Optical measuring arrangement for distance detection with carrier

Abstract

The invention relates to an optical measuring arrangement (100) for position and / or distance detection of a component, comprising an optical sensor that includes an optical resonator, wherein the optical resonator comprises a coupling mirror (101) and an end mirror (102) enclosing a resonator cavity, and wherein the optical resonator has a measurement target that is connectable to or connected with the component, which is configured to deflect a measurement beam back and forth between the two resonator mirrors (101, 102). A carrier (103) is assigned to the optical resonator, to which the coupling mirror (101) and the end mirror (102) are bonded separately and at a distance from one another.

Description

[0001] Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO Optical measuring arrangement for distance measurement with carrier

[0002] The present application claims priority from German patent application 102025 107494.1 dated February 27, 2025. The entire disclosure of that patent application is incorporated into the present application by reference.

[0003] The invention relates to an optical measuring arrangement for position and / or distance detection of a component relative to a reference, comprising an optical sensor and an optical resonator. The optical resonator includes an input mirror and an end mirror enclosing a resonator cavity. The optical resonator also includes a measuring target that can be connected to or is connected to the component and is configured to deflect a measuring beam back and forth between the two resonator mirrors, i.e., the input mirror and the end mirror. The invention further relates to a projection exposure system, a lithography system, and an inspection system.

[0004] Projection exposure systems are used to create extremely fine structures, particularly on semiconductor devices or other microstructured components. The operating principle of these systems is based on the creation of ultra-fine structures down to the nanometer range by means of a generally reduced-size image of structures on a mask, a so-called reticle, onto a wafer, which is coated with photosensitive material. The minimum dimensions of the generated structures depend directly on the wavelength of the light used. This light is shaped in an illumination optic to optimally illuminate the reticle. Recently, light sources with emission wavelengths in the nanometer range, for example between 1 nm and 120 nm, particularly in the 13.5 nm range, have been increasingly used. This wavelength range is also known as the EUV range.

[0005] The microstructured components are manufactured not only with EUV systems but also with established DUV systems operating at wavelengths between 100 nm and 400 nm, particularly 193 nm (Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO). With the increasing demand for ever smaller structures, the requirements for optical correction in these systems have also risen. To improve efficiency, each new generation of projection exposure systems in the EUV or DUV range increases throughput.

[0006] In the operation of microlithographic projection exposure systems, where the mask and wafer are typically moved relative to each other in a scanning process, the positions of the optical elements, especially mirrors, which are partially movable in all six degrees of freedom, must be set with high accuracy relative to each other, and this position / alignment must be maintained in order to avoid or at least reduce aberrations and associated impairments of the image result or image shifts.

[0007] Various approaches are known in the prior art for measuring the position of individual mirrors, as well as the wafer or wafer stage and the reticles or reticle stages. In addition to interferometric or encoder-based measurement arrangements, frequency-based position and / or distance measurement using an optical resonator is also known.

[0008] The two resonator mirrors, i.e., the coupling mirror and the end mirror, must be correctly positioned and aligned relative to each other. Prior art, for example from DE 102023 116485 B3, describes a method for temporarily blasting mirrors for an optical resonator into place and then permanently fixing them by laser welding. A disadvantage of this prior art solution is that both resonator mirrors require two surfaces suitable for blasting and a stop surface for alignment.

[0009] The object of the present invention is to provide an optical measuring arrangement, a projection exposure system, a lithography system, and an inspection system that eliminates or at least reduces the aforementioned disadvantages. Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO This object is achieved by the independent claims. Advantageous embodiments with expedient further developments are specified in the dependent claims.

[0010] The optical measuring arrangement is characterized in particular by the fact that the optical resonator is associated with a support to which the coupling mirror and the final mirror are bonded separately and at a distance from each other. By means of the common support, which is preferably formed as a support plate, the surfaces of the resonator mirrors that are to be joined no longer need to be specially treated, i.e., polished, to provide contact surfaces. This simplifies the fixing of the resonator mirrors. It is advantageous if at least one of the resonator mirrors, preferably both resonator mirrors, has a flat joining surface on the side facing the support, i.e., on its bonding surface.

[0011] To prevent or reduce measurement inaccuracies of the optical measuring arrangement due to adhesive drift, it is preferred if the coupling mirror and the end mirror are bonded separately and spaced apart from each other to, in particular on, the support such that adhesive shrinkage at the bonding points occurs exclusively or predominantly perpendicular to the measuring direction. In other words, the direction of adhesive shrinkage is preferably oriented exclusively or predominantly perpendicular to the measuring direction. For this purpose, it is preferred if the position of the support and / or the resonator mirrors in the measuring direction, or at least in the measuring direction relative to a reference point in space, i.e., in particular to a reference point in a projection lens, a projection exposure system, or a lithography system, is fixed or definable (especially immutably).It is preferred that the resonator mirrors and / or the support are radially attached to an object, particularly in a permanently fixed manner. The object can be, for example, an optical element or a support structure of a projection lens, but can also be another object of the projection exposure system or a lithography system. By defining the position of the resonator mirrors and / or the support in the measuring direction and relative to a reference point through a radially acting attachment, the adhesive shrinkage of the adhesive points or adhesive surfaces connecting the resonator mirrors to the support (Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO) results exclusively or predominantly in an adjustment of the resonator mirrors and / or the support perpendicular to the measuring direction, or the adjustment of the resonator mirrors due to adhesive shrinkage occurs exclusively or predominantly perpendicular to the measuring direction.As a result, the distances or changes in distance determined by the optical measuring arrangement are insensitive or less sensitive to adhesive shrinkage or adhesive drift of the adhesive points connecting the resonator mirrors to the substrate.

[0012] Furthermore, it is advantageous if the object is formed as a socket, i.e., if the support or the resonator mirrors are held or secured by means of a socket, wherein the support or the resonator mirrors are radially connected or connectable to the socket on their outer surface by means of at least one adhesive point or adhesive surface. Thus, preferably, the adhesive points or adhesive surfaces are arranged or can be arranged radially on the support or on at least one of the resonator mirrors. It is particularly preferred if the position of the support and / or the resonator mirrors is fixed or definable by means of the socket, at least in the measuring direction with respect to a reference point, and in particular if it is fixed immutably or approximately immutably.The position can be determined, for example, by means of the mount, in that the mount is attached or attachable to an object, such as a projection lens or a projection exposure system or a lithography system, in particular to a supporting structure, or is stored or can be stored on an object.

[0013] As an alternative to a radial connection, the connection of the support and / or the resonator mirrors can also be arranged axially to the measuring direction. It is preferred that the support and / or the resonator mirrors are connected or connectable axially to an object, in particular an object of a projection lens, or a projection exposure system or a lithography system, by means of at least one adhesive point or adhesive surface. Through this connection to the object, the position of the support and / or the resonator mirrors in the measuring direction relative to a reference point in space, i.e., in particular to a reference point in a projection lens, a projection exposure system, or a lithography system, is fixed or definable (in particular, immutably). The object can, for example, be a socket, a connection, or a support structure.Preferably, the support (Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO) is axially connected or connectable to a mount by means of at least one adhesive point or surface, or the resonator mirrors are held or connected or connectable to a common mount axially to the measuring direction by means of at least one adhesive point or surface. However, the support and / or the resonator mirrors can also be connected or connectable to an object, in particular an object of a projection lens, a projection exposure system, or a lithography system, without a mount, wherein the position of the support and / or the resonator mirrors in the measuring direction relative to a reference point is or can be determined by the connection to the object.

[0014] In an embodiment where the carrier is axially connected or connectable to an object or a socket by means of at least one adhesive point or surface, those adhesive points connecting the object or socket to the carrier cause a displacement of the carrier in a first direction (e.g., in the measuring direction) due to adhesive shrinkage, while the adhesive points or surfaces connecting the resonator mirrors to the carrier cause an opposite displacement of the resonator mirrors in a second direction (e.g., then against the measuring direction) due to adhesive shrinkage. If the degree of adhesive shrinkage of the adhesive points is equal or approximately equal, this results in the displacement of the carrier plate and the resonator mirrors due to adhesive shrinkage mutually compensating for each other.This compensation consequently results in adhesive shrinkage causing no or only a reduced adjustment of the resonator mirrors in the measuring direction. For complete or nearly complete compensation, it is advantageous if the degree of adhesive shrinkage of the compensating adhesive points or surfaces is the same or nearly the same, i.e., differing by a maximum of 10%, preferably 5%, and particularly preferably by a maximum of 3%.

[0015] In an embodiment where, on the other hand, the resonator mirrors are axially connected or connectable to an object or a mount by means of at least one adhesive point or surface, the adhesive shrinkage of these points causes a shift of the resonator mirrors in a first direction (e.g., in the measuring direction), while the adhesive points or surfaces connecting the resonator mirrors to the mounting plate cause an opposite shift of the resonator mirrors in a second direction (e.g., then against the measuring direction) due to the adhesive shrinkage. If the degree of adhesive shrinkage of the points is equal or approximately equal, this results in the shift of the mounting plate and the resonator mirrors due to adhesive shrinkage mutually compensating for each other. Consequently, this compensation means that adhesive shrinkage leads to no or only a reduced shift of the resonator mirrors in the measuring direction.For complete or nearly complete compensation, it is advantageous if the degree of adhesive shrinkage of the compensating adhesive points or adhesive surfaces is the same or nearly the same, i.e., differs by a maximum of 10%, preferably 5%, and particularly preferably by a maximum of 3%.

[0016] Furthermore, according to one embodiment, a contact line is formed on one component consisting of a support and resonator mirror (i.e., coupling mirror and / or end mirror), and the other component consisting of a support and resonator mirror is arranged on this contact line such that an adhesive-free contact line, i.e., an adhesive-free contact line, is formed between the support and the resonator mirror. The support and the respective resonator mirrors thus have a common contact line, i.e., a contact line, which is formed without adhesive. The contact line can, in particular, be formed as an annular edge. The resonator mirrors can contact a common contact line or contact separately formed contact lines. The contact line can also be formed as a contact surface or as a contact point.Preferably, one component, consisting of a support and a resonator mirror, has a plurality of contact points, lines, and / or surfaces, wherein the other component, also consisting of a support and a resonator mirror, is arranged on it such that contact points, lines, and / or surfaces are formed between the support and the resonator mirror. Due to the at least one contact point, line, or surface free of adhesive, adhesive shrinkage of the adhesive points or surfaces does not result in any change in the relative position between the resonator mirror and the support, since their position is determined by the contact point, line, or surface free of adhesive.The at least one adhesive-free contact point, contact line, or contact surface creates a mechanical tension between the substrate and the resonator mirrors during adhesive shrinkage (Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO), thus preventing or at least reducing rigid body displacement between the resonator mirrors and the substrate. The contact line can be formed as a circle, an open circle, a broken circle, an ellipse, one or more circular segments, an S-shape, or a spiral. The contact points or contact lines can also have a wedge-shaped geometry.

[0017] To further secure the carrier to the resonator mirrors, the contact line or contact surface preferably has an opening into which the adhesive can be applied. Preferably, the resonator mirrors and the carrier are first aligned relative to each other in a predetermined or predeterminable position, and then the adhesive is introduced into the opening of the contact line or contact surface. The opening is preferably at least partially integrated into the contact line or contact surface, in particular by grinding, but can alternatively also be integrated into the respective resonator mirror or the carrier, in particular by grinding, for example, using a laser machining or etching process. Due to the direct contact of the carrier with the respective resonator mirror via the contact line, adhesive shrinkage during curing does not lead to a change in the position of the resonator mirrors relative to the carrier.

[0018] The optical measuring arrangement preferably includes an evaluation unit configured to determine a change in the length of the optical resonator from a measurement of its resonance frequency. In particular, it is advantageous to have a control unit configured to detect the distance between the component and a reference by tracking the frequency of a measurement beam emitted by the light source to the resonance frequency of the optical resonator. The light source can be a tunable light source or a frequency-stabilized light source, with the frequency of the light source being tracked to the resonance frequency of the optical resonator by means of a frequency shifter (for example, an IQ modulator) and a pound-driver-Hall effect.

[0019] Furthermore, it is advantageous if the coupling mirror is connected to the end mirror only indirectly, i.e., preferably only by means of the support and / or an optional common mount. Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO

[0020] Furthermore, it is advantageous if the resonator mirrors are free of common adhesive points.

[0021] In a preferred embodiment, the carrier has a recess arranged such that a measuring beam is directed, or can be directed, through the recess of the carrier onto the coupling mirror. The recess of the carrier is thus preferably adapted to the position and size of the optical surface of the coupling mirror.

[0022] Alternatively, it is advantageous if the support for a measuring beam is at least partially transparent. The support therefore has at least one region transparent to the wavelength of the measuring beam used, arranged in such a way that the measuring beam penetrates the support and is directed onto the coupling mirror.

[0023] The support is preferably made of the same material as at least one of the resonator mirrors. Particularly preferably, the support and all mirrors of the optical resonator are made of the same material, especially a material with a low coefficient of thermal expansion. Alternatively, the support can also be made of a different material than the resonator mirrors. For example, the support can be made of an optical material, a metal (e.g., steel), or a metal alloy (e.g., Invar). Alternatively, the support can also be made of ceramic.

[0024] Furthermore, it is advantageous if the coupling mirror and the end mirror each have an optical surface facing the resonator cavity, and that the support is bonded to the back of the resonator mirrors facing away from the optical surface.

[0025] Alternatively, it is preferred that the support is arranged between the coupling mirror and the end mirror. The support is thus located within the resonator cavity. Preferably, the coupling mirror is connected to the support at its front side facing the optical surface, while the end mirror is bonded to the support at its rear side facing away from the optical surface. The resonator mirrors are preferably arranged parallel to the measuring direction, but offset from each other in the measuring direction.

[0026] Alternatively, it is also possible that the coupling mirror and the end mirror each have an optical surface facing the resonator cavity, and that the support is partially bonded to the resonator mirrors on the front side facing the optical surface. The support is therefore located within the resonator cavity.

[0027] Alternatively, it is also preferred that the coupling mirror and the end mirror are bonded to the support at least partially on their outer surface.

[0028] Furthermore, it is preferred if the resonator mirrors have a common mount and the resonator mirrors or the support are radially fixed to the mount, in particular by gluing, welding, or crimping. The resonator mirrors can be radially connected to the mount at their outer surface. The mount is preferably connected or connectable to the resonator mirrors by means of adhesive points or surfaces radially attached to the outer surface of the resonator mirrors. Alternatively, the mount can also be connected or connectable to the support or the resonator mirror by means of axially attached adhesive points or surfaces. Alternatively, the support can also be connected to the mount at its outer surface. The mount is preferably connected or connectable to the support by means of adhesive points or surfaces radially attached to the outer surface of the support.Preferably, the mount has at least one mechanical decoupling element, wherein the resonator mirrors or the support are preferably radially connected or connectable to the at least one, preferably a plurality, of mechanical decoupling elements. The mount preferably defines the position of the support and / or the resonator mirrors in the measuring direction relative to a reference point, preferably permanently.

[0029] Furthermore, it is recommended that the connection between the support and the resonator mirror be implemented as adhesive points or adhesive pads. Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO The projection exposure system is characterized in particular by the fact that it has at least one previously described optical measuring arrangement according to the invention, which is configured to determine the distance of an optical element of the projection exposure system relative to a reference. The optical element can in particular be a lens or a mirror, preferably an EUV mirror. By detecting the position of the optical elements, their position or orientation can be determined and the position or deformation can preferably be adjusted by means of actuators. This improves the image quality of the projection exposure system.The advantages and embodiments mentioned for the optical measuring arrangement are also applicable to the projection exposure system comprising at least one optical measuring arrangement.

[0030] Furthermore, at least one optical measuring arrangement according to the invention can also be used in a projection lens, in particular in a projection lens of a projection exposure system, for determining the position and / or distance of a movable or immovable component of the projection lens.

[0031] The optical measuring arrangement according to the invention can also be used in a lighting system, in particular in a lighting system for a projection exposure system. The lighting system preferably has at least one optical measuring arrangement. This arrangement is configured to detect the position or distance of a movable or immovable component. The at least one optical measuring arrangement is directly or indirectly connected to, or connectable to, the component to be measured. The component can, in particular, be an optical element or a support structure.The lighting system of a lithography system comprises, in particular, a light source configured to generate light in an EUV or DUV wavelength range and a plurality of optical elements configured to redirect the light generated by the light source and couple it into the projection exposure system. The advantages and embodiments mentioned for the optical measuring arrangement also apply to the lighting system comprising at least one optical measuring arrangement. Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO The lithography system is characterized, in particular, by having at least one optical measuring arrangement. The component of the lithography system can preferably be at least one or more optical elements, support structures, stages, or masks of the lithography system.By detecting the position of components, for example those formed as optical elements, using the optical measuring arrangement, their position or orientation, or even a deformation of the optical surface, can be detected, and the position or deformation can preferably be adjusted by means of actuators. The advantages and embodiments mentioned for the optical measuring arrangement are also applicable to the lithography system comprising at least one optical measuring arrangement. The inspection system according to the invention for checking an optical element, a wafer, a wafer stage, a reticle, or a reticle stage comprises at least one optical measuring arrangement according to the invention. The optical measuring arrangement is configured to detect the position or distance of a component, for example, an optical element, a wafer, a wafer stage, a reticle, or a reticle stage.Preferably, an evaluation unit is provided that compares the detected positions or distances, in particular of component structures, with predetermined distances or positions of the structures or components and, in the event of a deviation by a predetermined limit value, initiates corrective action. The at least one optical measuring arrangement is directly or indirectly connected to, or connectable to, the component to be measured. The advantages and embodiments mentioned for the optical measuring arrangement also apply to the inspection system comprising the at least one measuring arrangement. An example of such an inspection system for mask or wafer inspection (without the measuring arrangement according to the invention) is known from German patent application DE 102012205181 A1, the entire content of which is incorporated into the present application by reference.

[0032] The optical measuring arrangement according to the invention can also be used in a coordinate measuring machine, which then has at least one optical measuring arrangement according to the invention. Coordinate measuring machines are used for the inspection or measurement of components, whereby the component is usually scanned and distances or positions are determined based on the scanning. For this purpose, an optical system as well as a movable frame structure and / or a high-precision positioning system are provided, which carries the component or object to be inspected. The optical measuring arrangement is preferably connected directly or indirectly to this movable component, i.e., frame structure or positioning system. By means of the at least one optical measuring arrangement, the position or distance of the movable component can be determined, thereby controlling the scanning of the object.Furthermore, the optical measuring arrangement can also be used to detect and thus inspect the distance or position of the component itself. The advantages and embodiments mentioned for the optical measuring arrangement also apply to the coordinate measuring machine comprising at least one optical measuring arrangement. An example of such a coordinate measuring machine (without the measuring arrangement according to the invention) is known from publication DE102019213794A1, the entire content of which is incorporated into the present application by reference. Further features, properties, and advantages of the present invention are described in more detail below with reference to embodiments and the accompanying figures. All features described so far and below are advantageous both individually and in any combination with one another.The embodiments described below are merely examples and do not limit the scope of the invention. They are shown as follows:

[0033] Figure 1a shows a schematic representation of a microlithographic projection exposure system designed for operation in the EUV,

[0034] Figure 1b shows a schematic representation of a microlithographic projection exposure system designed for operation in DUV,

[0035] Figure 2 shows a schematic representation of a first embodiment of an optical measuring arrangement,

[0036] Figure 3 is a top view of Fig. 2, Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO

[0037] Figure 4 is a schematic representation of the support of Figure 2,

[0038] Figure 5 is a schematic representation of the optical measuring arrangement according to Figure 2, composed of Figures 3 and 4 in top view.

[0039] Figure 6 shows a schematic representation of a second embodiment of an optical measuring arrangement,

[0040] Figure 7 shows a schematic representation of a third embodiment of an optical measuring arrangement,

[0041] Figure 8 shows a schematic representation of a fourth embodiment of an optical measuring arrangement,

[0042] Figure 9 shows a schematic representation of a fifth embodiment of an optical measuring arrangement in side view,

[0043] Figure 10 shows a schematic representation of a sixth embodiment of an optical measuring arrangement in side view,

[0044] Figure 11 shows a schematic representation of a sixth embodiment of an optical measuring arrangement in top view.

[0045] Figure 12 shows a schematic representation of a seventh embodiment of an optical measuring arrangement in top view.

[0046] Figure 13 shows a schematic representation of an eighth embodiment of an optical measuring arrangement in a side view and

[0047] Figure 14 shows a schematic top view of a ninth embodiment of an optical measuring arrangement. Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO. Figure 1a shows a schematic representation of an exemplary projection exposure system 600 designed for operation in EUV, in which the present invention can be implemented. However, the invention can also be used in other nanopositioning systems.

[0048] According to Fig. 1a, a lighting device in a projection exposure system 600 designed for EUV has a field facet mirror 603 and a pupil facet mirror 604. The light from a light source unit, which comprises a plasma light source 601 and a collector mirror 602, is directed onto the field facet mirror 603. In the light path after the pupil facet mirror 604, a first telescope mirror 605 and a second telescope mirror 606 are arranged. Further down the light path is a deflecting mirror 607, which directs the incident radiation onto an object field in the object plane of a projection lens comprising six mirrors 651-656. At the location of the object field, a reflective structure-bearing mask 621 is arranged on a mask table 620, which is imaged into an image plane by means of the projection lens, in which a substrate 661 coated with a light-sensitive layer (photoresist) is located on a wafer table 660.

[0049] The invention can also be used in a DUV system, as shown in Figure 1b. A DUV system is fundamentally constructed like the EUV system described above in Figure 1a, except that mirrors and lenses can be used as optical elements in a DUV system, and the light source of a DUV system emits useful radiation in a wavelength range of 100 nm to 400 nm.

[0050] The DUV lithography system 700 shown in Figure 1b has a DUV light source 701. For example, an ArF excimer laser can be used as the DUV light source 701, which emits radiation 702 in the DUV range at, for example, 193 nm. A beam shaping and illumination system 703 directs the DUV radiation 702 onto a photomask 704. The photomask 704 is designed as a transmissive optical element and can be arranged outside the systems 703. The photomask 704 has a structure which is reduced in size and projected onto a wafer 706 or the like by means of the projection system 705. The projection system 705 comprises several lenses 707 and / or mirrors 708 for imaging the Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO photomask 704 onto the wafer 706. Individual lenses 707 and / or mirrors 708 of the projection system 705 can be arranged symmetrically to the optical axis 709 of the projection system 705.It should be noted that the number of lenses 707 and mirrors 708 of the DUV lithography system 700 is not limited to the number shown. More or fewer lenses 707 and / or mirrors 708 may be used. In particular, the beam shaping and illumination system 703 of the DUV lithography system 700 has several lenses 707 and / or mirrors 708. Furthermore, the mirrors are typically curved on their front surface for beam shaping. An air gap 710 between the last lens 707 and the wafer 706 can be replaced by a liquid medium with a refractive index > 1. The liquid medium can be, for example, highly purified water. Such a setup is also called immersion lithography and offers increased photolithographic resolution.

[0051] Figure 2 shows an optical measuring arrangement 100 for position and / or distance detection of a component (not shown), in particular a lens or a mirror, preferably an EUV mirror, relative to a reference, for example a frame structure or a reference body. The optical measuring arrangement 100 comprises an optical sensor having an optical resonator, which includes at least one coupling mirror 101 and an end mirror 102 enclosing a resonator cavity. The optical resonator has a measuring target (not shown) that can be connected to or is connected to the component and is configured to deflect a measuring beam back and forth between the two resonator mirrors 101, 102, i.e., the coupling mirror and the end mirror.In the optical resonator, i.e. between the single-coupling mirror 101, the measuring target and the end mirror 102, a standing wave is formed, so that the optical measuring arrangement 100 is set up for frequency-based distance detection of the component relative to a reference.

[0052] The coupling mirror and the end mirror must be aligned with each other. For this purpose, the optical resonator is assigned a common support 103, which in this case is formed as a support plate 103, to which the coupling mirror 101 and the end mirror 102 are bonded separately and spaced apart from each other. By bonding the two resonator mirrors 101 and 102 separately and spaced apart from each other on a common support plate 103, it is unnecessary to form contact surfaces on the mirrors, thus simplifying the joining process.To prevent or reduce measurement inaccuracies of the optical measuring arrangement 100 due to adhesive drift or shrinkage, it is preferred that the coupling mirror 101 and the end mirror 102 are bonded separately and at a distance from each other to the support plate 103, such that adhesive shrinkage of the adhesive points 105 occurs exclusively or predominantly perpendicular to the measuring direction 104. The adhesive points between the resonator mirrors 101, 102 and the support plate are therefore applied axially, so that the adhesive does not shrink, or only shrinks to a reduced extent, in the measuring direction 104 of the optical measuring arrangement 100 after or during curing, but mainly or completely perpendicular to the measuring direction 104.For this purpose, the position of the support 103 and / or the resonator mirrors 101, 102 is (immutably) fixed or definable, at least in the measuring direction 104, relative to a reference point in space, i.e., in particular to a reference point in a projection lens, a projection exposure system, or a lithography system. The resonator mirrors 101, 102 and / or the support 103 are radially connected to an object, in particular immutably. The object can, for example, be an optical element or a supporting structure of a projection lens, but can also be another object of a projection exposure system or a lithography system.By defining the position of the resonator mirrors 101, 102 and / or the support 103 in the measuring direction 104 relative to a reference point by means of a radially designed connection, the adhesive shrinkage of the adhesive points 105 connecting the resonator mirrors 101, 102 to the support 103 occurs exclusively or predominantly perpendicular to the measuring direction. By defining the position of the resonator mirrors 101, 102 and / or the support 103 in the measuring direction 104, z, any adjustment of the relative position between the support 103 and the resonator mirrors 101, 102 in the measuring direction 104, z is prevented or at least reduced. As a result, the distances or changes in distance determined by the optical measuring arrangement 100 are insensitive or less sensitive to adhesive shrinkage or adhesive drift.

[0053] In Figure 2, the resonator mirrors 101, 102 are held by means of a socket 111, wherein the resonator mirrors are radially connected or connectable to the socket 111 at their lateral surface 113 by means of at least one adhesive point or adhesive surface. Thus, preferably, the adhesive points or adhesive surfaces are arranged or can be arranged radially on at least one lateral surface 113 of one of the resonator mirrors Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO 101, 102. This means that the position of the resonator mirrors 101, 102 in the measuring direction 104 is fixed or can be fixed by means of the socket 111, in particular immutably or approximately immutably. The position can be determined, for example, by means of version 111, in that version 111 is attached or attachable to an object not shown in more detail, for example a projection lens or a projection exposure system or a lithography system, or is stored or can be stored on an object.Alternatively, the support 103 can also be held by means of a socket 111, wherein the support 103 is radially connected or connectable to the socket 111 at a lateral surface 112. The socket 111 determines the position of the support 103 and thus also of the resonator mirrors 101, 102 connected to the support 103 in the measuring direction 104, z in space, thereby preventing or at least reducing any change in the relative position between the resonator mirrors 101, 102 and the support 103 due to adhesive shrinkage in the measuring direction 104.

[0054] This makes the distance measured by the optical measuring arrangement 100 less sensitive to adhesive shrinkage. The adhesive can be applied as single or multiple adhesive dots 105, or as adhesive surfaces or adhesive lines. Preferably, the carrier plate 103 and the resonator mirrors 101, 102 are bonded together by means of adhesive pads 114, i.e., an adhesive dot 105 can be designed as an adhesive pad 114.

[0055] The coupling mirror 101 is therefore connected to the end mirror 102 only indirectly, preferably exclusively by means of the support plate 103. Optionally, the two resonator mirrors 101 and 102 can each be arranged in a socket 111 or in a common socket 111, which in turn is directly connected to the support plate 103. Furthermore, the resonator mirrors 101 and 102 are free of any common adhesive points 105.

[0056] The carrier plate 103 has a recess 106, which is arranged such that a measuring beam (not shown in detail) is directed through the recess 106 of the carrier plate 103 onto the coupling mirror, i.e., in this case, onto the back side 109 of the coupling mirror 101 in Fig. 2. The recess 106 is shown in more detail in Fig. 4. The position and size of the recess are adapted to the optical surface 107 of the coupling mirror. Alternatively, and not shown in Figures 2 to 12, the carrier plate 103 could be made at least partially transparent to the measuring beam, i.e., to the wavelength of the measuring beam used. The carrier plate 103 therefore has at least one area transparent for the wavelength of the measuring beam used, which is arranged in such a way that the measuring beam penetrates the carrier plate and is directed onto the coupling mirror 101.

[0057] Preferably, at least one contact point, contact line, or contact surface (not shown) is formed on a carrier 103 and a resonator mirror 101, 102, wherein the other carrier 103 and resonator mirror 101, 102 is arranged on this carrier 103 or resonator mirror 101, 102 such that an adhesive-free contact point, contact line, or contact surface is formed between the carrier 103 and the resonator mirror 101, 102. This prevents the relative position between the carrier 103 and the resonator mirror 101, 102 from shifting due to adhesive shrinkage, as the position is fixed by the adhesive-free contact point, contact line, or contact surface.The adhesive-free contact point, the adhesive-free contact line 116, or the adhesive-free contact surface thus causes mechanical tension between the support 103 and the resonator mirrors 101, 102 during adhesive shrinkage, preventing or at least reducing rigid body displacement between the resonator mirrors 101, 102 and the support 103. The contact line 116 can be formed as a circle, an open circle, a broken circle, an ellipse, one or more circular segments, an S-shape, or a spiral. The contact points or contact lines 116 can also be wedge-shaped, meaning they can have different or varying heights. The resonator mirrors 101, 102 can also share a common adhesive-free contact point, adhesive-free contact line 116, or adhesive-free contact surface with the socket 111 or the connection that defines their position in the measuring direction 104.Similarly, the carrier 103 can also have a common adhesive-free support point or adhesive-free support line 116 or adhesive-free support surface with the socket 111 or the connection that determines the position in the measuring direction 104. The embodiments of Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO optical measuring arrangements 100 shown in Figures 6 to 14 may also have such adhesive-free contact points, contact lines or contact surfaces, in particular between the carrier 103 and the resonator mirrors 101, 102 and / or between the carrier 103 and the socket 111, and / or between the resonator mirror 101, 102 and the socket 111, and / or between the carrier 103 and a connection that determines the position in the measuring direction 104 and / or between a resonator mirror 101, 102 and a connection that determines the position of the resonator mirrors 101, 102 in the measuring direction 104.

[0058] Figures 3 to 5 show the embodiment of Figure 2 in detail from different perspectives. Figures 2, 3, and 5 clearly show that the resonator mirror-support plate arrangement is radially connected to a common socket 111 at its outer surface 113. In this case, this connection is also made using adhesive points 105 or adhesive pads 114. Alternatively, the connection between the socket and the support plate 103 or between the socket 111 and the resonator mirrors 101, 102 can also be made by laser welding, chemical bonding, splintering, etc. The adhesive points 105 or adhesive pads 114 between the socket 111 and the resonator mirrors 101, 102 are therefore also arranged perpendicular to the measuring direction 104, which means that the effect of adhesive shrinkage does not affect, or only reduces, the distance measurement of the optical measuring arrangement 100.In the present case, the socket 111 is only partially represented by a mechanical decoupling element 115, which mechanically and thermally decouples the resonator mirrors 111 from the socket 111. The mechanical decoupling elements 115 are preferably distributed regularly around the circumference of the resonator mirrors 101, 102.

[0059] In the embodiment shown in Figures 2 to 5, the coupling mirror 101 and the end mirror 102 each have an optical surface 107, 108 facing the resonator cavity. The support plate 103 is bonded to the resonator mirrors 101, 102 on the back side 109 facing away from the optical surface.

[0060] The embodiment shown in Figure 6 differs in that the support plate 103 is arranged between the coupling mirror 101 and the end mirror 102. The coupling mirror 101 is bonded to the support plate 103 at its front face 110, which faces the optical surface 107, by means of adhesive dots 105 or adhesive pads 114, while the end mirror 102 is bonded to the support plate 103 at its rear face 109, which faces the optical surface 108. In other words, the support plate 103 is arranged within the resonator cavity. The recess 106 of the support plate 103 is arranged such that the measuring beam propagating in the resonator cavity can strike the optical surface 107 of the coupling mirror 101. The recess 106 is therefore adapted to the position and size of the optical effective surface 107 of the coupling mirror 101.The mechanical decoupling elements 115 of the common version 111 are in this case radially connected, i.e., connected or connectable to the outer surface 112 of the support plate 103.

[0061] In the embodiment shown in Figure 7, the resonator mirrors 101, 102 are bonded to the support plate 103 at their rear side 109. The mechanical decoupling elements 115 of the socket 111 are also bonded axially to the support plate 103, rather than radially. This means that the adhesive point 105 or the adhesive pad 114 is arranged on the support plate 103 such that the adhesive shrinkage during or after curing occurs completely or mainly in or against the measuring direction 104. The socket 111 defines the position of the support 103 in the measuring direction 104 relative to a reference point.The adhesive points 105 that connect the socket 111 to the carrier 103 cause the carrier 103 to shift in a first direction (in this case, in the direction of measurement 104) due to adhesive shrinkage, while the adhesive points 105 or adhesive surfaces that connect the resonator mirrors 101, 102 to the carrier 103 cause the resonator mirrors 101, 102 to shift in the opposite direction (in this case, opposite to the direction of measurement 104) due to adhesive shrinkage. If the degree of adhesive shrinkage at the adhesive points is equal or approximately equal, the shifts of the carrier plate and the resonator mirrors 101, 102 due to adhesive shrinkage will cancel each other out. This compensation consequently leads to no or only a reduced adjustment of the resonator mirrors 101,102 in the measuring direction 104Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO due to adhesive shrinkage.This principle of compensating for the opposite adjustment due to adhesive shrinkage also applies to the figures shown in Figures 8, 10, 11 and 16.

[0062] 14 illustrated embodiments.

[0063] The embodiment shown in Figure 8 differs in that the optical support plate 103 with both resonator mirrors 101, 102 is bonded to the support plate 103 at the front side 110 facing the optical effective surface 107, 108 of the resonator mirrors 101, 102. The mechanical decoupling elements 115 of the common socket 111 are in turn bonded axially to the support plate 103. The socket 111, or a connection not shown in detail, determines the position of the support in the measuring direction 104 relative to a reference point.Adhesive shrinkage of the adhesive points 105, which connect the carrier to the socket 111 or the connection, causes a displacement of the carrier in a first direction (in this case, opposite to the measurement direction 104), while adhesive shrinkage of the adhesive points 105 connecting the resonator mirrors 101, 102 to the carrier 103 causes a displacement of the resonator mirrors 101, 102 in an opposite second direction (in this case, in the measurement direction 104). If the degree of adhesive shrinkage of the adhesive points is equal or approximately equal, this results in the displacement of the carrier plate and the resonator mirrors 101, 102 due to adhesive shrinkage compensating for each other. Consequently, this compensation means that adhesive shrinkage leads to no displacement or only a reduced displacement of the resonator mirrors 101, 102 in the measurement direction 104.

[0064] In the embodiment shown in Figure 9, the resonator mirrors 101, 102 are bonded to the support plate 103 in certain areas on their lateral surface 113 by means of adhesive dots 105 or adhesive pads 114.

[0065] In the embodiment shown in Figure 9, the mechanical decoupling elements 115 of the common socket 111 are axially bonded to the carrier plate 103, wherein the adhesive points 105 or the adhesive pads 114 are arranged such that the adhesive shrinkage during or after curing of the adhesive occurs completely or mainly perpendicular to the measuring direction 104. Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO In the embodiment shown in Figures 10 and 11, the mechanical decoupling elements 115 of the common socket 111 are radially bonded to the carrier plate 103, that is, bonded to the lateral surface 112 of the carrier plate 103.

[0066] In the embodiment shown in Figure 12, the mechanical decoupling elements 115 are bonded radially to the outer surface 113 of the carrier plate 103.

[0067] The embodiments shown in Figures 13 and 14 differ in that one of them, consisting of a support plate 103 and resonator mirrors 101, 102, has a bearing line 116 or a bearing surface on which the other, consisting of a support plate 103 and resonator mirrors 101, 102, rests directly such that an adhesive-free contact line is formed between the resonator mirrors 101, 102 and the support plate 103. The bearing line 116 can be formed as an annular cutting edge. In this example, the bearing line 116, which is formed as an annular cutting edge, is located in the support plate 103, but it can also be located on the resonator mirrors.

[0068] The support surface 101, 102 is formed with an opening into which the adhesive can be applied to bond the resonator mirrors 101, 102 to the support plate 103. An example of such an opening is shown in Figure 14, where the opening consists of a capillary opening and a volume, so that the adhesive is drawn into the volume. Preferably, the opening is incorporated into the annular cutting edge, preferably ground in, but it can also be formed in the support plate 103 or the respective resonator mirrors 101, 102. Due to the direct contact between the support plate 103 and the resonator mirrors 101, 102 via the support surface 116, adhesive shrinkage during curing does not cause a displacement of the resonator mirrors 101, 102 relative to the support plate 103; rather, the positioning is maintained despite the adhesive shrinkage.The adhesive shrinkage therefore does not affect the relative position between the resonator mirrors 101,102 and the support plate 103.

[0069] The optical measuring arrangement 100 according to the invention for measuring the distance of a component relative to a reference can be used in a projection lens, in an illumination system, in a projection exposure system, in a lithography system, in an inspection system, in a measuring machine, or in a coordinate measuring machine. Furthermore, other applications where distances need to be measured are also conceivable.

[0070] P1064WO / 2024P00901 WO

[0071] REFERENCE MARK LIST

[0072] 100 optical measuring arrangement

[0073] 101 Coupling mirror (of the optical resonator) 102 End mirror (of the optical resonator)

[0074] 103 T beam / T beam plate

[0075] 104 Measuring direction (of the optical sensor)

[0076] 105 adhesive dots

[0077] 106 Recess (of the carrier plate)

[0078] 107 Optical effective area (of the coupling mirror) 108 Optical effective area (of the end mirror)

[0079] 109 Back side (of the resonator mirror)

[0080] 110 Front side (of the resonator mirror)

[0081] Version 111

[0082] 112 Surface area (of the carrier plate)

[0083] 113 Surface area (of the resonator mirror)

[0084] 114 adhesive pads

[0085] 115 mechanical decoupling element (of the socket) 116 support line

[0086] 600 Projection exposure system

[0087] 601 Plasma light source

[0088] 602 Collector mirrors

[0089] 603 Field faceted mirror

[0090] 604 pupil facet mirrors

[0091] 605 first telescope mirror

[0092] 606 second telescope mirror

[0093] 607 Deflection mirror

[0094] 620 mask table

[0095] 621 Mask

[0096] 651 Mirror (projection lens)

[0097] 652 Mirror (projection lens)

[0098] 653 Mirror (projection lens)

[0099] 654 Mirror (projection lens)

[0100] 655 Mirror (projection lens) Carl Zeiss SMT GmbH

[0101] P1064WG / 2024P00901 WO

[0102] 656 Mirror (projection lens)

[0103] 660 wafer table

[0104] 661 coated substrate

[0105] 700 DUV lithography system

[0106] 701 DUV light source

[0107] 702 DUV radiation / beam path

[0108] 703 Beam shaping and illumination system (DUV) 704 Photomask

[0109] 705 Projection System

[0110] 706 wafers

[0111] 707 lens

[0112] 708 mirrors

[0113] 709 optical axis

Claims

Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO Claims 1. Optical measuring arrangement (100) for position and / or distance detection of a component with an optical sensor comprising an optical resonator, wherein the optical resonator comprises an input mirror (101) and an end mirror (102) enclosing a resonator cavity, wherein the optical resonator has a measuring target connectable to or connected with the component, which is configured to deflect a measuring beam back and forth between the two resonator mirrors (101, 102), characterized in that a support (103) is associated with the optical resonator, to which the input mirror (101) and the end mirror (102) are bonded separately and spaced apart from each other, and that a support line (116) is formed on one of the support (103) and resonator mirrors (101, 102), and that the other of the support (103) and resonator mirrors (101, 102) is arranged on this support line. is,that an adhesive-free contact line is formed between the support (103) and the resonator mirror (101, 102).

2. Optical measuring arrangement (100) according to claim 1 , characterized in that the coupling mirror (101) and the end mirror (102) are bonded separately and spaced apart from each other to the carrier (103) in such a way that the adhesive shrinkage of the adhesive points (105) occurs exclusively or predominantly perpendicular to the measuring direction (104) of the optical sensor.

3. Optical measuring arrangement (100) according to claim 1 or 2, characterized in that the position of the support (103) and / or the resonator mirrors (101, 102) in the measuring direction to a reference point is fixed or definable.

4. Optical measuring arrangement (100) according to one of claims 1 to 3, characterized in that the coupling mirror (101) is connected to the final mirror (102) exclusively indirectly. Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO 5. Optical measuring arrangement (100) according to one of claims 1 to 4, characterized in that the resonator mirrors (101, 102) are free of common adhesive points (105).

6. Optical measuring arrangement (100) according to one of claims 1 to 5, characterized in that the carrier (103) has a recess (106) which is arranged such that a measuring beam is directed through the recess of the carrier (103) onto the coupling mirror (101).

7. Optical measuring arrangement (100) according to one of claims 1 to 6, characterized in that the support (103) is made of the same material as at least one of the resonator mirrors (101,102).

8. Optical measuring arrangement (100) according to one of claims 1 to 7, characterized in that the coupling mirror (101) and the end mirror (102) each have an optical effective surface (107, 108) facing the resonator cavity, and that the support (103) is bonded to the resonator mirrors (101, 102) on the back side (109) facing away from the optical effective surface (107, 108).

9. Optical measuring arrangement (100) according to one of claims 1 to 8, characterized in that the carrier (103) is arranged between the coupling mirror (101) and the end mirror (102).

10. Optical measuring arrangement (100) according to one of claims 1 to 9, characterized in that the coupling mirror (101) and the end mirror (102) each have an optical working surface (107, 108) facing the resonator cavity and the support (103) is partially bonded to the resonator mirrors (101, 102) on the front side (110) of the resonator mirrors (101, 102) facing the optical working surface (107, 108).

11. Optical measuring arrangement (100) according to one of claims 1 to 10, characterized in that the coupling mirror (101) and the end mirror (102), Carl Zeiss SMT GmbH P1064WO / 2024P00901 WO are bonded to the carrier (103) at least partially on their outer surface.

12. Optical measuring arrangement (100) according to one of claims 1 to 11, characterized in that the carrier (103) is connected or connectable to a socket at its outer surface (112).

13. Optical measuring arrangement (100) according to one of claims 1 to 11, characterized in that the resonator mirrors (101, 102) have a common socket (111) and the resonator mirrors (101, 102) or the support (103) are radially fixed with the socket (111).

14. Optical measuring arrangement (100) according to one of claims 1 to 13, characterized in that the connection between the support (103) and the resonator mirror (101, 102) is designed as an adhesive point (105) or as an adhesive pad (114).

15. Projection exposure system (600, 700) with at least one optical measuring arrangement (100) according to one of claims 1 to 14.

16. Lithography system with at least one optical measuring arrangement (100) according to one of claims 1 to 14.

17. Inspection system with at least one optical measuring arrangement (100) according to one of claims 1 to 14.

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