Secondary Ion Mass Spectrometry Research Papers (original) (raw)

The local surface chemistry of a low-Ni austenitic stainless steel AISI type 304 used for tensile testing in hydrogen atmosphere is characterized by secondary ion mass spectrometry (SIMS). A chemical map on cylindrical austenitic stainless steel samples can be obtained even after a tensile test. In an effort to obtain the proper chemical element distribution on the samples, the influence of contamination and sample orientation is discussed. An iron oxide on top of a chromium oxide layer is present and Si segregation at grain boundaries is detected. Oxides are judged to reduce the initial hydrogen attack but to be of minor importance for crack propagation during the embrittlement process.

- by and +2
- •
- Materials Engineering, Condensed Matter Physics, Secondary Ion Mass Spectrometry, Surface Chemistry

In high-strength steels it is often difficult to distinguish between hydrogen embrittlement and various other brittle failure mechanisms. The objective of this work was to develop a sensitive analytical procedure based on secondary ion mass spectrometry (SIMS) that would allow in-service identification of local hydrogen accumulation, either during quality control or during failure analysis of electroplated items. Dynamic SIMS was found useful in identifying when baking of Cd-plated AISI 4340 steel was not carried out, thus potentially leading to hydrogen embrittlement. In all non-baked samples, an increase in the hydrogen signal was found at the Cd/steel interface. In baked samples, either a peak was not observed at the interface, or it was insignificant based on determination of the ratios between the hydrogen signals in the coating, interface and substrate. This reproducible effect was monitored even after 16 months storage in a desiccator. These observations make the procedure practical in suggesting more accurate, reliable and cost effective recommendations for prevention of failures. The main effect of baking was found to be effusion of hydrogen from the interface and the substrate steel into the atmosphere. A mechanism for delayed failure is suggested.

- by Noam Eliaz
- •
- Materials Engineering, Mechanical Engineering, Civil Engineering, Corrosion Science

The electron and hole mobility of Si complementary metal on oxide field effect transistors (CMOS) can be enhanced by introducing a biaxial tensile stress in the Si channel. This paper outlines several key analytical techniques needed to investigate such layers. Raman scattering is used to measure the strain in the Si channel as well as to map the spatial distribution of strain in Si at a lateral resolution better than 0.5 μm. Atomic force microscopy (AFM) is used to measure the surface roughness. Transmission electron microscopy (TEM) is used to reveal dislocations in the structure, the nature of the dislocations and the propagation of the dislocations. Secondary ion mass spectrometry (SIMS) is used to monitor the Ge content profile in the structure and the thickness of each layer. In the long term, inline nondestructive techniques are desired for epi-monitoring in manufacturing. Two techniques, spectroscopic ellipsometry (SE) and x-ray reflectivity (XRR), have shown promise at this stage.

We propose to use cluster ions that are much larger than the molecular ions as primary ions for organic secondary ion mass spectrometry. Incident Ar cluster ion beams with energies from 10 to 20 keV and a mean size of about 1000 atoms/cluster were used. Secondary ions were measured for a thin arginine film target (200 nm) bombarded with large Ar cluster ions using a time-of-flight technique. Molecular ions of arginine and characteristic fragment ions were detected with high sensitivity. When large Ar cluster ions such as Ar 1500 were incident on the arginine target, molecular ions of arginine were detected with little fragment ions. This indicates that large cluster ions can ionize arginine molecules without damaging them.

The doping process of Zn is widely used for fabricating InP-based optoelectronic devices. Methods generally used for Zn doping in InP are in-situ doping during the growth and postgrowth ex-situ doping, such as closed ampoule diffusion and diffusion from evaporated Zn-thin film. In-situ Zn doping by metal-organic chemical vapor deposition shows low doping efficiency due to the high-equilibrium vapor pressure of Zn. 1 Moreover, the hole concentration saturates approximately at 1-2 ϫ 10 18 /cm 3 , presumably due to a similar self-concentration mechanism.

Undoped TiO 2 and Ag-TiO 2 (up to 23 at.% Ag) cermet thin films and polycrystalline powders have been prepared by sol-gel process. Their structure, composition, surface morphology and optical properties have been investigated by X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and ultraviolet-visible spectroscopy (UV-VIS spectroscopy). It has been observed that while Ag does not form a solid solution with TiO 2 , it promotes the anatase to rutile phase transformation. The transformation temperature decreases from 827 jC for undoped TiO 2 to about 650 jC for 23 at.% Ag-doped TiO 2. SIMS analyses show that Ag is mostly present on the surface of the films. XPS studies confirm that these Ag are in the Ag 0 state. Optical analyses show that with increasing Ag content, the refractive index (n) increases and the optical absorption behavior of the cermet films is modified, but the band gap of the anatase TiO 2 is not influenced.

A model based on the Nernst-Planck equations is discussed for the trivalent ion exchange process in lithium niobate crystals. Due to the material anisotropy and the different valence state of the exchanged species, a correction to the ion flux expression is considered to include the strain effects. The model is then used to describe the erbium ion exchange in both X-and Z-cut lithium niobate crystals. In this case, the dopant in-depth profiles measured by secondary ion mass spectrometry are well fitted by the theoretical profiles predicted by the model, supporting its validity. Since the model allows to predict the dopant profile into the substrate, it can be used to tailor the process parameters.

- by Marco Bazzan and +1
- •
- Secondary Ion Mass Spectrometry, Physical sciences, CHEMICAL SCIENCES, THERMAL AND MASS DIFFUSION

Porous graphitic carbon (PGC) particles were functionalized in situ in packed beds at elevated temperature with neat di-tert-amylperoxide (DTAP) in a column oven. The performance of these particles for high performance liquid chromatography (HPLC) was assayed before and after functionalization with the following analytes: benzene, toluene, ethyl benzene, n-propyl benzene, n-butyl benzene, p-xylene, phenol, 4-methylphenol, phenetole, 3,5-xylenol, and anisole.

- by Matthew Linford
- •
- Engineering, Thermodynamics, Technology, Principal Component Analysis

The distribution of gold and other trace elements in the ore-stage pyrite from the high-sulfi dation Au-Ag-Cu Pascua deposit in the El Indio belt in north-central Chile was studied using electron-microprobe and secondary-ion mass spectrometry (SIMS) imaging and analysis. The images show that concentrations of Au and Cu are concentrically zoned, and those of Ag, As, Se and Te are zoned both concentrically and sectorally. The principal trace-element associations are As-Ag, Au-Cu and Se-Te. We propose that the fi rst two associations, As-Ag and Au-Cu, refl ect coupled substitutions for Fe, whereas Te and Se replace S by direct-ion exchange. The near-identical patterns of sector zoning of Ag and As suggest that silver enters the structure of pyrite via a coupled substitution with As, in which one atom of Ag and one of As substitute for two Fe atoms, yielding (Ag + 0.5 As 3+ 0.5 )S 2. Gold and copper were excluded during an interval in which growth conditions promoted the development of | hk0 | sectors at the expense of | 111 | sectors; their enrichment patterns show only slight evidence of sectoral preferences. With the analytical methods employed, we could not distinguish unequivocally between incorporation of gold as minute inclusions of the native metal or a coupled substitution of gold as an Au 3+ ion and copper as a Cu + ion for two Fe 2+ ions, yielding (Au 3+ 0.5 Cu + 0.5 )S 2 . However, we favor the latter interpretation. Incorporation of gold as Au 3+ is also consistent with evidence of unusually oxidizing conditions during the formation of the Pascua deposit. The zonation of invisible gold and associated trace elements in the ore-stage pyrite at Pascua is the fi rst documented example of crystallographic structural control of the surface on the incorporation of multiple trace elements in pyrite. Moreover, the nature of this zonation provides clear evidence that incorporation of gold in pyrite does not necessarily involve coupled substitution with arsenic, as proposed for many other deposits. Not only can arsenic behave as a metal in the structure of pyrite, but its sectoral pattern of incorporation is a potentially sensitive indicator of redox conditions during mineralization.

- by Jeanne Paquette
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- Geology, Arsenic, Secondary Ion Mass Spectrometry, Structural Control

We describe an open-source freeware programme for high throughput analysis of nanoSIMS (nanometrescale secondary ion mass spectrometry) data. The programme implements basic data processing and analytical functions, including display and driftcorrected accumulation of scanned planes, interactive and semi-automated definition of regions of interest (ROIs), and export of the ROIs' elemental and isotopic composition in graphical and text-based formats. Additionally, the programme offers new functions that were custom-designed to address the needs of environmental microbiologists. Specifically, it allows manual and automated classification of ROIs based on the information that is derived either from the nano-SIMS dataset itself (e.g. from labelling achieved by halogen in situ hybridization) or is provided externally (e.g. as a fluorescence in situ hybridization image). Moreover, by implementing post-processing routines coupled to built-in statistical tools, the programme allows rapid synthesis and comparative analysis of results from many different datasets. After validation of the programme, we illustrate how these new processing and analytical functions increase flexibility, efficiency and depth of the nanoSIMS data analysis. Through its custom-made and open-source design, the programme provides an efficient, reliable and easily expandable tool that can help a growing community of environmental microbiologists and researchers from other disciplines process and analyse their nanoSIMS data. Received

A corrosion mechanism is proposed for Al 3 Mg 2 , based on electrochemical tests, XPS, and depth profiling using XPS and ToF-SIMS. After short ($2 min) solution exposure, the surface consists of a surface film above dealloying. The dealloying is attributed to selective Mg dissolution and the surface rearrangement of Al into islands, although the metallic Al could alternatively be formed by two reduction reactions. The surface film thickness was $10 nm. After exposure to ultra-pure water, the composition was AlMg 1.3 O 0.2 (OH) 5.1 corresponding to Al(OH) 3 Á1.1 Mg(OH) 2 Á0.2MgO. After exposure to 0.01 M Na 2 SO 4 , the composition was AlMg 0.2 O 0.4 (OH) 2.5 corresponding to Al(OH) 3 Á0.1Al 2 O 3 Á0.2MgO. Longer exposure produced a thicker surface film, more pronounced metallic Al islands and more MgH 2 . Three possibilities are identified for MgH 2 formation. Al(OH) 3 formation is attributed to a precipitation reaction. Bulk nanoporous Al 3 Mg 2 formation is predicted to be possible by Mg dealloying of Mg 17 Al 12 .

- by H. Ardelean and +3
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- Materials Engineering, Mechanical Engineering, Civil Engineering, Corrosion Science

Millisecond annealing as an equipment technology provides temperature profiles which favour dopant activation but nearly eliminate dopant diffusion to form extremely shallow, highly electrically activated junctions. For the 45-nm technology node and beyond, precisely controlled gate under-diffusion is required for optimum device performance. Therefore, on boron and arsenic beamline-implanted wafers, various annealing schemes were investigated for the formation of ultra-shallow and custom-shaped junctions. The main scheme consisted of flash annealing with peak temperatures ranging from 1250 to 1300 • C, combined with spike rapid thermal annealing with peak temperatures in the range from 900 to 1000 • C to achieve a desired junction depth. As alternative, to reduce the sheet resistance of pMOS and nMOS source-drain extensions, combinations of two or three flash anneals in succession were tested. Finally, the standard flash anneal condition of a 750 • C intermediate temperature followed by the flash anneal was changed to a high intermediate temperature of 950 • C followed by the flash anneal up to 1300 • C. The results of all these annealing schemes were analysed by four-point probe measurement. Selected samples were analysed by Hall-effect measurements for peak activation, and by secondary ion mass spectrometry for profile shape as well as diffusion effects. Transmission electron microscopy was used to study residual defects. Selected boron and arsenic dopant profiles were also compared to predictive simulation results which address the diffusion and activation at extrinsic concentrations. (W. Lerch). annealings and source/drain extension annealings have reduced drastically from soak annealing for several seconds via high rampup spike rapid thermal annealing (RTA) to millisecond annealing (MSA). At the same time, increasing peak temperatures were used to raise the dopant activation. Today, MSA either in the form of flash lamp [1] or laser annealing [2] is applied to complementary MOSFETs (CMOS) as the activation method of choice for implanted impurities in source and drain regions to fulfil the above requirements. A simple replacement of conventional RTA by MSA can cause problems because insufficient gate under-diffusion during the activation process results in a reduction of the drive current. On the other hand, MSA reduces the gate depletion in poly silicon [3,4] and 0921-5107/$ -see front matter

Surface oxidation of titanium was performed by cw-Nd:YAG laser (k = 1.064 Am) treatment in air. Different colors of the samples were obtained by varying the beam scan velocity. At the optical microscope, the samples showed a pattern of two-color bands. Compositional analyses performed by grazing incidence X-ray diffractometry, Raman spectroscopy, and secondary ion mass spectrometry revealed the formation of a titanium oxide coating that consisted of a mixture of polycrystalline oxide phases (Ti 2 O, TiO, Ti 2 O 3 and TiO 2 ). The refractive index and the thickness of the transparent oxide surface layer, as well as the chromaticity coordinates, were calculated from the reflectance spectrum of the samples. In order to elucidate the origin of the samples color, the properties of the laser-oxidized samples were compared with those of anodized ones with similar colors. The comparison allowed to conclude that the color was formed in all cases by light interference phenomena within the transparent oxide surface layer, which in the case of laser treated samples was only the thin outer zone of the titanium oxidized layer. D

The ISO technical report 14187 provides an introduction to (and examples of) the information that can be obtained about nanostructured materials by using surface analysis tools. In addition, both general issues and challenges associated with characterizing nanostructured materials and the specific opportunities and challenges associated with individual analytical methods are identified. As the size of objects or components of materials approaches a few nanometers, the distinctions among 'bulk', 'surface', and 'particle' analysis blur. This technical report focuses on issues specifically relevant to surface chemical analysis of nanostructured materials. The report considers a variety of analysis methods but focuses on techniques that are in the domain of ISO/TC 201 including Auger electron spectroscopy, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and scanning probe microscopy. Measurements of nanoparticle surface properties such as surface potential that are often made in a solution are not discussed.

Novel tungsten precursors, WH 2 (iPrCp) 2 and WH 2 (EtCp) 2 , with attractive thermal properties are introduced for Metal Organic Chemical Vapor Deposition (MOCVD) and Atomic Layer Deposition (ALD) of tungsten containing films. Their thermal behavior has been assessed using a vapor pressure measurement set-up and a thermal gravimetric apparatus (TG/DSC/DTA). Thin films of WC x and WN x C y were deposited depending on the reactant used. Kinetics of the surface reaction using WH 2 (iPrCp) 2 precursor has been evaluated carrying out MOCVD at low temperature ranging 350°C to 400°C. On-line QMS analysis of the deposition process was used to characterize the precursor decomposition pathway. Physical and electrical properties of the films were evaluated by X-Ray Reflectrometry (XRR), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), Secondary Ions Mass Spectrometry (SIMS), and four-point probe. Oxygen containing, porous and amorphous WC x (x ∼ 0.5) and WN x C y (x ∼ 0.4, y ∼ 0.2) thin films have been achieved.

The plastic substrates, reflective layers, dyes, and adhesives of four archival-grade, recordable DVDs and one standard-grade recordable DVD were analyzed to determine their chemical compositions and/or physical dimensions. Chemical analyses by ATR-FTIR, ToF-SIMS, XPS, EDX/STEM, and RBS show that all these DVDs use very similar polycarbonate plastic substrates and acrylate-based adhesives, but different reflective layers and dye write layers. In addition, physical measurements by AFM show differences in the DVD groove depth, width, and other dimensions. These chemical and physical analyses may help explain variations in DVD lifetimes and facilitate development of the next generation archival-grade DVDs.

In this study, we explored the effect of hydrogen on sliding friction and wear behavior of a hydrogen-free DLC film in dry nitrogen. More specifically, we subjected this film to a very brief (~3 min) hydrogen plasma treatment in a sputter ion plating system to determine if the friction and wear behavior would change. All tests were performed in dry nitrogen using a pin-on-disk machine under a 0.5 N load and at 0.1 m/s sliding velocity. The friction coefficient of as-deposited DLC film was high and unsteady (varying between 0.1 and 0.8) and it could only last for a sliding distance of~12 m. However, after the hydrogen plasma treatment, the same film was able to provide a friction coefficient of less than 0.01 and lasted for a sliding distance of more than 450 m. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to elucidate the nature and extent of the chemical changes that occurred during hydrogen plasma treatment. 2-and 3-D TOF-SIMS images of such surfaces revealed the formation of a hydrogen-rich top surface layer during the hydrogenplasma treatment. Based on the combined results of tribological and surface analytical studies, we provided a mechanistic explanation for the very critical role of hydrogen on friction and wear of DLC films.

Epoxy resin composites reinforced with E-glass (E), 3D glass (3D) and carbon fibre (CF) were subjected to an intense UV and high temperature accelerated degradation environment. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to provide a molecular characterisation of the surface of the degraded composites. The response at the surface of the epoxy resin composites to oxidative degradation is influenced by the composite reinforcement type and characteristics. XPS results indicate that 3D resin composites exhibit more surface oxidation as a result of the accelerated degradation in comparison with E and CF composites. Principal components analysis (PCA) of the ToF-SIMS positive ion spectra showed that E and 3D resin composites suffered chain scission while CF composites suffered chain scission and cross-linking reactions as a result of the intense UV exposure. The extent of the surface oxidation, cross-linking/condensation reaction and loss of low molecular weight (lower than C 4 H x ) aliphatic hydrocarbons may be indicated using PCA of both the ToF-SIMS positive and negative ion spectra. PCA also provides insight for proposing epoxy resin chain scission and oxidation reaction mechanisms.

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was utilized to obtain characteristic mass spectra from three different smokeless powders and six different black powder samples. In these mass spectra, peaks indicative of both the organic and inorganic additive constituents in the gunpowders were observed. TOF-SIMS was able to successfully differentiate between the different black and smokeless gunpowder samples analyzed with the aid of principal components analysis (PCA), a multivariate statistical analysis approach often used to reduce the dimensionality of complex data. TOF-SIMS was also used to obtain information about the spatial distribution of the various additives contained within the gunpowder samples. SIMS imaging demonstrated that that the samples could potentially be characterized by their 2-D structure, which varied from sample to sample. These results clearly demonstrate the feasibility of utilizing TOF-SIMS as a tool for the characterization and differentiation of gunpowder samples for general forensic applications. #

- by Christine Mahoney and +1
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- Forensic Science, Principal Component Analysis, Mass Spectrometry, Secondary Ion Mass Spectrometry

Introduction: The combination of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) results in the formation of a precipitate. In a previous study, we demonstrated the formation of 4-chloroaniline (PCA) in the precipitate by using x-ray photon spectroscopy (XPS) and time of flight secondary ion mass spectrometry (TOF-SIMS). The TOF-SIMS results showed a peak at 127 amu, which is characteristic of 4-chloroaniline. However, this could also be characteristic of other isomers of 4-chloroaniline such as 2-chloroaniline and 3-chloroaniline. Aims and Methods: The aim of this study was to further identify the precipitate by using gas chromatography-mass spectrometry (GC-MS). Results: The results showed an absence of other aniline derivatives in the precipitate. Only PCA was found. Conclusions: Further investigations of the precipitate should address the bioavailability of PCA leaching out from dentin and its cytotoxicity. Until the precipitate is studied further, it would appear prudent to minimize its formation by avoiding the use of CHX together with NaOCl. (J Endod 2010;36:312-314)

- by Rana Sodhi
- •
- Dentistry, Secondary Ion Mass Spectrometry, Drug interactions, X Rays

Fluorine and chlorine X‑ray count rates are known to vary significantly during electron probe microanalysis (EPMA) of apatite. Since the rate, timing, and magnitude of this variation are a function of apatite orientation and composition, as well as EPMA operating conditions, this represents a significant problem for volatile element analysis in apatite. Although the effect is thought to be an intrinsic crystallographic response to electron-beam exposure, the mechanisms and causes of the count rate variability remain unclear. We tackle this by examining directly the effects of electron-beam exposure on apatite, by performing secondary ion mass spectrometry (SIMS) depth profiles of points previously subject to electron-beam irradiation. During irradiation of fluorapatite, oriented with the c-axis parallel to the electron beam, halogens become progressively concentrated at the sample surface, even under a relatively low power (15 nA, 10–15 kV) beam. This surface enrichment corresponds to an observed increase in EPMA FKa X‑ray count rates. After prolonged irradiation, the surface region starts to lose halogens and becomes progressively depleted, corresponding with a drop in EPMA count rates. Under normal EPMA operating conditions there is no halogen redistribution in fluorapatite oriented with the c-axis perpendicular to the electron beam, or in chlorapatite. We infer that anionic enrichment results from the migration of halogens away from a center of charge build-up caused by the implantation of electrons from the EPMA beam, assisted by the thermal gradient induced by electron-matter interactions. The process of surface enrichment is best explained by halogen migration through interstitial crystallographic sites in the c-axis channel. This suggests that once the thermal and electric fields are removed, halogens may relax back to their original positions on very long timescales or with sample heating.

- by Mike Stock and +2
- •
- Mineralogy, Crystallography, Secondary Ion Mass Spectrometry, Apatite

Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography with fluorescence detection (LC-FL) methods have been proposed for the determination of low level nitrite and nitrate in biological, food and environmental samples. The methods include derivatization of aqueous nitrite with 2,3-diaminonaphthalene (DAN), enzymatic reduction of nitrate to nitrite, extraction with toluene and chromatographic analyses of highly fluorescent 2,3-naphthotriazole (NAT) derivative of nitrite by using GC-MS in selected-ion-monitoring (SIM) mode and LC-FL. Nitrite and nitrate ions in solid samples were extracted with 0.5 M aqueous NaOH by sonication. The recoveries of nitrite and nitrate ions based on GC-MS and LC-FL results were 98.40% and 98.10% and the precision of these methods, as indicated by the relative standard deviations (RSDs) were 1.00% for nitrite and 1.20% for nitrate, respectively. The limits of detection of the GC-MS in SIM mode and LC-FL methods based on S/N = 3 were 0.02 and 0.29 pg/ml for nitrite and 0.03 and 0.30 pg/ml for nitrate, respectively.

- by mehmet akyuz
- •
- Analytical Chemistry, Water, Mass Spectrometry, Secondary Ion Mass Spectrometry

This paper reviews a range of instrumental microanalytical techniques for their potential in following the development of nanotechnology. Needs for development in secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM), Auger emission spectrometry (AES) laser mass spectrometry, X-ray photon spectroscopy are discussed as well as synchrotron-based methods for analysis. Objectives for development in all these areas for the coming 5 years are defined. Developments of instrumentation in three European synchrotron installations are given as examples of ongoing development in this field. D 2004 Published by Elsevier B.V.

Degradation of the photocathode materials employed in photoinjectors represents a challenge for sustained operation of nuclear physics accelerators and high power free electron lasers (FEL). Photocathode quantum efficiency degradation is due to residual gases in the electron source vacuum system being ionized and accelerated back to the photocathode. These investigations are a first attempt to characterize the nature of the photocathode degradation, and employ multiple surface and bulk analysis techniques to investigate damage mechanisms including sputtering of the Cs-oxidant surface monolayer, other surface chemistry effects, and ion implantation. Surface and bulk analysis studies were conducted on two GaAs photocathodes, which were removed from the JLab FEL DC photoemission gun after delivering electron beam, and two control samples. The analysis techniques include helium ion microscopy, Rutherford backscattering spectrometry (RBS), atomic force microscopy, and secondary ion mass spectrometry (SIMS). In addition, two high-polarization strained superlattice GaAs photocathode samples, one removed from the continuous electron beam accelerator facility (CEBAF) photoinjector and one unused, were also analyzed using transmission electron microscopy (TEM) and SIMS. It was found that heat cleaning the FEL GaAs wafer introduces surface roughness, which seems to be reduced by prolonged use. The bulk GaAs samples retained a fairly well organized crystalline structure after delivering beam but show evidence of Cs depletion on the surface. Within the precision of the SIMS and RBS measurements, the data showed no indication of hydrogen implantation or lattice damage from ion back bombardment in the bulk GaAs wafers. In contrast, SIMS and TEM measurements of the strained superlattice photocathode show clear crystal damage in the wafer from ion back bombardment.

This paper gives an overview of recent progress in microstructure-specific hydrogen mapping techniques. The challenging nature of mapping hydrogen with high spatial resolution, i.e. at the scale of finest microstructural features, led to the development of various methodologies: thermal desorption spectrometry, silver decoration, the hydrogen microprint technique, secondary ion mass spectroscopy, atom probe tomography, neutron radiography, and the scanning Kelvin probe. These techniques have different characteristics regarding spatial and temporal resolution associated with microstructure-sensitive hydrogen detection. Employing these techniques in a site-specific manner together with other microstructure probing methods enables multi-scale, quantitative, three-dimensional, high spatial, and kinetic resolution hydrogen mapping, depending on the specific multi-probe approaches used. Here, we present a brief overview of the specific characteristics of each method and the progress resulting from their combined application to the field of hydrogen embrittlement.

- by Dierk Raabe
- •
- Microstructure, Hydrogen, Secondary Ion Mass Spectrometry, Hydrogen Storage

Abstract—Surface properties have an enormous effect on the success or failure of a biomaterial device, thus signifying the considerable importance of and the need for adequate characterization of the biomaterial surface. Microscopy techniques used in the analysis of biomaterial surfaces include scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and confocal microscopy. Spectroscopic techniques include X-ray photoelectron spectroscopy, Fourier

Silicon samples implanted at medium fluences (2 × 1014-2 × 1015 ions/cm2) with arsenic, phosphorus and BF2 at 0° and 7° of tilt were analyzed by secondary ion mass spectrometry (SIMS) to investigate the effects of direct axial channeling on the as-implanted chemical profiles for a variety of experimental settings which are common in microelectronic device fabrication. The importance of axial channeling for each species is discussed and related to the actual implant energy and to the fluence required to obtain acontinuous amorphous silicon layer; arsenic (60-150 keV) and phosphorus (80-150 keV) dopant profiles are deeply affected by the implant tilt angle; on the contrary, boron resulting from the dissociation of BF2 molecule at 70 keV, has turned out to be less sensitive to implant angle configuration. The ineffectiveness of 7° of tilt in avoiding axial channeling is pointed out.

- by Mariano Anderle and +1
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- Geochemistry, Arsenic, Secondary Ion Mass Spectrometry, Phosphorus

A specially designed mill which allowed the control of pH throughout grinding was used to study the effect of grinding conditions on chalcopyrite flotation and chalcopyrite separation from pyrite. The mechanism of galvanic interaction between minerals and grinding media was investigated by ethylene diamine-tetra acetic acid disodium salt (EDTA) extraction and X-ray photoelectron spectroscopy (XPS) measurements.

The characterisation and comparison of pencil markings on paper is an area of questioned document analysis that has previously not received much attention. Despite this, there would be value in an examiner being able to analyse two pencil markings and coming to a conclusion about whether they were from a similar or different source. Previous studies have analysed raw materials and bulk pencil cores for purposes of characterisation and differentiation, but to date, no studies have successfully analysed pencil markings non-destructively off a paper substrate. In this work, pencils from a number of manufacturers were analysed by inductively coupled plasma mass spectrometry (ICP-MS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Analysis of data using multivariate techniques (principal component analysis), showed that ToF-SIMS can successfully be used to analyse such pencil markings to deduce whether two markings can be differentiated, in terms of inorganic elemental composition. It was possible to discriminate between pencil markings from different manufacturers, and it was also indicated that pencils from the same manufacturer, but discrete batches, can be significantly different. #

- by William Skinner and +1
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- Forensic Science, Principal Component Analysis, Mass Spectrometry, Secondary Ion Mass Spectrometry

We report small fibrous structures associated with a new specimen of Shuvuuia deserti, which we hypothesize are remnants of feather-like epidermal appendages. Multiple analyses suggest that these structures are epidermally derived and contain epitopes consistent with beta-keratin, a protein expressed only in extant "reptiles" and birds. Morphological, microscopic, mass spectrometric, and immunohistochemical studies are consistent with the interpretation that these structures are related to feathers. These data suggest that proteinaceous components may survive across geological time and support the view that alvarezsaurids (Shuvuuia and its allies) are either a lineage of birds or are a lineage phylogenetically close to them. J. Exp. Zool. (Mol. Dev. Evol.) 285:146-157, 1999.

- by Loren Knapp
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- Secondary Ion Mass Spectrometry, Phylogeny, Mongolia, Reptiles

The Yarlung Zangbo Suture Zone (YZSZ) is believed to be composed of material largely derived from the destruction of the Neo-Tethys that occurred from early Mesozoic to early Cenozoic. We report here geochronological and petrological data obtained for newly discovered alkaline gabbro blocks embedded in a mélange zone of the western YZSZ. Single zircon U-Pb analyses from one representative gabbro sample by SIMS (Secondary Ion Mass Spectrometry) yielded a combined crystallization age of about 363.7 ± 1.7 Ma (1σ). In situ Hf isotopic analyses yielded ε Hf (t) values of +2.6 to + 5.5, suggesting an enriched mantle source. All of the gabbro samples show typical Ocean Island Basalt (OIB) affinity with little or no continental crust contamination. They also display strong geochemical similarities with the Hawaii basalts and the Xigaze seamount basalts suggestive of their intra-oceanic setting. These observations, in combination with the Early Carboniferous layered gabbros reported at Luobusa, indicate that these rocks could represent remnants of the Paleo-Tethys. We propose that a branch ocean separating the Western Qiangtang terrane and the Lhasa terrane from the Gondwana continent might have been present during the Late Devonian and the Early Carboniferous, providing new constrains on the configuration of Paleo-Tethys in Tibetan Plateau during early Late Paleozoic.

- by Réjean Hébert
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- Geology, Geochemistry, Geophysics, Secondary Ion Mass Spectrometry

The use of focused ion beam (FIB) milling for the preparation of transmission electron microscopy (TEM) specimens is described. The operation of the FIB instrument is discussed and the conventional and lift-out techniques for TEM specimen preparation and the advantages and disadvantages of each technique are detailed. The FIB instrument may be used for rapid site-specific preparation of both cross-section and plan view TEM specimens. ᭧ PERGAMON 0968-4328/99/$ -see front matter ᭧

Mg redistribution into a subsequently regrown GaN epilayer by metalorganic chemical vapor deposition (MOCVD) is studied. Dopant profiles from secondary ion mass spectrometry (SIMS) on n-p-n GaN samples have been analyzed. The regrowth study in a Mg-free reactor reveals that a Mg-rich film is present on MOCVD as-grown GaN:Mg base layers and can be removed by an acid etch, and that a slow Mg decay into the sequentially regrown GaN results from this Mg-rich surface film. We believe the commonly seen Mg memory effect in MOCVD causes the accumulation of Mg on the surface. From a MOCVD regrowth on n-p-n GaN grown by molecular beam epitaxy (MBE), the Mg diffusion constant is calculated to be about 3 Â 10 À15 cm 2 /s at 1160 C for Mg concentrations between 5 Â 10 17 cm À3 and 1 Â 10 19 cm À3 . The roles of memory effect, surface segregation, and diffusion associated with Mg are addressed.

Secondary Ion Mass Spectrometry (SIMS) analyses were carried out on type 304 austenitic stainless steel. On annealed specimen exposed to hydrogen (10 MPa, 358 K), Element Depth Profiles SIMS mode was able to describe quantitatively the hydrogen profile content computed by the Fick's law. Based on SIMS analyses on the wake of a fatigue crack (propagation in hydrogen gas at 0.6 MPa and RT), it was possible to compute an apparent diffusivity and solubility in the crack tip region. The apparent solubility and diffusivity in the deformed regions were two times and five orders of magnitude higher than the ones on annealed material, respectively. High hydrogen content was found around the crack tip, where the plastic deformation was well developed (pronounced slip activity). The high apparent diffusivity is presumed to result from enhanced hydrogen transport induced by cyclic plastic activity at the crack tip.

- by Tohru Awane
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- Hydrogen, Secondary Ion Mass Spectrometry, Hydrogen Storage, Fatigue

The physical and chemical forms of sulfide mineral surfaces are reviewed. The initial surfaces and oxidation products have been studied by scanning Auger microscopy, X-ray photoelectron spectroscopy, scanning tunneling microscopy, atomic force microscopy, scanning electron microscopy and time-of-flight secondary ion mass spectrometry. Changes to surface speciation as a function of time, pH, Eh and collector adsorption, related to mineral flotation, have been followed with these techniques. Oxidation products are formed in different processes, namely: metal-deficient sulfides, polysulfides and sulfur; oxidized fine sulfide particles; colloidal hydroxide (e.g., Fe(OH) 3 , Pb(OH) 2 ) particles and flocs; continuous surface layers (e.g., hydroxide, oxyhydroxide, oxide species) of varying depth; sulfate and carbonate species; isolated, patchwise and face-specific oxide, hydroxide and hydroxycarbonate development. The actions of collector molecules (e.g., xanthate, dithiophosphinates) have been identified in various modes, namely: adsorption to specific surface sites; colloidal precipitation from solution; detachment of small sulfide particles from larger particle surfaces; detachment of small oxide/hydroxide particles; removal of adsorbed and amorphous oxidized surface layers; inhibition of oxidation; disaggregation of larger particles; and patchwise or face-specific coverage. The different modes of oxidation and collector action are exemplified using case studies from the literature and recent research.

Talc mineralisation occurs as hematite–talc schist between soft hematite ore and dolomitic itabirite at Gongo Soco, Quadrilátero Ferrífero of Minas Gerais, Brazil. The hematite–talc schist and soft hematite have a prominent tectonic foliation of tabular hematite. Tabular hematite without preferential orientation is superimposed on the tectonic foliation. The talcose schist is enriched in F and has a constant Fe/S ratio. Electron-microprobe analyses indicate trace amounts of S in different generations of hematite. The whole-rock Fe/S ratio possibly represents sulfate S from hematite-hosted fluid inclusions. Fluid inclusions in foliation-overprinting hematite and chlorite geothermometry from talcose rocks suggest, respectively, temperatures from <200°C to ~300°C. Tourmaline, a rarely observed mineral in the hematite–talc schist, belongs to the alkali group and falls in the dravite compositional field. Boron-isotope determinations of tourmaline crystals, using secondary ion mass spectrometry, vary from −20‰ to −12‰ δ11B. This compositional isotopic range and the tourmaline chemical composition suggest a meta-evaporitic origin. A non-marine evaporitic setting is the most likely source of acidic, highly oxidising fluids, which resulted in the abundant F-bearing talc and the presence of otherwise immobile Ti in hematite. Oxidising brines were channelled along shear zones and converted dolomitic itabirite into the Gongo Soco soft hematite and the talc mineralisation. The latter is envisaged as the hydrothermal wall-rock alteration of dolomitic itabirite, which gave rise to the soft hematite ore.

- by tis faculdade de minas
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- Geology, Geochemistry, Secondary Ion Mass Spectrometry, Mineral Chemistry

Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) was applied to validate GRGDS peptide patterned surfaces. The structuring of the surfaces included several steps: micro contact printing (lCP), chemical etching and aminofunctionalization followed by chemical coupling of spacer-linked GRGDS peptides via an isothiocyanate anchor. TOF-SIMS analysis of characteristic ions and molecular fragments with a lateral resolution of 100 nm allowed proving the change in chemical properties of the surface with each step during the structuring process. We found that the application of polydimethylsiloxane as stamp material resulted in the contamination of the surface with this polymer. TOF-SIMS investigations, however, also showed that during the preparation process the contaminations were removed and do not influence the bio functionality of the surface patterns. The results of the surface analysis carried out with TOF-SIMS were confirmed by complementary cell adhesion experiments with murine fibroblasts. As a result, specific cell adhesion restricted to GRGDS peptide functionalized areas was obvious by the formation of focal adhesion contacts in the fibroblasts. Thus, TOF-SIMS is the method of choice in chemical characterization of surfaces in structuring and functionalization processes, because it offers the opportunity to follow surface contamination during the preparation process and to assess the influence of the contamination on the applicability of the final substrate.

This study thoroughly explores the use of time-of-flight secondary ion mass spectrometry (ToF-SIMS) for determining the deposition sequence of fingermarks and ink on a porous paper surface. Our experimental work has demonstrated that mapping selected endogenous components present in natural fingermarks enables the observation of friction ridges on a laser-printed surface, only when a fingerprint is deposited over this layer of ink. Further investigations have shown limited success on ink-jet printing and ballpoint pen inks. 51 blind tests carried out on natural, latent fingermarks on laser-printed surfaces; up to 14th depletion with samples aged for up to 421 days have resulted in a 100% success rate. Development with ninhydrin was found to affect the fingermark residue through mobilisation of ions, therefore sequencing determination was compromised; whilst iodine fuming and 1,2-indanedione developers did not. This implied that selected development methods affected success in fingermark-ink deposition order determination. These results were further corroborated through inter-laboratory validation studies. The adopted protocol and extensive series of tests have therefore demonstrated the effectiveness and limitations of ToF-SIMS in providing chronological sequencing information of fingermarks on questioned documents; successfully resolving this order of deposition query. N Attard Montalto, JJ Ojeda, A Reynolds, L Doodkorte, M de Puit, M Ismail, M Bailey, and BJ Jones Analyst, 2014,139, 4641-4653

Barium impact on the gate oxide breakdown was studied using E-ramp and constant current stress (CCS) charge to breakdown. Wafers were contaminated with Ba after a 7.5 nm gate oxide growth and 300 nm poly-silicon deposition. The measurements were done on capacitors having areas of 0.1, 1, 4, and 16 mm 2. Up to a contamination level of 4 Â 10 14 atoms/cm 2 no degradation in oxide integrity was observed either by E-ramp or CCS. Time of flight (ToF)-SIMS measurement of Ba diffusion profile at 800°C shows a diffusion of Ba over distances of some tens of nanometers, thus Ba does not reach the gate oxide region. The effect on the gate oxide breakdown can be correlated with the slow diffusion of Ba in poly-Si. Therefore, no major concern of yield and reliability due to Ba contamination is seen for the integration of Ba containing dielectrics into memories.

Hydrogen depth distributions in silicon, zinc oxide, and glass are of great interest in material research and industry. Time-offlight SIMS has been used for hydrogen depth profiling for many years. However, some critical information, such as optimal instrumental settings and detection limits, is not easily available from previous publications. In this work, optimal instrumental settings and detection limits of hydrogen in silicon, zinc oxide, and common glass were investigated. The recommended experimental settings for hydrogen depth profiling using time-of-flight SIMS are: (i) keeping pressure in the analysis chamber as low as possible, (ii) using a cesium beam for sputtering and monitoring the Hsignal, (iii) employing monatomic ion analysis beams with the highest currents, and (iv) using interlace mode. In addition, monatomic secondary ions from a matrix are recommended as references to normalize the Hsignal. Detection limits of hydrogen are limited by the pressure of residual gases in the analysis chamber. The base pressure of the analysis chamber (with samples) is about 7 Â 10 À10 mbar in this study, and the corresponding detection limits of hydrogen in silicon, zinc oxide, and common glass are 1.3 Â 10 18 atoms/cm 3 , 1.8 Â 10 18 atoms/cm 3 , and 5.6 Â 10 18 atoms/cm 3 , respectively.

- by Mark Engelhard
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- Condensed Matter Physics, Glass, Secondary Ion Mass Spectrometry, Zinc Oxide

Fluid-saturated experiments were conducted to investigate the partitioning of boron among haplogranitic melt, aqueous vapor and brine at 800 °C and 100 MPa. Experiments were carried out in cold-seal pressure vessels for 1 to 21 days, and utilized powdered synthetic subaluminous haplogranite glass doped with 1000 ppm B (crystalline H3BO3) and variable amounts of NaCl and H2O at a fluid/haplogranite

- by Graham D. Layne and +2
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- Geology, Geochemistry, Secondary Ion Mass Spectrometry, Chemical Geology

The aim of this review is to give a compact overview about the literature on mass spectrometry (MS) of polymers published during 2006/2007. The citations are drawn from SciFinder January 25, 2008, using the search terms "poly*" and "mass spectrometry" with restrictions to review and journal contributions in the English language including refined searches in Web of Science. More than 750 relevant papers, reviews, (1, 2) and historical summaries were published in these two years, demonstrating the importance of MS for polymer analysis. We were therefore forced to select the most important references. This is always a subjective decision and may not always represent the best choices. In contrast to the previous review in this series (5), which focused on MS principles, including matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF), electrospray ionization (ESI) TOF, TOF secondary ion mass spectrometry (SIMS), etc., in this paper, we categorize according to applications of MS for polymer analysis. Even this choice is arbitrary.

An electrically active defect has been observed at a level position of ϳ0.70 eV below the conduction band edge (E c ) with an extrapolated capture cross section of ϳ5ϫ10 Ϫ14 cm 2 in epitaxial layers of 4H-SiC grown by vapor phase epitaxy with a concentration of approximately 1ϫ10 13 cm Ϫ3 . Secondary ion mass spectrometry revealed no evidence of the transition metals Ti, V, and Cr. Furthermore, after electron irradiation with 2 MeV electrons, the 0.70 eV level is not observed to increase in concentration although three new levels are observed at approximately 0.32, 0.62, and 0.68 eV below E c with extrapolated capture cross sections of 4ϫ10 Ϫ14 , 4ϫ10 Ϫ14 , and 5ϫ10 Ϫ15 cm 2 , respectively. However, the defects causing these levels are unstable and decay after a period of time at room temperature, resulting in the formation of the 0.70 eV level. Our results suggest strongly that the 0.70 eV level originates from a defect of intrinsic nature. The unstable behavior of the electron irradiation-induced defects at room temperature has not been observed in the 6H-SiC polytype.

Fluxless bonding can be used for fine-pitch low-soldervolume interconnections for three-dimensional large-scale integrated-circuit (3D-LSI) applications. Surface treatments with hydrogen radicals, formic acid, vacuum ultraviolet (VUV), and Ar plasma were evaluated as candidate methods for fluxless bonding. Three-µm-thick Sn solders were evaluated for intermetallic-compound (IMC) bonding of 3D integration as a target material for fluxless bonding. X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a scanning electron microscope (SEM), and a focused ion beam scanning ion microscope (FIB-SIM) were used to examine the samples. The experiments shows solder oxides and organic contaminants on the surfaces of the microbumps were most effectively eliminated without flux by hydrogen radical treatment among various treatments we evaluated. Bonding strength was also improved by the hydrogen radical treatment, since the shear strength was more than 50 times stronger than that of the untreated samples. 2011 Electronic Components and Technology Conference

Atomic force microscopy and secondary ion mass spectrometry measurements have been performed on high temperature (1320 °C) annealed polycrystalline Si/SiO2/single crystal Si structures. Enhanced oxygen out-diffusion from the Sit 2 film and the growth of Sit2 protrusions into the polycrystalline Si are observed resulting in interfaeial "degradation"/roughening up to 100 nm into the polycrystalline Si. Only minor roughening is observed at the crystalline Si/SiO2 interface. It is argued that the presence of grain boundaries accelerates the O out-diffusion process.

- by D. Mathiot
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- Engineering, Technology, Secondary Ion Mass Spectrometry, Atomic Force Microscopy

Arsenic (As) and phosphorus (P) implantations are concurrently used to create the n-zones of recent microelectronic device pn-junctions. We studied the As-P codiffusion effect on the junction depths during the dopant activation process. As diffusion is accelerated during codiffusion. The acceleration magnitude depends on As concentration and varies during annealing time. Contrasting with usual transient-enhanceddiffusion phenomena, a time delay can be observed before As diffusion acceleration occurs. P diffusion shows no specific modification due to codiffusion. Its diffusion behavior can be understood considering the usual Fermi level and electrical effects linked to the time evolution of the two dopant distributions. The behavior of As during codiffusion is discussed using finite element simulations.

- by C. Girardeaux
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- Engineering, Technology, Arsenic, Secondary Ion Mass Spectrometry

The present study illustrates the interest of using the elastic recoil detection analysis (ERDA) method to characterize any geological sample matrix with respect to hydrogen. ERDA is combined with Rutherford back scattering (RBS) and particle induced X-ray emission (PIXE), allowing the simultaneous characterization of the matrix with respect to major and trace elements (Z > 15). Analyses are performed by mapping of a 4 Â 16 lm 2 incident beam of 4 He + on large areas (50 Â 200 lm 2 ). The method is almost not destructive and requires no calibration with respect to well known hydrous samples. Hydrous and nominally anhydrous phases in contact with each other in the same sample may both be characterized. The depth of the analyses is limited to several lm beneath the surface, allowing tiny samples to be investigated, provided their sizes are larger than the incident beam. Our setup has been improved in order to allow H determination on a micrometric scale with a 5-15% relative uncertainty and a detection limit of 94 wt ppm H 2 O. We present multi-elemental mappings on a large panel of samples: (1) natural and analogue synthetic glasses from Stromboli volcano (0.44-4.59 wt% H 2 O), natural rhyolitic glasses (1466-1616 wt ppm H 2 O); (2) magmatic rhyolitic melt inclusions from Guadeloupe Island (4.37-5.47 wt% H 2 O) and their quartz host crystal (2020 ± 230 wt ppm H 2 O); (3) nominally anhydrous natural (82-260 wt ppm H 2 O) and experimentally hydrated (240-790 wt ppm H 2 O) olivines; natural clinopyroxenes (159-716 wt ppm H 2 O); natural orthopyroxenes (201-452 wt ppm H 2 O); a natural garnet (90 wt ppm H 2 O)