Particle-optical apparatus, electron microscopy system and electron lithography system
AssigneeLEO Elektronenmikroskopie GmbH
InventorsOliver Kienzle, Rainer Knippelmeyer
Life of this patent
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Abstract
A particle-optical apparatus is provided for directing a beam of charged particles on an object plane or to image the object plane with the beam onto an image plane or intermediate image plane. The apparatus comprises a stack of lens assemblies which are disposed in beam direction at a fixed distances spaced apart from which other and are controllable for providing successively adjustable deflection fields for a beam traversing the stack. Each lens assembly provides at least one field source member for a magnetic or electric field. In particular, two rows of a plurality of field source members per lens assembly can be provided.
Claims21
A particle-optical apparatus for manipulating at least one beam of charged particles, the apparatus comprising:
- a stack of plural lens assemblies, the lens assemblies being disposed spaced apart from each other in a direction of the beam traversing the stack, wherein each lens assembly comprises at least one row of field source members for generating at least one of an electric field and a magnetic field for manipulating the beam, the row extending in a second direction tranversely oriented with respect to the first direction;
- and
- a controller adapted for applying a selectable excitation pattern to the at least one row of field source members of each lens assembly, wherein a first excitation pattern applied to the at least one row of field source members of a first lens assembly is different from a second excitation pattern applied to the at least one row of field source members of a second lens assembly different from the first lens assembly.
A method of operating a particle-optical apparatus, wherein the particle-optical apparatus provides a beam path for at least one beam of charged particles through at least one focusing lens and through at least one stack of at least four lens assemblies which are spaced apart in a direction of the beam path, wherein each of the lens assemblies comprises a plate oriented transversely to the beam direction and having at least one aperture formed therein and having at least one field source member for providing a beam manipulating field, the method comprising:
- exciting the at least one focusing lens and exciting the at least four field source members of the lens assemblies of the at least one stack such that a first optical plane is imaged by the beam into a second optical plane which is optically conjugated to the first optical plane;
- changing the excitation of the at least one focusing lens;
- and
- changing the excitation of the at least four lens assemblies such that positions of the first and second optical planes along the beam path are maintained substantially constant when changing the excitation of the at least one focusing lens.
A particle-optical apparatus providing a beam path for at least one beam of charged particles, the beam path having at least two optically conjugated planes, the apparatus comprising:
- at least one focusing lens;
- at least one stack of at least four lens assemblies which are spaced apart in a direction of the beam path, wherein each of the lens assemblies comprises a plate oriented transversely to the beam direction and having at least one aperture formed therein and having at least one field source member for providing a beam manipulating field;
- and
- a controller for exciting the at least one focusing lens and exciting the field source members of the lens assemblies of the stack, wherein the controller is adapted to change the excitation of the at least one focusing lens and to change the excitation of the field source members of the lens assemblies of the stack such that positions of the two optically conjugated planes along the beam path are maintained substantially constant when changing the excitation of the at least one focusing lens.
Dependencies are inferred from the claim text.