NOTCHED MAGNETIC LENS FOR IMPROVED SAMPLE ACCESS IN AN SEM

摘要

A magnetic immersion lens apparatus includes an outer pole piece and an inner pole piece with a gap therebetween. The outer pole piece has an opening that permits energetic particles from a target in front of the immersion lens to pass through the outer pole piece to an external detector. The outer or inner pole piece has one or more notches near the gap. This abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

主权项

1. A system, comprising:
a charged particle optical column configured to generate a primary beam of charged particles and focus the primary beam onto a target, the charged particle optical column including a magnetic immersion lens, the magnetic immersion lens having an outer pole piece and an inner pole piece with a gap therebetween, the outer pole piece having an opening that permits energetic particles from the target to pass through the outer pole piece to an external detector, wherein the inner or outer pole piece has one or more notches proximate the gap.