Back to results
US 5,221,844 AGranted
Charged particle beam device
AssigneeU.S. Philips Corporation
InventorsKarel D. van der Mast, Alan F. De Jong
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeU.S. Philips Corporation
InventorsKarel D. van der Mast, Alan F. De Jong
Estimating the term…
In an electron microscope correction of spherical and chromatic aberration can be achieved in a number of freely adjustable directions by using a multipole correction element whereby a magnetic or electrostatic octupole field, rotatable about the optical axis, or a combined rotatable magnetic and electrostatic quadrupole field is generated. A corrected overall image can be obtained by combination of images successively corrected in different directions. In the case of holographic images, correction in the direction perpendicular to the line direction in the hologram enhances the accuracy of phase determination. A correction element of this kind, having comparatively small dimensions of from 1 to 2 cm, can be simply mounted, notably in a transmission electron microscope, in a space provided for the stigmator.
A charged particle beam device, comprising a source for emitting a charged particle beam to an object plane, particle-optical elements which are arranged along an optical axis and which comprise at least one lens for forming an image of the object plane, and a correction element for correction of spherical and/or chromatic aberration in the image of the at least one lens, said correction element comprising a multipole element for generating a magnetic and/or electric potential distribution in a correction plane extending perpendicularly to the optical axis, characterized in that the charged particle beam device comprises means for rotating the potential distribution in the correction plane in order to adjust a correction direction during exposure.
Dependencies are inferred from the claim text.