Film deep ultraviolet reflectivity mapping method, film deep ultraviolet reflectivity mapping instrument and photoetching exposure method

Abstract

The invention discloses a film deep ultraviolet reflectivity mapping method, a film deep ultraviolet reflectivity mapping instrument and a photoetching exposure method. A two-dimensional deep ultraviolet reflectance map of an extreme ultraviolet (EUV) thin film is obtained using a deep ultraviolet (DUV) reflectance measurement assembly having a deep ultraviolet (DUV) light source and a DUV spectrophotometer. A representation of the two-dimensional DUV reflectance map may be displayed. Additionally or alternatively, a determination may be made as to whether an EUV film is available for EUV lithography without a dynamic airlock DUV light reflecting film by analyzing a two-dimensional DUV reflectance map, and an indication of the determination is output. In response to determining that the EUV thin film is available, the EUV thin film may be mounted on an EUV lithography mask to form an EUV mask assembly, and EUV lithography may be performed using the EUV mask assembly to form an EUV photolithography on and / or in an EUV photosensitive photoresist layer disposed on the surface of the semiconductor wafer, and / or in an EUV photosensitive photoresist layer disposed on the surface of the semiconductor wafer. A latent image of a pattern of EUV reflecting and absorbing regions of the photomask is formed.

Description

Technical Field

[0001] The embodiments of the present invention relate to a thin film deep ultraviolet reflectivity mapping method, a thin film deep ultraviolet reflectivity mapping instrument and a photolithography exposure method. Background Art

[0002] The following are related to the semiconductor device field, integrated circuit (IC) field and related fields. Summary of the invention

[0003] The embodiment of the present invention provides a method for mapping the deep ultraviolet reflectivity of a thin film. The method for mapping the deep ultraviolet reflectivity of a thin film includes: obtaining a two-dimensional deep ultraviolet reflectivity map of an extreme ultraviolet thin film using a deep ultraviolet reflectivity measurement component; and a representation diagram showing the two-dimensional deep ultraviolet reflectivity map. The deep ultraviolet reflectivity measurement component includes: a deep ultraviolet light source configured to emit deep ultraviolet light onto the extreme ultraviolet thin film to generate reflected deep ultraviolet light reflected by the extreme ultraviolet thin film, and a deep ultraviolet spectrophotometer configured to measure the intensity of the reflected deep ultraviolet light as a function of wavelength or photon energy.

[0004] The embodiment of the present invention provides a thin film deep ultraviolet reflectivity mapper. The thin film deep ultraviolet reflectivity mapper includes: a base; a thin film platform configured to support an associated extreme ultraviolet film; a deep ultraviolet reflectivity measurement component; and a motorized component fixed to the base and configured to scan deep ultraviolet light on the associated extreme ultraviolet film in two mutually orthogonal directions by moving the thin film platform and / or the deep ultraviolet reflectivity measurement component relative to the base. The deep ultraviolet reflectivity measurement component includes (i) a deep ultraviolet light source configured to emit deep ultraviolet light onto the associated extreme ultraviolet film supported by the thin film platform to generate reflected deep ultraviolet light reflected by the extreme ultraviolet film, and (ii) a deep ultraviolet spectrophotometer configured to measure the intensity of the reflected deep ultraviolet light as a function of wavelength or photon energy.

[0005] The embodiment of the present invention provides a photolithography exposure method. The photolithography exposure method includes: obtaining a two-dimensional deep ultraviolet reflectivity map of an extreme ultraviolet film; determining that the deep ultraviolet reflectivity of the extreme ultraviolet film is less than a maximum deep ultraviolet reflectivity threshold by analyzing the two-dimensional deep ultraviolet reflectivity map; and in response to determining that the deep ultraviolet reflectivity of the extreme ultraviolet film is less than the maximum deep ultraviolet reflectivity threshold, performing extreme ultraviolet photolithography using an extreme ultraviolet mask assembly including an extreme ultraviolet mask and an extreme ultraviolet film mounted on the extreme ultraviolet mask, so as to form a latent image of a pattern of extreme ultraviolet reflection areas and absorption areas of the photomask on an extreme ultraviolet light-sensitive photoresist layer disposed on a semiconductor wafer surface and / or in an extreme ultraviolet light-sensitive photoresist layer disposed on a semiconductor wafer surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The various aspects of the present disclosure will be best understood by reading the following detailed description in conjunction with the accompanying drawings. It should be noted that, in accordance with industry standard practice, various features are not drawn to scale. In fact, for the sake of clarity of discussion, the size of various features can be arbitrarily increased or reduced.

[0007] Figure 1 An extreme ultraviolet lithography system including an extreme ultraviolet (EUV) light source and an EUV scanner is schematically illustrated, and further illustrated is a method for evaluating deep ultraviolet (DUV) reflectivity of an EUV film used with an EUV photomask employed in the EUV scanner, wherein the method utilizes a DUV mapping device.

[0008] Figure 2 and Figure 3 A side view and a top view of an EUV film DUV mapping device are schematically shown, respectively.

[0009] Figure 4 A top view of an EUV film DUV mapping apparatus according to another embodiment is schematically shown.

[0010] Figure 5 A method of operating an EUV film DUV mapping apparatus to evaluate an EUV film is schematically illustrated.

[0011] Description of Reference Numerals

[0012] 10: Extreme ultraviolet light source

[0013] 12: EUV Scanner

[0014] 14: Vacuum chamber

[0015] 16: EUV light collecting mirror

[0016] 18: Vacuum port / port

[0017] 20: Port

[0018] 22: Extreme ultraviolet light

[0019] 24: Lighting module

[0020] 30: EUV lithography masks / photomasks

[0021] 32: Photomask holder

[0022] 34: Thin Film / EUV Thin Film

[0023] 36: Frame / film frame / mounting seat

[0024] 38: Semiconductor chips

[0025] 40: Chip holder

[0026] 42: Projection module

[0027] 44: Dynamic air lock

[0028] 50 alt :Thin Film DUV Reflectivity Mapper

[0029] 52, 56, 110, 112, 114, 116, 120, 122: Operation

[0030] 54: EUV film components

[0031] 58: Operation / EUV film usability test / film DUV reflectivity mapping method

[0032] 60: Operation / EUV film availability test / evaluation operation

[0033] 62: Maximum DUV reflectivity threshold

[0034] 64: Controller

[0035] 66: Display

[0036] 68: User input devices

[0037] 70: Base

[0038] 72: Thin film platform

[0039] 74: DUV reflectivity measurement component

[0040] 76: Deep UV light source

[0041] 78: DUV spectrophotometer

[0042] 80: Electric assembly / first mechanism / first linear translation mechanism

[0043] 80 alt :Electric assembly / first linear translation mechanism

[0044] 80a: First straight track

[0045] 80b: Second straight track

[0046] 82: Electric assembly / second mechanism / second linear translation mechanism

[0047] 82 alt :Electric assembly / second linear translation mechanism

[0048] 84: Film platform holder

[0049] 90: Rotary motor

[0050] 92: Rotating unit housing

[0051] 94: Circular orbit

[0052] 96: Incident position

[0053] 100: Limit Detector

[0054] 102: Electrical cables

[0055] A1, A2: Graphic arrows

[0056] X, Y, Z: direction DETAILED DESCRIPTION

[0057] The following disclosure provides many different embodiments or examples for implementing the different features of the provided target. Specific examples of components and arrangements are described below to simplify the disclosure. Of course, these are only examples and are not intended to be limiting. For example, the following description of forming a first feature on or on a second feature may include an embodiment in which the first feature and the second feature are formed to be in direct contact, and may also include an embodiment in which an additional feature may be formed between the first feature and the second feature so that the first feature and the second feature may not be in direct contact. In addition, the disclosure may reuse reference numbers and / or letters in various examples. This repetition is for the purpose of brevity and clarity, rather than indicating the relationship between the various embodiments and / or configurations discussed.

[0058] Additionally, for ease of description, spatially relative terms, such as "beneath," "below," "lower," "above," "upper," and the like, may be used herein to describe the relationship of one device or feature illustrated in the figures to another (other) device or feature. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0059] An extreme ultraviolet (EUV) lithography exposure tool (also referred to herein as an EUV scanner) may include a dynamic gaslock (DGL) positioned between a projection module and a semiconductor wafer coated with a photoresist, where a latent image will be formed on the semiconductor wafer. The DGL provides a gas flow (e.g., nitrogen or argon) at a rate and flow pattern designed to provide contamination control. In some designs, the DGL may include a DGL film inserted between the projection module and the semiconductor wafer. The DGL film filters out-of-band light from an extreme ultraviolet light source. Out-of-band light is primarily deep ultraviolet light (DUV) having a wavelength in the spectral range of 193nm-238nm. Photoresists that are sensitive to EUV are also partially sensitive to the DUV spectrum; therefore, the DGL film advantageously blocks DUV light from reaching the photoresist.

[0060] However, the DGL film also reduces the EUV light yield, which in turn reduces the EUV source intensity used for EUV lithography exposure. In some examples, this can result in a reduction in yield of about 10%. Removing the DGL film will advantageously avoid this undesirable EUV light absorption, but at the expense of undesirable DUV light reaching the photoresist. As a result, DUV light will also interact with EUV-sensitive photoresists and may cause degradation of latent images designed to be produced by EUV light. For example, the impact of DUV light can remove the smallest features in the latent image (sometimes called critical dimensions) from the design specifications. This impact is sometimes most common in the corners of the latent image. The latent image degradation caused by DUV, in turn, can lead to a reduction in the yield of integrated circuits (ICs) manufactured using EUV lithography exposure.

[0061] Another method of suppressing undesirable DUV light is to design the EUV film disposed on the lithography mask to provide high EUV transmittance as well as low DUV reflectivity. The EUV film is primarily used to protect the surface of the lithography mask from contamination such as particles. Therefore, the EUV film is designed to have high EUV transmittance. By designing the EUV film to have low DUV reflectivity at the same time, the EUV film can also be used to remove undesirable DUV light, thus potentially making a separate DGL film that blocks DUV unnecessary.

[0062] In some embodiments disclosed herein, a thin film DUV reflectivity mapping method is disclosed for evaluating the availability of an EUV film for additional DUV light removal functionality. In some embodiments disclosed herein, a thin film DUV reflectivity mapper is also disclosed. In another embodiment disclosed herein, a lithography exposure method includes obtaining a two-dimensional DUV reflectivity map of an EUV film (e.g., using the above method and / or apparatus), determining that the DUV reflectivity of the EUV film is less than a maximum DUV reflectivity threshold by analyzing the two-dimensional DUV reflectivity map, and, in response to determining that the DUV reflectivity of the EUV film is less than the maximum DUV reflectivity threshold, using the EUV film in EUV lithography exposure. The latter operation, for example, may require mounting an EUV film on an EUV lithography mask to form an EUV mask assembly, and performing EUV lithography using the EUV mask assembly to form a latent image of a pattern of EUV reflective regions and absorptive regions of the mask on an extreme ultraviolet light-sensitive photoresist layer disposed on a semiconductor wafer surface and / or on a photomask and / or in an extreme ultraviolet light-sensitive photoresist layer disposed on a semiconductor wafer surface.

[0063] In the following, some non-limiting illustrative examples of such methods and devices are described.

[0064] Reference Figure 1 The extreme ultraviolet (EUV) lithography system includes an EUV light source 10 and an EUV scanner 12. The illustrative EUV light source 10 is a laser produced plasma (LPP) EUV light source, such as a pulsed tin plasma EUV light source. In operation, the EUV light source 10 may be a high power laser (not shown), such as carbon dioxide (CO 2 ) laser or another pulsed laser driven by carbon dioxide (CO 2) laser or another pulsed laser injects or emits a pulsed laser beam, for example, through an optical window into the vacuum (or other environmentally controlled) chamber 14. In some embodiments, the laser beam is injected from below or behind the EUV collecting mirror 16 through a small hole, hole or opening arranged at or near the center of the EUV collecting mirror 16. In some embodiments, the EUV collecting mirror 16 is a multi-layered structure that forms a reflective mirror at and / or near the operating wavelength of the extreme ultraviolet light source 10. A target droplet generator (not shown) is mounted at a vacuum port 18 of the vacuum chamber 14, and droplets of a target material (for example, tin) are injected into the vacuum chamber 14. The target droplets are pushed toward a droplet catcher (not shown) mounted at a port 20 opposite to the port 18. The light pulses of the laser are timed to hit the target droplets when they pass through the focus of the EUV collecting mirror 16 (for example, at or near the ignition point) to generate a plasma that generates extreme ultraviolet light. For example, in the case of tin droplets, the EUV light has a spectrum that generally spans a 2% FWHM bandwidth within a range centered at about 13.5 nanometers. More generally, the EUV light generated can be centered at a selected wavelength within the EUV range between about 1 nanometer and about 100 nanometers. EUV collector mirror 16 reflects and focuses the plasma-generated EUV light to form EUV light 22, which exits EUV light source 10 and enters EUV scanner 12. It should be understood that Figure 1 The EUV light source 10 shown in is a non-limiting illustrative example, and more generally, any EUV light source that produces EUV light at the desired EUV wavelength may be utilized, such as, by way of another non-limiting example, an EUV light source that employs a rotating annular crucible having an interior surface carrying tin or other target material.

[0065] Further Figure 1 As shown, the EUV scanner 12 includes a vacuum chamber (such as Figure 1), and includes an illumination module 24 configured to receive EUV light. The illumination module 24 includes one or more optical components (for example, EUV mirrors) that direct the EUV light 22 onto an EUV lithography mask 30 (also referred to herein and in the art as a mask or photomask or master photomask or the like). The photomask 30 is mounted on a photomask holder 32 (for example, an electrostatic chuck). The photomask 30 has a pattern of EUV reflecting areas and EUV absorbing areas that form an image of a photoresist layer on a semiconductor wafer 38 to be transferred to an EUV scanner disposed on a wafer holder 40, which may, for example, include an electrostatic chuck for holding the semiconductor wafer 38. The EUV light-sensitive and patterned surface of the photomask 30 is appropriately protected by a pellicle 34 that is mounted on the front of the photomask 30 by a frame 36 that separates the pellicle 34 from the front of the photomask 30 by a defined distance.

[0066] The film 34 is an EUV film 34 including an extreme ultraviolet light transmissive film, which can prevent particles from being deposited on the front surface of the photomask 30. The EUV film is relatively thin, which allows the transmission of extreme ultraviolet light. For example, in some non-limiting illustrative embodiments, the EUV film 34 can have a thickness of 10 nanometers to 100 nanometers, and can also be set to a greater or lesser thickness. The EUV film 34 can be made of various materials, such as graphene, carbon nanotubes, etc. in a non-limiting illustrative embodiment. Since the film 34 is relatively thin, it is relatively fragile. The film frame 36 supports the fragile film 34 above the surface of the photomask 30 at a spacing distance sufficient to bring the film 34 out of the focal plane of the light from the illumination module 24 that hits the photomask 30 during the photolithography process. For example, in some non-limiting illustrative embodiments, the film frame 36 can have a thickness of several millimeters (mm) to place the film 34 on the surface of the photomask 30. The film frame 36 can be made of any suitable material, such as anodized aluminum, stainless steel, plastic, silicon (Si), titanium, silicon dioxide, aluminum oxide (Al 2 O 3 ) or titanium dioxide (TiO 2 ). The film frame 36 is a rectangular frame or other surrounding frame that coincides with the entire perimeter of the film 34 and supports the entire perimeter of the film 34.

[0067] The projection module 42 of the EUV scanner 12 projects EUV reflected from the EUV lithography mask 30 onto the semiconductor wafer 38, and more specifically, onto an EUV light-sensitive photoresist layer disposed (e.g., coated) on the surface of the semiconductor wafer 38. The projection module 42 includes a plurality of EUV mirrors configured to project an image of the photomask 30 onto the photoresist coating the semiconductor wafer 38 to form a latent image of the pattern of EUV reflecting regions and absorbing regions of the photomask 30 on and / or in the EUV light-sensitive photoresist. This constitutes an EUV lithography exposure. In some embodiments, the EUV scanner 12 is configured to perform a step-and-shoot EUV lithography exposure to form a two-dimensional array of latent images of the photomask 30 on and / or in the photoresist coating the semiconductor wafer 38. For example, each latent image may correspond to a single integrated circuit (IC) die to be fabricated on semiconductor wafer 38 .

[0068] After the EUV lithography exposure (or multiple EUV lithography exposures) are completed, the semiconductor wafer 38 is removed from the EUV scanner 12, and an appropriate developer is applied to develop the latent image by etching away the portion of the photoresist exposed to the extreme ultraviolet light (this is the case of a positive EUV photoresist); or conversely, the latent image is developed by etching away the portion of the photoresist not exposed to the extreme ultraviolet light (this is the case of a negative EUV photoresist). The development produces a pattern of openings in the developed photoresist, through which subsequent semiconductor processing steps such as etching and deposition are performed to form a semiconductor device structure or the like in the lithography control area.

[0069] The above process ideally operates only with EUV light generated by EUV light source 10. However, in practice, EUV light source 10 also generates some undesirable deep ultraviolet (DUV) light (e.g., in the DUV wavelength range of about 190 nm to about 250 nanometers). DUV light can also interact with the EUV-sensitive photoresist coating semiconductor wafer 38. In other words, EUV-sensitive photoresist also has some DUV light sensitivity. The interaction of DUV light with EUV-sensitive photoresist reduces the fidelity between the latent image and the pattern of the EUV reflecting and absorbing regions of photomask 30, ultimately resulting in defects in semiconductor devices having fabricated regions defined by the developed photoresist layer.

[0070] As previously described, one way to address the problem of stray DUV light reaching the photoresist coating the semiconductor wafer 38 is to provide a dynamic gas lock (DGL) 44 having a DUV light reflecting film. The DGL 44 is located in the optical path in front of the semiconductor wafer 38 disposed on the wafer holder 40, and provides a gas flow (e.g., nitrogen or argon) at a rate and flow pattern designed to provide contamination control. The DGL 44 may include a DUV reflecting film that forms a filter adjusted to block DUV light from reaching the photoresist coating the semiconductor wafer 38. The DUV reflecting film of the DGL 44 is a consumable component with a usable life of several months or so, and replacement of the DGL film requires shutting down the operation of the EUV scanner 12. As previously described, the DGL film also has the side effect of absorbing some of the EUV light, which in some cases can result in a reduction in the EUV light intensity of about 10%.

[0071] In some embodiments disclosed herein, the EUV film 34 comprises an extreme ultraviolet light transmissive film that also has a high DUV light reflectivity. As such, the EUV film provides the desired function of reducing or eliminating the amount of stray DUV light reaching the semiconductor wafer 38. In some such embodiments, the DGL film may be omitted, as the DUV photoresist blocking function of the DGL film is replaced by the EUV film having a low DUV reflectivity.

[0072] However, this approach would benefit from providing a way to ensure that the EUV film actually has sufficient DUV reflectivity to provide the desired reduction in DUV light reaching the semiconductor wafer 38. Such an evaluation of EUV films is challenging. As previously mentioned, the EUV film 34 is very thin to achieve sufficient extreme ultraviolet light transmittance, for example, the EUV film 34 can have a thickness of 10 nanometers to 100 nanometers, and can also be set to a thickness of greater or less. The EUV film 34 may also have a large two-dimensional area, and this area may vary greatly between different EUV films. As two non-limiting illustrative examples, EUV films used for research may have a relatively small area of ​​about 1 cm×1 cm, while EUV films 34 used for commercial semiconductor manufacturing facility purposes have a much larger area of ​​143 mm×110 mm. In order to provide finer feature definition, larger area EUV films are also considered. The thinness and relatively large area together make the EUV film a relatively fragile component. In addition, the DUV reflectivity can vary over the (potentially relatively large) two-dimensional area of ​​the EUV film. DUV reflectivity can also vary as a function of wavelength across the DUV spectrum.Furthermore, different EUV films can be designed to operate at different angles of incidence of incident EUV light.

[0073] Reference Figure 1, an illustrative thin film DUV reflectivity mapper 50 (described later) Figure 2 and Figure 3 34 ), produces a two-dimensional DUV reflectivity map (i.e., image) of the EUV film 34. Each data point in the two-dimensional DUV reflectivity map is a vector (or other suitable data structure) of reflectivity values ​​as a function of wavelength. Some embodiments of the thin film DUV reflectivity mapper 50 may also provide for measuring a two-dimensional DUV reflectivity map at a user-selectable angle of incidence or at multiple angles of incidence (e.g., a two-dimensional DUV reflectivity map is obtained for each angle of incidence measured).

[0074] Continue to refer to Figure 1 , a lithography exposure method is shown that verifies the usability of EUV pellicle 34 using a pellicle DUV reflectivity mapper 50. In operation 52, an EUV pellicle assembly 54 is formed, which in the illustrative example includes the EUV pellicle 34 mounted on a frame 36. In this case, the frame 36 is the same as the frame used to mount the EUV pellicle 34 on the photomask 30, where the pellicle 34 is spaced apart from the front of the photomask 30 by a defined distance. The frame 36 provides structural support for the thin EUV pellicle 34. In other embodiments, the EUV pellicle assembly 54 may include the EUV pellicle 34 mounted on a pellicle carrier (not shown) of the type used for transporting and storing the EUV pellicle. Again, in this alternative embodiment of the EUV pellicle assembly 54, the pellicle carrier provides structural support for the EUV pellicle 34.

[0075] In operation 56, the EUV pellicle assembly 54 is mounted on a platform of the pellicle DUV reflectivity mapper 50. In operation 58, the pellicle DUV reflectivity mapper 50 is operated to obtain a DUV reflectivity map of the EUV pellicle 34. As will be discussed further below, this requires scanning DUV light from a deep ultraviolet light source in two dimensions across the surface of the EUV pellicle 34 and measuring the DUV light reflected from the EUV pellicle 34 as a function of wavelength using a spectrophotometer.

[0076] In operation 60, the DUV reflectivity map of the EUV pellicle 34 is evaluated (i.e., analyzed) to determine the availability of the EUV pellicle 34 for EUV lithography exposure. In some examples, the availability of the EUV pellicle 34 determined is whether the EUV pellicle 34 can be used for EUV lithography exposure without installing a DGL film that blocks DUV light in the DGL 44. In some embodiments, operation 60 determines whether the EUV pellicle 34 is available by determining whether the DUV reflectivity of the EUV pellicle 34 is less than a maximum DUV reflectivity threshold 62 obtained by analyzing the two-dimensional DUV reflectivity map.

[0077] In some non-limiting illustrative embodiments of operation 60, the reflectivity metric derived from the two-dimensional DUV reflectivity map is the maximum DUV reflectivity located on the two-dimensional DUV reflectivity map. In other words, the derived reflectivity metric is the highest DUV reflectivity at any location in the two-dimensional scan. To determine the DUV reflectivity at a given location, the DUV reflectivity at that location over the wavelengths scanned by the spectrophotometer may be summed. In this case, the maximum DUV reflectivity threshold 62 is the maximum allowable DUV reflectivity at any location on the EUV film that is considered usable for the film.

[0078] In some other non-limiting illustrative embodiments of operation 60, the reflectivity metric derived from the two-dimensional DUV reflectivity map is the total DUV reflectivity integral over the two-dimensional surface of the EUV film. The integral appropriately covers all positions scanned in two dimensions and all wavelengths scanned by the spectrophotometer. In this case, the maximum DUV reflectivity threshold 62 is the maximum total DUV reflectivity of the EUV film for which the film is considered usable.

[0079] In another non-limiting illustrative embodiment of operation 60 , the two analyses described above may be performed such that the EUV pellicle 34 is considered usable only if the EUV pellicle 34 meets both the maximum DUV reflectivity criteria on a per-location basis and the maximum total DUV reflectivity criteria.

[0080] In response to determining at operation 60 that the DUV reflectivity of the EUV pellicle 34 is less than the maximum DUV reflectivity threshold 62, the EUV pellicle 34 may be mounted on the EUV lithography mask 30 to form an EUV mask assembly (e.g., mounted in the EUV scanner 12, such as Figure 130 ), and EUV lithography is performed using the EUV mask assembly (e.g., by the EUV scanner 12) to form a latent image of the pattern of EUV reflective regions and absorptive regions of the photomask 30 in an EUV light-sensitive photoresist layer disposed on a surface of the semiconductor wafer 38 and / or in an EUV light-sensitive photoresist layer disposed on a surface of the semiconductor wafer 38. If the EUV film assembly 54 includes an EUV film 34 mounted on a frame 36, this EUV film assembly 54 may be mounted on the EUV lithography mask 30 to form the EUV mask assembly. Alternatively, if the EUV film assembly 54 includes an EUV film 34 held by a film carrier, the EUV film 34 is transferred from the film carrier to a mounting seat 36 for mounting on the EUV lithography mask 30. If the availability determination is availability without a DGL film, EUV lithography performed using the EUV mask assembly to form a latent image may be performed without using a DGL film. It should also be noted that EUV lithography performed using the EUV mask assembly may form a plurality of latent images, such as a two-dimensional array or latent images using a step-and-scan process performed by the EUV scanner 12 .

[0081] As previously described, operation 60 determines the usability of the EUV pellicle 34 for EUV lithography exposure. Additionally or alternatively, the DUV reflectivity map of the EUV pellicle 34 may be evaluated to identify any DUV reflectivity “hot spots,” i.e., areas of the EUV pellicle 34 having elevated DUV reflectivity. For example, a DUV reflectivity hot spot may correspond to any area of ​​the DUV reflectivity map where the local DUV reflectivity exceeds a maximum DUV reflectivity threshold 62. Identifying such a DUV reflectivity hot spot of the EUV pellicle 34 may be beneficial, for example, to facilitate reviewing the manufacturing process analysis used to manufacture the EUV pellicle 34 to determine the root cause of the DUV reflectivity hot spot in the manufacturing process.

[0082] Control of the thin film DUV reflectivity mapper 50 and / or the performance of operations 58 and 60 constituting the EUV thin film usability test may be appropriately controlled by a controller 64 (e.g., an illustrative computer) or other electronic processing device. The illustrative controller 64 includes a display 66 for displaying a rendering of a DUV reflectivity map of the thin film 34, and / or for displaying an indication of a determination (from operation 60) of whether the EUV thin film 34 can be used for EUV lithography without a dynamic airlock DUV light reflective film, and / or for displaying other information. The illustrative controller 64 optionally includes an illustrative keyboard, touch pad, and / or other user input device 68 by which a user may enter or select configuration settings of the thin film DUV reflectivity mapper 50, such as the DUV wavelength range scanned by the spectrophotometer, the angle of incidence, etc., and / or enter or select other information, such as a value for the maximum DUV reflectivity threshold 62.

[0083] The representation of the DUV reflectivity map of the film 34, which is optionally displayed on the display 66, may employ a variety of rendering methods. For example, the DUV reflectivity values ​​measured at locations on the EUV film 34 may be color-coded to produce a representation that is a heat map, such as with "hot" colors (e.g., red representing the highest DUV reflectivity values) and "cold" colors (e.g., blue representing the lowest DUV reflectivity values), as well as intermediate colors (green, yellow, orange, etc.) representing intermediate reflectivity values. This is merely one non-limiting, illustrative example of a suitable representation.

[0084] The EUV film usability test, including operations 58 and 60, may be performed at different times. In one use case, the EUV film usability test 58, 60 may be performed on a newly acquired EUV film to determine the usability of the EUV film before the EUV film is put into commercial use for the first time to perform EUV lithography exposure. In another use case, the EUV film usability test 58, 60 may be performed as part of a physical failure analysis (PFA) process. In this use case, if a semiconductor manufacturing facility finds that an IC manufacturing workflow is producing an undesirably low yield, it may be suspected that this may be due to stray DUV light degrading the latent image produced by the EUV lithography step performed using the EUV scanner 12. In this case, the EUV film usability test 58, 60 may be applied to determine whether excessive DUV reflectivity from the EUV film 34 is the cause of the observed low yield. In yet another use case, in the development of EUV films, the EUV film usability test 58, 60 may be applied to manufactured EUV films as part of a study to determine whether the EUV film has an appropriately low DUV reflectivity. These are just some non-limiting illustrative examples of use cases for EUV pellicle usability testing.

[0085] Furthermore, it should be understood that the thin film DUV reflectivity mapper 50 can be used to perform a thin film DUV reflectivity mapping method 58 (an example of which is described later herein). Figure 5 ), without subsequently performing an evaluation operation 60. For example, in the context of thin film manufacturing R&D, DUV reflectivity plots of thin films produced during the research process can be analyzed as a function of wavelength and / or angle of incidence to determine the underlying mechanisms controlling the DUV reflectivity, leading to research to achieve low levels of DUV reflectivity in subsequently manufactured EUV thin films.

[0086] Now refer to Figure 2 and Figure 3 , an illustrative thin film DUV reflectivity mapper 50 is shown in side view ( Figure 2 ) and top view ( Figure 3 ) is shown in the manner of Figure 2 and Figure 3 The illustrative film DUV reflectivity mapper 50 includes a base 70, a film stage 72 configured to support an EUV film (e.g., mounted on a frame 36 or in a film carrier), and a DUV reflectivity measurement assembly 74, including (i) a deep ultraviolet light source 76 configured to emit DUV light onto the EUV film supported by the film stage 72 to produce reflected DUV light reflected by the EUV film, and (ii) a DUV spectrophotometer 78 configured to measure the intensity of the reflected DUV light as a function of wavelength or photon energy. Motorized assemblies 80, 82 are fixed to the base 70 and configured to measure the intensity of the reflected DUV light in two mutually orthogonal directions ( Figure 2 and Figure 3 The DUV light (emitted onto the film by the deep ultraviolet light source 76) is scanned on the EUV film in the direction X and direction Y specified in FIG.

[0087] The deep ultraviolet light source 76 can be any type of light source that emits light in the deep ultraviolet (DUV) spectrum, and the DUV reflectivity of the EUV film will be measured in the deep ultraviolet spectrum (e.g., in some embodiments, at least 190nm to 250nm, because it constitutes the DUV range emitted by some embodiments of the extreme ultraviolet light source 10, and EUV-sensitive photoresists are also sensitive to it). In some non-limiting illustrative embodiments, the deep ultraviolet light source 76 includes a photomultiplier tube, and the generation of DUV light includes operating the photomultiplier tube of the deep ultraviolet light source 76 to emit DUV light onto the EUV film. The deep ultraviolet light source 76 can also optionally include one or more optical components, such as lenses and / or reflectors that operate in the DUV light range. These are merely some non-limiting illustrative embodiments, and more generally, the deep ultraviolet light source 76 can be any deep ultraviolet light source that emits in the desired spectral range.

[0088] The DUV spectrophotometer 78 suitably includes an optical detector sensitive in the DUV range of the DUV reflectivity of the EUV film to be measured, optically coupled to a grating or other spectrally dispersive component that can be electronically adjusted (e.g., tilted in the case of a grating) to select a narrow DUV wavelength window (e.g., a 1 nm window width in some non-limiting illustrative embodiments) detected by the optical detector. The optical detector can be, for example, a silicon photodiode, an avalanche photodiode (APD), a CMOS sensor, or other silicon-based light sensor. The DUV spectrophotometer 78 can optionally include a quartz, sapphire, or other window, or such a window can be omitted to maximize DUV sensitivity at low DUV wavelengths. These are merely some non-limiting illustrative embodiments, and more generally, the DUV spectrophotometer 78 can be any DUV spectrophotometer that provides sensitivity in a desired spectral range and has a desired spectral resolution.

[0089] exist Figure 1 In the illustrative embodiment, the electric assembly 80, 82 includes: a first mechanism 80, fixed to the base 70 and configured to be in a first direction (without loss of generality in Figure 2 and Figure 3 The film platform 72 is moved relative to the base 70 in a direction (marked as the Y direction in the figure); and a second mechanism 82 is fixed to the first mechanism 80 and is configured to move in a second direction (without loss of generality in a direction) orthogonal to the first direction (e.g., the Y direction) Figure 2 and Figure 3 The film platform 72 is moved relative to the base 70 in the X direction (marked as the X direction in FIG. 1 ).

[0090] exist Figure 2A third direction, labeled as the Z direction, is shown in the side view of FIG. 7 , wherein the X direction, the Y direction, and the Z direction are suitably orthogonal to each other and form a conventional Cartesian coordinate system. The EUV film being measured is suitably mounted on the film platform 72, and the plane of the EUV film is oriented transverse to the Z direction. In other words, the surface normal of the EUV film supported by the film platform 72 is a unit vector oriented to coincide with or be parallel to the Z direction.

[0091] exist Figure 2 and Figure 3 In the illustrative example, the film platform holder 84 (see Figure 2 ) provides a structural connection between the film platform 72 and the second linear translation mechanism 82. Figure 3 As shown, the first linear translation mechanism 80 is Figure 2 , Figure 3 In the embodiment of the present invention, the first linear track 80 extending along the Y direction a and a second linear track 80 extending along the Y direction b The first straight track 80 a and the second linear track 80 b The first linear translation mechanism 80 is located at or near the opposite end of the second linear translation mechanism 82. A suitable motor driver of the first linear translation mechanism 80, such as an electric screwdriver or a stepper motor, is operable to move the second linear translation mechanism 82 along the Y direction. The second linear translation mechanism 82 includes a linear track oriented along the X direction, and a suitable motor driver of the second linear translation mechanism 82, such as an electric screwdriver or a stepper motor, is operable to move the film platform 72 along the X direction. In other words, the second linear translation mechanism 82 directly supports the film platform 72 and directly moves (i.e., linearly translates) the film platform 72 along the X direction. The first linear translation mechanism 80 directly supports the second linear translation mechanism 82 (and thus indirectly supports the film platform 72), and directly moves the first linear translation mechanism 80 along the Y direction (and thus indirectly moves the film platform 72 along the Y direction).

[0092] Therefore, in Figure 2 and Figure 3 In the thin film DUV reflectivity mapper 50, a two-dimensional DUV reflectivity map of the EUV film is acquired by scanning the extreme ultraviolet light emitted to the EUV film on the two-dimensional surface of the EUV film using the following combination: moving the EUV film (supported by the film stage 72) in a first direction (e.g., Y direction) relative to the DUV reflectivity measurement assembly 74; and moving the EUV film in a second direction (e.g., X direction) relative to the DUV reflectivity measurement assembly 74. The first direction and the second direction are orthogonal to each other.

[0093] exist Figure 2 and Figure 3In the embodiment, the DUV reflectivity measurement assembly 74 is fixed on the base 70 and does not move relative to the base 70; Figure 2 and Figure 3 The motorized assemblies 80, 82 are configured to translate the thin film platform 72 relative to the pedestal 70 and relative to a fixed DUV reflectivity measurement assembly 74 fixed to the pedestal 70. However, other configurations of motorized assemblies are also contemplated.

[0094] To provide another non-limiting illustrative example, Figure 4 An alternative illustrative thin film DUV reflectivity mapper 50 is shown. alt A top view of Figure 2 and Figure 3 The thin film DUV reflectivity mapper 50 is the same as the thin film DUV reflectivity mapper 50 except that the thin film DUV reflectivity mapper 50 alt Using different electric components 80 alt , 82 alt , electric components 80 alt , 82 alt A device is fixed to a pedestal 70 and configured to scan DUV light (emitted onto the film by a deep ultraviolet light source 76) on the EUV film in two mutually orthogonal (e.g., X and Y) directions by translating a film stage 72 and / or a DUV reflectivity measurement assembly 74 relative to the pedestal 70. Alternative Thin Film DUV Reflectivity Mapper 50 alt Electric components 80 alt , 82 alt Includes: a first linear translation mechanism 80 alt , fixed to the base 70 and configured in a first direction (e.g., Figure 4 The DUV reflectivity measurement assembly 74 is translated relative to the base 70 in the Y direction in the embodiment; and the second linear translation mechanism 82 alt , fixed to the base 70 and configured to be in a second direction orthogonal to the first direction (e.g., Figure 4 The film platform 72 is translated relative to the base 70 in the X direction (in the embodiment of the present invention).

[0095] exist Figure 4 Alternative Thin Film DUV Reflectivity Mapper 50 alt In the first linear translation mechanism 80 alt and the second linear translation mechanism 82 alt The first linear translation mechanism 80 suitably comprises a first linear track and a second linear track oriented along the Y direction and the X direction, respectively. alt and the second linear translation mechanism 82 altEach of suitably includes an electric drive, such as an electric screwdriver or stepper motor, operable to respectively move the DUV reflectivity measurement assembly 74 and the film stage 72. The base 70 serves as a reference frame for these movements.

[0096] Therefore, in Figure 4 Alternative Thin Film DUV Reflectivity Mapper 50 alt In the present invention, a two-dimensional DUV reflectivity map of the EUV film is acquired by scanning extreme ultraviolet light emitted onto the EUV film over the two-dimensional surface of the EUV film using the following combination: moving the DUV reflectivity measurement assembly 74 relative to the EUV film (supported by the film stage 72) in a first direction (e.g., the Y direction); and moving the EUV film in a second direction (e.g., the X direction) relative to the DUV reflectivity measurement assembly 74 (by moving the film stage 72).

[0097] Again, these are merely non-limiting illustrative examples. In yet another contemplated non-limiting illustrative embodiment (not shown), it is contemplated that the pellicle platform is fixed relative to the pedestal, and a motorized assembly fixed to the pedestal is configured to scan the DUV light on the EUV pellicle in both the X-direction and the Y-direction relative to the pedestal.

[0098] The DUV reflectivity of the EUV film can depend on the incident angle of the DUV light on the EUV film. Figure 2 As can be clearly seen from the side view, the thin film DUV reflectivity mapper 50 or 50 alt Optionally, a rotary motor 90 is further included, which is configured to adjust the incident angle of the DUV light emitted by the deep ultraviolet light source 76 onto the EUV film supported by the film platform 72. Figure 3 or Figure 4 The rotary unit housing 92, clearly seen in the top view of FIG. , provides housing and support for the rotary motor 90. Figure 2 As can be clearly seen from the side view of FIG. 7 , the rotary motor moves the deep ultraviolet light source 76 and the DUV spectrophotometer 78 along a circular track 94 centered at the incident position 96 of the DUV light onto the EUV film supported by the film platform 72. Generally speaking, the reflection angle of the DUV light reflected into the DUV spectrophotometer 78 is equal to the incident angle of the DUV light applied by the deep ultraviolet light source 76 (where these angles are appropriately measured relative to the surface normal of the EUV film); therefore, adjusting the incident angle of the deep ultraviolet light source 76 requires a corresponding adjustment in the position of the DUV spectrophotometer 78.

[0099] General reference Figures 2 to 4 , Thin Film DUV Reflectivity Mapper 50 or 50 altAdditional components may be included, such as one or more limit detectors 100, to detect translationally moving components (e.g., Figure 2 and Figure 3 The thin film platform 72 in the embodiment of the embodiment is moved to the maximum (or minimum) allowed position, and one or more electrical cables 102 are used to transmit power to various motors to drive the deep ultraviolet light source 76 and collect DUV reflectivity data collected by the DUV spectrophotometer 78. Figure 2 and Figure 3 The electrical cable 102 connected to the second linear translation mechanism 82 in the example of FIG. 1 is designed to accommodate the movement of the translation member, for example, constructed by a wire tracker or the like.

[0100] Continue to refer to Figures 2 to 4 And further refer to Figure 1 In some embodiments, in some or all of the electrical cables 102, the thin film DUV reflectivity mapper 50 (or 50 alt ) and control film DUV reflectivity mapper 50 (or 50 alt ) is connected to a computer or other controller 64 to obtain a DUV reflectivity map. The thin film DUV reflectivity mapper 50 (or 50 alt ) is suitable for performing operation 58 or a lithography exposure method. In operation 58, the thin film DUV reflectivity mapper 50 (or 50 alt ) (eg, by the controller 64 ) to obtain a DUV reflectivity map of the EUV film 34 .

[0101] Now refer to Figure 5 , by way of a flow chart illustrating the operation of a thin film DUV reflectivity mapper 50 (or 50 alt ) to evaluate EUV films. Figure 5 The method includes a thin film DUV reflectivity mapping operation 58, a non-limiting illustrative thin film DUV reflectivity mapping operation 58 in Figure 5 110, 112, 114 and 116. In operation 110, the motor assembly 80, 82 (or 80 alt , 82 alt ) Place incident DUV light from a deep ultraviolet light source 76 at a starting position on the EUV film supported by the film platform 72.

[0102] In operation 112, a DUV spectrum of the location is measured within a desired spectral range. In one non-limiting illustrative example, the spectral range of the DUV spectrum is measured from 190 nm to 500 nm, for example, in one non-limiting illustrative example, measured in 1 nm steps. In another non-limiting illustrative example, the spectral range of the DUV spectrum is measured from at least 190 nm to 250 nm, which is comparable to the DUV wavelength range of about 190 nm to about 250 nm, within which the extreme ultraviolet light source 10 (see Figure 1 ) may generate undesirable DUV light in some embodiments. In some of such embodiments, the DUV spectrum is measured over at least 190 nm to 250 nm in 1 nm steps, although smaller or larger steps are also contemplated. To acquire the DUV spectrum in operation 112, a spectral window (e.g., approximately 1 nm in one non-limiting illustrative example) of light entering the DUV light detector of the DUV spectrophotometer 78 is swept through the desired spectral range (e.g., 190-250 nm, or 190-500 nm in two non-limiting illustrative examples) using a grating or other spectral dispersion component of the DUV spectrophotometer 78. In some embodiments, a user may input the desired endpoint of the DUV spectrum to be measured, and may also select increments (i.e., steps) via a keyboard, touch pad, or other user input device 68 of a computer or other controller 64.

[0103] In operation 114, the motorized assembly 80, 82 (or 80 alt , 82 alt ) The incident DUV light from the deep ultraviolet light source 76 is placed at the next position on the EUV film supported by the film platform 72, and the process flow is passed through Figure 5 The graphical arrow A1 shown in FIG. 1 returns to operation 112 to obtain the DUV spectrum of the next position. Operations 112 and 114 thus iteratively scan the DUV light emitted by the deep ultraviolet light source 76 onto the EUV film on the two-dimensional surface of the EUV film. During this iterative process, the DUV spectrum obtained by each execution of operation 112 is collected at operation 116 (e.g., Figure 5 ), to collect a DUV reflectivity map of the EUV film supported by the film platform 72. The two-dimensional DUV reflectivity map may be suitably stored, for example, in a three-dimensional array (or similar data structure), where two dimensions are spatial positions (set to a starting position by operation 110 and to each next position by operation 114), and the third dimension corresponds to the wavelength (or equivalently the photon energy) of the reflectivity value on the DUV spectrum obtained at that position.

[0104] Despite Figure 55. In some embodiments, the two-dimensional DUV reflectivity map acquired by operation 58 is repeated at two or more different incident angles set by the rotation motor 90 (see Figure 2 ). For example, if DUV reflectivity maps are collected at each of four different incident angles, the output of operation 58 may be four two-dimensional DUV reflectivity maps, or equivalently, a four-dimensional data array (or similar data structure) including two spatial dimensions, one wavelength dimension, and one incident angle dimension.

[0105] The two-dimensional DUV reflectivity map obtained in operation 58 can be used in a variety of ways. Figure 5 In operation 120, a representation of the two-dimensional DUV reflectivity map is displayed (e.g., on an illustrative display 66 of a computer or other controller 64). For example, the DUV reflectivity values ​​measured at locations on the EUV film 34 may be color-coded to produce a representation in the form of a heat map, such as with "hot" colors (e.g., red representing the highest DUV reflectivity values) (optionally, the spectrum is integrated at each location) and "cold" colors (e.g., blue representing the lowest DUV reflectivity values), as well as intermediate colors (green, yellow, orange, etc.) representing intermediate reflectivity values. This is merely one non-limiting, illustrative example of a suitable representation.

[0106] Additionally or alternatively, the two-dimensional DUV reflectivity map obtained by operation 58 may be obtained by operation 60 (in Figure 1 and Figure 5 ) to determine whether the EUV film can be used for EUV lithography (e.g., without a dynamic gas-locked DUV light reflective film) by analyzing the two-dimensional DUV reflectivity map. In some examples, the availability of the EUV film 34 is determined based on a reflectivity indicator derived from the two-dimensional DUV reflectivity map, such as: the maximum DUV reflectivity at any position on the two-dimensional DUV reflectivity map (optionally, integrating the spectrum at each position); the total DUV reflectivity integral on the two-dimensional surface of the EUV film (i.e., the sum or integral at all positions of the two-dimensional scan and all wavelengths scanned by the spectrophotometer); a combination thereof, etc.

[0107] In operation 122, an indication is output (e.g., on an illustrative display 66 of a computer or other controller 64) determining whether the EUV pellicle is usable for EUV lithography (e.g., without a dynamic airlock DUV light reflective film). This indication may be a simple indication of "pass" or "fail," where "pass" indicates that the EUV pellicle is usable for EUV lithography and "fail" indicates that the EUV pellicle is not usable for EUV lithography. Alternatively, the indication may include more (or alternative) information, such as displaying the value of a reflectivity indicator determined from a two-dimensional DUV reflectivity map.

[0108] It should also be noted that operation 120 and operations 60 , 122 are not mutually exclusive, for example, the output may include a display of a representation of a DUV reflectivity map per operation 120 and a display of an indication of whether an EUV pellicle is usable for EUV lithography per operations 60 , 122 .

[0109] Some further embodiments are described below.

[0110] In a non-limiting illustrative embodiment, a thin film DUV reflectivity mapping method includes: obtaining a two-dimensional DUV reflectivity map of an EUV thin film using a DUV reflectivity measurement assembly, the DUV reflectivity measurement assembly including: a deep ultraviolet light source configured to emit DUV light onto the EUV thin film to produce reflected DUV light reflected by the EUV thin film, and a DUV spectrophotometer configured to measure the intensity of the reflected DUV light as a function of wavelength or photon energy; and displaying a representation of the two-dimensional DUV reflectivity map.

[0111] In some embodiments, the two-dimensional deep ultraviolet reflectivity map of the extreme ultraviolet film is obtained by scanning the deep ultraviolet light emitted to the extreme ultraviolet film on the two-dimensional surface of the extreme ultraviolet film using a combination of moving the extreme ultraviolet film in a first direction relative to the deep ultraviolet reflectivity measurement assembly and moving the extreme ultraviolet film in a second direction relative to the deep ultraviolet reflectivity measurement assembly, wherein the first direction and the second direction are orthogonal to each other. In some embodiments, the deep ultraviolet reflectivity measurement assembly is located at a fixed position relative to a base, and wherein: the moving the extreme ultraviolet film in the first direction relative to the deep ultraviolet reflectivity measurement assembly is performed using a first mechanism fixed to the base; and the moving the extreme ultraviolet film in the second direction relative to the deep ultraviolet reflectivity measurement assembly is performed using a second mechanism fixed to the first mechanism. In some embodiments, the two-dimensional deep ultraviolet reflectivity map of the EUV film is obtained by scanning the EUV light emitted to the EUV film on the two-dimensional surface of the EUV film using the following combination: moving the EUV reflectivity measurement component relative to the EUV film in a first direction; and moving the EUV film in a second direction relative to the EUV reflectivity measurement component; wherein the first direction and the second direction are mutually orthogonal. In some embodiments, the moving of the EUV reflectivity measurement component relative to the EUV film in the first direction is performed using a first linear translation mechanism fixed to a base; and the moving of the EUV film in the second direction relative to the EUV reflectivity measurement component is performed using a second linear translation mechanism fixed to the base. In some embodiments, the film deep ultraviolet reflectivity mapping method further includes: adjusting the deep ultraviolet reflectivity measurement component to select an incident angle and a reflection angle, the deep ultraviolet light source emitting the deep ultraviolet light to the EUV film at the incident angle, and the deep ultraviolet spectrophotometer measuring the intensity of the reflected deep ultraviolet light at the reflection angle. In some embodiments, the film deep ultraviolet reflectivity mapping method further comprises: operating a photomultiplier tube of the deep ultraviolet light source to emit the deep ultraviolet light onto the extreme ultraviolet film. In some embodiments, the deep ultraviolet spectrophotometer measures the intensity of the reflected deep ultraviolet light as a function of wavelength or photon energy over a spectral range of at least 190 nanometers to 250 nanometers. In some embodiments, the representation of the two-dimensional deep ultraviolet reflectivity map displayed is a heat map.In some embodiments, the film deep ultraviolet reflectivity mapping method further includes: determining whether the extreme ultraviolet film can be used for extreme ultraviolet lithography without a dynamic air-locked deep ultraviolet light reflective film by analyzing the two-dimensional deep ultraviolet reflectivity map; and outputting an indication of determining whether the extreme ultraviolet film can be used for extreme ultraviolet lithography without a dynamic air-locked deep ultraviolet light reflective film. In some embodiments, determining whether the extreme ultraviolet film is usable includes: if the deep ultraviolet reflectivity index derived from the two-dimensional deep ultraviolet reflectivity map is equal to or lower than a maximum threshold, then determining that the extreme ultraviolet film is usable.

[0112] In a non-limiting illustrative embodiment, a thin film DUV reflectivity mapper includes: a base; a thin film platform configured to support an associated EUV thin film; a DUV reflectivity measurement assembly including (i) a deep ultraviolet light source configured to emit DUV light onto an associated EUV thin film supported by the thin film platform to produce reflected DUV light reflected by the EUV thin film, and (ii) a DUV spectrophotometer configured to measure the intensity of the reflected DUV light as a function of wavelength or photon energy; and a motor assembly fixed to the base and configured to scan the DUV light on the associated EUV thin film in two mutually orthogonal directions by moving the thin film platform and / or the DUV reflectivity measurement assembly relative to the base.

[0113] In some embodiments, the deep ultraviolet reflectivity measurement assembly is fixed relative to the base, and the motor assembly includes: a first mechanism fixed to the base and configured to move the film platform relative to the base in a first direction; and a second mechanism fixed to the first mechanism and configured to move the film platform relative to the base in a second direction orthogonal to the first direction. In some embodiments, the motor assembly includes: a first mechanism fixed to the base and configured to move the deep ultraviolet reflectivity measurement assembly relative to the base in a first direction; and a second mechanism fixed to the base and configured to move the film platform relative to the base in a second direction orthogonal to the first direction. In some embodiments, the deep ultraviolet reflectivity measurement assembly further includes a rotary motor configured to adjust the incident angle of the deep ultraviolet light emitted by the deep ultraviolet light source to the associated extreme ultraviolet film supported by the film platform. In some embodiments, the thin film deep ultraviolet reflectivity mapper further comprises: an electronic controller, the electronic controller comprising a display, the electronic controller configured to control the deep ultraviolet reflectivity mapper to obtain a two-dimensional deep ultraviolet reflectivity map of the associated extreme ultraviolet thin film supported by the thin film platform, and to display a representation of the two-dimensional deep ultraviolet reflectivity map on the display. In some embodiments, the thin film deep ultraviolet reflectivity mapper further comprises an electronic controller, the electronic controller comprising a display, the electronic controller configured to: control the deep ultraviolet reflectivity mapper to obtain a two-dimensional deep ultraviolet reflectivity map of the associated extreme ultraviolet thin film supported by the thin film platform, and determine whether the associated extreme ultraviolet thin film can be used for extreme ultraviolet lithography without a dynamic air-locked deep ultraviolet light reflective film by analyzing the two-dimensional deep ultraviolet reflectivity map, and output an indication of the determination whether the associated extreme ultraviolet thin film can be used for extreme ultraviolet lithography without a dynamic air-locked deep ultraviolet light reflective film on the display.

[0114] In a non-limiting illustrative embodiment, a lithography exposure method includes: obtaining a two-dimensional DUV reflectivity map of an EUV pellicle; determining that the DUV reflectivity of the EUV pellicle is less than a maximum DUV reflectivity threshold by analyzing the two-dimensional DUV reflectivity map; and in response to determining that the DUV reflectivity of the EUV pellicle is less than the maximum DUV reflectivity threshold, mounting the EUV pellicle on an EUV lithography mask to form an EUV mask assembly, and performing EUV lithography using the EUV mask assembly to form a latent image of a pattern of EUV reflective regions and absorptive regions of the mask on and / or in an extreme ultraviolet light-sensitive photoresist layer disposed on a surface of a semiconductor wafer.

[0115] In some embodiments, the EUV light-sensitive photoresist layer is also DUV light-sensitive. In some embodiments, the EUV lithography is performed without using a dynamic air-locked DUV light reflective film.

[0116] In a non-limiting illustrative embodiment, a two-dimensional DUV reflectivity map of an EUV pellicle is obtained using a DUV reflectivity measurement assembly having a deep ultraviolet light source and a DUV spectrophotometer. A representation of the two-dimensional DUV reflectivity map can be displayed. Additionally or alternatively, a determination can be made whether the EUV pellicle can be used for EUV lithography without a dynamic airlock DUV light reflective film by analyzing the two-dimensional DUV reflectivity map, and an indication of the determination can be output. In response to determining that the EUV pellicle is usable, the EUV pellicle can be mounted on an EUV lithography mask to form an EUV mask assembly, and EUV lithography can be performed using the EUV mask assembly to form a latent image of a pattern of EUV reflective regions and absorptive regions of a photomask on and / or in an EUV light-sensitive photoresist layer disposed on a surface of a semiconductor wafer.

[0117] The foregoing summarizes the features of several embodiments so that those skilled in the art can better understand the various aspects of the present disclosure. Those skilled in the art will appreciate that they can easily use the present disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or achieve the same advantages as the embodiments described herein. Those skilled in the art will also appreciate that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they can make various changes, substitutions, and modifications without departing from the spirit and scope of the present disclosure.

Claims

1. A method for mapping the deep ultraviolet reflectivity of a thin film, characterized in that: include: obtaining a two-dimensional deep ultraviolet reflectivity map of the extreme ultraviolet film using a deep ultraviolet reflectivity measurement assembly, the deep ultraviolet reflectivity measurement assembly comprising: a deep ultraviolet light source configured to emit deep ultraviolet light onto the extreme ultraviolet film to produce reflected deep ultraviolet light reflected by the extreme ultraviolet film, and a deep ultraviolet spectrophotometer configured to measure the intensity of the reflected deep ultraviolet light as a function of wavelength or photon energy; as well as A representation of the two-dimensional deep UV reflectivity map is shown.

2. The method for mapping the deep ultraviolet reflectivity of thin films according to claim 1, characterized in that: The two-dimensional deep ultraviolet reflectivity map of the extreme ultraviolet film is obtained by scanning the deep ultraviolet light emitted to the extreme ultraviolet film on the two-dimensional surface of the extreme ultraviolet film using a combination of moving the extreme ultraviolet film in a first direction relative to the deep ultraviolet reflectivity measuring component and moving the extreme ultraviolet film in a second direction relative to the deep ultraviolet reflectivity measuring component, wherein the first direction and the second direction are orthogonal to each other.

3. The method for mapping the deep ultraviolet reflectivity of thin films according to claim 1, characterized in that: The two-dimensional deep ultraviolet reflectivity map of the EUV film is obtained by scanning the EUV light emitted to the EUV film over the two-dimensional surface of the EUV film using the following combination: moving the deep ultraviolet reflectivity measurement assembly relative to the extreme ultraviolet film in a first direction; and moving the extreme ultraviolet film in a second direction relative to the deep ultraviolet reflectivity measurement assembly; The first direction and the second direction are orthogonal to each other.

4. A thin film deep ultraviolet reflectivity mapper, comprising: Pedestal; a film platform configured to support an associated EUV film; a deep ultraviolet reflectivity measurement assembly comprising (i) a deep ultraviolet light source configured to emit deep ultraviolet light onto the associated extreme ultraviolet film supported by the film platform to produce reflected deep ultraviolet light reflected by the extreme ultraviolet film, and (ii) a deep ultraviolet spectrophotometer configured to measure the intensity of the reflected deep ultraviolet light as a function of wavelength or photon energy; as well as A motorized assembly is fixed to the base and configured to scan the deep ultraviolet light on the associated extreme ultraviolet film in two mutually orthogonal directions by moving the film platform and / or the deep ultraviolet reflectivity measurement assembly relative to the base.

5. The thin film deep ultraviolet reflectivity mapper according to claim 4, characterized in that: The deep ultraviolet reflectivity measurement assembly is fixed relative to the base, and the electric assembly includes: a first mechanism fixed to the base and configured to move the film platform relative to the base in a first direction; and A second mechanism is fixed to the first mechanism and is configured to move the film platform relative to the base in a second direction orthogonal to the first direction.

6. The thin film deep ultraviolet reflectivity mapper according to claim 4, characterized in that: The electric component comprises: a first mechanism fixed to the base and configured to move the deep ultraviolet reflectivity measurement assembly relative to the base in a first direction; and A second mechanism is fixed to the base and configured to move the film platform relative to the base in a second direction orthogonal to the first direction.

7. The thin film deep ultraviolet reflectivity mapper according to claim 4, characterized in that: The deep ultraviolet reflectivity measurement assembly further includes a rotary motor configured to adjust an incident angle of the deep ultraviolet light emitted by the deep ultraviolet light source onto the associated extreme ultraviolet film supported by the film platform.

8. A photolithography exposure method, comprising: Obtain a two-dimensional deep-UV reflectivity map of the EUV film; Determining that the deep ultraviolet reflectivity of the extreme ultraviolet film is less than a maximum deep ultraviolet reflectivity threshold by analyzing the two-dimensional deep ultraviolet reflectivity map; as well as In response to the determining that the deep ultraviolet reflectivity of the EUV pellicle is less than the maximum deep ultraviolet reflectivity threshold, performing EUV photolithography using an EUV mask assembly including an EUV mask and the EUV pellicle mounted on the EUV mask to form a latent image of a pattern of EUV reflecting areas and absorbing areas of the photomask on and / or in an EUV light-sensitive photoresist layer disposed on a surface of a semiconductor wafer.

9. The photolithography exposure method according to claim 8, characterized in that: The extreme ultraviolet light-sensitive photoresist layer is also deep ultraviolet light-sensitive.

10. The photolithography exposure method according to claim 8, characterized in that: The EUV lithography is performed without using a dynamic air-locked deep ultraviolet light reflective film.

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