masses up to 10,000 mass units can be routinely measured
separation of isotopes
chemical information can be obtained by identifying molecular
and cluster sputtered ions
detection limits of 1 ppm of a monolayer
surface sensitivity < 1nm
lateral resolution better than 100 nm for elements, or 0.5
um for big molecules
depth resolution < 1nm
Operational
regimes and modes odes
of operation
The operational regimes
include:
surface analysis - also known as Static SIMS - employs low
primary ion densities and low ion dose to prevent surface destruction
as much as possible
imaging - using fine focussed ion beam rastering over the
surface produces mass resolved images of the surface
depth profiling - known as Dynamic SIMS - high primary ion
dose densities are applied to remove the surface layer by layer;
by acquiring spectra during the sputtering the in-depth distribution
of elements and small clusters (e.g. oxides) can be monitored.
The modes
of operation and the involved analysis parameters depend on the
instrument used. A table for our instrument can be found if you
click on the link below.
Applications
Microelectronics
for detecting surface contamination (elemental, molecular), de-lamination,
lubricant degradation, depth distribution of impurities; thin
films technology, corrosion, painting failure (such as craters)
etc.
