Deflection unit in a charged particle beam device

摘要

A charged particle beam column comprises: a particle source (12); an objective lens (20); a pre-lens deflection unit (30) for deflecting a beam of charged particles away from the optical axis (16) on such a path (14b,14c) that the combined action of the objective lens (20) and the pre-lens deflection unit (30) directs the beam of charged particles towards the optical axis (16) to hit the specimen surface (18) from a first direction; and an in-lens deflection unit (40) arranged in the vicinity of the objective lens (20) for redirecting the deflected beam of charged particles on such a path (14d) that the combined action of the objective lens (20) and the in-lens deflection unit (40) redirects the beam of charged particles towards the optical axis (16) to hit the specimen surface (18) under said large beam landing angle from a second direction substantially opposite to said first direction.