Zeiss GeminiSEM Series, Инструкция по эксплуатации

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ZEISS 3 Product and Functional Description | 3.2 Main Components
Apertures
The electron beam passes through the anode aperture
3
first, afterwards through a single
hole aperture
5
.
The anode aperture defines the maximum possible probe current.
For the Gemini 2 column, three different column configurations are available:
§
40 nA high resolution configuration
Anode aperture diameter Probe current Typical application
55 μm 3 pA to 40 nA High resolution and most an-
alytical applications
§
100 nA high current configuration
Anode aperture diameter Probe current Typical application
90 μm 3 pA to 100 nA Combined high resolution
and analytical investigations
with high throughput
§
300 nA high current configuration
Anode aperture diameter Probe current Typical application
150 μm 3 pA to 300 nA Special high-current applica-
tions
Condenser A double condenser system allows the continuous regulation of the probe current. The upper
condenser
4
is used to continuously adjust the probe current. The lower condenser
6
is
used for aperture matching of the objective lens in order to guarantee optimum resolution at
each probe current and EHT setting.
Stigmator The stigmator is located inside the condenser and compensates for astigmatism so that the elec-
tron beam becomes rotationally symmetrical.
Deflection System
The electron beam is focused by the objective lens
9
onto the specimen
11
while being de-
flected in a point-by-point scan over the specimen surface by the scanning coils.
Before the electron beam exits the objective lens, the electrostatic lens creates an opposing field
which reduces the potential of the electrons by +8 kV. The energy of the electrons reaching the
specimen surface therefore corresponds to the set acceleration voltage (EHT).
Signal Detection When the primary electron beam hits the specimen, certain interaction products are released,
which can be recorded by specific detectors, e.g. the InLens SE detector
8
. For more informa-
tion refer to Principle of Signal Detection [
}
40] .
Instruction Manual ZEISS GeminiSEM series | en-US | Rev. 2 | 349500-8138-000 37