bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative AES IX and quantitative XPS II: Auger and x‐ray photoelectron intensities and sensitivity factors from spectral digital databases reanalysed using a REELS database
Authors: Seah M. P. , Gilmore I. S. , Spencer S. J. 
Published: January 2005

AbstractAn extension has been made of previous analyses of peak area intensities for elemental spectra in digital Auger and x‐ray photoelectron databases. The intensities, instead of being analysed after removal of a background derived from the Tougaard Universal cross‐section, are now analysed after removal of the extrinsic characteristic loss background calculated by deconvolving the relevant angle‐averaged reflected electron energy‐loss spectroscopy (REELS) spectrum. The angle‐averaged REELS data for each element are calculated from a digital REELS database using a recently defined scaling of the measured characteristic losses from the elastic peak. The new background removal procedure leads to an improvement in the correlation between experiment and theory for intensities in both AES and XPS. Analysis of these correlations shows that a systematic divergence remains for each element, which is the same for XPS as for AES. This divergence is attributed to an inadequacy either of the angle‐averaged REELS method or of the material‐to‐material dependence of the TPP‐2M equation used in the calculation of the inelastic mean free paths. Correction for this is possible in a new matrix‐less quantification formulation using average matrix sensitivity factors. This leads to correlations between experiment and theory with scatter factors of ×/÷1.08 and ×/÷1.11 for AES and XPS, respectively, for a wide range of elements and peaks. These scatter factors are much better than for previous correlations and underpin the choice of formulae to calculate the relevant theoretical intensity predictions. These calculations lead directly to values of average matrix sensitivity factors, appropriate for use with spectrometers giving true spectra or with those spectrometers that may be calibrated to provide such spectra. © Crown Copyright 2001. Published by John Wiley & Sons, Ltd.
Optical characterization techniques for process monitoring
Authors: Pickering C. 
Published: January 2005

AbstractThe aim of this special issue is to bring to the attention of the surface science community the potential and application of optical techniques. This paper gives an overview of the major optical characterization techniques and the subsequent papers. Where possible, links with other surface science techniques are discussed and the use of optical methods for process monitoring and control is emphasized. © Crown Copyright 2001. Published by John Wiley & Sons, Ltd.
Reflection anisotropy spectroscopy: a new probe of metal surfaces
Authors: Martin D. S. , Weightman P. 
Published: January 2005

AbstractReflection anisotropy spectroscopy (RAS) is a non‐destructive optical probe of surfaces capable of operation within a wide range of environments. The RAS technique was developed to study semiconductor growth and more recently has been used to probe the optical properties of metal surfaces. Surface sensitivity has been demonstrated with the detection of reconstruction, adsorbate interaction and the observation of transitions involving surface‐localized electronic states. The RAS technique has non‐ultrahigh vacuum (UHV) environment capability and thus opens up the study of metal surfaces in catalytic and corrosive environments at high pressure and at the solid/liquid interface. The combination of RAS with a full range of surface science techniques applied to the study of well‐defined surfaces aids in the interpretation of RAS spectra. The focus of this article will be on well‐characterized metal surfaces prepared and studied under UHV conditions. Copyright © 2001 John Wiley & Sons, Ltd.
Spectroscopic ellipsometry for monitoring and control of surfaces, thin layers and interfaces
Authors: Pickering C. 
Published: January 2005

AbstractSpectroscopic ellipsometry can provide information non‐destructively on layer thickness, composition, refractive index, crystallinity and surface/interface roughness. This article discusses its use for ex situ/in‐line monitoring and in situ/real‐time control. Examples are given based on silicon epitaxial surfaces, GaN nucleation layers, SiGe/Si and other multilayer structures. Real‐time data analysis methods are discussed and in situ spectroscopic ellipsometry is shown to provide insights into surface effects during SiGe epitaxial growth. © Crown Copyright 2001. Published by John Wiley & Sons, Ltd.
Surface photovoltage spectroscopy of semiconductor structures: at the crossroads of physics, chemistry and electrical engineering
Authors: Kronik Leeor , Shapira Yoram 
Published: January 2005

AbstractThe possibility of obtaining a detailed picture of the electronic structure makes surface photovoltage spectroscopy (SPS) eminently suitable for bridging the gap between the chemical, physical, optical and electrical properties of semiconductors. In SPS, changes in band bending (both at the free semiconductor surface and at buried interfaces) are monitored as a function of external illumination. Surface photovoltage spectroscopy can provide detailed, quantitative information on bulk properties (e.g. bandgap and type, carrier diffusion length and lifetime) and can be used for complete construction of surface and interface band diagrams, including the measurement of energy levels in quantum structures. A particular strength is that a comprehensive analysis of surface and bulk defect state distributions and properties is made possible. Measurements using SPS are contactless and non‐destructive. In addition, they can be performed both in situ and ex situ, at any reasonable temperature, on any semiconducting material, at any ambient and at any lateral resolution down to the atomic scale. This review starts with an overview of SPS‐related surface and interface theory, describes the SPS experimental set‐up and presents applications for surface and interface characterization of a wide variety of materials and structures, cross‐correlating them with other methodologies. Copyright © 2001 John Wiley & Sons, Ltd.
Raman spectroscopy of GaN, AlGaN and AlN for process and growth monitoring/control
Authors: Kuball M. 
Published: January 2005

AbstractThe use of micro‐Raman spectroscopy to monitor non‐invasively GaN, AlGaN and AlN material parameters for process and growth monitoring/control is demonstrated. Concepts to determine the crystalline quality, the stress, the free carrier concentration, the aluminium composition and the temperature from the Raman modes are reviewed. Raman monitoring of processing and growth is illustrated on selected examples: the high‐temperature processing of ion‐implanted and non‐implanted GaN layers, the Raman monitoring of AlGaN/GaN heterostructure field‐effect transistors and the in situ Raman monitoring of GaN growth at elevated temperatures. Ultraviolet Raman spectroscopy has been employed to characterize material properties of GaN surface layers and GaN/AlGaN interfaces. Raman mapping is illustrated on bulk AlN crystals to investigate stress fields related to growth striations and defects. Copyright © 2001 John Wiley & Sons, Ltd.
Optical testing techniques for new semiconductor processes and new materials
Authors: Reader A. , Moore C. , Brinker R. , Hennessy J. 
Published: January 2005

AbstractIndustrial semiconductor manufacturing—and therefore industrial semiconductor metrology—is being faced with a new generation of processes and materials coming out of development laboratories worldwide. These need careful monitoring, particularly in the early stages of manufacture. Many metrology challenges are well met by optical techniques, and the article discusses three such techniques that have transferred to industrial production process control. Laser ellipsometry brings high precision to ultrathin 25 Å gate oxide measurements and can analyse many types of (transparent) new materials. Impulsive stimulated thermal scattering is a new opto‐acoustic technique and therefore is covered more fully here—it complements laser ellipsometry by analysing single and bilayer metal (opaque) films after these have been exposed to a variety of semiconductor processes. Photoluminescence is invaluable for analysing compound semiconductors, where it measures directly the quality of epitaxial layers and so helps to understand and reduce defect mechanisms and improve yields. The article concludes by discussing industrial requirements for integrating the measurement system into a deposition system for in situ process control. Copyright © 2001 John Wiley & Sons, Ltd.
NESSPIOM—Network for enhanced semiconductor surface processing through in situ optical monitoring
Authors: Pemble Martyn E. 
Published: January 2005

AbstractThe activities of the Network for Enhanced Semiconductor Surface Processing through In situ Monitoring (NESSPIOM), based in the UK and funded through the Engineering and Physical Sciences Research Council, are described. This group, consisting of academics and industrialists, is evaluating the potential benefits that may accrue from the use of optical monitoring methods during semiconductor surface modification, both from a fundamental and an applied perspective. The findings of the network to date are presented. Interferometry, light scattering techniques and diode laser spectroscopy are highlighted as methods that may result in improved materials or processes, whereas other techniques such as reflectance anisotropy spectroscopy, spectroscopic ellipsometry, surface photoabsorption and second harmonic generation are found to provide more fundamental information. The future for the application of methods such as this within both the academic and industrial communities is discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Manipulation experiments on Si(111)7 × 7 by scanning tunnelling microscopy
Authors: Kraus A. , Hanbücken M. , Koshikawa T. , Neddermeyer H. 
Published: January 2005

AbstractWe describe our results on atomic‐scale manipulation of clean and H‐covered Si(111) surfaces by using scanning tunnelling microscopy. In particular, we focus on the manipulation of surface atoms by using a well‐defined distance decrease between sample and tip, with the sample‐tip voltage switched off. For comparison we also applied voltage pulses to the tip and recorded the tunnelling current simultaneously. For H‐covered Si(111) surfaces the desorption of H is associated with a dramatic current increase. For Si(111)7 × 7, the removed Si adatom very often is found in a neighbouring 7 × 7 unit cell half, where it fluctuates above rest atom sites already at room temperature. Copyright © 2005 John Wiley & Sons, Ltd.
Novel structures of carbon layers on a Pt(111) surface
Authors: Fujita Tomohiro , Kobayashi Wataru , Oshima Chuhei 
Published: January 2005

AbstractThe growth behaviour of carbon layers formed on a Pt(111) surface has been investigated by means of scanning tunnelling microscopy. A carbon layer with a ($\sqrt{19}$ × $\sqrt{19}$)R23.4° structure was grown by benzene exposure of 3 L at 1000 K. After exposure of >10 L, graphene islands with hexagonal shapes appeared in the surface terraces. The graphene islands grew beyond step edges, and their growth often caused bunching of the step edges by Pt atom migration. Copyright © 2005 John Wiley & Sons, Ltd.
Electronic structures of nanostructured transition metals on the Au(788) surface
Authors: Fujisawa H. , Shiraki S. , Nantoh M. , Kawai Maki 
Published: January 2005

AbstractThe electronic structures of nanostructured transition metals (Fe, Co, Ni) grown by step decoration of the Au(788) surface are investigated by normal emission angle‐resolved photoemission spectroscopy (ARPES). As the coverage of the transition metals is increased, the intensity of Au 5d valence bands decreases but the peak positions do not change, suggesting that the mixing between Au 5d and 3d of transition metals is negligibly weak. The coverage dependences of ARPES spectra near the Fermi level (EF) for Fe, Co and Ni are discussed and compared with the photoemission results on bulk materials. In the higher coverage regions, we identify the observed 3d peaks near EF as ferromagnetic exchange splitting bands with similar exchange energy to the bulk. In contrast, at lower coverages, the exchange splitting vanishes for Fe and Co and becomes small for Ni. The origins of this behaviour are attributed to atomic volume, structural dimensionality and finite temperature effects. Copyright © 2005 John Wiley & Sons, Ltd.
Characteristics of ion‐beam‐synthesized tantalum silicide film
Authors: Liang J. H. , Ruan W. M. 
Published: January 2005

AbstractThis paper deals with the characteristics of ion‐beam‐synthesized tantalum silicide film on different substrates as a function of annealing conditions. An implantation of 2 × 1017 40 kV Ta ions cm−2 was performed using an ion implanter of metal vapour vacuum arc. Silicon wafers of <100> and <111> orientation were chosen as representatives of different substrates. Rapid thermal annealing conditions included annealing temperatures of 550–1000 °C and annealing times of 5–90 s. Annealing‐induced variations in microstructure, composition, resistivity and diffusion in the tantalum silicide film were analysed by means of x‐ray diffractometry, Rutherford backscattering spectrometry, resistometry and secondary ion mass spectrometry, respectively, in order to compare the as‐implanted and as‐annealed specimens. The results revealed that tantalum silicide film possesses the most optimum properties when annealed at 850 °C for 30 s in both the <100> and <111> specimens. Copyright © 2005 John Wiley & Sons, Ltd.
Abnormal electron emission from MgO thin film under ion irradiation
Authors: Tsujita T. , Nagatomi T. , Takai Y. 
Published: January 2005

AbstractEnergy distributions of secondary electrons from an MgO thin‐film surface under ion irradiation were investigated. The abnormal ion‐induced secondary electron emission was observed in addition to the normal emission. The abnormal emission observed in the present study is found to be a kind of self‐sustained emission because it continued after stopping ion irradiation. The energies of the abnormal secondary electrons are lower than the vacuum level at the MgO surface by ∼7–10 eV and its energy distribution is close to the profile of the density‐of‐states of the valence band of MgO. The results strongly suggested that the abnormal electron emission observed in the present study is due to field emission of the valence electrons of MgO through a mechanism other than the Malter effects or the Townsend Avalanche effect. Copyright © 2005 John Wiley & Sons, Ltd.
Diffusion phenomena at the interface between dielectric films and compound semiconductors
Authors: Shiramizu T. , Tanimura J. , Kurokawa H. , Sasaki H. , Abe S. 
Published: January 2005

AbstractThe diffusion phenomena at the interface between dielectric films and compound semiconductors under two kinds of condition (humid or dry thermal) have been studied by means of secondary ion mass spectrometry (SIMS). Under the humid condition—the pressure cooker test at 121 °C, 100% relative humidity and 2 atm—we confirmed that oxygen diffused into dielectric films of SiNx or SiOxNy from the surface and that both Ga and As diffused into films from GaAs substrates simultaneously. Because such diffusion phenomena did not occur under the dry thermal condition at 120 °C, the diffusion was assumed to be influenced by the existence of water vapour. In addition, we investigated the selective diffusion of Ga from AlGaAs into SiOx under the dry thermal condition with rapid thermal annealing. We found that the diffusion velocities depended on the SiOx growing method and the diffusion into SiOx deposited by sputtering was more remarkable than that by plasma chemical vapour deposition Copyright © 2005 John Wiley & Sons, Ltd.
Effects of BaTiO3 overlayers deposited on SrTiO3(001) on its 105 K phase transition
Authors: Matsushita Kyohiko , Kitahara Amane , Sakaue Kiyoshi , Takahashi Isao , Terauchi Hikaru , Doi Syuichi 
Published: January 2005

AbstractWe investigated effects of a BaTiO3 overlayer deposited epitaxially on an SrTiO3(001) surface on the 105 K phase transition of SrTiO3. With the use of x‐ray reflectivity and Bragg reflection we observed the critical behaviour of the 105 K phase transition in the interfacial region and in the bulk. For T < Tc(Tc = 105 K), rocking‐curve‐widths of x‐ray reflectivity and of Bragg reflections are found to exhibit power law behaviour (Tc − T)2β, where β obtained by x‐ray reflectivity (βINTERFACE) is almost the same as that obtained by Bragg reflection (βBULK = 0.34 ± 0.02). The present result shows a sharp contrast to the critical behaviour of SrTiO3 having free SrTiO3(001) surfaces, where 2βSURFACE ≈ βBULK is reported. In this study, we find that the critical behaviour of the BaTiO3/SrTiO3 interface is influenced significantly by the surface condition generated by the epitaxial cap layer. It is likely that a change of dimensionality and/or tensile stress at the interface could affect the critical behaviour of this interfacial region. Copyright © 2005 John Wiley & Sons, Ltd.
Electronic stopping of keV nitrogen ions interacting with a Pt(110)(1 × 2) surface—a tool to characterize electronic surfaces
Authors: Robin A. , Postnikov A. V. , Heiland W. 
Published: January 2005

AbstractIon channeling is used to investigate the electronic density corrugation at surfaces by analysing the electronic stopping behaviour of ions scattering grazingly off a clean single crystalline Pt(110)(1 × 2) surface. We use the fact that under these conditions the elastic contribution can be separated from the inelastic energy‐loss processes, which are closely related to the electronic density sampled along the projectiles trajectories. Therefore, we have a direct probe of the surface electronic density structure. Here, experiments and their theoretical interpretation for N+ ions at primary ion energies of 1–10 keV are presented. Multi‐peak features of the energy spectra, depending on the azimuthal surface orientation, are attributed to different particle trajectories. A detailed analysis of trajectory calculations affords an unambiguous assignment of the observed peak structures to three trajectory classes, each sampling specific energy losses. The comparison of the experimental energy‐loss values with results obtained from a surface‐adapted energy‐loss model for ion scattering that includes the electron density allows us to investigate the electronic surface of the sample. The results are compared with calculated surface electron density contours. Reasonable agreement is obtained, showing that the presented method is suitable to characterize the electronic density structure at crystalline surfaces. Copyright © 2005 John Wiley & Sons, Ltd.
Angle‐dependent neutralization of low‐energy alkali ions scattered from alkali‐covered Si surfaces
Authors: Kan T. , Yasue T. , Koshikawa T. 
Published: January 2005

AbstractAn angle‐resolved ion scattering apparatus has been developed to observe the charge exchange process between low‐energy ions and surfaces. The incident angle‐dependent neutralization was observed for Li+ ions scattered from a Cs‐adsorbed Si(111) surface. The shadowing effects have an important role in the neutralization efficiency. The azimuthal angle dependence of the neutralization efficiency of D2+ ions scattered from a clean Si(100) surface also showed minima along the crystallographic orientations. This anisotropy is explained by the blocking effects of the outgoing particles scattered in the bulk. It is suggested that the crystallographic information has to be considered to explain the angle‐dependent neutralization efficiency, and it is shown that the depth information is also important to understand the neutralization efficiency. Copyright © 2005 John Wiley & Sons, Ltd.
High‐resolution Auger depth profiling by sub‐keV ion sputtering
Authors: Inoue Masahiko , Shimizu Ryuichi , Lee Hyung Ik , Kang Hee Jae 
Published: January 2005

AbstractAuger electron spectroscopy depth profiling of a GaAs/AlAs superlattice sample was performed with Ar+ ions of 100–500 eV using a compact floating‐type low‐energy ion gun. The practical etching rate of >1.5 nm min−1 was ensured in the energy region beyond 150 eV. High depth resolutions of 1.3, 1.6, 1.8 and 2.0 nm (84 − 16%) were obtained with Ar+ ions of 100, 150, 200 and 300 eV at the leading edge of Al LVV depth profiles, respectively.At the sputtering energy of 100 eV, remarkable improvement of the depth resolution at the leading edge (Δzl = 1.3 nm) has been observed but this is followed by considerable deterioration at the trailing edge (Δzt = 2.7 nm). Dynamic Monte‐Carlo simulation for sputtering energies of 150–300 eV was performed for comparison. Although the Monte‐Carlo simulation overestimates the depth resolutions by ∼0.6 nm larger than the relevant experimental values, it describes the energy dependence of the depth resolution with considerable success. Copyright © 2005 John Wiley & Sons, Ltd.
Multilayer mirrors for µ‐XPS using a Schwarzschild objective
Authors: Takenaka Hisataka , Ichimaru Satoshi , Nagai Koumei , Ohchi Tadayuki , Ito Hisashi , Gullikson E. M. 
Published: January 2005

AbstractThe development of highly reflective multilayer mirrors for use in the wavelength region around 6 nm has made it possible to use a multilayer‐coated Schwarzschild objective for micro‐x‐ray photoemission spectroscopy. For this purpose, CoxCr1−x/C and W/C multilayers were fabricated by magnetron sputtering and the soft x‐ray reflectivities were measured. The peak reflectivity of the Cr/C multilayer was found to be the highest with ∼18.9% at a wavelength of 6.42 nm and an incident angle of 88°. It is believed that a Cr/C multilayer will provide sufficient performance for use on a Schwarzschild mirror for x‐ray photoemission spectroscopy using 6 nm x‐rays. Copyright © 2005 John Wiley & Sons, Ltd.
Depth profiling of polycrystalline layers under a surface using x‐ray diffraction at small glancing angle of incidence
Authors: Fujii Y. , Komai T. , Ikeda K. 
Published: January 2005

AbstractAn analysis method for evaluating a polycrystal structure under a surface using x‐ray diffraction at small glancing angle incidence was studied. Intensities of the diffracted x‐rays on a polycrystalline iron surface were measured at various incidence angles, and the dependency of the incidence angles was investigated by analysing the intensity of x‐ray propagation in surface layer materials characterized by a complex refractive index that changes continuously with depth. The dependence of the diffracted x‐ray intensities on the glancing angle was analysed and the depth profile of the polycrystalline layers of oxidized iron was evaluated to an accuracy of the order of nanometres. Copyright © 2005 John Wiley & Sons, Ltd.
Development of the spin‐polarized atom‐surface scattering method for characterizing surface magnetism: detection efficiency of the microchannel plate
Authors: Ikedo Y. , Sueyoshi Y. , Shimizu T. , Hirose E. , Hori H. , Torikai E. 
Published: January 2005

AbstractThe energy, charge and angle dependence of the detection efficiency of the microchannel plate (MCP) for caesium (Cs) atoms and ions was studied for measuring the spin asymmetry of the ionization probability in the atom‐surface scattering process. Based on the model of a spin‐dependent scattering of a spin‐polarized and energy‐tunable Cs atomic beam at a magnetic surface, we have developed a new experimental method for characterizing surface magnetism. Copyright © 2005 John Wiley & Sons, Ltd.