CPC H01J 37/28 (2013.01) [H01J 37/145 (2013.01); H01J 37/1474 (2013.01); H01J 37/244 (2013.01); H01J 2237/24475 (2013.01); H01J 2237/2448 (2013.01)] | 15 Claims |
1. An electron beam apparatus comprising:
an electron source configured to generate a primary electron beam along a primary optical axis;
a compound objective lens comprising a magnetic lens and an electrostatic lens, the magnetic lens comprising a cavity configured to allow the primary electron beam to pass through; and
a first electron detector configured to detect a first portion of a plurality of signal electrons generated from a sample,
wherein the first electron detector is located immediately upstream from a polepiece of the magnetic lens with respect to a path of the primary electron beam along the primary optical axis and inside the cavity of the magnetic lens.
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