Foil lens correctors, charged particle microscope systems including the same, and associated methods

A CPM system comprising:

• a charged particle source configured to generate a charged particle beam;
• and
• a foil lens corrector for correcting spherical aberration in the charged particle beam,
• wherein the foil lens corrector comprises:
• a foil configured to be positioned in line with an optical axis of the CPM system;
• and
• an electrode assembly configured to generate a corrector electrostatic potential,
• wherein the foil comprises graphene, wherein the foil is configured to support a space charge such that the optical axis intersects the space charge, and wherein the foil lens corrector is configured such that the corrector electrostatic potential generates an offsetting spherical aberration in the charged particle beam to at least partially correct a spherical aberration in the charged particle beam.

A method of operating a CPM system, the method comprising:

• directing a charged particle beam along an optical axis to a specimen positioned in a specimen plane;
• and
• operating a foil lens corrector positioned along the optical axis to generate a corrector electrostatic potential that generates an offsetting spherical aberration in the charged particle beam,
• wherein the operating the foil lens corrector comprises directing the charged particle beam to a foil of the foil lens corrector such that:
• the charged particle beam is incident upon the foil with a foil landing energy that is at least 5 keV and at most 80 keV;
• and
• the charged particle beam is transmitted through the foil with a transmission ratio that is at least 20%.