Charged particle-optical systems, methods and components

A particle-optical component for manipulating a plurality of beamlets of charged particles, the particle-optical component comprising:

• a first multi-aperture plate having a plurality of apertures and a second multi-aperture plate having a plurality of apertures, wherein the second multi-aperture plate is spaced apart from the first multi-aperture plate such that a gap is formed therebetween;
• wherein the plurality of apertures of the first multi-aperture plate is arranged such that each aperture of the plurality of apertures of the first multi-aperture plate is aligned with a corresponding aperture of the plurality of apertures of the second multi-aperture plate;
• and
• wherein a first width of the gap at a location of a first aperture of the plurality of apertures of the first multi-aperture plate is by at least 5 greater than a second width of the gap at a location of a second aperture of the plurality of apertures of the first multi-aperture plate;
• the particle-optical component further comprising a fourth aperture plate having at least one aperture, the first multi-aperture plate being disposed between the fourth aperture plate and the second multi-aperture plate, and further comprising a mounting structure comprising at least one actuator for displacing the fourth aperture plate relative to the first multi-aperture plate such that in a first position one aperture of the at least one aperture of the fourth aperture plate is in alignment with a first aperture of the first multi-aperture plate and in a second position different from the first position the one aperture is in alignment with a second aperture of the first multi-aperture plate.

A method of operating a particle-optical system, comprising:

• positioning a testing aperture plate having at least one aperture in a first position relative to a multi-aperture component comprising a plurality of apertures such that in the first position, a first set of apertures of the testing aperture plate is in alignment with a first set of apertures of the multi-aperture component, with the respective sets of apertures comprising at least one aperture each;
• transmitting a set of beamlets of charged particles through the first set of apertures of the testing aperture plate and the first set of apertures of the multi-aperture component aligned therewith;
• determining at least one of positions, shapes and dimensions of the transmitted beamlets in a predetermined plane and a total intensity or individual intensities of the transmitted beamlets;
• positioning the testing aperture plate in a second position relative to the multi-aperture component such that the first set of apertures of the testing aperture plate is in alignment with a second set of apertures of the multi-aperture component;
• transmitting a set of beamlets of charged particles through the first set of apertures of the testing aperture plate and the second set of apertures of the multi-aperture component aligned therewith;
• and
• determining at least one of positions, shapes and dimensions of the transmitted beamlets in the predetermined plane and a total intensity or individual intensities of the transmitted beamlets.

A particle-optical arrangement, comprising:

• a charged particle source for generating at least one beam of charged particles;
• and
• at least one particle-optical component comprising:
• a first multi-aperture plate having a plurality of apertures and a second multi-aperture plate having a plurality of apertures, wherein the second multi-aperture plate is spaced apart from the first multi-aperture plate such that a gap is formed therebetween;
• wherein the plurality of apertures of the first multi-aperture plate is arranged such that each aperture of the plurality of apertures of the first multi-aperture plate is aligned with a corresponding aperture of the plurality of apertures of the second multi-aperture plate;
• wherein a first width of the gap at a location of a first aperture of the plurality of apertures of the first multi-aperture plate is by at least 5 greater than a second width of the gap at a location of a second aperture of the plurality of apertures of the first multi-aperture plate;
• wherein the at least one particle-optical component is arranged such that the second multi-aperture plate is traversed by a beam path of the charged particles downstream of the first multi-aperture plate;
• and
• wherein the particle-optical arrangement further comprises a first electrode traversed by the beam path of the charged particles upstream of the first multi-aperture plate;
• a second electrode traversed by the beam path of the charged particles downstream of the second multi-aperture plate;
• and
• a voltage supply system configured to apply different electric potentials to the first and second multi-aperture plates and the first and second electrodes.

A method of manipulating charged particle beamlets, the method comprising:

• applying a predetermined first electric potential to a first multi-aperture plate and a predetermined second electric potential different from the predetermined first potential to a second multi-aperture plate;
• transmitting a plurality of charged particle beamlets through apertures of a first multi-aperture plate having a plurality of apertures and, subsequently, through a second multi-aperture plate having a plurality of apertures,
• and transmitting the plurality of charged-particle beamlets through at least one focusing particle-optical lens;
• wherein the second multi-aperture plate is spaced apart from the first multi-aperture plate such that a gap is formed therebetween;
• wherein the plurality of apertures of the first multi-aperture plate is arranged such that each aperture of the plurality of apertures of the first multi-aperture plate is aligned with a corresponding aperture of the plurality of apertures of the second multi-aperture plate;
• wherein a first width of the gap at a location of a first aperture of the plurality of apertures of the first multi-aperture plate is by at least 5% greater than a second width of the gap at a location of a second aperture of the plurality of apertures of the first multi-aperture plate;
• and
• wherein the applied predetermined electric potentials are chosen such that at least one particle-optical aberration of the at least one focusing particle-optical lens is compensated.

A particle-optical arrangement, comprising:

• a charged particle source for generating at least one beam of charged particles;
• at least one magnetic lens configured to generate a first magnetic field in a path of the at least one beam;
• at least a first multi-aperture plate having a plurality of apertures, wherein the at least first multi-aperture plate is disposed to be traversed by a beam path of the at least one beam of charged particles;
• at least one coil arrangement configured to generate a second magnetic field such that a magnetic flux density at the at least first multi-aperture plate is substantially zero.

A method of manipulating charged particle beamlets, the method comprising:

• generating at least one of a charged-particle beam and a plurality of charged-particle beamlets;
• transmitting the at least one of the charged-particle beam and the plurality of charged-particle beamlets through at least one magnetic lens generating a first magnetic field;
• transmitting the at least one of the charged-particle beam and the plurality of charged-particle beamlets through at least one multi-aperture plate having a plurality of apertures;
• and
• generating a second magnetic field by applying a predetermined electric current to a coil arrangement traversed by the plurality of charged particle beamlets such that the second magnetic field at least partially compensates the first magnetic field and a magnetic flux density at the at least one multi-aperture plate is substantially zero.

A method of focusing a plurality of charged particle beamlets, the method comprising:

• transmitting at least one of a charged particle beam and a plurality of charged-particle beamlets through a first multi-aperture plate and a second multi-aperture plate, each having a plurality of apertures, with centers of the first and second multi-aperture plates being spaced a distance w0 apart,
• applying a first electric potential U1 to the first multi-aperture plate,
• applying a second electric potential U2 to the second multi-aperture plate, the second electric potential being different from the first electric potential;
• at least one of generating an electrical field traversed by the beam path upstream of the first multi-aperture plate and an electrical field traversed by the beam path downstream of the second multi-aperture plate, such that a first field strength E1 of an electrical field upstream and in the vicinity of the first multi-aperture plate differs from a second field strength E2 of an electrical field downstream and in the vicinity of the second multi-aperture plate by at least about 200 V/mm,
• wherein for charged particles having a charge q and having and a kinetic energy Ekin upon traversing the first multi-aperture plate, the following relationship is fulfilled:
• 0.0001
• ≤
• 3
• 4
• ·
• q
• w
• 0
• ·
• E
• kin
• ⁢
• (
• U
• 1
• -
• U
• 2
• )
• 2
• E
• 1
• -
• E
• 2
• ≤
• 0.2
• .

A particle-optical arrangement, comprising

• a first multi-aperture plate having a plurality of apertures and a second multi-aperture plate having a plurality of apertures, wherein the second multi-aperture plate is spaced apart from the first multi-aperture plate such that a gap is formed therebetween;
• and
• a magnetic lens arrangement comprising a first pole piece and a second pole piece and a coil for inducing magnetic flux in the first and second pole pieces;
• wherein the first multi-aperture plate is magnetically coupled to or integrally formed with the first pole piece of the magnetic lens arrangement and the second multi-aperture plate is magnetically coupled to or integrally formed with the second pole piece of the magnetic lens arrangement;
• wherein the plurality of apertures of the first multi-aperture plate is arranged such that each aperture of the plurality of apertures of the first multi-aperture plate is aligned with a corresponding aperture of the plurality of apertures of the second multi-aperture plate;
• and
• wherein a first width of the gap at a location of a first aperture of the plurality of apertures of the first multi-aperture plate is by at least 5 greater than a second width of the gap at a location of a second aperture of the plurality of apertures of the first multi-aperture plate.

A particle-optical component, comprising a first multi-aperture plate having a plurality of apertures,

• a second multi-aperture plate having a plurality of apertures,
• a fourth aperture plate having at least one aperture,
• a mounting structure comprising at least one actuator for displacing the fourth aperture plate relative to the first multi-aperture plate to a first position and to a second position, which is different from the first position,
• wherein the second multi-aperture plate is spaced apart from the first multi-aperture plate such that a gap is formed therebetween;
• wherein the plurality of apertures of the first multi-aperture plate is arranged such that each aperture of the plurality of apertures of the first multi-aperture plate is aligned with a corresponding aperture of the plurality of apertures of the second multi-aperture plate;
• and
• wherein the first multi-aperture plate is disposed between the fourth aperture plate and the second multi-aperture plate.

A particle-optical component, comprising

• a first multi-aperture plate having a plurality of apertures;
• a third multi-aperture plate having a plurality of apertures,
• wherein the plurality of apertures of the third multi-aperture plate is arranged such that each aperture of the plurality of apertures of the third multi-aperture plate is aligned with a corresponding aperture of the plurality of apertures of the first multi-aperture plate, and wherein a diameter of an aperture of the third multi-aperture plate is smaller than a diameter of a corresponding aperture of the first multi-aperture plate aligned with the aperture of the third multi-aperture plate;
• and
• a voltage supply system configured to apply different electric potentials to the first and third multi-aperture plates of the particle-optical component.