Method for producing a composite component having a hollow structure, composite component and semiconductor technology system

Abstract

The invention relates to a method for producing a composite component (25), comprising: providing a first component (26), providing a second component (27), and producing the composite component (25) by connecting the first component (26) to the second component (27) forming a joining surface (31). The first component (26) has a first surface (29) with a curved inner surface region (29a) and a flat outer surface region (29b), and the second component (27) has a second surface (30) with a curved inner surface region (30a) and a flat outer surface region (30b). During the connection, the first component (26) and the second component (27) are connected to one another at least at the flat surface regions (29b, 30b), forming the joining surface (31). When the two components (26, 27) are connected, a hollow structure (32) is formed, which extends at least partially along the curved surface regions (29a, 30a). During the connection, the first component (26) and the second component (27) are also connected to one another at the curved surface regions (29a, 30a), forming the joining surface (31). The invention also relates to a composite component (25).

Description

[0001] Stuttgart, December 1, 2025 SZ00404PCT Rp / pt

[0002] Method for manufacturing a composite component with a hollow structure, composite component and semiconductor technology equipment

[0003] Reference to related registration

[0004] This application claims priority over German patent application DE 102025101436.1 dated 16.01.2025, the entire disclosure content of which is incorporated by reference into this application.

[0005] Background of the invention

[0006] The invention relates to a method for manufacturing a composite component, preferably for a semiconductor technology system, in particular for an EUV lithography system, comprising: providing a first component, providing a second component, and manufacturing the composite component by joining the first component to the second component to form a joining surface. The invention also relates to a composite component manufactured by such a method. The invention further relates to a composite component, preferably for a semiconductor technology system, in particular for an EUV lithography system, comprising: a first component, which preferably has a mirror surface for reflecting radiation, in particular for reflecting EUV radiation, and a second component, which has a second surface that is joined to a first surface of the first component at a joining surface.The invention also relates to a semiconductor technology system, in particular an EUV lithography system, with at least one such composite component.

[0007] 2024PF00875WO 01.12.25 SZ00404PCT A composite structure for microlithography, in particular a wafer holder, comprising two or more components whose surfaces are joined, is described in W02008 / 017449A2. The components can be joined using a variety of joining methods described in W02008 / 017449A2. The composite structure can have at least one, in particular closed, cavity. The cavity can be formed between the two components and can be designed to accommodate heating elements, embedded parts, or as a cooling channel.

[0008] A method for manufacturing a mirror for a lithography system, in which cooling channels are incorporated between two components in the form of mirror parts, is described in WO2022 / 214289A1. In the method described therein, a first mirror part and a second mirror part are provided. Cooling channels having elongated openings are provided in the first mirror part in the region of a first connecting surface, and / or cooling channels having elongated openings are provided in the region of a second connecting surface of the second mirror part. The first connecting surface of the first mirror part and the second connecting surface of the second mirror part may have a curvature.

[0009] WO2022 / 214290A1 describes a similar method for manufacturing a mirror, in which the first joining surface of the first mirror part and the second joining surface of the second mirror part may have a curvature. Cooling channels and / or auxiliary channels may be formed in the second mirror part. It is possible for the curvature of the first joining surface to have a concave shape and the curvature of the second joining surface to have a convex shape, or vice versa.

[0010] The use of curved connecting surfaces is particularly advantageous in cases where the mirror has a curved optical surface.

[0011] 2024PF00875WO 01.12.25 SZ00404PCTO surface, a constant distance between the cooling channels and the optical surface can be created with minimal effort. In particular, the curvature of the connecting surface(s) can correspond to the intended curvature of the optical surface of the mirror.

[0012] WO 2022 / 179735 A1 describes an optical element in which the cross-section of a cooling channel is divided into a first and a second sub-body and / or in which the cooling channel is curved. The curved cooling channel may have a constant distance from a curved surface to which a reflective coating is applied. The two sub-bodies are joined at a planar interface. To create the curved cooling channel, a first curved groove-shaped depression of varying depth is formed in the first sub-body, and a second curved groove-shaped depression of varying depth is formed in the second sub-body.

[0013] Object of the invention

[0014] The object of the invention is to improve a method for manufacturing a composite component, to provide a composite component with improved properties and a semiconductor technology system with at least one such composite component.

[0015] Subject matter of the invention

[0016] This task is solved according to a first aspect by a method of the type mentioned above, wherein the first component has a first surface with a curved inner surface region and a flat outer surface region, and wherein the second component has a second surface with a curved inner surface region and a flat outer surface region, wherein, when joining the first

[0017] 2024PF00875WO 01.12.25 SZ00404PCT Component and the second component are joined together, at least in the flat surface areas, forming the joining surface, and wherein a hollow structure is formed when the first and second components are joined, extending at least partially along the curved surface areas. The hollow structure is preferably permeable to a fluid. The hollow structure extends at least in the area of ​​the two curved surface areas between the two components of the composite component.

[0018] The geometry of the curved surface region of the first component is typically essentially the negative of the geometry of the curved surface region of the second component; that is, the curvatures are opposite and of the same magnitude. If the curved surface region of the first component has a concave curvature, the curved surface region of the second component typically has a convex curvature, usually with essentially the same radius of curvature, or vice versa. As described above, the surface shape, or curvature, of the respective curved surface regions follows the typically curved mirror surface in this case.If the mirror surface is a freeform surface, the curved surface areas are typically also designed as freeform surfaces to achieve a consistent, defined distance between the curved surface areas and the curved mirror surface. A consistent distance has typically proven advantageous for the optical performance of a composite component in the form of a mirror component.

[0019] Depending on the joining method used, joining the surfaces of two components in the form of mirror parts is challenging, especially if no joining agent is used.

[0020] 2024PF00875WO 01.12.25 SZ00404PCT For example, when joining flat surfaces by high-temperature bonding, it is generally necessary to pre-blow the surfaces to be joined together. Pre-blow is already complex for flat surfaces and presents a significantly greater challenge for curved joining surfaces with regard to the fabrication and preparation of the joining partners. For this purpose, auxiliary channels may be required, as described in WO2022 / 214290A1 cited above.

[0021] In practice, therefore, when joining components, especially mirror parts, flat surfaces are usually joined together, i.e., a flat joining surface is created. To nevertheless achieve curved cooling channels, the cross-section of the cooling channels can be divided between the two components when using a flat joining surface, as described in WO 2022 / 179735 A1. However, this involves considerable manufacturing effort in forming the cooling channels, partly because the depth of the groove-shaped depressions, which are usually created by grinding, varies depending on the location.

[0022] In the proposed method, the two components are joined in the flat surface areas—and, if applicable, in the curved surface areas (su)—which simplifies the joining process. The hollow structure, which may be intended for temperature control of the composite component, is formed, among other places, in the curved surface areas, simplifying its production using conventional mechanical manufacturing methods. The outer, flat surface area of ​​each surface typically completely surrounds the curved inner surface area; that is, the outer surface area is continuous.

[0023] 2024PF00875WO 01.12.25 SZ00404PCT In the event that a mirror surface is formed on one side of the first component facing away from the joining surface – usually after the two components have been joined – the first component typically has a significantly smaller thickness than the second component. This is advantageous because, in this case, the curved surface areas and thus the hollow structure can be formed – at least partially – near the mirror surface to be tempered.

[0024] Joining a first component, which is significantly thinner in the axial direction than the second component, in a joining process or during blasting is generally advantageous because the thinner first component can adapt to the fit or surface shape of the stiffer second component during joining. Particularly when a mirror surface is to be formed on the first component, the first component preferably has a minimum thickness of 5 mm or less, more preferably 4 mm or less, and more preferably 3 mm or less.

[0025] In one variant, the curved surface area of ​​one of the two surfaces is at least partially, and in particular completely, recessed relative to the flat surface area, while in the other of the two surfaces, the curved surface area projects at least partially, and in particular completely, beyond the flat surface area. Between the respective outer, flat surface area and the respective inner, curved surface area of ​​the first and second surfaces, a continuous edge or wall area can extend, extending essentially perpendicular to the flat surface area. In this case, the geometry of the projecting volume area of ​​the respective component, at whose end face the curved surface area is formed, typically corresponds essentially to the negative of the geometry of the cavity at the bottom of which the curved surface area is located.

[0026] 2024PF00875WO 01.12.25 SZ00404PCTO surface area of ​​the first component. The aforementioned volume area preferably has at least two generally parallel oriented edges, at which the fluid is supplied to the two curved surface areas via a fluid distributor or discharged via a fluid collector.

[0027] In one variant, the first and second components are joined at their curved surface areas, forming the joining surface. In this case, the curved surface areas of the two components lie against each other and are permanently joined – with or without the use of an adhesive. The joining surface in this case extends not only along the flat surface areas but also along the curved surface areas.

[0028] In this variant, the two components are processed so that they can be joined not only on the flat surfaces but also on the curved surfaces. Polishing is generally required to enable joining. In the variant described here, both the flat and curved surfaces are typically polished. The surrounding edges or walls between the flat and curved surfaces can also be polished if necessary.

[0029] In a further development of this variant, when the first component is supplied to the curved surface area of ​​the first surface and / or when the second component is supplied to the curved surface area of ​​the second surface, recesses are formed that, when the first component is connected to the second component, create cooling channels within the hollow structure through which a fluid flows. The recesses, e.g., in the form of grooves or the like, can be located in the curved surface area of ​​the first surface.

[0030] 2024PF00875WO 01.12.25 SZ00404PCTO surface area of ​​the first component and into the curved surface area of ​​the second component. In this case, the position of the recesses is typically chosen so that they together form the cross-section of the respective cooling channel.

[0031] Preferably, the recesses are formed only in the curved surface area of ​​one of the two components, as this simplifies the production of the cooling channels. If the curved surface area follows the curvature of the (later) mirror surface, the curved cooling channels with a constant channel height can be formed in one of the two components without the need to create an additional recess in the other component for this purpose.

[0032] The typically groove-shaped recesses can be created in the respective component(s) by mechanical processing, e.g., by grinding, typically after the curved surface area(s) has a fit or surface form of sufficient quality. If the first component has a mirror surface, the cooling channels are preferably formed in the curved surface area of ​​the second component. The recesses can extend over the entire length or width of a respective curved surface area, but it is also possible that the recesses do not extend to the edge of the curved surface area. In this case, the surface of the other component typically also has recesses that connect to the recesses, so that a continuous cooling channel is formed when the components are joined.

[0033] In another variant, when providing the component in which the curved surface area is at least partially recessed compared to the flat surface area, at least one

[0034] 2024PF00875WO 01.12.25 SZ00404PCT, in particular a groove-shaped recess is formed, adjacent to the curved surface area. If the two components are joined at the curved surface areas, it is advantageous, depending on the joining method used, if the curved surface areas can be completely polished, e.g., to allow the two curved surface areas to be peened (so).

[0035] If the curved surface area is recessed relative to the flat surface area, a problem arises: polishing the curved surface area with a polishing tool, such as a rotating polishing pad, is not possible all the way to its lateral edge. This is because the lateral distance to the wall of a surrounding edge area adjoining the curved surface area is insufficient to allow the polishing tool to move freely. To nevertheless achieve complete polishing of the curved surface area, a groove-shaped recess, for example in the form of a graduated step, is formed between the lateral edge and the wall – typically on both opposite sides of the curved surface area. This recess cannot be polished and remains in the composite component after the two components are joined.

[0036] The shape of the groove-shaped recess should be chosen so that pronounced turbulence does not occur when a fluid flows through it. Ideally, the groove-shaped recess has no sharp edges. The temperature control channels are typically connected to each other via the groove-shaped recess, which homogenizes the fluid flow from a fluid distributor or into a fluid collector. Ideally, the groove-shaped recess runs laterally outside of any optically visible section of the—typically—

[0037] 2024PF00875WO 01.12.25 SZ00404PCT curved - mirror surface or outside the lateral edge of the mirror surface. To create the groove-shaped recess, the bottom of the recess in the respective component is widened.

[0038] In particular, if the two curved surface areas do not need to be polished, the provision of the groove-shaped recess can be omitted.

[0039] In an alternative variant, the first and second components are spaced apart at their curved surface areas after joining, and the hollow structure runs through a gap between the two curved surface areas. In this case, the two curved surface areas have a non-zero distance, meaning they are not joined during the joining process and do not need to be polished to fuse together. However, polishing the curved surface areas may still be advisable. The curved surface areas can also be coated if desired.

[0040] In the variant described here, the space between the two curved surface areas is typically flushed with a fluid, for example, to temper, and in particular cool, a mirror surface of the composite component. By providing a space whose lateral extent essentially corresponds to the lateral extent of the mirror surface, complete decoupling of the mirror surface from mechanical stresses introduced into the component material from the back of the optical element can be achieved.

[0041] In one variant, when the first component is supplied to the curved surface area of ​​the first surface and / or when the second component is supplied to the curved surface area

[0042] 2024PF00875WO 01.12.25 SZ00404PCT Flow-guiding structures are formed on the second surface. In this case, it may also be advantageous to polish the curved surface areas to improve fluid flow. If the curved surface areas have a surface shape of sufficient quality, flow-guiding structures can be introduced into the respective curved surface area by mechanical processing, e.g., by grinding, in order to improve or support the fluid flow and thus the temperature control effect of the hollow structure through which the fluid flows.

[0043] The flow-guiding structures can be, for example, grooves or channels oriented transversely or diagonally to the fluid flow direction, creating turbulence that enhances the local temperature control effect. This can occur at points on the mirror surface above the gap that are subject to higher thermal stress than other points. Typically, the more thermally stressed points on the mirror surface are located near its center, so such flow-guiding structures are preferentially formed in or near the center of the gap. This is particularly relevant if the gap is shallow, i.e., if the distance between the two curved surfaces is relatively small, and, for example,If the gap is on the order of 0.5 to 5 mm, passive valves, such as Tesla valves, can also be used as flow guide structures to direct the fluid flow through the gap.

[0044] In another variant, at least one section of the hollow structure is formed when the first component and / or the second component is supplied, which preferably serves as a fluid distributor for supplying the fluid to the temperature control channels or the intermediate space, or as a fluid collector for draining the fluid from the temperature control channels or the intermediate space.

[0045] 2024PF00875WO 01.12.25 SZ00404PCTZ is configured as a space. The fluid distributor and the fluid collector can be configured in different ways, for example, as described in WO 2022 / 179735 A1 cited above, which is incorporated in its entirety by reference into this application. For example, the fluid distributor and / or the fluid collector can have connecting channels that connect one or more of the temperature control channels or the space to a fluid inlet or a fluid outlet. The connecting channels can, for example, be configured as bores that extend perpendicular or substantially perpendicular to the planar surface areas and that can run in one component or in both components. It is possible that the fluid distributor and the fluid collector have a separate connecting channel for each temperature control channel, but it is also possible that one connecting channel connects, for example,two or more temperature control channels with the fluid inlet or fluid outlet.

[0046] It is also possible for the fluid distributor and / or the fluid collector to have a chamber that widens towards the joining surface or the gap / temperature control channels and extends across the full width of the curved surface areas at the gap or temperature control channels, as also described in WO 2022 / 179735 A1. The width of the chamber in a direction perpendicular to the flat surface areas can increase linearly, quadratically, sigmoidally, etc. The respective chamber can be directly connected to a fluid inlet or outlet, or it is possible for the respective chamber to be connected to an inlet or outlet channel, which in turn is connected to the fluid inlet or outlet and which may, for example, be in the form of a bore. The distributor channels can also originate from a common inlet channel or...into a common outlet channel. It goes without saying that for the design of the...

[0047] 2024PF00875WO 01.12.25 SZ00404PCT Fluid distributor and fluid collector, combinations of the examples described here or other configurations are also possible.

[0048] When the first and / or second component is provided, it is typically prepared for subsequent joining. This preparation may include machining the first and / or second component. For this purpose, conventional mechanical machining processes such as grinding, lapping, polishing, etc., may be performed. It is also possible that one of the two components is machined to form a reflective surface before joining, for example, by pre-contouring or polishing, etc. After or, if applicable, before joining the first and second components, a coating for reflecting radiation, particularly EUV radiation, is typically applied to one of the two components to form the reflective surface.

[0049] When providing the components, they can be manufactured or produced in pairs. Particularly if the material of both components is essentially transparent to radiation, a suitable immersion fluid can be introduced between them, allowing for a joint measurement of both components, for example, on a test rig. This provides a sound basis for assessing the machining quality and surface form, specifically the quality of the surface form on curved and / or flat surfaces. During parallel machining, the surface form of both components can be continuously measured relative to each other, and the surface form can subsequently be corrected if necessary. It goes without saying that more than two components can also be joined together to form a composite component in the manner described above.

[0050] 2024PF00875WO 01.12.25 SZ00404PCT In another variant, the components are joined together during the formation of the joining surface without the use of an adhesive, preferably by high-temperature bonding or laser welding, or the components are joined together during the formation of the joining surface using an adhesive, preferably selected from the group comprising: adhesives, thermal paste, glass frit, glass solder. Particularly in the case of a composite component in the form of an optical element, specifically a mirror for EUV lithography, it has proven advantageous to join the two components together without the use of an adhesive.

[0051] A suitable method for this purpose is high-temperature bonding: In high-temperature bonding, also known as direct bonding, two or more components, which usually consist essentially of one or different glass materials, are typically heated to a temperature above the glass transition temperature of the glass material. The glass transition temperature is material-dependent and is typically around...

[0052] 1000°C or above. When the glass transition temperature is exceeded, the glass enters a viscous state. This allows the respective surfaces of the components to melt, forming covalent bonds that cause the two components to permanently bond together at the joining surface without the use of an adhesive.

[0053] In silicate bonding, the surface areas involved are first joined using an alkaline liquid. A subsequent heat treatment drives off the moisture. Laser welding using pulsed laser radiation, especially with pulse durations on the order of femtoseconds or picoseconds, allows glass materials to be joined without the use of an adhesive.

[0054] 2024PF00875WO 01.12.25 SZ00404PCT that other methods which do not require an adhesive can also be used to create the connection between the two components.

[0055] Alternatively, the two components can be joined using an adhesive, such as a thermally conductive or glass or glass solder paste, or a glass frit, for example in the form of a film or a preform, or a glass solder. In particular, one of the methods described in W02008 / 017449A2 or one of the methods described in DE 102023205562 A1, both of which are incorporated by reference into this application, can be used for joining the two components.

[0056] In general, in addition to rigid joining methods such as high-temperature bonding, laser welding, stack sealing, glass frit bonding, etc., ductile bonds can also be used to join the two components. A wide variety of materials are suitable as ductile joining materials, provided they meet the following requirements—especially in the case of a composite component in the form of an optical element: The bonding material must be resistant to the operating conditions, e.g., resistant to a fluid flowing through the hollow structure, such as water, and to any heat introduced. The material must prevent the fluid, e.g., water, from reaching the joining surface or the interface between the two components, and the heat transfer between the two components must be sufficient to ensure the optical performance of the optical element.Besides an adhesive, a thermal paste can be used as a ductile material. The latter typically requires a sealing layer at the edges of the joining surface, preventing contact with the fluid. Such a sealing layer is typically present in almost all thermally conductive materials.

[0057] 2024PF00875WO 01.12.25 SZ00404PCT The joining agents used are required to avoid or minimize so-called hydrogen induced outgassing (HIO).

[0058] Another aspect of the invention relates to a composite component manufactured according to the method described above or one of its variants. The composite component can, in particular, be a mirror component in which the hollow structure serves for temperature control by means of a temperature control fluid. However, it is also possible for the composite component to fulfill a non-optical function.

[0059] For example, the composite component may be a holding device for holding an object, such as a wafer, as described, for example, in the W02008 / 017449A2 cited at the beginning, or a supporting component, etc.

[0060] A further aspect of the invention relates to a composite component of the type mentioned at the outset, wherein the first component has a first surface with a curved inner surface region and a flat outer surface region, wherein the second component has a second surface with a curved inner surface region and a flat outer surface region, and wherein the first surface and the second surface are connected to each other at least along the flat surface regions along the joining surface, the composite component having a hollow structure that extends at least partially along the curved surface regions. The hollow structure is preferably permeable to a fluid.

[0061] The permanent bond between the two components on the two flat surface areas can be achieved using one of the joining methods described above, i.e., with or without an adhesive. This also applies if no adhesive is used.

[0062] When 2024PF00875WO 01.12.25 SZ00404PCT is used, the joining surface on the composite component is detectable. As described above, the composite component can be an optical component, for example a mirror component, or a non-optical component.

[0063] In one embodiment, the curved surface area of ​​one of the two surfaces is at least partially recessed relative to the flat surface area, while on the other surface, the curved surface area protrudes at least partially beyond the flat surface area. If the composite component is a mirror, the curved surface area of ​​the first component, where the mirror surface is formed, is typically recessed relative to the flat surface area; that is, the first component forms a "lid" that is placed on top of the second component, the "pot." The protruding curved surface area, or...The protruding partial volume of the second component, on which the curved surface area is formed, projects into the recessed partial volume of the first component, the bottom of which is formed by the curved surface area of ​​the first surface of the first component.

[0064] In one embodiment, the first component and the second component are connected to each other at the curved surface areas along the joining surface, wherein recesses are formed in the curved surface area of ​​the first surface and / or in the curved surface area of ​​the second surface, forming cooling channels of the hollow structure through which a fluid can flow, wherein preferably the cooling channels run at an approximately or substantially constant distance from the curved mirror surface. In this case, the two components are, in addition to the flat surface areas,

[0065] 2024PF00875WO 01.12.25 SZ00404PCT The curved surface areas are connected to each other, and the recesses in the component(s) form a plurality of cooling channels. It is generally advantageous for the cooling channels to be aligned parallel and essentially the same length. However, deviations from this arrangement are also possible. The recesses, and thus the cooling channels, typically have a uniform depth along their entire length and follow the curvature of the joined curved surface areas, which typically follow the curvature of the mirror surface.

[0066] On the component where the curved surface area is at least partially recessed compared to the flat surface area, the preferably groove-shaped recess described above can be formed, which borders the curved surface area.

[0067] In an alternative embodiment, the first and second components are spaced apart from each other at their curved surface areas, and the hollow structure extends through a gap between the two curved surface areas, preferably with the gap running at an approximately or substantially constant distance to the curved mirror surface. As described above, this allows for surface-level temperature control of the composite component.

[0068] In the embodiment described here, flow-guiding structures can be formed on the curved surface region of the first surface and / or on the curved surface region of the second surface. The flow-guiding structures can be designed, in particular, in the manner described above in connection with the method.

[0069] 2024PF00875WO 01.12.25 SZ00404PCT The composite structure described here, if the hollow structure is permeable to a fluid, typically includes a fluid distributor for supplying the fluid to the temperature control channels or to the intermediate space and / or a fluid collector for discharging the fluid from the temperature control channels or from the intermediate space. The fluid distributor and / or the fluid collector can be configured in particular as described above in connection with the method.

[0070] In a further embodiment, the first component and the second component are made of the same material, preferably the same glass material, or the first component is made of a first material and the second component is made of a second material, wherein preferably the coefficient of thermal expansion of the first material is lower than the coefficient of thermal expansion of the second material. Alternatively or additionally, the material of the first component and / or the material of the second component is / are selected from the group comprising: glass, preferably fused silica, in particular titanium-doped fused silica, glass ceramics, ceramics, in particular SiSiC or cordierite, semiconductors, in particular silicon, metals, in particular aluminum or copper.

[0071] The first and second components of the composite can be made of the same material, preferably the same glass material, or of two or more different materials, in particular two or more different glass materials. The term "same glass material" means that the glass material of both components has practically the same properties, for example, because the two components were cut from the same glass blank.

[0072] Different glass materials are present, for example, when the glass material of the two components has practically different properties, or when the two components consist of different types of glass.

[0073] 2024PF00875WO 01.12.25 SZ00404PCTI Especially in the case of a mirror component whose mirror surface heats up considerably due to the incident radiation, e.g., during irradiation with EUV radiation, it is advantageous if the coefficients of thermal expansion of the two materials differ as little as possible, since otherwise asymmetric deformation and thus an undesirable change in the surface shape can occur. It can therefore be beneficial if the two components are made of the same material.

[0074] In the case of a composite component in the form of an EUV mirror, the first material is typically a zero-expansion material, such as titanium-doped quartz glass or a glass-ceramic with a very low coefficient of thermal expansion. The second material can be the same as the first. Even if the first and second materials were cut from the same glass blank, they can still differ in their physical properties or quality. For example, the second material might be cut from a region of the glass blank that exhibits a larger spatial gradient of the coefficient of thermal expansion and / or a larger spatial gradient of the zero-crossing temperature than the first material.Furthermore, a spatially averaged deviation from a target zero-crossing temperature can be greater for the second material than for the first. The materials of the two components can also be different types of glass, such as undoped quartz glass.

[0075] It is also possible that the materials of one or both components are not glass. The material of the first and / or second component could, for example, be a ceramic, such as SiSiC or cordierite, or a semiconductor, such as...

[0076] 2024PF00875WO 01.12.25 SZ00404PCT Silicon, or a metal, for example aluminum or copper. Copper has very good thermal properties, especially very high thermal conductivity. It is possible that the material of the first component is a glass material and the material of the second component is one of the materials mentioned above. Combining two components made of different materials that are not glass materials into a composite component is also possible, provided that a suitable joining process exists for the two components or the corresponding materials.

[0077] Another aspect of the invention relates to a semiconductor technology system, in particular an EUV lithography system, which has at least one composite component designed as described above. For the purposes of this application, a semiconductor technology system is understood to be an optical system that can be used in the field of semiconductor technology. In addition to a projection exposure system, orIn a lithography system used for the production of semiconductor devices, the semiconductor technology system can, for example, be an inspection system for inspecting a photomask used in such a projection exposure system (hereinafter also referred to as a reticle), for inspecting a semiconductor substrate to be structured (hereinafter also referred to as a wafer), or a metrology system used for measuring a projection exposure system or parts thereof, for example, for measuring projection optics. As described above, the component can be an optical component, such as a mirror component. However, it is also possible that it is a non-optical component, such as a support structure for a wafer, a mask, or the like.

[0078] 2024PF00875WO 01.12.25 SZ00404PCT Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures of the drawing, which show details essential to the invention, and from the claims. The individual features can be implemented individually or in any combination in a variant of the invention.

[0079] drawing

[0080] Examples of implementation are shown in the schematic drawing and are explained in the following description. It shows

[0081] Fig. 1 schematically shows a projection exposure system for EUV projection lithography in meridional section.

[0082] Fig. 2a, b schematic sectional views of two components before and after joining them to form a mirror component by joining them on flat and curved surface areas,

[0083] Fig. 2c is a schematic representation of a top view of the second component of Fig. 2a, which has recesses for forming temperature control channels,

[0084] Fig. 2d shows a schematic cross-sectional view of the mirror component in a plane in which a plurality of connecting channels run,

[0085] Fig. 3a, b schematic sectional views analogous to Fig. 2a, b, in which the two components are joined only at the flat surface areas and are spaced apart from each other at the curved surface areas, 2024PF00875WO 01.12.25 SZ00404PCT. Fig. 3c a schematic representation analogous to Fig. 2c, in which flow-guiding structures are formed on the curved surface area of ​​the second component, as well as

[0086] Fig. 3d is a schematic representation analogous to Fig. 2d in a plane in which a chamber of a fluid distributor runs.

[0087] In the following description of the drawings, identical reference symbols are used for identical or functionally equivalent components.

[0088] The following section describes, with reference to Fig. 1, the essential components of an optical arrangement for EUV lithography in the form of a projection exposure system 1 for microlithography. The description of the basic structure of the projection exposure system 1 and its components is not intended to be restrictive.

[0089] One embodiment of a lighting system 2 of the projection exposure system 1 has, in addition to a light or radiation source 3, a lighting optic 4 for illuminating an object field 5 in an object plane 6. In an alternative embodiment, the light source 3 can also be provided as a separate module from the rest of the lighting system. In this case, the lighting system does not include the light source 3.

[0090] A reticule 7 located in the object field 5 is illuminated. The reticule 7 is held by a reticule holder 8. The reticule holder 8 can be moved, particularly in one scanning direction, via a reticule displacement drive 9.

[0091] Figure 1 shows a Cartesian xyz coordinate system for illustrative purposes. The x-direction runs perpendicular to the plane of the drawing.

[0092] 2024PF00875WO 01.12.25 SZ00404PCT The y-direction runs horizontally and the z-direction runs vertically. The scan direction runs along the y-direction in Fig. 1. The z-direction runs perpendicular to the object plane 6.

[0093] The projection exposure system 1 comprises a projection system 10. The projection system 10 serves to image the object field 5 onto an image field 11 in an image plane 12. A structure on the reticulum 7 is imaged onto a light-sensitive layer of a wafer 13 located in the image plane 12 within the area of ​​the image field 11. The wafer 13 is held by a wafer holder 14. The wafer holder 14 can be displaced, particularly along the y-direction, via a wafer transfer drive 15. The displacement of the reticulum 7 via the reticulum transfer drive 9 and of the wafer 13 via the wafer transfer drive 15 can be synchronized with each other.

[0094] Radiation source 3 is an EUV radiation source. Specifically, radiation source 3 emits EUV radiation 16, which is also referred to below as useful radiation, illumination radiation, or illumination light. The useful radiation has a wavelength in the range between 5 nm and 30 nm. Radiation source 3 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 3 can be a free-electron laser (FEL).

[0095] The illumination radiation 16 emanating from the radiation source 3 is focused by a collector mirror 17. The collector mirror 17 can be a collector mirror with one or more ellipsoidal and / or hyperboloid reflective surfaces. The at least one

[0096] 2024PF00875WO 01.12.25 SZ00404PCT The reflective surface of the collector mirror 17 can be illuminated with the illuminating radiation 16 at grazing incidence (Gl), 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 mirror 17 can be structured and / or coated to optimize its reflectivity for the useful radiation and to suppress stray light.

[0097] After the collector mirror 17, the illumination radiation 16 propagates through an intermediate focus in an intermediate focal plane 18. The intermediate focal plane 18 can represent a separation between a radiation source module, comprising the radiation source 3 and the collector mirror 17, and the illumination optics 4.

[0098] The illumination optics 4 comprise a deflecting mirror 19 and, downstream of this in the beam path, a first faceted mirror 20. The deflecting mirror 19 can be a planar deflecting mirror or, alternatively, a mirror with an effect that influences the beam beyond the mere deflection effect. Alternatively or additionally, the deflecting mirror 19 can be designed as a spectral filter that separates a useful wavelength of the illumination radiation 16 from stray light of a different wavelength. The first faceted mirror 20 comprises a plurality of individual first facets 21, which are also referred to as field facets in the following. Only a few of these facets 21 are shown in Fig. 1 as examples. Downstream of the first faceted mirror 20 in the beam path of the illumination optics 4 is a second faceted mirror 22. The second faceted mirror 22 comprises a plurality of second facets 23.

[0099] The illumination optics 4 thus form a doubly faceted system. This basic principle is also known as a honeycomb condenser (Fly's Eye Integrator).

[0100] Designated 2024PF00875WO 01.12.25 SZ00404PCT. The individual first facets 21 are imaged into the object field 5 with the aid of the second faceted mirror 22. The second faceted mirror 22 is the last beam-shaping, or indeed the last, mirror for the illumination radiation 16 in the beam path before the object field 5.

[0101] The projection system 10 comprises a plurality of mirrors Mi, which are numbered according to their arrangement in the beam path of the projection exposure system 1.

[0102] In the example shown in Fig. 1, the projection system 10 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 16. The projection system 10 is a double-obscured optical system. The projection optics 10 have an image-side numerical aperture greater than 0.4 or 0.5, and which can also be greater than 0.6, for example, 0.7 or 0.75.

[0103] The mirrors Mi, just like the mirrors of the lighting optics 4, can have a highly reflective coating for the lighting radiation 16.

[0104] Figures 2a and 2b show a process flow for the production of a composite component 25, which in the example shown is a mirror component. The mirror component 25 can, for example, form one of the mirrors Mi of the projection optics 10 of the EUV lithography system 1. The mirror component 25 consists of two components 26 and 27, which in the example shown are made of titanium-doped quartz glass, which has a low coefficient of thermal expansion. The two components 26 and 27 provided for the process are cut from the same glass blank and therefore consist of the same material.

[0105] 2024PF00875WO 01.12.25 SZ00404PCT Glass material. Alternatively, two components 26, 27 made of two different glass materials can be used.

[0106] Before joining the two components 26, 27 to form the mirror component 25, the two components 26, 27 are prepared. The first component 26 is pre-contoured, i.e., it is essentially provided in a cuboid or thin cylindrical shape. The size of the first component 26, in particular its length and width or diameter, can be adapted to the size of a mirror surface 28 that will be formed later on a top surface of the first component 26.

[0107] A first surface 29 of the first component 26, where it is to be joined to a second surface 30 of the second component 27, is also prepared for the subsequent joining process. As can be seen in Fig. 2a, the first surface 29 has a convexly curved inner surface region 29a and a flat outer surface region 29b. The second component 27 has a second surface 30 with a concavely curved inner surface region 30a and a flat outer surface region 30b. The curvatures, more precisely the radii of curvature, of the two convexly and concavely curved surface regions 29a and 30a correspond to each other.

[0108] The curved surface area 29a of the first surface 29 is recessed relative to the flat surface area 29b. A circumferential wall 33 extending vertically in the Z direction of an XYZ coordinate system is formed between the two surface areas 29a and 29b. The curved inner surface area 29a forms the base of a recess in the first component 26, which is bounded at its edges by the circumferential wall 33.

[0109] 2024PF00875WO 01.12.25 SZ00404PCT The curved surface area 30a of the second surface 30 projects beyond the flat surface area 30b of the second surface 30. The curved surface area 30a forms the end face of a projecting volume area of ​​the second component 27, whose circumferential wall 34 extends in the Z-direction perpendicular to the flat surface area 30b.

[0110] When preparing the two components 26, 27 for joining, the surfaces 29, 30 are cleaned and the curved surface areas 29a, 30a as well as the flat surface areas 29b, 30b are polished to a surface quality that allows for cracking.

[0111] The two components 26, 27 are then blasted together. This blasting serves as preparation for joining the two components 26, 27, which in the example shown is done by high-temperature bonding. During high-temperature bonding, the two components 26, 27 are heated to a maximum temperature above the glass transition temperature, whereby the two surfaces 29, 30 bond permanently to form the mirror component 25, forming a bonding surface 31, both at the curved surface areas 29a, 30a and at the flat surface areas 29b, 30b.

[0112] As can be seen in Figures 2a, b and 2c, which show a top view of the second component 27, groove-shaped depressions 35 are formed in the curved surface region 30a of the second surface 30 of the second component 27. The groove-shaped depressions 35 have a constant depth, i.e., the bottom of the groove-shaped depressions 35 follows the curvature of the curved surface region 30b of the second surface 30. When the two components 26, 27 are joined, the depressions 35 are covered by the curved surface region 29a of the first component 26, creating a closed cross-section. This means that the groove-shaped depressions 35 form cooling channels 36 in the mirror component 25, which are designed for the flow of a fluid 39 (see Figure 2d).

[0113] 2024PF00875WO 01.12.25 SZ00404PCT As can be seen in Fig. 2c, the recesses 35 and thus the cooling channels 36 do not extend over the entire width of the curved surface area 30a in the X direction. The cooling channels 36 form a section of a hollow structure 32 (see Fig. 2b) which is designed to allow the flow of a fluid 39, in particular water, to cool the mirror component 25.

[0114] The temperature control channels 36 are connected to a fluid distributor 37 and a fluid collector 38, both formed in the second component 27, via a groove-shaped recess 36a, b formed in the first component 26, allowing fluid 39 to flow through them. The recess 36a, b adjoins the curved surface area 29a and serves as a polishing overflow, i.e., it separates the curved surface area 29a of the first surface 29 from the surrounding wall 33 of the recess formed in the first component 26. The recess 36a, b, or the lateral separation from the wall 33, enables the curved surface area 29a to be polished over its entire surface using a polishing tool in the form of a rotating polishing pad.

[0115] The return 36a on the right side of the first component 26 in Fig. 2a, b connects each temperature control channel 36 to the fluid distributor 37 formed in the second component 27. The return 36a extends in the Y direction across the entire width of the temperature control channels 36 in Fig. 2a, b, so that the temperature control channels 36 are in fluid communication with each other via the return 36a. This enables homogenization of the fluid flow of the fluid 39 flowing out of the fluid distributor 37, more precisely from connecting channels 37b of the fluid distributor 37. The connecting channels 37b extend in the vertical direction Z and originate from a straight inlet channel 37a of the fluid distributor 37, which extends in the Y direction. Both the inlet channel

[0116] 2024PF00875WO 01.12.25 SZ00404PCT37a, through which the fluid 39 flows into the hollow structure 32, as well as the connecting channels 37b, are designed as bores in the example shown. As can be seen in Fig. 2c and in Fig. 2d, the connecting channels 37b run adjacent to the circumferential wall 34 of the projecting volume region of the second component 27 and extend into the first component 26, i.e., a section of the connecting channels 37b also runs along the first component 26.

[0117] The fluid collector 38 is constructed like the fluid distributor 37 and has an outlet channel 38a for the outlet of the fluid 39 at an outlet opening and connecting channels 38b that extend from the outlet channel 38a in the vertical direction Z and carry the fluid away from the temperature control channels 36. In the example shown, each of the temperature control channels 36 is assigned a connecting channel 37b, 38b of the fluid distributor 37 and the fluid collector 38, but this is not mandatory: Each connecting channel 37b, 38b can also serve to supply or discharge the fluid 39 to / from several temperature control channels 36.

[0118] In the mirror component 25 shown in Fig. 2b, d, the curved cooling channels 36 run at an approximately or substantially constant distance A from the also curved mirror surface 28, onto which a reflective coating 28a is applied. In the example shown, the distance A is approximately 3 cm, but can also be larger or smaller.

[0119] Figures 3a-d show a mirror component 25 which differs from the mirror component 25 described in connection with Figures 2a-d essentially in that the connection of the two components 26, 27 takes place only at the planar surface areas 29b, 30b and not at the curved surface areas 29a, 30a. The two curved surface areas 29a, 30a of the two surfaces 29, 30 are separated from each other in the mirror component 25 described in Figures 3a-d.

[0120] 2024PF00875WO 01.12.25 SZ00404PCT The mirror surfaces 28 are spaced apart and separated from each other by a gap 40, which has a constant height H between approximately 0.5 and 5 mm, e.g., approximately 2 mm. The gap 40 forms part of the hollow structure 32 and is permeable to fluid 39 to enable full-surface temperature control of the mirror surface 28. A distance A between the gap 40 and the curved mirror surface 28 is approximately constant and is approximately 3 cm.

[0121] As can be seen in Fig. 3c, several flow-guiding structures 41 in the form of passive valves, more precisely Tesla valves, are formed in the curved surface region 30a of the lower component 27. The flow-guiding structures 41 are designed to support the flow of the fluid 39 from the fluid distributor 37 to the fluid collector 38 and to suppress the flow of the fluid 39 in the opposite direction. Flow-guiding structures with other flow-guiding effects, such as the formation of vortices, may also be provided.

[0122] In the example shown in Figs. 3a-d, the fluid distributor 37 has an inlet channel 37a and a chamber 37b, which extends from the inlet channel 37a, widens in the vertical direction Z, and extends across the entire width of the gap 40 at the level of the gap (see Fig. 3c). In the example shown, the width of the chamber 37b increases linearly in the Z direction, but it is also possible for the width of the chamber 37b to have a, for example, square or sigmoidal (i.e., S-shaped) profile depending on its position in the Z direction.

[0123] The entire hollow structure 32 of the mirror component 35 is produced by mechanical processing, including drilling and grinding. Therefore, no machining steps are required for the production of the hollow structure 32.

[0124] 2024PF00875WO 01.12.25 SZ00404PCT required, where the material of the two components 26, 27 must be transparent to the radiation used in the processing.

[0125] Instead of the mirror component 25, other composite components can also be formed in the manner described above, which can be used in the EUV lithography system 1 or in another semiconductor technology system. Such a composite component does not necessarily have to be an optical component. Rather, it can also be a non-optical component, for example, a holding component for a wafer or for a mask, or another mechanical component.

[0126] The connection between the two components 26, 27 can also be made by means other than high-temperature bonding, for example by silicate bonding or laser welding, i.e., without the use of an adhesive. However, it is also possible to join the two components 26, 27 using an adhesive. The adhesive can be selected, for example, from the group comprising: adhesives, thermal paste, glass frit, or glass solder. When using an adhesive, it is advantageous to apply a sealing varnish in the areas where the adhesive can come into contact with the fluid 39, which prevents the outgassing of contaminants from the adhesive into the environment.

[0127] 2024PF00875WO 01.12.25 SZ00404PCT

Claims

Patent claims 1. Method for manufacturing a composite component (25), preferably for a semiconductor technology system, in particular for an EUV lithography system (1), comprising: Providing a first component (26), Providing a second component (27), Producing the composite component (25) by joining the first component (26) with the second component (27) forming a joining surface (31), wherein the first component (26) has a first surface (29) with a curved inner surface region (29a) and a flat outer surface region (29b), and wherein the second component (27) has a second surface (30) with a curved inner surface region (30a) and a flat outer surface region (30b), wherein when joining the first component (26) and the second component (27) are joined together at least in the flat surface regions (29b, 30b) to form the joining surface (31), wherein when joining the two components (26, 27) a hollow structure (32) is formed which extends at least partially along the curved surface regions (29a, 30a), and wherein when joining the first component (26) and the second component (27) are also joined together at the curved surface regions (29a, 30a) to form the joining surface (31).

2. Method according to claim 1, wherein on one of the two surfaces (29) the curved surface area (29a) is at least partially recessed relative to the flat surface area (29b) and wherein on the other of the two surfaces (30) the curved surface area (30b) extends at least partially beyond the flat surface area (30a). 2024PF00875WO 01.12.25 SZ00404PCT3. Method according to claim 1 or 2, wherein, when providing the first component (26) in the curved surface area (29a) of the first surface (29) and / or when providing the second component (27) in the curved surface area (30a) of the second surface (30), recesses (35) are formed which, when connecting the first component (26) with the second component (27) with a fluid (39), form flowable temperature control channels (36) of the hollow structure (32).

4. Method according to one of claims 2 or 3, wherein, when providing the component (26) in which the curved surface area (29a) is at least partially recessed relative to the flat surface area (29b), a recess (36a, 36b) in particular a groove-shaped recess is formed which adjoins the curved surface area (29a).

5. Method according to one of the preceding claims, wherein, when providing the first component (26) and / or when providing the second component (27), at least one section of the hollow structure (32) is formed, which is preferably designed as a fluid distributor (37) for supplying the fluid (39) to the temperature control channels (36) or the intermediate space (40) or as a fluid collector (37) for discharging the fluid (39) from the temperature control channels (37) or the intermediate space (40).

6. A method according to one of the preceding claims, wherein the components (26, 27) are joined together during the formation of the joining surface (31) without the use of a joining agent, preferably by high-temperature bonding, by silicate bonding or by laser welding, or wherein the components (26, 27) are joined together during the formation of the joining surface (31) using a joining agent which is preferably selected from the group comprising: adhesive, thermal paste, glass frit, or glass solder. 2024PF00875WO 01.12.25 SZ00404PCT7. Composite component (25), preferably for a semiconductor technology system, in particular for an EUV lithography system (1), manufactured according to the method according to one of the preceding claims.

8. Composite component (25), preferably for a semiconductor technology system, in particular for an EUV lithography system (1), comprising: a first component (26) which preferably has a mirror surface (28) for reflecting radiation, in particular for reflecting EUV radiation (16), and a second component (27) which is connected to the first component (26) at a joining surface (31), wherein the first component (26) has a first surface (29) with a curved inner surface region (29a) and a flat outer surface region (29b), wherein the second component (27) has a second surface (30) with a curved inner surface region (30b) and a flat outer surface region (30a), wherein the first surface (29) and the second surface (30) are connected to each other at least at the flat surface regions (29b, 30b) along the joining surface (31), wherein the composite component (25) has a hollow structure (32) which extends at least partially along the curved surface regions (29a, 30a), and wherein the first component (26) and the second component (27) are also connected to each other at the curved surface regions (29a, 30a) along the joining surface (31).

9. Composite component according to claim 8, in which, on one of the two surfaces (29), the curved surface area (29a) is at least partially recessed compared to the flat surface area (20b). 2024PF00875WO 01.12.25 SZ00404PCT and where, on the other of the two surfaces (30), the curved surface area (30a) protrudes at least partially over the flat surface area (30b).

10. Composite component according to claim 8 or 9, in which recesses (35) are formed in the curved surface area (29a) of the first surface (29) and / or in the curved surface area (30a) of the second surface (30), which form cooling channels (36) of the hollow structure (32) through which a fluid (39) can flow, wherein preferably the cooling channels (32) run at an approximately constant distance (D) to the curved mirror surface (28).

11. Composite component according to any one of claims 8 to 10, wherein the first component (26) and the second component (27) are made of the same material, preferably the same glass material, or wherein the first component (26) is made of a first material and the second component (27) is made of a second material, wherein preferably a coefficient of thermal expansion of the first material is less than a coefficient of thermal expansion of the second material and / or wherein the material of the first component (26) and / or the material of the second component (27) is selected from the group comprising: glass, preferably quartz glass, in particular titanium-doped quartz glass, glass ceramic, ceramic, in particular SiSiC or cordierite, semiconductors, in particular silicon, metals, in particular aluminium or copper.

12. Semiconductor technology plant, in particular EUV lithography plant (1), comprising: at least one composite component (25) according to one of claims 8 to 11. 2024PF00875WQ 01.12.25 SZ00404PCT

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