Abstract: An electron-optical corrector for rendering superfluous both the third-order opening error and the anisotropic part of the extra-axial third-order coma, using round lenses and hexapole fields, the corrector includes at least three coaxially arranged hexapole fields with at least one round lens field is arranged between adjacent hexapole fields, so that the hexapole fields are imaged onto each other in pairs. The intensities of the hexapole fields are selected so that the image error coefficient of the three-fold astigmatism is equal to 0, and at least three hexapole fields in the Larmor reference system are rotated in relation to each other at an angle about the optical axis.

Abstract: An electron-optical arrangement provides a primary beam path for a beam of primary electrons and a secondary beam path for secondary electrons. The electron-optical arrangement includes a magnet arrangement having first, second and third magnetic field regions. The first magnetic field region is traversed by the primary beam path and the secondary beam path. The second magnetic field region is arranged in the primary beam path upstream of the first magnetic field region and is not traversed by the secondary beam path. The first and second magnetic field regions deflect the primary beam path in substantially opposite directions. The third magnetic field region is arranged in the secondary beam path downstream of the first magnetic field region and is not traversed by the first beam path. The first and third magnetic field regions deflect the secondary beam path in a substantially same direction.

Abstract: An electron microscopy system comprises an objective lens (19) which images a field displaceable in x-direction on a fixed beam axis (17). The objective lens has an astigmatic effect which is compensated for by a beam shaper (63) on the fixed axis. Furthermore, lens configurations can selectively act on the primary electron beam or the secondary electron beam.

Abstract: Disclosed is a lens array having a laterally movable axis for corpuscular rays, particularly for transmission from areas of an object surface onto the focal plane by means of electrons. The inventive array consists of a combined lens comprising a cylinder lens and a quadrupole lens provided with slit diaphragms which can be impinged upon by electric and/or magnetic fields. The optical axis of the quadrupole lens is oriented parallel to the axis of the cylinder lens and defines the optical axis of the projection, the position of which can be altered in relation to the axis of the cylinder lens. The quadrupole lens is in focus in the sector in which the cylinder lens is not in focus and is out of focus in the section in which the cylinder lens is in focus. The inventive combined lens can be operated as an immersion lens for projecting secondary electrons. The immersion field consists of at least two adjacent axially aligned fields.

Abstract: An examining system for imaging an object positionable in an object plane, includes an illumination device for supplying energy to a delimited field of the object such that charged particles emerge from locations of the field, the field being displaceable in the plane of the object, a first deflector for providing a variable deflection field for guiding charged particles emerging from locations of a selectable region of the object through a fixed, predetermined beam cross-section, and a position-sensitive detector disposed in the beam path such that the charged particles, after having passed through the first deflector, impinge on the position-sensitive detector, wherein particles emerging from different locations of the region are imaged on different locations of the position-sensitive detector which are allocated to the locations of emergence.

Abstract: Disclosed is a lens array having a laterally movable axis for corpuscular rays, particularly for transmission from areas of an object surface onto the focal plane by means of electrons. The inventive array consists of a combined lens comprising a cylinder lens and a quadrupole lens provided with slit diaphragms which can be impinged upon by electric and/or magnetic fields. The optical axis of the quadrupole lens is oriented parallel to the axis of the cylinder lens and defines the optical axis of the projection, the position of which can be altered in relation to the axis of the cylinder lens. The quadrupole lens is in focus in the sector in which the cylinder lens is not in focus and is out of focus in the section in which the cylinder lens is in focus. The inventive combined lens can be operated as an immersion lens for projecting secondary electrons. The immersion field consists of at least two adjacent axially aligned fields.

Abstract: An electrostatic corrector with a rectilinear optical axis has two corrective parts, which are arranged one behind the other along the optical axis and which have respective quadrupole fields and superimposed circular lens fields. The astigmatic intermediate image of one cross-section that is created by an axis point lies in one corrective part and the astigmatic intermediate image of the other cross-section, which is perpendicular to the first cross-section, lies in the other corrective part. An object of the invention is to eliminate the chromatic aberration of particle lenses. To achieve this, an electrostatic corrector is used, which includes two corrector units having similar instrumental construction, with each of the two corrector units having input and output sides on which two additional electrostatic quadrupoles are located. The two corrector units represent the axial paths in a telescopic manner in a 1:1 representation.

Abstract: An electrostatic corrector for eliminating the chromatic aberration of particle lenses, includes a corrector having a straight optical axis and an electrostatic quadrupole for allocating to the objective lens. Two corrector pieces are positioned behind the quadrupole, along the optical axis in the direction of radiation. Each corrector piece has three electrical quadrupole fields with an overlying circular lens field. The quadrupole fields, however, are rotated 90° about the optical axis in relation to each other. This arrangement is adjusted so that the astigmatic first image of one sectional view lies in one corrector piece and the astigmatic first image perpendicular thereto, of the other sectional view, lies in the other corrector piece, with another electrostatic quadrupole being located on the output side.

Abstract: The invention relates to an electron/ion gun for electron or ion beams, including a beam source and a monochromator. According to the invention, the monochromator is equipped with an additional beam guidance system and a switchover element which are provided at the input of the monochromator, and which convey the particles coming from the beam source to either the monochromator or the rest of the beam guidance system.

Abstract: An electron microscopy system comprises an objective lens (19) which images a field displaceable in x-direction on a fixed beam axis (17). The objective lens has an astigmatic effect which is compensated for by a beam shaper (63) on the fixed axis. Furthermore, lens configurations can selectively act on the primary electron beam or the secondary electron beam.

Abstract: The invention relates to an electrostatic corrector based on an electrostatic corrector with a rectilinear optical axis (1) and two corrective parts (8, 9), which are arranged one behind the other along the optical axis and have respective quadrupole fields and superimposed circular lens fields. The astigmatic intermediate image of one cross-section that is created by an axis point lies in one corrective pan and the astigmatic intermediate image of the other cross-section, which is perpendicular to said first cross-section, lies in the other corrective part. The aim of the invention is to eliminate the chromatic aberration of particle lenses. To achieve this, the invention provides a corrector comprising two corrective units with a similar instrumental construction, each having one of the corrective parts, on whose respective input and output sides two additional electrostatic quadrupoles are located. Said corrective units represent the axial paths in a telescopic manner in a 1:1 representation.

Abstract: The invention relates to a method for eliminating axial image deformations &agr;n in electron optical systems, where the extra-axial image deformation of the order n+m with the same behavior in &agr;n, which thus has the form &agr;n&ggr;m, is modified by shifting or tilting the beam path towards the optical axis until compensation of the axial image deformation has been achieved, whereby &ggr; describes the extra-axial image coordinate as a complex number in both sections. The invention also relates to an adjustment method for eliminating all first-, second- and third-order axial image deformations during correction of the third-order spherical aberration in electron optical systems with hexapoles.

Abstract: A device for correcting third-order spherical aberration in the objective lens of an electron microscope, including an objective lens and a correction device which is formed by two hexapoles and a round-lens doublet arranged therebetween having two round lenses with the same focal length, whereby a single round lens (3) is arranged between the objective lens (2) and the correction device (1) in such a way that a parallel optical path hits the correction device (1) and the coma-free plane (6) of the objective lens is represented on the plane of the first hexapole (8) of the correction device (1) or two round lenses with different focal lengths are arranged between the objective lens and the correction device, whereby the distance between the round lens (14) close to the objective and the coma-free plane (16) of the objective and the distance between the round lens (15) close to the correction device and the coma-free plane (17) of the correction device is the same is terms of focal length and the distance betw

Abstract: The invention relates to an electron/ion gun for electron or ion beams, comprising a beam source and a monochromator. According to the invention, said monochromator is equipped with an additional beam guidance system and a switchover element which conveys the particles coming from the beam source to either the monochromator or the rest of the beam guidance system is provided at the input of the monochromator.

Abstract: The invention relates to an electron energy filter for electron microscopes as well as to an electron microscope equipped with such a filter. The filter comprises three sector magnets with the deflection field in the first sector magnet being homogeneous. The deflection field in each of the two other sector magnets is an inhomogeneous gradient field. To generate the gradient field, the pole pieces of the two other sector magnets have the form of segments of truncated double cones. The electron beam passes the first homogeneous sector magnet twice. Multipole elements are arranged in front of, behind and between the three sector magnets. The filter has a large dispersion also for high-energy electrons while at the same time providing a compact configuration. All second-order aberrations and the significant second-rank aberrations are corrected by means of the multiple elements.