[labnetwork] SEM Liner Tube Voltage Issue

[Nicki Shaw]

Hello,
We are troubleshooting a SEM column issue on our FIB-SEM following a planned power interruption. In short, any advice regarding the disassembly of a Gemini SEM column or liner tube troubleshooting/maintenance would be greatly appreciated.
The tool in question is a ZEISS Auriga 40, and we have observed the following:

  *
The SEM image is significantly rotated relative to the expected alignment, despite the scan rotation being off.
  *
The Inlens detector does not get a signal, but the SESI detector gets a signal with some apertures. The emission view shows that the apertures are significantly misaligned, despite no manual changes being performed.
  *
The image rotation improves as SEM voltage is increased, becoming nearly correct at 21 kV—at which point the liner tube shuts off.

During troubleshooting, we measured the liner tube voltage:

  *   When running the liner without connecting it to the column (with a resistor in place to draw current), the voltage ramps normally.
  *   When the liner is connected to the column, the voltage plateaus at 600–700 V instead of reaching the expected 8000 V.

We have checked:

  *   The liner tube cable and relay box connections.
  *   The power module and associated lens control boards.

Given these observations, it seems likely that there is a voltage leak inside the column affecting the liner tube voltage. Has anyone encountered a similar issue, or can provide insight into further troubleshooting steps? We are considering opening the column to check for a short but have not attempted any disassembly other than replacing the filament.
Any advice would be greatly appreciated!
All the best,
Nicki
Senior Facility Microscopist
Quantum-Nano Fabrication and Characterization Facility (QNFCF)
200 University Ave W | Waterloo, Ontario | N2L 3G1
Office: QNC 1611
P: +1 519-888-4567 ext. 42022
[cid:cb186fce-e5ea-43b2-a514-a35479f49e98]
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