Imaging system, method for repairing an imaging system

Abstract

Imaging system comprising a vacuum chamber (18) and a control unit (28), wherein a plurality of optical elements defining a beam path (15) are arranged in the vacuum chamber (18). A transducer (30, 31, 32) is arranged in the vacuum chamber (18). A vacuum flange (33) is arranged in a wall of the vacuum chamber (18). An electrical conductor (34, 35, 36, 37) designed for transmitting electrical signals is formed between the control unit (28) and the transducer (30, 31, 32), wherein the electrical conductor (34, 35, 36, 37) extends through the vacuum flange (33). In the electrical conductor section (34, 35, 36, 37) a plug connection (34) is formed with a plug receptacle (39) and with a plug (40) inserted into the plug receptacle (39), wherein the plug receptacle (39) is arranged on an outside of the vacuum flange (33).An electronic component (44) is arranged in a connector housing (41) of the connector (40), which is designed for signal shaping of electrical signals transmitted between the control unit (28) and the transducer (30, 31, 32). The invention also relates to a method for repairing an imaging system.

Description

[0001] The invention relates to an imaging system and a method for repairing an imaging system.

[0002] Imaging systems in which the optical elements shaping the beam path are arranged in a vacuum chamber are often mirror optics designed to reflect very short-wavelength electromagnetic radiation in the extreme ultraviolet spectral range (EUV radiation).

[0003] The imaging system can, for example, be part of a mask inspection system designed for inspecting photomasks. Photomasks are used in microlithographic projection exposure systems, which are used to manufacture integrated circuits with extremely small structures. A mask inspection system can generate an aerial image of a section of the photomask, projecting the photomask onto an EUV image sensor of an EUV camera. Based on this image on the EUV image sensor, an assessment can be made as to whether the photomask is free of defects and contaminants.

[0004] In another application, the imaging system is a component of a microlithographic projection exposure system. Microlithographic projection exposure systems are used for the production of integrated circuits with extremely small structures. A photomask illuminated with EUV radiation is projected onto a lithography object by an EUV projection lens to transfer the mask structure onto the lithography object.

[0005] The imaging system comprises several optical elements that shape the beam path. These optical elements have a precisely defined shape and are precisely positioned to ensure that the image produced by the imaging system is of sufficient quality.

[0006] Transducers, such as sensors or actuators, are located within the vacuum chamber to monitor the operation of the imaging system or to adjust its settings. A control unit for activating the transducers is often located at a considerable distance from the vacuum chamber, which makes the transmission of electrical signals between the control unit and the transducers somewhat complex.

[0007] The invention is based on the objective of presenting an imaging system and a method for repairing an imaging system, with which the aforementioned disadvantages are reduced. This objective is achieved by the features of the independent claims. Advantageous embodiments are specified in the dependent claims.

[0008] An imaging system according to the invention comprises a vacuum chamber and a control unit, wherein a plurality of optical elements defining a beam path are arranged in the vacuum chamber. A transducer is arranged in the vacuum chamber. A vacuum flange is arranged in a wall of the vacuum chamber. An electrical conductor section designed for transmitting electrical signals is formed between the control unit and the transducer, the electrical conductor section extending through the vacuum flange. A plug connection with a receptacle and a plug inserted into the receptacle is formed in the electrical conductor section, the receptacle being arranged on an outer surface of the vacuum flange. An electronic component is arranged in a plug housing of the plug, which is designed for signal shaping of an electrical signal transmitted between the control unit and the transducer.

[0009] The invention addresses the fact that, when an electrical signal is transmitted along a conductor, a voltage drop inevitably occurs due to electrical resistance. The resulting distortion of the electrical signal is undesirable and can lead to malfunctions in the imaging system. The invention proposes a method to counteract the risk of such distortion through signal shaping.

[0010] For this purpose, an electronic component is positioned within the electrical conductor path to influence the state of the transmitted electrical signal. By arranging it directly on the outside of a vacuum flange of the vacuum chamber, the risk of the electronic component interfering with the beam path within the vacuum chamber is reduced. In particular, this prevents the electronic component from disrupting the beam path through thermal fluctuations or the release of foreign substances.

[0011] By arranging the electronic component within a connector that engages with a connector receptacle on the outside of the vacuum flange, the remaining signal path between the electronic component and the transducer in the vacuum chamber is kept as short as possible.

[0012] A transducer is generally defined as a component used to convert one form of energy into another. Transducers can be, in particular, sensors and / or actuators. A sensor can be designed to acquire information about the state of optical elements in the vacuum chamber, for example, about the temperature, position, or orientation of an optical element. An actuator can be designed to influence the state of optical elements in the vacuum chamber, for example, to change the position of an optical element relative to a frame of the imaging system. An actuator can also perform other functions, such as adjusting a thermal manipulator. The transducer can be a mechatronic system.

[0013] The beam path in the vacuum chamber can be an imaging beam path, in particular an imaging beam path of a projection lens. The beam path can, for example, be that of a mask inspection system or a microlithographic projection exposure system. The optical elements in the vacuum chamber can be mirror elements, especially mirror elements with high reflectivity for EUV radiation. EUV radiation is defined as electromagnetic radiation with wavelengths in the range between 5 nm and 30 nm.

[0014] In one embodiment, the electrical signal is a supply signal used to provide the transducer with electrical energy. The electrical signal can be a DC voltage signal or an AC voltage signal.

[0015] The electrical signal can alternatively or additionally be an information transmission signal. The electrical signal can serve to transmit a measurement signal acquired by a transducer in the form of a sensor. The electrical signal can serve to transmit a control signal with which a transducer in the form of an actuator is controlled. Sensors and actuators are typical examples of transducers.

[0016] The electrical conductor path can include sections in which the electrical signal is transmitted via cables. The cables can comprise at least 90%, preferably at least 95%, of the length of the electrical conductor path. The length of the conductor path between the electronic component and the control unit can be at least twice, preferably at least five times, and more preferably at least ten times, the length of the conductor path between the electronic component and the transducer. The electronic component is an integral part of the electrical conductor path. The electronic component is configured such that, depending on the switching state, the transmission of electrical signals is either permitted or interrupted.

[0017] Signal shaping in the electronic component can, for example, consist of adjusting the voltage of a transmitted electrical signal to a predetermined value. This compensates for any voltage drop experienced by the electrical signal between the control unit and the connector. In other words, the electronic component can act as a voltage stabilizer.

[0018] Signal shaping can involve transforming the electrical signal to reduce the risk of information loss. For example, signal shaping can involve converting an analog electrical signal into a digital one. This allows a measurement signal to be transmitted analogously from a sensor to the electronic component and digitally from the electronic component to the control unit. Digital transmission reduces the risk of the electrical signal's information content being corrupted. The electronic component can also amplify the electrical signal. For instance, in the case of a digital electrical signal, the electronic component can act as a repeater. In the case of an analog electrical signal, the electronic component can act as a preamplifier, such as a preamplifier for a capacitive sensor.

[0019] Signal shaping can consist of filtering that reduces the bandwidth of the electrical signal. By reducing the bandwidth of the electrical signal to frequencies where the risk of distortion is low, the risk of information alteration can also be reduced.

[0020] The electronic assembly can include passive components such as capacitors, inductors, and resistors. An electronic assembly consisting solely of passive components might, for example, be designed to filter an electrical signal. The electronic assembly can also include active components, such as an operational amplifier, an analog-to-digital converter, a DC-DC converter, or an LDO (low-dropout voltage regulator). The active components can be used for voltage stabilization. In the event of an increase in voltage, the conductor cross-sections of the cables can be reduced, thus enabling longer cable runs at a lower cost. The electrical power required to operate the active components can be supplied via a conductor from the control cabinet to the connector.The components of the electronic assembly can be arranged on a circuit carrier. This circuit carrier can, in particular, be a printed circuit board.

[0021] The connector can include a connector housing. The electronic component can be located inside the connector housing. One or more cables can extend between the control unit and the connector. Each cable can define one or more conductor paths extending between the control unit and the connector, enabling the transmission of electrical signals between the control unit and the connector. The electronic component can include terminal contacts through which electrical contact is made towards the transducer. The electronic component can also include terminal contacts through which electrical contact is made towards the control unit.

[0022] A special feature of this application is the use of cable termination technologies that are also permitted in cleanrooms (no soldered connections, no connections such as screw connections that can generate electrically conductive particles). The aim is to enable an assembly and disassembly process that meets cleanroom cleanliness requirements without having to replace the entire cable assembly. In this case, the swap component is not the entire cable assembly, but only the electronic control unit inside the connector housing.

[0023] The control unit can be located at a greater distance from the connector. This distance can be greater than 10 m, in particular greater than 20 m, and in particular greater than 40 m. This distance can be bridged by cables extending from the control unit to the connector. These cables can be a series connection of cable segments.

[0024] The vacuum chamber can be operated within a cleanroom. The control unit can be located inside or outside the cleanroom. The control unit can be part of a control cabinet. The control cabinet can be equipped with an extraction system. This can be particularly helpful if the control cabinet is located inside the cleanroom, to prevent the cleanroom from being contaminated by impurities from the control cabinet.

[0025] The connector can comprise multiple contacts through which an electrical connection can be established with mating contacts of the connector receptacle. These contacts can be in electrical contact with terminals of the electronic component. The electronic component can comprise a first set of terminals for contacting the control unit and a second set of terminals for contacting the connector receptacle.

[0026] The electronic component can be replaceable. This allows the electronic component to be replaced in case of a fault, while other components of the connector and / or cable assembly can continue to be used.

[0027] For easy replacement of the electronic component, it is advantageous if the component's contacts are designed for mechanical connection. Other contact methods, such as soldering or electrically conductive adhesives, generally require more effort when replacing the electronic component. The mechanical connection can, for example, be designed as a clamping contact. The clamping contact can lock automatically when a cable is inserted. The clamping contact can be designed so that increased force is required to release it, or an actuator is engaged. It is also possible that an actuator, such as a clamping screw, is used for both connecting and disconnecting the mechanical connection.Mechanical contacting makes it possible to disconnect and connect the terminals of the electronic component without tools or using simple mechanical tools.

[0028] To prevent contamination of the cleanroom by the operation of the electronic component, the electronic component can be enclosed. The enclosure can be hermetically sealed to prevent the release of substances from the electronic component into the cleanroom atmosphere. The enclosure can be applied to the components of the electronic component as a coating or potting compound, particularly as a conformal coating. Alternatively, the enclosure can be a separate component from the electronic component. This component can be located inside the connector housing. In one embodiment, the connector housing itself is hermetically sealed and forms an enclosure for the electronic component.

[0029] The connector housing can be designed to open, allowing access to its interior. For example, two parts of the connector housing can be separable, or the housing can be hinged. Sealing elements can be arranged or formed between the parts of the connector housing so that the housing is hermetically sealed again after opening and closing.

[0030] The pressure difference between the interior of the vacuum chamber and the environment can exist above the vacuum flange. An inner side of the vacuum flange can face the interior of the vacuum chamber. An outer side of the vacuum flange can face the environment. A cleanroom atmosphere can be present in the environment.

[0031] A plurality of connector receptacles can be formed on the outside of the vacuum flange. Each connector receptacle can be configured to receive a connector. Several or all of the connectors can individually or in combination have the features disclosed in connection with a connector according to the invention. Cables can extend from several or all of the connectors to the control unit. The number of connector receptacles on the outside of the vacuum flange can be greater than 10, preferably greater than 20.

[0032] One or more connector receptacles can be formed on the inside of the vacuum flange. Connectors can be inserted into these receptacles to establish an electrical connection to the transducers of the optical system. The transducers can be, for example, sensors that acquire measurements of the condition of optical elements within the optical system. Alternatively, or in addition, the transducers can be actuators that influence the condition of optical elements within the optical system.

[0033] The imaging system can be designed so that no further processing of the electrical signal occurs between the inside of the vacuum flange and the transducers. If electrical signals are only transmitted via cables within the vacuum chamber, the risk of contamination of the residual gas atmosphere in the vacuum chamber due to signal transmission is low. An electrical conductor path between a transducer and the control unit can extend via a first cable to the inside of the vacuum flange, through the vacuum flange to the outside of the vacuum flange, through the connector, and via a second cable from the connector to the control unit. Within the connector, electrical signals can be routed via the electronic component, thus shaping the electrical signals.

[0034] The invention also relates to a method for repairing an imaging system, wherein the imaging system comprises a vacuum chamber and a control unit, wherein a plurality of optical elements defining a beam path are arranged in the vacuum chamber, wherein a transducer is arranged in the vacuum chamber, and wherein a vacuum flange is arranged in a wall of the vacuum chamber. An electrical conductor designed for transmitting electrical signals is formed between the control unit and the transducer. The electrical conductor extends through the vacuum flange.The electrical conductor path includes a plug connection with a plug and a plug receptacle, the plug receptacle being located on the outside of the vacuum flange, and an electronic component being arranged in a plug housing of the plug. This component is designed for signal shaping of electrical signals transmitted between the control unit and the transducer. The plug is detached from the plug receptacle, the plug housing is opened, and the electronic component is removed from the plug housing and replaced.

[0035] The disclosure includes further developments of the method with features that are described in connection with the imaging system according to the invention.

[0036] The invention is described below by way of example with reference to the accompanying drawings and advantageous embodiments. The drawings show: Fig. 1: an exemplary embodiment of an imaging system according to the invention; Fig. 2: a detail from Fig. 1 in enlarged view; Fig. 3: unplug Fig. 2 in a different state; Fig. 4: A top view of the plug Fig. 3 in the open state; Fig. 5: the view according to Fig. 4 in a different state of the plug; Fig. 6: an embodiment of an electronic component; Fig. 7: the view according to Fig. 6 in an alternative embodiment of the invention; Fig. 8: a view of a plug according to the invention; Fig. 9: an alternative embodiment of an imaging system according to the invention.

[0037] With a Fig. Microlithographic photomasks 17 can be examined using the mask inspection system shown in Figure 1.

[0038] Microlithographic photomasks 17 are generally intended for use in a microlithographic projection exposure system (see Fig. 9) to be used. In the microlithographic projection exposure system, the photomask 17 is illuminated with extreme ultraviolet radiation (EUV radiation) at a wavelength of, for example, 13.5 nm to image a structure formed on the photomask 17 onto the surface of a lithographic object in the form of a wafer. The wafer is coated with a photoresist that reacts to the EUV radiation. The mask inspection system is used to examine whether the photomask meets the specifications and is free of defects.

[0039] In the mask inspection facility, according to Fig. 1. The photomask 17 is arranged such that an EUV beam path 15 emanating from an EUV radiation source 14 is directed onto the photomask 17 via an illumination system 16. The illumination system 16 shapes the EUV radiation into a beam that illuminates an inspection area on the surface of the photomask 17 with uniform brightness. The illuminated area can, for example, have dimensions of 0.5 mm x 0.8 mm. A field aperture is arranged in the illumination system 16 to limit the illuminated area to the inspection area on the surface of the photomask 17. A positioning system 26 allows the photomask to be moved in the xy-plane to bring different inspection areas on the surface of the photomask 17 into the area of ​​the EUV beam path 15.

[0040] The edge lengths of the photomask 17 can, for example, be between 100 mm and 200 mm. The photomask can have an aspect ratio between 1:1 and 1:3, preferably between 1:1 and 1:2, and particularly preferably between 1:1 or 1:2. The photomask can be substantially rectangular. The photomask can preferably be 5 to 7 inches (12.7 cm to 17.8 cm) long and wide, and particularly preferably 6 inches (15.2 cm) long and wide. Alternatively, the photomask can be 5 to 7 inches (12.7 cm to 17.8 cm) long and 10 to 14 inches (25.4 cm to 35.6 cm) wide, and preferably 6 inches (15.2 cm) long and 12 inches (30.5 cm) wide.

[0041] The EUV beam path 15, reflected from the photomask 17, continues via a projection lens 22 to an EUV camera 23, which is equipped with an image sensor 24. The projection lens 22 projects the inspection field on the surface of the photomask 17 onto the image sensor 24 of the EUV camera 23. The EUV radiation source 14, the illumination system 16, the photomask 17, the projection lens 22, and the EUV camera 23 are arranged in a vacuum chamber 18, in which a negative pressure is maintained during operation of the mask inspection system.

[0042] The illumination system 16 and the projection lens 22 comprise several optical elements, including EUV mirrors that shape the EUV beam path. Precise positioning of the EUV mirrors is required for high image quality in the mask inspection system. Actuators are provided for adjusting the position of the EUV mirrors relative to a frame of the projection lens 22. The projection lens 22 also includes sensors to determine the actual position of the EUV mirrors relative to the frame. Of the majority of sensors and actuators, in Fig. 1 a sensor 30 and two actuators 31, 32 are indicated by way of example.

[0043] The actuators 31, 32 are controlled, and the measured values ​​from sensor 30 are processed, in a control unit 28 located in a control cabinet 27. The control cabinet 27 and the vacuum chamber 18 are located together in a cleanroom. The control cabinet 27 is equipped with an extraction system 29 to prevent contamination of the cleanroom atmosphere from the control cabinet 27. The distance between the control cabinet 27 and the vacuum chamber 18 can be, for example, between 20 m and 50 m.

[0044] Electrical signals are transmitted from the sensor 30 to the actuators 31, 32 via first cables 37, which extend from the sensors and actuators 30, 31, 32 to a vacuum flange 33 located in the wall of the vacuum chamber 18. The first cables 37 are connected to the vacuum flange 33 via internal connectors 36 and electrically coupled to contacts within the vacuum flange 33. External connectors 34 are located on the outside of the vacuum flange 33, to which second cables 35 are connected. The second cables 35 extend to the control cabinet 27 and define electrical conductor paths between the control unit 28 and the external connectors 34. Each of the cables 34, 37 can be configured as a cable bundle containing multiple parallel electrical conductor paths.

[0045] The connectors 34, 36 each comprise a connector receptacle and a plug. The connector receptacle is part of the vacuum flange 33, and the plug forms a termination for one of the cables 35, 37. In the simplified representation according to Fig. Figure 2 shows two inner connector receptacles 38 and two outer connector receptacles 39. In reality, the number of connector receptacles on both sides can be significantly larger, for example between 20 and 30. The number of poles can also be larger than shown. Fig. 2, where only two poles are shown per connector socket.

[0046] In one of the outer connector receptacles 39, a complete plug connection 34 is shown, in which a plug 40 connected to the cable 35 is inserted into the outer connector receptacle 39. The plug 40 comprises according to Fig. 3 A connector housing 41, which is composed of an upper shell 42 and a lower shell 43. The upper shell 42 and the lower shell 43 can be separated from each other to allow access to the interior of the connector housing 41. A printed circuit board 44 is arranged inside the connector housing 41. The printed circuit board 44 forms an electronic component that is involved in the transmission of electrical signals between the control unit 28 and the sensors / actuators 30, 31, 32.

[0047] In the present embodiment, the circuit board 44 serves as a voltage stabilizer. Specifically, the circuit board 44 can compensate for a voltage drop that occurs due to the long transmission distance between the control unit 28 and the connector 40. This ensures that the sensors / actuators 30, 31, 32 are driven with a defined voltage. Depending on the requirements, the circuit board 44 can also perform other functions, such as acting as a repeater, an analog-to-digital converter, or a frequency filter.

[0048] In Fig. Figure 4 shows a top view of the opened connector housing 41 of the connector 40. The upper shell 42 has been removed, revealing the opened lower shell 43. A recess 50 is formed in the lower shell 43, in which the circuit board 44 is seated. On one side of the recess 50 is a plug-in area 45, in which the mating contacts for the poles of the outer connector receptacle 39 are arranged. Cables 35 extend from the opposite cable connection area 52 towards the control cabinet 27.

[0049] A plurality of passive electronic components 46 and active electronic components 47 are arranged on the circuit board 44. The circuit board 44 further comprises a first set 48 of connection contacts 51 for electrical contact with the cable 35 and a second set 49 of connection contacts 51 for contact with the plug contacts in the plug area 45. The connection contacts 51 are designed as clamping contacts that can be connected solely by applying a compressive force and separated solely by applying a tensile force.

[0050] In Fig. Figure 4 shows a state in which all connection contacts 51 are disconnected. In this state, the circuit board 44 can be removed from the recess 50. Fig. Figure 5 shows the state after removal of the circuit board 44, in which the recess 50 is empty.

[0051] In the event of a fault in the circuit board 44, a technician can quickly restore the functionality of the mask inspection system by disconnecting the connector 40 from the outer connector receptacle 39 and replacing the circuit board 44 as described. First, the connector housing 41 is opened by separating the upper shell 42 from the lower shell 43. The connections to the cable 35 and to the plug contacts in the plug area 45 are disconnected by pulling the respective connectors off the terminal contacts 51. The circuit board 44 is removed from the recess 50 and replaced with a new, undamaged circuit board 44. After re-establishing electrical contact via the terminal contacts 51, the upper shell 42 is reattached to the lower shell 43. The fully assembled connector 40 can then be plugged back into the outer connector receptacle 39, and the mask inspection system can resume operation.This results in a significant speedup compared to repairs that require opening vacuum chamber 18 and taking steps inside vacuum chamber 18.

[0052] The operation of electronic components generally carries a risk of contamination of the cleanroom atmosphere. To minimize this risk, the connector can be designed so that the electronic components 46, 47 are hermetically sealed from the environment. Fig. Figure 6 shows a cross-sectional view of the printed circuit board 44, in which the electronic components 46, 47 are covered with a potting compound 53, for example, in the form of a conformal coating. If substances are released from the electronic components 46, 47, they remain trapped in the potting compound 53. Contamination of the cleanroom atmosphere by the substances is thus prevented. The connection contacts 51 are located outside the potting compound 53 and are accessible for the connection of electrical contacts.

[0053] In the alternative embodiment according to Fig. In Figure 7, the circuit board 44 is provided with a cover 54, which provides protection for all electronic components 46, 47. A circumferential sealing ring 55 is arranged between the cover 54 and the surface of the circuit board 44, so that the area enclosed by the cover 54 is hermetically sealed from the environment. The risk of the cleanroom atmosphere being contaminated by substances released during the operation of the electronic components 46, 47 is reduced. Fig. Figure 8 shows another embodiment in which the connector housing 41 itself forms a hermetically sealed enclosure for the circuit board 44.

[0054] In Fig. Figure 9 schematically depicts a microlithographic EUV projection exposure system. The projection exposure system comprises an exposure beam source 64, an illumination system 60, and a projection lens 22, which are operated together in a vacuum chamber 73.

[0055] The exposure source 64 generates electromagnetic radiation in the EUV range, specifically with a wavelength between 5 nm and 30 nm. The exposure radiation emitted from the exposure source 64 is focused by a collector 65 into an intermediate focal plane 66. Exposure radiation passing from the intermediate focal plane 66 is directed by the illumination system 60 into an object plane 62, so that an object field in the object plane 62 is illuminated with uniform radiation intensity.

[0056] The illumination system 60 comprises a deflecting mirror 67, which deflects the exposure radiation onto a first faceted mirror 68. A second faceted mirror 69 is arranged downstream of the first faceted mirror 68. The facets of the first faceted mirror 68 are imaged onto the object plane 62 by the second faceted mirror 69. A photomask 63 is arranged in the object plane 62 and is imaged onto an image plane 71 by a plurality of mirrors M1-M6 of the projection lens 22. A structure formed on the photomask 63 is transferred to a radiation-sensitive layer of a wafer 70 arranged in the image plane 71.

[0057] Outside the vacuum chamber 73, a control cabinet 27 is arranged, designed to control the interaction of the components of the microlithographic projection system. An actuator 31, which can be used to adjust one of the mirror elements, is shown as an example. Electrical signals are transmitted via cables 35 and 37 through the vacuum flange 33. The cable 35 coming from the control cabinet 27 is connected, as described, via a connector 40 to a connector receptacle on the outside of the vacuum flange 33.

Claims

[1] Imaging system with a vacuum chamber (18) and with a control unit (28), wherein a plurality of optical elements defining a beam path (15) are arranged in the vacuum chamber (18), wherein a transducer (30, 31, 32) is arranged in the vacuum chamber (18), wherein a vacuum flange (33) is arranged in a wall of the vacuum chamber (18), wherein an electrical conductor section (34, 35, 36, 37) designed for transmitting electrical signals is formed between the control unit (28) and the transducer (30, 31, 32), wherein the electrical conductor section (34, 35, 36, 37) extends through the vacuum flange (33), wherein a plug connection (34) with a plug receptacle (39) and with a plug inserted into the plug receptacle (39) is located in the electrical conductor section (34, 35, 36, 37). (40) is trained,wherein the connector receptacle (39) is arranged on an outside of the vacuum flange (33) and wherein an electronic assembly (44) is arranged in a connector housing (41) of the connector (40), which is designed for signal shaping of an electrical signal that is transmitted between the control unit (28) and the transducer (30, 31, 32). [2] Imaging system according to claim 1, wherein the beam path (15) is an imaging beam path of a projection lens (22). [3] Imaging system according to claim 1 or 2, wherein the electrical signal is a supply signal for supplying the transducer (30, 31, 32) with electrical energy. [4] Imaging system according to one of claims 1 to 3, wherein the connector (40) comprises a connector housing (41) and wherein the electronic assembly (44) is arranged inside the connector housing. [5] Imaging system according to any one of claims 1 to 4, wherein the distance between the plug (40) and the control unit (28) is greater than 10 m. [6] Imaging system according to one of claims 1 to 5, wherein the control unit (28) is part of a control cabinet (27) and wherein the control cabinet (27) is provided with an extraction system (29). [7] Imaging system according to any one of claims 1 to 6, wherein the electronic component (44) is interchangeable. [8] Imaging system according to any one of claims 1 to 7, wherein the electronic component (44) has connection contacts (51) and wherein the connection contacts (51) are designed for mechanical contacting. [9] Imaging system according to any one of claims 1 to 8, wherein the electronic component (44) is provided with a covering (53, 54). [10] Imaging system according to claim 9, wherein the enclosure is formed by the connector housing (41) of the connector (40). [11] Imaging system according to any one of claims 1 to 10, wherein the connector housing (41) is designed to be opened to allow access to the interior of the connector housing (41). [12] Method for repairing an imaging system, wherein the imaging system comprises a vacuum chamber (18) and a control unit (28), wherein a plurality of optical elements defining a beam path (15) are arranged in the vacuum chamber (18), wherein a transducer (30, 31, 32) is arranged in the vacuum chamber (18), wherein a vacuum flange (33) is arranged in a wall of the vacuum chamber (18), wherein an electrical conductor section (34, 35, 36, 37) designed for transmitting electrical signals is formed between the control unit (28) and the transducer (30, 31, 32), wherein the electrical conductor section (34, 35, 36, 37) extends through the vacuum flange (33), wherein a plug connection (34) with a plug receptacle (39) and with a The plug receptacle (39) is designed for the inserted plug (40),wherein the connector receptacle (39) is arranged on an outside of the vacuum flange (33) and wherein an electronic assembly (44) is arranged in a connector housing (41) of the connector (40), the electronic assembly being designed for signal shaping of an electrical signal transmitted between the control unit (28) and the transducer (30, 31, 32), wherein the connector (40) is detached from the connector receptacle (39), wherein the connector housing (41) is opened, and wherein the electronic assembly (44) is removed from the connector housing (41) and replaced.

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