bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial resolution tests of scanning Auger microscopy under different topographical conditions
Authors: Umbach A. , Hoyer A. , Brünger W. H. 
Published: May 2005

AbstractHighly focused electron beams have been scanned across chemical edges of different surface structures in a scanning Auger microscope with a field emission gun. For the case of a fracture plane across a multilayer structure with 100 nm Ta and 100 nm Si layers, a resolution of 35 nm for the Ta signal and 53 nm for the Si signal was found.In contrast to these flat samples, analytical problems in semiconductor technology require analysis of submicrometre features with high aspect ratios. Under these conditions, the scanning Auger microscopy (SAM) resolution is drastically affected by electron scattering. To study these effects, we used x‐ray mask structures consisting of 0.6 μm high Au on Si (100) fabricated by x‐ray lithography.We scanned over a heterogeneous step of this kind with the three different electron beam energies 10, 20 and 30 keV and measured the lateral intensity distribution of the Si signal. This signal does not stop at the edge but extends into the gold plane over a distance that increases with beam energy as expected.When analysing small features, this effect leads to a misinterpretation of the Auger spectra. This problem becomes more severe as the feature size is reduced. This has been demonstrated for gold bars of different widths and different sized columns.To minimize the contribution of nearby regions to the spectrum, the lowest beam voltage is recommended, which is sufficient to achieve the required beam diameter.
VAMAS surface chemical analysis technical working party: An update for 1988
Authors: Seah M. P. 
Published: May 2005

AbstractA brief overview is presented of the VAMAS Surface Chemical Analysis Technical Working Party project. This project is aimed at providing the reference working base for surface analysis. There are currently 20 projects covering AES, XPS, SIMS, sputtered neutral mass spectrometry and sputter‐depth profiling. The coordination of the projects leads to considerable gains in confidence and in project output, together with a reduction in the workload necessary to meet the project targets. This arises simply because of the increased availability of characterized samples, reference methodologies and software within the overall programme. This Technical Working Party has been active for 4 years now and definitive milestones are being achieved that would be impossible without the overall coordination.
Investigation of the early stages of thin‐film growth of Ni on thermally grown SiO2 by means of RBS, AES and TEM
Authors: Anklam H.‐J. , Mattheis R. , Thrum F. 
Published: May 2005

AbstractTo study the type of growth of Ni on thermally grown SiO2 three analytical methods, RBS, AES and transmission electron microscopy (TEM), were used. An SiO2 thickness of ∼ 30 nm has been proved to give optimal conditions with respect to sample preparation and measurement.On identical samples the differential sticking coefficient (by RBS), type of growth (by AES) and saturation cluster density (by TEM) have been determined in dependence on substrate temperature.The growth can be characterized by a pseudo‐Stranski‐Krastanov mechanism with incomplete condensation for substrate temperatures exceeding 575 K and a high saturation cluster density (∼ 3 × 1012 cm−2) that is independent of substrate temperature.
Contributions of AES in four metallurgical studies
Authors: Grabke Hans Jürgen 
Published: May 2005

AbstractFour recent studies are reported characterizing the possible contributions of surface science to metallurgy. The grain boundary segregation of phosphorus was studied by AES analyses of fractured specimens—after many studies on ferritic iron steels—in the austenitic range for FeP, FeMnP, FeCP and FePB alloys. Also, in Ni20% Cr the grain boundary segregation of P and its effects on carbide precipitation were investigated.On surfaces of ternary alloys FeMI, co‐segregation of the metal M and non‐metal element I can lead to the formation of two‐dimensional or three‐dimensional surface compounds, as demonstrated for the system FeCrN. The formation of such nitrides in the first transient state of the oxidation of high‐temperature alloys can strongly deteriorate the protective properties of the chromia layer formed—as shown for the oxidation of Fe20% Cr in N2H2OH2.
Analysis of epitaxial CdxHg1 − xTe layers using RBS, SIMS and EER
Authors: Diskett D. J. , Avery A. J. , Blackmore G. , Irvine S. J. C. , Giess J. , Berlouis L. E. A. 
Published: May 2005

AbstractA combination of the techniques of Rutherford backscattering spectrometry (RBS), secondary ion mass spectrometry (SIMS) and electrolyte electroreflectance (EER) have been used to profile through epitaxial layers and heterostrutures of CdxHg1 − xTe. The layers analysed by these techniques were grown either by photosensitized or thermal metal organic vapour phase epitaxy (MOVPE). The use of the EER technique, combined with electro‐chemical etching, for depth profiling of layers is described. Good agreement between RBS and EER measurements of x has been achieved with a resolution of ±0.010 for RBS and ±0.002 for EER. A depth resolution of better than 50 Å has been achieved by all three of the techniques. SIMS has been used to profile for trace impurities in layers grown using the interdiffused multilayer process (IMP). Assessment of layer crystal quality using ion channelling and EER broadening parameter measurements is discussed. The advantages and disadvantages of each of the analysis techniques are discussed and compared.
Comparison of beam‐induced profile broadening effects of gallium and copper in oxygen‐bombarded silicon
Authors: Homma Yoshikazu , Maruo Tetsuya 
Published: May 2005

AbstractOxygen‐induced profile broadening in secondary ion mass spectrometry (SIMS) has been studied for Ga and Cu in silicon under 10 keV O2+ bombardment at impact angles of 2–82°. A beam‐induced broadening effect was evident for impact angles <30° to the surface normal. In this range of impact angles, the SIMS signal of Cu showed exceptionally long decay, and its decay length decreased with increase in impact angle. By contrast, the decay length of Ga had a maximum at around 27° and decreased below this value. This difference in decay behaviour is attributed to the difference in impurity transport during beam‐induced oxidation. While Cu segregates at the SiO2/Si interface, Ga diffuses rather uniformly in the surface SiO2 layer.
Non‐destructive depth profiling through quantitative analysis of surface electron spectra
Authors: Tougaard S. , Hansen H. S. 
Published: May 2005

AbstractA theory is presented that allows detailed quantitative information on in‐depth concentration profiles to be extracted through analysis of surface electron spectra. The depth profile is determined from analysis of a single spectrum and the method is therefore fast and non‐destructive. The validity of the method is tested through anlaysis of model spectra from a wide variety of inhomogeneous systems. It is demonstrated that the method can clearly distinguish between different classes of in‐depth profiles. Moreover, the formalism can be used to distinguish between different overlayer growth mechanisms. The resolution in the determination of the detailed concentration depth profile is of the order of the inelastic mean free path λ. The accuracy of the total amount of material within depths of 4–6 λ determined by the analysis is, in all cases, better than 10–15%.
Secondary ion yield matrix effects in SIMS depth profiles of Si/Ge multilayers
Authors: Gillen Greg , Phelps John M. , Nelson Randall W. , Williams Peter , Hues Steven M. 
Published: May 2005

AbstractThin multilayer samples of Si/Ge, with individual layer thicknesses of 4–33 nm, have been analyzed by secondary ion mass spectrometry (SIMS) using Ar+, O2+ and Cs+ primary ion beams. Bombardment with both Ar+ and O2+ produced positive secondary ion depth profiles in which pronounced distortions were observed. Similar effects were found in negative secondary ion depth profiles with Cs+ bombardment. In each case, the SIMS depth profiles were characterized by abrupt interfacial secondary ion signal variations and a shift in the secondary ion signal maxima indicating that the layers were superposed, a condition that was not consistent with sample preparation, as verified by Auger electron spectroscopy. Auger electron spectroscopy depth profiling was also used to quantify the level of oxygen in the films. From these data it was concluded that the distortions in the positive secondary ion depth profiles under Ar+ bombardment were the result of secondary ion yield variations induced by enhanced incorporation of ambient oxygen, during sample preparation, into the stronger oxide‐forming silicon layers. Under O2+ and Cs+ bombardment, the profile distortions were introduced by differential incorporation of the implanted primary species into the lower‐sputter‐yield silicon layers.
Surface analysis preparations for multilayer plated through‐holes
Authors: Love Brian J. 
Published: May 2005

AbstractSurface analysis on multilayer printed wiring board interconnections has been, at best, difficult to achieve. This has been primarily related to geometric considerations, which prevent adequate detection of x‐rays, Auger emissions, etc. We have developed a method for analysing solder defects on plated through‐holes via a microsectioning technique to generate a coupon and then embedding the coupon in conductive foil for analysis. Samples are shown that have been produced using this technique. Reasonable spectra have been generated on specimens prepared by this technique. This preparation allows analysis on soldered holes, which, because of geometric constraints, are difficult to analyse.
Detection of substrate‐related species during depth profiling of a‐Si: H films with SIMS
Authors: Herion J. , Beyer W. , Wagner H. 
Published: May 2005

AbstractThin films of hydrogenated amorphous silicon (a‐Si:H) were deposited on various substrates (e.g. Cr, Ti, GaAs) and analysed by secondary ion mass spectrometry (SIMS). Depth profiles were measured using oxygen ions of 9 keV as a primary beam. Spatially resolved (or imaging) SIMS was used to determine the local distribution of the various species. At nearly normal incidence of the primary beam, the intensity of substrate‐related species showed a step‐like increase at ∼ 20% of the film thickness and remained at a relatively high level throughout the rest of the film. For substrates consisting of Cr films evaporated on crystalline silicon, variations of the deposition temperature and of the thickness of the a‐Si:H films did not markedly influence the phenomenon. By changing the angle of incidence of the primary beam, a considerable shift of the step towards the interface between the film and the substrate was obtained. The results of depth profiling experiments, of imaging by SIMS and optical microscopy can be explained qualitatively by a beam‐induced effect.
RBS and ERD analysis of semiconductor device materials
Authors: Kuiper A. E. T. 
Published: May 2005

AbstractThe number of applications of Rutherford back‐scattering spectrometry (RBS) in the field of integrated circuit (IC)‐related materials research is ever‐increasing. Both qualitative and quantitative information about thin‐film material can be derived from a single RBS spectrum, as is demonstrated from various example that are typical for semiconductor research. Such examples include kinetic studies of thin‐film reactions. The RBS facility constructed at Philips Research Laboratories in Eindhoven for in situ investigations is described.Hydrogen, which in principle cannot be detected in RBS, can be measured with the related technique of elastic recoil detection (ERD). ERD can be performed readily in conventional RBS equipment, which adds to its attractiveness as a complementary technique. Examples are discussed to show how RBS and ERD combine in characterizing thin films.
The drastic effect of oxygen on surface segregation
Authors: Mezey L. Z. , Hofer W. , Varga P. , Giber J. 
Published: May 2005

AbstractThe temperature and oxygen partial pressure of the environment of a solid may produce non‐oxidizing or oxidizing conditions for any of the components in the surface. Under non‐oxidizing (free surface) conditions, one of the components of a binary alloy segregates. The oxidizing effect may enhance or diminish its surface content, and the other component may even segregate. This effect is investigated here using the experimental results (ISS and AES) and theoretical calculations of a new method. Agreement between theory and experiment is shown for AuPd and CuPd, and as well for S‐contaminated CuFe.
Surface characterization of rhodium–copper alloys
Authors: Delplancke M. P. , Jardinier‐Offergeld M. , Bouillon F. 
Published: May 2005

AbstractThis paper presents the results of a surface analysis of copper–rhodium alloys by Auger electron spectroscopy during heat treatments under vacuum. It is shown that copper segregation takes place in the first atomic layer at every rhodium concentration. Special attention is given to the influence of diffusion rate on the composition of the surface region. The results are compared with theoretical models. A segregation enthalpy is determined for a 1.5 at.% Rh alloy at 873 K.
Role of oxygen contamination on titanium nitriding
Authors: Saillard P. , Gicquel A. , Amouroux J. , Moncoffre N. , Tousset J. 
Published: May 2005

AbstractTitanium nitridation has been achieved in a tubular reactor under a radio frequency low‐pressure plasma. The influence of the plasma working parameters (substrate temperature, nature of the gas phase and plasma input power) on the superficial nitride/oxide ratio has been investigated. The influence of the oxygen bulk contamination on nitridation kinetics is also reported.
Immersion ellipsometry of semiconductor surfaces
Authors: Ohlídal Ivan , Líbezný Milan 
Published: May 2005

AbstractIn this paper, three methods of immersion ellipsometry based on measuring the ellipsometric parameters in air and non‐absorbing liquids are used for analysing silicon, germanium and gallium arsenide single crystals covered with very thin native oxide layers under normal laboratory conditions. If the values of the extinction coefficients of the semiconductors are known with sufficient accuracy, the values of the refractive indices of these semiconductors and the thicknesses and the refractive indices of the effective surface layers can be determined with satisfactory or high accuracy (the effective layer represents a double layer consisting of the native layer and the interface layer). If the values of the optical parameters characterizing the interface layer between the silicon substrate and its native oxide layer are known, the values of both the thickness and the refractive index of the native oxide layer can be determined. The values of all the optical parameters (including the extinction coefficient) of the system formed by a silicon surface covered with the native oxide layer can be determined with good accuracy if the experimental data corrresponding to this system are interpreted together with those corresponding to a silicon surface covered with a thick SiO2 (amorphous) film. This procedure can be used if the values of the optical parameters of the interface layer are known in a reliable way. The methods are applied at a wavelength of 632.8 nm.
An ELS and AES study of InP(100) surfaces during Sb atom condensation
Authors: Gruzza B. , Pariset C. , Abdellaoui S. 
Published: May 2005

AbstractAuger electron spectroscopy (AES) and electron loss spectroscopy (ELS) have been performed in order to investigate InP (100) surfaces subjected to a controlled Sb deposition.The combination of these two electron spectroscopies and a fine analysis of AES signals as a function of surface coverage allows us to propose a model for the formation of Sb/InP interfaces.Indium droplets present on the sample after Ar+cleaning disappear during the first Sb deposit to form an InSb surface compound, which gives the surface great stability.If the deposit is formed at a high temperature after this first stage, no more Sb atoms can be condensed, whereas at room temperature the growth mode is of the Franck Van Der Merwe type.
SIMS of microelectronic structures using a liquid metal ion gun
Authors: Bishop H. E. , Greenwood S. J. 
Published: May 2005

AbstractA 30 keV gallium ion beam with a minimum probe size of 50 nm has been used as the primary beam in the SIMS examination of microelectronic devices. By operating this gun at a 2 nA probe current, 20 μm square pits have been machined through selected areas of a device. The incident angle of the beam is 60°, so that one pit wall forms a 30°taper section through the device. Secondary electron and ion images from this section reveal the subsurface structure in detail. Oxide and nitride layers as thin as 40 mm can be identified readily and traces of fluroine and chlorine from processing have been observed.
Surface analytical scanning electron microscopy in ultrahigh vacuum combined with scanning tunnelling microscopy
Authors: Ichinokawa T. 
Published: May 2005

AbstractA scanning electron microscope of ultrahigh vacuum with a field emission gun is operated at primary energies in the range 100 eV to 3 keV. The instrument can form the images that contain information on surface chemical composition, chemical bonding state (electronic structure) and surface crystal structure at a microscopic resolution of several hundred angstroms (Å) using the techniques of scanning Auger electron microscopy, scanning electron energy‐loss microscopy and scanning low‐energy electron diffraction (LEED) microscopy. Scanning tunnelling microscopy (STM) also has been combined with a SEM in order to obtain the atomic resolution for the solid surface.The instrumentation and examples of their applications are presented both for scanning LEED microscopy and STM.
Application of an STM/SEM instrument for the study of materials: Tip effects and data correlation
Authors: Gómez‐Rodríguez J. M. , Vázquez L. , Baró A. M. 
Published: May 2005

AbstractWe have used scanning tunnelling microscopy (STM) to study the surface topography of several materials in the nanometre range. In order to solve some problems of STM, we have integrated it with a conventional scanning electron microscopy (SEM). The aim of this paper is to analyse critically this combination. We emphasize the importance of tip effects in STM, for which purpose we use the image of the tip obtained by SEM. Also, we correlate the images obtained by both techniques in order to gain insight into the operation of both microscopes. In summary, we find that this combination represents an important step in the study of the surface topography of materials of technological interest.
A new SIMS instrument for submicron microarea analysis
Authors: Nomura S. , Shichi H. , Mitani E. , Izumi E. 
Published: May 2005

AbstractA new type of SIMS instrument has been developed for submicron microarea analysis. The instrument is incorporated with an electron beam, which provides scanning electron microscopy (SEM) images of a sample. The operator determines the area to be analysed by observing the SEM image without damaging the sample, then switches the electron beam to an ion beam and carries out a SIMS analysis of that area. Electron and ion Beams with diameters of <20 nm and <70 nm, respectively, are focused on the sample. Some application data of the micro‐area elemental analysis are presented.
The Auger parameter and the polarization energy: A simple electrostatic model
Authors: Moretti G. 
Published: May 2005

AbstractIn this paper we discuss the core‐hole screening mechanisms in the framework of the model proposed by Veal and Paulikas. If only the polarization of the ligands contributes to the relaxation energy, the non‐local screening mechanism, then the Wagner Auger parameter shifts can be estimated by a simple electrostatic model that takes into account the number, the distance and the electronic polarizability of the first neighbours of the atom with the core hole.The model has been verified for several compounds, comparing the calculated polarization energies with the experimental values obtained via the Auger parameter data taken from the literature. The same approach cannot be applied to systems containing the late transition metal ions for which a local screening mechanism occurs by a charge transfer from the ligand to the spatially localized d levels. The Auger parameter obtained from the main core photoemission peak of the late transition metal ions is almost insensitive to the chemical nature of the ligand itself and the screening energy is similar to that observed in the metallic state. In this case, the relaxation energy can be estimated from the energy separation between the main and the satellite structures in the core photoemission peak.
Quantitative surface analysis (AES) of SiC
Authors: Jørgensen B. , Morgen P. 
Published: May 2005

AbstractWe present an analysis of the critical factors for the determination of surface concentrations from derivative Auger spectra. A new spectroscopic quantity, Pσ2, should supersede the peak‐to‐peak signal. This quantity is the product of the negative‐peak‐to‐background value, P, multiplied by the square of the width of the peak, σ. The method is applied here to Si and C in an SiC sample, but will apply to any multicomponent system. The analysis needs the derivative Auger spectra of the clean components and the sample in question. We also examine relevant changes in material properties between the reference materials and the SiC sample, as several properties of the SiCSiC system vary owing to large differences in atomic densities for the three materials. In this system, lineshapes, back‐scattering of primary electrons and inelastic mean free paths vary for the Auger electrons. Our analysis shows that the lineshape changes could induce errors in directly derived, uncorrected concentrations by factor of 2 (for SiC), while the two other corrections are on the 10% level. With the present method, an Ar ion bombarded surface of SiC shows only a slight enrichment of C, which is much less pronounced than without the corrections.
XPS and UPS studies of gas‐phase oxidation, electrochemistry and corrosion behaviour of Ti and Ti5Ta
Authors: Siemensmeyer B. , Schultze J. W. 
Published: May 2005

AbstractOwing to its high corrosion resistance, Ti is used as a containment material for processes in hot nitric acid. The corrosion stability of Ti can be improved still further by alloying with 5% Ta. The oxidation behaviour of Ti and Ti5Ta and the composition and stability of their oxide layers are compared by means of XPS, UPS, electrochemical measurements and corrosion test. Thin oxide layers of up to 2 nm have been formed by gas‐phase oxidation. Three regions can be observed due to chemisorption, oxide formation and oxide growth. The average composition of the oxide layer after an oxygen exposure of 1000 L is Ti2O3, with a layer thickness of 1.8 nm. The change of Ti oxidation states during oxidation shows that the metal/oxide interface is a mixed oxide of TiO, Ti2O3 and TiO2, while TiO2 is formed at the oxide/vacuum interface. The change of work function during oxidation is similar for Ti and Ti5Ta.Thicker oxide layers have been built electrochemically, with no differences in capacity measurements between Ti and Ti5Ta, indicating similar electronic properties. No significant Ta enrichment in 1 N H2SO4 and 1 N HNO3 is found up to 10 V. Preferential dissolution of Ti in corrosion tests in hot HNO3 leads to Ta enrichments by factors of >10, which explains the improved corrosion stability of the alloy. The surface is covered by a barrier oxide of ∼10 nm and a porous outer layer with a thickness of >50 nm.