Apparatus and method for particle beam analysis and / or processing of a sample

Abstract

A device (100) for analyzing and / or processing a sample (200) using a particle beam (112) is proposed, comprising a sample stage (120) for holding the sample (200); a providing unit (110) for providing the particle beam (112), the providing unit (110) comprising an opening (114) for directing the particle beam (112) to a processing location (202) on the sample (200); and a shielding element (116) for shielding an electric field (E) generated by a charge (Q) accumulated on the sample (200); wherein the shielding element (116) covers the opening (114), is implemented in a sheet-like form, and comprises an electrically conductive material; wherein the shielding element (116) comprises a raised portion (117) which is raised with respect to the sample stage (120); and wherein the raised portion (117) has a through-hole (118) for the particle beam (112) to pass through to the sample (200).

Description

Technical Field

[0001] This invention relates to an apparatus and a corresponding method for using particle beams to analyze and / or process samples.

[0002] The contents of priority application DE 10 2020 124 306.5 are incorporated herein by reference in their entirety. Background Technology

[0003] Microlithography is used to produce microstructured components, such as integrated circuits. Microlithography processes are performed using a microlithography apparatus equipped with an illumination system and a projection system. In this case, an image of a mask (shield) illuminated by the illumination system is projected onto a substrate (e.g., a silicon wafer) via the projection system. The substrate is coated with a photosensitive layer (photoresist) and positioned within the image plane of the projection system to transfer the mask structure onto the photosensitive coating of the substrate.

[0004] In this context, the mask, or microlithography mask, is used for extensive exposure, making it crucial that the mask be free of defects. Consequently, significant effort is made to inspect the microlithography mask for defects and repair any identified ones. Defects in microlithography masks can be on the order of several nanometers. Repairing such defects requires equipment that provides extremely high spatial resolution for the repair process.

[0005] Suitable devices for this purpose are based on particle beam-induced processes that activate local etching or deposition processes.

[0006] EP 1 587 128 B1 discloses an apparatus that uses a beam of charged particles, particularly an electron beam from an electron microscope, to initiate a chemical process. Using charged particles can induce charging of the sample, provided the sample is non-conductive or has only poor conductivity. This can lead to uncontrolled beam deflection, thus limiting the achievable process resolution. Therefore, it is proposed to configure the shielding element very close to the processing location to minimize sample charging and improve process resolution and process control.

[0007] For the required repair process, the treatment gas must be brought to the treatment location. Typical treatment gases may already be highly reactive in their ground state; furthermore, highly reactive atoms or molecules may be introduced during the treatment process, which may, for example, attack and / or deposit on components of the particle beam apparatus. This can lead to shorter maintenance intervals for the corresponding particle beam apparatus and / or process instability.

[0008] The processing speed achievable with this particle beam-induced process depends in particular on the processing gas pressure at the processing location. For high processing speeds, a high processing gas pressure at the processing location is preferable. This can be achieved, for example, by supplying processing gas through the particle beam outlet, whereby the processing gas can then flow unimpeded into the particle beam apparatus. On the other hand, from the perspective of the lifespan of the components used, efforts should be made to minimize the flow of processing gas from the processing location into the particle beam apparatus.

[0009] DE 102 08 043A1 discloses a material handling system that can be used in a material handling method that involves material deposition from a gas, such as CVD (chemical vapor deposition), or material removal using a supplied reactive gas. In this case, in particular, the gaseous reaction leading to material deposition or material removal is initiated by an energy beam directed to a region of the workpiece to be treated. Summary of the Invention

[0010] In this context, one object of the present invention is to provide an improved apparatus for analyzing and / or processing samples using a particle beam.

[0011] According to a first aspect, an apparatus for analyzing and / or processing samples using a particle beam is proposed. The apparatus includes a sample stage for holding the sample and a providing unit for providing the particle beam. The providing unit includes an opening for guiding the particle beam to a processing position on the sample and a shielding element for shielding an electric field generated by charges accumulated on the sample. The shielding element covers the opening, is implemented in a sheet-like manner, and comprises a conductive material. Furthermore, the shielding element includes a protrusion relative to the sample stage and has a through-hole for the particle beam to pass through to the sample.

[0012] The advantage of this device is that the uncontrolled influence of the electric field formed between the shielding element and the sample due to the charge on the sample or sample surface on the particle beam is reduced. Because of the protruding portion of the shielding element, the distance between the shielding element and the sample surface can be kept very small in the region of the processing position, without having to keep the entire shielding element at a very small distance, thus reducing the complexity of positioning the sample relative to the shielding element. It can also be said that it increases the leeway regarding the tilt between the sample and the providing unit.

[0013] The apparatus includes a sample stage for holding a sample. Preferably, the sample stage is disposed within a vacuum housing. The sample stage preferably has a positioning unit for positioning the sample stage relative to a providing unit. The positioning unit may be configured to move the sample stage, for example, along three spatial axes. Furthermore, the positioning unit may be configured to rotate the sample stage about at least one, preferably at least two, of these axes. The sample stage is preferably held by a holding structure in a vibration-decoupled and / or actively damped manner.

[0014] The particle beam contains charged particles, such as ions, electrons, or positrons. Therefore, the providing unit has a beam generating unit, for example, containing an ion source or an electron source. The particle beam composed of charged particles can be influenced by electric and magnetic fields, i.e., accelerated, directed, shaped, and / or focused, for example. For this purpose, the providing unit may have multiple elements configured to generate the corresponding electric and / or magnetic fields. These elements are particularly arranged between the beam generating unit and a shielding element. The particle beam is preferably focused onto a processing location. This is understood to mean, for example, that the particle beam has a predetermined diameter, particularly a minimum diameter, when it impacts the processing location. The providing unit preferably includes a dedicated housing in which the aforementioned elements are disposed, preferably implemented as a vacuum housing, which is maintained, for example, at 10... -7 -10 -8 Under residual gas pressure of millibars.

[0015] A shielding element is disposed on an opening at the supply unit through which the particle beam is guided to the processing position on the sample, and the shielding element is thus formed in the beam direction of the supply unit closest to the sample stage.

[0016] For example, consider a scanning electron microscope. To achieve high resolution, the electron beam must be controlled very precisely, particularly regarding electron energy, beam diameter at the point of impact on the sample (hereinafter referred to as the focal point), and temporal stability of the impact point. Especially when the sample has portions composed of non-conductive or only slightly conductive materials, the incidence of charged particles leads to charge accumulation on the sample, which creates an electric field. The particles in the particle beam, as well as secondary electrons and backscattered electrons detected for image generation, are affected by this electric field, which can lead to, for example, a reduction in resolution.

[0017] The shielding element performs the task of shielding the electric field of the charge, that is, spatially defining the electric field, specifically defining it to the minimum possible gap between the shielding element and the sample. For this purpose, the shielding element contains a conductive material. For example, the shielding element is grounded, so that the charge striking the shielding element is dissipated.

[0018] The shielding element itself is implemented in a sheet-like manner, forming a three-dimensional shape with raised portions on its surface that protrude relative to the sample stage. The raised portions are preferably located closest to the sample stage, meaning the distance between the sample stage or sample and the shielding element is minimized in the area of ​​the raised portions.

[0019] The surface of the shielding element forms raised areas, especially in the raised portions.

[0020] In this context, "protrusion" is understood to mean that the cross-sectional edge of the shielding element extending through the protrusion has a protruding profile according to a mathematical definition of the protrusion. This definition is as follows:

[0021] Function f: C→R, where C is a function of R. n A convex subset of C is called convex if the following equation (1) holds for all x, y in C and for all a in the interval [0,1].

[0022] f(a·x+(1–a)·y)≤·a·f(x)+(1-a)·f(y) Equation (1).

[0023] In equation (1), R n This represents an n-dimensional vector space over the real number system. In the case of a shielding element, n = 2, i.e., R. n =R 2 C is the projection of the shielding element onto the sample stage, and f describes the height of the shielding element above the sample stage.

[0024] For the case where the relationship between the left and right sides of equation (1) does not include the "equal to" case, i.e., requiring a true "less than", and if the cases x = y and a = 0 or a = 1 are excluded, this is also referred to in technical terms as a strict convexity. A preferred embodiment of a convex portion in a shielding element is such that the edge of the cross-section of the shielding element passing through the convex portion has a strictly convex orientation in this sense. Examples of regions with this shape are spheres or segments of spheres. Furthermore, if a body of revolution is formed based on a function, such as a parabola of revolution formed by the rotation of a parabola, a strictly convex function will produce a corresponding region.

[0025] In the raised portion, the shielding element has through-holes through which the particle beam passes and is incident on the sample. In the space above the shielding element (from which the particle beam originates), the electric field of the charge on the sample is effectively shielded by the shielding element. Note that the shielding element may have more through-holes, and one or more of these through-holes may also be configured on the outside of the raised portion of the shielding element.

[0026] For example, during sample analysis or processing using a particle beam, the distance between the protruding portion of the shielding element and the sample is at most 1 mm, preferably at most 500 μm, preferably at most 100 μm, preferably at most 50 μm, preferably at most 25 μm, and preferably at most 10 μm. The smaller the distance, the less influence the electrical interference field has on the particle beam.

[0027] Therefore, particle beams can be controlled very precisely and are less affected by random and / or uncontrollable disturbances. Consequently, very high resolution can be achieved during image acquisition (such as in scanning electron microscopy) and during processing methods performed using particle beams (such as particle beam-induced etching or deposition processes, ion implantation, and / or further structural modification processes).

[0028] The providing unit can be, for example, an electron column, which can provide an electron beam with an energy range of 10 eV to 10 keV and a current range of 1 μA to 1 pA. However, it can also be an ion source providing an ion beam. The focused particle beam is preferably focused onto the surface of the sample, for example, to achieve an irradiation area with a diameter in the range of 1 nm to 100 nm.

[0029] The shielding element has a length and width, for example, ranging from 1 mm to 50 mm.

[0030] The material thickness of the shielding element ranges, for example, from 1 nm to 100 μm, preferably from 10 nm to 100 μm, more preferably from 100 nm to 50 μm, even more preferably from 1 μm to 30 μm, and even more preferably from 5 μm to 15 μm. The material thickness of the shielding element is selected in a suitable manner depending on the expected mechanical and / or thermal loads, such as due to pressure differentials, electrostatic forces, etc. If a particularly thin material thickness is required, the shielding element can be implemented, for example, as a film or as a self-supporting membrane.

[0031] The cross-sectional area of ​​the through hole can range, for example, from 100 μm. 2 -2500μm 2 Between, preferably 400μm 2 -1600μm 2 Between, preferably at 750μm 2 -1400μm 2 between.

[0032] The diameter of the through-hole is, for example, between 10 μm and 50 μm, preferably between 20 μm and 40 μm, and even more preferably between 25 μm and 35 μm. The diameter is, for example, related to the distance between two oppositely arranged points of the through-hole.

[0033] The protrusion has a diameter ranging from, for example, 100 μm to 5 mm, preferably 500 μm to 3 mm, and more preferably 1 mm to 2 mm, and extends in the direction toward the sample stage by a distance of, for example, at least 10 μm, preferably at least 50 μm, and more preferably at least 100 μm. That is, the difference between the distance between the nearest point of the shielding element and the sample stage and the distance between the farthest point of the shielding element and the sample stage is at least 10 μm, preferably at least 50 μm, and most preferably at least 100 μm.

[0034] According to one specific embodiment of the device, the device includes a gas supplier configured to supply processing gas through a through-hole in a shielding element to a processing location on the sample.

[0035] In this specific embodiment, the processing gas flows through a through-hole in the direction of the particle beam. In this specific embodiment, it is advantageous if the flow resistance through the through-hole is as low as possible, so that the processing gas can be efficiently and purposefully guided to the processing location. Furthermore, an aperture can be provided to restrict the gas flow direction opposite to the particle beam to the supply unit. In this case, the processing gas is supplied, for example, to the region between the shielding element and the aperture. If the shielding element has multiple openings, the processing gas can flow through each of the multiple openings, which is advantageous for reducing flow resistance.

[0036] According to another specific embodiment of the apparatus, the apparatus includes a gas supply configured to supply processing gas to a gap, wherein the gap is formed by a sample disposed on a sample stage and by a shielding element.

[0037] The processing gas flows through a gap to the processing position on the sample. This specific embodiment is advantageous because the processing gas supplied to the processing position can be well controlled in this way. In particular, the flow rate of the processing gas flowing into the supply unit in the opposite direction of the beam is reduced because only the through-hole is available for this purpose. Corrosion of the components of the supply unit (especially the detector) can therefore be reduced due to contact with the processing gas and / or the reactive molecules formed by the processing gas.

[0038] The supply unit has, for example, a circulation plate containing an opening for the particle beam. A gas supply is provided, for example, through the circulation plate via a supply opening on the sample-facing side of the plate. The processing gas can then flow through the gap between the sample and the shielding element to the processing position.

[0039] The sample is, for example, a micro-lithography mask with a feature size in the range of 10 nm to 10 μm. For instance, this could be a transmissive lithography mask for DUV lithography (DUV: "deep ultraviolet light," operating wavelength in the range of 30-250 nm) or a reflective lithography mask for EUV lithography (EUV: "extreme ultraviolet light," operating wavelength in the range of 1-30 nm). The processing in this case includes, for example, etching processes that locally remove material from the sample surface, deposition processes that locally apply material to the sample surface, and / or similar local activation processes, such as forming a passivation layer or a compaction layer.

[0040] Suitable process gases for deposition materials or for growing elevated structures, particularly alkyl compounds of main group elements, metals, or transition elements. Examples include cyclopentadienyltrimethylplatinum CpPtMe3 (Me=CH4), methyl-cyclopentadienyltrimethylplatinum MeCpPtMe3, tetramethyltin SnMe4, trimethylgallium GaMe3, ferrocene Cp2Fe, diarylchromium Ar2Cr, and / or carbonyl compounds of main group elements, metals, or transition elements (e.g., hexacarbonylchromium Cr(CO)6, hexacarbonylmolybdenum Mo(CO)6, hexacarbonyltungsten W(CO)6, octacarbonyldicobalt Co2(CO)8, dodecacarbonyltriruthenium Ru3(CO)). 12 Iron pentacarbonyl Fe(CO)5), and / or alkoxy compounds of main group elements, metals, or transition elements (e.g., tetraethyl orthosilicate Si(OC2H5)4, titanium tetraisopropoxy Ti(OC3H7)4), and / or halide compounds of main group elements, metals, or transition elements (e.g., tungsten hexafluoride WF6, tungsten hexachloride WCl6, titanium tetrachloride TiCl4, boron trifluoride BF3, silicon tetrachloride SiCl4), and / or complexes containing main group elements, metals, or transition elements (e.g., bis(hexafluoroacetylacetone)copper Cu(C5F6HO2)2, dimethyl gold trifluoroacetylacetone Me2Au(C5F3H4O2)), and / or organic compounds (e.g., carbon monoxide CO, carbon dioxide CO2, aliphatic and / or aromatic hydrocarbons, etc.).

[0041] Suitable processing gases for etching materials include, for example: xenon difluoride (XeF2), xenon dichloride (XeCl2), xenon tetrachloride (XeCl4), water vapor (H2O), heavy water (D2O), oxygen (O2), ozone (O3), ammonia (NH3), nitrosyl chloride (NOCl), and / or one of the following halides: XNO, XONO2, X2O, XO2, X2O2, X2O4, X2O6, where X is a halide. Other processing gases for etching materials are detailed in the applicant's U.S. Patent Application No. 13 / 0103281.

[0042] For example, additive gases that can be mixed in proportion with the processing gas to better control the processing include: oxidizing gases (e.g., hydrogen peroxide H₂O₂, nitrous oxide N₂O, nitrogen oxide NO, nitrogen dioxide NO₂, nitric acid HNO₃, and other oxygen-containing gases), and / or halides (e.g., chlorine Cl₂, hydrogen chloride HCl, hydrogen fluoride HF, iodine I₂, hydrogen iodide HI, bromine Br₂, hydrogen bromide HBr, phosphorus trichloride PCl₃, phosphorus pentachloride PCl₅, phosphorus trifluoride PF₃, and other halogen-containing gases), and / or reducing gases (e.g., hydrogen H₂, ammonia NH₃, methane CH₄, and other hydrogen-containing gases). These additive gases can be used, for example, in etching processes, as buffer gases, as passivation media, etc.

[0043] According to another specific embodiment of the device, the gas supplier includes a supply channel integrated into the shielding element.

[0044] This specific embodiment allows for very precise guidance of the process gas to the processing location. This improves the speed and efficiency of the particle beam-induced processing process because there is always a sufficient quantity of process gas molecules and depletion is avoided. In this specific embodiment, the shielding element is produced, in particular, by a special manufacturing method, especially by the LIGA manufacturing method (LIGA: an abbreviation from the German Lithographie, Galvanik und Abformung (photolithography, electroplating and molding)).

[0045] The shielding element can be implemented, for example, as a segmented hollow structure, with a supply channel formed inside the shielding element. At the outer edge of the shielding element, the interior is fluidly connected to the gas supply. In this case, a transition piece or a reduction piece can be used. The outlet for supplying the gas is advantageously configured as close as possible to the through-hole in the raised region.

[0046] In another example, the shielding element comprises a microporous material covered with an hermetically tight coating, having an inlet for supplying process gas and an outlet for discharging process gas. The outlet is preferably formed in a protrusion opposite the processing location.

[0047] In a specific embodiment of the device, the device is configured to establish electrical contact with the sample via a protrusion of the shielding element. This is particularly advantageous for samples with conductive surfaces, as the charge can flow directly away from the sample surface, resulting in no interfering electric field being formed.

[0048] In a further specific embodiment, a protective layer may be deposited on the sample surface around the processing location using a particle beam induced etching process before the sample comes into contact with the shielding element. The protective layer is advantageously conductive and serves to prevent mechanical damage to the sample caused by the shielding element when it comes into contact with the sample. After analysis or processing, the protective layer may be removed again, for example, by a particle beam induced etching process.

[0049] According to another specific embodiment of the device, the through-hole includes a point where there is a minimum distance between the shielding element and the sample stage.

[0050] This is understood to mean that the minimum geometric distance between the shielding element (if it has no opening) and the sample stage is located at a point on the shielding element occupied by the via. Therefore, in particular, the edge of the via forms the point of the shielding element closest to the sample stage.

[0051] According to another specific embodiment of the device, the shielding element includes a planar portion and a protruding portion extending from the planar portion along the direction of the sample stage.

[0052] The planar portion can be used, for example, to secure a shielding element to a providing device, such as a retaining structure secured to the edge of an opening. During sample analysis or processing, the planar portion preferably extends substantially parallel to the sample surface.

[0053] The planar portion of the shielding element can be made of a different material than the raised portion. The shielding element can therefore consist of two parts (i.e., the planar portion and the raised portion), which can be connected together by screws, adhesive bonding, welding, and / or by appropriate corresponding connecting elements.

[0054] According to another specific embodiment of the device, the protrusion is designed in a funnel shape, specifically having a circular cross-section.

[0055] Alternatively, the protruding portion can be described as forming the surface of a solid of revolution based on a convex function.

[0056] However, the protruding portion may also have a cross-section that deviates from a circular shape, especially an elliptical cross-section.

[0057] Preferably, the protrusion is designed to taper gradually toward the through hole.

[0058] According to a further specific embodiment, for any combination of two points on the surface of the protrusion of the shielding element, the protrusion is configured such that a connecting line connecting the two points on the surface of the protrusion of the shielding element extends outside the shielding element.

[0059] It can also be said that the convex part forms a region that satisfies strict convexity from a mathematical perspective. If equation (1) requires that the left side is truly "less than" relative to the right side, then the function is strictly convex.

[0060] Examples of regions with this shape are spheres or spherical segments. Furthermore, if a solid of revolution is formed based on a function, such as a parabola formed by rotating a parabola, then strictly convex functions (e.g., parabolas) produce the corresponding regions.

[0061] The fact that the connecting line extends outward is understood to mean that the connecting line has no common point with the protrusion. Therefore, the connecting line also does not intersect with the protrusion or the shielding element. It should be noted that a planar region does not conform to this specific embodiment, because the connecting line between two points on the plane itself lies within the plane.

[0062] According to another specific embodiment of the device, the shielding element includes a layer of conductive material on its surface, wherein the thickness of the layer is greater than or equal to the penetration depth of the particles of the particle beam into the material.

[0063] This has the advantage of preventing charge buildup in or on the shielding element itself. For example, materials that can form a natural oxide layer (which is a poor conductor) may not be suitable.

[0064] In an advantageous embodiment, the shielding element is made entirely of conductive material. This can be a pure material or alloy, composite material, and / or a material with a microstructure.

[0065] The requirements for materials depend on the specific application. Besides electrical conductivity, the magnetic and chemical properties of the material may also be relevant. Preferably, for example, the material is non-magnetic. Furthermore, the material is preferably chemically inert, so that it reacts only to a very small extent or not at all with the supplied process gases and / or with other reaction products. This results in a long lifespan for the shielding element.

[0066] For example, the shielding element comprises a precious metal. For example, the shielding element comprises at least one element from a list containing gold, nickel, palladium, platinum, and iridium. In a specific embodiment, the shielding element is formed of gold or nickel.

[0067] The shielding element preferably has a very smooth surface. For example, the RMS value of the surface roughness is at most 50 nm, preferably at most 10 nm, more preferably at most 5 nm, and even more preferably at most 2 nm.

[0068] According to another specific embodiment of the device, the shielding element has exactly one through hole.

[0069] Alternatively, the shielding element can be implemented as a single-aperture aperture. The aperture is preferably circular. Other opening geometries, such as square, hexagonal, octagonal, rectangular, and / or elliptical, are also available.

[0070] The sidewalls of the shielding element defining the via are preferably inclined relative to the axis of symmetry of the via, forming an upward-opening cone opposite to the beam direction. Therefore, the opening cross-section of the via on the sample side is smaller than that on the opposite side. This has the advantage of enabling the detection of secondary electrons or backscattered electrons from the sample at a larger solid angle. This can improve detection efficiency, signal-to-noise ratio, and / or resolution.

[0071] According to another specific embodiment of the device, the shielding element has a plurality of through holes spaced apart from each other by a web.

[0072] The web, for example, is formed of the material of a shielding element and is located between and separates the two through-holes from each other. The web preferably has the smallest possible width. Depending on the geometry of the through-holes, the web may have a constant width or a variable width. For example, the width of the web is between 1 μm and 100 μm, preferably between 1 μm and 50 μm, more preferably between 5 μm and 30 μm, and even more preferably between 10 μm and 20 μm.

[0073] It can also be said that the shielding elements form a mesh or are formed by a mesh.

[0074] A shielding element with multiple through-holes advantageously allows the particle beam to reach a large portion of the sample or sample surface without affecting the shielding effect of the electric field. In other words, it expands the processing location or processing area. Therefore, a better overview can be achieved. However, with multiple through-holes, the gas flow opposite to the beam direction may increase significantly when gas is supplied into the gap between the sample and the shielding element.

[0075] If the shielding element has multiple through-holes, the through-holes are preferably configured to closely surround the deepest point of the protrusion in the shielding element. For example, the deepest through-hole contains the deepest point of the protrusion, and the other through-holes are configured to be directly adjacent to the deepest through-hole.

[0076] For example, the protrusion can be implemented such that there is a deepest planar region, rather than a deepest point, in which multiple through holes are configured.

[0077] According to another specific embodiment of the device, each through hole has a hexagonal cross-section.

[0078] The geometry of the through hole can affect the field distribution of the electric field to be shielded below the through hole, and it can also affect the particle beam.

[0079] The hexagonal geometry allows for a high area footprint while offering a good trade-off in terms of further electrostatic properties.

[0080] Other possible geometric shapes include square, rectangular, circular, elliptical, pentagonal, and octagonal shapes.

[0081] The arrangement of multiple through holes relative to each other can be regular or irregular. Furthermore, through holes can be arranged in a manner that allows them to rotate relative to each other about an axis of symmetry.

[0082] According to another specific embodiment of the device, the web is formed such that the sample stage side cross-sectional area of ​​a corresponding one of the plurality of through holes in a first plane perpendicular to the surface normal of the shielding element on the through hole is smaller than the opening side cross-sectional area of ​​the corresponding through hole in a second plane parallel to the first plane.

[0083] According to another specific embodiment of the device, one of the plurality of through holes has geometric features that distinguish it from the other through holes.

[0084] This specific embodiment is advantageous if multiple vias, for example, have the same geometry and are regularly arranged, because it may be difficult to distinguish the vias from each other. Therefore, it is possible to determine, for example, the via containing the point where the shielding element is least distanced from the sample stage or sample. It can also be said that the via with geometrical features marks a reference location, based on which the positions of other vias can be definitively determined.

[0085] For example, distinguishable through-holes are marked. Such markings can be formed by portions with additional material and / or portions with missing material.

[0086] Multiple through holes may also have markings that distinguish them from each other, thus there are multiple marked and clearly identifiable through holes.

[0087] Through holes with geometric features can have different geometries than other through holes; for example, two through holes can be connected to form a single through hole, thus forming a double through hole.

[0088] Starting with the distinguishable vias, it is possible to determine the deepest via, especially the one best suited for analysis and / or processing, since the shielding of the electric field is optimal at this via.

[0089] According to another specific embodiment of the device, one of the through holes contains the point of minimum distance between the shielding element and the sample stage, and the other through holes are arranged symmetrically with respect to the one through hole.

[0090] In particular, the via configuration can be rotationally symmetric and / or mirror symmetric. A symmetric configuration can have at least one axis of symmetry.

[0091] According to another embodiment of the device, the device includes a beam generating unit and a beam guiding element. The beam guiding element is disposed between the beam generating unit and the shielding assembly and is configured to guide the particle beam. Furthermore, a voltage source is provided for applying a voltage between the shielding element and the beam guiding element.

[0092] The beam generation unit is configured to generate a particle beam. For example, it is a thermionic cathode used to generate an electron beam. The beam guiding unit is configured to accelerate particles in the particle beam. The beam guiding unit can be configured to deflect the particle beam, shape the particle beam, focus the particle beam, etc.

[0093] Applying a voltage between the shielding element and the beam guiding element creates an electric field between these elements. The particle beam passes through this electric field and can therefore be affected by it, such as accelerated, decelerated, shaped, and / or deflected. Thus, the particle beam can be directly affected by the sample surface.

[0094] The trajectory of charged particles from the sample, traveling in the opposite direction to the particle beam as they pass through the aperture, is also influenced by the electric field. For example, an energy filter for secondary electrons and backscattered electrons can be established by appropriately setting the potentials of the shielding element and the beam guiding element. In this case, the sample or stage is suitable as a reference point, where, for example, the shielding element has a negative potential and the beam guiding element has a positive potential relative to the sample or stage for the energy filter.

[0095] Furthermore, due to the fact that the shielding element has a specific potential, an electric field is also generated between the shielding element and the sample. This electric field can be set to better extract secondary electrons from the deep structures of the sample surface. For this purpose, it is advantageous for the shielding element to have a positive potential relative to the sample or sample stage. This has the advantage of improved detection for these electrons emitted from deeper regions of a sample with a high aspect ratio. Aspect ratio is understood to represent, for example, the ratio of the height to the width of a structure. For example, a high aspect ratio exists if the height / width ratio is ≥0.5. This has a further advantage, such as the ability to capture secondary electrons emitted by the shielding element. Therefore, undesirable chemical reactions that might be initiated by such secondary electrons can be avoided.

[0096] In a specific embodiment of the device, the shielding element is fixed to the providing unit by a retaining device.

[0097] The connection between the retaining device and the shielding element can be achieved, for example, by welding, clamping and / or adhesive bonding.

[0098] In specific embodiments, the retaining device and the shielding element are implemented as a single component, particularly integrally. This can be achieved through special manufacturing methods, especially the LIGA manufacturing method (LIGA: an abbreviation from the German Lithographie, Galvanik und Abformung (photolithography, electroplating and molding)).

[0099] According to another specific embodiment of the device, the shielding unit is secured to the providing unit by a retaining device, wherein the retaining device and the shielding element are electrically insulated from each other. Another voltage source is provided for applying a voltage between the retaining device and the beam guiding element and / or the shielding element.

[0100] In this specific embodiment, two electric fields are formed, such that a first electric field exists between the beam guiding element and the holding device, and a second electric field exists between the holding device and the shielding element. Therefore, specifically, two field portions appear below the beam guiding element, which can be used, for example, to focus the particle beam. Subsequently, magnetic focusing, which may produce residual magnetism effects, can be eliminated.

[0101] If the particle beam is an electron beam, the holding device is preferably set to a negative potential relative to the beam guiding element, so that the electrons are slowed down. For example, the energy of the electron beam is set to have an energy higher than the desired landing energy on the sample (also called a boost voltage or Uboost), and therefore can be set to the desired energy.

[0102] According to another specific embodiment of the device, the shielding element is held in an electrically insulating manner, and a detection unit is provided for detecting the current flowing out of the shielding element.

[0103] The detection unit (e.g., a current measuring device) can be used as a detector in various ways. In particular, by combining a voltage applied between the shielding element and the holding device or beam guiding element, acting as an energy filter, it is possible, for example, to distinguish between low-energy secondary electrons ranging from a few electron volts to tens of electron volts and backscattered electrons with higher energies within the beam energy range. For example, the shielding element can then be used as a secondary electron detector.

[0104] Since the backscattering efficiency of backscattered electrons depends on the electron energy and the number of atoms in the material, information about the number of atoms in the material can also be obtained through an energy filter.

[0105] Furthermore, the gas pressure in the shielding element region can be deduced from the detected current, as there is a positive correlation between gas pressure and current. Increased gas pressure causes more collisions between particles in the particle beam and gas molecules, resulting in greater scattering. This leads to an increase in the number of particles scattered to the shielding element, and consequently, an increase in the detected current.

[0106] According to another specific embodiment of the device, the shielding element comprises multiple portions that are electrically insulated from each other and define through-holes, wherein voltage can be applied between two oppositely configured portions in each case via a corresponding voltage source.

[0107] The shielding element can therefore be additionally used as a deflection unit. Thus, a separate deflection unit positioned above the shielding element can be eliminated. This simplifies the device construction and improves efficiency. First, the solid angle at which backscattered or secondary electrons can be detected is not additionally reduced by a separate deflection unit. Second, the operating voltage of the deflection unit can be lower because the diameter of the via is, for example, only 30 μm–150 μm. The smaller the via, the greater the electric field gradient for the same voltage.

[0108] Preferably, the shielding unit comprises eight such portions. The shielding unit is therefore also called an octet unit.

[0109] In this specific embodiment, the shielding element may be further used as an astigmatism reducer and / or lens for the particle beam, particularly for focusing the particle beam onto the sample. The astigmatism reducer is configured to correct astigmatism.

[0110] Furthermore, the shielding element can be used as a "beam blanker." In conventional particle beam columns, beam blankers for rapidly switching the particle beam on and off are positioned within the column where the particles have high energy, thus requiring a high voltage to deflect the beam. In this specific embodiment, the beam is deflected at a point where its energy has decreased, therefore such a high voltage is not necessary. This simplifies the structure; moreover, a faster switching time is possible. Furthermore, by incorporating a current measuring device, the current to the particle beam can be determined as it is guided to the shielding element.

[0111] In a specific embodiment, a capacitance measuring device configured to determine the capacitance between the shielding element and the sample may be provided.

[0112] For example, the distance between the shielding element and the sample can be determined based on capacitance. This is especially possible when the sample is conductive or contains conductive portions.

[0113] According to another specific embodiment of the device, a plurality of shielding elements are provided, arranged one after another in the beam direction, each of which covers the opening. At least one of the plurality of shielding elements is movably held to provide a settable aperture opening.

[0114] The shielding element is held in a movable manner, and its relative position to other shielding elements is set. This results in an opening that can be set in the beam direction. By reducing the size of the opening, for example, it is possible to reduce the volumetric flow rate of the process gas opposite to the beam direction.

[0115] The shielding element is preferably configured relative to the opening to minimize the impact of changes in focal point during a predetermined focusing interval and / or changes in beam energy during a predetermined energy interval on the beam position and / or on the detection efficiency.

[0116] The process of changing the focus and / or beam energy can also be called "oscillation".

[0117] Specifically, when the shielding element is assembled to the supply unit, this configuration of the shielding element is set for the corresponding supply unit. Optimizing the position as described above ensures high stability of the device, particularly in terms of resolution.

[0118] According to the second aspect, a method is proposed for analyzing and / or processing a sample using a particle beam via the apparatus according to the first aspect. In the first step, the sample is positioned on a sample stage. In the second step, a particle beam is provided. In the third step, the particle beam is radiated through a through-hole to a processing location on the sample.

[0119] This method has the same advantages as the apparatus already described.

[0120] The specific embodiments and features described for the device are adapted to the proposed method, and vice versa.

[0121] According to a specific embodiment of the method, the method additionally includes the step of supplying a processing gas to a processing location, wherein the processing gas flows to the processing location on the sample only through the gap formed by the shielding unit and the sample.

[0122] According to another specific embodiment of the method, the method includes contacting a sample surface with a shielding element, wherein a protrusion of the shielding element has at least one contact point that contacts the sample surface.

[0123] If the sample has a conductive surface, this method can avoid charging the entire sample, as the charge can flow away through the electrical contact points and the shielding unit.

[0124] In the case of sensitive samples, a protective layer can be pre-deposited locally on the sample surface. This protective layer is, for example, formed in the region around the processing location where the shielding element first contacts the sample. The protective layer can be fabricated, in particular, by a particle beam induced etching process. The protective layer is advantageously conductive. Preferably, the protective layer is made of a material that can be removed again by a selective etching process without residue and without damaging the sample surface. The protective layer can be removed again in a subsequent cleaning process or in a particle beam induced etching process.

[0125] The term "one; one" in this context should not be construed as limited to exactly one element. Instead, multiple elements may be provided, such as two, three, or more. Any other numbers used herein should not be construed as a strict limitation on the number of elements stated. Rather, upward and downward numerical deviations are possible unless otherwise indicated.

[0126] Further possible embodiments of the present invention may include combinations of features or specific embodiments not explicitly mentioned in the foregoing or hereinafter with reference to exemplary embodiments. In such cases, those skilled in the art will also add individual aspects as improvements or supplements to the various basic forms of the invention. Attached Figure Description

[0127] Other advantageous configurations and aspects of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. Hereinafter, the invention will be explained in more detail based on preferred embodiments with reference to the accompanying drawings.

[0128] Figure 1 A schematic diagram of a first exemplary embodiment of a device for analyzing and / or processing samples using a particle beam is shown.

[0129] Figure 2 An excerpt of a schematic diagram of a second exemplary specific embodiment of an apparatus for analyzing and / or processing samples using a particle beam is shown;

[0130] Figure 3 An excerpt of a schematic diagram of a third exemplary embodiment of a device for analyzing and / or processing samples using a particle beam is shown;

[0131] Figure 4 Six different exemplary embodiments of the shielding element are schematically shown;

[0132] Figure 5 A cross-section of an exemplary embodiment of a shielding element is schematically shown;

[0133] Figure 6 Another exemplary embodiment of the shielding element is schematically shown;

[0134] Figure 7 A schematic diagram of a fourth exemplary embodiment of a device for analyzing and / or processing samples using a particle beam is shown;

[0135] Figure 8 A schematic diagram of a fifth exemplary embodiment of a device for analyzing and / or processing samples using a particle beam is shown;

[0136] Figure 9 Another exemplary embodiment of the shielding element is schematically shown;

[0137] Figure 10 An excerpt of a sixth exemplary embodiment of a device for analyzing and / or processing samples using a particle beam is shown schematically;

[0138] Figure 11 A schematic block diagram showing an exemplary specific embodiment of a method for analyzing and / or processing samples using particle beams;

[0139] Figure 12 An excerpt of a seventh exemplary embodiment of a device for analyzing and / or processing samples is shown schematically;

[0140] Figure 13An excerpt of a schematic diagram of an eighth exemplary embodiment of a device for analyzing and / or processing samples using a particle beam is shown;

[0141] Figure 14A -D respectively shows the cross-section through the shielding element in different specific embodiments; and

[0142] Figure 15 A diagram is shown to explain the term "protrusion".

[0143] Unless otherwise specified, identical elements or elements having the same function will have the same reference numerals in the drawings. It should also be noted that the schematic diagrams in the figures are not necessarily drawn to scale. Detailed Implementation

[0144] Figure 1 The image shows the method for using particle beam 112 to analyze and / or process sample 200 (see image). Figure 2 , 3 A schematic diagram of a first exemplary embodiment of device 100 (or 12). Device 100 is preferably configured in a vacuum housing (not shown). Device 100 includes a providing unit 110 for providing a particle beam 112 and a sample stage 120 for holding a sample 200, the sample stage being configured below the providing unit 110.

[0145] Specifically, the providing unit 110 includes a particle beam generating unit 111, which generates a particle beam 112. The particle beam 112 is composed of charged particles, such as ions or electrons. Figure 1 The example includes an electron beam. Therefore, the providing unit 110 is also called an electron column, where the device 100 forms, for example, a scanning electron microscope. The electron beam 112 is guided by a beam guiding element ( Figure 1 (Not shown in the image) Guiding. This is also called an electro-optical unit. Furthermore, Figure 1 The electron column 110 contains a detector (not shown) for detecting electronic signals, such as those originating from backscattered electrons and / or secondary electrons.

[0146] The electron column 110 has a dedicated vacuum housing, which is evacuated to, for example, 10. -7 Hambar-10 -8The residual gas pressure is millibars. An opening 114 for the electron beam 112 is disposed on the lower side. The opening 114 is covered by a shielding element 116. The shielding element 116 is implemented in a sheet-like manner and contains a conductive material. For example, the shielding element 116 is formed of gold. The shielding element 116 has a protrusion 117 that protrudes relative to the sample stage 120. The protrusion 117 is curved in the direction of the sample stage 120. The protrusion 117 has a through-hole 118 for the particle beam to pass through. The through-hole 118 particularly includes the point closest to the protrusion 117 on the sample stage. The distance between the shielding element 116 and the sample stage 120 is therefore minimized in the region of the through-hole 118. During operation of the apparatus 100, the distance between the through-hole 118 and the sample 200 is preferably between 5 μm and 30 μm, preferably 10 μm. Preferably, the sample stage 120 has a positioning unit (not shown) through which the distance between the sample stage 120 and the electron column 110 can be set.

[0147] Shielding element 116 may have a planar region 116A (see...) Figure 14A -D), the protrusion 117 protrudes from the planar region. The planar region 116A preferably extends radially from the upper end of the protrusion 117. The shielding element 116 is fixed at the opening 114 of the electron column 110, for example at the outer edge of the planar region 116A.

[0148] A ground potential is applied to the shielding element 116. Therefore, the shielding element is configured to shield the electric field E. To illustrate this, in Figure 1 The charge Q that generates the electric field E is shown as an example. Charge Q is shown below the shielding element 116, in the processing region 202 of sample 200 (see Figure 202). Figure 2 , 3 Or 12) in the area where the device 100 is used. Especially when the sample 200 is non-conductive or only slightly conductive (at least partially), when the particle beam 112 is incident on the sample 200, the sample 200 is charged, thus forming an electric field E, such as... Figure 1 As shown. Figure 1 The negative charge Q generated due to the incident electron beam 112 is shown as an example.

[0149] Due to the shielding effect of the electric field E, firstly, the accuracy regarding the impact point and the focal position of the electron beam 112 on the sample 200 is improved, which enhances resolution and process control. Secondly, the flight trajectories of backscattered electrons and secondary electrons flying in the opposite direction to the electron beam 112 in the direction of the beam providing unit 111 are less affected, which also improves resolution, process control, and additional sensitivity.

[0150] Figure 2This is an excerpt of a schematic diagram of a second exemplary embodiment of an apparatus 100 for analyzing and / or processing sample 200 using particle beam 112. Unless otherwise described below, Figure 2 The device 100 in the middle may have the same Figure 1 The device 100 shown has the same features. In particular, the example configuration shown is for performing a particle beam induced processing procedure.

[0151] When the operating device 100 is in operation, the sample stage 120 on which the sample 200 is disposed is located below the supply unit 110, such that the through hole 118 is located above the processing position 202 on the sample 200 in the beam direction. A gap is formed between the sample 200 and the supply unit 110 (particularly the shielding element 116).

[0152] In this example, the supply unit 110 has a gas supplier 130 configured to supply processing gas PG into the gap. The processing gas PG flows along the gap to the processing position 202 on the sample 200. The gas supplier 130 ensures that the processing position 202 is adequately supplied with processing gas PG; secondly, the volumetric flow rate of the processing gas PG entering the supply unit 110 through the through-hole 118 is relatively low, particularly much lower than when the processing gas PG is guided from above through the through-hole 118 to the processing position 202.

[0153] Sample 200 is, for example, a photomask having feature sizes ranging from 10 nm to 10 μm. For instance, this could be a transmissive photomask for DUV lithography (DUV: "deep ultraviolet," operating wavelength range 30-250 nm) or a reflective photomask for EUV lithography (EUV: "extreme ultraviolet," operating wavelength range 1-30 nm). The processing in this case includes, for example, etching processes that locally remove material from the surface of sample 200, deposition processes that locally apply material to the surface of sample 200, and / or similar local activation processes, such as forming a passivation layer or a compaction layer.

[0154] Processing gas PGs can comprise mixtures of various gaseous substances. Suitable processing gas PGs for deposition materials or for growing overhead structures are particularly alkyl compounds of main group elements, metals, or transition elements. Examples include cyclopentadienyltrimethylplatinum CpPtMe3 (Me=CH4), methyl-cyclopentadienyltrimethylplatinum MeCpPtMe3, tetramethyltin SnMe4, trimethylgallium GaMe3, ferrocene Cp2Fe, diarylchromium Ar2Cr, and / or carbonyl compounds of main group elements, metals, or transition elements (e.g., hexacarbonylchromium Cr(CO)6, hexacarbonylmolybdenum Mo(CO)6, hexacarbonyltungsten W(CO)6, octacarbonyldicobalt Co2(CO)8, dodecacarbonyltriruthenium Ru3(CO)). 12Iron pentacarbonyl Fe(CO)5), and / or alkoxy compounds of main group elements, metals, or transition elements (e.g., tetraethyl orthosilicate Si(OC2H5)4, titanium tetraisopropoxy Ti(OC3H7)4), and / or halide compounds of main group elements, metals, or transition elements (e.g., tungsten hexafluoride WF6, tungsten hexachloride WCl6, titanium tetrachloride TiCl4, boron trifluoride BF3, silicon tetrachloride SiCl4), and / or complexes containing main group elements, metals, or transition elements (e.g., bis(hexafluoroacetylacetone)copper Cu(C5F6HO2)2, dimethyl gold trifluoroacetylacetone Me2Au(C5F3H4O2)), and / or organic compounds (e.g., carbon monoxide CO, carbon dioxide CO2, aliphatic and / or aromatic hydrocarbons, etc.).

[0155] Suitable processing gases for etching materials include, for example: xenon difluoride (XeF2), xenon dichloride (XeCl2), xenon tetrachloride (XeCl4), water vapor (H2O), heavy water (D2O), oxygen (O2), ozone (O3), ammonia (NH3), nitrosyl chloride (NOCl), and / or one of the following halides: XNO, XONO2, X2O, XO2, X2O2, X2O4, X2O6, where X is a halide.

[0156] For example, additive gases that can be mixed in proportion with the processing gas PG to better control the processing include: oxidizing gases (e.g., hydrogen peroxide H₂O₂, nitrous oxide N₂O, nitrogen oxide NO, nitrogen dioxide NO₂, nitric acid HNO₃, and other oxygen-containing gases), and / or halides (e.g., chlorine Cl₂, hydrogen chloride HCl, hydrogen fluoride HF, iodine I₂, hydrogen iodide HI, bromine Br₂, hydrogen bromide HBr, phosphorus trichloride PCl₃, phosphorus pentachloride PCl₅, phosphorus trifluoride PF₃, and other halogen-containing gases), and / or reducing gases (e.g., hydrogen H₂, ammonia NH₃, methane CH₄, and other hydrogen-containing gases). This additive gas can be used, for example, in etching processes, as a buffer gas, as a passivation medium, etc.

[0157] Figure 3 An excerpt shows a schematic diagram of a third exemplary embodiment of an apparatus 100 for analyzing and / or processing sample 200 using particle beam 112. This particularly includes Figure 2 A specific embodiment of the device 100 shown.

[0158] In this configuration, the shielding element 116 includes a channel that forms the final conduit portion of the gas supply 130. Therefore, in this configuration, the process gas PG is guided through the shielding element 116. This allows the process gas PG to be very close to the processing position 202. Consequently, the escape of the process gas PG into the vicinity of the device 100 is reduced, and thus the consumption of the process gas PG is reduced. Specifically, a higher process gas pressure can be achieved at the processing position 202 while simultaneously reducing process gas consumption. Therefore, the processing speed can be increased.

[0159] The shielding element 116 with integrated gas supply is manufactured, for example, by a special manufacturing method, particularly the LIGA manufacturing method (LIGA: an abbreviation of German Lithographie, Galvanik und Abformung (photolithography, electroplating and molding)).

[0160] Figure 4 Six different exemplary embodiments (A)-(F) of the shielding element 116 are schematically shown. Figure 4 The shielding element 116 is shown in plan view, for example in the bundle direction, so the protrusion 117 is indicated only by dashed lines in various cases. For example, the protrusion 117 starts from this line; in particular, the shielding element may be implemented outward in a planar manner. Figure 4 The examples shown all include a shielding element 116 with a rounded outer edge, but different geometries are also possible. Each of the shielding elements 116 shown can be used according to... Figure 1-3 In device 100 of 7, 8, 10 or 12.

[0161] exist Figure 4 In the example shown in (A), the shielding element 116 is implemented as a single-aperture aperture. The shielding element 116 has a diameter of, for example, 4 mm, and the through-hole 118 has a diameter of 30 μm. The protrusion 117 has a diameter of, for example, 2 mm.

[0162] exist Figure 4 In the example shown in (B), the shielding element 116 has a plurality of through holes 118, only one of which is identified by reference numerals for clarity. A web 119 is located between two through holes 118, and the web is made of, for example, the material of the shielding element 116. For example, the shielding element 116 is formed of a gold film with a thickness of 10 μm, wherein the through holes 118 are formed by a stamping method. In this example, the plurality of through holes 118 are located in the protrusions 117 of the shielding element 116. In this example, the through holes 118 all have the same size and geometry, but it is also possible to provide a plurality of through holes 118 with different sizes and / or different geometries.

[0163] exist Figure 4In example (C), the shielding element 116 has a plurality of through holes 118, only one of which is identified by reference numerals for clarity. All through holes 118 here have a hexagonal geometry. Therefore, the corresponding web 119 between two through holes 118 has a constant width. In this example, the plurality of through holes 118 are also at least partially located in the protrusion 117.

[0164] exist Figure 4 In example (D), the shielding element 116 has a plurality of through holes 118, only one of which is identified by reference numerals for clarity. All through holes 118 here have a square geometry. Therefore, the corresponding web 119 between two through holes 118 has a constant width. In this example, the plurality of through holes 118 are also at least partially located in the protrusion 117.

[0165] exist Figure 4 In the example of (E), the shielding element 116 has multiple through holes 118, only one of which is identified by reference numerals for clarity. All through holes 118 here have a hexagonal geometry. However, through holes 118 of different sizes are provided.

[0166] The largest through-hole 118 is located at the center of the protrusion 117. The central through-hole 118 contains the point of the shielding element 116 closest to the sample stage 120 (see [reference]). Figure 1-3 5, 7, 8, 10, or 12). The central through-hole 118 is preferably a particle beam 112 for analyzing or processing sample 200 (see...). Figure 1-3 (7, 8, 10, or 12) Through-holes 118 are guided through. Six slightly smaller through-holes 118 are arranged directly adjacent to the central through-hole 118. For example, the web width of the web 119 between these through-holes 118 is 10 μm. A total of twelve additional through-holes 118 are arranged radially outward, specifically in a hexagonal pattern. For example, the web width between these outer through-holes 118 is 50 μm.

[0167] The shielding element 116 in this example makes it possible to first generate an overview record of the sample 200 by scanning the particle beam 112 over each through-hole 118; however, secondly, the free cross-sectional area is reduced by the wide web 119, thereby reducing the volumetric flow rate of the processed gas through the shielding element 116.

[0168] exist Figure 4In the example of (F), the shielding element 116 has a plurality of through holes 118, only one of which is identified by reference numerals for clarity. All through holes 118 here have a hexagonal geometry. In this example, all through holes 118 have the same dimensions and the web 119 has a constant width, for example, 40 μm. The shielding element 116 of this example has, for example, the same advantages as the shielding element 116 of example (E).

[0169] Figure 5 The diagram schematically shows an excerpt of a cross-section of an exemplary embodiment of a shielding element 116 having a plurality of through holes 118. Figure 5 The excerpt only shows one of the through holes, 118. For example, see the reference... Figure 1-4 The shielding element 116 is implemented as described. The outlet opening 118 is defined by two webs 119. The cross-section of the webs 119 is formed such that the sample stage side cross-sectional area 118A in a first plane perpendicular to the surface normal N of the shielding element 116 on the through hole 118 is smaller than the opening side cross-sectional area 118B of the through hole 118 in a second plane parallel to the first plane.

[0170] It can be said that the web 119 tapers upwards. For example, the web 119 can be implemented as a triangle or trapezoid. This cross-section allows for the detection of backscattered electrons or secondary electrons emitted by the sample 200 over a larger solid angle range above the shielding element 116, such as... Figure 5 An example of a cone with an opening angle α is shown in the description.

[0171] Therefore, detection efficiency and / or resolution can be improved while maintaining the same mechanical stability as the shielding element 116.

[0172] If the shielding element 116 is implemented as a single-aperture aperture (see...) Figure 4 (A)), for example, the sidewalls of individual through holes 118 are shaped accordingly to achieve the same effect. For example, the sidewalls of through holes 118 are formed into cones (not shown).

[0173] Figure 6 Another exemplary embodiment of the shielding element 116 is schematically shown, which is implemented similarly to... Figure 4 The shielding element in (F) differs in that one of the through-holes 118 has a geometric feature. In this example, through-hole 118* comprises two adjacent through-holes 118, with the web 119 between them removed. Therefore, this through-hole 118* is clearly distinguishable from the other through-holes 118, thus enabling orientation. In particular, starting from through-hole 118*, it is possible to find the central through-hole 118 closest to the sample stage 120 (see...). Figure 1-3 5, 7, 8, 10 or 12).

[0174] Figure 7 The image shows the method for using particle beam 112 to analyze and / or process sample 200 (see image). Figure 2 , 3 A schematic diagram of a third exemplary embodiment of device 100 (or 12). Unless otherwise stated below, Figure 7 The device 100 in the middle may have the same Figure 1 , 2 The same features as device 100 in any of the three.

[0175] In this example, the providing unit 110 includes a beam guiding element 113 disposed between the shielding element 116 and the beam generating unit 111. A voltage source U0 is configured to apply a specific accelerating voltage between the beam generating unit 111 and the beam guiding element 113. The charged particles of the particle beam 112 are thus accelerated in the direction of the beam guiding element 113.

[0176] The shielding element 116 is held, for example, insulated from the providing unit 110. A separate voltage source U1 is configured to apply a voltage between the beam guiding element 113 and the shielding element 116. Thus, an electric field (not shown) is formed between the beam guiding element 113 and the shielding element 116. This electric field can be controlled by the voltage applied via the other voltage source U1. The particle beam 112 can therefore be guided, particularly accelerated, decelerated, and / or deflected, in the region between the beam guiding element 113 and the shielding element 116. This also applies to charged particles from sample 200 that pass through the shielding element 116 in the opposite direction to the beam. It can also be said that the beam guiding element 113, together with the shielding element 116 and the voltage source U1, forms a photoelectric element.

[0177] As Figure 7 As an alternative to the example in the text, another voltage source U1 may be configured between, for example, the beam guiding element 113 and the shielding element 116 implemented as a magnetic pole shoe.

[0178] Figure 8 The image shows the method for using particle beam 112 to analyze and / or process sample 200 (see image). Figure 2 , 3 A schematic diagram of a fourth exemplary embodiment of device 100 (or 12). This example device 100 has the same... Figure 7 The device 100 has the same structure. However, the shielding element 116 here is additionally held by the holding device 116*. The holding device 116* is implemented here as a separate element, and the shielding element 116 is electrically insulated from the holding device 116*. An additional voltage source U2 is configured to apply a voltage between the beam guiding element 113 and the holding device 116*.

[0179] Therefore, two electric fields (not shown) are generated sequentially in the beam direction, through which the particle beam 112 passes and can be influenced. A large number of different field configurations can be set through this architecture.

[0180] As an alternative to the architecture shown, an additional voltage source U2 may also be configured between the holding device 116* and the shielding element 116.

[0181] Another alternative is to arrange a voltage source U1 between the holding device 116* and the beam guiding element 113, and to arrange an additional voltage source U2 between the holding device 116* and the shielding element 116.

[0182] Figure 8 Also shown is a current measuring device I1 configured to detect the current flowing from the shielding element 116. The current measuring device I1 can be used as a detector in various ways. In particular, by combining a voltage applied between the shielding element 116 and the holding device 116* or beam guiding element 113 and acting as an energy filter, it is possible, for example, to distinguish between low-energy secondary electrons ranging from a few electron volts to tens of electron volts and backscattered electrons with higher energies within the beam energy range. The shielding element 116 can then be used, for example, as a secondary electron detector.

[0183] Furthermore, since there is a positive correlation between gas pressure and current, the gas pressure in the region of shielding element 116 can be inferred from the detected current. An increase in gas pressure leads to more collisions between particles in the particle beam and gas molecules, resulting in greater scattering and thus an increase in the number of particles scattered to shielding element 116, which in turn leads to an increase in the detected current.

[0184] Figure 9 Another exemplary embodiment of the shielding element 116 is schematically shown, comprising eight portions Ia, Ib, IIa, IIb, IIIa, IIIb, IVa, IVb, each insulated from each other and abutting a via 118. Voltage can be applied to the respective pairs of opposing portions (i.e., Ia-Ib, IIa-IIb, IIIa-IIIb, IVa-IVb) via controllable voltage sources UI, UII, UIII, UIV, respectively assigned to the pair. By forming this shielding element 116 as a beam deflection element, additional control over the particle beam 112 is possible (see [link to shielding element]). Figure 1-3 7, 8, 10 or 12).

[0185] Figure 10 The diagram schematically illustrates the use of particle beam 112 to analyze and / or process sample 200 (see...). Figure 2 , 3An excerpt of another exemplary embodiment of device 100 (or 12). Unless otherwise described below, Figure 10 The device 100 may have the same Figure 1 , 3 The device 100 in any one of 7 or 8 has the same characteristics.

[0186] A key feature of this exemplary embodiment is that two shielding elements 116 are arranged one after the other in the bundle direction, both covering the opening 114. In this case, one of the shielding elements 116 is held by the positioning unit 140. Therefore, the shielding element 116 can move relative to the shielding element 116 fixedly positioned above it. In this way, the two shielding elements 116 form a settable aperture. Specifically, the positioning unit 140 includes one or more flexures and / or piezoelectric actuators. The shielding element 116 can thus move along at least one axis. Preferably, the shielding element 116 can move along at least two axes. Additionally and / or alternatively, the shielding element 116 can be held in a rotatable manner.

[0187] Figure 11 The image shows the use of particle beam 112 (see...). Figure 1-3 7, 8, 10 or 12) to analyze and / or process sample 200 (see Figure 2 , 3 A schematic block diagram of an exemplary specific embodiment of the method (or 12). The method is preferably implemented through... Figure 1-3 It may be performed by one of the devices 100 in 7, 8, 10 or 12.

[0188] In the first step S1, sample 200 is positioned on sample stage 120. This includes, for example, positioning sample 200 below shielding element 116 (see...). Figure 1-10 Or 12), so that through hole 118 (see Figure 1-10 Or 12) Processing position 202 on sample 200 (see Figure 2 , 3 Or directly above 12).

[0189] In the second step S2, a particle beam 112 is provided, and in the third step S3, the particle beam 112 is radiated through the through-hole 118 onto the processing position 202 on the sample 200, and the sample 200 is analyzed and / or processed in this manner.

[0190] Figure 12 A schematic diagram of another exemplary embodiment of a device for analyzing and / or processing sample 200 using particle beam 112 is shown. Unless otherwise described below, Figure 12 The device 100 may have the same Figure 1 , 3The device 100 in any one of 7, 8 or 10 has the same characteristics.

[0191] In this exemplary embodiment, the device 100 is configured to establish electrical contact with the sample 200 via the protrusion 117 of the shielding element 116. This is particularly advantageous when the sample 200 has a conductive surface, as the charge can flow directly away from the sample surface, thus preventing the formation of an interfering electric field. Specifically, in this exemplary embodiment, a protective layer 204 is deposited on the sample surface around the processing location 202 via a particle beam-induced process before the sample 200 contacts the shielding element 116. Specifically, the deposition process is performed by the device 100. For this purpose, molybdenum hexacarbonylMo(CO)6 is used, for example, as the processing gas PG (see Figure 2 Or 3). The resulting protective layer 204 is advantageously conductive, and when the shielding unit 116 comes into contact with the sample 200, the protective layer 204 serves to prevent the shielding unit 116 from causing mechanical damage to the sample 200. After analysis or processing, the protective layer 204 can be removed again, for example by a particle beam induced etching process.

[0192] Figure 13 This is an excerpt of a schematic diagram of an eighth exemplary embodiment of an apparatus 100 for analyzing and / or processing sample 200 using particle beam 112. Unless otherwise stated below, Figure 13 The device 100 in the middle may have the same Figure 1-3 The device 100 in any one of 7, 8, 10 or 12 has the same characteristics.

[0193] In this example, the supply unit 110 includes a gas supplier 130 configured to supply processing gas PG to a processing position 202 on the sample 200 via a through-hole 118 of the shielding element 116. The processing gas PG flows through the through-hole 118 in the beam direction of the particle beam 112 and thus reaches the processing position 202 on the sample 200.

[0194] With this configuration of the gas supplier 130, for example, there is a process gas PG that also flows in the opposite direction to the beam generation unit 111 (see [link]). Figure 1 , 7 Or 8) and the risk of chemical reaction with the components in the supply unit 110. Therefore, in this example, an aperture 132 is provided above the nozzle or outlet of the gas supply 130. The aperture 132 has a through-hole for the particle beam 112. The aperture 132 prevents unobstructed upward gas flow in the opposite direction to the beam direction.

[0195] Simultaneously, a potential can be applied to aperture 132, and aperture 132 can therefore be used for beam guidance and / or as a detector. In addition to aperture 132, differential pump stages (not shown) may be provided, which further reduce upward gas flow opposite to the beam direction.

[0196] Figure 14A -D respectively shows a cross-section through the shielding element 116 in different specific embodiments. The respective shielding elements 116 shown in these figures can be specifically combined Figure 1-3 The device 100 of type 7, 8, 10, 12 or 13 is used.

[0197] Figure 14A All shielding elements 116 shown in -D have a planar portion 116A from which a protruding portion 117 extends. The shielding elements 116 shown here differ particularly in the geometry of their respective protruding portions 117. However, it should be noted that the planar portion 116A is not a necessary feature of the shielding element 116. In a specific embodiment (not shown), the shielding element 116 does not include the planar portion 116A. In a further specific embodiment, the shielding element 116 is composed of the protruding portion 117.

[0198] Figure 14A The shielding element 116 shown has a hemispherical protrusion 117, with a through-hole 118 disposed at the deepest part of this hemisphere. It should be noted that the protrusion 117 does not need to comprise a complete hemisphere. In a further specific embodiment, the protrusion 117 includes a smaller portion from a spherical surface. Furthermore, the shape does not need to be perfectly spherical, but may also exhibit corresponding deviations, such as compression or stretching of the shape.

[0199] Figure 14B Showing with Figure 14A The shielding element 116 shown is geometrically identical, but has more openings (not referenced in the figures) in addition to the through hole 118. Alternatively, the protrusion 117 of the shielding element 116 can be described as a mesh.

[0200] Figure 14C The shielding element 116 shown has a protrusion 117 in the form of a paraboloid of revolution, wherein a through hole 118 is disposed at the deepest part of the paraboloid of revolution.

[0201] Figure 14D The shielding element 116 shown has a conical protrusion 117, wherein a through hole 118 is disposed at the apex of the cone.

[0202] It should be noted that, Figure 4 (A)-(F), Figure 6 or Figure 9Each shielding element 116 shown may be referenced as follows Figure 14A Shaped as shown by -D. In other words, Figure 14A Each shielding element 116 shown in -D can also have a reference. Figure 4 Additional features of the shielding element 116 described in (A)-(F), 6 or 9.

[0203] Figure 14A The specific embodiment shown in -C is an example of a protrusion 117 that is mathematically defined as strictly convex. Based on the reference... Figure 15 Illustrative examples are used to explain the term "convex".

[0204] Figure 15 A diagram is shown to explain the term "convex". Figure 15 Curve 117 is shown, which, for example, represents the cross-sectional edge of the portion passing through the protrusion 117. Two points P1 and P2 on curve 117 are highlighted. The straight line LIN connecting these two points P1 and P2 is further shown.

[0205] Curve 117 is convex, which can be discerned, for example, by the fact that the straight line LIN connecting any pair of points P1 and P2 on curve 117 extends beyond curve 117, as shown by way of example. Figure 15 Points P1 and P2 in the diagram.

[0206] Although the invention has been described based on exemplary embodiments, it can be modified in various ways. In particular, the features and aspects explained in the various exemplary embodiments can be combined with each other, even if not expressly mentioned in the corresponding description of the exemplary embodiments.

[0207] List of reference numerals

[0208] 100 devices

[0209] 110 Providing Unit

[0210] 111 beam generation unit

[0211] 112 Particle Beam

[0212] 113 Beam Guiding Elements

[0213] 114 Opening

[0214] 116 Shielding Components

[0215] 116* Holding device

[0216] 116A Planar Section

[0217] 117 Protruding parts

[0218] 118 Through Hole

[0219] 118* Through Hole

[0220] 118A Cross-sectional area

[0221] 118B cross-sectional area

[0222] 119 Web

[0223] 120 Sample Stage

[0224] 130 Gas Supply Unit

[0225] 132 aperture

[0226] 140 positioning units

[0227] 200 samples

[0228] 202 Processing Location

[0229] 204 protective layer

[0230] A. Opening angle

[0231] E electric field

[0232] I1 Current measuring device

[0233] Part Ia

[0234] Part Ib

[0235] Part IIa

[0236] Part IIb

[0237] Part IIIa

[0238] Part IIIb

[0239] IVa part

[0240] IVb part

[0241] LIN connects straight lines

[0242] Point P1

[0243] P2 point

[0244] PG processing gas

[0245] Q charge

[0246] S1 Method Steps

[0247] S2 Method Steps

[0248] S3 Method Steps

[0249] U0 voltage source

[0250] U1 voltage source

[0251] U2 voltage source

[0252] UI Voltage Source

[0253] UII voltage source

[0254] UIII Voltage Source

[0255] UIV voltage source

Claims

1. An apparatus (100) for analyzing and / or processing a sample (200) using a particle beam (112), said sample (200) being a photolithographic mask, said apparatus comprising: A sample stage (120) is used to hold the sample (200); A providing unit (110) for providing the particle beam (112), the providing unit comprising: An opening (114) is provided for guiding the particle beam (112) to a processing position (202) on the sample (200); and A shielding element (116) is used to shield the electric field (E) generated by the charge (Q) accumulated on the sample (200); The shielding element (116) covers the opening (114), is implemented in a sheet form, and contains conductive material; The shielding element (116) includes a protruding portion (117) that is raised relative to the sample stage (120) and bent in the direction of the sample stage (120). The protrusion (117) has a through-hole (118) through which the particle beam (112) passes into the sample (200); and The device (100) is configured such that, during the analysis or processing of the sample (200) using the particle beam (112), the distance between the protrusion (117) of the shielding element (116) and the sample (200) is at most 500 µm.

2. The apparatus of claim 1, comprising a gas supplier (130) configured to supply processing gas (PG) to the processing position (202) on the sample (200) through the through-hole (118) of the shielding element (116).

3. The apparatus of claim 1 or 2, comprising a gas supply (130) configured to supply processing gas (PG) into a gap, wherein the gap is formed by the sample (200) disposed on the sample stage (120) and the shielding element (116).

4. The apparatus of claim 2, wherein the gas supply (130) includes a supply channel integrated into the shielding element (116).

5. The apparatus of claim 1 or 2, wherein the through hole (118) is contained at a point where there is a minimum distance between the shielding element (116) and the sample stage (120).

6. The apparatus of claim 1 or 2, wherein the shielding element (116) includes a planar portion (116A) and the protruding portion (117) extends from the planar portion in the direction of the sample stage (120).

7. The device as claimed in claim 1 or 2, wherein the protrusion (117) is implemented in a funnel shape.

8. The device as claimed in claim 1 or 2, wherein the protrusion (117) is configured to have a circular cross-section.

9. The device as claimed in claim 1 or 2, wherein the protrusion (117) includes a strictly protruding portion, a spherical surface, or a spherical segment.

10. The apparatus of claim 1 or 2, wherein the protrusion (117) is configured such that any combination of two points (P1, P2) on the surface of the protrusion (117) of the shielding element (116) is connected by a straight line (LIN) connecting the two points (P1, P2) on the surface of the protrusion (117) of the shielding element (116) extending outside the shielding element (116).

11. The apparatus of claim 1 or 2, wherein the shielding element (116) comprises a layer of conductive material on its surface, wherein the thickness of the layer is greater than or equal to the penetration depth of the particles of the particle beam (112) into the material.

12. The apparatus of claim 1 or 2, wherein the shielding element (116) has exactly one through hole (118).

13. The device as claimed in claim 1 or 2, wherein the shielding element (116) has a plurality of through holes (118) spaced apart from each other by a web (119).

14. The device of claim 13, wherein each of the through holes (118) has a hexagonal cross-section.

15. The apparatus of claim 13, wherein the web (119) is shaped such that the sample stage side cross-sectional area (118A) of a corresponding one of the plurality of through holes (118) in a first plane perpendicular to the surface normal of the shielding element (116) on the through hole (118) is smaller than the opening side cross-sectional area (118B) of the corresponding through hole (118) in a second plane parallel to the first plane.

16. The apparatus of claim 13, wherein one of the plurality of through holes (118) has a geometric feature that distinguishes the through hole (118) from the other through holes (118).

17. The apparatus of claim 13, wherein one of the plurality of through holes (118) contains a point where there is a minimum distance between the shielding element (116) and the sample stage (120), and the other through holes (118) are arranged symmetrically with respect to the one through hole (118).

18. The apparatus of claim 1 or 2, comprising a beam generating unit (111) and a beam guiding element (113) disposed between the beam generating unit (111) and the shielding element (116) and configured to guide the particle beam (112), wherein a voltage source (U1) is provided for applying a voltage between the shielding element (116) and the beam guiding element (113).

19. The apparatus of claim 18, wherein the shielding element (116) is secured to the supply unit (110) by a retaining device (116*), wherein the retaining device (116*) and the shielding element (116) are electrically insulated from each other, wherein another voltage source (U2) is provided for applying a voltage between the retaining device (116*) and the beam guiding element (113) and / or the shielding element (116).

20. The apparatus of claim 1 or 2, wherein the shielding element (116) is held in an electrically insulating manner and includes a detection unit (I1) for detecting the current flowing from the shielding element (116).

21. The apparatus of claim 1 or 2, wherein the shielding element (116) comprises a plurality of portions (Ia, Ib, IIa, IIb, IIIa, IIIb, IVa, IVb) that are electrically insulated from each other and define the through-hole (118), wherein a voltage can be applied between two oppositely arranged portions (Ia, Ib, IIa, IIb, IIIa, IIIb, IVa, IVb) in each case by a corresponding voltage source (UI, UII, UIII, UIV).

22. The apparatus of claim 1 or 2, wherein a plurality of shielding elements (116) are arranged one after another in the beam direction and cover the opening (114), wherein at least one of the plurality of shielding elements (116) is held in a displaceable manner to provide a settable aperture opening.

23. A combination of an apparatus and a sample (200) as claimed in any one of claims 1 to 22, wherein the sample (200) is a photolithographic mask.

24. A method for analyzing and / or processing a sample (200) by a particle beam (112) using the apparatus (100) as described in any one of claims 1 to 22, wherein the sample (200) is a photolithographic mask, the method comprising the steps of: The sample (200) is placed on the sample stage (120) (S1); Provide (S2) the particle beam (112); and The particle beam (112) is radiated (S3) through the through hole (118) to the processing position (202) on the sample (200).

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