Page 179 - Inorganic Mass Spectrometry - Fundamentals and Applications

Secondary Ion Mass Spectrometry 167

A-DIDA System 1 ion Source 8 Gate Valve 15 Target Manipulator
2 Extraction Electrode 9 Beam Deflection 16 Sam le Holder (opt.)
3 Acceleration Electrode 10 Orfice (optlonal) 17 Blana) Po?
4 Insulator 11 Beam Monitor (opt.) 18 Energy Filter
5 Cover 12 View Port 19 Mass Spectrometer
6 Turbomolecular Pump 13 UHV-Pump 20 Particle Multiplier
7 Orifice 14 Blank Port

Atomika Dynamic In Depth Analyzer (ADIDA), quadrupole-based-imaging
secondary ion mass spectrometry (SIMS) instrument.

The development of high-brightness field desorption liquid metal ion sources
allowed sub~crometer images to be obtained. In 1975 Krohn and Ringo suggested
that a finely focused liquid metal ion source could be used for scanning probe SIMS
et
imaging [46]. In 1979 Seliger al. demonstrated a liquid gallium ion source with
a
a 100-nm-diameter beam with current density of 1.5 Ncm2 [47]. In 1980 Prewitt
and Jeffries obtained the first secondary ion images, using liquid gallium source
a
of
E4.81. A notable application of the liquid metal ion source was the development
a high-image-resolution SIMS instrument by Levi-Setti and coworkers at the Uni-
versity of Chicago [49] (Fig. 4.10). This instrument operated in the 4.0- to 60-keV
range and demonstrated image resolution of 20 nm with a 4.0-keV In* probe [3].
The application of time-of-flight (TOE;) mass spectrometers to SMS was
first reported by Chait and Standing in 198 1 [so]. Their instrument used a pulsed
alkali metal ion source and a linear flight tube. Steffens et al. developed an im-