Shielded detector for charged particle microscopy

A charged particle beam system, comprising:

• a vacuum chamber;
• a charged particle beam column, operably coupled with the vacuum chamber and configured to direct a beam of charged particles into the vacuum chamber;
• a sample stage, disposed in the vacuum chamber;
• and
• a detector, comprising:
• a detector, configured to generate an electrical signal in response to a particle incident on an active layer of the detector, the active layer defining an absorption surface oriented toward the sample stage;
• and
• a filter, comprising a membrane of carbon material comprising carbon nanotubes, the filter being disposed between the sample stage and the detector to shield the absorption surface from a subset of the incident particles, the subset comprising electrons, ions, and photons having an energy less than about 40 eV.