Charged-particle beam apparatus for voltage-contrast inspection and methods thereof

A non-transitory computer readable medium storing a set of instructions that is executable by one or more processors of a charged-particle beam apparatus to cause the charged particle beam apparatus to perform a method comprising:

• forming a primary charged-particle beam along a primary optical axis from charged particles emitted by a charged-particle source;
• condensing, using a condenser lens configuration, the primary charged-particle beam based on a selected mode of operation comprising a first mode and a second mode of the apparatus, wherein:
• operating in the first mode comprises condensing the primary charged-particle beam using the condenser lens configuration, and
• operating in the second mode comprises condensing the primary charged-particle beam sufficiently to form a crossover between the condenser lens configuration and an objective lens of the apparatus;
• and
• focusing the primary charged-particle beam exiting the condenser lens configuration on a surface of a sample to form a probe spot.

A charged-particle beam apparatus comprising:

• a charged-particle source configured to emit charged particles;
• an aperture plate configured to form a primary charged-particle beam along a primary optical axis from the emitted charged particles;
• a first condenser lens configured to condense the primary charged-particle beam and operable in a first mode and a second mode, wherein:
• in the first mode, the first condenser lens is configured to condense the primary charged-particle beam, and
• in the second mode, the first condenser lens is configured to condense the primary charged-particle beam sufficiently to form a crossover along the primary optical axis;
• and
• a second condenser lens configured to adjust a first beam current of the primary charged-particle beam in the first mode and adjust a second beam current of the primary charged-particle beam in the second mode, wherein the second beam current is larger than the first beam current.