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5 Commissioning and First Operating Steps | 5.5 Modifying Gun Parameters
ZEISS
7. Deactivate the
Touch Alarm Disable
checkbox.
INFO:
The
Touch Alarm Disable
option connects the stage potential with low impedance
to the ground. This may be required with the usage of micromanipulators. Activating this
checkbox disables both, touch alarm and specimen current measurement.
à
This activates the touch alarm that helps to avoid collisions of the stage.
8. Move the stage to the position of the Faraday cup.
9. Acquire an image of the Faraday cup.
10. Activate the
Spot
checkbox.
à
Green crosshairs are displayed on the image. This crosshairs indicate the position of the
beam spot.
11. Grab the crosshairs and move them into the hole of the Faraday cup.
à
The probe current is measured continuously.
à
The measured probe current is displayed in
the
Specimen I
readout.
5.5.5 Changing the Extractor Voltage
The Extractor voltage is preset by the factory or by the ZEISS service representative. Within certain
limits, the operator may carefully increase the extractor voltage in order to optimize the probe
current for particular applications.
Info
Use a Faraday cup to measure the probe current when changing the extractor voltage.
Info
The newly set extractor value is only valid for the current work session. After a restart of the
SmartSEM software, the microscope restores the nominal extractor voltage.
Info
Reducing the extractor voltage may impair the performance and resolution of the microscope.
4
Avoid reducing the extractor voltage.
4
If at all, reduce the extractor voltage only for a short time (1–2 h) and by maximum 500 V.
Prerequisite
ü
The user privilege
Extractor
is required to change the extractor voltage.
Procedure
1. From the
Menu Bar
, select
Beam > Gun Setup
.
à
The
Gun Service
dialog is displayed.
2. To increase the extractor voltage, double-click the
Extractor V Target
readout.
à
The
Extractor V Target
window is displayed.
3. Enter a higher value.
4. Click
OK
.
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Instruction Manual ZEISS GeminiSEM series | en-US | Rev. 2 | 349500-8138-000