Inspection or qualification device for processing objects used in extreme ultraviolet (EUV) lithography equipment.

Abstract

An apparatus for determining one or more properties of an object for use in an EUV lithography system comprises a support, an emission system, a detector system, and an emission tuning module. The support is for holding up the object (e.g., a pellicle, reticle, or reticle-pellicle assembly). The emission system is operable to generate and deliver an emission beam to incident on the object when it is supported by the support. The detector system is operable to receive the emission that interacts with the object when it is supported by the support. The emission tuning module is operable to adjust one or more properties of the emission beam delivered to the object or the emission received by the detector system so as to determine the properties of multiple different objects, each having different properties, thereby controlling the EUV emission dose.

Description

[Technical Field]

[0001] (Cross-reference of related applications)

[0001] This application claims priority to European application 23170758.9, filed on 28 April 2023, which is incorporated herein by reference in its entirety.

[0002]

[0002] The present invention relates to an inspection or qualification apparatus for processing objects used in an extreme ultraviolet (EUV) lithography apparatus. In particular, the apparatus may be suitable for inspecting and / or measuring the properties of EUV pellicles, EUV reticles, or reticle-pellicle assemblies used in an EUV lithography apparatus. The present invention also relates to related methods for using such an apparatus. [Background technology]

[0003]

[0003] A lithography apparatus is a machine constructed to apply a desired pattern onto a substrate. A lithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithography apparatus may, for example, project a pattern of a patterning device (e.g., a mask or reticle) onto a radiative material (resist) layer provided on a substrate. In this specification, unless otherwise specified, the terms patterning device, mask, and reticle are synonymous and may be used interchangeably.

[0004]

[0004] The wavelength of radiation that a lithography apparatus uses to project a pattern onto a substrate determines the minimum size of features that can be formed on that substrate. Using a lithography apparatus that uses EUV radiation, which is electromagnetic radiation with wavelengths in the range of 4 to 20 nm, it is possible to form smaller features on a substrate than with conventional lithography apparatuses (for example, electromagnetic radiation with a wavelength of 193 nm may be used).

[0005]

[0005] Patterning devices (e.g., reticles) used to impart patterns to a radiation beam in a lithography apparatus may constitute part of a reticle assembly. The reticle assembly may include a pellicle that protects the patterning devices from particulate contamination. The pellicle may be supported by a pellicle frame. Since it is important that the reticle and pellicle are free from contaminants, both may be inspected to assess whether contaminants are present (and, if present, whether they are located on the pellicle or the reticle). Such an inspection process may be called a qualification process. Various inspection tools or inspection devices (which may be alternatively called qualification tools or qualification devices) may be used for such inspection or qualification of the pellicle and reticle.

[0006]

[0006] In addition to inspecting the reticle and pellicle to determine the presence of contaminants, various properties of the pellicle and / or reticle may be determined as part of the qualification process. For example, the effective chemical reflectance of the reticle (i.e., reflectance in the wavelength distribution used in the lithography apparatus) may be determined. Similarly, the effective chemical transmittance of the pellicle (i.e., transmittance in the wavelength distribution used in the lithography apparatus) may be determined. The effective chemical reflectance of the reticle is desirable to be maximized and uniform with little variation throughout the reticle. The effective chemical reflectance may be estimated by measuring the spectral reflectance curve of the reticle with a spectrally resolved reflectometer. Typically, the peak reflectance R max , the spectral width of the spectral reflectance curve (e.g., characterized by the full width at half maximum (FWHM)) and the center wavelength (CLW) of the spectral reflectance curve. 50) may be determined. Alternatively, the effective chemical reflectance may be measured directly, for example, as described in U.S. Patent No. 6,856,395 (also published as U.S.2002 / 0175690). It is desirable that the effective chemical transmittance of the pellicle be maximized (preferably greater than 90%) and uniform (preferably with an absolute variation of less than 1%). It is desirable that the effective chemical reflectance of the pellicle be minimized (preferably less than 0.1%) and uniform (preferably with a relative variation of less than 10%).

[0007]

[0007] Whether or not specified herein, it may be desirable to provide an inspection or qualification device that avoids or mitigates one or more problems related to the prior art. [Overview of the Initiative]

[0008]

[0008] According to a first aspect of the present invention, there is an apparatus for determining one or more properties of an object used in an extreme ultraviolet (EUV) lithography apparatus, comprising: a support for supporting the object; a radiation system operable to generate a radiation beam containing EUV radiation and to deliver the radiation beam so as to be incident on the object when it is supported by the support; a detector system operable to receive the EUV radiation that has interacted with the object when it is supported by the support; and a radiation tuning module operable to adjust one or more properties of the radiation beam delivered to the object or radiation received by the detector system so as to determine the properties of a plurality of different objects, each having different properties.

[0009]

[0009] The radiation adjustment module controls one or more characteristics of the radiation beam delivered to the object or the radiation received by the detector system, such as the amount of radiation (or dose), the wavelength of the radiation, and / or the direction of the radiation beam relative to the object. As a result, the apparatus according to the first embodiment is advantageous because it can be used to inspect a wider range of objects, as will be further discussed below.

[0010]

[0010] The object may be a pellicle, a pellicle assembly (i.e., a pellicle and a pellicle frame), a reticle, or a reticle-pellicle assembly. Additionally or alternatively, the object may be a dynamic gas-lock window, an EUV beam attenuator, an EUV beam splitter, and / or a thin film membrane or window. Typically, pellicles, pellicle assemblies, and reticles are inspected and / or qualified using separate, custom-made equipment due to the significant differences in the properties of the two objects. Furthermore, inspection and qualification tools for inspecting pellicle-reticle assemblies are not readily available. In some embodiments, the equipment is suitable for inspecting EUV pellicles, EUV reticles, or reticle-pellicle assemblies for use in EUV lithography equipment.

[0011]

[0011] The term “radiation adjustment module” means anything that enables the control or selection of one or more characteristics of the radiation beam delivered to an object or the radiation received by the detector system. “Radiation adjustment module” may alternatively be called “radiation control module” or “radiation selection module.” It should also be understood that a radiation adjustment module does not have to be a separate physical subunit of the device (although it may be a separate physical subunit in some embodiments). For example, a radiation adjustment module may be implemented simply by appropriate control of other subunits of the device.

[0012]

[0012] Generally, a radiation tuning module should be understood as any means for controlling one or more characteristics of the radiation beam supplied to the apparatus, for example, to enable spectral and spatial measurements of different objects or samples within the same apparatus. In particular, a radiation tuning module may be operable to do any of the following: (a) select the exposure amount (e.g., to suit the type of object or sample), (b) select the beam geometry and divergence when incident on the object or sample, (c) select the wavelength distribution of the radiation beam, and / or (d) select the angle of incidence when incident on the object or sample. The exposure amount used here may be the output from the radiation system (e.g., dose per pulse) multiplied by the exposure time.

[0013]

[0013] The radiation adjustment module may be operable to determine the characteristics of the pellicle, pellicle assembly, reticle, or reticle-pellicle assembly.

[0014]

[0014] The radiation tuning module may be operable to determine any of the following characteristics of an EUV-transmitting object with an EUV transmittance in the range of 0.01% to 100%, an EUV-reflective object with an effective EUV reflectance in the range of 0.1% to 75%, and / or an EUV-reflective object with an effective EUV reflectance in the range of 0.002% to 0.2%.

[0015]

[0015] The apparatus may be operable to determine one or more of the following properties of an object, namely, in-band EUV transmission, in-band EUV reflection, in-band EUV scattering, photoemission, in-band EUV curvature of the object, and / or spectral function curves of EUV reflection, transmission, or scattering.

[0016]

[0016] The device is operable to operate in one or more different operating modes, and at least one of one or more characteristics of the radiation beam delivered to the object or the radiation received by the detector system may be different between any two operating modes.

[0017]

[0017] For example, each of a pellicle, a pellicle assembly, a reticle, or a reticle-pellicle assembly may be given one operating mode.

[0018]

[0018] The device may include a controller operable to control a radiation adjustment mechanism. The device may include a user interface. The user interface may include, for example, a control panel or a computer. The user may be able to use the user interface to control the radiation adjustment mechanism and / or select one from among multiple operating modes.

[0019]

[0019] The detector system may include a reflection sensor configured to receive a portion of the radiation beam delivered to the object and reflected by the object.

[0020]

[0020] It should be understood that, as used herein, a portion of the radiation beam delivered to the object and reflected by the object is intended to mean any type of scattering in which the radiation scatters back from the object (i.e., does not include only specular reflection).

[0021]

[0021] The reflection sensor may include any type of sensor array including any array of radiation-sensitive sensing elements. For example, the reflection sensor may include a charge-coupled device (CCD) array or a complementary metal-oxide semiconductor (CMOS) array.

[0022]

[0022] The detector system may include a transmission sensor configured to receive a portion of the radiation beam delivered to the object and transmitted by the object.

[0023]

[0023] The transmission sensor may include any type of sensor array including any array of radiation-sensitive sensing elements. For example, the transmission sensor may include a charge-coupled device (CCD) array or a complementary metal-oxide semiconductor (CMOS) array.

[0024]

[0024] The detector system may include at least one spectrometer having a detector operable to determine spectral decomposition reflection and / or transmission from an object supported by a support.

[0025]

[0025] The radiation adjustment module may be operable to control the amount of radiation delivered to the object via the radiation beam or received by the detector system.

[0026]

[0026] The amount of radiation may be referred to as the radiation dose amount. It should be understood that the radiation dose amount may be characterized by the total energy of the radiation or alternatively by the total number of photons of the radiation. This may be referred to as the average intensity of the radiation. However, in embodiments where the radiation beam includes a pulsed radiation beam, the amount of radiation may be defined as the radiation dose amount and also as a spatial distribution or a dose amount per unit area.

[0027]

[0027] Advantageously, controlling the amount of radiation delivered to an object or received by a detector system can, as will be considered below, allow for the inspection of both (a) EUV pellicles and pellicle assemblies (i.e., pellicles and pellicle frames), and (b) EUV reticles using reflected EUV radiation. An EUV reticle blank may have a reflectivity of about 63%. When patterned with an absorbing layer (which may have a reflectivity of about 1%), a typical patterned reticle may have a reflectivity of about 30%. In contrast, an EUV pellicle may typically have a reflectivity of about 0.04%. Thus, the amount of reflected EUV radiation can vary by about three orders of magnitude. Detecting both signals using a common detector or camera may be impractical or impossible, as it may be impossible to provide a detector with such a large dynamic range.

[0028]

[0028] Advantageously, the radiation adjustment module can control the amount of EUV radiation delivered to an object or received by the detector system, and can adjust the EUV radiation dose depending on the type of object being inspected so that the reflected EUV radiation remains within the dynamic range of the detector system.

[0029]

[0029] In some embodiments, it may be desirable to inspect the reticle, which is part of the reticle-pellicle assembly, without removing the pellicle. EUV pellicles typically have a transmittance of approximately 90%. Therefore, the EUV radiation reflected by the reticle, which is part of the reticle-pellicle assembly, and received by the detector has an effective reflectance of 0.81 times the actual reflectance. Again, the radiation adjustment module can control the dose of EUV radiation, so the dose can be adjusted to take this into consideration.

[0030]

[0030] The adjustment module may be operable to control the amount or dose of the EUV radiation beam either (a) before it is incident on the object while the EUV radiation is supported by the support, or (b) after the EUV radiation has interacted with the object while the EUV radiation is supported by the support.

[0031]

[0031] The radiation adjustment module may be operable to control the amount of EUV radiation delivered to an object via the radiation beam or received by the detector system by at least two orders of magnitude.

[0032]

[0032] In some embodiments, the radiation adjustment module is operable to control the amount or dose of radiation by at least three orders of magnitude.

[0033]

[0033] The radiation adjustment module may include multiple filters that can enter and exit the path of the radiation beam. Each of the multiple filters may have a different transmittance.

[0034]

[0034] With this configuration, the dose of radiation beam delivered to an object can be controlled by moving multiple filters in and / or out of the path of the radiation beam. Each of the multiple filters may include a spectral purity filter (SPF). Each of the multiple filters may include a thin film filter (TMF).

[0035]

[0035] Multiple filter bodies may be movable in and out of the path of the radiation beam upstream or downstream of the object supported by the support.

[0036]

[0036] The device may further include a movable support member, which supports a plurality of filters, and the movable support member is movable so that each of the filters can be placed in the path of the radiation beam.

[0037]

[0037] For example, the support member may include a rotating body or a wheel. A portion of the rotating body may be positioned in the path of the radiation beam, and by rotating the rotating body, different filters of several filters can be positioned in the path of the radiation beam upstream or downstream of the object supported by the support. Alternatively, the support member may include a translatable body arranged to move in one linear direction. A portion of the translatable body may be positioned in the path of the radiation beam, and by moving the translatable body in one linear direction, different filters of several filters can be positioned in the path of the radiation beam upstream or downstream of the object supported by the support.

[0038]

[0038] The apparatus may further include a storage module for storing multiple filters, and a device for moving each of the filters between a storage position in the storage module and a usage position in the path of the radiation beam.

[0039]

[0039] The storage module may function as a library for storing multiple different spectral filters. The device may be equipped with a robotic arm or the like, which may be able to retrieve spectral filters from the library and place them at their point of use in the path of the radiation beam. Similarly, the device may be able to retrieve spectral filters from their point of use in the path of the radiation beam and move them to the library for storage.

[0040]

[0040] Each of the filters may comprise a film or membrane having a thickness in the range of 200 to 2000 nm.

[0041]

[0041] Each of the filters may contain zirconium, niobium, ruthenium, or aluminum.

[0042]

[0042] The radiation adjustment module may include a mechanism for adjusting the radiation source of the radiation system.

[0043]

[0043] For example, a radiation system generally comprises a radiation source capable of operating to generate radiation, and one or more optical systems configured to receive the radiation and deliver the radiation beam to incident on an object supported by a support. In some embodiments, the radiation source itself may be tunable to control the dose of radiation. For example, the pulsed dose emitted from the radiation source may be controlled by one or more parameters relating to the operation of the radiation source, such as discharge voltage or laser pulse energy. In some embodiments, the beamforming optical system or beam delivery optical system of the radiation system itself may be tunable to control the dose of radiation.

[0044]

[0044] The radiation adjustment module may be operable to adjust the amount of radiation that interacts with the object while it is supported by the support before it is received by the detector system.

[0045]

[0045] The radiation adjustment module may be operable to control one or more parameters of the beamline purge gas.

[0046]

[0046] For example, the radiation adjustment module may be operable to control the type of purge gas and / or the beamline purge gas pressure.

[0047]

[0047] The radiation adjustment module may be operable to control the amount of radiation dose received by the detector system by controlling the exposure time of the detector system.

[0048]

[0048] For example, the radiation adjustment module may be operable to control the time the radiation beam is incident on the object, and consequently the time the reflected and transmitted beams of radiation are received by the detector system. For example, in some embodiments, the acquisition time for measuring the pellicle may be approximately 50 seconds. It is possible to reduce the acquisition time to about 1 second, resulting in an attenuation coefficient of 50.

[0049]

[0049] The radiation adjustment module may be operable to control the direction of the radiation beam relative to an object.

[0050]

[0050] The direction of a radiation beam relative to an object may be determined by one or more angles. Generally, the direction of a radiation beam relative to an object may be determined by two angles: the angle of incidence (the angle between the normal to the surface of the object and the direction of radiation propagation) and the azimuthal angle (the angle between the projection of the direction of radiation propagation onto the plane of the object and the reference direction).

[0051]

[0051] The radiation adjustment module may be operable to control the angle of incidence of the radiation beam to the object.

[0052]

[0052] It should be understood that the incident angle of the radiation beam is the angle between the normal to the surface of the object and the direction of radiation propagation.

[0053]

[0053] In general, it is sometimes desirable to inspect an object using radiation that is roughly consistent with the radiation that will be received while in use within the lithography apparatus. For example, it may be desirable to use radiation that has the same spectrum (center wavelength and bandwidth) and the same angle of incidence as the radiation used within the lithography tool. Various lithography tools may project radiation onto an object at various angles of incidence. Therefore, advantageously, by controlling the angle of incidence, the apparatus may be suitable for inspecting objects used with various EUV lithography tools.

[0054]

[0054] The radiation adjustment module may be operable to control the angle between the projection of the direction of propagation of the radiation beam onto the surface of the object and the reference direction.

[0055]

[0055] The angle between the projection of the direction of radiation propagation onto the surface or plane of an object and the reference direction is sometimes called the azimuth angle.

[0056]

[0056] Controlling the azimuth angle of radiation can enable measurements at multiple azimuth angles. Advantageously, this may allow the device to distinguish whether a contaminant detected on the reticle-pellicle assembly is on the pellicle or the reticle. For example, a contaminant may move within the reflectance map depending on the azimuth angle, and such movement may differ depending on whether the contaminant is on the reticle or the pellicle.

[0057]

[0057] The radiation system may include a radiation source that is operable to generate radiation and a beamforming optical system configured to receive the radiation and deliver the radiation beam to incident on an object that is supported by a support.

[0058]

[0058] Extreme ultraviolet (EUV) radiation may have wavelengths in the range of 4 to 20 nm. For example, EUV radiation may have wavelengths of 6.7 nm or 13.5 nm.

[0059]

[0059] The radiation source may be an EUV radiation source capable of operating to produce EUV in a spectral region of at least 12.5 to 15 nm.

[0060]

[0060] The radiation source may be a laser-generated plasma EUV source. The radiation source may be a discharge-generated plasma EUV source. The radiation source may be an EUV tube EUV source.

[0061]

[0061] The radiation system may be operable to operate in any one of several different operating modes, each having a different wavelength and / or bandwidth.

[0062]

[0062] The emission system may be operable to operate in a narrowband operating mode in which the EUV emission has a center wavelength of 13.52 nm and a bandwidth of 2%.

[0063]

[0063] Advantageously, when operating in this mode, the EUV emission has spectral characteristics similar to the EUV emission used in known types of lithography equipment. Emission in this mode of operation is sometimes called "effective-band EUV".

[0064]

[0064] The emission system may be capable of operating in a broadband operating mode in which the EUV emission has a spectral region of 12 nm to 16 nm.

[0065]

[0065] This type of radiation is sometimes called "broadband EUV".

[0066]

[0066] The beamforming optical system may be configured to control one or more properties of the radiation incident on an object when it is supported by a support. For example, the beamforming optical system may be configured to generate an EUV radiation beam having desired properties (e.g., spatial dimensions, number of EUV photons per pulse, uniformity, etc.).

[0067]

[0067] The beamforming optical system may include at least one mirror having a multilayer stack configured to reflect EUV radiation and perform spectral filtering.

[0068]

[0068] In other words, a multilayer stack may be configured to reflect in-band EUV radiation well and out-of-band radiation poorly. In this way, such a mirror can achieve in-band spectral filtering.

[0069]

[0069] The apparatus may further include a spectral purity filter positioned between the radiation source and the support and configured to block visible radiation, infrared radiation, and ultraviolet radiation.

[0070]

[0070] It should be understood that the term "ultraviolet radiation" used herein is intended to mean radiation with wavelengths longer than EUV radiation.

[0071]

[0071] The apparatus may further include a monitoring system that can be operated to determine the intensity of the radiation beam.

[0072]

[0072] Supports for supporting an object may be suitable for supporting a reticle, a pellicle, and / or a reticle-pellicle assembly.

[0073]

[0073] The central part of the support may be transparent.

[0074]

[0074] The support is a frame for supporting an object and may include a frame that defines a central opening.

[0075]

[0075] In other words, the support may be generally hollow and / or transparent. Advantageously, this allows the detector system to detect the portion of the radiation that is transmitted through the object. This can be particularly useful for inspecting and qualifying pellicles (which typically transmit about 90% of the incident radiation).

[0076]

[0076] The support may be suitable for supporting the pellicle, pellicle assembly, reticle, and reticle-pellicle assembly.

[0077]

[0077] The radiation system may include a spectral purity filter (SPF) located upstream of the support in the optical path.

[0078]

[0078] The apparatus may further include a moving mechanism that can operate to move the support relative to the radiation beam delivered by the radiation system.

[0079]

[0079] For example, the moving mechanism may be capable of operating to scan an object with a radiation beam. The support may be called a stage device or positioning stage.

[0080]

[0080] Additionally or alternatively, the moving mechanism may be operable to collect objects from the input (when they are loaded into the device for inspection or qualification) and / or send the objects to the output (after inspection or qualification is complete).

[0081]

[0081] The support may include a holder for holding an object.

[0082]

[0082] The radiation adjustment module may be operable to control the geometry of the radiation beam.

[0083]

[0083] The device may further include a chamber in which a support is disposed, and a load lock that forms an interface between the chamber and the surrounding environment.

[0084]

[0084] The chamber may be configured to provide a controlled atmosphere for inspecting an object. The chamber may be sealable. The chamber may be a vacuum chamber. The chamber may be a high vacuum process chamber. A load lock may be considered a loading system for loading an object onto a support within the process chamber. In some embodiments, the support, radiation system, and detector system are all located within the chamber. The chamber may be called an inspection chamber.

[0085]

[0085] The support (also called the stage device) may be configured to receive an object from the load lock and move that object within the chamber.

[0086]

[0086] The device may further include a transport mechanism configured to transport objects from the load lock to the support and vice versa.

[0087]

[0087] The transfer mechanism may be located at least partially within the load lock. The transfer mechanism may be mounted on a support (also called a stage device).

[0088]

[0088] The load lock may include a first door, a second door, and a load lock chamber, the first door being configured to isolate the surrounding environment from the load lock chamber, and the second door being configured to isolate the chamber from the load lock chamber.

[0089]

[0089] The chamber may include a first parking position and a second parking position for temporarily storing objects.

[0090]

[0090] The support may be configured to transport an object from the support to a first parking position and vice versa, and the support may be configured to transport an object from the support to a second parking position and vice versa.

[0091]

[0091] The apparatus may further include a second load lock that forms an interface between the chamber and the surrounding environment.

[0092]

[0092] It should be understood that one or more aspects or features referred to in the above or below description may be combined with one or more other aspects or features.

[0093]

[0093] Embodiments of the present invention will now be described with reference to the attached schematic diagrams, which are merely examples. [Brief explanation of the drawing]

[0094] [Figure 1] This is a schematic diagram of a lithography system equipped with a lithography device and a radiation source. [Figure 2] This is a schematic diagram of an embodiment of the inspection device relating to this disclosure. [Figure 3A] This is a schematic diagram of a first embodiment of a support member equipped with multiple thin-film filters having different EUV transmittances, which can constitute part of the radiation adjustment module of the inspection apparatus shown in Figure 2. [Figure 3B] This is a schematic diagram of a second embodiment of a support member equipped with multiple thin-film filters having different EUV transmittances, which can constitute part of the radiation adjustment module of the inspection apparatus shown in Figure 2. [Figure 4] This is a schematic diagram of two angles (incident angle θ and azimuth angle φ) that can determine the direction of the radiation beam relative to the object being inspected. [Figures 5A-5F] Figure 2 shows a first embodiment of a load lock device for an inspection device of the type shown. [Figure 6A-6C] Figure 2 shows a second embodiment of a load lock device for the type of inspection equipment shown. [Modes for carrying out the invention]

[0095]

[0094] Figure 1 shows a lithography system comprising a radiation source SO and a lithography apparatus LA. The radiation source SO is configured to generate an EUV radiation beam B and to supply this EUV radiation beam B to the lithography apparatus LA. The lithography apparatus LA comprises an illumination system IL, a support structure MT configured to support a reticle-pellicle assembly 15 including a patterning device MA (e.g., a reticle or mask), a projection system PS, and a substrate table WT configured to support a substrate W.

[0096]

[0095] The illumination system IL is configured to adjust the EUV radiation beam B before it is incident on the patterning device MA. For this reason, the illumination system IL may include a faceted field mirror device 10 and a faceted pupil mirror device 11. Both the faceted field mirror device 10 and the faceted pupil mirror device 11 give the EUV radiation beam B a desired cross-sectional shape and a desired intensity distribution. In addition to or instead of the faceted field mirror device 10 and the faceted pupil mirror device 11, the illumination system IL may include other mirrors or devices.

[0097]

[0096] After being adjusted in this manner, the EUV radiation beam B interacts with the patterning device MA. This interaction results in the generation of a patterned EUV radiation beam B'. The projection system PS is configured to project the patterned EUV radiation beam B' onto the substrate W. For this purpose, the projection system PS may include a number of mirrors 13, 14 configured to project the patterned EUV radiation beam B' onto the substrate W held by the substrate table WT. The projection system PS may apply a reduction factor to the patterned EUV radiation beam B', thereby forming an image of a feature smaller than the corresponding feature in the patterning device MA. For example, a reduction factor of 4 or 8 may be applied. Although the projection system PS is shown in Figure 1 as having only two mirrors 13, 14, the projection system PS may include various numbers of mirrors (e.g., 6 or 8 mirrors).

[0098]

[0097] The substrate W may include a pre-formed pattern. In such cases, the lithography apparatus LA aligns the image formed by the patterned EUV radiation beam B' with the pre-formed pattern on the substrate W.

[0099]

[0098] The lithography apparatus LA may be used, for example, in scan mode, in which the pattern applied to the radiation beam B is projected onto the substrate W while the support structure (e.g., mask table) MT and the substrate table WT are scanned synchronously (i.e., dynamic exposure). The velocity and direction of the substrate table WT relative to the support structure (e.g., mask table) MT may be determined by the reduction and image inversion characteristics of the projection system PS. The patterned radiation beam incident on the substrate W may include a radiation band. The radiation band may be called the exposure slit. During scan exposure, the exposure slit may move across the exposure field of the substrate W as the substrate table WT and the support structure MT move.

[0100]

[0099] A small amount of gas (e.g., hydrogen) at a relative vacuum, i.e., a pressure significantly lower than the ambient pressure, may be supplied into the radiation source SO, the illumination system IL, and / or the projection system PS.

[0101] [000100] The radiation source SO shown in Figure 1 is of a type that may be called, for example, a laser-generated plasma (LPP) source. The laser system 1, which may include, for example, a CO2 laser, is configured to store energy in a fuel such as tin (Sn) supplied from, for example, a fuel ejector 3, via a laser beam 2. In the following description, tin will be mentioned, but any suitable fuel may be used. The fuel may be, for example, in liquid form, or may be, for example, a metal or alloy. The fuel ejector 3 may have a nozzle configured to guide, for example, tin in the form of droplets, along a trajectory toward a plasma-forming region 4. The laser beam 2 is incident on the tin in the plasma-forming region 4. The storage of laser energy in the tin generates a tin plasma 7 in the plasma-forming region 4. During the de-excitation and recombination of electrons by plasma ions, radiation including EUV radiation is emitted from the plasma 7.

[0102] [000101] EUV radiation from the plasma is collected and focused by a collector 5. The collector 5 includes, for example, a peritor-normal incident radiation collector 5 (sometimes more commonly called a normal incident radiation collector). The collector 5 may have a multilayer mirror structure configured to reflect EUV radiation (e.g., EUV radiation having a desired wavelength such as 13.5 nm). The collector 5 may have an elliptical configuration with two foci. The first of the foci may be in the plasma-forming region 4, and the second of the foci may be in the intermediate focus 6, which will be discussed below.

[0103] [000102] The laser system 1 may be spatially separated from the radiation source SO. In such cases, the laser beam 2 may be delivered from the laser system 1 to the radiation source SO by a beam delivery system (not shown) which includes, for example, a suitable guide mirror and / or beam expander and / or other optical systems. The laser system 1, the radiation source SO, and the beam delivery system may together be considered a radiation system.

[0104] [000103] The radiation reflected by the collector 5 forms an EUV radiation beam B. The EUV radiation beam B is focused at an intermediate focus 6 to form an image at the intermediate focus 6 of the plasma present in the plasma-forming region 4. The image at the intermediate focus 6 functions as a virtual radiation source for the illumination system IL. The radiation source SO is positioned such that the intermediate focus 6 is located at or near the aperture 8 of the closed structure 9 of the radiation source SO.

[0105] [000104] The SO radiation source and / or lithography apparatus shown in Figure 1 may include components not shown. For example, the SO radiation source may be equipped with a spectral filter. The spectral filter may substantially transmit EUV radiation but substantially block radiation of other wavelengths, such as infrared radiation.

[0106] [000105] Figure 1 shows the SO radiation source as a laser-generated plasma (LPP) source, but EUV radiation may be generated using any suitable radiation source such as a discharge-generated plasma (DPP) source or a free-electron laser (FEL).

[0107] [000106] The reticle assembly 15 includes a patterning device MA and a pellicle 19. The pellicle 19 is attached to the patterning device MA via a pellicle frame 17. The pellicle 19 and the pellicle frame 17 are sometimes collectively referred to as the pellicle assembly. The reticle-pellicle assembly 15 is sometimes referred to as the reticle assembly 15. The patterning device MA reflects the radiation beam B and imparts a pattern to it. The pellicle 19 is provided adjacent to the patterning device MA. The pellicle 19 is provided in the path of the radiation beam B so that it passes through the pellicle 19 both when the radiation beam B approaches the patterning device MA from the illumination system IL and when it is reflected by the patterning device MA and heads toward the projection system PS. The pellicle 19 includes a thin film or membrane that substantially transmits EUV radiation (but absorbs a small amount of EUV radiation). In this specification, an EUV-transmitting pellicle or a film that substantially transmits EUV radiation means that the pellicle 19 transmits at least 65% of the EUV radiation, preferably at least 80%, and more preferably at least 90%. The pellicle 19 serves to protect the patterning device MA from particle contamination.

[0108] [000107] Although efforts are made to maintain a clean environment inside the lithography apparatus LA, particles may still be present inside the lithography apparatus LA. Without the pellicle 19, particles may adhere to the patterning device MA. Particles on the patterning device MA may adversely affect the pattern applied to the radiation beam B and, consequently, the pattern transferred to the substrate W. The pellicle 19 advantageously provides a barrier between the patterning device MA and the environment inside the lithography apparatus LA to prevent particles from adhering to the patterning device MA.

[0109] [000108] The pellicle 19 is positioned sufficiently far from the patterning device MA so that particles incident on the surface of the pellicle 19 do not fall within the field plane of the lithography apparatus LA. As used herein, the term “field plane” is intended to mean the image plane of the projection system PS (on which the substrate W is located), or any optically conjugate plane such as the objective plane of the projection system PS (on which the patterning device MA is located). The distance between the pellicle 19 and the patterning device MA serves to limit the extent to which particles on the surface of the pellicle 19 impart a pattern to the radiation beam B that is imaged onto the substrate W. It should be understood that even if a particle is in the radiation beam B, if its position is not within the field plane of the radiation beam B (for example, not on the surface of the patterning device MA), the image of that particle will not be focused on the surface of the substrate W. If there are no other considerations, it may be desirable to position the pellicle 19 considerably far from the patterning device MA. However, in reality, the space available for housing the pellicle within the lithography apparatus LA is limited due to the presence of other components. In some embodiments, the distance between the pellicle 19 and the patterning device MA may be, for example, about 1 mm to 10 mm, 1 mm to 5 mm, or 2 mm to 2.5 mm.

[0110] [000109] The pellicle 19 may include a boundary and a film. The boundary of the pellicle 19 may be hollow and generally rectangular (for example, in the form of a rectangular frame surrounding a central rectangular opening), and the film may be bounded by the boundary. As is known in the art, the pellicle 19 may be formed by depositing one or more thin layers of material onto a silicon substrate. The silicon substrate supports one or more thin layers during this construction stage of the pellicle 19. Once layers of the desired or target thickness and composition are deposited, the central part of the silicon substrate is removed by etching (this may be called back etching). The peripheral part of the rectangular silicon substrate is not etched (or alternatively, etched to a lesser degree than the central part). This peripheral part forms the boundary of the final pellicle, while one or more thin layers form a film of the pellicle (bounded by the boundary). The boundary of the pellicle 19 may be formed from silicon.

[0111] [000110] Alternatively, the pellicle may be formed from a film of carbon nanotubes (CNTs).

[0112] [000111] The pellicle 19 may require some support from a more rigid pellicle frame 17. The pellicle frame 17 may provide two functions. Firstly, the pellicle frame 17 may support the pellicle 19 and keep the pellicle membrane taut. Secondly, the pellicle frame 17 may facilitate the connection of the pellicle 19 to the patterning device (reticle) MA. In one known configuration, the pellicle frame 17 may comprise a generally rectangular body that is bonded to the boundary of the pellicle 19 and a titanium mounting mechanism that is bonded to the sides of this body. An intermediate fixing member (known as a stud) is fixed to the patterning device (reticle) MA. The intermediate fixing member (stud) on the patterning device (reticle) MA may engage (e.g., detachably engage) with a mounting member of the pellicle frame 17.

[0113] [000112] The reticle assembly 15 may be prepared for use in the lithography apparatus LA by attaching the pellicle 19 to the pellicle frame 17 and attaching the pellicle frame 17 to the patterning device MA. The reticle assembly 15, comprising the patterning device MA and the pellicle 19 supported adjacent to the patterning device MA by the pellicle frame 17, may be prepared remotely from the lithography apparatus LA, and the reticle assembly may be transported to the lithography apparatus LA for use in the lithography apparatus LA. For example, the reticle assembly 15 may be formed on the patterning device MA by attaching the pellicle frame 17 supporting the pellicle 19 to the patterning device MA. The reticle assembly 15 may then be transported to another location where the lithography apparatus LA is located and provided to the lithography apparatus LA for use in the lithography apparatus LA.

[0114] [000113] Embodiments of the present disclosure relate to an apparatus for determining one or more characteristics of an object (e.g., reticle MA, pellicle 19, or reticle assembly 15) used in an EUV lithography apparatus LA of the type shown in Figure 1 and described above. Such an apparatus may be used to evaluate the quality of an object (or its suitability for functioning as required) and may be called a qualification apparatus. Alternatively, the apparatus may be called an inspection apparatus.

[0115] [000114] Spectral EUV reflectance measurement is an established method for evaluating the chemical beam compatibility of EUV mask blanks. This method uses effective reflectance R eff Because it directly provides a full area diagram, it can be used for quality verification of components used in EUV lithography. In spectral mode, the reflectance curve R(λ) is measured by scanning a single wavelength or by scanning multiple wavelengths. Specific characteristics of this reflectance curve are evaluated for product suitability assessment.

[0116] [000115] Commercially available EUV reflectometers measure in spectral mode, i.e., at about 100 spectral channels, i.e., at different wavelengths with a spectral resolution λ / Δλ greater than 100 to 1000, for a single spot of about 1×1 mm 2 to measure the complete spectral reflectivity curve R(λ), for example, from 10 to 15 nm.

[0117] [000116] In the multi-color reflectometry method, a complete spectral scan may be recorded in parallel, for example, recording about 2000 spectral channels with a bandwidth of about 1.7 picometers for a spot of 0.1×1 mm 2 . As the wavelength scan becomes obsolete, the complete curve R(λ) may be recorded in less than 5 seconds, and at wavelengths where the maximum reflectivity CWL 50 exceeds 1 pm, an accuracy of R max of 0.1% is obtained. The EUV reflectometer tool positions the blank at the measurement position using a vacuum robot. The operating time of the EUV source may exceed 300 Mpulse, and measurements are made at more than 80 sites per blank for more than 2000 blanks.

[0118] [000117] However, the parameters related to the use of EUV optical components such as masks, mirrors, pellicles, etc. in the scanner device are effective values, for example, R given by the convolution of the transmittance P(λ) of the projector optical system spectral transmittance of the scanner eff , and sample characteristics such as the spectral reflectivity curve convolved with the spectral transmittance, for example, R(λ).

[0119] [000118] Conventionally, the effective value is estimated from the spectral reflectivity curve by modeling using spectral reflectivity measurement values from a small number of measurement sites (for example, with an area of less than 4 mm 2 ), and R max , CWL 50 , and in some cases R eff may be extrapolated to the map of.

[0120] [000119] Using our unique "spectral integration" technique, R eff By measuring only this, it becomes possible to measure the total sample surface value in high-speed processing. Then, for example, R eff Multiple frames of values ​​are combined into a map. In this way, the entire area of ​​the mask blank (>225,000 mm) is covered. 2 ) can be evaluated for eligibility in less than one hour of measurement time.

[0121] [000120] In the "spectral integration" EUV characterization, the EUV source emission is spectrally filtered to a center wavelength of 13.52 nm and a bandwidth of 2% by multilayer, VUV, UV, visible light, and IT cutoff spectral purity filters. Both the transmitted and reflected beams are recorded with a CCD camera at approximately 20 × 20 mm. 2 In this area, T is obtained with a spatial resolution of 13.5 μm. eff and R eff Effective measurement can be performed in a few seconds.

[0122] [000121] Tools for measuring EUV reflectance and transmittance of this type may be used to qualify EUV pellicles. Generally, for EUV transmittance of about 90%, the repeatability and accuracy of the tools may exceed 0.1%. Such tools can simultaneously measure reflectance of less than 0.01% with repeatability and sensitivity of less than 0.001%. Since such tools are used in industrial processes for lithography manufacturing, they are designed not to add particles to the sample up to a detection limit of 0.5 μm.

[0123] [000122] Such tools may offer a variety of solutions, including ultra-clean handling spectral EUV mask blank tools, mask blank mapping optimized for high-reflectivity mask blanks and blanks coated with absorbent materials, mask blank mapping combined with pellicle EUV transmittance and EUV reflectance mapping, and automated loading from reticle pods.

[0124] [000123] Such tools have a spectral resolution of less than 2 pm, such as 1.7 pm, and a maximum reflectance CWL. 50 For wavelengths less than 1 pm, and R max Regarding spectral accuracy of less than 0.1 abs, 20 × 20 microns. 2 Spatial resolution of 152 × 152 mm 2 Mapped areas with more than 30 minutes of masks / blanks may have measurement times of less than 1 hour.

[0125] [000124] Referring to Figure 2, an apparatus 100 for determining one or more properties of an object for use in an extreme ultraviolet (EUV) lithography apparatus LA, according to an embodiment of the present disclosure, will now be described. The apparatus 100 comprises a support 110, a radiation system 120, a detector system 130, and a radiation adjustment module 140.

[0126] [000125] The support 110 is for supporting the object 112 to be inspected. The support 110 may be suitable for supporting the reticle MA, the pellicle 19, the pellicle assembly (i.e., the pellicle 19 and the pellicle frame 17), and / or the reticle-pellicle assembly 15. In some embodiments, the support 110 may include a clamping mechanism or holder (not shown) for holding the object 112 in place. In some embodiments, the support 110 may include multiple clamping mechanisms, each suitable for holding different types of objects 112 in place. The support 110 may be suitable for supporting the pellicle, the pellicle assembly, the reticle, and the reticle-pellicle assembly. Table 1 shows examples of objects 112 that can be supported by the support 110 and inspected or qualified using the apparatus 100.

[0127] [Table 1]

[0128] [000126] For example, in the case of a pellicle, the EUV transmittance is preferably 80% or more, for example 90% or more, and the EUV reflectance is preferably 0.2% or less, more preferably 0.1% or less, for example 0.01%. In the case of a reticle, the EUV reflectance is preferably 60% or more, for example 65% or more. In the case of a reticle-pellicle assembly, the EUV reflectance is preferably 35% or more, for example 65% or more. In the case of a dynamic gas lock window (i.e., a DGL film), the EUV transmittance is preferably 50% or more, more preferably 80% or more, and the EUV reflectance is preferably 5% or less. For thin film / EUV windows used as beam attenuators or beam splitters, as illustrated in Table 1, the EUV transmittance is preferably 0.1% or more, for example 30% or more, more preferably 70% or more, for example 80% or more, while the EUV reflectance is preferably 0.1% or more, for example 5% or more, more preferably 10% or more, particularly preferably 30% or more, and more preferably 70% or more.

[0129] [000127] The radiation system 120 is operable to generate a radiation beam 122 containing EUV radiation and to deliver the radiation beam 122 so as to be incident on an object 112 when it is supported by the support 110. Extreme ultraviolet (EUV) radiation may have wavelengths in the range of 4 to 20 nm. For example, EUV radiation may have wavelengths of 6.7 nm or 13.5 nm.

[0130] [000128] Generally, the radiation system 120 comprises a radiation source capable of generating radiation and one or more optical systems configured to receive the radiation and deliver the radiation beam 122 to incident on an object 112 when it is supported by the support 110. The radiation system 120 may comprise any of the EUV radiation sources discussed above in relation to the lithography apparatus LA (i.e., a laser-generated plasma (LPP) source, a discharge-generated plasma (DPP) source, or a free-electron laser (FEL)), however the power required for the radiation system 120 of the inspection apparatus may be significantly less than the power required for the radiation source SO of the lithography apparatus LA to support high throughput. Therefore, the radiation system 120 may have a simpler configuration. In one embodiment, a potentially broadband radiator is used in combination with one or more spectral filters to generate EUV radiation.

[0131] [000129] Generally, the radiation system 120 comprises a radiation source 120a and a beamforming optical system 120b. The radiation source 120a is operable to generate radiation. The beamforming optical system 120b is configured to receive the radiation and deliver the radiation beam 122 to incident on an object 112 when it is supported by the support 110.

[0132] [000130] Extreme ultraviolet (EUV) radiation may have wavelengths in the range of 4 to 20 nm. For example, EUV radiation may have wavelengths of 6.7 nm or 13.5 nm. Radiation source 120a may be an EUV radiation source capable of producing EUV in the spectral region of at least 12.5 to 15 nm.

[0133] [000131] In some embodiments, the device radiation system 120 may be operable to operate in one of several different operating modes, each having radiation 122 of a different wavelength and / or bandwidth. One of the several different operating modes may be selectable via a radiation adjustment module 140.

[0134] [000132] In some embodiments, the emission system 120 may be operable to operate in a narrowband operating mode in which the EUV emission 122 has a center wavelength of 13.52 nm and a bandwidth of 2%. This may be achieved, for example, by spectral filtering with a spectral purity filter placed in the path of the emission 122 before the emission 122 is incident on the object 112. Advantageously, when operating in such an operating mode, the EUV emission has spectral characteristics similar to those of EUV emission used in known types of lithography equipment. Thus, in such embodiments, the effective chemical beam transmittance or reflectance can be measured directly. Emission in such an operating mode is sometimes referred to as "effective in-band EUV".

[0135] [000133] In some embodiments, the radiation system 120 may be operable to operate in a broadband operating mode in which the EUV radiation 122 has a spectral region of 12 nm to 16 nm. Radiation in such an operating mode may be called “broadband EUV”. Such embodiments may be used to obtain the spectral distribution of reflection or transmission of an object 112. In such embodiments, there may be no spectral filter in the path of the EUV radiation 122 (or, if such a spectral filter exists, it may be moved out of the path of the radiation beam) to enable the measurement of a spectral reflectance curve.

[0136] [000134] The beamforming optical system 120b may be configured to control one or more properties of the radiation 122 incident on the object 112 when it is supported by the support 110. For example, the beamforming optical system 120b may be configured to generate an EUV radiation beam having desired properties (e.g., spatial dimensions, number of EUV photons per pulse, uniformity, etc.).

[0137] [000135] In some embodiments, the beamforming optical system 120b includes at least one mirror having a multilayer stack configured to reflect EUV radiation and perform spectral filtering. That is, the multilayer stack may be configured to reflect in-band EUV radiation well and out-of-band radiation poorly. In this way, such a mirror can achieve in-band spectral filtering. Such a mirror may receive EUV radiation under pernormal incidence (i.e., at incidence angles of 45° or less).

[0138] [000136] In some embodiments, the beamforming optical system 120b includes at least one grazing incident mirror (which may also perform spectral filtering) configured to reflect EUV radiation. Such a mirror may receive EUV radiation under grazing incidence (i.e., at an incidence angle of 25° or greater).

[0139] [000137] In some embodiments, the apparatus 100 further comprises a separate spectral purity filter 124 disposed between the radiation source 120 and the support 110 and configured to block visible radiation, infrared radiation, and ultraviolet radiation. It should be understood that as used herein, “ultraviolet radiation” is intended to mean radiation having wavelengths longer than EUV radiation. (See Figures 5A to 6C for further consideration below) In embodiments comprising a process chamber or vacuum chamber, the spectral purity filter 124 may be provided on the wall of the chamber to provide a window into which the radiation beam can enter the chamber.

[0140] [000138] The detector system 130 is operable to receive EUV radiation 132, 134 interacting with the object 112 when it is supported by the support 110. In this embodiment, the detector system 130 comprises a reflectance sensor 136 and a transmission sensor 138. Optionally, the detector system 130 may further comprise a scattering and / or photoelectron detector 185. The scattering and / or photoelectron detector 185 may be positioned near the location where the radiation beam 122 enters the object 112. The scattering and / or photoelectron detector 185 may be operable to determine in-band EUV scattering and / or photoelectron emission. It should be understood that other embodiments may comprise only one of these sensors. Furthermore, it should be understood that in some uses of the apparatus 100, one of the reflectance sensor 136 and the transmission sensor 138 may not be able to receive radiation. For example, in some objects 112 (including, for instance, a reticle), substantially all of the incident radiation 122 may be reflected or absorbed, in which case the transmission sensor 138 will not receive any radiation.

[0141] [000139] The reflection sensor 136 is configured to receive the portion 132 of the radiation beam 122 delivered to the object 112 that is reflected by the object 112. As used herein, the portion 132 of the radiation beam 122 delivered to the object 112 that is reflected by the object 112 is intended to mean any type of scattering that the radiation scatters back from the object 112 (i.e., not just specular reflection).

[0142] [000140] The reflective sensor 136 may include any type of sensor array, which may include any array of radiation-sensitive sensing elements. For example, the reflective sensor 136 may include a charge-coupled device (CCD) array or a complementary metal-oxide-semiconductor (CMOS) array.

[0143] [000141] The transmission sensor 138 is configured to receive a portion 134 of the radiation beam 122 delivered to the object 112, which is transmitted through the object 112.

[0144] [000142] The through-sensor 138 may include any type of sensor array, which may include any array of radiation-sensitive sensing elements. For example, the through-sensor 138 may include a charge-coupled device (CCD) array or a complementary metal-oxide-semiconductor (CMOS) array.

[0145] [000143] In some embodiments, the detector system 130 may include at least one spectrometer with a detector operable to determine spectrally resolved reflection or transmission from an object 112 supported by the support 110. For example, in some embodiments, the reflection sensor 136 may include a color optics 136a operable to split the portion 132 of the radiation beam 122 reflected by the object 112 into spectral components, and a detector 136b operable to determine spectrally resolved reflection from the object 112 supported by the support 110. Similarly, in some embodiments, the transmission sensor 138 may include a color optics 138a operable to split the portion 134 of the radiation beam 122 transmitted by the object 112 into spectral components, and a detector 138b operable to determine spectrally resolved transmission from the object 112 supported by the support 110.

[0146] [000144] In some embodiments, the central portion of the support 110 may be transparent. For example, as schematically shown in Figure 2, the support 110 may have a frame for supporting an object, which defines a central opening 114. That is, the support 110 may be generally hollow and / or transparent. Advantageously, this allows the portion 134 of the radiation 122 that passes through the object 112 to be detected by the detector system 130 (transmission sensor 138). This may be particularly useful for inspecting or qualifying the pellicle 19 (which typically transmits about 90% or more of the incident EUV radiation).

[0147] [000145] The device 100 may further include a moving mechanism 150 that can be operated to move the support 110 relative to the radiation beam 122 delivered by the radiation system 120. For example, the moving mechanism 150 may be operable to move the object 112 linearly in one, two, or three dimensions relative to the radiation beam 122. For example, the moving mechanism 150 may be operable to scan the object 112 with the radiation beam 122 or to step through the radiation beam 122. Additionally or alternatively, the moving mechanism 150 may be operable to rotate the object 112. For example, the moving mechanism 150 may be operable to rotate the object 112 about an axis roughly parallel to the plane of the object 112, thereby allowing the moving mechanism 150 to control the angle of incidence of the incident radiation 122. Furthermore, a mechanism may be provided to move the reflective sensor 136 and / or the transmissive sensor 138 so that they can receive radiation 132, 134 within the range of the incident angle of the incident radiation 122. Additionally or alternatively, the moving mechanism 150 may be operable to rotate the object 112 about an axis roughly perpendicular to the plane of the object 112, thereby (as will be further discussed below with reference to Figure 4) the device 100 may be able to distinguish whether the contaminant detected on the reticle-pellicle assembly 15 is on the pellicle 19 or on the reticle MA. The support 110 may be referred to as the stage device.

[0148] [000146] Additionally or alternatively, the moving mechanism 150 may be operable to collect the object 112 from the input (when it is loaded into the apparatus 100 for inspection) and / or send the object 112 to the output (after inspection is complete). Such input and / or output may be equipped with a load lock for a vacuum chamber, as will be further discussed below with reference to Figures 5A to 6C.

[0149] [000147] The radiation adjustment module 140 is operable to adjust one or more characteristics of the radiation beam 122 delivered to the object 112 and / or radiation 132, 134 received by the detector system 130.

[0150] [000148] For example, the radiation adjustment module 140 may control the amount (dose) of radiation 132, 134 delivered to the object 112 and / or received by the detector system 130, the wavelength and spectral bandwidth of the radiation beam 122, and / or the orientation of the radiation beam 122 relative to the object 112. As a result, the apparatus 100 according to the first embodiment is advantageous for allowing the apparatus to be used to inspect or qualify a wider range of objects 112, as will be further discussed below. In particular, the radiation adjustment module 140 of the apparatus 100 may be able to determine the characteristics of multiple different objects, each having different characteristics.

[0151] [000149] In some embodiments, the radiation adjustment module 140 may be operable to determine any of the following characteristics of an EUV-transmitting object: (a) an EUV-transmitting object with an EUV transmittance in the range of 0.01% to 100%, (b) an EUV-reflective object with an effective EUV reflectance in the range of 0.1% to 75%, and / or (c) an EUV-reflective object with an effective EUV reflectance in the range of 0.002% to 0.2%.

[0152] [000150] In some embodiments, the apparatus 100 may be operable to determine one or more of the following properties of an object, namely (i) effective band EUV transmission, (ii) effective band EUV reflection, (iii) effective band EUV scattering, (iv) photoemission, (v) effective band EUV curvature of the object, and / or (vi) spectral EUV reflectance curve.

[0153] [000151] In some embodiments, the apparatus 100 is operable to operate in one or more different operating modes, any two operating modes differing in at least one of the characteristics of one or more of the radiation beam 122 delivered to the object 112 or the radiation 132, 134 received by the detector system 130. For example, one operating mode may be given to each of the pellicle, pellicle assembly, reticle, or reticle-pellicle assembly.

[0154] [000152] In some embodiments, the apparatus 100 may include a controller 142 that can be operated to control the radiation adjustment mechanism 140. The apparatus 100 may further include a user interface 144. The user interface 144 may include, for example, a control panel or a computer. The user may use the user interface 144 to control the radiation adjustment mechanism 140 and / or to select one of several operating modes of the apparatus 100.

[0155] [000153] Object 112 may be a pellicle 19, a reticle MA, a pellicle assembly (i.e., pellicle 19 and pellicle frame 17), or a reticle-pellicle assembly 15. Typically, the pellicle 19 and the reticle MA are inspected using separate, custom-made equipment due to the significant differences in the properties of the two objects. Furthermore, tools for inspecting or qualifying the pellicle-reticle assembly 15 are not readily available. In some embodiments, the apparatus 100 is suitable for inspecting or qualifying the EUV pellicle 19, EUV reticle MA, EUV pellicle assembly (i.e., pellicle 19 and pellicle frame 17), or a reticle-pellicle assembly 15 for use in an EUV lithography apparatus LA.

[0156] [000154] The emission system 120 may include one or more spectral purity filters (SPFs). Such spectral purity filters (SPFs) may be located upstream and / or downstream of the support 110 in the optical path.

[0157] [000155] In some embodiments, the radiation adjustment module 140 is operable to control the amount of radiation 122 delivered to an object via the radiation beam 122 or radiation 132, 134 received by the detector system 130.

[0158] [000156] The quantities of radiation 122, 132, and 134 are sometimes called radiation doses. It should be understood that radiation doses can be characterized by the total energy of the radiation, or alternatively, the total number of photons of the radiation. This is sometimes called the average intensity of the radiation. However, in embodiments in which radiation beam 122 includes a pulsed radiation beam, the radiation quantity may be defined as a radiation dose, and also as a spatial distribution, or dose per unit area.

[0159] [000157] Advantageously, controlling the amount of radiation 122 delivered to object 112 or received by detector system 130 may allow for inspection and / or qualification of both the EUV pellicle and EUV reticle within apparatus 100 using reflected EUV radiation, as will be considered below. An EUV reticle blank may have a reflectivity of about 63%. When patterned with an absorbing layer (which may have a reflectivity of about 1%), a typical patterned reticle may have a reflectivity of about 30%, although in some cases, as with contact hole masks, this value may be higher. In contrast, an EUV pellicle may typically have a reflectivity of about 0.04%. Thus, the amount of reflected EUV radiation can vary by about three orders of magnitude. Detecting both signals using a common detector or camera may be impractical or impossible, as it may be impossible to provide a detector with such a large dynamic range.

[0160] [000158] Advantageously, the radiation adjustment module 140 can control the amount (i.e., dose) of the EUV radiation beam 122 and / or reflected EUV radiation 132, so that the dose can be adjusted depending on the type of object 112 being inspected so that the reflected EUV radiation 132 remains within the dynamic range of the reflectance sensor 136 of the detector system 130.

[0161] [000159] In some embodiments, it may be desirable to inspect the reticle MA, which is part of the reticle-pellicle assembly 15, without removing the pellicle. The EUV pellicle typically has a transmittance of approximately 90%. Therefore, the EUV radiation reflected by the reticle MA, which is part of the reticle-pellicle assembly 15, and received by the detector (e.g., the reflectance sensor 136) has an effective reflectance of 0.81 times the actual reflectance. Again, the radiation adjustment module 140 can control the amount of the EUV radiation beam 122, and the radiation dose can be adjusted to take this into account.

[0162] [000160] In some embodiments, the radiation adjustment module 140 is operable to control the amount of EUV radiation 122, 132, 134 delivered to the object 112 via the EUV radiation beam 122 or received by the detector system 130 by at least two orders of magnitude. In some embodiments, the radiation adjustment module 122 is operable to control the amount or dose of radiation by at least three orders of magnitude.

[0163] [000161] It should be understood that there may be various different mechanisms by which the radiation adjustment module 140 can control the dose of the radiation beam 122 and / or the intensity of the radiation 132, 134 received by the detector system 130. Advantageously, the dose of EUV radiation is designed to be suitable for measuring the reflectivity of a pellicle (less than 0.1%) and can be attenuated by up to three orders of magnitude when measuring highly reflective objects (greater than 10%, e.g., a reticle). The mechanisms by which the radiation adjustment module 140 can control the dose of the radiation beam 122 and / or the intensity of the radiation 132, 134 received by the detector system 130 may include, for example, (a) attenuating the EUV radiation using one or more thin-film filters (TMFs), (b) operating the radiation source 120a at a lower yield, (c) attenuating the radiation received by the radiation-sensitive parts of the reflectance sensor 136 and / or transmission sensor 138, (d) changing the purge gas or purge gas pressure in the path of the EUV radiation, and / or (e) shortening the detector capture time. Five examples of these will be considered below. It should be understood that each of these mechanisms can be used alone or in combination with other mechanisms.

[0164] [000162] In a first exemplary mechanism in which the radiation adjustment module 140 can control the dose of the radiation beam 122, the radiation adjustment module 140 comprises a plurality of filters (i.e., partial permeators) that are movable in and out of the path of the radiation beam (either upstream or downstream of the object 112 supported by the support 110) and each having a different transmittance.

[0165] [000163] This configuration allows the dose of radiation delivered to object 112 or detector system 130 to be controlled by moving multiple filters in and / or out of the path of the radiation beam. Each of the multiple filters may include a spectral purity filter (SPF).

[0166] [000164] Each of the filters may include a thin film filter (TMF). Each of the filters may comprise a film or membrane with a thickness in the range of 200 to 2000 nm. Each of the filters may contain one of the following: zirconium, niobium, ruthenium, or aluminum.

[0167] [000165] In some embodiments, the apparatus 100 further includes a movable support member, and a plurality of filters are supported by the support member, and the movable support member is movable so that each of the plurality of filter bodies can be placed in the path of the radiation beam 122. Such a configuration will be considered with reference to Figures 3A and 3B.

[0168] [000166] Figure 3A schematically shows a support member 200 equipped with a rotating body or wheels. Specifically, the support member 200 is rotatable about a rotation axis 202, as indicated by arrow 204. The support member 200 supports two filters 206, 208 (e.g., thin film filters) spaced apart from the rotation axis 202. Each of the two filters 206, 208 has a different EUV transmittance. A portion of the rotating body 200 is positioned in the path of the radiation beam 122. The optical axis of the radiation beam 122 is indicated by reference numeral 210 in Figure 3A. In Figure 3A, the support member 200 is oriented so that the first filter 206 of the filters is positioned in the path of the radiation beam 122. By rotating the rotating body 200 180° about the rotation axis 202, the second filter 208 of the filters can be moved into the path of the radiation beam 122. Therefore, by controlling the orientation of the support member 200, it is possible to select which of the two filters 206 and 208 is positioned in the path of the radiation beam 122 (upstream or downstream of the object 112 supported by the support 110). Since the two filters 206 and 208 have different EUV transmittances, the dose of radiation beam 122 delivered to the object 112 and the detector system 130 can be controlled. In this example, since two different doses can be selected (using the two different filters 206 and 208), it may be possible to allow the device 100 to operate in two different modes. For example, one of these modes may be suitable for inspecting the reticle MA, and the other of these modes may be suitable for inspecting the pellicle.

[0169] [000167] Figure 3B schematically shows a support member 250 having a translationable body configured to move in one linear direction, as indicated by arrow 252. The support member 250 supports two filters 254, 256 (e.g., thin film filters). Each of the two filters 254, 256 has a different EUV transmittance. A portion of the body 250 is positioned in the path of the radiation beam 122. The optical axis of the radiation beam 122 is indicated by reference numeral 258 in Figure 3B. In Figure 3B, the support member 250 is positioned such that the first filter 254 of the filters is positioned in the path of the radiation beam 122. By moving the body 250 in direction 252, the second filter 256 of the filters can be moved into the path of the radiation beam 122. Therefore, by controlling the position of the support member 250, it is possible to select which of the two filters 254, 256 is positioned in the path of the radiation beam 122 (upstream of the object 112 supported by the support 110). Since the two filters 254, 256 have different EUV transmittances, the dose of radiation delivered to the object 112 and / or the detector system 130 can be controlled. In this example, since two different intensities can be selected (using the two different filters 254, 256), it may be possible to allow the device 100 to operate in two different modes. For example, one of these modes may be suitable for inspecting the reticle MA, and the other of these modes may be suitable for inspecting the pellicle.

[0170] [000168] The two exemplary configurations shown in Figures 3A and 3B each comprise two filters 206, 208, 254, and 256 supported by support members 200 and 300, respectively, but it should be understood that in other embodiments, either type of support member 200 or 300 may comprise three or more filters.

[0171] [000169] In some embodiments, the apparatus 100 further includes a storage module for storing a plurality of filters (partially permeable filters) and a device for moving each of the filters between a storage location in the storage module and a usage location in the path of the radiation beam 122 or radiation beams 132, 134. The storage module may function as a library for storing a plurality of different filters. The apparatus may include a robotic arm or the like, which may be operable to take a filter from the library and place it in the usage location in the path of the radiation beams 122, 132, 134. Similarly, the apparatus 100 may be operable to take a filter from the usage location in the path of the radiation beams 122, 132, 134 and move it to the library for storage.

[0172] [000170] In a second exemplary mechanism in which the radiation adjustment module 140 can control the dose of radiation beams 122 and / or radiation beams 132, 134, the radiation adjustment module 140 comprises a radiation source adjustment mechanism of the radiation system 120.

[0173] [000171] For example, as described above, the radiation system 120 generally comprises a radiation source operable to generate radiation and one or more optical systems (e.g., including one or more spectral filters) configured to receive the radiation and deliver the radiation beam 122 to incident on an object 112 when it is supported by the support 110. In some embodiments, the radiation source itself may be tunable to control the dose of radiation. In some embodiments, the beamforming optical system or beam delivery optical system of the radiation system 120 may be tunable to control the dose of radiation.

[0174] [000172] In such embodiments, the dose of EUV pulses from the radiation source may be reduced when it is necessary to qualify a high reflectivity object. One simple mechanism for tuning the radiation source of the radiation system 120 is to adjust one or more parameters for operating the radiation source. For example, in the case of a discharge power supply, the operating voltage can typically be reduced from 10kV to 5kV, and the pulse yield decreases by more than 5 times. In a laser-generated plasma (LPP) source, the laser pulse energy may decrease with a yield decrease that is roughly proportional to the decrease in laser pulse energy. Attenuation of the EUV radiation beam by operating the radiation source with different parameters provides the option of attenuation by about 5 times.

[0175] [000173] In a third exemplary mechanism in which the radiation adjustment module 140 can control the dose of radiation 132, 134 received by the detector system 130, the radiation adjustment module 140 is operable to adjust the attenuation of radiation received by the radiation-sensitive parts of the reflectance sensor 136 and / or transmission sensor 138.

[0176] [000174] For example, in one example, the dose of radiation 122 incident on object 112 may be selected so that sensors 136, 138 receiving EUV radiation 132, 134 interacting with object 112 at a low dose receive an appropriate dose of EUV radiation (e.g., within the dynamic range of the sensors). Other EUV radiation 132, 134 interacting with object 112 (which has a high intensity) may be attenuated by the radiation adjustment module 140 so that sensors 136, 138 receiving it receive an appropriate dose of EUV radiation (e.g., within the dynamic range of the sensors). Advantageously, this may make it possible to perform simultaneous measurements using both the reflectance sensor 136 and the transmission sensor 138 with the same incident radiation beam 112 (while maintaining the radiation received by both the reflectance sensor 136 and the transmission sensor 138 within the dynamic range of the sensors).

[0177] [000175] In a fourth exemplary mechanism in which the radiation adjustment module 140 can control the dose of radiation 132, 134 received by the detector system 130, the radiation adjustment module 140 is operable to control one or more parameters of the beamline purge gas. For example, the radiation adjustment module 140 may be operable to control the type of purge gas and / or the beamline purge gas pressure.

[0178] [000176] In such embodiments, the beam path behind the radiation system 120 may be purged with argon at a pressure of about 1 Pascal to obtain an EUV transmittance of more than 93%. The EUV radiation beams 122, 132, and 134 can be attenuated by (a) operating at a higher beamline pressure, or (b) using a different beamline gas (for example, nitrogen, oxygen, neon, and xenon are all applicable). For example, by operating the apparatus 100 with xenon gas at a pressure of 1 Pa, the EUV transmittance is reduced threefold to about 30%.

[0179] [000177] In a fifth exemplary mechanism in which the radiation adjustment module 140 can control the dose of radiation 132, 134 received by the detector system 130, the radiation adjustment module 140 can be operated to control the exposure time of the detector system 130. For example, the radiation adjustment module 140 may be operated to control the time that the radiation beam 122 is incident on the object 112, and therefore the time that the radiation beams 132, 134 are received by the detector system 130.

[0180] [000178] For example, in some embodiments, the acquisition time for measuring the pellicle may be approximately 50 seconds. It is possible to reduce the acquisition time to about 1 second, thereby obtaining an attenuation coefficient of 50.

[0181] [000179] In some embodiments, the radiation adjustment module 140 is operable to control the orientation of the radiation beam 122 with respect to the object 112.

[0182] [000180] The orientation of the radiation beam 122 with respect to the object 112 may be specified by one or more angles. Generally, the orientation of the radiation beam 122 with respect to the object 112 may be specified by two angles, namely the angle of incidence θ and the azimuth angle φ, as will be described below with reference to Figure 4.

[0183] [000181] Figure 4 shows the surface 112a of object 112 when supported by the support 110. Also shown are the normal 112b of surface 112a, the incident radiation beam 122 delivered by the radiation system 120, and the portion 132 of the radiation reflected from object 112. Figure 4 also shows a set of right-handed Cartesian coordinate axes in which the surface 112a of object 112 onto which the radiation beam 122 is incident coincides with the xy plane, and the normal 112b of that plane is parallel to the z axis.

[0184] [000182] As shown in Figure 4, the incident angle θ of the radiation beam 122 is the angle between the normal 112b of the surface 112a of the object 112 and the propagation direction of the radiation beam 122. Furthermore, the azimuth angle φ is the angle between the projection line 122a, obtained by projecting the propagation direction of the radiation 122 onto the plane of the object 112, and the reference direction (the x-direction in this example).

[0185] [000183] In some embodiments, the radiation adjustment module 140 is operable to control the incident angle θ of the radiation beam 122 with respect to the object 112. Generally, it may be desirable to inspect or qualify the object 112 using radiation 122 that is roughly consistent with the radiation that will be received when used in a lithography apparatus LA. For example, it may be desirable to use radiation having the same spectrum (center wavelength and bandwidth) and the same incident angle θ as radiation B used in a lithography tool LA. Different lithography tools LA may project radiation onto an object at different incident angles. Therefore, advantageously, by controlling the incident angle θ, the apparatus 100 may be suitable for inspecting objects used in various EUV lithography tools LA.

[0186] [000184] Additionally or alternatively, in some embodiments, the radiation adjustment module 140 is operable to control the azimuth angle φ, i.e., the angle between the projection line of the radiation beam propagation direction onto the object surface and the reference direction. By controlling the azimuth angle φ of the radiation 122, it may be possible to perform measurements at multiple azimuth angles. Advantageously, this may allow the apparatus 100 to distinguish whether a contaminant detected on the reticle-pellicle assembly 15 is on the pellicle 19 or on the reticle MA. For example, the image of the contaminant may move within the reflectance map as a function of the azimuth angle φ, and such movement may differ depending on whether the contaminant is on the reticle MA or on the pellicle 19. For example, two reflectance maps may be determined with the radiation at a fixed incidence angle θ, but approaching from opposite sides of the object (e.g., φ=0 and φ=180°), and the movement of the image of the contaminant between the two reflectance maps may be used to determine whether the contaminant is on the reticle MA or on the pellicle 19.

[0187] [000185] Generally, in order to control the orientation of the radiation beam 122 relative to the object 112, the radiation adjustment module 140 may be operable to control the propagation direction of the radiation beam 122 and / or the position or orientation of the object 112 supported by the support 110.

[0188] [000186] Generally, the apparatus 100 further comprises a chamber 160 in which the support 110 is disposed, as will be further discussed below with reference to Figures 5A to 6C. The chamber 160 is configured to provide a controlled atmosphere for inspecting the object 112. The chamber 160 may be sealable. The chamber 160 may be a vacuum chamber. In some embodiments, the support 110, the radiation system 120, and the detector system 130 are all disposed within the chamber 160. The chamber 160 is sometimes referred to as the inspection chamber.

[0189] [000187] In some embodiments, the apparatus 100 further includes a load lock 170 that forms an interface between the chamber 160 and the surrounding environment, as will be further discussed below with reference to Figures 5A to 6C. A support 110 (also called a stage apparatus) may be configured to receive an object 112 from the load lock 170 and move the object 112 within the chamber 170.

[0190] [000188] In some embodiments, the apparatus 100 further includes a transfer mechanism configured to transfer an object 112 from the load lock 170 to the support 110 and vice versa, as will be further discussed below with reference to Figures 5A to 6C. The transfer mechanism may be located at least partially within the load lock 170. Additionally or alternatively, the transfer mechanism may be mounted on the support 110 (also called the stage apparatus).

[0191] [000189] The load lock 170 may include a first door, a second door, and a load lock chamber, the first door being configured to isolate the surrounding environment from the load lock chamber, and the second door being configured to isolate the chamber 160 from the load lock chamber.

[0192] [000190] In some embodiments, the chamber 160 may include one or more parking positions 180 for temporarily storing objects, as will be further discussed below with reference to Figures 5A to 6C. The support 110 may be configured to transport objects 112 from the support 110 to each of the parking positions 180 and vice versa.

[0193] [000191] In some embodiments, the apparatus 100 may further include a second load lock that forms an interface between the chamber and the surrounding environment, as will be further discussed below with reference to Figures 5A to 6C.

[0194] [000192] Some embodiments of the present disclosure relate to the manufacture of components used in an apparatus. The apparatus may be a lithography apparatus such as an extreme ultraviolet (EUV) lithography apparatus LA that can be used to manufacture integrated circuit chips (a schematic is described above with reference to Figure 1).

[0195] [000193] During the manufacturing of a component, it may be desirable to test the component to ensure that it meets certain standards. Some tests may be performed in a specific environment, such as a vacuum environment. This may be located inside a vacuum chamber (e.g., chamber 160 shown in Figure 2). Naturally, it should be understood that other processing, measurement, or handling of the component may also be performed inside the vacuum chamber. To maintain the vacuum environment inside the vacuum chamber, a pre-chamber (also known as a load lock) may be provided (e.g., load lock 170 shown in Figure 2). The component can be inserted into the load lock under ambient pressure. The load lock is then sealed and the air is evacuated until a vacuum matching the vacuum of the vacuum chamber is widely distributed within the load lock. The load lock is then opened relative to the vacuum chamber, and the component can be moved from the load lock to the vacuum chamber in preparation for testing or other procedures. To remove the component from the vacuum chamber, this process is reversed. In other words, the component is transferred to the load lock under vacuum, and the load lock is detached from the vacuum chamber. Ambient pressure is then restored to the load lock by introducing air into the space within the load lock. Once ambient pressure is reached, the load lock can be opened and the components can be removed.

[0196] [000194] For sensitive and delicate components such as the pellicle 19 of the EUV lithography system LA, pumping and venting times may be several hours in order to maintain the mechanical integrity of the component by keeping the pressure difference low and to reduce the risk of contamination by keeping the gas flow velocity low. This is significantly longer than the time it takes to test the component in a vacuum chamber, and can be, for example, up to twice as long.

[0197] [000195] Two solutions to the above problem will now be explained with reference to Figures 5 and 6, respectively.

[0198] [000196] According to the first solution, the apparatus 100 (shown in Figure 2 and of the type described above) comprises a vacuum chamber 160 and a load lock 170 that forms an interface between the vacuum chamber 160 and the surrounding environment. A support 110 (also referred to herein as a stage apparatus) is configured to receive an object 112 from the load lock 170 and move the object 112 within the vacuum chamber 160. It should be understood that the apparatus 100 may further comprise any of the features disclosed above with reference to Figure 2. However, for the sake of understanding the first solution, some features are not shown in Figures 5A to 5F.

[0199] [000197] Furthermore, according to the first solution, in order to reduce the total manufacturing time and / or testing time, and more specifically to improve the throughput of the component / object 112, it is proposed to use part of the vacuum chamber 160 for storing the component so that the loading and / or unloading stages of the first object 112 can be performed at the same time as the second object 112 is being tested.

[0200] [000198] Specifically, in embodiments of the present disclosure, the vacuum chamber 160 of the apparatus 100 includes a first parking position and a second parking position. According to one embodiment, the parking position refers to a position or location where a component or object 112 can be temporarily stored.

[0201] [000199] Accordingly, according to a first embodiment of the present disclosure, it is proposed to provide two parking positions within the vacuum chamber 160. By applying two parking positions within the vacuum chamber 160, as shown below, the operation of the load lock 170, e.g., blowing air out of or into the load lock 170, while the first object 112 is inside the load lock 170, can be performed simultaneously with the processing of the second object 112 located inside the vacuum chamber 160, e.g., inspection. Possible steps in this process are further shown in Figures 5A to 5F below. Figures 5A to 5F schematically show a plan view of an apparatus 100 according to one embodiment. In the embodiment shown in the figures, the inspection apparatus comprises a vacuum chamber 160, a load lock 170, and a support (stage apparatus) 110, and the vacuum chamber 160 includes two parking positions 182 and 184, also indicated as PP1 and PP2.

[0202] [000200] In some embodiments, a load lock, such as a load lock 170, may be considered an interface between a first atmosphere and a second atmosphere, such as an ambient atmosphere or an ambient environment and a vacuum environment. Such a load lock may comprise, for example, a first door (dotted line) 172, a second door 174, and a load lock chamber 176. The first door 172 is configured to separate the ambient environment from the load lock chamber 176. The second door 174 is configured to separate the vacuum chamber 110 from the load lock chamber 176. Generally, the load lock chamber 176 needs to be large enough to accommodate a component, such as product A or product B.

[0203] [000201] Figure 5A shows the apparatus 100 in a first process step in which a first component (product A, e.g., a pellicle) is measured or inspected in a vacuum chamber 160, while a second component (product B) is loaded into a load lock 170. In the embodiment shown in the figure, the stage apparatus 110 comprises an X stage 110a and a Y stage 110b. The X stage 110a is configured to move an object 112 (product A in Figure 5A) supported by the stage apparatus 110 in the X direction. The Y stage 110b is configured to move product A in the Y direction.

[0204] [000202] The load lock 170 is disconnected from the vacuum chamber 160, i.e., the door 174 is closed. After product B is loaded into the load lock 170, specifically into the load lock chamber 176, the first door 172 can also be closed, allowing air to be expelled from the load lock chamber 176. This process of expelling air can be carried out while product A is being measured.

[0205] [000203] In the second step shown in Figure 5B, product A is moved to a first storage area (parking position 1, PP1, 182). In some embodiments, this step can be performed by, for example, a stage device 110, specifically an X stage 110a and a Y stage 110b. In some embodiments, the stage device 110 may include, for example, one or more linear motors, such as a linear motor for moving object 112 along the X direction and a linear motor for moving object 112 along the Y direction.

[0206] [000204] In the third step shown in Figure 5C, the load lock door 174 to the vacuum chamber 160 is opened, product B is removed from the load lock 170 and moved into the vacuum chamber 160, while product A remains in the first storage area 182.

[0207] [000205] In the fourth step shown in Figure 5D, product B is moved to a second storage area (parking position 2, PP2, 184). In the embodiment shown in the figure, the load lock 170 includes a transfer mechanism 190 configured to transfer object 112 from the load lock 170 to the stage device 110 and vice versa. It can be noted that such a transfer mechanism may also be located on the stage device 110 or elsewhere within the vacuum chamber 160. In one embodiment, the end 192 of the transfer mechanism 190 may be configured, for example, to hold object 112 and to raise and lower object 112.

[0208] [000206] In the fifth step shown in Figure 5E, product A is returned from the first storage area 182 to the load lock 170. In this regard, it can be noted that this transfer can be performed by the stage device 110 by applying two parking positions PP1 and PP2. Thus, by using two parking positions, it is not necessary to install or use an additional transfer robot in the vacuum chamber 160.

[0209] [000207] Finally, in the sixth step shown in Figure 5F, the load lock 170 is sealed, i.e., the load lock door 174 is closed, and the environment is returned to ambient conditions while product B is being tested. Once the load lock 170 is returned to ambient conditions, product A can be unloaded.

[0210] [000208] By using the first and second storage areas 182 and 184 within the vacuum chamber 160, the measurement cycle time can be reduced by approximately 1.5 times. Specifically, this is because the second component / object 112 may be loaded or unloaded while the first component / object 112 is being measured. In this configuration, the loading / unloading time of one component / object 112 overlaps with the measurement process time of another component / object 112, thereby improving the throughput of the components being inspected / measured and reducing the total processing time.

[0211] [000209] According to the second solution, a second load lock may be used. In this configuration, the loading and unloading of two different objects 112 may occur simultaneously. For example, while the first component 112 is being measured / inspected, the second component 112 may be unloaded after the previous measurement / inspection, and the third component 112 may be loaded before the subsequent measurement / inspection. This process may reduce the measurement cycle time by up to twofold. This may result in a significant improvement in throughput, and thus reduce the number of manufacturing equipment and / or cleanroom space required to manufacture the components / objects 112.

[0212] [000210] Possible steps of using the vacuum chamber 160 having two load locks are shown in Figures 6A to 6C. Figures 6A to 6C schematically show cross-sectional views in the vertical plane (XZ plane).

[0213] [000211] Figure 6A shows an apparatus 100 according to an embodiment of the present disclosure. In the embodiment shown in the figure, the apparatus 100 comprises a vacuum chamber 160 having two load locks 170a and 170b. Three components (products A, B, and C), for example, objects 112 used in an EUV lithography apparatus, are located in the vacuum chamber 160 and the two load locks 170a and 170b, respectively. The load locks 170a and 170b may have a structure similar to, for example, load lock 170, i.e., including a first door, a second door, and a load lock chamber, as described above. In the embodiment shown in the figure, product A has already been processed in the vacuum chamber 160 and moved to the second load lock 170b. The second load lock 170b is detached from the vacuum chamber 160 and returned to ambient conditions in preparation for unloading product A. Product B is loaded into the vacuum chamber 160 from the first load lock 170a for processing. Subsequently, the first load lock 170a is detached from the vacuum chamber 160 and returned to ambient conditions so that product C can be loaded into the first load lock 170a. Figures 6A to 6C further schematically show a stage device 110 located inside the vacuum chamber 160. In the embodiment shown in the figures, the load locks 170a and 170b further include transfer mechanisms 190a and 190b for transferring the object 112 from the load lock chamber to the vacuum chamber 160 and vice versa.

[0214] [000212] Next, while product B is measured and / or processed in the vacuum chamber 160, the first load lock 170a containing product C can be moved from ambient pressure to a vacuum. Subsequently, product A is unloaded from the second load lock 170b, and the second load lock 170b is then returned to a vacuum in preparation for receiving product B. The door separating the second load lock 170b from the vacuum chamber 160 is then opened, and product B is transported to the second load lock 170b after the measurement / inspection process is complete. This is shown in Figure 3B.

[0215] [000213] At the same time, the first load lock 170a is kept under vacuum conditions so that product C can be passed into the vacuum chamber 160.

[0216] [000214] When the first load lock 170a is brought under vacuum conditions, the door 174a that separates the first load lock 170a from the vacuum chamber 160 opens, and product C is transferred to the vacuum chamber 160. At the same time, the second load lock 170b is detached from the vacuum chamber 160 and can be evacuated to ambient pressure so that product B can be unloaded. Finally, measurement, inspection and / or processing of product C can be performed while the next components are loaded into the first load lock 170a. These steps are schematically shown in Figure 3C.

[0217] [000215] References to masks or reticles in this book may be interpreted as references to patterning devices (masks or reticles are examples of patterning devices), and these terms may be used interchangeably. In particular, the term mask assembly is synonymous with reticle assembly and patterning device assembly. Furthermore, the term reticle assembly may be used interchangeably with the term reticle-pellicle assembly.

[0218] [000216] While the text specifically refers to embodiments of the present invention in relation to lithography apparatus, embodiments of the present invention may be used in other apparatuses. Embodiments of the present invention may constitute part of a mask inspection apparatus, a metrology apparatus, or any apparatus for measuring or processing objects such as wafers (or other substrates) or masks (or other patterning devices). These apparatuses are sometimes commonly referred to as lithography tools. Such lithography tools may operate under vacuum conditions or ambient (non-vacuum) conditions.

[0219] [000217] The term "EUV radiation" is sometimes considered to encompass electromagnetic radiation having wavelengths in the range of 4 to 20 nm, for example, in the range of 13 to 14 nm. EUV radiation may have wavelengths less than 10 nm, for example, in the range of 4 to 10 nm, such as 6.7 nm or 6.8 nm.

[0220] [000218] Although this text specifically refers to the use of lithography equipment in the manufacture of ICs, it should be understood that lithography equipment described herein may have other applications. Other possible applications include the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memory, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, and the like.

[0221] [000219] While specific embodiments of the present invention have been described above, it will be understood that the present invention can be implemented in ways other than those described. The above description is illustrative and not limiting. Accordingly, it will be apparent to those skilled in the art that modifications to the described invention can be made without departing from the following claims and clauses. 1. An apparatus for determining one or more properties of an object used in an extreme ultraviolet (EUV) lithography apparatus, Support for supporting objects, A radiation system capable of generating a radiation beam containing EUV radiation and delivering the radiation beam to incident on an object supported by a support, A detector system capable of receiving EUV radiation interacting with an object while it is supported by a support, A device comprising a radiation tuning module that is operable to adjust one or more characteristics of radiation delivered to an object or radiation received by a detector system, so as to determine the characteristics of multiple different objects, each having different characteristics. 2. The apparatus of Clause 1, wherein the radiation adjustment module is operable to determine the characteristics of the pellicle, pellicle assembly, reticle, or reticle-pellicle assembly. 3. The radiation adjustment module, EUV-transparent objects with EUV transmittance ranging from 0.01% to 100%. EUV reflective objects having an effective EUV reflectivity in the range of 0.1% to 75%, and / or An apparatus according to Clause 1 or Clause 2, which is operable to determine any of the properties of an EUV reflective object having an effective EUV reflectance in the range of 0.002% to 0.2%. 4. The following characteristics of the object, namely Effective band EUV transmission, Effective band EUV reflection, In-band EUV scattering, photoelectron emission, The effective in-band EUV curvature of the object, and / or Spectral function curves of EUV reflection, transmission, or scattering A device according to any one of the clauses 1 to 3, which is operable to determine one or more of the following. 5. An apparatus according to any one of the clauses 1 to 4, wherein the apparatus is operable to operate in one or more different operating modes, and any two operating modes differ in at least one of the characteristics of the radiation beam delivered to the object or the radiation received by the detector system. 6. The apparatus according to any one of clauses 1 to 5, wherein the detector system comprises a reflectance sensor configured to receive a portion of a radiation beam delivered to an object that is reflected by the object. 7. The apparatus according to any one of clauses 1 to 6, wherein the detector system comprises a transmission sensor configured to receive a portion of a radiation beam delivered to an object that is transmitted through the object. 8. The apparatus of any one of the clauses 1 to 7, comprising a detector system comprising at least one spectrometer with a detector capable of determining spectrally resolved reflectance and / or transmission from an object supported by a support. 9. An apparatus according to any one of clauses 1 to 8, wherein the radiation adjustment module is operable to control the amount of radiation delivered to an object via a radiation beam or received by a detector system. 10. The apparatus of Clause 9, wherein the radiation adjustment module is operable to control the amount of EUV radiation delivered to an object via the radiation beam or received by a detector system by at least two orders of magnitude. 11. The apparatus of Clause 9 or Clause 10, wherein the radiation adjustment module comprises a plurality of filters that are accessible in and out of the path of the radiation beam, each having a different transmittance. 12. The apparatus of clause 11, further comprising a movable support member, wherein a plurality of filters are supported by the support member, and the movable support member is movable so that each of the filters can be placed in the path of the radiation beam. 13. The apparatus of Clause 11, further comprising a storage module for storing multiple filters, and a device for moving each of the filters between a storage location within the storage module and a usage location within the path of the radiated beam. 14. An apparatus according to any one of the clauses 11 to 13, wherein each of the multiple filters comprises a film or membrane having a thickness in the range of 200 to 2000 nm. 15. An apparatus according to any one of the clauses 11 to 14, wherein each of the filters contains either zirconium, niobium, ruthenium, or aluminum. 16. A device under any one of the paragraphs 1 to 15, in which the radiation adjustment module comprises a mechanism for adjusting the radiation source of the radiation system, directly or indirectly dependent on paragraph 9 or paragraph 10. 17. An apparatus of any one of Clauses 1 to 16, as directly or indirectly dependent on Clause 9 or Clause 10, wherein the radiation adjustment module is operable to adjust the amount of radiation that interacts with an object while it is supported by a support before it is received by a detector system. 18. An apparatus under any one of the clauses 1 to 17, where the radiation adjustment module is operable to control one or more parameters of the beamline purge gas, directly or indirectly dependent on clause 9 or clause 10. 19. An apparatus of any one of Clauses 1 to 18, as directly or indirectly dependent on Clause 9 or Clause 10, wherein the radiation adjustment module is operable to control the amount of radiation dose received by the detector system by controlling the exposure time of the detector system. 20. An apparatus of any one of the clauses 1 to 19, wherein the radiation adjustment module is operable to control the direction of the radiation beam relative to an object. 21. An apparatus according to any one of the clauses 1 to 20, wherein the radiation adjustment module is operable to control the angle of incidence of the radiation beam to an object. 22. An apparatus according to any one of the clauses 1 to 21, wherein the radiation adjustment module is operable to control the angle between the projection of the direction of propagation of the radiation beam onto the surface of an object and the reference direction. 23. The radiation system A radiation source capable of generating radiation, An apparatus according to any one of the clauses 1 to 22, comprising a beamforming optical system configured to receive radiation and deliver the radiation beam to incident on an object supported by a support. 24. An apparatus of any one of the clauses 1 to 23, wherein the radiation system is operable to operate in any one of several different operating modes, each having a different wavelength and / or bandwidth. 25. An apparatus according to any one of Clauses 1 to 24, wherein the emission system is operable to operate in a narrowband operating mode having a central wavelength of 13.52 nm and a bandwidth of 2% for EUV emission. 26. An apparatus according to any one of Clauses 1 to 25, wherein the emission system is operable to operate in a broadband operating mode, which includes emission having a spectral region of 12 nm to 16 nm for EUV emission. 27. An apparatus of any one of the clauses 1 to 26, as directly or indirectly dependent on clause 23, wherein the beamforming optical system comprises at least one mirror having a multilayer stack configured to reflect EUV radiation and perform spectral filtering. 28. The apparatus of any one of the clauses 1 to 27, as directly or indirectly dependent on clause 23, further comprising a spectral purity filter disposed between the radiation source and the support and configured to block visible radiation, infrared radiation, and ultraviolet radiation. 29. The apparatus of any one of the clauses 1 to 28, further comprising a monitoring system capable of determining the intensity of a radiation beam. 30. The apparatus of any one of the clauses 1 to 29, wherein the support is a frame for supporting an object, comprising a frame defining a central opening. 31. An apparatus according to any one of the clauses 1 to 30, wherein the radiation system comprises a spectral purity filter (SPF) located upstream of the support in the optical path. 32. The apparatus of any one of the clauses 1 to 31, further comprising a moving mechanism capable of moving a support relative to a radiation beam delivered by a radiation system. 33. An apparatus according to any one of the clauses 1 to 32, wherein the support comprises a holder for holding an object. 34. An apparatus of any one of the clauses 1 to 33, wherein the radiation adjustment module is operable to control the geometry of the radiation beam. 35. Chambers with supports installed inside, The apparatus according to any one of the clauses 1 to 34, further comprising a load lock that forms an interface between the chamber and the surrounding environment. 36. The apparatus of Clause 35, further comprising a transfer mechanism configured to transfer an object from a load lock to a support and vice versa. 37. The apparatus of Clause 35 or 36, wherein the load lock comprises a first door, a second door, and a load lock chamber, wherein the first door is configured to isolate the surrounding environment from the load lock chamber, and the second door is configured to isolate the chamber from the load lock chamber. 38. The apparatus according to any one of the clauses 35 to 37, wherein the chamber comprises a first parking position and a second parking position for temporarily storing an object. 39. The apparatus of Clause 38, wherein the support is configured to transport an object from the support to a first parking position and vice versa, and the support is configured to transport an object from the support to a second parking position and vice versa. 40. The apparatus of any one of the clauses 1 to 39, further comprising a second load lock that forms an interface between the chamber and the surrounding environment.

Claims

1. An apparatus for determining one or more properties of an object used in an extreme ultraviolet (EUV) lithography apparatus, Support for supporting objects, A radiation system capable of generating a radiation beam containing EUV radiation and delivering the radiation beam so as to be incident on an object supported by the support, A detector system capable of receiving EUV radiation interacting with an object while it is supported by the aforementioned support, A device comprising: a radiation tuning module that is operable to adjust one or more characteristics of the radiation beam delivered to the object or the radiation received by the detector system so as to determine the characteristics of a plurality of different objects, each having different characteristics.

2. The apparatus according to claim 1, wherein the radiation adjustment module is operable to determine the characteristics of the pellicle, pellicle assembly, reticle, or reticle-pellicle assembly.

3. The radiation adjustment module, EUV-transmitting objects with an EUV transmittance ranging from 0.01% to 100%. EUV reflective objects having an effective EUV reflectance in the range of 0.1% to 75%, and / or The apparatus according to claim 1 or 2, which is operable to determine any property of an EUV reflective object having an effective EUV reflectance in the range of 0.002% to 0.2%.

4. The following properties of an object, namely Effective band EUV transmission, Effective band EUV reflection, In-band EUV scattering, photoelectron emission, The effective in-band EUV curvature of the object, and / or Spectral function curves of EUV reflectance, transmission, or scattering An apparatus according to any one of claims 1 to 3, which is operable to determine one or more of the following.

5. The apparatus according to any one of claims 1 to 4, wherein the apparatus is operable to operate in one or more different operating modes, and any two operating modes differ in at least one of one or more characteristics of the radiation beam delivered to the object or the radiation received by the detector system.

6. The detector system, A reflection sensor configured to receive a portion of the radiation beam delivered to the object that is reflected by the object, and / or The apparatus according to any one of claims 1 to 5, comprising a transmission sensor configured to receive a portion of the radiation beam delivered to the object, the portion that is transmitted through the object.

7. The apparatus according to any one of claims 1 to 6, wherein the detector system comprises at least one spectrometer having a detector that is operable to determine spectrally resolved reflectance and / or transmission from an object supported by the support.

8. The apparatus according to any one of claims 1 to 7, wherein the radiation adjustment module is operable to control the amount of radiation delivered to the object via the radiation beam or received by the detector system.

9. The apparatus of claim 8, wherein the radiation adjustment module is operable to control the amount of EUV radiation delivered to the object via the radiation beam or received by the detector system by at least two orders of magnitude.

10. The apparatus according to claim 8 or 9, wherein the radiation adjustment module comprises a plurality of filters that can enter and exit the path of the radiation beam, each having a different transmittance.

11. The apparatus according to any one of claims 10, wherein each of the plurality of filters comprises a film or membrane having a thickness in the range of 20 to 2000 nm.

12. The apparatus according to claim 10 or 11, wherein each of the plurality of filters comprises zirconium, niobium, ruthenium, or aluminum.

13. The apparatus according to any one of claims 1 to 12, in which the radiation adjustment module comprises a mechanism for adjusting the radiation source of the radiation system, directly or indirectly dependent on claim 8 or claim 9.

14. The apparatus of any one of claims 1 to 13, in which the radiation adjustment module is operable to adjust the amount of radiation that interacts with the object while it is supported by the support before it is received by the detector system, directly or indirectly dependent on claim 8 or claim 9.

15. The apparatus according to any one of claims 1 to 14, in which the radiation adjustment module is operable to control the amount of radiation dose received by the detector system by controlling the exposure time of the detector system, as directly or indirectly dependent on claim 8 or claim 9.

16. The radiation adjustment module, a) Control the direction of the radiation beam relative to the object, and / or b) Controlling the angle of incidence of the radiation beam to the object, and / or c) The apparatus of any one of claims 1 to 15, which is operable to control the angle between the projection of the propagation direction of the radiant beam onto the surface of the object and a reference direction.

17. The apparatus according to any one of claims 1 to 16, wherein the radiation system is operable to operate in any one of a plurality of different operating modes, each having a different wavelength and / or bandwidth.

18. The apparatus according to any one of claims 1 to 17, wherein the radiation system is operable to operate in a narrowband operating mode having a central wavelength of 13.52 nm and a bandwidth of 2%.

19. The apparatus according to any one of claims 1 to 18, wherein the emission system is operable to operate in a broadband operating mode in which the EUV emission includes emission having a spectral region of 12 nm to 16 nm.

20. The apparatus according to any one of claims 1 to 19, wherein the radiation adjustment module is operable to control the geometry of the radiation beam.

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