Particle-optical component and system comprising a particle-optical component

A deflection assembly for particle-optical imaging of a first cross-section of a beam of charged particles in a first plane to a second cross-section of the beam in a second plane, comprising:

• a magnetic lens doublet comprising a first focusing lens positioned between the first plane and the second plane and a second focusing lens positioned between the first focusing lens and the second plane, wherein the first and second focusing lenses are positioned on a common symmetry axis, wherein a symmetry plane of the doublet is positioned between the first and the second focusing lenses, wherein a distance between the first plane and the symmetry plane is twice as large as a focal length of the first focusing lens, and wherein a distance between the second plane and the symmetry plane is twice as large as a focal length of the second focusing lens;
• and
• a beam shifting assembly which is positioned between the first and the second focusing lenses and traversed by the beam for providing an adjustable axial shift between the beam entering the beam shifting assembly and the beam emerging therefrom,
• wherein at least one of the first focusing lens and the second focusing lens comprises an axis shifting device for providing a corrective magnetic field which is superposable on the magnetic field provided by the focusing lens and acts on the beam such that an optical axis of the focusing lens is shiftable parallel to the symmetry axis thereof.

A projection system for transferring a pattern defined on a mask to a particle-sensitive substrate by means of a beam of charged particles, the system comprising:

• a source of charged particles;
• a beam shaping aperture for shaping a cross-section of the particle beam;
• a first particle-optical imaging apparatus for imaging the beam shaping aperture onto the mask;
• and
• a second particle-optical imaging apparatus for imaging the mask onto the substrate,
• wherein at least one of the first and the second particle-optical imaging apparatus comprises a magnetic lens assembly comprising
• a focusing lens device for providing a magnetic field which has substantially rotational symmetry in respect of a symmetry axis of the assembly and acts on a beam of charged particles traversing said magnetic field as a focusing lens with an optical axis;
• an axis shifting device comprising at least one axis shifting coil for producing a corrective magnetic field which is superposable on the magnetic field provided by the focusing lens device and acts on the beam such that the optical axis is shiftable parallel to the symmetry axis of the assembly,
• wherein the axis shifting device comprises a first set of axially spaced apart rings which are positioned concentrically in respect of the symmetry axis and are made of a material which is substantially not electrically conductive and has a high magnetic permeability, wherein the at least one axis shifting coil is provided with a plurality of current conductor windings for producing the corrective magnetic field, and wherein the current conductor windings of the axis shifting coil engage around at least one of the rings of the first ring set;
• and
• at least one stigmator coil with a plurality of current conductor windings which engage around at least one of the rings of the first and second ring set.

A projection system for transferring a pattern defined on a mask to a particle-sensitive substrate by means of a beam of charged particles, the system comprising:

• a source of charged particles;
• a beam shaping aperture for shaping a cross-section of the particle beam;
• a first particle-optical imaging apparatus for imaging the beam shaping aperture onto the mask;
• and
• a second particle-optical imaging apparatus for imaging the mask onto the substrate,
• wherein at least one of the first and the second particle-optical imaging apparatus comprises a deflection assembly comprising
• a magnetic lens doublet comprising a first focusing lens positioned between the first plane and the second plane and a second focusing lens positioned between the first focusing lens and the second plane, wherein the first and second focusing lenses are positioned on a common symmetry axis, wherein a symmetry plane of the doublet is positioned between the first and the second focusing lenses, wherein a distance between the first plane and the symmetry plane is twice as large as a focal length of the first focusing lens, and wherein a distance between the second plane and the symmetry plane is twice as large as a focal length of the second focusing lens;
• and
• a beam shifting assembly which is positioned between the first and the second focusing lenses and traversed by the beam for providing an adjustable axial shift between the beam entering the beam shifting assembly and the beam emerging therefrom,
• wherein at least one of the first focusing lens and the second focusing lens comprises an axis shifting device for providing a corrective magnetic field which is superposable on the magnetic field provided by the focusing lens and acts on the beam such that an optical axis of the focusing lens is shiftable parallel to the symmetry axis thereof.

An electron microscopy system, comprising:

• a sample holder for receiving a sample to be examined;
• an electron source;
• a focusing assembly for focusing electrons emitted from the electron source onto the sample;
• and
• a detector for detecting electrons emerging from the sample due to an interaction of the electrons focused onto the sample,
• wherein the focusing assembly comprises a magnetic lens assembly comprising
• a focusing lens device for providing a magnetic field which has substantially rotational symmetry in respect of a symmetry axis of the assembly and acts on a beam of charged particles traversing said magnetic field as a focusing lens with an optical axis;
• and
• an axis shifting device comprising at least one axis shifting coil for producing a corrective magnetic field which is superposable on the magnetic field provided by the focusing lens device and acts on the beam such that the optical axis is shiftable parallel to the symmetry axis of the assembly,
• wherein the axis shifting device comprises a first set of axially spaced apart rings which are positioned concentrically in respect of the symmetry axis and are made of a material which is substantially not electrically conductive and has a high magnetic permeability, wherein the at least one axis shifting coil is provided with a plurality of current conductor windings for producing the corrective magnetic field, and wherein the current conductor windings of the axis shifting coil engage around at least one of the rings of the first ring set.

An electron microscopy system, comprising:

• a sample holder for receiving a sample to be examined;
• an electron source;
• a focusing assembly for focusing electrons emitted from the electron source onto the sample;
• and
• a detector for detecting electrons emerging from the sample due to an interaction of the electrons focused onto the sample,
• wherein the focusing assembly comprises a deflection assembly comprising
• a magnetic lens doublet comprising a first focusing lens positioned between the first plane and the second plane and a second focusing lens positioned between the first focusing lens and the second plane, wherein the first and second focusing lenses are positioned on a common symmetry axis, wherein a symmetry plane of the doublet is positioned between the first and the second focusing lenses, wherein a distance between the first plane and the symmetry plane is twice as large as a focal length of the first focusing lens, and wherein a distance between the second plane and the symmetry plane is twice as large as a focal length of the second focusing lens;
• and
• a beam shifting assembly which is positioned between the first and the second focusing lenses and traversed by the beam for providing an adjustable axial shift between the beam entering the beam shifting assembly and the beam emerging therefrom,
• wherein at least one of the first focusing lens and the second focusing lens comprises an axis shifting device for providing a corrective magnetic field which is superposable on the magnetic field provided by the focusing lens and acts on the beam such that an optical axis of the focusing lens is shiftable parallel to the symmetry axis thereof.

An electron microscopy system, comprising:

• a sample holder for receiving a sample to be examined;
• an electron source for illuminating the sample with electrons;
• a position sensitive detector;
• and
• a lens assembly for imaging onto the position sensitive detector electrons emerging from the sample due to an interaction of the electrons focused onto the sample,
• wherein the lens assembly comprises a magnetic lens assembly comprising
• a focusing lens device for providing a magnetic field which has substantially rotational symmetry in respect of a symmetry axis of the assembly and acts on a beam of charge particles traversing said magnetic field as a focusing lens with an optical axis;
• and
• an axis shifting device comprising at least one axis shifting coil for producing a corrective magnetic field which is superposable on the magnetic field provided by the focusing lens device and acts on the beam such that the optical axis is shiftable parallel to the symmetry axis of the assembly,
• wherein the axis shifting device comprises a first set of axially spaced apart rings which are positioned concentrically in respect of the symmetry axis and are made of a material which is substantially not electrically conductive and has a high magnetic permeability, wherein the at least one axis shifting coil is provided with a plurality of current conductor windings for producing the corrective magnetic field, and wherein the current conductor windings of the axis shifting coil engage around at least one of the rings of the first ring set.

An electron microscopy system, comprising:

• a sample holder for receiving a sample to be examined;
• an electron source for illuminating the sample with electrons;
• a position sensitive detector;
• and
• a lens assembly for imaging onto the position sensitive detector electrons emerging from the sample due to an interaction of the electrons focused onto the sample,
• wherein the lens assembly comprises a deflection assembly comprising
• a magnetic lens doublet comprising a first focusing lens positioned between the first plane and the second plane and a second focusing lens positioned between the first focusing lens and the second plane, wherein the first and second focusing lenses are positioned on a common symmetry axis, wherein a symmetry plane of the doublet is positioned between the first and the second focusing lenses, wherein a distance between the first plane and the symmetry plane is twice as large as a focal length of the first focusing lens, and wherein a distance between the second plane and the symmetry plane is twice as large as a focal length of the second focusing lens;
• and
• a beam shifting assembly which is positioned between the first and the second focusing lenses and traversed by the beam for providing an adjustable axial shift between the beam entering the beam shifting assembly and the beam emerging therefrom,
• wherein at least one of the first focusing lens and the second focusing lens comprises an axis shifting device for providing a corrective magnetic field which is superposable on the magnetic field provided by the focusing lens and acts on the beam such that an optical axis of the focusing lens is shiftable parallel to the symmetry axis thereof.