Device and method for tempering elements in microlithographic projection exposure systems

Abstract

Microlithographic projection exposure system (100; 400) provided for the EUV range or for the DUV range, comprising an illumination device (102; 402) and a projection lens (104, 340, 640; 404) with at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) which, for its temperature control, is at least partially surrounded by at least one temperature control fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007), wherein the temperature control fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) is connected to at least one temperature control fluid reservoir (470, 480, 615, 515, 516, 519, 460, 920, 1020) and wherein at least one temperature control element (702, 704, 706, 906, 916, 1006) for temperature control of the temperature control fluid on or in the temperature control fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007), whereby - a plurality of temperature control fluid lines (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) are provided and at least two different regions of the at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are each independently connected to at least one separate one of the temperature control fluid lines (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) or - several elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are provided and at least two of the elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are connected to the tempering fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) or - several elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) and several tempering fluid lines (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) are provided and at least two of the elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are independently traversed by at least one separate tempering fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) - and wherein the element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) is designed as at least one measuring frame (370, 371, 372) and / or as at least one supporting frame (380, 381, 382).

Description

Background of the invention

[0001] The present invention relates to devices for controlling the temperature of elements in microlithographic projection exposure systems. Furthermore, the invention relates to a method for controlling the temperature of elements in microlithographic projection exposure systems.

[0002] Microlithography is used to manufacture microstructured components, such as integrated circuits or LCDs. The microlithography process is carried out in a so-called projection exposure system, which has an illumination device and a projection lens. The image of a mask (= reticle) illuminated by the illumination device is projected by the projection lens onto a substrate (e.g., a silicon wafer) coated with a light-sensitive layer (= photoresist) and arranged in the image plane of the projection lens, in order to transfer the mask structure to the light-sensitive coating of the substrate.

[0003] The terms microlithographic projection exposure system, projection exposure system, (EUV or DUV) system and lithography scanner are used synonymously below.

[0004] In projection lenses designed for the DUV range, i.e., at wavelengths of, for example, 193 nm or 248 nm, lenses are preferably used as optical elements for the imaging process. To achieve higher resolution in lithography optics, projection lenses designed for the EUV range, which operate at wavelengths of, for example, 13.5 nm or 7 nm, have been used for several years.

[0005] In projection lenses designed for the EUV range, mirrors are used as optical elements for the imaging process due to the lack of suitable translucent refractive materials. These mirrors operate either at near-normal incidence or at grazing incidence. Due to their reflective effect on light rays, mirrors are significantly more position-sensitive than lenses. Thus, a mirror tilt of a factor of 2 translates into a change in beam direction, whereas a lens typically significantly compensates for the change in the refractive beam direction influence between the front and back surfaces.

[0006] A significant influence on the mirror shape comes from the thermal expansion of the mirror material. Therefore, materials with low thermal expansion coefficients, such as Zerodur or ULE (ultra low expansion), are used for EUV mirrors. Such materials react much less strongly to temperature changes than glass or quartz glass. Nevertheless, significant error contributions can occur within the available aberration budget. These error contributions consist of the effects of an inhomogeneous temperature distribution and inhomogeneities of the so-called zero crossing temperature (ZCT) in the bulk of the material, for example due to varying stoichiometry between SiO 2 and TiO 2in the ULE material. Both local and global temperature changes compared to the intended operating temperature of the microlithographic projection exposure system can cause aberrations that can only be partially corrected by manipulators.

[0007] The operating state is often defined by an assumed maximum power of the EUV system at the operating wavelength, for example at a wavelength of 13.5 nm. If this maximum power is not achieved, for example because a reticle with less reflectivity on average is used, then, according to the state of the art, infrared heaters can, for example, heat "topping up" and ensure that the mirrors are operated close to the averaged zero-crossing temperature, where they are particularly insensitive due to the quadratic deformation dependence on the temperature difference to this temperature.

[0008] DE 10 2013 111 801 A1 discloses a cooling system for at least one system component of an optical system for EUV applications. DE 10 2011 005 778 A1 discloses an optical element for a projection exposure system in semiconductor lithography, comprising an optically active surface and at least one cooling component for cooling the optical element.

[0009] To transport the heat from the projection lens and generally to maintain a suitable temperature for the elements of the projection lens, temperature control fluids, usually water, are used, which flow through the system at least in certain areas. Fig. 1 shows an EUV projection lens 640 according to the prior art. The support frame 381, which supports the EUV mirrors 691, 692, 693, and 694, takes over the entire temperature control of the EUV projection lens through its water cooling. There is only a single temperature control fluid line 602 that runs through the entire support frame 381. The four EUV mirrors 691, 692, 693, and 694 are connected to the support frame 381 via active mechanical bearings 695. The measuring frame 371 serves as a reference for the position measurement 625 of the EUV mirrors 691, 692, 693, and 694. Heat flows Q1 in the direction of the measuring frame 371 and Q2 in the direction of the mirror 692 are shown as examples. The EUV light 502 from the structure-bearing mask 120 (not shown in Fig. 1) is reflected by the four EUV mirrors 691, 692, 693 and 694 and is transmitted as EUV light 504 to the wafer 124 (not shown in Fig. 1). The temperature control fluid line 602 conducts the temperature control fluid through the support frame 381. The temperature control fluid line 602 is fed by a temperature control fluid reservoir 615 for the support frame 381. A temperature control element 702 is arranged after the support frame temperature control inlet 607. A temperature sensor 802 is arranged in the support frame 381. The temperature sensor 802 is coupled to the temperature control element 702. The coupling and control are not shown in the Fig. 1 (see Fig. 2). After flowing through the temperature control fluid line 602, the temperature control fluid enters the fluid reservoir 615 via a support frame temperature control outlet 614. If the temperature control element 702 is designed for the sake of simplicity so that it can only heat, a so-called recooling system or, synonymously, a recooling unit must be integrated into the arrangement. Without this recooling system, the temperature control fluid would constantly heat up. A recooling system is a device that removes excess heat from a system by means of a heat exchanger. For the sake of clarity, this recooling system is not shown in the Fig. 1 shown.

[0010] The temperature control of the support frame 381 performs the tasks described below. - First, the thermal stabilization of the support frame structure ensures stable positioning of the mirrors. Rigid-body movements can be compensated for by actuators. However, the forces transferred to the mirrors by the actuators generate wavefront errors due to mirror deformation. Furthermore, the additional power dissipated in the actuator units can lead to thermal drift of the optical image. - Thermal stabilization of the mirror environment. Heating of the mirror environment can lead to wavefront errors. This is caused by mirror deformations due to deviations of the mirror temperature from the design temperature (zero crossing temperature) and deviations from the manufacturing and measurement temperatures. - Shielding of the measuring frame (=reference for mirror positioning) against heat loads, such as mirror preheating, waste heat from actuators, encoders and sensors, in order to avoid deformation of the measuring reference. - Thermal control of the measuring frame to bring the measuring frame from a non-thermally controlled state to a stable thermally controlled operating state. This is necessary, for example, during system recovery. - Thermal control of the measuring frame during operation to keep the measuring frame within the tolerance limits with regard to absolute temperature and temperature drift (time derivative of the measuring frame temperature).

[0011] These five aforementioned requirements for the temperature control of the support frame can currently only be met by a compromise solution in the thermal architecture with regard to structure (support frame, measuring frame) and mirror heating.

[0012] Fig. Figure 5 shows a DUV projection lens according to the prior art. The surface temperature controller 450 is traversed by the temperature control fluid line 452. The temperature control fluid line inlet 454 and the temperature control fluid line outlet 456 establish the connection to the DUV temperature control fluid reservoir 460. A temperature sensor 806 is coupled to the temperature control element 706. The coupling and control are not shown in the figure for reasons of clarity. Fig. 6. The surface temperature controller 450 encloses at least partially the DUV projection lens 404. Q5 represents the heat flows from consumers and Q6 the heat flows from the projection lens 404. 408 denotes the DUV light at the entrance to the DUV projection lens 404. 458 denotes the DUV light to the wafer 424 (not shown). Fig. 5). The surface temperature controller 450 is traversed by only a single temperature control fluid line 452. It is therefore not possible to bring and maintain different areas of the surface temperature controller 450 at different temperature levels. This, too, represents a compromise solution.

[0013] In view of the problems described above, the object is to provide a device and a method that solve the above-mentioned problems, in particular to improve the thermal stabilization of lithography systems.

[0014] According to the invention, the aforementioned object is achieved by a microlithographic projection exposure system, in particular for the DUV range or the EUV range. The projection exposure system comprises an illumination device and a projection lens with at least one element, which, for its temperature control, is traversed at least in part by at least one temperature control fluid line provided for conducting a temperature control fluid. The temperature control fluid line is connected to at least one temperature control fluid reservoir, and at least one temperature control element for temperature control of the temperature control fluid is provided on or in the temperature control fluid line.In this case, a plurality of temperature control fluid lines are provided and at least two different regions of the at least one element are each independently traversed by at least one separate temperature control fluid line, or a plurality of elements are provided and at least two of the elements are each traversed by the temperature control fluid line, or a plurality of elements and a plurality of temperature control fluid lines are provided and at least two of the elements are each independently traversed by at least one separate temperature control fluid line. The three options mentioned above are particularly advantageous because they allow different elements or different regions of an element to be temperature-controlled differently. The element is designed as at least one measuring frame and / or as at least one support frame.

[0015] In one embodiment, the at least two separate temperature control circuits are connected in parallel. This is advantageous because it allows independent temperature control of different elements or different areas of an element. This allows different areas of an element, such as the support frame, to be kept at different temperatures. This makes it possible to supply individual areas with different flow temperatures. The general goal is to prevent heat flows that transfer into the temperature control fluid on one side of an element from being distributed throughout the entire system.

[0016] In one embodiment, two of the temperature control circuits are fed from a common temperature control fluid reservoir. This is advantageous because the installation space requirement is reduced.

[0017] In one embodiment, two of the temperature control circuits are fed from separate temperature control fluid reservoirs. This is advantageous because it allows for particularly precise adjustment of the temperature of the temperature control fluid in the respective temperature control fluid line.

[0018] Preferably, the temperature control fluid in the temperature control fluid reservoirs is kept below the target temperature for the element to be temperature-controlled. This allows a pure heater to be sufficient as a temperature control element. Cooling of the temperature control fluid is not necessary. The heaters are arranged either at the outlet of the temperature control fluid reservoirs and / or at the inlet of the element to be temperature-controlled. If the temperature control element 702 can only heat, a so-called recooling system, or synonymously a recooling unit, must be integrated into the arrangement. Without this recooling system, the temperature control fluid would constantly heat up.

[0019] The temperature control elements can be located outside the vacuum, i.e., far away from the element to be temperature-controlled, on the temperature control fluid line. This is advantageous because the heaters do not interfere with the interior of the projection lens. However, if highly precise maintenance of the element's temperature is necessary, the heater must be placed as close to the element as possible. This also reduces transport disturbances.

[0020] For large elements, such as the supporting frame, the spatial temperature distribution must be measured, i.e. at least two temperature sensors per element must be installed and evaluated.

[0021] In one embodiment, at least two of the elements are connected in series and are traversed by the same temperature control fluid line. This is particularly advantageous because it represents a particularly simple and space-saving solution.

[0022] In one embodiment, each element is provided with at least one temperature sensor for measuring the temperature on or in the element. The temperature sensors are intended to measure the elements to be tempered. Depending on the control task, the temperature sensors are mounted at locations where the variable to be controlled can be measured as representatively as possible. For example, the average temperature, the spatial temperature gradient, or the temporal temperature gradient are determined. The inlet and outlet temperatures can also be measured and thus the heat flow released or absorbed can be measured. The temperature sensors must not be placed too close to the temperature control fluid line in the element in order to obtain a measured value that is representative of the thermal state of the element.

[0023] In one embodiment, at least one controller is provided for controlling the temperature control elements, in particular on the basis of the temperature measured by the temperature sensor on or in the element.

[0024] However, the elements can also be temperature-controlled without control. The temperature of the respective element is brought close to the water temperature, and thus close to the reference temperature, by low thermal resistance (large cooling surfaces and / or high heat transfer coefficients of the contact between the temperature control fluid and the element) and the highest possible heat capacity flow (high water flow and / or high heat capacity of the fluid). The spatial distribution of the cooling lines also reduces temperature gradients within the elements. High-frequency disturbances with frequencies above the control bandwidth of the thermal control loop of the element cooling and the associated element deformations can thus be largely suppressed.

[0025] In one embodiment, at least one surface temperature controller, in particular one with an actively controlled and / or passively controlled temperature control, is arranged between at least two of the elements, in particular between the support frame and the measuring frame. This is particularly advantageous because the surface temperature controllers can suppress thermal disturbances particularly efficiently. By shielding the measuring frame, high-frequency disturbances with time constants of less than one hour can be suppressed. A temperature control fluid flows through active surface coolers. The temperature control fluid carries the heat output out of the system. The active surface cooler serves as a heat sink. Passively temperature-controlled surface coolers delay and mitigate thermal effects caused by heat loads on the measuring frame. However, they only form a resistance that directs the heat flows in a different direction.Passive shields direct the heat flow to the active shields, which ultimately carry the heat output out of the system. Passively controlled doesn't actually mean controlled, but rather supplies a constant water temperature. However, the temperature setpoint of the passively controlled elements can also change due to the active control of other elements. Actively controlled means that at least one feedback controller regulates the inlet temperature.

[0026] Surface temperature controllers conduct the water through thin gaps. The material is usually steel, aluminum, or ceramic. Surface temperature controllers exhibit high thermal conductivity.

[0027] In one embodiment, the beam path of an EUV light and at least one mirror are enclosed by at least one, in particular actively temperature-controlled, surface temperature controller.

[0028] In one embodiment, the temperature control fluid reservoir and the temperature control element are arranged outside the projection lens. This is advantageous because it avoids introducing additional heat loads into the projection lens.

[0029] According to the invention, the aforementioned object is also achieved by a method for temperature control of at least one element in a microlithographic projection exposure system intended for the EUV range or the DUV range. The at least one element is traversed by at least one temperature control fluid line provided for conducting a temperature control fluid and is temperature controlled at least by the following steps: - Defining a target temperature of at least one element, - measuring the actual temperature of the at least one element by means of at least one temperature sensor on or in the at least one element, - Comparing the actual temperature with the target temperature using a comparison element, - Reading the value of the deviation of the actual temperature from the target temperature into a controller, -Regulating the temperature of the tempering fluid by means of at least one tempering element provided on or in the at least one tempering fluid line until the deviation of the actual temperature from the target temperature of the element is below a predetermined limit value.

[0030] The identical procedure can also be applied for different tempering of different areas of a single element. Short description of the characters

[0031] Various embodiments are explained in more detail below with reference to the figures. The figures and the relative sizes of the elements depicted in the figures are not to be considered to scale. Rather, individual elements may be exaggerated or reduced in size for clarity and understanding. Fig. 1 shows a schematic representation of a state-of-the-art EUV projection lens. Fig. Figure 2 shows a schematic representation of an element from an EUV system which is tempered according to the invention. Fig. 3 shows a schematic representation of an EUV projection lens according to the invention with a parallel circuit. Fig. 4 shows a schematic representation of an EUV projection lens according to the invention with a series circuit. Fig. Figure 5 shows a schematic representation of a prior art DUV projection lens. Fig. 6 shows a schematic representation of a DUV projection lens according to the invention. Fig. Figure 7 shows a microlithographic projection exposure system designed for the EUV range. Fig. Figure 8 shows a microlithographic projection exposure system designed for the DUV range. Best way of carrying out the invention

[0032] Fig. 2 shows a schematic representation of an element 930 from an EUV system that is temperature-controlled according to the invention. It is a parallel circuit 900 of two temperature control circuits. The element 930 can be, for example, a measuring frame, a support frame, or a mirror support frame. The temperature control fluid line 919 runs through the lower region of the element 930. The temperature control fluid line 921 runs through the upper region of the element 930. The temperature sensor 907 measures the temperature in the lower region of the element and transmits the measured temperature value to the controller 902, which controls the temperature control element 906, which is arranged on the temperature control fluid line 919. The temperature control fluid line 919 is fed from the temperature control fluid reservoir 920 and has a temperature control fluid inlet 904 and a temperature control fluid outlet 908.If, for the sake of simplicity, the temperature control element 906 is designed to only heat, a so-called recooling system, or synonymously a recooling unit, must be integrated into the arrangement. Without this recooling system, the temperature control fluid would continuously heat up. For the sake of clarity, this recooling system is not shown in the . Fig. 2 shown.

[0033] The temperature sensor 917 measures the temperature in the upper region of the element 930 and transmits the measured temperature value to the controller 912, which controls the temperature control element 916 arranged on the temperature control fluid line 921. The temperature control fluid line 921 is also fed from the temperature control fluid reservoir 920 and has a temperature control fluid inlet 914 and a temperature control fluid outlet 918. In an embodiment not shown, each of the two temperature control circuits has its own temperature control fluid reservoir.

[0034] Fig. Figure 3 shows a schematic representation of an EUV projection lens 340 according to the invention with a parallel circuit. In order to reduce thermally induced drifts and wavefront errors, the five methods described in the prior art (see explanations of the Fig. 1) are solved by several different temperature control and shielding systems. The heat flows Q3 in the direction of the measuring frame 372 and Q4 in the direction of the mirror 392 are shown only as examples. The mirrors 391, 392, 393, 394 are mounted on active mechanical bearings 395. The support frame 382 is traversed by the temperature control fluid line 302. A temperature sensor 804 measures the temperature in the support frame 382. A temperature control element 704 controls the temperature of the temperature control fluid until the target temperature of the support frame 382 is reached. The control required for this is shown in Fig. 3 is not shown. For regulation purposes, please refer to the illustration in Fig. 2. The surface temperature controller 398, also referred to as "cooler and thermal shield," is traversed by the temperature control fluid line 306. The surface temperature controller 398 thermally shields the measuring frame 372. The mirror support frame 397 is traversed by the temperature control fluid line 304. The measuring frame 372 is traversed by the temperature control fluid line 308, which is fed by its own fluid reservoir 516. The mirror 393 is traversed by its own temperature control fluid line 310, which is fed by its own fluid reservoir 519. Each element has at least one temperature sensor 804. All of the aforementioned temperature control fluid lines 302, 304, 306 are assigned a common fluid reservoir 515. The EUV light 502 from the structure-supporting mask 120 (not shown in Fig. 3) is reflected by the mirrors and leaves the lens as EUV light 504 in the direction of the wafer 124 (not shown in Fig. 3). In summary, the following can be stated: - Thermal stabilization of the support frame 382 is achieved through a controlled water cooling system. This can consist of multiple cooling circuits. - The temperature control of the mirror environment is achieved by water cooling of the mirror support frames 390, 396, 397, 399. - The beam path and the optical surfaces of the mirrors are enclosed by a single- or multi-layer, actively cooled surface cooler 398, so that stray light and heat conduction from the beam path to the measuring frame 372 are suppressed. For reasons of clarity, this is not shown in the Fig. 3. Thermal power from the support frame 382 to the measuring frame 372 is shielded by an active or passive surface cooler 398 (cooling shield CS). - The thermal control of the measuring frame 372 is achieved via an actively controlled water cooling of the measuring frame 372.

[0035] Design measures to suppress thermal drift of the measuring frame 372 can be divided into the following time periods: - Disturbances with time constants of more than one hour can be suppressed by thermal control of the measuring frame and / or the support frame. - Disturbances of the measuring frame with time constants of less than one hour can be suppressed by shielding the measuring frame with cooled or passive surface coolers between the support frame and the measuring frame.

[0036] The water cooling of the measuring frame is therefore very slow, and has a long time constant. This means that the disturbance can be compensated for over a long period of time. The inner cooler suppresses high-frequency disturbances; without the inner cooler, thermal power would affect the measuring frame.

[0037] Furthermore, different control objectives within the EUV projection lens, such as absolute temperature stability for the mirror support frame and / or drift stability (support frame, mirror, measuring frame) for the surface cooler, can be pursued with largely independent control loops. This allows for a reduction of thermally induced drift and wavefront errors.

[0038] Fig. Figure 4 shows a schematic representation of an EUV projection objective according to the invention with a series connection. A single temperature control fluid reservoir 1020 feeds the single temperature control fluid line 1007. A temperature control element 1006 is arranged on the temperature control fluid line 1007 downstream of the temperature control fluid inlet 1004. Three elements are connected in series as an example. In the present example, the fluid first flows through the surface temperature controller 1010, also called the inner cooler. The fluid then flows through the support frame 1012. Finally, the fluid flows through the mirror support frame 1014. The inner cooler 1010 is temperature controlled first because it is located closest to the most thermally sensitive measuring frame. The element with the highest heat load, the mirror support frame 1014 - due to the mirror preheating and the waste heat of the actuators - comes at the end to avoid a carryover of the thermal power throughout the system via the temperature control fluid.The support frame 1012 is placed in between.

[0039] Fig. Figure 6 shows a schematic representation of a DUV projection lens 404 according to the invention. The surface temperature controller 451 is traversed by two independent temperature control fluid lines 476, 486. The upper temperature control fluid line 476 is fed from the temperature control fluid reservoir 470. The lower temperature control fluid line 486 is fed from the temperature control fluid reservoir 480. Two areas of the surface temperature controller 451 can thus be temperature controlled independently of one another. Each of the two areas has a temperature sensor 806 and a temperature control element 706. The upper temperature control fluid line 476 has an inlet 474 and an outlet 478. The lower temperature control fluid line 486 has an inlet 484 and an outlet 488. For reasons of clarity, the temperature control of the two areas is shown in Fig. 6 not shown.

[0040] The Fig. The EUV lithography system 100 shown in Figure 7 comprises a beam shaping and illumination system 102 and a projection system 104. The beam shaping and illumination system 102 and the projection system 104 are each arranged in a Fig. 7, each vacuum housing is evacuated by means of an evacuation device (not shown). The vacuum housings are surrounded by a machine room (not shown), in which the drive devices for mechanically moving or adjusting the optical elements are provided. Furthermore, electrical controls and the like can also be provided in this machine room.

[0041] The EUV lithography system 100 has an EUV light source 106. A plasma source (or a synchrotron), for example, can be provided as the EUV light source 106, which emits radiation 108 in the EUV range, e.g., in the wavelength range between 5 nm and 20 nm. In the beam-shaping and illumination system 102, the EUV radiation 108 is focused, and the desired operating wavelength is filtered out of the EUV radiation 108. The EUV radiation 108 generated by the EUV light source 106 has a relatively low transmissivity through air, which is why the beam guidance spaces in the beam-shaping and illumination system 102 and in the projection system 104 are evacuated.

[0042] The Fig. The beam-shaping and illumination system 102 shown in Figure 7 has five mirrors 110, 112, 114, 116, 118. After passing through the beam-shaping and illumination system 102, the EUV radiation 108 is directed onto the photomask (reticle) 120. The photomask 120 is also designed as a reflective optical element and can be arranged outside the systems 102, 104. Furthermore, the EUV radiation 108 can be directed onto the photomask 120 by means of a mirror 122. The photomask 120 has a structure that is imaged in a reduced size onto a wafer 124 or the like by means of the projection system 104.

[0043] The projection system 104 (also referred to as the projection lens) has six mirrors M1-M6 for imaging the photomask 120 onto the wafer 124. It should be noted that the number of mirrors of the EUV lithography system 100 is not limited to the number shown. More or fewer mirrors may also be provided. Roughly schematically shown are the force frame 380, which essentially supports the mirrors of the projection lens, and the sensor frame 370, which essentially serves as a reference for the position of the mirrors of the projection lens. Furthermore, the mirrors are usually curved at their front side for beam shaping.

[0044] Fig. 8 shows a schematic representation of a microlithographic projection exposure system according to the invention for the DUV range 400. The DUV projection exposure system 400 comprises a beam shaping and illumination device 402 and a projection objective 404. DUV stands for “deep ultraviolet” (DUV) and denotes a wavelength of the working light between 30 and 250 nm. The DUV projection exposure system 400 has a DUV light source 406. For example, an ArF excimer laser can be provided as the DUV light source 406, which emits radiation 408 in the DUV range at, for example, 193 nm.

[0045] The Fig.The beam-shaping and illumination device 402 shown in Figure 8 directs the DUV radiation 408 onto a photomask 420. The photomask 420 is designed as a transmissive optical element and can be arranged outside the beam-shaping and illumination device 402 and the projection lens 404. The photomask 420 has a structure that is imaged in a reduced size onto a wafer 424 or the like by means of the projection lens 404.

[0046] The projection lens 404 has a plurality of lenses 428, 440 and / or mirrors 430 for imaging the photomask 420 onto the wafer 424. Individual lenses 428, 440 and / or mirrors 430 of the projection lens 404 can be arranged symmetrically to the optical axis 426 of the projection lens 404. It should be noted that the number of lenses and mirrors of the DUV projection exposure system 400 is not limited to the number shown. More or fewer lenses and / or mirrors can also be provided. Furthermore, the mirrors are typically curved at their front side for beam shaping.

[0047] An air gap between the last lens 440 and the wafer 424 can be replaced by a liquid medium 432 having a refractive index > 1. The liquid medium 432 can be, for example, ultrapure water. Such a setup is also referred to as immersion lithography and features increased photolithographic resolution.

[0048] The following terms are used synonymously: EUV system is used synonymously with EUV projection exposure system and with microlithographic projection exposure system for the EUV range. DUV system is used synonymously with DUV projection exposure system and microlithographic projection exposure system for the DUV range. When the word cooling is used, it also includes temperature control, i.e. cooling and / or heating. Thus, fluid, temperature control fluid and cooling fluid are used synonymously. Surface cooler and surface temperature controller are also used synonymously. Photomask and reticle are used synonymously. Wafer and substrate coated with a light-sensitive layer (photoresist) are used synonymously. Sensor frame and measurement frame are used synonymously and abbreviated to SFr (sensor frame). Force frame and support frame are used synonymously and abbreviated to FFr (force frame). Mirror support frame is abbreviated to MSF (mirror support frame). List of reference symbols 100 (microlithographic) projection exposure system for the EUV range (=EUV system) 102 EUV (beam shaping and) illumination device 104 EUV projection lens with six mirrors (M1 to M6) 106 EUV light source 108 EUV radiation 110, 112, 114, 116, 118 Mirror of the EUV illumination device 102 120 photomask, reticle (reflective) 122 mirrors 124 wafers (=substrate coated with a light-sensitive layer (photoresist)) 302, 304, 306, 308, 310 Tempering fluid line 340 EUV projection lens with four mirrors (391, 392, 393, 394) 370, 371, 372 Sensor frame = measuring frame = Sensor Frame (SFr) 380, 381, 382 Force frame = supporting frame = Force Frame (FFr) 390 Mirror support frame (MSF) 395 active mechanical bearings 396 Mirror support frame (MSF) 397 Mirror support frame (MSF) 398 Surface temperature controller (CS:Cooler and thermal shield) 399 Mirror support frame (MSF) 400 (microlithographic) projection exposure system for the DUV range (=DUV system) 402 DUV (beam shaping and) illumination device 404 DUV projection lens 406 DUV light source 408 DUV light at the entrance to the DUV projection lens 404 420 photomask, reticle (transmitting) 424 wafers 426 optical axis of the projection lens 404 428 lenses 430 mirrors 432 liquid medium 440 last lens 450 Surface temperature controller DUV (SdT) 451 Surface temperature controller DUV 452 Tempering fluid line 454 Tempering fluid inlet 456 Tempering fluid outlet 458 DUV light to the wafer 460 temperature control fluid storage tanks 470 temperature control fluid storage tanks 474 Tempering fluid inlet 476 Tempering fluid line 478 Tempering fluid outlet 480 temperature control fluid storage tanks 484 Tempering fluid inlet 486 Tempering fluid line 488 Tempering fluid outlet 502 EUV light from the structure-bearing mask 321 504 EUV light towards wafer 124 507 Support frame temperature control inlet 508 Surface temperature control inlet 509 Sensor frame temperature control inlet 510 Sensor frame temperature control outlet 511 Surface temperature control outlet 512 Mirror support frame temperature control inlet 513 Mirror support frame temperature control outlet 514 Support frame temperature control outlet 515 Fluid reservoir for FFr / MSF / CS 516 fluid reservoir for SFr 517 Mirror temperature control inlet 518 Mirror temperature control outlet 519 Fluid reservoir for mirrors 525 Position measurement 602 Tempering fluid line 607 Support frame temperature control inlet 614 Support frame temperature control outlet 615 Fluid reservoir for support frame 625 Position measurement 640 EUV projection lens with four mirrors (691, 692, 693, 694) 695 active mechanical bearings Q1 Heat flows towards the measuring frame 371 Q2 Heat flows towards the mirror 692 Q3 Heat flows towards the measuring frame 372 Q4 Heat flows towards the mirror 392 Q5 Heat flows from consumers (DUV) Q6 Heat flows from the DUV projection lens 404 702 Tempering element 704 Tempering element 706 Tempering element 802 Temperature Sensor (EUV SdT) 804 Temperature Sensor (EUV) 806 Temperature sensor (DUV) 900 parallel connection 902 controller 904 Tempering fluid inlet 906 Tempering element 907 temperature sensor 908 Tempering fluid outlet 912 controller 914 Tempering fluid inlet 916 Tempering element 917 temperature sensor 918 Tempering fluid outlet 919 Tempering fluid line 920 temperature control fluid reservoir 921 Tempering fluid line 930 Element (CHF, FFr, MSF) 1000 series connection 1004 Tempering fluid inlet 1006 Tempering element 1007 Temperature control fluid line 1008 Tempering fluid outlet 1010 Element 1, e.g. surface temperature controller 1012 Element 2, e.g. supporting frame 1014 Element 3, e.g. mirror support frame 1020 Tempering fluid storage tank

Claims

[1] Microlithographic projection exposure apparatus (100; 400) intended for the EUV range or for the DUV range, comprising an illumination device (102; 402) and a projection lens (104, 340, 640;404) with at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014), which for its temperature control is traversed at least in regions by at least one temperature control fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) provided for conducting a temperature control fluid, wherein the temperature control fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) is connected to at least one tempering fluid reservoir (470, 480, 615, 515, 516, 519, 460, 920, 1020) and wherein at least one tempering element (702, 704, 706, 906, 916, 1006) for tempering the tempering fluid is provided on or in the tempering fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007), wherein; - a plurality of temperature control fluid lines (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) are provided and at least two different regions of the at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are each independently connected to at least one separate one of the temperature control fluid lines (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) or - several elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are provided and at least two of the elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are connected to the tempering fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) or - several elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) and several tempering fluid lines (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) are provided and at least two of the elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are independently traversed by at least one separate tempering fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) - and wherein the element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) is designed as at least one measuring frame (370, 371, 372) and / or as at least one supporting frame (380, 381, 382). [2] Projection exposure system according to claim 1, wherein each temperature control fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) is assigned at least one separate temperature control element (702, 704, 706, 906, 916, 1006), so that the respective temperature control fluid in the respective temperature control fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) can be separately temperature controlled. [3] Projection exposure system according to claim 1 or 2, wherein at least two temperature control circuits each having at least one of the temperature control fluid lines (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) are connected in parallel to one another. [4] Projection exposure system according to claim 3, wherein at least two of the temperature control circuits - from a common tempering fluid reservoir (470, 480, 615, 515, 516, 519, 460, 920, 1020) or - are fed by at least one separate temperature control fluid reservoir (470, 480, 615, 515, 516, 519, 460, 920, 1020). [5] Projection exposure system according to at least one of claims 1 to 4, wherein at least two of the elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) are connected in series and are traversed by one and the same tempering fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007). [6] Projection exposure apparatus according to at least one of claims 1 to 5, wherein at least one temperature sensor (804, 806, 907, 917) for measuring the temperature at or in the element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) is intended. [7] Projection exposure apparatus according to at least one of claims 1 to 6, wherein at least one controller is provided for controlling the temperature control element (702, 704, 706, 906, 916, 1006) on the basis of the temperature measured by the temperature sensor (804, 806, 907, 917) on or in the element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014). [8] Projection exposure apparatus according to at least one of claims 1 to 7, wherein at least one surface temperature controller (398, 451) is arranged between at least two of the elements (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014). [9] Projection exposure system (100) according to claim 8, wherein at least one surface temperature controller (398, 451) is arranged between the support frame (380, 381, 382) and the measuring frame (370, 371, 372). [10] Projection exposure system (100) according to claim 8 or 9, wherein a beam path of an EUV light and at least one mirror (391, 392, 393, 394) are enclosed by at least one surface temperature controller (398). [11] Projection exposure system according to at least one of claims 1 to 10, wherein the temperature control fluid reservoir (470, 480, 615, 515, 516, 519, 460, 920, 1020) and the temperature control element (702, 704, 706, 906, 916, 1006) are arranged outside the projection lens (104, 340, 640; 404). [12] Method for tempering at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) in a microlithographic projection exposure apparatus (100; 400) intended for the EUV range or for the DUV range, wherein the at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) of at least one tempering fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) provided for conducting a tempering fluid and is tempered with at least the following steps: - Defining a target temperature of at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014), - measuring the actual temperature of the at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) by means of at least one temperature sensor (804, 806, 907, 917) on or in the at least one element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014), - Comparing the actual temperature with the target temperature; - regulating the temperature of the tempering fluid by means of at least one tempering element (702, 704, 706, 906, 916, 1006) provided on or in the at least one tempering fluid line (302, 304, 306, 308, 310, 452, 476, 486, 602, 919, 921, 1007) until the deviation of the actual temperature from the target temperature of the element (370, 372, 380, 382, ​​390, 396, 397, 399, 391, 392, 393, 394, 398, 451, 930, 1010, 1012, 1014) is below a predetermined limit value. [13] Method according to claim 12, wherein the temperature control is carried out by means of at least one closed control loop.

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