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Thermo Fisher Scientific

EPU and Tomo run fail (looping result was 2.6um,out of spec)


EPU and Tomo run fail (looping result was 2.6um,out of spec)


Krios G3i


These are possible resolutions for the issue:

  • Replace the whole stage.


These are possible causes for the issue:

  • Floating rod X axis mechanism could not move accurately to the set value


A saved recognizable feature coordination in the stage OCX did not appear when set the saved coordinate again. Therefore, it affect the results of EPU and Tomography.

Perform the looping test in section 5.2 of DOC 4022 190 60682. It was found the looping result was 2.6um. It fails the specification (see attach). Please take note this specification is not in this DOC 4022 190 60682. This specification can be found in the factory Final Test.

The root cause is in the floating rod X axis mechanism. It cannot be repaired in the field and the floating rod need to be replaced. For Krios the whole stage need to be replace instead of floating rod. Problem solved after replaced the stage.