Multi-beam charged particle source with alignment means

Abstract

The present invention relates to an apparatus and method for generating a plurality of substantially collimated charged particle beamlets. The apparatus comprises: a charged particle source for generating a diffuse charged particle beam; a beam splitter for splitting the diffuse charged particle beam into an array of charged particle beamlets; and a deflector array comprising an array of deflectors, one deflector per charged particle beamlet in the array of charged particle beamlets, wherein the deflector array is configured to substantially collimate the array of diffuse charged particle beamlets. The apparatus further comprises a beam steering device configured to generate an electric field and / or a magnetic field in at least an area between the charged particle source and the deflector array. The apparatus comprises a central axis, and the beam steering device is configured to generate an electric field and / or a magnetic field that is substantially parallel to and substantially perpendicular to the central axis.

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to an apparatus and method for generating a plurality of charged particle beamlets. [Background technology]

[0002] Charged particle beams are used in a variety of systems, such as lithography, inspection, and imaging systems. Some of these systems use a single charged particle source to generate a charged particle beam that is then split into multiple charged particle beamlets.

[0003] In particular, US 2004 / 0232349 A1 describes an apparatus for generating a plurality of charged particle beamlets, comprising a charged particle source for generating a divergent charged particle beam, focusing means for refracting said divergent charged particle beam, and a lens array comprising a plurality of lenses, said lens array being arranged between said charged particle source and said focusing means.

[0004] In applications where the size of the array of charged particle beamlets in the plane of the collimator is large, it becomes impractical to use a single electron lens for collimation. As described in US 2004 / 0232349 A1, a deflector array can be used as a focusing means, in particular for collimating diffuse charged particle beamlets. The deflector array comprises a deflector for each charged particle beamlet in order to deflect the beamlet. Summary of the Invention

[0005] A drawback of known devices for generating a plurality of charged particle beamlets is that the position of the array of charged particle beamlets needs to be precisely aligned with the position of a collimating device, such as an array of deflectors of a deflector array.

[0006] Inaccurate alignment with the deflector array will, inter alia, result in not all beamlets traversing through the center of the corresponding deflector in the deflector array, and hence inaccurate alignment may result in deviations from the desired deflection for each beamlet, or even blocking of the beamlet when it misses the aperture of the corresponding deflector.

[0007] It is an object to at least partially overcome at least one of the above identified drawbacks and / or to at least partially provide an alternative apparatus for generating a plurality of charged particle beamlets, which allows alignment of the charged particle beamlets with respect to an array of deflectors.

[0008] According to a first aspect, there is provided an apparatus for generating a plurality of charged particle beamlets, the apparatus comprising: a charged particle source for producing a diffuse charged particle beam; a beam splitter for splitting the diffuse charged particle beam into an array of charged particle beamlets; a deflector array having a plurality of deflectors, one deflector for each charged particle beamlet of the array of charged particle beamlets, wherein the deflector array is configured to at least substantially collimate the array of diffuse charged particle beamlets; a beam steering device configured to generate an electric field and / or a magnetic field in at least an area between the charged particle source and the deflector array; the apparatus comprises a central axis, the center of the charged particle source, the center of the beam splitter, and the center of the deflector array are arranged on the central axis, and the beam manipulation device comprises: an electric field substantially parallel and / or perpendicular to the central axis, and / or Magnetic field substantially parallel and / or perpendicular to the central axis is configured to generate

[0009] In the apparatus of the present invention, the beam steering device allows steering the charged particle beamlets to optimize their alignment on the deflector array. Due to the presence of the steering device, the mechanical alignment of the elements of the apparatus for generating the multiple charged particle beamlets may not be very precise. More importantly, the alignment of the charged particle beamlets can be adjusted during operation of the apparatus, for example, to compensate for any thermal expansion of the elements of the apparatus and / or to compensate for any drift.

[0010] Considering a Cartesian coordinate system for the apparatus with a Z axis parallel to the central axis and X and Y axes in a plane perpendicular to the central axis, the electric and / or magnetic fields generated by the beam steering device can be assigned as follows:

[0011] A magnetic field extending along the Y-axis and / or an electric field extending along the X-axis can be used to move the array of charged particle beamlets in a direction along the X-axis. By carefully controlling the magnitude of the magnetic and / or electric fields, the actual position along the X-axis of the array of charged particle beamlets on the deflector array can be controlled to align the array of charged particle beamlets with the deflector array.

[0012] A magnetic field extending along the X-axis and / or an electric field extending along the Y-axis can be used to move the array of charged particle beamlets in a direction along the Y-axis. By carefully controlling the magnitude of the magnetic and / or electric fields, the actual position along the Y-axis of the array of charged particle beamlets on the deflector array can be controlled to align the array of charged particle beamlets with the deflector array.

[0013] A magnetic field extending at least partially along the Z-axis can be used to rotate the array of charged particle beamlets about the Z-axis. By carefully controlling the magnitude of the magnetic field, the actual position of the array of charged particle beamlets on the deflector array about the Z-axis can be controlled to align the array of charged particle beamlets with the deflector array. Note that such magnetic fields are typically created using a coil of conductive wire arranged in the XY plane, preferably with the central axis of the coil positioned on the Z-axis. Because the magnetic field of such a coil bends around the coil's conductive wire, the magnetic fields before and after the coil are not perfectly parallel to the Z-axis when viewed along the Z-axis. Therefore, such a magnetic field also provides a lensing effect. This lensing effect can be compensated for by controlling the divergence of the charged particle beam from the charged particle source, for example, by adjusting the voltage on the electrodes of the charged particle source, such as the voltage on the extraction electrode.

[0014] Additionally, the pitch between beamlets of an array of charged particle beamlets can be adjusted by using electrostatic and / or magnetic fields configured to provide field variations in a direction parallel to the central axis.

[0015] In a preferred embodiment, the beam manipulation device is configured to combine several of these magnetic and / or electric fields by combining one or more of the embodiments described below. This allows for adjusting the misalignment of the charged particle beamlets in more than one direction / rotational alignment. The specific placement of the beam manipulation device depends, among other things, on the specific use of the apparatus and / or the required precision of alignment in a specific application of the apparatus for generating multiple charged particle beamlets.

[0016] In an embodiment, the beam steering device comprises one or more first coils for generating a magnetic field in a first direction substantially perpendicular to the central axis. An apparatus according to this embodiment provides a relatively simple beam steering device, which makes it possible to adjust the alignment of the array of charged particle beamlets when misalignment and / or drift is mainly in a direction perpendicular to the central axis and the first direction.

[0017] In an embodiment, the beam steering device comprises, in addition to the one or more first coils, one or more second coils for generating a magnetic field in a second direction that is substantially perpendicular to the central axis and substantially perpendicular to the first direction. The apparatus according to this embodiment provides a beam steering device that allows adjusting the alignment of the array of charged particle beamlets in a plane perpendicular to the central axis, in particular along two orthogonal directions, for example along the X-axis and Y-axis as defined above.

[0018] In an embodiment, the beam steering device comprises a third coil for generating a magnetic field in a direction at least partially along and substantially parallel to the central axis. An apparatus according to this embodiment provides a beam steering device that allows adjusting the alignment of the array of charged particle beamlets with respect to rotation about the central axis.

[0019] It should be noted that the magnetic field from the third coil may also provide a variation in the pitch between the beamlets of the array of charged particle beamlets. Hence, in an embodiment, the third coil is a first third coil, and the beam steering device further comprises a second third coil configured to provide a magnetic field variation in a direction parallel to the central axis to the magnetic field, and the first coil and the second coil are configured to adjust the pitch between the beamlets of the array of charged particle beamlets, preferably without substantially adjusting the rotation about the central axis. By using two third coils, the combined effects of the rotation and the pitch variation can be at least partially disentangled.

[0020] In an embodiment, the beam steering device comprises one or more first electrodes for generating a magnetic field in a first direction substantially perpendicular to the central axis. The apparatus according to this embodiment provides a relatively simple beam steering device, which makes it possible to adjust the alignment of the array of charged particle beamlets when the shear and / or drift is mainly in a direction perpendicular to the central axis and parallel to the first direction.

[0021] It should be noted that an electrostatic field in a first direction substantially perpendicular to the path along which the charged particle travels provides a force on the charged particle substantially parallel to the first direction, whereas a magnetic field in a first direction substantially perpendicular to the path along which the charged particle travels provides a force on the charged particle substantially perpendicular to the first direction.

[0022] In an embodiment, the beam manipulation device comprises, in addition to the one or more first electrodes, one or more second electrodes for generating an electrostatic field in a second direction that is substantially perpendicular to the central axis and substantially perpendicular to the first direction. The apparatus according to this embodiment provides a beam manipulation device that allows adjusting the alignment of the array of charged particle beamlets in a plane perpendicular to the central axis, in particular along the X-axis and the Y-axis.

[0023] In an embodiment, the beam manipulation device comprises one or more third electrodes for generating an electrostatic field along and in a direction substantially parallel to the central axis, and the one or more third electrodes are configured to provide an electrostatic field variation in a direction parallel to the central axis to adjust the pitch between beamlets of the array of charged particle beamlets.

[0024] It should be noted that this latter embodiment can be advantageously combined with an embodiment in which the beam steering device comprises a third coil for generating a magnetic field in a direction at least partially along and substantially parallel to the central axis, as explained above. As already indicated above, the magnetic field due to the third coil can provide a rotation of the array of charged particle beamlets about the central axis and a change in pitch between the beamlets of the array of charged particle beamlets. By combining one or more third electrodes with the coil, the combined effect of the rotation and the change in pitch due to the third coil can be at least partially disentangled.

[0025] In addition to or as an alternative to generating magnetic and / or electric fields as described above, the manipulation device can also be configured to generate a multipole field, such as a quadrupole field or an octapole field. For example, by using a quadrupole magnetic and / or electric field, the array of charged particle beamlets can be, for example, packed more closely together in a first direction and spread out in a second direction, which can be substantially perpendicular to the first direction. Thus, the pitch between charged particle beamlets in the first direction can be reduced, while the pitch between charged particle beamlets in the second direction can be increased.

[0026] One or more of these quadrupole magnetic and / or electric fields can be generated using one or more of the embodiments described below:

[0027] In an embodiment, the beam steering device comprises one or more fourth coils for generating a quadrupole magnetic field in a plane substantially perpendicular to the central axis. In an embodiment, the beam steering device comprises four fourth coils, two of which are arranged on either side of the central axis and have a first common coil axis, and the other two are arranged on either side of the central axis and have a second common coil axis perpendicular to the first common coil axis, the first and second common coil axes being arranged in a plane substantially perpendicular to the central axis. Preferably, the four fourth coils are arranged at substantially the same distance from the central axis.

[0028] In a further embodiment, the beam steering device comprises two sets of fourth coils, each set configured to generate a quadrupole magnetic field in a plane substantially perpendicular to the central axis, and a first common coil axis of the first set arranged at an acute angle to a first common coil axis of the second set, In an embodiment, the angle between the first common coil axis of the first set and the first common coil axis of the second set is substantially 45 degrees.

[0029] In an embodiment, the beam manipulation device comprises one or more fourth electrodes for generating a quadrupole electrostatic field in a plane substantially perpendicular to the central axis. In an embodiment, the beam manipulation device comprises four fourth electrodes, two of which are arranged on either side of the central axis and on a first common electrode axis, and two of which are arranged on either side of the central axis and on a second common electrode axis perpendicular to the first common electrode axis, the first and second common electrode axes being arranged in a plane substantially perpendicular to the central axis. Preferably, the four fourth electrodes are arranged at substantially the same distance from the central axis.

[0030] In a further embodiment, the beam steering device comprises two sets of fourth electrodes, each set configured to generate a quadrupole electrostatic field in a plane substantially perpendicular to the central axis, and wherein a first common electrode axis of the first set is arranged at an acute angle to a first common electrode axis of the second set, In an embodiment, the angle between the first common electrode axis of the first set and the first common electrode axis of the second set is substantially 45 degrees.

[0031] Additionally or alternatively, in said further embodiment, the beam manipulation device comprises a fourth set of coils configured to generate a quadrupole magnetic field in a plane substantially perpendicular to the central axis, and a first common coil axis of the fourth set of coils arranged substantially parallel to a first common electrode axis of the fourth set of electrodes.

[0032] It should be noted that in further embodiments, the beam manipulation device may also comprise further coils and / or electrodes for generating higher order multipole magnetic and / or electrostatic fields, arranged between the charged particle source and the deflector array or between the charged particle source and the collimator lens.

[0033] In an embodiment, the apparatus further comprises a control system for the beam steering device, the control system being configured to adjust the electric and / or magnetic fields based on a signal from the sensor, the sensor being configured to measure a deviation of one or more charged particle beamlets of the array of charged particle beamlets from a desired alignment. Thus, the apparatus for generating a plurality of charged particle beamlets can be actively controlled to maintain a desired alignment of the charged particle beamlets. In an embodiment, the sensor is located at or near the deflector array or the collimator lens.

[0034] In an embodiment, the beam splitter comprises a lens array comprising a plurality of lenses, one lens for each charged particle beamlet.

[0035] In an alternative embodiment, the apparatus comprises a lens array comprising a plurality of lenses, one lens for each charged particle beamlet, the lens array being positioned between the beam splitter and the deflector array.

[0036] In an embodiment, the apparatus comprises a collimator lens disposed between the beam splitter and the charged particle source, and a converging lens disposed between the beam splitter and the deflector array, the converging lens configured to provide a common crossover of the plurality of charged particle beamlets between the converging lens and the deflector array. Preferably, the converging lens and the deflector array are configured to provide a beam expander.

[0037] In an alternative embodiment, the apparatus comprises a collimator lens disposed between the beam splitter and the charged particle source, and a diverging lens disposed between the beam splitter and the deflector array. Preferably, the diverging lens and the deflector array are configured to provide a beam expander. In this embodiment, common crossovers of multiple charged particle beamlets can be avoided.

[0038] The use of a collimator makes it possible to ensure that the charged particle beam impinging on the beam splitter is a substantially collimated charged particle beam, which at least substantially prevents the problems that arise when splitting a diffuse charged particle beam with a substantially planar aperture plate or electrode plate where the incoming beam does not pass through an aperture plate of the planar aperture plate or electrode plate perpendicular to the plane of the electrode plate, as described, for example, in US 2004 / 0232349 A1.

[0039] According to a second aspect, the present invention provides a method for generating a plurality of charged particle beamlets, the method comprising: generating a diffuse charged particle beam using a charged particle source; splitting the diffuse charged particle beam into an array of charged particle beamlets using a beam splitter; deflecting substantially each charged particle beamlet of the array of charged particle beamlets using a deflector array comprising an array of deflectors comprising one deflector per charged particle beamlet, wherein the deflector array is configured to at least substantially collimate the array of diffuse charged particle beamlets; generating an electric and / or magnetic field using a beam steering device in at least an area between the charged particle source and the deflector array to align the array of charged particle beamlets with respect to the deflector array; the apparatus comprises a central axis, the center of the charged particle source, the center of the beam splitter, and the center of the deflector array are arranged on the central axis, and the beam manipulation device comprises: an electric field substantially parallel and / or perpendicular to the central axis, and / or Magnetic field substantially parallel and / or perpendicular to the central axis Generates.

[0040] In the method of the present invention, the beam steering device steers the charged particle beamlets to optimize their alignment on the deflector array. Due to the presence of the steering device, the mechanical alignment of the elements of the apparatus for generating the multiple charged particle beamlets may not be very accurate. More importantly, the alignment of the charged particle beamlets can be adjusted during operation of the apparatus, for example, to correct any thermal expansion of the elements of the apparatus and / or to correct any drift. In particular, electric and / or magnetic fields are generated to adjust the alignment of the array of charged particle beamlets by providing one or more of the following: deflecting the array of charged particle beamlets in a first direction substantially perpendicular to the central axis; deflecting the array of charged particle beamlets in a second direction substantially perpendicular to the first direction and the central axis; a rotation of the array of charged particle beamlets about a central axis; an extension in a first direction substantially perpendicular to the central axis and a contraction in a second direction substantially perpendicular to the first direction and to the central axis of the array of charged particle beamlets; Expanding or contracting the array of charged particle beamlets in a radial direction relative to the central axis (thereby changing the pitch between beamlets in the array of charged particle beamlets).

[0041] In an embodiment, the apparatus further comprises a control system for the beam steering device, the control system adjusting the electric and / or magnetic fields based on signals from the sensor, the sensor determining deviations of one or more charged particle beamlets of the array of charged particle beamlets from a desired alignment. Thus, the apparatus for generating a plurality of charged particle beamlets is actively controlled to maintain a desired alignment of the charged particle beamlets. In an embodiment, the sensor is located at or near the deflector array or the collimator lens.

[0042] In an embodiment, the beam splitter comprises a lens array comprising a plurality of lenses, one lens for each charged particle beamlet, and each charged particle beamlet of the array of charged particle beamlets is refracted by a lens of the lens array.

[0043] In an embodiment, the apparatus comprises a lens array comprising a plurality of lenses, one lens for each charged particle beamlet, the lens array being disposed between the beam splitter and the deflector array, and each charged particle beamlet of the array of charged particle beamlets being refracted by a lens of the lens array.

[0044] The various aspects and features described and illustrated in this specification may, wherever possible, be applied individually. These individual aspects, in particular those described in the accompanying dependent claims, may be the subject of divisional patent applications.

[0045] The invention will now be described on the basis of exemplary embodiments shown in the accompanying drawings. [Brief explanation of the drawings]

[0046] [Figure 1A] 1 illustrates schematically an example of an apparatus for generating a plurality of charged particle beamlets, the apparatus having a beam steering device configured to generate a magnetic field substantially perpendicular to a central axis. [Figure 1B] 1B shows a schematic representation of the device of FIG. 1A in a plane perpendicular to the central axis. [Figure 2A] 1 illustrates schematically an example of an apparatus for generating a plurality of charged particle beamlets, the apparatus having a beam steering device configured to generate a magnetic field substantially perpendicular to a central axis. [Figure 2B] 1A and 2A in a plane perpendicular to the central axis. [Figure 3A] 10 shows a further example of an apparatus for generating a plurality of charged particle beamlets, the apparatus having a beam steering device configured to generate a magnetic field that is at least partially parallel to the central axis; [Figure 3B] 3B shows a schematic representation of the device of FIG. 3A in a plane perpendicular to the central axis. [Figure 4A] 10 shows a schematic representation of a further example of an apparatus for generating a plurality of charged particle beamlets, the apparatus having a beam steering device configured to generate an electric field substantially perpendicular to the central axis; [Figure 4B] 4B shows a schematic representation of the device of FIG. 4A in a plane perpendicular to the central axis. [Figure 5A] 10 shows a schematic representation of a further example of an apparatus for generating a plurality of charged particle beamlets, the apparatus comprising a beam steering device configured to generate a quadrupole magnetic field or an electrostatic field substantially perpendicular to the central axis; [Figure 5B] 5B shows a schematic representation of a first example of the apparatus of FIG. 5A in a plane perpendicular to the central axis, with coils arranged on the X and Y axes to generate a quadrupole magnetic field. [Figure 5C] 5B shows a second example of the device of FIG. 5A in a plane perpendicular to the central axis, with the coil positioned in the XY plane and rotated through 45 degrees clockwise relative to the position of the coil in FIG. 5B. [Figure 5D] 5B shows a schematic representation of a third example of the apparatus of FIG. 5A in a plane perpendicular to the central axis, with electrodes arranged on the X and Y axes to generate a quadrupole electrostatic field. [Figure 5E]5D shows a fourth example of the device of FIG. 5A in a plane perpendicular to the central axis, with the electrodes positioned in the XY plane and rotated through 45 degrees clockwise relative to the position of the electrodes in FIG. 5D. DETAILED DESCRIPTION OF THE INVENTION

[0047] It should be noted that a beam manipulation device according to the invention is preferably configured to combine several magnetic and / or electric fields. This allows adjusting the misalignment of the charged particle beamlets in more than one directional / rotational alignment. In order to more clearly explain examples of beam manipulation devices allowing adjusting the alignment of the beamlets, these different examples are described separately below, but it should be understood that a beam manipulation device according to the invention may combine one or more of the embodiments described below.

[0048] 1 shows a first example of an apparatus 10 for generating a plurality of charged particle beamlets 16. The apparatus 10 comprises a charged particle source 11 having an extraction electrode 19 for generating a divergent charged particle beam 12. The divergent charged particle beam 12 is directed onto a collimating lens 13, after which the at least substantially collimated charged particle beam 12 is directed onto a beam splitter 14 for splitting the charged particle beam 12 into an array of charged particle beamlets 16.

[0049] In this example, the beam splitter 14 comprises a lens array configured to focus each charged particle beamlet 16. Additionally, the lens array is combined with electrodes 141 to provide a diverging lens for generating a diverging array of charged particle beamlets 16. The diverging charged particle beamlets 16 are directed to a deflector array 15 comprising an array of deflectors, one deflector per charged particle beamlet 16. The apparatus 10 has a central axis CA, and the centers of the charged particle source 11, the beam splitter 14, and the deflector array 15 are disposed on the central axis CA. The deflector array 15 is configured to substantially deflect each charged particle beamlet 16 to provide a substantially collimated array of charged particle beamlets 16. It should be noted that the diverging lens provided by the beam splitter 14 and electrodes 141 and the deflector array 15 together form a beam expander. In the example shown in FIG. 1, the lens array is configured to focus each charged particle beamlet 16 substantially into the plane of the deflector array 15 .

[0050] The position of the array of diffuse charged particle beamlets 16 needs to be precisely aligned with the position of the array of deflectors of the deflector array 15. To assist and / or adjust the alignment, the apparatus 10 of the present invention comprises a beam steering device comprising a first coil 17 and a second coil 18 arranged on either side of the central axis CA. The coils 17, 18 are configured to generate a magnetic field BX in the area between the charged particle source 11 and the deflector array 15, in particular in the area between the beam splitter 14 and the deflector array 15.

[0051] As shown schematically in Figure 1, the magnetic field BX extends substantially in a direction parallel to the X-axis and substantially perpendicular to the central axis CA. If the charged particle beamlets 16 comprise positively charged particles and the magnetic field BX extends in the direction of the positive X-axis, the magnetic field BX will generate a force on the positively charged particles, which will cause them to move in the direction of the positive Y-axis, as shown schematically in Figure 1B.

[0052] In the figure, the white circles represent the positions of the charged particle beamlets when the magnetic or electrostatic field of the manipulation device is turned off, and the black circles represent the positions of the charged particle beamlets when the magnetic or electrostatic field of the manipulation device is turned on.

[0053] It should be noted that the combination of beam splitter 14 and electrode 141 is configured to generate an electrostatic field along and in a direction substantially parallel to the central axis, and is thus configured to operate as the one or more third electrodes identified above. Beam splitter 14 and electrode 141 may be configured to provide an electrostatic field variation in a direction parallel to the central axis, particularly in deflector array 15, to adjust the inter-beamlet pitch of the array of charged particle beamlets.

[0054] FIG. 2A illustrates a first alternative example of an apparatus 10′ for generating a plurality of charged particle beamlets 16′. The apparatus 10′ includes a charged particle source 11′ having an extraction electrode 19′ for generating a diffuse charged particle beam 12′. The diffuse charged particle beam 12′ is directed onto a beam splitter 14′ for splitting the diffuse charged particle beam 12′ into an array of charged particle beamlets 16′. The charged particle beamlets 16′ are directed onto a deflector array 15′ including an array of deflectors, one deflector per charged particle beamlet 16′. The apparatus 10′ includes a central axis CA, and the centers of the charged particle source 11′, the beam splitter 14′, and the deflector array 15′ are located on the central axis CA. The deflector array 15′ is configured to substantially deflect each charged particle beamlet 16′ toward the central axis CA, with the deflection increasing with distance to the central axis CA. In particular, the deflector array 15' is configured to deflect substantially each charged particle beamlet 16' to provide a substantially collimated array of charged particle beamlets 16'. In the example shown in Figure 2A, the beam splitter 14' comprises a lens array configured to focus each charged particle beamlet 16' substantially into the plane of the deflector array 15'. Such a system is also described, for example, in US 2004 / 0232349 A1, in particular Figure 7 thereof.

[0055] Again, the position of the array of charged particle beamlets 16' needs to be precisely aligned with the position of the array of deflectors in the deflector array 15'. To assist and / or adjust the alignment, the apparatus 10' of the present invention comprises a beam steering device comprising a first coil 17' and a second coil 18' arranged on either side of the central axis CA. The coils 17', 18' are configured to generate a magnetic field BY in the area between the charged particle source 11' and the deflector array 15', in particular in the area between the beam splitter 14' and the deflector array 15'.

[0056] If the charged particle beamlet 16' comprises positively charged particles and the magnetic field BY extends in the direction of the positive Y-axis, the magnetic field BY generates a force on the positively charged particles, which causes them to move in the direction of the negative X-axis.

[0057] The amount of deviation ΔX depends, among other things, on the strength of magnetic field BY. Therefore, by controlling the strength of magnetic field BY, the amount of deviation ΔX can be controlled so that the array of charged particle beamlets 16′ is precisely aligned with the apertures in deflector array 15′.

[0058] Note that negatively charged particles move in the opposite direction, towards the positive X-axis.

[0059] As shown schematically in Figure 1A, coils 17, 18 can be configured to provide a magnetic field BX in a direction parallel to the X-axis and substantially perpendicular to the central axis CA. As shown schematically in Figure 2A, coils 17', 18' can be configured to provide a magnetic field B Y in a direction parallel to the Y-axis and substantially perpendicular to the central axis CA. By combining the beam steering devices of the examples of Figures 1A and 2A, the alignment of beamlet 16' can be adjusted in both the X and Y directions, as shown schematically in Figure 2B.

[0060] 3A , the apparatus 20 comprises a charged particle source 21 having an extraction electrode 29 for generating a diffuse charged particle beam 22, a beam splitter 23 for splitting the diffuse charged particle beam 22 into an array of diffuse charged particle beamlets 24, and a deflector array 25 comprising an array of deflectors with one deflector per charged particle beamlet 24, wherein the centers of the charged particle source 21, the beam splitter 23, and the deflector array 25 are arranged on a central axis CA. The deflector array 25 is configured to deflect substantially each charged particle beamlet 24 toward the central axis CA, the deflection preferably being configured to provide a substantially collimated array of charged particle beamlets 26. Preferably, the beam splitter 23 comprises a lens array configured to focus each diffuse charged particle beamlet 24 substantially into the plane of the deflector array 25.

[0061] The apparatus 20 further comprises a beam steering device including a coil 27 disposed about a central axis CA. Preferably, the central axis CA and the central axis of the coil 27 are substantially coincident. The coil 27 is configured to generate a magnetic field B surrounding the coil 27, and is configured to generate a magnetic field BZ at least in the area within the coil 27 and in the area between the charged particle source 21 and the deflector array 25, particularly in the area between the beam splitter 23 and the deflector array 25. During use, the magnetic field BZ generates a force on the charged particles, which provides a rotation ΔRZ of the array of charged particle beamlets 24 about the central axis CA, as shown schematically in FIG. 3B . The amount of rotation ΔRZ depends, inter alia, on the strength of the magnetic field BZ. Therefore, by controlling the strength of the magnetic field BZ, the amount of rotation ΔRZ can be controlled so that the array of charged particle beamlets 26 is precisely aligned with the aperture in the deflector array 25.

[0062] Note that, as shown in FIG. 3B, the array of charged particle beamlets with negatively charged particles rotates in the opposite direction relative to the rotation of the array of charged particle beamlets with positively charged particles.

[0063] It should be further noted that the magnetic field on one side adjacent to the coil 27 circulates toward the central axis CA, and the magnetic field on the other side adjacent to the coil 27 circulates away from the central axis CA. Therefore, the magnetic fields in front of and behind the coil 27 are not perfectly parallel to the Z axis when viewed along the Z axis. Such magnetic fields provide an additional lensing effect. This lensing effect can be compensated for by controlling the divergence of the charged particle beam 22 from the charged particle source 21, for example, by adjusting the voltage on the electrodes of the charged particle source 21, such as the voltage on the extraction electrode 29.

[0064] 4A , the apparatus 30 includes a charged particle source 31 having an extraction electrode 39 for generating a diffuse charged particle beam 32, a beam splitter 33 for splitting the diffuse charged particle beam 32 into an array of diffuse charged particle beamlets 34, and a deflector array 35 including an array of deflectors, one deflector per charged particle beamlet 34. The centers of the charged particle source 31, the beam splitter 33, and the deflector array 35 are arranged on a central axis CA. The deflector array 35 is configured to deflect substantially each charged particle beamlet 34 toward the central axis CA, the deflection preferably being configured to provide a substantially collimated array of charged particle beamlets 36. Preferably, the beam splitter 33 includes a lens array configured to focus each diffuse charged particle beamlet 34 substantially into the plane of the deflector array 35.

[0065] To assist and / or adjust the alignment, the apparatus 30 in this example comprises a beam steering device comprising a first electrode 37 and a second electrode 38 arranged on either side of a central axis CA. The electrodes 37, 38 are configured to generate an electric field EX in the area between the charged particle source 31 and the deflector array 35, in particular in the area between the beam splitter 33 and the deflector array 35.

[0066] As shown schematically in FIG. 4A , the electrodes 37, 38 can be configured to provide an electric field EX in a direction parallel to the X-axis and substantially perpendicular to the central axis CA. If the charged particle beamlets 34 comprise positively charged particles and the electric field EX extends in the direction of the positive X-axis, as shown schematically in FIG. 4B , the electric field EX generates a force on the positively charged particles, which causes them to move in the direction of the positive X-axis. The amount of deviation ΔX depends, among other things, on the strength of the electric field EX. Therefore, by controlling the strength of the electric field EX, the amount of deviation ΔX can be controlled so that the array of charged particle beamlets 36 is precisely aligned with the aperture in the deflector array 35.

[0067] Note that negatively charged particles move in the opposite direction, towards the negative X-axis.

[0068] It is further noted that the apparatus 30 may also be provided with electrodes that generate an electric field in the Y direction, e.g., in the direction of the positive Y axis. If the charged particle beamlets 34 comprise positively charged particles, the electric field extending in the direction of the positive Y axis will generate a force on the positively charged particles, which will cause them to move in the direction of the positive Y axis.

[0069] 5A , the apparatus 40 comprises a charged particle source 41 for generating a diffuse charged particle beam 42, a beam splitter 43 for splitting the diffuse charged particle beam 42 into an array of diffuse charged particle beamlets 44, and a deflector array 45 comprising an array of deflectors, one deflector per charged particle beamlet 44, wherein the centers of the charged particle source 41, the beam splitter 43, and the deflector array 45 are arranged on a central axis CA. The deflector array 45 is configured to deflect substantially each charged particle beamlet 44 toward the central axis CA, the deflection preferably being configured to provide a substantially collimated array of charged particle beamlets 46. Preferably, the beam splitter 43 comprises a lens array configured to focus each diffuse charged particle beamlet 44 substantially into the plane of the deflector array 45.

[0070] To assist and / or adjust the alignment, the apparatus 40 in this example comprises a beam steering device comprising a quadrupole deflector 47. In this particular example, the quadrupole deflector 47 comprises a set of coils, in particular coils 48, 49, 50, 51, which are arranged in a plane centered on and perpendicular to a central axis CA, in particular all at the same distance from the central axis CA, as shown schematically in FIG. 5B. The coils 48, 49, 50, 51 are configured to generate a quadrupole magnetic field in the area between the charged particle source 41 and the deflector array 45, in particular in the area between the beam splitter 43 and the deflector array 45.

[0071] 5B, coils 48, 49, 50, 51 can each be configured to provide a magnetic field B in a direction toward or away from the array of charged particles 46. The combined magnetic field B of coils 48, 49, 50, 51 generates: a. a force F1 between the first coil 48 and the second coil 49 on a positively charged particle, the force F1 pushing the positively charged particle in a direction substantially parallel to the diagonal of the +X, +Y direction; b. a force F2 between the second coil 49 and the third coil 50 on the positively charged particle, the force F2 pushing the positively charged particle in a direction substantially parallel to the diagonal of the -X, +Y directions; c. A force F3 between the third coil 50 and the fourth coil 51 on the positively charged particle, the force F3 pushing the positively charged particle in a direction substantially parallel to the diagonal of the -X, -Y direction; d. A force F4 between the fourth coil 51 and the first coil 48 on a positively charged particle, which pushes the positively charged particle in a direction substantially parallel to the diagonal of the +X, -Y direction.

[0072] 5B, the quadrupole deflector 47 provides compression of the array in directions parallel to the diagonal of the +X, +Y directions (along the F1, F3 directions) and expansion of the array in directions parallel to the diagonal of the -X, Y directions (along the F2, F4 directions). The amount of expansion and compression depends, among other things, on the strength of the magnetic field B. Therefore, by controlling the strength of the magnetic field B, the amount of expansion and compression can be controlled so that the array of charged particle beamlets 46 is precisely aligned with the aperture in the deflector array 45.

[0073] Note that when coils 48, 49, 50, 51 are driven to provide a magnetic field B in the opposite direction to that shown in FIG. 5B, the force on the charged particle also acts in the opposite direction to that shown in FIG. 5B.

[0074] It is further noted that negatively charged particles move in the opposite direction, hence the extension will be parallel to the F1, F3 directions and the compression will be parallel to the F2, F4 directions.

[0075] Additionally or alternatively, the quadrupole deflector 47 comprises a second set of coils, in particular coils 48′, 49′, 50′, 51′, which are all arranged around the central axis CA, in particular at the same distance from the central axis CA, as shown schematically in FIG. 5C. The coils 48′, 49′, 50′, 51′ are configured to generate a quadrupole magnetic field in the area between the charged particle source 41 and the deflector array 45, in particular in the area between the beam splitter 43 and the deflector array 45.

[0076] 5C, coils 48', 49', 50', 51' can each be configured to provide a magnetic field B in a direction toward or away from the array of charged particles 46. The combined magnetic field B of coils 48', 49', 50', 51' generates: a. a force F1' between the first coil 48' and the second coil 49' on a positively charged particle, the force F1' pushing the positively charged particle in a direction substantially parallel to the +X direction; b. a force F2' between the second coil 49' and the third coil 50' on the positively charged particle, the force F2' pushing the positively charged particle in a direction substantially parallel to the +Y direction; c. a force F3' between the third coil 50' and the fourth coil 51' on the positively charged particle, the force F3' pushing the positively charged particle in a direction substantially parallel to the -X direction; d. A force F4' between the fourth coil 51' and the first coil 48' on a positively charged particle, the force F4' pushing the positively charged particle in a direction substantially parallel to the -Y direction.

[0077] 5C, the quadrupole deflector 47 provides a compression of the array of charged particle beamlets 46 in a direction parallel to the X-axis and an expansion of the array in a direction parallel to the Y-axis. The amount of expansion and compression depends, among other things, on the strength of the magnetic field B. Therefore, by controlling the strength of the magnetic field B, the amount of expansion and compression can be controlled so that the array of charged particle beamlets 46 is precisely aligned with the aperture in the deflector array 45.

[0078] Note that when coils 48', 49', 50', 51' are driven to provide a magnetic field B in the opposite direction to that shown in Figure 5C, the force on charged particle beamlet 46 also acts in the opposite direction to that shown in Figure 5C.

[0079] It is further noted that the negative charged particle beamlets travel in the opposite direction to the example of FIG. 5C, which results in expansion being parallel to the X-axis and compression being parallel to the Y-axis.

[0080] Additionally or alternatively, the quadrupole deflector 47 comprises a set of four electrodes, in particular electrodes 48'', 49'', 50'', 51'', all arranged around a central axis CA, in particular at the same distance from the central axis CA, as shown schematically in FIG. 5D. The electrodes 48'', 49'', 50'', 51'' are configured to generate a quadrupole electrostatic field in the area between the charged particle source 41 and the deflector array 45, in particular in the area between the beam splitter 43 and the deflector array 45.

[0081] As shown schematically in FIG. 5D, electrodes 48'', 49'', 50'', 51'' can each be configured to provide an electrostatic field E directed toward or away from the array of charged particles 46''. When the electrodes are provided with potentials as shown schematically in FIG. 5D, the combined electrostatic field E of electrodes 48'', 49'', 50'', 51'' generates the following: a. a force F1″ that pulls negatively charged particles near the electrode 48″ in a direction substantially parallel to the −Y direction; b. a force F2″ pushing negatively charged particles near electrode 49″ in a direction substantially parallel to the +X direction; c. a force F3″ that pulls negatively charged particles near the electrode 50″ in a direction substantially parallel to the +Y direction; d. Force F4'' pushing negatively charged particles near electrode 51'' in a direction substantially parallel to the -X direction.

[0082] The quadrupole deflector 47 therefore provides a compression of the array of negative charged particle beamlets 46'' in a direction parallel to the X-axis and an expansion of the array in a direction parallel to the Y-axis, as shown schematically in FIG. 5D. The amount of expansion and compression depends, among other things, on the strength of the electrostatic field E. Therefore, by controlling the strength of the electrostatic field E, the amount of expansion and compression can be controlled so that the array of charged particle beamlets 46 is precisely aligned with the aperture in the deflector array 45.

[0083] It should be noted that when electrodes 48'', 49'', 50'', 51'' are driven to provide an electrostatic field E in the opposite direction to that shown in Figure 5D, the force on the negative charged particle beamlets also acts in the opposite direction to that shown in Figure 5D.

[0084] It is further noted that the positive charged particle beamlets move in the opposite direction to the example shown in FIG. 5D, and hence when using the same configuration of electrostatic field E as shown in FIG. 5D, the extension will be parallel to the X axis and the compression will be parallel to the Y axis.

[0085] Additionally or alternatively, the quadrupole deflector 47 includes a set of four electrodes, specifically electrodes 48'", 49'", 50'", and 51'", all positioned about a central axis CA, specifically at the same distance from the central axis CA, as shown schematically in FIG. 5E. Electrodes 48'", 49'", 50'", and 51'" are positioned in the XY plane and are rotated 45 degrees clockwise relative to the positions of electrodes 48", 49", 50", and 51" in FIG. 5D. When applying potentials as shown in FIG. 5E to electrodes 48'", 49'", 50'", and 51'", the quadrupole deflector 47 provides a compression of the array in a direction parallel to the diagonal in the +X, +Y direction (parallel to the F1'" and F3'" directions) and an expansion of the array in a direction parallel to the diagonal in the -X, +Y direction (parallel to the F2'" and F4'" directions). The amount of stretching and compression depends, among other things, on the strength of the electrostatic field E. Therefore, by controlling the strength of the electrostatic field E, the amount of stretching and compression can be controlled so that the array of charged particle beamlets 46''' is precisely aligned with the apertures in the deflector array 45.

[0086] It should be noted that the illustrative embodiments of Figures 5B, 5C, 5D, and 5E may be used individually or in combination in a quadrupole deflector 47 according to the present invention.

[0087] It should be understood that the above description is included to illustrate the operation of the preferred embodiments and is not intended to limit the scope of the invention. From the above discussion, many variations will become apparent to those skilled in the art that would still be encompassed by the scope of the invention.

[0088] As indicated above, the manipulation device according to the present invention preferably combines one or more of the examples presented above in order to provide the desired possibilities for correcting the trajectory of the charged particle beam, in particular for aligning the charged particle beam on the deflector array.

[0089] Additionally, the manipulation devices 27, 38, and 47 of FIGS. 3A, 4A, 5A, 5B, 5C, 5D, and 5E, respectively, may also be used and / or combined in the beam expander of FIG.

[0090] In summary, the present invention relates to an apparatus and method for generating a plurality of substantially collimated charged particle beamlets, the apparatus comprising: a charged particle source for generating a diffuse charged particle beam; a beam splitter for splitting the diffuse charged particle beam into an array of charged particle beamlets; a deflector array comprising an array of deflectors comprising one deflector for each charged particle beamlet of the array of charged particle beamlets, wherein the deflector array is configured to substantially collimate the array of diffuse charged particle beamlets; The apparatus further comprises a beam steering device configured to generate an electric and / or magnetic field in at least an area between the charged particle source and the deflector array, the apparatus comprising a central axis, the beam steering device configured to generate an electric and / or magnetic field substantially parallel to and substantially perpendicular to the central axis. The following is a summary of the claims as originally filed: [1] An apparatus for generating a plurality of charged particle beamlets, comprising: a charged particle source for producing a diffuse charged particle beam; a beam splitter for splitting the diffuse charged particle beam into an array of charged particle beamlets; a deflector array having an array of a plurality of deflectors, one deflector for each charged particle beamlet of the array of charged particle beamlets, wherein the deflector array is configured to at least substantially collimate the array of diffuse charged particle beamlets; a beam steering device configured to generate an electric and / or magnetic field in at least an area between the charged particle source and the deflector array; Equipped with the apparatus has a central axis, the charged particle source, a center of the beam splitter, and a center of the deflector array are arranged on the central axis, and the beam manipulation device is an electric field substantially parallel and / or perpendicular to the central axis, and / or a magnetic field substantially parallel and / or perpendicular to said central axis An apparatus configured to generate a [2] The apparatus described in [1], further comprising a control system for controlling the beam manipulation device, the control system configured to adjust the electric field and / or magnetic field based on a signal from a sensor, the sensor configured to measure deviation from a desired alignment. [3] The apparatus described in [1] or [2], wherein the beam manipulation device comprises one or more first coils for generating a magnetic field in a first direction substantially perpendicular to the central axis. [4] The apparatus described in [3], wherein the beam manipulation device comprises one or more second coils for generating a magnetic field in a second direction substantially perpendicular to the central axis and substantially perpendicular to the first direction. [5] The apparatus described in any one of [1] to [4], wherein the beam manipulation device includes a third coil for generating a magnetic field along the central axis and in a direction substantially parallel to the central axis. [6] The apparatus described in [5], wherein the third coil is a first third coil, and the beam manipulation device further comprises a second third coil configured to provide a magnetic field with a variation of the magnetic field in a direction parallel to the central axis, and the first coil and second coil are configured to adjust the pitch between beamlets of the array of charged particle beamlets, preferably without substantially adjusting rotation about the central axis. [7] The apparatus described in any one of [1] to [6], wherein the beam manipulation device comprises one or more fourth coils configured to generate a quadrupole magnetic field in a plane substantially perpendicular to the central axis, and preferably the beam manipulation device comprises a set of four fourth coils, two of which are arranged on either side of the central axis and have a first common coil axis, and the other two of which are arranged on either side of the central axis and have a second common coil axis perpendicular to the first common coil axis, the first and second common coil axes being arranged in a plane substantially perpendicular to the central axis, and preferably the four fourth coils are arranged at substantially the same distance from the central axis. [8] The apparatus described in [7], wherein the beam steering device comprises two sets of four coils, each set configured to generate a quadrupole magnetic field in a plane substantially perpendicular to the central axis, and the first common coil axis of the first set is arranged at an acute angle to the first common coil axis of the second set, preferably the acute angle between the first common coil axis of the first set and the first common coil axis of the second set is substantially 45 degrees. [9] The apparatus described in any one of [1] to [8], wherein the beam manipulation device comprises one or more first electrodes for generating an electrostatic field in a first direction substantially perpendicular to the central axis.

[10] The apparatus described in [9], wherein the beam manipulation device comprises one or more second electrodes for generating an electrostatic field in a second direction substantially perpendicular to the central axis and substantially perpendicular to the first direction.

[11] The apparatus described in any one of [1] to

[10] , wherein the beam manipulation device comprises one or more third electrodes for generating an electrostatic field in a direction along and substantially parallel to the central axis, and the one or more third electrodes are configured to provide an electrostatic field with a variation of the electrostatic field in a direction parallel to the central axis to adjust the pitch between beamlets of the array of charged particle beamlets.

[12] The apparatus described in any one of [1] to

[11] , wherein the beam manipulation device comprises one or more fourth electrodes for generating a quadrupole electrostatic field in a plane substantially perpendicular to the central axis, and preferably the beam manipulation device comprises a set of four fourth electrodes, two of which are arranged on either side of the central axis and on a first common electrode axis, and the other two are arranged on either side of the central axis and on a second common electrode axis perpendicular to the first common electrode axis, the first and second common electrode axes being arranged in a plane substantially perpendicular to the central axis, and preferably the four fourth electrodes are arranged at substantially the same distance from the central axis.

[13] The apparatus of

[12] , wherein the beam manipulation device comprises two sets of four electrodes, each set configured to generate a quadrupole electrostatic field in a plane substantially perpendicular to the central axis, and wherein the first common electrode axis of the first set is arranged at an acute angle to the first common electrode axis of the second set, preferably the acute angle between the first common electrode axis of the first set and the first common electrode axis of the second set is substantially 45 degrees.

[14] The beam splitter comprises a lens array having a plurality of lenses, one lens for each charged particle beamlet; the apparatus comprises a lens array having a plurality of lenses, one lens for each charged particle beamlet, the lens array being positioned between the beam splitter and the deflector array or between the beam splitter and a collimator lens; The device according to any one of [1] to

[13] .

[15] A method for generating a plurality of charged particle beamlets, comprising: generating a diffuse charged particle beam using a charged particle source; splitting the diffuse charged particle beam into an array of charged particle beamlets using a beam splitter; deflecting substantially each charged particle beamlet of the array of charged particle beamlets using a deflector array having an array of a plurality of deflectors, one deflector per charged particle beamlet, wherein the deflector array is configured to at least substantially collimate the array of diffuse charged particle beamlets; generating an electric and / or magnetic field using a beam steering device in at least an area between the charged particle source and the deflector array to align the array of charged particle beamlets with respect to the array of deflectors of the deflector array; Equipped with the apparatus has a central axis, the charged particle source, a center of the beam splitter, and a center of the deflector array are arranged on the central axis, and the beam manipulation device comprises: an electric field substantially parallel and / or perpendicular to the central axis, and / or a magnetic field substantially parallel and / or perpendicular to said central axis A method for generating

[16] The method of

[15] , wherein the apparatus further comprises a control system for the beam steering device, the control system adjusting the electric and / or magnetic fields based on signals from a sensor configured to determine deviations from a desired alignment, preferably the sensor being located at or near the deflector array or collimator lens.

[17] The beam splitter comprises a lens array having a plurality of lenses, one lens for each charged particle beamlet, and each charged particle beamlet of the array of charged particle beamlets is refracted by a lens of the lens array; or the apparatus comprises a lens array having a plurality of lenses, one lens for each charged particle beamlet, the lens array being disposed between the beam splitter and the deflector array or the collimator lens, and each charged particle beamlet of the array of charged particle beamlets being refracted by a lens of the lens array. The method according to

[15] or

[16] .

Claims

1. 1. An apparatus for generating a plurality of charged particle beamlets, the apparatus comprising: a charged particle source for generating a diffuse charged particle beam; a beam splitter for splitting the diffuse charged particle beam into an array of charged particle beamlets; a deflector array having an array of a plurality of deflectors, one deflector for each charged particle beamlet in the array of charged particle beamlets; a beam steering device configured to generate an electric and / or magnetic field in at least an area between the charged particle source and the deflector array; the deflector array is configured to collimate an array of diffuse charged particle beamlets; the electric and / or magnetic fields are configured to optimize alignment of the charged particle beamlets on the deflector array; the apparatus has a central axis, and the charged particle source, a center of the beam splitter, and a center of the deflector array are disposed on the central axis; the beam steering device is configured to generate an electric field having a vector component perpendicular to the central axis and / or a magnetic field having a vector component perpendicular to the central axis; The apparatus, wherein the beam steering device further comprises a third coil for generating a magnetic field having a vector component oriented along and parallel to the central axis.

2. 2. The apparatus of claim 1, further comprising a control system for controlling the beam steering device, the control system configured to adjust the electric and / or magnetic fields based on signals from a sensor, the sensor configured to measure deviations of one or more charged particle beamlets in the array of charged particle beamlets from a desired alignment.

3. 3. The apparatus of claim 1, wherein the beam steering device comprises one or more first coils for generating a magnetic field having a vector component in a first direction perpendicular to the central axis.

4. 4. The apparatus of claim 3, wherein the beam steering device comprises one or more second coils for generating a magnetic field that is perpendicular to the central axis and includes a vector component in a second direction that is perpendicular to the first direction.

5. 2. The apparatus of claim 1, wherein the third coil is a first third coil, and the beam manipulation device further comprises a second third coil configured to provide a magnetic field with a variation of the magnetic field in a direction parallel to the central axis, and the first third coil and the second third coil are configured to adjust the pitch between beamlets of the array of charged particle beamlets, preferably without adjusting rotation about the central axis.

6. 6. The apparatus of claim 1, wherein the beam steering device comprises one or more fourth coils configured to generate a quadrupole magnetic field in a plane perpendicular to the central axis.

7. The apparatus described in claim 6, wherein the beam manipulation device comprises a set of four fourth coils, two of which are arranged on either side of the central axis and have a first common coil axis, and the other two are arranged on either side of the central axis and have a second common coil axis perpendicular to the first common coil axis, the first and second common coil axes being arranged in a plane perpendicular to the central axis, and preferably the four fourth coils being arranged at substantially the same distance from the central axis.

8. 8. The apparatus of claim 7, wherein the beam steering device comprises two sets of fourth coils comprising a first set and a second set, each set configured to generate a quadrupole magnetic field in a plane perpendicular to the central axis, and wherein the first common coil axis of the first set is arranged at an acute angle to the first common coil axis of the second set, preferably the acute angle between the first common coil axis of the first set and the first common coil axis of the second set is 45 degrees.

9. The apparatus of any one of claims 1 to 8, wherein the beam manipulation device comprises one or more first electrodes for generating an electrostatic field in a first direction perpendicular to the central axis.

10. 10. The apparatus of claim 9, wherein the beam steering device comprises one or more second electrodes for generating an electrostatic field in a second direction perpendicular to the central axis and perpendicular to the first direction.

11. 11. The apparatus of claim 1, wherein the beam manipulation device comprises one or more third electrodes for generating an electrostatic field in a direction along and parallel to the central axis, the one or more third electrodes being configured to provide an electrostatic field with a variation of the electrostatic field in a direction parallel to the central axis to adjust the pitch between beamlets of the array of charged particle beamlets.

12. 12. The apparatus of claim 1, wherein the beam steering device comprises one or more fourth electrodes for generating a quadrupole electrostatic field in a plane perpendicular to the central axis, preferably the beam steering device comprises a set of four fourth electrodes, two of which are arranged on either side of the central axis and on a first common electrode axis and the other two of which are arranged on either side of the central axis and on a second common electrode axis perpendicular to the first common electrode axis, the first and second common electrode axes being arranged in a plane perpendicular to the central axis, preferably the four fourth electrodes being arranged at substantially the same distance from the central axis.

13. 13. The apparatus of claim 12, wherein the beam steering device comprises two sets of fourth electrodes comprising a first set and a second set, each set configured to generate a quadrupole electrostatic field in a plane perpendicular to the central axis, and wherein the first common electrode axis of the first set is arranged at an acute angle to the first common electrode axis of the second set, preferably the acute angle between the first common electrode axis of the first set and the first common electrode axis of the second set is 45 degrees.

14. the beam splitter comprises a lens array having a plurality of lenses, one lens for each charged particle beamlet; or the apparatus comprises a lens array having a plurality of lenses, one lens for each charged particle beamlet, the lens array being positioned between the beam splitter and the deflector array or between the beam splitter and a collimator lens; An apparatus according to any one of claims 1 to 13.

15. the beam steering device at least two sets of coils arranged on opposite sides of the central axis and having a common coil central axis, wherein the common coil central axis is arranged in a plane substantially perpendicular to the central axis; and / or at least two sets of electrodes arranged on either side of the central axis and on a common electrode axis, the common electrode axis being arranged in a plane substantially perpendicular to the central axis; 15. The apparatus of claim 1, comprising:

16. Apparatus according to any one of the preceding claims, wherein the beam manipulation devices are arranged in an array of the diffuse charged particle beamlets.

17. 1. A method for generating a plurality of charged particle beamlets, comprising: generating a diffuse charged particle beam using a charged particle source; splitting the diffuse charged particle beam into an array of charged particle beamlets using a beam splitter; deflecting substantially each charged particle beamlet of the array of charged particle beamlets using a deflector array having an array of a plurality of deflectors, one deflector per charged particle beamlet, wherein the deflector array is configured to collimate the array of diffuse charged particle beamlets; generating an electric and / or magnetic field using a beam steering device in at least an area between the charged particle source and the deflector array to align the array of charged particle beamlets with respect to the array of deflectors of the deflector array; Equipped with the charged particle source, a center of the beam splitter, and a center of the deflector array are arranged on a central axis of the apparatus, and the beam manipulation device is capable of generating an electric field having a vector component perpendicular to the central axis and / or a magnetic field having a vector component perpendicular to the central axis, thereby moving the array of charged particle beamlets in a direction perpendicular to the central axis; The method, wherein the beam manipulation device further comprises a third coil, the third coil generating a magnetic field including a vector component along and parallel to the central axis for rotating the array of charged particle beamlets around the central axis.

18. 18. The method of claim 17, wherein the apparatus further comprises a control system for the beam steering device, the control system adjusting the electric and / or magnetic fields based on signals from a sensor configured to determine a deviation of one or more charged particle beamlets in the array of charged particle beamlets from a desired alignment, preferably the sensor being located at or near the deflector array or collimator lens.

19. the beam splitter comprises a lens array having a plurality of lenses, one lens for each charged particle beamlet, and each charged particle beamlet of the array of charged particle beamlets is refracted by a lens of the lens array; or 19. The method of claim 17 or 18, wherein the apparatus comprises a lens array having a plurality of lenses, one lens for each charged particle beamlet, the lens array being arranged between the beam splitter and the deflector array or between the beam splitter and a collimator lens, and each charged particle beamlet of the array of charged particle beamlets being refracted by a lens of the lens array.

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