Method and device for producing an element, element, in particular optical element, and lithography system

Abstract

The invention relates to a method for producing an element (2, 2a), in particular an element (2, 2a) of a semiconductor technology system, very particularly an optical element (2) of a lithography system, in particular of a projection exposure system (100, 200), comprising a substrate (125) and a surface (4), in particular an optical surface, on the substrate (125), wherein at least one hollow structure region (5) for conducting a temperature-controlled fluid (128) is formed in the substrate (125). According to the invention, the hollow structure region (5) is generated by die-sinking EDM using an electrode (7) for producing sparks, the electrode (7) being advanced by means of an advancing device (8) along an at least partially curved path (9) so as to bore through the substrate (125) in order to produce the hollow structure region (5).

Description

[0001] Method and device for producing an element, element, in particular optical element, and lithography system

[0002] This application claims priority from German patent application No. 10 2023 211 553.0, the contents of which are incorporated herein by reference.

[0003] The invention relates to a method for producing an element, in particular an element of a semiconductor technology system, very particularly an optical element of a lithography system, in particular a projection exposure system, having a substrate and a surface arranged on the substrate, in particular an optical surface, wherein at least one hollow structure region for guiding a temperature-controlled fluid is formed in the substrate.

[0004] The invention further relates to a device for producing an element, in particular an element of a semiconductor technology system, very particularly an optical element of a lithography system, in particular a projection exposure system, having a substrate and a surface arranged on the substrate, in particular an optical surface, wherein the device is configured to form at least one hollow structure region for guiding a temperature-controlled fluid in the substrate.

[0005] The invention also relates to an element, in particular an element of a semiconductor technology system, very particularly an optical element, with a substrate having one or more hollow structure regions.

[0006] The invention also relates to a semiconductor technology system, in particular a lithography system, very particularly a projection exposure system for semiconductor lithography, comprising an illumination system with a radiation source and an optics system which has at least one optical element.

[0007] Optical elements for guiding and shaping radiation in projection exposure systems are known from the prior art. In these known optical elements, a surface of the optical element often guides and shapes the light waves incident on the optical element. Precise control of the surface shape is therefore particularly advantageous for forming an exact wavefront with desired properties. The surface can deviate from a desired shape, for example, if the energy introduced by the radiation leads to heating and thus distortion of the optical element.

[0008] It is known that heat is generated in optical elements of lithography systems, among other things, by the absorption of EUV or DUV light, by mirror heating, the power loss of an actuator, a plasma, and / or electrical currents, which is dissipated by cooling. It is known from the prior art to maintain various elements of a lithography system, in particular optical elements, and furthermore, in particular mechanical elements such as mounts and / or frames, at a constant temperature, in particular by cooling them.

[0009] For cooling such elements, in particular optical elements that interact with light waves, it is known from the prior art that a hollow structure region for guiding a fluid is formed in a substrate and / or element body of the element. The hollow structure region can in particular be cooling channels for conducting a cooling medium in the optical element. If the cooling medium flows in the cooling channel or the cooling medium is regularly exchanged in the cooling channel and, moreover, the cooling medium is in a thermally conductive connection with the region of the element to be cooled, in particular an element body carrying an optical surface of an optical element, the energy introduced into the element body directly by the radiation, or energy absorbed by heat transport between different elements of the lithography system, can be dissipated again through the cooling channels from the element body.This allows the element body to be kept at a constant temperature or brought to this temperature.

[0010] For this purpose, it is known from the prior art to introduce cooling channels into the element body of the element, in particular the optical element. In the prior art, this is done by providing individual parts with a groove, which is then closed with a cover. This creates a closed cooling channel. According to the prior art, individual sections of such milled channels are connected by bores to form a single ring line.

[0011] A disadvantage of the milled cooling channels known from the prior art is that, particularly in the case of optical elements, the cooling channels impair the optical performance of the optical element and are not able to cool the optical element completely evenly. A further disadvantage of the milled cooling channels known from the prior art is that, particularly in the case of mechanical elements, the cooling channels have joints that represent mechanical and / or chemical weak points.

[0012] There are no known optical elements in the state of the art that enable high cooling performance on the one hand and do not impair the optical performance of the optical element on the other.

[0013] The present invention is based on the object of creating a method for producing elements, in particular optical elements, which avoid the disadvantages of the prior art, in particular enabling stable and efficient temperature control of the elements.

[0014] According to the invention, this object is achieved by a method having the features recited in claim 1. The present invention is further based on the object of creating a device for producing elements, in particular optical elements, which avoids the disadvantages of the prior art, in particular enabling stable and efficient temperature control of the elements.

[0015] According to the invention, this object is achieved by a device having the features mentioned in claim 9.

[0016] The present invention is further based on the object of creating an element, in particular an optical element, which avoids the disadvantages of the prior art, in particular can be reliably temperature controlled.

[0017] According to the invention, this object is achieved by an element having the features mentioned in claim 17.

[0018] The present invention is further based on the object of creating a semiconductor technology system, in particular a lithography system, which avoids the disadvantages of the prior art, in particular is capable of forming temporally constant and reliably shaped wavefronts.

[0019] This object is achieved according to the invention by a semiconductor technology system having the features mentioned in claim 42.

[0020] The method according to the invention serves to produce an element, in particular an element of a semiconductor technology system, and very particularly an optical element of a lithography system, in particular a projection exposure system, having a substrate and a surface arranged or formed on the substrate, in particular an optical surface. In the method according to the invention, at least one hollow structure region for guiding a temperature-controlled fluid is formed in the substrate. According to the invention, it is provided that the hollow structure region is produced by sinking spark erosion with an electrode for spark generation, wherein the electrode is driven forward through the substrate by means of a drive device along an at least partially curved path to produce the hollow structure region.

[0021] The method according to the invention also serves to produce an element that does not have an optical surface arranged or formed on the element body. This can, for example, be a mechanical element of a semiconductor technology system.

[0022] Within the scope of the invention, the term "substrate" can be understood as synonymous with the term "element body," with both terms representing a spatial-physical basis of the element. However, it can also be provided that the element body is formed from the substrate. In this case, the substrate represents a spatial-physical basis of the element body. The method according to the invention can be combined with other manufacturing methods for hollow structures, in particular with drilling methods, laser ablation methods, and / or etching methods, to produce the at least one hollow structure region.

[0023] By means of the method according to the invention, free-form hollow structure regions can be formed which are suitable for tempering the elements, in particular for cooling surfaces of elements, in particular optical elements, preferably of lithography systems whose optical surfaces are designed as free-form surfaces.

[0024] Furthermore, by means of the method according to the invention, hollow structure regions can be formed in positions or created in positions that would be inaccessible for forming the hollow structure region by milling. This allows the hollow structure region to be arranged in a thermally optimal position. Furthermore, the effort involved in manufacturing and developing the element, in particular the optical element, can be reduced, since multiple individual parts do not need to be formed to form the hollow structure region using the method according to the invention.

[0025] It can be provided that the propulsion device moves through the hollow structure area during drilling. This movement of the propulsion device has the advantage that the force can be applied to the electrode in a spatially direct and therefore particularly efficient manner.

[0026] As a contactless alternative or additional embodiment, the propulsion device can be provided with magnets arranged outside the element body, which, through their attractive force, guide or advance the electrode along the desired curved path. This eliminates the need for miniaturization of the propulsion device, which may be necessary if the device moves along the hollow structure area. Thus, the hollow structure area itself contains only the electrode and, under certain circumstances, the additional conducting devices mentioned later, preferably electrical lines or cables.

[0027] Alternatively or additionally, it can be provided that the electrode is propelled by means of a flow pressure of the electrolyte in the resulting hollow structure area. In this case, the propulsion device consists of a pressure generating device, in particular a pump device, for introducing the electrolyte into the hollow structure area, as well as preferably at least one brake or an additional drive unit for controlling the direction of the spark erosion.

[0028] The method according to the invention is therefore used for producing free-form channels (hollow structure regions) by erosion. For this purpose, an erosion tool can be used, which can be moved through the material of the substrate or the element body by attached actuators. It can be provided that the hollow structure region has one or more channels for conducting a temperature-controlled fluid, in particular at least one cooling channel.

[0029] However, the hollow structure region can also preferably be a channel for guiding a tempered fluid, in particular a cooling channel.

[0030] The method according to the invention makes it possible to produce channels in mechanical components, such as mirror frames, and / or to produce channels in optical elements, such as mirrors, in particular metal mirrors, and / or at least one, preferably conductive, ceramic and / or at least one, preferably conductive, glass.

[0031] The fluid for tempering the element can be either a liquid, preferably water, or a gas. The tempering can further comprise both heating and cooling. Insofar as the term "cooling channel" is used within the scope of the invention, this is to be understood as referring to a channel for tempering, i.e. possibly also a heating channel. Insofar as the term "fluid" is used within the scope of the invention, this is to be understood as referring to a gas. Insofar as the term "optical surface" is used within the scope of the invention, this can also refer to a "reflecting surface", in particular an optical surface of a mirror, in particular a mirror for reflecting EUV radiation, preferably with a wavelength in the range of 5 - 30 nm, particularly preferably 13.5 nm. The disclosure of the invention is to be understood accordingly.

[0032] In an advantageous development of the method according to the invention, it can be provided that an electrolyte within the resulting hollow structure region is guided to the electrode by means of a conducting device and / or is removed from the electrode.

[0033] If the electrolyte is led to the electrode within the resulting hollow structure area or is drained from the electrode, further drilling to supply the erosion area with the electrolyte can be omitted.

[0034] In the context of the invention, the term electrolyte is understood to mean an erosion fluid to enable spark erosion.

[0035] Particularly in the case of deep channels or comparatively long channels, in particular with an extension that corresponds to at least 20 times the diameter of the hollow structure area, it is advantageous if the conduit device is guided if necessary.

[0036] If the electrolyte is conveyed to the electrode or removed from the electrode by means of the conduit device, the supply and removal of the electrolyte can be spatially separated. In particular, the conduit device can comprise two conduits, one of which is intended for supplying the electrolyte to the electrode and one of which is intended for returning the electrolyte from the electrode.

[0037] The conduit device can be provided with a conduit, preferably a polymer tube, for supplying or discharging the electrolyte to or from the electrode. The electrolyte travels in the opposite direction of flow within the hollow structure. The conduit running within the hollow structure creates a spatial separation between the forward and return flow of the electrolyte.

[0038] The removed material from the substrate is preferably transported away by the electrolyte or the erosion fluid. The flow of erosion fluid is preferably carried through the conduit device and the resulting hollow structure area or the resulting drill channel.

[0039] In an advantageous development of the method according to the invention, it can be provided that the line device is guided by means of a guide device at least approximately centrally in the resulting hollow structure region, e.g. a channel, in particular a cooling channel.

[0040] If the piping system is guided at least approximately centrally within the existing hollow structure area, e.g., a channel, by means of the guide device, mechanical stresses in the piping system and thus a potential reduction in flow due to kinking are prevented. Such kinking of the piping system can occur when forming curved free-form ducts when the piping system is guided around a tight bend.

[0041] The direction of flow of the electrolyte can advance or slow it down due to the resulting flow pressure on the electrode or the EDM tool.

[0042] In an advantageous development of the method according to the invention, it can be provided that the at least one hollow structure region is formed in the substrate at a constant distance, preferably at a distance of 1 mm to 5 mm, from the optical surface.

[0043] The inventors have recognized that the method according to the invention is particularly suitable for temperature control, in particular cooling, of complex elements, in particular optical freeform surfaces, if the at least one hollow structure region in the substrate is formed at a constant distance, preferably at a distance of 1 mm to 5 mm, from a surface, in particular from the optical surface of an optical element. The distance of 1 mm to 5 mm has proven to be particularly suitable within the scope of the invention for the absorption powers typically occurring in a lithography system, in particular in an EUV projection exposure system, as well as for the materials used. If the hollow structure region or the channel is formed at a constant distance from a surface, in particular from the optical surface of the optical element, this is advantageously constantly cooled.

[0044] Preferably, the hollow structure extends at least 5%, more preferably at least 10%, in particular at least 20%, of its length at a constant distance from the surface of the element.

[0045] Preferably, over at least 50%, more preferably at least 60%, in particular at least 70%, of the length of the hollow structure region, in particular the length of a channel, the diameter of the hollow structure region or the diameter of the channel changes by no more than + / - 10%.

[0046] The element, in particular the optical element, or the substrate of the element may be formed partially or completely from a metallic, glassy, ​​ceramic-like and / or ceramic material.

[0047] The hollow structure produced by the method according to the invention can preferably have a round, oval, or polygonal cross-section. The following cross-sections are particularly possible: e.g., polygonal, in particular triangular, or rectangular, e.g., square.

[0048] It can be provided that the hollow structure region or the channel is formed at a varying distance from the optical surface, which is selected such that highly absorbent regions of the optical surface, which are thus strongly heated during operation of the lithography system, are located at a short distance from a nearest hollow structure region and can thus be cooled with a higher cooling power. This results in a cooling power across the entire optical surface that is tailored to the absorbed absorption energy.

[0049] In an advantageous development of the method according to the invention, it can be provided that a plurality of hollow structure regions are formed which run at least largely parallel to one another.

[0050] The formation of hollow structure areas or channels running parallel to one another has the advantage that a network of preferably equidistant sinks, e.g. heat sinks, can be formed in the element or the element body.

[0051] It can be provided that a majority of the hollow structure regions or channels run predominantly parallel to one another and / or that all hollow structure regions or channels run predominantly parallel to one another. However, it can also be provided that a majority or all of the hollow structure regions or channels run only partially, but predominantly, parallel to one another. In an advantageous development of the method according to the invention, it can be provided that at least two, preferably three, independently controllable control units, in particular drive units, of the propulsion device are controlled asynchronously to form a curved section of the hollow structure region.

[0052] It can be provided that the electrode or EDM tool is connected to the drive unit. The control units move the EDM tool forward in a straight line when controlled synchronously. The EDM tool thus strikes the workpiece, and the resulting erosion process removes the substrate material or the workpiece material.

[0053] If the control units are set to selected different speeds, an asynchronous advance results, which results in a curved bore channel or hollow structure area.

[0054] A direction of curvature can be selected by targeted or deliberate control of the control units.

[0055] In an advantageous development of the method according to the invention, it can be provided that the drive units are designed as motor units, in particular as piezo stepper motors.

[0056] It can be provided that a single drive unit is designed as an array, each comprising one or more piezo stepper motors.

[0057] It may be provided that the control units are designed as brakes.

[0058] Particularly when propulsion is driven by the flow pressure of the electrolyte, control of the direction, especially the curvature, of the resulting hollow structure region can also be achieved by decelerating the electrode or the propulsion device. Asynchronous deceleration, in particular, results in the electrode pivoting in a desired direction.

[0059] For this purpose, the brakes can be actuated. In particular, the brakes can be actuated by piezo motors and / or piezo stepper motors.

[0060] If the propulsion system has motor units, these can be assisted or slowed down by the flow pressure.

[0061] In an advantageous development of the method according to the invention, it can be provided that the control units are pressed against the walls or the inner walls of the hollow structure area during drilling by spring tension. If the control units, i.e., in particular the drive units and / or the brakes, are pressed against the walls or the inner walls of the hollow structure area during drilling by spring tension, the walls of the hollow structure area can serve as abutments for a movement or force effect of the drive device. This eliminates the need for complex supports for the control unit relative to a point outside the hollow structure area.

[0062] Because the control units are pressed against the walls of the hollow structure area by spring preload, the corresponding actuation, e.g. the piezo stepper motors, can be designed to be correspondingly weaker and thus more space-saving.

[0063] The invention further relates to a device for producing an element, in particular an optical element.

[0064] The device according to the invention for producing an element, in particular an element of a semiconductor technology system, very particularly an optical element of a lithography system, in particular a projection exposure system, comprises a substrate and a surface arranged or formed on the substrate, in particular an optical surface. The device according to the invention is designed to form at least one hollow structure region in the substrate. According to the invention, an erosion drilling device is provided and designed to form the hollow structure region by sinking spark erosion. The erosion drilling device comprises an electrode for spark generation and a propulsion device for drilling the electrode along an at least partially curved path.

[0065] The device according to the invention also serves to produce an element that does not have an optical surface arranged or formed on the substrate or an element body. This can, for example, be a mechanical element of a semiconductor technology system.

[0066] It can be provided that the propulsion device moves through the hollow structure area during drilling.

[0067] Alternatively or additionally, the propulsion device can be configured to propel the electrode through the substrate or the element body without contact by means of magnetic and / or electric fields.

[0068] Using the device according to the invention, a guided or freely controlled bore can be created in the element body. As with die-sinking EDM, a tool energized with electricity, the electrode, is guided within the element body or the workpiece. In particular, the electrode is not guided by an external CNC machine, i.e., one located outside the element body, but rather by the propulsion unit, which preferably moves into the borehole. The propulsion device can also be referred to as a propulsion unit and / or guide unit.

[0069] By means of the device according to the invention, any desired shape of the bore can be realized within the element body, which can be optimized to the respective technical requirements.

[0070] Using the device according to the invention, restrictions in bore design can be almost completely eliminated. Furthermore, only one machining step is required to produce the hollow structure area, which represents a significant reduction in manufacturing effort compared to the prior art.

[0071] By means of the device according to the invention, free-form hollow structure regions can be manufactured by active guidance, ie movement and rotation, of the electrode through the propulsion device.

[0072] As the erosion process progresses, the propulsion device preferably moves into the resulting hollow structure area.

[0073] In an advantageous development of the device according to the invention, it can be provided that the electrode is designed as a sphere.

[0074] Preferably, the spherical electrode is connected to the propulsion device.

[0075] Using a spherical electrode, the erosion process can be carried out particularly efficiently, as the spherical electrode, shaped like a half-shell, can work or eat into the material of the element body at a constant distance from it. The cross-section of the hollow structure or channel can preferably be round, oval, or polygonal.

[0076] In an advantageous development of the device according to the invention, it can be provided that the electrode is shaped such that the hollow structure region has a polygonal, in particular triangular and / or oval, in particular circular, cross-section.

[0077] By means of a suitable shaping of the electrode, hollow structural regions, e.g. channels, with any non-circular cross-sectional areas can be created.

[0078] Within the scope of the invention, triangular and / or oval cross-sections of the at least one hollow structure region have proven particularly suitable. In particular, when forming a triangular hollow structure region, a constant distance from the optical surface to be cooled across the cross-section of the hollow structure region can be achieved by orienting an edge of the triangular cross-section parallel to the optical surface to be cooled. A freely selectable cross-sectional shape of the hollow structure region or the bore can be optimized, in particular, for heat transfer to the region to be cooled or heated, in particular the optical surface to be cooled or heated.

[0079] The hollow structure area can also have a polygonal, in particular rectangular, for example also square, cross-section.

[0080] It can further be provided that the hollow structure region has complex cross-sectional shapes, which can also have longitudinal grooves to optimize heat transfer.

[0081] In an advantageous development of the device according to the invention, it can be provided that the propulsion device has at least two, preferably three, independently controllable control units, in particular drive units.

[0082] The at least two, preferably three, independently controllable control units are preferably designed as drive units, particularly preferably as motor units.

[0083] Alternatively or additionally, it may be provided that one or more or all control units are designed as brakes.

[0084] In order to guide the electrode on a three-dimensionally curved path, in particular to form a free-form hollow structure area, it is advantageous if the propulsion device is designed to direct the propulsion direction of the electrode in three spatial directions.

[0085] For this purpose, preferably three independently controllable control units can be provided.

[0086] Alternatively or additionally, it can be provided that the electrode is propelled by means of the flow pressure of the electrolyte in the resulting hollow structure area. In this case, the propulsion device consists of a pressure generating device, in particular a pump device, for introducing the electrolyte into the hollow structure area, as well as at least one brake for controlling the direction of the spark erosion.

[0087] If only two independently controllable control units are provided, it is advantageous if the propulsion device is configured to move the electrode in another direction in the third spatial direction, in particular forward. In particular, it can be provided for this purpose that the electrode is pressed forward by the flow pressure of an incoming electrolyte, while a lateral deflection is realized by the at least two, preferably three, independently controllable control units. In an advantageous development of the device according to the invention, it can be provided that the propulsion device has drive units designed as motor units.

[0088] If the propulsion device preferably has three independently controllable motor units, both the propulsion and the steering of the electrode can be realized by means of motor units. In particular, the propulsion device can be realized by one or more piezo stepper motors.

[0089] In an advantageous development of the device according to the invention, it can be provided that the control units are designed for preferably spring-biased support on a wall, in particular an inner wall, of the hollow structure region and for exerting force, at least in one direction of propulsion.

[0090] Supporting the control units against the wall of the hollow structure area has the advantage that this support can serve as an abutment for exerting force in the desired propulsion or steering direction. This eliminates the need for complex abutments, especially outside the hollow structure area.

[0091] In an advantageous development of the device according to the invention, it can be provided that a conducting device is set up for conducting an electrolyte within the resulting hollow structure region to the electrode and / or for transporting an electrolyte and / or removed fragments of the substrate within the resulting hollow structure region away from the electrode.

[0092] In particular, it can be provided that the removed material of the substrate is transported away from the resulting hollow structure area by the electrolyte or the erosion fluid.

[0093] Furthermore, it may be advantageous if the conduit system, particularly in deep or long hollow structure areas or channels, is additionally guided and / or moved with additional drive units, in particular motor units. This movement can be designed, in particular, to allow the conduit system to be guided loosely without kinking.

[0094] In an advantageous development of the device according to the invention, it can be provided that at least one channel fluidically connected to the line device is guided through the electrode.

[0095] If a channel fluidically connected to the conducting device is passed through the electrode, the electrolyte reaches the site of the erosion process, i.e., in the case of a spherical electrode, for example, the tip of the sphere. The conducting device itself can be passed through the electrode. This prevents a dissolution process of the electrode itself from taking place within the electrode. For this purpose, it can be provided, in particular, that the conducting device is made of an electrically insulating material.

[0096] It can be provided that the conducting device comprises one or more electrical lines or cables for supplying the electrode with a current or a voltage.

[0097] In this case, it is advantageous if the electrical lines are routed in the same way as the lines for transporting the electrolyte. In particular, the electrical lines can be arranged in close proximity to, and preferably parallel to, the lines for transporting the electrolyte.

[0098] Advantageously, it can be provided that the device for the initial positioning of the electrode and / or the propulsion device on the substrate has a flange device.

[0099] Alternatively or additionally, it can be provided that a starting hole, which is drilled in a conventional manner, is arranged on the substrate as an initial guide for the electrode and / or the propulsion device.

[0100] Furthermore, it can be provided that the flange device is designed to tightly close the hollow structure region in order to enable easy control and adjustment of a liquid pressure of the electrolyte during the erosion process.

[0101] If the flange device is not used, it is advantageous if the electrolyte is supplied via a supply line of the line device.

[0102] The invention further relates to an element, in particular an element of a semiconductor technology system, very particularly for a projection exposure system for semiconductor lithography having the features mentioned in claim 17.

[0103] The element can in particular be a mirror, in particular a mirror for reflecting EUV radiation, preferably with a wavelength in the range of 5 - 30 nm, particularly preferably 13.5 nm.

[0104] The element according to the invention, in particular an optical element, comprises a substrate having one or more hollow structure regions, in particular hollow structures for tempering the substrate, which are incorporated into the substrate according to the method according to the invention described above.It is provided here that at least one hollow structure region has an inner surface which at least partially has a surface topography whose geometric shape results from a superposition of crater walls which extend into the substrate material of the substrate, and / or at least one hollow structure region has an inner surface to which particles adhere at least partially, whose geometric shape is predominantly circular and whose diameter is not greater than 50 micrometers, preferably not greater than 20 micrometers, particularly preferably not greater than 10 micrometers and / or at least one hollow structure region has an inner surface which has crack structures, wherein the geometric width of the crack structure in the transverse direction is not greater than 1 micrometer, preferably not greater than 500 nm, particularly preferably not greater than 300 nm.

[0105] The presence of the aforementioned spatial and physical features of the inner lateral surface indicates the use of the method according to the invention described above. In particular, the described crater structures, particle structures, and / or crack structures can only be produced in a practically relevant manner by means of spark erosion.

[0106] The described surface topography of the inner shell surface also has the advantage that, due to the surface topography, microturbulences can form in a fluid flowing in the hollow structure area (see below), enabling efficient heat transfer between the substrate and the fluid without causing disruptive vibrations. This maintains an essentially laminar flow of the fluid.

[0107] The element according to the invention is suitable for a lithography system, in particular an EUV projection exposure system, and comprises a substrate, an optical surface arranged or formed on the substrate, and at least one hollow structure region formed in the substrate. According to the invention, the hollow structure region is drilled along a path that is at least partially curved.

[0108] The features described below in connection with the optical surface arranged or formed on the substrate are also applicable or transferable to a surface of an element, for example, an embodiment of the element according to the invention described later, which, for example, does not have an optical surface arranged or formed on the substrate. This can be, for example, a mechanical element of a semiconductor technology system.

[0109] In particular, it can be provided that the hollow structure area, in particular the channel, is drilled by means of spark erosion.

[0110] Within the scope of the invention, the term "drilling" refers to the formation of a hollow structure region, in particular a channel, in a solid material of the substrate. In particular, the hollow structure region, in particular the channel, is lined with intact solid material. Milling a portion of the channel and subsequently closing the milled section to create a channel is not considered drilling within the scope of the invention—in accordance with general technical usage.

[0111] Because the hollow structure area is drilled along a path that is at least partially curved, the hollow structure area can also be considered as a free-form hollow structure area.

[0112] By drilling at least one hollow structure region, the need to seal a groove, as is common with milled hollow structure regions known from the prior art, is eliminated. Such groove closures represent a potential weak point for leaks.

[0113] In an advantageous development of the element according to the invention, it can be provided that the at least one hollow structure region is formed in the substrate at a constant distance, preferably at a distance of 1 mm to 5 mm, from the surface.

[0114] Within the scope of the invention, a distance of the at least one hollow structure region of 1 mm to 5 mm from a surface of the element, in particular from the optical surface of the optical element, has proven advantageous in order to enable the most constant and reliable cooling of the surface, in particular of the optical surface.

[0115] The substrate of a mechanical element can, in particular, be a mirror frame, a force frame, or a force frame, which is designed to exert forces on the optical surface in order to specifically deform it and / or change its orientation. To exert the corresponding force, servo motors, preferably actuators, particularly preferably piezo actuators, can be provided and / or arranged in the substrate.

[0116] It can be provided that the at least one hollow structure region is arranged in such a way as to enable cooling of other heat sources of the element. In particular, the at least one hollow structure region can be arranged near the servo motors for deforming the optical surface in order to cool it.

[0117] In an advantageous development of the element according to the invention, it can be provided that a plurality of hollow structure regions extending at least largely parallel to one another are formed and are preferably designed for the flow through of a medium, in particular a cooling medium.

[0118] If several hollow structure regions running at least largely parallel to one another are arranged for preferential flow through the hollow structure regions, this results in a temperature profile that is as constant as possible along the plane of the hollow structure regions. If the multiple hollow structure regions were to be flowed through in the same flow direction, the temperature in this region of the hollow structure regions would be lowest upon entry of the medium, in particular the cooling medium or coolant, and highest upon exit. During flow through, in particular counter-flow, the resulting temperature gradient is balanced out, resulting in a uniform temperature profile along the region of the hollow structure regions.

[0119] In an advantageous development of the element according to the invention, it can be provided that the optical surface is an aspherical surface and / or a free-form surface.

[0120] Of particular advantage is the formation of freeform hollow structure regions in the vicinity of complex surfaces of the optical surface, i.e., for example, in the vicinity of aspherical surfaces or freeform surfaces. The optical element according to the invention has a high degree of superiority over elements known from the prior art, particularly in this case.

[0121] In an advantageous development of the element according to the invention, it can be provided that the substrate is formed partially or entirely from a metal or a semi-metal, in particular amorphous silicon, and / or the, preferably optical, surface has a layer system, and / or the at least one hollow structure region has radii of curvature of at least 0.1 cm, preferably at least 0.5 cm, particularly preferably at least 1 cm along a flow direction of a medium, in particular a cooling medium, and / or is designed to conduct a medium, in particular a cooling medium, essentially in laminar flow.

[0122] Within the scope of the invention, it was recognized that the aforementioned materials and / or parameters of the hollow structure region benefit particularly from the formation of the at least one hollow structure region along an at least partially curved path.

[0123] Furthermore, it was recognized that limiting the radii of curvature and avoiding sharp edges along the hollow structure region to be formed enables a particularly advantageous flow of the medium, in particular the cooling medium, in the hollow structure region. The medium is preferably a fluid. The at least partially curved free-form hollow structure region of the element according to the invention achieves a particularly good and uniform cooling performance. Furthermore, this prevents turbulence in the cooling medium, which could lead to vibrations in the element.

[0124] It can be provided that the radius of curvature is less than 20 cm at at least one point along the hollow structure region. This allows a minimum curvature to be achieved in order to form the hollow structure region at least approximately parallel to the optical surface.

[0125] The fact that the hollow structure was manufactured using the inventive erosion process can be recognized, among other things, by the fact that the inner wall of the hollow structure, in particular an inner wall or an inner surface of the hollow structure, has a homogeneous, matte surface structure. Further features that indicate that the hollow structure region or a cooling channel was manufactured using an inventive erosion process are presented in the exemplary embodiment (see Figures 15 to 17).

[0126] In particular, it can be provided that the optical element according to the invention partially or completely comprises the inventive element described below, and vice versa. Furthermore, it can be provided that the optical element according to the invention is partially or completely designed according to the inventive element described below, and vice versa.

[0127] It can be provided within the scope of the invention that the element body and the substrate described below are partially or completely identical.

[0128] According to a further embodiment, the element is part of a wafer inspection system for semiconductor lithography.

[0129] According to a further embodiment, the element is part of a mask inspection system for semiconductor lithography.

[0130] In the context of the present invention, the terms hollow structure and hollow structure region are used synonymously.

[0131] In an advantageous development of the element according to the invention, it can be provided that the substrate is partially or completely formed from a metallic, glassy, ​​ceramic-like and / or ceramic material.

[0132] This results in advantageous material properties of the substrate.

[0133] In an advantageous development of the element according to the invention, it can be provided that the at least one hollow structure region is round, oval or polygonal in cross section.

[0134] By avoiding edges, the flow properties of the hollow structure area can be improved.

[0135] In an advantageous development of the element according to the invention, it can be provided that a diameter of the hollow structure region changes by less than 10% over at least half of its length.

[0136] By avoiding bottlenecks, the flow properties of the hollow structure region can be improved. In an advantageous development of the element according to the invention, it can be provided that the hollow structure region extends at a constant distance from a surface of the element for at least 5% of its total length.

[0137] The element according to the invention preferably comprises: a substrate and a coating applied to the substrate for reflecting radiation, in particular EUV radiation, preferably with a wavelength in the range of 5-30 nm, particularly preferably 13.5 nm, wherein the substrate has at least one hollow structure, preferably in the form of a channel, particularly preferably in the form of a channel through which a fluid can flow, in particular in the form of a cooling channel through which a cooling fluid can flow, which is produced using the method described above. As a rule, the hollow structure serves to control the temperature of the EUV mirror and, for this purpose, a fluid flows through it. The fluid can be a liquid, preferably water, or a gas. However, it is also possible for the hollow structure to be incorporated into the substrate for another purpose, for example, to accommodate one or more components, e.g., in the form of sensors, actuators, etc.to be integrated into the substrate. During the manufacture of the hollow structure, the substrate typically does not yet have a reflective coating to prevent interaction between a material-removing erosion process and the materials of the reflective coating. The reflective coating is therefore typically applied to the substrate only after the hollow structure has been manufactured.

[0138] The invention also relates to an element, in particular an optical element, in particular a mirror, in particular a mirror for reflecting EUV radiation, preferably with a wavelength in the range of 5 - 30 nm, particularly preferably 13.5 nm, comprising: a substrate with an introduced hollow structure region, which has at least one channel, preferably through which a fluid can flow, which channel is formed by material-removing machining by erosion, wherein the channel is curved and wherein the channel has a diameter between 1 mm and 20 mm, preferably between 1 mm and 5 mm, and / or a length of at least 10 cm, preferably of at least 15 cm, in particular of at least 20 cm. The channel can be formed during material-removing machining by erosion, in particular in the manner described above, ieThe curved channel can be formed using the method described above, in which a removal front is formed by erosion, which is moved through the substrate or the element body. The curved channel can be designed, in particular, for the flow of a fluid, e.g., a cooling fluid.

[0139] In one embodiment, the substrate is monolithic. As described above, a monolithic substrate can avoid stresses in the substrate material that occur when two or more sub-bodies are joined together to form a multi-part substrate.

[0140] In a further embodiment, the channel has a first section and a second, adjacent section, whose longitudinal directions are aligned at an angle between 70° and 100°, preferably at an angle of 90°, to each other. Deflections at a comparatively large angle of approximately 90° can be advantageous when guiding a fluid through the channel in order to effectively control the temperature of the substrate.

[0141] In one embodiment, the first section and the second section merge into one another at a rounded section. A continuous transition between the two sections along a rounded section has proven advantageous over a transition in the form of a bend, as described in more detail below.

[0142] A further aspect of the invention relates to an element, in particular an optical element, for reflecting radiation in the form of a mirror, in particular a mirror for reflecting EUV radiation, preferably with a wavelength in the range of 5 - 30 nm, particularly preferably 13.5 nm, preferably comprising: a preferably monolithic substrate, a reflective coating for reflecting radiation, in particular EUV radiation, preferably with a wavelength in the range of 5 - 30 nm, particularly preferably 13.5 nm.5 nm, which is applied to a surface of the preferably monolithic substrate, and at least one hollow structure which runs in the preferably monolithic substrate and which is designed for a fluid to flow through, wherein the hollow structure has a first section and a second, adjacent section which are aligned to one another at an angle between 60° and 120°, preferably at an angle between 80° and 100°, in particular at an angle of 90°, and wherein the hollow structure has a rounded section at which the first section and the second section merge into one another. The two sections are typically channel sections which, immediately adjacent to the rounded section, typically run essentially in a straight line. Immediately adjacent to the rounded section, the two sections have longitudinal axes which are aligned to one another at the angle described above.In particular, the first section and the second section can be aligned at an angle of more than 90°, for example more than 100°, to each other.

[0143] At a transition between two sections of the substrate's hollow structure in the form of a corner or sharp edge, especially when the two sections are aligned approximately perpendicularly, i.e., at an angle between 60° and 120°, flow separation can occur at the wall of the hollow structure, leading to turbulence and causing flow-induced vibrations. For this reason, it is proposed that the two sections of the hollow structure merge at a rounded section with a streamlined shape.

[0144] A rounded section is understood to be a section that has no corners. At the rounded section, the first section thus merges continuously into the second section. The cross-section or diameter of the hollow structure within the rounded section is typically constant, but can also vary if necessary. The cross-section or diameter of the rounded section generally corresponds to the cross-section of both sections, but this is not necessarily the case if the rounded section is arranged at a junction, see below. The substrate is preferably monolithic, i.e. it is formed in one piece and does not have a joining surface at which two or more partial bodies of the substrate are connected to one another.

[0145] The rounded section can be produced by material-removing machining by erosion, as described above in connection with the method for producing a hollow structure or for producing a channel.

[0146] In one embodiment, a radius of curvature R of the rounded section and a diameter D of the rounded section have a ratio R / D that is between 2 and 6, preferably between 2.5 and 5, in particular between 2.5 and 3.5. With an R / D ratio of more than 2, significant improvements in flow-induced vibrations, e.g. > 50%, can already be achieved. Ideally, the R / D ratio is between approximately 2.5 and 3.5, e.g. 3.0, since this is typically where the greatest improvements in flow-induced vibrations are typically achieved. A value of the R / D ratio of more than 6 should not be exceeded. In this embodiment, the rounded section has a constant radius of curvature.

[0147] The flow cross-section of the rounded section is typically circular, but may deviate from a circular geometry and, for example, have an elliptical geometry. In this case, the diameter of the rounded section is understood to be the so-called equivalent diameter, i.e., the diameter of a circle whose area corresponds to the non-circular flow cross-section of the rounded section, as described above.

[0148] It has been found that the ratio between the diameter of the rounded section and the radius of curvature of the rounded section is an essential parameter for a streamlined flow pattern without turbulence and thus for the avoidance of flow-induced vibrations.

[0149] In a further embodiment, the diameter D of the rounded section is between 2 mm and 20 mm, preferably between 2 mm and 12 mm. A diameter of the rounded section or the channel structures of the hollow structure within the specified range allows for the generation of a sufficient volume flow for efficient temperature control of the element under the given boundary conditions. The flow velocity of the fluid in the hollow structure is generally in the order of meters per second.

[0150] In one embodiment, the hollow structure has a plurality of temperature control channels, in particular in the form of cooling channels, which run beneath the surface to which the, in particular reflective, coating is applied, and the hollow structure has a fluid distributor connected to the temperature control channels, in particular to the cooling channels, via distributor channels, and a fluid collector connected to the temperature control channels, in particular to the cooling channels, via collector channels. The temperature control channels, which usually serve to cool the substrate and are therefore also referred to below as cooling channels, generally run in a near-surface region below the surface. A near-surface region is understood to mean a distance from the surface of the substrate that is 10 mm or less.The distance from the surface is measured in the thickness direction of the substrate, which is usually perpendicular to the generally flat underside of the substrate. The short distance of the cooling channels from the surface allows for effective cooling of the mirror surface. The distance is defined as the minimum distance between the respective cooling channel and the surface with the, in particular, reflective coating.

[0151] The fluid distributor and the fluid collector generally each have a larger flow cross-section than a single cooling channel. This enables favorable flow conditions to be set. The fluid distributor and / or the fluid collector are preferably arranged at a greater distance from the surface to which the coating, in particular the reflective coating, is applied than the cooling channels. This arrangement makes it possible to keep the deformation of the surface due to the fluid pressure in the fluid distributor and / or the fluid collector, which generally have larger cavities than the cooling channels, within acceptable limits. The fluid distributor is typically connected to a fluid inlet, and the fluid collector is typically connected to a fluid outlet. Each cooling channel can be connected to exactly one distributor channel and exactly one collector channel, but it is also fundamentally possible for a group of two or, if necessary, three to be connected.more than two cooling channels are connected to a common distribution channel and a common collector channel.

[0152] In a further embodiment, the first section forms an end section of the temperature control channel, in particular of the cooling channel, adjacent to a distribution channel, and the second section forms a distribution channel section adjacent to the end section and / or the first section forms an end section of the temperature control channel, in particular of the cooling channel, adjacent to a collector channel, and the second section forms a collector channel section adjacent to the end section.

[0153] The cooling channels typically run essentially parallel to the surface to which the coating, in particular a reflective coating, is applied. Since the installation space within the substrate is limited, a distribution channel or a collector channel, which is connected to a respective cooling channel, is generally led away from the surface with the coating, in particular a reflective coating, at an approximately right angle, i.e. the collector or distribution channel section and an adjacent end section of the cooling channel generally run at approximately a right angle to one another, i.e. there is approximately a 90° deflection of the fluid flowing through the hollow structure.

[0154] The rounded section described above, especially when choosing a suitable ratio of radius of curvature to diameter, can prevent or at least significantly reduce flow-induced vibrations.

[0155] In principle, the fluid distributor and the fluid collector can be designed in different ways. For example, the flow cross-section of the fluid distributor or the fluid collector can taper from the distributor channels or the collector channels, e.g., in the manner of a funnel, so that the cavities formed by the fluid distributor and the fluid collector in the substrate are not unnecessarily large.

[0156] In a further embodiment, the fluid distributor forms an inlet channel from which the distributor channels branch off and / or the fluid collector forms an outlet channel from which the collector channels branch off. In this embodiment, the fluid collector and the fluid distributor generally run substantially transversely to the longitudinal direction of the distributor channels or transversely to the longitudinal direction of the collector channels. The distributor channels or the collector channels generally branch off from the inlet channel or the outlet channel at substantially right angles. The fluid distributor and the fluid collector can in this case, for example, be designed in the form of cylindrical channels that extend from an inlet opening or an outlet opening on an outer side of the substrate into the substrate. The inlet channel and the outlet channel can in this case, for example,in the form of bores, in particular hollow bores, but it is also possible that these are produced by the erosion process described above.

[0157] In a further development of this embodiment, the first section forms an opening section of the distributor channel adjacent to the inlet channel and the second section forms a branching section of the inlet channel adjacent to the opening section and / or the first section forms an opening section of the collector channel adjacent to the outlet channel and the second section forms a branching section of the outlet channel adjacent to the opening section of the collector channel.

[0158] As described above, the longitudinal direction of the inlet channel or the outlet channel preferably runs substantially perpendicular to the longitudinal direction of a respective collector channel or distributor channel. A streamlined geometry is also advantageous at a respective branch of a distributor or collector channel, which can be achieved by providing a rounded section at a branch of the inlet channel or the outlet channel. In this way, steps can be avoided and edges rounded, making the geometry of the hollow structure more streamlined and preventing or at least significantly reducing fluid separation in the inlet channel and the outlet channel.

[0159] The ratio of diameter D to radius R of the rounded section is preferably within the value range described above. However, it is also possible for the rounded section at the branching point not to have a constant radius of curvature. The flow diameter of the rounded section at the branching point is also not necessarily constant. For example, the cross section of the rounded section can taper starting from the inlet channel or starting from the outlet channel. In a further embodiment, the angle between the branching section of the inlet channel and the mouth section of the distributor channel is greater than 90°, preferably greater than 100° and / or the angle between the branching section of the outlet channel and the mouth section of the collector channel is greater than 90°, preferably greater than 100°. It has been found that it is advantageous for the flow guidance if the branching section of the inlet channel orof the outlet channel and the mouth section of the distributor channel or the collector channel are aligned at an obtuse angle to each other.

[0160] In a further embodiment, the material of the substrate is selected from the group comprising: quartz glass, in particular titanium-doped quartz glass, and glass ceramic. In order to avoid deformation of the surface to which the, in particular reflective, coating is applied, which may be due to inhomogeneous heating of the substrate material, the substrates of mirrors for EUV lithography are typically made of so-called zero-expansion material, which has a very low thermal expansion coefficient. As described above, these materials are hard and brittle and are therefore difficult to machine. However, using the erosion process described above, hollow structures of virtually any shape can also be produced in such materials.

[0161] In a further embodiment, the material of the substrate has a zero-crossing temperature that lies between 0°C and 100°C, preferably between 19°C and 40°C, particularly preferably between 19°C and 32°C. As described above, the zero-crossing temperature is determined, among other things, as a function of the average incident radiation power during operation of the EUV mirror.

[0162] In one embodiment, the material of the substrate has a spatial variation of the zero-crossing temperature that is less than 3 K, preferably less than 2 K, particularly preferably less than 1 K, in particular less than 0.1 K. As described above, a high spatial homogeneity of the zero-crossing temperature is typically required to operate the mirror efficiently.

[0163] In an advantageous development of the element according to the invention, it can be provided that the surface is an optical surface and has molybdenum-silicon layers.

[0164] The invention further relates to a semiconductor technology system, in particular a lithography system, especially a projection exposure system for semiconductor lithography.

[0165] The system according to the invention, in particular a lithography system, further in particular a projection exposure system for semiconductor lithography, with an illumination system having a radiation source and an optical system which has at least one optical element, is characterized in that at least one of the elements is produced by means of a method according to the invention and / or at least one of the elements is produced by means of a device according to the invention and / or at least one of the elements is an optical element according to the invention and / or at least one element of the system is an element according to the invention.

[0166] The semiconductor technology system can be a projection exposure system for EUV semiconductor lithography, a projection exposure system for DUV semiconductor lithography, a mask inspection system or a wafer inspection system.

[0167] The lithography system according to the invention has the advantage of having efficiently temperature-controlled, in particular coolable, optical elements that simultaneously comprise highly stable interconnected components. This minimizes temperature-related and / or aging-related drift of the elements, thereby increasing the service life and reliability of the system, in particular of the lithography system.

[0168] Similar optics to those of the projection exposure system are also used in other semiconductor technology systems, for example in the mask inspection system for EUV lithography or the wafer inspection system for EUV lithography.

[0169] Within the scope of the invention, the term "cooling" or "cooling" is also to be understood as maintaining a constant temperature of the element and / or the element body or the substrate. Due to the introduction of radiant energy during the interaction of the, preferably optical, element and / or the element body with radiation and / or power loss from actuators, maintaining a constant temperature can, in particular, comprise cooling. However, maintaining a constant temperature can also comprise heating, which can be achieved by the subject matter of the invention just as cooling can.

[0170] Features described in connection with one of the subject matters of the invention, specifically the method according to the invention, the device according to the invention, the optical element according to the invention, the element according to the invention, or the system according to the invention, can also be advantageously implemented for the other subject matters of the invention. Likewise, advantages mentioned in connection with one of the subject matters of the invention can also be understood to apply to the other subject matters of the invention.

[0171] It should also be noted that terms such as "comprising," "having," or "with" do not exclude other features or steps. Furthermore, terms such as "a" or "the," which indicate a singular number of steps or features, do not exclude a plurality of features or steps—and vice versa.

[0172] In a purist embodiment of the invention, however, it may also be provided that the features introduced in the invention with the terms "comprising," "having," or "with" are listed exhaustively. Accordingly, one or more lists of features may be considered complete within the scope of the invention, for example, for each claim. The invention may, for example, consist exclusively of the features mentioned in claim 1.

[0173] It should be noted that terms such as "first" or "second" etc. are used primarily for reasons of distinguishing between respective device or process features and are not necessarily intended to indicate that features are mutually dependent or related to one another.

[0174] In the following, embodiments of the invention are described in more detail with reference to the drawing.

[0175] The figures each show preferred embodiments in which individual features of the present invention are illustrated in combination with one another. Features of one embodiment can also be implemented independently of the other features of the same embodiment and can therefore be readily combined by a person skilled in the art to form further useful combinations and subcombinations with features of other embodiments.

[0176] In the figures, functionally identical elements are provided with the same reference numerals.

[0177] They show:

[0178] Figure 1 shows an EUV projection exposure system in meridional section;

[0179] Figure 2 shows a DUV projection exposure system;

[0180] Figure 3 is a schematic representation of a longitudinal section through a possible embodiment of a device according to the invention and a substrate;

[0181] Figure 4 is a schematic representation of a cross section through a further possible embodiment of the device according to the invention and of the substrate;

[0182] Figure 5 is a schematic representation of a cross section through another possible embodiment of the device according to the invention and the substrate;

[0183] Figure 6 is a schematic representation of a longitudinal section through another possible embodiment of a device according to the invention and a substrate;

[0184] Figure ? a schematic representation of a longitudinal section through another possible embodiment of a device according to the invention and a substrate; Figure 8 a schematic representation of a longitudinal section through another possible embodiment of a device according to the invention and a substrate;

[0185] Figure 9 is a schematic representation of a cross section through an element body with a hollow structure region according to the prior art;

[0186] Figure 10 is a schematic representation of a longitudinal section through an optical element according to the invention;

[0187] Figure 1 1 shows a block diagram of a possible embodiment of the method according to the invention;

[0188] Figure 12 is a schematic sectional view of an element with a hollow structure having a plurality of temperature control channels in the form of cooling channels, the end sections of which merge into distribution channels or collector channels via rounded sections;

[0189] Figure 13 shows schematic sectional views of the element according to Figure 12 in a sectional plane perpendicular to the sectional plane in Figure 12;

[0190] Figure 14 schematically shows a section of a sectional view through the element in a region of the inlet channel;

[0191] Figure 15 shows an exemplary schematic cross-section of a possible embodiment of an inner surface of a hollow structure region;

[0192] Figure 16 shows a further exemplary schematic cross-section of a possible embodiment of an inner surface of a hollow structure region; and

[0193] Figure 17 shows a further exemplary schematic cross-section of a possible embodiment of an inner surface of a hollow structure region.

[0194] In the following, the essential components of a semiconductor technology system are described by way of example, with reference to Figure 1, using an EUV projection exposure system 100 for microlithography as an example, particularly as an example of a lithography system. The description of the basic structure of the EUV projection exposure system 100 and its components should not be understood as limiting.

[0195] An illumination system 101 of the EUV projection exposure system 100 comprises, in addition to a radiation source 102, an illumination optics 103 for illuminating an object field 104 in an object plane 105. A reticle 106 arranged in the object field 104 is exposed. The reticle 106 is held by a reticle holder 107. The reticle holder 107 can be displaced, in particular in a scanning direction, via a reticle displacement drive 108.

[0196] Figure 1 shows a Cartesian xyz coordinate system for illustrative purposes. The x-direction runs perpendicular to the drawing plane. The y-direction runs horizontally, and the z-direction runs vertically. The scanning direction in Figure 1 runs along the y-direction. The z-direction runs perpendicular to the object plane 105.

[0197] The EUV projection exposure system 100 comprises a projection optics 109. The projection optics 109 serves to image the object field 104 into an image field 110 in an image plane 111. The image plane 111 runs parallel to the object plane 105. Alternatively, an angle other than 0° between the object plane 105 and the image plane 111 is also possible.

[0198] A structure on the reticle 106 is imaged onto a light-sensitive layer of a wafer 112 arranged in the image plane 111 in the region of the image field 110. The wafer 112 is held by a wafer holder 113. The wafer holder 113 can be displaced, in particular along the y-direction, via a wafer displacement drive 114. The displacement of the reticle 106, on the one hand, via the reticle displacement drive 108, and the wafer 112, on the other hand, via the wafer displacement drive 114, can be synchronized with each other.

[0199] The radiation source 102 is an EUV radiation source. The radiation source 102 emits, in particular, EUV radiation 115, which is also referred to below as useful radiation or illumination radiation. The useful radiation 115 has, in particular, a wavelength in the range between 5 nm and 30 nm, in particular 13.5 nm. The radiation source 102 can be a plasma source, for example, an LPP source ("Laser Produced Plasma") or a DPP source ("Gas Discharged Produced Plasma"). It can also be a synchrotron-based radiation source. The radiation source 102 can be a free-electron laser ("FEL").

[0200] The illumination radiation 115 emanating from the radiation source 102 is focused by a collector 116. The collector 116 can be a collector with one or more ellipsoidal and / or hyperboloidal reflection surfaces. The at least one reflection surface of the collector 116 can be exposed to the illumination radiation 115 at grazing incidence (Gl), i.e., at angles of incidence greater than 45°, or at normal incidence (NI), i.e., at angles of incidence less than 45°. The collector 116 can be structured and / or coated, on the one hand, to optimize its reflectivity for the useful radiation 115 and, on the other hand, to suppress stray light.

[0201] After the collector 1 16, the illumination radiation 1 15 propagates through an intermediate focus in a

[0202] Intermediate focal plane 117. The intermediate focal plane 117 can represent a separation between a radiation source module, comprising the radiation source 102 and the collector 116, and the illumination optics 103.

[0203] The illumination optics 103 comprises a deflecting mirror 118 and, downstream of this in the beam path, a first facet mirror 119. The deflecting mirror 118 can be a flat deflecting mirror or, alternatively, a mirror with a beam-influencing effect beyond the pure deflection effect. Alternatively or additionally, the deflecting mirror 118 can be designed as a spectral filter that separates a useful light wavelength of the illumination radiation 115 from stray light of a different wavelength. If the first facet mirror 119 is arranged in a plane of the illumination optics 103 that is optically conjugated to the object plane 105 as the field plane, it is also referred to as a field facet mirror. The first facet mirror 119 comprises a plurality of individual first facets 120, which are also referred to below as field facets. Only a few of these facets 120 are shown in Figure 1 as examples.

[0204] The first facets 120 can be designed as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or partially circular edge contour. The first facets 120 can be designed as flat facets or, alternatively, as convexly or concavely curved facets.

[0205] As is known, for example, from DE 10 2008 009 600 A1, the first facets 120 themselves can also be composed of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirror 119 can, in particular, be designed as a microelectromechanical system (MEMS system). For details, reference is made to DE 10 2008 009 600 A1.

[0206] Between the collector 116 and the deflecting mirror 118, the illumination radiation 115 runs horizontally, i.e. along the y-direction.

[0207] In the beam path of the illumination optics 103, a second facet mirror 121 is arranged downstream of the first facet mirror 119. If the second facet mirror 121 is arranged in a pupil plane of the illumination optics 103, it is also referred to as a pupil facet mirror. The second facet mirror 121 can also be arranged at a distance from a pupil plane of the illumination optics 103. In this case, the combination of the first facet mirror 119 and the second facet mirror 121 is also referred to as a specular reflector. Specular reflectors are known from US 2006 / 0132747 A1, EP 1 614 008 B1, and US Pat. No. 6,573,978.

[0208] The second facet mirror 121 comprises a plurality of second facets 122. In the case of a pupil facet mirror, the second facets 122 are also referred to as pupil facets. The second facets 122 can also be macroscopic facets, which can, for example, be round, rectangular, or hexagonal in shape, or alternatively, facets composed of micromirrors. Reference is also made to DE 10 2008 009 600 A1 in this regard.

[0209] The second facets 122 may have planar or alternatively convex or concave curved reflection surfaces.

[0210] The illumination optics 103 thus forms a double-faceted system. This basic principle is also referred to as a fly's-eye integrator.

[0211] It may be advantageous not to arrange the second facet mirror 121 exactly in a plane which is optically conjugated to a pupil plane of the projection optics 109.

[0212] With the help of the second facet mirror 121, the individual first facets 120 are imaged into the object field 104. The second facet mirror 121 is the last beam-forming mirror or actually the last mirror for the illumination radiation 115 in the beam path before the object field 104.

[0213] In a further, not-shown embodiment of the illumination optics 103, a transmission optics can be arranged in the beam path between the second facet mirror 121 and the object field 104, which transmission optics contributes in particular to the imaging of the first facets 120 into the object field 104. The transmission optics can have exactly one mirror, but alternatively also two or more mirrors arranged one behind the other in the beam path of the illumination optics 103. The transmission optics can in particular comprise one or two mirrors for normal incidence (NI mirrors, "normal incidence" mirrors) and / or one or two mirrors for grazing incidence (GL mirrors, "grazing incidence" mirrors).

[0214] In the embodiment shown in Figure 1, the illumination optics 103 has exactly three mirrors after the collector 116, namely the deflection mirror 118, the field facet mirror 119 and the pupil facet mirror 121.

[0215] In a further embodiment of the illumination optics 103, the deflection mirror 118 can also be omitted, so that the illumination optics 103 can then have exactly two mirrors after the collector 116, namely the first facet mirror 119 and the second facet mirror 121.

[0216] The imaging of the first facets 120 by means of the second facets 122 or with the second facets 122 and a transmission optics into the object plane 105 is usually only an approximate imaging.

[0217] The projection optics 109 comprises a plurality of mirrors Mi, which are numbered according to their arrangement in the beam path of the EUV projection exposure system 100. In the example shown in Figure 1, the projection optics 109 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve, or a different number of mirrors Mi are also possible. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 115. The projection optics 109 are doubly obscured optics. The projection optics 109 have an image-side numerical aperture that is greater than 0.5 and can also be greater than 0.6, for example, 0.7 or 0.75.

[0218] Reflection surfaces of the mirrors Mi can be designed as freeform surfaces without a rotational symmetry axis. Alternatively, the reflection surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one rotational symmetry axis of the reflection surface shape. The mirrors Mi, like the mirrors of the illumination optics 103, can have highly reflective coatings for the illumination radiation 115. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

[0219] The projection optics 109 has a large object-image offset in the y-direction between a y-coordinate of a center of the object field 104 and a y-coordinate of the center of the image field 110. This object-image offset in the y-direction can be approximately as large as a z-distance between the object plane 105 and the image plane 111.

[0220] The number of intermediate image planes in the x- and y-directions in the beam path between the object field 104 and the image field 110 can be the same or can be different, depending on the design of the projection optics 109. Examples of projection optics with different numbers of such intermediate images in the x- and y-directions are known from US 2018 / 0074303 A1.

[0221] Each of the pupil facets 122 is assigned to exactly one of the field facets 120 to form a respective illumination channel for illuminating the object field 104. This can, in particular, result in illumination according to the Köhler principle. The far field is divided into a plurality of object fields 104 using the field facets 120. The field facets 120 generate a plurality of images of the intermediate focus on the pupil facets 122 assigned to them.

[0222] The field facets 120 are each imaged onto the reticle 106 by an associated pupil facet 122, superimposed on one another, to illuminate the object field 104. The illumination of the object field 104 is, in particular, as homogeneous as possible. It preferably has a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

[0223] By arranging the pupil facets, the illumination of the entrance pupil of the projection optics 109 can be geometrically defined. By selecting the illumination channels, in particular the subset of the pupil facets that guide light, the intensity distribution in the entrance pupil of the projection optics 109 can be adjusted. This intensity distribution is also referred to as the illumination setting.

[0224] A likewise preferred pupil uniformity in the area of ​​defined illuminated sections of an illumination pupil of the illumination optics 103 can be achieved by redistributing the illumination channels.

[0225] Further aspects and details of the illumination of the object field 104 and in particular of the entrance pupil of the projection optics 109 are described below.

[0226] The projection optics 109 can, in particular, have a homocentric entrance pupil. This can be accessible. It can also be inaccessible.

[0227] The entrance pupil of the projection optics 109 cannot usually be precisely illuminated with the pupil facet mirror 121. When imaging the projection optics 109, which telecentrically images the center of the pupil facet mirror 121 onto the wafer 112, the aperture rays often do not intersect at a single point. However, a surface can be found in which the pairwise determined spacing of the aperture rays is minimized. This surface represents the entrance pupil or a surface conjugate to it in spatial space. In particular, this surface exhibits a finite curvature.

[0228] It is possible that the projection optics 109 have different entrance pupil positions for the tangential and sagittal beam paths. In this case, an imaging element, in particular an optical component of the transmission optics, should be provided between the second facet mirror 121 and the reticle 106. With the help of this optical component, the different positions of the tangential entrance pupil and the sagittal entrance pupil can be taken into account.

[0229] In the arrangement of the components of the illumination optics 103 shown in Figure 1, the pupil facet mirror 121 is arranged in a surface conjugated to the entrance pupil of the projection optics 109. The first field facet mirror 119 is arranged tilted relative to the object plane 105. The first facet mirror 119 is arranged tilted relative to an arrangement plane defined by the deflection mirror 118.

[0230] The first facet mirror 119 is arranged tilted to an arrangement plane which is defined by the second facet mirror 121.

[0231] Figure 2 shows an exemplary DUV projection exposure system 200 as an example of a semiconductor technology system. The DUV projection exposure system 200 has an illumination system 201, a device called a reticle stage 202 for receiving and precisely positioning a reticle 203, by means of which the subsequent structures on a wafer 204 are determined, a wafer holder 205 for holding, moving, and precisely positioning the wafer 204, and an imaging device, namely a projection optics system 206, with a plurality of optical elements, in particular lenses 207, which are held via mounts 208 in an objective housing 209 of the projection optics system 206.

[0232] Alternatively or in addition to the lenses 207 shown, various refractive, diffractive and / or reflective optical elements, including mirrors, prisms, end plates and the like, may be provided.

[0233] The basic functional principle of the DUV projection exposure system 200 provides that the structures introduced into the reticle 203 are imaged onto the wafer 204.

[0234] The illumination system 201 provides a projection beam 210 in the form of electromagnetic radiation required for imaging the reticle 203 onto the wafer 204. A laser, a plasma source, or the like can be used as the source for this radiation. The radiation is shaped in the illumination system 201 via optical elements such that the projection beam 210 has the desired properties regarding diameter, polarization, wavefront shape, and the like when it strikes the reticle 203.

[0235] An image of the reticle 203 is generated by the projection beam 210 and transferred to the wafer 204 in a correspondingly reduced size by the projection optics 206. The reticle 203 and the wafer 204 can be moved synchronously, so that regions of the reticle 203 are imaged onto corresponding regions of the wafer 204 practically continuously during a so-called scanning process.

[0236] Optionally, an air gap between the last lens 207 and the wafer 204 can be replaced by a liquid medium having a refractive index greater than 1.0. The liquid medium can be, for example, ultrapure water. Such a setup is also referred to as immersion lithography and features increased photolithographic resolution.

[0237] The use of the invention is not limited to use in projection exposure systems 100, 200, in particular not with the described structure. The invention is suitable for any lithography systems or microlithography systems, but in particular for projection exposure systems with the described structure. The invention is also suitable for EUV projection exposure systems which have a smaller image-side numerical aperture than that described in connection with Figure 1 and which do not have an obscured mirror M5 and / or M6. In particular, the invention is also suitable for EUV projection exposure systems which have an image-side numerical aperture of 0.25 to 0.5, preferably 0.3 to 0.4, particularly preferably 0.33. Furthermore, the invention and the following exemplary embodiments are not to be understood as being limited to a specific design.

[0238] The following figures represent the invention merely by way of example and in a highly schematic manner. Figure 3 shows a schematic representation of a possible embodiment of a device 1 for producing an element 2, 2a (see Figures 12 and 13), in particular an element 2, 2a, for example a mechanical element 2a and / or an optical element 2, of a semiconductor technology system and further in particular for producing an optical element 2 of a lithography system, in particular the projection exposure system 100, 200, with a substrate 125 or an element body 3 and a surface 4 arranged or formed on the substrate 125, in particular an optical surface. Here, the device 1 is configured to form at least one hollow structure region 5 in the substrate 125. For this purpose, an erosion drilling device 6 is provided and configured to form the hollow structure region 5 by sinking spark erosion.The erosion drilling device 6 comprises an electrode 7 for spark generation and a propulsion device 8 for drilling the electrode 7 along an at least partially curved path 9.

[0239] In the embodiment shown in Figure 3, the electrode 7 is preferably designed as a sphere.

[0240] Furthermore, in the embodiment shown in Figure 3, the propulsion device 8 preferably has at least two, particularly preferably three, independent controllable control units 10, which are designed in particular as drive units 10a.

[0241] In the exemplary embodiment, preferably three control units 10 are provided.

[0242] In the embodiment according to Figure 3, the control units 10 are preferably designed for spring-loaded support on a wall, in particular on an inner wall, of the hollow structure region 5 and / or for exerting force at least in one direction of propulsion of the electrode 7.

[0243] Furthermore, in the embodiment of the device 1 according to Figure 3, a conducting device 11 is provided and arranged for conducting an electrolyte 12 within the resulting hollow structure region 5 to the electrode 7 and / or for transporting the electrolyte 12 and / or removed fragments of the element body 3 within the resulting hollow structure region 5 away from the electrode 7.

[0244] In the embodiment shown in Figure 3, preferably at least one channel fluidically connected to the line device 11 is passed through the electrode 7.

[0245] Figure 4 shows a schematic representation of an exemplary section through a resulting hollow structure region 5. The shape of the cross section of the hollow structure region 5 can depend in particular on the electrode 7.

[0246] In the embodiment shown in Figure 4, the electrode 7 is shaped such that the hollow structure region 5 has a polygonal, in particular triangular, cross-section. In an embodiment not shown, the electrode 7 can be shaped such that the hollow structure region 5 has an oval, in particular circular, or a polygonal, i.e., polygonal, cross-section.

[0247] Furthermore, in the embodiment shown in Figure 4, the propulsion device 8 preferably has exactly three independently controllable drive units 10a designed as motor units.

[0248] Figure 5 shows a further schematic representation of an exemplary section through an element body 3 or substrate 125 with a hollow structure region 5.

[0249] In the embodiment shown in Figure 5, the electrode 7 is designed as a sphere, resulting in a circular cross-section of the hollow structure region 5.

[0250] Figure 6 shows a schematic representation of the device 1 before drilling begins. The electrode 7 is positioned relative to the element body 3 or substrate 125 by means of a flange device 14. Furthermore, a sealed space is created for the electrolyte 12. For this purpose, the conduit device 11 is passed through the flange device 14 in a sealed manner.

[0251] Sealing the flange device 14 against the element body 3 or substrate 125 has the advantage that the electrolyte 12 can be placed under a sufficiently high pressure to enable circulation of the electrolyte 12.

[0252] Figure 7 shows a schematic representation of a possible embodiment of the device 1 at the beginning of the production of the hollow structure region 5. In the embodiment shown in Figure 7, the electrode 7 is arranged in a countersunk hole 15, preferably prepared or pre-drilled in a conventional manner. The flange device 14 is preferably arranged above the countersunk hole 15. The countersunk hole 15 provides stable guidance for the electrode 7 at the beginning of the spark erosion process.

[0253] Figure 8 shows a schematic representation of a further possible embodiment of the device 1 in a modification of Figure 3. In the embodiment shown in Figure 8, in further analogy to the embodiment of the device 1 shown in Figure 3, the flange device 14 is arranged above the entrance to the hollow structure region 5.

[0254] Figure 9 shows a schematic representation of a section through an element body 3 or substrate 125 with a hollow structure region 5 produced according to the prior art. The hollow structure region 5 known from the prior art is formed by a groove in the element body 3 or substrate 125 and a cover 16.

[0255] Figure 10 shows a schematic representation of the element 2 in a sectional view. The optical element 2 for the lithography system, in particular for the EUV projection exposure system 100, comprises the element body 3 or substrate 125, the surface 4 arranged or formed on the element body 3 or substrate 125, in particular an optical surface, and at least one hollow structure region 5 formed in the element body 3 or substrate 125. The hollow structure region 5 is drilled along the at least partially curved path 9 (not shown in Figure 10).

[0256] In the embodiment shown in Figure 10, the hollow structure region 5 in the element body 3 or substrate 125 is preferably formed at a constant distance, particularly preferably at a distance of 1 mm to 5 mm, from the preferably optical surface 4.

[0257] In the embodiment shown in Figure 10, the preferably optical surface 4 is an aspherical surface and / or a freeform surface.

[0258] Furthermore, in the embodiment shown in Figure 10, the element body 3 or substrate 125 is formed partially or entirely from a metal or a semi-metal, in particular amorphous silicon.

[0259] Preferably, the surface 4 in the embodiment shown in Figure 10 has a layer system.

[0260] In the illustrated embodiment, the surface 4 is an optical surface and has molybdenum-silicon layers.

[0261] Furthermore, in the embodiment shown in Figure 10, the at least one hollow structure region 5 is formed along a flow direction of a cooling medium such that the hollow structure region 5 has radii of curvature of at least 0.1 cm, preferably at least 0.5 cm, particularly preferably at least 1 cm.

[0262] Alternatively or additionally, the at least one hollow structure region 5 in the embodiment shown in Figure 10 is designed to conduct the cooling medium essentially in laminar flow.

[0263] In an embodiment not shown, a plurality of hollow structure regions 5 running parallel to one another are formed in the element body 3 or substrate 125 and are preferably configured for flow, in particular for counter-flow, of the cooling medium.

[0264] Figure 11 shows a block diagram of a possible embodiment of a method for producing the element 2, 2a, in particular the element 2, 2a of the semiconductor technology system, very particularly the optical element 2 of the lithography system, in particular the projection exposure system 100, 200, with the substrate 125 or the element body 3 and the surface 4 arranged or formed on the substrate 125, in particular an optical surface. In the method, at least one hollow structure region 5 is formed in the substrate 125.

[0265] In a production block 50, the hollow structure region 5 is created by sinking spark erosion using the electrode 7 for spark generation. In a propulsion block 51, the electrode 7 is advanced by the propulsion device 8 along the at least partially curved path 9, drilling through the element body 3 or the substrate 125 to create the hollow structure region 5.

[0266] In an electrolyte block 52, the electrolyte 12 is preferably conducted to the electrode 7 and / or removed from the electrode 7 by means of the conducting device 11, preferably within the resulting hollow structure region 5.

[0267] In the embodiment shown in Figure 11, within the electrolyte block 52, the conducting device 11 is preferably guided by means of the guide device 13 at least approximately centrally in the resulting hollow structure region 5.

[0268] Within the scope of the propulsion block 51, the at least one hollow structure region 5 is formed in the substrate 125 preferably at a constant distance, particularly preferably at a distance of 1 mm to 5 mm, from the, preferably optical, surface 4.

[0269] Instead of the surface 4, which can in particular be an optical surface, this can also be a surface 125a of the element 2a (see Figure 12).

[0270] The generation block 50 may further preferably comprise a formation of several hollow structure regions 5 running at least largely parallel to one another.

[0271] Within the scope of the propulsion block 51, it can preferably be provided that the at least two, preferably three, independently controllable control units 10, in particular the drive units 10a, of the propulsion device 8 are controlled asynchronously to form a curved section of the hollow structure region 5.

[0272] Furthermore, within the scope of the propulsion block 51, it can preferably be provided that the drive units 10a are designed as motor units, in particular as piezo stepper motors.

[0273] In an embodiment of the method not shown, it can be provided that the control units 10 are designed as brakes.

[0274] Furthermore, within the scope of the propulsion block 51, it can preferably be provided that the control units 10 are pressed against the walls of the hollow structure region 5 in a spring-loaded manner during drilling. Figures 12 and 13 show schematic sectional views of an element of the projection exposure system of Fig. 1 with a hollow structure 5.

[0275] As can be seen in Figure 12, the fluid 128 enters an inlet channel 133 of the hollow structure or hollow structure region 5 via an inlet opening 129, which forms a fluid distributor and from which a plurality of distributor channels 134 branch off, each of which is connected to a temperature control channel 5a, which are referred to below as cooling channels 5a. The cooling channels 5a are arranged at a distance A' of approximately 5 mm from the planar surface 125a of the substrate 125 in the example shown and extend parallel to the surface 125a, i.e., parallel to an XY plane of an XYZ coordinate system. The cooling channels 5a run rectilinearly, are aligned parallel, and extend in the longitudinal direction, which corresponds to the Y direction, over approximately the entire portion of the surface 125a of the substrate 125 covered by a coating 126 (see Figure 13).From the cooling channels 5a, the fluid 128 flows via a plurality of collector channels 136 to a fluid collector, which in the example shown in Figure 13 is designed as an outlet channel 135. The outlet channel 135 has the outlet opening described above, not illustrated in Figures 12 and 13, through which the fluid 128 exits the hollow structure 5 of the substrate 125.

[0276] As can be seen in Figure 13, the hollow structure 5 has a first rounded section 137a, at which a respective distribution channel 134 transitions into a cooling channel 5a. Correspondingly, the hollow structure 5 also has a second rounded section 137b, at which a respective cooling channel 5a transitions into a collector channel 136. In the example shown, the cooling channels 5a run straight in the horizontal direction, which corresponds to the Y direction, and the distribution channels 134 and the collector channels 136 run straight in the vertical direction, which corresponds to the Z direction. Accordingly, the longitudinal axes of the cooling channels 5a are aligned at an angle y of 90° to the distribution channels 134 and the collector channels 136, respectively.The rounded section 137a,b serves to create the most streamlined flow path possible and thus avoids or at least significantly reduces the occurrence of turbulence, such as would occur with a non-rounded, "angular" 90° bend. The reduction in turbulence results in a reduction in the flow-induced vibrations of, for example, the reflective optical element 2.

[0277] For optimized flow guidance at the 90° bend, it is advantageous if the rounded section 137a, b has a constant radius of curvature R. An essential parameter for optimal flow guidance is the ratio between the radius of curvature R of the rounded section 137a, 137b and the flow diameter D.

[0278] Preferably, the at least one hollow structure region 5 is round, oval or polygonal in cross section.

[0279] Preferably, a diameter of the hollow structure region 5 changes by less than 10% over at least half of its length. Preferably, the hollow structure region 5 extends at a constant distance from a surface 125a of the element 2a for at least 5% of its entire length.

[0280] Figure 14 schematically shows a section of a sectional view through the element 2a in a region of the inlet channel 133.

[0281] In this case, an angle y' between a branching section 133a of the inlet channel 133 and the mouth section of the distributor channel 134 is preferably greater than 90°, preferably greater than 100° and / or an angle y' between the branching section 133a of the outlet channel 135 and the mouth section of the collector channel 136 is preferably greater than 90°, preferably greater than 100°.

[0282] The elements 2a or optical elements 2 shown in Figures 3 to 8, 10 and 12 to 17, which are produced by means of the device 1 or are designed as explained in connection with Figure 10 or Figures 12 to 14 and / or were produced according to the method explained in connection with Figure 11, are particularly suitable for a semiconductor technology system, in particular a lithography system, in particular the projection exposure system 100, 200 for semiconductor lithography, which comprises an illumination system 101, 201 with a radiation source 102 and an optics 103, 109, 206, which has at least one optical element 116, 118, 119, 120, 121, 122, Mi, 207.

[0283] If optical elements 2 produced with the device 1 and / or optical elements 2 produced by the method explained in connection with Figure 11 and / or optical elements 2 as explained in connection with Figure 10 are present in the projection exposure systems 100, 200 illustrated and explained in Figures 1 and 2, the projection exposure systems 100, 200 can achieve particularly good illumination performance. The optical element 2 can be, in particular, a mirror, in particular an EUV mirror.

[0284] It can be provided in particular that one or more of the optical elements 116, 118, 119, 120, 121, 122, Mi, 207 is an element 2, 2a according to the invention, in particular an optical element 2, or is produced with a device 1 according to the invention and / or the method according to the invention.

[0285] It can further be provided that at least one of the elements 2, 2a of the system, in particular of the lithography system, further in particular of the projection exposure system 100, 200, is an element 2, 2a according to the invention.

[0286] The element 2, 2a can in particular be mechanisms (e.g., mirror frames), cooled substrates, e.g., glass or ceramic blocks, or the substrate of the mechanism or a mirror. Figure 15 shows an exemplary schematic, microscopic cross-section of a possible configuration of an inner surface of the hollow structure region 5.

[0287] The hollow structure region 5 is incorporated into the substrate 125 by means of the method described in connection with Figure 11.

[0288] The inner surface has at least one crater 180.

[0289] The inner surface here has at least partially a surface topography whose geometric shape results from a superposition of crater ridges 181 that extend into the substrate material of the substrate 125.

[0290] Characteristic of a surface eroded by the process described in connection with Figure 11 are the countless adjacent craters 180 with their converging crater ridges 181. In addition, microfine abrasion particles adhere to the surface (see Figure 16).

[0291] Figure 16 shows a further exemplary schematic, microscopic cross-section of a possible embodiment of an inner surface of the hollow structure region 5.

[0292] Particles 182 adhere at least partially to the inner surface, the geometric shape of which is predominantly circular and the diameter of which is not greater than 50 micrometers, preferably not greater than 20 micrometers, particularly preferably not greater than 10 micrometers.

[0293] The cross-section shown in Figure 16 represents an exemplary enlargement of a section of Figure 15.

[0294] By further magnification, the crater walls 181 and the adhering microparticles 182 as well as a hole in the inner surface can be clearly seen on the same workpiece.

[0295] Figure 17 shows a further exemplary schematic, microscopic cross-section of a possible embodiment of an inner surface of the hollow structure region 5.

[0296] The inner lateral surface has crack structures 183, wherein the geometric width of the crack structure 183 in the transverse direction is not greater than 1 micrometer, preferably not greater than 500 nm, particularly preferably not greater than 300 nm.

[0297] The schematic cross-section shown in Figure 17 represents an exemplary, even greater magnification of a section of Figure 15 compared to Figure 16. If, for example, such a high magnification is selected in an electron microscope, preferably at a voltage of 15 kV, the microcracks 183 become very clear. Smaller structures also become visible in particle 182 at the selected magnification.

[0298] List of reference symbols

[0299] 1 device

[0300] 2 optical element

[0301] 2a Element

[0302] 3 Element bodies

[0303] 4 Surface

[0304] 5 Hollow structure area

[0305] 5a Temperature control channel / cooling channel

[0306] 6 Erosion drilling device

[0307] 7 Electrode

[0308] 8 Propulsion equipment

[0309] 9 track

[0310] 10 Control unit

[0311] 10a Drive unit

[0312] 11 Line equipment

[0313] 12 Electrolyte

[0314] 13 Guide device

[0315] 14 Flange device

[0316] 15 Countersunk hole

[0317] 16 lids

[0318] 125 Substrat

[0319] 125a flat surface

[0320] 126 Coating

[0321] 128 Fluid

[0322] 129 Inlet opening

[0323] 133 Inlet channel / fluid distributor

[0324] 134 distribution channel

[0325] 135 exhaust duct

[0326] 136 Collector channel / fluid collector

[0327] 137a rounded section

[0328] 137b rounded section

[0329] 180 craters

[0330] 181 Crater Wall

[0331] 182 particles

[0332] 183 Crack structure

[0333] 50 Generation block 51 Driving block

[0334] 52 Electrolyte block

[0335] 100 EUV projection exposure system

[0336] 101 Lighting system

[0337] 102 Radiation source

[0338] 103 Lighting optics

[0339] 104 Object field

[0340] 105 Object level

[0341] 106 reticles

[0342] 107 reticle holders

[0343] 108 Reticle displacement drive

[0344] 109 Projection optics

[0345] 110 image field

[0346] 111 Image plane

[0347] 112 wafers

[0348] 113 wafer holders

[0349] 114 Wafer relocation drive

[0350] 115 EUV / useful / illumination radiation

[0351] 116 collector

[0352] 117 Intermediate focal plane

[0353] 118 deflecting mirrors

[0354] 119 first facet mirror / field facet mirror

[0355] 120 first facets / field facets

[0356] 121 second facet mirror / pupil facet mirror

[0357] 122 second facets / pupil facets

[0358] 200 DUV projection exposure system

[0359] 201 Lighting system

[0360] 202 reticle days

[0361] 203 reticles

[0362] 204 wafers

[0363] 205 wafer holders

[0364] 206 Projection optics

[0365] 207 lens

[0366] 208 version

[0367] 209 lens housings

[0368] 210 projection beam

[0369] Mi Mirror

Claims

Patent claims:

1. A method for producing an element (2, 2a), in particular an element (2a) of a semiconductor technology system, very particularly an optical element (2) of a lithography system, in particular a projection exposure system (100, 200), with a substrate (125) and a surface (4) arranged on the substrate (125), in particular an optical surface, wherein at least one hollow structure region (5) for guiding a temperature-controlled fluid (128) is formed in the substrate (125), characterized in that the hollow structure region (5) is produced by sinking spark erosion with an electrode (7) for spark generation, wherein the electrode (7) is driven forward by means of a driving device (8) along a path (9) which is curved at least in sections, drilling through the substrate (125) to produce the hollow structure region (5).

2. Method according to claim 1, characterized in that an electrolyte (12) within the resulting hollow structure region (5) is guided to the electrode (7) by means of a conducting device (11) and / or is removed from the electrode (7).

3. Method according to claim 2, characterized in that the line device (11) is guided by means of a guide device (13) at least approximately centrally in the resulting hollow structure region (5).

4. The method according to claim 1, 2 or 3, characterized in that the at least one hollow structure region (5) is formed in the substrate (125) at a constant distance, preferably at a distance of 1 mm to 5 mm, from the surface (4).

5. Method according to one of claims 1 to 4, characterized in that a plurality of hollow structure regions (5) extending at least largely parallel to one another are formed.

6. Method according to one of claims 1 to 5, characterized in that at least two, preferably three, independently controllable control units (10), in particular drive units (10a), of the propulsion device (8) are controlled asynchronously to form a curved section of the hollow structure region (5).

7. Method according to claim 6, characterized in that the drive units (10a) are designed as motor units, in particular as piezo stepper motors.

8. Method according to claim 6 or 7, characterized in that the control units (10) are pressed against the walls of the hollow structure region (5) in a spring-loaded manner during drilling.

9. Device (1) for producing an element (2, 2a), in particular an element (2a) of a semiconductor technology system, very particularly an optical element (2) of a lithography system, in particular a projection exposure system (100, 200), with a substrate (125) and a surface (4) arranged on the substrate (125), in particular an optical surface, wherein the device (1) is designed to form at least one hollow structure region (5) in the substrate (125), characterized in that an erosion drilling device (6) is provided and designed to form the hollow structure region (5) by sinking spark erosion, which comprises an electrode (7) for spark generation and a propulsion device (8) for drilling the electrode (7) along an at least partially curved path (9).

10. Device (1) according to claim 9, characterized in that the electrode (7) is designed as a sphere.

11. Device (1) according to claim 9, characterized in that the electrode (7) is shaped such that the hollow structure region (5) has a polygonal, in particular triangular, and / or oval, in particular circular, cross-section.

12. Device (1) according to claim 9, 10 or 11, characterized in that the propulsion device (8) has at least two, preferably three, independently controllable control units (10), in particular drive units (10a).

13. Device (1) according to claim 12, characterized in that the propulsion device (8) has drive units (10a) designed as motor units.

14. Device (1) according to claim 12 or 13, characterized in that the control units (10) are designed for, preferably spring-biased, support on a wall of the hollow structure region (5) and for exerting force, at least in one direction of propulsion.

15. Device (1) according to one of claims 9 to 14, characterized in that a conducting device (11) is arranged for conducting an electrolyte (12) within the resulting hollow structure region (5) to the electrode (7) and / or for transporting an electrolyte (12) and / or removed fragments of the substrate (125) within the resulting hollow structure region (5) away from the electrode (7).

16. Device (1) according to claim 15, characterized in that at least one channel fluidically connected to the line device (11) is passed through the electrode (7).

17. Element (2a), in particular an element (2a) of a semiconductor technology system, very particularly an optical element (2), with a substrate (125) having one or more hollow structure regions (5), in particular hollow structures for tempering the substrate (125), which are incorporated into the substrate (125) according to the method according to one of claims 1 to 8, wherein at least one hollow structure region (5) has an inner lateral surface which at least partially has a surface topography whose geometric shape results from a superposition of crater ridges (181) extending into the substrate material of the substrate (125), and / or at least one hollow structure region (5) has an inner lateral surface to which particles (182) adhere at least partially, whose geometric shape is predominantly circular and whose diameter is not greater than 50 micrometers, preferably not greater than 20 micrometers,particularly preferably not larger than 10 micrometers and / or at least one hollow structure region (5) has an inner surface which has crack structures, wherein the geometric width of the crack structure in the transverse direction is not larger than 1 micrometer, preferably not larger than 500 nm, particularly preferably not larger than 300 nm., 18. Element (2, 2a) according to claim 17, characterized in that the hollow structure region (5) is drilled along a path (9) which is at least partially curved.

19. Element (2, 2a) according to claim 17 or 18, characterized in that the at least one hollow structure region (5) is formed in the substrate (125) and / or in an element body (3) formed by the substrate (125) at a constant distance, preferably at a distance of 1 mm to 5 mm, from a preferably optical surface (4) of the substrate (125).

20. Element (2, 2a) according to one of claims 17 to 19, characterized in that a plurality of hollow structure regions (5) extending at least largely parallel to one another are formed and are preferably arranged for the flow through of a medium, in particular a cooling medium.

21. Element (2, 2a) according to claim 19 or 20, characterized in that the, preferably optical, surface (4) is an aspherical surface and / or a free-form surface.

22. Element (2, 2a) according to one of claims 19 to 21, characterized in that the substrate (125) is formed at least partially from a metal or a semi-metal, in particular amorphous silicon, and / or the, preferably optical, surface (4) has a layer system, and / or the at least one hollow structure region (5) has radii of curvature of at least 0.1 cm, preferably at least 0.5 cm, particularly preferably at least 1 cm along a flow direction of a cooling medium, and / or is designed to conduct a medium, in particular a cooling medium, in a substantially laminar flow.

23. Element (2, 2a) according to one of claims 17 to 22, characterized in that the substrate (125) is formed partially or completely from a metallic, glassy, ​​ceramic-like and / or ceramic material.

24. Element (2, 2a) according to one of claims 17 to 23, characterized in that the at least one hollow structure region (5) is round, oval or polygonal in cross section.

25. Element (2, 2a) according to one of claims 17 to 24, characterized in that a diameter of the hollow structure region (5) changes by less than 10% over at least half of its length.

26. Element (2, 2a) according to one of claims 17 to 25, characterized in that the hollow structure region (5) extends for at least 5% of its total length at a constant distance from a surface (125a) of the element (2a).

27. Element (2, 2a) according to one of claims 17 to 26, characterized in that a coating (126) applied to the substrate (125) is provided for reflecting radiation, in particular EUV radiation (115), preferably with a wavelength in the range of 5 - 30 nm, particularly preferably 13.5 nm.

28. Element (2, 2a) according to one of claims 17 to 27, characterized in that the hollow structure region (5) introduced into the substrate (125) has at least one channel (5a) through which a fluid (128) can preferably flow, which channel is formed by the material-removing machining by means of erosion, wherein the channel (5a) is curved and wherein the channel (5a) has a diameter (D) between 1 mm and 20 mm, preferably between 1 mm and 5 mm, and / or a length (Lc) of at least 10 cm, preferably of at least 15 cm, in particular of at least 20 cm.

29. Element (2, 2a) according to one of claims 17 to 28, characterized in that the substrate (125) is monolithic.

30. Element (2, 2a) according to claim 28 or 29, characterized in that the channel (5a) has a first section and a second, adjacent section, the longitudinal directions of which are aligned at an angle between 70° and 100°, preferably at an angle of 90°, to one another. 31 . Element (2, 2a) according to claim 30, characterized in that the first section and the second section merge into one another at a rounded section (137a, 137b).

32. Element (2, 2a) according to one of claims 17 to 31, characterized by a preferably monolithic substrate (125), a reflective coating (126) for reflecting radiation, in particular EUV radiation (115), preferably with a wavelength in the range of 5 - 30 nm, particularly preferably 13.5 nm, which is applied to a surface (125a) of the preferably monolithic substrate (125), and at least one hollow structure region (5) which runs in the preferably monolithic substrate (125) and which is designed for a fluid (128) to flow through, wherein the hollow structure region (5) has a first section and a second, adjacent section which are aligned with one another at an angle between 60° and 120°, preferably at an angle between 80° and 100°, in particular at an angle of 90°, and wherein the hollow structure region (5) has a rounded section (137a, 137b) at which the first section and the second section merge into one another.

33. Element (2, 2a) according to claim 32, characterized in that a radius of curvature R of the rounded portion (137a, 137b) and a diameter D of the rounded portion (137a, 137b) have a ratio R / D which is between 2 and 6, preferably between 2.5 and 5, in particular between 2.5 and 3.

5.

34. Element (2, 2a) according to claim 33, characterized in that the diameter D of the rounded portion (137a, 137b) is between 2 mm and 20 mm, preferably between 2 mm and 12 mm.

35. Element (2, 2a) according to one of claims 27 to 34, characterized in that the hollow structure region (137a, 137b) has a plurality of temperature control channels (5a), in particular in the form of cooling channels (5a), which run below the surface (125a) to which the, in particular reflective, coating (126) is applied, and the hollow structure region (5) has a fluid distributor (133) connected to the temperature control channels (5a) via distributor channels (134) and a fluid collector (135) connected to the temperature control channels (5a) via collector channels (136).

36. Element (2, 2a) according to one of claims 32 to 35, characterized in that the first section forms an end section of the tempering channel (5a) adjacent to a distributor channel (134) and the second section forms a distributor channel section adjacent to the end section and / or the first section forms an end section of the tempering channel (5a) adjacent to a collector channel (136) and the second section forms a collector channel section adjacent to the end section.

37. Element (2, 2a) according to claim 36, characterized in that the fluid distributor forms an inlet channel (133) from which the distributor channels (134) branch off and / or the fluid collector forms an outlet channel (135) from which the collector channels (136) branch off.

38. Element (2, 2a) according to claim 37, characterized in that the first section forms an opening section of the distributor channel (134) adjacent to the inlet channel (133) and the second section forms a branching section of the inlet channel (133) adjacent to the opening section and / or the first section forms an opening section of the collector channel (136) adjacent to the outlet channel (135) and the second section forms a branching section (133a) of the outlet channel adjacent to the opening section of the collector channel (136).

39. Element (2, 2a) according to claim 38, characterized in that an angle (y') between the branching section of the inlet channel (133) and the mouth section of the distributor channel (134) is greater than 90°, preferably greater than 100° and / or in which an angle (y') between the branching section (133a) of the outlet channel (135) and the mouth section of the collector channel (136) is greater than 90°, preferably greater than 100°.

40. Element (2, 2a) according to one of claims 17 to 39, characterized in that the material of the substrate (125) has a zero crossing temperature (TZC) which is between 0°C and 100°C, preferably between 19°C and 40°C, particularly preferably between 19°C and 32°C.

41. Element (2, 2a) according to one of claims 17 to 40, characterized in that the material of the substrate (125) has a spatial variation of the zero crossing temperature (ATZC) which is less than 3 K, preferably less than 2 K, particularly preferably less than 1 K, in particular less than 0.1 K.

42. Element (2, 2a) according to one of claims 19 to 41, characterized in that the surface (4) is an optical surface and has molybdenum-silicon layers.

43. Semiconductor technology system, in particular lithography system, in particular Projection exposure system (100, 200) for semiconductor lithography, comprising a plurality of elements (2, 2a), an illumination system (101, 201) with a radiation source (102) and an optics system (103, 109, 206) which has at least one optical element (116, 118, 119, 120, 121, 122, Mi, 207), characterized in that at least one element (2, 2a) of the system, in particular one of the optical elements (116, 118, 119, 120, 121, 122, Mi, 207), is produced by means of a method according to one of claims 1 to 8, and / or at least one element (2, 2a) of the system, in particular one of the optical elements (116, 118, 119, 120, 121 , 122, Mi, 207), is produced by means of a device (1) according to one of claims 9 to 16, and / or at least one element (2, 2a) of the system, in particular one of the optical elements (116, 118, 119, 120, 121, 122, Mi, 207), is an element (2, 2a) according to one of claims 17 to 42.

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