Device and method for cleaning components; lithography system

Abstract

The invention relates to a device for cleaning components (2), in particular components of a lithography system, comprising a radiation source (24) which emits laser radiation (5) and a beam guidance device (25) for directing the laser radiation (5) to the component (2). A guide device (1) is provided into which the beam guidance device (25) introduces the laser radiation (5). A front section of the guide device (1) has a deflecting optic (4), wherein the laser radiation (5) extends within the guide device (1) along a beam path to the deflecting optic (4), and the deflecting optic (4) deflects the laser radiation (5).The guide device (1) is dimensioned such that the guide device (1) has a diameter of no more than 20 mm at its widest point and the guide device (1) has a length along the beam path up to the deflecting optics (4) that is at least twice as long as the diameter.

Description

[0001] The invention relates to a device for cleaning components, in particular components of a lithography system, comprising a radiation source which emits laser radiation and a beam guidance device to supply the laser radiation to the component.

[0002] The invention also relates to a method for cleaning components, in particular components of a lithography system, having a complex geometry comprising at least one recess with an aspect ratio greater than two and with a diameter of at most 22 mm at the narrowest point.

[0003] The invention further relates to a lithography system, in particular a projection exposure system for semiconductor lithography, with an illumination system comprising a radiation source and optics, which includes at least one optical element and at least one associated holding device.

[0004] Various cleaning devices and methods for cleaning components are known from the prior art.

[0005] Particularly high demands are placed on cleaning devices and procedures for cleaning components of a lithography system.

[0006] A device for cleaning a plasma radiation source using laser radiation is known from DE 10 2020 201 558 A1.

[0007] From DE 10 2022 200 205 B3 a cleaning device for a mirror in an EUV projection exposure system using laser radiation is known.

[0008] Furthermore, devices are known from the prior art that are not based on laser radiation and are suitable not only for cleaning the outer surface of a component but also for cleaning hard-to-reach areas.

[0009] Areas that are difficult to access include, in particular, boreholes, blind holes, threaded holes, channels, pipes, and similar recesses. Such geometries can have a high aspect ratio, especially an aspect ratio greater than two. However, difficult-to-access areas can also include protrusions and undercuts. Many components, especially those of a lithography system, contain such difficult-to-access areas, such as the holding devices for optical elements.

[0010] Current laser-based cleaning methods are only suitable for cleaning large areas. However, contaminants tend to accumulate particularly frequently in recesses, raised areas, or similar locations, making targeted cleaning in these areas necessary, especially when such areas are located in a lithography system with high cleanliness requirements.

[0011] For cleaning hard-to-reach areas, various methods are used according to the state of the art, such as cleaning with a fluid cleaning agent, ultrasound, or heating. However, these methods have proven to be less than ideal for the cleaning result and / or are associated with high costs. The cleaning result can be compromised, for example, by drying residues, oxidation, cross-contamination, and / or insufficient removal of certain unwanted substances (such as Teflon grease). The high costs can result, for example, from the component size, the associated cleaning system size, the duration of downtime, and / or the necessary sealing of the areas (especially when using fluid cleaning agents).

[0012] To avoid these and other disadvantages, the use of laser radiation for cleaning has proven advantageous. For example, compared to wet cleaning methods, drying residues are avoided, and the flexible application of laser radiation means that large components, in particular, do not necessarily have to be transported from their point of use to a cleaning location, but can be cleaned directly at their point of use. However, current technology lacks laser-based cleaning methods for hard-to-reach areas.

[0013] The present invention is based on the objective of creating a device for cleaning components using laser radiation that is improved compared to the prior art and in particular also enables the cleaning of hard-to-reach places.

[0014] According to the invention, this problem is solved by a device having the features mentioned in claim 1.

[0015] The present invention also aims to create a method for cleaning components using laser radiation that is improved compared to the prior art and in particular also enables the cleaning of hard-to-reach areas.

[0016] According to the invention, this problem is solved by a method with the features mentioned in claim 14.

[0017] The present invention further aims to create a lithography system which has components that are cleaned while avoiding the disadvantages of the prior art.

[0018] According to the invention, this problem is solved by a lithography system with the features mentioned in claim 15.

[0019] The device according to the invention for cleaning components, in particular components of a lithography system, comprises a radiation source which emits laser radiation and a beam guidance device for supplying the laser radiation to the component. According to the invention, a guide device is provided into which the beam guidance device introduces the laser radiation, wherein a front section of the guide device has a deflecting optic, wherein the laser radiation propagates within the guide device along a beam path up to the deflecting optic, wherein the deflecting optic deflects the laser radiation, and wherein the guide device is dimensioned such that the guide device has a diameter of at most 20 mm at its widest point and the guide device has a length along the beam path up to the deflecting optic that is at least twice as long as the diameter at the widest point of the guide device.

[0020] The device according to the invention is advantageously suited, due to the dimensioning of the guide mechanism, to cleaning not only flat components or planar or flat outer surfaces of a component, but also hard-to-reach areas of a component or components with complex geometries, including at least one recess, in particular with an aspect ratio greater than two. This can, for example, but is not limited to, boreholes, blind holes, threaded holes, channels, pipes, and similar geometries. The aspect ratio refers to the ratio of the minimum width or minimum diameter to the depth of the recess. The term "boreholes" also includes holes that were not necessarily produced by drilling.

[0021] The device according to the invention is also designed to clean undercuts. This includes threads. The solution according to the invention can advantageously be used to clean recesses into which the guide device can be at least partially inserted.

[0022] According to the invention, the guide device is dimensioned such that it has a diameter of at most 20 mm at its widest point. In a preferred embodiment, this diameter is at most 18 mm, and in a particularly preferred embodiment, at most 16 mm. Alternatively, but not preferably, an analogous guide device with a diameter greater than 20 mm can be designed. This allows, in particular, the cleaning of surfaces and / or recesses with a diameter larger than the diameter of the guide device.

[0023] It should be noted that the diameter can refer not only to a circular cross-section, but also to the maximum distance between two points on any shaped cross-section of the guide device. In particular, the guide device can have a circular or a non-circular cross-section. In other words, the guide device can also be described as a lance.

[0024] According to the invention, the deflecting optics have the task of deflecting the laser radiation from the beam path in the guide device onto the component, in particular the lateral inner walls of the recess. This applies especially to solid angles that do not point along the incident beam path and that could not be reached by the laser radiation without the use of the deflecting optics. In a preferred embodiment, the deflecting optics deflect the laser radiation at an angle of 45° to 135°, in particular at an angle of 75° to 105°, and most preferably at an angle of 90°.

[0025] The deflection optics are preferably designed in such a way that they are suitable for the spectral range of the laser radiation.

[0026] It has proven advantageous to equip the deflecting optics with a cooling device to regulate their temperature against laser-induced heating. The cooling device can be operated, for example, with compressed air, purge gases, or water. Alternatively or additionally, the cooling device can also be used to supply gaseous media with a protective function, such as nitrogen, particularly as protection against oxidation.

[0027] Designing the deflection optics as a mirror has proven to be particularly suitable, with the mirror preferably being completely or at least partially reflective.

[0028] The guidance device can be part of the beam guidance system. The guidance device can be integrally formed with the beam guidance system or permanently connected to it. Alternatively, the guidance device can be detachably connected to the beam guidance system.

[0029] The guidance device is specifically designed to direct the laser radiation to areas of the component that are difficult to access, particularly recesses with an aspect ratio greater than two.

[0030] It is advantageous if the laser beam parameters are adjustable. Preferably, the adjustable beam parameters include the power, beam diameter, focus, Rayleigh length, pulse length, and / or wavelength of the laser radiation. Preferably, the beam parameters are selected such that contaminants on the surface of the component are heated, preferably briefly, by the absorbed laser radiation to such an extent that the plasma threshold is exceeded, or the contaminants are ablated and / or vaporized according to the principle of laser ablation. In particular, a laser power of approximately 20 W to 1000 W has proven to be especially suitable. Furthermore, preferably, the beam parameters, especially the wavelength, are selected such that the laser radiation does not couple into the material of the component.

[0031] By selecting suitable beam parameters, the device according to the invention enables the cleaning of components by laser ablation or laser vaporization, whereby contaminants or other unwanted substances are removed and / or mobilized from the components. It has been shown that the device is also suitable for stripping coatings from components. Furthermore, the selection of suitable beam parameters prevents damage to the component from the laser radiation.

[0032] It has proven particularly suitable to use the device according to the invention in a clean environment, especially in a cleanroom or an airlock. This applies especially to the use of the device for components of a lithography system, since the lithography system as a whole places high demands on cleanliness.

[0033] It has also proven advantageous if the device is equipped with an enclosure or cover that prevents the uncontrolled emission of laser radiation. The enclosure or cover should be suitable for laser safety purposes. In particular, this protects persons who are in the immediate vicinity of the device and / or the component being cleaned.

[0034] The enclosure or cover can also be designed in such a way as to cover the access opening of the difficult-to-reach location, for example a borehole, after a front section of the guide device has been inserted and positioned.

[0035] According to the invention, the guiding device may have a rod or a tube with an aspect ratio greater than two, wherein the rod or the tube extends along the beam path and wherein the deflecting optics are fixed at a front end region of the rod or the tube.

[0036] The extension of the rod or tube along the beam path is to be understood in particular as running parallel to or at an angle of less than 45° to the beam path, with small angles being preferred. Preferably, the rod or tube extends substantially parallel to the beam path.

[0037] The dimensions of the rod or tube are suitable for at least partially inserting the rod or tube into a recess with an aspect ratio greater than two in order to allow cleaning of the lateral inner walls.

[0038] The rod or tube preferably also serves as a mount for the deflecting optics.

[0039] According to one embodiment of the invention, the rod consists of a light-transmitting medium, in particular glass, wherein the beam path can also pass through the rod.

[0040] According to another embodiment of the invention, the guiding device may have a flexible light guide which is configured to direct the laser radiation at least partially to the deflecting optics, wherein the deflecting optics are fixed at a front end region of the light guide.

[0041] An optical fiber is an optically transparent, preferably flexible or bendable medium, wherein the laser radiation can propagate through the medium and wherein the laser radiation is guided from one end of the optical fiber to the other end by total internal reflection at the side walls of the optical fiber. This applies in particular to fiber optics.

[0042] The laser radiation is guided, at least partially, through the optical fiber to the deflecting optics. This means that at least part of the beam path passes through the optical fiber, while another part can pass through a vacuum, a gas, a gas mixture, a glass body, or another medium. Lenses or other optical components can also be located along the beam path.

[0043] The deflecting optics at the front end of the light guide can preferably be designed as a mirror-like coating.

[0044] The described design of the guide device advantageously enables the laser radiation to be introduced, at least partially, into recesses with an aspect ratio greater than two, thus facilitating the cleaning of the lateral inner walls. Such a guide device is particularly suitable for cleaning recesses with a non-linear profile, especially channels, including cooling channels, and pipelines.

[0045] The optical fiber can have a breakage monitoring device. Preferably, the radiation source is switched off in the event of a detected fiber break for laser safety reasons.

[0046] In one embodiment of the invention, it is provided that the deflecting optics symmetrically enclose and / or cover the cross-section of the rod, tube, or light guide in the front end region, wherein an impact point of the laser radiation on the deflecting optics is different from a center of the deflecting optics, wherein the beam path is at least partially rotatable about an axis along the rod, tube, or light guide, and wherein the deflecting optics always deflects the laser radiation in a direction that points away from a center of the rod, tube, or light guide.

[0047] By rotating the beam path and thus the laser radiation, it is particularly advantageous to selectively target different areas of the component, especially the lateral inner walls of a recess, with the laser radiation for cleaning purposes.

[0048] It is advantageous if the deflecting optics are designed in such a way that they can deflect the laser radiation into different directions within a circular environment by varying the rotation angle of the beam path. In particular, the deflecting optics can have a conical shape, with the rod, tube, or light guide meeting at the apex of the cone, the conical surface being mirrored, and the conical surface being concave.

[0049] When the laser radiation is rotated around the axis of the rod, tube, or light guide, it is advantageous if the laser radiation always hits the deflecting optics.

[0050] The center of the deflecting optic may have a recess or a hole. In particular, the rod or tube may protrude through this recess or hole.

[0051] In a further embodiment of the invention, it can be provided that the rod, the tube, or the light guide with the deflecting optics attached to it is rotatable about an axis which runs at least approximately parallel to the rod, the tube, or the light guide and through the point of impact of the laser radiation on the deflecting optics.

[0052] By rotating the deflecting optics, different areas of the component, especially the lateral inner walls of a recess, can be easily targeted with the laser radiation for cleaning purposes.

[0053] According to the invention, the deflecting optics rotate together with the rod, tube, or light guide, since the deflecting optics are connected to the rod, tube, or light guide. In particular, the laser radiation is deflected into different directions of a circular environment by varying the rotation angle of the deflecting optics.

[0054] It has proven particularly suitable for realizing the rotation of the beam path, rod, tube, or light guide or deflecting optics by means of a brushless motor.

[0055] The aforementioned embodiments result, in particular, in four variants of the invention through combination.

[0056] First, the guiding device can comprise a rod or tube with an aspect ratio greater than two, wherein the rod or tube extends along the beam path, the deflecting optics being fixed at a front end region of the rod or tube, the deflecting optics symmetrically enclosing the cross-section of the rod or tube in the front end region, the point of impact of the laser radiation on the deflecting optics being different from a center of the deflecting optics, the beam path being at least partially rotatable about an axis along the rod or tube, and the deflecting optics always deflecting the laser radiation in a direction away from a center of the rod or tube. In other words, the laser radiation is moved on the component by the rotation of the beam path, in particular on the lateral inner walls of one of the recesses of the component, while the deflecting optics can be largely stationary.In this process, the point of impact of the laser radiation on the deflecting optics shifts, and with a suitable shape of the deflecting optics, in particular a conical shape as previously described in more detail, the laser radiation is thus deflected in variable spatial directions and therefore onto variable areas of the component.

[0057] Secondly, the guiding device can include a flexible optical fiber configured to direct the laser radiation at least partially to the deflecting optics, wherein the deflecting optics are fixed at a front end region of the optical fiber, the deflecting optics symmetrically covering the cross-section of the optical fiber in the front end region, the point of incidence of the laser radiation on the deflecting optics being different from a center of the deflecting optics, the beam path being rotatable at least partially about an axis along the optical fiber, and the deflecting optics always deflecting the laser radiation in a direction away from a center of the rod or tube. In other words, the movement of the laser radiation on the component is realized analogously to the previous variant, but in the present variant, the beam path does not lead along a rod or tube, but at least partially through an optical fiber.

[0058] Thirdly, the guiding device can comprise a rod or tube with an aspect ratio greater than two, wherein the rod or tube extends along the beam path, and wherein the deflecting optics are fixed at a leading end region of the rod or tube, and wherein the rod or tube with the deflecting optics fixed to it is rotatable about an axis that runs at least approximately parallel to the rod or tube and through the point of incidence of the laser radiation on the deflecting optics. In other words, in this variant, the laser radiation is again guided along a rod or tube, but the movement of the laser radiation on the component is achieved by the movement of the deflecting optics, induced by the movement of the rod or tube, while the beam path can be largely stationary. The rod or tube is not coaxial with the beam path.The point of impact of the laser radiation on the deflecting optics can remain largely stationary. By using a suitable shape for the deflecting optics, particularly a surface angled relative to the beam path, the laser radiation is deflected in variable spatial directions and thus onto variable areas of the component.

[0059] Fourth, the guiding device can include a flexible optical fiber configured to guide the laser radiation at least partially to the deflecting optics, with the deflecting optics being fixed at a front end region of the optical fiber. The optical fiber with the deflecting optics fixed to it is rotatable about an axis that runs at least approximately parallel to the optical fiber and through the point of incidence of the laser radiation on the deflecting optics. In other words, this variant combines the at least partial guiding of the laser radiation by an optical fiber from the third variant with the movement of the laser radiation on the component by the movement of the deflecting optics. Preferably, in the fourth variant, the optical fiber and the beam path are coaxial.

[0060] It should be noted that the four previously mentioned preferred variants are not exhaustive. For example, the movement of the laser radiation on the component can also be achieved by a combination of moving the beam path and moving the deflecting optics.

[0061] The radiation source can be designed in particular as a fiber laser, diode laser or LED laser.

[0062] Pulsed laser radiation has proven advantageous.

[0063] This enables particularly high power densities on the component to be cleaned, and thus more effective cleaning.

[0064] Furthermore, it is advantageous if the radiation source emits laser radiation in the infrared spectral range.

[0065] Infrared light has proven particularly suitable for cleaning components of substances that exhibit high emissivity or absorption in this spectral range. In particular, rust, fluorinated substances (especially Teflon), and paints can be removed effectively. Furthermore, such radiation can be harmless to certain components, depending on their material and surface finish, and can enable non-destructive cleaning.

[0066] A wavelength of 1000 nm to 1100 nm or a photon energy of 1.24 eV to 1.13 eV is particularly preferred. In a preferred embodiment, this is achieved using an Nd:YAG laser with a wavelength of approximately 1064 nm as the radiation source.

[0067] According to the invention, the deflecting optics can be provided to have a curvature.

[0068] It has proven advantageous if the curvature is suitable for focusing the laser radiation onto the component. Particularly for focusing on the lateral inner walls of the recess, the focus length is preferably on the order of half the diameter of the recess.

[0069] Focusing allows the power density to be increased to the level required for cleaning.

[0070] A curvature with a circular or parabolic cross-section has proven to be particularly suitable.

[0071] In a further development of the invention, it can be provided that the deflecting optics can be tilted and / or oscillated relative to the beam path.

[0072] By tilting the deflection optics, the deflection angle of the laser beam can be varied to reach different areas on the component, especially the inner walls of the recess. This can be particularly advantageous for cleaning undercuts or threads.

[0073] The tilting of the deflecting optics can, in particular, be an oscillating tilt. The positioning speed of a focal point of the laser radiation or of an effective point of the laser radiation on the component is preferably at least 0.1 m / s, more preferably at least 1 m / s, and particularly preferably at least 5 m / s. Low positioning speeds are especially suitable for low-power radiation sources, such as diode lasers or LED lasers.

[0074] It is advantageous to provide a removal device, in particular a compressed air nozzle and / or a suction system, to extract and / or blow away contaminants or their transformed forms that are dissolved by the laser radiation. Alternatively and / or additionally, the removal device can also be designed to operate with purge gases and / or protective gases to flush away contaminants or their transformed forms that are dissolved by the laser radiation. For example, gaseous nitrogen can be used to simultaneously prevent oxidation.

[0075] The contaminants or their transformed forms released from the component by the laser radiation can be of a smoke-like or vaporous nature. The use of the extraction system prevents deposits and cross-contamination on the component.

[0076] In a preferred embodiment, the discharge device comprises a cover, for example a dome, which encloses the opening of the recess to be cleaned and thus prevents the escape of dissolved contaminants or transformed forms of these contaminants into other areas of the component.

[0077] In a further embodiment, the discharge device includes a monitoring unit to provide analytical data on the discharged contaminants or the transformed forms of these contaminants. The monitoring unit may, in particular, include a particle counter.

[0078] Within the scope of the invention, it may be provided that the guide device is movable by means of a multi-axis kinematic system.

[0079] This increases the spatial flexibility of the guide system and can have a positive effect on the cleaning result.

[0080] The multi-axis kinematics are preferably implemented as five-axis or six-axis kinematics. Angle-controlled rotations, especially about a separate longitudinal axis of the guide device, can also be considered as an axis of the kinematics.

[0081] In a further development of the invention, a propulsion device can be provided and set up to move the guide device within a partially closed geometry, in particular a cooling channel, of the component by means of compressed air.

[0082] A partially closed geometry can be, in particular, a borehole, a blind hole, a channel, especially a cooling channel, a pipeline or a similar depression.

[0083] By using the propulsion device, the deflecting optics in the front section of the guide device can be flexibly inserted into such a closed geometry in order to clean even deep areas of the lateral inner walls.

[0084] In a preferred embodiment, the propulsion device is combined with a feature of the invention in which the guide device has a flexible optical fiber configured to direct the laser radiation to the deflecting optics. Such a configuration is particularly suitable for cleaning meandering channels, especially cooling channels in a component of a lithography system.

[0085] It has proven advantageous to provide at least one second guidance device, wherein the guidance device is decoupleable from the beam guidance device in order to exchange the guidance device for the second guidance device, wherein the second guidance device differs from the original guidance device in at least one of the following features: diameter of the guidance device, curvature of the deflecting optics, tilt angle of the deflecting optics relative to the beam path, components included, and / or arrangement of the components.

[0086] The included components can be the aforementioned components of the various embodiments and further developments of the invention, or other components.

[0087] The possibility of replacing the guide device allows the guide device to always be selected in such a way that the characteristics of the guide device are particularly suitable for the geometry to be cleaned or the hard-to-reach area.

[0088] The device according to the invention may be automated. In particular, the device may include a measuring device that measures the component and / or locates and / or analyzes contaminants on the component in order to selectively clean the component of contaminants.

[0089] The present invention also relates to a method for cleaning components, in particular components of a lithography system, with a complex geometry having at least one recess with an aspect ratio greater than two and with a diameter of at most 22 mm at its narrowest point. The method according to the invention provides that the guide device of an inventive device for cleaning components is inserted at least partially into the recess of the component, wherein the guide device has a diameter at its widest point that is smaller than the diameter of the recess at its narrowest point, wherein the guide device is inserted into the recess at least twice as deep as the diameter of the guide device, and wherein the laser radiation is deflected by the deflecting optics onto lateral inner walls of the recess.

[0090] The device in question is, in particular, a device with one or more features as described above. The advantages are analogous to those already described.

[0091] The guide element of the device according to the invention has dimensions such that it can be inserted into recesses with an aspect ratio greater than two and preferably with a diameter of no more than 22 mm at the narrowest point. The method according to the invention is therefore particularly advantageous for cleaning such recesses compared to the prior art. The guide element can also be inserted into recesses with a diameter larger than the diameter of the guide element. Thus, the method according to the invention is also suitable for cleaning recesses with a diameter greater than 22 mm at the narrowest point, especially recesses with an aspect ratio greater than two.

[0092] The laser radiation can be directed to different areas of the lateral inner walls of the depression using a suitable guiding device, in particular by rotating the beam path, rod, tube, or light guide.

[0093] With a suitable guide device, the deflecting optic can also be tilted during the process to reach and clean other areas of the lateral inner walls of the recess. This has proven particularly advantageous for cleaning recesses with threads or undercuts.

[0094] For the application of the method for cleaning channels, especially cooling channels in a component of a lithography system, it has proven particularly advantageous if the guide device has a propulsion mechanism to iteratively move the guide device within the channel and clean the currently accessible areas of the lateral inner walls of the recess, in this case, the channel. In particular, the aforementioned possibilities of rotation and tilting can also be used to clean different areas.

[0095] Furthermore, it has proven advantageous if the guide device can be moved during the process using multi-axis kinematics.

[0096] It may be planned that the component is measured during the process and / or contaminants on the component are located and / or analyzed in order to subsequently clean the component of contaminants in a targeted manner.

[0097] It is advantageous to adjust the beam parameters during the process.

[0098] Furthermore, it is advantageous if the control device can be changed during the procedure.

[0099] Furthermore, the procedure can include control sequences to verify the cleaning progress and / or the integrity of the component, for example, using a camera, a monitoring unit, a removal device, and / or a measuring laser. In particular, the control sequence can also include recording a cleaning process.

[0100] It can be advantageous if parts of the process run in parallel, in particular a cleaning and a control sequence, in order to adapt the cleaning sequence to the result of the control as needed.

[0101] According to the invention, it can also be provided that the method for cleaning components is automated.

[0102] The present invention further relates to a lithography system, in particular a projection exposure system for semiconductor lithography, comprising an illumination system with a radiation source and optics, which have at least one optical element and at least one associated holding device. According to the invention, at least one of the optical elements or one of the associated holding devices is cleaned by means of a device and / or a method according to the invention.

[0103] The device or method is, in particular, a device or method with one or more features as described above. The advantages are analogous to those already described.

[0104] Lithography systems include, in particular, projection exposure systems for semiconductor lithography using EUV (extreme ultraviolet) light and DUV (deep ultraviolet) light.

[0105] Features described in connection with one of the subject matter of the invention, in particular those given by the inventive method, the inventive apparatus, or the inventive lithography system, can also be advantageously implemented for the other subject matter of the invention. Likewise, advantages mentioned in connection with one of the subject matter of the invention can also be understood to relate to the other subject matter of the invention.

[0106] It should also be noted that terms such as "comprehensive," "exhibiting," or "with" do not exclude other characteristics or steps. Furthermore, terms such as "a" or "that," which indicate a singular number of steps or characteristics, do not exclude a plurality of characteristics or steps—and vice versa.

[0107] In a purist embodiment of the invention, however, it may also be provided that the features introduced in the invention with the terms "comprising," "comprising," or "with" are exhaustively listed. Accordingly, one or more lists of features within the scope of the invention may be considered complete, for example, for each claim. The invention may, for instance, consist exclusively of the features mentioned in claim 1.

[0108] It should be noted that designations such as "first" or "second" etc. are primarily used for the purpose of distinguishing between the respective device or process features and are not necessarily intended to indicate that features are mutually dependent or related to each other.

[0109] Exemplary embodiments of the invention are described in more detail below with reference to the drawing.

[0110] The figures each show preferred embodiments in which individual features of the present invention are combined with one another. Features of an embodiment can also be implemented independently of the other features of the same embodiment and can therefore be readily combined by a person skilled in the art to form further meaningful combinations and subcombinations with features of other embodiments.

[0111] In the figures, functionally identical elements are provided with the same reference symbols.

[0112] They show: Fig. 1 an EUV projection exposure system in meridional section; Fig. 2 a DUV projection exposure system; Fig. 3 a basic side view of an embodiment of a guide device of the device according to the invention; Fig. 4 a basic top view of the in Fig. 3 embodiment of a guide device of the device according to the invention shown; Fig. 5 a basic side view of a further embodiment of a guide device of the device according to the invention; Fig. 6 a basic side view of a further embodiment of a guide device of the device according to the invention; Fig. 7 a basic top view of the in Fig. 6 shown embodiment of a guide device of the device according to the invention; Fig. 8 a basic side view of a further embodiment of a guide device of the device according to the invention; Fig. 9 a basic representation of components of a guide device for an exemplary tilt angle of a deflecting optic; Fig. 10 A schematic representation of components of a guide device for an exemplary tilt angle of a deflecting optic, which differs from the tilt angle in Fig. 9 distinguishes; Fig. 11 a schematic representation of a further embodiment of a guide device of the device according to the invention; Fig. 12 a schematic representation of a further embodiment of a guide device of the device according to the invention; Fig. 13 a basic representation of a further embodiment of a guide device of the device according to the invention; Fig. 14 a schematic representation of a further embodiment of a guide device of the device according to the invention; Fig. 14a a single presentation of a in Fig. 14 shown detachable motor bell with optical attachment of the guide device; Fig. 15 a basic representation of a cleaning system; and Fig. 16 a basic representation of another cleaning system.

[0113] The following will first refer to Fig. 1. The essential components of an EUV projection exposure system 100 for microlithography are described as an example of a lithography system. The description of the basic structure of the EUV projection exposure system 100 and its components is not intended to be restrictive.

[0114] An illumination system 101 of the EUV projection exposure system 100 comprises, in addition to a radiation source 102, an illumination optic 103 for illuminating an object field 104 in an object plane 105. A reticule 106 arranged in the object field 104 is exposed. The reticule 106 is held by a reticule holder 107. The reticule holder 107 can be moved, particularly in a scanning direction, by means of a reticule displacement drive 108.

[0115] In Fig. Figure 1 shows a Cartesian xyz coordinate system for illustrative purposes. The x-direction runs perpendicular to the plane of the drawing. The y-direction runs horizontally, and the z-direction runs vertically. The scan direction runs in Fig. 1 along the y-direction. The z-direction runs perpendicular to the object plane 105.

[0116] The EUV projection exposure system 100 comprises a projection optic 109. The projection optic 109 serves to image the object field 104 onto an image field 110 in an image plane 111. The image plane 111 is parallel to the object plane 105. Alternatively, an angle other than 0° between the object plane 105 and the image plane 111 is also possible.

[0117] A structure on the reticulum 106 is imaged onto a photosensitive layer of a wafer 112 located in the image plane 111 within the image field 110. The wafer 112 is held by a wafer holder 113. The wafer holder 113 can be displaced, particularly along the y-direction, via a wafer transfer drive 114. The displacement of the reticulum 106 via the reticulum transfer drive 108 and of the wafer 112 via the wafer transfer drive 114 can be synchronized.

[0118] Radiation source 102 is an EUV radiation source. Specifically, radiation source 102 emits EUV radiation 115, which is also referred to as useful radiation or illumination radiation. The useful radiation 115 has a wavelength in the range between 5 nm and 30 nm. Radiation source 102 can be a plasma source, for example, an LPP source (laser-produced plasma) or a DPP source (gas-discharged produced plasma). It can also be a synchrotron-based radiation source. Radiation source 102 can be a free-electron laser (FEL).

[0119] The illumination radiation 115, emanating from the radiation source 102, is focused by a collector 116. The collector 116 can be a collector with one or more ellipsoidal and / or hyperboloid reflective surfaces. The at least one reflective surface of the collector 116 can be illuminated with the illumination radiation 115 at grazing incidence (GI), i.e., with angles of incidence greater than 45°, or at normal incidence (NI), i.e., with angles of incidence less than 45°. The collector 116 can be structured and / or coated, both to optimize its reflectivity for the useful radiation 115 and to suppress stray light.

[0120] After the collector 116, the illumination radiation 115 propagates through an intermediate focus in an intermediate focal plane 117. The intermediate focal plane 117 can represent a separation between a radiation source module, comprising the radiation source 102 and the collector 116, and the illumination optics 103.

[0121] The illumination optics 103 comprise a deflecting mirror 118 and, downstream in the beam path, a first faceted mirror 119. The deflecting mirror 118 can be a planar deflecting mirror or, alternatively, a mirror with an effect that influences the beam shape beyond the mere deflection effect. Alternatively or additionally, the deflecting mirror 118 can be designed as a spectral filter that separates a useful wavelength of the illumination radiation 115 from stray light of a different wavelength. If the first faceted mirror 119 is arranged in a plane of the illumination optics 103 that is optically conjugate to the object plane 105 as the field plane, it is also referred to as a field faceted mirror. The first faceted mirror 119 comprises a plurality of individual first facets 120, which are also referred to as field facets in the following. Of these facets 120, the following are in the Fig. 1 only some examples are shown.

[0122] The first facets 120 can be designed as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or semicircular border contour. The first facets 120 can be designed as planar facets or alternatively as convexly or concavely curved facets.

[0123] As is known, for example, from DE 10 2008 009 600 A1, the first facets 120 can themselves each be composed of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirror 119 can in particular be designed as a microelectromechanical system (MEMS system). For details, reference is made to DE 10 2008 009 600 A1.

[0124] Between the collector 116 and the deflecting mirror 118, the illumination radiation 115 runs horizontally, i.e. along the y-direction.

[0125] In the beam path of the illumination optics 103, a second faceted mirror 121 is arranged downstream of the first faceted mirror 119. If the second faceted mirror 121 is arranged in a pupil plane of the illumination optics 103, it is also referred to as a pupil faceted mirror. The second faceted mirror 121 can also be arranged at a distance from a pupil plane of the illumination optics 103. In this case, the combination of the first faceted mirror 119 and the second faceted mirror 121 is also referred to as a specular reflector. Specular reflectors are known from US 2006 / 0132747 A1, EP 1 614 008 B1, and US 6,573,978.

[0126] The second facet mirror 121 comprises a plurality of second facets 122. In the case of a pupil facet mirror, the second facets 122 are also referred to as pupil facets.

[0127] The second facets 122 can also be macroscopic facets, which may, for example, have round, rectangular, or hexagonal edges, or alternatively, facets composed of micromirrors. Reference is also made to DE 10 2008 009 600 A1 in this regard.

[0128] The second facets 122 can have planar or alternatively convex or concave curved reflective surfaces.

[0129] The illumination optics 103 thus form a double-faceted system. This basic principle is also known as a fly's eye integrator.

[0130] It may be advantageous not to arrange the second faceted mirror 121 exactly in a plane which is optically conjugate to a pupil plane of the projection optics 109.

[0131] With the aid of the second faceted mirror 121, the individual first facets 120 are imaged into the object field 104. The second faceted mirror 121 is the last beam-shaping, or indeed the last, mirror for the illumination radiation 115 in the beam path before the object field 104.

[0132] In another embodiment of the illumination optics 103, not shown, a transmission optic can be arranged in the beam path between the second facet mirror 121 and the object field 104, which contributes in particular to imaging the first facets 120 into the object field 104. The transmission optic can have exactly one mirror, or alternatively two or more mirrors, which are arranged one behind the other in the beam path of the illumination optics 103. The transmission optic can in particular comprise one or two mirrors for normal incidence (NI mirrors, "normal incidence" mirrors) and / or one or two mirrors for grazing incidence (GI mirrors, "grazing incidence" mirrors).

[0133] The lighting optic 103, in the version that is in the Fig. Figure 1 shows exactly three mirrors after the collector 116, namely the deflecting mirror 118, the field facet mirror 119 and the pupil facet mirror 121.

[0134] In a further embodiment of the lighting optics 103, the deflecting mirror 118 can also be omitted, so that the lighting optics 103 can then have exactly two mirrors after the collector 116, namely the first faceted mirror 119 and the second faceted mirror 121.

[0135] The imaging of the first facets 120 by means of the second facets 122 or with the second facets 122 and a transmission optic into the object plane 105 is regularly only an approximate imaging.

[0136] The projection optics 109 comprise a plurality of mirrors Mi, which are numbered according to their arrangement in the beam path of the EUV projection exposure system 100.

[0137] In the Fig. In the example shown, the projection optics 109 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve, or any other number of mirrors Mi are also possible. The penultimate mirror M5 and the last mirror M6 each have an aperture for the illumination radiation 115. The projection optics 109 is a double-obscured optic. The projection optics 109 has an image-side numerical aperture that is greater than 0.5 and can also be greater than 0.6, for example, 0.7 or 0.75.

[0138] The reflective surfaces of the mirrors Mi can be designed as freeform surfaces without an axis of rotational symmetry. Alternatively, the reflective surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflective surface shape. The mirrors Mi, like the mirrors of the illumination optics 103, can have highly reflective coatings for the illumination radiation 115. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

[0139] The projection optics 109 has a large object-image offset in the y-direction between a y-coordinate of a center of the object field 104 and a y-coordinate of the center of the image field 110. This object-image offset in the y-direction can be approximately as large as a z-distance between the object plane 105 and the image plane 111.

[0140] The projection optics 109 can be anamorphic. In particular, they have different magnifications βx, βy in the x and y directions. The two magnifications βx, βy of the projection optics 109 are preferably (βx, βy) = (+ / - 0.25, + / - 0.125). A positive magnification β indicates a projection without image inversion. A negative magnification β indicates a projection with image inversion.

[0141] The projection optics 109 thus lead to a reduction in the x-direction, that is, in the direction perpendicular to the scan direction, in a ratio of 4:1.

[0142] The projection optics 109 lead to a reduction of 8:1 in the y-direction, that is, in the scan direction.

[0143] Other magnification ratios are also possible. Magnification ratios with the same sign and absolute values ​​in the x and y directions, for example with absolute values ​​of 0.125 or 0.25, are also possible.

[0144] The number of intermediate image planes in the x- and y-directions in the beam path between the object field 104 and the image field 110 can be the same or, depending on the design of the projection optics 109, can differ. Examples of projection optics with different numbers of such intermediate images in the x- and y-directions are known from US 2018 / 0074303 A1.

[0145] Each of the pupil facets 122 is assigned to exactly one of the field facets 120 to form an illumination channel for illuminating the object field 104. This can result, in particular, in illumination according to Köhler's principle. The far field is divided into a multitude of object fields 104 by means of the field facets 120. The field facets 120 generate a plurality of images of the intermediate focus on the pupil facets 122 assigned to each of them.

[0146] The field facets 120 are each superimposed on the reticulum 106 by an associated pupil facet 122 to illuminate the object field 104. The illumination of the object field 104 is particularly homogeneous. It preferably exhibits a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

[0147] The illumination of the entrance pupil of the projection optics 109 can be geometrically defined by the arrangement of the pupil facets. By selecting the illumination channels, in particular the subset of pupil facets that guide light, the intensity distribution in the entrance pupil of the projection optics 109 can be adjusted. This intensity distribution is also referred to as the illumination setting.

[0148] Another preferred pupil uniformity in the area of ​​defined illuminated sections of an illumination pupil of the illumination optics 103 can be achieved by a redistribution of the illumination channels.

[0149] Further aspects and details of the illumination of the object field 104 and, in particular, the entrance pupil of the projection optics 109 are described below.

[0150] The projection optic 109 can, in particular, have a homocentric entrance pupil. This may be accessible. It may also be inaccessible.

[0151] The entrance pupil of the projection optics 109 cannot always be illuminated exactly by the pupil facet mirror 121. When the projection optics 109 image the center of the pupil facet mirror 121 telecentrically onto the wafer 112, the aperture rays often do not intersect at a single point. However, a surface can be found where the pairwise determined separation of the aperture rays is minimized. This surface represents the entrance pupil or a surface conjugate to it in real space. In particular, this surface exhibits a finite curvature.

[0152] The projection optics 109 may have different entrance pupil positions for the tangential and sagittal beam paths. In this case, an imaging element, in particular an optical component of the transmission optics, should be provided between the second faceted mirror 121 and the reticle 106. This optical component will allow the different positions of the tangential and sagittal entrance pupils to be taken into account.

[0153] During the Fig. In the arrangement of the components of the illumination optics 103 shown in Figure 1, the pupil facet mirror 121 is arranged in a plane conjugate to the entrance pupil of the projection optics 109. The first field facet mirror 119 is arranged tilted relative to the object plane 105. The first facet mirror 119 is arranged tilted relative to an arrangement plane defined by the deflecting mirror 118.

[0154] The first faceted mirror 119 is arranged at an angle to an arrangement plane defined by the second faceted mirror 121.

[0155] In Fig. Figure 2 shows an exemplary DUV projection exposure system 200. The DUV projection exposure system 200 comprises an illumination system 201, a device called a reticule stage 202 for receiving and precisely positioning a reticule 203, by which the subsequent structures on a wafer 204 are determined, a wafer holder 205 for holding, moving and precisely positioning the wafer 204 and an imaging device, namely a projection optic 206, with several optical elements, in particular lenses 207, which are held in a lens housing 209 of the projection optic 206 by means of holding devices 208, which in the exemplary embodiment are designed as mounts.

[0156] Alternatively or in addition to the lenses 207 shown, various refractive, diffractive and / or reflective optical elements, including mirrors, prisms, end plates and the like, may be provided.

[0157] The basic operating principle of the DUV projection exposure system 200 provides that the structures introduced into the reticulum 203 are imaged onto the wafer 204.

[0158] The illumination system 201 provides a projection beam 210 in the form of electromagnetic radiation, which is required for imaging the reticulum 203 onto the wafer 204. A laser, a plasma source, or the like can be used as the source of this radiation. In the illumination system 201, the radiation is shaped by optical elements such that the projection beam 210, upon striking the reticulum 203, exhibits the desired properties with regard to diameter, polarization, wavefront shape, and the like.

[0159] Using the projection beam 210, an image of the reticulum 203 is generated and transferred, appropriately reduced in size, to the wafer 204 by the projection optics 206. The reticulum 203 and the wafer 204 can be moved synchronously, so that areas of the reticulum 203 are mapped onto corresponding areas of the wafer 204 practically continuously during a so-called scan process.

[0160] Optionally, the air gap between the last lens 207 and the wafer 204 can be replaced by a liquid medium with a refractive index greater than 1.0. This liquid medium could, for example, be highly purified water. Such a setup is also known as immersion lithography and offers increased photolithographic resolution.

[0161] The use of the invention is not limited to use in projection exposure systems 100, 200, and in particular not limited to systems with the described setup. The invention is suitable for any lithography or microlithography systems, but especially for projection exposure systems with the described setup. The invention is also suitable for EUV projection exposure systems, which have a lower image-side numerical aperture than those associated with Fig. The invention is particularly suitable for EUV projection exposure systems that have an image-side numerical aperture of 0.25 to 0.5, preferably 0.3 to 0.4, and most preferably 0.33. Furthermore, the invention and the following embodiments are not limited to a specific design.

[0162] The following Fig. Figures 3 to 16 present the invention only by way of example and in a highly schematic form.

[0163] The device according to the invention for cleaning components 2, in particular components of a lithography system, especially in the manner described in principle by reference to the Fig. 1 and Fig. The assembly shown in Figure 2 comprises a guide device 1, a radiation source 24 which emits a laser radiation 5, and a beam guidance device 25 to supply the laser radiation 5 to the component 2.

[0164] The device according to the invention is designed such that the beam guidance device 25 introduces the laser radiation 5 into the guide device 1.

[0165] The Fig. Figures 3 to 8 show different embodiments of the guide device 1 of the device according to the invention for cleaning the component 2, in particular a recess 2a of the component 2.

[0166] The Fig. Figure 3 shows a side view of an embodiment of the guide device 1. The laser radiation 5 is guided from the radiation source 24 via the beam guide 25 into the guide device 1. The guide device 1 has a rod 3a or a tube 3b with an aspect ratio greater than two. A front section of the guide device 1, or a front end region of the rod 3a or tube 3b, also has a deflecting optic 4 (here a mirror) which symmetrically surrounds the rod 3a or the tube 3b in its front end region and has a curvature. The laser radiation 5 propagates within the guide device 1 along the rod 3a or the tube 3b on a beam path to the deflecting optic 4. The deflecting optic 4 deflects the laser radiation 5. In the embodiment according to Fig. 3 The deflecting optics 4 deflect the laser radiation 5 onto a lateral inner wall 2b of the recess 2a, wherein the laser radiation 5 is preferably focused.

[0167] The guide device 1 is dimensioned such that it has a diameter of no more than 20 mm at its widest point and a length along the beam path up to the deflecting optics 4 that is at least twice as long as the diameter at the widest point of the guide device 1.

[0168] The beam path can be rotated at least partially about an axis 6 along the rod 3a or the tube 3b. The laser radiation represented by dashed lines symbolizes the path of the laser radiation 5 after a rotation of the beam path by 180°, wherein the laser radiation 5 is deflected before and after the rotation in a direction that points away from the center of the rod 3a or the tube 3b, in particular towards opposite lateral inner walls 2b of the recess 2a in order to clean them.

[0169] Furthermore, a discharge device, in particular a compressed air nozzle 20 and / or a suction device 21, may be provided to suction and / or blow away contaminants dissolved by the laser radiation 5 or transformed forms of the contaminants.

[0170] In Fig. 4 is a top view of the Fig. The guide device 1 shown in Figure 3 illustrates the previously described rotation of the beam path (symbolized here by an arrow) of the beam path or the laser radiation 5 by 180°. The point of impact 5a of the laser radiation 5 on the deflecting optics 4 is different from the center of the deflecting optics 4.

[0171] The Fig. Figure 5 shows a side view of another embodiment of the guide device 1. In contrast to the one described in the Fig. 3 and Fig. In the embodiment shown in Figure 4, the guide device 1 comprises a translucent rod 3a, in particular a glass rod, or a light guide 3c, at the front end of which the deflecting optics 4 are located. The deflecting optics 4 covers the translucent rod 3a or the light guide 3c at its front end. In this case, the beam path runs through the translucent rod 3a or the light guide 3c.

[0172] The Fig. Figure 6 shows a side view of another embodiment of the guide device 1, which is similar to the one described in the Fig. 3 and Fig. 4. The embodiment shown has a rod 3a or a tube 3b, wherein the deflecting optics 4 in the embodiment according to Fig. 6 is not necessarily arranged symmetrically around the front end region of the rod 3a or the tube 3b.

[0173] In contrast to the previously shown embodiments, the rod 3a or the tube 3b can be rotated about an axis 6, which runs at least approximately parallel to the rod 3a or the tube 3b and through the point of impact 5a of the laser radiation 5 on the deflecting optics 4. The axis 6 is not coaxial with the longitudinal axis of the rod 3a or the tube 3b. For example, by rotating the rod 3a or the tube 3b by 180°, the laser radiation 5 can again be directed before and after the rotation onto opposite lateral inner walls 2b of the recess 2a in order to clean them.

[0174] In Fig. 7 is a top view of the Fig. The guide device 1 shown in Figure 6 is depicted, and the rotation of the rod 3a or the tube 3b described therein is indicated by an arrow. The deflecting optic 4 is fixed to the rod 3a or the tube 3b and rotates with it. It should be noted that the indicated shape of the deflecting mirror 4 is by no means to be understood as restrictive, but merely represents one possibility. The deflecting mirror 4 can also have a different shape.

[0175] The Fig. Figure 8 shows a side view of another embodiment of the guide device 1, which is similar to the one in Fig. In the embodiment shown in Figure 5, a translucent rod 3a, in particular a glass rod, or an optical fiber 3c is included, wherein the beam path again passes through the translucent rod 3a or the optical fiber 3c. In contrast to the embodiment shown in Figure 5, the beam path is in the translucent rod 3a or the optical fiber 3c. Fig. embodiment shown in 5, but analogous to the one in the Fig. 6 and Fig. In the embodiment shown in Figure 7, the translucent rod 3a or the optical fiber 3c is rotatable about an axis 6, which runs at least approximately parallel to the translucent rod 3a or the optical fiber 3c and through the point of impact 5a of the laser radiation 5 on the deflecting optics 4. In the present example, this corresponds to a rotation of the translucent rod 3a or the optical fiber 3c about its own central longitudinal axis, i.e., about itself.

[0176] The Fig. 9 and Fig. Figure 10 shows the preferably tiltable and / or oscillatable deflecting optics 4 at two different tilt angles. As can be seen in the comparison, this results in a deflection of the laser radiation 5 in different spatial directions and a position of the points of impact of the laser radiation on the lateral inner wall 2b of the recess 2a of the component 2 at different heights relative to the height of the deflecting optics 4. One of the Fig. The similar tilting motion shown in 10 has proven to be particularly suitable for cleaning undercuts, for example also threads.

[0177] The Fig. 11, Fig. 12, and Fig. Figure 13 shows three further embodiments of the guide device 1 of the device according to the invention, each of which has a light guide 3c. The embodiment of the guide device 1 with a flexible light guide 3c has proven advantageous for probe-like applications in recesses with a non-linear profile, particularly in channels, especially in cooling channels of components of lithography systems, and in pipelines. The laser radiation 5 is guided at least partially by the light guide 3c through the guide device 1 to the deflecting optics 4, as shown in the Fig. 11 and Fig. 12 illustrated embodiments partly also by means of a translucent rod 3a, in particular a glass rod, and radiates through a hollow shaft.

[0178] The deflecting optics 4 have a curvature, preferably for focusing the laser radiation 5.

[0179] The deflecting optic 4 is preferably rotatable by means of a brushless motor 7, preferably comprising a motor winding 8, a motor bell 9, a stator 10, a stator housing 11, ball bearings 12, and connecting leads 13. Vacant spaces can preferably be filled with a potting compound 14.

[0180] A changeover interface 15 can be provided in a rear area of ​​the guide device 1 in order to exchange the guide device 1 for a second guide device. The second guide device is preferably part of the device according to the invention. The device according to the invention may optionally have further guide devices, in particular a third or fourth guide device.

[0181] The guide device 1 can be provided with an enclosure 16 to protect against the uncontrolled emission of laser radiation 5. The enclosure 16 has recesses or windows 17 for the controlled emission of laser radiation 5. In the front end region of the guide device 1, this enclosure 16 is preferably dome-shaped.

[0182] The in Fig. 11, Fig. 12, and Fig. The 13 embodiments of such a guide device 1 shown differ in the arrangement of the elements, these arrangements merely representing examples of a larger number of technically possible arrangements. In particular, combinations of the embodiments shown are also possible.

[0183] The Fig. 14 and the Fig. Figure 14a shows a particularly compact modification of the three embodiments according to the Fig. 11 to 13, especially the Fig. 11. In contrast to the embodiment according to the Fig. In the present embodiment, an enclosure 16 for the guide device 1 was omitted. It should be noted that alternative laser protection measures can be implemented. Optional focusing optics 18 within the hollow shaft can provide additional focusing of the laser radiation 5. Fig. 14 and the Fig. Figure 14a also shows an optional trim weight 19 on the deflecting optic 4. Furthermore, a compressed air nozzle 20 and / or a suction device 21 or another discharge device may be provided.

[0184] It is for the embodiments according to the Fig. 11 to 14a are particularly advantageous if a propulsion device is provided and set up to move the guide device 1 within a partially closed geometry of the component 2 using compressed air. This applies in particular to the application for cleaning channels, especially cooling channels in a component of a lithography system.

[0185] In Fig. Figure 14a shows the preferably detachable motor bell with optical attachment 22 again separately. It is advantageous if at least a second guide device or second guide device unit, here a second detachable motor bell with optical attachment 22, is provided so that the guide device or a guide device unit of the guide device can be replaced. The second guide device or second guide device unit differs from the original guide device 1 or the original guide device unit in at least one feature (diameter of the guide device 1, curvature of the deflecting optics 4, tilt angle of the deflecting optics 4 relative to the beam path, components included, arrangement of the components). The guide device unit can preferably comprise at least a front section of the guide device 1.

[0186] The laser radiation 5 in Fig. 3 to 14 can preferably be pulsed.

[0187] The embodiments of the guide device 1 according to the Fig. 4 to 14 can be analogous to Fig. 3. The radiation source 24 and the beam guidance device 25 are added to obtain a device according to the invention. The radiation source 24 can preferably emit laser radiation 5 in the infrared spectral range.

[0188] In particular for the embodiment according to the Fig. 14 A diode laser, a laser diode light source, an LED laser, or a cascaded LED light source can be particularly suitable as a radiation source 24. Such a radiation source 24 is preferably positioned directly in front of the focusing optics or lenses 18, so that the radiation or laser radiation 5 is directed analogously to the Fig. 14 shines through the focusing optics or lenses 18. The light guide 3c can preferably be omitted or replaced by another flexible component, in particular to move the guide device 1 in a manner analogous to an endoscope or flexoscope, for example through channels to be cleaned.

[0189] The Fig. 15 and Fig. Figure 16 presents two exemplary cleaning systems 23 in which the device according to the invention can be used. The device according to the invention can be part of the cleaning system 23. The cleaning system 23 can be particularly advantageously combined with the device according to the invention. However, the cleaning system 23 can also be used without the device according to the invention.

[0190] In the Fig. 15 and Fig. The device according to the invention is not shown in Figure 16. The cleaning system 23 according to the Fig. 15 and Fig. 16 can have its own radiation source 24 and its own beam guidance device 25, which, however, can also be part of the device according to the invention. Insofar as the cleaning system 23 is used in combination with the device according to the invention, the radiation source 24 and the beam guidance device 25 are, according to the exemplary embodiments according to the Fig. 15 and Fig. 16 to be regarded as part of the device according to the invention.

[0191] In the present embodiment, the radiation source 24 can in particular be a fiber laser, a diode laser or an LED laser and can optionally be extended by an additional measuring laser for measuring the component.

[0192] The beam guidance device 25 can preferably be designed as a light guide.

[0193] The beam guidance device 25 is preferably mounted on a tripod 26, which can optionally be replaced by a multi-axis kinematic system, in particular a six-axis robot. The beam guidance device 25 comprises several optional optics (lenses) 35 and a tiltable and / or rotatable deflecting optic 36, which directs the laser radiation 5 at a variable angle onto a planar or flat outer plane of the component 2. A local extraction system 38 can be provided in the cleaning system 23 in the vicinity of the point of effect of the laser radiation 5 on the component 2.

[0194] For surface cleaning, the cleaning system 23 preferably has a rotary table 27 for receiving the component 2 to be cleaned, which is optionally mounted on a linear table 28 that can be moved in several spatial directions. The rotary table 27 can have a mirror plate 29 to direct portions of the laser radiation 5 that have been reflected by the component 2 back onto the component 2 in order to improve the cleaning effect.

[0195] The cleaning system 23 shown comprises a control unit 30 with an operating device, which can be at least partially automated. This applies in particular to automated cleaning programs. The cleaning system 23 is provided with a housing 37, which can optionally be secured with an interlock device to automatically switch off the radiation source 24 for safety reasons in the event of unauthorized access. The cleaning system 23 preferably also includes an air inlet 31, which is optionally equipped with a drive wheel or a pump, in particular an impeller, and preferably an exhaust air inlet 32, which is optionally equipped with a suction device and / or a monitoring unit to provide analytical data on the removed contaminants or the transformed forms of these contaminants.Optionally, the cleaning system 23 also includes a thermal sensor 33 to ensure fire protection and / or a camera 34, preferably with an infrared light protection filter.

[0196] The in Fig. 15 and Fig. The embodiments of such a cleaning system 23 shown in Figure 16 differ in the positioning of the beam guidance device 25.

[0197] In Fig. 15 the beam guidance device 25 is preferably positioned vertically using a tripod 26, wherein the laser radiation 5 is directed at least approximately horizontally onto the component 2 by the deflection optics 36.

[0198] In Fig. 16 the beam guidance device 25 is positioned horizontally, whereby the laser radiation 5 is directed at least approximately perpendicularly onto the component 2 by the deflection optics 36.

[0199] The in the Fig. 15 and Fig. The cleaning system 23 shown in Figure 16 can, as mentioned above, be combined with the device according to the invention. For this purpose, the guide device 1 according to the invention is mounted such that the beam guidance device 25 can introduce the laser radiation 5 into the guide device 1. For particularly advantageous positioning of the guide device 1, a multi-axis robot can be provided in addition to or as an alternative to the tripod 26, which carries the guide device 1 and preferably also the beam guidance device 25. The positioning of the guide device 1 so that even difficult-to-access areas can be cleaned, in particular so that the guide device 1 can also be inserted into recesses 2a of the component 2, can be carried out by the multi-axis robot, optionally also in combination with the rotary table 27 and the linear table 28.

[0200] The in the Fig. 15 and Fig. The cleaning systems shown in Figure 16 can be used in particular for cleaning components of lithography systems, especially projection exposure systems. The cleaning can preferably take place in a cleanroom or in an airlock leading to a cleanroom or vacuum chamber.

[0201] The in the Fig. 15 and Fig. The cleaning systems shown in Figure 16 enable fast and preferably automated surface cleaning, especially of the outer surfaces of component 2. To also clean hard-to-reach areas, such as drill holes, the device according to the invention can be used (as described).

[0202] The component 2 to be cleaned could, for example, be frames, holding devices, in particular mounts for optics, plates, vacuum chambers or the like.

[0203] The cleaning system 23 can also include several radiation sources 24 or beam guiding devices 25. Furthermore, the cleaning system 23 can include a radiation source 24 and a beam guiding device 25 designed to perform surface cleaning, and additionally a device according to the invention that cleans hard-to-reach areas of the component 2. It is also possible that the beam guiding device 25, which is provided for surface cleaning, and the device according to the invention share a radiation source 24.

[0204] The exemplary embodiment also serves to disclose a method according to the invention for cleaning components 2, in particular components of a lithography system, especially components of an EUV projection exposure system 100 or a DUV projection exposure system 200, as exemplified by the Fig. 1 and Fig. Figure 2 is shown. In particular, the method according to the invention can be used to clean components 2 that have a complex geometry, especially recesses 2a in the component 2 with an aspect ratio greater than two and with a diameter of at most 22 mm at the narrowest point. However, the method according to the invention can also be applied analogously to recesses 2a with a diameter of more than 22 mm at the narrowest point. The guide device 1 according to the invention, in particular as shown in the embodiments described above, can be inserted at least partially into the recess 2a of the component 2. The guide device 1 is inserted into the recess 2a to a depth at least twice as deep as the diameter of the guide device 1.The deflecting optics 4 allow the laser radiation 5 to be deflected onto the lateral inner walls 2b of the recess 2a, so that the lateral inner walls 2b are reliably cleaned.

[0205] The device and method according to the invention are particularly suitable for cleaning components of a lithography system. The component to be cleaned can be one of the optical elements of the lithography system, in particular an optical element 116, 118, 119, 120, 121, 122, Mi, 207 of a projection exposure system 100, 200 according to the Fig. 1 and Fig. 2. It may also be a holding device, for example a version 208 of the DUV projection exposure system 200. Reference symbol list 1 Guide device 2 components 2a Recess (of component 2) 2b Side inner wall (of recess 2a of component 2) 3a Staff 3b pipe 3c Optical fiber 4 Deflection optics (mirrors) 5 Laser radiation 5a Point of impact (of the laser radiation 5 on the deflecting optics 4) 6-axis 7 Brushless Motor 8 Motor windings 9 Engine bell 10 stators 11 Stator housing 12 ball bearings 13 connecting cables (copper enamel wire) 14 Potting compound 15 Interchangeable interface 16 Enclosure 17 cutouts / windows 18 focusing optics (lenses) 19 Trim weight 20 compressed air nozzle 21 Extraction 22 Detachable engine bell with optical attachment 23 Cleaning system 24 Radiation source 25 Beam guidance device 26 Tripod 27 turntables 28 Linear table 29 Mirror plate 30 Control unit 31 Air inlet opening 32 Exhaust air opening 33 Thermosensor 34 Camera 35 optics 36 Deflection optics 37 cases 38 Local suction 100 EUV projection system 101 Lighting system 102 Radiation source 103 Lighting optics 104 object field 105 Object level 106 reticles 107 label holders 108 Reticle displacement drive 109 Projection optics 110 image field 111 Image plane 112 wafers 113 wafer holders 114 Wafer transfer drive 115 EUV / Useful / Illumination radiation 116 Collector 117 Intermediate focus plane 118 Deflection mirrors 119 first faceted mirror / field faceted mirror 120 first facets / field facets 121 Second faceted mirror / Pupil faceted mirror 122 second facets / pupil facets 200 DUV projection exposure system 201 Lighting system 202 reticulation days 203 reticles 204 wafers 205 wafer holders 206 Projection optics 207 lens 208 Holding device / socket 209 lens bodies 210 projection beam Mi Mirror QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 201 558 A1

[0006] DE 10 2022 200 205 B3

[0007] DE 10 2008 009 600 A1 [0123, 0127] US 2006 / 0132747 A1

[0125] EP 1 614 008 B1

[0125] US 2018 / 0074303 A1

[0144]

Claims

[1] Device for cleaning components (2), in particular components of a lithography system, comprising a radiation source (24) which emits laser radiation (5) and a beam guiding device (25) for supplying the laser radiation (5) to the component (2), characterized byin that a guide device (1) is provided, into which the beam guiding device (25) introduces the laser radiation (5), wherein a front section of the guide device (1) has a deflection optics (4), wherein the laser radiation (5) propagates within the guide device (1) along a beam path up to the deflection optics (4), wherein the deflection optics (4) deflects the laser radiation (5), and wherein the guide device (1) is dimensioned such that the guide device (1) has a diameter of at most 20 mm at the widest point and the guide device (1) has a length along the beam path up to the deflection optics (4) which is at least twice as long as the diameter at the widest point of the guide device (1). [2] Device according to claim 1, characterized byin that the guide device (1) has a rod (3a) or a tube (3b) with an aspect ratio of greater than two, wherein the rod (3a) or the tube (3b) extends along the beam path and wherein the deflection optics (4) are fixed to a front end region of the rod (3a) or the tube (3b). [3] Device according to claim 1, characterized by in that the guide device (1) has a flexible optical fiber (3c) which is designed to guide the laser radiation (5) at least partially to the deflection optics (4), wherein the deflection optics (4) is fixed to a front end region of the optical fiber (3c). [4] Device according to claim 2 or 3, characterized byin that the deflection optics (4) symmetrically enclose and / or cover the cross-section of the rod (3a), the tube (3b), or the light guide (3c) in the front end region, wherein a point of incidence (5a) of the laser radiation (5) on the deflection optics (4) is different from a center of the deflection optics (4), wherein the beam path is at least partially rotatable about an axis (6) along the rod (3a), the tube (3b), or the light guide (3c), and wherein the deflection optics (4) always deflect the laser radiation (5) in a direction which points away from a center of the rod (3a), the tube (3b), or the light guide (3c). [5] Device according to claim 2 or 3, characterized bythat the rod (3a), the tube (3b), or the light guide (3c) with the deflection optics (4) fixed thereto is rotatable about an axis (6) which runs at least approximately parallel to the rod (3a), the tube (3b), or the light guide (3c) and through the point of impact (5a) of the laser radiation (5) on the deflection optics (4). [6] Device according to one of claims 1 to 5, characterized by that the laser radiation (5) is pulsed. [7] Device according to one of claims 1 to 6, characterized by that the radiation source (24) emits laser radiation (5) in the infrared spectral range. [8] Device according to one of claims 1 to 7, characterized by that the deflection optics (4) has a curvature. [9] Device according to one of claims 1 to 8, characterized by that the deflection optics (4) can be tilted and / or oscillated relative to the beam path. [10] Device according to one of claims 1 to 9, characterized bythat a removal device, in particular a compressed air nozzle (20) and / or a suction device (21), is provided in order to suck out and / or blow away contaminants or converted forms of the contamination dissolved by the laser radiation (5). [11] Device according to one of claims 1 to 10, characterized by that the guide device (1) can be moved using multi-axis kinematics. [12] Device according to one of claims 1 to 11, characterized by that a propulsion device is provided and arranged to move the guide device (1) within a partially closed geometry, in particular a cooling channel, of the component (2) by means of compressed air. [13] Device according to one of claims 1 to 12, characterized bythat at least one second guide device is provided, wherein the guide device (1) can be decoupled from the beam guiding device (25) in order to exchange the guide device (1) for the second guide device, wherein the second guide device differs from the original guide device (1) in at least one of the following features: - diameter of the guide device (1), - Curvature of the deflection optics (4), - Tilt angle of the deflection optics (4) relative to the beam path, - components contained, - Arrangement of components. [14] Method for cleaning components (2), in particular components of a lithography system, with a complex geometry comprising at least one recess (2a) with an aspect ratio of greater than two and with a diameter of at most 22 mm at the narrowest point, characterized bythat the guide device (1) of a device according to one of claims 1 to 13 is introduced at least partially into the recess (2a) of the component (2), wherein the guide device (1) has a diameter at the widest point which is smaller than the diameter of the recess (2a) at the narrowest point, wherein the guide device (1) is introduced into the recess (2a) at least twice as deep as the diameter of the guide device (1), and wherein the laser radiation (5) is deflected by the deflection optics (4) onto lateral inner walls (2b) of the recess (2a). [15] Lithography system, in particular projection exposure system (100, 200) for semiconductor lithography, with an illumination system (101, 201) with a radiation source (102) and an optics (103, 109, 206) which has at least one optical element (116, 118, 119, 120, 121, 122, Mi, 207) and at least one associated holding device (208), characterized bythat at least one of the optical elements (116, 118, 119, 120, 121, 122, Mi, 207) or one of the associated holding devices (208) - by means of a device according to one of claims 1 to 13 and / or - is purified by a process according to claim 14.

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