ZEISS
3 Product and Functional Description | 3.2 Main Components
Operating
Principle
Gallium ions (Ga⁺) are extracted from a liquid metal ion source
1
. The ions are accelerated by
the acceleration voltage to an energy of maximum 30 keV. The ion emission is adjusted by the ex-
tractor and the suppressor voltage.
Gallium is used up during operation. Therefore, the gallium emitter cartridge is a consumable.
The gallium emitter has to be regenerated by heating from time to time; the heating procedure
removes the gallium oxide, which has been created during operation.
Condenser
The electrostatic condenser collimates and focuses the ion beam.
Probe Currents
After passing the condenser, the beam current is defined by a set of software-controlled mechani-
cal apertures. By using the different apertures in combination with the different condenser set-
tings, the probe current can be continuously adjusted in the range between 1 pA and 100 nA.
Objective Lens
The objective lens is designed as an electrostatic Einzel-lens system. It focuses the beam onto the
specimen surface.
3.2.3.1 Imaging Modes
Purpose
With the FIB option, different imaging modes are available to operate the microscope.
1
2
3
Fig. 11: Imaging modes available with the
option
Imaging Mode
FIB Mode
Characteristics
Typical Application
1
SEM imaging
§
Electron beam is active.
§
Ion beam is blanked.
§
The SE signal is synchronized
to the SEM scan.
High resolution imaging.
2
FIB imaging
§
Electron beam is blanked.
§
Ion beam is active.
§
The SE signal is synchronized
to the FIB scan.
§
Channeling contrast imaging.
§
Voltage contrast imaging.
§
Defining milling patterns on the
specimen surface.
§
Grain analysis.
3
Crossbeam
operation
Image is composed of SEM and
FIB components.
Setting the coincidence point.
Mill
§
No image.
§
Mills with the milling parame-
ters set (milling current).
§
Ion beam milling or ion beam
deposition.
Instruction Manual ZEISS Crossbeam 350 | en-US | Rev. 3 | 349500-8111-000
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