Multiple particle beam system with improved contacting device for an electrostatic lens system within a magnetic lens

Abstract

The invention discloses a multiple particle beam system comprising a multi-beam generator for generating a plurality of individual charged first particle beams and comprising a magnetic lens, in particular an objective lens, through which the individual charged first particle beams collectively pass. An electrostatic lens system is arranged within the magnetic lens. This electrostatic lens system is electrically contacted by means of a specially shaped multi-part contacting device, which is also arranged inside the magnetic lens.

Description

[0001] Multiple particle beam system with improved contacting device for an electrostatic lens system within a magnetic lens

[0002] Field of the invention

[0003] The invention relates to multiple particle beam systems in general and to multi-beam particle microscopes operating with a plurality of individual charged particle beams in particular. Specifically, the invention relates to a multiple particle beam system with an improved contacting device for an electrostatic lens system within a magnetic lens, in particular within an objective lens.

[0004] Prior art

[0005] With the ongoing development of ever smaller and ever more complex microstructures such as semiconductor components, there is a need to further develop and optimize planar production techniques and inspection systems for producing and inspecting small dimensions of the microstructures. For instance, the development and production of the semiconductor components require monitoring of the design of test wafers, and the planar production techniques require process optimization for reliable production with high throughput. Moreover, there have been recent demands for an analysis of semiconductor wafers for reverse engineering and for a customized, individual configuration of semiconductor components. Therefore, there is a need for inspection means which can be used with high throughput to examine the microstructures on wafers with high accuracy.

[0006] Typical silicon wafers used in the production of semiconductor components have diameters of up to 300 mm. Each wafer is divided into 30 to 60 repeating regions ("dies") with a size of up to 800 mm2. A semiconductor device comprises multiple semiconductor structures, which are produced in layers on a surface of the wafer by planar integration techniques. Semiconductor wafers typically have a plane surface on account of the production processes. The structure size of the integrated semiconductor structures in this case extends from a few pm to the critical dimensions (CDs) of 5 nm, and the structure sizes will become even smaller in the near future; in future, structure sizes or critical dimensions (CDs) are expected to be less than 3 nm, for example 2 nm, or even less than 1 nm. In the case of the aforementioned small structure sizes, defects of the order of the critical dimensions must be identified quickly over a very large area. For multiple applications, the specification requirement regarding the accuracy of ameasurement provided by an inspection device is even higher, for example by a factor of two or one order of magnitude. For example, a width of a semiconductor feature must be measured with an accuracy better than 1 nm, for example 0.3 nm or even less, and a relative position of semiconductor structures must be determined with an overlay accuracy better than 1 nm, for example 0.3 nm or even less.

[0007] The MSEM, a multi-beam scanning electron microscope, is a relatively new development in the field of charged particle systems (“charged particle microscopes”, CPMs). For example, a multi-beam scanning electron microscope is disclosed in US 7 244 949 B2 and in US 2019 / 0355544 A1. In the case of a multi-beam electron microscope or MSEM, a sample is irradiated simultaneously with a plurality of individual electron beams, which are arranged in a field or grid. For instance, 4 to 10000 individual electron beams may be provided as primary radiation, with each individual electron beam being separated from an adjacent individual electron beam by a pitch of 1 to 200 micrometres. For example, an MSEM has approximately 100 separate individual electron beams (“beamlets”), which are arranged for example in a hexagonal grid, with the individual electron beams being separated by a pitch of approximately 10 pm. The multiplicity of individual charged particle beams (primary beams) is focused, in each case on an individual basis, on a surface of a sample to be examined and this focussing is effected by way of a common large-field optics unit including, inter alia, a common objective lens. For example, the sample can be a semiconductor wafer that is secured to a wafer holder mounted on a movable stage. When the wafer surface is illuminated by the primary individual charged particle beams, interaction products, for example secondary electrons or backscattered electrons, emanate from the surface of the wafer. Their respective start points correspond to those locations on the sample on which the plurality of primary individual particle beams is focused in each case. The amount and the energy of the interaction products depend inter alia on the material composition and the topography of the wafer surface. The interaction products form multiple secondary individual particle beams (secondary beams) that are collected by the common objective lens and, following a passage through a projection imaging system of the multi-beam inspection system, are incident on a detector arranged in a detection plane. The detector comprises multiple detection regions, each of which comprises multiple detection pixels, and the detector captures an intensity distribution for each of the secondary individual particle beams. An image field of 100 pm x 100 pm, for example, is obtained.

[0008] The multi-beam electron microscope of the prior art comprises a sequence of electrostatic and magnetic elements. At least some of the electrostatic and magnetic elements are adjustable in order to adapt the focus position and the stigmation of the plurality of individual charged particle beams. The multi-beam system with charged particles of the prior art moreover comprises atleast one cross-over plane of the primary or the secondary individual charged particle beams. The system of the prior art also comprises detection systems to make the adjustment easier. The multi-beam particle microscope of the prior art comprises at least one beam deflector (deflection scanner) for collective scanning of a region of the sample surface by means of the plurality of primary individual particle beams in order to obtain an image field of the sample surface. Further details regarding a multi-beam electron microscope and a method for operating same are described in US 2023 / 043036 A1, the disclosure of which is fully incorporated by reference in the present patent application.

[0009] As requirements on the resolution of a multiple particle beam system become more exacting, the complexity of multiple particle beam systems also increases. For example, the number of particle-optical elements and in particular dynamic correction elements increases. DE 102021 105201 A1 discloses a multiple particle beam microscope and an associated method with fast autofocus around an adjustable working distance, the disclosure of which is fully incorporated by reference in the present patent application. DE 10 2021 105 201 A1 proposes a system having fast autofocus correction lenses for high-frequency adaptation of the focus setting, the position, the landing angle and the rotation of individual particle beams upon incidence on a wafer surface during the wafer inspection. A preferred solution relates to multi-part autofocus correction lenses, for example an autofocus correction lens with two electrostatic lenses. These two electrostatic lenses can be arranged in the particle-optical beam path, inter alia, within a magnetic objective lens.

[0010] Often, a magnetic objective lens is also part of an objective lens system, which for example additionally contains an electrostatic objective lens for generating an electrostatic immersion field. An objective lens is also often in close proximity to a beam splitter, which in the case of a multi-beam particle microscope separates the primary path and the secondary path of the charged particle beams by means of magnetic and / or electrostatic fields.

[0011] In the interior of the magnetic objective lens or in the immediate vicinity thereof, it is also possible to arrange still further particle-optical components, such as the above-described beam deflector for collective scanning of a region of a sample surface or a beam trap which can be arranged at the level of a rear (upper) focal plane of the objective lens or of the objective lens system. A beam deflector and its design including its contacting is disclosed for example in GB 2521819 A, the disclosure of which is fully incorporated by reference in the present patent application. A beam trap within a magnetic objective lens is described for example in DE 10 2019008249 B3, the disclosure of which is also fully incorporated by reference in the present patent application.Activation of the particle-optical elements listed by way of example requires correspondingly electrically contacting the particle-optical elements in a vacuum. This electrical contacting is often difficult for several reasons: For the one part, the available space within a magnetic lens and in particular within a magnetic objective lens is very limited. This is true in particular when a plurality of particle-optical components has to be contacted individually. For the other part, they are particle-optical components to parts of which a high voltage must be applied, and this makes it impossible for example to use wires to establish contact between the pole shoes of the objective lens due to voltage flashovers.

[0012] It is also not a good option to enlarge a bore in a magnetic lens on account of more space being required inside the magnetic lens. This would require an even stronger excitation of the magnetic lens during operation, and this in turn is scarcely possible because often the magnetic lens is already operated in the saturation range of its magnetic material.

[0013] US 2014 / 0014852 A1 and WO 2011 / 043668 A1 disclose background art for the present patent application.

[0014] Description of the invention

[0015] The object of the invention is therefore to provide an improved multiple particle beam system and in particular an improved multi-beam particle microscope, in which an electrical contacting of an electrostatic lens element within a magnetic lens and in particular within an objective lens is made possible in a simple way. The intention is to make it possible to establish a plurality of electrical contact connections in an extremely confined space in flashover-resistant fashion, in order to control electrostatic round lenses and multi-pole correctors. In particular, within a magnetic lens multiple electrostatic lenses are to be contacted individually, easily and in flashover-resistant fashion.

[0016] The object is achieved by the subject matter of the independent patent claim. Advantageous embodiments of the invention are evident from the dependent patent claims.

[0017] The present patent application claims the priority of the German patent application No. 102025 106812.7 filed on 24 February 2025, the disclosure of which is fully incorporated by reference in the present patent application.The invention essentially proposes a contacting device having multiple specially shaped contacting bodies which do not touch one another. A special geometry allows a simple and flashover-resistant contact connection of a plurality of ring electrodes in the extremely confined space within a magnetic lens. The special geometry makes it possible to establish an external, i.e. outwardly leading, contact connection at a different height than the height at which the contacted electrostatic lenses, such as ring electrodes, are actually themselves arranged. The contacting device can also be combined with existing contact connections such as a contact connection of a collective beam deflector.

[0018] Specifically, the invention relates to a multiple particle beam system which comprises the following:

[0019] a multi-beam generator for generating a multiplicity of individual charged first particle beams; a magnetic lens, in particular an objective lens, through which the individual charged first particle beams collectively pass,

[0020] an electrostatic lens system, in particular a ring electrode system, which is arranged within the magnetic lens and comprises a first electrostatic lens and a second electrostatic lens which can be controlled individually and are centred in relation to one another and arranged one after the other with respect to the particle-optical beam path in such a way that the individual charged first particle beams collectively pass through them one after the other; and a multi-part contacting device for contacting the electrostatic lens system, the contacting device also being arranged within the magnetic lens,

[0021] wherein the contacting device has a substantially hollow-cylindrical first contacting body for contacting the first electrostatic lens,

[0022] wherein the contacting device has a substantially hollow-cylindrical second contacting body for contacting the second electrostatic lens,

[0023] wherein the first contacting body and the second contacting body are arranged one after the other with respect to the particle-optical beam path,

[0024] wherein the first contacting body and the second contacting body do not touch one another, wherein the first contacting body has a substantially encircling side wall which has a first cutout extending along a direction parallel to the particle-optical axis of the multiple particle beam system,

[0025] wherein the second contacting body has a substantially encircling side wall which has a first projection extending along a direction parallel to the particle-optical axis of the multiple particle beam system,

[0026] wherein the first projection is arranged within the first cutout and the second contacting body is externally electrically contacted on the first projection.The individual charged first particle beams can be electron beams, for example. However, they may also be other individual charged particle beams, for example protons, myons or ions.

[0027] In principle, the magnetic lens may be any desired magnetic lens. The magnetic lens of a magnetic objective lens is preferred. It is possible for the magnetic lens to be a component of an objective lens system which comprises, in addition to the magnetic lens, other lenses such as an electrostatic lens.

[0028] The electrostatic lens system according to the invention is arranged within the magnetic lens. It is therefore located in a region with very limited space. It is possible, for example, that the electrostatic lens system is arranged at least partially within a bore in a pole shoe of the magnetic lens.

[0029] The electrostatic lens system comprises a plurality of electrostatic lenses, which can be controlled individually and are centred in relation to one another and arranged one after another with respect to the particle-optical beam path in such a way that the individual charged first particle beams collectively pass through them one after another. The various electrostatic lenses are thus arranged at different heights with respect to the particle-optical beam path or the particle-optical axis of the multiple particle beam system. The electrostatic lenses are for example ring electrodes, cylinder electrodes or tube electrodes, these terms being used synonymously in the context of this patent application.

[0030] According to the invention, the multiple particle beam system comprises a multi-part contacting device for contacting the electrostatic lens system, the multi-part contacting device also being arranged within the magnetic lens. The contacting device is made of an electrically conductive material and according to the invention it has multiple parts, because it comprises at least two contacting bodies which do not touch one another. This lack of contact ensures that the contacting bodies are sufficiently insulated from one another within the vacuum or high vacuum of the multiple particle beam system. Each contacting body is used to electrically contact an associated electrostatic lens. This makes it possible to contact and thus also apply voltage to each electrostatic lens individually.

[0031] Each contacting body is substantially hollow-cylindrical. In particular, the substantially encircling side wall of each contacting body is a constituent part of the substantially hollow-cylindrical shape of the contacting body. A shape is also substantially hollow-cylindrical when, in addition to the substantially encircling side wall of the contacting body, further shapedelements are present on the contacting body. These elements can be for example cutouts, projections or recesses, etc.

[0032] According to the invention, the first cutout in the substantially encircling side wall of the first contacting body extends along a direction parallel to the particle-optical axis of the multiple particle beam system. The first projection of the second contacting body extends in the same direction. In this case, this first projection can be formed flush, or in line with, the substantially encircling side wall of the second contacting body, but the first projection can also be outwardly offset from the substantially encircling side wall of the hollow-cylindrical second contacting body. The first projection itself can have a constant thickness, or width, in its direction of extent, but the first projection can also have a variable thickness, or width. It is possible for example that the first projection has a radially inwardly directed thickened portion in an upper portion corresponding to the region that projects the farthest. This facilitates and stabilizes the external electrical contacting of the second contacting body on the first projection. In any case, the first projection is arranged within the first cutout.

[0033] In the course of this patent application, the term "external electrical contacting" is understood as meaning that it results in an electrical contact connection being established outside the vacuum or high vacuum of the multiple particle beam system. Embodiment variants for such external electrical contacting are known to a person skilled in the art and are described for example in GB 252 181 9 A, the disclosure of which is fully incorporated by reference in the present patent application. An external electrical contacting element can, for example, be designed as a contacting element in the form of a rod. The external electrical contacting from inside the vacuum or high vacuum to outside the vacuum or high vacuum can be carried out in vacuum-tight fashion, in a manner known per se.

[0034] According to a preferred embodiment of the invention, the first contacting body and the second contacting body are externally electrically contacted at the same height with respect to the direction parallel to the particle-optical axis. In principle, the first contacting body can be contacted at any desired position on its encircling side wall. Preferably, however, it is contacted in an upper region of the encircling side wall into which the projection of the second contacting body also extends. Although the first contacting body and the second contacting body are in principle arranged one after the other (it would also be possible to say one above the other or one below the other) in the particle-optical beam path, it is nevertheless possible to contact the first contacting body and the second contacting body at the same height overall on account of the special shaping of the contacting device. This has advantages in particular when the associated contacted first and second electrostatic lenses protrude very deeply into or areinstalled very deeply in a magnetic lens. The electrostatic lenses then do not need to be contacted at the respective depth of the electrostatic lens itself, but rather can be drawn up (or down) and thus out of the magnetic lens by means of the respective contacting body owing to the particular shaping of the contacting body. Instead of thus arranging multiple external electrical contact connections one after another or one below another, it is possible to arrange multiple external electrical contact connections spaced apart at the same height, or next to one another. In this way, it is easier to externally electrically contact the plurality of contacting bodies.

[0035] According to a preferred embodiment of the invention, an outer radius of the first contacting body and an outer radius of the second contacting body match at least in the region of the first cutout and first projection. However, the matching in terms of the outer radius can also extend over a larger region. In the region in which the outer radii of the two contacting bodies match, a common insulation body can easily be provided. This thus makes it possible to conjointly electrically insulate the first contacting body and the second contacting body. Furthermore, the insulation body can take over functions relating to guiding / aligning the contacting device.

[0036] According to a preferred embodiment of the invention, the first contacting body and the second contacting body are pushed one in the other annularly and without touching. In this case, the second contacting body can be pushed either completely or only partially in the first contacting body. This pushing-in is advantageous in particular when one or more further contacting bodies are also provided in addition to the first and the second contacting body. These contacting bodies can then also be pushed into the first contacting body annularly and without touching. Moreover, this embodiment variant of the invention gives rise to flexible possibilities for the specific arrangement of the electrostatic lenses of the electrostatic lens system. In any case, however, the first contacting body is the one that has one or more cutouts in this embodiment, too.

[0037] According to a further, preferred embodiment of the invention, the first contacting body has a recess in the circumferential direction, underneath which the substantially encircling side wall of the second contacting body is arranged flush with the outside. The terms above and below, or upper and lower, refer in this case to the particle-optical beam path, i.e. "upper" is close to the source and "lower" is remote from the source. This embodiment variant of the invention in principle results in a larger flush or in-line outer surface or height of the contacting device overall. It is then also possible to advance the second contacting body flush with the substantially encircling side wall and allow its first projection to project in a flush manner. As a result, the region of a common insulation body around the first contacting body and around thesecond contacting body can be considerably enlarged. This in turn opens up possibilities of also designing the insulation body in the form of a guide element and a stop element in order to ensure precise positioning of the contacting bodies and precise maintenance of a spacing between the contacting bodies.

[0038] According to a preferred embodiment of the invention, the insulation body has a first stop for positioning the first contacting body with respect to the direction of the particle-optical axis of the multiple particle beam system. In addition or alternatively, the insulation body has a second stop for positioning the second contacting body with respect to the direction of the particle-optical axis of the multiple particle beam system. The first and the second stop can each be designed in the form of annularly encircling surfaces. They can, however, also be designed in other ways. The first stop can, for example, ensure a correct position of the first contacting body when the first contacting body is being pushed into the insulation body. The second stop can be used for example to ensure that the second contacting body does not touch the first contacting body.

[0039] According to a preferred embodiment of the invention, the encircling side wall of the first contacting body bears against the first stop of the insulation body. In addition or alternatively, the second contacting body has a projection in the circumferential direction which bears against the second stop of the insulation body. This projection is preferably located in the lower region of the second contacting body. The interaction between the projection and the second stop thus prevents the second contacting body from being able to be pushed further into the insulation body.

[0040] According to a preferred embodiment of the invention, the first electrostatic lens is screwed to the first contacting body. In addition or alternatively, the second electrostatic lens is screwed to the second contacting body. The screwed connection makes it possible to establish good contact between the electrostatic lens and the respective contacting body, and this allows precise positioning.

[0041] According to a preferred embodiment of the invention, the first electrostatic lens is screwed in the first contacting body, and the first contacting body surrounds the first electrostatic lens around the full circumference. In this way, the electrostatic lens can be contacted over a large area.

[0042] According to a further, preferred embodiment of the invention, the multiple particle beam system has an evacuable or evacuated beam tube in which the individual charged first particlebeams are at least section-wise guided. The second electrostatic lens is realized by a beam tube section of the beam tube that protrudes into the magnetic lens. The use of a beam tube section to realize an electrostatic lens is fundamentally known from the prior art. By means of the contacting device according to the invention, this special type of electrostatic lens can now be contacted very well and also flexibly.

[0043] According to a preferred embodiment of the invention, the contacting device is arranged within a bore in a pole shoe of the magnetic lens. This can be an upper pole shoe or a lower pole shoe. Preferably, it is an upper pole shoe, in particular of an objective lens. It is not necessary for the entire contacting device to be located strictly within the bore in the pole shoe; the contacting device can, for example, protrude all the way through the bore in the pole shoe.

[0044] According to a preferred embodiment of the invention, for the bore in the pole shoe and in terms of the diameter d of the bore, the following relation applies: 20 mm < d < 30 mm. The bore thus has a relatively small diameter d. However, even in the case of such a small bore it is possible to provide the contacting device according to the invention without any problems.

[0045] According to a preferred embodiment of the invention, for an inside diameter di of the first electrostatic lens and / or of the second electrostatic lens, the following relation applies: 5 mm < di < 20 mm.

[0046] According to a preferred embodiment of the invention, the contacting device is resistant to high voltage and / or vacuum. In this way, flashovers between contacting bodies and between contacting bodies and other components of the multiple particle beam system are avoided. The resistance to vacuum is required as always for multiple particle beam systems and is ensured by using outgassing-free materials and shapes. The resistance to high voltage is ensured by the choice of materials and by the choice of the spacings between adjacent elements. The required resistances to voltage can amount to 100 V, 1000 V, 10000 V or more.

[0047] According to a further, preferred embodiment of the invention, the electrostatic lens system comprises a third electrostatic lens which can be controlled individually and is centred in relation to the particle-optical axis. It is, however, arranged at a different height than the first and the second electrostatic lens. In this embodiment, the contacting device has a substantially hollow-cylindrical third contacting body for contacting the third electrostatic lens. The third contacting body is arranged downstream of the second contacting body with respect to the particle-optical beam path. The third contacting body does not touch the first contacting body and does not touch the second contacting body. The first contacting body has a second cutoutin the substantially encircling side wall, the second cutout extending along the direction parallel to the particle-optical axis of the multiple particle beam system. The second contacting body has a substantially encircling side wall which has a second projection extending along a direction parallel to the particle-optical axis of the multiple particle beam system. In this case, the second projection is arranged within the second cutout and the third contacting body is externally electrically contacted on the second projection. In this embodiment of the invention, it is thus possible to easily contact three electrostatic lenses overall by means of associated contacting bodies.

[0048] According to a further, preferred embodiment of the invention, the first contacting body and the third contacting body are externally electrically contacted at the same height with respect to the direction parallel to the particle-optical axis of the multiple particle beam system. This can also apply to the external electrical contacting of the second contacting body. In this case, the first projection and the second projection of the second contacting body and the third contacting body then have different lengths. This can also apply correspondingly to the associated cutouts of the first contacting body, but the cutouts of the first contacting body can also all have identical lengths.

[0049] According to a preferred embodiment of the invention, an outer radius of the first contacting body and an outer radius of the third contacting body match at least in the region of the second cutout. This preferably also applies to the outer radius of the first contacting body and the outer radius of the second contacting body in the region of the first cutout and first projection. This in turn has advantages as regards providing a common insulation body.

[0050] According to a preferred embodiment of the invention, a / the common insulation body for conjointly electrically insulating the first contacting body and the third contacting body is arranged at least in the region in which the outer radius of the first contacting body and the outer radius of the third contacting body match. Preferably, this also applies to the second contacting body, or corresponding regions of the second contacting body. In turn, the common insulation body can take on additional tasks relating to guiding and / or positioning the contacting bodies in relation to one another and, if necessary, in relation to further elements of the multiple particle beam system.

[0051] According to a further, preferred embodiment of the invention, the electrostatic lens system comprises a fourth electrostatic lens which can be controlled individually and is centred in relation to the particle-optical axis. The contacting device furthermore has a substantially hollow-cylindrical fourth contacting body for contacting the fourth electrostatic lens. In thiscase, the fourth contacting body is arranged downstream of the third contacting body with respect to the particle-optical beam path. The fourth contacting body does not touch the first contacting body, does not touch the second contacting body and does not touch the third contacting body. The first contacting body has a third cutout in the substantially encircling side wall, the third cutout extending along the direction parallel to the particle-optical axis of the multiple particle beam system. Moreover, the fourth contacting body has a substantially encircling side wall which has a third projection extending along a direction parallel to the particle-optical axis of the multiple particle beam system. The third projection is arranged within the third cutout and the fourth contacting body is externally electrically contacted on the third projection. In this way, four electrostatic lenses overall can be safely electrically contacted easily and in a way requiring very little space. In all other respects, reference is made to the above statements.

[0052] According to a further, preferred embodiment of the invention, the electrostatic lens system has a fifth or further electrostatic lens and the contacting device has a fifth or further contacting body. The requirements and exemplary embodiments described above also apply analogously to this embodiment variant.

[0053] According to a further, preferred embodiment of the invention, the first contacting body has a plurality of cutouts for receiving projections, wherein the cutouts extend to different extents, and thus have different depths, in the direction parallel to the particle-optical axis of the multiple particle beam system. However, it would also be possible for the cutouts to all have the same depth. However, this then creates regions within the cutouts in which no projections are inserted. This is harmless, however, since the various contacting bodies must be provided without touching one another in any case. It is possible that the multiplicity of cutouts is evenly distributed around the circumference of the first contacting body. In that case, the external electrical contact connections are evenly distributed, or as far apart as possible from one another, around the circumference. This offers advantages when the space available is limited.

[0054] According to a preferred embodiment of the invention, the magnetic lens is an objective lens. However, it could also be a different lens, for example a condenser lens, a field lens or a projection lens. Specifically, however, the embodiment variant comprising an objective lens is advantageous because it has been found that the arrangement of multiple electrostatic lenses within an objective lens offers particular advantages.

[0055] According to a preferred embodiment of the invention, the multiple particle beam system furthermore comprises the following:a double deflector for collective deflection of the individual charged first particle beams which is arranged within the objective lens; and / or

[0056] a beam trap arranged within the objective lens.

[0057] These features are already known per se from the prior art. It should now be emphasized that the multiple particle beam system according to the invention can also be combined with these embodiment variants of a multiple particle beam system and also works well with them given the resulting even smaller installation space available.

[0058] According to a preferred embodiment of the invention, the multiple particle beam system further comprises a controller configured to individually control the objective lens, the first electrostatic lens and the second electrostatic lens. Furthermore, the controller is configured to statically adjust a focus stroke by means of the objective lens. In addition, a dynamic change in focus can be adjusted by means of the first electrostatic lens and a dynamic telecentricity correction can be adjusted by means of the second electrostatic lens, or vice versa. This means that one of the two electrostatic lenses is used to dynamically change the focus and the other of the two electrostatic lenses is used to dynamically correct the telecentricity. A dynamic change in focus and / or dynamic telecentricity correction may be required and carried out in the course of a fast autofocus correction, as is described for example in DE 102021 105201 A1 , the disclosure of which is fully incorporated by reference in the present patent application.

[0059] According to a preferred embodiment of the invention, the electrostatic lens that is controlled for the dynamic change in focus has a length LF in the direction of the particle-optical axis Z for which the following relation applies: 5 mm < LF < 20 mm. This length specification refers to the length of the component, not to the field region.

[0060] According to a preferred embodiment of the invention, the electrostatic lens that is controlled for the dynamic telecentricity correction has a length LT in the direction of the particle-optical axis Z for which the following relation applies: 5 mm < LT < 40 mm. This length specification refers to the length of the component, not to the field region.

[0061] According to a preferred embodiment of the invention, an application of voltage to the electrostatic lens that is controlled for the dynamic change in focus can be varied by at least + / - 500 V. The variation of + / - 500 V can be effected by a mean value that differs from 0 V, for example by a mean value of 1000 V, 1500 V or 2000 V. The contacting device according to the invention is capable of transmitting the required dynamic application of voltage.According to a preferred embodiment of the invention, an application of voltage to the electrostatic lens that is controlled for the dynamic telecentricity correction can be varied by at least + / - 200 V. This variation can in turn be effected by a mean value, which can also amount to 0 V, but it can also lie in the low-voltage range or in the high-voltage range.

[0062] According to a preferred embodiment of the invention, the multiple particle beam system is designed in the form of a multi-beam particle microscope. However, it can also be designed differently, for example in the form of a multi-beam lithography system.

[0063] The above-described embodiments of the invention may be combined with one another in full or in part, provided that no technical contradictions arise as a result.

[0064] In this context, the invention will be understood even better with reference to the accompanying figures, in which:

[0065] Fig. 1 : shows a schematic illustration of a multi-beam particle microscope (MSEM); Fig. 2: schematically shows a section through a multi-beam particle microscope; Fig. 3: schematically shows an objective lens with a two-part fast autofocus correction electrode arranged therein;

[0066] Fig. 4: shows a three-dimensional illustration of a contacting device;

[0067] Fig. 5: shows a perspective illustration, in a sectional view, of a magnetic lens with a contacting device;

[0068] Fig. 6: shows a sectional view of a magnetic lens with a contacting device;

[0069] Fig. 7: schematically shows a contacting device with two contacting bodies;

[0070] Fig. 8: schematically shows a contacting device with three contacting bodies;

[0071] Fig. 9: schematically shows a further contacting device with three contacting bodies; Fig. 10: schematically shows a further contacting device with three contacting bodies; Fig. 11 : schematically shows a perspective illustration of contacting devices; and Fig. 12: schematically shows a perspective illustration of further contacting devices.

[0072] Fig. 1 schematically shows a multiple particle beam system 1 in the form of a multi-beam particle microscope 1. The multi-beam particle microscope 1 comprises a beam-generating apparatus 300 having a particle source, for example an electron source. By means of the beam-generating apparatus 300, charged particles or electrons are generated for example by means of thermal field emission. The emitted charged particles form a divergent particle beam 309, and the latter is collimated by a sequence of condenser lenses 303.1 and 303.2 and incident on a multi-beam generator 305 having a multi-aperture arrangement. The multi-beamgenerator 305 comprises multiple multi-aperture plates 304, 306 and a field lens 307. The multi-beam generator 305 generates a plurality of individual particle beams 3 or individual electron beams 3, which are arranged in a field, the latter being imaged onto a further field formed by beam spots 5 in the object plane 101. The pitch between centre points of apertures in a multi-aperture plate 306 can be for example 5 pm, 100 pm and 200 pm. The diameters D of the apertures are smaller than the pitch between the centre points of the apertures; examples of the diameters are 0.2 times, 0.4 times and 0.8 times the pitches between the centre points of the apertures.

[0073] The multi-aperture generator, which has the multi-aperture arrangement, and the field lens 308 are configured to create a plurality of focal points 323 of primary beams 3 in a raster arrangement on a surface 321. The surface 321 need not be a plane surface but rather can be a spherically curved surface in order to account for an image field curvature of the subsequent particle-optical system.

[0074] The multi-beam particle microscope 1 furthermore comprises a system of electromagnetic lenses 103 and an objective lens 102, which image the beam foci 323 from the intermediate image surface 321 into the object plane 101 with reduced size. In between, the individual first particle beams 3 pass through the beam switch 400 and a collective beam deflection system 500, by means of which the plurality of individual first particle beams 3 are deflected during operation and the image field is scanned. The individual first particle beams 3 incident on the object plane 101 form for example a substantially regular field, wherein pitches between adjacent incidence locations 5 can be for example 1 pm, 10 pm or 40 pm. The field formed by the incidence locations 5 can have a rectangular or hexagonal symmetry, for example.

[0075] The object 7 to be examined may be of any desired type, for example a semiconductor wafer or a biological sample, and may comprise an arrangement of miniaturized elements or the like. The surface 15 of the object 7 is arranged in the object plane 101 of the objective lens 102. The objective lens 102 may comprise one or more electron-optical lenses. For example, it may be a magnetic objective lens and / or an electrostatic objective lens.

[0076] The primary particles 3 incident on the object 7 generate interaction products, for example secondary electrons, backscattered electrons or primary particles, which have experienced a reversal of movement for other reasons, and these interaction products emanate from the surface of the object 7 or from the first plane 101 or object plane 101. The interaction products emanating from the surface 15 of the object 7 are shaped by the objective lens 102 to form secondary particle beams 9. In the process, the secondary beams 9 pass through the beamswitch 400 downstream of the objective lens 102 and are supplied to a projection system 200. The projection system 200 comprises an imaging system 205 with projection lenses 206, 208 and 210, a contrast stop 214 and a multi-particle detector 207. Incidence locations 25 of the second individual particle beams 9 on detection regions of the multi-particle detector 207 are located with a regular pitch in a third field. Exemplary values are 10 pm, 100 pm and 200 pm.

[0077] The multi-beam particle microscope 1 furthermore comprises a computer system or control unit or controller 10, which in turn can be embodied in one piece or in multiple pieces and which is designed both to control the individual particle-optical components of the multi-beam particle microscope 1 and to evaluate and analyse the signals obtained by the multi-detector 207 or detection unit.

[0078] Further information relating to such multi-beam particle beam systems or multi-beam particle microscopes 1 and component parts used therein, such as particle sources, multi-aperture plate and lenses, can be obtained from the international patent applications WO 2005 / 024881 A2, WO 2007 / 028595 A2, WO 2007 / 028596 A1 , WO 2011 / 124352 A1 and WO 2007 / 060017 A2 and the German patent applications DE 102013016 113 A1 and DE 102013014976 A1, the disclosure of which is fully incorporated by reference in the present application.

[0079] Fig. 2 schematically shows a section through a multiple particle beam system 1 in the form of a multi-beam particle microscope 1. The multiple particle beam system 1 initially comprises a particle source 301. In the example shown, this particle source 301 emits an individual particle beam comprising charged particles, e.g. electrons. In Fig. 2, particle beams or a particle-optical beam path are illustrated schematically by the dashed line with reference sign 3. The individual particle beam initially passes through a condenser lens system 303 and is subsequently incident on a multi-aperture arrangement. This multi-aperture arrangement, possibly with further particle-optical component parts, serves as a multi-beam generator 305. The first particle beams emanating from the multi-beam generator 305 then pass through a field lens or a field lens system 308 and subsequently enter a beam switch 400. This beam switch 400 comprises a beam tube arrangement 460, which has a Y-shaped embodiment and three limbs 461, 462 and 463 in the example shown. Here, in addition to two flat, interconnected structures for holding the magnetic sectors 410, 420, the beam switch 400 includes the magnetic sectors 410 and 420 which are contained in, or secured to, said structures. After passing through the beam switch 400, the first particle beams pass through a scan deflector 500 and, thereupon, a particle-optical objective lens 102, before the first particle beams 3 are incident on an object 7, in this case a semiconductor wafer with HV structures. As a result of this incidence, secondary particles, e.g. secondary electrons, are released from the object 7. Thesesecondary particles form second particle beams, to which a second particle-optical beam path 9 is assigned. After emerging from the object 7, the second particle beams initially pass through the particle-optical objective lens 102 and subsequently pass through the scan deflector 500, before entering the beam switch 400. Subsequently, the second particle beams 9 emerge from the beam switch 400, pass through a projection lens system 205 (illustrated in much simplified fashion), pass through an electrostatic element 222 and then are incident on a particle-optical detection unit 207 (in this case, reference sign 222 denotes what is referred to as the antiscan, which compensates the otherwise occurring scanning movement of the secondary beams 9 upon incidence on the detection unit 207).

[0080] Situated within the beam switch 400, there is the beam tube arrangement 460, which also extends beyond the beam switch 400 in the example shown. Splitting the beam path within the beam switch 400 into the first particle-optical beam path 3 and the second particle-optical beam path 9 is implemented within the beam switch 400 with the aid of magnetic sectors 410, 420. In the example illustrated in Fig. 2, the beam tube arrangement 460 also continues outside of the beam switch 400. In this case, it extends, in particular, to the particle-optical objective lens 102 or into the particle-optical objective lens 102 (beam tube extension). The beam tube arrangement 460 expands into vacuum chambers 350, 355 and 250 in the region of the particle source 301, in the region of the multi-beam generator 305, and in the region of the detector unit 207. At least in the region of the beam switch 400, the beam tube arrangement normally has a one-piece embodiment, i.e., it has neither weld points or weld seams nor solder points or solder seams. The beam tube arrangement contains copper in the shown example; however, it could also contain titanium or any other element or any other compound. Here, there is a high vacuum in the region of the beam tube arrangement 460 within the beam switch 400, preferably with a pressure of less than 10'5mbar, in particular less than 10'7mbar and / or 10-9mbar. A vacuum preferably in each case with pressures of less than 10'5mbar, in particular less than 10'7mbar and / or 10'9mbar, prevails in the chambers 350, 355 and 250 already mentioned.

[0081] In the example shown, the objective lens 102 has an upper pole shoe 108 and a lower pole shoe 109. A winding 110 for generating a magnetic field is situated between the two pole shoes 108 and 109. In this case, the upper pole shoe 108 and the lower pole shoe 109 can be electrically insulated from one another. In the example shown, the particle-optical objective lens 102 is a single magnetic lens in the form of an immersion lens; however, the objective lens or the objective lens system can also comprise further magnetic lenses or electrostatic lenses.A fast autofocus correction lens 824 can be integrated, in a plurality of configurations and at a plurality of positions, optionally together with further fast correctors, in the multi-beam particle microscope 1 shown in Fig. 2. Depending on the position, the fast autofocus correction lens 824 acts more or less strongly on the focus of the individual particle beams 3 in this case; however, it may also act on other particle-optical parameters such as the position, the landing angle and / or the rotation of the individual particle beams 3. Additionally, a second or an additional or a plurality of further autofocus correction lens(es) can be integrated in the primary path and / or in the secondary path; optionally, further fast correction means can be provided in the primary path and / or in the secondary path.

[0082] Fig. 3 schematically illustrates one embodiment of the invention with a two-part autofocus correction lens 824. Here, this fast autofocus correction lens 824 is arranged between the upper pole shoe 108 and the lower pole shoe 109 of the objective lens 102. Specifically, the two-part fast autofocus correction lens 824 is integrated in the beam tube extension 464. In the example shown, the beam tube extension 464 is at earth potential. The two parts 824a and 824b are each embodied as fast electrostatic lenses. By way of example, they can be arranged in interruptions in the beam tube extension 464 but can also be provided as tube lenses within the beam tube extension 464 in each case. In this respect, Fig. 3 is only a schematic illustration. In the example shown, the two parts 824a and 824b of the fast autofocus correction lens 824 fulfil different tasks: In the example shown, the first part 824a substantially serves to set the focus upon incidence on the object 7, consequently in the object plane, in high-frequency fashion. An electrostatic lens normally does not act on the azimuthal beam parameters of the individual particle beams 3 passing therethrough. However, if the electrostatic lens, in this case the lens 824a, is in the magnetic field - in this case within the magnetic objective lens 102 with its two pole shoes 108 and 109 - then the charged particles within the inhomogeneous magnetic field experience a change in velocity, which is why the azimuthal beam parameters can change within the lens field. The second part 824b of the fast autofocus correction lens 824 substantially serves to compensate this unwanted effect. In principle, the lens 824b also has a focusing effect on the individual particle beams 3 passing therethrough. However, a compensation of the azimuthal deviations can substantially be attained in the case of a different polarity of the two parts 824a and 824b. Here, it is not necessarily the case that the voltages applied to the two parts 824a and 824b are of equal magnitude but opposite sign, although this may be so. What needs to be taken into account here is that the magnetic field of the objective lens 102 is not homogeneous. Overall, the two parts 824a and 824b of the fast autofocus correction lens 901 are set such that the integral J B(z) / v(z) dz disappears upon passage through the object lens 102. This corresponds to the compensation of the unwanted azimuthaleffects but facilitates the adjustment of the focus in the case of a fast readjustment in the object plane 101.

[0083] The multiple particle beam system of which details are illustrated in Fig. 3 can be equipped with a contacting device according to the invention. This will be set out in greater detail below.

[0084] Fig. 4 first shows a three-dimensional illustration of a contacting device 900. The contacting device 900 has multiple parts and, in the exemplary embodiment shown, comprises a first contacting body 901 and a second contacting body 902. The contacting device 900 is illustrated in a disassembled state. In this way, details of the contacting device 900 can be illustrated more clearly. In an installation situation, the first contacting body 901 and the second contacting body 902 are brought closer together, but not so close that they touch, by a movement along the particle-optical axis Z of a multiple particle beam system (not illustrated). The first contacting body 901 is substantially hollow-cylindrical. It comprises a substantially encircling side wall 903. This side wall 903 has a first cutout 904, which in the example shown is designed in the form of a slit along the direction z of the particle-optical axis Z. The second contacting body 902 also has a substantially encircling side wall 905, which comprises a first projection 906. This first projection 906 extends along the direction z and thus in the same direction as the cutout 904 in the first contacting body 901. In this case, the first projection 906 is dimensioned such that it can be inserted or pushed into the cutout 904 of the first contacting body 901 without touching. The first projection 906 is then arranged within the first cutout 904.

[0085] The first contacting body 901 and the second contacting body 902 can then be externally electrically contacted at the same height with respect to the particle-optical axis Z in the assembled state. The first contacting body 901 can be contacted by means of a contacting element (not illustrated in Fig. 4) on the substantially encircling side wall 903. In the example shown, the side wall 903 has an opening 907 in which a contacting element can engage. This opening 907 is located close to the upper edge of the encircling side wall 903. An upper portion, which is made thicker in the example shown, of the first projection 906 of the second contacting body 902 is located at the same height in the assembled state. On the rear side, a depression (not illustrated) may also be made in this thickened portion in order to give a good contacting position to a contacting element for the external electrical contacting.

[0086] In the example shown, the first projection 906 is flush or in line with the encircling side wall 905 of the second contacting body 902. However, it would also be possible to provide the projection 906 to protrude. In the example illustrated in Fig. 4, it is furthermore such that the outer radius rA of the first contacting body 901 and the outer radius rA of the second contacting body 902match. In the assembled configuration of the multi-part contacting device 900, this has the advantage that a flush / in-line outer casing is formed over large regions of the first contacting body 901 and the second contacting body 902. This region can contain a common insulation body 912 for conjointly electrically insulating the first contacting body 901 and the second contacting body 902 (the common insulation body 912 is not illustrated in Fig. 4 for the sake of simplification).

[0087] In addition, in the example shown, the first contacting body 901 has a recess 920 in the circumferential direction, underneath which the substantially encircling side wall 905 of the second contacting body 902 can be arranged flush with the outside. This makes the common outer casing or the region with a common outer radius rA even larger.

[0088] In addition, in the example shown, the second contacting body 902 has a projection 923 in the circumferential direction. This can serve as a second stop 922 for a common insulation body 912.

[0089] Fig. 5 shows a schematic illustration, in a perspective sectional view, of a magnetic lens 910, for example an objective lens, comprising a contacting device 900. For better understanding, the first contacting body 901 and the second contacting body 902 are illustrated below in Fig.

[0090] 5 again as versions of reduced size of the illustrations according to Fig. 4.

[0091] Fig. 5 schematically indicates a magnetic lens 910, such as an objective lens 102. The example shown illustrates an upper pole shoe with a bore 919 (cf. also Fig. 6). The contacting device 900 is arranged within this bore 919. In the illustration according to Fig. 5, the plurality of individual charged particle beams 3 enters the device from above along the particle-optical axis Z. The individual charged particle beams are at least section-wise guided in a beam tube 460, which is evacuated. Coming from above, the individual charged particle beams first pass through a double deflector 500a, 500b for collective deflection of the individual charged first particle beams. Then, they pass through a first electrostatic lens 911 and a second electrostatic lens (not explicitly illustrated in Fig. 5). The first electrostatic lens 911 is contacted by means of the first contacting body 901: In the example shown, the electrostatic lens 911 is screwed in the first contacting body 901. It can also be seen that the first contacting body 901 and the second contacting body 902 are pushed one into the other annularly and without touching. An outer radius of the first contacting body 901 and an outer radius of the contacting body 902 match one another in large regions. In this region a common insulation body 912 is arranged for conjointly electrically insulating the first contacting body 901 and the second contacting body 902.In the example shown, the first contacting body 901 is externally electrically contacted by means of a contacting element 908 in the form of a rod. The second contacting body 902 is outwardly electrically contacted by means of a contacting element 909. In this context, outwardly means that the contacting takes place out of the vacuum to the outside. The contacting element 908 engages in the opening 907 of the first contacting body 901. In the example shown, the contacting element 909 engages in the widened upper region of the first projection 906 of the second contacting body 902. With reference to the particle-optical axis Z, the locations where this external electrical contacting takes place are at the same height. The contacting location is thus clearly above the position of the first electrostatic lens 911 and even further above a second electrostatic lens, which is to be arranged below the first electrostatic lens 911 (not illustrated in Fig. 5). Fig. 5 shows that lateral contacting by means of a contacting element 908 at the height of the first electrostatic lens 911 would simply not be possible, since the first electrostatic lens is arranged within the bore 919 in the pole shoe of the magnetic lens 910.

[0092] Fig. 5 also shows that the contacting body 900 according to the invention is compatible with already known contact connections of the double deflector 500a, 500b: This double deflector 500a, 500b is contacted in each case by a plurality of contacting elements, of which the five contacting elements 914, 915, 916, 917 and 918 can be seen in Fig. 5. Eight evenly distributed contacting elements overall are provided for each deflector unit 500a and 500b.

[0093] Fig. 6 shows a straight sectional illustration of the arrangement in Fig. 5, the section not passing through the cutout 904 in the first contacting body 901 or through the projection 906 of the second contacting body 902. Instead, in this respect the section is rotated about the Z axis by a few degrees. In this type of illustration, it is possible to clearly see the common insulation body 912, which goes around regions of the first contacting body 901 and the second contacting body 902 and provides a common electrical insulation means. The insulation body 912 has a first stop 921 for accurate positioning of the first contacting body 901 with respect to the direction z of the particle-optical axis Z of the multiple particle beam system 1. When the first contacting body 901 is being pushed into the insulation body 912, this first stop 921 can define the position of the first contacting body 901 in the z-direction. At the same time, the first contacting body 901 is prevented from accidentally touching a deflection plate or a multipole electrode of the deflector 500b. The gap between the first contacting body 901 and the scan deflector 500b is denoted in Fig. 6 by reference sign 925.As already set out in connection with Fig. 4, the second contacting body 902 has a projection 923 in the circumferential direction at the bottom, this projection bearing against a second stop 922 of the insulation body 912. As a result, the second contacting body 902 can be guided and positioned by means of the insulation body 912, and the first contacting body 901 and the second contacting body 902 are prevented from touching. Instead, this region has a gap, which is denoted in Fig. 6 by reference sign 924.

[0094] In the example shown in Fig. 6, the first electrostatic lens 911 is screwed to the first contacting body 901. In addition, the second electrostatic lens (not illustrated) is also screwed to the second contacting body 902. The screwing takes place, for example, in the bottom region of the contacting body 902.

[0095] Moreover, in this particular case, it is such that the first contacting body 901 goes all the way around the circumference of the first electrostatic lens 911. In the example shown, this does not apply to a second electrostatic lens which can be screwed onto the second contacting body 902 at the bottom.

[0096] As already mentioned, in the present example the contacting device 900 is also arranged within a bore 919 in a pole shoe of the magnetic lens 910. In the example shown, for the diameter d of the bore 919 the following relation applies: 20 mm < d < 30 mm. This dimension is therefore very small and there is little installation space in this region. Nevertheless, under these conditions, the electrostatic lens(s) 911 can be easily and elegantly contacted. In the example shown, the inside diameter di of the first electrostatic lens 911 is also smaller than the diameter d of the bore 919. The inside diameter di typically falls within the following range: 5 mm < di < 20 mm.

[0097] Lastly, the entire contacting device 900 is resistant to a high voltage and vacuum.

[0098] Fig. 7 again schematically shows a schematic sectional illustration of a contacting device 900: The first contacting body 901 and the second contacting body 902 are centred relative to one another and arranged one after the other with respect to the particle-optical beam path / the particle-optical axis Z. The first contacting body 901 and the second contacting body 902 are spaced apart, i.e. do not touch. The first projection 906 is arranged in a cutout 904 of the first contacting body 901. In this case, the width of the projection 906 is slightly smaller than the width b of the first cutout 904, and therefore the first projection 906 also does not touch the first contacting body 901. In the example shown, an in-line outer casing extends over the entire height, in the z-direction, of the contacting device 900, i.e. the outer radii rA are identical in theregion of the first contacting body 901 and the second contacting body 902. Therefore, a common insulation body 912 (not illustrated in Fig. 7) can be arranged all around the circumference of the first contacting body 901 and the second contacting body 902.

[0099] Fig. 8 schematically shows a contacting device 900 with three contacting bodies 901, 902, 926. These contacting bodies 901 , 902, 926 are centred in relation to one another and centred in relation to the particle-optical axis Z. They are also arranged one after another. In the case of three contacting bodies 901, 902, 926 overall, in the example shown a first cutout 906 and a second cutout 927 are provided in the first contacting body 901. In the example shown, both cutouts 906, 927 have the same width b, but different depths. A depth of the first cutout 904 is T1 ; a depth of the second cutout is T2. The first projection 906 of the second contacting body 902 is arranged in the first cutout 904, as in the example according to Fig. 7. Similarly, a second projection 927 is arranged in the second cutout 927 in the first contacting body 901. Since the cutout 904 in which the first projection 906 is arranged only has the depth T1, a further region of the first contacting body 901 can be seen at the bottom in the section illustrated in Fig. 8. A transition region between the region of the encircling side wall of the second contacting body 902 and the first projection 906 juts out in the example shown. Analogously, the transition region between the substantially encircling side wall of the third contacting body 926 and the second projection 927 juts out. These jutting-out portions ensure that the first projection 906 and the second projection 927 can be guided at a spacing past the respective other contacting bodies 901, or 901 and 902, respectively. In the example shown in Fig. 8, it is further such that an outer radius rA is constant over the entire length of the contacting device 900 in the z-direction. A common insulation body (not illustrated in Fig. 8) can thus in turn be arranged all the way around the contacting device 900.

[0100] Fig. 9 schematically shows a schematic sectional view of a further contacting device 900 with three contacting bodies 901 , 902, 926. By contrast to the exemplary embodiment illustrated in Fig. 8, the first contacting body 901 extends in the z-direction only as far as the second contacting body 902. A common outer radius rA therefore exists only in a shorter, upper region, i.e. around the first contacting body 901.

[0101] Fig. 10 schematically shows a further contacting device 900 with three contacting bodies 901 , 902 and 926. By contrast to the exemplary embodiment illustrated in Fig. 8, an intermediate region 928 in the form of a connecting piece is provided between the hollow-cylindrical region of the second contacting body 902 and the first projection 906. Analogously, an intermediate region 929 is arranged between the third contacting body 926 and the second projection 927. These intermediate regions 928 and 929 also correspond in principle to a jutting-out portion,as has been described in connection with Fig. 8. By contrast in the exemplary embodiment illustrated in Fig. 8, a cutout in the first contacting body 901 in Fig. 10 is not a complete cutout, i.e. the first contacting body 901 does not have any completely continuous cutouts or slots. The outer radius rA of the contacting device 900 is in turn identical over the entire region of the contacting device 900, and therefore in turn a common insulation body can be provided all the way around the multi-part contacting device 900 for common electrical insulation (not explicitly illustrated in Fig. 10).

[0102] Fig. 11 schematically shows a perspective illustration of further contacting devices 900. Specifically, Fig. 11a illustrates a contacting device 900 with a first contacting body 901. The first contacting body 901 substantially has a hollow-cylindrical shape and has a first cutout 904. A second contacting body 902 is also substantially hollow-cylindrical and comprises a substantially encircling side wall, which has a first projection 906 extending along the direction of the particle-optical axis Z. In turn, the first projection 906 is arranged within the first cutout 904, it holding true overall that the first contacting body 901 and the second contacting body 902 do not touch. Both contacting bodies 901, 902 can be externally electrically contacted in the upper region of the contacting device 900, the location of the external electrical contacting of the second contacting body 902 being in the upper region of the first projection 906.

[0103] In Fig. 11b, a third contacting body 926 is additionally provided. The third contacting body 926 is in turn substantially hollow-cylindrical and serves for contacting a third electrostatic lens (not illustrated in Fig. 11). The third contacting body 926 is arranged downstream of the second contacting body 902 with respect to the particle-optical beam path. In addition, the third contacting body 926 does not touch the first contacting body 901 and does not touch the second contacting body 902. The first contacting body 901 has a second cutout 930 in its substantially encircling side wall, the second cutout extending in turn along the direction parallel to the particle-optical axis Z of the device. For the sake of clarity, the particle-optical axis Z is not explicitly depicted in Fig. 11b. However, it runs centrally through the contacting device 900. The third contacting body 926 further has a substantially encircling side wall, which has a second projection 927 extending along the z-direction. In this case, the second projection 927 is arranged within the second cutout 930 without touching it and the third contacting body 926 can be externally electrically contacted on the second projection 927 or specifically on the upper region thereof. It is thus possible to contact the first contacting body 901, the second contacting body 902 and the third contacting body 926 in each case at the same height with respect to the particle-optical axis Z for the external electrical contacting.Fig. 12 expands on the contacting device 900 illustrated in Fig. 11 by one further contacting body or by two further contacting bodies: According to Fig. 12a, there is provided a substantially hollow-cylindrical fourth contacting body 933, on the substantially encircling side wall of which a third projection 932 is arranged. It is arranged in a third cutout 931 in the first contacting body 906 without touching. In Fig. 12b, there is further provided a substantially hollow-cylindrical fifth contacting body 936, which has a fourth projection 935 on its substantially encircling side wall. This projection is arranged in turn in a fourth cutout 934 in the first contacting body 901 without touching.

[0104] For all the embodiments illustrated in Fig. 11 and 12, it holds true that an outer radius rA is constant over the entire region in the z-direction of the contacting device 900. It is therefore possible to provide a common electrical insulation body all around this entire region.

[0105] Each of the contacting bodies 901, 902, 926, 933, 936 illustrated in Figures 11 and 12 can contact a respective electrostatic lens. For the sake of clarity, the electrostatic lenses are not illustrated in Figures 11 and 12. In any case, it is possible to establish the external electrical contact connections regardless of the exact position of the electrostatic lenses in the z-direction in each case in the upper region of the contacting device. It is possible that cutouts 904, 930, 931, 934 are arranged equidistantly in the first contacting body. However, this need not be the case.

[0106] According to a preferred embodiment of the invention, the multiple particle beam system furthermore comprises the following:

[0107] a double deflector 500a, 500b for collective deflection of the individual charged first particle beams 3 which is arranged within the objective lens 102; and / or

[0108] a beam trap arranged within the objective lens 102.

[0109] These features are already known per se from the prior art. It should now be emphasized that the multiple particle beam system 1 according to the invention can also be combined with these embodiment variants of a multiple particle beam system 1 and also works well given the resulting even smaller installation space available.

[0110] According to a preferred embodiment of the invention, the multiple particle beam system 1 further comprises a controller 10 configured to individually control the objective lens 102, the first electrostatic lens 824a and the second electrostatic lens 824b (cf. Fig. 3). Furthermore, the controller 10 is configured to statically adjust a focus stroke by means of the objective lens 102. In addition, a dynamic change in focus can be adjusted by means of the first electrostatic lens 824a and a dynamic telecentricity correction can be adjusted by means of the secondelectrostatic lens 824b, or vice versa. This means that one of the two electrostatic lenses 824a, 824b is used to dynamically change the focus and the other of the two electrostatic lenses is used to dynamically correct the telecentricity. A dynamic change in focus and / or dynamic telecentricity correction may be required and carried out in the course of a fast autofocus correction, as is described for example in DE 102021 105201 A1, the disclosure of which is fully incorporated by reference in the present patent application.

[0111] According to a preferred embodiment of the invention, the electrostatic lens 824a, 824b, 911 that is controlled for the dynamic change in focus has a length LF in the direction of the particle-optical axis Z for which the following relation applies: 5 mm < LF < 20 mm. In this case, the length specification relates to the component length.

[0112] According to a preferred embodiment of the invention, the electrostatic lens 824a, 824b, 911 that is controlled for the dynamic telecentricity correction has a length LT in the direction of the particle-optical axis Z for which the following relation applies: 5 mm < LT < 40 mm. In this case, the length specification relates to the component length.

[0113] According to a preferred embodiment of the invention, an application of voltage to the electrostatic lens 824a, 824b, 911 that is controlled for the dynamic change in focus can be varied by at least + / - 500 volts. The variation of + / - 500 volts can be effected by a mean value that differs from 0 V, for example by a mean value of 1000 V, 1500 V or 2000 V. The contacting device 900 according to the invention is capable of transmitting the required dynamic application of voltage.

[0114] According to a preferred embodiment of the invention, an application of voltage to the electrostatic lens 824a, 824b, 911 that is controlled for the dynamic telecentricity correction can be varied by at least + / - 200 V. This variation can in turn be effected by a mean value, which can also amount to 0 V, but it can also lie in the low-voltage range or in the high-voltage range.

[0115] According to a preferred embodiment of the invention, the multiple particle beam system 1 is designed in the form of a multi-beam particle microscope 1. However, it can also be designed differently, for example in the form of a multi-beam lithography system.

[0116] The above-described embodiments of the invention may be combined with one another in full or in part, provided that no technical contradictions arise as a result.The figures should not be construed as limiting for the invention but instead merely serve for better understanding of the invention.

[0117] The invention discloses a multiple particle beam system 1 comprising a multi-beam generator 305 for generating a plurality of individual charged first particle beams 3 and comprising a magnetic lens 910, 102, in particular an objective lens 102, through which the individual charged first particle beams 3 collectively pass. An electrostatic lens system 824a, 824b, 911 is arranged within the magnetic lens 910, 102. This electrostatic lens system 824a, 842b, 911 is electrically contacted by means of a specially shaped multi-part contacting device 900, which is also arranged inside the magnetic lens 910, 102.

[0118] List of reference signs

[0119] 1 Multiple particle beam system, multi-beam particle microscope

[0120] 3 Primary particle beams, first individual particle beams

[0121] 5 Beam spots, incidence locations

[0122] 7 Object, sample, wafer

[0123] 9 Secondary particle beams, second individual particle beams

[0124] 10 Computer system, controller

[0125] 15 Sample surface, wafer surface

[0126] 25 Image point of a second individual particle beam

[0127] 101 Object plane

[0128] 102 Objective lens

[0129] 103 Field lens

[0130] 105 Axis

[0131] 108 Upper pole shoe

[0132] 109 Lower pole shoe

[0133] 110 Winding

[0134] 111 Beam cross-over

[0135] 200 Detector system

[0136] 205 Projection lens system

[0137] 206 Projection lens

[0138] 207 Multi-particle detector

[0139] 208 Projection lens

[0140] 210 Projection lens

[0141] 212 Beam cross-over

[0142] 214 Aperture filter, contrast stopCollective anti-deflection system Vacuum chamber

[0143] Beam-generating apparatus

[0144] Particle source

[0145] Collimation lens system

[0146] Multi-aperture array, filter plate

[0147] Multi-beam generator

[0148] Multi-aperture plate, multi-aperture array Field lens, aperture plate

[0149] Field lens

[0150] Particle beam

[0151] Intermediate image plane

[0152] Beam foci

[0153] Vacuum chamber

[0154] Vacuum chamber

[0155] Beam switch, magnet arrangement Magnetic sector

[0156] Magnetic sector

[0157] Beam tube

[0158] Limb

[0159] Limb

[0160] Limb

[0161] Beam tube extension

[0162] Scan deflector

[0163] Displacement stage or positioning device Fast autofocus correction lens Contacting device

[0164] First contacting body

[0165] Second contacting body

[0166] Encircling side wall

[0167] First cutout

[0168] Encircling side wall

[0169] First projection

[0170] Opening

[0171] Contacting element

[0172] Contacting element

[0173] Flange11 First electrostatic lens

[0174] 12 Insulation body

[0175] 13 Second electrostatic lens 914 Contacting element

[0176] 915 Contacting element

[0177] 916 Contacting element

[0178] 917 Contacting element

[0179] 918 Contacting element

[0180] 919 Bore

[0181] 920 Recess

[0182] 921 First stop

[0183] 922 Second stop

[0184] 923 Projection

[0185] 924 Gap

[0186] 925 Gap

[0187] 926 Third contacting body 927 Second projection

[0188] 928 Intermediate region

[0189] 929 Intermediate region

[0190] 930 Second cutout

[0191] 931 Third cutout

[0192] 932 Third projection

[0193] 933 Fourth contacting body 934 Fourth cutout

[0194] 935 Fourth projection

[0195] 936 Fifth contacting body

[0196] x Direction

[0197] y Direction

[0198] z Direction

[0199] Z Particle-optical axis

[0200] T1 Depth of the first cutout T2 Depth of the second cutout b Width of cutouts

[0201] rA Outer radius

[0202] di Lens inside diameter

[0203] d Bore diameter

Claims

Claims1. Multiple particle beam system, comprising the following:a multi-beam generator for generating a plurality of individual charged first particle beams;a magnetic lens, in particular an objective lens, through which the individual charged first particle beams collectively pass,an electrostatic lens system, in particular a ring electrode system, which is arranged within the magnetic lens and comprises a first electrostatic lens and a second electrostatic lens which can be controlled individually and are centred in relation to one another and arranged one after the other with respect to the particle-optical beam path in such a way that the individual charged first particle beams collectively pass through them one after the other; anda multi-part contacting device for electrically contacting the electrostatic lens system, the contacting device also being arranged within the magnetic lens,wherein the contacting device has a substantially hollow-cylindrical first contacting body for contacting the first electrostatic lens,wherein the contacting device has a substantially hollow-cylindrical second contacting body for contacting the second electrostatic lens,wherein the first contacting body and the second contacting body are arranged one after the other with respect to the particle-optical beam path,wherein the first contacting body and the second contacting body do not touch one another,wherein the first contacting body has a substantially encircling side wall which has a first cutout extending along a direction parallel to the particle-optical axis of the multiple particle beam system,wherein the second contacting body has a substantially encircling side wall which has a first projection extending along a direction parallel to the particle-optical axis of the multiple particle beam system,wherein the first projection is arranged within the first cutout and the second contacting body is externally electrically contacted on the first projection.

2. Multiple particle beam system according to the preceding claim,wherein the first contacting body and the second contacting body are externally electrically contacted at the same height with respect to the direction parallel to the particle-optical axis.

3. Multiple particle beam system according to either of the preceding claims, wherein an outer radius of the first contacting body and an outer radius of the second contacting body match at least in the region of the first cutout and first projection.

4. Multiple particle beam system according to the preceding claim,wherein a common insulation body for conjointly electrically insulating the first contacting body and the second contacting body is arranged at least in the region in which the outer radius of the first contacting body and the outer radius of the second contacting body match.

5. Multiple particle beam system according to one of the preceding claims, wherein the first contacting body and the second contacting body are pushed one in the other annularly and without touching.

6. Multiple particle beam system according to the preceding claim,wherein the first contacting body has a recess in the circumferential direction, underneath which the substantially encircling side wall of the second contacting body is arranged flush with the outside.

7. Multiple particle beam system according to one of Claims 4 to 6,wherein the insulation body has a first stop for positioning the first contacting body with respect to the direction of the particle-optical axis of the multiple particle beam system, and / orwherein the insulation body has a second stop for positioning the second contacting body with respect to the direction of the particle-optical axis of the multiple particle beam system.

8. Multiple particle beam system according to one of Claims 4 to 7,wherein the encircling side wall of the first contacting body bears against the first stop of the insulation body; and / orwherein the second contacting body has a projection in the circumferential direction, which bears against the second stop of the insulation body.

9. Multiple particle beam system according to one of the preceding claims, wherein the first electrostatic lens is screwed to the first contacting body; and / or wherein the second electrostatic lens is screwed to the second contacting body.

10. Multiple particle beam system according to the preceding claim,wherein the first electrostatic lens is screwed in the first contacting body, and wherein the first contacting body surrounds the first electrostatic lens around the full circumference.

11. Multiple particle beam system according to one of the preceding claims,which further comprises an evacuable beam tube in which the individual charged first particle beams are at least section-wise guided,wherein the second electrostatic lens is realized by a beam-tube section of the beam tube that protrudes into the magnetic lens.

12. Multiple particle beam system according to one of the preceding claims, wherein the contacting device is arranged within a bore in a pole shoe of the magnetic lens.

13. Multiple particle beam system according to the preceding claim,wherein, for a diameter d of a bore, the following relation applies:20 mm < d < 30 mm.

14. Multiple particle beam system according to one of the preceding claims, wherein, for an inside diameter di of the first electrostatic lens and / or of the second electrostatic lens, the following relation applies:5 mm < di < 20 mm.

15. Multiple particle beam system according to one of the preceding claims, wherein the contacting device is resistant to a high voltage and / or vacuum.

16. Multiple particle beam system according to one of the preceding claims, wherein the electrostatic lens system comprises a third electrostatic lens which can be controlled individually and is centred in relation to the particle-optical axis,wherein the contacting device has a substantially hollow-cylindrical third contacting body for contacting the third electrostatic lens,wherein the third contacting body is arranged downstream of the second contacting body with respect to the particle-optical beam path,wherein the third contacting body does not touch the first contacting body and does not touch the second contacting body,wherein the first contacting body has a second cutout in the substantially encirclingside wall, the second cutout extending along the direction parallel to the particle-optical axis of the multiple particle beam system,wherein the third contacting body has a substantially encircling side wall which has a second projection extending along the direction parallel to the particle-optical axis, wherein the second projection is arranged within the second cutout and the third contacting body is externally electrically contacted on the second projection.

17. Multiple particle beam system according to the preceding claim,wherein the first contacting body and the third contacting body are externally electrically contacted at the same height with respect to the direction parallel to the particle-optical axis.

18. Multiple particle beam system according to one of Claims 16 to 17,wherein an outer radius of the first contacting body and an outer radius of the third contacting body match at least in the region of the second cutout and second projection.

19. Multiple particle beam system according to the preceding claim,wherein a / the common insulation body for conjointly electrically insulating the first contacting body and the third contacting body is arranged at least in the region in which the outer radius of the first contacting body and the outer radius of the third contacting body match.

20. Multiple particle beam system according to the preceding claim,wherein the electrostatic lens system comprises a fourth electrostatic lens which can be controlled individually and is centred in relation to the particle-optical axis,wherein the contacting device has a substantially hollow-cylindrical fourth contacting body for contacting the fourth electrostatic lens,wherein the fourth contacting body is arranged downstream of the third contacting body with respect to the particle-optical beam path,wherein the fourth contacting body does not touch the first contacting body, does not touch the second contacting body and does not touch the third contacting body, wherein the first contacting body has a third cutout in the substantially encircling side wall, the third cutout extending along the direction parallel to the particle-optical axis, wherein the fourth contacting body has a substantially encircling side wall which has a third projection extending along the direction parallel to the particle-optical axis, wherein the third projection is arranged within the third cutout and the fourth contacting body is externally electrically contacted on the third projection.

21. Multiple particle beam system according to the preceding claim,wherein the electrostatic lens system comprises a fifth or further electrostatic lens, andwherein the contacting device comprises a fifth or further contacting body.

22. Multiple particle beam system according to one of the preceding claims, wherein the first contacting body has a plurality of cutouts for receiving projections, wherein the cutouts extend to different extents, and thus have different depths, in the direction parallel to the particle-optical axis.

23. Multiple particle beam system according to one of the preceding claims, wherein the magnetic lens is an objective lens.

24. Multiple particle beam system according to the preceding claim, further comprising the following:a double deflector for collective deflection of the individual charged first particle beams which is arranged within the objective lens; and / ora beam trap arranged within the objective lens.

25. Multiple particle beam system according to one of Claims 23 to 24,further comprising a controller configured to individually control the objective lens, the first electrostatic lens and the second electrostatic lens,wherein the controller is further configuredto statically adjust a focus stroke by means of the objective lens, and to adjust a dynamic change in focus by means of the first electrostatic lens and a dynamic telecentricity correction by means of the second electrostatic lens, or to adjust a dynamic telecentricity correction by means of the first electrostatic lens and a dynamic change in focus by means of the second electrostatic lens.

26. Multiple particle beam system according to Claim 25,wherein the electrostatic lens that is controlled for the dynamic change in focus has a length LF in the direction of the particle-optical axis Z for which the following relation applies:5 mm < LF < 20 mm.

27. Multiple particle beam system according to one of Claims 25 to 26,wherein the electrostatic lens that is controlled for the dynamic telecentricitycorrection has a length LT in the direction of the particle-optical axis Z for which the following relation applies:5 mm < LT < 40 mm.

28. Multiple particle beam system according to one of Claims 25 to 27,wherein an application of voltage to the electrostatic lens that is controlled for the dynamic change in focus can be varied by at least + / - 500 V.

29. Multiple particle beam system according to one of Claims 25 to 28,wherein an application of voltage to the electrostatic lens that is controlled for the dynamic telecentricity correction can be varied by at least + / - 250 V.

30. Multiple particle beam system according to one of the preceding claims, wherein the multiple particle beam system is in the form of a multi-beam particle microscope.

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