Charged particle beamlet exposure system

摘要

The invention relates to a charged-particle-optical system for a charged particle beam exposure apparatus, said system comprising:
- a first aperture means (3) comprising at least a first substantially round aperture for partially shielding an emitted charged particle beam (2) for forming a charged particle beamlet;
- a lens system comprising at least one lens (4) for focussing a charged particle beamlet from said first aperture within or in the vicinity of an image focal plane of said lens;
- a deflector means (5), substantially located in said image focal plane, comprising at least one beamlet deflector for the deflection of a passing charged particle beamlet upon the reception of a control signal, and
- a second aperture means (6) comprising at least one second substantially round aperture positioned in the conjugate plane of the first aperture, and said second aperture being aligned with said first aperture and said beamlet deflector for blocking said charged particle beamlet upon deflection by said beamlet deflector and to transmit it otherwise.