Charged particle beam apparatuses have many functions, in a plurality of industrial fields, including, but not limited to, electron beam (wafer) inspection, critical dimensioning of semiconductor devices during manufacturing, defect review of semiconductor devices during manufacturing, exposure systems for lithography, detecting devices and testing systems. Thus, there is a high demand for structuring, testing and inspecting specimens within the micrometer and nanometer scale.
Micrometer and nanometer scale process control, inspection or structuring is often done with charged particle beams, e.g. electron beams, which are generated and focused in charged particle beam devices, such as electron microscopes or electron beam pattern generators. Charged particle beams offer superior spatial resolution compared to, e.g. photon beams due to their short wavelengths.
Particularly for electron beam inspection (EBI) technology, throughput is of foremost interest. It is inter alia referred to, in particular, to surface inspection at low landing energies <500 eV and low secondary electron (SE) extraction fields. Normally, for high current density electron probe generation, compound objective lenses are used (superimposed magnetic and electrostatic retarding field lenses). In those lenses, the electron energy inside the column is reduced to the final landing energy. Further, for the purpose of pre-charging a wafer to a desirable surface potential, for example in order to increase detection sensitivity of voltage contrast (VC) defects in the wafer fabrication process, or to dis-charge/neutralize wafer charging effects, a flood gun can be used.
In view of the above, it is beneficial to provide an improved charged particle beam device and a method of operating thereof that overcome at least some of the problems in the art.