Multi-aperture array consisting of a plurality of functional units, multiple-particle beam system having the multi-aperture array, and method for producing the multi-aperture array

Abstract

The invention relates to a multi-aperture array for manipulating a plurality of charged first individual particle beams having the following: a main body having a plurality N of apertures, wherein, during operation of the multi-aperture array, one of the charged first individual particle beams passes through each aperture; at least a plurality of first electrodes embedded in the main body, wherein one of the first electrodes is arranged at each of the apertures to individually influence the first individual particle beam passing through the aperture, and wherein each of the first electrodes is or can be connected to a control unit, wherein the multi-aperture array is composed of a plurality M of functional units and wherein each functional unit comprises a part of the main body and the subset of the apertures associated with this part of the main body with the electrodes arranged thereon.

Description

[0001] Multi-aperture array consisting of several functional units, multi-particle beam system with the multi-aperture array and method for fabricating the multi-aperture array

[0002] Field of invention

[0003] The invention relates generally to multi-particle beam systems and in particular to multi-beam particle microscopes that operate with a multitude of charged single-particle beams. Specifically, the invention relates to a multi-aperture array comprising several functional units, to a multi-particle beam system comprising the multi-aperture array, and to a method for fabricating the multi-aperture array.

[0004] State of the art

[0005] With the continuous development of increasingly smaller and more complex microstructures, such as semiconductor devices, there is a need for the further development and optimization of planar fabrication techniques and inspection systems for the production and inspection of these small microstructures. The development and fabrication of semiconductor devices, for example, requires verification of test wafer designs, and planar fabrication techniques necessitate process optimization for reliable, high-throughput manufacturing. Furthermore, the analysis of semiconductor wafers for reverse engineering and the customized configuration of semiconductor devices is increasingly required. Therefore, there is a need for inspection tools that can be used with high throughput to examine microstructures on wafers with high accuracy.

[0006] Typical silicon wafers used in the production of semiconductor devices have diameters of up to 300 mm. Each wafer is divided into at least 30 to 60 repeating regions ("dies") with a size of up to 800 mm. 2A semiconductor device comprises multiple semiconductor structures fabricated in layers on a wafer surface using planar integration techniques. Due to the fabrication processes, semiconductor wafers typically have a flat surface. The feature size of the integrated semiconductor structures ranges from a few millimeters to critical dimensions (CDs) of a few nanometers, with feature sizes expected to become even smaller in the near future. It is anticipated that future feature sizes, or critical dimensions (CDs), will correspond to the 3 nm, 2 nm, or even smaller technology nodes of the International Technology Roadmap for Semiconductors (ITRS). At these small feature sizes, defects of critical dimension size must be identified quickly across a very large area.For several applications, the specification requirement for the accuracy of a measurement provided by an inspection instrument is even higher, for example by a factor of two or an order of magnitude. For example, the width of a semiconductor feature must be measured with sub-1 nm accuracy, such as 0.3 nm or even less, and the relative position of semiconductor structures must be determined with a sub-1 nm superposition accuracy, such as 0.3 nm or even less.

[0007] A more recent development in the field of charged particle microscopes (CPM) is the MSEM, a multi-beam scanning electron microscope. A multi-beam scanning electron microscope is disclosed, for example, in US 7,244,949 B2 and US 2019 / 0355544 A1. In a multi-beam electron microscope, or MSEM, a sample is simultaneously irradiated with a multitude of single-electron beams arranged in a field or grid. For example, 4 to 10,000 single-electron beams can be provided as primary radiation, with each single-electron beam separated from an adjacent single-electron beam by a distance of 1 to 200 micrometers. For example, an MSEM has approximately 100 separate single-electron beams (beamlets) arranged, for example, in a hexagonal grid, with the single-electron beams separated by a distance of approximately 2 to 50 pm.A multitude of charged single-particle beams (primary beams) are typically focused by a common objective lens onto the surface of a sample under investigation. The sample can be, for example, a semiconductor wafer mounted on a wafer holder, which is itself mounted on a movable stage. During illumination of the wafer surface with the charged primary single-particle beams, interaction products, such as secondary electrons or backscattered electrons, are emitted from the wafer surface. Their starting points correspond to the locations on the sample onto which the multitude of primary single-particle beams are focused. The quantity and energy of the interaction products depend on the material composition and the topography of the wafer surface.The interaction products form several secondary single-particle beams (secondary beams), which are collected by the common objective lens and directed by a projection imaging system of the multi-beam inspection system onto a detector located in a detection plane. The detector comprises several detection areas, each containing several detection pixels, and the detector records an intensity distribution for each of the secondary single-particle beams. This results in an image field of, for example, 100 pm x 100 pm.

[0008] The prior art multi-beam electron microscope comprises a series of electrostatic and magnetic elements. At least some of the electrostatic and magnetic elements are adjustable to adapt the focus position and stigmatization of the multiple charged single-particle beams. The prior art multi-beam charged particle system also includes at least one intersection plane of the primary or secondary charged single-particle beams. Furthermore, the prior art system includes detection systems to facilitate adjustment. The prior art multi-beam particle microscope includes at least one deflection scanner for collectively scanning an area of ​​the sample surface using the multiple primary single-particle beams to obtain an image field of the sample surface.

[0009] To separate the particle-optical beam path of the primary beams from the particle-optical beam path of the secondary beams, a so-called beam splitter (also called a "beam separator" or "beam divider") is used. This separation is achieved by means of special arrangements of magnetic fields and / or electrostatic fields, for example, using a Wien filter.

[0010] Multi-particle beam systems are generally divided into those operating with a single column and those operating with multiple columns. In single-column systems, the individual particle beams pass at least partially through the same particle optics or through one or more global particle lenses. Furthermore, in a single column, the individual particle beams are relatively close to one another. Despite the partially global particle optics elements, even single-column systems require individual control and / or shaping of the individual particle beams to correct imaging errors such as field curvature, field astigmatism, and other aberrations. A so-called micro-optics system can be used for this individual control and / or shaping of the individual particle beams.Micro-optics is often also referred to as a multi-beam particle generator for generating and shaping a multitude of individual particle beams. The multi-beam particle generator, or micro-optics, comprises a sequence of several multi-aperture plates that can be used for active beam shaping, or at least one of which can be used for active beam shaping. For this purpose, electrodes can be provided in the aperture area, which can be controlled collectively or individually. These can be, for example, ring electrodes or multipole electrodes. According to another example, a multi-aperture plate can be monolithic, with a voltage applied to the entire plate; that is, the monolithic multi-aperture plate is then at a specific potential, so that its apertures, in conjunction with other particle-optical elements, can create a lensing effect.Other configurations of a multi-aperture plate for active beam shaping are also possible.

[0011] For optimal single-particle beam shaping / control, it is essential that the apertures through which a single-particle beam passes are precisely aligned. For example, the centers of the apertures may need to be perfectly aligned. Furthermore, the apertures in known multi-aperture plates are relatively small; for instance, aperture diameters are often less than 100 pm, sometimes only 90 pm or less. These two conditions—small aperture diameters and precise alignment of the apertures / electrodes, including control—can be met by applying MEMS techniques to fabricate micro-optics. In other words, the fabrication of micro-optics and their multi-aperture plates utilizes processes similar to those used in semiconductor manufacturing.

[0012] The diverse functions of semiconductor devices are made possible by combining areas with different doping concentrations or by the influence of insulating layers. To meet these requirements, semiconductor devices are manufactured by depositing various layers sequentially onto a wafer-shaped substrate (planar technology). A semiconductor material, usually silicon, is used as the substrate, while silicon dioxide, for example, serves as the insulating layer. The deposited layers can then be structured using lithographic processes. This allows for the production of integrated circuits with conductive traces, i.e., semiconductor chips, or micro-optics with multi-aperture plates or arrays for multi-particle beam systems.

[0013] Individual manipulation of charged single-particle beams passing through the apertures of a multi-aperture plate requires a large number of electrodes that must be correctly positioned within the semiconductor material and electrically insulated from it. Furthermore, numerous conductive traces are needed to apply voltage to the electrodes located at each aperture. The number of these traces can be very large, and several may be required per aperture. This applies, for example, to the so-called multistigmator of a micro-optic, which has a multipole electrode, such as an octupole electrode, at each aperture. In this case, eight conductive traces per aperture are required. If the number of single-particle beams in a multi-beam particle beam system is increased, more than 1000 conductive traces are quickly required for a multi-aperture array.Each of these conductor tracks must also be carefully positioned in the semiconductor material, for example silicon, and electrically insulated from the semiconductor material, which is why the production of multi-aperture arrays for multi-beam particle beam systems is very complex, requiring many process steps and a lot of experience.

[0014] In multi-beam particle beam systems, such as multi-beam particle microscopes or lithography systems, it is a system requirement that each individual particle beam can be shaped and manipulated equally perfectly using a multi-aperture array. Only if this is the case for all individual particle beams is a multi-aperture array usable. Otherwise, the entire multi-aperture array is unusable, which occurs relatively frequently given the ever-increasing performance demands placed on multi-aperture arrays. This waste results in very high costs and hinders the sustainable production of multi-aperture arrays. The problem of waste becomes increasingly serious the more apertures a multi-aperture array has, or the more individual particle beams a multi-particle beam system uses.

[0015] Description of the invention

[0016] It is therefore an object of the present invention to provide a multi-aperture array for a multiple particle beam system that is simpler to manufacture and produces less waste. This is intended to apply in particular to a multiple particle beam system that operates with a large number of individual particle beams, for example with more than 100 individual particle beams, or even more than 300 individual particle beams or more than 1000 individual particle beams.

[0017] The problem is solved by the subject matter of independent claim 1. Advantageous embodiments of the invention are evident from the dependent claims.

[0018] The present patent application claims priority from German patent application No. 10 2024 128 159.6 dated September 27, 2024, the disclosure of which is incorporated in its entirety by reference into the present patent application. A fundamental concept of the invention is to reduce the scrap rate and thus the overall costs in the production of a multi-aperture array by assembling the array from several functional units with electrodes for single-beam manipulation. These functional units, due to their smaller size and / or their smaller number of electrodes and conductor tracks, can be manufactured with a higher probability of being defect-free and can also be tested before the multi-aperture array is assembled. Surprisingly, however, it is not automatically the case that the smallest possible functional units are automatically the most advantageous.

[0019] The assembly of a multi-aperture array from several functional units is made possible by the continuously improving manufacturing techniques for semiconductor chips: For example, advanced packaging techniques are used in the production and assembly of so-called "subchips." These manufacturing techniques can also be used for the production of multi-aperture arrays.

[0020] According to a first aspect of the invention, this relates to a multi-aperture array for manipulating a plurality N of charged first single-particle beams, comprising: a base body with a plurality K of apertures, wherein, in operation of the multi-aperture array, one of the charged first single-particle beams passes through an aperture at a time; at least a plurality of first electrodes embedded in the base body, wherein one of the first electrodes is arranged at each of the apertures in order to individually influence the first single-particle beam passing through the aperture; and wherein each of the first electrodes is connectable to or connected to a control unit.wherein the multi-aperture array is composed of a plurality f of functional units and wherein each functional unit comprises a part of the base body and the subset of apertures with the electrodes arranged thereon belonging to that part of the base body.

[0021] According to the invention, the base body of the multi-aperture array is therefore multi-part, and the number of its parts corresponds to the number f of functional units. The electrodes embedded in the base body or in its respective parts are distributed accordingly among the f functional units and are components of the functional units. The charged first single-particle beams can be, for example, electron beams, ion beams, muon beams, or other charged particle beams. The base body of the multi-aperture array has a plurality of apertures, and during operation of the multi-aperture array, one of the charged first particle beams passes through an aperture or apertures assigned to it. The number of apertures is matched to the number of charged first single-particle beams.The term "array" indicates that the multitude of apertures are arranged relative to each other in a fixed grid. The apertures can be arranged, for example, in a rectangular or hexagonal grid. Preferably, the apertures are arranged in a hexagonal grid, and the total number K of apertures corresponds to the number N of the charged first single-particle beams or an integer multiple of N, where the number of particle beams is 3N (N - 1) + 1, and where N and K are both natural numbers.

[0022] The concept of a functional unit is central to the present invention. According to the invention, the base body of the multi-aperture array is multi-part, meaning it is physically multi-part. The base body is therefore composed not only of several conceptual parts, but also of several real parts. These real parts each have a function or active effect on single-particle beams that pass through an aperture. In other words, the real parts each comprise at least one aperture and at least one electrode that is associated with or surrounds the aperture. In the context of the present invention, a functional unit corresponds in principle to a so-called "subchip" in known semiconductor manufacturing.The methods known from semiconductor manufacturing for the production and arrangement of subchips also correspond in principle to the methods that can be used for the production and arrangement of functional units relative to each other as well as for the arrangement of the functional units on a carrier element.

[0023] Preferably, a functional unit comprises more than one aperture and, accordingly, more than one electrode or more than one multipole electrode. It is highly preferred that a functional unit has significantly more than just a few apertures and associated electrodes, e.g., approximately 100 apertures and associated electrodes or multipole electrodes. The concept of functional units for a multi-aperture array only unfolds its strength for reducing rejects with a large number of apertures or a large number of single-particle beams of a multi-particle beam system, for example, with N > 169, N > 300, or N > 1000. According to a preferred embodiment of the invention, the functional units are arranged laterally to one another. The functional units are then arranged in the same plane. A lateral arrangement of the functional units can be in one direction x or in two directions x and y.The specific arrangement of the functional units depends in practice on the size of the functional units, that is, on the number of apertures with their respective associated electrodes per functional unit. Generally speaking, it is preferred that the number of apertures with their respective associated electrodes of different functional units is preferably identical or at least approximately identical (for example, in the case of an odd total number of apertures in a multi-aperture array).

[0024] According to a preferred embodiment of the invention, the functional units are arranged vertically relative to one another. The functional units are thus arranged one above the other, or stacked, along the propagation direction of charged single-particle beams that penetrate the multi-aperture array during operation. The stacking of functional units, or the stacking of "subchips," is also known in principle from semiconductor manufacturing. In principle, several subchips are assembled to form a three-dimensional overall chip.

[0025] According to a preferred embodiment of the invention, the functional units are arranged both laterally and vertically relative to each other. They thus form at least a first layer of functional units and a second layer of functional units. Of course, more than two layers of functional units, for example three or four layers, can also be provided. In this way, it is possible to produce even complex multi-aperture arrays with a relatively low reject rate.

[0026] The total number K of correctors can correspond to the number N of charged particle beams that pass through the multi-aperture array during operation. This is the case when the multi-aperture array is single-layered. In the multi-layered case, a single particle beam can pass through several correctors sequentially; then K > N, where K is an integer multiple of N.

[0027] According to a preferred embodiment of the invention, the functional units of a layer of functional units are essentially identical in operation. Thus, any intended correction of individual particle beam properties in the respective layer is identical. For example, it is possible that all functional units of a layer correct a focus position, or that all functional units of a layer adjust a stigmatization, or that all functional units of a layer perform a deflection. A layer of functional units therefore essentially assumes the function of a single multi-aperture plate according to the prior art with its correctors arranged therein. However, in the operation of a particle-optical arrangement, the functional units of a layer are only essentially identical: Normally, each individual particle beam must be corrected individually.

[0028] According to a preferred embodiment of the invention, the number of functional units in the first layer and the number of functional units in the second layer are identical. This is advantageous, for example, if the complexity of the functional units in the first layer and in the second layer is also the same, and thus a comparable reject rate exists in both layers during the production of the functional units.

[0029] According to an alternative embodiment of the invention, the number of functional units in the first layer differs from the number of functional units in the second layer. This is advantageous, for example, when correctors for the single-particle beams are arranged in the different layers and differ significantly in complexity. For instance, a layer of functional units, each having apertures with ring electrodes arranged thereon, is easier to manufacture than a layer of functional units, each having a plurality of apertures with multipole electrodes, such as octupole electrodes, arranged thereon.

[0030] According to a preferred embodiment of the invention, conductors for the second layer of functional units are routed through the first layer of functional units. For this purpose, at least some of the functional units can then have at least one bond pad on both their upper and lower surfaces.

[0031] According to a further preferred embodiment of the invention, each functional unit has at least one bond pad. A bond pad is understood to be a small, conductive metal surface on the part of the base body of the multi-aperture array belonging to the functional unit, which serves as a contact point for electrical connections. The connection is made on the one hand with the electrodes of the respective functional unit and on the other hand with an associated contact pad outside the multi-aperture array in the narrower sense, for example, with a contact pad on a support element of the multi-aperture array or a support element for the multi-aperture array. According to a preferred embodiment of the invention, the multi-aperture array has a support element. At least some functional units are arranged on the support element and connected to the support element.It is therefore also possible that a functional unit is only indirectly connected to the carrier element, for example by means of another functional unit. Functional units on the carrier element can be connected, for example, by gluing or bonding.

[0032] According to a preferred embodiment of the invention, the support element has wiring and / or a mounting structure for attaching the functional units. The support element preferably does not include electrodes for influencing the individual particle beams. The support element is thus a significantly differently structured element compared to a functional unit. Furthermore, the support element is not a component of the multi-aperture array in the narrower sense. The multi-aperture array in the narrower sense and the support element together form a particle-optical arrangement.

[0033] According to a preferred embodiment of the invention, the support element is designed as a frame. In this embodiment, the support element is essentially provided in outer regions of the base body with the plurality N of apertures. However, it is also possible for the frame to be provided additionally at points or in sections on the inside, for example to form a support point or a supporting region for the multi-aperture array in the narrower sense. For this purpose, a web can be formed, for example.

[0034] Additionally or alternatively, the support element can also be designed in multiple parts.

[0035] According to a preferred embodiment of the invention, an interposer is arranged between the base body and the support element. An interposer is understood to be an intermediate layer between the base body and the support element, which allows electrical connections to be established between the various functional units and the support element. An interposer enables a high connection density and efficient signal transmission and is known from semiconductor manufacturing, particularly in connection with 2.5D techniques. Silicon interposers are frequently used in the latter, where, for example, through-silicon vias (TSVs) are established.

[0036] According to a preferred embodiment of the invention, the material of the support element comprises or consists of silicon. However, it is also possible to use a different material, and in particular a different semiconductor material, for the support element.

[0037] According to a preferred embodiment of the invention, the first electrodes are designed as ring electrodes. In this case, a ring electrode is arranged at each of the apertures. Only one conductor track assigned to this respective ring electrode is then required in the respective functional unit to electrically contact or control the ring electrode.

[0038] The present invention is particularly advantageous when not just one electrode (i.e., a first electrode) is provided at each aperture, but rather several electrodes are provided at each aperture. This is the case, for example, when multipole electrodes are used. According to a preferred embodiment of the invention, the multi-aperture array further comprises a plurality of second and / or additional electrodes, with each of the second and / or additional electrodes being arranged at one of the apertures to individually influence the first single-particle beam passing through the aperture. Each of the second and / or additional electrodes can be connected to, or is connected to, a control unit. This can be the same control unit to which the first plurality of electrodes is connected, but it need not be.According to this embodiment of the invention, the multi-aperture array is more complex overall and therefore more difficult to manufacture without defects. This increases the reject rate. Therefore, in a multi-aperture array with a second or further plurality of electrodes, it is particularly advantageous to subdivide the multi-aperture array into several functional units.

[0039] According to a preferred embodiment of the invention, a deflection unit is provided in each of the apertures which are arranged in the same position by means of the electrodes associated with it.

[0040] According to a preferred embodiment of the invention, a stigmatization unit is provided in each of the apertures arranged in the same position by means of its associated electrodes. For example, it is possible to provide a quadrupole electrode or an octupole electrode with a total of eight electrodes at each aperture of the position. The greater the number of electrodes per aperture, the more significant the advantages of the multi-aperture array according to the invention with a plurality of functional units become in terms of reject reduction. According to a preferred embodiment of the invention, the base body consists of a semiconductor material, in particular silicon. Accordingly, in this embodiment, the functional units or "subchips" are based on a semiconductor material, and in particular on silicon.

[0041] According to an alternative embodiment of the invention, the base body consists of glass. Accordingly, in this embodiment, the functional units or “subchips” are based on glass, and in particular on silicate glass, borate glass, or borosilicate glass.

[0042] The embodiments described above according to the first aspect of the invention can be combined wholly or partially, provided that this does not result in any technical contradictions.

[0043] According to a second aspect of the invention, it relates to a multiple particle beam system with at least one multi-aperture array, as described above in several embodiments. It is possible to align several multi-aperture arrays with one another and to successively arrange them such that the charged first single-particle beams successively penetrate the multiple multi-aperture arrays and manipulate or influence the single-particle beams through the multi-aperture arrays.

[0044] According to a preferred embodiment of the invention, the plurality-

[0045] Particle beam system, a multi-beam particle microscope.

[0046] According to an alternative embodiment of the invention, the multiple-

[0047] A particle beam system is a lithography system.

[0048] Of course, the multi-particle beam system can also be configured differently.

[0049] According to a second aspect of the invention, it relates to a method for producing a multi-aperture array, as described above in various embodiments, comprising the following steps:

[0050] (a) Determining a total number K of correctors of the multi-aperture array;

[0051] (b) Determining a defect-free rate or yield Y in the production of a single corrector;

[0052] (c) For a plurality f = 1..F with F < K of functional units from which the multi-aperture array is composed, perform the following: (c1) Determine a number A_f of functional units required to produce exactly one fault-free functional unit, based on the fault-free rate according to step (b), and

[0053] (c2) Determine a number G_f of functional units required to assemble a properly functioning multi-aperture array from the properly functioning functional units, based on the number A_f according to step (c1);

[0054] (d) Determine an optimal number G_opt of functional units for the error-free assembled multi-aperture array based on the values ​​for the number G_f of functional units determined in step (c2);

[0055] (e) Manufacturing functional units for the multi-aperture array to be assembled based on the determined optimal number G_opt and testing each of the manufactured functional units with regard to their error-free function;

[0056] (f) Constructing the multi-aperture array, wherein the multi-aperture array is composed of the optimal number G_opt of functional units, wherein the functional units have been tested as error-free in step (e).

[0057] The total number K of correctors can correspond to the number N of charged particle beams that pass through the multi-aperture array during operation. This is the case when the multi-aperture array is single-layered. In the multi-layered case, a single particle beam can pass through several correctors sequentially; then K > N, where K is an integer multiple of N. K, N, f, and F are natural numbers.

[0058] The functional units are tested for error-free operation before being assembled into the multi-aperture array. This testing can be carried out in various ways, for example, in a special test setup.

[0059] According to a preferred embodiment of the invention, the optimal number G_opt is the minimum number G_f of functional units according to step (d). This embodiment is based on the understanding that while the manufacturing costs of a single functional unit depend on the number of apertures with the electrodes arranged therein, this is not the sole determining factor. Instead, the manufacturing costs of a single functional unit depend significantly on the costs of the entire MEMS manufacturing process. To the zeroth order, the costs are therefore proportional to the number of functional units per multi-aperture array. In this respect, it is advantageous, both for cost reasons and, consequently, for resource conservation, to select the minimum number G_f of functional units for the fabrication of the multi-aperture array.The embodiments and aspects of the invention described above can be combined in whole or in part, provided that no technical contradictions result.

[0060] The invention will be better understood with the help of the attached figures. These show:

[0061] Fig. 1: schematically shows a multi-beam particle beam system;

[0062] Fig. 2: shows schematically the structure of a micro-optics;

[0063] Fig. 3: shows a schematic top view of a multi-aperture array;

[0064] Fig. 4: schematically shows a section of a multi-aperture array in a

[0065] Sectional view, where the base body consists of a semiconductor material;

[0066] Fig. 5: schematically shows a multi-aperture array according to the invention with several

[0067] Functional units;

[0068] Fig. 6: schematically shows multi-aperture arrays according to the invention, each with several

[0069] Functional units;

[0070] Fig. 7: schematically shows a multi-aperture array according to the invention with laterally and vertically arranged functional units;

[0071] Fig. 8: schematically shows several multi-aperture arrays according to the invention;

[0072] Fig. 9: schematically shows a top view of a multi-aperture device according to the invention.

[0073] Array;

[0074] Fig. 10: schematically shows a top view of a multi-aperture device according to the invention.

[0075] Array;

[0076] Fig. 11: shows tables for determining an optimal number of functional units for a multi-aperture array according to the invention;

[0077] Fig. 12: shows a table for determining an optimal number of functional units for a multi-aperture array according to the invention; and

[0078] Fig. 13: schematically shows a method for producing a product according to the invention.

[0079] Multi-aperture arrays.

[0080] Fig. 1 schematically shows a multi-beam particle beam system 1 in the form of a multi-beam particle microscope 1. The multi-beam particle microscope 1 has a beam generation device 300 with a particle source, for example, an electron source. Charged particles or electrons are generated by the beam generation device 300, for example, by thermal field emission. The emitted charged particles form a diverging particle beam 309, which is collimated by a sequence of condenser lenses 303.1 and 303.2 and strikes a multi-beam particle generator 305 with a multi-aperture arrangement. The multi-beam particle generator 305 comprises several multi-aperture plates 304, 306 and a field lens 307. A multitude of single-particle beams 3 or 3 are emitted by the multi-beam particle generator 305.Single electron beams 3 are generated, arranged in a field which is imaged onto another field formed by beam spots 5 in the object plane 101. The distance between the centers of apertures of 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 distance between the centers of the apertures; examples of the diameters are 0.2 times, 0.4 times, and 0.8 times the distances between the centers of the apertures.

[0081] The multi-aperture arrangement 305 and the field lens 308 are configured to generate a plurality of focal points 323 of primary beams 3 in a grid arrangement within a surface 321. The surface 321 need not be a flat surface, but can be a spherically curved surface to accommodate field curvature of the preceding and subsequent particle optical systems.

[0082] The multi-beam particle microscope 1 further comprises a system of electrostatic and magnetic field lenses 103 and an objective lens 102, which reduce the size of the beam foci 323 from the intermediate image surface 321 onto the object plane 101. The first individual particle beams 3 pass through the beam splitter 400 and a collective beam deflection system 500, which deflects the multitude of the first individual particle beams 3 during operation and scans the image field. The first individual particle beams 3 incident on the object plane 101 form, for example, a substantially regular field, with distances between adjacent point locations 5 being, for example, 1 pm, 10 pm, or 40 pm. The field formed by the point locations 5 can, for example, have a rectangular or hexagonal symmetry.

[0083] The object 7 to be examined can be of any type, for example a semiconductor wafer or a biological sample, and it can comprise an array of miniaturized elements or the like. The surface 15 of the object 7 is located in the object plane 101 of the objective lens 102. The objective lens 102 can comprise one or more electron-optical lenses. It can be, for example, a magnetic objective lens and / or an electrostatic objective lens.

[0084] The primary particles 3 striking object 7 generate interaction products such as secondary electrons, backscattered electrons, or primary particles that have undergone a reversal of motion for other reasons. These products originate from the surface of object 7 or from the first plane 101 or object plane 101. The interaction products emanating from the surface 15 of object 7 are shaped into secondary particle beams 9 by the objective lens 102. After passing through the objective lens 102, the secondary beams 9 pass through the beam splitter 400 and are directed to a projection system 200. The projection system 200 has an imaging system 205 with projection lenses 206, 208 and 210, a contrast aperture 214 and a multi-particle detector 207. The impact points 25 of the second single-particle beams 9 on the detection areas of the multi-particle detector 207 are located in a third field at a regular distance from each other.Example values ​​are 10 pm, 100 pm and 200 pm.

[0085] The multi-beam particle microscope 1 further comprises a computer system or a control unit or controller 10, which in turn may be designed as a single unit or as a multi-part unit, and which is designed both for controlling the individual particle-optical components of the multi-beam particle microscope 1 and for evaluating and analyzing the signals obtained with the multi-detector 207 or the detection unit.

[0086] Further information on such multi-beam particle beam systems or multi-beam particle microscopes 1 and components used therein, such as particle sources, multi-aperture plates 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 10 2013 014 976 A1, the disclosure of which is incorporated in full by reference into the present application.

[0087] The multi-aperture array according to the invention can be integrated into the multi-particle beam system 1 shown in Fig. 1. The multi-aperture arrangement 305 forms a micro-optics 305, by means of which, in the example shown, the multitude of first individual particle beams 3 are initially generated at the first of the multi-aperture plates (so-called filter plate 304) during operation of the multi-particle beam system 1 and are also actively shaped at further multi-aperture plates or multi-aperture arrays. The micro-optics 305 itself can be configured differently. In particular, at least one multi-aperture array of the micro-optics 305 can be configured according to the invention.

[0088] Fig. 2 shows an example of a micro-optics 305 configured as a multi-beam generator 305. In the illustrated example, the multi-beam generator 305 comprises, in the z-direction, which corresponds to the propagation direction of the single-particle beams 3, a sequence of six multi-aperture plates 304, 306.1, 306.2, 306.3, 306.4, and 310, as well as an optional global lens electrode 307. Each of the multi-aperture plates 304, 306.1 to 306.4, and 310 comprises a plurality of apertures 351, each penetrated by the plurality of single-particle beams 3. The cross-section through the apertures 351 in Figure 2 is not to scale.

[0089] The multiple multi-aperture plates 304, 306.1, 306.2, 306.3, 306.4, and 310 are spaced apart from each other by spacers 93.1 to 93.5. Furthermore, a spacer 96 is provided between the final multi-aperture plate 310 and the global lens electrode 307. When a collimated particle or electron beam 309 strikes the first multi-aperture plate 304, also called the filter plate or pre-aperture plate, it generates the multiple individual particle beams 3. The pre-aperture plate 304 comprises a metallic layer 99 on its beam-entry side to stop and absorb the electrons of the electron beam 309 around the multiple apertures 85. In the example shown, the material of the preparation plate 304 is made of a conductive material, e.g. doped silicon, and is at earth potential.

[0090] The next multi-aperture plate shown in Figure 2 is a multi-stigmator plate 306.1. The multi-stigmator plate 306.1 comprises a plurality of four or more electrodes 82, e.g., eight electrodes for each of the apertures. During operation of the multi-beam particle microscope 1, different voltages, for example, in the range between -20 V and +20 V, can be applied to each of these electrodes, thereby influencing each individual particle beam 3 individually. For example, it is possible to deflect each individual particle beam 3 in any direction down to a few pm using an antisymmetric voltage difference in order to pre-correct a distortion correction of the illuminating unit. An astigmatism pre-correction of each individual particle beam 3 can also be performed. With an offset voltage, each multipole element can additionally function as a single lens. The multi-stigmator plate 306.1 can comprise a multi-aperture array according to the invention, but it can also be manufactured according to the prior art on a semiconductor basis or on a silicon basis.

[0091] The multi-aperture plates 306.2, 306.3, and 306.4 can, in principle, be any path correction plates made of a conductive material, monolithically formed, and each subjected to a voltage V1, V2, and V3, respectively, as shown in the example. It is also possible for the multi-aperture plates 306.2, 306.3, and 306.4 to form a single-lens array. Different apertures 351 in the same multi-aperture plate 306.2, 306.3, and 306.4 can be identical or different, for example, having different diameters, in order to account for a field dependency of the correction when correcting the path of the individual particle beams 3.

[0092] The multi-aperture plate 310 is a two-layer multi-aperture plate comprising a plurality of ring electrodes 81 for the plurality of apertures, each ring electrode being configured to individually modify or correct the focal position of the first single-particle beam 3 passing through it. The lower layer containing the ring electrodes 81 can be silicon-based. The upper layer is insulated from the layer containing the ring electrodes 81 and is made of a conductive material such as doped silicon.

[0093] The extraction electrode or field lens 307 comprises a ring electrode 94 to which a high voltage of, for example, 3 kV to 20 kV can be applied, e.g., 12 kV to 17 kV. In the example shown, the field lens 307 provides a global electrostatic lens field for global focusing of the multitude of individual particle beams 3.

[0094] The active multi-aperture plates according to Fig. 2 can be designed as a multi-aperture array 700 according to the invention, which is composed of several functional units, when using a large number of single particle beams 3 or apertures 351.

[0095] Fig. 3 schematically shows a top view of a section of a multi-aperture array. This could, for example, be the multi-aperture array 306.1 shown in Fig. 2. In the example shown, the multi-aperture array 306.1 has seven apertures 85, each aperture being equipped with eight electrodes 82, each forming a multipole electrode or octupole electrode. Each of the electrodes 82 can be individually controlled by the controller 10. Therefore, it is necessary that each of the electrodes 82 is connected to an individual conductor track 86. Fig. 3 impressively illustrates the complexity of the conductor track arrangement 86, even with only seven apertures 85. Modern multi-beam particle microscopes have significantly more apertures 85, for example, 61 apertures, 91 apertures, or even more.Multi-aperture arrays, which comprise multipole electrodes with a multitude of electrodes 82, therefore often contain around 1000 conductor tracks 86. Manufacturing and positioning each electrode correctly, as well as precisely positioning and separately electrically insulating each conductor track, is complex and time-consuming, and thus extremely prone to errors. Fig. 4 schematically shows a cross-sectional section of a multi-aperture array 306, where the base body 360 of the multi-aperture array 306 is made of a semiconductor material, for example, silicon. The multi-aperture array 306 can, for example, be a multi-stigmator; in Fig. 4, a single stigmator is shown accordingly. In this example, the electrodes 82 are not directly embedded in the base body 360, but are surrounded by an electrical insulation layer 83 within the base body 360. Only inside aperture 351 is electrode 82, or rather electrodes 82, exposed.In the example shown, a connecting wire 87 is arranged at the point where the conductor track 86, which contacts the electrode 82, exits the base body 360. This connecting wire 87 leads to a contact pad 398, which is arranged on a support element 390. The contact pad 398 is insulated from the support element 390 by means of an insulating layer 397, since the support element 390 is also made of silicon and thus of a semiconductor material. A conduction layer 371 is arranged on the top surface 370 of the base body 360 to dissipate any charged particles that strike it. The same applies to the bottom surface 380 of the base body 360, where a conduction layer 381 is arranged. This layer extends along the sides and bottom surface of the support element 390. In principle, a multi-aperture array 700 according to the invention can be composed of units or functional units, as shown in Fig. 4 as a section of the multi-aperture array 700.

[0096] Fig. 5 schematically shows a multi-aperture array 700 according to the invention with several functional units 701, 702. In the example shown, the multi-aperture array 700 according to the invention is embedded in a micro-optic 305 of a multi-beam particle beam system, as shown, for example, in Fig. 1. However, the multi-aperture array 700 according to the invention can also be used at another location within a multi-beam particle beam system 1. Examples of this are described elsewhere in this patent application.

[0097] In Fig. 5a, an illuminating particle beam 309 first strikes a first multi-aperture plate or filter plate 304. The illuminating particle beam 309 partially passes through the filter plate 304, forming individual particle beams 3. However, a large proportion of the charged particles associated with the illuminating particle beam 309 are absorbed by the filter plate 304 or, if the filter plate 304 is appropriately contacted / grounded, are deflected from it. The cross-section of the formed individual particle beams 3 is determined by the shape of the apertures 85 of the filter plate 304.

[0098] With respect to the particle-optical beam path after the filter plate 304, the multi-aperture array 700 according to the invention is arranged as follows: In the example shown, the multi-aperture array 700 comprises a base body 360 with a plurality K of apertures 85 through which, during operation of the multi-aperture array 700, one of the charged first single-particle beams 3 passes. At least one first electrode 82 is arranged at each of the apertures 85 and is embedded in the base body 360 of the multi-aperture array 700. This at least first electrode 82 is configured to individually influence the associated first single-particle beam 3 that passes through the aperture 85. Each of the first electrodes 82 is connected to a control unit 10 (not explicitly shown in Fig. 5).

[0099] According to the invention, the multi-aperture array 700 is composed of a plurality f of functional units 701, 702, in the present case of two functional units 701, 702. Each functional unit 701, 702 comprises a portion of the base body 360 and the subset of apertures 85 belonging to this portion of the base body, with the electrodes 82 arranged thereon. In the example shown, the two functional units 701 and 702 are arranged laterally to each other. The lateral boundary is designated by reference numeral 710 in Fig. 5A. The two functional units 701 and 702 can be fabricated using known MEMS techniques (SOI technology). The lateral arrangement of functional units 701, 702 is also known from the manufacture of semiconductor chips or specifically from the arrangement of so-called "subchips" and can be used for the manufacture of the functional units 701 and 702 of the multi-aperture array 700 according to the invention.The laterally arranged functional units 701, 702 are connected to each other at their upper and / or lower surfaces. This is illustrated in Fig. 5a by the web 391 beneath the functional units 701, 702. Alternatively, the functional units 701, 702 can also be joined directly laterally.

[0100] In the example shown, the multi-part base body 360, or the functional units 701 and 702, are arranged on a support element 390. The functional units 701 and 702 are directly or indirectly connected to the support element 390. The functional units can be connected to the support element, for example, by gluing or bonding. The web 391 can be a component of the support element 390. The support element 390 advantageously includes wiring and / or a fastening structure for attaching the functional units 701 and 702. The support element does not have any electrodes for influencing the individual particle beams 3. The complex elements to manufacture, such as the electrodes 82, are therefore exclusively assigned to the functional units 701 and 702. In the example shown, the support element 390 is designed as a frame and is a single piece. However, it can also be designed as a multi-part structure.

[0101] In the example shown, a multi-aperture plate 310 is arranged in the propagation direction z of the charged single-particle beams 3. This plate has a plurality of apertures 85 through which the charged single-particle beams 3 pass. In the example shown, the multi-aperture plate 310 is a passive multi-aperture plate, meaning that no electrodes are arranged in the region of the apertures 85. Furthermore, in the example shown, the multi-aperture plate 310 is the last multi-aperture plate of the micro-optics 305. However, this need not be the case. Therefore, Fig. 5a is only an illustrative example of a micro-optics 305 comprising the multi-aperture array 700 according to the invention.

[0102] Fig. 5b shows another example of a micro-optic 305 with a multi-aperture array 700 according to the invention. The embodiment shown in Fig. 5b differs from the embodiment shown in Fig. 5a by the provision of an interposer 711, which is arranged between the multi-part base body 360 and the support element 390. The interposer forms an intermediate layer between the base body 360 and the support element 390, which allows electrical connections to be established between the various functional units 701, 702 and the support element 390. An interposer 711 enables a high connection density and efficient signal transmission and is known from semiconductor manufacturing, particularly in connection with 2.5D techniques. The interposer 711 is preferably a silicon interposer. The support element 390 is also preferably made of silicon.

[0103] In the embodiments shown in Fig. 5, the multi-aperture array 700 is configured such that it comprises exactly one layer of functional units 701, 702. However, it is also possible to provide multiple layers, as will be described below in connection with other embodiments.

[0104] Furthermore, it should be noted again at this point that the multitude of first electrodes 82 can, in principle, be of different electrode types. For example, the first electrodes could be ring electrodes. It is also possible that a multitude of second and / or further electrodes 82 are provided at the apertures 85 of the functional units 701, 702, such that a deflection unit or a stigmatization unit is provided in each of the apertures 85 by means of its associated electrodes 82. The more complex the functional unit 701, 702, the more advantageous the multi-part nature of the base body 360 or the assembly of the multi-aperture array 700 from a plurality of functional units 701, 702 becomes.

[0105] Fig. 6 schematically shows further examples of multi-aperture arrays 700 according to the invention, each with several functional units 701, 702. Fig. 6A again schematically and by way of example shows a micro-optic 305. In the illustrated example, the micro-optic 305 comprises two multi-aperture arrays 700.1 and 700.2 between the filter plate 304 and a terminal multi-aperture plate 310. The structure of each multi-aperture array 700.1 and 700.2 corresponds to the structure of the multi-aperture array 700 described in more detail in Fig. 5A. It is also possible that each multi-aperture array 700.1 or 700.2 is connected to the respective support element 390.1, 390.2 by means of an interposer 711 (not explicitly shown in Fig. 6). In the example shown in Fig. 6, it is possible, for instance, that the first multi-aperture array 700.1 forms a multi-stigmator unit and that the second multi-aperture array 700.The device comprises two ring electrodes for maintaining image field curvature in an object plane 101. However, other embodiments are also possible.

[0106] Fig. 6b shows another example with two multi-aperture arrays 700.1 and 700.2 according to the invention: The two multi-aperture arrays 700.1 and 700.2 are arranged sequentially with respect to the particle-optical beam path, and the charged single-particle beams 3 pass through the two multi-aperture arrays 700.1 and 700.2 successively. In the example shown, the multi-aperture array 700.1 consists of two functional units 701.1 and 700.2.

[0107] The electrodes 82 are arranged laterally to each other (lateral boundary 710.1) in the multi-aperture array 700.1. The electrodes 82 can each be configured as multipole electrodes, in particular as octupole electrodes, within the multi-aperture array 700.1. Thus, stigmatization—or, if necessary, deflection—can be achieved using the electrodes.

[0108] In the example shown, the multi-aperture array 700.2 also comprises two laterally arranged functional units 701.2 and 702.2. In this example, the multi-aperture array 700.2 is configured as an objective lens array. In the embodiment shown in Fig. 6b, the electrodes 82 can, for example, be ring electrodes. The charged single-particle beams 3 are focused by means of the objective lens array.

[0109] 700.2 are imaged directly onto object 7, where they strike object 7 at impact points 5. The overall arrangement of particle-optical elements according to Fig. 6b thus differs fundamentally from the embodiment shown in Fig. 1. Fig. 7 shows a further embodiment of a multi-aperture array according to the invention.

[0110] 700. In the illustrated embodiment, the multi-aperture array 700 comprises four functional units 701, 702, 703, and 704. In the illustrated embodiment, these are arranged both laterally and vertically relative to each other. The functional units

[0111] Functional units 701 and 702 form a first layer, and functional units 703 and 704 form a second layer. In the example shown, the number of functional units 701, 702, 703, 704 is identical in both the first and second layers. The lateral boundary is designated by reference numeral 710 in Fig. 7, and the vertical boundary is designated by reference numeral 712. In the multilayer arrangement of functional units 701, 702, 703, 704 shown, conductors for the second (upper) layer of functional units 703 and 704 are routed through the functional units 701 and 702 of the first (lower) layer. For this purpose, functional units 701 and 702 each have a bond pad on their upper and lower surfaces (not explicitly shown). This applies generally to multilayer arrangements, including those with three, four, or even more layers of functional units.

[0112] In the example shown, the functional units 703, 704 can, for example, form the multistigmator unit, and the functional units 701 and 702 can form a focusing unit and each comprise, for example, ring electrodes 82.

[0113] In each of the embodiments shown in Figs. 7a and 7b, the functional unit 703 is arranged directly on the functional unit 701. The same applies to the arrangement of the functional unit 704 on the functional unit 702.

[0114] In the embodiment shown in Fig. 7a, the multi-aperture array 700 according to the invention is again integrated into a micro-optic 305. In the embodiment shown in Fig. 7b, the multi-aperture array 700 according to the invention is part of an objective lens array with which the charged single-particle beams 3 can be directly focused onto the object 7.

[0115] Fig. 8 schematically shows further embodiments of the multi-aperture arrays 700 according to the invention. For the sake of clarity, the electrodes in the apertures 85 are not explicitly shown.

[0116] According to the embodiment shown in Fig. 8a, the multi-aperture array 700 comprises two layers 751 and 752. The first layer includes two functional units 701 and 702, and the second layer, in the example shown, includes four functional units 703, 704, 705, and 706. The functional units 701 to 706 of each layer 751, 752 are arranged laterally to each other (reference numeral 710). The two layers 751 and 752 are arranged vertically to each other (reference numeral 712). The first layer 751 is connected to a carrier body 390. An interposer (not shown) can also be used between the first layer 751 of functional units 701, 702 and the carrier body 900.

[0117] The embodiment shown in Fig. 8b comprises three layers 751, 752, and 753. The first layer 751 and the third layer 753 each have two functional units 701, 702 and 707 and 708, respectively. The second, or middle, layer 752, in contrast, comprises four functional units 703, 704, 705, and 706. The first layer 751 is connected to a support element 390 (with or without an interposer).

[0118] The embodiment shown in Fig. 8c comprises a multi-aperture array 700 according to the invention with a total of four layers 751, 752, 753, and 754. The first layer 751 and the second layer 752 each comprise two functional units 701, 702 and 703 and 704, respectively. In contrast, layers 753 and 754 each comprise four functional units: the third layer 753 comprises the functional units 705, 706, 707, and 708; and the fourth layer 754 comprises the functional units 709, 713, 714, and 715. Again, the first layer 751 is connected to the support element 390 either directly or indirectly (for example, by means of an interposer – not shown).

[0119] In the embodiments shown in Fig. 8, it is preferably the case that the functional units in a layer 751, 752, 753, 754 are essentially identical in function. This means that the electrodes 82 provided in a layer are configured identically in all functional units belonging to that layer, for example as ring electrodes, deflectors, or stigmators. However, the electrodes of each layer 751, 752, 753, 754 can still be individually controlled for each individual particle beam in order to influence the respective individual particle beam individually or to an individual degree.

[0120] The specific arrangement of the multi-aperture arrays 700 according to the invention in the particle-optical beam path of a multi-particle beam system 1 is possible in a variety of ways. For example, it is possible to integrate the multi-aperture arrays 700 each as a component of a micro-optics 305, as schematically shown in Fig. 1. However, it is also possible to integrate the multi-aperture arrays 700 into an object lens array and to image the charged first single-particle beams 3 directly onto an object surface 101 of an object 7 by means of the multi-aperture array 700. Fig. 9 schematically shows a top view of a multi-aperture array 700 according to the invention. In the example shown, the multi-aperture array 700 again comprises two functional units 701 and 702. Each functional unit 701, 702 comprises a part of the base body 360, namely the two components 360.1 and 360.2. In the example shown, the base body 360.1, 360.2 is made of silicon.Each part of the base body 360.1 and 360.2 comprises a plurality of apertures 85, in each of which at least a first plurality of electrodes (not explicitly shown) is arranged. In the example shown, the functional units 701 and 702 are arranged laterally to each other. A lateral boundary 710 extends in the y-direction in the example shown. The lateral boundary 710 is designed such that it runs as a boundary between the functional units 701 and 702 between two groups of apertures 85 without cutting through any individual apertures 85. In the example shown, the apertures 85 are arranged in a hexagonal configuration relative to each other, but they could also be arranged differently, e.g., in a rectangular grid. Each of the electrodes 82, which are arranged on or in the apertures 85, requires electrical contact. For this purpose, electrodes are provided in the parts of the base body 360.1 and 360.2.Two conductor tracks are incorporated (not explicitly shown) that lead to one of the bond pads 720.1, 720.2.

[0121] The functional units 701 and 702 are arranged on a frame-like support element 390. In the example shown, the support element 390 comprises several ASICs 392 for the individual control of electrodes 82 of the functional units 701 and 702. The ASICs 392 are connected to a control unit 10 (not shown). The ASICs 392 are connected to contact pads 398 by means of a conductor 393. The contact pads 398 are in turn connected to the bond pads 720.1 and 720.2 by means of a connecting wire 87 or by means of several connecting wires 87. An interposer (not shown) can be provided between the functional units 701 and 702 and the support element 390.

[0122] Fig. 10 schematically shows another top view of a multi-aperture array 700 according to the invention. Unlike the embodiment shown in Figure 9, the multi-aperture array 700 comprises four functional units 701, 702, 703, and 704. Together, they form a layer with essentially identical functional units 701, 702, 703, and 704. The embodiment includes two lateral boundaries 710 and 712 arranged crosswise to each other; one boundary 710 extends in the x-direction, the other boundary 712 in the y-direction. The lateral boundaries 710 and 712 do not intersect any apertures 85. In the region of the boundaries 710 and 712, the functional units 701, 702, 703, and 704 rest on webs 391 of the support element 390. In the embodiment shown in Fig. 10, the functional units 701, 702, 703 and 704 are essentially the same size or have an approximately identical number of apertures 85 with corresponding electrodes 82 (not explicitly shown).This facilitates the production of functional units 702, 703, 704, 705 and reduces scrap and costs.

[0123] It is also possible that, in addition to the positions of functional units 701, 702, 703, and 704, one or more further positions of functional units can be provided. These can then be arranged directly on the functional units 701, 702, 703, and 704. In this respect, it should be noted again that the embodiments of a multi-aperture array 700 according to the invention shown in the figures are to be understood as merely exemplary and schematic.

[0124] Figures 11 and 12 show tables for determining an optimal number of functional units for a multi-aperture array 700 according to the invention. In the illustrated examples, it is assumed that a single corrector can be manufactured without defects with a probability of 99%. A single corrector is understood to be the electrode or the plurality of electrodes arranged at a single aperture 85 of the multi-aperture array 700. A corrector thus corresponds to a possibly multi-part element for beam shaping or influencing as it passes through exactly one aperture 85.

[0125] Figure 11a shows a multi-aperture array 700 with a total of 91 correctors or apertures 85, each containing electrodes 82. Hypothetically, the entire multi-aperture array 700 can be composed of varying numbers of functional units. In the extreme case, with 91 correctors, there are 91 functional units; in the simplest case (as in the prior art), only a single functional unit is provided. The number of functional units is shown in the first column of Figure 11.

[0126] The second column of Fig. 11a indicates the yield or defect-free rate Y per functional unit. With 91 functional units, the yield per functional unit is 99%, since it is initially assumed that a single corrector can be produced defect-free with a yield of 99%. The respective yield for smaller numbers of functional units is obtained by multiplying the probabilities together. If the multi-aperture array 700 comprises only one "functional unit," the yield per functional unit is only 0.40. For any number of functional units, it is also possible to calculate how many functional units are needed on average to produce exactly one functional unit. If the functional unit is very small and comprises only one corrector, then on average 1.01 functional units are needed to produce exactly one functional unit.

[0127] If a functional unit is significantly larger or if only a single functional unit is available (state of the art situation), then on average 2.50 functional units are required to manufacture one functional unit.

[0128] Based on this information, it is also possible to calculate how many functional units are needed to produce a fully functional Multi-Aperture Array 700: In the case of exactly one functional unit per Multi-Aperture Array 700, this is 2.50 functional units. In the case of a Multi-Aperture Array 700 being subdivided into exactly two functional units, this is 3.16 functional units; in the case of exactly three functional units, this is 4.07 functional units, and so on. In the case of 91 functional units from which the Multi-Aperture Array 700 is composed, this is 91.92 functional units.

[0129] In the example shown in Fig. 11a, the fewest functional units required to assemble exactly one functional multi-aperture array are indeed needed when the multi-aperture array is not subdivided into multiple functional units, but rather comprises exactly one "functional unit". In other words, achieving a high yield of 99% in the fabrication of a single corrector is advantageous not to subdivide the multi-aperture array into multiple functional units.

[0130] The situation is different, however, when the number of correctors sorted into a multi-aperture array 700 increases: examples of this are shown in Figure 11b and Figure 12.

[0131] Fig. 11b shows the situation with a total of 331 correctors to be arranged in a multi-aperture array 700. For comparability, a yield of 99% is again assumed for the production of a single corrector.

[0132] If a multi-aperture array is not subdivided into several functional units, the yield per functional unit is very low, namely 0.04 on average. 27.85 "functional units" or production attempts are required to produce exactly one functional unit or exactly one functional multi-aperture array 700.

[0133] When a Multi-Aperture Array 700 is divided into exactly two functional units, the situation is already improved: The yield per functional unit is 0.19. On average, 5.28 functional units are required to produce exactly one functional unit. To produce a complete, functional Multi-Aperture Array 700, an average of 10.55 functional units are required.

[0134] A minimum, or optimal, result is achieved with exactly three functional units: The yield per functional unit is 0.33, and an average of 3.03 functional units are required to produce exactly one functional unit. In this case, the number of functional units needed to produce exactly one functional multi-aperture array 700 is 9.09. Compared to fabricating a multi-aperture array in one piece, this represents an improvement of approximately three times. It is important to understand that while the manufacturing cost of a single functional unit depends on the number of apertures 85 with the electrodes 82 arranged within them, this is not the sole determining factor. Instead, the manufacturing cost of a single functional unit depends significantly on the cost of the MEMS manufacturing process. Therefore, to the zeroth order, the cost is proportional to the number of functional units per multi-aperture array 700.Therefore, for both cost reasons and related reasons of resource conservation, it makes sense to choose the minimum number G_f of functional units for the production of the multi-aperture array 700.

[0135] The situation shown in Fig. 12, with a total of 1000 correctors per Multi-Aperture Array 700, illustrates the result even more clearly: Again, it is assumed that a single corrector can be manufactured without defects with a probability of 99%. If—as is currently the case in the prior art—a Multi-Aperture Array is not manufactured from multiple functional units, then, on average, approximately 23,163 functional units would be required to produce a functional Multi-Aperture Array 700 with 1000 correctors. This is a very high quantity and a very high rate of rejects, which is completely unacceptable.

[0136] Instead, it is optimal that a multi-aperture array 700 with 1000 correctors should be divided into 10 functional units. Then, on average, only slightly more than 27 (27,32) functional units are needed to assemble a fully functional multi-aperture array 700. Fig. 13 schematically shows a method for manufacturing a multi-aperture array 700 according to the invention.

[0137] In process step S1, a total number K of correctors of the multi-aperture array 700 is determined.

[0138] In process step S2, a defect-free rate Y or a yield Y is determined for the production of a single corrector. The defect-free rate can be, for example, 99%, as shown in the tables in Figures 11 and 12.

[0139] In a further process step S3, a number A_f of functional units is determined that is needed to produce exactly one error-free functioning functional unit, based on the error-free rate Y according to step S2.

[0140] In process step S4, the number G_f of functional units required to assemble a flawlessly functioning multi-aperture array 700 from the flawlessly functioning functional units is determined, based on the number A_f according to process step S3. Then, process steps S3 and S4 are repeated multiple times for a plurality of f=1..F with F < K of functional units from which the multi-aperture array 700 is composed. As illustrated in Figures 11 and 12, the values ​​of the third and fourth columns are thus calculated in each case.

[0141] In a further process step S5, an optimal number G_opt of functional units for the multi-aperture array 700 to be assembled is determined, based on the values ​​for the number G_f of functional units determined in step S4. Preferably, the optimal number G_opt corresponds to the minimum number G_f of functional units according to process step S4.

[0142] In a further step S6, functional units for the assembled multi-aperture array 700 are manufactured based on the determined optimal number G_opt. The manufactured functional units are tested for error-free operation, for example, in a test setup. Once enough error-free functional units are available, the actual manufacturing step can begin: In process step S7, the multi-aperture array 700 is manufactured, composed of the optimal number G_opt of functional units, which were tested as error-free in step S6. Each functional unit contains approximately the same number of correctors. If this is not possible to achieve exactly the same number, the deviation in the number of correctors per functional unit should be kept as small as possible.

[0143] This approach allows for the production of a multi-aperture array 700 according to the invention with significantly less scrap. Furthermore, the reduction in scrap also significantly lowers the costs of producing a multi-aperture array 700 with a high number of correctors.

[0144] It should be noted once again that the examples and figures described above only illustrate the invention without limiting the invention to them.

[0145] Reference symbol list

[0146] 1. Multi-beam particle system, multi-beam particle microscope

[0147] 3 primary particle beams, first single-particle beams

[0148] 5 beam spots, points of impact

[0149] 7. Object, sample, wafer

[0150] 9 secondary particle beams, second single-particle beams

[0151] 10 Computer system, control

[0152] 15 Sample surface, wafer surface

[0153] 25 pixels of a second single-particle beam

[0154] 81 Ring electrode

[0155] 82 Multipole electrode

[0156] 83 electrical insulation layer

[0157] 84 Semiconductor layer, silicon layer

[0158] 85 aperture

[0159] 86 conductor track

[0160] 87 Connecting wire

[0161] 93 spacers

[0162] 94 Ring electrode

[0163] 96 spacers

[0164] 99 Absorbing and conductive layer

[0165] 101 Object plane Objective lens

[0166] Field lens

[0167] axis

[0168] Beam crossing, crossover

[0169] Detector system

[0170] Projection lens system

[0171] Projection lens

[0172] Multi-particle detector

[0173] Projection lens

[0174] Projection lens

[0175] Beam crossing, crossover in the projection path

[0176] Aperture filter, contrast aperture

[0177] Collective anti-deflection system

[0178] Beam generating device

[0179] Particle source

[0180] Collimation lens system

[0181] Multi-aperture plate, multi-aperture array, filter plate, pre-aperture plate

[0182] Micro-optics, multi-aperture arrangement, multi-beam particle generator

[0183] Multi-aperture plate, multi-aperture array

[0184] Extraction electrode, field lens

[0185] Field lens

[0186] Particle beam

[0187] Multi-aperture plate (final)

[0188] Intermediate image plane

[0189] Beam focus

[0190] Stopping area

[0191] Membrane area

[0192] Aperture

[0193] basic body

[0194] Top side of the base body, upper drainage layer

[0195] Underside of the base body, lower drainage layer

[0196] Support element

[0197] Bridge, support point

[0198] ASIC

[0199] Conductor 97 Insulation layer 98 Contact pad 99 Conductor 00 Beam switch, magnet assembly 00 Scan deflector 00 Moving table or positioning device 00 Multi-aperture array 01 Functional unit

[0200] 702 Functional unit

[0201] 703 Functional unit

[0202] 704 Functional unit

[0203] 705 Functional unit

[0204] 706 Functional unit

[0205] 707 Functional unit

[0206] 708 Functional unit

[0207] 709 Functional unit

[0208] 710 lateral border

[0209] 711 Interposer

[0210] 712 vertical boundary

[0211] 713 Functional unit

[0212] 714 Functional unit

[0213] 715 Functional unit

[0214] 720 Bondpad

[0215] 751 Location

[0216] 752 Location

[0217] 753 Location

[0218] 754 Location x direction y direction

[0219] Direction

Claims

33 Patent claims 1. A multi-aperture array for manipulating a plurality N of charged first single-particle beams, comprising: a base body with a plurality K of apertures, wherein, during operation of the multi-aperture array, one of the charged first single-particle beams passes through an aperture at a time; at least a plurality of first electrodes embedded in the base body, wherein one of the first electrodes is arranged at each of the apertures to individually influence the first single-particle beam passing through the aperture; and wherein each of the first electrodes is connectable to or connected with a control unit, wherein the multi-aperture array is composed of a plurality f of functional units, and wherein each functional unit comprises a part of the base body and the subset of apertures belonging to that part of the base body with the electrodes arranged thereon.

2. Multi-aperture array according to claim 1, wherein the functional units are arranged laterally to each other.

3. Multi-aperture array according to one of the preceding claims, wherein the functional units are arranged vertically to each other.

4. Multi-aperture array according to one of the preceding claims, wherein the functional units are arranged both laterally and vertically to each other and form at least a first layer of functional units and a second layer of functional units.

5. Multi-aperture array according to the preceding claim, wherein the number of functional units in the first layer and the number of functional units in the second layer are identical.

6. Multi-aperture array according to claim 4, wherein the number of functional units in the first layer differs from the number of functional units in the second layer.

7. Multi-aperture array according to any one of claims 4 to 6, where the functional units in one position are essentially identical in operation.

8. Multi-aperture array according to any one of claims 4 to 7, wherein lines for the second layer of functional units pass through the first layer of Functional units are routed through them.

9. Multi-aperture array according to any one of the preceding claims, wherein each functional unit has a bond pad.

10. Multi-aperture array according to any of the preceding claims, wherein the multi-aperture array has a support element; and wherein at least some functional units are arranged on the support element and connected to the support element.

11. Multi-aperture array according to the preceding claim, wherein the support element has wiring and / or a fastening structure for attaching the functional units.

12. Multi-aperture array according to claims 10 to 11, wherein the support element does not have electrodes for influencing the individual particle beams.

13. Multi-aperture array according to one of claims 10 to 12, wherein the support element is designed as a frame.

14. Multi-aperture array according to one of claims 10 to 13, wherein the support element is formed in multiple parts.

15. Multi-aperture array according to one of claims 10 to 14, wherein an interposer is arranged between the base body and the support element.

16. Multi-aperture array according to any one of claims 10 to 15, wherein the material of the support element comprises silicon or consists of silicon.

17. Multi-aperture array according to any one of the preceding claims, the first electrodes are designed as ring electrodes.

18. Multi-aperture array according to any one of the preceding claims 1 to 16, further comprising a plurality of second and / or further electrodes, wherein one of the second and / or further electrodes is arranged at one of the apertures to individually influence the first single-particle beam passing through the aperture, and wherein each of the second and / or further electrodes is connectable to or connected to a control unit.

19. Multi-aperture array according to the preceding claim, wherein in each of the apertures which are arranged in the same position a deflection unit is provided by means of the electrodes associated therewith.

20. Multi-aperture array according to one of claims 18 to 19, wherein in each of the apertures which are arranged in the same position a stigmatization unit is provided by means of the electrodes associated therewith.

21. Multi-aperture array according to one of the preceding claims, wherein the base body consists of a semiconductor material, in particular silicon.

22. Multi-aperture array according to any one of claims 1 to 20, wherein the base body consists of a glass.

23. Multi-particle beam system with at least one multi-aperture array according to one of the preceding claims.

24. Multi-particle beam system according to claim 23, wherein the multi-particle beam system is a multi-beam particle microscope.

25. A multiple particle beam system according to claim 23, wherein the multiple particle beam system is a lithography system.

26. Method for fabricating a multi-aperture array according to any one of claims 1 to 22, comprising the following steps: (a) Determining a total number K of correctors of the multi-aperture array; (b) Determining a defect-free rate Y in the production of a single corrector; (c) For a plurality of f = 1..F with F < K of functional units from which the multi-aperture array is composed, in each case: (c1) Determine a number A_f of functional units required to produce exactly one fault-free functional unit, based on the fault-free rate according to step (b), and (c2) Determine a number G_f of functional units required to assemble a fault-free multi-aperture array from the fault-free functional units, based on the number A_f according to step (c1); (d) Determine an optimal number G_opt of functional units for the multi-aperture array to be assembled based on the values ​​for the number G_f of functional units determined in step (2c); (e) Manufacturing functional units for the multi-aperture array to be assembled based on the determined optimal number G_opt and testing each of the manufactured functional units with regard to their error-free function; (f) Constructing the multi-aperture array, wherein the multi-aperture array is composed of the optimal number G_opt of functional units, wherein the functional units have been tested as error-free in step (e).

27. Method according to the preceding claim, wherein the optimal number G_opt is the minimum number G_f of functional units according to step (d).

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