaking of the distribution in the forward direction suggests that a significant fraction of the atoms is ejected by a direct mechanism.