FEI Quanta FEG 250, User'S Operation Manual

Page: 104 / 228

Alignments: Quanta FEG System Alignments
6-2
Quanta FEG System Alignments
At the Alignments page select an alignment procedure available from
the list box. Always follow the instructions given in the Instructions
module. You can find some additional explanation in this chapter.
COMMON RULES
Alignments should be performed in the quad 1. In other case it is not
possible to ensure the correct functionality of the Contrast, Brightness
and Auto functions used at the Alignments pages.
Before you align the Electron column, be sure that the final lens
aperture is clean and properly centred.
During adjustment procedures it is allowed to change the
magnification, the scanning speed, to use reduced area and to
optimize an image contrast / brightness. It is also possible to correct
an astigmatism and to focus an image (for a particular alignment it is
forbidden).
During adjustment procedures it is not allowed to change a Vacuum
Mode, a Spot size and a High Voltage. Do not use the Beam Shift at
any time during the adjustment procedures, as this is set to the zero
value at each alignment section. All specimen movements can be
made using the stage, either mechanical or motor driven, where
appropriate.
TABLE 6-1 ALIGNMENT PROCEDURES OVERVIEW
Procedure Function
Final Lens Aperture Strip
Alignment Mechanical alignment eliminates image shift when focusing.
1 - Gun Alignment Centres the electron beam at various high voltages and spot sizes.
2 - Stigmator Alignment Eliminates image shift during normal stigmator correction.
3 - Stage Rotation Center Sets the stage rotation centre for the compucentric rotation.
5 - Emitter Startup Enables electron gun - Emitter switching On / Off.
94 - CCD Camera Alignment Optimizes the CCD camera imaging performance.
154 - Venting Water Bottle Enables to vent the water bottle in case of refilling