18
PIPS II Owners Manual and Users Guide
guns is minimized, and gun consumables have been eliminated. The new
focus electrodes in each gun have improved the low energy spot size, keeping
the spot size approximately constant across all beam energies. This results in
dramatically faster milling rates at low energy, such that it is now practical to
mill to perforation at energies as low as 100 eV.
1.1.3.
Gas Flow Optimization
The optimum gas flow for all beam energies is calibrated at the factory, and
may be selected by using the automatic gas flow option. The gas flow of each
gun may also be set manually.
1.1.4.
Compact Vacuum System
Specimen contamination is reduced with an oil-free vacuum system consisting
of a molecular drag pump (MDP) backed by a 2-stage diaphragm pump (DP).
Additionally, a liquid-nitrogen trap is available to further reduce contaminants
and water vapor.
1.1.5.
Touch-screen Interface
Operation of the system is controlled by the user via a touch-screen interface,
which is customer selectable between several languages.
1.1.6.
Versatile Sample Holders
The Gatan specimen post, for single-sided milling, and the DuoPost, for
double-sided milling, eliminate transfer of material onto the specimen by
secondary sputtering from the specimen platform and provide excellent
thermal contact with the specimen to prevent specimen overheating. Lastly,
both specimen posts allow the specimen to have an unobstructed view of the
ion beam and thus ion polishing can be performed at angles approaching 0°.
In order to allow for centering the thin section at the rotation axis the sample
mount includes a manual x-y stage. This allows the user to compensate for a
sample that is mounted off-axis in the post.
1.1.7.
Stereo Microscope
An optional optical stereo microscope is used to inspect the specimen in its
working position at any time during the thinning process to achieve very
precise control over the final stage of specimen thinning. This feature is
especially important for insulators and semi-conductors since these materials
are transparent to light and the interference-fringe technique can be used to
control the final specimen thickness in the region of interest to an accuracy of
about ±10 nm.
