Device for amplifying laser radiation and method for setting a state of a base frame of a device for amplifying laser radiation, which state is as dimensionally stable as possible

Abstract

The present invention relates to a device for amplifying laser radiation, having a base frame (20) and at least one optical amplifier (9) arranged on the base frame (20) for amplifying the laser radiation, wherein the base frame (20) has a plurality of interconnected base-frame frame segments (25), wherein each of the base-frame segments (25) comprises a segment temperature control device (30) for actively controlling the temperature of the respective base-frame segment (25), wherein the segment temperature control devices (30) can be controlled independently of one another.

Description

[0001] Device for amplifying laser radiation and

[0002] Method for setting a state of a base frame of a device for amplifying laser radiation that is as dimensionally stable as possible

[0003] The present invention relates to a device for amplifying laser radiation, in particular to a device for amplifying laser radiation for a device for providing laser radiation for an EUV lithography system, comprising a base frame and at least one optical amplifier arranged on the base frame for amplifying laser radiation. Furthermore, the invention relates to a method for adjusting the base frame of a device for amplifying laser radiation to a state that is as dimensionally stable as possible.

[0004] Such devices for amplifying laser radiation are used, for example, in lithography systems that utilize extreme ultraviolet radiation, or EUV radiation. These lithography systems typically include a system for providing laser radiation, by means of which a target material is excited. The target material, for example, tin, is thereby converted into a plasma state, releasing EUV radiation. Typically, a laser radiation source generates laser radiation, particularly pulsed laser radiation. This laser radiation is amplified in one or more serially arranged optical amplifiers to obtain the radiation power required to excite the target material.

[0005] Devices known in the prior art for amplifying laser radiation have one or more optical amplifiers arranged on a base frame, each comprising a cavity, for example designed as a quartz tube, into which a gaseous laser medium, i.e., a laser gas, is introduced and excited with a high-frequency voltage. The laser radiation radiated into the cavity is optically amplified by the excited laser gas and then exits the cavity. During amplification, waste heat is generated, which is removed from the cavity together with the heated laser gas. The heated laser gas usually has to be actively cooled before it can be fed back into the cavity. Particularly in such devices for EUV lithography systems, the high radiation outputs can lead to significant heat generation and, as a result, to deformation of the base frame of the device.Since such deformations of the base frame influence the beam guidance of the laser radiation, it is necessary to tune the device, i.e. adjust the optical beam guidance components, in a state in which the base frame has the same shape or deformation as during later operation. It is therefore common practice to initially put the device for amplifying laser radiation into a quasi-operating mode for a predetermined period during start-up in order to induce a deformation of the base frame similar to that during operation. The device can only be tuned once this quasi-operating mode has been reached. Since the predetermined period for reaching the quasi-operating mode is usually chosen to be long enough to ensure that this state is reached, long waiting times occur during which the device is not available for production.The availability of the device and the EUV lithography system it contains is therefore limited.

[0006] Against this background, the task arises of increasing the availability of a device for amplifying laser radiation for an EUV lithography system and thus the availability of the EUV lithography system.

[0007] To achieve this object, a device for amplifying laser radiation according to claim 1 is proposed. This device for amplifying laser radiation comprises a base frame and at least one optical amplifier arranged on the base frame for amplifying laser radiation, wherein the base frame has a plurality of interconnected base frame segments, wherein each of the base frame segments comprises a segment temperature control device for actively temperature control of the respective base frame segment, wherein the segment temperature control devices are controllable independently of one another.

[0008] The segment temperature control devices provided according to the invention enable the temperature of the base frame to be influenced segment by segment. This means that differences between the base frame segments can be compensated for by controlling the segment temperature control devices differently. A dimensionally stable state of the base frame, which is desired for tuning the device, can therefore be achieved more quickly than would be possible with uniform temperature control. In this respect, the device for amplifying laser radiation - and thus also an EUV lithography system comprising this device - can be brought into the most dimensionally stable state possible more quickly during start-up. Downtime, for example, after maintenance work, can be shortened and the availability of the system increased. In the context of the present invention, temperature control refers to both cooling and heating.In the context of the invention, a segment temperature control device is understood to mean a device assigned to the respective base frame segment, which is designed to cool and / or heat the respective base frame segment.

[0009] The laser radiation provided for the EUV lithography system by a device for providing laser radiation may preferably be an excitation light beam by means of which, when directed onto a target material, a target material plasma can be generated, which in turn emits EUV radiation.

[0010] The optical amplifier preferably comprises a cavity into which laser radiation to be amplified can be introduced and from which amplified laser radiation can be discharged. The cavity preferably has an inlet for introducing laser gas and an outlet for discharging laser gas heated in the cavity. Any gaseous laser medium can be used as the laser gas. The laser gas preferably contains carbon dioxide, CO2, hydrogen, H2, and helium, He. A pair of electrodes is preferably assigned to the cavity, to which a high-frequency voltage can be applied, by means of which the laser gas can be brought into an excited state. The device further comprises at least one, preferably several, optical beam guiding elements, for example mirrors.

[0011] According to an advantageous embodiment of the invention, the base frame segments are arranged adjacent to one another along a longitudinal direction of the base frame. This results in the temperature control of the base frame being able to vary along its longitudinal direction.

[0012] According to an advantageous embodiment of the invention, each of the base frame segments comprises a base body, within which at least one base body channel is arranged for conducting a heat transfer medium, in particular a liquid one. In this respect, the base body can be tempered, i.e., cooled and / or heated, by means of the heat transfer medium. The base body is preferably made of a metal, for example, aluminum.

[0013] In this context, a design has proven advantageous in which the base bodies of several, in particular all, base frame segments are identically designed. This provides the advantage that at least the base body can be manufactured as a common part for all segments. Segment-specific adaptations can be achieved by adding add-on parts to the base body.

[0014] According to an advantageous embodiment of the invention, each of the base frame segments comprises at least one temperature control plate arranged on a surface of the base body, which plate has at least one plate channel for guiding a heat transfer medium, in particular a liquid one. Preferably, several temperature control plates are provided on each base body. The at least one temperature control plate can protect the base body from external heat influences in the manner of a shield, in particular in the manner of a heat shield. The temperature control plates allow adaptation to the design of the respective component arranged on the base frame segment, in particular an optical amplifier.When changing components or revising the temperature control concept, only the at least one temperature control plate can be replaced without having to replace the base body. This enables cost-effective adaptations. The plate channel of the at least one temperature control plate is fluidically connected to the base body channel of the base body, thus forming a common heat transfer circuit. Alternatively, it can be provided that the plate channel and the base body channel are not fluidically connected to one another. If several temperature control plates are arranged on a base body, the plate channels of these temperature control plates are preferably fluidically connected.

[0015] According to an advantageous embodiment of the invention, each of the base frame segments has a thermal insulation layer arranged between the base body and the temperature control plate. The thermal insulation layer can reduce, or in particular prevent, unwanted heat exchange between the temperature control plate and the base body.

[0016] According to an advantageous embodiment of the invention, it is provided that it comprises a measuring device for measuring a deformation of the base frame and / or for measuring a rate of change of the deformation of the base frame. The measuring device can be used to determine the current shape or deformation state of the base frame. In particular, the measuring device can be used to detect whether the base frame has reached a substantially stable state, which allows the device to be reliably tuned so that it can be used following tuning. By measuring the deformation or the rate of change of the deformation, this state can be reliably detected, so that long waiting times when starting up the system can be avoided.According to an advantageous embodiment of the invention, the base frame segments are arranged adjacent to one another along a longitudinal direction of the base frame, wherein the measuring device is configured to measure a deformation of the base frame in the longitudinal direction and / or perpendicular to the longitudinal direction. By measuring the deformation of the base frame in the longitudinal direction and / or perpendicular to the longitudinal direction, significant deformations of the base frame can be detected with high reliability. Alternatively, it can be provided that the measuring device is configured to measure a deformation of the base frame at predetermined key points. These key points are preferably selected such that they are exposed to greater deformation during start-up than other regions of the base frame, preferably than the majority of other regions of the base frame.Alternatively, the key points can be selected such that they are each arranged in the region of a beam guiding element, for example a mirror, so that they are characteristic of the deformation of the base frame acting on the beam guiding.

[0017] According to an advantageous embodiment of the invention, the measuring device comprises at least one strain gauge. A strain gauge can provide a cost-effective way of measuring the deformation of the base frame. Preferably, the measuring device comprises multiple strain gauges. The multiple strain gauges can be arranged such that deformations of the base frame can be measured in multiple spatial directions. Alternatively or additionally, multiple strain gauges can be interconnected such that a difference in the strain between two strain gauges is determined. This can, for example, enable temperature compensation.

[0018] According to an advantageous embodiment of the invention, the measuring device has at least one optical measuring device, in particular an optical length measuring device, for example an interferometric length measuring device. Such an optical measuring device can enable greater measurement precision than is the case with strain gauges. Such optical measuring devices are therefore particularly suitable for applications in which minor deformations are observed. The optical measuring device preferably extends over more than half the length of the base frame in its longitudinal direction, particularly preferably over more than 80% of the length, for example over more than 90% of the length. The measuring device preferably comprises a plurality of optical measuring devices, in particular a plurality of optical length measuring devices, for example a plurality of interferometric length measuring devices.The multiple optical measuring devices can be aligned parallel. Alternatively or additionally, the measuring devices can be aligned in different spatial directions.

[0019] The object mentioned at the outset is further achieved by a device for providing laser radiation for an EUV lithography system having a laser radiation source and a device for amplifying laser radiation as described above.

[0020] In the device according to the invention for providing laser radiation for an EUV lithography system, the same technical advantages and effects can be achieved as have already been explained in connection with the device for amplifying laser radiation according to the invention.

[0021] A further subject of the invention is a method for setting a state of a base frame of a device for amplifying laser radiation that is as dimensionally stable as possible, wherein at least one optical amplifier for amplifying laser radiation is arranged on the base frame, wherein the base frame has a plurality of interconnected base frame segments, wherein each of the base frame segments comprises a segment temperature control device for actively temperature control of the respective base frame segment, wherein the segment temperature control devices are controlled independently of one another.

[0022] The method according to the invention can achieve the same technical advantages and effects as have already been explained in connection with the device for amplifying laser radiation according to the invention.

[0023] According to an advantageous embodiment of the invention, it is provided that each of the base frame segments comprises a base body, within which at least one base body channel is arranged for guiding a, in particular liquid, heat transfer medium, wherein each of the base frame segments has at least one temperature control plate arranged on a surface of the base body, which has at least one plate channel for guiding a, in particular liquid, heat transfer medium.

[0024] According to an advantageous embodiment of the invention, a measuring device is used to measure a deformation of the base frame and / or a rate of change of the deformation of the base frame. The measuring device can be used to determine the current shape or deformation state of the base frame. In particular, the measuring device can be used to detect whether the base frame has reached a substantially stable state, which allows the device to be reliably tuned so that it can be used following tuning. By measuring the deformation or the rate of change of the deformation, this state can be reliably detected, thus avoiding long waiting times when starting up the system. Downtime, for example after maintenance work, can be shortened and the availability of the system can be increased.

[0025] According to an advantageous embodiment of the invention, it is provided that a dimensionally stable state is detected as soon as the rate of change of the deformation is smaller than a predetermined maximum value. With such an embodiment, it is assumed that rates of change below the maximum value have no significant influence on the beam guidance elements. This detection enables particularly reliable detection of the dimensionally stable state and is therefore well suited to shortening the time required to reach the quasi-operating state for tuning and enabling higher availability. Preferably, within the scope of the method, a signal is generated which indicates that the stable temperature control state has been detected and that tuning of the device, in particular of beam guidance elements of the device, can begin.The signal may be an electrical, optical, acoustic or other machine-detectable or user-detectable signal.

[0026] According to an advantageous embodiment of the invention, it is provided that the segment tempering devices are controlled independently of one another and as a function of the deformation and / or measured rate of change measured by the measuring device.

[0027] Alternatively or in addition to the advantageous embodiments explained above, the advantageous embodiments and features explained in connection with the device according to the invention can be used in the method.

[0028] Further details and advantages of the invention will be explained below with reference to the exemplary embodiments shown in the figures. Herein:

[0029] Fig. 1 shows a block diagram of an EUV lithography system with a device for amplifying laser radiation according to an embodiment of the invention; Fig. 2 shows a device for providing laser radiation with a device for amplifying laser radiation according to an embodiment of the invention in a schematic representation;

[0030] Fig. 3 shows a base frame of a device for amplifying laser radiation according to an embodiment of the invention;

[0031] Fig. 4a shows the base frame according to Fig. 3 with a measuring device comprising several strain gauges in the undeformed state in a schematic representation;

[0032] Fig. 4b shows the base frame according to Fig. 3 with a measuring device comprising several strain gauges in a deformed state in a schematic representation;

[0033] Fig. 5a shows a beam center point after passing through a device for providing laser radiation with an undeformed base frame according to Fig. 4a;

[0034] Fig. 5b shows a beam center point after passing through a device for providing laser radiation with a deformed base frame according to Fig. 4a;

[0035] Fig. 6 Time course of a measurement of the deformation when starting up a device for providing laser radiation;

[0036] Fig. 7 shows a base frame segment of the base frame from Fig. 3 in a perspective view;

[0037] Fig. 8 shows a base body of the base frame segment according to Fig. 7 in a perspective view in which the interior of the base body is identified;

[0038] Fig. 9 shows a tempering plate of the base frame segment according to Fig. 7 in a perspective view.

[0039] The illustration in Fig. 1 shows an EUV lithography system 101 with a device 2 for amplifying laser radiation 11 according to an exemplary embodiment of the invention. The EUV lithography system 101 comprises at least one radiation source 1, by which, in particular, pulsed, laser radiation 11 can be generated. Even if only one radiation source 1 is illustrated here, two radiation sources 1 can be provided, for example, to generate pre-pulses and main pulses of the laser radiation 11, which each follow one another in close temporal proximity and are focused on a target area 40.

[0040] A further component of the EU lithography system 101 is a device 2 for amplifying laser radiation, by which the laser radiation 11 generated by the radiation source 1 is optically amplified. The amplified laser radiation 11 is then fed to a focusing device 3, which focuses the laser radiation 11 onto a target area 40. A target material is arranged in the target area, which emits extreme ultraviolet radiation, EUV radiation, when irradiated with the laser radiation. According to the exemplary embodiment, the target area 40 is arranged in a target chamber 4 in which vacuum conditions prevail. The target material can be tin, for example, which is provided in droplet form. The tin droplet can be heated by a pre-pulse, for example pulsed laser radiation 11 with a wavelength of 1 micrometer, so that the tin droplet expands, vaporizes, ionizes and / or forms a weak or, if necessary,A strong plasma is generated. A main pulse following the pre-pulse briefly, for example, pulsed laser radiation 11 with a wavelength of 10.6 micrometers, can convert the substantial portion of the material affected by the pre-pulse into the plasma state, generating extreme ultraviolet radiation 42, EUV radiation. This EUV radiation 42 is then fed to an exposure device 5 of the lithography system 10, in which the EUV radiation 42 can be used to expose semiconductor substrates.

[0041] Fig. 2 shows a device 100 for providing laser radiation according to a first embodiment of the invention, which can be used in the system shown in Fig. 1. In addition to a laser radiation source 1, the device 100 comprises a device 2 for optically amplifying the laser radiation 11 with a plurality of, here two, optical amplifiers 9. The optical amplifiers each have a cavity 10 designed as quartz tubes. Between the optical amplifiers 9, optical beam guiding components (not shown in the illustration), for example mirrors, are provided, which guide the laser radiation from one optical amplifier 9 to the next. Each of the cavities 10 has an inlet 12 for introducing laser gas 14 and an outlet 13 for removing laser gas 14. Further components of the optical amplifiers 9 are electrode pairs 17, wherein one electrode pair 17 is assigned to each cavity 10.The respective electrode pair 17 can be used to excite the laser gas contained in the cavity 10, so that the laser radiation 11 introduced into the cavity 10 is optically amplified. A mixture containing CO2, N2, and He is used as the laser gas 14. In the present embodiment, two optical amplifiers 9, each with a cavity 10, are connected in series, so that the already amplified laser radiation emerging from the first cavity 10 enters the second cavity 10 and is amplified there again. The doubly amplified laser radiation then exits the device 3.

[0042] Each optical amplifier 9, i.e. each cavity 10, of the device 2 for amplifying the laser radiation 11 is assigned a separate circuit for the laser gas 14. In Fig. 2 it can be seen that a first circuit, here the one shown on the left, comprises a conveying device 19 designed as a compressor. The conveying device 19 conveys the heated laser gas emerging from the cavity 10 through a cooler 16 back into the cavity 10. A second circuit, here the one shown on the right, comprises, in addition to the conveying device 19 and the cooler 16, a catalyst 15 for regenerating the laser gas 14. According to a modification of this exemplary embodiment, a common circuit can be provided for several, in particular all, cavities 10. It is also possible for several separate circuits to each comprise several cavities 10.

[0043] During operation of the device 2 for amplifying the laser radiation, a high degree of waste heat is generated. Since all components 9, 10, 15, 16, 19 of the device 2, including the beam guidance elements, are arranged on a base frame 20 (shown only in Figure 3), the base frame 20 is exposed to the waste heat of these components 9, 10, 15, 16, 19. This high heat exposure can lead to deformation of the base frame 20 of the device.

[0044] Since such deformations of the base frame influence the beam guidance of the laser radiation, it is necessary that the device tuning, i.e., the adjustment of the optical beam guidance components, be carried out in a state in which the base frame has the same shape or the same deformation as during subsequent operation. In order to be able to perform the tuning as quickly as possible during start-up of the device, i.e., without unnecessary waiting times, special measures have been taken for device 2 according to the exemplary embodiment, which will be explained below with reference to the illustration in Fig. 3.

[0045] Fig. 3 shows a base frame 20 of a device 2 for amplifying laser radiation. The base frame 20 is essentially beam-shaped. In order to determine the current shape or deformation state of the base frame 20, a measuring device 21 is arranged on the base frame 20, by means of which the deformation of the base frame 20 and a rate of change of the deformation of the base frame 20 are measured. In the exemplary embodiment, the measuring device 21 comprises two optical length measuring devices 22, which are preferably designed as interferometric length measuring devices. The optical length measuring devices 22 are only symbolically indicated in Fig. 3. By means of the measuring device 21, it can be detected whether the base frame 20 has reached a substantially dimensionally stable state, which allows the device 2 to be reliably tuned.

[0046] The illustration in Fig. 3 further shows that the base frame 20 comprises a plurality of interconnected base frame segments 25. One of these base frame segments 25 is shown enlarged in the highlighted detail. Each of these base frame segments 25 can, for example, support an optical amplifier 9 or a unit consisting of several optical amplifiers 9. In addition, the other components 15, 16, 19 required for the operation of the respective optical amplifier 9 are also arranged on the respective base frame segment 25.

[0047] Each of the base frame segments 25 comprises a segment temperature control device 30 for actively controlling the temperature of the respective base frame segment 25, which is explained further below in connection with the illustrations in Figs. 7 to 9. These segment temperature control devices 30 can be controlled independently of one another and make it possible to influence the temperature of the base frame 20 segment by segment. Since the base frame segments 25 are arranged adjacent to one another along the longitudinal direction L of the base frame 20, the temperature of the base frame 20 can be controlled differently in its longitudinal direction. In particular, the segment temperature control devices 30 can be controlled independently of one another and depending on the deformation and / or measured rate of change measured by the measuring device 21.

[0048] The illustrations in Fig. 4a and 4b show a section of the base frame 20 according to Fig. 3 with an alternative measuring device 21 which has a plurality of strain gauges 23 instead of the optical length measuring devices 22. Fig. 4a shows the base frame 20 schematically in an undeformed state and Fig. 4b shows the base frame 20 schematically in a deformed state. In this exemplary embodiment, the strain gauges 23 are arranged such that they behave in opposite directions when the base frame 20 is deformed, ie one of the strain gauges 23, for example the upper one in Fig. 4b, is stretched while another of the strain gauges 23, for example the lower one in Fig. 4b, is compressed. The illustration in Fig. 5a and 5b illustrates the effects of the deformation of the base frame 20 on the path of the laser radiation in the device 2. Fig.5a shows a beam center 27 at the output of the device 100 for providing laser radiation with an undeformed base frame 20. Here, it can be seen that the beam center 17 is located at the center 24 of the crosshairs shown. Fig. 5b, on the other hand, shows a beam center 27 of the laser radiation with a deformed base frame 20. It can be seen that the beam center 27 has moved away from the center 24 of the crosshairs.

[0049] Fig. 6 shows a time course of a deformation measurement during the start-up of a device 100 for providing laser radiation. The value Vc shown here as the measured value of the deformation is, for example, a stress dependent on the deformation, in particular of a strain gauge 23. It can be seen that the deformation changes more quickly at the beginning of the start-up of the device 100 than at later times. In this respect, the rate of change of the deformation decreases with increasing time. In the diagram, a point A is marked at which the rate of change of the deformation falls below a predetermined maximum value. This point A is equated with an essentially dimensionally stable state of the base frame 20. This means that upon reaching point A, tuning of the device 2 can begin, since there is no fear of even greater deformations of the base frame 20 occurring.

[0050] The illustration in Fig. 7 shows a base frame segment 25 of the base frame 20 according to Fig. 3.

[0051] The base frame segment 25 comprises a base plate 28 and a base body 26 held on the base plate 28, which is preferably made of a metal, for example aluminum. The base plate 28 is also preferably made of a metal, for example also of aluminum. The base body 26 can be actively temperature-controlled, i.e. cooled and / or heated. In addition, a plurality of temperature control plates 31, 32, 33, 34 are arranged on the base body 26, which can also be actively temperature-controlled. The temperature control plates 31, 32, 33, 34 are preferably actively cooled and can thus keep heat away from the base body 26 like a heat shield. This effect can be further enhanced by arranging a thermal insulation layer between the temperature control plates 31, 32, 33, 34 and the base body 26. This is not shown in Figs. 7 to 9 for reasons of clarity. The illustration in Fig.Figure 8 shows the base body 26 of the base frame segment 25 according to Figure 7. Arranged within the base body are several, here two, separate base body channels 36, 37 for conducting a heat transfer medium, in particular a liquid one. A heat transfer medium can be conducted through these base body channels 36, 37. Depending on whether the heat transfer medium has a higher or lower temperature than the base body 26, the base body 26 can be cooled or heated by the heat transfer medium. It can be seen that the course of the base body channels 36, 37 is of little complexity. This comparatively straight course is possible because the base body 26 is supplemented by the temperature control plates 31, 32, 33, 34, which also contribute to the temperature control of the base body.

[0052] The illustration in Fig. 9 shows an example of a temperature control plate 31 of the temperature control plates 31, 32, 33, 34 from Fig. 7. The temperature control plate 33 comprises a plate channel 35 for conducting a liquid heat transfer medium. As shown in Fig. 7, the plate channel 35 of this temperature control plate 33 can be fluidly connected to the respective plate channels of the other temperature control plates 31, 32, 34, so that a heat transfer medium can flow through all temperature control plates 31, 32, 33, 34 of a base frame segment 25.

[0053] The above-described device 2 for amplifying laser radiation can be operated such that a deformation of the base frame 20 and / or a rate of change of the deformation of the base frame 20 is measured by means of the measuring device 21. In particular, when the device 2 is started up, a dimensionally stable state of the base frame 20 can be detected when a point A is reached from which the rate of change of the deformation is smaller than a predetermined maximum value.

[0054] Furthermore, it is possible that at the beginning of the start-up process, i.e., when the base frame 20 is cold, an intentional misalignment is performed. This misalignment is selected such that the beam guidance elements of the device are correctly aligned with the base frame 20 after start-up, i.e., when the base frame 20 is warm and dimensionally stable. The respective parameters of the misalignment state are read from a memory in which parameters of several different misalignment states are stored. Different parameters are stored for several measured deformation values. Depending on the measured deformation, the appropriate parameter set is read out, and the beam guidance elements are adjusted based on this parameter set.To achieve the most dimensionally stable state possible for the base frame 20 of the above-described device 2 for amplifying laser radiation, the segment temperature control devices 30 can be controlled independently of one another. In this way, differences between the base frame segments 25 can be compensated. Consequently, the dimensionally stable state of the base frame 20, which is desired for tuning the device 2, can be achieved more quickly than would be possible with uniform temperature control.

[0055] Reference symbol:

[0056] 1 radiation source

[0057] 2 Device for amplifying laser radiation

[0058] 3 Focusing device

[0059] 4 Target chamber

[0060] 5 Exposure device

[0061] 9 optical amplifier

[0062] 10 Cavity

[0063] 11 Laser radiation

[0064] 12 Entrance

[0065] 13 Outlet

[0066] 14 Laser gas

[0067] 15 Catalyst

[0068] 16 coolers

[0069] 17 electrode pairs

[0070] 19 Conveyor system

[0071] 20 base frame

[0072] 21 Measuring device

[0073] 22 optical length measuring device

[0074] 23 strain gauges

[0075] 24 Center of the crosshair

[0076] 25 Base frame segment

[0077] 26 base bodies

[0078] 27 Beam center point

[0079] 28 Base plate

[0080] 29 Support arm

[0081] 30 segment temperature control device

[0082] 31 Tempering plate

[0083] 32 Tempering plate

[0084] 33 Tempering plate

[0085] 34 Tempering plate

[0086] 35 plate channel

[0087] 36 Base body channel

[0088] 37 Base body channel

[0089] 42 EUV radiation

[0090] 100 Device for providing laser radiation 101 EUV lithography system

[0091] A point t time

[0092] Vc measured value of the deformation

Claims

Patent claims 1. Device for amplifying laser radiation, in particular a device for amplifying laser radiation for a device for providing laser radiation for an EUV lithography system (101), with a base frame (20) and with at least one optical amplifier (9) arranged on the base frame (20) for amplifying the laser radiation, characterized in that the base frame (20) has a plurality of interconnected base frame segments (25), wherein each of the base frame segments (25) comprises a segment tempering device (30) for actively tempering the respective base frame segment (25), wherein the segment tempering devices (30) are controllable independently of one another.

2. Device according to claim 1, characterized in that the base frame segments (25) are arranged adjacent to one another along a longitudinal direction (L) of the base frame (20).

3. Device according to one of the preceding claims, characterized in that each of the base frame segments (25) comprises a base body (26), within which at least one base body channel (36, 37) is arranged for guiding a, in particular liquid, heat transfer medium.

4. Device according to claim 3, characterized in that the base bodies (26) of several base frame segments (25) are identically designed.

5. Device according to claim 3 or 4, characterized in that each of the base frame segments (25) has at least one tempering plate (31, 32, 33, 34) arranged on a surface of the base body (26), which has at least one plate channel (35) for guiding a, in particular liquid, heat transfer medium.

6. Device according to claim 5, characterized in that each of the base frame segments (25) has a thermal insulation layer arranged between the base body (26) and the temperature control plate (31, 32, 33, 34).

7. Device according to one of the preceding claims, characterized by a measuring device (21) for measuring a deformation of the base frame (20) and / or for measuring a rate of change of the deformation of the base frame (20).

8. Device according to claim 7, characterized in that the base frame segments (20) are arranged adjacent to one another along a longitudinal direction (L) of the base frame (20), wherein the measuring device (21) is designed to measure a deformation of the base frame (20) in the longitudinal direction (L) and / or perpendicular to the longitudinal direction (L).

9. Device according to one of the preceding claims, characterized in that the measuring device (21) comprises at least one strain gauge (23).

10. Device according to one of the preceding claims, characterized in that the measuring device (21) has at least one optical measuring device (22), in particular an optical length measuring device, for example an interferometric length measuring device.

11. Device for providing laser radiation for an EUV lithography system (101) with a laser radiation source (1) and a device (2) according to one of the preceding claims.

12. Method for setting a state of a base frame (20) of a device (2) for amplifying laser radiation that is as dimensionally stable as possible, wherein at least one optical amplifier (9) for amplifying laser radiation is arranged on the base frame (20), wherein the base frame (20) has a plurality of interconnected base frame segments (25), wherein each of the base frame segments (25) comprises a segment tempering device (30) for actively tempering the respective base frame segment (25), wherein the segment tempering devices (30) are controlled independently of one another.

13. The method according to claim 12, characterized in that each of the base frame segments (25) comprises a base body (26), within which at least one base body channel (36, 37) is arranged for guiding a, in particular liquid, heat transfer medium, wherein each of the base frame segments (25) comprises at least one arranged on a surface of the base body (26) Tempering plate (31, 32, 33, 34) which has at least one plate channel (35) for guiding a, in particular liquid, heat transfer medium.

14. Method according to one of claims 12 or 13, characterized in that a deformation of the base frame (20) and / or a rate of change of the deformation of the base frame (20) is measured by means of a measuring device (21).

15. Method according to claim 14, characterized in that a dimensionally stable state is recognized as soon as the rate of change of the deformation is smaller than a predetermined maximum value.

16. Method according to one of claims 14 or 15, characterized in that the segment tempering devices (30) are controlled independently of one another and in dependence on the deformation and / or measured rate of change measured by the measuring device (21).

Images