Assembly, projection optics and system of semiconductor technology

Abstract

The invention relates to an assembly (30) of a semiconductor technology system (1, 101), comprising interconnected components (31, 32), wherein the components (31, 32) are metallurgically bonded with a composite material (33), comprising a composite base material and at least one stabilizer. The stabilizer consists of a chemical compound from the group of toluene derivatives or from the group of phenols. Furthermore, the invention relates to a projection optic and a semiconductor technology system with an assembly according to the invention.

Description

[0001] The invention relates to a component assembly, a projection optic and a system of semiconductor technology.

[0002] Semiconductor technology systems, particularly projection exposure systems for semiconductor lithography, are subject to stringent image quality requirements to ensure the production of the desired microscopic structures with minimal defects. In a lithography or microlithography process, an illumination system illuminates a photolithographic mask, also known as a reticulum. The light passing through or reflecting from the mask is projected by a projection optic onto a substrate (e.g., a wafer) coated with a photosensitive layer (photoresist) and positioned in the image plane of the projection optic. This transfers the structural elements of the mask onto the photosensitive coating of the substrate.The requirements for positioning the image on the wafer and the intensity of the light provided by the illumination system are increased with each new generation, leading to a higher load on the optical elements.

[0003] The light sources used have emission wavelengths from 100 nm to 400 nm in a range known as the DUV range. More recently, light sources with emission wavelengths in the range of a few nanometers, for example between 1 nm and 120 nm, particularly in the 13.5 nm range, have been increasingly used. This emission wavelength range is also referred to as the EUV range.

[0004] Due to the increasing demands of new generations of projection exposure systems, particularly in the field of EUV lithography, the bonding materials used to date can no longer reliably meet the requirements for their mechanical properties and / or chemical stability. This can have an immediate or over time negative impact on the image quality of the projection exposure system. Especially when using short-wavelength electromagnetic radiation of high intensity, optical components can be subjected to considerable stress, and chemically sensitive surfaces or bonding materials, such as adhesives or putties, can be damaged.

[0005] German patent application DE 10 2015 119 786 A1 describes in general terms the use of putty as an adhesive for the manufacture of imaging optics. With imaging optics, especially in common mass production processes, the difficulty can arise that material and manufacturing deviations can lead to the desired or required optical properties of the optical system not being achieved, necessitating the use of corrective elements. To correct unwanted deviations, an optical corrective element in the form of a lens or prism is used, for example, in imaging optics. To determine the correction requirement, a measurement step is performed beforehand in which the geometry of an optical element is determined. The value determined in this measurement step is compared with a predetermined target value.

[0006] The optical correction element is inserted into the imaging optics using a suitable adhesive or putty. The putty used for this purpose has the same optical properties as the correction element to ensure an optically homogeneous component. Alternatively, the optical properties of the putty can be specifically chosen to achieve a distinct optical effect through bonding within an adhesive gap. The adhesive gap can be of uniform thickness or have a different predefined geometry, for example, wedge-shaped, to achieve a specific optical effect. Putties that can be cured thermally or by UV light are described.

[0007] Furthermore, German patent application DE 102 53 874 A1 discloses an optical functional component with a usable surface and a frequency conversion layer for converting electromagnetic radiation of a first wavelength range into electromagnetic radiation of a second wavelength range. The usable surface is a surface of the functional component on which, for example, an optical grating is applied. In this case, the optical functional component is composed of a first plane-parallel plate and a second plane-parallel plate. The plane-parallel plates are conventional optical components for microlithography, which are transparent to UV light and also to visible light.

[0008] Between the two plates is a cement homogeneously mixed with a fluorescent substance. Spacers in the form of appropriately sized glass fiber pieces are added to the mixture. The two plates are joined so that their respective contact surfaces are largely parallel to each other. To eliminate air bubbles, it may be advisable to evacuate the entire assembly. A uniformly thick, fluorescent cement layer of a few micrometers forms, bonding the flat contact surfaces of the plates together. The volume created by the spacers between the contact surfaces is essentially completely filled by the cement layer to form a frequency conversion layer.

[0009] In various application areas, a particular challenge for a cement is its long-term stability, especially against radiation influences, during the operation of semiconductor technology systems.

[0010] The object of the present invention is to provide a device which eliminates the described disadvantages of the prior art.

[0011] This problem is solved with regard to devices having the features of independent claims 1, 10 and 11. The dependent claims relate to advantageous further developments and variants of the invention.

[0012] An assembly according to the invention for a semiconductor technology system comprises interconnected components, wherein the components are metallurgically bonded with a composite material comprising a composite base material and at least one stabilizer. The stabilizer consists of a chemical compound from the group of toluene derivatives or from the group of phenols or sterically hindered amines.

[0013] Particularly in semiconductor technology equipment, adhesive bonding of components is frequently exposed to high-energy radiation. Depending on the intensity and wavelength, only specially selected composite materials are suitable as adhesive systems, as otherwise premature aging of the adhesive bond can occur.

[0014] The stabilizers are added to the composite material and have the effect of neutralizing radicals that can be generated by the light sources used in the DUV or EUV range in semiconductor technology systems. Due to their good solubility or dispersibility, incorporating the stabilizers into the composite base material results in no or only a negligible change in the material properties during processing. The composite material is stabilized in the beam path of the illumination system over a long period of time.

[0015] In an advantageous embodiment, at least one component can be an optical component. The composite material is preferably used as a cement or adhesive for optical components, such as lenses, prisms, plano-optics, or optical fibers. Bonding optical components to each other or to mounting devices places particularly high demands on the adhesive, the processing method, and the cleanliness of the bonding surfaces. It is often necessary to carry out bonding processes under cleanroom conditions.

[0016] Depending on the requirements and application, a suitable adhesive solution must be provided. Various composite materials are available as optical adhesives. If fast processes and short cycle times are required, UV optical adhesives based on acrylate or epoxy resins are often a good choice. Appropriately modified systems are particularly low in outgassing, flexible, and have a coefficient of thermal expansion that can be adapted to the specific requirements.

[0017] Elastomers are also used for low-stress bonding of optical components. Optics bonded with low stress are not subjected to induced stresses.

[0018] In an advantageous embodiment, the stabilizer may consist at least of butylhydroxytoluene (BHT) and / or sebacic acid bis(2,2,6,6-tetramethyl-4-piperidyl) ester.

[0019] Such a stabilizer is highly soluble or dispersible in the composite base material and has a comparatively high boiling point of 265°C for its intended use. Furthermore, butylhydroxytoluene belongs to a class of compounds that do not contain undesirable heteroatoms, such as sulfur or phosphorus.

[0020] The selection of a suitable composite material, for example for lens bonding, therefore depends on various factors. Particularly with optical components for use in semiconductor technology systems, the type of lenses to be bonded and their materials, in conjunction with the operating environment in which they are used, play a crucial role. In particular, long-term stability in high-energy radiation environments must be ensured with regard to a reliable adhesive bond and permanently stable optical properties, such as transparency.

[0021] The stabilizer butylhydroxytoluene, also known as 2,6-di-tert-butyl-p-cresol or BHT, is characterized by the fact that at the wavelengths used in DUV systems, especially above 300 nm, the light absorption is extremely low or negligible.

[0022] For example, in a specific application in a DUV system with a wavelength of 365 nm, two lenses that are located directly in the beam path or are exposed to scattered light are joined together using a composite material according to the invention as a cement.

[0023] In a further advantageous embodiment of the invention, the composite base material can be a silicone adhesive.

[0024] The addition of stabilizers also makes it possible to intercept radicals at later times, thus effectively preventing subsequent cross-linking.

[0025] Silicone adhesives are particularly suitable for bonding optical components, such as lenses made of different materials like glass or plastic to other lenses, prisms, mirrors, and optical fibers. These elastomers are frequently used for low-stress bonding to prevent induced stresses in the joints.

[0026] In a further advantageous embodiment of the invention, the composite base material can be an acrylic adhesive.

[0027] Besides their use in semiconductor technology, these adhesives are frequently used in medical technology for bonding medical devices. They are characterized by excellent adhesive strength and are also resistant to heat, chemicals, and moisture.

[0028] Advantageously, the composite base material can be an epoxy adhesive.

[0029] This composite material, frequently and preferably used as an adhesive, is particularly suitable for bonding optical assemblies, such as lens bonding. These are two-component adhesives that are mixed before use. Epoxy adhesives generally offer reliable bond strength, durability, and temperature resistance.

[0030] In an advantageous embodiment, the composite base material can be a multi-component curing material.

[0031] The adhesive's curing time can be taken into account during processing. A longer curing time may be required for certain materials or applications. The viscosity of the composite material also plays a role during processing, depending on the application method and the size of the contact area. Ultimately, various factors must be considered during processing to achieve a strong and durable bond between components in semiconductor technology systems.

[0032] Advantageously, the mass fraction of the stabilizer can be no more than 5 wt.%.

[0033] A higher mass fraction is conceivable without negatively affecting the processing properties of the composite material, but its effectiveness as a radical scavenger over the lifetime of a system is not required in practice. A mass fraction of the stabilizer between 0.05 and 3.0 wt.% is particularly preferred.

[0034] In an advantageous embodiment, the mass fraction of the stabilizer can be at least 0.01 wt.%.

[0035] Although even lower proportions below 0.01 wt.% are effective as radical scavengers, a minimum proportion of at least 0.05 wt.% is preferred in order to provide reliable long-term connections in practice, permanently and over the entire lifetime of a system.

[0036] Another aspect of the invention includes a projection optic comprising an assembly according to the invention for mapping an object field into an image field.

[0037] Another aspect of the invention includes a semiconductor technology system comprising an assembly according to the invention.

[0038] DUV systems operate in the wavelength range between 190 nm and 370 nm, particularly at wavelengths of 193 nm, 248 nm, and 365 nm. In contrast, EUV systems operate in the wavelength range of short-wave ultraviolet radiation, for example, at wavelengths of 1 nm, 13.5 nm, and 120 nm.

[0039] Exemplary embodiments and variants of the invention are explained in more detail below with reference to the drawings. They show Fig. 1. Schematic representation in meridional section of a projection exposure system for EUV projection lithography, Fig. 2 schematically in meridional section a projection exposure system for DUV projection lithography, and Fig. 3 a schematic representation of an assembly according to the invention.

[0040] The following will first refer to the Fig. 1. The essential components of a projection exposure system 1 for microlithography are described as an example. The description of the basic structure of the projection exposure system 1 and its components is not intended to be restrictive.

[0041] One embodiment of a lighting system 2 of the projection exposure system 1 has, in addition to a radiation source 3, a lighting optic 4 for illuminating an object field 5 in an object plane 6. In an alternative embodiment, the radiation 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 radiation source 3.

[0042] 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.

[0043] In the 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 the Fig. 1 along the y-direction. The z-direction runs perpendicular to the object plane. 6.

[0044] The projection exposure system 1 comprises a projection optic 10. The projection optic 10 serves to image the object field 5 onto an image field 11 in an image plane 12. The image plane 12 is parallel to the object plane 6. Alternatively, an angle other than 0° between the object plane 6 and the image plane 12 is also possible.

[0045] A structure on the reticulum 7 is imaged onto a photosensitive layer of a wafer 13 located in the image plane 12 within the image field 11. The wafer 13 is held by a wafer holder 14. The wafer holder 14 can be moved, particularly along the y-direction, via a wafer transfer drive 15. The movement of the reticulum 7 via the reticulum transfer drive 9 and of the wafer 13 via the wafer transfer drive 15 can be synchronized.

[0046] 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).

[0047] The illumination radiation 16 emanating from the radiation source 3 is focused by a collector 17. The collector 17 can be a collector with one or more ellipsoidal and / or hyperboloid reflective surfaces. The at least one reflective surface of the collector 17 can be illuminated with the illumination radiation 16 at grazing incidence (GI), i.e., with angles of incidence greater than 45° relative to the normal direction of the mirror surface, or at normal incidence (NI), i.e., with angles of incidence less than 45°. The collector 17 can be structured and / or coated to optimize its reflectivity for the useful radiation and to suppress stray light.

[0048] After the collector 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 17, and the illumination optics 4.

[0049] The illumination optics 4 comprise a deflecting mirror 19 and, downstream 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 shape 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. If the first faceted mirror 20 is arranged in a plane of the illumination optics 4 that is optically conjugate to the object plane 6 as the field plane, it is also referred to as a field faceted mirror. The first faceted mirror 20 comprises a plurality of individual first facets 21, which are also referred to as field facets in the following. Of these facets 21, the following are in the Fig. 1 only some examples are shown.

[0050] The first facets 21 can be designed as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or semicircular border contour. The first facets 21 can be designed as planar facets or alternatively as convexly or concavely curved facets.

[0051] As is known, for example, from DE 10 2008 009 600 A1, the first facets 21 can themselves each be composed of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirror 20 can in particular be designed as a microelectromechanical system (MEMS system). For details, reference is made to DE 10 2008 009 600 A1.

[0052] Between the collector 17 and the deflecting mirror 19, the illumination radiation 16 runs horizontally, i.e. along the y-direction.

[0053] In the beam path of the illumination optics 4, a second faceted mirror 22 is arranged downstream of the first faceted mirror 20. If the second faceted mirror 22 is arranged in a pupil plane of the illumination optics 4, it is also referred to as a pupil faceted mirror. The second faceted mirror 22 can also be arranged at a distance from a pupil plane of the illumination optics 4. In this case, the combination of the first faceted mirror 20 and the second faceted mirror 22 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.

[0054] The second facet mirror 22 comprises a plurality of second facets 23. In the case of a pupil facet mirror, the second facets 23 are also referred to as pupil facets.

[0055] The second facets 23 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.

[0056] The second facets 23 can have planar or alternatively convex or concave curved reflective surfaces.

[0057] The illumination optics 4 thus form a double-faceted system. This basic principle is also known as a honeycomb condenser (Fly's Eye Integrator).

[0058] It can be advantageous not to arrange the second faceted mirror 22 exactly in a plane that is optically conjugate to a pupil plane of the projection optics 10. In particular, the pupil faceted mirror 22 can be arranged tilted relative to a pupil plane of the projection optics 10, as described, for example, in DE 10 2017 220 586 A1.

[0059] With the aid of the second faceted mirror 22, the individual first facets 21 are imaged into the object field 5. 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.

[0060] In another embodiment of the illumination optics 4, not shown, a transmission optic can be arranged in the beam path between the second facet mirror 22 and the object field 5, which contributes in particular to imaging the first facets 21 into the object field 5. 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 4. The transmission optic can in particular comprise one or two mirrors for normal incidence (NI mirrors) and / or one or two mirrors for grazing incidence (GI mirrors).

[0061] The lighting optics 4, in the version shown in the Fig. Figure 1 shows exactly three mirrors after the collector 17, namely the deflecting mirror 19, the field facet mirror 20 and the pupil facet mirror 22.

[0062] In a further embodiment of the lighting optics 4, the deflecting mirror 19 can also be omitted, so that the lighting optics 4 after the collector 17 can then have exactly two mirrors, namely the first faceted mirror 20 and the second faceted mirror 22.

[0063] The mapping of the first facets 21 by means of the second facets 23 or with the second facets 23 and a transmission optic into the object plane 6 is regularly only an approximate mapping.

[0064] The projection optics 10 comprise a plurality of mirrors Mi, which are numbered according to their arrangement in the beam path of the projection exposure system 1.

[0065] In the Fig. In the example shown, the projection optics 10 comprise 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 optics 10 are a double-obscured optic. The projection optics 10 have 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.

[0066] 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 4, can have highly reflective coatings for the illumination radiation 16. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

[0067] The projection optics 10 has a large object-image offset in the y-direction between a y-coordinate of a center of the object field 5 and a y-coordinate of the center of the image field 11. This object-image offset in the y-direction can be approximately as large as a z-distance between the object plane 6 and the image plane 12.

[0068] The projection optics 10 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 10 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.

[0069] The projection optics 10 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.

[0070] The projection optics 10 lead to a reduction of 8:1 in the y-direction, that is, in the scan direction.

[0071] 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.

[0072] The number of intermediate image planes in the x- and y-directions in the beam path between the object field 5 and the image field 11 can be the same or, depending on the design of the projection optics 10, different. Examples of projection optics with different numbers of such intermediate images in the x- and y-directions are known from US 2018 / 0074303 A1.

[0073] Each pupil facet 23 is assigned to exactly one of the field facets 21 to form an illumination channel for illuminating the object field 5. This can result, in particular, in illumination according to Köhler's principle. The far field is divided into a multitude of object fields 5 by means of the field facets 21. The field facets 21 generate a plurality of images of the intermediate focus on the pupil facets 23 assigned to each of them.

[0074] The field facets 21 are each superimposed on the reticulum 7 by an associated pupil facet 23 to illuminate the object field 5. The illumination of the object field 5 is particularly homogeneous. It preferably exhibits a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

[0075] The illumination of the entrance pupil of the projection optics 10 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 10 can be adjusted. This intensity distribution is also referred to as the illumination setting.

[0076] Another preferred pupil uniformity in the area of ​​defined illuminated sections of an illumination pupil of the illumination optics 4 can be achieved by a redistribution of the illumination channels.

[0077] Further aspects and details of the illumination of the object field 5 and, in particular, the entrance pupil of the projection optics 10 are described below.

[0078] The projection optics 10 can, in particular, have a homocentric entrance pupil. This can be accessible. It can also be inaccessible.

[0079] The entrance pupil of the projection optics 10 cannot always be illuminated exactly by the pupil facet mirror 22. When the projection optics 10 image the center of the pupil facet mirror 22 telecentrically onto the wafer 13, 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.

[0080] The projection optics 10 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 22 and the reticle 7. This optical element can accommodate the different positions of the tangential and sagittal entrance pupils.

[0081] During the Fig. In the arrangement of the components of the illumination optics 4 shown in Figure 1, the pupil facet mirror 22 is arranged in a surface conjugate to the entrance pupil of the projection optics 10. The field facet mirror 20 is arranged tilted relative to the object plane 6. The first facet mirror 20 is arranged tilted relative to an arrangement plane defined by the deflecting mirror 19.

[0082] The first faceted mirror 20 is arranged at an angle to an arrangement plane defined by the second faceted mirror 22.

[0083] Fig. Figure 2 schematically shows in meridional section another projection exposure system 101 for DUV projection lithography, in which the invention can also be applied.

[0084] The design of the projection exposure system 101 and the principle of the imaging process are comparable to that in Fig. The structure and procedure described in section 1 are identical. The components are 100 times larger than the others. Fig. 1 raised reference numeral denotes the reference numerals in Fig. So, 2 starts with 101.

[0085] Unlike one such as in Fig. Due to the longer wavelength of the DUV radiation 116 used as useful light in the range of 100 nm to 300 nm, in particular 193 nm, refractive, diffractive and / or reflective optical elements 117, such as lenses, mirrors, prisms, plane plates and the like, can be used in the DUV projection exposure system 101 for imaging or illumination. The projection exposure system 101 essentially comprises a lighting system 102, a reticule holder 108 for receiving and precisely positioning a reticule 107 provided with a structure, by which the subsequent structures on a wafer 113 are determined, a wafer holder 114 for holding, moving and precisely positioning this wafer 113 and a projection lens 110, with several optical elements 117, which are held in a lens housing 119 of the projection lens 110 via mounts 118.

[0086] The housing 119 is designed to be gas-tight, with its interior being purged with a gas under a slight overpressure.

[0087] The illumination system 102 provides DUV radiation 116 required for imaging the reticulum 107 on the wafer 113. A laser, a plasma source, or the like can be used as the source for this radiation 116. In the illumination system 102, the radiation 116 is shaped by optical elements such that, upon striking the reticulum 107, the DUV radiation 116 exhibits the desired properties with respect to diameter, polarization, wavefront shape, and the like.

[0088] The construction of the following projection optics 101 with the lens housing 119 differs in principle from that in, except for the additional use of refractive optical elements 117 such as lenses, prisms, end plates. Fig. The structure described in section 1 is therefore not described further.

[0089] Fig. Figure 3 shows a schematic representation of an assembly 30 according to the invention, consisting of optical components 31, 32 of a system for semiconductor technology, as used, for example, in the following: Fig. 1 and Fig. The components described in section 2 can be used. For example, the assemblies 30 according to the invention can be used in the projection optics 10 of the system described in the invention. Fig. The projection exposure system described in section 1 can be used for EUV projection lithography. Likewise, the assemblies 30 according to the invention can be used in the projection optics 101 of the [document / model] described in [document / model]. Fig. The projection exposure system described in section 2 can be used for DUV projection lithography.

[0090] As a preferred embodiment, a partial view of a first optical component 31 and a partial view of a second optical component 32 are shown, which are joined together by means of a composite material 33 acting as an adhesive or putty.

[0091] A gap 34 forms between the first optical component 31 and the second optical component 32 due to the thickness of the composite material 33.

[0092] During bonding, the composite material 33 in its liquid state can be squeezed out of the adhesive gap 34 to a certain extent in the edge areas before it hardens.

[0093] According to the invention, the composite material 33 consists of a composite base material and at least one stabilizer from the group of toluene derivatives or from the group of phenols. A radical-scavenging component of the stabilizer, consisting of butylhydroxytoluene, also known as 2,6-di-tert-butyl-p-cresol or BHT, is particularly preferred. Reference symbol list 1 Projection exposure system 2 Lighting system 3. Radiation source 4 Lighting optics 5 object field 6 Object level 7 reticles 8 label holders 9 Reticle displacement drive 10 Projection optics 11 Image field 12 Image plane 13 wafers 14 wafer holders 15 wafer transfer drive 16 EUV radiation 17 Collector 18 Intermediate focus plane 19 deflecting mirrors 20 faceted mirrors 21 facets 22 faceted mirrors 23 facets 30 assembly 31 First optical component 32 Second optical component 33 Composite material, adhesive, putty 34 adhesive gap 101 Projection exposure system 102 Lighting system 107 reticles 108 label holders 110 Projection optics 113 wafers 114 wafer holders 116 DUV radiation 117 Optical element 118 versions 119 lens bodies 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 2015 119 786 A1

[0005] DE 102 53 874 A1

[0007] DE 10 2008 009 600 A1 [0051, 0055] US 2006 / 0132747 A1

[0053] EP 1 614 008 B1

[0053] US 6,573,978

[0053] DE 10 2017 220 586 A1

[0058] US 2018 / 0074303 A1

[0072]

Claims

[1] Assembly (30) of a system (1, 101) of semiconductor technology, comprising components (31, 32) joined together, characterized by , - that the components (31, 32) are bonded together with a composite material (33), comprising a composite base material and at least one stabilizer, and - that the stabilizer consists of a chemical compound from the group of toluene derivatives or from the group of phenols or from the group of sterically hindered amines. [2] Assembly (30) according to claim 1, characterized by , that at least one component (31, 32) is an optical component. [3] Assembly (30) according to claim 1 or 2, characterized by that the stabilizer consists at least of butylhydroxytoluene (BHT) and / or sebacic acid bis(2,2,6,6-tetramethyl-4-piperidyl) ester. [4] Assembly (30) according to one of claims 1 to 3, characterized by that the composite base material is a silicone adhesive. [5] Assembly (30) according to one of claims 1 to 3, characterized by that the composite base material is an acrylic adhesive. [6] Assembly (30) according to one of claims 1 to 3, characterized by that the composite base material is an epoxy adhesive. [7] Assembly (30) according to any one of claims 1 to 6, characterized by that the composite base material is a multi-component curing material. [8] Assembly (30) according to any one of claims 1 to 7, characterized by that the mass fraction of the stabilizer is at most 5 wt.%. [9] Assembly (30) according to any one of claims 1 to 8, characterized by that the mass fraction of the stabilizer is at least 0.01 wt.%. [10] Projection optics (10) comprising an assembly (30) according to any one of claims 1 to 9 for imaging an object field into an image field. [11] Semiconductor technology system (1, 101) comprising an assembly (30) according to any one of claims 1 to 9.

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