bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deposition of MgO/Au cermet films by triode sputtering and their characterization
Authors: Ritz Victor H. 
Published: December 2004

AbstractCermet films, which consist of a mixture of insulator and metal microcrystals, have been suggested as a way to achieve high secondary‐electron emission with good electrical conductivity in cathodes for high‐power microwave tubes. We have radio frequency (rf) sputtered 75% MgO and 25% Au (mol.%) films, 4000 Å thick, from composite targets in a turbopumped ultrahigh vacuum system. A triode sputtering source operated at 1.8 mTorr Ar pressure provided high deposition rates (60 Å min−1) over the surface of a cylindrical cathode that was rotated slowly to insure uniform deposition. The low pressure of the triode sputtering source enabled one to operate in a region of the Thornton structure‐zone diagram (J. Vac. Sci. Technol. 11, 666 (1974)) conductive to the formation of densely packed grains (zone T). The cathode substrate was sputter‐etched before film deposition to remove the surface oxide and contamination, and the deposited cermet was lightly sputtered afterwards with low‐energy Ar ions to enhance the surface MgO concentration by preferential sputtering. The resulting films were characterized by AES and SEM as to their bulk chemical composition, surface contamination, film morphology and thickness. The deposition rate in a geometry in which a small, relatively inexpensive, disk‐shaped target was used to coat a larger cylindrical substrate could be approximated by correcting an average planar deposition rate for the difference in areas. The films showed no evidence of a porous columnar structure but were finely grained and densely packed. Films deposited on Type 304 stainless‐steel substrates adhered well and passed simple adhesive tape tests. The films were the same composition as the sputtering target, with no bulk C contamination or impurity migration from the substrate.
Characterization of nitrogen distribution profiles in fcc transition metal nitrides by means of Tc measurements
Authors: Lengauer Walter 
Published: December 2004

AbstractThe suitability of characterizing the nitrogen distributions in near‐surface regions of compact samples of TiN, ZrN, HfN, VN and NbN by means of a series of inductive Tc measurements with successive etching was investigated. The distribution profiles could be determined for TiN, ZrN and VN with an accuracy exceeding that of established microanalytical tools. One problem encountered in the characterization process was the non‐isotropic removal of layers. For HfN and NbN, nitrogen profile measurements were not possible because of the intrinsic Tc behaviour.
Water interactions in Al/PET
Authors: Chtaïb M. , Peremans A. , Novis Y. , Caudano R. , Butaye L. , Adams F. , Lutgen P. , Feyder G. 
Published: December 2004

AbstractTwo cases of water interaction with virgin PET and with metallized (Al) PET were studied using thermal desorption spectroscopy (TDS) and dynamic secondary ion mass spectrometry (SIMS), respectively. On the one hand, the TDS approach tends to show that the water is weakly bound to the polyester (∼ 10 kcal mol−1); on the other hand, the SIMS study performed on metallized PET shows an enhancement of the water concentration around the interface. These results are discussed in order to elucidate the presence of such moisture and its influence on the metal/polymer adhesion and corrosion.
XPS investigation of anodic oxides grown on p‐type InP
Authors: Faur Maria , Faur Mircea , Jayne D. T. , Goradia M. , Goradia C. 
Published: December 2004

AbstractChemical composition of anodic oxides grown on lightly doped p‐type InP have been investigated by XPS. Anodization was performed in the constant current density (Jc) mode using an ortho‐phosphoric acid solution mixed with acetonitrile (ACN). The electrolyte was chosen after experimentation on the effect of the anodization parameters (electrolyte, viscosity of the electrolyte and pH,Jcand illumination level) and annealing conditions on the uniformity and stability of the oxide and the contamination level, as determined by SEM/EDAX, SIMS and XPS. Based on our XPS investigation, it appears that the inhomogeneity with depth of the anodic oxides grown on p‐type InP is strongly dependent on the growth conditions. Depending on the anodization procedure, the anodic oxide appears complex and the presence of In(OH)3, In2O3, InPO4, In(PO3)3, In(PO3)4and other non‐stoichiometric In(POy)xcompounds have been identified. Depending on the anodization conditions, it appears that both amorphous and crystalline phosphorus‐rich condensed phosphates, of interest for surface passivation of InP, can be grown on p‐type InP.
Interpretation of surface textural changes in SrTiO3 ex‐oxalate samples using XPS and IR spectroscopies
Authors: Munuera G. , Gonzalez‐Elipe A. R. , Espinos J. P. , Lopez‐Molina E. 
Published: December 2004

AbstractXPS, IR and x‐ray diffraction (XRD) have been used to study high‐surface‐area ‘ex‐oxalate’ polycrystalline SrTiO3 materials. Changes of surface area and pore size distribution are induced during lixiviation with a 0.1 M HCl solution, which removes carbonate impurities. The study shows the presence in the original sample of a microcrystalline SrCO3 phase at its surface and isolated CO species, these latter remaining even after outgassing at 773 K for 15 h. However, a complete elimination of the SrCO3 and other carbonate species at the surface is achieved by heating the acid‐lixiviated sample at 773 K, although carbonate species still remain in the bulk of the SrTiO3 material after this treatment. The usefulness of the combined use of XPS and IR for the characterization of surface and bulk species in this type of powdered material is pointed out during this study.
Spectral properties of the Al and Mg Kα1 lines determined by the PAX method
Authors: Richter K. H. 
Published: December 2004

AbstractThe Lorentzian widths and the spin‐orbit separation of the Al and Mg Kα1 lines have been studied, using photoelectron spectroscopy for the study of x‐rays10 and neon and argon as converter atoms. The natural widths of the title lines have been determined. The recommended properties of the Al and Mg Kα1 lines are collected in Table 3.
Study of surface passivation of InP
Authors: Faur Mircea , Faur Maria , Jenkins Phillip , Goradia Manju , Bailey Sheila , Jayne Douglas , Weinberg Irving , Goradia Chandra 
Published: December 2004

AbstractThe effects of various surface preparation procedures, including chemical treatments in HF, HNO3,o‐H3PO4and H2SO4solutions and anodic oxidation, on the passivating properties of InP have been investigated in order to optimize the fabrication procedures ofn+porp+nInP solar cells made by thermal diffusion. The InP substrates used in this study werep‐type Cd‐doped to a level of 1.7 × 1016cm−3, Zn‐doped to levels of 2.2 × 1016and 1.2 × 1018cm−3andn‐type S‐doped to 4.4 × 1018cm−3. The passivating properties have been evaluated from photoluminescence (PL) data; good agreement was found between the level of surface passivation and the composition of different surface layers as revealed by x‐ray photoelectron spectroscopy (XPS) analysis.
Determination of the atomic mixing layer in sputter profiling of Ta/Si multilayers by TEM and AES
Authors: Hofmann S. , Mader W. 
Published: December 2004

AbstractSputter‐deposited multilayers of Si and Ta with a nominal period length of a double layer (Ta + Si) of 20 nm were studied with AES depth profiling and with transmission electron microscopy (TEM). The asymmetric shape of the measured Si layer profiles was fitted to model calculations based on preferential sputtering of Si and an atomic mixing zone length of 4 nm for 3 keV Ar+ ions at a 36° incidence angle. TEM images of cross‐sections of the original sample show sharp Si/Ta and Ta/Si interfaces, with a width of ∼ 0.5 nm. The atomic mixing zone length of the sputter‐profiled sample was observed directly by TEM and was determined to be 4.0 nm, in accordance with the AES profile evaluation. It is concluded that the observed asymmetric broadening of the shape of the measured AES sputtering profiles is due mainly to atomic mixing and is enhanced by preferential sputtering of Si.
XPS analysis of passive films on the amorphous alloy Fe70Cr10P13C7: Effect of the applied potential
Authors: Rossi A. , Eisener B. 
Published: December 2004

AbstractPassive films formed in 1N HCI at different potentials on mechanically polished samples of the alloy Fe70Cr10P13C7 were studied by XPS surface analysis. The thickness of the films increases with the applied potential; at 0.4 V/SCE (saturated calomel electrode) a discontinuity is observed. The passive films are enriched in chromium oxyhydroxide; phosphates are incorporated in notable amounts. The substrate underneath the film is enriched in phosphorus. The outstanding corrosion resistance of this alloy may thus be attributed to this enrichment of phosphorus underneath the film, reducing to a great extent the ionic conductivity of the interface, and to the incorporation of phosphates in the passive film.
Calibration of a basic secondary ion mass spectrometer, by means of elastic recoil detection, for hydrogen isotopes implanted into graphite
Authors: Paynter R. W. , Turgeon S. , Sabet‐Sharghi R. , Leblanc L. , Pageau J. F. , Ross G. G. 
Published: December 2004

AbstractA secondary ion mass spectrometer equipped with a low‐resolution argon ion source and a small quadrupole ion mass analyser was calibrated for moderate to high concentrations of hydrogen and deuterium in graphite. The polished graphite samples were implanted with hydrogen isotope ions of 1 or 2 KeV energy. The depth profiles of the implanted hydrogen were determined by means of elastic recoil detection (ERD) and compared with those obtained by SIMS. Linear correlations were found between the peak D+/C+ or CH+/C+ ratio and the maximum D or H concentration determined by ERD, as well as between the integral of the SIMS profile curves and the total quantity of hydrogen isotope.
SIMS imaging studies of the corrosion of alloy 800 and alloy 600 surfaces under secondary side boiler conditions
Authors: McIntyre N. S. , Davidson R. D. , Weisener C. G. , Taylor K. R. , Gonzalez F. C. , Rasile E. M. , Brennenstuhl A. M. 
Published: December 2004

AbstractThe nickel‐rich superalloys Alloy 600 and Alloy 800 have been corroded in mildly alkaline deuterated aqueous conditions typical of secondary coolant circuits in a nuclear power station. The oxide films and substrates of these alloys have been analysed by imaging SIMS depth profiling, which makes it possible to describe elemental distribution in all three dimensions. The measurement of the distribution of the secondary ions NiO−, FeO− and CrO− appears useful for detailing the behaviour of nickel, iron and chromium within oxidized phases. The measurement of D− distribution outlines the extent of oxide hydration. For Alloy 800, evidence of sodium migration into the grain boundaries of the alloy substrate is found. For Alloy 600, no grain boundary sodium ingress can be identified under comparable corrosion conditions.
Separation of sample geometry and material effects within the secondary electron cascade: Preliminary results for gold
Authors: Crone M. , Barkshire I. R. , Prutton M. 
Published: December 2004

AbstractExperimental results are reported for the energy‐analysed angular distributions of the secondary electron cascade with energies from 200 eV up to 2450 eV using an incident beam energy of 20 keV and samples of Au and Au on Si. These angular distributions are compared to those of the Auger electron emission of the same samples. The dependence of the shape of the secondary electron cascade on the angle of incidence and the take‐off angle to the analyser is examined. In the case of Au, the results are reported for a bulk and a layered specimen consisting of a thin Au film on an Si substrate. It is concluded for these samples that the contributions of the sample geometry and atomic number to the shape of the electron spectrum can be separated within a power law description of the secondary electron cascade.
Scanning probe microscope imaging of polyaniline thin films in non‐contact mode
Authors: Porter T. L. , Sykes A. G. , Caple G. 
Published: December 2004

AbstractThe structure of electropolymerized thin films of polyaniline has been studied using the techniques of contact and non‐contact scanning probe microscopy (SPM). Films exposed to Ir+ cations in solution, as well as unexposed films, were examined. Contact‐mode SPM images of these films reveal only a diffuse, amorphous surface structure in both types of film, while non‐contact SPM images indicate an intricate, nanometer‐scale domain structure. Film growth is in a layer‐by‐layer mode, with each layer consisting of small polymer bundles of average dimension 1000 ± 75 Å. The Ir+ incorporation in these films does not involve a restructuring of the film morphology. The relevance of the microscopic domain structure to models describing conduction mechanisms in these films is also discussed.
Applications of focused ion beams in microelectronics production, design and development
Authors: Stevie F. A. , Shane T. C. , Kahora P. M. , Hull R. , Bahnck D. , Kannan V. C. , David E. 
Published: December 2004

AbstractFocused ion beam (FIB) systems using gallium liquid metal ion sources can remove material with a lateral resolution below 50 nm and can produce metal deposition at a similar resolution with ion beam‐enhanced chemical vapour deposition. These capabilities have resulted in many valuable applications for the microelectronics industry. Circuit modifications are possible because existing connections can be severed and reconnected to different locations. Testing of circuitry can be enhanced by isolation of specific circuits, removal of overlayers and by creation of probe pads where desired. Grain sizes can be determined from secondary electron images by the delineation of individual grains due to orientation‐dependent channeling of the ion beam. Secondary ion mass spectrometry analyses of small areas can provide ion images, elemental identification of small areas and endpoint detection with depth profiles. Scanning electron microscopy and transmission electron microscopy sections are prepared routinely using the FIB. These FIB‐prepared sections are notable because specific features, such as defects, can be exposed and a range of materials including silicon, indium phosphide, gallium arsenide and even metal layers can be cut without distortion. Transmission electron micrographs of superior quality have been obtained with a large area of very uniform thickness that permits identification of features such as areas under stress.
Surface characterization of SiC mirrors exposed to fast atomic oxygen
Authors: Raikar Ganesh N. , Gregory John C. , Partlow William D. , Herzig Howard , Choyke W. J. 
Published: December 2004

AbstractTwo chemical vapor deposited silicon carbide (SiC) mirrors were exposed to the 5 eV fast atomic oxygen environment in low Earth orbit on NASA's Long Duration Exposure Facility (LDEF) which remained in space for nearly 6 years. The samples were characterized using the techniques of x‐ray photoelectron spectroscopy (XPS), ellipsometry, and reflectance measurements. The normal‐incidence optical reflectance of the atomic‐oxygen‐exposed portion of one sample degraded considerably over the 60–160 nm span. The XPS results showed the presence of SiO2‐like species, the thickness varying from 1 to 8 nm depending upon the location of the samples on the spacecraft. The XPS results are in good agreement with those from ellipsometry measurements.
Angle‐resolved XPS study of plasma‐treated teflon PFA surfaces
Authors: Shi M. K. , Martinu L. , Sacher E. , Selmani A. , Wertheimer M. R. , Yelon A. 
Published: December 2004

AbstractTeflon PFA (polytetrafluoroethylene‐co‐perfluoroalkoxy vinyl ether) was treated by a low‐pressure microwave (2.45 GHz) plasma in O2, N2, H2, He and their mixtures. X‐ray photoelectron spectroscopy measurements showed ablation of fluorine and incorporation of new O‐ and N‐containing groups into the surface. Among the different gases, H2 is the most efficient for defluorination, N2 + H2 for surface functionalization, while O2 showed the least performance for both effects. Plasma treatments using N2 + H2 and O2 + H2 resulted in intermediate defluorination, i.e. between those in the pure gases, and sequential treatment by He/(N2 + H2) showed an additive effect of He and N2 + H2 alone. Angle‐resolved XPS measurements revealed a pronounced gradient in the near‐surface composition following H2, N2 + H2 and He/(N2 + H2) plasma treatments, in contrast to a more uniform depth distribution upon O2, N2 and He exposures. The surface modification of Teflon PFA leads to an enhanced adhesion of metals such as Cu, Ag and Au.
Experimental requirements for surface charge spectroscopy (SCS) measurements. Examples of SCS measurements on high‐ and low‐resistivity Si samples
Authors: Ermolieff A. , Charrasin V. , Marthon S. , Piaguet J. , Deleonibus S. 
Published: December 2004

AbstractThe surface charge spectroscopy (SCS) method investigated by x‐ray photoelectron spectroscopy is used with structures such as semiconductors covered with a thin dielectric layer to estimate the electrical quality of the dielectric film and to determine approximately the breakdown voltage of the dielectric and the interface state density between the semiconductor and the insulator.The experimental conditions for SCS measurements were investigated and the most important error sources, inducing imprecise or wrong results, were established.Because of the nature of the sample, binding energy reference is one of the most important points for validity of these measurements. The effects on the determination of the Si 2p photoelectron line position due to bad electrical contact between the spectrometer and the semiconductor, with and without its native oxide film, were studied.Surface potential modifications when low‐energy flood gun electrons are injected into the dielectric surface were also studied as a function of semiconductor resistivity. Because it is often necessary in SCS measurements to bias the sample, this point was also considered.Three SCS measurements are reported, two on similar low‐resistivity samples to check reproducibility of the measurements and one on a high‐resistivity sample. It is shown that the determination of the interface state density is uncertain in the case of high‐resistivity samples and how confident it is possible to be in the SCS results.Two examples of erroneous experiments are also given to illustrate the consequences of inadequate experimental conditions.It is also pointed out that the SCS method gives information on the electrical properties of very thin dielectric film.
Characterization of MgO layers on different alumina and glass substrates by grazing incidence diffractometry and grazing incidence X‐ray reflectometry
Authors: Wulff H. , Klimke J. , Gerova E. 
Published: December 2004

AbstractMagnesium oxide thin films were deposited at an average evaporation rate of 1.8 nm s−1 onto different crystalline alumina substrates and amorphous float glass. The deposits were made in an electron‐beam evaporator at substrate temperatures between 25°C and 190°C under different oxygen partial pressures. Films of 0.1, 0.5 and 1 μm thickness were deposited. These coatings were investigated by grazing incidence diffractometry (GID) to vary the depth of penetration. For films 0.1 μm thick the additional use of grazing incidence x‐ray reflectometry (GIXR) was possible. The deposite films were polycrystalline with different 〈100〉 textures depending on the substrate temperature. All the MgO thin‐film reflexes measured were strongly broadened compared with the reflexes of a standard polycrystalline MgO material. The crystal size and the microstrain of the MgO coatings were calculated by profile analysis using the Fourier transformation method. It was demonstrated that the x‐ray profiles of the MgO reflexes are influenced by the roughness of the substrate surface. Only small gradients were found in the particle sizes and microstrains within the deposited films. The oxygen partial pressure did not significantly influence the film properties measured by GID. The GIXR roughness and mass density measurements agreed with the results of GID. Magnesium oxide films deposited at higher temperatures show a diminished crystallinity and less interface roughness.
XPS investigation of surface oxidation and reduction in nanocrystalline CexLa1 − xO2 − y
Authors: Trudeau M. L. , Tschöpe A. , Ying J. Y. 
Published: December 2004

AbstractInert gas condensation was used to generate nanocrystalline La‐doped CeO2 − x. Non‐stoichiometric CeO2 − x‐based materials were found to be excellent catalysts in recent studies for the selective reduction of SO2. To understand better the stoichiometry‐related catalytic properties, the surface chemistry of nanocrystalline La‐doped CeO2 − x was investigated through in situ oxidation‐reduction thermal treatments. Oxidation in CO2 and reduction in H2 atmospheres were performed between 30°C and 600°C in a reaction chamber connected to a x‐ray photoelectron spectrometer analytical chamber. Curve fitting and target factor analysis were used to obtain a semi‐quantitative measurement of the transformation between +3 and +4 oxidation states during these reactions. Target factor analysis was found to be a very useful tool for analyzing the contributions corresponding to Ce+3 and Ce+4.
Surface structure and properties of polymers irradiated with hyperthermal atomic oxygen
Authors: Kleiman J. I. , Gudimenko Y. I. , Iskanderova Z. A. , Tennyson R. C. , Morison W. D. , McIntyre M. S. , Davidson R. 
Published: December 2004

AbstractSurface properties of Kapton® were analysed after different exposures to ground state fast atomic oxygen (FAO) and vacuum ultraviolet radiation in the atomic oxygen beam facility at the University of Toronto Institute for Aerospace Studies. X‐ray photoelectron spectroscopy, scanning electron microscopy and contact angle measurements were used to characterize the chemical and physical changes to the surfaces of the materials analysed. The most important changes in the surface chemistry of Kapton induced by the various exposures to FAO were oxidative degradation of the polymer and substantial changes in supermolecular organization and morphology of the surface layer. A very weak adhesion of the rough top layer to the original Kapton has been observed after an atomic oxygen irradiation with a total fluence of 1.3 × 1021 atoms cm−2, which is comparable to some low earth orbit (LEO) exposures. Comparison was made between pristine samples and the cleaned surface of samples that had been exposed in the atomic oxygen beam facility and in the LEO environment. An ageing effect was observed in the surface layer of exposed samples after a prolonged storage. For several polymer materials, a correlation was found between the erosion yield when exposed to FAO and the dispersion component of the surface tension of the pristine material.
Germanium behaviour during the low‐temperature plasma‐assisted oxidation of SiGe alloys
Authors: Tételin C. , Wallart X. , Nys J. P. , Vescan L. 
Published: December 2004

AbstractIn this paper, we investigate the germanium behaviour during the low‐temperature plasma‐assisted oxidation of strained epitaxial Si1 − xGex (x = 0.1, 0.2) layers. For an oxidation temperature of 500°C and an oxide thickness between 80 and 200 Å, using Auger depth profiling, we find that the oxidation process leads to the formation of a pure SiO2 top layer and the rejection of Ge at the oxide/alloy interface. Taking into account in a suitable way the broadening effect affecting the Auger profiles, we show that a pure Ge layer is formed at the interface.