Abstract:
The invention relates to an apparatus for generating a plurality of charged particle beamlets, comprising a charged particle source for generating a diverging charged particle beam, a converging means for refracting said diverging charged particle beam and a lens array comprising a plurality of lenses, wherein said lens array is located between said charged particle source and said converging means.In this way, it is possible to reduce aberrations of the converging means.
Abstract:
The invention provides a method and apparatus for automatically aligning a beam of charged particles with an aperture. Thereby, a defocusing is introduced and a signal calculated based on an image shift is applied to a deflection unit. Further, a method for correction of astigmatism is provided. Thereby, the sharpness is evaluated for a set of frames generated whilst varying the signals to a stigmator.
Abstract:
The invention provides a method for automatically aligning a beam of charged particles with an aperture. Thereby, the beam is defelcted to two edges of the aperture. From the signals required to obtain an extinction, a correction deflection field is calculated. Furter, a method for automatically aligning a beam of charged particles with an optical axis is provided. Thereby a defocusing is introduced and a signal calculated based on an introduced image shift is applied to a deflection unit. Further, a method for correction of the astigmatism is provided. Thereby the sharpness is evaluated for a sequence of frames measured whilst varying the signals to a stigmator.
Abstract:
An aberration-correcting microscopy instrument is provided. The instrument has a first magnetic deflector disposed for reception of a first non-dispersed electron diffraction pattern. The first magnetic deflector is also configured for projection of a first energy dispersed electron diffraction pattern in an exit plane of the first magnetic deflector. The instrument also has an electrostatic lens disposed in the exit plane of a first magnetic deflector, as well as a second magnetic deflector substantially identical to the first magnetic deflector. The second magnetic deflector is disposed for reception of the first energy dispersed electron diffraction pattern from the electrostatic lens. The second magnetic deflector is also configured for projection of a second non-dispersed electron diffraction pattern in a first exit plane of the second magnetic deflector. The instrument also has an electron mirror configured for correction of one or more aberrations in the second non-dispersed electron diffraction pattern. The electron mirror is disposed for reflection of the second non-dispersed electron diffraction pattern to the second magnetic deflector for projection of a second energy dispersed electron diffraction pattern in a second exit plane of the second magnetic deflector.
Abstract:
The present invention provides an aberration correction device (100). The aberration correction device comprises a Wien filter element (110), a quadrupole element (310) for compensating a focusing property of the Wien filter element (110), and at least one multipole element (410) for spherical aberration correction. The Wien filter element (110) and said quadrupole element (310) are adapted to generate, in combination, an astigmatic image. Furthermore, the at least one multipole element (410) is adapted to act essentially in a plane of sagittal or meridional focus of the astigmatic image. Thereby, chromatic aberration is reduced as well as spherical aberration can be corrected.
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:
In the type of scanning transmission electron microscopes carrying an aberration corrector, a method of assuring more simplified and manipulatable adjustment of the corrector and a scanning transmission electron microscope having that function are provided. A Ronchigram image is acquired using a spherical standard specimen and parameters necessary for the adjustment are acquired from the thus obtained Ronchigram.
Abstract:
The present invention provides an aberration corrector functioning under a condition outside the setting optical condition of an incorporated charged particle beam apparatus.An intermediate potential region different from the ground potential of an aberration corrector is provided in the space between the stages of multipole lenses constructing the aberration corrector to adjust a potential. Using this, when selecting an incident (outgoing) condition, an outgoing (incident) condition can be adjusted.
Abstract:
The invention relates to an apparatus for generating a plurality of charged particle beamlets, comprising a charged particle source for generating a diverging charged particle beam, a converging means for refracting said diverging charged particle beam and a lens array comprising a plurality of lenses, wherein said lens array is located between said charged particle source and said converging means. In this way, it is possible to reduce aberrations of the converging means.
Abstract:
The invention relates to an apparatus for generating a plurality of charged particle beamlets, comprising a charged particle source for generating a diverging charged particle beam, a converging means for refracting said diverging charged particle beam and a lens array comprising a plurality of lenses, wherein said lens array is located between said charged particle source and said converging means. In this way, it is possible to reduce aberrations of the converging means.