Zeiss SIGMA Series, Instruction Manual

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ZEISS 3 Product and Functional Description | 3.3 Optional Components and Accessories
Filtering Grid
Without switching on the filtering grid
2
voltage, the InLens Duo detector
1
has the same
characteristics as the InLens SE Detector [
}
38] . The InLens Duo detector primarly detects sec-
ondary electrons (SEs).
By switching on the filtering grid voltage, the SEs will be rejected and only backscattered electrons
(BSEs) will be detected.
Below a landing energy of 1.5 kV the filtering grid has the additional function of selecting the de-
sired energy of the BSEs. The operator can select the threshold energy of inelastically scattered
BSEs to enhance contrast and resolution.
3.3.1.2 BSE Detectors
Purpose A signal source commonly used in electron microscopy are backscattered electrons (BSE). The use
of this type of signal makes it possible to effectively display compositional differences in the speci-
men. There are different types of detectors for backscattered electrons. Most of these detectors
use semiconductor diodes for signal detection. The following semiconductor detectors are avail-
able:
§
Backscattered electron detectors (BSD):
– aBSD1-LH
– 5-segment HDBSD
§
Angle-selective backscattered (AsB) detectors (lens mounted):
– HDAsB
Another type of detector is the YAG BSD. For more information on this detector, refer to YAG BSD
Detector [
}
65] .
Position Whereas the SE detector views the specimen from the side (refer to SE Detector [
}
44] ), BSE de-
tectors view the specimen from above. This position offers a very large solid angle that can be
used for the detection of backscattered electrons.
BSD Detectors BSD detectors are located in the specimen chamber and is usually moved into a “parked” position
when it is not being used. When needed, the detector is moved into its “active” position either
manually (HDBSD) or automatically (aBSD).
1
2
3
4
5
6
7
8
11
9
10
12
Fig. 43: Location of the HDBSD detector
Instruction Manual ZEISS SIGMA series | en-US | Rev. 7 | 352102-9344-006 57