Method and device for mask repair

Abstract

A method for processing an object for lithography comprising: Providing a first gas comprising first molecules; Providing a particle beam on a working area of the object for removing a first material (A) in the working area based at least in part on the first gas; wherein the first material comprises chromium and nitrogen, and wherein the first material comprises at least 1 atomic percent nitrogen, preferably at least 5 atomic percent nitrogen, more preferably at least 10 atomic percent nitrogen, most preferably at least 20 atomic percent nitrogen; wherein the first molecules comprise a halogen compound; wherein the halogen compound comprises a noble gas halide; Providing a second gas comprising second molecules, wherein the removal of the first material is further based at least in part on the second gas; wherein the second molecules comprise an oxygen-containing component; wherein the first material comprises chromium nitride.

Description

1. Technical FieldThe present invention relates to methods, apparatus and computer program for processing an object for lithography. In particular, the present invention relates to a method for removing a material, to a corresponding apparatus, to a method for the lithographic processing of a wafer, and to a computer program for carrying out the methods.2. Prior ArtIn the semiconductor industry, increasingly smaller structures are being produced on a wafer in order to ensure an increase in the integration density. For the production of the structures, lithographic methods are used, among other things, which image them on the wafer. The lithographic methods may include, for example, photolithography, ultraviolet (UV) lithography, DUV lithography (i.e., deep ultraviolet (UV) lithography), EUV lithography (i.e., extreme ultraviolet (UV) lithography), X-ray lithography, nanoimprint lithography, etc. In this case, masks are usually used as objects for lithography (e.g. photomasks, exposure masks, reticles, stamps in nanoimprint lithography, etc.), which comprise a pattern in order to image the desired structures on a wafer, for example.DE 10 2017 208 114 A1 relates to a method for particle beam-indexed etching of a photolithographic mask, comprising the steps of: (a) providing an activating particle beam at a location to be etched; (b) providing an etching gas at the location to be etched; (c) wherein the etching gas comprises a first gaseous component and water vapor as a second gaseous component and wherein the first gaseous component comprises nitrogen, oxygen and chlorine in a compound.US 2010 / 0 203 431 A1 describes a method and an apparatus for local processing with a particle beam using an activating gas for etching a material. Compounds suitable for beam induced etching are disclosed. The invention is particularly suitable for electron beam induced etching of chromium materials on lithography masks. In one embodiment, a polar compound, such as ClNO2gas, is activated by the electron beam to selectively etch a chromium material on a quartz substrate. By using an electron beam instead of an ion beam, many are avoided with ion beam induced mask repair, such as staining and riverbedding. Endpoint detection is not critical because the electron beam and gas do not substantially etch the substrate.DE 10 2017 205 629 A1 describes a method and an apparatus for repairing at least one defect of a photolithographic mask for the extreme ultraviolet (EUV) wavelength range, wherein the method comprises the steps of: (a) determining at least one defect; and (b) determining a repair shape for the at least one defect; (c) wherein the repair shape is diffraction-based in order to take account of a phase disturbance by the at least one defect.DE 10 2017 212 848 A1 describes a method for compensating at least one defect of a mask blank, the method comprising the following steps: (a) obtaining data relating to a position of at least one defect of the mask blank; (b) obtaining design data for pattern elements which are to be produced on the mask blank; (c) determining whether the at least one defect is arranged relative to a pattern element to be produced in such a way that it has substantially no effect when exposing a wafer using the mask blank provided with the pattern element to be produced; (d) otherwise, displacing the at least one defect on the mask blank so that it has substantially no effect when exposing the wafer using the mask blank provided with the pattern element to be produced.DE 103 38 019 A1 relates to a method for etching a chromium layer in a vacuum chamber, comprising the steps of introducing a halogen compound into the vacuum chamber, directing an electron beam onto the region of the chromium layer to be etched and introducing an oxygen-containing compound into the vacuum chamber. This document describes a further method for the high-resolution removal of a layer made of a metal and / or a metal oxide which are attached to an insulator or a substrate with poor thermal conductivity, having the method steps of arranging the layer with a focused electron beam with an energy of 3-30 keV, wherein the electron beam is guided such that the energy input per time and area leads to local heating of the layer above its melting and / or evaporation point and wherein the removal of the layer takes place without the supply of reaction gases into the vacuum chamber.DE 10 2008 011 530 A1 describes a method for processing an object having miniaturized structures, comprising the steps of: supplying a reaction gas to a surface of the object; processing an object by directing an energetic beam onto a processing location in an area to be processed on the surface of the object in order to deposit material on the object or remove material from the object; detecting interaction products of the beam with the object; and deciding whether the processing of the object has to be continued or can be ended on the basis of information obtained from the detected interaction products of the beam with the object; wherein the decision as to whether the processing of the object has to be continued or can be ended is divided into a plurality of surface segments, and the interaction products detected when the beam impinges on regions of the same surface segment are integrated to form an overall signal.In the context of a lithographic method, a mask may be exposed to high physical and chemical stresses (e.g. during a mask exposure, a mask cleaning, etc.). Accordingly, there are imposed high demands on the durability of the mask materials, which may become more stringent as the development of technology in lithography advances.Since mask defects cannot generally be ruled out in the complex mask production, the mask materials can also form on the mask as mask defects (e.g. as defects, excess material, malformed material, particles lying on them, etc.).It is generally known to repair or repair mask defects, for example via a particle beam-based etching process. However, previous mask repair methods only consider a limited number of mask materials.The present invention is therefore based on the object of specifying methods and apparatuses which optimize the processing of objects for lithography.3. SUMMARY OF THE INVENTIONThis object is at least partially achieved by the various aspects of the present invention. The invention is defined in the independent claims. Preferred embodiments are set forth in the dependent claims.A first aspect of the invention relates to a method for processing an object for lithography. The method of the first aspect comprises providing a first gas comprising first molecules. Furthermore, the method comprises providing a particle beam on a working region of the object for removing a first material in the working region based at least in part on the first gas. The first material may comprise chromium and nitrogen. Furthermore, the first material can comprise at least 1 atomic percent (at. %) nitrogen, preferably at least 5 atomic percent (at. %) nitrogen, more preferably at least 10 atomic percent nitrogen, particularly preferably at least 20 atomic percent nitrogen.The invention addresses the problem of removing materials on an object for lithography that are designed to be resistant to removal under chemical and / or physical stress.Recently, established chromium-containing mask materials have been designed specifically with a certain nitrogen content in order to meet the current and future requirements. The nitrogen content can be stoichiometrically increased compared to the established chromium-containing mask materials (e.g. go beyond the degree of nitrogen contamination). Due to this certain nitrogen content, the mask materials may have an increased chemical resistance to the requirements of lithography. These nitrogen-containing mask materials can, for example, make up a layer of a mask (e.g. a layer of a pattern element).Thus, for example, chromium-containing material having a high nitrogen content of at least 1 atomic percent (at least 5 at. %, at least 10 at. % and / or at least 20 at. %) can be specifically designed in order to explicitly prevent the removal of this chromium-containing material under chemical / physical influences. The high nitrogen content can furthermore be designed in such a way that it prevents removal / wear of the chromium-containing material even in the event of permanent or regular chemical / physical stress. This type of resistant chromium-containing materials is usually designed for the extreme conditions in lithographic methods in which the object can be used for lithography. For example, the object may be exposed to a (damaging) plasma during a lithographic method. For example, a lithographic process may require exposing the object to a hydrogen environment (e.g., to avoid defects). In this case, during a lithographic exposure of the object, a (parasitic) highly reactive hydrogen plasma can be released with hydrogen radicals, which can act on the material of the object. The plasma represents a high chemical / physical stress on the object and may cause material removal as well as material damage to the object (e.g. in a similar manner to plasma etching). However, the material-removing effect is not desired in the object of lithography, since this can have a negative influence on the properties of the object and thus on the quality of the lithographic method. Therefore, the high nitrogen content in the chromium-containing material can be designed (explicitly) in order to ensure a high resistance of the first material to the material-removing effect of a plasma (e.g. in particular of the highly reactive hydrogen plasma). Furthermore, the object may be exposed to numerous further mechanical / chemical influences during lithography, which (e.g. in combination with the plasma action) may damage the object. For example, the further damaging influences can comprise strong temperature fluctuations, exposure radiation, and also chemical reactions of the object with purge gases. The high nitrogen content is therefore usually designed to counteract the totality of the damaging material-removing influences during lithography in principle, so that mechanical / chemical wear and removal of the chromium-containing material is made more difficult.The inventors have recognized that this material can also be removed in a particle beam-induced manner in order to correct errors which may be produced by excess material. The inventive concept is accordingly based on removing materials which are designed to be resistant to removal in particular by means of a particle beam-based method. The inventors herein have encountered the unexpected finding that a chromium-containing material having a high nitrogen content of at least 1 atomic percent (at least 5 atomic percent, at least 10 at. %, and / or at least 20 at. %) can be removed with the aid of a provided gas and a provided particle beam (e.g. via a particle beam-induced etching). This was a surprising finding for the inventors, since it was unpredictable that the first material-resistant to the aggressive conditions of lithography-can be processed or even removed on a particle beam basis (e.g. without using a plasma, which is known to be able to etch the object during lithography). Furthermore, it was unexpected for the inventors, in view of the resistant first material, that in the case of particle beam-based removal of the first material, the provision of a gas which comprises first molecules is in principle sufficient. According to the invention, it is not necessary to resort to a complex gas mixture (e.g. with different types of molecules designed for the resistant material). This can ensure that the complexity in the particle beam-based removal is reduced, as a result of which, for example, easier process control of the method according to the invention can be carried out (since, for example, the provision of a single gas makes a lower requirement for the technical implementation than the provision of a gas mixture composed of, for example, two or more different gases). The invention thus makes it possible to process objects for lithography that have resistant materials (e.g. with a high nitrogen content).The unit atomic percent, as described herein, may refer to a molar fraction of the respective material, where atomic percent indicates, for example, the relative number of particles (e.g., nitrogen atoms) with respect to the total number of particles of the substance (e.g., total number of atoms of the first material). The atomic percentage can be detected, for example, by secondary ion mass spectroscopy, SIMS and / or Auger electron spectroscopy and / or X-ray photoelectron spectroscopy, XPS (as well as, for example, by photoelectron spectroscopy, PES).The object for lithography as described herein may thereby comprise a lithographic mask. The lithographic mask may be designed to be used in lithography for the production of semiconductor-based chips (e.g. during exposure of a semiconductor-based wafer). The lithographic mask may further comprise any type of lithographic mask capable of imaging an image based on a source of electromagnetic radiation (of any wavelength) and a pattern comprised on the lithographic mask. The image can comprise a transformation of the pattern. The lithographic mask may comprise e.g. an EUV mask, a DUV mask, a UV mask, an X-ray lithography mask, a binary mask, a phase shifting mask etc. Further, the lithographic mask may also include a nanoimprint lithography stamp or a lithography mask that can image a pattern based on a source of particles.The workspace referred to herein may include a local area of the object for lithography. However, it is also conceivable for the working area to comprise the entire object for lithography. The working region can furthermore have any desired surface dimension, shape and / or geometry. For example, the workspace may be on a scale associated with a particular dimension of the object. For example, the determined dimension may comprise a critical dimension CD of a pattern element (i.e. pattern element) of the object. The critical dimension CD can comprise, for example, a defined structure width of the pattern element as well as a defined distance between two (characteristic) pattern elements. The working region can, for example, span an area A which results over the critical dimension CD of the pattern element (for example, A can correspond to a function of the critical dimension CD, with A=f(CD), for example, A can be proportional to the critical dimension). Furthermore, the removal of the first material within the working area can be effected in such a way that the first material is not necessarily removed over the entire surface of the working area, but is (locally) removed in a partial area of the working area. Alternatively, the removal can take place within the working region in such a way that the first material is removed over the entire surface of the working region. Furthermore, the first gas can be provided in a targeted manner on a partial region of the working region (for example via a locally positionable gas line having a gas nozzle). Likewise, the provision of the particle beam can be effected in such a way that it is aligned on a partial region of the working region, such that the particles of the particle beam are irradiated on the partial region. Furthermore, the method can comprise the particle beam being controlled and / or focused locally in a targeted manner in the subregion or within the working region (in order, for example, to control a reaction of the particle beam-induced etching locally).The method of the first aspect described herein is in principle also conceivable with a different nitrogen content of the first material, e.g. <5 atomic percent or even <1 atomic percent or >50 atomic percent nitrogen content. Accordingly, a further aspect of the invention can comprise removing the first material with the provided first gas and the provided particle beam, wherein the further aspect can comprise at least one further of the features described herein, without being limited to the nitrogen content of the first material.Furthermore, the inventors have recognized that the method described herein is also conceivable for a material as the first material which comprises a different element (e.g. a different metal) instead of chromium (or in addition to chromium). The first material may accordingly be considered a nitrogen-based material (e.g., a nitride-based material, e.g., a metal nitride). For example, instead of chromium, the first material may comprise at least one of the following: niobium, titanium and / or tantalum. In this case, the first material may comprise, for example, niobium nitride (e.g. NbN, Nb 2 N, Nb 4 N 3), and / or titanium nitride (e.g. TiN) and be removed according to the method described herein. The nitrogen content of the niobium nitride and of the titanium nitride may correspond to the nitrogen contents of the first material described herein.In one example, the method of the first aspect includes the first material being capable of absorbing radiation associated with the object. For example, this radiation associated with the object may comprise electromagnetic radiation having a particular wavelength that may be used in a lithographic method for which the object is designed. For example, the radiation associated with the object may correspond to an exposure radiation of the object in the lithographic method. The specific wavelength of the exposure radiation can be understood as a lithographic wavelength of the object. In an example, the object for lithography comprises an EUV mask for an EUV lithography method, wherein the lithographic wavelength (i.e. the wavelength of the exposure radiation) may in this case have 13.5 nm. Further, the radiation may refer to, for example, a DUV lithography method (e.g., 193 nm and 248 nm lithographic wavelength, respectively), an i-line lithography method (e.g., 265 nm lithographic wavelength), as well as any other lithography method (e.g., having a different lithographic wavelength), depending on the object.In an example, the first material has an intrinsic material parameter indicative of a significant (e.g., high) absorption of the lithographic wavelength of the object (e.g., an absorption coefficient, an absorption contribution, an imaginary part of the refractive index of the first material). Further, the first material may comprise a material typically present at the object to absorb the lithographic wavelength (e.g. a material corresponding to an absorption layer (e.g. a pattern element) of the object).In a further example, the first material not only has an intrinsic material parameter per se, which indicates a significant absorption. Additionally, the first material may be geometrically configured such that it can effectively absorb the radiation associated with the object in a local area of the object. For example, the first material in a (local) region of the object can be geometrically constructed in such a way that it causes a significant absorption of the radiation of the lithographic wavelength in the (local) region via its absorbing material property and its geometrical construction. In this case, the first material in the (local) region can make an imaging contribution in a lithographic method, since there is an actual (i.e. effective) absorption of the radiation of lithographic wavelength. The geometry of the first material can be defined, for example, by the layer thickness of the material or by a distance through which radiation of a lithographic wavelength would pass through the first material (i.e. an absorption distance) in a lithographic method. The absorption distance can take into account, for example, the optical refraction of the radiation of lithographic wavelength or an irradiation vector of the exposure radiation. For example, the method may include not removing a very thin layer of a material that per se (i.e. intrinsically) absorbs, since this thin layer cannot absorb the radiation of lithographic wavelength geometrically significantly and thus does not make an actual (i.e. effective) imaging contribution in a corresponding lithographic method. For example, the significant absorption can be defined or calculated over the layer thickness or absorption distance of the first material. The layer thickness of the first material can comprise at least 20 nm, preferably at least 35 nm, more preferably at least 50 nm, most preferably at least 60 nm. The layer thickness of the first material can, however, also be less than 60 nm, for example less than 50 nm or less than 35 nm. The significant absorption can furthermore be described in such a way that the intensity of the radiation of lithographic wavelength is attenuated by 70%, preferably 80%, most preferably 90%, in a lithographic method (across the first material).In one example, the method of the first aspect comprises the first material corresponding to a layer material of a pattern element of the object. In one example, the method comprises the layer material corresponding to a material of an absorption layer of the pattern element. The absorption layer can comprise the layer of the pattern element which is explicitly aligned for absorbing the radiation of lithographic wavelength.In one example, the method includes where the first material includes at least 10 atomic percent chromium, preferably at least 20 atomic percent chromium, most preferably at least 30 atomic percent chromium. In another example, the method includes where the first material includes at least 10 atomic percent chromium oxide, preferably at least 20 atomic percent chromium oxide, most preferably 30 atomic percent chromium oxide. In another example, the method includes where the first material includes at least 2 atomic percent chromium in metallic compound, preferably at least 3 atomic percent chromium in metallic compound, most preferably at least 4 atomic percent chromium in metallic compound. The atomic percentage can be detected, for example, by secondary ion mass spectroscopy, SIMS and / or Auger electron spectroscopy and / or X-ray photoelectron spectroscopy, XPS (as well as, for example, by photoelectron spectroscopy, PES). In particular, the proportion of the metallic chromium can be detected by means of an XPS analysis.In an example, the method of the first aspect includes where the first material includes a chromium nitride. The chromium nitride may comprise, for example, CrN and / or Cr 2 N. Chromium nitride can be characterized by high hardness and extreme corrosion resistance. The inventors have recognized that chromium nitride or a material having a chromium nitride fraction can also be processed or removed using the method according to the invention. Chromium nitride can be detected, for example, by conventional physical / chemical analysis methods (for example by X-ray spectroscopy). For example, in CrN, there may be a refractive index n of 0.9295 and an absorption coefficient kβ of 0.0336. For example, in Cr 2 N may have a refractive index n of 0.9272 and an absorption coefficient kβ of 0.0376.In one example, the first gas may be considered a substantial etch gas for removing the first material. The first gas can be designed in such a way that it substantially influences the etching behavior of the first material. For example, the molecules of the first gas may be selected to cause an etching / removing effect of the first material. Or, the first molecules can also be selected such that, in conjunction with a reaction induced by the particle beam, they bring about an etching / removing effect of the first material.In one example, the method of the first aspect comprises the first molecules of the first gas comprising at least one halogen atom. The inventors have recognized that a gas comprising molecules having a halogen is particularly suitable for removing the resistant first material (e.g. having the high nitrogen content described herein). Such a first gas (i.e. etching gas) can advantageously remove the resistant first material in a technically desired manner in conjunction with the particle beam provided. For example, removal residues, long etching times, inhomogeneous material removals can be avoided with such a first gas in the method of the first aspect.In one example, the method of the first aspect comprises the first molecules comprising a halogen compound. For example, the halogen compound may comprise a chemical compound having at least one halogen atom, wherein the halogen atom enters into a chemical compound with at least one further chemical component (e.g. any further chemical element / atom and / or any further chemical group / substance compound, etc.). In one example, the halogen compound may exclusively comprise halogens of the same type (e.g., the first molecules may comprise F 2, Cl 2, Br 2, etc.).In one example, the method of the first aspect comprises the halogen compound comprising a nitrosyl halide and / or a nitrosyl halide. In one example, the method of the first aspect comprises the nitrosyl halide comprising at least one of nitrosyl chloride, NOCl, nitrosyl fluoride, NOF, nitrosyl bromide, NOBr. In another example, the method of the first aspect comprises the nitrosyl halide comprising at least one of: nitrosyl chloride, ClNO 2, nitrosyl fluoride, FNO 2. The inventors have thereby recognized that such first molecules (e.g. nitrosyl chloride or nitrosyl chloride) can also advantageously remove the resistant first material in a technically desired manner within the scope of the method of the first aspect.In one example, the halogen compound comprises a noble gas halide. For example, the inert gas halide may comprise a chemical compound having at least one halogen atom and at least one inert gas atom.In one example, the noble gas halide comprises at least one of xenon difluoride, XeF 2, xenon dichloride, XeCl 2, xenon tetrachloride, XeCl 4, xenon tetrafluoride, XeF 4, xenon hexafluoride, XeF 6. The inventors have thereby recognized that such noble gas halides (e.g. in particular xenon difluoride) can also advantageously remove the resistant first material in a technically desired manner within the scope of the method of the first aspect.In a further example, the first molecules comprise a quadrupole moment (or a multipole moment with at least four poles) which is greater than zero. For example, xenon difluoride may have a quadrupole moment greater than zero.In one example, the halogen compound comprises an interhalogen compound (i.e., an interhalogen). For example, the interhalogen compound may comprise a chemical compound of at least two different halogens with each other. The inventors have recognized that interhalogens are also suitable as first molecules of the first gas in order to remove the resistant first material in a technically desired manner. For example, the interhalogen compound may comprise at least one of the following: ClF, ClF 3, BrF, BrF 3, ICl, ICl 3, BrCl, IF, IF 3, IBr, IBr 3.In another example, the first gas comprises a combination of the first molecules mentioned herein. The first gas can also be understood as a combination of different gases with different first molecules. For example, the first gas may comprise any combination of one or more nitrosyhalides, nitrosylhalides, noble gas halides and / or interhalides as first molecules.For example, the first gas may comprise a nitrosyl halide and a noble gas halide. In this case, for example, the first gas may comprise NOCl and / or NOF as nitrosyl halide and XeF 2 as noble gas halide.For example, the first gas may comprise a nitrosyl halide and a noble gas halide. In this case, for example, the first gas may comprise ClNO 2 and / or FNO 2 as the nitrosyl halide and XeF 2 as the noble gas halide.For example, the first gas may comprise a nitrosyl halide and a nitrosyl halide. In this case, for example, the first gas may comprise NOCl and / or NOF as nitrosyl halide and ClNO 2 and / or FNO 2 as nitrosyl halide.In one example, the first molecules comprise polar molecules. It has been found that polar molecules with a dipole moment can in principle be suitable for the method. In another example, the first molecules may also comprise non-polar molecules. The invention is furthermore based on the concept that even nonpolar molecules without a dipole moment can in principle be suitable for the method. In an additional example, the first molecules comprise triatomic molecules. According to the present invention, there is no need for necessarily complex compounds having more than three atoms per molecule for a suitable method of the first aspect.In one example, the method of the first aspect comprises a first dipole moment associated with the first molecules comprising at least 1 D (D: Debye), preferably at least 1.5 D, more preferably at least 1.7 D, most preferably at least 1.8 D. In a further example, the method comprises the first dipole moment comprising at least less than 2.5 D, preferably at least less than 2.3 D, particularly preferably at least less than 2.1 D, most preferably at least less than 2 D. The inventors have recognized that a probability of adhesion of the (first) molecules on a surface depends on their dipole moment (e.g., the probability of adhesion may be proportional to the dipole moment). The invention takes advantage of this effect in the removal of the first material. In the case of particle beam-based removal (e.g. particle beam-induced etching), a defined (local) gas concentration of the first gas (i.e. of the etching gas) over a specific period of time is usually required in order to allow the reaction of the removal to proceed in a defined manner. It can therefore be helpful to set the defined (local) gas concentration in a targeted manner. However, due to chemical and / or physical interactions during the removal of the first material, the defined (local) gas concentration may change to a technically undesirable extent. For example, this may comprise a (local) depletion of the first gas within the working area, such that the process of removing the first material is influenced in an undesired manner. The inventors herein have recognized that using first molecules having the dipole moments described herein may imply improved conditions of likelihood of first molecules adhering to a surface (e.g., the surface of the first material). This can enable, for example, an optimized occupancy of the first molecules in the working area of the object. This technical effect can therefore be used to achieve optimized conditions in the design of the defined (local) gas concentration, as a result of which the removal of the first material can be optimized.In an example, the method of the first aspect further comprises providing a second gas comprising second molecules, wherein the removing of the first material is further based at least in part on the second gas. The second gas described herein may be considered in this context as additive gas with respect to the substantial etching gas (i.e. the first gas). The second gas can thereby further influence the removal or the particle beam-induced etching of the first material as additive gas and adapt process parameters / results more accurately (e.g. etching rate, anisotropy factor, selectivity, sidewall angle, surface roughness, etc.). In principle, the features described herein for the provision of the first gas can also apply for the provision of the second gas, and vice versa.In one example, the method of the first aspect comprises a first dipole moment associated with the first molecules and a second dipole moment associated with the second molecules differing from one another by a maximum of 0.1 D, preferably a maximum of 0.08 D, particularly preferably a maximum of 0.07 D, most preferably a maximum of 0.06 D. This example is based on the idea that the first molecules of the first gas (i.e. of the substantial etching gas) have a dipole moment similar to the second molecules of the second gas (i.e. of the additive gas). The inventors have recognized that this circumstance may be advantageous in removing the first material. In particle beam-based removal, as described herein, a defined (local) gas concentration over a specific period of time is usually required in order to allow the removal reaction to proceed in a defined manner. This is of increased importance in particular when using a more complex gas mixture which comprises at least two gases (e.g. the first and the second gas). This is associated with increased requirements for maintaining the defined (local) gas concentration. For example, here too, a (local) depletion of the second gas (and / or of the first gas) can occur to an increased extent within the working region, such that the removal of the first material can be influenced in an undesired manner. The inventors herein have recognized that using first and second molecules with similar dipole moments (as described herein) may imply similar adhesion properties of the first and second molecules to a surface. This can result in a similar probability of adhesion of the first and second molecules, as a result of which an equivalent covering of the surface with the first and second molecules can be made possible. In particular, this allows the surface of the first material to be covered in a defined manner with the first and second molecules during the removal. This technical effect can accordingly allow optimized conditions in the design of the defined (local) gas concentration when using the first and second gases. This mechanism of action can accordingly specifically optimize the removal of the first material.As mentioned herein, the probability of adhesion of the molecules may be proportional to their dipole moment. Thus, in one example, the method includes taking into account the first and second dipole moments of the first and second molecules (as described herein) as a parameter in removing the first material. For example, the first and second dipole moments may define a process parameter (e.g., a gas mass flow of the first and / or second gas) at the removal.In one example, the method includes providing the first gas and the second gas at least partially simultaneously. For example, the first gas and the second gas can be introduced simultaneously into the environment of the working area or into the environment of the object, e.g. during the removal of the first material. This can further comprise that during the removal (at least partially) a first gas flow rate of the first gas as well as a second gas flow rate of the second gas are present, so that the presence of both gases in the environment of the working area / object is ensured. It is possible here, for example, for the first and second gas mass flow to be substantially identical. In other examples, however, they can also be different from one another. Simultaneously providing the first and second gases may further comprise varying the first gas flow rate and the second gas flow rate (upon removal of the first material).In one example, the method includes providing the first gas and the second gas at least partially staggered in time. For example, for the removal of the first material, it may be necessary that only one of the two gases is to be provided or introduced in the environment of the working area / object in a process step of the removal. For example, at the beginning of the removal of the first material, it may be necessary for only the first gas (or the second gas) to be introduced into the environment of the working area / object first. Subsequently, the second gas (or the first gas) can be added or provided at a later point in time. Furthermore, it is also conceivable that during the removal, a stepwise change is made between the (exclusive) provision / introduction of the first gas (without the second gas) and the (exclusive) provision / introduction of the second gas (without the first gas). Furthermore, it is also possible that a process end of the removal of the first material comprises the exclusive provision / introduction of one of the two gases. For example, it is conceivable that a process end of the generation is defined by the exclusive provision / introduction of the second gas.In an example, the method of the first aspect comprises that the second molecules comprise water, H 2 O, and / or heavy water, D 2 O. In this case, water and / or heavy water have proven to be advantageous additive gas for the removal of the resistant first material, and also with respect to the selectivity of the removal of the first material. In a particularly advantageous example, the method comprises NOCl as the first gas and H 2 O as the second gas. In a further particularly advantageous example, the method comprises XeF 2 as the first gas and H 2 O as the second gas. In another example, the second molecules of the second gas may also comprise semi-heavy water, HDO.In another example, the second gas (or molecules) may comprise an oxygen-containing component, a halide, and / or a reducing component. The oxygen-containing component can have, for example, an oxygen-containing molecule. For example, the oxygen-containing component may include at least one of oxygen (O 2), ozone (O 3), hydrogen peroxide (H 2 O 2), dinitrogen monoxide (N 2 O), nitrogen monoxide (NO), nitrogen dioxide (NO 2), nitric acid (HNO 3). The halide may include, for example, at least one of Cl 2, HCl, XeF 2, HF, I 2, HI, Br 2, HBr, NOCl, NOF, ClNO 2, FNO 2, PCl 3, PCl 5. The reducing component may comprise a molecule having a hydrogen atom. For example, the reducing component may comprise at least one of the following: H 2, NH 3, CH 4.In one example, the method of the first aspect includes selectively removing the first material such that a second material of the object is substantially not removed. For example, the method can be designed such that during the removal according to the invention (e.g. based on particle beam-induced etching), a selectivity of the removal (e.g. an etching selectivity) of the first material compared to the second material is present. The selectivity may allow, for example, the second material to be removed at a lower removal rate than the first material when the second material is subjected to the method (as described herein). Accordingly, the method may include adjusting a defined selectivity (e.g., an increased etch selectivity). This can be ensured, for example, by a suitable selection of the first and / or second gas, as well as suitable gas parameters of the first and / or second gas (e.g. gas flow rate, gas pressure, gas concentration, etc.). For example, in particular, the selection of the second gas (e.g., water and / or heavy water as described herein) and the gas parameters of the second gas may be used to adjust the selectivity of the removal of the first material over the second material. The method can furthermore be carried out in such a way that substantially no physical / chemical stress is present on the second material.In an example, the second material may include a material at any location of the object for lithography, as well as a material within the workspace. Furthermore, a material is conceivable as the second material, which would in principle be exposed to the material-removing effect of the method. For example, this can comprise the second material being exposed to the first (or second gas) during the method and / or being present in a closer (as well as in the immediate) environment of the particle beam. For example, the second material can abut the first material or be mechanically coupled to the first material (e.g. also indirectly via a material lying therebetween). In this case, it is conceivable that, when removing the first material, a surface of the second material is exposed, so that the second material would be exposed to the material-removing effect of the method. According to the invention, the removal of the second material can be counteracted via the selectivity of the process. In a typical application of the method, the second material can be, for example, a part of a layer of the object which adjoins the first material (directly or indirectly). For example, the object can have a characteristic layer structure in which a cover layer adjoins a reflective layer stack (e.g. a Bragg mirror). The characteristic layer structure may further comprise a buffer layer adjoining the cover layer. In this case, an absorption layer can additionally adjoin the buffer layer. In an example, a portion of the absorbent layer may comprise the first (to be removed) material of the method. The method can accordingly be configured with such a selectivity that the second material comprises the material of the buffer layer, the material of the cover layer and / or the material of the reflective layer stack. In one example, the selectivity is configured such that the second material explicitly comprises the material of the cover layer of the reflective layer stack of the object. This can make it possible for the method to be terminated in a targeted manner by means of the reduced removal rate of the covering layer without attack on the reflective layer stack. The cover layer can accordingly function as a distance stop (e.g. etching stop), so that damage to the reflective layer stack, which would be associated with damage to the optical properties of the object, can be prevented.The process can be carried out in such a way that the selectivity of the removal of the first material compared to the second material is at least 2:1. In one example, the selectivity of removing the first material over the second material is at least 15:1, preferably at least 25:1, most preferably at least 50:1.In one example, the method of the first aspect includes the method further including removing at least one intermediate material disposed between the first material and the second material. As described herein with respect to the characteristic layer structure, the intermediate material may comprise, for example, a part of the buffer layer of the object. Furthermore, it is also conceivable that the at least one intermediate material comprises a part of the buffer layer and a part of the cover layer of the object. The intermediate material does not necessarily have to include the properties of the first material (or of the second material) mentioned herein.In one example, the method of the first aspect comprises the method further comprising removing at least one surface material of the object. The surface material can comprise, for example, a material of the object which has a surface which is accessible to the first gas and / or second gas, as well as to the particle beam (for example a free-standing surface of the object). The surface material can comprise any material and is not limited to the substances and substance fractions of the first or second material mentioned herein. In this case, the surface material can be removed, for example, in order to expose the first material arranged underneath for the method according to the invention. With respect to the characteristic layer structure of the object described herein, the surface material may be, for example, a part of a surface layer adjoining the absorption layer (e.g. opposite the buffer layer). The surface layer may comprise an antireflection layer, an oxide layer, a passivation layer in this example.In one example, the method of the first aspect comprises the particle beam being based at least partially on an acceleration voltage of less than 3 kV, preferably less than 1 kV, more preferably less than 0.6 kV. In these ranges of the acceleration voltage, removal of the first material (as described herein) can advantageously take place.Furthermore, it is also conceivable that the particle beam is based on an acceleration voltage of less than 30 kV, preferably less than 20 kV. In one example, an acceleration voltage of between 3 kV and 30 kV can be used for imaging purposes within the scope of the method (e.g. in the case of image recording before or after removal and / or image recording during removal).In one example, the particle beam comprises a current intensity between 1 pA and 100 pA, preferably between 5 pA and 80 pA, most preferably between 10 pA and 60 pA.In one example, the method of the first aspect includes the method further comprising determining an endpoint of the removing based at least in part on detecting electrons emitted from the object. For example, the electrons can be emitted on the basis of an interaction of the provided particle beam with a material of the object or with a material of the working region. Thus, these can be electrons which emerge from an active region of the particle beam incident on the material, physically conditioned, on account of the particle beam. In one example, the electrons include scattered electrons and / or secondary electrons. The scattered electrons may include, for example, object-backscattered electrons (BSE) and / or forward-scattered electrons (FSE). The detected electrons can provide indications on a material property in the effective range of the particle beam, whereby the material processed with the particle beam can be deduced. For example, the determination of the end point can comprise the determination by means of the detected electrons that the particle beam is no longer (any longer) acting on the first material. This may indicate that the first material has been removed and the end point of the process (i.e., the end of the process) is reached. Furthermore, the determination of the end point can comprise the determination, via the detected electrons, that the particle beam processes the second material (which is selectively not to be removed) and that the end point of the method is reached. In principle, the detected electrons can be used to determine the material currently being processed with the particle beam without this being related to the end point determination (e.g. for process monitoring, as logging of the process history, etc.). The particle beam can furthermore be configured such that there is a sufficient signal difference of the detected electrons depending on the material of the active region (e.g. via an acceleration voltage, current intensity, etc.).In one example, the method of the first aspect comprises the particle beam comprising an electron beam. For example, the removal described herein may include electron beam induced etching (further known as (F)EBIE (focused) electron beam induced etching, for example).However, it is also conceivable for the particle beam to comprise an ion beam (e.g. made of gallium ions, helium ions, etc.). For example, the removal of the first material may be based on ion beam induced milling / etching (e.g., focused ion beam (FIB) milling).Furthermore, a use of a plurality of particle beams is also conceivable as the particle beam.In one example, the method is carried out in such a way that a side wall angle of the first material is 70° to 90°, preferably 74° to 90°, more preferably 78° to 90°, most preferably 80° to 90°. The side wall angle can be related, for example, to the plane of a layer arranged under the first material, or also to the (planar) plane of the object.In one example, the method takes place in such a way that a surface of the second material has a root mean square roughness, RMS, of less than 3 nm, preferably less than 2 nm, more preferably less than 1 nm, most preferably less than 0.5 nm.In one example, the method of the first aspect comprises the method being carried out in such a way that a defect of the object is repaired. For example, the method may include repairing an opaque defect of the object.An opaque defect is a defect on the object for lithography, which should actually not be opaque, i.e. clear, after the object has been designed (e.g. transparent or designed in such a way that no targeted absorption for radiation of a specific wavelength, e.g. of the lithographic wavelength, is present). A clear defect, on the other hand, is a defect on the object for lithography, which should actually be opaque after the object has been designed (e.g. opaque or strongly absorbing to radiation of a specific wavelength, e.g. the lithographic wavelength). In particular, it may be defined opaque with respect to a lithography method for which the object may be used. For example, the object for lithography may comprise an EUV mask for an EUV lithography method, wherein opaque in this case may refer to the lithographic wavelength of 13.5 nanometers. It is also conceivable that opaque refers to a DUV lithography method (at 193 nanometers and 248 nanometers of lithography wavelength, for example), an i-line lithography method (at 265 nanometers of lithography wavelength, for example), as well as any other lithography method depending on the object. Furthermore, an opaque defect may comprise, for example, a defect location comprising opaque material of a layer of a lithographic mask (e.g. this may comprise a layer configured as a layer for an opaque pattern element of the object). The method can thereby comprise removing the first material such that the defect is no longer opaque.For example, repair of the defect may first include locating the defect (e.g., via a scanning electron microscope, an optical microscope, etc.). In this case, the working region used for removing the first material can be defined based on at least one characteristic of the localized defect (e.g. based on a position, shape, size, type of the defect, etc.). The remedying the defect of the object may further include generating a repair shape including the defect. The repair form may serve as the workspace for the methods recited herein, in one example. The repair form can have a pixel grid, for example, as a result of which a location of the defect can be made possible. The pixel grid can be designed, for example, such that it follows the contour of the defect, so that each pixel of the pixel grid corresponds substantially to a location of the defect and thus represents a defect pixel. In another example, the pixel grid has a fixed geometric shape (e.g., a polygon, a rectangle, a circle, etc.) that completely encompasses the defect, wherein not each pixel forcibly represents a location of the defect. Here, the pixel grid may include defect pixels corresponding to a location of the defect and non-defect pixels corresponding to a location that does not cover a part of the defect. In one example, the method comprises directing the particle beam at least onto a defect pixel of the pixel grid of the repair shape during the generation of the material. Furthermore, the particle beam can be configured such that it can be directed onto each defect pixel during the removal of the first material. This can ensure that the removal of the first material is locally limited to the defect pixels and thus only the defect is processed.In a further example, the method can be used in a processing of the object, which comprises a local material production. The processing as well as the local material generation can be carried out, for example, as part of defect processing of the object (for example, when a clear defect and / or a defective location is repaired, when a particle is removed, etc.). Thus, the first material does not necessarily have to be a layer material of the object. The material generation may include, for example, the deposition of a material corresponding to the properties of the first material (as described herein). For example, in the context of local material generation, an erroneous generation of the first material may occur. Accordingly, the process according to the invention can be used to remove the incorrectly produced material, as the first material (as described herein). For example, it may also be necessary within the scope of a complex repair to produce the first material in a targeted manner and to remove it in a targeted manner (for example, this may be necessary if the first material has been produced as a sacrificial layer).In an example, the method of the first aspect comprises the object comprising an EUV mask and / or a DUV mask. For example, the characteristic layer structure described herein can correspond to a layer structure of an EUV mask.A second aspect relates to an apparatus for processing an object for lithography, comprising: means for providing a first gas; means for providing a particle beam on a working region of the object, wherein the apparatus is configured to perform a method of the first aspect. Furthermore, the device can comprise means for executing a computer program (e.g. a computer system, a computing unit, etc.). The apparatus can substantially correspond to a scanning electron microscope which can provide an electron beam as a particle beam on the object. The scanning electron microscope can be configured in this case such that it can provide the gases described herein. The first gas (and / or the second gas) can be stored, for example, in corresponding storage containers and can be conducted in the working region of the object via a gas supply system (for example a gas line with a gas nozzle).A third aspect relates to an object for lithography, wherein the object has been processed with a method of the first aspect. In this case, it can be detected, for example, by means of an optical examination of the object, whether the object has been processed using a method of the first aspect. For example, an optical examination can have been carried out or be carried out initially for the object for lithography (e.g. within the scope of defect qualification of the object, e.g. following production of the object and / or when the object is introduced into a semiconductor facility). The optical examination can be based, for example, on an optical or particle-optical microscope (for example on a mask metrology device, a mask microscope) and can comprise, for example, an image recording. During processing of the object according to one example of the first aspect following the initial examination, the first material may have been removed as described herein. The removal of the first material can be detected via a repeated optical examination (e.g. in the context of repair checking or renewed defect qualification). The detection can be carried out, for example, by comparing the initial optical examination with the repeated optical examination (for example, by comparing the corresponding image recordings). Furthermore, the detection of the method can also be based on a material analysis of the object (e.g. Auger spectroscopy, X-ray spectroscopy, etc.), which is carried out e.g. in addition with the initial or repeated optical examination.A fourth aspect relates to a method for processing a semiconductor-based wafer. The method of the fourth aspect further comprises lithographically transferring a pattern associated with an object for lithography onto the wafer, wherein the object has been processed according to any of the examples of the first aspect of the invention mentioned herein. The lithographic transfer may thereby comprise a lithography method for which the object is designed (e.g. EUV lithography, DUV lithography, i-line lithography, etc.). For example, the method of the fourth aspect may comprise providing a beam source of electromagnetic radiation (e.g. EUV radiation, DUV radiation, i-line radiation, etc.). Furthermore, provision of a developable lacquer layer on the wafer may be included. The lithographic transfer can furthermore be based at least in part on the beam source and the provision of the developable lacquer layer. In this case, the pattern can be imaged onto the lacquer layer (in a transformed form), for example by means of the radiation of the radiation source.The methods described herein can be deposited, for example, in writing. This can be realized, for example, via a digital file, analog (e.g., in paper form), in a user manual, in a recipe (which is stored, for example, in a device and / or a computer of a semiconductor work). It is furthermore conceivable that a written protocol is created when one of the methods described here is carried out. The protocol can thereby enable, for example, that the execution of the method and its details (e.g. the recipe) can be detected at a later point in time (e.g. within the scope of a fault assessment, a material review board, an audit, etc.). The log can comprise, for example, a log file (i.e. log file), which can be stored, for example, in a device and / or in a computer.A fifth aspect relates to a computer program comprising instructions which, when executed by a computer system, cause the computer system to perform a method according to the first aspect and / or a method according to the fourth aspect.A further aspect relates to the mentioned apparatus having a memory which comprises the computer program. The apparatus may further comprise means for executing the computer program. Alternatively, it is also possible for the computer program to be stored elsewhere (e.g. in a cloud) and for the apparatus to have only means for receiving instructions resulting from the execution of the program elsewhere. This or the like can make it possible, for example, for the method to be able to run automatically or autonomously within the device. Thus, the intervention, e.g. via an operator, can be minimized, so that the costs as well as the complexity in the processing of masks can be minimized.The features mentioned herein (as well as examples) of the methods can also be applied or apply in a corresponding manner to the mentioned device as well as to the mentioned object. Likewise, the features (as well as examples) of the device mentioned herein, as well as the features (as well as examples) of the object mentioned herein, can be applied or apply in a corresponding manner to the methods described herein.4. Brief Description of the FiguresIn the following detailed description, background technical information and embodiments of the invention are described with reference to the figures, in which: FIG. 1 schematically illustrates, in a plan view, an exemplary repair situation of an object for lithography from the prior art. FIG. 2 shows a schematic diagram of an exemplary method of the invention. FIG. 3 a- bschematically illustrates, in a cross-section, processes in a method of the invention by way of example.5. DETAILED DESCRIPTION OF POSSIBLE EMBODIMENTSFIG. 1 schematically illustrates, in a plan view, an exemplary repair situation of an object for lithography. The object for lithography may thereby comprise a lithographic mask suitable for any lithography method (e.g. EUV lithography, DUV lithography, i-line lithography, nanoimprint lithography, etc.). In an example, the lithographic mask may comprise an EUV mask, a DUV mask, an i-line lithography mask and / or a nanoimprint stamp. Further, the object for lithography may include a binary mask (e.g., a chrome mask, an OMOG mask), a phase mask (e.g., a chrome-free phase mask, an alternating phase mask (e.g., a rim phase mask)), a halftone phase mask, a triton phase mask, and / or a reticle (e.g., with pellicle). The lithographic mask can be used, for example, in a lithography method for the production of semiconductor chips.The object for lithography can thereby comprise (undesired) defects. For example, a defect may be caused in the manufacture of the object. Furthermore, a defect can also be caused by (lithographic) processing of the object, a process deviation in (lithographic) processing, transport of the object, etc. Due to the usually costly and complex production of an object for lithography, the defects are therefore usually repaired.In the exemplary embodiments described here, for illustrative purposes, frequently recourse is made here to an EUV mask as an example of an object for lithography. However, instead of the EUV mask, any object is conceivable for lithography (e.g. as described herein).FIG. 1 can schematically illustrate, in a plan view, two local states D, R of a section 1000 of an EUV mask as part of a repair of a defect of the mask. The section 1000 shows a part of a pattern element PE of the EUV mask. The pattern element PE can also be understood as a pattern element of the EUV mask. The pattern element PE can be a part of a designed pattern which can be transferred to a wafer, for example, by a lithographic method. The local state D thereby shows an opaque defect 1010, which adjoins the pattern element PE. The opaque defect 1010 may be e.g. characterized by excess (opaque) material, which should not be present at the defect location after mask design. The excess (opaque) material may correspond to an opaque material of the pattern element PE, for example, as well as any other material of a layer of the pattern element PE (as described herein). With reference to FIG. 1 (state D), a defect-free pattern element PE in the cutout 1000 would have to have a rectangular shape, it being evident that this desired state is not present due to the opaque defect 1010. Therefore, the excess (opaque) material in the region of the opaque defect 1010 is usually removed via a repair process RV, such that a repaired state R of the pattern element PE can be generated. Thus, it is shown in state R that an opaque effect no longer occurs in the original defect region 1020(i.e. at the original location of the opaque defect) and no excess (opaque) material is present any longer. By removing the defect 1010, the desired state of the rectangular shape of the pattern element PE is thus restored after a repair process.During use in lithography apparatus, a lithographic mask may be exposed to extreme physical and chemical environmental conditions. This applies in particular to the exposure of EUV masks (as well as DUV masks, or other masks as described herein) during a corresponding lithography method, wherein in particular the opaque material of a pattern element PE can be highly exposed to these influences. For example, during EUV exposure a hydrogen plasma can be released with hydrogen radicals, which can attack the opaque material of the pattern element PE, among other things, and cause a material-modifying and / or material-removing effect. Further damaging influences can occur in the EUV lithography process and mask cleaning processes. Damage to the mask material comprises, for example, a chemical and physical change of the material by (EUV) radiation, temperature, as well as a reaction with hydrogen or another reactive hydrogen species (e.g. radicals, ions, plasma, etc.). The change in material may further be caused by a reaction with purge gases (e.g., N 2, extreme clean dry air - XCDA ®, noble gases, etc.) in conjunction with the exposure radiation (e.g., EUV radiation, DUV radiation). The damage to the material can likewise be caused or enhanced by downstream processes (e.g. a mask cleaning). The downstream processes can additionally attack, for example, the opaque material of the pattern element PE damaged by chemical / physical reactions during the exposure process and thus enhance damage.In general, therefore, the material properties of an EUV mask, in particular the opaque material of the EUV mask (or of the pattern element PE), are designed to be resistant to the aggressive physical / chemical conditions during lithography in order to specifically counteract the material-removing effects. In this case, a chemically resistant material can be used in a targeted manner as opaque material of a pattern element PE. In particular, chromium nitride-containing materials, as well as chromium-containing materials with a high nitrogen content (as described herein), can be used as a resistant material in an EUV mask due to their very high chemical resistance. The chromium nitride-containing materials can have, for example, the form Cr a N b Z c( a, b>0, c≥0, Z: one or more further elements). Here, Z may include a metal, non-metal, semimetal, alkali metal (e.g., Li, Na, K, Rb, Cs). Further, Z may include an alkaline earth metal (e.g., Be, Mg, Ca, Sr, Ba), a 3rd main group element (e.g., B, Al, Ga, In, Tl), a 4th main group element (e.g., C, Si, Ge, Sn, Pb), a 5th main group element (e.g., N, P, As, Sb, Bi). Further, Z may include a chalcogenide (e.g., O, S, Se, Te), a halogen (e.g., F, Cl, Br, I), a rare gas (atom) (e.g., He, Ne, Ar, Kr, Xe), a transition group element (e.g., Ti, Hr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg).However, this type of resistant (opaque) materials of a pattern element PE or an EUV mask can significantly complicate the repair process RV of an opaque defect 1010, since the resistant (opaque) material is intended to be removed in a targeted manner during the repair process. In particular, this circumstance may make mask repair difficult by means of electron beam-induced etching processes.FIG. 2 shows a schematic diagram of an exemplary method 200 of the invention. The method 200 can be used to remove material of an EUV mask. In particular, the method 200 can be used to remove material of an opaque defect 1010 in the course of a repair operation.The method 200 can thereby comprise providing a first gas which has first molecules. The first gas can comprise, for example, NOCl and / or XeF 2 as first molecules. Furthermore, other gases are also conceivable as the first gas, as described herein.Further molecules are suitable for the method 200 as first molecules of the first gas. For example, the first molecules may comprise molecules that may be understood as acid halides of nitrogen-containing (e.g., inorganic) acids. The first molecules may also comprise molecules which are cleavable under suitable reaction conditions into chlorine radicals and nitrogen oxides and / or, further, for example, another nonpolar species are cleavable. Furthermore, the first molecules can comprise molecules which deliver at least one of the following molecules in aqueous solution: NO, HCl, HNO 2, HNO 3.Furthermore, the method 200 may comprise providing 220 a particle beam on a working region of the object for removing a first material in the working region based at least in part on the first gas. The first material may comprise chromium and nitrogen. The method 200 can furthermore have the characteristic 230 that the first material comprises at least 5 atomic percent nitrogen, preferably at least 10 atomic percent nitrogen, particularly preferably at least 20 atomic percent nitrogen. The method 200 can further comprise an electron beam as a particle beam, such that an electron beam-induced etching of the first material can be enabled according to the method 200.The first material can correspond in particular to the resistant (opaque) material of the EUV mask (as described herein), which is to be removed in the context of the repair of an opaque defect.The method 200 may further include providing a second gas as additive gas, which may assist the etch process (e.g. in view of etch selectivity, etch rate, anisotropy factor, etc.). In particular, NOCl can be used as the first gas and H 2 O (i.e. water (vapor)) as additive gas in the context of the method 200 in the electron beam-induced etching. It is likewise conceivable that in the electron beam-induced etching, XeF 2 is used as the first gas and H 2 O (i.e. water (vapor)) is used as the additive gas in the context of the method 200. Furthermore, the second molecules can comprise a dipole moment between 1.6 D and 2.1 D, preferably between 1.7 D and 2 D, more preferably between 1.8 D and 1.95 D, most preferably between 1.82 D and 1.9 D. It is likewise conceivable for the second molecules to comprise at least one oxygen atom, but no nitrogen atom. Furthermore, the second molecules may comprise molecules which, upon reaction with NOCl, provide at least one of the following molecules: NO, HCl, HNO 2, HNO 3.FIGS. 3 a- bschematically illustrate, in a cross-section, exemplary operations of the method 200 that may take place as part of a repair of a defect of an object for lithography.FIG. 3 aschematically illustrates an example characteristic layer structure of a reflective lithographic mask for the EUV wavelength range (i.e. an EUV mask). The exemplary EUV mask can be designed, for example, for an exposure wavelength in the range of 13.5 nm. The EUV mask may comprise a substrate S made of a material having a low thermal expansion coefficient, such as quartz. Other dielectrics, glass materials or semiconducting materials can likewise be used as substrates for EUV masks.A deposited multilayer film (ML) or a reflective layer stack ML can adjoin the substrate S, which layer stack has, for example, 20 to 80 pairs of alternating molybdenum (Mo) and silicon (Si) layers, which are also referred to as MoSi layers. The individual layers of the multilayer film ML may differ in their refractive index, resulting in a Bragg mirror which can reflect incident radiation (e.g. EUV radiation).In order to protect the reflective layer stack ML, a cover layer D (also referred to as a capping layer) can be applied, for example, to the uppermost layer of the reflective layer stack ML. The cover layer D can protect the reflective layer stack ML from damage due to chemical processes during the production and / or during the use of the EUV mask (e.g. during a lithographic method). The covering layer D can comprise ruthenium, and also elements or compounds of elements which increase the reflectivity at 13.5 nm wavelength by not more than 3%. Furthermore, the covering layer D can comprise Rh, Si, Mo, Ti, TiO, TiO2, ruthenium oxide, niobium oxide, RuW, RuMo, RuNb, Cr, Ta, nitrides, as well as compounds and combinations of the aforementioned materials.On the cover layer D, there may be a plurality of layers which may comprise, for example, the layers of the pattern element (i.e. pattern element layers). The pattern element layers can comprise a buffer layer P, an absorption layer A and / or a surface layer O. The properties of the pattern element layers (e.g. an intrinsic material property of a pattern element layer, a layer thickness of a pattern element layer, etc.) and the geometry of the pattern element PE formed therefrom may be configured to cause an opaque effect with respect to the exposure wavelength of the EUV mask. For example, the pattern element PE can be designed such that it is opaque (i.e. opaque or strongly light-absorbing) with respect to a light radiation having a wavelength of 13.5 nm. The pattern element layers can correspond to the layers of the opaque defect 1010, wherein the opaque defect 1010 does not necessarily have to have all the pattern element layers. For example, the opaque defect 1010 may include only the buffer layer P and the absorption layer A.The buffer layer P may be located on the cover layer D. Further, the absorption layer A may be located on the buffer layer P. The absorption layer A can be effectively designed to absorb the radiation of lithographic wavelengths (as described herein). Accordingly, the absorption layer A can contribute the main contribution to an opaque effect of the pattern element (or of the opaque defect 1010). The optical properties of the absorption layer A can be described, for example, by a complex refractive index, which can comprise a phase-shifting contribution (i.e. n) and an absorption contribution (i.e. k). For example, n and k can be understood as intrinsic material properties of the absorption layer. Only certain chemical elements and / or compounds of chemical elements have phase-shifting and / or absorptive properties advantageous for the corresponding lithography method (e.g. an EUV lithography method). FIG. 3 a shows, by way of example, the layer thickness d of the absorption layer A. The layer thickness d of the absorption layer A (as well as a layer thickness of another layer of the mask) is determined here, for example, along a normal vector with respect to the planar plane of the mask. Further, the surface layer O may be located on the absorption layer A. The surface layer O can comprise an antireflection layer, oxidation layer and / or passivation layer. In addition to the absorption layer A, the buffer layer P and / or the surface layer O can also contribute to the absorption or to the opaque effect of the pattern element PE or of the opaque defect 1010.In principle, each of the pattern element layers described herein can comprise the mentioned resistant material (i.e. chromium nitride or chromium with a high nitrogen content). Usually, for example, the absorption layer A has the (high) chromium nitride content or chromium with a high nitrogen content. Furthermore, however, the buffer layer can also have, for example, the (high) chromium nitride content or chromium with a high nitrogen content.The first material of the method 200 can accordingly comprise a material of any pattern element layer. In particular, the first material of the method 200 may comprise the material of the absorption layer A.FIG. 3 b shows a result of an exemplary method 200 for removing a part of the absorption layer A. The absorption layer A is designed as the first material of the method 200. Initially, a part of the surface layer O can be removed. For example, this can be effected analogously to the method 200 via electron beam-induced etching in a separate step. The removal of the surface layer does not necessarily have to be effected with the first and / or second gas (as described herein). It is also conceivable that the electron beam-induced etching is designed exclusively for the removal of the surface layer (e.g. with an etching gas which is adapted to the material of the surface layer). After removing the surface layer O, a portion of the absorption layer A as the first material may then be removed (e.g., to repair an opaque defect) in the method 200. FIG. 3 b illustrates a selective electron beam-induced etching of the absorption layer A with respect to the buffer layer P. Accordingly, the method 200 may be set such that the etching rate of the absorption layer A is increased with respect to the etching rate of the buffer layer P. For example, the etch selectivity may be adjusted via the properties of the second gas in the method 200 (e.g., via a suitable selection of the second gas (e.g., water), or the gas mass flow of the second gas). Furthermore, the etch selectivity can also be adjusted via the properties of the first gas (e.g. via the selection of the first gas (e.g. NOCl or XeF 2), or the gas flow rate of the first gas). In this example, the buffer layer P thus functions as an etch stop via the selected etch selectivity.FIG. 3 cshows a further result of an exemplary method 200 for removing a part of the absorption layer A. Initially, a part of the surface layer O can be removed in this case (as described herein). After removing the surface layer O, a part of the absorption layer A can subsequently be removed as the first material in the context of the method 200. In this case, a part of the buffer layer P can also be etched as intermediate material. Accordingly, the method 200 may be set such that the etching rate of the absorption layer A, as well as the etching rate of the buffer layer P, is increased compared to the etching rate of the capping layer D. The etching rate of the absorption layer A may be of the same order of magnitude as the etching rate of the buffer layer P. The etching selectivity may be adjusted as described herein. As shown in FIG. 3 c, this can result in selective electron beam-induced etching of the absorption layer A and of the buffer layer P with respect to the covering layer D. In this example, the capping layer D therefore functions as an etch stop via the selected etch selectivity.In one example, the surface layer O is not removed separately, but rather via the same process that is used for the local removal of the absorption layer A (or of the absorption layer A and of the buffer layer P) in the context of a method 200.In principle, in the case of mask repair, it may also be necessary to produce or deposit material (as repair material). In the mask repair by means of electron beam-induced deposition of chromium nitride (e.g. in the form of Cr a N b Z c, as described herein), chromium oxides or other chromium-containing depositions, undesired material deposition can also occur in this case. The undesired material deposition can be caused, for example, by beam tails of the electron beam and secondary electrons generated thereby. Further, the unwanted deposition (of the repair material) may be caused by secondary electrons generated at locations adjacent to the repaired defect, as well as secondary electrons exiting vertical edges of the processed material and propagating to locations adjacent to the repaired defect. Also, forward scattered electrons (FSE) exiting from the flanks of already present material as well as backscattered electrons (BSE) exiting from the surface in the vicinity of the repaired location may contribute to undesired material deposition.Another application of method 200 is therefore the removal of material deposited by these mentioned mechanisms on areas in the vicinity of the repaired defect. Thus, in one example, the method 200 also includes creating a repair material.In the course of the production of the repair material, a deposition gas can be used in the electron beam-induced deposition. At least one of the following can be included as deposition gas in the invention: (metal, transition element, main group) alkyls such as cyclopentadienyl (Cp)- or methylcyclopentadienyl (MeCp)trimethyl platinum (CpPtMe 3 or. MeCpPtMe 3), tetramethyltin SnMe 4, trimethylgallium GaMe 3, ferrocene Cp 2 Fe, bis-aryl-chromium Ar 2 Cr and further such compounds. Further, at least one of the following may be included as the first gas in the invention: (metal, transition element, main group) carbonyls such as chromium hexacarbonyl Cr(CO) 6, molybdenum hexacarbonyl Mo(CO) 6, tungsten hexacarbonyl W(CO) 6, dicobalt octacarbonyl Co 2( CO) 8, Trirutheniumdodecacarbonyl Ru 3( CO) 12, iron pentacarbonyl Fe(CO) 5 and other such compounds. Further, any one of the following may be included as the first gas in the invention: (metal, transition element, main group) alkoxides such as tetraethoxysilane Si(OC 2 H 5)4, tetraisopropoxytitanium Ti(OC 3 H 7)4 and other such compounds.Furthermore, at least one of the following can be included as deposition gas in the invention: (metal, transition element, main group) halides such as WF 6, WCl 6, TiCl 6, BCl 3, SiCl 4 and further such compounds. Furthermore, at least one of the following (metal, transition element, main group) complexes can be included as deposition gas in the invention, such as copper bishexafluoroacetylacetonate Cu(C 5 F 6 HO 2)2, dimethyl gold trifluoroacetylacetonate Me 2 Au(C 5 F 3 H 4 O 2) and further such compounds. Furthermore, one of the following may be included as separation gas in the invention: organic compounds such as CO, CO 2, aliphatic or aromatic hydrocarbons, constituents of vacuum pump oil, volatile organic compounds and further such compounds.The method 200 (or the method of the first aspect) can be carried out via the apparatus according to the invention described herein. In one example, the apparatus includes a mask repair apparatus for repairing lithographic masks. The device can be used to locate and repair mask defects. The device can comprise parts such as the device described in U.S. Pat. No. 2020 / 0 103 751 A1 (see FIG. 3A corresponding therein). The device can comprise, for example, a control unit, which can be part of a computer system, for example. The apparatus may be configured in an example such that the computer system and / or the control unit controls the process parameters of the method of the first aspect disclosed herein. This configuration can make it possible for the method according to the invention mentioned herein to be able to proceed in a targeted manner and also in an automated manner, for example without manual interventions. This configuration of the device can be realized or enabled, for example, via the computer program according to the invention described herein.

Claims

A method of processing an object for lithography, comprising: providing a first gas comprising first molecules; providing a particle beam on a working area of the object to remove a first material (A) in the working area based at least in part on the first gas; wherein the first material comprises chromium and nitrogen, and wherein the first material comprises at least 1 atomic percent nitrogen, preferably at least 5 atomic percent nitrogen, more preferably at least 10 atomic percent nitrogen, particularly preferably at least 20 atomic percent nitrogen; wherein the first molecules comprise a halogen compound; wherein the halogen compound comprises a noble gas halide; providing a second gas comprising second molecules, wherein the removal of the first material is further based at least in part on the second gas; wherein the second molecules comprise an oxygen-containing component; wherein the first material comprises chromium nitride.The method of claim 1, wherein the first material is capable of absorbing radiation associated with the object.Method according to Claim 1 or 2, wherein the first material corresponds to a layer material of a pattern element (PE) of the object.The method of any one of claims 1-3, wherein the inert gas halide comprises at least one of xenon difluoride, XeF 2, xenon dichloride, XeCl 2, xenon tetrafluoride, XeF 4, xenon hexafluoride, XeF 6.The method of any one of claims 1-4, wherein the oxygen-containing component comprises an oxygen-containing molecule.The method of claim 5, wherein the oxygen-containing molecule comprises at least one of water (H 2 O), heavy water (D 2 O), oxygen (O 2), ozone (O 3), hydrogen peroxide (H 2 O 2), dinitrogen monoxide (N 2 O), nitrogen monoxide (NO), nitrogen dioxide (NO 2), nitric acid (HNO 3).The method of any one of claims 1-6, wherein the second molecules comprise water, H 2 O, and / or heavy water, D 2 O.The method of any of claims 1-7, wherein the first molecules comprise xenon difluoride and the second molecules comprise water.The method of any of claims 1-7, wherein the first molecules comprise xenon difluoride and the second molecules comprise heavy water.The method according to any one of claims 1-9, wherein the halogen compound further comprises a nitrosyl halide and / or a nitrosyl halide.The method of claim 10, wherein the nitrosyl halide comprises at least one of: nitrosyl chloride, NOCl, nitrosyl fluoride, NOF, nitrosyl bromide, NOBr; and / or wherein the nitrosyl halide comprises at least one of: nitrosyl chloride, ClNO 2, nitrosyl fluoride, FNO 2.The method of any one of claims 1-11, wherein the halogen compound further comprises an interhalogen compound.The method according to any one of claims 1 to 12, wherein a first dipole moment associated with the first molecules comprises at least 1 D, preferably at least 1.5 D, more preferably at least 1.7 D, most preferably at least 1.8 D.The method of claim 13, wherein a first dipole moment associated with the first molecules and a second dipole moment associated with the second molecules differ from each other by a maximum of 0.1 D, preferably a maximum of 0.08 D, more preferably a maximum of 0.07 D, most preferably a maximum of 0.06 D.The method of any one of claims 1 to 14, wherein the first material is selectively removed such that a second material (O, P, D, ML, S) of the object is substantially not removed.The method of claim 15, wherein the method further comprises removing at least one intermediate material (P) disposed between the first material and the second material (D, ML, S).The method according to any one of claims 1 to 16, wherein the method further comprises removing at least one surface material (O) of the object.Method according to one of Claims 1 to 17, wherein the particle beam is based at least partially on an acceleration voltage of less than 3 kV, preferably less than 1 kV, more preferably less than 0.6 kV.The method of any one of claims 1 to 18, the method further comprising: determining an endpoint of the removing based at least in part on detecting electrons emitted from the object.Method according to one of Claims 1 to 19, wherein the particle beam comprises an electron beam.Method according to one of Claims 1 to 20, wherein the method is carried out in such a way that an opaque defect of the object is repaired.The method according to any one of claims 1 to 21, wherein the object comprises an EUV mask and / or a DUV mask.An apparatus for processing an object for lithography, comprising: means for providing a first gas; means for providing a second gas; means for providing a particle beam on a work area of the object, the apparatus being configured to perform a method according to any one of claims 1 to 22; a memory comprising the computer program of claim 26; and means for executing the computer program of claim 26 such that the apparatus automatically performs the method according to any one of claims 1 to 22.Object for lithography, wherein the object has been processed with a method according to one of claims 1 to 22.A method of processing a semiconductor-based wafer comprising: lithographically transferring a pattern associated with an object for lithography to the wafer, wherein the object has been processed according to any of methods 1 to 22.A computer program comprising instructions which, when executed by a computer system, cause the computer system to perform a method according to any one of claims 1 to 22 and / or claim 25.

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