Sputtered neutral mass spectroscopy

INTERFACIAL CHEMISTRY CHARACTERIZED BY XPS AND SPUTTERED NEUTRAL MASS SPECTROSCOPY... 

The superior corrosion performance and strong adhesion of the plasma coating system can be attributed to the coating properties and, more importantly, to the nature of interfacial chemistry. Two techniques were applied to study the surface and interfacial chemistry of the plasma coating system (1) in situ plasma deposition and XPS analysis and (2) in-depth profiling of sputtered neutral mass spectroscopy (SNMS). 

SNMS Sputtered Neutral Mass Spectroscopy Surface, bulk Plasma discharge noble gases 0.6-20 keV Sputtered atoms ionized by atoms or electrons then mass analyzed 0.1-0.6 nm (or deeper ion milling) 1 cm Elemental analysis Z a 3 depth profile deleclion limit ppm 4.6... 

In other articles in this section, a method of analysis is described called Secondary Ion Mass Spectrometry (SIMS), in which material is sputtered from a surface using an ion beam and the minor components that are ejected as positive or negative ions are analyzed by a mass spectrometer. Over the past few years, methods that post-ion-ize the major neutral components ejected from surfaces under ion-beam or laser bombardment have been introduced because of the improved quantitative aspects obtainable by analyzing the major ejected channel. These techniques include SALI, Sputter-Initiated Resonance Ionization Spectroscopy (SIRIS), and Sputtered Neutral Mass Spectrometry (SNMS) or electron-gas post-ionization. Post-ionization techniques for surface analysis have received widespread interest because of their increased sensitivity, compared to more traditional surface analysis techniques, such as X-Ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES), and their more reliable quantitation, compared to SIMS. 

Another important characteristic is that ion beams can produce a variety of the secondary particles/photons such as secondary ions/atoms, electrons, positrons. X-rays, gamma rays, and so on, which enable us to use ion beams as analytical probes. Ion beam analyses are characterized by the respectively detected secondary species, such as secondary ion mass spectrometry (SIMS), sputtered neutral mass spectrometry (SNMS), electron spectroscopy, particle-induced X-ray emission (PIXE), nuclear reaction analyses (NRA), positron emission tomography (PET), and so on. 

There are several methods available to probe the actual interphase to demonstrate the existence of interpenetrating networks directly. Among these techniques are depth profiling by SIMS (secondary ion mass spectrometry) or SNMS (sputtered neutral mass spectrometry), and the use of X-ray photoelectron spectroscopy (XPS) depth profiling or Auger electron spectroscopy (AES) depth profiling. 

Sputtered neutral mass spectrometry (SNMS) depth profiles document that carbon is present in the skin of all fibers to a depth of about 50 nm (Figure 15), whether a given fiber has a secondary carbon sheath overgrowth or not [11]. X-ray photoelectron spectroscopy (XPS)... 

FIGURE 40.18 Depth profiles by laser secondary neutral mass spectrometry (laser SNMS), secondary ion mass spectrometry (SIMS) with Ar and 02 primary ions, and Auger electron spectroscopy (AES) of implanted boron. Reprinted from Higashi, Y., Quantitative depth profiling by laser-ionization sputtered neutral mass spectrometry (1999) Spectrochimica Acta Part B Atomic Spectroscopy, 54(1), 109-122. Copyright (1999), with permission from Elsevier Science. 

Higashi, Y. (1999) Quantitative depth profiling by laser-ionization sputtered neutral mass spectrometry. Spectrochimica Acta Part B Atomic Spectroscopy, 54, 109-122. 

We will first consider, however, Secondary Ion Mass Spectroscopy (SIMS) in which both neutral and charged species are sputtered from the surface, and detected by means of a mass spectrometer. This involves ion beams of lower energy than in the techniques described previously. 

Resonant and non-resonant laser post-ionization of sputtered uranium atoms using SIRIS (sputtered initited resonance ionization spectroscopy) and SNMS (secondary neutral mass spectrometry) in one instrument for the characterization of sub-pm sized single microparticles was suggested by Erdmann et al.94 Resonant ionization mass spectrometry allows a selective and sensitive isotope analysis without isobaric interferences as demonstrated for the ultratrace analysis of plutonium from bulk samples.94 Unfortunately, no instrumental equipment combining both techniques is commercially available. 

Hi) Methods based on mass spectrometry Spark-source mass spectrometry Glow-discharge mass spectrometry Inductively coupled-plasma mass spectrometry Electro-thermal vaporization-lCP-MS Thermal-ionization mass spectrometry Accelerator mass spectrometry Secondary-ion mass spectrometry Secondary neutral mass spectrometry Laser mass spectrometry Resonance-ionization mass spectrometry Sputter-initiated resonance-ionization spectroscopy Laser-ablation resonance-ionization spectroscopy... 

Ions have greater masses than electrons thus their transfer of energy to surface species is much more efficient. Ions incident on surfaces can break chemical bonds and eject atoms, molecules, or molecular clusters. Most of these species are neutral, but the ion impact may also ionize a fraction of these ejected particles. The detection of these ions, called secondary-ion mass spectroscopy (SIMS), is an important technique of surface-composition analysis. Ion bombardment is used frequently to remove unwanted molecular or atomic layers of impurities in order to clean a surface efficiently. Ion sputtering is also used to deposit thin films of the bombarded material... 

SNMS Secondary (sputtered) neutral (ion) mass spectroscopy... 

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