DE102022203881A1 - CIRCUIT BOARD FOR AN OPTICAL SYSTEM, OPTICAL SYSTEM, LITHOGRAPHY EQUIPMENT AND METHOD FOR MANUFACTURING A CIRCUIT BOARD FOR AN OPTICAL SYSTEM - Google Patents

Abstract

A circuit board (24) for an optical system (4, 10) of a lithography system (1) is proposed, with a first conductor track (100) having at least a first section (110) and a second conductor track (200) having at least a second section (220), wherein the first conductor track (100) and the second conductor track (200) are arranged on different levels of the printed circuit board (24), the first section (110) and the second section (220) being parallel in a projection plane (P). are arranged on different sides of the axis (A) relative to the printed circuit board level (L) with respect to an axis (A) lying in the projection plane (P).

Description

The present invention relates to a printed circuit board for an optical system of a lithography system, an optical system with such a printed circuit board, a lithography system with such an optical system and a method for producing a printed circuit board for an optical system of a lithography system.

Microlithography is used to produce microstructured components such as integrated circuits. The microlithography process is carried out using a lithography system which has an illumination system and a projection system. The image of a mask (reticle) illuminated by the illumination system is projected by the projection system onto a substrate coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection system, for example a silicon wafer, in order to place the mask structure on the light-sensitive coating of the substrate transferred to.

Driven by the striving for ever smaller structures in the manufacture of integrated circuits, EUV lithography systems are currently being developed which use light with a wavelength in the range from 0.1 nm to 30 nm, in particular 13.5 nm. Since most materials absorb light of this wavelength, reflective optics, ie mirrors, must be used in such EUV lithography systems instead of—as before—refractive optics, ie lenses.

A large number of actuator/sensor devices, such as sensors and actuators, are installed in lithography systems. In general, an actuator/sensor device is suitable for displacing an optical element assigned to the actuator/sensor device, such as a mirror, and/or a parameter of the assigned optical element, such as a position of the assigned optical element or a temperature of the assigned optical element to detect. Such an actuator/sensor device must be electrically connected to an integrated circuit (IC) for activation and evaluation. Integrated circuits are assembled on printed circuit boards (also called printed circuit boards), and the assembled printed circuit boards are installed in the lithography system.

Conventional printed circuit boards have parallel conductor tracks. However, if a magnetic field acts on the parallel conductor tracks of the conventional printed circuit board, a disruptive voltage is disadvantageously induced in the conductor tracks. Such a disruptive voltage can significantly disrupt the control and/or evaluation of an actuator/sensor device in the lithography system.

Against this background, it is an object of the present invention to provide an improved circuit board for an optical system.

According to a first aspect, a circuit board for an optical system of a lithography system is proposed, which has a first conductor track having at least a first section and a second conductor track having at least a second section, the first conductor track and the second conductor track being arranged on different levels of the circuit board , wherein the first section and the second section are arranged in a plane of projection parallel to the plane of the circuit board with respect to an axis lying in the plane of projection on different sides of the axis.

The fact that the first section and the second section are arranged in the projection plane parallel to the circuit board plane on different sides of the axis with respect to the axis lying in the projection plane results in a first magnetic field resulting from a current flow through the first conductor track and a at least partially cancel the second magnetic field resulting from a current flow through the second conductor track.

In addition, interference that affects the first conductor track and the second conductor track from outside is minimized. A disturbance which acts on the conductor tracks, for example due to an external (homogeneous) electromagnetic field, is at least partially eliminated or completely eliminated by the presently proposed arrangement of the conductor tracks. Overall, an EMC-robust cable routing of the conductor tracks on the printed circuit board is created in the present case.

The printed circuit board can also be referred to as a printed circuit board. The optical system is preferably projection optics of the lithography system or projection exposure system. However, the optical system can also be an illumination system. The projection exposure system can be an EUV lithography system. EUV stands for "Extreme Ultraviolet" and designates a working light wavelength between 0.1 nm and 30 nm. The projection exposure system can also be a DUV lithography system. DUV stands for "Deep Ultraviolet" and describes a working light wavelength between 30 nm and 250 nm.

According to one embodiment, the first section and the second section are arranged in the projection plane symmetrically to the axis lying in the projection plane.

According to a further embodiment, the first interconnect comprises a plurality of first sections and the second interconnect comprises a plurality of second sections. In this case, one of the first sections and one of the second sections are arranged in the projection plane on different sides of the axis lying in the projection plane.

According to a further embodiment, one of the first sections and one of the second sections are arranged in the projection plane symmetrically to the axis lying in the projection plane.

According to a further embodiment, one of the first sections and one of the second sections intersect in the projection plane at a crossing point. The crossing point lies in particular on the axis lying in the projection plane.

According to a further embodiment, the first section and the second section each consist of a first section and a second section. In the projection plane, the first section of the first section and the first section of the second section are symmetrical with respect to the axis lying in the projection plane, and the second section of the first section and the second section of the second section are also symmetrical with respect to the axis lying in the projection plane .

According to a further embodiment, the first section and the second section of the first section and the first section and the second section of the second section are each semicircular.

According to a further embodiment, the first section and the second section of the first section and the first section and the second section of the second section are each trapezoidal.

According to a further embodiment, the first section and the second section each have the shape of a sinus. In this case, the sine of the first section is preferably shifted by 180° to the sine of the second section.

According to a further embodiment, the printed circuit board has at least one flexible area which at least partially encompasses the first conductor track and the second conductor track.

The flex area can be part of the circuit board, but it can also be the entire circuit board. The use of the flexible area of the printed circuit board significantly increases flexibility during installation in the lithography system. This is of particular advantage in light of the prevailing space restrictions in the optical systems of the lithography system.

According to a further embodiment, a flexible component comprising an integrated circuit is additionally arranged on the flexible area.

By arranging the flexible component and thus the integrated circuit (IC; Integrated Circuit) on the flexible area of the printed circuit board, the flexibility when installing the integrated circuit in the lithography system is significantly increased. This is of particular advantage in light of the prevailing space restrictions in lithography systems.

Consequently, integrated circuits can also be installed in the lithography system in the bent state. As a result, possible interference in an actuator/sensor device connected to the integrated circuit can advantageously be reduced or prevented. Such possible interference includes, in particular, interference from heat generated by the integrated circuit and electromagnetic interference.

Due to the flexibility of the flexible printed circuit board and the flexible IC, it is possible in applications to minimize the length of the electrical lines required to connect the IC and the actuator/sensor device. Such a minimization of the length of the electrical lines also reduces signal propagation lengths and thus reduces the influence of possible interference in data transmission and control. The reduction in heat input from the IC to the associated actuator/sensor device also advantageously results in a lower thermal load on the optics.

The flexible area of the printed circuit board can also be referred to as the flexible area. The flexible component can also be referred to as a flexible component. Correspondingly, the flexible integrated circuit can also be referred to as a flexible integrated circuit or as a flexible IC or as a flex IC.

According to a further embodiment, the flexible component includes a logic module, a processor, an analog-to-digital converter and/or a digital-to-analog converter.

According to a further embodiment, the flexible component has a flexible substrate on which the integrated circuit and the conductor tracks are arranged.

According to a further embodiment, the flexible component has a flexible substrate on which the integrated circuit is manufactured.

According to a further embodiment, the flexible area of the printed circuit board and the component arranged on the flexible area are arranged, in particular installed, in a bent state in the optical system. Such a bent state brings space-specific advantages in applications. Furthermore, the bent state can advantageously reduce or prevent possible interference in an actuator/sensor device connected to the integrated circuit.

According to a further embodiment, the printed circuit board integrates the at least one flexible area and the flexible component comprising the integrated circuit.

According to a further embodiment, the printed circuit board has the at least one flexible area and at least one rigid area connected to the flexible area.

According to a further embodiment, the circuit board has two rigid areas between which the flexible area is arranged.

• - zwei unterschiedliche Leiterplattenlagen der Leiterplatte,
• - eine Oberseite der Leiterplatte und eine der Leiterplattenlagen der Leiterplatte,
• - eine Unterseite der Leiterplatte und eine der Leiterplattenlagen der Leiterplatte, oder
• - die Oberseite der Leiterplatte und die Unterseite der Leiterplatte.

According to a further embodiment, the different levels of the circuit board on which the first conductor track and the second conductor track are arranged are formed by:

• - two different circuit board layers of the circuit board,
• - a top of the circuit board and one of the circuit board layers of the circuit board,
• - an underside of the printed circuit board and one of the printed circuit board layers of the printed circuit board, or
• - the top of the circuit board and the bottom of the circuit board.

According to a second aspect, an optical system for a lithography system is proposed, the optical system having a circuit board according to the first aspect or according to one of the embodiments of the first aspect.

According to one embodiment, the optical system is in the form of illumination optics or projection optics of a lithography system.

According to a further embodiment, the optical system also comprises a number of actuator/sensor devices, the flexible component being connected to the number of actuator/sensor devices using at least one conductor track of the printed circuit board. The respective actuator/sensor device is, for example, an actuator (or actuator) for actuating an optical element, a sensor for sensing an optical element or an environment in the optical system, or an actuator and sensor device for actuating and sensing in the optical system. The sensor is a temperature sensor, for example. The actuator is, for example, a PMN actuator (PMN; Lead Magnesium Niobate) or a PZT actuator (PZT; Lead Zirconate Titanate). The actuator is set up in particular to actuate an optical element of the optical system. Examples of such an optical element include lenses, mirrors and adaptive mirrors.

According to a further embodiment, the optical system comprises a number of displaceable optical elements for guiding radiation in the optical system, with the respective optical element being assigned at least one of the actuator/sensor devices, with the respective actuator/sensor device for displacing the associated optical element and/or for detecting a parameter of the associated optical element, in particular a position of the associated optical element or a temperature in the region of the associated optical element.

According to a further embodiment, the optical system has a vacuum housing in which the printed circuit board is arranged.

According to a third aspect, a lithography system is proposed which has an optical system according to the second aspect or according to one of the embodiments of the second aspect.

According to a fourth aspect, a method for producing a circuit board for an optical system of a lithography system is proposed. The method includes arranging a first conductor track having at least a first section and a second conductor track aufwei send at least one second section on different planes of the printed circuit board, the first section and the second section being arranged in a plane of projection parallel to the plane of the printed circuit board on different sides of the axis with respect to an axis lying in the plane of projection.

The embodiments described for the proposed printed circuit board apply correspondingly to the proposed method and vice versa. Furthermore, the definitions and explanations for the optical system and for the lithography system also apply accordingly to the proposed method.

"A" is not necessarily to be understood as being limited to exactly one element. Rather, a plurality of elements, such as two, three or more, can also be provided. Any other count word used here should also not be understood to mean that there is a restriction to precisely the stated number of elements. Rather, numerical deviations upwards and downwards are possible, unless otherwise stated.

Further possible implementations of the invention also include combinations of features or embodiments described above or below with regard to the exemplary embodiments that are not explicitly mentioned. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

• 1 zeigt einen schematischen Meridionalschnitt einer Projektionsbelichtungsanlage für eine EUV-Projektionslithographie;
• 2 zeigt eine schematische Darstellung einer ersten Ausführungsform einer Leiterplatte für ein optisches System einer Lithographieanlage;
• 3 zeigt die erste Ausführungsform der Leiterplatte nach 2 mit eingezeichneten magnetischen Feldern;
• 4 zeigt eine schematische Darstellung einer zweiten Ausführungsform einer Leiterplatte für ein optisches System einer Lithographieanlage;
• 5 zeigt eine schematische Darstellung einer dritten Ausführungsform einer Leiterplatte für ein optisches System einer Lithographieanlage; und
• 6 zeigt eine schematische Ansicht einer Ausführungsform eines Verfahrens zum Herstellen einer Leiterplatte für ein optisches System einer Lithographieanlage.

Further advantageous refinements and aspects of the invention are the subject matter of the dependent claims and of the exemplary embodiments of the invention described below. The invention is explained in more detail below on the basis of preferred embodiments with reference to the enclosed figures.

• 1 shows a schematic meridional section of a projection exposure apparatus for EUV projection lithography;
• 2 shows a schematic representation of a first embodiment of a printed circuit board for an optical system of a lithography system;
• 3 12 shows the first embodiment of the printed circuit board 2 with marked magnetic fields;
• 4 shows a schematic representation of a second embodiment of a printed circuit board for an optical system of a lithography system;
• 5 shows a schematic representation of a third embodiment of a printed circuit board for an optical system of a lithography system; and
• 6 shows a schematic view of an embodiment of a method for producing a printed circuit board for an optical system of a lithography system.

Elements that are the same or have the same function have been provided with the same reference symbols in the figures, unless otherwise stated. Furthermore, it should be noted that the representations in the figures are not necessarily to scale.

1 shows an embodiment of a projection exposure system 1 (lithography system), in particular an EUV lithography system. One embodiment of an illumination system 2 of the projection exposure system 1 has, in addition to a light or radiation source 3, illumination optics 4 for illuminating an object field 5 in an object plane 6. In an alternative embodiment, the light source 3 can also be provided as a separate module from the rest of the illumination system 2. In this case, the lighting system 2 does not include the light source 3 .

A reticle 7 arranged in the object field 5 is exposed. The reticle 7 is held by a reticle holder 8 . The reticle holder 8 can be displaced via a reticle displacement drive 9, in particular in a scanning direction.

In the 1 a Cartesian coordinate system with an x-direction x, a y-direction y and a z-direction z is drawn in for explanation. The x-direction x runs perpendicularly into the plane of the drawing. The y-direction y runs horizontally and the z-direction z runs vertically. The scanning direction is in the 1 along the y-direction y. The z-direction z runs perpendicular to the object plane 6.

The projection exposure system 1 includes projection optics 10. The projection optics 10 are used to image the object field 5 in an image field 11 in an image plane 12. The image plane 12 runs parallel to the object plane 6. Alternatively, there is also an angle other than 0° between the object plane 6 and the Image plane 12 possible.

A structure on the reticle 7 is imaged onto a light-sensitive layer of a wafer 13 arranged in the region of the image field 11 in the image plane 12 . The wafer 13 is held by a wafer holder 14 . The wafer holder 14 can be displaced in particular along the y-direction y via a wafer displacement drive 15 . The displacement on the one hand of the reticle 7 via the reticle displacement drive 9 and on the other hand of the wafer 13 via the Wafer displacement drive 15 can be synchronized with each other.

The light source 3 is an EUV radiation source. The light source 3 emits in particular EUV radiation 16, which is also referred to below as useful radiation, illumination radiation or illumination light. The useful radiation 16 has in particular a wavelength in the range between 5 nm and 30 nm. The light source 3 can be a plasma source, for example an LPP source (Engl .: Laser Produced Plasma, plasma generated with the help of a laser) or a DPP (Gas Discharged Produced Plasma) source. It can also be a synchrotron-based radiation source. The light source 3 can be a free-electron laser (FEL).

The illumination radiation 16 emanating from the light source 3 is bundled by a collector 17 . The collector 17 can be a collector with one or more ellipsoidal and/or hyperboloidal reflection surfaces. The at least one reflection surface of the collector 17 can be in grazing incidence (Engl.: Grazing Incidence, GI), i.e. with angles of incidence greater than 45°, or in normal incidence (Engl.: Normal Incidence, NI), i.e. with incidence angles smaller than 45° , are acted upon by the illumination radiation 16 . The collector 17 can be structured and/or coated on the one hand to optimize its reflectivity for the useful radiation and on the other hand to suppress stray light.

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

The illumination optics 4 comprises a deflection mirror 19 and a first facet mirror 20 downstream of this in the beam path. The deflection mirror 19 can be a plane deflection mirror or alternatively a mirror with an effect that influences the bundle beyond the pure deflection effect. Alternatively or additionally, the deflection mirror 19 can be designed as a spectral filter, which separates a useful light wavelength of the illumination radiation 16 from stray light of a different wavelength. If the first facet mirror 20 is arranged in a plane of the illumination optics 4 which is optically conjugate to the object plane 6 as the field plane, it is also referred to as a field facet mirror. The first facet mirror 20 includes a multiplicity of individual first facets 21, which can also be referred to as field facets. Of these first facets 21 are in the 1 only a few shown as examples.

The first facets 21 can be embodied as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or part-circular edge contour. The first facets 21 can be embodied as planar facets or alternatively as convexly or concavely curved facets.

Like for example from the DE 10 2008 009 600 A1 is known, the first facets 21 themselves can each also be composed of a large number of individual mirrors, in particular a large number of micromirrors. The first facet mirror 20 can be embodied in particular as a microelectromechanical system (MEMS system). For details refer to the DE 10 2008 009 600 A1 referred.

The illumination radiation 16 runs horizontally between the collector 17 and the deflection mirror 19, ie along the y-direction y.

A second facet mirror 22 is arranged downstream of the first facet mirror 20 in the beam path of the illumination optics 4. If the second facet mirror 22 is arranged in a pupil plane of the illumination optics 4, it is also referred to as a pupil facet mirror. The second facet mirror 22 can also be arranged at a distance from a pupil plane of the illumination optics 4 . In this case, the combination of the first facet mirror 20 and the second facet mirror 22 is also referred to as a specular reflector. Specular reflectors are known from US 2006/0132747 A1 , the EP 1 614 008 B1 and the U.S. 6,573,978 .

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

The second facets 23 can also be macroscopic facets, which can have round, rectangular or hexagonal borders, for example, or alternatively facets composed of micromirrors. In this regard, also on the DE 10 2008 009 600 A1 referred.

The second facets 23 can have plane or alternatively convexly or concavely curved reflection surfaces.

The illumination optics 4 thus forms a double-faceted system. This basic principle is also known as a honeycomb condenser (English: Fly's Eye Integrator).

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

The individual first facets 21 are imaged in the object field 5 with the aid of the second facet mirror 22 . The second facet mirror 22 is the last beam-forming mirror or actually the last mirror for the illumination radiation 16 in the beam path in front of the object field 5.

In another embodiment of the illumination optics 4 that is not shown, transmission optics can be arranged in the beam path between the second facet mirror 22 and the object field 5 , which particularly contributes to the imaging of the first facets 21 in the object field 5 . The transmission optics can have exactly one mirror, but alternatively also have two or more mirrors, which are arranged one behind the other in the beam path of the illumination optics 4 . The transmission optics can in particular comprise one or two mirrors for normal incidence (NI mirror, normal incidence mirror) and/or one or two mirrors for grazing incidence (GI mirror, grazing incidence mirror).

The illumination optics 4 has the version in which 1 shown, exactly three mirrors after the collector 17, namely the deflection mirror 19, the first facet mirror 20 and the second facet mirror 22.

In a further embodiment of the illumination optics 4, the deflection mirror 19 can also be omitted, so that the illumination optics 4 can then have exactly two mirrors after the collector 17, namely the first facet mirror 20 and the second facet mirror 22.

The imaging of the first facets 21 by means of the second facets 23 or with the second facets 23 and transmission optics in the object plane 6 is generally only an approximate imaging.

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

At the in the 1 example shown, the projection optics 10 includes six mirrors M1 to M6. Alternatives with four, eight, ten, twelve or another number of mirrors Mi are also possible. The projection optics 10 are doubly obscured optics. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection optics 10 has an image-side numerical aperture which is greater than 0.5 and which can also be greater than 0.6 and which, for example, is 0.7 or 0.75.

Reflection surfaces of the mirrors Mi can be designed as free-form surfaces without an axis of rotational symmetry. Alternatively, the reflection surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflection surface shape. Just like the mirrors of the illumination optics 4, the mirrors Mi can have highly reflective coatings for the illumination radiation 16. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

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

The projection optics 10 can in particular be anamorphic. In particular, it has different image scales βx, βy in the x and y directions x, y. The two image scales βx, βy of the projection optics 10 are preferably at (βx, βy)=(+/−0.25, /+−0.125). A positive image scale β means an image without image reversal. A negative sign for the imaging scale B means imaging with image inversion.

The projection optics 10 thus leads to a reduction in the ratio 4:1 in the x-direction x, ie in the direction perpendicular to the scanning direction.

The projection optics 10 lead to a reduction of 8:1 in the y-direction y, ie in the scanning direction.

Other imaging scales are also possible. Image scales with the same sign and absolutely the same in the x and y directions x, y, for example with absolute values of 0.125 or 0.25, are also possible.

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

In each case one of the second facets 23 is assigned to precisely one of the first facets 21 in order to form a respective illumination channel for illuminating the object field 5 . In this way, in particular, lighting can result according to Köhler's principle. The far field is broken down into a large number of object fields 5 with the aid of the first facets 21 . The first facets 21 generate a plurality of images of the intermediate focus on the second facets 23 assigned to them.

The first facets 21 are each imaged onto the reticle 7 by an associated second facet 23 in a superimposed manner in order to illuminate the object field 5 . In particular, the illumination of the object field 5 is as homogeneous as possible. It preferably has a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

The illumination of the entrance pupil of the projection optics 10 can be defined geometrically by arranging the second facets 23 . The intensity distribution in the entrance pupil of the projection optics 10 can be set by selecting the illumination channels, in particular the subset of the second facets 23 that guide light. This intensity distribution is also referred to as illumination setting or illumination pupil filling.

A likewise preferred pupil uniformity in the area of defined illuminated sections of an illumination pupil of the illumination optics 4 can be achieved by redistributing the illumination channels.

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

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

The entrance pupil of the projection optics 10 cannot regularly be illuminated exactly with the second facet mirror 22 . When imaging the projection optics 10, which telecentrically images the center of the second facet mirror 22 onto the wafer 13, the aperture rays often do not intersect at a single point. However, a surface can be found in which the distance between the aperture rays, which is determined in pairs, is minimal. This surface represents the entrance pupil or a surface conjugate to it in position space. In particular, this surface shows a finite curvature.

The projection optics 10 may have different positions of the entrance pupil for the tangential and for the sagittal beam path. In this case, an imaging element, in particular an optical component of the transmission optics, should be provided between the second facet mirror 22 and the reticle 7 . With the help of this optical element, the different positions of the tangential entrance pupil and the sagittal entrance pupil can be taken into account.

At the in the 1 shown arrangement of the components of the illumination optics 4, the second facet mirror 22 is arranged in a conjugate to the entrance pupil of the projection optics 10 surface. The first facet mirror 20 is arranged tilted to the object plane 6 . The first facet mirror 20 is tilted relative to an arrangement plane that is defined by the deflection mirror 19 . The first facet mirror 20 is tilted relative to an arrangement plane that is defined by the second facet mirror 22 .

2 shows a schematic representation of a first embodiment of a printed circuit board 24 for an optical system 4, 10 of a lithography system 1. The optical system 4, 10 is, for example, the illumination optics 4 or the projection optics 10 of the lithography system 1 1 .

In the 2 shows the right part of the drawing a vertical section V of the circuit board 24 perpendicular to the circuit board plane L of the circuit board 24. The left part of the drawing 1 however, shows a projection plane P, which is parallel to the circuit board plane L. The circuit board 24 of 2 comprises a first conductive line 100 having N first sections 110 and a second conductive line 200 having N second sections 220, with N ≥ 1. Without loss of generality, N in 2 equals 3 (N=3). In practical applications, N can also be significantly greater, for example greater than 100, or greater than 1000 or greater than 10000. For reasons of drawing, the left-hand part of the drawing 2 only the lower first portion 110 and the lower second portion 220 are referenced.

Like the right part of the drawing 2 illustrated, the first conductive line 100 and the second conductive line 200 are arranged on different levels of the printed circuit board 24 . In the embodiment of 2 the first conductor track 100 is arranged on the upper side of the circuit board 24 and the second conductor track 200 is arranged on the underside of the circuit board 24 . Further examples of the arrangement of the first conductor track 100 and the second conductor track 200 on different levels of the circuit board 24 include that the two conductor tracks 100, 200 are arranged in different circuit board layers of the circuit board 24, that one of the two conductor tracks 100, 200 in one of the circuit board layers of the circuit board 24 and the other is arranged on top of the circuit board 24, and that one of the conductor tracks 100, 200 is arranged in one of the circuit board layers and the other on the underside of the circuit board 24 is arranged.

Furthermore, the left part of the drawing shows 2 that the first section 110 and the second section 220 are arranged in the projection plane P parallel to the printed circuit board plane L with respect to an axis A lying in the projection plane P on different sides of the axis A.

In the embodiment after 2 the first section 110 of the first conductor track 100 has a first section 111 and a second section 112. Correspondingly, the second section 220 of the second conductor track 200 has a first section 221 and a second section 222.

In the embodiment after 2 the first subsection 111 and the second subsection 112 of the first section 110 of the first conductor track 100 are each semicircular. Correspondingly, the first partial section 221 and the second partial section 222 of the second section 220 of the second conductor track 200 are also each formed in the shape of a semicircle.

Like the left part of the drawing 2 further shows, the first section 111 of the first section 110 and the first section 221 of the second section 220 are arranged symmetrically with respect to the axis A lying in the projection plane P. Correspondingly, the second section 112 of the first section 110 and the second section 222 of the second section 220 are also arranged symmetrically with respect to the axis A lying in the projection plane P. Thus, the first section 110 and the second section 220 are always arranged on different sides of the axis A in the projection plane P with respect to the axis A lying in the projection plane P. In this case, the first section 110 and the second section 220 are also arranged symmetrically with respect to the axis A.

As stated above, the first conductive line 100 generally has a plurality of N first sections 110 and the second conductive line 200 has a corresponding plurality N of second sections 220. In the plane of projection P are each one of the first sections 110 and one of the second sections 220 arranged on different sides of the axis A lying in the projection plane P. In each case one of the first sections 110 and one of the second sections 220 are arranged symmetrically to the axis A lying in the projection plane P. In the embodiment of 2 . one of the first sections 110 and one of the second sections 220 intersect at a crossing point K.

Next shows the 3 the embodiment of the circuit board 24 after 2 with drawn magnetic fields Φ1 and Φ2. If as in the example of 3 Φ1 is equal to Φ2 (Φ1 = Φ2), the induced voltage U _ind is equal to 0 (with U _ind = d(Φ1- Φ2)/dt).

Overall, it should be noted here that the fact that the first section 110 and the second section 220 are arranged in the projection plane P parallel to the printed circuit board L on different sides of the axis A with respect to the axis A lying in the projection plane P results in a a first magnetic field resulting from a current flow through the first conductor track 100 and a second magnetic field resulting from a current flow through the second conductor track 200 at least partially or completely cancel.

In addition, interference that affects the first interconnect 100 and the second interconnect 200 from the outside is minimized. A disturbance which acts on the conductor tracks 100, 200, for example due to an external electromagnetic field, is at least partially eliminated or completely eliminated by the arrangement of the conductor tracks 100, 200 proposed here.

4 shows a schematic representation of a second embodiment of a circuit board 24 for an optical system 4, 10 of a lithography system 1. The second embodiment according to 4 differs from the first embodiment according to the 2 and 3 in the form of sections 111, 112, 221, 222. In the second embodiment according to 4 these sections 111, 112, 221, 222 are each trapezoidal.

5 shows a schematic representation of a third embodiment of a printed circuit board 24 for an optical system 4, 10 of a lithography system 1.

The third embodiment after 5 is based on the first embodiment according to the 2 and 3 and differs in the shape of sections 110 and 220. In the third embodiment, after 5 the first section 110 and the second section 220 each have the shape of a sinus. The sine of the first section 110 is shifted by 180° to the sine of the second section 220.

The circuit board 24 of each of the embodiments of 2 until 5 preferably has a flexible area on which the first conductor track 100 and the second conductor track 200 are at least partially arranged (not shown). In addition, a flexible component comprising an integrated circuit is preferably additionally arranged on the flexible region. By arranging the flexible component and thus the integrated circuit (IC; Integrated Circuit) on the flexible area of the printed circuit board 24, the flexibility when installing the integrated circuit in the lithography system 1 is significantly increased. This is of particular advantage in light of the prevailing space restrictions in the lithography system 1.

• In Schritt S1 wird eine Leiterplatte 24 bereitgestellt (siehe hierzu beispielsweise 2 bis 5).

6 shows a schematic view of an embodiment of a method for producing a circuit board 24 for an optical system 4, 10 of a lithography system 1. Examples for the optical system 4, 10 and for the lithography system 1 are in FIG 1 shown. The embodiment of the method according to 6 includes steps S1 and S2:

• In step S1, a printed circuit board 24 is provided (see, for example, 2 until 5 ).

In step S2, a first conductor track 100 having at least a first section 110 and a second conductor track 200 having at least a second section 220 are arranged on different levels of the printed circuit board 24 provided, with the first section 110 and the second section 220 being in a projection plane P parallel to the Printed circuit board level L can be arranged on different sides of the axis A with respect to an axis A lying in the projection plane P (see, for example, 2 until 5 ).

Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

reference list

1

projection exposure system

2

lighting system

3

light source

4

lighting optics

5

object field

6

object level

7

reticle

8th

reticle holder

9

reticle displacement drive

10

projection optics

11

image field

12

picture plane

13

wafers

14

wafer holder

15

Wafer displacement drive

16

illumination radiation

17

collector

18

intermediate focal plane

19

deflection mirror

20

first facet mirror

21

first facet

22

second facet mirror

23

second facet

24

circuit board

100

first track

110

first section

111

first part of the first part

112

second part of the first part

200

second track

220

second part

221

first part of the second part

222

second part of the second part

A

axis

K

crossing point

L

board level

M1

Mirror

M2

Mirror

M3

Mirror

M4

Mirror

M5

Mirror

M6

Mirror

P

projection plane

S1

process step

S2

process step

V

vertical section

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102008009600 A1 [0056, 0060]
• US20060132747A1 [0058]
• EP 1614008 B1 [0058]
• US6573978 [0058]
• DE 102017220586 A1 [0063]
• US 20180074303 A1 [0077]

Claims (15)

Printed circuit board (24) for an optical system (4, 10) of a lithography system (1), with a first conductor track (100) having at least one first section (110) and a second conductor track (200) having at least one second section (220), wherein the first conductor track (100) and the second conductor track (200) are arranged on different levels of the printed circuit board (24), the first section (110) and the second section (220) being in a projection plane (P) parallel to the printed circuit board plane (L ) are arranged on different sides of the axis (A) with respect to an axis (A) lying in the projection plane (P). circuit board after claim 1 , wherein the first section (110) and the second section (220) are arranged in the projection plane (P) symmetrically to the axis (A) lying in the projection plane (P). circuit board after claim 1 or 2 , wherein the first conductor track (100) has a plurality of first sections (110) and the second conductor track (200) has a plurality of second sections (220), wherein in the projection plane (P) one of the first sections (110) and one of the second sections (220) are arranged on different sides of the axis (A) lying in the projection plane (P). circuit board after claim 3 , wherein in the projection plane (P) one of the first sections (110) and one of the second sections (220) are arranged symmetrically to the axis (A) lying in the projection plane (P). circuit board after claim 4 , wherein in the projection plane (P) one of the first sections (110) and one of the second sections (220) intersect at a crossing point (K). circuit board after claim 5 , wherein the first section (110) and the second section (220) each consist of a first section (111, 221) and a second section (112, 222), wherein in the plane of projection (P) the first section (111) of the first section (110) and the first section (221) of the second section (220) are symmetrical with respect to the axis (A) lying in the projection plane (P) and the second section (112) of the first section (110) and the second section (212) of the second section (220) are symmetrical with respect to the axis (A) lying in the projection plane (P). circuit board after claim 6 , wherein the first section (111) and the second section (112) of the first section (110) and the first section (221) and the second section (222) of the second section (220) are each circular or wherein the first section (111) and the second section (112) of the first section (110) and the first section (221) and the second section (222) of the second section (220) are each trapezoidal. circuit board after claim 5 , wherein the first section (110) and the second section (220) each have the shape of a sine, the sine of the first section (110) being shifted by 180° to the sine of the second section (220). Circuit board according to one of Claims 1 until 8th , The printed circuit board (24) having at least one flexible region which at least partially comprises the first conductor track (100) and the second conductor track (200). circuit board after claim 9 , wherein a flexible component comprising an integrated circuit is additionally arranged on the flexible region. Circuit board according to one of Claims 1 until 10 , wherein the different levels of the printed circuit board (24), on which the first conductor track (100) and the second conductor track (200) are arranged, are formed by: - two different printed circuit board layers of the printed circuit board (24), - an upper side of the printed circuit board ( 24) and one of the printed circuit board layers of the printed circuit board (24), - an underside of the printed circuit board (24) and one of the printed circuit board layers of the printed circuit board (24), or - the upper side of the printed circuit board (24) and the lower side of the printed circuit board (24). Optical system (4, 10) for a lithography system (1), wherein the optical system (4, 10) has a printed circuit board (24) according to one of Claims 1 until 11 includes. Optical system (4, 10) according to claim 12 , wherein the optical system (4, 10) is designed as an illumination optics (4) or as a projection optics (10) of a lithography system (1). Lithography system (1) with an optical system (4, 10). claim 12 or 13 . Method for producing a circuit board (24) for an optical system (4, 10) of a lithography system (1), with arrangement (S2) of a first conductor track (100) having at least a first section (110) and a second conductor track (200) having at least one second section (220) on different planes of the printed circuit board (24), the first section (110) and the second section (220) being in a projection plane (P) parallel to the printed circuit board plane (L) with respect to a projection plane (P ) lying axis (A) can be arranged on different sides of the axis (A).

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