Device, method and computer program for processing of a surface of a substrate

Abstract

This invention relates to an apparatus, method, and computer program including instructions for processing a substrate surface in a vacuum environment. The apparatus includes a fluid applicator configured to apply a fluid to a region of the surface; a manipulator configured to move the fluid and / or particles affected by the fluid to at least a certain extent on the substrate surface; and a positioner for relative positioning of the fluid applicator and / or the manipulator relative to the surface.

Description

Device, method, and computer program for processing a substrate surface The present invention relates to a device and a method for processing a substrate surface, and a corresponding computer program. More specifically, the processing includes cleaning and / or purging the surface, for example removing particles from a surface area. Due to the continuously increasing integration density in the microelectronics field, substrates with better surfaces are required, such as photomasks, mask blanks, or wafers. For example, a photomask is designed to image smaller structural elements into the photoresist layer of a wafer. The same applies to templates used in nanoimprint lithography. To meet these requirements, the exposure wavelength is becoming shorter. Currently, argon fluoride (ArF) excimer lasers are mainly used for exposure purposes, and the emission wavelength of these lasers is 193 nm. The trend is towards shorter wavelengths, extending into the extreme ultraviolet (EUV) wavelength range (10 nm to 15 nm), and towards corresponding EUV photomasks. For example, phase masks or phase-shifting masks, as well as masks for multiple exposures, can achieve the necessary increase in resolution capacity. Due to the continuously decreasing size of structural elements, defects often occur in photomask production. Due to the high production cost, defective photomasks, photolithographic masks, and templates used in nanoimprint lithography are repaired as much as possible. When repairing a photomask, parts of absorber patterns that are present at positions on the mask not envisioned by the design can be removed. Additionally, even if the mask design envisions absorber pattern elements, absorber material can be deposited at positions on the mask where there is no absorber material. Both types of repair processes generate debris fragments or particles that settle on opaque, transparent, or reflective sites on the photomask and cause imaging defects in photolithographic exposure, which are visible on the structured wafer. Another problem is that particles from the environment settle on the surface of a photomask or another substrate surface or on components of an optical lithographic exposure system. In addition, the handling of a photomask during its production and / or operation may generate particles that can settle on the photomask. There are also two difficulties for optical lithography exposure systems that use electromagnetic radiation in the EUV wavelength range. For EUV photomasks, there is currently no satisfactory protection (such as a pellicle) for the surface of their carrier structural elements. Therefore, EUV photomasks are particularly prone to particle deposition on this structured surface. Secondly, EUV radiation sources typically use tin plasmas to generate EUV radiation (see Oscar O. Versolato et al.: “Physics of laser-driven tin plasma sources of EUV radiation for nanolithography”, Plasma Sources Sci. Technol. 28 (2019) 083001, doi: 10 / 1088 / 1361-6595 / ab302). Particulates from the hot plasma can deposit on the components of the EUV exposure system, particularly on the system's optical components or elements, including the EUV photomask, and may impair the system's function. The structural measurements of optical lithography photomasks are getting smaller and smaller, making the cleaning process increasingly difficult (see T. Shimomura and T. Liang et al.: “50 nm particle removal from EUV mask blank using standard wet clean”, Proc. of SPIE Vol. 7488, S. 74882F-1 - 74882F-8). In addition, due to the reduction of the exposure wavelength, the smaller and smaller foreign particles or dirt particles adhering to the surface of the photomask or the surface of the optical elements of the exposure system become visible on the wafer during the exposure process. Given the decreasing size of the structures, customized solutions are becoming increasingly important for the processing and cleaning of photomasks and—more generally—substrates. In particular, it may be necessary to eliminate various defects on the same substrate at an acceptable level of cost and inconvenience. The processing of the surface, especially the movement of particles and the extraction (lifting) and / or removal of individual particles from the surface, is usually a difficult and time-consuming process. External constraints may limit the available tools and processing options. In addition, completely removing the particles adhering to the substrate surface from the substrate may be expensive and inconvenient. The prior art discloses solutions in the form of devices and methods for processing surfaces: these include local spraying of the surface in a subsequent treatment after substrate processing (US 2022 359 187 A1, US 11 062 898 B2), the use of a hand-held module for the application and suction removal of cleaning liquid (US 11 392 041 B2), and electrochemical, particle beam-based methods for local deposition or removal of material, for example (US 7 674 706 B2). However, these solutions have many disadvantages. In addition, they have less flexibility in the selection of possible processing tools and generally require separate disposal steps. Therefore, an object of the present invention is to provide a device and method capable of at least partially improving the processing of a substrate surface. This object is achieved by the aspects described herein. A first aspect of the present invention relates to a device for processing a substrate surface in a vacuum environment. The device has a fluid applicator configured to apply a fluid to an area of the surface. The device further includes a manipulator configured to move the fluid (out of the area) at least to some extent. Alternatively or additionally, the manipulator can be configured to move the particles affected by the fluid (out of the area) at least to some extent on the substrate surface. Additionally, the device includes a positioner for relatively positioning the fluid applicator and / or the manipulator relative to the surface. This device enables targeted, effective, and fluid-like processing of the substrate surface, where fluid is understood herein to refer to liquid. The processing operations can include, for example, cleaning the substrate surface by removing particles, and can also include, for example, removing dark defects from a lithography mask, and thus can provide a higher-quality substrate, such as a mask. Generally, due to the pressure and / or inaccessibility present in a vacuum environment, for example, for handheld instruments, the infeasibility in a vacuum environment is a limiting factor for substrate processing devices and / or methods, especially for available tools and / or media (such as liquids). In addition, known solutions typically follow a one-stage approach to surface processing and rely on the successful execution of the first time or a simple repetition of that time. The device is capable of performing automated processing in a vacuum and in situ, and although the ambient pressure is low, the processing can also be carried out in a liquid-like manner. Specifically, rather than simply flooding the surface with a cleaning agent as in the known prior art, at least one manipulator acts on the area to be processed in an additional step. The processing can be achieved in a controlled and local manner and can utilize the synergy between continuous and / or at least partially parallel steps, thereby improving processing efficiency. Therefore, compared with solutions based solely on surface washing, liquids and / or particles can be specifically and effectively removed. A vacuum environment can be generated, for example, by a single-stage or multi-stage vacuum pump within a vacuum chamber. Here, the vacuum chamber can be, for example, the vacuum chamber of a (particle beam) microscope and / or a vacuum chamber where a substrate and a surface to be processed naturally have structures during their manufacturing process. Therefore, positioning the device in a vacuum environment constitutes a time-saving, space-saving, and labor-saving option because the substrate can be processed (such as cleaned) directly in situ. The fluid applicator configured to apply fluid to a surface area can be, for example, a nozzle (such as made of a conductive material to avoid charging by a particle beam or due to static electricity, and / or made of a non-conductive material), and the fluid can flow out of the nozzle. Alternatively or additionally, the fluid applicator can include a porous material (such as a polymer sponge), and the fluid can flow out of the porous material. In any case, the fluid applicator can be suitable for local and controlled application of the fluid, for example, within an area of 5 mm × 5 mm or 1 mm × 1 mm on the surface, such as on, at, and / or around particles. Therefore, the fluid can be applied substantially such that the fluid is applied within the mentioned areas but does not extend beyond these areas. The fluid can be applied to the surface in the area in a dropwise manner, as a (non-)opaque film, and / or in any pattern form. The fluid can also be applied outside the area here. In one example, a two-dimensional film can be applied to the surface, where the covered area covers the area but optionally also extends beyond the area. For example, a fluid can wash away particles on the substrate surface, for example because the fluid exerts a force on the particles by flowing around the particles, and the force is large enough to overcome the adhesion interaction between the particles and the surface, such that the particles are separated from and / or loosened from the surface and are carried away / washed away by the fluid. Additionally or alternatively, the fluid can interact with the particles, for example in a way that splits / breaks the particles into smaller components. This can include, for example, at least partial dissolution and / or dispersion of the particles and / or particle components in the fluid, and in this form at least partially carry away the particles and / or particle components. In this example, the movement of the particles can occur in a step-by-step manner. In all these illustrative cases, the particles are at least partially removed. Generally, all aspects related to particles described herein also apply to other contaminants, such as films, liquids, etc., other defects and / or structures (such as lithography mask structures) on the substrate surface. The fluid can include a liquid. For example, the liquid can be compatible with the particles, general applications (such as regarding the substrate surface, pressure in a vacuum environment, etc.), the fluid applicator, and / or the manipulator. The manipulator can at least to a certain extent move the fluid and / or the particles affected by the fluid out of the area on the substrate surface. The use of the manipulator can, for example, be fully compatible with the use of the fluid applicator and the selected fluid described herein in order to have the maximum possible effect. Thus, the device can generally be set to perform at least two steps that may be compatible with each other: First, and as described herein, the fluid can be applied to the surface with the fluid applicator so as to exhibit its effect on the surface as described herein. Second, the manipulator can be used simultaneously, at least partially in parallel, and / or subsequently so as to move the fluid and / or one or more particles affected by the fluid at least to a certain extent, for example out of the area. This may depend on the interaction between the fluid and the particles and can be achieved in various ways as follows: The manipulator can be set to, for example, move the particles on the surface at least to a certain extent, and the particles ultimately do not leave the surface. For example, the particles can thus be moved to sites where there is only a smaller adverse effect (if any). The manipulator can alternatively, for example, completely remove the particles from the surface by sucking, wiping, extracting, etc. The positioner for relatively positioning the fluid applicator and / or the manipulator with respect to the surface can be set to move and / or rotate the fluid applicator and the manipulator with respect to each other and / or with respect to other components specified herein as described herein. Additionally, the device can have, for example, another positioner that can be set to move and / or rotate all other components specified herein with respect to each other. Generally, the positioning herein can relate to movement (along one or more axes, such as two or three axes) and / or rotation (around one or more axes, such as two or three axes). In an exemplary embodiment, the locator can be a common locator for the fluid applicator and the manipulator, such that the fluid applicator and the manipulator move relative to the substrate in a predetermined relative position and orientation with respect to each other. Alternatively or additionally, the locator can move the substrate relative to the fluid applicator and the manipulator. The fluid applicator and the manipulator can also optionally move relative to each other by means of the locator. In another example, the locator moves at least two of the mentioned components (fluid applicator, manipulator, and substrate) relative to each other. For example, the fluid applicator, the manipulator, and / or the substrate can be positioned pairwise relative to each other in order to optimize all positions with respect to each other. The movement of the corresponding devices by means of the locator can include translational movement in space along one, two, or three axes and / or rotation about one or more axes. Generally, the rotation can include free rotation or rotation restricted to a certain angular range. In many examples, the translation can also be spatially restricted, for example taking into account the available space within a vacuum chamber and / or the maximum deflection of the locator. In another possible embodiment, the fluid applicator and the manipulator can move collectively relative to the substrate, for example, and with respect to the relative alignment of the fluid applicator and the manipulator with respect to each other, only the distance between the fluid applicator and the manipulator can be changed, while in this example, the relative orientation of the fluid applicator and the manipulator with respect to each other remains unchanged. In principle, there can be one or more (identical or different) embodiments of the same components of the device, such as two fluid applicators and / or two manipulators. In an exemplary embodiment, the manipulator can include a pumping device, a suction device, and / or a mechanical probe: If the manipulator has a pumping device, then at least part of the movement of the fluid and / or particles affected by the fluid can occur through pumping of the fluid (optionally together with the affected particles). If the manipulator has a suction device, then at least part of the movement of the fluid and / or particles affected by the fluid can occur in the form of sucking in the fluid and / or particles affected by the fluid (e.g., sucking into a sponge, at least temporarily adhering to the suction device for extracting particles and / or fluid, etc.) by means of the suction device. In the case of a mechanical probe, the fluid and / or particles can be mechanically moved, comminuted, extracted, and / or mechanically affected and / or moved in some other way. This enables advantageous treatment of the surface, such as cleaning, in order to specifically remove particles and / or, for example, correct defective parts of a lithography mask. In particular, such a manipulator enables treatment of a surface that is compatible with the use of the fluid. In an exemplary embodiment for the mechanical separation of defects and / or particles, the fluid can additionally or exclusively be used to remove broken-off material and / or shavings that may occur during the treatment of the defects and / or particles. This can be done, for example, in a second separate step after or simultaneously with the treatment of the defects and / or particles. For example, an exemplary simultaneous removal of the particles to be removed and the formed broken material / shavings can be implemented such that the mechanical separation is carried out in an immersion manner (i.e., in the presence of the fluid). The suction device can include, for example, a nozzle that is used to suck away the fluid (locally) from the surface and / or suck away the particles dispersed and / or dissolved in the fluid. The suction device can include, for example, a container that is used to suck up the fluid and / or the particles dispersed and / or dissolved in the fluid (the container can be connected to the suction device, for example). Alternatively, the suction device can include, for example, a (polymer) sponge (e.g., containing polydimethylsiloxane or consisting of polydimethylsiloxane) or another porous device suitable for sucking up the fluid. In a further example, the manipulator can include a mechanical probe. Such a probe can be, for example, an atomic force microscope probe with a tip that can be set to come into local contact with the substrate surface and / or the particles on the substrate surface in order to analyze them and / or exert a mechanical action on them. The probe can be set to, for example, move the particles on the surface and / or extract the particles on the surface by applying a force. In an exemplary embodiment, the imaging method described herein can be utilized to instantaneously observe such use of the probe. For example, the device can further include introducing ultrasonic and / or megasonic waves into the fluid located on the substrate surface. The ultrasonic and / or megasonic waves can advantageously be emitted, for example, from the fluid to the particles. Such use of the ultrasonic and / or megasonic waves can, for example, affect the particles to be removed because the ultrasonic and / or megasonic waves exert a great pressure on them so that they split and / or break into such small components and / or agitate the particles to such an extent that they become separated from the surface and / or reduce the adhesion of the particles on the surface to such an extent that they become separated from the surface, thereby being transported away in a greatly improved manner, for example, by the applied fluid. This effect can also be accompanied by heating, which promotes, for example, dispersion, dissolution, and / or separation from the surface in the fluid. This may be related to a frequency in the range of, for example, 20 kHz to 10 MHz. The sound generator can provide this frequency and introduce it into the fluid, for example, through a mechanical probe or other suitable device, for example, directly by means of a fluid applicator. The frequency can, for example, be matched to the size, properties, composition, shape, and / or position of the particles, to the amount, properties, and / or nature of the applied fluid, and / or to the nature and / or properties of the surface. In one example, the fluid can be configured to at least partially move and / or at least partially absorb one or more particles on a surface. Thus, if surface processing requires the movement of particles, the fluid represents an advantageous option—even if this is initially difficult or even impossible to achieve without damaging the surface. Thus, using the fluid can increase safety and reduce malfunctions. Possible interactions between the fluid and the particles can include, for example, the following mechanisms: For example, the particles can dissolve directly in the fluid. Additionally or alternatively, the particles can be partially dissolved or chemically modified and / or the interaction between the particles and the surface can be altered such that they can be removed in a subsequent processing step, for example by means of a manipulator, for example by subsequent use of a mechanical probe and / or by further processing, such as etching (as described herein). The fluid here can have the following properties: It can have low chemical reactivity towards the particles and can remove the particles mainly by mechanical evacuation. It can be surface-active and thus can alter the interaction between the particles and the surface. It can be directly reactive and result in chemical and / or mechanical modification of the particles. It can undergo a chemical reaction in a particle-beam-induced manner. In this example, the active substance can be generated by a particle beam. The device can have means for providing such a particle beam (for example, an electron beam). The fluid can additionally or alternatively contain dissolved chemical substances that react directly and / or become reactive (for example, corrosive) in a particle-beam-induced manner. The exemplary properties mentioned can also occur in combination. The action of the fluid on the particles can include the following actions: The application of the fluid can be accompanied by the supply of mechanical energy to overcome or reduce the binding energy between the particles and the surface. This can be controlled and / or influenced, for example, by the way the fluid is supplied and / or by the way the fluid is evacuated, for example. In a further example, the fluid can cause a reduction in the binding energy between the particles and the surface through physical and / or chemical effects. Subsequently, it can be promoted / made possible to remove the particles, for example, by means of a suitable mechanical probe. In an exemplary embodiment, the fluid comprises an ionic liquid, preferably containing: ammonium salts, imidazole salts, morpholine salts, phosphonium salts, piperidine salts, pyridine salts, pyrrolidone salts, and / or sulfonium salts. Ionic liquids are particularly advantageous because they generally have a low vapor pressure and are thus suitable for use / able to remain liquid even at low pressures. Thus, using a liquid at low pressure enables the supplementation of the toolset available for processing the substrate surface in a vacuum environment. Although, considering the low pressure in the vacuum chamber, conventional methods are mainly limited to using gases, such as etching gases and deposition gases, or solids, such as mechanical probes, etc., in the present invention, a liquid fluid in a vacuum environment can be used. Another advantageous aspect of ionic liquids is that they have an inherent charge. Compared with previously known liquids, they do not need to be mixed with charged particles to avoid static charges. Generally, ionic liquids can have salts that have, for example, cations (such as imidazolium, pyridinium, quaternary ammonium, and quaternary phosphonium) and anions (such as halogens, trifluoromethanesulfonates, tetrafluoroborates, and hexafluorophosphates). Further advantageous properties of theirs are nonflammability, incombustibility, high thermal stability, relatively low viscosity, a wide liquid temperature range, and high conductivity. In addition, they may be suitable as reaction solvents: when using them, the dissolved substances are only dissolved ionically, and the reaction proceeds under conditions completely different from those when using water or standard organic solvents. This unconventional reactivity opens up various possible modes of use in the devices and / or methods described herein. The ammonium salts can include, for example, at least one of the following salts: • pentyltriethylammonium bis(trifluoromethanesulfonyl)imide • butyltrimethylammonium bis(trifluoromethanesulfonyl)imide • benzyl(ethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide • cyclohexyltrimethylammonium bis(trifluoromethanesulfonyl)imide • diethyl(methyl)propylammonium bis(fluorosulfonyl)imide • diethyl(2-methoxyethyl)methylammonium bis(fluorosulfonyl)imide • ethyl(2-methoxyethyl)dimethylammonium bis(fluorosulfonyl)imide • ethyl(2-methoxyethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide • ethyl(3-methoxypropyl)dimethylammonium bis(trifluoromethanesulfonyl)imide • ethyl(dimethyl)(2-phenylethyl)ammonium bis(trifluoromethanesulfonyl)imide • methyltrioctylammonium bis(trifluoromethanesulfonyl)imide • tetrabutylammonium chloride • tetrabutylammonium iodide • tetrabutylammonium tetrafluoroborate • tetrahexylammonium iodide • tetrapentylammonium iodide • tetraoctylammonium iodide • tetrabutylammonium hexafluorophosphate ‧ tetraheptylammonium iodide • tetrapentylammonium bromide • tetrapentylammonium chloride • tetrabutylammonium trifluoromethanesulfonate • tetrahexylammonium bromide • tetraheptylammonium bromide • tetraoctylammonium bromide • tetrapropylammonium chloride • tributylmethylammonium bis(trifluoromethanesulfonyl)imide • tetrabutylammonium acetate • trimethylpropylammonium bis(trifluoromethanesulfonyl)imide • tributyl(methyl)dicyanoammonium • tetrabutylammonium p-toluenesulfonate • tributylmethylammonium iodide The imidazolium salts may include at least one of the following salts, for example: • 1-methylimidazolium hydrobromide • 1-methylimidazolium trifluoromethanesulfonate • 1-methylimidazolium bis(trifluoromethanesulfonyl)imide • 1-vinylimidazolium bis(trifluoromethanesulfonyl)imide • 1-allyl-3-methylimidazolium chloride • 1-allyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide • 1-butyl-3-methylimidazolium bromide • 1-butyl-3-methylimidazolium chloride • 1-butyl-3-methylimidazolium tetrafluoroborate • 1-butyl-3-methylimidazolium hexafluorophosphate • 1-butyl-3-methylimidazolium trifluoromethanesulfonate • 1-butyl-2,3-dimethylimidazolium chloride • 1-butyl-2,3-dimethylimidazolium hexafluorophosphate • 1-butyl-2,3-dimethylimidazolium tetrafluoroborate • 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide • 1-butyl-3-methylimidazolium tetrachloroferrate • 1-butyl-3-methylimidazolium iodide • 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide • 1-butyl-3-methylimidazolium methanesulfonate • 1-butyl-3-methylimidazolium tris(trifluoromethyl)borate • 1-butyl-3-methylimidazolium tribromide • 1-butyl-3-methylimidazolium thiocyanate • 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate • 3,3'-(butane-1,4-diyl)bis(1-vinyl-3-imidazolium) bis(trifluoromethanesulfonyl)imide • 1-butyl-3-methylimidazolium dicyanamide • 1-butyl-3-methylimidazolium tricyanomethanide • 1-butyl-3-methylimidazolium trifluoroacetate • 1-butyl-3-methylimidazolium methylsulfate • 1-butyl-3-methylimidazolium hydrogen sulfate • 1-butyl-3-methylimidazolium hexafluoroantimonate • 1,3-dimethylimidazolium dimethyl phosphate • 1,3-dimethylimidazolium chloride • 1,2-dimethyl-3-propylimidazolium iodide • 2,3-dimethyl-1-propylimidazolium bis(trifluoromethanesulfonyl)imide • 1-decyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide • 1,3-dimethylimidazolium iodide • 1,3-dimethylimidazolium methylsulfate • 1,3-Dimethylimidazolium bis(trifluoromethanesulfonyl)imide • 1-Decyl-3-methylimidazolium bromide • 1-Decyl-3-methylimidazolium chloride • 1-Decyl-3-methylimidazolium tetrafluoroborate • 1-Dodecyl-3-methylimidazolium bromide • 1-Dodecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide • 1-Ethyl-3-methylimidazolium chloride • 1-Ethyl-3-methylimidazolium hexafluorophosphate • 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate • 1-Ethyl-3-methylimidazolium tetrafluoroborate • 1-Ethyl-3-methylimidazolium bromide • 1-Ethyl-3-methylimidazolium iodide • 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide • 1-Ethyl-3-methylimidazolium ethyl sulfate • 1-Ethyl-3-methylimidazolium p-toluenesulfonate • 1-Ethyl-3-methylimidazolium dicyanamide • 1-Ethyl-3-methylimidazolium tetrachloroferrate • 1-Ethyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide • 1-Ethyl-3-methylimidazolium hydrogen sulfate • 1-Ethyl-3-methylimidazolium methanesulfonate • 1-Ethyl-3-methylimidazolium nitrate • 1-Ethyl-3-methylimidazolium thiocyanate • 1-Ethyl-3-methylimidazolium tris(trifluoromethyl)borate • 1-Ethyl-3-methylimidazolium acetate • 3-Ethyl-1-vinylimidazolium bis(trifluoromethanesulfonyl)imide • 1-Ethyl-3-methylimidazolium tricyanomethanide • 1-Ethyl-3-methylimidazolium trifluoroacetate • 1-Ethyl-3-methylimidazolium methyl sulfate • 1-Ethyl-3-methylimidazolium diethyl phosphate • 1-Hexyl-3-methylimidazolium chloride • 1-Hexyl-3-methylimidazolium hexafluorophosphate • 1-Hexyl-3-methylimidazolium tetrafluoroborate • 1-Hexyl-3-methylimidazolium trifluoromethanesulfonate • 1-Hexyl-3-methylimidazolium bromide • 1-(2-Hydroxyethyl)-3-methylimidazolium chloride • 1-(2-Hydroxyethyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ‧ 1-Hexyl-2,3-Dimethylimidazolium iodide • 1-Hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide • 1-(2-Hydroxyethyl)-3-methylimidazolium tetrafluoroborate • 1-Hexyl-3-methylimidazolium iodide • 1-Methyl-3-propylimidazolium iodide • 1-Methyl-3-n-octylimidazolium bromide • 1-Methyl-3-n-octylimidazolium chloride • 1-Methyl-3-n-octylimidazolium hexafluorophosphate • 1-Methyl-3-n-octylimidazolium trifluoromethanesulfonate • 1-Methyl-3-n-octylimidazolium tetrafluoroborate • 1-Methyl-3-propylimidazolium bromide • 1-Methyl-3-propylimidazolium chloride • 1-Methyl-3-propylimidazolium tetrafluoroborate • 1-Methyl-3-pentylimidazolium bromide • 1-Methyl-3-n-octylimidazolium bis(trifluoromethanesulfonyl)imide • 1-Methyl-3-propylimidazolium bis(trifluoromethanesulfonyl)imide • 1-Methyl-3-(4-sulfobutyl)imidazolium bis(trifluoromethanesulfonyl)imide • 1-Methyl-3-(4-sulfobutyl)imidazolium hydrogen sulfate • 1-Benzyl-3-methylimidazolium chloride • 1-Benzyl-3-methylimidazolium tetrafluoroborate • 1-Benzyl-3-methylimidazolium hexafluorophosphate, The morpholinium salt may include, for example, 4-Ethyl-4-methylmorpholinium bromide. The phosphonium salts may include, for example, at least one of the following salts: • Tributylhexylphosphonium bromide • Tributylhexadecylphosphonium bromide • Tributylmethylphosphonium iodide • Tributyln-octylphosphonium bromide • Tetrabutylphosphonium bromide • Tetran-octylphosphonium bromide • Tetrabutylphosphonium tetrafluoroborate • Tetrabutylphosphonium hexafluorophosphate • Tetrabutylphosphonium O,O-diethyldithiophosphate • Tributyl(2-methoxyethyl)phosphonium bis(trifluoromethanesulfonyl)imide • Tributylmethylphosphonium bis(trifluoromethanesulfonyl)imide • Trihexyl(tetradecyl)phosphonium dicyanamide • Trihexyl(tetradecyl)phosphonium chloride • Tributyl(ethyl)phosphonium diethyl phosphate • Tributyl(methyl)phosphonium dimethyl phosphate The piperidinium salts may include, for example, at least one of the following salts: • 1-Butyl-1-methylpiperidinium bromide • 1-Butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide • 1-Methyl-1-propylpiperidinium bromide • 1-Methyl-1-propylpiperidinium bis(fluorosulfonyl)imide The pyridinium salts may include, for example, at least one of the following salts: • 1-methylpyridinium hexafluorophosphate • 1-methylpyridinium bis(trifluoromethanesulfonyl)imide • 1-butylpyridinium chloride • 1-butylpyridinium bromide • 1-butylpyridinium hexafluorophosphate • 1-butyl-4-methylpyridinium bromide • 1-butyl-4-methylpyridinium hexafluorophosphate • 1-butyl-3-methylpyridinium bromide • 1-butylpyridinium tetrafluoroborate • 1-butyl-3-methylpyridinium chloride • 1-butyl-4-methylpyridinium chloride • 1-butyl-4-methylpyridinium tetrafluoroborate • 1-butylpyridinium bis(trifluoromethanesulfonyl)imide • 1-butyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide • 1-ethylpyridinium bromide • 1-ethylpyridinium chloride • 1-ethyl-3-methylpyridinium ethyl sulfate • 1-ethyl-3-(hydroxymethyl)pyridinium ethyl sulfate • 1-ethyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide • 1-ethyl-2-methylpyridinium bromide • 1-ethyl-4-methylpyridinium bromide • 1-hexylpyridinium hexafluorophosphate • 1-propylpyridinium chloride The pyrrolidinium salts may include, for example, at least one of the following salts: • 1-allyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide • 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide • 1-butyl-1-methylpyrrolidinium chloride • 1-butyl-1-methylpyrrolidinium bromide • 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide • 1-butyl-1-methylpyrrolidinium dicyanamide • 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate • 1-ethyl-1-methylpyrrolidinium tetrafluoroborate • 1-ethyl-1-methylpyrrolidinium bromide • 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide • 1-methyl-1-propylpyrrolidinium bis(fluorosulfonyl)imide • 1-(2-methoxyethyl)-1-methylpyrrolidinium bis(fluorosulfonyl)imide • 1-butyl-1-methylpyrrolidinium hexafluorophosphate • 1-methyl-1-n-octylpyrrolidinium bis(trifluoromethanesulfonyl)imide • 1-methyl-1-pentylpyrrolidinium bis(trifluoromethanesulfonyl)imide The sulfonium salts may include, for example, at least one of the following salts: • trimethylsulfonium iodide • tributylsulfonium iodide • triethylsulfonium bis(trifluoromethanesulfonyl)imide In addition to or in place of the ionic liquid, the fluid may further include, for example, a vacuum-compatible oil. In one example, the fluid may have a [value less than 1·10] at the operating temperature of the device, preferably at room temperature. -6 millibar, less than 1·10 -7 millibar, less than 1·10 -8 millibar or less than 1·10 -9 vapor pressure of the millibar. This low vapor pressure provides a great advantage in that the fluid remains in liquid form even at low pressures, for example when used in the vacuum chamber described herein. This means that the advantages of processing the substrate under reduced pressure (such as avoiding harmful atmospheric gases) and the advantages of the special mechanical properties of the liquid (such as compared to gases) can be utilized, while the mechanical properties of the liquid are usually not obtainable at low pressures. The above vapor pressure enables the liquid fluid to be used without failure at typical pressures in the vacuum chamber, for example in the processing of lithography masks and / or electron microscopes. Exemplary embodiments of the device for processing the substrate surface may further include means for (local) gas supply and / or (local) gas removal. The supplied gas can be used, for example, for overall or local gas control, such as as an etching gas or a deposition gas. This means that the means for supplying gas and / or removing gas have the following advantages: If the gas is used for gas control (for example by supplying an inert gas, such as an elemental gas, such as nitrogen, helium, argon, neon, krypton, etc., or a gaseous molecular compound, such as sulfur hexafluoride), then it is not necessary, for example, to reduce the internal pressure of the vacuum chamber to a level without inert gas, and no adverse effects on the substrate are expected. On the contrary, the inert gas creates a pure environmental condition for the substrate, and the relatively high pressure enables the use of various fluids, such as ionic liquids, which are in liquid form when the ambient pressure is higher than the vapor pressure of the corresponding fluid. This enables controlled adjustment of the fluids, gases, and pressures used according to the environment (such as particles to be removed, surface properties, etc.). In this way, the transfer of (ionic) liquid to the gas phase can be reduced; at the same time, the substrate remains in (at least partially) a vacuum. Generally, the vacuum described herein is not about a complete vacuum, but only about an environment with a pressure reduction of about 1 bar compared to the gas pressure at the Earth's surface. If gas is provided, for example for (particle beam-based) etching and / or deposition, then this enables further advantageous options for controlled and / or local processing of the substrate surface. For example, an etching gas, such as water vapor and / or nitrosyl chloride, can be used to spontaneously etch particles whose main component is tin. The etching gas is adsorbed at the surface, such that local processing can be induced, for example, only by applying a particle beam (such as a focused electron beam). For example, in one step, the surface of the particles can be modified and / or the surface area of the particles can be increased by deposition of a deposition gas to facilitate removal of the particles. Useful deposition gases include the following compounds: • (metal, transition element, main group) alkyls such as cyclopentadienyl (Cp) or methylcyclopentadienyl (MeCp) trimethylplatinum (CpPtMe 3 or MeCpPtMe 3 ), tetramethyltin (SnMe 4 ), trimethylgallium (GaMe 3 ), ferrocene (Cp 2 Fe), diarylchromium (Ar 2 Cr) and other such compounds. • (metal, transition element, main group) carbonyl compounds such as chromium hexacarbonyl (Cr(CO) 6 ), molybdenum hexacarbonyl (Mo(CO) 6 ), tungsten hexacarbonyl (W(CO) 6 ), dicobalt octacarbonyl (Co 2 (CO) 8 ), dodecacarbonyltriruthenium (Ru 3 (CO) 12 ), iron pentacarbonyl (Fe(CO) 5 ) and other such compounds. • (metal, transition element, main group) alkoxides such as tetraethoxysilane (Si(OC 2 H 5 )), titanium tetraisopropoxide (Ti(OC 3 H 7 ) 4 ), and other such compounds. • (metal, transition element, main group) halides such as WF 6 , WCl 6 , TiCl 6 , BCl 3 , SiCl 4 and other such compounds. • (Metal, transition element, main group) complexes such as bis(hexafluoroacetylacetone)copper (Cu(C 5 F 6 HO 2 )) 2 , dimethylgold(III) trifluoroacetylacetonate (Me 2 Au(C 5 F 3 H 4 O 2 )) and other such compounds. • Organic compounds such as CO, CO 2 , aliphatic or aromatic hydrocarbons, components of vacuum pump oils, volatile organic compounds, and other such compounds. In an exemplary embodiment, the device has an internal pressure set to generate 1·10 -9 to 2·10 3 mbar, 1·10 -7 to 1·10 2 mbar, 1·10 -6 to 1 mbar, or 1·10 -6 to 1·10 -2 mbar of vacuum environment. For example, the internal pressure when applying a liquid can be lower than 1·10 2 mbar, lower than 1 mbar, or lower than 1·10 -2 mbar. Alternatively or additionally, the internal pressure can be higher than 1·10 -9 , higher than 1·10 -7 or higher than 1·10 -6 . Working at low pressure is fundamentally advantageous because contamination of the substrate by particles in a gas, for example, can be greatly reduced under reduced pressure. Specifically, in the context of the present invention, particularly when using a fluid in liquid form, the internal pressure of the vacuum chamber can be appropriately adjusted, particularly according to the vapor pressure of the fluid, because this enables the advantageous use of the fluid in liquid form. For example, when the fluid used and its vapor pressure are known, the pressure inside the vacuum chamber can be established, for example, at 105%, 110%, 115%, 120%, 130%, 140%, 150%, 200%, 300%, 400%, 500%, 1000%, 10000% or any intermediate value or at least the values mentioned of the vapor pressure of the fluid, in order to ensure that the fluid is in liquid form. A vacuum can be generated, for example, using a rotary vane pump, a membrane pump, a scroll pump, a turbomolecular pump, an oil diffusion pump, an ion getter pump, a titanium sublimation pump, and / or a cold trap. In an exemplary embodiment, for example, the same or different pumps can be operated continuously through multiple stages to obtain the final pressure. For example, a first pump (such as a membrane pump) can generate an initial pressure (such as 0.01 to 1·10 -3 mbar). Subsequently, in a second stage, a second pump (such as a turbomolecular pump) can generate a high vacuum (such as up to 1·10 -7 mbar). Usually, this step-by-step approach is necessary because the second pump can only be safely opened at a certain initial pressure. In addition, more stages using, for example, a third, fourth, etc. pump can generate even lower pressures. In an exemplary embodiment, the device can further include a particle beam source for applying a particle beam to a surface. Additionally, the exemplary device preferably can include at least one detector for particle beam-based imaging of the surface. The particle beams described herein can generally be, for example, photon beams (such as in the infrared (IR), visible light (VIS), ultraviolet (UV), and / or extreme ultraviolet (EUV) ranges), elementary particles (such as electrons, protons, and / or neutrons), atoms, ions, and / or molecules. The particle type can vary depending on the use. In an exemplary embodiment, the particle beam can be a focused particle beam such that when the focal plane of the particle beam is close to the substrate surface, the particle beam can be applied to a small area of the surface, for example. Focusing can be achieved using optical elements such as lenses and / or mirrors, for example for photon beams or for electric and / or magnetic fields (such as, for example, cylindrically symmetric and / or inhomogeneous), for example for electron beams and / or ion beams. The particle type and energy are related to the resolution limit (for example through its de Broglie wavelength) and can be matched to the required resolution. An exemplary particle beam as described herein can be applied to a surface for processing the surface (as described herein, for example, particle beam induced etching and / or deposition) and / or for particle beam based surface observation (such as scanning particle microscopy). Detectors for observation can additionally be provided: These can be, for example, IR / VIS / UV / EUV cameras / detectors, optical microscopes, detectors for detecting backscattered and / or emitted particles and / or detectors for detecting secondary electrons and / or other particles. For example, an observation device, such as an electron beam combined with at least one electron detector in a scanning electron microscope (SEM), can be used for observation before, during, and / or after surface treatment (in this case a cleaning operation). In one example, as described herein, the surface is observed before and / or at the start of such treatment in order to identify particles to be removed and the fluid applicator and manipulator are positioned at an appropriate location close to the identified particles. During the treatment, the particle beam and the associated at least one detector can be switched off. After processing (for example cleaning by removing particles), the surface is observed again to determine whether the particles have been successfully removed or whether the treatment needs to be carried out again and / or adjusted. In another example, the surface is observed continuously: As described herein, particles can be identified and removed by applying a fluid and using a manipulator while the particle beam is still applied to the surface, and the operations described herein can be observed simultaneously, where, for example, additional tools as well as the fluid applicator and manipulator can also be used. However, for example, the same particle beam and / or another particle beam can also be used not only for imaging but alternatively or additionally for other purposes, such as for deposition and / or for etching. Exemplary particle beam based etching and / or deposition operations can be carried out, for example, in such a way that, by means of a focused particle beam acting locally on a fluid and / or gas, particles and / or other structures are locally etched or locally deposited. For this purpose, the particle beam and the supplied fluid and / or gas can be matched to each other. For example, the device described herein can be configured to process the surface of a lithography mask. Especially in the case of a lithography mask, processing operations on the surface, especially cleaning operations, for example for eliminating defects, are necessary because any defect in the lithography mask will be transferred to the products produced with it. For example, the device may include a suitable holder for holding the lithography mask (and / or another substrate). For example, the devices described herein may also be configured to detect the position of the fluid applicator and / or manipulator. The detection of the position, especially the position relative to the surface, is advantageous for optimally positioning the fluid applicator and / or manipulator. Such positioning may be crucial for the accuracy, time spent, and / or safety of the surface treatment. For example, the respective position can be measured by directing a particle beam onto the fluid applicator and / or manipulator. For example, the particle beam may be directed onto the fluid applicator and / or manipulator and reflected from it. If the reflected particle beam is detected by a suitable detector, the detector will detect that the signal of the reflected particle beam changes, for example when the fluid applicator and / or manipulator reaches the contact point with the surface (e.g., when it travels along the surface direction by the positioner). The particle beam may include, for example, an electron beam and / or an ion beam and / or a photon beam. Alternatively or additionally, the detection of the position may include the detection of an electric current between the substrate and the fluid applicator and / or manipulator. In this example, a suitable detector will detect a sudden increase in the current when the fluid applicator and / or manipulator reaches the contact point with the surface and the current is initiated through the contact between the surface and the fluid applicator and / or manipulator (e.g., when it travels along the surface direction by the positioner). Through the two exemplary procedures for detecting the position, the contact point with the surface can be determined very accurately, so that the fluid applicator and / or manipulator can be precisely positioned at the surface, for example as close as possible to the defect / particle to be treated. Alternatively or additionally, the position may also be detected, for example, using a distance sensor and / or using a microscope and / or a camera. For example, the devices described herein may also include a device for X-ray spectroscopy of the surface and / or particles disposed on the surface. X-ray spectroscopy is especially capable of precisely identifying regions, defects, and / or particles to be treated on the surface. Based on this identification, other steps that the device can perform can be carried out more accurately, quickly, and safely. For example, the X-ray spectroscopy may be energy-dispersive. The principle of energy-dispersive X-ray spectroscopy (EDX) is to use the X-radiation emitted from the region where the particle beam is applied to determine the elemental composition of that region. The atoms in that region are excited by the particle beam and emit X-radiation. The wavelength of the X-radiation is specific to the element and allows the composition of the examined region (e.g., the particle) to be determined. For example, elemental analysis at the microscopic scale can be performed by using a scanning electron microscope and X-ray spectroscopy in combination, so-called SEM-EDX. SEM-EDX is particularly suitable for local inspections, such as the inspection of a single particle. In a further example, such a device can additionally or alternatively be used for X-ray fluorescence analysis: the excitation of X-rays can cause the emission of X-rays through the fluorescence principle, which can be detected and used, for example, for large-area analysis. Detection can be accomplished using, for example, a Si(Li) detector and / or a silicon drift detector. For example, if a particle is to be dissolved in a fluid, an exact match of the selected fluid to the elemental composition of the particle is crucial for the successful execution of the surface treatment. In addition, the device can include, for example, devices for Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), secondary neutral particle mass spectrometry (SNMS), Rutherford backscattering spectroscopy (RBS), and / or low-energy ion scattering spectroscopy (LEIS). Another aspect of the present invention lies in a method for processing a substrate surface in a vacuum environment. This method can include the following steps: relatively positioning a fluid applicator and / or a manipulator with respect to the surface using a positioner; applying a fluid to an area of the surface using the fluid applicator; and moving the fluid and / or particles affected by the fluid on the surface to at least a certain extent using the manipulator. This method constitutes an advantageous solution, where the surface can be processed in a controlled and local manner, which is particularly relevant considering that there may be small structures on the surface to be processed. For example, if small particles are to be removed, such local processing operations may be required. Such particles can have a diameter, for example, in the range of about 1 nm to about 100 μm. The particles can have various shapes and can interact with the substrate in any desired way. For example, the steps of positioning, applying, and moving can be performed in that order. However, the order can also be changed and / or the steps can be parallel. For example, during the positioning of the fluid applicator and / or the manipulator, the fluid can at least partially already have been applied to the surface and / or moved / removed. Additionally, one or more of the additional steps described herein can be included in this order or a different order of step sequences. Additionally, for example, all the steps described herein can be repeated. For example, in the method, the fluid applicator and / or the manipulator can be positioned relative to the surface using a locator. For this purpose, the user can use a control unit and position the fluid applicator and / or the manipulator, for example, through input via a keyboard or a mouse and / or a remote control device. At the same time, the user can receive feedback, for example, on individual positions and alignments, through an imaging method. For a known area to be processed, the locator can also position the fluid applicator and / or the manipulator accordingly, for example, in a fully or at least partially automated manner, using coordinates (such as particles) determined for points on the substrate to be processed. In an example where particles are to be removed from the surface, the appropriate end positions of the fluid applicator and the manipulator are, for example, on two opposite sides of the particle, such that the fluid flow from the fluid applicator to the manipulator can wash away the particle. For example, the fluid applicator and the manipulator can thus be positioned at an equal distance from and / or with the same relative orientation as the particle, such that the fluid applicator and the manipulator are opposite each other in a mirror-image configuration on the opposite sides of the particle. In other examples, the fluid applicator and the manipulator can also be positioned non-uniformly / asymmetrically relative to the particle. Applying fluid to a surface area using a fluid applicator can be done, for example, automatically or through user input (such as via a keyboard or a mouse and / or a remote control device). This step can occur, for example, after positioning or even at least partially during positioning. For example, the manipulator can be at least partially positioned and / or the position of the manipulator can be readjusted / corrected only after the fluid is applied. The fluid and / or the particles affected by the fluid can be removed from the area on the surface to at least a certain extent. For example, the movement of the manipulator may have started (and optionally ended) during the application of the fluid, or only after the fluid is applied. The manipulator can be formed as described herein. For example, when the manipulator includes a nozzle for aspirating the removal of the fluid (such as particles to be removed dissolved in the fluid), it may be advantageous to maintain a constant fluid flow through the area to be processed on the surface for a certain period of time. The method for processing a surface described herein can be combined with other surface processing and / or cleaning methods that are simultaneous and / or at least partially offset temporarily. In one example, as another step, the method and the movement of the particles affected by the fluid can additionally include identifying the particles on the surface before relative positioning and / or before application. The identification of the particles enables precise adjustment of all further steps based on the results related to the identified particles, such as size, position, critical structures on the substrate near the particles that are to remain intact, etc. This improves the efficiency, safety, and speed at which the method can be performed. This identification can be related not only to particles but also to other structures, such as (misapplied) parts of the structure of a photomask, other impurities, etc. The method may also include, for example, introducing ultrasonic and / or megasonic waves into a fluid present on a substrate surface. Such use of ultrasonic and / or megasonic waves can bring about the advantages described herein, such as simplifying the removal of particles to be removed. In one example, the method may also include mechanically acting on the identified particles with a manipulator. In addition to applying the fluid, mechanical action can also be advantageously used to move the particles, such as when the fluid action alone cannot trigger any movement. The manipulator here may include, for example, a mechanical probe capable of acting on the particles, such as to move the particles or extract the particles / remove the particles from the surface. The probe can be, for example, an atomic force microscope probe and can also be used in an atomic force microscope. Such a probe can be set to contact the particle to be removed, such that the particle adheres to the probe tip, and the adhered particle is lifted and thus removed from the surface. For example, the method may also include affecting the particles through the fluid, preferably by dissolving, dispersing, and / or altering the particle surface. Such an effect on the particles advantageously synergizes with, for example, the mechanical effect on the particles and / or the use of a manipulator for aspirating and removing the fluid together with the particles, because these steps can more easily move and / or remove the affected particles as described herein. The dissolution, dispersion, and / or alteration of the particle surface can be carried out as described herein. This method may also include, for example, generating a controlled gas within a vacuum chamber. This step brings about the advantages described herein, namely fewer soil particles in the gas in the vacuum chamber, a low degree of surface exposure, and compliance with the planned method. As described herein, the control of the gas can include supplying an appropriate gas and establishing a desired pressure. In addition, the method can include conforming the internal pressure within the vacuum chamber to the fluid. In particular, precise conformity with the fluid used in terms of the fluid vapor pressure is advantageous, because there are thus no great limitations in terms of the selection of the pressure range or the selection of the fluid used. This brings a high degree of flexibility to surface processing and improves the efficiency and safety of the method. For example, the gas can be changed one or more times during the method such that ideal conditions exist for each step. In addition, the method can include supplying a gas. As described herein, this can include, for example, an inert gas, a deposition gas, and / or an etching gas and brings about the advantages described herein. For example, the method may include, for example, locally supplying deposition gas to the area. This reduces the accuracy of the method and the consumption of the gas used. Generally, such supply may supplement the deposition methods described herein, for example, for moving and / or fixing particles. The local supply of gas (such as etching gas or deposition gas) allows the gas to locally exhibit its effect, such as depositing material or etching elements. These steps may additionally be induced by a locally applied particle beam, such as a focused electron beam that can also be provided by the device. The method may further include applying a particle beam to the surface and preferably observing the surface through particle beam-based imaging. The use of a particle beam, for example, for the purposes described herein, can advantageously act on the surface, particles and / or structures present on the surface, fluids, gases, etc., and facilitate further steps, which improves the efficiency of the method. Additionally or alternatively, it can enable particle beam-based imaging and thus constitutes an important safety mechanism. During the method, a uniform particle beam may be used, for example, for observing the surface, or it may be turned on and off one or more times, and / or different particle beams with different parameters and / or particles may be used in different and / or at least partially overlapping time periods. Generally, this method may include evaluating / estimating the particle dose required for observation (such as the electron dose in the example of the electron beam of an electron microscope). Such an estimate may include recording the dose that has been applied and / or the dose to be applied. For example, the dose may be expressed relative to a dose threshold at which, for example, damage to the substrate surface, material deposition from the deposition gas, etc. is expected. Additionally, the method may include guiding the particle beam onto the area for particle beam-induced deposition, preferably for enlarging the surface of the identified particles. This can affect the particles, especially the surface of the particles, such that subsequent steps, such as the movement of the particles through a fluid and / or a manipulator, are facilitated and simplified. The electron beam can be focused to a small focal spot with a diameter of several nanometers or even < 1 nm. The advantage of the electron beam-induced deposition process is that the deposition reaction can be precisely localized. In addition, the electron beam inducing the deposition process basically does not damage the substrate, such as a photomask with troublesome particles on it. For example, particle beam-induced deposition can be carried out in a manner of depositing material on the particle surface, for example, in order to move the particles. This can be achieved by the deposition gas described herein. Or it can be envisioned that the deposition is achieved by means of a particle beam and a fluid. Deposition can be carried out until the particles reach their target size and the size of the erosion area has increased such that the particles can be moved, for example, by using a fluid. In another example, particle beam induced deposition can be used to fix particles as described herein. The method can also include detecting the position of the fluid applicator and / or the manipulator. This can preferably be achieved by directing the particle beam onto the fluid applicator and / or the manipulator and / or detecting the electric current between the substrate and the fluid applicator and / or the manipulator. These method steps bring the above advantages, especially the precise determination of the contact points with the surface and the associated improvement in the accuracy and precision of the method. These method steps can occur, for example, only during positioning and / or continuously / repeatedly during processing in order to observe the position throughout the processing duration and to be able to avoid and / or quickly correct potentially unwanted position changes. The method can also include, for example, identifying the particles by X-ray spectroscopy and preferably conforming further steps at least partly based on this analysis. This improves the planability of the method steps and thus its efficiency and the time spent. In addition, unsuccessful surface processing attempts can be reduced. X-ray spectroscopy, especially EDX, can draw conclusions about the (elemental) composition of the area to be processed on the substrate surface. In one example, in a first step, the particles can be identified by an electron microscope. In a subsequent step, the particle composition can be determined by EDX. Based on the information obtained thereby (such as the composition, size, position, number, surface properties, grain size, etc. of the particles), subsequent steps can be planned. For example, appropriate fluids, appropriate internal pressure, appropriate atmospheric gas, appropriate etching gas, appropriate manipulator, etc. can be used as described herein. The method can also include, for example, fixing the identified particles in appropriate positions on the surface. This constitutes an appropriate solution in cases where the particles cannot be completely removed from the surface. For example, when the particles cannot be completely removed from the surface but are located at and / or have moved to non-problematic points, it may be helpful to fix the particles there. Particle beam induced deposition - as described herein - can, for example, ensheath the particles there, for example by depositing material on and around the particles and fixing the material to the surface. Another aspect of the invention relates to a computer program comprising instructions for performing the method steps described herein. Such a computer program can at least partly automate the steps of the corresponding method. Specifically, the automation of error-prone steps and / or steps that require dealing with large amounts of data can avoid errors, minimize the time spent, improve accuracy and / or optimize the planning of the method. For example, a computer program can be executed by a computer connected to the corresponding device. Additionally or alternatively, the computer program can be executed at least in part by the corresponding control unit, as described herein, which enables a user to at least partially control the corresponding device. Furthermore, there are possible embodiments in which the computer program assumes an auxiliary role such that the individual steps of the method are influenced by the user and the instructions in the computer program in a partially automated manner. For example, the computer program can be instructed to execute individual steps or a series of steps based on the user's instructions. Generally, all functions described herein related to a device and / or device part can also be implemented as steps of a method or instructions of a computer program, and vice versa. Similarly, all steps of a method can be translated into instructions in a computer program, and vice versa. A more detailed description of the currently preferred embodiments of the device of the present invention and the method of the present invention for removing at least a single particle from a substrate is provided below. Processing examples in the form of particle removal are used below to describe the device according to the present invention and the method according to the present invention. However, these are not limited to the examples described below. On the contrary, these can be used for processing or removing any type of particle, structure, material, etc. Figure 1 shows a device 100 for processing a surface 102 of a substrate 103. The device has a fluid applicator 104, which in the illustrated exemplary embodiment is designed as a nozzle for applying a fluid 105a (such as an ionic liquid described herein). The fluid applicator 104 is aligned at an oblique angle relative to the surface 102, and the nozzle opening is positioned close to the surface 102 and to the left of the particle 101. The nozzle is aligned such that the fluid 105a flows and / or is compressed in the direction of the particle 101 when leaving the nozzle and impacts the left side of the particle 101. The direction of the arrow representing the fluid 105a indicates the flow direction of the fluid 105a. When the fluid applicator 104 and / or the manipulator 106 includes a nozzle, its nozzle opening can have, for example, an approximately circular shape and can have, for example, the following diameters: less than 1 μm (such as in the form of a nano-nozzle and / or a nano-pipette), less than 10 μm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.5 mm, less than 2 mm (or even larger) or any intermediate value. In other examples, the nozzle opening can have, for example, comparable dimensions and / or different opening shapes, such as an elongated shape, an elliptical shape, a rectangular shape, or an irregular shape, etc., for example having comparable dimensions related to the circular nozzle opening described herein. The exemplary particle 101 has an irregular shape and dimensions roughly corresponding to the nozzle opening. The dimensions of the particle 101 are not to scale and it can be much larger or much smaller. The fluid 105a can interact with the particle 101 in one of the ways described herein, for example it is washed away by the fluid 105b and the particle 101 is moved by the fluid 105b. The device 100 additionally includes a manipulator 106. In the embodiment shown in schematic form, the fluid 105b is sucked away by the manipulator 106. The exemplary manipulator 106 in FIG. 1 is designed in the form of a suction device having a nozzle for removing the fluid 105b together with the particle 101 by suction. The manipulator 106 is aligned in FIG. 1, like the fluid applicator 104, at an oblique angle relative to the surface 102 of the substrate 103. The nozzle opening of the manipulator 106 is directed towards the right side direction of the particle 101 such that the flow direction of the fluid 105b guides the fluid 105b towards the nozzle opening of the manipulator 106. The manipulator 106 can be positioned, for example, closer to the surface 102 than the fluid applicator 104. The positioning of the manipulator 106 close to the surface 102 facilitates the removal of the fluid 105b by suction. Like the fluid applicator 104, the manipulator 106 can also be in contact with the surface 102 or further removed from the surface 102. The angles at which the manipulator 106 and the fluid applicator 104 are aligned relative to the surface 102 are slightly different. But they may also be, for example, the same or significantly different. The manipulator 106 and the fluid applicator 104 of the shown device 100 are positioned and aligned at an angle of approximately 180° to each other (i.e., relative to each other) in the plane of the surface 102 and are located on different sides of the particle 101. As described herein, this angle can be varied in the following ways: The fluid applicator 104 and the manipulator 106 can have different configurations. For example, when both the fluid applicator 104 and the manipulator 106 have nozzles - one fluid applicator 104 for applying the fluid 105a, and the manipulator 106 for removing the fluid 105b by suction - the two can be opposite to each other such that the openings of the two nozzles are aligned facing each other, i.e., at a first 180° angle in a first plane (e.g., a plane parallel to the surface 102 of the substrate 103). In other exemplary embodiments, the nozzle openings can be rotated relative to each other arbitrarily, for example, rotated at the following first angles in the first plane: 175°, 170°, 165°, 160°, 155°, 150°, 145°, 140°, 135°, 130°, 125°, 120°, 115°, 110°, 105°, 100°, 95°, 90°, 85°, 80°, 75°, 70°, 65°, 60°, 55°, 50°, 45°, 40°, 35°, 30°, 25°, 20°, 15°, 10°, 5° or any other value between 0° and 180°. For example, the nozzles can also be aligned in parallel, i.e., aligned at a first angle of 0° in the first plane such that the openings point in the same direction. The nozzles can also be rotated away from the first plane (e.g., the plane of the surface) in the same or different ways, for example, inclined at an oblique or acute angle relative to the surface. This second angle can be, for example, 0°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90° or an intermediate value. When the fluid applicator 104 and / or the manipulator 106 do not have any nozzles, as in the example of Figure 1, different exemplary configurations can also be additionally implemented. The device 100 additionally has a particle beam source 107 that emits a particle beam 108. The particle beam 108 is applied to the surface 102 and, in particular, to the region of the particles 101. Generally, the particle beam 108 is focused such that it can be applied locally, for example, within a range equivalent to and / or smaller than the size of the particles 101. The particle beam source 107 can provide particles, such as electrons, for example, with an acceleration voltage of 0.01 kV to 30 kV, which enables sub-nanometre focusing. The typical current of the particle beam (e.g., an electron beam) can be, for example, within the following ranges: 0 to 300 nA, 3 pA to 20 nA, 100 pA to 300 nA, 1 nA to 300 nA or 1 pA to 100 nA. The device 100 also has a mechanical probe 109. The mechanical probe 109 in FIG. 1 is in the form of an atomic force microscope tip and is configured to act mechanically on the particle 101 and / or for an atomic force microscope. The probe 109 can be moved and / or detected with an accuracy of about 50 pm (for example, in the range of 10 - 100 pm). In addition, the device 100 has a local gas supply device 110, which can be configured to supply, for example, an inert gas to provide a gas and / or supply an etching gas. The gas supply device 110 is configured as a nozzle in the device 100, which, like the other components of the device 100, can be positioned and aligned / rotated relative to the substrate 103. In particular, a gas that affects the particle 101, for example, by particle beam-based deposition, can thus be supplied locally, that is, for example, in the vicinity of the particle 101. The nozzle can be a single nozzle that serves as a gas supply device for at least one type of gas, and the gas is supplied continuously or simultaneously. In another case, there can be a set of nozzles, for example, one, two, three, or more nozzles, where in each case one nozzle serves as a gas supply device for the corresponding type of gas. The device 100 also has an optical microscope 111. Additionally or alternatively, the device 100 can also have at least one detector for particle beam-based imaging. The subsequent figures, FIGS. 2 to 4, show three different embodiments of the manipulator: a suction device (FIG. 2), an evacuation device (FIG. 3), and a mechanical probe (FIG. 4). The features described below can generally be applied to the manipulator according to the present invention, regardless of the specific embodiment (suction device, evacuation device, or mechanical probe) of the corresponding figure: FIG. 2 shows a schematic side view of a device 200 according to the present invention, which has a manipulator in the form of a suction device, where the suction device includes a polymer sponge 206. FIG. 2 shows in detail a schematic side view of a manipulator in the form of a polymer sponge 206 that sucks / evacuates a fluid 205, such as an ionic liquid, applied to a surface 202. The manipulator can be moved relative to the surface 202, for example, by means of a corresponding positioner. The pure fluid 205 or the fluid together with dispersed and / or dissolved particles (not shown) can be absorbed by the polymer sponge 206 here. The gray arrow illustrates the direction of fluid flow. The fluid 205 in FIG. 2 is specifically applied to a site on the surface 202 by a fluid applicator 204. The polymer sponge 206 has a rectangular cross-section, but in other possible embodiments, it can have other shapes, such as an irregular quadrilateral or a more complex-shaped cross-section. This shape can especially conform to the surface 202. The manipulator / polymer sponge 206 is inclined at an acute angle relative to the surface 202 and is disposed close to the surface 202 without contacting the surface 202, but may also be positioned closer to the surface 202 such that the manipulator / polymer sponge 206 contacts the surface 202, and / or is inclined at an angle different from the surface 202. The polymer sponge 206 is positioned close enough to the surface 202 so that the polymer sponge 206 contacts the fluid 205. Due to the adhesion force between the polymer sponge 206 and the fluid 205, the polymer sponge 206 can absorb the fluid 205, as schematically indicated by the arrow. If the polymer sponge 206 has at least partially absorbed the fluid 205, the cohesive force additionally acts on the fluid 205 and contributes to the absorption. FIG. 3 shows a schematic side view of a device 300 according to the present invention, the device 300 having a manipulator in the form of a fluid applicator 304 and a suction device 306. The fluid 305 is specifically applied to a site on the surface 302 through the fluid applicator 304. The suction of the suction device 306 in FIG. 3 specifically affects and / or controls, for example, the flow direction, flow rate, flow profile, fluid film thickness, and / or other parameters of the fluid flow from the fluid applicator 304 to the suction device 306, in order to suck in the fluid 305 applied to the surface 302, such as an ionic liquid. The gray arrows illustrate the direction of fluid flow. For example, the force generated by the liquid flow can be utilized to at least partially move and / or wash away one or more particles affected by the fluid 305. In particular, the adhesion between the nozzle of the suction device 306 and the fluid volume can affect the above flow characteristics. The manipulator 306 can be moved relative to the surface 302, for example, by means of a corresponding positioner. The pure fluid 305 or the fluid together with dispersed and / or dissolved particles (not shown) can be sucked in by the suction device 306. For this purpose, the nozzle opening of the suction device can have, for example, the same size or a larger size as the particles to be removed in their original shape and / or the shape affected by the fluid 305. FIG. 4 shows a schematic side view of a device 400 according to the present invention, the device 400 having a manipulator in the form of a fluid applicator 404 and a mechanical probe 406. The fluid applicator 404 in Figure 4 applies a fluid (such as an ionic liquid) to the site on the surface 402 where the particles 401 are present, so as to subsequently move the particles 401 affected by the fluid 405 and / or move the fluid 405 at least to a certain extent (as shown by the right - hand arrow) on the substrate surface 402 with the aid of a mechanical probe 406. The mechanical probe 406 has a tip substantially supported at a right angle in the example of Figure 4, such as an AFM tip. Figure 5 shows a schematic side view of a device 500 according to the present invention in deposition and / or etching based on a fluid and a particle beam. The device 500 includes a fluid applicator 504, a fluid manipulator 506, and a particle beam source 507. The particle beam source 507 is configured as described herein to direct a particle beam 508 onto the surface 502, and in Figure 5, the particle beam 508 is directed onto the particles 501 on the surface 502. The fluid applicator 504 applies a fluid 505 (such as an ionic liquid) to the site on the surface 502 where the particles 501 are present, so as to affect the particles 501 through the fluid 505. Specifically, in Figure 5, the particle surface 501a of the particles 501 is affected because material is deposited there from the fluid 505 in a particle - beam - induced manner, and / or because the interaction between the fluid and the particle beam at least partially etches and / or abrades the particle surface 501a in some other way. This can enable / simplify any subsequent evacuation removal performed by the manipulator 506. In Figure 5, during deposition and / or etching, the manipulator 506 is spaced apart from the site of the particles 501 by a positioner (not shown) so as to enable uninterrupted deposition and / or etching. Similarly, the fluid applicator 504 and / or other components of the device 500 (possibly not shown) can be appropriately positioned. Figure 6 shows a schematic side view of a device 600 according to the present invention in deposition and / or etching based on a gas beam and a particle beam. The device 600 includes a fluid applicator 604, a fluid manipulator 606, a particle beam source 607, which is configured as described herein to direct a particle beam 608 onto the surface 602, and in Figure 6, onto the particles 601 on the surface 602, and a (local) gas supply device 610. The gas supply device 610 provides a gas 610a near the surface 602 where the particles 601 are present, so as to affect the particles 601 through the gas 610a. Specifically, in Figure 6, the particle surface 601a of the particles 601 is affected because material is deposited there from the gas 610a in a particle - beam - induced manner and / or because the interaction between the gas 610a and the particle beam at least partially etches and / or abrades the particle surface 601a in some other way. This can enable / simplify the subsequent evacuation removal performed by the manipulator 606, and for example, through the additional use of a fluid. 100: Device 101: Particle 102: Surface 103: Substrate 104: Fluid applicator 105a, 105b: Fluid 106: Manipulator 107: Particle beam source 108: Particle beam 109: Mechanical probe 110: Gas supply device 111: Optical microscope 200: Device 202: Surface 204: Fluid applicator 205: Fluid 206: Polymer sponge 300: Device 302: Surface 304: Fluid applicator 305: Fluid 306: Exhaust device 400: Device 401: Particle 402: Surface 404: Fluid applicator 405: Fluid 406: Mechanical probe 500: Device 501: Particle 501a: Particle surface 502: Surface 504: Fluid applicator 505: Fluid 506: Fluid manipulator 507: Particle beam source 508: Particle beam 600: Device 601: Particle 601a: Particle surface 602: Surface 604: Fluid applicator 606: Fluid manipulator 607: Particle beam source 608: Particle beam 610: Gas supply device 610a: Gas The presently preferred exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which: FIG. 1 shows a side view of a device according to the present invention; FIG. 2 shows a schematic side view of a manipulator in the form of a suction device according to the present invention, wherein the suction device includes a polymer sponge; FIG. 3 shows a schematic side view of a device according to the present invention, the device having a manipulator in the form of an exhaust device; FIG. 4 shows a schematic side view of a device according to the present invention, the device having a manipulator in the form of a mechanical probe; FIG. 5 shows a schematic side view of a device according to the present invention in deposition and / or etching based on fluid and particle beam; and FIG. 6 shows a schematic side view of a device according to the present invention in deposition and / or etching based on gas and particle beam. 100: Device 101: Particle 102: Surface 103: Substrate 104: Fluid applicator 105a, 105b: Fluid 106: Manipulator 107: Particle beam source 108: Particle beam 109: Mechanical probe 110: Gas supply device 111: Optical microscope

Claims

1. An apparatus (100) for processing the surface (102) of a substrate (103) in a vacuum environment, wherein the apparatus (100) comprises: A fluid applicator (104) configured to apply a fluid (105a, 105b) to a region of the surface (102); a manipulator (106) configured to move the fluid (105a, 105b) and / or particles affected by the fluid (105a, 105b) on the surface (102) of the substrate (103) to at least a certain extent; and a positioner for relative positioning of the fluid applicator (104) and / or the manipulator (106) relative to the surface (102).

2. The apparatus (100) as claimed in claim 1, wherein the manipulator (106) includes a vacuum device, a suction device and / or a mechanical probe.

3. The apparatus (100) as described in claim 1 or 2 further includes the ability to introduce ultrasonic and / or megasonic waves into the fluid positioned on the surface (102).

4. The apparatus (100) as claimed in claim 1, wherein the fluid (105a, 105b) is configured to at least partially move and / or at least partially absorb one or more particles (101) on the surface (102).

5. The apparatus (100) as claimed in claim 1, wherein the fluid (105a, 105b) comprises an ionic liquid.

6. The apparatus (100) as claimed in claim 5, wherein the ionic liquid comprises: Ammonium salts, imidazole salts, morpholine salts, phosphonium salts, piperidine salts, pyridine salts, pyrrolidone salts and / or strontium salts.

7. The apparatus (100) as claimed in claim 1, wherein the fluid (105a, 105b) operates at room temperature and has a vapor pressure of less than 1.10-6 millibars.

8. The apparatus (100) as described in claim 1 further includes means (110) for gas supply and / or gas removal.

9. The apparatus (100) as claimed in claim 1, wherein the apparatus (100) has a vacuum environment configured to generate 1.10⁻⁹ to 2.10³ millibars.

10. The apparatus (100) as claimed in claim 1 further includes a particle beam source (107) for applying a particle beam (108) to the surface (102), and at least one detector for particle beam imaging of the surface.

11. The apparatus (100) as claimed in claim 1, wherein the apparatus (100) is configured to process the surface (102) of a photomask.

12. The apparatus (100) as claimed in claim 1 further includes an analytical device for performing X-ray spectral analysis on the surface (102) and / or particles (101) disposed on the surface.

13. A method for processing the surface (102) of a substrate (103) in a vacuum environment, comprising the steps of: positioning a fluid applicator (104) and / or a manipulator (106) relative to the surface (102) with a positioner; applying a fluid to a region of the surface (102) with the fluid applicator (104); and moving the fluid and / or particles (101) affected by the fluid (105a, 105b) on the surface (102) to at least a certain extent with the manipulator (106).

14. The method as claimed in claim 13, wherein the processing includes moving the particle (101) affected by the fluid (105a, 105b), the method further comprising the step of identifying the particle (101) on the surface (102) before the relative positioning and / or before the fluid application step.

15. The method as described in claim 13 or 14 further includes introducing ultrasonic and / or megasonic waves into the fluid (105a, 105b) present on the surface (102).

16. The method as described in claim 13 further includes mechanically manipulating the identified particle (101) by means of the manipulator (106).

17. The method as described in claim 13 further includes influencing the particle (101) by means of the fluid, and by means of dissolving, dispersing and / or altering the surface of the particle.

18. The method as described in claim 13 further includes generating a controlled gas within a vacuum chamber.

19. The method as described in claim 17 further includes bringing the internal pressure of the vacuum chamber into contact with the fluid (105a, 105b).

20. The method as described in claim 13 further includes supplying a gas.

21. The method as described in claim 13 further includes applying a particle beam (108) to the surface (102) and observing the surface (102) by particle beam imaging.

22. The method as described in claim 21 further includes directing the particle beam (108) onto the region for particle beam-induced deposition and for expanding the surface of the identified particle (101).

23. The method as described in claim 13 further includes detecting the position of the fluid applicator (104) and / or the manipulator (106) by: directing a particle beam onto the fluid applicator (104) and / or the manipulator (106); and / or detecting the flow of current between the substrate (103) and the fluid applicator (104) and / or the manipulator (106).

24. The method as described in claim 13 further includes analyzing the surface of the particle (101) by X-ray spectroscopy, and adjusting further method steps based at least in part on the analysis.

25. The method as described in claim 13 further includes fixing the identified particle (101) at a location on the surface (102) by particle beam induced deposition.

26. A computer program comprising instructions for performing method steps as described in any one of claims 13-25.

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