bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulsed laser induced ablation applied to epitaxial growth of semiconductor materials: Selenides and tellurides plume analysis
Authors: Teghil R. , Guidoni A. Giardini , Mele A. , Piccirillo S. , Coreno M. , Marotta V. , Di Palma T. M. 
Published: May 2005

AbstractIn this study the analysis of ionic and neutral species produced by the interaction between laser radiation and SnSe and SnTe targets is reported. Time of flight mass spectrometry and emission spectroscopy are used for the characterization of the ablated material. Relations between target and plume composition are discussed in order to improve the understanding of the laser deposition process.
Initial growth of AlN on clean and oxidized iron studied by AES and EELS
Authors: Malengreau F. , Vermeersch M. , Sporken R. , Philippe L. , Han B. Y. , Caudano R. 
Published: May 2005

AbstractWe have studied by Auger electron spectroscopy (AES) and electron energy loss spectroscopy (EELS) the room temperature growth of aluminium nitride (AlN) at the surface of clean and oxidized polycrystalline iron. The films were deposited by reactive rf‐sputtering in an N2‐Ar atmosphere. Very low coverages were possible thanks to a precise partial pressure controller based on electron impact emission spectroscopy (EIES).The AlN/Fe interface study has revealed the formation of an iron nitride at the surface of the substrate and of a compound close to AlN as a first monolayer. AlN clusters grow directly on this nitride layer and we did not detect the formation of any alloy between iron and aluminium. A modelization of the AES signal intensities suggests a Stranski‐Krastanov growth mode.For the oxidized iron, Auger lines showed an Fe2O3 surface layer on an Fe3O4 film oxide. The former oxide was reduced to Fe3O4 by the incoming aluminium which forms a two‐phase film made of Al2O3 and AlN resulting in an (AlN)x(Al2O3)1‐x stoichiometry. The concentration of this oxide phase decreases after the diffusion of the oxygen stops. Pure AlN begins to grow on this two‐phase film.
Investigation of CdS passivation layers on Hg1−xCdxTe
Authors: Kačiulis S. , Mattogno G. , Viticoli S. , Marini M. E. , Cesqui F. , Alfuso S. , Mercuri A. 
Published: May 2005

AbstractCdS thin films were deposited on sapphire substrates and on the HgxCd1‐xTe epitaxial and single crystal samples by using chemical decomposition on thiourea and anodic non‐aqueous sulphidation techniques, respectively. The chemical composition and depth profiles of deposited films were investigated by selected area XPS combined with Ar+ ion sputtering. Lateral homogeneity of CdS films was studied by using scanning Auger microscopy. Nearly stoichiometric CdS films were obtained on sapphire and HgxCe1‐xTe. The thickness, chemical composition and sputtering rate at 2 keV ion energy were determined from XPS data. In both cases (either deposited on sapphire or on HgxCd1‐xTe) the CdS films were found to be very non‐homogeneous in thickness.
An XPS study of diamond films grown on differently pretreated silicon substrates
Authors: Arezzo F. , Severini E. , Zacchetti N. 
Published: May 2005

AbstractX‐ray photoelectron spectroscopy was used to investigate how different pretreatments modify the chemical composition and bonding on silicon substrate surface and, to detect the intermediate phases present at the diamond film interface. The pretreatments were mechanical scratching with a diamond powder, ultrasonic abrasion with diamond suspension and in situ negative dc biasing. The XPS results indicated the presence of hydrocarbons and the formation of new chemical species on the Si substrates such as oxides and carbides. The very important role played by silicon carbide on diamond nucleation and growth was underlined by the phases found at the diamond films interface.
Characterization of nanophase powders prepared by laser synthesis
Authors: Giorgi R. , Martelli S. , Turtù S. , Zappa G. , Borsella E. , Botti S. 
Published: May 2005

AbstractSibased (SiCN and SiCAl) nanopowders prepared by laser synthesis process have been studied by XPS and XAES analyses.The changes of the silicon coordination as a function of the carbon fraction in SiCN powders have been investigated by a detailed analysis of Si 2p and Si KLL lines and the measurements of the Auger parameter Ek(Si KLL) + Eb(Si 2p). The non‐linear dependence of the Auger parameter on the carbon fraction has been interpreted as due to the formation of a carbonitride nanophase, indicating that the ternary powders are not merely a mixture of silicon carbide and silicon nitride.In SiCAl powders it has been found that the incorporation of aluminium results in a modified structure of the silicon carbide, as shown by the variation of the different spectral features.
Surface versus bulk composition of a phosphate glass
Authors: Meisel W. , Sprenger D. , Gütlich P. 
Published: May 2005

AbstractTransmission and conversion electron Mössbauer spectroscopy as well as photoelectron spectroscopy were applied to study alterations of the surface layer of an iron containing industrial phosphate glass as compared with its bulk. In the surface layer, after polishing and exposure to ambient atmosphere, Fe2+ is partially oxidized to Fe3+. This oxidation, however, does not increase the O/P ratio in this layer, because it goes along with a strong leaching of network modifiers. This leaching leads to a net decrease of the O/P ratio because it overcompensates the relative oxygen increase by Fe2+ oxidation and by uptake of water.
Investigation of the thermal degradation of polyacrylonitrile on various glasses
Authors: Keller B. A. , Löwe Ch. , Hany R. 
Published: May 2005

AbstractThe thermal degradation of adsorption layers of polyacrylonitrile (PAN) on the surface of Schott 8330 and Schott 8512 glass was investigated by Fourier transform infrared spectroscopy (FTIR), 13C magic angle spinning solid state nuclear magnetic resonance spectroscopy with cross‐polarization (CP‐MAS NMR), and thermal gravimetric analysis (TGA). In contrast to the neat polymer, dehydrogenation of PAN on a glass surface takes place in an inert atmosphere. In the case of Schott 8512 glass (3% FeO) under oxidizing conditions we observed a complexation of nitrile groups to surface species.
Surface structure of AlSn layered systems codeposited in the presence of oxygen
Authors: Kövér L. , Némethy A. , Barna P. B. , Adamik M. 
Published: May 2005

AbstractAlSn layer structures were prepared by simultaneous evaporation of Al and Sn onto a Si substrate covered by amorphous SiO2, at a substrate temperature of 470–480 K and an oxygen partial pressure of 5 × 10−3 Pa and 1.3 × 10−2 Pa, respectively. The chemical state and the depth distribution of the species formed in the surface layers were analysed by XPS and the cross‐section of the layer system was investigated by transmission electron microscopy. The results obtained confirm the formation of an AlOSn solid phase, segregated to the surface, which prevents the growth of various size Al crystals. At higher oxygen partial pressures a cermet‐like structure is observed above the Al film‐substrate interface, while on the top of this layer an amorphous, homogeneous overlayer can be identified.
Impurity segregation in an Fe‐3.5 at.%Si bicrystal
Authors: Reichl B. M. , Eisl M. M. , Böhmig S. D. , Störi H. 
Published: May 2005

AbstractIn polycrystalline materials, the segregation kinetics is determined by complex transport phenomena like grain boundary diffusion, volume diffusion and surface diffusion. A fundamental investigation of these phenomena was performed, studying the simplest model system, which provides two grains and a well defined grain boundary. In the temperature range between 600 and 750 °C the segregation of Si, P and S in an Fe‐3.5 at.%Si bicrystal was investigated by means of AES. In early segregation runs, diffusion of P and S out of the grain boundary accompanied the segregation via bulk diffusion, while in later runs a combined bulk and surface diffusion was found. Model calculations were performed to analyse the segregation kinetics of subsequent segregation runs.
Evaluation of temperature‐dependent surface chemistry in Zr2Fe and ZrVFe via X‐ray photoemission spectroscopy
Authors: Kovač J. , Sakho O. , Manini P. , Sancrotti M. 
Published: May 2005

AbstractThe near atomic composition and the character of chemical bonds in two non‐evaporable gettering alloys have been investigated via core level (Zr 3d; Fe 2p; V 2p; O 1s; C 1s) XPS (hv = 1253.6 eV). The samples have been measured in UHV after in‐air fracturing and various annealing steps (up to 850 °C). For T > 400 °C a progressive and sizeable decrease of the near surface C content along with an increase in the Zr concentration is observed in both alloys. An annealing‐induced Zr enrichment at the surface is found, the metallic atomic concentrations being permanently far from the nominal bulk stoichiometry. The annealing induces a strong evolution in the chemical bonds, the metallic species being completely oxidized in‐air fractured samples while progressively emerging a metallic character at increasing temperatures. Surface metallization proceeds faster in Zr2Fe than in the V‐containing getter.
Advances in Auger microanalysis for semiconductor technology
Authors: Pamler W. 
Published: May 2005

AbstractSemiconductor technology issues some of the most intriguing challenges for Auger analysis. The minimum feature size is approaching the quarter‐micron range, while simultaneously, the vertical dimension is being utilized for further integration resulting in an extremely nonplanar surface after numerous processing steps. Although the ultimate limitations of Auger electron spectroscopy combined with sputter depth profiling (lateral resolution < 100 nm, depth resolution < 3 nm) are compatible with such advanced processes, the analysis is often restricted by sample‐related issues. An example is a depth profile through an Al/TiN/Ti metallization system which, under routine analysis conditions, has a depth resolution as poor as several hundred nanometers. Similarly, the lateral resolution accessible in the microanalysis of the sidewall of a conductor line is considerably degraded by scattering of primary electrons into adjacent areas, or the thickness of an oxide film found at the bottom of contact or via holes cannot be determined by sputter profiling because of shadowing of the ion beam and deposition of sputtered material from the sidewall to the bottom.This paper illustrates that, nevertheless, answers for such difficult analytical tasks can be found by careful optimization of analysis conditions, by simple but unconventional modification of the Auger instrument, or by novel data evaluation methods. With these results, significant input can be provided for process engineering and failure analysis in semiconductor technology.
Low‐energy field emission Auger electron spectroscopy
Authors: Forsyth N. M. , Bean S. 
Published: May 2005

AbstractAs one of the most powerful surface analytical techniques, Auger electron spectroscopy (AES) has repeatedly shown itself to be invaluable in solving problems involving submicron spatially resolved features. Recent developments of this technique towards higher spatial resolution at low primary beam energies and high‐sensitivity chemical state analysis have extended the application of AES as a problem‐solving tool.The MICROLAB 310‐F from Fisons Instruments (VG Scientific) uses a Schottky field emission source and optimized electron optics to give unparalleled performance at low primary beam energies (3 keV or less) and up to 50 times the usable beam current density when compared to a conventional LaB6 emitter. Two examples of analysis of small features will be shown, demonstrating the advantages of a low primary beam energy for AES analysis.
Secondary ion mass spectrometry of SiGe structures grown by surfactant‐mediated epitaxy and by low pressure chemical vapour deposition
Authors: Herion J. , Siekmann H. , Voigtländer B. , Vescan L. 
Published: May 2005

AbstractGermanium–silicon heterostructures grown by surfactant‐mediated epitaxy and GexSi1 − x/Si quantum well structures grown by low pressure chemical vapour deposition have been in investigated by secondary ion mass spectrometry (SIMS) using a low energy (2 keV) Cs+ primary beam and detecting negative secondary ions. Depth profiles have been obtained for both types of samples at angles of incidence of 10° and 60° (off normal). Due to the low bombardment energy, the depth resolution was sufficient to resolve the quantum wells, but pronounced matrix effects and interface transients of the secondary ion yield were observed at 10°. It was found that the artefacts are considerably reduced at 60°. It is shown that well‐known qualitative concepts relating to the Cs concentration at the surface can explain most aspects of the results.
Silicon‐insulator interface probing by reflected optical second harmonic generation
Authors: Kravetsky I. V. , Kulyuk L. L. , Micu A. V. 
Published: May 2005

AbstractOptical second harmonic generation (SHG) has been applied to the study of the silicon–insulator (SI) interface. Results from real‐time measurements of the SHG intensity during etching process of SiO2 and Si3N4 insulator layers are presented and analysed taking into consideration various contributions to the nonlinear polarization in the SI interface such as the silicon substrate, the static electric field, the inhomogeneous deformation and the crystalline oxide interlayer. The symmetry properties of the silicon–insulator interface have also been determined by an analysis of the SHG rotational dependences.
Characterization and reliability of Ti/Ni/Au, Ti/Ni/Ag and Ti/Ni back‐side metallizations in the die‐bonding of power electronic devices
Authors: Scandurra A. , Porto A. , Mameli L. , Viscuso O. , Del Bo V. , Pignataro S. 
Published: May 2005

AbstractThe surface compositions of three different back‐side metals: Ti/Ni/Au 0.1/0.4/0.1 μm, Ti/Ni/Ag 0.1/0.4/0.1 and 0.1/0.4/2 μm and Ti/Ni 0.1/04 μm after thermal treatment at 180°C in air were investigated by means of XPS technique. In the Ti/Ni/Au metal the Ni diffusion through the Au layer was observed, while in the Ti/Ni/Ag metal Ni was not found on the silver surface. Ti/Ni/Ag was found to be sensitive to contamination from elements such as sulphur and chlorine found on the silver surface after thermal treatment, while Ti/Ni metal is sensitive to oxidation. NiO, Ni(OH)2, NiOOH and Ni2O3 species were found on the Ni as deposited surface. The surface compositions were correlated to their wetting property using the Pb88Sn10Ag2 and Pb95.5Sn2Ag2.5 wt.% soft solder alloys. The wetting was studied measuring the contact angle between the surface and the drop of molten solders.
SIMS and X‐ray diffraction characterization of carbon‐doped GaAs, AlxGa1 − xAs films grown by MBE
Authors: Gerardi C. , Giannini C. , Tapfer L. , Fischer A. , Ploog K. H. 
Published: May 2005

AbstractIn this article we report on analyses of GaAs and AlxGa1 − xAs carbon‐doped films, grown by solid source molecular beam epitaxy by using secondary ion mass spectrometry, x‐ray diffraction, and Hall effect measurement.Carbon is an amphoteric dopant, i.e. it behaves as an acceptor or a donor impurity when it occupies an As or a Ga site, respectively. Comparison between x‐ray diffraction and Hall effect measurements indicates that, for concentrations below 4 × 1019 cm−3, carbon is preferentially incorporated on As site, both in GaAs and AlxGa1 − xAs layers. We find that the presence of Al strongly enhances the substitutional carbon incorporation. SIMS analyses show that the total amount of carbon largely exceeds the substitutional carbon content recorded by HRDXD. The results can be explained considering that carbon is on substitutional as well as interstitial sites. Furthermore, we show that the interstitial carbon concentration can be reduced for both GaAs:C and AlxGa1 − xAs:C growing at an increased As4 flux and higher substrate temperature.
XPS analysis of sol‐gel processed doped and undoped TiO2 films for sensors
Authors: Zanoni R. , Righini G. , Montenero A. , Gnappi G. , Montesperelli G. , Traversa E. , Gusmano G. 
Published: May 2005

AbstractWe have used x‐ray photoelectron spectroscopy (XPS) to probe the actual surface composition of alkali‐doped and undoped TiO2 films prepared by the sol‐gel technique. The role of thermal pretreatments, conducted at various temperatures, and the effect of doping with Na are discussed. XPS results are compared with the electrical response of prototype devices having TiO2 films as the active element, with the help of electrochemical impedance spectroscopy (EIS) measurements.
Interfacial phenomena in PbBiSrCaCuO/Ag and AgIn: Wettability, AES and XPS studies
Authors: Polak M. , Baram J. , Froumin N. 
Published: May 2005

AbstractTwo complementary approaches have been applied to the study of interfacial processes between PbBiSrCaCuO ceramic and silver or silver alloys. One is based on wettability measurements of molten silver (and silver–indium) using the sessile‐drop technique (at 950 °C) followed by AES analysis, and the other approach uses XPS/depth profiling of silver films on PbBiSrCaCuO annealed at 20–700 °C. Extensive interfacial interactions and diffusion processes occur in these systems, which lead to enhanced wettability. Such phenomena are correlated with previously reported electrical properties and are relevant to the optimization of metal/superconductor composite materials and device applications.
Characterization of MoOx/ZrO2 system by XPS and IR spectroscopies
Authors: Gazzoli D. , Prinetto F. , Campa M. C. , Cimino A. , Ghiotti G. , Indovina V. , Valigi M. 
Published: May 2005

AbstractMoOx/ZrO2 samples (Mo content, 0.7 to 4.0 atoms nm−2) have been investigated by XPS and Fourier transform Infrared (FTIR) spectroscopies. After heating in O2 (773K), XPS shows the presence of MoVI species; while the IR analysis shows bands in the 830–1012 cm−1 region, arising from MoVI species of various nuclearity. In the early stages of the reduction (H2 at 500 K) both XPS and IR show the formation of MoV. In agreement with previous ESR results, the intensity of IR and XPS bands from MoV does not appreciably change by further increasing the extent of reduction up to 803 K. On extensively reduced samples, both IR and XPS show the presence of MoIV in addition to MoVI and MoV. Upon NO adsorption at RT, dinitrosyls of MoIV were detected by IR. A further rise in the extent of reduction with H2 at 803 K, led to a drop in the intensity of the IR band from MoIV and XPS detected Mo metal.
High temperature corrosion characterization by the combined use of surface microsurgery and surface analysis
Authors: Bennett M. J. 
Published: May 2005

AbstractCharacterization of both the chemical and physical nature of interactions at interfaces is crucial to mechanistic understanding of the behaviour of metallic and ceramic materials, including coatings, in aggressive environments at high temperatures. This can be achieved post exposure by the use of defined surface analytical techniques but is reliant upon the deployment of appropriate surface microsurgery procedures, such as metallography, fractography, taper section polishing, selective etching, complete dissolution, etc., for the preparation of surfaces prior to analysis. Recent studies undertaken at the Harwell Laboratory on the combined use of surface microsurgery and surface analysis in the characterization of high temperature corrosion attack are reviewed. These have aimed to improve the precision and the effectiveness of surface microsurgery procedures to ensure the optimum exploitation of the capabilities of surface analytical techniques, especially those in more common usage, such as scanning electron microscopy, electron probe microanalysis, laser Raman spectroscopy, secondary ion mass spectrometry, etc. Although most of the examples presented are of thick (> 1 μm) corrosion scales and of internal attack, several of the surface microsurgery procedures have relevance to the analysis of sub‐micron layers.
Surface analytical investigations of Al and (Ti, Al) nitrides formed by ion implantation and their corrosion properties
Authors: Simson S. , Heide N. , Schultze J. W. 
Published: May 2005

AbstractNitrides of Ti, Al and TiAlx alloys were prepared by low energy ion implantation (3 keV N2+). The layer thickness was ∼ 10 nm. The nitride layers were characterized using XPS, UPS and a Kelvin probe. The insulating properties known for bulk AlN were found also for the prepared AlNimpl layers. The work functions for the alloys and the nitrides and their variation with the ion dose were determined. Peak parameters for the XP spectra deconvolution were established. Despite their thinness, the layers showed anodic stability in 0.5 M H2SO4 up to 1.3 V (SHE) for (TiAl)Nimpl and even up to 1.8 V (SHE) for AlNimpl. Above these potentials, the nitrides were oxidized to metal oxides.
Non‐destructive characterization of chromium phosphate coated aluminium with SE and FTIRS correlated to surface analytical analyses by AES and TEM
Authors: Goeminne G. , De Laet J. , Terryn H. , Vereecken J. 
Published: May 2005

AbstractNon‐destructive optical investigations (SE and FTIRS) of chromium phosphate conversion layers on aluminium are correlated to AES and TEM investigations. The AES results support the duplex model of the structure. FTIR‐spectra provide a non‐destructive characterization in agreement with the Auger data. Fitting the SE‐data with a proper model makes it possible to determine the thickness accurately. A correlation is made between the thickness obtained with SE, FTIRS and AES. It is shown that for thin layers a good agreement is obtained.
Theoretical and experimental study of the infrared reflectance of multilayer oxide films on metals
Authors: Lefez B. , Lenglet M. 
Published: May 2005

AbstractTheoretical calculations have been made for different single and duplex systems (Cr2O3/Fe, MnCr2O4/Fe, MnCr2O4/Cr2O3/Fe and Cr2O3/MnCr2O4/Fe) in order to study the initial stages of high temperature oxidation of AISI 304 and 316 stainless steels by FTIR specular reflectance spectroscopy at variable incidence. Used in conjunction with physical methods like SIMS or AES, the vibrational spectroscopy gives access to structural and compositional information in the analysis of multilayer systems with a high level of complication.
Analytical and electrochemical study of passive films formed on nickel—chromium alloys: Influence of the chromium bulk concentration
Authors: Boudin S. , Vignes J‐L. , Lorang G. , Da Cunha Belo M. , Blondiaux G. , Mikhailov S. M. , Jacobs J. P. , Brongersma H. H. 
Published: May 2005

AbstractDepth composition and chemical states of elements constituting the overlayers of NixCr alloys (x = 0–30 at.%) passivated in borate buffer solutions (pH = 9.2) were determined as a function of the chromium bulk content of the alloy. Depth sputter profiling was performed using both Auger electron spectroscopy (AES) and low energy ion scattering spectroscopy (LEIS). Chemical bonding and (oxy‐hydroxy) structures of alloying elements in the passive films were investigated by x‐ray photoelectron spectroscopy (XPS). The electrochemical study mainly consists in establishing the cathodic reduction kinetics of the passive layers to characterize the resistance of the internal Cr2O3 barrier to reduction.Very thin films (less than 2.5 nm) were obtained in those conditions showing duplex structures where minor external nickel oxy‐hydroxide layers are depicted covering an inner protective barrier mainly composed of chromium oxide Cr2O3. Only at high bulk chromium contents (> 15 at.%) are complete Cr2O3 layers built at the interface with the metallic alloy. Beneath the film, in the underlying matrix, a metallic nickel enrichment combined with a chromium depletion is observed, which seems to confirm, as for FeCr alloys, a mechanism by which Cr oxidizes preferentially in this medium during the first steps of the film growth.