Particle beam system having a multi-source system and a multi-beam particle microscope

Abstract

The present invention discloses a particle beam system with a multi-source system. The multi-source system includes an electron emitter array, which serves as a particle multi-source. In this multi-source system, the inhomogeneous emission characteristics of the various emitters are corrected or pre-corrected by means of particle optical components (which can be produced by MEMS technology) for subsequent particle optical imaging. The beam current of individual particle beams can be adjusted in the multi-source system.

Description

Technical Field

[0001] The present invention relates to a particle beam system employing multiple particle beam operations. Background Art

[0002] Like a single-beam particle microscope, a multi-beam particle microscope can be used to analyze an object at a microscopic scale. For example, an image of the object (which represents the surface of the object) can be recorded using these particle microscopes. Thus, for example, the structure of the surface can be analyzed. Although in a single-beam particle microscope, a single particle beam of charged particles (such as, for example, electrons, positrons, muons, or ions, etc.) is used to analyze an object, in a multi-beam particle microscope, multiple particle beams are used for this purpose. The multiple particle beams (also referred to as a bundle) are simultaneously guided to the surface of the object, so that a significantly larger area of the surface of the object can be sampled and analyzed compared to a single-beam particle microscope within the same period of time.

[0003] WO 2005 / 024 881 A2 discloses a multiple particle beam system in the form of an electron microscope system that employs multiple electron beam operations to scan an object to be inspected using a parallel beam of electrons. The beam of electrons is produced by an electron beam produced by an electron source guided at a multi-aperture plate having multiple openings. A part of the electrons of the electron beam impinges on the multi-aperture plate and is absorbed there, while another part of the beam passes through the openings in the multi-aperture plate, so that the electron beam is shaped in the beam path downstream of each opening, and the cross-section of the foregoing electron beam is defined by the cross-section of the opening. Furthermore, in the beam path upstream and / or downstream of the multi-aperture plate, a suitably selected electric field provided has the effect that each opening in the multi-aperture plate serves as a lens on the electron beam passing through the opening, so that the electron beam is focused in a plane at a distance from the multi-aperture plate. The plane (where the focus of the electron beam is formed) is imaged onto the surface of the object to be inspected by a downstream optical unit, so that individual electron beams impinge on the object in a focused manner as a main beam. There, they generate interaction products (such as backscattered electrons or secondary electrons) emitted from the object, which are shaped to form a secondary beam and guided to a detector by a further optical unit. There, each of the secondary beams impinges on a separate detector element, so that the electron intensity detected by the foregoing detector element provides information related to the object at the position where the corresponding main beam impinges on the object. The beam of main beams is systematically scanned over the surface of the object in order to generate an electron micrograph of the object in the manner customary for a scanning electron microscope.

[0004] In the illustrated multiple particle beam system, high resolution and high throughput are highly relevant for practically satisfactory and successful use. In this context, it is particularly necessary to set the intensity of the particle beam.

[0005] US2017 / 0025241 A1 discloses a multi-beam particle beam system in which the current density within the particle beam is variable. Specifically, the irradiance in the text is set even before the multi-beam is formed from the primary electron beam. To set this irradiance, as in US2017 / 0025241 A1, a double collimator is used, and the aforementioned double collimator is directly downstream of the electron source in the beam direction. By varying the lens excitation of the double collimator, the current density of the electrons passing through the openings in the multi-aperture plate downstream of the double collimator can be varied.

[0006] However, if the number of particle beams utilized is further increased, the multi-beam particle beam system described above reaches its limit. Even to obtain sufficient beam current for the individual beams, it is necessary to use as many particles as possible from the particle source. However, in that case, the emission characteristics of the particle source become more important, more precisely the uniformity of the emission characteristics over the entire utilized emission angle. When using a relatively large emission angle, the emission characteristics of a particle source such as a thermal field emission (TFE) source are no longer uniformly consistent throughout. Therefore, in the corresponding particle beam system, the irradiance at the multi-aperture plate is subsequently no longer uniformly consistent throughout, and there are relatively large variations in the current density among the different individual beams. However, in the case of a multi-particle detection system, and further in the case of a system with only minor variations (which are typically less than a few percent) in the current intensity among the various individual beams, so that all individual image fields of the multi-image field are scanned with an equivalent number of particles or electrons per pixel. For example, this is a prerequisite for obtaining individual images with approximately the same brightness.

[0007] Therefore, using a particle source with a large emission angle, and at the same time a significant requirement for the current of each individual beam, represents a challenge in the case of an inspection system operating with a multi-beam particle beam system due to varying emission characteristics.

[0008] In addition, there are multi-beam particle beam systems that use multi-source operation. This method also increases the number of individual particle beams available for a multi-beam particle beam system. In principle, a photocathode and a cold field emitter array (cold FEA) are known as multi-sources. However, the disadvantage of using a photocathode is that these have unstable emission characteristics, a short service life, and low brightness. In contrast, a cold field emitter array has a relatively high brightness and a small virtual source size. In addition, it can be produced by methods customary in microstructuring technology, such as a combination of lithography methods and subsequent etching and / or deposition methods (MEMS technology; microelectromechanical systems technology). However, the emission characteristics of a cold field emitter array are still non-uniform, and it is difficult to produce individual tips for emission with reproducible characteristics and specifications, especially considering its emission characteristics, considering its overall current, and considering its virtual source diameter.

[0009] US2014 / 0057212 A1 discloses a lithography system that operates with multiple individual particle beams. It does not include a multi-source, but a single source.

[0010] US2016 / 0111251 A1 discloses a multi-beam electron microscope that also operates with a single source instead of a multi-source. Moreover, different options for field curvature correction are disclosed.

[0011] DE 10 2014 008 083 A1 discloses a particle beam system with a single source. Various settings of a multi-aperture plate for beam shaping are disclosed, in particular a field generator for generating a multipole field.

[0012] US2012 / 0295203 A1 discloses a lithography system that operates with a single source. In the region close to the source, a two-stage system of successive individual lenses for setting the relative position of a crossover is disclosed.

[0013] US2014 / 0042334 A1 discloses a lithography system with a single source.

[0014] US 8,618,496 B2 discloses various field generators for manipulating individual particle beams. No multi-source system is disclosed.

[0015] WO 2007 / 028595 A2 discloses a particle beam system with a single source. Various multi-aperture plate settings are disclosed, in which plates with curved surfaces and thus varying distances from each other are also used.

[0016] US2013 / 0344700 A1 discloses a further lithography system that operates with a single source.

[0017] US 8,384,051 B2 discloses a further lithography system that employs single-source operation. The cited reference focuses on issues related to detection.

[0018] WO 2005 / 024881 A2 discloses a multi-particle beam system that employs single-source operation. The arrangements of multi-aperture plates are disclosed, and multiple aspects of image field effect correction are discussed. SUMMARY OF THE INVENTION

[0019] Accordingly, an object of the present invention is to provide a particle beam system that employs multiple individual beam operations, which ensures good beam uniformity of the individual beams, even when using a large number of individual beams and (simultaneously) a high beam current for each individual beam. In particular, the particle beam system should be suitable for a multi-beam inspection system.

[0020] A further object of the present invention is to increase the throughput in the particle beam system.

[0021] A further object of the present invention is to improve the availability of the multi-sources for a multi-beam particle beam system.

[0022] A further object of the present invention is to minimize the imaging aberrations of the particle beam system as much as possible.

[0023] This object is achieved by the independent patent claims. Preferred embodiments of the present invention are apparent from the dependent patent claims.

[0024] This patent application claims the priority of German Patent Application No. 10 2020 115 183.7, the entire disclosure of which is incorporated herein by reference.

[0025] Herein, the present invention is based on the following considerations: If the inhomogeneity in terms of the beam current density of the individual particle beams of the multi-sources is compensated or removed before actual particle optical imaging occurs, then existing particle multi-sources (which generate electrons through cold field emission for particle beam systems with high resolution and high throughput) can be used. According to the present invention, it is therefore proposed to initially roughly shape the individual particle beams close to the multi-sources, where MEMS technology can be used to produce lenses, deflectors, stigmators, etc. used in this process. The actual final beam shaping (where the individual particle beams are formed for high-resolution particle optical imaging) is only carried out later within the particle beam system. Near the multi-sources, the energy of the individual particle beams is still relatively low, and the individual particle beams can be influenced or deflected using a relatively low voltage or current. Furthermore, for a low-risk design of MEMS devices, a low voltage or current is a good prerequisite, where relatively high requirements are imposed on the insulation of the wire traces thereon.

[0026] Moreover, due to this two-stage shaping of the individual particle beams, it has become possible to pre-thin the individual particle beams originally emitted by multiple sources close to their origin; this reduces the Coulomb effect, which is considered a disadvantage in view of high resolution.

[0027] Specifically, according to a first aspect, the present invention relates to a particle beam system, which comprises the following:

[0028] A multi-source system, comprising:

[0029] - A particle multi-source, in particular an electron emitter array, arranged to generate multiple charged individual particle beams by field emission, in particular cold field emission;

[0030] - A first multi-aperture plate, having multiple first openings through which at least part of the individual particle beams pass;

[0031] - A first multi-lens array, which comprises multiple individually adjustable particle lenses and is arranged in the beam path downstream of the first multi-aperture plate such that the individual particle beams passing through the first multi-aperture plate also pass through the first multi-lens array;

[0032] - A second multi-aperture plate, having multiple second openings, arranged in the beam path downstream of the first multi-lens array such that the individual particle beams passing through the first multi-lens array also pass through the second multi-aperture plate; and

[0033] - A beam current limiting multi-aperture plate, having multiple beam current limiting openings, arranged in the beam path downstream of the second multi-aperture plate such that part of the individual particle beams impinge on the beam current limiting multi-aperture plate and are absorbed there, and part pass through the openings in the beam current limiting multi-aperture plate; and

[0034] - A controller, arranged to supply an individually adjustable excitation to the particle lenses of the first multi-lens array and thus individually set the focusing of the associated particle lenses for each individual particle beam.

[0035] Thus, in this case, the particle multi-source of the multi-source system generates electrons or emits electron beams. The particle multi-source can in this case be implemented as an electron emitter array, where the individual emitters or tips are arranged in a regular pattern. For example, they can be arranged in a checkerboard pattern or in a hexagonal pattern. For example, this electron emitter array can be manufactured using MEMS technology, where methods such as lithography are combined with subsequent etching and / or deposition methods. For example, metal emitters, silicon-based emitters, and / or carbon nanotube-based emitters are suitable for the emitters of the electron emitter array. The particle multi-source comprises multiple real particle sources; in particular, it can have multiple tips.

[0036] In this multi-source system, the first multi-aperture plate, the first multi-lens array, and the second multi-aperture plate are arranged in this order in the beam path downstream of the particle multi-source. Here, for the purposes of this patent application, the multi-aperture plate on the one hand is distinguished from the multi-lens array on the other hand throughout the text. The multi-aperture plate is a plate having multiple openings. Here, a voltage can be applied to the entire multi-aperture plate. This may or may not be the case. In any case, all the openings in the multi-aperture plate have a uniform globally identical potential. In contrast, compared to the multi-aperture plate, the multi-lens array as considered in this patent application is a more complex component: For the purposes of this patent application, the multi-lens array includes multiple lenses that are substantially arranged parallel to each other, each of which is individually adjustable and independent of each other, such that the individual lenses of the multi-lens array can have different refractive powers from each other, and these refractive powers can vary independently of each other on an individual basis for each lens.

[0037] According to an advantageous embodiment variant, a multi-lens array comprises the following:

[0038] - a lens multi-aperture plate having multiple openings; and

[0039] - multiple electrodes arranged around the multiple openings in the lens multi-aperture plate to individually affect the individual particle beams passing through the corresponding openings.

[0040] For example, the electrodes can be ring electrodes; however, other embodiment variants are also possible. For example, in the case of azimuthally segmented electrodes (such as quadrupoles or octupoles, etc.), the same voltage can be applied to all the electrodes. In addition, a focusing effect can be caused by coils that enclose each opening in the lens multi-aperture plate in a plane perpendicular to the beam direction. This is described for deflection coils in DE 10 2014 008 083B4.

[0041] Preferably, the openings in the first multi-aperture plate, the second multi-aperture plate, and the first multi-lens array are circular in each case, and overall, the individual openings are arranged in a hexagonal structure; however, other setting options are also possible. The number of openings in the first multi-aperture plate, the second multi-aperture plate, and the first multi-lens array can be matched to the number of individual particle beams or to the number of emitters or tips of the particle multi-source. In this case, in the case of a hexagonal arrangement, it is advantageous if the number of individual particle beams formed is 3n(n - 1)+1, where n is any natural number. However, alternatively, multiple individual particle beams can also be formed from one emitter. For example, this can be achieved by means of a first multi-aperture plate with more openings, specifically m openings per emitter. However, in that case, it is further advantageous if the number of openings in the first multi-aperture plate, the second multi-aperture plate, and the first multi-lens array is the same as each other in each case. Moreover, the openings should be centered above each other in the beam path of the individual particle beams. Here, it is advantageous if the diameter of the openings in the first multi-aperture plate is smaller than the diameter of the openings in the first multi-lens array and the second multi-aperture plate. Different from the case of the first multi-lens array and the second multi-aperture plate, the individual particle beams at least partially pass through the first multi-aperture plate; that is, the first multi-aperture plate can also block the electrons emitted by the emitter.

[0042] A series of openings in the first multi-aperture plate, the first multi-lens array, and the second multi-aperture plate form individual lenses. In this case, a substantially identical first voltage U1, which can also be zero, is applied to the first multi-aperture plate and to the second multi-aperture plate. In contrast, the individual adjustable voltage U2+V at the first multi-lens array i is substantially different from the first voltage U1. In this case, the notation V i means that the adjustable voltage varies around the value U2, that is, U2 is the average value or reference value.

[0043] Depending on the excitation of the individually adjustable particle lenses, the order of the openings in the first multi-aperture plate, in the first multi-lens array, and in the second multi-aperture plate has different focusing effects. Thus, after passing through the individual lenses, the individual particle beams have different divergences and subsequently expand to different extents along a short travel along the deflection path. These individual particle beams, which have subsequently expanded to different extents, are incident on a beam current limiting multi-aperture plate with multiple beam current limiting openings. Some of the particles of the individual particle beams hit the beam current limiting multi-aperture plate and are absorbed there, and some of these pass through the openings in the beam current limiting multi-aperture plate. This allows the beam current intensity to be individually set for each individual particle beam within the multi-source system. Thus, in particular, different emission characteristics or current intensities of individual sources or tips can be compensated for by this adjustment procedure. In this way, conventional particle multi-sources based on electron emitter arrays can also be used in high-resolution particle beam systems. The final beam shaping of the individual particle beams for actual particle optical imaging is only carried out later in the particle beam system. Preferably, immediately after passing through the beam current limiting multi-aperture plate, the following relationship applies to the deviation δ of the individual beam current from the arithmetic mean of the beam currents: δ ≤ 5%, preferably δ ≤ 2%, and optimally δ ≤ 1%.

[0044] A controller configured to supply individually adjustable excitation to the particle lenses of the first multi-lens array and thus individually adjust the focusing of the associated particle lenses for each individual particle beam can be the same as the controller for the entire particle beam system. However, this need not be the case. In particular, the adjustable excitation is a voltage and / or a current.

[0045] Furthermore, the openings in the beam current limiting multi-aperture plate are preferably centered relative to the openings in the first multi-aperture plate, in the first multi-lens array, and in the second multi-aperture plate. The diameter of the beam current limiting openings is smaller than the diameter of the openings in the second multi-aperture plate and in the first multi-lens array.

[0046] The second multi-aperture plate and the beam current limiting multi-aperture plate can also be functionally combined or integrated with each other. Thus, the second multi-aperture plate and the beam current limiting multi-aperture plate need not be two separate component parts. However, structural separation has electro-optical advantages.

[0047] According to a preferred embodiment of the present invention, the particle beam system further comprises the following: a final beam shaping system, which is arranged in the beam path downstream of the multi-source system, and by means of which the individual particle beams have the shape for subsequent particle optical imaging. In this case, the term "final beam-shaping" indicates that the individual particle beams finally used for the actually relevant particle optical imaging are formed by means of the final beam shaping system. Within the scope of this final beam shaping, parameters such as homogeneous individual particle beam current density, rotation, telecentricity, astigmatism (to be removed), etc. are taken into account or set for the subsequent particle optical imaging. Due to the settings made, particle optical imaging with high resolution and high throughput is possible. The individual structural components of this final beam shaping system will still be discussed in more detail within the scope of this patent application below.

[0048] According to a preferred embodiment of the present invention, the first multi-aperture plate is implemented as an extraction electrode; and / or the second multi-aperture plate is implemented as a corresponding electrode; and / or the (final) beam current limiting multi-aperture plate is implemented as an anode. This embodiment variant is based on the fact that existing particle multi-sources that generate multiply charged individual particle beams by field emission in any case have various electrodes in the form of perforated plates. In this case, the same voltage can be applied to the extraction electrode and to the corresponding electrode. The same voltage as applied to the extraction electrode and / or the corresponding electrode, or a different voltage, can also be applied to the anode.

[0049] According to a preferred embodiment of the present invention, the following relationship applies to the distance A between the particle multi-source and the beam current limiting multi-aperture plate: 0.1 mm ≤ A ≤ 30 mm, preferably 0.1 mm ≤ A ≤ 20 mm, and most preferably 0.1 mm ≤ A ≤ 10 mm. Therefore, the beam current limiting multi-aperture plate is arranged very close to the particle multi-source. In this case, the distance A is measured from the tip of the particle emitter to the surface of the beam current limiting multi-aperture plate facing the particle multi-source. Therefore, the thickness of the multi-source system in the direction of the optical axis Z of the particle beam system is less than 30 mm, preferably less than 20 mm, and most preferably less than 10 mm. In this case, the multi-source system can still have further components that contribute to the overall thickness or overall extent of the multi-source system.

[0050] According to a further embodiment of the present invention, the multi-source system further comprises a suppression electrode. A voltage is applied to this electrode such that it presses electrons out of the source region of the particle multi-source.

[0051] According to a further embodiment of the present invention, the multi-source system includes a second multi-lens array, where the second multi-lens array includes multiple individually adjustable and focusable particle lenses and is arranged in the beam path downstream of the beam current limiting multi-aperture plate such that the particles of the individual particle beams passing through the beam current limiting multi-aperture plate substantially also pass through the second multi-lens array. Furthermore, the controller is arranged to supply individually adjustable excitations to the particle lenses of the second multi-lens array and thus individually set the focusing of the associated particle lenses for each individual particle beam. In particular, the first and second multi-lens arrays can have the same design, which simplifies the manufacture of the particle beam system. However, the first and second multi-lens arrays can also have different configurations. Furthermore, the statements made above have been made with respect to the first multi-lens array applicable to the second multi-lens array. Due to the individually adjustable excitations, the second multi-lens array can individually set the focal lengths for the respective individual particle beams. When passing through the first multi-lens array, due to the different lens excitations for the individual particle beams, the focal lengths for the individual particle beams have been slightly changed. These deviations can now be corrected by providing the second multi-lens array. In addition, with the aid of the second multi-lens array, field curvature correction for subsequent particle optical imaging can be carried out. This is because if the subsequent field curvature (caused by subsequent particle optical imaging) is known, it can be compensated by appropriate excitations of the particle lenses of the second multi-lens array.

[0052] According to a further preferred embodiment of the present invention, the multi-source system further includes a first multi-deflector array through which the individual particle beams pass and which is arranged in the beam path downstream of the beam current limiting multi-aperture plate. Here, the controller is further arranged to supply individually adjustable excitations to the first multi-deflector array and thus individually deflect the individual particle beams. In this case, for example, the multi-deflector array serves as a direction correction for the individual particle beams. For example, possible beam migrations that may occur due to the openings in the multi-aperture plate (which are misaligned due to manufacturing tolerances) can be compensated. The structure of the multi-deflector array is known in principle (see, for example, DE 10 2014 008083B9); this is preferably with respect to the electrostatic deflection fields in the openings of the multi-deflector array. In this case, electrodes that are subdivided in the azimuthal direction and can be driven in pairs for appropriate direction correction can be provided.

[0053] According to a preferred embodiment of the present invention, the multi-source system further includes a multi-astigmatism corrector array through which the individual particle beams pass. In this case, the controller is further arranged to supply adjustable excitations to the multi-astigmatism corrector array. The astigmatism correctors of the multi-astigmatism corrector array provide multipole fields that depend on the excitations of the aforementioned astigmatism correctors and can be used to change the position and angle at which the individual particle beams are incident on the object to be inspected. However, it is also possible to affect the astigmatism of each individual particle beam. The imaging aberrations of the particle optical imaging can be corrected.

[0054] According to a preferred embodiment of the present invention, the multi-source system is at least partially manufactured by MEMS technology. Additionally, it is possible that all components of the multi-source system have been manufactured by MEMS technology.

[0055] According to a preferred embodiment of the present invention, the particle multi-source has at least one of the following emitter types: a metal emitter, a silicon-based emitter, a carbon nanotube-based emitter.

[0056] According to a further preferred embodiment of the present invention, the particle beam system further includes a magnetic field generating member arranged such that the particle multi-source is disposed in a magnetic field. In particular, in this case, the emitter plane in which the tip of the multi-source is located is disposed within the magnetic field. Thus, the charged particles or electrons are initiated into the particle beam system within the magnetic field; as such, they are generated within the magnetic field. The targeted arrangement of the magnetic field relative to the emitter plane enables a defined starting angle distribution to be imposed on the electrons. Thus, the starting velocity vectors projected onto the emitter plane have a specific direction, specifically orthogonal to the correspondingly applied magnetic field. This embodiment variant is advantageous because it provides an opportunity to correct the landing angle in the object plane or on the sample. In principle, the aberration occurring in the object plane is proportional to the image-side focal length. To obtain a shorter focal length of the objective lens (which results in smaller aberration), the operation can be performed using magnetic immersion. However, this results in the object plane still being within the magnetic field. Thus, the individual particle beams incident on the object plane or the object undergo Larmor rotation, which is proportional to the radius R or the distance from the optical axis Z. Thus, the individual particle beams have an angular momentum about the optical axis Z. By providing an appropriately formed magnetic field, this angular momentum can be compensated for at the source. This contributes to the telecentric landing of the individual particle beams in the object plane. This is particularly required when inspecting so-called High Aspect Ratio (HAR) structures, where the ratio of width to depth can be approximately 1:100 or greater.

[0057] According to a preferred embodiment of the present invention, the magnetic field generated by the magnetic field generating member has a component perpendicular and / or parallel to the emission direction of the charged particles from the multi-source. In this case, the perpendicular component ensures the deflection or influence of the generalized angular momentum on the electrons in the magnetic field.

[0058] According to a further preferred embodiment variant, the magnetic field generating member is implemented such that the initial angular distribution of the charged particles caused by the magnetic field after the emission of the charged particles from the particle source depends on the radial distance of the respective particle source from the optical axis of the particle beam system. This is particularly preferably useful for correcting the Larmor rotation occurring in the object plane, which is proportional to the distance r of the incidence point from the optical axis Z.

[0059] In this case, the magnetic field generating member can have an integral or multi-part embodiment. For example, it can include pole pieces, where the coils are arranged in a suitable manner. In this case, it is advantageous to arrange the magnetic field generating member on the side of the particle beam system remote from the beam path, for example above the particle multi-source or above the entire multi-source system.

[0060] According to a further preferred embodiment of the present invention, the particle beam system further comprises the following:

[0061] - A condenser lens system, which is arranged in the direction of the beam path downstream of the multi-source system and upstream of the final beam shaping system;

[0062] - A field lens system, which is arranged in the direction of the beam path downstream of the final beam shaping system; and

[0063] - An objective lens system, which is arranged in the direction of the beam path downstream of the field lens system,

[0064] where an intermediate image plane is formed between the final beam shaping system and the field lens system.

[0065] The final beam shaping system is arranged in the beam path downstream of the multi-source system (as already explained above) and is used to shape the individual particle beams for subsequent particle optical imaging. In this case, shaping the individual particle beams by means of the final beam shaping system is carried out at a relatively high energy of the individual particle beams and is thus highly precise. Furthermore, this precision is decisive for the quality of the subsequent particle optical imaging from the intermediate image plane to the object plane. In this case, the images of the multi-sources are located in the intermediate image plane; thus, they can be regarded as virtual particle sources for the subsequent imaging from the intermediate image plane to the object plane.

[0066] According to a preferred embodiment, the final beam shaping system comprises the following:

[0067] - A final multi-aperture plate, having multiple openings, arranged such that some of the individual particle beam portions are incident on the final multi-aperture plate and are absorbed there, and some pass through the openings in the final multi-aperture plate; and

[0068] - A third multi-lens array, which includes multiple adjustable particle lenses and is disposed in the beam path downstream of the last multi-aperture plate such that the individual particle beams passing through the last multi-aperture plate substantially also pass through the third multi-lens array,

[0069] wherein the controller is further configured to supply an adjustable excitation to the particle lenses of the third multi-lens array.

[0070] In this case, all the lenses of the third multi-lens array may undergo the same excitation; however, it is also possible to differentially excite the lenses of the multi-lens array on an individual basis. Only the components of the individual particle beams suitable or intended for particle optical imaging pass through the last multi-aperture plate. Thus, the individual particle beams are geometrically shaped by the last multi-aperture plate. In contrast, the individual particle beams are focused by the third multi-lens array and in particular imaged onto an intermediate image plane.

[0071] According to a further embodiment of the invention, the last beam shaping system comprises the following:

[0072] A last multi-aperture plate having multiple openings and configured such that individual particle beam portions are incident on the last multi-aperture plate and absorbed therein and portions pass through the openings in the last multi-aperture plate;

[0073] A multi-lens plate having multiple openings and disposed in the beam path downstream of the last multi-aperture plate such that the individual particle beams passing through the last multi-aperture plate also pass through the multi-lens plate; and

[0074] At least one first aperture plate having a single opening and disposed in the beam path downstream of the multi-lens plate such that the individual particle beams passing through the multi-lens plate also pass through the opening in the at least first aperture plate; and

[0075] wherein the controller is further configured to supply an adjustable excitation to the at least one first aperture plate. Additionally, two, three, four, or more aperture plates may be provided, and each of these may subsequently be supplied with an adjustable excitation by the controller. Preferably, in this case, the particle beam system further comprises a second multi-deflector array disposed in the beam path immediately upstream of the last multi-aperture plate, wherein the controller is further configured to supply individual adjustable excitations to the second multi-deflector array and thereby differentially deflect the individual particle beams.

[0076] With this embodiment variant, it is possible to influence the pitch between individual particle beams in the intermediate image plane. Specifically, the design of the (multiple) global electrostatic electrodes downstream of the multi-lens plate is such that a negative field curvature can be generated in the intermediate image plane. The amplitude of this negative field curvature can be selected such that it completely compensates for the (positive) field curvature that subsequently occurs during the particle-optical imaging from the intermediate image plane to the object plane. Thus, in that case, no further field curvature correction is required.

[0077] According to a further embodiment of the invention, the condenser lens system comprises one or more global condenser lenses, in particular an electrostatic or magnetic double condenser. However, the condenser lens system can also comprise a condenser lens array having multiple openings through which the individual particle beams pass. Thus, the choice regarding the condenser lens system is between a global lens system and a microlens system.

[0078] According to a further preferred embodiment of the invention, the objective lens system comprises a global magnetic objective lens. In this actual situation: all individual particle beams pass through the same (larger) opening of the magnetic objective lens. However, alternatively, the objective lens system can also comprise an objective lens array having multiple openings arranged in the beam path such that the individual particle beams pass through the openings in the objective lens array. In this case, in fact, the objective lens array substantially represents a single-lens (Einzel-lens) array. Other specific embodiment variants are also possible. However, in any case, in fact, the objective lens array (such as an example of a microlens array) can in turn be produced using MEMS technology. The aforementioned field lens system has a focusing effect on the individual particle beams. This means that the individual particle beams form an intersection point in the direction of the objective lens system. Advantageously, this intersection point is located upstream of the objective lens. If an objective lens array is now used instead of a global magnetic objective lens, it is also possible to omit the intersection point of the individual particle beams that would otherwise be required in the particle-optical beam path. This has an advantage due to the Coulomb effect. In this case, the objective lens array is just arranged upstream of the intersection point of the individual particle beams that would otherwise exist; however, this has the consequence that the pitch of the holes in the objective lens array is significantly smaller than the pitch of the individual particle beams in the intermediate image plane. So, preferably, no intersection point of the individual particle beams is provided between the field lens system and the object plane. In particular, no intersection point is subsequently provided in the region of the objective lens system.

[0079] According to a further aspect of the invention, the latter, as described above in a plurality of embodiment variants, relates to a multi-beam particle microscope having a particle beam system. In this case, the multi-beam particle microscope can, in a manner known per se, comprise a beam splitter to separate the primary particle beam from the secondary particle beam. Moreover, it can, in a manner known per se, comprise a detection unit which facilitates the spatially resolved detection of the secondary electron beam.

[0080] The embodiments described above with respect to the first and second aspects of the present invention may be combined with each other, either partially or wholly, as long as no technical contradictions occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] The present invention will be better understood with reference to the accompanying drawings. In the drawings:

[0082] Figure 1 Schematic illustration showing a multi-beam particle microscope;

[0083] Figure 2 Schematic illustration showing a multi-source system according to the present invention;

[0084] Figure 3 Schematic illustration showing a particle beam system including a multi-source system and further system components;

[0085] Figure 4 Schematic illustration showing a particle beam system including a multi-source system, an objective lens array, and further system components;

[0086] Figure 5 Particle beam system for correcting the direction of individual particle beams;

[0087] Figure 6 Schematic illustration showing a magnetic field generating member above a particle multi-source according to a first example;

[0088] Figure 7 Schematic illustration showing a hierarchy of magnetic field generating members having a particle multi-source according to a second example; and

[0089] Figure 8 Schematic illustration showing a magnetic field generating member above a particle multi-source according to a third example. DETAILED DESCRIPTION

[0090] Figure 1 FIG. 1 is a schematic illustration of a particle beam system 1 in the form of a multi-beam particle microscope 1 that uses multiple particle beams. The particle beam system 1 generates multiple particle beams that impinge on an object to be inspected to produce interaction products (such as secondary electrons) there, which are emitted from the object and subsequently detected. The particle beam system 1 is of the scanning electron microscope (SEM) type and uses a plurality of primary particle beams 3 that are incident on the surface of the object 7 at a plurality of positions 5 and produce a plurality of electron beam spots or points (which are spatially separated from each other) there. The object 7 to be inspected can be of any desired type, such as a semiconductor wafer or a biological sample, and includes an arrangement of miniaturized elements or the like. The surface of the object 7 is disposed in the first plane 101 (object plane) of the objective 102 of the objective lens system 100.

[0091] Figure 1 The enlarged excerpt I1 in [description] shows a plan view of the object plane 101 having a regular rectangular field 103 with an incident position 5 formed in the first plane 101. In Figure 1 it, the number of incident positions is 25, which forms a 5×5 field 103. The number 25 of incident positions is a number chosen for reasons of simplicity of illustration. In practice, the number of beams, and thus the number of incident positions, can be chosen to be significantly larger, such as 20×30, 100×100, and so on.

[0092] In the illustrated embodiment, the field 103 of the incident position 5 is a substantially regular rectangular field having a constant pitch P1 between adjacent incident positions. Exemplary values of this pitch P1 are 1 micron, 10 microns, and 40 microns. However, the field 103 can also have other symmetries, such as hexagonal symmetry, etc.

[0093] The diameter of the beam spot shaped in the first plane 101 can be small. Exemplary values of the aforementioned diameter are 1 nanometer, 5 nanometers, 10 nanometers, 100 nanometers, and 200 nanometers. The focusing of the particle beam 3 for shaping the beam spot 5 is performed by the objective lens system 100.

[0094] The primary particles impinging on the object generate interaction products, such as secondary electrons, backscattered electrons, or reversed primary particles that have undergone movement for other reasons, which are emitted from the surface of the object 7 or from the first plane 101. The said interaction products emitted from the surface of the object 7 are shaped by the objective lens 102 to form a secondary particle beam 9. The particle beam system 1 provides a particle beam path 11 for guiding the multiple secondary particle beams 9 to the detector system 200. The detector system 200 includes a particle optical unit having a projection lens 205 for directing the secondary particle beam 9 to the particle multi-detector 209.

[0095] Figure 1 The excerpt I2 in [description] shows a plan view of the plane 211 (in which the individual detection regions of the particle multi-detector 209, on which the secondary particle beam 9 is incident at positions 213, are located). The incident positions 213 are located in a field 217 having a regular pitch P2 relative to each other. Multiple exemplary values of this pitch P2 are 10 microns, 100 microns, and 200 microns.

[0096] The primary particle beam 3 is generated in a beam generating device 300, which includes at least one particle source 301 (such as an electron source), at least one collimating lens 303, a multi-aperture arrangement 305, and a field lens 307, or a field lens system composed of multiple field lenses. The particle source 301 generates at least one divergent particle beam 309, which is collimated or at least substantially collimated by at least one collimating lens 303 to shape the beam 311 irradiating the multi-aperture arrangement 305.

[0097] Figure 1 Excerpt I3 in it shows a plan view of the multi-aperture arrangement 305. The multi-aperture arrangement 305 includes a multi-aperture plate 313 having a plurality of openings or holes 315 formed therein. The midpoints 317 of the openings 315 are disposed in a field 319 which is imaged onto a field 103 formed by the beam point 5 in the object plane 101. The pitch P3 between the midpoints 317 of the holes 315 can have exemplary values of 5 microns, 100 microns, and 200 microns. The diameter D of the holes 315 is less than the pitch P3 between the midpoints of the holes. Exemplary values of the diameter D are 0.2×P3, 0.4×P3, and 0.8×P3.

[0098] Particles of the irradiation particle beam 311 pass through the holes 315 and form a particle beam 3. Particles of the irradiation beam 311 hitting the plate 313 are absorbed by the latter and do not contribute to the formation of the particle beam 3.

[0099] Due to the applied electrostatic field, the multi-aperture arrangement 305 focuses each of the particle beams 3 such that a beam focus 323 is formed in a plane 325. Alternatively, the beam focus 323 can be virtual. The diameter of the beam focus 323 can be, for example, 10 nanometers, 100 nanometers, and 1 micron.

[0100] The field lens 307 and the objective lens 102 provide a first imaging particle optical unit for imaging the plane 325 (where the beam focus 323 is formed) onto the first plane 101 such that the incident position 5 or the field 103 of the beam point appears there. If the surface of the object 7 is disposed in this first plane, the beam points are correspondingly formed on the object surface.

[0101] The objective lens 102 and the projection lens arrangement 205 provide a second imaging particle optical unit for imaging the first plane 101 onto the detection plane 211. Thus, the objective lens 102 is a lens that is part of both the first and the second particle optical units, while the field lens 307 belongs only to the first particle optical unit, and the projection lens 205 belongs only to the second particle optical unit.

[0102] The beam switch 400 is disposed in the beam path of the first particle optical unit between the multi-aperture arrangement 305 and the objective lens system 100. The beam switch 400 is also part of the second optical unit in the beam path between the objective lens system 100 and the detector system 200.

[0103] Further information about this multi-beam particle beam system and components used therein, such as, for example, particle sources, multi-aperture plates, and lenses, etc., can be obtained from a number of international patent applications WO 2005 / 024881A2, WO 2007 / 028595 A2, WO 2007 / 028596 A1, WO 2011 / 124352 A1, and WO 2007 / 060017A2 as well as the German patent applications DE 10 2013 016 113 A1 and DE 10 2013 014 976A1, the entire disclosures of which are hereby incorporated by reference herein for reference.

[0104] The multi-particle beam system further includes a computer system 10 configured to control the individual particle optical components of the multi-particle beam system and to evaluate and analyze signals obtained by the multi-detector 209. In this case, the computer system 10 can be constructed from a number of individual computers or components. In addition, it can include a controller according to the present invention.

[0105] Figure 2 A schematic illustration showing a multi-source system 500 according to the present invention. In this case, the multi-source system 500 includes a particle multi-source, which is illustrated in the exemplary example by particle sources 501, 502, 503, and 504. The particle multi-source is an array of electron emitters fabricated using MEMS technology. For example, the charged particles emitted are electrons generated by field emission. They form individual particle beams 3. Since the brightness of the individual particle sources 501, 502, 503, and 504 can deviate from each other, the individual particle beams 3 are pre-shaped in the multi-source system 500. Specifically, the beam current intensity of the individual particle beams 3 is set by the multi-source system 500. Further (coarse or preliminary) beam shaping is also possible or is schematically illustrated.

[0106] Specifically, electrons leave the tips of the particle sources 501, 502, 503, and 504, and the tips 511, 512, 513, and 514 are indicated by the tips of a "V".

[0107] After emission, the individual particle beams 3 pass through a first multi-aperture plate 521 (a voltage U1 has been applied thereto in the exemplary example). In this case, the first multi-aperture plate 521 serves as an extraction electrode. Here, the openings in the first multi-aperture plate 521 are selected such that the first aperture plate 521 blocks multiple portions of the emitted individual particle beams.

[0108] A first multi-lens array 523 is disposed in the beam path downstream of the first multi-aperture plate 521. It has multiple individually adjustable particle lenses, which are in Figure 2as shown by the flat cylinders. For example, these can be toroidal electrodes. In the example shown, the voltage U2+V i is applied to the first multi-lens array 523. In this case, the particle lenses of the first multi-lens array 523 can be controlled by the controller 10. The controller 10 is arranged to supply individually adjustable excitations to the particle lenses and thus individually adjust the focusing of the associated particle lenses for each individual particle beam 3. The second multi-aperture plate 522 is arranged in the beam path downstream of the first multi-lens array 523. In the example shown, a voltage U1 is substantially applied thereto. Thus, the first multi-aperture plate 521, the first multi-lens array 523, and the second multi-aperture plate 522 form a series of single lenses for the individual particle beams 3. Overall, a focusing effect on the individual particle beams is manifested.

[0109] The focusing effect on the individual particle beams varies depending on how large the voltage V i is selected. They are focused differently or expanded to different extents. This is evident when considering the beam current limiting multi-aperture plate 524 (which is arranged in the beam path downstream of the second multi-aperture plate 522). The openings in the beam current limiting multi-aperture plate 524 are smaller in diameter than the openings in the second multi-aperture plate 522 and in the first multi-lens array 523. Generally, all plates or arrays are arranged such that their openings are located above each other in a concentrated manner. According to an alternative embodiment of the invention, the second multi-aperture plate 522 and the beam current limiting multi-aperture plate 524 can also be functionally combined or merged with each other.

[0110] In the example shown, the voltage V1 is selected such that the associated lens is strongly excited or the individual particle beam 3 is strongly focused. In this process, almost all of it passes through the beam current limiting multi-aperture plate 524. In contrast, the second and fourth lenses of the first multi-lens array 523 are less strongly excited, and the individual particle beam 3 passing between them is expanded to a larger extent. Thus, a larger proportion of the associated individual particle beam 3 is blocked by the beam current limiting multi-aperture plate 524. The third lens in the first multi-lens array 523 is strained the least, and the associated individual particle beam 3 is expanded to the maximum possible extent. Thus, in this case, a larger portion of the individual particle beam 3 is blocked at the beam current limiting multi-aperture plate 524. The voltages at the lenses in the first multi-lens array 523 can now be selected in a targeted manner such that the beam current intensity of the individual particle beam 3 is approximately the same after passing through the beam current limiting multi-aperture plate 524. Thus, the different brightness levels of the particle sources 501, 502, 503, and 504 can be corrected or pre-corrected for subsequent particle optical imaging. Preferably, immediately after passing through the beam current limiting multi-aperture plate 524, the following relationship applies to the deviation δ of the individual beam current from the arithmetic mean of the beam currents: δ ≤ 5%, preferably δ ≤ 2%, and optimally δ ≤ 1%.

[0111] A multi-deflector array 525 is provided in the beam path below the beam current limiting multi-aperture plate 524. This multi-deflector array can likewise be excited by the controller 10. Here, a voltage U2 can be applied in a targeted and individual manner to each aperture in the multi-deflector array 525. The direction of the respective particle beam 3 can be corrected based on the applied voltage and the direction of the electric field in the deflector. This is particularly important if the beam 3 impinges on the beam current limiting multi-aperture plate 524 in a manner that is not exactly parallel to the optical axis Z (not illustrated here). This can be the case if the alignment of the plates is not perfect; in practice, the accuracy in aligning the plates relative to one another is limited, for example resulting in an inclined beam axis. For the rightmost respective particle beam 3 originating from the source 504, the correction function of the deflectors of the multi-deflector array 525 is illustrated by way of example: in this case, the respective particle beam 3 is deflected significantly to the left.

[0112] Furthermore, in the exemplary embodiment shown, the multi-source system 500 includes a multi-astigmatism corrector array 526.

[0113] In the exemplary embodiment shown, all components of the multi-source system 500 can be controlled by the controller 10. In this case, the controller 10 can be the same as the overall controller of the multi-beam particle microscope 1. However, this may also be a separate controller 10.

[0114] Here, the multi-source system 500 is relatively small in the direction of the optical axis Z (not depicted): in the exemplary embodiment shown, the overall extent in the direction of the optical axis Z can be less than 20 mm.

[0115] Figure 3 A schematic illustration showing a particle beam system 1 including a multi-source system 500 and further system components is presented. The beam path is shown in a very simplified manner. In particular, Figure 3 It is shown that the multi-source system 500 according to the invention is integrated in an existing particle beam system 1. Multiple respective particle beams 3 are generated by means of the multi-source system 500, and the respective particle beams 3 are pre-shaped. In particular, the different brightness levels of the particle sources 501, 502, 503 are compensated for in this process. A condenser lens system CL1..N is provided in the beam path downstream of the multi-source system 500. In particular, this can be multiple condenser lens systems. However, it would also be possible to replace the global condenser lens CL1..N with a condenser lens array.

[0116] The final beam shaping system 600 is arranged in the beam path downstream of the condenser lens system CL1..N. The latter is only shown in a schematic and highly simplified manner. It includes the final multi-aperture plate. However, it may also still include further particle optical components, such as a third multi-lens array or an astigmatism corrector array, etc. Importantly, the final beam shaping of the individual particle beams 3 for enabling high-quality imaging is carried out by means of the final beam shaping system 600. In this case, the individual particle beams are intercepted by the final multi-aperture plate, and only the centrally arranged individual particle beam components pass through the final multi-aperture plate. This allows for the elimination or compensation in further beam paths of aberrations (which occur in the multi-source system 500 during beam shaping or which have not yet occurred in further beam paths). After passing through the final beam shaping system 600, the individual particle beams 3 are focused into the intermediate image plane 325. It is thus taken into account that, Figure 3 the illustrative diagrams in Figure 3 are also highly simplified to clearly ensure an appropriate level. Then, by subsequent particle optical imaging, the individual particle beams 3 focused into the intermediate image plane 325 are imaged onto the object plane 101. For this purpose, they initially pass through the field lens system FL1..N (by means of which the individual particle beams 3 are focused). The individual particle beams 3 cross at the crossover point 401, are then focused by the global objective lens 102 (in this case the global magnetic objective lens 102), and are imaged onto the sample 7 in the object plane 101 at the incidence position 5. Secondary electron beams 9 emanate from the incidence position 5, and these are separated from the main beam 3 by means of the beam switch 400. For simplicity, the detection system 200 with the particle multi-detector 209 is not shown in

[0117] In summary, Figure 3 shows the combination of the multi-source system 500 according to the invention and the final beam shaping system 600 with global lens elements.

[0118] Figure 4 Shows a further schematic illustrative diagram of a particle beam system 1 comprising a multi-source system 500 and further system components. The beam path is presented in a highly simplified manner. In the illustration, the same reference signs denote the same elements. Only the differences between Figure 3 and Figure 4 are discussed in more detail below. Different from Figure 3 Figure 4 includes an objective lens array 102a. The latter is schematically illustrated and may be realized, for example, by a single lens array. Different from Figure 3 [[ID=319Figure 4 Shows the combination of the multi-source system 500 and the final beam shaping system 600 according to the present invention, both of which have global lens elements (condensing lens systems CL1..N and field lens systems FL1..N), and have a further microlens system in the form of an objective lens array 102a. Here, the objective lens array 102a can have different configurations. For example, it can include a plurality of sequentially arranged multi-aperture plates to which a voltage is applied in a suitable manner and especially by the controller 10. Additionally or alternatively, the objective lens array 102a can include a further multi-lens array. In Figure 4 the illustrated embodiment variant, instead of the beam switch 400 incorporated into the projection path of the detection unit (the latter two not illustrated), a detection unit with a segmented detector can also be provided in the region of the objective lens array 102a.

[0119] Figure 5 Shows a particle beam system 1 for correcting the direction of individual particle beams 3 in a schematic and very simplified manner. The multi-source system 500 with its particle sources 501, 502, 503, and 504 is combined with the final beam shaping system 600. The final beam shaping system 600 includes a final multi-lens plate 601 through which the individual particle beams 3a, 3b, 3c, and 3d pass. A final multi-aperture plate (not illustrated here) is provided above the multi-lens plate 601. Moreover, the final beam shaping system 600 includes aperture plates 620, 630, and 640 to which a global electric field can possibly be applied. Thus, the electrostatic field can be shaped in a targeted manner in the region of the final beam shaping system 600. As an alternative, a magnetic field can also be used for this purpose.

[0120] Specifically, the electromagnetic field also affects the extraction field close to the last multi-aperture plate: depending on the voltage applied to electrodes 620, 630, 640, the lens field in the multi-lens plate 601, and thus the focusing effect on individual beams can have different intensities. In particular, appropriate voltages at the electrodes 620 - 640 make it possible for the lens field to have a weaker focusing effect on individual particle beams in the outer regions (3a, 3d) than in the inner regions (3b, 3c). Thus, the possible field curvature can be compensated, the focal distribution of the foci in the image field having a relative profile. However, in this case, the field distribution at the electrodes 620 to 640 also acts on the intermediate image in a reduced-size manner; that is, the beam pitch between the beams in the intermediate image plane becomes smaller. The multi-deflector array 610 provided between the multi-source system 500 and the last beam shaping system 600 contributes to correcting the beam pitch of the individual particle beams 3a, 3b, 3c, and 3d in the intermediate image (not illustrated here). In the example shown, each of the individual particle beams 3a and 3b is deflected to the left, while the individual particle beams 3c and 3d are deflected to the right by appropriately controlling the deflectors in the multi-deflector array 610. By means of this embodiment variant, it is possible to affect the pitch between the individual particle beams 3 in the intermediate image plane. Specifically, a negative field curvature can be generated in the intermediate image plane. The amplitude of this negative field curvature can be selected such that it completely compensates for the (positive) field curvature that subsequently occurs during particle optical imaging from the intermediate image plane to the object plane. Thus, in that case, no further field curvature correction is required.

[0121] Generating a magnetic field in the region of the particle multi-source allows for the targeted application of generalized angular momentum to the emitted particles or electrons, the aforementioned generalized angular momentum overall contributing to the individual particle beams being telecentrically incident in the object plane 101 after passing through the particle beam system. The Larmor rotation caused by the magnetic immersion in the region of the objective lens can be compensated. In this regard, Figures 6 to 8 Several examples are shown:

[0122] Figure 6 a shows a magnetic field generating member 700 for generating a divergent magnetic field. For this purpose, multiple coil windings 702 are provided in the pole shoe 701, having a rotationally symmetric embodiment around the optical axis Z. The magnetic field B is oriented as indicated by the reference numeral 703. Projected onto the emitter plane of the multi-source system 500, the magnetic field B has a component perpendicular to the optical axis Z. At right angles to this radial direction, the emitted electrons experience a corresponding initial angle distribution. The initial velocity vectors projected onto the emitter plane are schematically illustrated by multiple arrows in Figure 6 b.

[0123] Figure 7a shows a magnetic field generating member for generating a homogeneous magnetic field. This magnetic field substantially has no component orthogonal to the starting direction of the emitted electrons. Thus, the corresponding starting angle distribution is punctual or not present (see Figure 7 b).

[0124] Figure 8 a shows a further example for shaping the magnetic field to apply a dedicated starting angle distribution in the magnetic field to the emitted electrons. Two concentric pole shoes 701 and 701a are illustrated; each of them contains multiple coil windings 702 and 702a respectively. The direction of the magnetic field lines is indicated by 703. They are oriented in the relative direction between the two pole slots 701 and 701a. Thus, for the emitted electrons, this also generates a starting angle distribution traveling in the relative direction (see Figure 8 b).

[0125] Generally, a magnetic field is provided that is applied in such a way that during emission from multiple sources, the starting angle distribution of the electrons can be influenced in a targeted manner, subsequently ensuring the telecentric condition in the particle beam system 1 immediately after incidence on the object 7. This is particularly helpful for a good inspection of the HAR structure.

[0126] List of reference numerals

[0127] 1 Multi-beam particle microscope

[0128] 3 Primary particle beam (individual particle beam)

[0129] 5 Beam point, incidence position

[0130] 7 Object

[0131] 9 Secondary particle beam

[0132] 10 Computer system, controller

[0133] 100 Objective lens system

[0134] 101 Object plane

[0135] 102 Objective lens

[0136] 102a Objective lens array

[0137] 103 Field

[0138] 200 Detector system

[0139] 205 Projection lens

[0140] 209 Particle multi-detector

[0141] 211 Detection plane

[0142] 213 Incident position

[0143] 217 Field

[0144] 300 Beam generation device

[0145] 301 Particle source

[0146] 303 Collimating lens system

[0147] 305 Multi-aperture setting

[0148] 313 Multi-aperture plate

[0149] 315 Openings in the multi-aperture plate

[0150] 317 Midpoints of the openings

[0151] 319 Field

[0152] 307 Field lens system

[0153] 309 Divergent particle beam

[0154] 311 Irradiating particle beam

[0155] 323 Beam focus

[0156] 325 Intermediate image plane

[0157] 400 Beam switch

[0158] 401 Intersection point

[0159] 500 Multi-source system

[0160] 501 First particle source

[0161] 502 Second particle source

[0162] 503 Third particle source

[0163] 504 Fourth particle source

[0164] 511 First tip

[0165] 512 Second tip

[0166] 513 Third tip

[0167] 514 Fourth tip

[0168] 520 Suppression electrode

[0169] 521 First multi-aperture plate, extractor

[0170] 522 Second multi-aperture plate, corresponding electrode

[0171] 523 First multi-lens array

[0172] 524 Beam current limiting multi-aperture plate

[0173] 525 Multi-deflector array

[0174] 526 Multi-astigmatism corrector array

[0175] 600 Final beam shaping system

[0176] 601 Multi-lens plate

[0177] 610 Multi-deflector array

[0178] 620 Aperture plate

[0179] 630 Aperture plate

[0180] 640 Aperture plate

[0181] 650 Electric field lines

[0182] 700 Magnetic field generating component

[0183] 701 Pole piece

[0184] 702 Coil

[0185] 703 Magnetic field

[0186] Z optical axis

Claims

1. A particle beam system (1), comprising: A multi-source system (500), comprising: A particle multi-source configured to generate multiple charged individual particle beams (3) by field emission; A first multi-aperture plate (521) having multiple first openings through which at least part of the individual particle beams (3) pass; A first multi-lens array (523) comprising multiple individually adjustable particle lenses and arranged in the beam path downstream of the first multi-aperture plate (521) such that the individual particle beams (3) passing through the first multi-aperture plate (521) also pass through the first multi-lens array (523); A second multi-aperture plate (522) having multiple second openings and arranged in the beam path downstream of the first multi-lens array (523) such that the individual particle beams (3) passing through the first multi-lens array (523) also pass through the second multi-aperture plate (522); and A beam current limiting multi-aperture plate (524) having multiple beam current limiting openings and arranged in the beam path downstream of the second multi-aperture plate (522) such that part of the individual particle beams (3) are incident on the beam current limiting multi-aperture plate (524) and absorbed there, and part pass through the openings in the beam current limiting multi-aperture plate (524); And A first multi-deflector array (610) through which the individual particle beams (3) pass, and the first multi-deflector array is arranged in the beam path downstream of the beam current limiting multi-aperture plate (524); And A controller (10) configured to supply an individually adjustable voltage to the particle lenses of the first multi-lens array (523) and thus individually adjust the focusing of the associated particle lenses for each individual particle beam (3), and wherein the controller (10) is further configured to supply individually adjustable excitations to the first multi-deflector array (610) and thus individually deflect the individual particle beams (3) such that the pitch between the individual particle beams in the intermediate image plane is affected.

2. The particle beam system (1) according to claim 1, further comprising: A final beam shaping system (600) arranged in the beam path downstream of the multi-source system (500), and through the final beam shaping system, the individual particle beams (3) have a final shape for subsequent optical imaging.

3. The particle beam system (1) according to claim 1 or 2, Wherein the particle multi-source is an electron emitter array configured to generate multiple charged individual particle beams (3) by field emission.

4. The particle beam system (1) according to claim 1 or 2, Wherein the first multi-aperture plate (521) is implemented as an extraction electrode; and / or Wherein the second multi-aperture plate (522) is implemented as a corresponding electrode; and / or Wherein the beam current limiting multi-aperture plate (524) is implemented as an anode.

5. The particle beam system (1) according to claim 1 or 2, Wherein the same first voltage (U1) is applied to the first multi-aperture plate (521) and the second multi-aperture plate (522); and wherein an individual adjustable voltage (U2+V i ) at the first multi-lens array (523) is different from the first voltage (U1).

6. The particle beam system (1) according to claim 1 or 2, Wherein the following applies to the distance A between the particle multi-source and the beam current limiting multi-aperture plate (524): 0.1 mm ≤ A ≤ 30 mm.

7. The particle beam system (1) according to claim 1 or 2, Wherein the following applies to the distance A between the particle multi-source and the beam current limiting multi-aperture plate (524): 0.1 mm ≤ A ≤ 20 mm.

8. The particle beam system (1) according to claim 1 or 2, Wherein the following applies to the distance A between the particle multi-source and the beam current limiting multi-aperture plate (524): 0.1 mm ≤ A ≤ 10 mm.

9. The particle beam system (1) according to claim 1 or 2, wherein immediately after passing through the beam current limiting multi-aperture plate (524), the following relationship applies to the deviation δ of the individual beam current from the arithmetic mean of the beam currents: δ ≤ 5%.

10. The particle beam system (1) according to claim 1 or 2, wherein immediately after passing through the beam current limiting multi-aperture plate (524), the following relationship applies to the deviation δ of the individual beam current from the arithmetic mean of the beam currents: δ ≤ 2%.

11. The particle beam system (1) according to claim 1 or 2, wherein immediately after passing through the beam current limiting multi-aperture plate (524), the following relationship applies to the deviation δ of the individual beam current from the arithmetic mean of the beam currents: δ ≤ 1%.

12. The particle beam system (1) according to claim 1 or 2, Wherein the multi-source system (500) further comprises a suppression electrode (520).

13. The particle beam system (1) according to claim 1 or 2, Wherein the multi-source system (500) comprises a second multi-lens array, wherein the second multi-lens array comprises multiple individually adjustable and focusable particle lenses and is arranged in the beam path downstream of the beam current limiting multi-aperture plate (524) such that the particles of the individual particle beams (3) passing through the beam current limiting multi-aperture plate (524) substantially also pass through the second multi-lens array; and Wherein the controller (10) is further arranged to supply an individually adjustable voltage to the particle lenses of the second multi-lens array and thereby individually set the focusing of the associated particle lenses for each individual particle beam.

14. The particle beam system (1) according to claim 1 or 2, Wherein the multi-source system (500) further comprises a multi-astigmatism corrector array through which the individual particle beams pass; and Wherein the controller (10) is further arranged to supply an adjustable excitation to the multi-astigmatism corrector array.

15. The particle beam system (1) according to claim 1 or 2, wherein the multi-source system (500) is at least partially manufactured by MEMS technology.

16. The particle beam system (1) according to claim 1 or 2, Wherein the particle multi-source has at least one of the following emitter types: metal emitter, silicon-based emitter, carbon nanotube-based emitter.

17. The particle beam system (1) according to claim 1 or 2, further comprising a magnetic field generating member (700) arranged such that the particle multi-source is arranged in a magnetic field (703).

18. The particle beam system (1) according to claim 17, wherein the magnetic field (703) generated by the magnetic field generating member (700) has a component perpendicular to and / or a component parallel to the emission direction of the charged particles from the particle multi-source.

19. The particle beam system (1) according to claim 18, wherein the magnetic field generating member (700) is implemented such that the initial angular distribution of the charged particles caused by the magnetic field (703) after the charged particles exit from the particle sources (501, 502, 503, 504) depends on the radial distance between the respective particle sources (501, 502, 503, 504) and the optical axis of the particle beam system (1).

20. The particle beam system (1) according to claim 2, further comprising: a condenser lens system (CL1..N) disposed downstream of the multi-source system (500) and upstream of the final beam shaping system (600) in the direction of the beam path; a field lens system (FL1..N) disposed downstream of the final beam shaping system (600) in the direction of the beam path; and an objective lens system (102, 102a) disposed downstream of the field lens system (FL1..N) in the direction of the beam path, wherein an intermediate image plane (325) is formed between the final beam shaping system (600) and the field lens system (FL1..N).

21. The particle beam system (1) according to claim 20, wherein the final beam shaping system (600) comprises: a final multi-aperture plate having multiple openings arranged such that the individual particle beams (3) are partially incident on the final multi-aperture plate and absorbed therein, and partially pass through the openings in the final multi-aperture plate; and a second multi-lens array comprising multiple adjustable particle lenses and disposed in the beam path downstream of the final multi-aperture plate such that the individual particle beams (3) passing through the final multi-aperture plate substantially also pass through the second multi-lens array.

22. The particle beam system (1) according to claim 21, wherein the final beam shaping system (600) comprises: a final multi-aperture plate having multiple openings arranged such that the individual particle beams are partially incident on the final multi-aperture plate and absorbed therein, and partially pass through the openings in the final multi-aperture plate; a multi-lens plate (601) having multiple openings disposed in the beam path downstream of the final multi-aperture plate such that the individual particle beams (3) passing through the final multi-aperture plate also pass through the multi-lens plate (601); and at least one first aperture plate (620, 630, 640) having a single opening and disposed in the beam path downstream of the multi-lens plate (601) such that the individual particle beams (3) passing through the multi-lens plate (601) also pass through the opening in the at least one first aperture plate (620, 630, 640); and wherein the controller is further arranged to supply an adjustable excitation to the at least one first aperture plate (620, 630, 640).

23. The particle beam system (1) according to claim 22, further comprising: A second multi-deflector array, arranged in the beam path just upstream of the last multi-aperture plate; and wherein the controller is further arranged to supply individually adjustable excitations to the second multi-deflector array and thereby individually deflect the individual particle beams (3).

24. The particle beam system (1) according to claim 20, wherein the condenser lens system (CL1..N) comprises one or more global condenser lenses.

25. The particle beam system (1) according to claim 20, wherein the condenser lens system (CL1..N) comprises an electrostatic or magnetic double condenser.

26. The particle beam system (1) according to claim 20, wherein the condenser lens system (CL1..N) comprises a condenser lens array having multiple openings through which the individual particle beams (3) pass.

27. The particle beam system (1) according to claim 20, wherein the objective lens system (102) comprises a global magnetic objective lens (102).

28. The particle beam system (1) according to claim 20, wherein the objective lens system (102) comprises an objective lens array (102a) having multiple openings arranged in the beam path such that the individual particle beams (3) pass through the openings in the objective lens array (102a).

29. The particle beam system (1) according to claim 28, wherein no intersection of the individual particle beams (3) is provided between the field lens system (FL1..N) and the object plane (101).

30. A multi-beam particle microscope (1) comprising a particle beam system (1) according to any one of the preceding claims.

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