| 摘要 |
Apparatus and methods are disclosed for inspecting semiconductor wafers and other types of specimens using parallel charged particle beams (e.g., electron beams). An emitter array, including multiple charged-particle-beam (CPB) emitters produces multiple beams that propagate along respective beam axes. The beams pass simultaneously through projection lenses and a deflector so as to cause the beams to be focused simultaneously onto respective loci on the surface of the specimen so as to cause each locus to emit secondary electrons. The secondary electrons are detected by a secondary-electron (SE) array including multiple SE-detector units. Each SE detector unit receives and detects secondary electrons emitted from a respective locus. The deflector simultaneously scans the beams over respective regions on the specimen surface. Each SE detector is configured to detect secondary electrons but not backscattered electrons emitted from the respective locus. Alternatively, multiple channels can be provided, each channel corresponding to a respective beam. Each channel includes a respective set of lenses and deflectors for the respective beam. The channel pitch is adjustable to accommodate various die pitches on the specimen.
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