Charge neutralization, SIMS instrument

SIMS Analysis. The equipment and instrumental conditions have been described in detail (7.121. Mostly, a model 6300 Perkin Elmer spectrometer was used which was equipped with a 0-255 amu quadrupole mass analyzer. The primary beam of 4.5 keV Xe+ and 60 pA current was rastered in a 2x2 mm2 area. The total ion dose was not more than 3xl012 ions per cm2, which is considered a practical limit for static conditions (5rZ)- Charge neutralization was done by means of 500 eV electrons. Spectral optimization has been described (7.121. 

Some spectra were recorded on a non-commercial SIMS instrument designed and built at EG G in Idaho Falls, ID. It has been described (13.141. Essentially, it is equipped with a primary source of SF6 neutrals and anions and a 0-2000 amu quadrupole mass analyzer. Qualitatively, the spectra obtained were identical to those of the commercial instrument, but the secondary ion yield was higher and charge neutralization was not required. 

In Dynamic Secondary Ion Ma s Spectrometry (SIMS), a focused ion beam is used to sputter material from a specific location on a solid surface in the form of neutral and ionized atoms and molecules. The ions are then accelerated into a mass spectrometer and separated according to their mass-to-charge ratios. Several kinds of mass spectrometers and instrument configurations are used, depending upon the type of materials analyzed and the desired results. 

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