Inspection apparatus

Abstract

To provide an inspection apparatus for inspecting an object such as a pellicle for use in an EUV lithographic apparatus.SOLUTION: The inspection apparatus comprises: a vacuum chamber; a load lock forming an interface between the vacuum chamber and an ambient environment; a stage apparatus configured to receive the object from the load lock and displace the object inside the vacuum chamber. The vacuum chamber comprises a first parking position and a second parking position for temporarily storing the object.SELECTED DRAWING: Figure 2B

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to European Application No. 18202014.9, filed October 23, 2018, and European Application No. 19151427.2, filed January 11, 2019, each of which is incorporated by reference in its entirety herein.

[0002] The present invention relates to an inspection tool or apparatus that can be used to inspect objects, particularly objects used in the manufacture of integrated circuits using EUV lithography equipment. In particular, the inspection tool or apparatus may be used to inspect pellicles that protect patterned reticles from contamination, which are used in EUV lithography equipment. [Background technology]

[0003] A lithographic apparatus is a machine constructed to apply a desired pattern onto a substrate. Lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus can, for example, project a pattern in a patterning device (e.g. mask) onto a layer of radiation-sensitive material (resist) provided on the substrate.

[0004]

[0004] To project a pattern onto a substrate, a lithographic apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features that can be formed on the substrate. Lithographic apparatus using extreme ultraviolet (EUV) radiation having a wavelength in the range of 4-20 nm, e.g. 6.7 nm or 13.5 nm, may be used to form smaller features on a substrate than lithographic apparatus using radiation having a wavelength of, e.g., 193 nm.

[0005]

[0005] The aforementioned patterning devices are often protected by a pellicle in the case of EUV lithography apparatus. Prior to application of the pellicle, the pellicle must undergo a qualification or inspection process to determine whether it meets specifications.

[0006]

[0006] In known arrangements, such qualification processes can be quite time consuming and may not have the required accuracy. Summary of the Invention

[0007] It is an object of the present invention to provide an inspection apparatus for inspecting objects, such as pellicles, that reduces processing time and / or improves accuracy.

[0008] According to a first aspect of the present invention, there is provided an inspection apparatus for inspecting an object such as a pellicle for use in an EUV lithography apparatus, the inspection apparatus comprising: A vacuum chamber; a load lock forming an interface between the vacuum chamber and the ambient environment; a stage assembly configured to receive the object from the load lock and move the object into the vacuum chamber; A vacuum chamber includes a first parking position and a second parking position for temporarily storing an object.

[0009] According to a first aspect of the present invention, there is provided an inspection apparatus for inspecting an object such as a pellicle for use in an EUV lithography apparatus, the inspection apparatus comprising: A vacuum chamber; a first load lock forming an interface between the vacuum chamber and the ambient environment; a second load lock forming an interface between the vacuum chamber and the ambient environment; a stage assembly configured to receive the object from the first load lock and move the object into the vacuum chamber and provide the object to the second load lock; Equipped with.

[0010] According to a second aspect of the present invention, there is provided an inspection apparatus for inspecting an object such as a pellicle for use in an EUV lithography apparatus, the inspection apparatus comprising: a chamber configured to provide a regulated atmosphere for inspecting an object; a load lock forming an interface between the chamber and the ambient environment; a radiation beam source configured to generate a radiation beam for inspecting an object; a radiation beam measurement system configured to measure a property of the radiation beam; A radiation beam measurement system comprising: a member disposed on an optical path of the radiation beam between the radiation beam source and the object, the member comprising an aperture that allows a portion of the radiation beam to propagate to the object; at least one radiation sensor disposed on the member and configured to measure a characteristic of the radiation beam; Equipped with. [Brief description of the drawings]

[0011]

[0008] An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings.

[0012] [Figure 1] 1 depicts a lithography system comprising a lithographic apparatus and a radiation source. [Figure 2A] 1 shows a first embodiment of an inspection device according to a first aspect of the present invention. [Figure 2B] 1 shows a first embodiment of an inspection device according to a first aspect of the present invention. [Figure 2C] 1 shows a first embodiment of an inspection device according to a first aspect of the present invention. [Figure 2D] 1 shows a first embodiment of an inspection device according to a first aspect of the present invention. [Figure 2E] 1 shows a first embodiment of an inspection device according to a first aspect of the present invention. [Figure 2F] 1 shows a first embodiment of an inspection device according to a first aspect of the present invention. [Figure 3A] 2 shows a second embodiment of the inspection device according to the first aspect of the present invention. [Figure 3B] 2 shows a second embodiment of the inspection device according to the first aspect of the present invention. [Figure 3C] 2 shows a second embodiment of the inspection device according to the first aspect of the present invention. [Figure 4] 1 illustrates a radiation beam measurement system that can be applied in an inspection apparatus according to the present invention. [Diagram 5] 4 illustrates another radiation beam measurement system that can be applied in an inspection apparatus according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1 shows a lithography system comprising a radiation source SO and a lithographic apparatus LA. The source SO is configured to generate a beam of EUV radiation B and to provide the beam of EUV radiation B to the lithographic apparatus LA. The lithographic apparatus LA comprises an illumination system IL, a support structure MT configured to support a patterning device MA (e.g. a mask), a projection system PS, and a substrate table WT configured to support a substrate W.

[0014]

[0009] The illumination system IL is configured to condition the EUV radiation beam B before it is incident on the patterning device MA. To that end, the illumination system IL may comprise a facetted field mirror device 10 and a facetted pupil mirror device 11. The facetted field mirror device 10 and the facetted pupil mirror device 11 together impart a desired cross-sectional shape and a desired intensity distribution to the EUV radiation beam B. The illumination system IL may comprise other mirrors or devices in addition to or instead of the facetted field mirror device 10 and the facetted pupil mirror device 11.

[0015] After being so conditioned, the EUV radiation beam B interacts with the patterning device MA. As a result of this interaction, a patterned EUV radiation beam B' is generated. The projection system PS is configured to project the patterned EUV radiation beam B' onto the substrate W. To this end, the projection system PS may comprise a number of mirrors 13, 14 configured to project the patterned EUV radiation beam B' onto the substrate W held by a substrate table WT. The projection system PS may apply a demagnification factor to the patterned EUV radiation beam B', thereby forming an image of a smaller feature than a corresponding feature on the patterning device MA. For example, a demagnification factor of 4 or 8 may be applied. Although the projection system PS is shown in FIG. 1 as having only two mirrors 13, 14, the projection system PS may comprise a different number of mirrors, for example 6 or 8 mirrors. The substrate W may include a preformed pattern. In this case, the lithographic apparatus LA aligns the image formed by the patterned EUV radiation beam B' with the preformed pattern on the substrate W.

[0016] A relative vacuum, ie a small amount of gas (eg hydrogen) at a pressure significantly below atmospheric pressure, may be provided within the source SO, illumination system IL and / or projection system PS.

[0017] The source SO may be a laser-produced plasma (LPP) source, a discharge-produced plasma (DPP) source, a free-electron laser (FEL) or any other source capable of producing EUV radiation.

[0018] The present invention relates to the manufacture of a component of an apparatus or a component for use in an apparatus. The apparatus may be a lithography apparatus, for example an extreme ultraviolet (EUV) lithography apparatus that may be used to manufacture integrated circuit chips. The component may be, for example, a membrane or pellicle for use in the apparatus.

[0019] During the manufacture of a component, it may be necessary to inspect the component to ensure that it meets certain standards. Some inspections may be performed in a special environment, for example a vacuum environment. This may be provided in a vacuum chamber. It will of course be understood that other processing, measurements or manipulations of the component may also be performed in the vacuum chamber. To maintain the vacuum environment in the vacuum chamber, an ante-chamber (also known as a load-lock) may be provided. The load-lock may be inserted into the component at ambient pressure. The load-lock is then sealed and air is evacuated until vacuum conditions matching those of the vacuum chamber prevail in the load-lock. The load-lock may then be opened to the vacuum chamber and the component may then be moved from the load-lock to the vacuum chamber in preparation for inspection or other procedures to be performed. When it is desired to remove the component from the vacuum chamber, the process is reversed, i.e. the component is transferred in vacuum to the load-lock and the load-lock is isolated from the vacuum chamber. Ambient pressure is then restored to the load-lock by pumping air into the space inside the load-lock. Once ambient pressure is reached, the load-lock opens and the component can be removed.

[0020] For sensitive and / or delicate components, such as pellicles for EUV tools, pumping and venting times may be on the order of hours to maintain the mechanical integrity of the component by maintaining low pressure differentials and to reduce the risk of contamination by keeping gas flow rates low, which may be significantly longer, e.g., up to twice as long, than the time it takes to inspect the component in a vacuum chamber.

[0021] The present invention discloses two solutions to the above problem: In a first embodiment, the present invention provides an inspection apparatus for inspecting objects or components, such as for example pellicles used in an EUV lithography apparatus.

[0022] According to the first embodiment, the inspection device includes: A vacuum chamber; a load lock forming an interface between the vacuum chamber and the ambient environment; a stage assembly configured to receive the component from the load lock and move the object into the vacuum chamber; Equipped with.

[0023]

[0010] Also, according to the first embodiment, in order to reduce the total manufacturing and / or inspection time, more specifically, to increase the throughput of components, it is proposed to use part of the vacuum chamber for storing components, so that the loading and / or unloading steps of a first component can be performed at the same time that a second component is being inspected.

[0024] Specifically, in an embodiment of the present invention, the vacuum chamber of the inspection apparatus comprises a first parking position and a second parking position. According to the present invention, a parking position refers to a position or location where a component may be temporarily stored.

[0025] Therefore, according to a first embodiment of the invention, it is proposed to provide two parking positions inside the vacuum chamber. As will be explained below, employing two parking positions inside the vacuum chamber allows for operation of the load lock, including for example evacuating air from the load lock or pumping air into the load lock, while a first component is present inside the load lock, simultaneously with a process, such as inspection of a second component, which is placed inside the vacuum chamber. Possible steps of this process are explained in detail below in Figures 2A to 2F. Figures 2A to 2F show diagrammatically a top view of an inspection apparatus 100 according to the invention. In the embodiment shown, the inspection apparatus comprises a vacuum chamber 110 including two parking positions 140.1 and 140.2, also indicated as PP1 and PP2, a load lock 120 and a stage arrangement 130.

[0026] In an embodiment, a load lock such as load lock 120 may be considered as an interface between a first atmosphere and a second atmosphere, for example between an ambient atmosphere or environment and a vacuum environment. Such a load lock may comprise, for example, a first door 120.1 (dotted line), a second door 120.2 and a load lock chamber 120.3, where the first door 120.1 is configured to separate the ambient environment from the load lock chamber 120.3 and the second door 120.2 is configured to separate the vacuum chamber 110 from the load lock chamber 120.3. In general, the load lock chamber 120.3 should be large enough to accommodate a component, for example Product A or Product B.

[0027]

[0011] Figure 2A shows the inspection apparatus 100 during a first process step in which a first component (product A, e.g. a pellicle) is measured or inspected in a vacuum chamber while a second component (product B) is loaded into a load lock. In the embodiment shown, the stage assembly 130 comprises an X-stage 130.1 configured to move a product mounted on the stage assembly, i.e. product A in Figure 2A, in an X-direction, and a Y-stage configured to move product A in a Y-direction.

[0028] The load lock is isolated from the vacuum chamber, i.e. the door 120.2 is closed. After loading product B into the load lock, specifically into the load lock chamber 120.3, the first door 120.1 can also be closed and the air can be evacuated from the load lock chamber 120.3. This process of evacuating the air can be done while product A is being measured.

[0029] In a second step, shown in Fig. 2B, product A is moved to a first storage area (Parking Position 1, PP1, 140.1). In an embodiment, this step can be performed, for example, by the stage arrangement 130, specifically the X-stage 130.1 and the Y-stage 130.2. In an embodiment, the stage arrangement 130 can comprise one or more linear motors, for example a linear motor for moving an object, for example a pellicle, along the X-direction and a linear motor for moving an object along the Y-direction.

[0030]

[0012] In a third step shown in Figure 2C, the load lock door 120.2 to the vacuum chamber 110 is opened and product B is removed from the load lock 120 and moved to the vacuum chamber 110 while product A remains in the first storage area 140.1.

[0031] In a fourth step shown in Fig. 2D, product B is moved to a second storage area (parking position 2, PP2, 140.2). In the embodiment shown, the load lock 120 comprises a transfer mechanism 150 configured to transfer objects from the load lock 120 to the stage assembly 130 and vice versa. It can be noted that such a transfer mechanism may also be located in the stage assembly or elsewhere within the vacuum chamber 110. In an embodiment, an end 150.1 of the transfer mechanism may be configured, for example, to hold the object as well as to raise and / or lower the object.

[0032] 2E, the product A is returned from the first storage area 140.1 to the load lock 120. In this regard, it can be pointed out that this transfer can be performed by the stage device 130 since two parking positions PP1 and PP2 are employed. Thus, since two parking positions are used, it does not require the installation or use of an additional transfer robot in the vacuum chamber.

[0033]

[0015] Finally, in a sixth step shown in Figure 2F, the load lock 120 is sealed, i.e. the load lock door 120.2 is closed and returned to ambient conditions while product B is inspected. Once the load lock 120 has returned to ambient conditions, product A can be unloaded.

[0034]

[0016] By using the first and second storage areas in the vacuum chamber, the measurement cycle time can be reduced by about 1.5 times, specifically because the second component can be loaded or unloaded while the first component is undergoing measurement. In such a configuration, the loading / unloading time of one component overlaps with the measurement process time of another component, thus increasing the throughput of components to be inspected / measured and reducing the total processing time.

[0035]

[0017] According to a second embodiment of the first aspect of the invention, a second load lock may be used. In this configuration, loading and unloading may occur simultaneously. For example, while a first component is being measured, a second component may be unloaded after the previous measurement and a third component may be loaded before the later measurement. Using this process, the measurement cycle time may be reduced by up to a factor of two. This may significantly increase the throughput and therefore reduce the number of manufacturing tools and / or clean room space required to manufacture the components.

[0036] A possible sequence of steps using a vacuum chamber with two load locks is shown in Figures 3A to 3C. Figures 3A to 3C show schematic cross-sectional views in a vertical plane (XZ plane). Figure 3A shows an inspection apparatus 200 according to an embodiment of the invention. In the embodiment shown, the inspection apparatus comprises a vacuum chamber 210 with two load locks 1 and 2, also indicated with reference numbers 222 and 224. Three components (products A, B and C), for example objects such as pellicles used in EUV lithography devices, are located in the vacuum chamber 210 and in the load locks 222 and 224. The load locks 222 and 224 may have a similar structure to the load lock 120, for example, i.e., as described above, with a first door, a second door and a load lock chamber. In the embodiment shown, product A has already been processed in the vacuum chamber 210 and transferred to the load lock 224. The load lock 224 has been disconnected from the vacuum chamber 210 and returned to ambient conditions in preparation for the unloading of product A. Product B is loaded from load lock 222 into the vacuum chamber 210 for processing. Load lock 222 is then isolated from the vacuum chamber and returned to ambient conditions so that product C can be loaded into load lock 1. Figures 3A-3C further show diagrammatically a stage assembly 230 disposed inside the vacuum chamber 210. In the embodiment shown, the load locks 222 and 224 further comprise transfer mechanisms 252 and 254 for transferring objects from the load lock chamber to the vacuum chamber and vice versa.

[0037] Load lock 1, 222 containing product C can then be brought to vacuum conditions from ambient pressure while product B is measured and / or processed in the vacuum chamber. Product A is then unloaded from load lock 2, 224, which is then returned to vacuum conditions in preparation for receiving product B. Door 224.2 separating load lock 224 from vacuum chamber 210 is then opened and product B is transferred to load lock 224 after the measurement process is finished. This is shown in FIG. 3B. At the same time, load lock 222 continues to be brought to vacuum conditions so that product C can be passed to the vacuum chamber.

[0038] Once the load lock 222 is brought to vacuum conditions, the door 222.2 separating the load lock 222 from the vacuum chamber 210 opens and product C is transferred to the vacuum chamber 210. At the same time, the load lock 224 is isolated from the vacuum chamber 210 and can be evacuated to ambient pressure to allow product B to be unloaded. Finally, measurement and / or processing of product C can take place while the next component is loaded into the load lock 222. These steps are shown diagrammatically in FIG. 3C.

[0039] According to the invention, the inspection apparatus may further comprise a radiation source for inspecting the object and a detector for receiving radiation emitted, reflected or transmitted from the object in order to perform an inspection or quality assessment process. In the sense of the invention, such a radiation source may comprise any suitable form of radiation, for example electromagnetic radiation or a particle beam such as an electron beam or an ion beam.

[0040] According to a second aspect of the present invention, there is provided an inspection apparatus for inspecting an object, such as a pellicle.

[0041] Some lithography apparatus include a pellicle attached to a patterned reticle. The pellicle is a transparent film that is spaced a few millimeters from the reticle pattern. Contamination particles that are caught by the pellicle are in the far field of the reticle pattern and do not significantly affect the quality of the image projected by the lithography apparatus onto a substrate. If the pellicle was not present, contamination particles could land on the reticle pattern and obscure parts of the pattern, preventing it from being accurately projected onto a substrate.

[0042] An inspection apparatus, also referred to as a pellicle qualification system, may be configured to determine the optical properties (such as reflectivity and / or transparency) of the pellicle in order to determine whether the pellicle is of sufficient quality for use in a lithographic apparatus. Such qualification or inspection of a pellicle may involve directing a measurement radiation beam at the pellicle and detecting the intensity of the measurement radiation beam before and after interaction with the pellicle using a radiation sensor. This allows a comparison of the properties of the measurement radiation beam before and after interaction with the pellicle, so that it can be determined how the pellicle has affected the measurement radiation beam and whether the pellicle is of sufficient quality for use in a lithographic apparatus.

[0043] One known pellicle qualification system uses two radiation sensors to detect the intensity of a measurement radiation beam before it interacts with the pellicle. A first portion of the measurement radiation beam is directed along a main measurement path that interacts with the pellicle. A second portion of the measurement radiation beam is directed to the radiation sensor. Thus, the two radiation sensors are located on different optical paths and / or receive different angles of incident radiation relative to the main measurement path. The optical paths may be different from each other. The difference between the different optical paths may change over time. For example, optical components (e.g. lenses and / or mirrors) on the different optical paths may deteriorate differently, temperature and subsequent thermal deformation may change, vacuum or gas fluctuations may occur on the optical paths. Due to the different optical paths, random differences exist between the first and second portions of the measurement radiation beam, which reduces the accuracy of the known pellicle qualification system. A known method of improving the accuracy of the known pellicle qualification system involves the use of beam splitters and / or grazing mirrors. However, such optical components reduce the intensity of the radiation, which negatively affects the accuracy of the system. The inspection apparatus according to the second aspect of the present invention provides an alternative means of measuring the radiation beam used to inspect or qualify a pellicle.

[0044] Figure 4 shows a schematic top view (left side of Figure 4) and a side view (right side of Figure 4) of a new radiation beam measurement system, sometimes called a pellicle qualification system, for use in an inspection apparatus according to the second aspect of the present invention.

[0045] The inspection device according to the second aspect of the present invention includes, for example, a chamber configured to provide a regulated atmosphere for inspecting an object; a load lock forming an interface between the chamber and the ambient environment; a radiation beam source configured to generate a radiation beam for inspecting an object; a radiation beam measurement system configured to measure a characteristic of the radiation beam; It may be equipped with.

[0046] In an embodiment, the regulated atmosphere may be, for example, a vacuum environment. Other types of regulated atmospheres or environments are contemplated as well, depending on the type of radiation used for testing or qualification.

[0047] Within the meaning of the present invention, any suitable type of radiation may be used as the source of a radiation beam for the inspection or qualification of a pellicle.

[0048] According to a second aspect of the present invention, a radiation beam measurement system for use in an inspection apparatus or pellicle qualification system further comprising: a member disposed on an optical path of the radiation beam between the radiation beam source and the object, the member comprising an aperture that allows a portion of the radiation beam to propagate to the object; at least one radiation sensor disposed on the member and configured to measure a characteristic of the radiation beam; Equipped with.

[0049]

[0020] In an embodiment, the radiation beam measurement system comprises a number of radiation sensors (e.g. four or eight radiation sensors) arranged on a member arranged on the optical path of the radiation beam between the radiation beam source and the object, i.e. downstream of the radiation beam source and upstream of the object. In the example of Fig. 4, a member 400 of the radiation beam measurement system is equipped with eight radiation sensors (reference numbers 1 to 8). In the embodiment shown, the member 400 comprises a substantially rectangular aperture 410. The eight radiation sensors 1 to 8 are arranged on or along two opposite sides of the aperture 410. In Fig. 4, reference number 412 on the left side refers to the width of the radiation beam after passing through the aperture 410 and reference number 414 refers to the width of the radiation beam incident on the member 400. In an embodiment, the radiation beam measurement system comprises at least one radiation sensor configured to measure a characteristic such as the intensity of the radiation beam, i.e. the incident radiation beam as shown.

[0050] Using more radiation sensors may be preferable because noise present in the measurements performed by the radiation beam measurement system may be reduced by averaging the measurements performed by each radiation sensor. The radiation sensors may be configured to detect EUV radiation. The radiation sensors may, for example, comprise a photodiode and / or a camera, for example a charge coupled device. The radiation beam measurement system may be configured to determine a spatial intensity profile of the incident radiation beam. The radiation sensors may detect the measurement radiation beam closest to a central axis of the optical path of the radiation beam to be measured.

[0051] In an embodiment, the inspection system or pellicle qualification system may comprise a spectral purity filter (SPF) 422 and a detector 430, for example a charge coupled device (CCD). In the embodiment shown, the detector 430 is located downstream of the object, i.e. the pellicle 440, to be inspected or qualified. Thus, in such an embodiment, the detector receives radiation transmitted through the object 440. In general, the inspection apparatus according to the second aspect of the invention may be configured to receive any type of radiation resulting from the interaction of the radiation beam with the object 440. Such radiation may include, for example, radiation emitted by the object, radiation reflected by the object, or radiation transmitted through the object.

[0052] The spectral purity filter 422 may be configured to filter the incident radiation beam 450 before it is incident on the pellicle 440. Thus, the SPF 422 may be located upstream of the pellicle 440. The CCD, typically a detector 430, may be configured to detect the radiation beam 450 after it has interacted with the pellicle 440. The radiation sensors 1-8 of the radiation beam measurement system may be positioned to detect the radiation beam 450 after it has interacted with the spectral purity filter 422 and before it interacts with the CCD 430. A comparison of measurements made by the radiation beam measurement system and measurements made by the CCDs of the pellicle qualification system may be used to determine whether the pellicle 440 is suitable for use in the lithographic apparatus by determining what effect the pellicle 440 has on the radiation beam.

[0053] The spectral purity filter 422 may be held in place by a support. In the embodiment shown, the spectral purity filter 422 is attached to the member 400 via the support 420. In the embodiment shown, the member 400 comprises an aperture 410 through which at least a portion of the radiation beam (sometimes referred to as a first portion of the radiation beam) passes before the radiation beam is incident on the pellicle. Radiation sensors 1-8 of the radiation beam measurement system may be mounted on the member 400. Edges of the radiation sensors may be substantially aligned with edges of the aperture in the member 400. The surface of the member 400 on which the radiation beam measurement system is mounted, and the radiation sensors of the radiation beam measurement system, act to block a portion of the incident radiation beam 450 (sometimes referred to as a second portion of the incident radiation beam). Because the edge of the radiation sensor is substantially aligned with the edge of the aperture 410 in the member 400, the radiation beam measurement system can measure properties of the radiation beam 450 as close as possible to the central axis of the radiation beam without affecting the part of the radiation beam that interacts with the pellicle (and may be detected by the CCD 430 of the inspection apparatus or pellicle qualification system). The radiation beam measurement system may be the last optical component that interacts with the radiation beam before it is incident on the pellicle 440. This ensures that the effects of all other optical components on the optical path of the radiation beam are included and taken into account in the measurements made by the radiation beam measurement system. Therefore, changes in the optical path of the radiation beam have less impact on the accuracy of this new radiation beam measurement system compared to known radiation beam measurement systems.

[0054] The radiation beam measurement system advantageously allows in situ monitoring of the properties of the incident radiation beam (e.g. energy, spatial intensity profile, dose, etc.) without significantly affecting the radiation beam. This may improve the accuracy of subsequent measurements made with the radiation beam after it interacts with the pellicle. The radiation beam measurement system allows for setup calibration with reference to the CCD 430. For example, if the pellicle 440 is not disposed between the support and the CCD 430, both the radiation sensors 1-8 of the radiation beam measurement system and the CCD 430 may be used to determine the properties of the incident radiation beam 450. The direct measurement of the first portion of the radiation beam from the CCD 430 may be used to calibrate the indirect measurement from the radiation sensors 1-8 of the radiation beam measurement system. The radiation beam measurement system is compact and easy to install and handle. The radiation beam measurement system may be able to reconstruct the spatial intensity profile of the radiation, for example, by using a combination of known positions of the radiation sensors, making reference measurements, comparing the measurement results to a database of information on the properties of the radiation beam, and fitting an algorithm. The radiation beam measurement system may be less expensive to install and / or operate than known radiation beam measurement systems.

[0055]

[0021] In the embodiment shown in Figure 4, the radiation sensors 1-8 are provided along two opposite sides of the opening 410 extending in the Y direction. It may also be advantageous to have or provide radiation sensors along one or two sides extending in the X direction. Such an embodiment is shown diagrammatically in Figure 5. Figure 5 diagrammatically shows, in addition to the features shown in Figure 4, another pair of radiation sensors 20, 21 arranged on or along two opposite sides of the opening 410 extending in the X direction.

[0056] In an embodiment of the present invention, at least one radiation sensor is positioned along a perimeter of the opening 410 of the member 400 of the radiation beam measurement system. In an embodiment, at least one radiation sensor is positioned along each side of the opening 410 of the member 400.

[0057] In an embodiment, the inspection apparatus according to the present invention may be advantageously used to measure the transmission and / or reflection properties of an object such as a pellicle, in particular an EUV pellicle. Thus, in such an embodiment, the inspection apparatus may be referred to as an EUV pellicle transmission and / or reflection metrology tool. In such an embodiment, one or both properties measured by such a tool may be: a) the EUV radiation transmission of the membrane or pellicle, i.e. the fraction of total radiation that passes through the membrane or pellicle without being absorbed, and / or the EUV radiation that is reflected by the membrane, and / or b) The EUV radiation reflected by the membrane or pellicle, i.e., the fraction of EUV radiation that is reflected back by the membrane or pellicle.

[0058] It can also be noted that a portion of the EUV radiation may be absorbed by the membrane or pellicle. By measuring both the reflected and transmitted EUV radiation in combination with information about the total EUV radiation directed to the membrane or pellicle, the relationship between the three radiation components, i.e., reflected, absorbed, and transmitted, can be determined. For example, the reflection and transmission characteristics can be measured with a radiation detector, for example a CCD camera such as the CCD 430 described above. In particular, a CCD camera can be placed in the optical path of the transmitted EUV radiation as shown in Figures 4 and 5. Similarly, a CCD camera can be placed in the optical path of the reflected EUV radiation to determine the amount of reflected EUV radiation. Such cameras may be referred to as, for example, T-CCD (transmission) and R-CCD (reflection).

[0059] The present invention can also be described by the following clauses.

[0060] 1. An inspection apparatus for inspecting objects, such as pellicles, used in an EUV lithography apparatus, comprising: A vacuum chamber; a load lock forming an interface between the vacuum chamber and the ambient environment; a stage assembly configured to receive the object from the load lock and move the object into the vacuum chamber; An inspection apparatus, wherein the vacuum chamber comprises a first parking position and a second parking position for temporarily storing an object. 2. An inspection apparatus as described in clause 1, further comprising a transfer mechanism configured to transfer objects from the load lock to the stage apparatus and vice versa. 3. An inspection apparatus as described in clause 2, wherein the transport mechanism is disposed at least partially within the load lock. 4. The inspection apparatus of clause 2, wherein the transport mechanism is attached to the stage device. 5. An inspection apparatus as described in any of clauses 1 to 4, wherein the load lock comprises a first door, a second door, and a load lock chamber, the first door configured to separate an ambient environment from the load lock chamber, and the second door configured to separate a vacuum chamber from the load lock chamber. 6. An inspection apparatus as described in clause 1, wherein the stage apparatus is configured to transfer objects from the stage apparatus to a first parking position and vice versa, and the stage apparatus is configured to transfer objects from the stage apparatus to a second parking position and vice versa. 7. An inspection apparatus according to any one of clauses 1 to 6, wherein the stage arrangement comprises a holder for holding an object. 8. An inspection apparatus for inspecting objects such as pellicles used in an EUV lithography apparatus, comprising: A vacuum chamber; a first load lock forming an interface between the vacuum chamber and the ambient environment; a second load lock forming an interface between the vacuum chamber and the ambient environment; a stage assembly configured to receive the object from the first load lock and move the object into the vacuum chamber and provide the object to the second load lock; An inspection device comprising: 9. An inspection apparatus for inspecting objects such as pellicles used in an EUV lithography apparatus, comprising: a chamber configured to provide a regulated atmosphere for inspecting an object; a load lock forming an interface between the chamber and the ambient environment; a radiation beam source configured to generate a radiation beam for inspecting an object; a radiation beam measurement system configured to measure a property of the radiation beam; A radiation beam measurement system comprising: a member disposed on an optical path of the radiation beam between the radiation beam source and the object, the member comprising an aperture that allows a portion of the radiation beam to propagate to the object; at least one radiation sensor disposed on the member and configured to measure a characteristic of the radiation beam; An inspection device comprising: 10. An inspection apparatus as described in clause 9, wherein at least one radiation sensor is positioned along a perimeter of the opening. 11. An inspection device according to clause 9 or 10, wherein the opening has a substantially rectangular shape. 12. An inspection apparatus as described in clause 11, wherein the radiation beam measurement system comprises radiation sensors along at least two sides of the aperture. 13. An inspection apparatus as described in clause 11 or 12, wherein the radiation beam measurement system comprises at least one radiation sensor along each side of the aperture. 14. An inspection apparatus according to any of clauses 9 to 13, wherein the radiation beam measurement system further comprises a spectral purity filter positioned upstream of the member in the optical path. 15. An inspection apparatus as claimed in clause 14, wherein a spectral purity filter is attached to the member. 16. An inspection apparatus according to clause 14 or 15, wherein at least one radiation sensor is positioned downstream of the spectral purity filter. 17. An inspection apparatus according to any of clauses 9 to 16, further comprising a detector configured to receive radiation produced by interaction of the radiation beam with the object. 18. An inspection apparatus as described in clause 17, wherein the radiation includes radiation transmitted by the object. 19. An inspection apparatus as described in clause 18, wherein the detector is positioned downstream of the object. 20. An inspection apparatus according to any of clauses 17 to 19, wherein the detector comprises a CCD. 21. An EUV pellicle transmission measurement tool comprising an inspection apparatus according to any one of clauses 9 to 20. 22. An EUV pellicle transmission / reflection measurement tool comprising an inspection apparatus according to any one of clauses 9 to 20.

[0061]

[0024] Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it will be appreciated that the lithographic apparatus described herein have other applications, such as in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat panel displays, liquid crystal displays (LCDs), thin film magnetic heads, etc.

[0062]

[0025] Although specific reference is made herein to embodiments of the invention in relation to lithographic apparatus, embodiments of the invention may also be used in other apparatus. Embodiments of the invention may form part of a mask inspection apparatus, a metrology apparatus, or any apparatus that measures or processes objects such as wafers (or other substrates) or masks (or other patterning devices). These apparatus may be generally referred to as lithography tools. Such lithography tools may use vacuum conditions or ambient (non-vacuum) conditions.

[0063]

[0026] Although specific reference has been made above to the use of embodiments of the present invention in connection with optical lithography, it will be understood that the present invention may be used in other applications, such as imprint lithography, and is not limited to optical lithography, where the context permits.

[0064]

[0027] Where the context permits, embodiments of the present invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the present invention may also be implemented as instructions stored on a machine-readable medium that may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read-only memory (ROM), random access memory (RAM), magnetic storage media, optical storage media, flash memory devices, electrical, optical, acoustic or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Furthermore, firmware, software, routines, instructions may be described herein as performing certain actions. However, it should be understood that such description is merely for convenience and that such actions may actually result from a computing device, processor, controller, or other device executing the firmware, software, routines, instructions, etc., and that in performing the actions, actuators or other devices may interact with the material world.

[0065]

[0028] Although specific embodiments of the present invention have been described above, it will be understood that the invention can be practiced otherwise than as described. The above description is illustrative and not restrictive. Thus, it will be apparent to one skilled in the art that modifications can be made to the invention as described without departing from the scope of the claims.

Claims

1. 1. An inspection apparatus for inspecting an object, such as a pellicle, for use in an EUV lithography apparatus, comprising: A vacuum chamber; a load lock forming an interface between the vacuum chamber and the ambient environment; a stage assembly configured to receive the object from the load lock and move the object into the vacuum chamber; An inspection apparatus, wherein the vacuum chamber comprises a first parking position and a second parking position for temporarily storing the object.

2. The inspection apparatus of claim 1 , further comprising a transfer mechanism configured to transfer the object from the load lock to the stage assembly and vice versa.

3. The inspection apparatus of claim 2 , wherein the transfer mechanism is disposed at least partially within the load lock.

4. The inspection apparatus of claim 2 , wherein the transport mechanism is attached to the stage assembly.

5. the load lock comprising a first door, a second door, and a load lock chamber; the first door is configured to separate the ambient environment from the load lock chamber; The inspection apparatus of claim 1 , wherein the second door is configured to separate the vacuum chamber from the load lock chamber.

6. the stage assembly is configured to transfer an object from the stage assembly to the first parking position and vice versa; The inspection apparatus of claim 1 , wherein the stage assembly is configured to transfer objects from the stage assembly to the second parking position and vice versa.

7. 7. An inspection apparatus according to claim 1, wherein the stage device comprises a holder for holding the object.

8. 1. An inspection apparatus for inspecting an object, such as a pellicle, for use in an EUV lithography apparatus, comprising: A vacuum chamber; a first load lock forming an interface between the vacuum chamber and the ambient environment; a second load lock forming an interface between the vacuum chamber and the ambient environment; a stage assembly configured to receive the object from the first load lock and move the object into the vacuum chamber and provide the object to the second load lock; An inspection device comprising:

9. 1. An inspection apparatus for inspecting an object, such as a pellicle, for use in an EUV lithography apparatus, comprising: a chamber configured to provide a regulated atmosphere for inspecting the object; a load lock forming an interface between the chamber and the ambient environment; a radiation beam source configured to generate a radiation beam for inspecting the object; a radiation beam measurement system configured to measure a property of the radiation beam; said radiation beam measurement system comprising: a member disposed on an optical path of the radiation beam between the radiation beam source and the object, the member comprising an aperture allowing a portion of the radiation beam to propagate to the object; at least one radiation sensor disposed on the member and configured to measure the property of the radiation beam; An inspection device comprising:

10. The inspection apparatus of claim 9 , wherein the at least one radiation sensor is positioned along a perimeter of the opening.

11. 11. An inspection apparatus according to claim 9 or 10, wherein the opening has a generally rectangular shape.

12. The inspection apparatus of claim 11 , wherein the radiation beam measurement system comprises radiation sensors along at least two sides of the aperture.

13. 13. An inspection apparatus according to claim 11 or 12, wherein the radiation beam measurement system comprises at least one radiation sensor along each side of the aperture.

14. 14. An inspection apparatus according to any one of claims 9 to 13, wherein the radiation beam measurement system further comprises a spectral purity filter positioned on the optical path upstream of the member.

15. The inspection apparatus of claim 14 , wherein the spectral purity filter is attached to the member.

16. 16. The inspection apparatus of claim 14 or 15, wherein the at least one radiation sensor is positioned downstream of the spectral purity filter.

17. 17. The inspection apparatus of any one of claims 9 to 16, further comprising a detector configured to receive radiation resulting from interaction of the radiation beam with the object.

18. The inspection apparatus of claim 17 , wherein the radiation comprises radiation transmitted by the object.

19. The inspection apparatus of claim 18 , wherein the detector is positioned downstream of the object.

20. 20. The inspection apparatus of claim 17, wherein the detector comprises a CCD.

21. 21. An EUV pellicle transmission measurement tool comprising an inspection apparatus according to any one of claims 9 to 20.

22. An EUV pellicle transmission / reflection measurement tool comprising the inspection apparatus according to any one of claims 9 to 20.

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