Method and device for focusing a charged particle beam

摘要

The invention provides an objective lens 1 for focusing a charged particle beam 30 on a specimen. The objective lens comprises a first focusing lens 2 positioned between a charged particle source and the specimen for finely focusing the beam of charged particles on the specimen. The objective lens further comprises a second focusing electrostatic lens 20 positioned between the first focusing lens and the specimen for coarsely focusing the beam of charged particles on the specimen.