Ion Beam Spectrochemical Analysis IBSCA

Ion beam spectrochemical analysis (IBSCA) is a sputtering-based surface analytical technique similar to SIMS/SNMS. In IBSCA the radiation emitted by excited sputtered secondary neutrals or ions is detected. IBSCA was developed parallel to SIMS in the nineteen-sixties and early nineteen-seventies [4.246, 4.247]. It is also known 

For IBSCA analysis, standard HV or, better, UHV-equipment with turbomolecular pump and a residual gas pressure of less than 10 Pa is necessary. As is apparent from Fig. 4.46, the optical detection system, which consists of transfer optics, a spectrometer, and a lateral-sensitive detector, is often combined with a quadrupole mass spectrometer for analysis of secondary sputtered particles (ions or post-ionized neutrals). 

Typical ion sources employ a noble gas (usually Ar). The ionization process works either by electron impact or within a plasma created by a discharge the ions are then extracted from the region in which they are created. The ions are then accelerated and focused with two or more electrostatic lenses. These ion guns are normally operated to produce ions of 0.5-10 keV energy at currents between 1 and 10 pA (or, for a duoplasmatron, up to 20 pA). The chosen spot size varies between 100 pm and 5 mm in diameter. 

In insulator analysis an electron gun is also necessary to compensate for the positive ion current at the sample surface. Two types of operation are typical. 

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