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

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... more

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.

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,... more

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.

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... more

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.

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... more

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... more

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.

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... more

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.

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... more

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.

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... more

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.

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... more

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

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... more

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