5 Commissioning and First Operating Steps | 5.5 Modifying Gun Parameters
ZEISS
5.5.3 Setting the Probe Current
You can set a lower probe current to analyze surface details at a high resolution or higher probe
currents for analytical purposes, e.g. to analyze the material of the specimen.
Info
The maximum achievable probe current depends on the currently selected EHT and the in-
stalled aperture configuration.
Procedure
1. In the SEM Controls panel, select the Gun tab.
2. Activate the
OptiProbe
checkbox.
3. Double-click the
I Probe
readout.
à
The
I Probe
window is displayed.
4. In the input field, enter the desired value.
5.5.4 Continuously Modifying the Probe Current (License: OPTIPROBE)
Info
OptiProbe allows you to continuously adjust the probe current. The function automatically se-
lects a suitable aperture and the current mode while the extractor voltage is adjusted to meet
the probe current selected by the user.
Info
After cathode replacement or after re-alignment of the electron optical column, OptiProbe has
to be calibrated.
Prerequisite
ü
Requires the licenses OPTIPROBE and HIGH VOLTAGE
ü
Particular hardware and the specimen current amplifier are installed.
Procedure
1. In the SEM Controls panel, select the
Gun
tab.
2. Activate the
OptiProbe
checkbox.
3. Use the
I Probe
slider to set the desired probe current.
à
As soon as the probe current adjustment is finished, the
OptiProbe Status
readout
changes from
Busy
to
Ready
.
à
The probe current displayed in the
I Probe
readout corresponds to the actual probe cur-
rent (± 15 %).
4. To deactivate the function, deactivate the
OptiProbe
checkbox.
INFO:
If
OptiProbe
is deactivated, the
I Probe
readout continues to indicate the actual
probe current (± 15 %).
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.
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Instruction Manual ZEISS SIGMA series | en-US | Rev. 7 | 352102-9344-006
