5 Commissioning and First Operating Steps | 5.6 Working with Different Aperture Configurations and
Beam Modes
ZEISS
§
300 nA high current configuration
Anode aperture diameter
Probe current
Typical application
150 μm
3 pA to 300 nA
Special high-current applica-
tions
*
Calibration value: deviation of 10 % possible
Info
If you wish to change the installed configuration of your microscope, contact your local ZEISS
service representative.
Procedure
1. From the
Menu Bar
, select
View > SEM Status
.
à
The
SmartSEM Status
dialog is displayed.
2. In the
Select
tab, click
Anode Aperture Diameter
.
3. Select the
Display
tab.
à
The parameter
Aperture Size
is displayed.
5.6.3 Selecting the Aperture
With a Gemini 1 column, you can control the probe current by changing to a different aperture
within the multihole aperture.
Depending on your configuration (20 nA configuration or 100nA configuration) different aper-
tures are available.
The default aperture (central aperture / (1) 30 μm Aperture) has the optimum convergence angle
for the primary beam and the best resolution. The default aperture is suitable for most applica-
tions.
Small apertures are suitable for high-resolution imaging or current-sensitive specimens.
A larger aperture generates a larger probe current and is used for applications that require a high
beam brightness, e.g. EDX.
Changing to a smaller/larger aperture will reduce/increase the convergence angle accordingly. This
could lead to decrease in resolution.
Procedure
1. In the GeminiSEM Control panel, select the Control tab.
2. In the
Beam
section, select an aperture from the
Aperture
drop-down list.
3. To double the probe current, activate the
High Current
checkbox.
INFO:
High Current
is recommended for large apertures (60 and 120 μm). For small aper-
tures the depth of field increases.
INFO:
High Current
is not available for the standard aperture.
5.6.4 Selecting the Column Mode
With the Gemini column, different column modes are available.
Column Mode
Description
Normal
Standard imaging and analytical mode with high flexibility for
different applications.
Overview
The electron optics is set to a landing energy of 100 V, en-
abling large field of view. On GeminiSEM 560, the EHT in
Overview mode can be tuned within a larger range.
The image is distorted, but is useful for navigating the speci-
men.
90
Instruction Manual ZEISS GeminiSEM series | en-US | Rev. 2 | 349500-8138-000