Simple spherical aberration corrector for sem

Abstract

The invention relates to a compact corrector for correcting spherical aberration of a particle-optical lens in a charged-particle microscope system, according to the present disclosure a strong hexapole is configured to produce a strong hexapole field when a voltage is applied thereto, and a weak hexapole is positioned between the strong hexapole and a sample. The strong hexapole is positioned such that a crossover of a charged-particle beam of the charged-particle system does not pass through a center of the strong hexapole, such that the strong hexapole field applies at least A2 aberration and D4 aberration to the charged-particle beam. The weak hexapole is further positioned or otherwise configured such that when a voltage is applied to the weak hexapole, it produces a weak hexapole field that applies at least combined A2 aberration and combined D4 aberration to the charged-particle beam of the charged-particle microscope system.

Description

Background Technology

[0001] Particle optical microscopy uses circular lenses to guide a beam of electrons / charged particles to illuminate a sample. However, circular lenses produce a positive spherical aberration coefficient (Cs), which limits the angular size of the sample and suppresses resolution and probe current. Over the years, many Cs corrector systems have been developed to address spherical aberration in microscopy systems such as transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM).

[0002] However, Cs correctors are difficult to implement successfully in scanning electron microscope (SEM) columns due to their difficulty in fabrication and high manufacturing costs. This is because current Cs corrector designs used in SEM systems require numerous additional components, which can be difficult to manufacture and therefore expensive. Many of these additional components and excitations are typically needed to eliminate parasitic aberrations caused by mechanical errors inherent in common component manufacturing techniques. This makes such techniques prohibitively expensive for most SEM users. Because these factors have led to many current Cs correctors for SEM systems costing more than the SEM column itself, there is a desire to find simpler and more compact Cs corrector systems (e.g., with fewer parts, making them easier to manufacture) capable of correcting spherical aberrations in SEM optical columns. Furthermore, additional cost reductions can be perceived if highly precise manufacturing techniques such as MEMS are also used. Summary of the Invention

[0003] A compact corrector for correcting spherical aberration of particle optical lenses in a charged particle microscopy system according to this disclosure includes a first multipole element (e.g., a hexapole element, an octapole element, a dodecapole element, etc.) and a second multipole element. The first multipole element is configured to generate a strong hexapole field when a first voltage is applied thereto, and the second multipole element is configured to generate a weak hexapole field positioned between the first multipole element and the sample when the corrector module is used in the charged particle microscopy system. According to the invention, the strong hexapole is positioned such that the intersection of the charged particle beams of the charged particle system does not pass through the center of the first multipole element (i.e., the strong hexapole), such that the field of the first multipole element imposes at least A2 aberration and D4 aberration on the charged particle beam. The second multipole element is further positioned or otherwise configured such that when a second voltage is applied to the second multipole element, the weak hexapole field it generates imposes at least a combined A2 aberration and a combined D4 aberration on the charged particle beam of the charged particle microscopy system. In this way, the net combination of aberrations imposed on the charged particle beam by the weak hexapole field and the strong hexapole field results in the beam having the desired A2, C3, and D4 aberrations at or near the sample plane.

[0004] Additionally, the charged particle system including the compact corrector according to this disclosure includes: a sample holder configured to hold a sample; a charged particle source configured to emit a charged particle beam toward the sample; an optical column configured to guide the charged particle beam such that the charged particle beam is incident on the sample; and a detector system configured to detect emission from the sample irradiated by the charged particle beam. The optical column includes a compact corrector module comprising a first multipole (i.e., a strong hexapole) and a second multipole (i.e., a weak hexapole), the first multipole being configured to generate a strong hexapole field when a first voltage is applied to it, and the second multipole being positioned between the strong hexapole and the sample. The strong hexapole is positioned such that the intersection of the charged particle beam does not pass through the center of the strong hexapole, thereby causing the strong hexapole field to impose at least A2 and D4 aberrations on the charged particles when a second voltage is applied to the weak hexapole, which generates a weak hexapole field that imposes at least a combination of A2 and D4 aberrations on the charged particle beam.

[0005] Furthermore, the optical corrector module for charged particle columns according to the present invention, including split multipoles, comprises at least one split multipole consisting of two multipoles (e.g., wafer multipole, magnetic multipole, electrostatic multipole, etc.), the spacing between the two multipoles being less than any one of 100 mm, 10 mm, 1 mm, 100 μm, and 10 μm. Each of the multipoles includes at least two electrodes positioned to partially define a beam path through the multipole. According to the present invention, each of these electrodes includes: a first surface, which, when used in the charged particle column, faces upstream of the charged particle beam; and a second surface, which, when used in the charged particle column, faces downstream of the charged particle beam, wherein for each of the electrodes, the thickness between the first and second surfaces is less than 3 mm. Within the scope of this disclosure, the split multipole can be electrostatic and can correspond to a hexapole. Attached Figure Description

[0006] The specific embodiments are described with reference to the accompanying drawings. In the drawings, the leftmost numeral of the reference numeral indicates the drawing in which the reference numeral first appears. Identical reference numerals in different drawings indicate similar or identical items.

[0007] Figure 1 An example compact corrector according to the invention is shown for correcting A2, C3 and / or D4 aberrations at or near the sample plane.

[0008] Figure 2 An example charged particle microscope system for examining the components of a sample according to the present invention is shown, wherein the optical column of the charged particle microscope system includes a compact corrector for correcting A2, C3 and / or D4 aberrations at or near the sample plane.

[0009] Figure 3An alternative embodiment of an example compact corrector according to the present invention for correcting A2, C3 and / or D4 aberrations at or near the sample plane is shown.

[0010] Figure 4 An example Crewe corrector comprising a single split multipole is shown according to this disclosure.

[0011] Figure 5 It shows how to combine Figures 1 to 3 The example corrector is described, where a strong hexagon corresponds to a split consisting of two hexagons.

[0012] Figure 6 and Figure 7 The prior art Crewe-type corrector and the Crewe-type corrector according to this disclosure are shown respectively, wherein one or more of the six poles are split six poles.

[0013] Figure 8 A Rose-type corrector comprising at least one split hexapole is shown.

[0014] Figure 9 This is a diagram illustrating the optical behavior of a Rose-type corrector comprising two split hexapoles according to this disclosure.

[0015] In several views of the accompanying drawings, similar reference numerals refer to corresponding parts. Generally, in the drawings, elements that may be included in a given example are shown in solid lines, while elements that are optional for a given example are shown in dashed lines. However, elements shown in solid lines are not essential for all examples of this disclosure, and elements shown in solid lines may be omitted from certain examples without departing from the scope of this disclosure. Detailed Implementation

[0016] This document discloses a compact corrector system for correcting spherical aberrations of particle optical lenses in charged particle microscopy systems (including, but not limited to, SEM, STEM, TEM, and FIB). Specifically, the system disclosed herein uses multipole correction (such as, but not limited to, electromagnetic multipole, electrostatic multipole, split multipole, etc.) to correct A2, C3, and / or D4 aberrations. An example corrector system according to this disclosure includes a strong hexapole and a weak hexapole (e.g., 10x, 50x, 100x, etc., smaller than a strong hexapole), the strong hexapole being positioned such that its center is misaligned with the beam crossing point (e.g., either the strong hexapole is positioned within the system and the beam is manipulated, or a combination thereof, such that the center of the strong hexapole is positioned 0.1 mm to 2 mm from the beam crossing point), and the weak hexapole is located downstream of the strong hexapole. According to the invention, the misalignment of the strong hexapole is in the direction of the weak hexapole. Due to this displacement, when a first voltage is applied to the strong hexapole, it generates a strong hexapole field when the first voltage is applied to it, and when the corrector module is used in a charged particle microscope system, it generates a weak hexapole positioned between the strong hexapole and the sample.

[0017] According to the invention, a strong hexapole is positioned such that the intersection of the charged particle beam of the charged particle system does not pass through the center point of the strong hexapole (i.e., not within a distance of 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, 1.2 mm, 1.5 mm, or 2 mm from the center of the strong hexapole), such that the strong hexapole field imposes at least A2 and D4 aberrations on the charged particle beam. A second voltage can then be applied to a weak hexapole, causing it to generate a weak hexapole field that imposes at least a combination of A2 and D4 aberrations on the charged particle beam of the charged particle microscope system. In some embodiments, the weak and strong hexapoles can be positioned, charged, or otherwise configured such that the two hexapole fields further impose a combination of C3 aberrations on the beam. In this way, the net combination of aberrations imposed on the charged particle beam by the weak and strong hexapole fields can be adjusted such that the charged particle beam has the desired A2, C3, and / or D4 aberrations at or near the sample plane. Therefore, the compact corrector according to this disclosure can improve the resolution of charged particle microscopy. For example, the compact corrector according to this disclosure can improve the resolution of a 30 kV beam SEM optical column by at least 2.5 times.

[0018] This disclosure also describes various types of corrector systems including split multipoles. A split multipole consists of two hexapoles spaced apart by a distance (e.g., less than 20 mm), wherein each multipole comprises two or more electrodes with a thickness of less than 10 mm, 5 mm, 3 mm, or 1 mm. For example, in the case of a wafer multipole, such wafer multipoles consist of two or more electrodes with a thickness between 1 μm and 100 μm. In some embodiments, such wafer hexapoles may correspond to the systems and methods disclosed in and / or be constructed using the systems and methods disclosed in U.S. Patent filed July 22, 2022, entitled “CHARGED PARTICLE OPTICS COMPONENT SANDTHEIR FABRICATION,” the entire contents of which are incorporated herein by reference. The split multipole is configured to generate a strong multipole field when a voltage (e.g., 100 V to 300 kV) is applied to each of the wafer multipoles. By applying the same voltage to each of the multipoles, the combined electromagnetic fields generated by the two multipoles combine to provide a strong multipole effect. Because split multipoles are composed of multiple poles, they can be used to correct aberrations in charged particle beams with energies greater than 10 keV.

[0019] Figure 1 This is an illustration of an example compact corrector 100 according to the invention for correcting A2, C3, and / or D4 aberrations at or near a sample plane. The example compact multipole corrector 100 includes a strong hexapole 102 (e.g., a first hexapole, octapole, or twelfth-pole element) and a weak hexapole 104 (e.g., a second hexapole, octapole, or twelfth-pole element). The strong hexapole has an effective length L and is configured to generate a strong hexapole field when a first voltage is applied to it. The weak hexapole, when used in a charged particle system, is positioned downstream of the strong hexapole 102 and is configured to generate a weak hexapole field when a second voltage is applied to it. The strength and / or orientation of the strong and weak hexapoles can be adjusted to allow the fields they generate to contribute to A2, C3, and / or D4 to desired values. In various embodiments, the strong hexa pole 102 can be an electrostatic multipole with a length ranging from 0.01 mm to 10 mm (e.g., at least 5 mm), and the first voltage can be between 0.1 kV and 30 kV. Furthermore, the strength of the weak hexa pole 104 is at most 1 / 30, 1 / 50, or 1 / 100 of that of the strong hexa pole 102. Figure 9 As shown, in some embodiments, the strong hexaode 102 can be a split hexaode consisting of two hexaodes spaced apart by a distance less than 100 mm, 10 mm, 1 mm, 100 μm, and 10 μm. Such multi-electrodes consist of two or more electrodes with a thickness of less than 10 mm, 5 mm, 3 mm, or 1 mm.

[0020] During operation of the charged particle system including the compact corrector 100, the charged particle beam 106 is directed along the central axis 108 toward the first end 110 of the compact corrector. According to the invention, a weak hexapole 104 is positioned, excited, and / or otherwise configured such that the weak hexapole field is combined with a strong hexapole field to produce a combined aberration that imposes one or more of the A2, C3, and / or D4 aberration effects on the charged particle beam as it passes through the corrector 100. According to the invention, the contribution of the strong hexapole field to one or more of the A2, C3, and / or D4 aberrations, and this combined aberration effect produced by the combination of the strong and weak hexapole fields, results in a net outcome whereby the contribution of the strong hexapole field and the combined aberration effect for one or more of the A2, C3, and / or D4 aberrations have desired values ​​in the charged particles 106 at or near the sample plane. In some implementations, this can result in the charged particle beam 106 having A2, C3, and / or D4 aberrations of 0 or near 0 as it exits the corrector 100. Alternatively or additionally, the corrector can cause the charged particle beam 106 to have desired A2, C3, and / or D4 aberration values ​​as it exits the corrector 100, which, combined with other aberration effects from other optical elements downstream of the corrector 100 within the charged particle system, results in desired values ​​of A2, C3, and / or D4 aberrations in the charged particle beam 106 at the sample plane.

[0021] In prior art correctors, constitutive multipoles are positioned at the intersection of charged particle beams to prevent aberrations. However, in the example compact corrector 100, a strong hexapole 102 is positioned, or the charged particle beam 106 is adjusted, or a combination thereof, such that there is a displacement ∈ between the center 112 of the strong hexapole and the intersection 114 of the charged particle beam. Because the strong hexapole 102 is misaligned with the intersection 114 of the charged particle beam in this manner, the contribution of the strong hexapole field to the charged particle beam 106 is aberrations A2, C3, and D4. Specifically, the contribution of the strong hexapole field to each of the aberrations A2, C3, and D4 of the charged particle beam 106 is a function of displacement ∈. For example, in the model compact corrector 100 where the hexapole is a magnetic hexapole, using Hamilton's equations, the back-extrapolated contribution of the corrector at position 114 to each of the aberrations A2, C3, and D4 can be shown as:

[0022]

[0023]

[0024]

[0025] Furthermore, in the second example, in the compact corrector 100 with six poles 102 being electrostatic, the back extrapolation contribution of the corrector at position 114 to each of the aberrations A2, C3, and D4 can be shown as follows:

[0026]

[0027]

[0028]

[0029] Those skilled in the art will understand, based on (1) through (6), how the characteristics of the strong hexapole 102 (i.e., the first voltage, L, k, etc.) and the values ​​of displacement ∈ in such example systems affect or otherwise induce the A2, C3, and D4 aberrations in the charged particle beam as the charged particle beam 106 passes through the strong hexapole 102. Those skilled in the art will understand how the subsequent lens 118 and / or the weak hexapole 104 can be designed, positioned, or otherwise tuned such that the resulting values ​​of the A2, C3, and / or D4 aberrations of the charged particle beam 106 have desired values ​​in the sample plane. For example, displacement ∈ can be adjusted such that each of the A2, C3, and / or D4 aberrations has a desired non-zero or zero value in the sample plane. In another example, the size, position, and excitation of the subsequent lens 118 and the weak hexapole 104 can be selected such that their contributions to the aberrations A2, C3, and D4 in the charged particle beam 106 are combined with the corresponding contributions of the strong hexapole 104 to the charged particle beam, making A2 and D4 almost zero. In such embodiments, the characteristics of the strong hexapole 102, the weak hexapole 104, and / or the lens 118 can be tuned such that the contribution of the slightly negative spherical aberration compensation objective 116 to the spherical aberration of the charged particle beam 106 after it passes through the corrector 100. In the above equation, k is the intensity of the strong hexapole, and L is the effective length of the hexapole.

[0030] Figure 1 The weak hexapole is shown as an objective 116 close to the charged particle system. In some embodiments, the weak hexapole 104 may be positioned within the field of the objective 116 of the charged particle system, and / or within the objective 116 of the charged particle system itself. However, those skilled in the art will understand that, according to the invention, the weak hexapole 104 may be placed anywhere between the strong hexapole 102 and the sample under study, provided that (1) it can influence the beam 106 impacting the sample, and (2) the voltages applied to the weak hexapole 104 and / or the strong hexapole 102 are adjusted such that the A2, C3, and / or D4 contributions of each of their corresponding hexapole fields combine to produce the desired net A2, C3, and / or D4 contribution to the beam 106.

[0031] In addition, although not in Figure 1As shown, the weak hexapole 104 can be positioned upstream or downstream of a microscope beam scanning system (e.g., an AC scanning unit). For example, in one embodiment, the weak hexapole 104 can be positioned downstream of the microscope scanning unit and configured to dynamically adjust the hexapole field it creates based on the path of the beam passing through it. Additionally, in some embodiments of the invention, the weak hexapole can be dynamically tuned based on one or more components of the microscope system in which it uses the weak hexapole 104. For example, the weak hexapole 104 can be tunable to compensate for beam rotation caused by lenses in such microscope systems.

[0032] Figure 1 The compact corrector 100 is also shown as including an optional adapter lens 118 positioned between the strong hexapole 102 and the weak hexapole 104 and downstream of the weak hexapole. However, embodiments of the corrector system 100 may include only one of these adapter lenses, including or excluding such adapter lenses. For example, in embodiments of the invention, the corrector 100 may include a circular lens 118 positioned between the strong and weak hexapoles, which is positioned, charged, or otherwise configured to apply a lensing effect to the charged particle beam such that the magnitude of the D4 aberration in the charged particle beam 106 is affected to allow the charged particle beam to have a desired value of D4 aberration in the sample plane. Figure 1 In this embodiment, the multipole corrector 100 is shown as a box comprising multiple optical components (i.e., multipole and lens). In various embodiments, these optical components may be enclosed or partially enclosed by protective and / or support structures. Additionally, in embodiments including such structures, one or more of these optical components may not be within such structures.

[0033] Figure 2 This illustration shows an example charged particle microscope system 200 for examining / imaging the components of a sample 202 according to the present invention. The optical column of this charged particle microscope system includes a compact corrector 100 for correcting A2, C3, and / or D4 aberrations at or near the sample plane. The exemplary charged particle microscope system 200 may include an electron microscope (EM) setup or an electron lithography setup configured to irradiate and / or otherwise bombard the sample 202 with a charged particle beam 204 (typically an electron beam or ion beam). In various embodiments, the charged particle microscope system 200 may be or include one or more different types of EM and / or charged particle microscopes, such as, but not limited to, scanning electron microscopes (SEM), scanning transmission electron microscopes (STEM), transmission electron microscopes (TEM), charged particle microscopes (CPM), dual-beam microscope systems, etc. Additionally, in some embodiments, a TEM can also operate as a STEM. Figure 2An example charged particle microscope system 200 is shown as a SEM system 206. However, since the compact corrector 100 according to the invention can be composed of an electrostatic hexaode capable of accepting a wide range of excitations (e.g., including but not limited to 50 kV and 300 kV), the compact corrector is capable of correcting A2, C3 and / or D4 in TEM and STEM systems.

[0034] The example charged particle microscopy system 200 includes a charged particle source 208 (e.g., a thermionic source, a Schottky-emission source, a field emission source, a liquid metal ion source, a plasma ion source, etc.) that emits a charged particle beam 204 along an emission axis 210 and toward an accelerator lens 212. The emission axis 210 is a central axis that extends along the length of the example charged particle microscopy system 200 from the charged particle source 208 and passes through the sample 202.

[0035] Accelerator lens 212 accelerates / decelerates, focuses, and / or guides the charged particle beam 204 toward focusing column 214. Focusing column 214 focuses the charged particle beam 204 so that it is incident on sample 202. Additionally, focusing column 214 corrects and / or adjusts aberrations (e.g., geometric aberrations, chromatic aberrations) of the charged particle beam 204.

[0036] exist Figure 2 In this invention, the focusing column 214 is shown as including a compact corrector 100 for correcting aberrations A2, C3, and / or D4 at or near the sample plane. That is, Figure 2A charged particle microscope system 200 is shown, including a SEM multipolar corrector system 100 comprising a strong hexapole 102 and a weak hexapole 104, wherein the center of the strong hexapole 102 is offset from the axial intersection point 114 of the charged particle beam by a certain displacement ∈. The strong hexapole 102 can be configured to generate a strong hexapole field when a first voltage is applied thereto, and the weak hexapole 104 can be configured to generate a weak hexapole field when a second voltage is applied thereto. In some embodiments, the strong hexapole 102 may be a split hexapole consisting of two wafer hexapoles spaced apart by a distance less than any one of 100 mm, 10 mm, 1 mm, 100 μm, and 10 μm. Those skilled in the art will understand how the weak hexapole 104 can be positioned, excited, and / or otherwise configured such that the weak hexapole field contributes to one or more of the A2, C3, and / or D4 aberrations in the charged particle beam 204, in combination with the contribution of the strong hexapole field to one or more of the A2, C3, and / or D4 aberrations in the charged particle beam 204. In this way, by adjusting the positioning and excitation of the weak hexapole 104, the contribution of the weak hexapole field to one or more of the A2, C3, and / or D4 aberrations can be combined with the contribution of the strong hexapole field to give the charged particle beam 204 the desired A2, C3, and / or D4 aberrations at or near the sample plane.

[0037] Objective 216 is an optical element that focuses the charged particle beam 204 onto a point on sample 202. Objective 216 may include a monopolar lens, a magnetic-electrostatic compound lens, an electrostatic detector objective, or another type of objective. An additional benefit of the compact correctors 100 according to the invention is that they allow the charged particle beam to have an increased angular size. For example, the example compact corrector 100 may allow the charged particle beam to have an angular size greater than 20 mrad.

[0038] Figure 2 Example charged particle microscopy system 200 is also shown as including a sample holder 218 for holding sample 202. Example charged particle microscopy system 300 is also shown as including a detector system 220 configured to detect emission from sample 202 caused by incident charged particle beam 204 onto sample 202. Additionally, although Figure 2 Not shown, but the example charged particle microscope system 200 may include astigmatism correction and / or scanning coils for causing a charged particle beam 204 to scan the surface of the sample 202. For example, by operating the scanning coils, the orientation of the charged particle beam 204 can be shifted, thereby causing the charged particle beam to strike different locations on the sample 202. Those skilled in the art will understand that in a TEM or (S)TEM system, the detector system 220 may also include and / or consist of one or more detector locations below the sample.

[0039] Figure 2 An example charged particle microscope system 200, optionally including a computing device 230, is also shown. Those skilled in the art will understand that... Figure 2 The computing device 230 depicted herein is merely illustrative and is not intended to limit the scope of this disclosure. Computing systems and devices may include any combination of hardware or software capable of performing the indicated functions, including computers, network devices, internet devices, PDAs, wireless telephones, controllers, oscilloscopes, amplifiers, etc. The computing device 230 may also be connected to other devices not shown, or conversely, may operate as a stand-alone system.

[0040] Figure 3 This is an illustration of an alternative embodiment of an example compact corrector 300 according to the invention for correcting A2, C3, and / or D4 aberrations at or near the sample plane. The example compact multipole corrector 300 includes a strong hexadecimal 102 and a weak hexadecimal 104. The strong hexadecimal has an effective length L and is configured to generate a strong hexadecimal field when a first voltage is applied to it. The weak hexadecimal, when used in a charged particle system, is positioned downstream of the strong hexadecimal 102 and is configured to generate a weak hexadecimal field when a second voltage is applied to it. During operation of the charged particle system including the compact corrector 300, a charged particle beam 302 is directed along a central axis 304 toward a first end 306 of the compact corrector 300.

[0041] Figure 3 The compact corrector 300 is also shown as including optional adapter lenses 118 positioned on each side of the strong hexapole 102 and downstream of the weak hexapole 104. While in some embodiments, the AC scanning unit may be positioned upstream of the weak hexapole 104, Figure 3 An embodiment is shown in which the AC scanning unit 308 is positioned between the compact corrector 300 and the objective lens 310 of the microscope system.

[0042] Figure 4 An example Crewe corrector 400 comprising a single split multipole is shown according to this disclosure. Specifically, Figure 4 A Crewe-style hexapolar Cs corrector is described. As described above, in some embodiments, a strong multipole may correspond to a split multipole 402, which consists of two wafer hexapolars 404 having a thickness d and spaced apart by a distance (e.g., less than 20 mm). According to the invention, no optical components (lenses, multipoles, etc.) are positioned between the constituent wafer multipoles 404 of the split multipole. In the case where the split multipole 402 has a length L, the spacing can therefore be written as L⁻²d. The wafer multipole consists of two or more electrodes with a thickness of less than 10 mm, 5 mm, 3 mm, or 1 mm.

[0043] Figure 4The Crewe corrector 400 is also shown as including a first transition lens 406 and a second transition lens 408, wherein the first transition lens 406 applies a focusing effect to the charged particle beam 410 passing through the corrector 400, causing the charged particle beam to cross between the two constituent wafer multipoles 404 of the split multipole 402. Although Figure 4 The intersections are shown as being equidistant from each constituent wafer multipole, but in other embodiments (such as...) Figure 5 In the embodiment described herein, the first transition lens 406 may be configured to apply a focusing effect, such that the intersection of the charged particle beam 410 is not equidistant from each constituent wafer multipole 404.

[0044] Figure 5 It shows how to combine Figures 1 to 3 The example corrector 500 is described, wherein the strong hexagon 502 corresponds to the split hexagon 504 consisting of two wafer hexagons 506. Figure 5 The corrector 500 is shown as comprising three transition lenses 508 and a weak hexapole 510. As described above, the initial transition lens 512 applies a focusing effect to the charged particle beam 514 passing through the corrector 500, resulting in unequal spacing between the crossover points of the two crystal multipoles 506 of the split multipole 504. As described above, the weak hexapole 510 may be positioned, excited, and / or otherwise configured such that the weak hexapole field it generates contributes to one or more of the A2, C3, and / or D4 aberrations in the charged particle beam 514, in combination with the contribution of the strong hexapole field to one or more of the A2, C3, and / or D4 aberrations in the charged particle beam 514. In this way, by adjusting the positioning and excitation of the weak hexapole 510, the contribution of the weak hexapole field to one or more of the A2, C3 and / or D4 aberrations can be combined with the contribution of the strong hexapole field so that the charged particle beam 514 has the desired A2, C3 and / or D4 aberrations at or near the sample plane.

[0045] Figure 6 and Figure 7 Crewe-type correctors 600 and 700 according to this disclosure are shown, wherein one or more of the hexagons are split hexagons. Specifically, Figure 6 A corrector comprising two strong hexapoles 602 is shown, wherein a single adapter lens 604 is positioned at the axial intersection of the charged particle beam 606, which is equidistant from the two hexapoles 602. However, as Figure 7 As shown, according to the present invention, such Crewe-type correctors can also be manufactured with one or more split hexapoles. For example, Figure 7A Crewe-type corrector 700 according to the present invention is shown, wherein both strong hexagons 702 are split hexagons 704. However, those skilled in the art will understand that in some embodiments, only one of the strong hexagons 702 may be a split hexagon 704. Figure 7 The corrector 700 is also shown as including a single adapter lens 706 positioned at the axial intersection of the charged particle beam 708, which is equidistant from the two split hexapoles 704.

[0046] Figure 8 A Rose-type corrector 800 comprising at least one split hexapole is shown. Specifically, Figure 8 A Rose-type corrector is shown, in which one of the two strong hexapoles 802 corresponds to a split hexapole 804 composed of two wafer multipoles 806. However, those skilled in the art will understand how the corrector 800 can be configured to have two strong hexapoles 802 corresponding to the split hexapole 804. The corrector 800 is shown with two adapter lenses 808 positioned between the split hexapoles 804.

[0047] Figure 9 Figure 900 illustrates the optical behavior of a Rose-type corrector 800 comprising two split hexapoles according to the present disclosure. Specifically, Figure 900 shows the optical behavior taking into account aberrations present in a Rose-type corrector 800 comprising two split hexapoles. Figure 9 The behavior of axial light 902 passing through an example Rose-type corrector 800 is shown, wherein the two hexapoles are electrostatically split hexapoles 904 according to the invention. Specifically, Figure 9 A split hexaode 904 is shown, comprising two wafer hexaodes of length L and thickness d, wherein the same charge is applied to each of the wafer hexaodes. For example, with a wafer hexaode thickness of 2 mm, the length of the split hexaode can be 12 mm, and the voltage applied to each wafer hexaode can be ±170 V. In various embodiments, the split hexaode 904 can be configured to generate small dipole and / or quadrupole fields in addition to the hexaode field. While not limited to this disclosure, those skilled in the art will understand that the corrector strength of the Rose-type corrector 800 corresponds to...

[0048]

[0049] Figure 9 Also shown is a condenser lens 906 positioned upstream of the Rose-type corrector 800, and an objective lens 908 configured to focus a beam of charged particles onto the sample 910. An axial ray 902 is shown exiting the Rose-type corrector 800 parallel to the optical axis 912 and positioned at a distance x from the optical axis 912. exit Place.

[0050] Although Figures 4 to 9 Split multipoles included in several example corrector systems are shown, but those skilled in the art will understand how the split multipole techniques described herein can be included in other corrector systems as an alternative to any general multipole element where the secondary effects produced by the hexapole field are important.

[0051] Embodiments of the subject matter of this invention according to this disclosure are described in the following enumerated paragraphs.

[0052] A1. A compact corrector module for a charged particle microscopy system, the corrector module comprising: a strong hexadecimal pole configured to generate a strong hexadecimal field when a first voltage is applied thereto, wherein the strong hexadecimal pole is positioned such that the intersection of the charged particle beam of the charged particle system does not pass through the center of the strong hexadecimal pole, thereby causing the strong hexadecimal field to apply at least A2 aberration and D4 aberration to the charged particle beam of the charged particle microscopy system; and a weak hexadecimal pole, wherein when the corrector module is used in the charged particle microscopy system, the weak hexadecimal pole is positioned between the strong hexadecimal pole and the sample, wherein a weak hexadecimal field is generated when a second voltage is applied to the weak hexadecimal pole, the weak hexadecimal field applying at least a combination of A2 aberration and a combination of D4 aberration to the charged particle beam of the charged particle microscopy system.

[0053] A1.1. The compact corrector module according to paragraph A1, wherein the combination of A2 aberration and combined A2 aberration is applied to the charged particle beam in combination, resulting in the A2 aberration of the charged particle beam being 0 or close to 0 at or near the sample plane.

[0054] A1.2. The compact corrector module according to any one of paragraphs A1 to A1.1, wherein the combination of D4 aberration and combined D4 aberration applied to the charged particle beam results in the D4 aberration of the charged particle beam being 0 or close to 0 at or near the sample plane.

[0055] A1.3. The compact corrector module according to any one of paragraphs A1 to A1.2, wherein the strong hexapole field also applies the C3 aberration to the charged particle beam of the charged particle microscope system, and the weak hexapole field also applies the combined C3 aberration to the charged particle beam of the charged particle microscope system.

[0056] A1.3.1. The compact corrector module according to paragraph A1.3, wherein the combination of C3 aberration and combined C3 aberration is applied to the charged particle beam in combination, resulting in the C3 aberration of the charged particle beam being 0 or close to 0 at or near the sample plane.

[0057] A2. The compact corrector module described in any of paragraphs A1 to A1.3.1, wherein the selection of the second voltage is determined based on the distance between the intersection of the charged particle beams and the center of the strong hexaode.

[0058] A2.1. The compact corrector module according to paragraph A2, wherein the selection of the second voltage is determined based on the distance between the crosspoint of the charged particle beam and the center of the strong hexapole, such that one or more of the aberrations A2, C3 and D4 caused by the weak multipole field are combined with the aberrations A2, C3 and D4 caused by the strong multipole field.

[0059] A3. The compact corrector described in any of paragraphs A1 to A2.1, wherein the strength of the weak hexagon is at most 1 / 50 or 1 / 100 of that of the strong hexagon.

[0060] A4. The compact corrector described in any of paragraphs A1 to A3, wherein the weak hexagon is positioned within the objective lens when used in a charged particle system.

[0061] A5. The compact corrector described in any of paragraphs A1 to A4, wherein a weak hexapole is positioned within the objective lens field.

[0062] A6. The compact corrector according to any one of paragraphs A1 to A5, wherein the charged particle microscope is one of scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and transmission electron microscopy (TEM).

[0063] A7. The compact corrector described in any of paragraphs A1 to A6, wherein the strong hexapod is an electrostatic hexapod or an electromagnetic hexapod.

[0064] A7.1. The compact corrector as described in paragraph A7, wherein the strong hexa pole has a (effective) length of at least 5 mm.

[0065] A8. The compact calibrator described in any of paragraphs A1 to A7.1, wherein the calibrator module is a probe calibrator.

[0066] A9. The compact corrector according to any one of paragraphs A1 to A8 further includes an adapter lens positioned between the strong hexapole and the weak hexapole.

[0067] A9.1. The compact corrector as described in paragraph A9 also includes an additional adapter lens positioned downstream of the weak hexapole.

[0068] A10. The compact corrector described in any of paragraphs A1 to A9, wherein the first voltage applied to the strong hexa pole is between 50 kV and 300 kV.

[0069] A11. The compact corrector according to any one of paragraphs A1 to A10, wherein the compact corrector module is configured to allow the angular displacement of the charged particle beam of the charged particle microscope to be greater than 20 mrad.

[0070] A12. The compact corrector according to any one of paragraphs A1 to A11 further includes a focusing lens positioned upstream of the strong hexapole when used in a charged particle system.

[0071] A13. The compact corrector according to any one of paragraphs A1 to A12, wherein the compact corrector comprises only one strong hex pole.

[0072] B1. A charged particle system, the charged particle system comprising: a sample holder configured to hold a sample; a charged particle source configured to emit a beam of charged particles toward the sample; an optical column configured to guide the beam of charged particles such that it is incident on the sample, the optical column including a compact corrector module, the compact corrector module including: a strong hexadecimal pole configured to generate a strong hexadecimal field when a first voltage is applied thereto, wherein the strong hexadecimal pole is... The sample is positioned such that the intersection of the charged particle beam does not pass through the center of the strong hexapole, thereby causing the strong hexapole field to apply at least A2 and D4 aberrations to the charged particle beam; a weak hexapole is positioned between the strong hexapole and the sample, wherein when a second voltage is applied to the weak hexapole, the weak hexapole generates a weak hexapole field that applies at least the combined A2 and combined D4 aberrations to the charged particle beam; and a detector system configured to detect emission from the sample irradiated by the charged particle beam.

[0073] B1.1. The compact corrector module according to paragraph B1, wherein the combination of A2 aberration and combined A2 aberration is applied to the charged particle beam to cause the A2 aberration of the charged particle beam to be 0 or close to 0 at or near the sample plane.

[0074] B1.2. The compact corrector module according to any one of paragraphs B1 to B1.1, wherein the combined application of D4 aberration and combined D4 aberration to the charged particle beam results in the D4 aberration of the charged particle beam being 0 or close to 0 at or near the sample plane.

[0075] B1.3. The compact corrector module according to any one of paragraphs B1 to B1.2, wherein the strong hexapole field also applies the C3 aberration to the charged particle beam of the charged particle microscope system, and the weak hexapole field also applies the combined C3 aberration to the charged particle beam of the charged particle microscope system.

[0076] B1.3.1. The compact corrector module according to paragraph B1.3, wherein the combination of C3 aberration and combined C3 aberration is applied to the charged particle beam in combination, resulting in the C3 aberration of the charged particle beam being 0 or close to 0 at or near the sample plane.

[0077] B2. The compact corrector module described in any of paragraphs B1 to B1.3.1, wherein the selection of the second voltage is based on the distance between the intersection of the charged particle beams and the center of the strong hexaode.

[0078] B2.1. The compact corrector module according to paragraph B2, wherein the selection of the second voltage is determined based on the distance between the cross point of the charged particle beam and the center of the strong hexapole, such that one or more of the aberrations A2, C3 and D4 caused by the weak multipole field are combined with the aberrations A2, C3 and D4 caused by the strong multipole field.

[0079] B3. The compact corrector described in any of paragraphs B1 to B2.1, wherein the strength of the weak hexagon is at most 1 / 50 or 1 / 100 of that of the strong hexagon.

[0080] B4. The compact corrector described in any of paragraphs B1 to B3, wherein the weak hexagon is positioned within the objective lens when used in a charged particle system.

[0081] B5. A compact corrector according to any one of paragraphs B1 to B4, wherein a weak hexapole is positioned within the objective lens field.

[0082] B6. The compact corrector according to any one of paragraphs B1 to B5, wherein the charged particle microscope is one of scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and transmission electron microscopy (TEM).

[0083] B7. The compact corrector described in any of paragraphs B1 to B6, wherein the strong hexapod is an electrostatic hexapod or an electromagnetic hexapod.

[0084] B7.1. The compact corrector as described in paragraph B7, wherein the strong hexa pole has a length of at least 5 mm.

[0085] B8. The compact calibrator described in any of paragraphs B1 to B7.1, wherein the calibrator module is a probe calibrator.

[0086] B9. The compact corrector according to any one of paragraphs B1 to B8 further includes an adapter lens positioned between the strong hexapole and the weak hexapole.

[0087] B9.1. The compact corrector as described in paragraph B9 also includes an additional adapter lens positioned downstream of the weak hexapole.

[0088] B10. The compact corrector described in any of paragraphs B1 to B9, wherein the first voltage applied to the strong hexa pole is between 50 kV and 300 kV.

[0089] B11. The compact corrector according to any one of paragraphs B1 to B10, wherein the compact corrector module is configured to allow the angular displacement of the charged particle beam of the charged particle microscope to be greater than 20 mrad.

[0090] B12. The compact corrector according to any one of paragraphs B1 to B11 further includes a condenser lens positioned upstream of the strong hexapole when used in a charged particle system.

[0091] B13. The compact corrector according to any one of paragraphs B1 to B12, wherein the compact corrector comprises only one strong hex pole.

[0092] C1. An optical corrector module for a charged particle column, the optical corrector module comprising: a split multipole, the split multipole consisting of two wafer multipoles spaced less than 100 mm apart, each wafer multipole including: at least two electrodes positioned to partially define a beam path through the wafer multipole, wherein each of the electrodes includes: a first surface facing upstream of the charged particle beam when used in a charged particle column; and a second surface facing downstream of the charged particle beam when used in a charged particle column, wherein for each of the electrodes, the thickness between the first surface and the second surface is less than 3 mm.

[0093] C1.1. The optical corrector module according to paragraph C1, wherein the split multipole is configured to generate a strong multipole field when a first voltage is applied to each of the wafer multipoles.

[0094] C1.1.1 The optical corrector module according to paragraph C1.1, wherein the spacing between the two wafer multipoles of the split multipole is any one of 10 mm, 1 mm, 100 μm and 10 μm.

[0095] C1.2. The optical corrector module according to any one of paragraphs C1 to C1.1.1, wherein the thickness between the first surface and the second surface of each of the electrodes is less than 100 μm.

[0096] C1.2.1. The optical corrector module according to paragraph C1.2, wherein the thickness between the first surface and the second surface of each of the electrodes is between 1 μm and 100 μm.

[0097] C1.2.2. The optical corrector module according to any one of paragraphs C1.2 or C1.2.1, wherein the thickness between the first surface and the second surface of each of the electrodes is less than any one of 10 mm, 1 mm, 100 μm and 10 μm.

[0098] C1.3. The optical corrector module according to any one of paragraphs C1 to C1.2.2, wherein the distance between the wafer multipoles in the split multipole is less than 20 mm.

[0099] C1.4. The optical corrector module according to any one of paragraphs C1 to C1.3, wherein the third surface of each of the electrodes facing the charged particle beam has a maximum surface roughness of Ra 0.05 μm when the charged particle beam passes through the wafer multipole.

[0100] C1.5. The optical corrector module according to any one of paragraphs C1 to C1.4, wherein each wafer multipole is configured to be used with charged particle beam energy greater than 10 keV.

[0101] C1.6. The optical corrector module according to any one of paragraphs C1 to C1.4, wherein the voltage applied to the six poles of the wafer is between 100V and 300kV.

[0102] C1.7. An optical corrector module according to any one of paragraphs C1 to C1.6, wherein the voltage applied to each of the six electrodes of the wafer is the same.

[0103] C1.8. An optical corrector module according to any one of paragraphs C1 to C1.7, wherein no optical component is positioned between the two wafer multipoles along the path of the charged particle beam.

[0104] C1.9. The optical corrector module according to any one of paragraphs C1 to C1.8, wherein the split multipole is a split hexapole, the split hexapole being configured to generate a strong hexapole field when a first voltage is applied to each of the wafer multipole.

[0105] C1.9.1. The optical corrector module according to paragraph C1.9, wherein each of the wafer multipoles is a wafer hexapole, the wafer hexapole being configured to generate a hexapole field when a voltage is applied to each of the wafer hexapoles.

[0106] C1.10. An optical corrector module according to any one of paragraphs C1 to C1.9.1, comprising a first adapter lens and a second adapter lens, wherein the first adapter lens is an optical element immediately upstream of the split multipole, and the second adapter lens is an optical element immediately downstream of the split multipole.

[0107] C1.10.1. The optical corrector module according to paragraph C1.10, wherein a first axial ray applies a focusing effect that causes a beam of charged particles to cross between two constituent wafer multipoles of a split multipole.

[0108] C1.10.1.1. The optical corrector module according to paragraph C1.10.1, wherein the intersection of the charged particle beams is equidistant from each constituent wafer multipole.

[0109] C1.10.1.2. The optical corrector module according to paragraph C1.10.1, wherein the intersection of the charged particle beams is not equidistant from the multipole of each constituent wafer.

[0110] C2. The optical corrector module described in any of paragraphs C1 to C1.10, wherein the split multipole is a strong hexapole.

[0111] C2.0.1. The optical corrector module as described in paragraph C2, wherein the optical corrector module is a Crewe-type hexapole Cs corrector.

[0112] C2.0.2. The optical corrector module according to any one of paragraphs C2 to C2.0.1, wherein the corrector further includes a weak hexadecimal, which, when used in a charged particle column, is positioned between the strong hexadecimal and the sample.

[0113] C2.1. The optical corrector module according to paragraph C2, wherein the split hexapole is positioned such that the intersection of the charged particle beam does not pass through the center of the split hexapole, thereby causing the split hexapole field to impose at least A2 aberration and D4 aberration on the charged particle beam when used in a charged particle column.

[0114] C2.1.1. The optical corrector module according to paragraph C2.1, wherein when a second voltage is applied to the weak hexapole, the weak hexapole generates a weak hexapole field, which applies at least the combined A2 aberration and the combined D4 aberration to the charged particle beam.

[0115] C2.1.1.1. The optical corrector module according to paragraph C2.1.1, wherein the combination of A2 aberration and combined A2 aberration is applied to the charged particle beam in combination, resulting in the A2 aberration of the charged particle beam being 0 or close to 0 at or near the sample plane.

[0116] C2.1.1.2. The optical corrector module according to any one of paragraphs C2.1.1 to C2.1.1.1, wherein the combination of D4 aberration and combined D4 aberration applied to the charged particle beam results in the D4 aberration of the charged particle beam being 0 or close to 0 at or near the sample plane.

[0117] C2.1.3. The optical corrector module according to any one of paragraphs C2 to C2.1.1.2, wherein the strong hexapole field also applies the C3 aberration to the charged particle beam of the charged particle microscope system, and the weak hexapole field also applies the combined C3 aberration to the charged particle beam of the charged particle microscope system.

[0118] C2.1.3.1. The optical corrector module according to paragraph C2.1.3, wherein the combination of C3 aberration and combined C3 aberration is applied to the charged particle beam in combination, resulting in the C3 aberration of the charged particle beam being 0 or close to 0 at or near the sample plane.

[0119] C2.2. The optical corrector module described in any of paragraphs CA2.1.1 to C2.1.3.1, wherein the selection of the second voltage is based on the distance between the intersection of the charged particle beam and the center of the split hexapod.

[0120] C2.2.1. The optical corrector module according to paragraph C2.2, wherein the selection of the second voltage is determined based on the distance between the intersection of the charged particle beam and the center of the strong hexapole, such that one or more of the aberrations A2, C3 and D4 caused by the weak multipole field are combined with the aberrations A2, C3 and D4 caused by the strong multipole field.

[0121] C2.2.2. The optical corrector module described in any of paragraphs C2.2 to C2.2.1, wherein the intensity of the weak hexagon is at most 1 / 50 or 1 / 100 of that of the strong hexagon.

[0122] C2.3. The optical corrector module according to any one of paragraphs C2 to C2.2.2, wherein the weak hexapole is positioned within the objective lens when used in a charged particle system.

[0123] C2.4. An optical corrector module according to any one of paragraphs C2 to C2.3, wherein a weak hexapole is positioned within the field of the objective lens.

[0124] C2.5. An optical corrector module according to any one of paragraphs C2 to C2.4, wherein the strong hexapod is an electrostatic hexapod.

[0125] C2.6. The optical corrector module according to paragraph C2.5, wherein the strong hexagon has a (effective) length of at least 5 mm.

[0126] C2.8. The optical corrector module according to any one of paragraphs C2 to C2.7 further includes a transition lens positioned between the strong hexapole and the weak hexapole.

[0127] C2.8.1. The optical corrector module as described in paragraph C2.8 further includes an additional adapter lens positioned downstream of the weak hexapole.

[0128] C2.9. The optical corrector module according to any one of paragraphs C2 to C9, wherein the first voltage applied to the strong hexagon is between 50 kV and 300 kV.

[0129] C2.10. The optical corrector module according to any one of paragraphs C2 to C2.9, wherein the optical corrector module is configured to allow the angular displacement of the charged particle beam of the charged particle microscope to be greater than 20 mrad.

[0130] C2.11. The optical corrector module according to any one of paragraphs C2 to C2.10 further includes a condenser lens positioned upstream of the strong hexapole when used in a charged particle system.

[0131] C3. The optical corrector module according to any one of paragraphs C1 to C2.11, wherein the corrector further includes an additional multipole.

[0132] C3.1. The optical corrector module according to paragraph C3, wherein the additional multipole is a split multipole.

[0133] C3.1.1. The optical corrector module according to paragraph C3.1, wherein the additional multipole consists of two additional wafer multipoles spaced less than 10 mm apart, each additional wafer multipole comprising:

[0134] At least two additional electrodes, said at least two additional electrodes being positioned to partially define a beam path through the additional wafer multipole, wherein each of the additional electrodes comprises:

[0135] A first surface, when used in the charged particle column, faces upstream of the charged particle beam; and

[0136] The second surface, when used in the charged particle column, faces downstream of the charged particle beam.

[0137] C3.1.2. The optical corrector module according to any one of paragraphs C3.1 to C3.1.1, wherein the thickness between the first surface and the second surface of each of the additional electrodes is less than 3 mm.

[0138] C3.1.3. The optical corrector module according to any one of paragraphs C3.1 to C3.1.1, wherein the thickness between the first surface and the second surface of each of the additional electrodes is less than 100 μm.

[0139] C3.2. The optical corrector module according to any one of paragraphs C3 to C3.1.3, wherein when used in a charged particle system, the additional multipole is positioned downstream of the split multipole.

[0140] C3.3. The optical corrector module according to any one of paragraphs C3 to C3.1, wherein, when used in a charged particle system, the additional multipole is positioned upstream of the split multipole.

[0141] C3.4. An optical corrector module according to any one of paragraphs C3 to C3.3, wherein, when used in a charged particle system, the additional multipole is positioned downstream of the split multipole.

[0142] C3.5. An optical corrector module according to any one of paragraphs C3 to C3.4, wherein no multipole is positioned between a split multipole and an additional multipole.

[0143] C3.6. The optical corrector module according to any one of paragraphs C3 to C3.5 includes a transition lens positioned between the split multipole and the additional multipole.

[0144] C3.6.1. The optical corrector module according to paragraph C3.6, wherein the adapter lens is positioned at the axial intersection of the charged particle beam.

[0145] C3.6.2. An optical corrector module according to any one of paragraphs C3.6 to C3.6.1, wherein the axial intersection of the charged particle beam is equidistant from each of the split multipole and the additional multipole.

[0146] C3.6.3. An optical corrector module according to any one of paragraphs C3.6 to C3.6.2, wherein when the optical corrector module is used in a charged particle system, the charged particle beam is not a parallel beam as it passes through a split multipole.

[0147] C3.7. An optical corrector module according to any one of paragraphs C3 to C3.5, comprising a first adapter lens and a second adapter lens positioned between a split multipole and an additional multipole.

[0148] C3.7.1. The optical corrector module according to paragraph C3.7, wherein the first adapter lens is positioned upstream of the axial intersection of the charged particle beams, and the second adapter lens is positioned downstream of the axial intersection of the charged particle beams.

[0149] C3.7.2. An optical corrector module according to any one of paragraphs C3.7 to C3.7.1, wherein the axial intersection of the charged particle beam is equidistant from each of the split multipole and the additional multipole.

[0150] C3.7.3. An optical corrector module according to any one of paragraphs C3.7 to C3.7.2, wherein the axial intersection point of the charged particle beam is equidistant from each of the first and second adapter lenses.

[0151] C3.7.4. An optical corrector module according to any one of paragraphs C3.7 to C3.7.3, wherein when the optical corrector module is used in a charged particle system, the charged particle beam is a parallel beam as it passes through a split multipole.

[0152] C3.7.5. An optical corrector module according to any one of paragraphs C3.7 to C3.7.3, wherein when the optical corrector module is used in a charged particle system, the charged particle beam is substantially parallel as it passes through a split multipole.

[0153] C3.8. An optical corrector module according to any one of paragraphs C3 to C3.7.5, wherein both the split multipole and the additional multipole are electrostatic multipoles.

[0154] C3.9. An optical corrector module according to any one of paragraphs C3 to C3.8, wherein both the split multipole and the additional multipole are hexapoles.

[0155] C4. An optical corrector module according to any one of paragraphs C2 to C2.6, wherein the optical corrector module is a probe corrector.

[0156] C5. According to any one of paragraphs C1 to C4, the optical corrector module, wherein the corrector strength of the optical corrector module corresponds to the following relationship:

[0157] in

[0158] D1. A charged particle system comprising: a sample holder configured to hold a sample; a charged particle source configured to emit a beam of charged particles toward the sample; an optical column configured to guide the beam of charged particles such that the beam is incident on the sample, the optical column including an optical corrector module according to any one of paragraphs C1 to C5; and a detector system configured to detect emission generated by the sample irradiated by the beam of charged particles.

[0159] E1. The use of the corrector module as described in any of paragraphs A1 to A13 and C1 to C5. F1. The use of the charged particle system as described in any of paragraphs B1 to B13 and D1.

Claims

1. A charged particle microscope system comprising: a sample holder configured to hold a sample; a charged particle source configured to emit a charged particle beam toward the sample; an optical column configured to guide the charged particle beam so that it is incident on the sample, the optical column comprising a compact corrector module, the compact corrector module comprising: a strong multipole configured to produce a strong multipole field when a first voltage is applied thereto, wherein the strong multipole is positioned so that a crossover of the charged particle beam does not pass through a center of the strong multipole, so that the strong multipole field applies at least A2 and D4 aberrations to the charged particle beam; and a weak multipole positioned between the strong multipole and a sample plane, wherein the weak multipole is configured so that it produces a weak multipole field when a second voltage is applied thereto, the weak multipole field applying at least combined A2 and combined D4 aberrations to the charged particle beam; and a detector system configured to detect emissions produced by the sample illuminated by the charged particle beam, wherein there is only one strong multipole in the compact corrector module, wherein the compact corrector module does not include a multipole other than the strong multipole that is stronger than the weak multipole, wherein the combination of the A2 aberration and the combined A2 aberration applied to the charged particle beam results in the charged particle beam having a desired A2 aberration at the sample plane, and wherein the combination of the D4 aberration and the combined D4 aberration applied to the charged particle beam results in the charged particle beam having a desired D4 aberration at the sample plane.

2. The charged particle microscope system of claim 1, wherein: the strong multipole field further applies a C3 aberration to the charged particle beam of the charged particle microscope system; the weak multipole field further applies a combined C3 aberration to the charged particle beam of the charged particle microscope system; and the combination of the C3 aberration and the combined C3 aberration applied to the charged particle beam results in the charged particle beam having a desired D3 aberration at the sample plane.

3. The charged particle microscope system of claim 2, wherein the charged particle microscope system is configured to apply the second voltage based on a distance between the crossover of the charged particle beam and the center of the strong multipole so that one or more of the combined A2 aberration, the combined C3 aberration, and the combined D4 aberration caused by the weak multipole field combine with the A2 aberration, C3 aberration, and D4 aberration caused by the strong multipole field.

4. The charged particle microscope system of claim 1, wherein the charged particle microscope system is configured to apply the first voltage and the second voltage so that a strength of the weak multipole is at most 1 / 50 of a strength of the strong multipole.

5. The charged particle microscope system of claim 1, wherein, the weak multipole is located within an objective lens of the optical column of the charged particle microscope system.

6. The charged particle microscope system of claim 1, wherein, The weak multipole is positioned within a field of an objective lens of the optical column of the charged particle microscope system.

7. The charged particle microscope system of claim 1, further comprising a round lens positioned between the strong multipole and the weak multipole, wherein the round lens is positioned, charged, or otherwise configured such that a lens effect of the round lens causes a magnitude of the D4 aberration to be adjusted such that it combines with the combined D4 aberration to cause the charged particle beam to have a desired D4 aberration at the sample plane.

8. The charged particle microscope system of claim 1, wherein the strong multipole is an electrostatic multipole.

9. The charged particle microscope system of claim 8, wherein the strong multipole has a length of at least 5 mm.

10. The charged particle microscope system of claim 1, wherein, The strong multipole is a strong hexapole, and the weak multipole is a weak hexapole.

11. The charged particle microscope system of claim 1, wherein the charged particle microscope system is configured to apply the first voltage to the strong multipole such that the first voltage is between 0.1 kV and 30 kV.

12. The charged particle microscope system of claim 1, wherein the compact corrector module is configured to allow a fan angle of the charged particle beam of the charged particle microscope system to be greater than 20 mrad.

13. The charged particle microscope system of claim 1, wherein the charged particle microscope system is configured to apply the first voltage to the strong multipole such that the first voltage is between 50 kV and 300 kV, and wherein a strength of the weak multipole is at most 1 / 50 or 1 / 100 of a strong multipole.

14. A compact corrector module for a charged particle microscope system, the compact corrector module comprising: a strong multipole configured to produce a strong multipole field when a first voltage is applied thereto, wherein the strong multipole is positioned such that a crossover of a charged particle beam of the charged particle microscope system does not pass through a center of the strong multipole, such that the strong multipole field applies at least an A2 aberration and a D4 aberration to the charged particle beam; and a weak multipole positioned between the strong multipole and a sample plane when the compact corrector module is used in the charged particle microscope system, wherein the weak multipole is configured such that it produces a weak multipole field when a second voltage is applied to the weak multipole, the weak multipole field applying at least a combined A2 aberration and a combined D4 aberration to the charged particle beam; wherein the strong multipole is the only multipole of the compact corrector module that is stronger than the weak multipole.

15. The compact corrector module of claim 14, wherein a combined application of the A2 aberration and the combined A2 aberration to the charged particle beam results in the charged particle beam having a desired A2 aberration at the sample plane; and wherein a combined application of the D4 aberration and the combined D4 aberration to the charged particle beam results in the charged particle beam having a desired D4 aberration at the sample plane.

16. The compact corrector module of claim 14, wherein: The strong multipole field further applies a C3 aberration to the charged particle beam of the charged particle microscope system; The weak multipole field further applies a combined C3 aberration to the charged particle beam of the charged particle microscope system; and The combined application of the C3 aberration and the combined C3 aberration to the charged particle beam results in the charged particle beam having a desired D3 aberration at the sample plane.

17. The compact corrector module of claim 16, wherein the compact corrector module is configured to operate such that one or more of the combined A2 aberration, the combined C3 aberration, and the combined D4 aberration caused by the weak multipole field combine with the A2 aberration, C3 aberration, and D4 aberration caused by the strong multipole field.

18. The compact corrector module of claim 14, further comprising a round lens positioned between the strong multipole and the weak multipole, wherein the round lens is positioned, charged, or otherwise configured such that a lens effect of the round lens causes a magnitude of the D4 aberration to be adjusted such that it combines with the combined D4 aberration to cause the charged particle beam to have a desired D4 aberration at the sample plane.

19. The compact corrector module of claim 14, wherein the strong multipole is an electrostatic multipole.

20. The compact corrector module of claim 14, wherein, The strong multipole is a strong hexapole, and wherein the weak multipole is a weak hexapole. The strong multipole is a strong hexapole, and wherein the weak multipole is a weak hexapole.

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