Life Sciences Commons^™

Secondary Ion Mass Spectrometry Of Glasses: Aspects Of Quantification, H. Odelius, A. R. E. Lodding, L. O. Werme, D. E. Clark

Scanning Electron Microscopy

SIMS routines have been developed for the analysis of oxide materials, with applications particularly in element profiling of corrosion layers on glasses after weathering or leaching. The possibilities of quantification and reproducibility have been found critically sensitive to the buildup of charge on the insulating specimens. With control of constant specimen potential, relative sensitivity factors in the positive mass spectrum have been determined for about 20 elements in 10 different alkali-borosilicate glasses. Secondary ion yields were studied as functions of the energy range of ions admitted to the analyzer. At relatively low energies, including the top of the energy distribution, …

Sputter Crater Contour Mapping With Multilayered Films, L. L. Levenson, T. P. Massopust, J. Dick, M. C. Jaehnig, D. Griffith

Scanning Electron Microscopy

Multilayered films composed of alternating 200 Å Al and 267 Å Al203 layers are made by physical vapor deposition. Twenty-two pairs of these films are deposited on a polished Si wafer. Ion beam sputtering is used to form craters in the multilayered film. When a crater is viewed or photographed in situ by scanning electron microscopy, the Al₂O₃ layers appear bright and the Al layers appear dark. In the scanning electron microscope (SEM) the Al₂O₃ layers have a high secondary electron yield compared to Al. In secondary ion mass spectrometry (SIMS), using Cs^{+ …}

Mineralogical Application Of The Ion Microscope Elementary Analysis, A. Havette

Scanning Electron Microscopy

The ion microscope is an instrument which allows the study "in-situ" of polished solid surfaces by means of analysis of secondary ions emitted by the sample, this one being bombarded with neutral or ionized particles.

This instrument is a mass spectrometer and an ion microscope. It is then possible to study elements and their isotopes (mass spectra, counting, isotope abundances...) and to know the distribution of these elements in an area of around one hundred micrometers. Molecular and multicharged ions can be superimposed to elementary ions. Two methods can be used to suppress them but, in any case, it results …

Limits Of Quantitative Microanalysis Using Secondary Ion Mass Spectrometry, Peter Williams

Scanning Electron Microscopy

The limitations on secondary ion micro-analytical performance imposed by ionization probabilities, mass spectrometer transmission, requirements for standards and sputtering artifacts have been investigated. The sensitivity of a modern magnetic mass spectrometer for sputtered B⁺ from oxidized Si is ~ 10^-2 ions detected/atom sputtered. For this sensitivity, it is shown that ion microscopy of a part-per-million impurity is limited in lateral resolution to ~ 1 μm. For a 1% impurity, lateral resolution of ~ 30 nm is achievable. Depth profile analysis at the ppm level requires sample areas ~ 10 μm². Isotope abundance determinations in volumes ~ …