Method for operating an aerial image measurement system and such aerial image measurement system

Abstract

To provide an improved method for operating an aerial image measurement system and / or an aerial image measurement system. [Solution] A method for operating an airborne image measuring system (100) for qualification and / or measurement of an EUV mask (102), the airborne image measuring system comprising a vacuum chamber (104) having a measurement process chamber (106) and a process preparation chamber (108), an EUV plasma source (110), and a vacuum lock (112) for transferring the EUV mask into the process preparation chamber, the method comprising: performing preparatory measures in parallel in and / or in or within the vacuum chamber to prepare for qualification and / or measurement of the EUV mask; and qualifying and / or measuring the EUV mask by the airborne image measuring system by capturing an airborne image of the EUV mask.

Description

Technical Field

[0001] The present invention relates to a method for operating an aerial image measurement system for evaluating the qualification of an EUV mask (extreme ultraviolet lithography) by means of the aerial image measurement system. Furthermore, the present invention relates to an aerial image measurement system for evaluating the qualification of an EUV mask.

[0002] The content of the priority application DE 10 2024 139 602.4 is incorporated herein by reference in its entirety.

Background Art

[0003] Micro-lithography is used, for example, for manufacturing microstructured components such as integrated circuits. The micro-lithography process is carried out using a lithography apparatus having an illumination system and a projection system. Here, an image of a mask (reticle) illuminated by the illumination system is projected onto a substrate, for example a silicon wafer, coated with a photosensitive layer (photoresist) and arranged in the image plane of the projection system in order to transfer the mask structure to the photosensitive coating of the substrate.

[0004] Due to the ever smaller structures required in the manufacture of integrated circuits, EUV lithography apparatuses using light in the range from 0.1 nm to 30 nm, particularly at a wavelength of 13.5 nm, are currently under development. Since most materials absorb light at this wavelength, such EUV lithography apparatuses need to use reflective optical units, i.e. mirrors, instead of the refractive optical units, i.e. lens elements, used previously. Furthermore, so-called EUV masks are required for manufacturing microstructures on semiconductor wafers.

[0005] As the complexity of EUV masks increases, the accurate qualification evaluation of these masks is becoming increasingly important in semiconductor manufacturing. For example, the qualification evaluation of EUV masks is intended to enable accurate verification of mask errors and their potential impact on the lithography process.

[0006] A mask measurement system for recording aerial images, also known as an airborne image measurement system, provides a complete emulation of a scanner and uses measurements based on airborne images to evaluate mask defects under as many real-world manufacturing conditions as possible. This system provides highly accurate information about the printability of mask defects without requiring physical wafer printing. This enables rapid and reliable inspection of masks, contributing to the optimization of the manufacturing process. Measurement of EUV masks is performed in a vacuum chamber.

[0007] Mask measurement technology addresses both defect review and verification of mask repair. With the support of an EUV plasma source and high-precision positioning, detailed characterization of mask defects is achieved to assess their impact on the lithography process. By providing accurate reproduction of EUV printing behavior and integration of automated image analysis, the mask measurement system for recording aerial images provides a foundation for manufacturing EUV masks with as few defects as possible for use in mass production processes.

[0008] One challenge with known mask measurement techniques for recording aerial images is the significantly longer preparation time required compared to the actual measurement time for measuring EUV masks. For example, simply providing a stable and functioning EUV plasma source requires a start-up time of over 30 minutes, and exposure time calibration is often necessary. Since measurements with the mask measurement system for recording aerial images are impossible during this time, this start-up time must be considered unproductive time.

[0009] Furthermore, in preparation for measurement, the EUV mask is handled both externally and internally within the mask measurement system for recording aerial images. In addition, for preparation, an appropriate field diaphragm or aperture diaphragm is inserted into and adjusted in the optical unit of the mask measurement system for recording aerial images by a robotic arm located inside the vacuum chamber. Furthermore, the EUV mask is moved by the robotic arm from the outside into the vacuum chamber of the mask measurement system for recording aerial images via a vacuum lock, and the EUV mask is transferred to the robotic arm within the vacuum lock. Since one robotic arm is also used for handling optical elements, this handling must be completed first in order to perform mask handling. Then, one robotic arm moves the EUV mask onto the mask platform inside the vacuum chamber, where the EUV mask is precisely positioned for measurement purposes. This entire preparation process is time-intensive, requiring, for example, more than 40 minutes, which is in contrast to the measurement time of approximately 5 minutes per mask. Since measurement with the mask measurement system for recording aerial images is impossible during this time, this preparation process must be considered non-productive time. [Overview of the Initiative]

[0010] Against this backdrop, the object of the present invention is to provide an improved method for operating an aerial image measurement system and / or an improved aerial image measurement system.

[0011] Therefore, a method is proposed for operating an airborne image measurement system for the qualification and / or measurement of EUV masks. The airborne image measurement system comprises a vacuum chamber having a measurement process chamber and a process preparation chamber, an EUV plasma source disposed, for example, in the measurement process chamber, and a vacuum lock for transferring the EUV mask into the process preparation chamber. The method consists of the following steps: To prepare for the qualification and / or measurement of the EUV mask, preparatory measures must be performed at least partially in parallel in a vacuum chamber and / or in a vacuum lock, and, By capturing an aerial image of the EUV mask, the EUV mask is qualified and / or measured by an aerial image measurement system. Includes.

[0012] In a further embodiment, an aerial image measurement system for the qualification and / or measurement of EUV masks is proposed. The aerial image measurement system comprises a vacuum chamber having a measurement process chamber and a process preparation chamber; an EUV plasma source; a vacuum lock for transferring an EUV mask into the process preparation chamber; and a control device configured to perform preparatory measures in parallel in the vacuum chamber and / or in the vacuum lock or within the vacuum lock to prepare for the qualification and / or measurement of the EUV mask.

[0013] The vacuum chamber is preferably subdivided into at least two regions: a measurement process chamber and a process preparation chamber. The vacuum chamber preferably creates an environment with reduced pressure to minimize external influences such as particles and contaminants, which is crucial for performing a highly sensitive measurement process for the measurement and qualification of EUV masks.

[0014] A measurement process chamber is preferably provided for performing measurements, while a process preparation chamber is used to perform preparation work on the EUV mask before the EUV mask proceeds to measurement.

[0015] The EUV plasma source is integrated within the measurement process chamber and generates extreme ultraviolet (EUV) light with very short wavelengths. This EUV plasma source is crucial to the operation of the measurement system as it provides the light necessary for imaging and analyzing the EUV mask. Its positioning within the measurement process chamber allows the EUV mask to be illuminated directly and with minimal loss, making it possible to recognize extremely fine structures and defects on the mask.

[0016] The vacuum lock allows the EUV mask to be transferred from the external environment into the process preparation chamber of the vacuum chamber. For example, a load lock may be placed in front of the vacuum lock, forming an interface between the human operator and the aerial image measurement system. The load lock can be part of the front-end module of the aerial image measurement system. Preferably, the vacuum lock maintains the integrity of the vacuum and prevents the ingress of air or contaminants while the mask is being transferred into the process preparation chamber.

[0017] This ensures that mask handling proceeds smoothly without adversely affecting the conditions inside the vacuum chamber. The described setup enables clean and efficient preparation and execution of the measurement process, preferably ensuring accurate analysis of EUV masks under optimal conditions.

[0018] The aerial image measurement system can be configured to introduce the EUV mask to be measured into the vacuum lock without a protective housing, with a protective gas atmosphere already established within a load lock that can be positioned upstream of or included within the vacuum lock. For example, the protective gas atmosphere can be designed according to ISO-1. For example, the EUV mask can be moved from the load lock into the vacuum lock by a first robotic arm. Within the vacuum lock, the EUV mask is preferably transferred to a second robotic arm. The second robotic arm can handle the EUV mask within the vacuum chamber, and in particular can move the EUV mask from the process preparation chamber into the measurement process chamber where the measurement of the EUV mask takes place.

[0019] Alternatively, the aerial image measurement system may be designed so that the EUV mask is moved into a vacuum lock within a protective container, particularly via a load lock. For example, the protective container is sequentially placed inside an outer protective container. In the area of ​​the load lock, the protective container, along with the EUV mask, is removed from the outer protective container by a first robotic arm, for example, located outside the vacuum chamber, and introduced into the load lock. The protective container is then preferably moved from the load lock into the vacuum lock by the first robotic arm, and within the vacuum lock, is transferred to a second robotic arm located inside the process preparation chamber. The second robotic arm can then transfer the protective container to a protective container holder, for example, located inside the process preparation chamber. The second robotic arm can then preferably open the protective container in the protective container holder and remove the EUV mask from the protective container in order to handle the EUV mask in the vacuum chamber, particularly to move the EUV mask from the process preparation chamber into the measurement process chamber where the EUV mask measurement is performed. The process of removing the mask from the protective container can preferably be monitored by optical sensors, particularly cameras.

[0020] In particular, the present invention describes a further development of a mask measurement system for recording aerial images for EUV qualification, thereby enabling accurate analysis of printable mask defects in a shorter time. In particular, preparation time can be significantly reduced by this method, especially by parallelizing the preparation steps. This makes it possible to measure more EUV masks in the same amount of time. This improves productivity compared to existing systems. This method and measurement system reduce overhead costs and thereby increase efficiency. In this case, multiple preparation steps are preferably parallelized. Preferably, all preparation steps that can be performed simultaneously are parallelized. In this regard, for example, a preparation step performed by a first robotic arm can be performed simultaneously with a preparation step performed by a second robotic arm if the preparation step does not require interaction between the first and second robotic arms.

[0021] In a further embodiment, it is proposed that the preparation steps within the vacuum chamber include turning on and / or operating the EUV plasma source to stabilize it.

[0022] For example, the EUV plasma source can be turned on in parallel with the handling of the EUV mask and / or further preparation measures, for example, to set the operating conditions of the EUV plasma source (e.g., voltage and frequency).

[0023] In a further embodiment, the aerial image measurement system is further proposed to include a storage device having optical elements, the storage device being located in a process preparation chamber, and the preparation measures in the vacuum chamber include moving at least one of the optical elements between the storage device and the measurement process chamber, and / or adjusting at least one of the optical elements in the measurement process chamber.

[0024] The optical element can be arranged inside a storage device. The storage device can, for example, also have a plurality of holders for different types of optical elements. For example, the optical element can be arranged in a cassette inside the storage device. The storage device preferably can define a storage space where the optical element is arranged or retracted when the optical element is not required for the measurement of an EUV mask or the setting of the illumination characteristics of an EUV plasma source.

[0025] For example, in order to parallelize the measurement preparation, the illumination conditions of the light generated by an EUV plasma source can be prepared by selecting and inserting an optical element. For example, as the optical element, a field stop aperture and / or an aperture stop can be introduced into the beam path of the EUV plasma source, and / or an aperture stop already arranged in the beam path (for example, from a previous measurement) can be exchanged. For example, the aperture stop can be a sigma-NA stop (also called a sigma / NA stop). This is used to control the illumination characteristics of the optical system by defining the numerical aperture range (NA) and the sigma of the illumination.

[0026] In this case, the optical element preferably defines a component that can be arranged in the beam path so as to be able to set different illumination and / or imaging characteristics of the EUV plasma source. The optical element can preferably also include a system having a plurality of optical elements. Thus, depending on the type of measurement, preferably, an optical element can be selected and introduced into the beam path of the EUV plasma source by a second robotic arm.

[0027] The handling of this optical element is performed by a second robotic arm inside the vacuum chamber. The handling of the optical element can be performed, for example, in parallel with the handling of the EUV mask in the area of the vacuum lock. The handling of the EUV mask in the area of the vacuum chamber serves, for example, to transfer the EUV mask into the vacuum chamber via the vacuum lock and is performed by a first robotic arm.

[0028] In a further aspect, the preparation measures in or within the vacuum lock may include providing an EUV mask in the vacuum lock and / or introducing an EUV mask into the vacuum lock and / or transferring an EUV mask through the vacuum lock into the process preparation chamber. These mask handling processes can be carried out, for example, using a first robotic arm outside the vacuum chamber and / or by the interaction of the first robotic arm and the second robotic arm within the vacuum lock and / or using the second robotic arm within the vacuum chamber. The handling of the EUV mask within the vacuum chamber can also include removing the EUV mask from the protective container. The handling of the EUV mask can include handling the EUV mask disposed within the protective container, i.e., it can also include handling the protective container.

[0029] In a further aspect, the preparation measures within the vacuum chamber may include moving an EUV mask from the process preparation chamber into the measurement process chamber and / or aligning the EUV mask on a mask platform provided within the measurement process chamber.

[0030] The controlled transfer of the EUV mask between the two chambers is carried out within a vacuum environment. The process preparation chamber is used for the preparation before the EUV mask is transferred into the measurement process chamber where actual measurements are taken. This transfer process is preferably carried out without interrupting the vacuum in order to be accurate, avoid contamination, and ensure a stable environment for subsequent measurements. The handling process is preferably carried out by a second robotic arm.

[0031] The alignment of the EUV mask on a mask platform provided within the measurement process chamber preferably relates to the precise positioning of the EUV mask on a specific platform or holder located within the measurement process chamber. The mask platform preferably functions as a stable carrier that holds the EUV mask in place during the measurement process. Precise mask alignment is crucial to ensure that the measurement can be performed with high accuracy. The mask is preferably positioned to be precisely at the focus of the measurement optical unit of the airborne image measurement system and to have the correct orientation relative to the EUV plasma source. This enables correct imaging and analysis of the mask structure. The measurement optical unit preferably includes a plurality of optical elements, particularly mirrors and / or lens elements, as well as one or more optical elements and an optical sensor for recording an airborne image of the EUV mask.

[0032] In a further embodiment, it is proposed that turning on and / or operating the EUV plasma source includes raising the EUV plasma source to predetermined operating conditions, or operating the EUV plasma source at a reduced operating frequency compared to predetermined operating conditions.

[0033] In particular, to avoid adverse effects on consumables in the aerial image measurement system, the operating frequency of the plasma light source can initially be reduced compared to normal operating conditions. If the EUV plasma source is later required for measurement, the operating frequency can be increased to the operating conditions, which requires less preparation time compared to a cold start of the EUV light source.

[0034] In a further embodiment, it is proposed that preparation measures within the vacuum chamber include opening and / or closing flaps or doors provided to the process preparation chamber and / or the measurement process chamber and / or between the process preparation chamber and the measurement process chamber.

[0035] To avoid adverse effects on consumables, the vacuum chamber slide and / or door, as well as the consumable filter, can also be closed. Such a consumable filter can be placed, for example, between the process preparation chamber and the measurement process chamber. Consumables for the airborne image measurement system include, for example, components of the EUV plasma source such as electrodes or mirrors, optical components such as lens elements and filters that wear out as a result of operation, vacuum seals such as O-rings, mask holders and fixtures that wear out through repeated use, protective layers or filters for sensitive optical elements, cleaning materials for periodic maintenance of optical components and vacuum chambers, vacuum pump oil and filters, and gas cylinders for the plasma process.

[0036] Furthermore, a computer program product is proposed that operates the apparatus of the above method on a program-controlled device.

[0037] For example, computer program products, such as computer program means, can be provided or supplied as storage media such as memory cards, USB sticks, CD-ROMs, DVDs, or as downloadable files from a server on a network. For example, in a wireless communication network, this can be done by transferring an appropriate file containing the computer program product or computer program means.

[0038] Furthermore, a computer-readable (storage) medium is proposed that, when executed by a computer, contains instructions that cause the computer to perform the method described above.

[0039] These instructions are preferably designed to cause a computer to perform the aforementioned method, in which case a specific method or algorithm implemented in the computer is executed. For example, the medium can be a hard disk, CD-ROM, USB stick, or some other type of storage medium that stores the instructions necessary to cause the computer to perform the method.

[0040] In this context, "a," "an," or "one" should not necessarily be understood as being limited to exactly one element. Rather, it is possible to have multiple elements, such as two, three, or more. Furthermore, any other numerical values ​​used herein should not be interpreted as being limited to the number of elements stated. Rather, unless otherwise indicated, numerical deviations upward and downward are possible.

[0041] The embodiments and features described in the method are applicable to the proposed aerial image measurement system with necessary modifications, and vice versa.

[0042] Further possible embodiments of the present invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments that are not expressly mentioned. Those skilled in the art may also add individual aspects as improvements or supplements to each basic form of the present invention.

[0043] Further advantageous configurations and aspects of the present invention are the subject of the dependent claims and the exemplary embodiments of the present invention described below. The present invention is described in more detail below based on preferred embodiments with reference to the accompanying drawings. [Brief explanation of the drawing]

[0044] [Figure 1] A schematic diagram of an aerial image measurement system in one embodiment is shown. [Figure 2] A schematic diagram of an aerial image measurement system in a further embodiment is shown. [Figure 3] A schematic diagram of the sequence of parallelized preparatory steps within such an aerial image measurement system is shown. [Figure 4] A flowchart of one exemplary embodiment of this method for operating an aerial image measurement system is shown. [Modes for carrying out the invention]

[0045] In drawings, unless otherwise specified, identical or functionally identical elements are given the same reference numeral. Furthermore, please note that the illustrations in the drawings are not necessarily to scale.

[0046] Figure 1 shows an aerial image measurement system 100 according to one embodiment. The aerial image measurement system 100 is used for qualification and / or measurement of an EUV mask 102. The aerial image measurement system 100 comprises a vacuum chamber 104 having a measurement process chamber 106 and a process preparation chamber 108. Furthermore, the aerial image measurement system 100 comprises an EUV plasma source 110, for example, located in the measurement process chamber 106. The aerial image measurement system 100 also comprises a vacuum lock 112 for transferring the EUV mask 102 from a load lock 113 located upstream of the vacuum lock 112 into the process preparation chamber 108. The load lock 113 may already have a region where a protective gas atmosphere 115 is dominant. The aerial image measurement system 100 has a control device 114, which is configured to perform preparatory measures in parallel in or within the vacuum chamber 104 and / or vacuum lock 112 in order to prepare for the qualification and / or measurement of the EUV mask 102. The qualification and / or measurement of the EUV mask 102 is carried out by recording an aerial image of the EUV mask 102 by an optical sensor 111, in particular a camera. The captured aerial image is then analyzed by an evaluation device, which is not shown in more detail, thereby the EUV mask is qualified.

[0047] The aerial image measurement system 100 further comprises a storage device 116 having optical elements 118, the storage device being located within the process preparation chamber 108. In Figure 1, one of the optical elements 118 is located within the measurement process chamber 106 in the beam path 119 of the EUV plasma source 110. The aerial image measurement system 100 further comprises a flap or door 120, which in this case is located between the process preparation chamber 108 and the measurement process chamber 106. Within the measurement process chamber 106, there is further a mask platform 122 on which the EUV mask 102 is placed for measurement.

[0048] Therefore, the aerial image measurement system 100 is configured to introduce the EUV mask 102 to be measured into the vacuum lock 112 without a protective housing, with a protective gas atmosphere 115 already established in a load lock 113 located upstream of the vacuum lock 112. For example, the protective gas atmosphere 115 can be designed according to ISO-1. For example, the EUV mask 102 can be moved from the load lock 113 into the vacuum lock 112 by a first robotic arm 124. Inside the vacuum lock 112, the EUV mask 102 is transferred to a second robotic arm 126. The second robotic arm 126 can handle the EUV mask 102 in the vacuum chamber 104, and in particular can move the EUV mask 102 from the process preparation chamber 108 into the measurement process chamber 106 where the measurement of the EUV mask 102 takes place. Needless to say, multiple second robotic arms 126 can also be provided inside the process preparation chamber 108, as shown as an example in Figure 2. In this regard, for example, it is possible to move and / or replace two or more optical elements 118 simultaneously. Furthermore, the second robotic arm 126 can align the EUV mask 102 on the mask platform 122 with respect to the EUV plasma source 110 or beam path 119 for the purpose of qualifying and / or measuring the EUV mask.

[0049] The optical elements 118 can be placed in a storage device 116. The storage device 116 may include, for example, multiple holders 128 for different types of optical elements 118. Handling of the optical elements 118 is performed by a second robotic arm 126 inside the vacuum chamber 104. Handling of the optical elements 118 can be performed in parallel with, for example, handling of the EUV mask 102 by a first robotic arm 124 in the area of ​​the vacuum lock 113. Handling of the EUV mask 102 in the area of ​​the vacuum chamber 104 helps to transfer the EUV mask 102 into the vacuum chamber 104 via the vacuum lock 112.

[0050] Figure 2 shows an aerial image measurement system 200 according to a further embodiment. The aerial image measurement system 200 is designed so that the EUV mask 102 is moved through a load lock 113 into a vacuum lock 112 within a protective container (not shown). For example, the protective container is arranged sequentially within an outer protective container (not shown). In the area of ​​the load lock 112, the protective container, together with the EUV mask, is removed from the outer protective container by a first robotic arm 124 located outside the vacuum chamber 104, for example, and introduced into the load lock 113. The (inner) protective container is then preferably moved from the load lock 113 into the vacuum lock 112 by the first robotic arm 124, and within the vacuum lock 112, is transferred to a second robotic arm 126 located inside the process preparation chamber 108. The second robotic arm 126 can then transfer the (inner) protective container to a protective container holder 202 located inside the process preparation chamber 126, for example. The second robotic arm 126 can preferably then open the (inner) protective container in the protective container holder 202 and remove the EUV mask from the protective container in order to handle the EUV mask 102 in the vacuum chamber 104, in particular to move the EUV mask 102 from the process preparation chamber 108 into the measurement process chamber 106 where the measurement of the EUV mask 102 will be performed. The process of removing the EUV mask 102 from the protective container can be monitored by optical sensors 204, in particular by a camera.

[0051] Figure 3 shows a sequence diagram of parallelized preparatory steps. In this case, using the airborne image measurement systems 100, 200, the handling of the EUV mask 102 outside the vacuum chamber 104 S300 is performed before the handling of the EUV mask 102 inside the vacuum chamber 104 S302, as observed, for example, in the progression of time t. Then, the recording of an airborne image of the EUV mask 102 S304 is performed. In parallel with the handling of the EUV mask 102 outside and inside the vacuum chamber 104 S300, S302, preparatory steps performed in parallel here include turning on and / or operating the EUV plasma source 110 S306 to stabilize the EUV plasma source 110. This may also include raising the EUV plasma source 110 to a predetermined operating condition, or operating the EUV plasma source 110 at a reduced operating frequency compared to the predetermined operating condition. In this case, turning on and / or operating S306 is timed so that the EUV plasma source 110 is fully operational before the recording of the aerial image of the EUV mask 102 S304 is performed. Furthermore, for further parallelization of the preparation steps, concurrently with the handling of the EUV mask 102 by the first robotic arm 124 outside the vacuum chamber 104 S300 is the process of moving at least one of the optical elements 118 between the storage device 116 and the measurement process chamber 106 S308 and / or adjusting at least one of the optical elements 118 within the measurement process chamber 106 S310. The movement of the optical elements 118 S308 and / or adjustment S310 is preferably performed only insofar as the second robotic arm 126 is required for the handling of the EUV mask 102 inside the vacuum chamber 104 S302.

[0052] Figure 4 shows a schematic flowchart of one exemplary embodiment of the method. In this case, step S400 includes performing preparatory measures in or within the vacuum chamber 104 and / or vacuum lock 112 in order to prepare the EUV mask 102 for qualification and / or measurement. Step S402 includes qualifying and / or measuring the EUV mask 102 by airborne image measurement systems 100, 200 by capturing an airborne image of the EUV mask 102, for example by an optical sensor 111.

[0053] Although the present invention has been described based on exemplary embodiments, it can be modified in a variety of ways. [Explanation of Symbols]

[0054] 100 Aerial Image Measurement System 102 EUV Mask 104 Vacuum Chamber 106 Measurement process chamber 108 Process preparation chamber 110 EUV Plasma Source 111 Optical Sensors 112 Vacuum Lock 113 Road Rock 114 Control Devices 115 Protective gas atmosphere 116 Storage devices 118 Optical elements 119 Beampath 120 doors 122 Mask Platform 124 First robotic arm 126 Second robotic arm 128 Holder 200 Aerial Image Measurement System 202 Protective container holder 204 Optical Sensor S300 Handling S302 Handling S304 Record S306 Turn on and / or operate S308 Move S310 adjustment S400 Parallel Execution S402 Qualification and / or Measurement t Time progression

Claims

1. A method for operating an airborne image measuring system (100, 200) for qualification and / or measurement of an EUV mask (102), the airborne image measuring system (100, 200) comprising a vacuum chamber (104) having a measurement process chamber (106) and a process preparation chamber (108), an EUV plasma source (110), and a vacuum lock (112) for transferring the EUV mask (102) into the process preparation chamber (108), wherein the method is: To prepare for the qualification and / or measurement of the EUV mask (102), preparatory measures are performed in parallel in the vacuum chamber (104) and / or in the vacuum lock (112) or within the vacuum lock (112) (S400), The aerial image of the EUV mask (102) is captured, thereby qualifying and / or measuring the EUV mask (102) using the aerial image measurement system (100, 200) (S402), Methods that include...

2. The method according to claim 1, wherein the preparation in the vacuum chamber (104) includes turning on and / or operating the EUV plasma source (110) to stabilize the EUV plasma source (110) (S306).

3. The method according to claim 1 or 2, wherein the aerial image measuring system (100, 200) further comprises a storage device (116) having optical elements (118), the storage device being located within the process preparation chamber (108), and the preparation within the vacuum chamber (104) comprising moving at least one of the optical elements (108) between the storage device (116) and the measurement process chamber (106) (S308), and / or adjusting at least one of the optical elements (118) within the measurement process chamber (106) (S310).

4. The method according to any one of claims 1 to 3, wherein the preparation measures in or within the vacuum lock (112) include providing the EUV mask (102) in the vacuum lock (112) and / or introducing the EUV mask (102) into the vacuum lock (112) and / or transferring the EUV mask (102) through the vacuum lock (112) into the process preparation chamber (108).

5. The method according to any one of claims 1 to 4, wherein the preparation steps in the vacuum chamber (104) include moving the EUV mask (102) from the process preparation chamber (108) into the measurement process chamber (106), and / or aligning the EUV mask (102) on a mask platform (122) provided in the measurement process chamber (108).

6. The method according to any one of claims 2 to 5, wherein turning on and / or operating the EUV plasma source (110) (S306) includes raising the EUV plasma source (110) to a predetermined operating condition, or operating the EUV plasma source (110) at an operating frequency reduced compared to the predetermined operating condition.

7. The method according to any one of claims 1 to 6, wherein the preparation in the vacuum chamber (104) includes opening and / or closing a flap or door (120) provided to the process preparation chamber (108) and / or the measurement process chamber (106) and / or between the process preparation chamber (108) and the measurement process chamber (106).

8. An aerial image measurement system (100, 200) for qualification and / or measurement of an EUV mask (102), the aerial image measurement system (100, 200) comprising: a vacuum chamber (104) having a measurement process chamber (106) and a process preparation chamber (108); an EUV plasma source (110); a vacuum lock (112) for transferring the EUV mask (102) into the process preparation chamber (108); and a control device (114) configured to perform preparatory measures in parallel within the vacuum chamber (104) and / or in the vacuum lock (112) or within the vacuum lock (112) to prepare the EUV mask (102) for qualification and / or measurement.

9. A computer program product, wherein when the program is executed by a computer, it includes an instruction causing the computer to perform a step according to any one of claims 1 to 7.

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