Method for producing an optical arrangement and optical arrangement of composite optical elements

Abstract

The invention relates to a method for manufacturing an optical arrangement (100) of composite optical elements comprising the following steps: a. Providing a socket (101) with a first subsocket (101a) formed in the socket (101) with a first radius (102), b. Inserting and fixing a first optical element (103) in the first sub-socket (101a), c. Determining the optical axis (104) of the first optical element (103) and determining a deviation of the determined optical axis (104) of the first optical element (103) from a reference axis (105), d. Forming a further sub-socket (101b) with a second radius (106) that is larger than the first radius (102) of the first sub-socket (101a) by selectively removing material from the socket (101) and thereby forming a bearing line (107) in the further sub-socket (101b), whereby the height of the bearing line (107) is adjusted in such a way that the deviation of the optical axis (104) of the first optical element (103) from the reference axis (105) is at least partially compensated, and e. Inserting a further optical element (108) into the further sub-socket (101b) such that the further optical element (108) rests on the support line (107) and fixing the further optical element (108) in the further sub-socket (101b). The invention further relates to an optical arrangement, an arrangement for carrying out the method, a projection exposure system and a lithography system.

Description

[0001] The invention relates to a method for producing an optical arrangement of composite optical elements. The invention further relates to an optical arrangement, a measuring arrangement for implementing the method, a projection exposure system, and a lithography system.

[0002] 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 creating extremely fine structures down to the nanometer range by means of a generally reduced-size image of structures on a mask, a so-called reticle, on an element to be structured, a so-called wafer, which is provided with photosensitive material. The minimum dimensions of the created structures depend directly on the wavelength of the light used. This light is shaped in an illumination optics for optimal illumination of the reticle. Recently, light sources with an emission wavelength in the range of a few nanometers, for example between 1 nm and 120 nm, particularly in the range of 13.5 nm, have been increasingly used. This wavelength range is also referred to as the EUV range.

[0003] In addition to systems operating in the EUV range, the microstructured components are also manufactured using the DUV systems established on the market with a wavelength between 100 nm and 400 nm, in particular 193 nm.

[0004] In composite optical arrangements, i.e., arrangements with multiple optical elements, it is important to correctly align the individual optical elements. This places high demands on the parallelism and centrality of the optical elements within the common frame.

[0005] It is known from the prior art to produce optical assemblies using precision optical turning. This is described, for example, in DE 10 2005 013 755 A1. A first lens is inserted into a mount and fixed in place. The optical axis of the first lens is determined in a reference coordinate system. Adhesive is applied to the first lens, and the second lens is placed on top of the first lens. The center of curvature of the outer sphere is determined, and the second lens is then adjusted to the calculated optical axis of the first lens.

[0006] The detection of the centers of curvature for determining the optical axes is additionally described in EP2458321 B1, DE102004029735 A1, DE102010053422 B3, and DE102014001151 A1.

[0007] A disadvantage of the methods described in the prior art is that drift effects can occur over time, particularly due to the curing of the adhesive. This leads to the optical elements within the mount not being absolutely stationary, so that their alignment and their alignment relative to each other change over time. Furthermore, manufacturing and assembly tolerances also lead to deviations in the alignment of the optical elements in the mount.

[0008] It is therefore an object of the present invention to provide a method for producing an optical arrangement, an optical arrangement, a measuring arrangement for carrying out the method, a projection exposure apparatus and a lithography apparatus in which the disadvantages described above are eliminated or at least reduced.

[0009] The problem concerning the method is solved by a method having the features of claim 1. The problem concerning the optical arrangement is solved by an optical arrangement according to the features of claim 15. The problem concerning the arrangement is solved by an arrangement having the features of claim 16. The problem concerning the projection exposure system is solved by a projection exposure system having the features of claim 18. The problem concerning the lithography system is solved by a lithography system having the features of claim 19. Advantageous embodiments with expedient further developments are specified in the subclaims.

[0010] The method for producing an optical arrangement of composite optical elements comprises in particular the following steps: a. Providing a socket with a first sub-socket formed in the socket with a first radius, b. Inserting and fixing a first optical element in the first sub-mount, c. Determining the optical axis of the first optical element and determining a deviation of the determined optical axis of the first optical element from a reference axis, d. Forming a further sub-mount with a second radius which is larger than the first radius of the first sub-mount by removing material from the mount in certain areas and thereby forming a support line in the further sub-mount, wherein a height of the support line is adjusted such that the deviation of the optical axis of the first optical element from the reference axis is at least partially compensated, and e. Inserting a further optical element into the further sub-mount such that the further optical element rests on the support line and fixing the further optical element in the further sub-mount.

[0011] This makes it possible to compensate for or at least reduce any incorrect alignment or formation of the first optical element by aligning the second optical element. For this purpose, the first optical element can simply be inserted into the first sub-mount without further alignment / adjustment, so that only a rotational movement of the first optical element about the optical axis and a translational movement along the x and y axes aligned perpendicular to the optical axis is possible. It is optionally advantageous if centering elements, for example flexure joints, are present radially, i.e. on the inner circumference, in the first sub-mount. This also makes it possible to center the first optical element in the first sub-mount. The optical elements are preferably fixed by means of an adhesive. The adhesive is preferably applied at specific points for this purpose.For this purpose, at least one access hole can be formed in the mount to supply the adhesive to the submounts from the outside. The adhesive can also radially surround the optical element, preferably completely, at least in some areas. A deviation of the optical axis from the reference axis preferably occurs when the optical axis deviates from the reference axis by a predetermined or predeterminable value.

[0012] In one embodiment, it is advantageous if no deviation of the optical axis from the reference axis is detected if the detected optical axis is arranged parallel to the reference axis, i.e., if it is displaced parallel. This is particularly advantageous if the processing machine is an eccentric high-precision lathe. In other words, only a deviation in the form of a tilt of the optical axis relative to the reference axis is considered a deviation. A deviation therefore exists if the optical axis is tilted by a predetermined or predeterminable value relative to the reference axis.

[0013] The optical axis is preferably determined by determining the center of curvature of the optical element, in particular by determining the center of curvature of one or both spheres of the optical element. The optical elements can be formed as lenses or as mirrors. The optical axis can also be determined indirectly within the scope of the invention by observing a movement of a beam guided through the first optical element on a detector during rotation of the mount, i.e. of the optical element and the mount, in the processing machine. If the reference axis, for example the axis of rotation or the beam axis, and the optical axis do not coincide with one another, an ellipsoidal movement of the beam is detected on the detector during the rotation of the mount.In order to align the optical axis of the optical element with the reference axis, the spindle with the mount is tilted until the detector no longer detects any movement despite the rotation of the mount, i.e. the position of the beam on the detector remains constant despite the rotation of the mount. This is precisely the case when the reference light beam is guided through the center of curvature or focus of the optical element. The support line is then formed when the spindle with the mount is tilted, which in turn creates a support line with a variable height. The optical elements can be formed, for example, as spherical, cylindrical, or flat mirrors or lenses. The reference axis is preferably an axis of a light source of a processing machine, wherein the processing machine is preferably an optical precision lathe for optical directional turning.The reference axis is preferably oriented perpendicular to a spindle of the lathe. Particularly preferably, the rotational axis of the machining center's spindle coincides with the reference axis, or the reference axis is arranged parallel to a rotational axis of the machining center's spindle. However, the reference axis can also be any axis in a 3D reference coordinate system.

[0014] To optimally align the additional optical element with respect to the first optical element, the second sub-mount is formed in the mount by material removal, i.e., in particular, by rotation. During the material removal, a support line is formed, or in other words, the material is removed around a support line, creating a support line. The height of this support line or the contact line between the additional sub-mount and the additional optical element is adjusted such that a deviation from the previously detected optical axis of the first optical element is compensated or at least reduced by the alignment of the additional optical element.Based on the deviation of the optical axis from the reference axis, an evaluation unit calculates how an additional optical element must be aligned (tilted) relative to the first optical element in order to reduce or compensate for this deviation or the optical effect of this deviation. Since the additional optical element rests on the support line, i.e. the contact line between the optical element and the additional sub-mount is the support line, the alignment of the additional optical element in the additional sub-mount can be achieved by adjusting the height of the support line. The support line forms a circle whose height varies. The height of the support line is adjusted, for example, by tilting the spindle of the processing machine on which the mount is arranged.Because the height of the support line differs in one area from another, the additional optical element rests on the support line at an angle relative to the reference axis. The height of the support line is understood to be the extension in a 3D reference coordinate system, preferably of the processing machine, i.e. the assembly, along the z-axis or along another reference axis. The contact line between the sub-mount and the additional optical element thus varies along the z-axis in this coordinate system. Adjusting the height of the support line during production of the support line by means of material removal, in turn, makes this possible individually for each combination of optical elements in a mount.

[0015] Particularly preferably, the further optical element rests exclusively on the support line. For this purpose, the further optical element has a contact line that rests exclusively on the support line. A direct connection between the further optical element and the further sub-frame is therefore preferably established exclusively via the support line.

[0016] Furthermore, it is advantageous if the height of the support line, and thus also the height of the contact line, decreases continuously, at least in some areas. This results in the arrangement of the additional optical element being tilted relative to the reference axis.

[0017] The support line preferably comprises a ring edge formed on a base of the additional sub-mount. In this context, it is advantageous if the radius of the ring edge is smaller than the second radius of the additional sub-mount and larger than the first radius of the first sub-mount.

[0018] Alternatively, it is advantageous if the support line comprises a roof edge that extends radially into the further sub-mount. The contact line of the further optical element preferably contacts the edge of the roof edge, i.e., the edge of the roof edge is the support line. The edge of the roof edge preferably has a radius that is smaller than the second radius of the further sub-mount and greater than, equal to, or smaller than the first radius of the first sub-mount. The roof edge can, in particular, be formed as one flexural joint or as several flexural joints, or can comprise at least one flexural joint.

[0019] Furthermore, it is preferred if the mount is monolithically formed. The mount has an opening through which a reference beam can be guided. The opening is preferably formed concentrically or at least approximately concentrically to the first sub-mount or to all sub-mounts. However, the mount can also have several separately formed sub-mounts that are subsequently connected to one another, for example, by being screwed or glued together.

[0020] Within the scope of the invention, it is provided that the optical elements are rotationally symmetrical. The optical elements can be formed as mirrors or lenses. Furthermore, the individual optical elements in a mount can also differ from one another. Thus, it is also possible for one optical element to be formed as a mirror and the other of the optical elements as a lens. Likewise, all optical elements can be formed as lenses. However, the lenses can also be formed differently. The optical elements can be formed as spherical or cylindrical optical elements, or as a flat optical element.

[0021] Alternatively, it is also possible for the support line to be formed as three support points or as separate sections with a support line, and for the height of the support points to be adjusted such that a deviation of the detected optical axis from the reference axis is compensated or at least reduced. In this context, it is provided that the height of at least two of the support points or sections differ from one another. The support points are arranged such that they are located on a common virtual circular line.

[0022] Furthermore, it is particularly preferred if the height of the cured adhesive is less than the height of the support line. In other words, the height of the adhesive during application is selected such that, in the cured state, it is less than the support line. This has the advantage that the optical elements are drawn to the support line as the adhesive cures. The adhesive can be applied pointwise or over a large area. The adhesive can also be arranged in the further sub-mount between the sub-mount and the support line.

[0023] Furthermore, it is particularly preferred if the first sub-mount of the mount is formed by removing material from the mount, thereby forming a support line, and if the first optical element is inserted into the first sub-mount such that the first optical element rests on the support line. By also forming the support line in the first sub-mount, it is possible to produce a mount that is more drift-stable. The height of the support line of the first sub-mount is preferably as constant as possible within the framework of manufacturing tolerances. The more constant the height along the circle of the support line, the smaller the deviation of the optical axis from the reference axis. The first optical element is preferably inserted into the first sub-mount without further adjustment.Optionally, solid-state joints or centering elements can be arranged radially in the first sub-mount, enabling centering of the first optical element in the first sub-mount without further adjustment. Particularly preferably, the first optical element rests exclusively on the support line. Apart from the feature of the adjusted height, the support line of the first sub-mount can have the same properties and embodiments as described in connection with the support line of the further sub-mount.

[0024] In order to enable a more precise alignment of the further optical element with respect to the first optical element, it is advantageous if the optical axis of the first optical element is only detected when an adhesive for fixing the first optical element in the first sub-mount has cured.

[0025] Within the scope of the invention, additional sub-mounts can also be formed in the mount, which are designed analogously to the further sub-mount. For this purpose, it is particularly preferred if, following step e., a resulting optical axis of the optical elements arranged in the mount is detected, and that a deviation of the resulting optical axis from the reference axis is determined, and that steps d. and e. are repeated for an additional optical element in such a way that, by adjusting the height of the support line for the additional sub-mount of the additional optical element, the deviation of the resulting optical axis from the reference axis is at least partially compensated. If the resulting axis deviates from the reference axis, the spindle with the mount is consequently tilted again in such a way that the reference axis and the optical axis coincide with one another.The support line is again formed by rotating the frame in a tilted orientation, so that here too the height of the support line varies along the circle of the support line. In this way, any number of additional sub-frames can be formed in the frame and an additional optical element, which is aligned with the other optical elements of the frame, can be applied to the support line. The additional optical element preferably rests exclusively on the support line, i.e. the additional optical element has a direct connection to the additional sub-frame exclusively via the support line. The adhesive creates an indirect connection between the additional optical element and the additional sub-frame.Preferably, the connections between the additional sub-mount and the additional optical element are made by means of the adhesive, thus the only indirect connections between the additional optical element and the additional sub-mount. The resulting optical axis is the optical axis composed of the optical axes of the first optical element and the further optical element.

[0026] Furthermore, it is advantageous if, following the formation of the last sub-mount provided for the frame and the insertion of the last optical element provided into the last sub-mount, a lateral surface of the frame is removed in such a way that the resulting optical axis, i.e. the optical axis of all optical elements of the frame, coincides with the reference axis or deviates by a maximum value. A deviation from the reference axis occurs in particular if the resulting optical axis is tilted relative to the reference axis by a predetermined or predeterminable value. No deviation can occur if the resulting optical axis is merely shifted parallel to the reference axis.

[0027] The invention further relates to an optical arrangement produced according to the method according to the invention. The optical arrangement has at least a first sub-mount and a further sub-mount. A first optical element is received and fixed in the first sub-mount, and a further optical element is received and fixed in the further sub-mount. A support line is formed at least in the further sub-mount, wherein the height, in particular a profile of the height, of the support line is adapted such that a deviation of the first optical axis of the first optical element from a reference axis is compensated for or at least reduced by the alignment of the further optical element. The further optical element is arranged in the further sub-mount in such a way that it rests on the support line. Particularly preferably, the further optical element rests exclusively on the support line.The support line forms a circle or an ellipse in the submount, with the height of the circle being adjusted to the support line in such a way that a deviation of the first optical axis from the reference axis is compensated or at least reduced. In other words, the contact line between the optical element and the support line varies in space / in the reference system. The advantages and embodiments mentioned in connection with the method are also applicable to the optical arrangement.

[0028] The invention further relates to an arrangement for carrying out the method, comprising a lathe with a holder for holding a frame, a light source which is configured to emit a light beam along a reference axis through an opening formed in the frame and a detector which is configured to detect the light beam passing through the frame, as well as with an evaluation unit which is configured to determine a deviation of an optical axis of at least one of the elements arranged in the holder from the reference axis and to cause the lathe to produce at least one further sub-frame with a support line adapted to the detected deviation.The evaluation unit is particularly designed to adjust the height or the profile of the height of the support line along a circle depending on the deviation of the optical axis from the reference axis, such that the detected deviation is compensated or at least reduced by the formation of the additional optical sub-mount. The advantages and embodiments mentioned in connection with the method are also applicable to the arrangement.

[0029] It is particularly advantageous if the light beam from the light source can be coupled into the socket by means of a fiber collimator.

[0030] The invention further relates to a projection exposure system having at least one optical arrangement produced by the method according to the invention. The advantages and embodiments mentioned in connection with the method and the optical arrangement are also applicable to the projection exposure system.

[0031] The invention further relates to a lithography system having at least one optical arrangement produced by the method according to the invention. The advantages and embodiments mentioned in connection with the method and the optical arrangement are also applicable to the lithography system.

[0032] The method according to the invention and the optical arrangement produced according to the method according to the invention can also be used in an inspection system for inspecting a shape, position or geometry of an object.

[0033] Further features, properties, and advantages of the present invention are described in more detail below using embodiments with reference to the accompanying figures. All features described so far and below are advantageous both individually and in any combination. The embodiments described below are merely examples and do not limit the subject matter of the invention. They show: Fig. 1a a schematic representation of a microlithographic projection exposure system designed for operation in the EUV, Fig. 1b a schematic representation of a microlithographic projection exposure system designed for operation in DUV, Fig. 2 to 8 a schematic representation of an embodiment of a method for producing an optical arrangement, Fig. 9 a schematic representation of an optical arrangement with two sub-mounts and a roof edge as a support line, Fig. 10 a plan view of the Fig. 9, Fig. 11 a schematic representation of another roof edge, and Fig. 12 a schematic representation of an optical arrangement with three sub-mounts.

[0034] Fig. 1a shows a schematic representation of an exemplary projection exposure system 600 designed for operation in the EUV, in which the present invention can be implemented.

[0035] According to Fig. 1a, an illumination device in a projection exposure system 600 designed for EUV comprises 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. A first telescope mirror 605 and a second telescope mirror 606 are arranged in the light path downstream of the pupil facet mirror 604. A deflection mirror 607 is arranged downstream in the light path, which deflects the radiation incident upon it 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 by means of the projection lens into an image plane in which a substrate 661 coated with a light-sensitive layer (photoresist) is located on a wafer table 660.

[0036] The invention can be used in a DUV system as well as in Fig. 1b. A DUV system is basically like the EUV system described above from the Fig. 1a, whereby 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 from 100 nm to 400 nm.

[0037] The Fig. The DUV lithography system 700 shown in Figure 1b has a DUV light source 701. An ArF excimer laser, for example, can be provided 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 that is imaged in a reduced size onto a wafer 706 or the like by means of the projection system 705. The projection system 705 has a plurality of lenses 707 and / or mirrors 708 for imaging the 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 can also be provided. In particular, the beam shaping and illumination system 703 of the DUV lithography system 700 has a plurality of lenses 707 and / or mirrors 708. Furthermore, the mirrors are usually curved at their front side for beam shaping. An air gap 710 between the last lens 707 and the wafer 706 can be replaced by a liquid medium having a refractive index > 1. The liquid medium can be, for example, ultrapure water. Such a setup is also referred to as immersion lithography and has an increased photolithographic resolution.

[0038] The Fig. 2 to 8 schematically show a sequence of the method for producing an optical arrangement 100 of composite optical elements 103, 108, 114. For this purpose, an arrangement 200 is provided with a lathe 201, a detector 204 designed as a camera, and a spindle 206 with a holder 202, on which a mount 101 or a blank from which a mount 101 is manufactured is fastened. In the present case, the mount 101 and the spindle have corresponding threads in order to connect the spindle 206 to the mount 101. In addition, the arrangement 200 has a light source 203, wherein the mount 101 is arranged on the spindle 206 such that the light beam of the light source 203 is directed onto the detector 204 through an opening 116 formed in the mount 101. The light beam of the light source 203 lies on the spindle axis, thus coincides with it and forms a reference axis 105, 205 of the arrangement 200.The light beam from light source 203 can alternatively be coupled into mount 101 using a fiber collimator (not shown in detail). First, a first sub-mount 101a with a first radius 102 is manufactured in mount 101 by removing material from mount 101 using lathe 201 or a chisel on lathe 201. Mount 101 rotates with spindle 206 about the spindle axis, i.e., about reference axis 205. During the formation of first sub-mount 101, a support line 112 can optionally be formed, i.e., left in place while the material is removed. Support line 112 forms a circle. The center point of support line 112 can, for example, lie on reference axis 205, 105.

[0039] In Fig. 3 shows that a first optical element 103 is inserted into the first sub-mount 101a and fixed by means of an adhesive 117. The first optical element 103 is preferably inserted into the first sub-mount 101a without further adjustment. This only allows a rotational movement of the first optical element 103 about the optical axis 104 and a translational movement along the x- and y-axes oriented perpendicular to the optical axis 104. Optionally, the first sub-mount can also comprise centering elements arranged radially in the first sub-mount 101a, for example, flexure joints. This additionally makes it possible to center the first optical element 103 in the first sub-mount 101a. The adhesive 117 for fixing the first optical element 103 in the first sub-mount 101a can be applied pointwise or over a large area. Furthermore, the adhesive 117 canFurthermore, it is particularly preferred if the height of the cured adhesive 117 is less than the height 118 of the support line 112. In other words, the height of the adhesive 117 during application is selected such that, in the cured state, it has a lower height than the support line 112.

[0040] During the manufacture of the first sub-mount 101a, manufacturing tolerances may occur such that, for example, the height 118a of the support line 112 varies or the height of the adhesive 117 varies. Furthermore, the first optical element 103 itself may have manufacturing tolerances. This may lead to a tilt of the first optical element 103 and thus to a tilt of the optical axis 104 of the first optical element 103, or generally to a deviation of the optical axis 104 of the first optical element 103 from a predetermined optical axis. In this case, the height of the support line 112 is the extension from the base of the mount along the z-axis of the reference system of the arrangement 200.In order to optimally align the following optical elements relative to the first optical element 103, the optical axis 104 of the first optical element 103 is first determined, and a deviation of the determined optical axis 104 from the reference axis 105 is determined. The optical axis 104 is determined, for example, by determining the center of curvature of the optical element 103, in particular by determining the center of curvature of one or both spheres of the optical element. The optical elements 103, 108, 114 can be formed as lenses or as mirrors. The optical elements 103, 108, 114 can be formed, in particular, as spherical, cylindrical, or flat mirrors. The reference axis 105, 205 in this case is the spindle axis or the light beam emitted by the light source 203, which is detected by the camera 204.A deviation of the optical axis 104 from the reference axis 105, 205 would be recognized, for example, by the fact that when the mount 101 is rotated about the spindle axis, the light beam incident on the camera 204 does not strike a point constantly or approximately constantly, but describes an ellipse or a circle.

[0041] An evaluation unit (not shown in detail) uses the deviation of the determined optical axis 104 from the reference axis 105, 205 to calculate how a further optical element 108 must be aligned relative to the first optical element 103 in order to reduce or compensate for this deviation or the optical effect of this deviation. Since the further optical element 108 is intended to rest on the support line, i.e., the contact line between the further optical element 108 and the further sub-mount 101b is the support line 107, the alignment of the further optical element in the further sub-mount can be achieved by adjusting the height of the support line 107 or by adjusting the height of the contact line between the support line 107 and the further sub-mount 101b.The spindle 206 (and thus the mount 101) is now shifted and / or tilted in such a way that the spindle axis, i.e. the reference axis 105, 205 and the optical axis 104, are aligned with each other, i.e. are coincident (cf. . Fig. 4). To enable a more precise alignment of the further optical element 108 with respect to the first optical element 103, the optical axis 104 of the first optical element 103 is preferably only detected once an adhesive 117 for fixing the first optical element 103 in the first sub-mount 101a has cured. Alternatively or additionally, the optical axis 104 is determined indirectly by observing a movement of the reference beam guided by the first optical element 103 on the detector 204 during the rotation of the mount 101, i.e., the first optical element 103 in the mount 101, in the processing machine. If the reference axis 105, 205, for example, the spindle axis or the beam axis, and the optical axis 104 do not coincide, an ellipsoidal movement of the reference beam is detected on the detector 204 during the rotation of the mount 101.In order to align the optical axis 103 of the optical element 103 with the reference axis 105, 205, the spindle 206 with the mount 101 is now tilted until the detector 204 detects no or only a slight movement despite the rotational movement of the mount 101, i.e., the position of the reference beam on the detector 204 is constant or approximately constant despite the rotational movement of the mount 101. This is precisely the case when the reference light beam is guided through the center of curvature or focus of the optical element 103. The formation of the support line 107 then occurs in the tilted state of the spindle 206 with the mount 101, which in turn creates a support line 107 with a variable height.

[0042] In a next step, the further sub-mount 101b is formed with a second radius 106 that is larger than the first radius 102 of the first sub-mount 101a by partially removing material from the mount 101 using a lathe. In this process, a support line 107 of the further sub-mount 101b is produced. Because the height 118b of the support line 107 deviates along the circle or ellipse it forms, the further optical element 103 rests on the support line 107 tilted relative to the reference axis 105, 205. This tilted arrangement or alignment of the further optical element 108 relative to the reference axis 105, 205 in turn makes it possible to compensate for or at least reduce any incorrect alignment or faulty formation of the first optical element 103.The adjustment of the height 118b of the support line 107 during the formation of the support line 107 by means of material removal again makes it possible to perform this individually for each combination of optical elements in a mount 101. Thus, by tilting the spindle 206, the height 118b of the support line 107 is adjusted such that the deviation of the optical axis 104 of the first optical element 103 from the reference axis 105, 205 is at least partially compensated (cf. ). Fig. 5). Alternatively, it is also possible for the support line 107, 112 to be formed as three support points or as separate sections with a support line 107, 112. In this context, the height 118 of at least two of the support points or sections differs from each other. The support points are arranged on a common virtual circular line.

[0043] In the next step, the additional optical element 108 is inserted into the additional sub-mount 101b such that the additional optical element 108 rests on the support line 107 and preferably exclusively on the support line 107. The additional optical element 108 is in turn fixed in the additional sub-mount 101b by means of an adhesive 117. The adhesive 117 can also be introduced via a channel formed in the mount (not shown in detail) (see Fig. 6).

[0044] Subsequently, the holder 202 of the spindle 206 and the edge of the socket, i.e. a lateral surface 120 of the socket, are turned off (cf. Fig. 7), such that the resulting optical axis 113 coincides with the axis of the mount 119.

[0045] The outer surface 120 of the socket is then clamped and the thread is turned off.

[0046] In Fig. Figure 8 shows an example of an optical arrangement 100 produced using the method. The optical arrangement 100 has the advantage that adjustment of the individual optical elements 103, 108 is possible independently of the mount 101, such that all optical elements 103, 108 lie on a common (resulting) optical axis 113. The mount 101 is preferably formed monolithically in the present case. This makes it possible to compensate for or at least reduce an incorrect alignment or formation of the first optical element 103 by means of the alignment of the second optical element 108. For this purpose, the optical arrangement 100 has at least a first sub-mount 101a with a first radius 102 and a further sub-mount 101b with a second radius 106.A first optical element 103 is accommodated and fixed in the first sub-mount 101a, and a further optical element 108 is accommodated and fixed in the further sub-mount 101b. Both sub-mounts 101a and 101b each have a support line 107, 112 on which the optical elements 103 and 108 are arranged, respectively. The exclusive, direct connection between the sub-mount 101a,b and the respective optical element 103,108 is therefore the support line 107,112. The height 118b of the support line 107,112, i.e., the course of the height 118b along the circle or ellipse formed by the support line 107,113, of the further sub-mount 101b is adjusted such that a deviation of the optical axis 104 of the first optical element 103 from a reference axis 105,205 is compensated or at least reduced by the alignment of the further optical element 108. The support line 112 of the first sub-mount 101a is optional.In this case, the support lines comprise an annular cutting edge 110. The radius of the annular cutting edge 110 is smaller than the second radius 106 of the further sub-mount 101b and larger than the first radius 102 of the first sub-mount 101a. The support line 112 of the first sub-mount 101a can also have an annular cutting edge 110. The optical elements 103, 108 are rotationally symmetrical. The optical elements 103, 108, 114 can be formed as mirrors or as lenses. Furthermore, the individual optical elements 103, 108, 114 in a mount 101 can also differ from one another. Thus, it is also possible for one optical element to be formed as a mirror and the other of the optical elements as a lens. Likewise, all of the optical elements 103, 108, 114 can be formed as lenses. However, the lenses can also be formed differently.The optical elements 103, 108, 114 can be formed as spherical or cylindrical optical elements or as a planar optical element.

[0047] In the Fig. 9, Fig. 10 and Fig. 11 shows an alternative embodiment of the support line 107, 112. For this purpose, the support line 107, 112 comprises a roof edge 111 projecting radially into the sub-mount 101a, 101b. The edge of the roof edge 111 forms the support line 107 for the optical elements 103, 108, 114. The roof edge 110 is preferably formed in one piece and has a web projecting radially from the sub-mount 101a, 101b toward the center of the mount 101. In Fig. 11, the roof edge 110 is reversed so that the optical element 103, 108, 114 can be inserted the other way around.

[0048] Fig.12 shows an optical arrangement with three sub-mounts 101a, 101b, 101c. The additional sub-mount 101c can be formed analogously to the further sub-mount 101b. For this purpose, following the insertion of the further optical element 108, a resulting optical axis 113 of the optical elements 103, 108 arranged in the mount 101 is determined. If this axis deviates from the reference axis 105, 205, the spindle 206 is tilted or translated again such that the resulting optical axis 113 coincides with the reference axis 105, 205. The additional sub-mount 101c is then formed again by removing the material using the lathe 201, whereby a support line 115 with an adjusted height 118c is again formed.By adjusting the height 118c of the support line 115, i.e., the height profile along the circle or ellipse formed by the support line 115, of the additional sub-mount 101c for the additional optical element 114, the deviation of the resulting optical axis 113 from the reference axis 105, 205 is at least partially compensated. The additional optical element 113 is inserted into the additional sub-mount 101c such that it rests, preferably exclusively, on the support line 115.

[0049] The additional optical element 115 is then fixed in the additional sub-mount 101c by means of an adhesive 117. In this way, any number of additional sub-mounts 101c can be formed in the monolithic mount 101. The adhesive 117 establishes an indirect connection between the additional optical element 115 and the additional sub-mount 101c. Preferably, the connection between the additional sub-mount 101c and the additional optical element 115 by means of the adhesive 117 is the only, i.e., exclusive, indirect connection between the additional optical element 115 and the additional sub-mount 101c. The resulting optical axis 113 is the optical axis composed of the optical axes of the first optical element 103 and the further optical element 108.Subsequently, the holder 202 of the spindle 206 and the edge of the mount, i.e., a peripheral surface 120 of the mount, are machined such that the resulting optical axis 113 coincides with the reference axis 105 or deviates by a maximum of a predetermined or predeterminable value. The reference axis 105 is preferably the axis of rotation of the processing machine, a virtual axis arranged parallel to the axis of rotation, or any arbitrary axis in space. Subsequently, the peripheral surface 120 of the mount is clamped, and the thread is machined. LIST OF REFERENCE SYMBOLS 100 optical arrangement 101 version 101a first subversion 101b further subversion 101c additional subversion 102 first radius (first sub-version) 103 first optical element 104 optical axis (of the first optical element) 105 Reference axis 106 second radius (of the further sub-version) 107 Edition line (further subversion) 108 additional optical element 109 Floor (of the sub-frame) 110 ring cutting edge 111 roof edge 112 Edition line (first sub-version) 113 resulting optical axis 114 additional optical element 115 Edition line (additional sub-version) 116 Opening 117 Fixatives 118a Height of support line of first optical element 118b Height of support line of additional optical element 118c Height support line additional optical element 120 Surface area of ​​the socket 200 arrangement 201 Lathe 202 bracket 203 Light source 204 Detector 205 Reference axis 206 spindle 600 projection exposure system 601 plasma light source 602 collector mirror 603 field facet mirror 604 Pupillary facet mirror 605 first telescope mirror 606 second telescope mirror 607 Deflecting mirror 620 Mask table 621 Mask 651 Mirror (projection lens) 652 mirror (projection lens) 653 Mirror (projection lens) 654 mirror (projection lens) 655 Mirror (projection lens) 656 mirrors (projection lens) 660 wafer table 661 coated substrate 700 DUV lithography system 701 DUV light source 702 DUV radiation / beam path 703 Beam Forming and Illumination System (DUV) 704 Photomask 705 projection system 706 wafers 707 lens 708 mirrors 709 optical axis QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] DE 10 2005 013 755 A1

[0005] EP 2458321 B1

[0006] DE 102004029735 A1

[0006] DE 102010053422 B3

[0006] DE 102014001151 A1

[0006]

Claims

[1] A method for manufacturing an optical assembly (100) of composite optical elements comprising the following steps: a. Providing a socket (101) with a first sub-socket (101a) formed in the socket (101) with a first radius (102), b. Inserting and fixing a first optical element (103) in the first sub-mount (101a), c. Determining the optical axis (104) of the first optical element (103) and determining a deviation of the determined optical axis (104) of the first optical element (103) from a reference axis (105), d. Forming a further sub-mount (101b) with a second radius (106) which is greater than the first radius (102) of the first sub-mount (101a) by removing material from the mount (101) in some areas and thereby forming a support line (107) in the further sub-mount (101b), wherein a height of the support line (107) is adjusted such that the deviation of the optical axis (104) of the first optical element (103) from the reference axis (105) is at least partially compensated, and e. Inserting a further optical element (108) into the further sub-mount (101b) such that the further optical element (108) rests on the support line (107) and fixing the further optical element (108) in the further sub-mount (101b). [2] Method according to claim 1, characterized by that the further optical element (108) rests exclusively on the support line (107). [3] Method according to claim 1 or 2, characterized bythat the height of the support line (107) decreases continuously, at least in some areas. [4] Method according to one of claims 1 to 3, characterized by that the support line (107) comprises or is formed as an annular cutting edge (110) formed on a base (109) of the further sub-mount (101b). [5] Method according to claim 4, characterized by that a radius of the annular cutting edge (110) is smaller than the second radius (106) of the further sub-mount (101b) and larger than the first radius (102) of the first sub-mount (101a). [6] Method according to one of claims 1 to 5, characterized by that the support line (107) comprises a roof edge (111) projecting radially into the further sub-frame (101b). [7] Method according to one of claims 1 to 6, characterized by that the socket (101) is formed monolithically. [8] Method according to one of claims 1 to 7, characterized bythat the optical elements (103, 108) are rotationally symmetrical. [9] Method according to one of claims 1 to 8, characterized by that the support line (107) is formed as three support points or as sections formed separately from one another. [10] Method according to one of claims 1 to 9, characterized by that the height of the cured adhesive for fixing the optical elements (103, 108) in the sub-mount (101a, 101b) is less than the height of the support line (107). [11] Method according to one of claims 1 to 10, characterized by that the first sub-mount (101a) of the mount (101) is formed by removing material from the mount (101) and in the process forming a support line (112), and that the first optical element (103) is inserted into the first sub-mount (101a) such that the first optical element (103) rests on the support line (112). [12] Method according to one of claims 1 to 11, characterized by that the optical axis (104) of the first optical element (103) is only detected when an adhesive for fixing the first optical element (103) in the first sub-mount (101a) has hardened. [13] Method according to one of claims 1 to 12, characterized by that following step e., a resulting optical axis (113) of the optical elements (103, 108) arranged in the mount (101) is detected, and that a deviation of the resulting optical axis (113) from the reference axis (105) is determined, and that steps d. and e. are repeated for an additional optical element (114) in such a way that by adjusting the height of the support line (115) for the additional sub-mount (101c) of the additional optical element (114), the deviation of the resulting optical axis (113) from the reference axis (105) is at least partially compensated. [14] Method according to one of claims 1 to 13, characterized by that following the formation of the last sub-mount (101) provided for the mount and the insertion of the last optical element (103) provided into the sub-mount (101), a lateral surface (120) of the mount (101) is removed in such a way that a resulting optical axis (113) coincides with the reference axis (105) or deviates by a maximum of a predetermined or predeterminable value. [15] Optical arrangement (100) manufactured according to the method according to one of claims 1 to 14. [16] Arrangement (200) for carrying out the method according to one of claims 1 to 14, comprising a lathe (201) with a holder (202) for receiving the mount (101), a light source (203) which is designed to emit a light beam along a reference axis (105, 205) through an opening (116) formed in the mount, and a detector (204) which is designed to detect the light beam passing through the mount (101), as well as an evaluation unit (205) which is designed to determine a deviation of an optical axis (104, 113) of at least one of the optical elements (103, 108, 114) arranged in the holder (202) from the reference axis (105, 205) and to cause the lathe (201) to produce at least one further sub-mount (101b, 101c) with a light source adapted to the detected deviation. support line (107, 115). [17] Arrangement according to claim 16, characterized bythat the light beam of the light source (203) can be coupled into the socket (101) by means of a fiber collimator. [18] Projection exposure apparatus with at least one optical arrangement (100) produced by means of the method according to one of claims 1 to 14. [19] Lithography system with at least one optical arrangement (100) produced by the method according to one of claims 1 to 14.

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