Single stage charged particle beam energy width reduction system for charged particle beam system
AssigneeICT Integrated Circuit Testing Gesellschaft fur Halbleiternruftechnik mbH
InventorsJürgen Frosien, Ralf Degenhardt, Stefan Lanio, Gerald Schönecker
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Abstract
The present invention provides a charged particle beam device. The device comprises a first lens generating a crossover a second lens positioned after the crossover and an element acting in a focusing and dispersive manner in an x-z-plane with a center of the element having essentially same z-position as the crossover. Further, a multipole element, which acts in the x-z-plane and a y-z-plane is provided. A first charged particle selection element and a second charged particle selection element are used for selecting a portion of the charged particles. Thereby, e.g. the energy width of the charged particle beam can be reduced.
Claims27
Charged particle beam device with a z-axis along an optical axis, comprising:
- a first lens generating a crossover, the crossover having a z-position zc;
- a second lens positioned after the crossover;
- an element acting in a focusing and dispersive manner in an x-z plane, the center of the element acting in a focusing and dispersive manner having essentially the z-position zc;
- a multipole element, which acts in the x-z-plane and the y-z-plane, the center of the multipole element having essentially the z-position zc;
- a first charged particle selection element being positioned in beam direction before the element acting in a focusing and dispersive manner;
- and
- a second charged particle selection element being positioned in beam direction behind the element acting in a focusing and dispersive manner, wherein the second charged particle selection element is velocity dependent selection element.
Method of reducing a charged particle beam velocity distribution width with a system comprising a z-axis along an optical axis, an element acting in a focusing and dispersive manner having essentially a z-position zc, a quadrupole element, a first charged particle selection element and a second charged particle selection element, comprising:
- generating a crossover at the position zcwith a first lens;
- selecting charged particles with the first charged particle selection element;
- exciting the element acting in a focusing and dispersive manner and the quadrupole element;
- adjusting the field strength of the element acting in a focusing and dispersive mariner and the quadrupole element so that there is no focusing effect in a x-z-plane and that the charged particle beam appears to originate from the x-y-center-plane of the element acting in a focusing and dispersive manner with respect to a y-z-plane;
- and
- velocity dependently selecting charged particles with the second charged particle selection element.
Dependencies are inferred from the claim text.