Pellicle frame for extreme ultraviolet lithography

Abstract

A pellicle frame (17) comprising: a first portion (40); and a plurality of second portions (42). The first portion is for connecting to a border (19a) of a pellicle (19). The first portion comprises a hollow and generally rectangular body. The plurality of second portions are for connecting to a patterning device (MA). The first portion and the plurality of second portions are both formed from a first material. Each of the second portions is connected to the first portion by a spring portion (44), the spring portion being formed from the first material. Such a pellicle frame is advantageous since the first portion, the plurality of second portions and the spring portions are all formed from the same material. This significantly simplifies the manufacture of the pellicle frame. For example, all portions of the pellicle frame can be integrally formed together.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to European application 20170977.1, filed on 23 April 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a film frame suitable for use in extreme ultraviolet (EUV) lithography equipment. The film frame facilitates the connection of the film to a photomask or mask. The invention also relates to a film assembly including the film frame, and to a mask assembly including the film assembly. Background Technology

[0004] A photolithography apparatus is a machine configured to apply a desired pattern onto a substrate. Photolithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A photolithography apparatus can project a pattern from a patterning apparatus (e.g., a mask) onto a layer of radiation-sensitive material (resist) disposed on a substrate.

[0005] The wavelength of the radiation used by the lithography equipment to project a pattern onto a substrate determines the minimum size of the feature that can be formed on the substrate. Compared to conventional lithography equipment (which may, for example, use electromagnetic radiation with a wavelength of 193 nm), lithography equipment using EUV radiation, which is electromagnetic radiation with a wavelength in the range of 4 nm to 20 nm, can be used to form smaller features on the substrate.

[0006] A patterning apparatus (e.g., a mask) for imparting a pattern to a radiation beam in a photolithography device can form parts of a mask assembly. The mask assembly may include a protective film that shields the patterning apparatus from particle contamination. The protective film may be supported by a protective film frame.

[0007] It may be necessary to provide devices that avoid or mitigate one or more problems associated with existing technologies. Summary of the Invention

[0008] According to a first aspect of the present invention, a film frame is provided, comprising: a first portion for connection to a boundary of a film, the first portion including a hollow and generally rectangular body; and a plurality of second portions for connection to a pattern forming apparatus; wherein the first portion and the plurality of second portions are both formed of a first material; and wherein each of the second portions is connected to the first portion by a spring portion formed of the first material.

[0009] The diaphragm frame according to the first aspect of the invention is advantageous because the first portion, the plurality of second portions, and the spring portion are all formed of the same material, i.e., the first material. This significantly simplifies the manufacture of the diaphragm frame. For example, all parts of the diaphragm frame can be integrally formed together.

[0010] This contrasts with existing arrangements, where the first portion for connecting to the boundary of the film is formed of one material (e.g., silicon), and the plurality of second portions for connecting to the patterning apparatus are formed of another material (e.g., titanium or titanium alloy). This existing arrangement is significantly more complex to manufacture because the individual portions must be manufactured separately and then assembled together. Furthermore, this significantly increases the cost of manufacturing such an existing film frame (relative to the film frame according to the first aspect of the invention). This is especially true because the assembly of these separate portions is neither direct nor straightforward, given the rather stringent requirements for film frames used in EUV lithography equipment.

[0011] First, cleaning the surface film frame (and the resulting surface film assembly including the surface film frame) is important to reduce the risk of contaminating the patterning apparatus (mask), to which the surface film frame will be attached during use. For example, it may be desirable to ensure that the number of particles on the surface film frame is below a desired particle threshold (preferably, no particles will be set on the surface film frame). To achieve this, the components of the surface film frame can be maintained in a clean environment until the components are assembled. Assembly can be performed in a clean environment. These clean environments can be maintained under vacuum conditions. Maintaining multiple clean environments (or having clean environments with increased size, i.e., dimensions) will increase manufacturing costs. Furthermore, assembly within a clean environment is challenging.

[0012] Secondly, in use, the film frame is attached to a mask supported by a mask platform. In lithography equipment known as a scanner, where the patterning apparatus and wafer are scanned synchronously via EUV radiation beams, the mask platform and the film frame attached thereto are subjected to significant acceleration. It is important that all parts of the moving mask assembly are sufficiently well connected so that all parts remain connected regardless of these large accelerations. For this reason, it may be preferable to reduce the total number of connected parts. The novel film frame according to the first aspect of the invention achieves this.

[0013] It should be understood that each spring portion may include a portion of the first material having a smaller dimension than the first portion and the plurality of second portions.

[0014] In some embodiments, the first material may have a density of <10*10.-6 K -1 Preferably <10 -6 K -1 The coefficient of thermal expansion (CTE). The first material can be elastic. The first material can be ductile. In some embodiments, the first material can have a Young's modulus greater than 100 GPa. In some embodiments, the first material can have a yield stress less than 1000 MPa, preferably less than 900 MPa. In some embodiments, the first material can have a yield stress less than 5000 kg / m³. 3 More preferably less than 1500 kg / m 3 The density. The first material properties are selected, such as to ensure mask deformation of 400 pm or less in the image area. The first material can be suitable for use in a vacuum environment. The first material can be suitable for use in the environment within an EUV lithography apparatus.

[0015] The first material may include titanium.

[0016] For example, the first material can be a titanium alloy. For example, the first material can include grade 5 titanium. Grade 5 titanium can also be called Ti6Al4V, Ti-6Al-4V, or Ti 6-4. Grade 5 titanium comprises 6% aluminum (Al), 4% vanadium (V), and trace amounts of iron and oxygen; the remainder comprises titanium.

[0017] The first material may include at least 50% titanium. The first material may include at least 70% titanium. The first material may include at least 85% titanium.

[0018] Titanium is suitable for use in vacuum environments, and specifically for use in the environment within EUV lithography equipment. Furthermore, titanium is flexible enough to provide spring sections and ensures that the film frame is not too brittle, allowing it to remain intact during use.

[0019] There can be four second parts, each of which is connected to the first part by a spring part.

[0020] Each of the four second sections can be close to a corner of the first section.

[0021] Two of the second parts may be disposed on one side of the hollow and generally rectangular body of the first part, and the other two of the second parts may be disposed on the opposite side of the hollow and generally rectangular body of the first part.

[0022] Each of the plurality of second portions may include a generally cubic body such that each of the second portions is rectangular in the main plane of the membrane frame.

[0023] Each of the second parts thus provides a generally rectangular surface that can be adhered to the surface of the pattern forming apparatus.

[0024] Each of the spring sections can be configured to allow the first and second sections to make some relative movement along the direction of movement.

[0025] Each of the spring components may comprise a generally cubic or cuboid body. One of the dimensions of the spring component may be significantly smaller than the other two, such that each spring component is generally planar. Specifically, the dimension of the spring component in its direction of movement may be significantly smaller than the other two dimensions of the spring component.

[0026] In the plane of the film frame, each of the spring portions includes a portion of the first material extending along a connection direction from the first portion to one of the second portions. The spring portion has a smaller dimension along a movement direction located in the plane of the film frame and perpendicular to the connection direction to allow some relative movement between the second portion and the first portion along the movement direction.

[0027] That is, each spring portion is a relatively thin portion of the first material, which extends along the connection direction from the first portion to one of the second portions.

[0028] In use, the movement and flexibility provided by the spring portion allow the surface film frame to flex relative to the patterning apparatus, the second portion of which is connected to the patterning apparatus. This configuration accommodates the differential thermal expansion of the patterning apparatus, the surface film frame, and the surface film. This is advantageous because it reduces potentially harmful thermal stresses generated in the surface film frame (which could damage the surface film) and in the patterning apparatus (which could deform the pattern imaged on the wafer). This configuration also reduces the load on the adhesive that connects the surface film to the patterning apparatus (i.e., the adhesive layer between the first portion of the surface film frame and the surface film; and the adhesive layer between each of the second portions of the surface film frame and the patterning apparatus).

[0029] Although each of the spring sections comprises a generally cubic body, the dimension of this body along the direction of movement is significantly smaller than the other two. Specifically, the dimensions of the spring section allow for a certain degree of relative movement between the second and first sections along the direction of movement. It will be understood that the suitable dimensions to achieve this will largely depend on the elastic properties of the first material (e.g., titanium or a titanium alloy).

[0030] The spring portion is preferably large enough in a direction perpendicular to the plane of the diaphragm frame to prevent or at least significantly reduce any relative movement between the first portion and the plurality of second portions away from the plane of the diaphragm frame.

[0031] Typically, each spring section can move in a different direction.

[0032] Each pair of diagonally opposite spring sections can have the same direction of movement, such that the two spring sections have a first direction of movement and the two spring sections have a second direction of movement.

[0033] Each of the spring sections can be configured such that its direction of movement is approximately toward the center of the first section.

[0034] This is advantageous because it means that each spring section allows the film frame and any attached film in each vicinity of the second section (i.e., the location in which each of the second sections is connected to the pattern forming device during use) to move in a direction passing through the center of the first section. This arrangement allows the film frame (and film assembly) to expand uniformly in all directions without rotating relative to the pattern forming device to which the film frame is attached, which is beneficial. Therefore, in this arrangement, if there is uniform heating of the film frame (relative to the temperature of the pattern forming device to which the film frame is attached), the orientation and central position of the film frame relative to the pattern forming device will remain the same.

[0035] Each of the spring portions can be configured such that its connection direction extends through the center point on the second portion to which the spring portion is connected. In embodiments, one or more spring portions form a spring; for example, a first spring portion and a second spring portion can form a spring. For example, when the frame is heated and undergoes thermal deformation, the springs ensure that the frame is mechanically decoupled, i.e., disengaged, from the mask. Mechanical decoupling, i.e., disengagement, ensures that minimal force and torque are applied to the mask. The frame is constrained, for example, by springs at four points on the mask.

[0036] The spring can be a leaf spring, such as a single or double leaf spring. Preferably, the spring is a single leaf spring, such that the spring torque is substantially reduced and the mask deformation occurs in the z-direction of the mask rather than in the xy-plane of the mask.

[0037] The spring can be oriented towards the thermal center of the frame. The thermal center is a point on the frame that does not displace when a temperature change is applied. The advantage of a spring oriented towards the thermal center is that frame deformation, stress, and strain are symmetrical about this thermal center. The spring can be rotated within the frame so that the thermal center of the frame is in the middle, thus overlapping with the center of symmetry.

[0038] Each of the second parts may be disposed outside the generally hollow rectangular body of the first part.

[0039] The membrane frame may further include a plurality of side protrusions projecting from the hollow and generally rectangular body. Each side protrusion may be formed of the first material. Each side protrusion and the hollow and generally rectangular body may define a hole, and each of the plurality of second portions may be disposed in one of the holes.

[0040] That is, each side protrusion, together with the first part, forms a frame surrounding one of the second parts (and its corresponding spring part).

[0041] The side protrusions can be integrally formed with the first portion. Each protrusion projecting from the generally rectangular first portion can typically be in the form of a hollow triangle. A gap can be provided between each second portion and the side protrusions and / or the first portion. This gap allows for a limited degree of movement between each second portion and the first portion in the direction of movement. However, the side protrusions can be large enough to be substantially rigid. The side protrusions can thus act as solid stops to limit the range of movement between each second portion and the first portion in the direction of movement. Advantageously, this can prevent failure / malfunction of the spring portion. Such failure / malfunction may be at risk during the transport of the membrane frame, for example, during its installation into the membrane assembly and / or mask assembly.

[0042] According to a second aspect of the invention, a face film assembly is provided, comprising: a face film frame according to a first aspect of the invention; and a face film comprising: a boundary portion that is hollow and generally rectangular; and a diaphragm defined by the boundary portion; wherein the boundary portion of the face film is attached to the first portion of the face film frame.

[0043] The boundary portion of the membrane can be attached to the hollow and generally rectangular body of the first portion of the membrane frame.

[0044] The boundary portion of the membrane may be formed of a second material, which is different from the first material forming the membrane frame.

[0045] The boundary portion of the film can be formed of silicon.

[0046] As is known in the art, the surface film can be formed by depositing one or more thin layers of material onto a generally rectangular silicon substrate. The silicon substrate supports one or more thin layers during this stage of surface film construction. Once the desired or target thickness and layer composition have been applied, the central portion of the silicon substrate is removed by etching (this process can be referred to as reverse etching). The peripheral portions of the rectangular silicon substrate are not etched (or instead are etched to a lesser extent than the central portions). These peripheral portions form the boundary portions of the final surface film, while the one or more thin layers simultaneously form the diaphragms of the surface film (which are demarcated by the boundary portions).

[0047] Such a surface film typically requires some degree of support from a more rigid surface film frame. The surface film frame provides two functions: (a) it supports the surface film and can also tension the surface film diaphragm; and (b) it facilitates the connection of the surface film to the patterning apparatus (mask). To provide a degree of flexibility allowing for different thermal expansions of the surface film and mask over the operating temperature range experienced by these components during use, it is desirable to select a material for the connection to the patterning apparatus that is sufficiently elastic and suitable for the conditions within an EUV lithography apparatus. A suitable material is titanium. Because the main hollow rectangular portion of the surface film frame is typically adhered to the boundary portions, in known assemblies, this main hollow rectangular portion of the surface film frame is formed of a material whose thermal properties generally match those of the boundary portions of the surface film. For example, silicon is commonly used. For these reasons, there are known surface film frames comprising a silicon body bonded to the surface film and four titanium attachment mechanisms bonded to one side of this body.

[0048] Due to the very different thermal properties of silicon and titanium (titanium has a coefficient of thermal expansion approximately four times that of silicon), there is a significant bias in the art towards materials (such as titanium) used as the body of the surface coating frame, which have thermal properties different from those of silicon. This is because, as the temperature of the surface coating assembly changes, the differential thermal expansion of the frame and boundaries will cause the surface coating assembly to warp or buckle. This, in turn, can exert stress on the patterning apparatus, potentially leading to imaging errors such as increased overlap. However, surprisingly, the inventors have discovered that when using the new surface coating frame, the overlap is no worse than when using known surface coating frames. Therefore, the new surface coating frame provides a simpler and less expensive arrangement without compromising imaging performance.

[0049] The boundary portion of the membrane can be attached to the first portion of the membrane frame by an adhesive.

[0050] The adhesive may be a poly(methyl methacrylate) based adhesive.

[0051] Alternatively, the adhesive may be an epoxy resin adhesive.

[0052] According to a third aspect of the invention, a mask assembly is provided, comprising: a film assembly according to a second aspect of the invention; and a pattern forming apparatus, wherein a plurality of second portions of the film frame are attached to the pattern forming apparatus.

[0053] The mask assembly according to a third aspect of the invention is particularly superior to known arrangements that typically use an intermediate fixing member (referred to as a post) attached to a pattern forming apparatus and engaged with a film assembly, as discussed herein.

[0054] Compared to mask assemblies that use intermediate fixing members such as pillars (attached to the pattern forming apparatus) and engagement mechanisms (disposed on the film assembly) for engaging with the intermediate fixing members (pillars), the mask assembly according to the third aspect of the invention comprises fewer parts. Therefore, advantageously, manufacturing the mask assembly according to the third aspect of the invention is relatively simple. Fewer parts and simpler manufacturing processes can result in lower manufacturing costs.

[0055] This is especially true because the assembly of mask components is neither straightforward nor easy, given the rather stringent requirements for them used in EUV lithography equipment.

[0056] First, cleanliness is crucial for the mask assembly to minimize the risk of contaminating the patterning apparatus (mask). For example, it may be desirable to ensure that the number of particles on the mask assembly is below a desired particle threshold (preferably, no particles are set on the mask assembly). To achieve this, the component portions of the mask assembly can be maintained in a clean environment until the component portions are assembled. Assembly can be performed in a clean environment. These clean environments can be maintained under vacuum conditions. Maintaining multiple clean environments (or clean environments of increasing size) will increase manufacturing costs. Furthermore, assembly within a clean environment is challenging.

[0057] Secondly, in use, the mask assembly is supported by a mask platform. In lithography equipment known as a scanner, where the patterning apparatus and the wafer are scanned synchronously via EUV radiation beams, the mask platform and the film frame attached to it undergo significant acceleration. It is important that all parts of the moving mask assembly are sufficiently well connected so that all parts remain connected regardless of these large accelerations. For this reason, it may be preferable to reduce the total number of parts connected together. The novel mask assembly according to a third aspect of the invention achieves this.

[0058] It is estimated that there is a significant reduction in the cost of manufacturing a mask assembly according to the third aspect of the invention compared to the cost of manufacturing known mask assemblies. For example, the cost of manufacturing a known mask assembly may be approximately 10 times the cost of manufacturing a mask assembly according to the third aspect of the invention.

[0059] Furthermore, the significantly reduced complexity of the mask assembly and its fabrication results in fewer parts, fewer transport steps during the mask assembly manufacturing process, and, moreover, fewer transport steps can be involved. Therefore, the risk of particles or residues on the final mask assembly is lower. This is advantageous because such particles can lead to imaging errors or defects.

[0060] In some embodiments, the separation, i.e., the spacing, between the film and the pattern forming apparatus can be, for example, approximately between 1 mm and 10 mm, for example, between 1 mm and 5 mm, for example, between 2 mm and 2.5 mm.

[0061] The plurality of second portions of the film frame can be attached to the pattern forming apparatus by an adhesive.

[0062] The adhesive may be a poly(methyl methacrylate) based adhesive.

[0063] The material properties of PMMA adhesive, particularly its elasticity and the dimensions to which it can be applied or coated, result in relatively small deformation of the patterning apparatus due to the curing of PMMA (compared to other adhesives). In contrast, if the surface film frame is directly attached to the patterning apparatus using other adhesives, the deformation of the patterning apparatus due to the curing of those other adhesives can be significantly larger, leading to errors in the pattern projected onto the substrate by the photolithography equipment.

[0064] Compared to, for example, epoxy resin adhesives, PMMA adhesives are easier to remove and are relatively more flexible. Advantageously, this allows for easier replacement of the film assembly that forms the portion of the mask assembly according to the third aspect of the invention.

[0065] Alternatively, the adhesive may be an epoxy resin adhesive.

[0066] It should be understood that one or more aspects or features described above or mentioned in the following description may be combined with one or more other aspects or features. Attached Figure Description

[0067] Embodiments of the invention will now be described by way of example only, with reference to the accompanying illustrative drawings, in which:

[0068] - Figure 1It is a schematic diagram of a lithography system that includes lithography equipment and a radiation source;

[0069] - Figure 2 These are schematic illustrations of various devices and photolithography apparatuses according to embodiments of the present invention;

[0070] - Figure 3 This is a perspective view of a known type of membrane assembly;

[0071] - Figure 4 It includes Figure 3 A schematic cross-sectional view of a known mask assembly component of a film assembly;

[0072] - Figure 5 This is another schematic illustration of a known mask assembly;

[0073] - Figure 6 This is a perspective view of a novel membrane frame according to an embodiment of the present invention; and

[0074] - Figure 7 A schematic cross-section of a portion of a new mask assembly, which includes... Figure 6 The new membrane framework shown in the figure. Detailed Implementation

[0075] Figure 1 A lithography system is shown. The lithography system includes a radiation source SO and a lithography apparatus LA. The radiation source SO is configured to generate an extreme ultraviolet (EUV) radiation beam B. The lithography apparatus LA includes an illumination system IL, a support structure MT configured to support a mask assembly 15 including a patterning apparatus MA (e.g., a mask), a projection system PS, and a substrate stage WT configured to support a substrate W. The illumination system IL is configured to adjust the radiation beam B before it is incident on the patterning apparatus MA. The projection system is configured to project the radiation beam B (now patterned by the patterning apparatus MA) onto the substrate W. The substrate W may include a previously formed pattern. In this case, the lithography apparatus aligns the patterned radiation beam B with the pattern previously formed on the substrate W.

[0076] The radiation source SO, the irradiation system IL, and the projection system PS can all be constructed and arranged to be isolated from the external environment. A gas at a pressure below atmospheric pressure (e.g., hydrogen) can be placed in the radiation source SO. A vacuum can be provided in the irradiation system IL and / or the projection system PS. A small amount of gas at a pressure sufficiently below atmospheric pressure (e.g., hydrogen) can be placed in the irradiation system IL and / or the projection system PS.

[0077] Figure 1The radiation source SO shown belongs to the type that can be referred to as a laser-generated plasma (LPP) source. A laser 1, which can be, for example, a CO2 laser, is arranged to deposit energy via a laser beam 2 onto a fuel, such as tin (Sn), supplied from a fuel emitter 3. Although tin is mentioned in the following description, any suitable fuel can be used. The fuel can be, for example, in liquid form and can be, for example, a metal or alloy. The fuel emitter 3 may include nozzles arranged to guide tin, for example, in droplet form, along a track toward a plasma-forming region 4. The laser beam 2 is incident on the tin at the plasma-forming region 4. The laser energy deposited into the tin generates plasma 7 at the plasma-forming region 4. Radiation, including EUV radiation, is emitted from plasma 7 during the de-excitation and recombination of ions in the plasma.

[0078] EUV radiation is collected and focused by a near-normal incident radiation collector 5 (sometimes more commonly referred to as a normal incident radiation collector). Collector 5 may have a multilayer structure arranged to reflect EUV radiation (e.g., EVU radiation with a desired wavelength such as 13.5 nm). Collector 5 may have an elliptical configuration with two elliptical foci. The first focal point may be located at the plasma formation region 4, and the second focal point may be located at the intermediate focal point 6, as discussed below.

[0079] In other embodiments of the laser-generated plasma (LPP) source, collector 5 may be a so-called grazing-incidence collector, configured to receive EUV radiation at a grazing-incidence angle and focus the EUV radiation at an intermediate focal point. For example, the grazing-incidence collector may be a nested collector comprising multiple grazing-incidence reflectors. The grazing-incidence reflectors may be arranged axially symmetrical about the optical axis.

[0080] The radiation source SO may include one or more contaminant traps (not shown). For example, a contaminant trap may be located between the plasma formation region 4 and the radiation collector 5. The contaminant trap may be, for example, a rotating vane trap, or any other suitable form of contaminant trap.

[0081] Laser 1 can be separated from radiation source SO. In this case, laser beam 2 can be transmitted from laser 1 to radiation source SO by means of a beam delivery system (not shown) including, for example, suitable directional mirrors and / or beam expanders and / or other optical devices. Laser 1 and radiation source SO can be considered together as a radiation system.

[0082] Radiation reflected by collector 5 forms radiation beam B. Radiation beam B is focused at point 6 to form an image of plasma formation region 4, which serves as a virtual radiation source for irradiating system IL. Point 6, where radiation beam B is focused, may be referred to as the intermediate focal point. Radiation source SO is arranged such that intermediate focal point 6 is located at or near opening 8 in the enclosure structure 9 of radiation source SO.

[0083] A radiation beam B is transmitted from a radiation source SO to an irradiation system IL, which is configured to modulate the radiation beam. The irradiation system IL may include a faceted field mirror assembly 10 and a faceted pupil mirror assembly 11. The faceted field mirror assembly 10 and the faceted pupil mirror assembly 11 together provide a radiation beam B with a desired cross-sectional shape and a desired angular distribution. The radiation beam B is transmitted from the irradiation system IL and incident on a mask assembly 15 held by a support structure MT. The mask assembly 15 includes a pattern forming device MA and a surface film 19, which is held in place by a surface film frame 17. The pattern forming device MA reflects and patternes the radiation beam B. In addition to or in place of the faceted field mirror assembly 10 and the faceted pupil mirror assembly 11, the irradiation system IL may also include other mirrors or devices.

[0084] After reflection from the patterning apparatus MA, the patterned radiation beam B enters the projection system PS. The projection system includes multiple mirrors configured to project the radiation beam B onto a substrate W held by a substrate stage WT. The projection system PS can apply a reduction factor to the radiation beam to form an image with features smaller than the corresponding features on the patterning apparatus MA. For example, a reduction factor of 4 can be applied. Although in Figure 1 The projection system PS has two mirrors, but the projection system can include any number of mirrors (e.g., six mirrors).

[0085] The photolithography apparatus can be used, for example, in a scanning mode, where a support structure (e.g., a mask stage) MT and a substrate stage WT are scanned simultaneously while a pattern to be applied to a radiation beam is projected onto a substrate W (i.e., dynamic exposure). The velocity and orientation of the substrate stage WT relative to the support structure (e.g., the mask stage) MT can be determined by the reduction ratio 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 referred to as an exposure slit. During scanning exposure, the movement of the substrate stage WT and the support structure MT allows the exposure slit to travel across the entire exposure field of the substrate W.

[0086] Figure 1The radiation source SO and / or lithography apparatus shown may include components not illustrated. For example, a spectral filter may be incorporated into the radiation source SO. The spectral filter may substantially transmit EUV radiation but substantially block radiation of other wavelengths, such as infrared (IR) radiation.

[0087] In other embodiments of the lithography system, the radiation source SO can take other forms. For example, in an alternative embodiment, the radiation source SO may include one or more free-electron lasers. These one or more free-electron lasers may be configured to emit EUV radiation that can be supplied to one or more lithography apparatuses.

[0088] As briefly described above, the mask assembly 15 includes a surface film 19 disposed adjacent to the patterning apparatus MA. The surface film 19 is positioned in the path of the radiation beam B such that the radiation beam B passes through the surface film 19 in both its approach to the patterning apparatus MA from the irradiation system IL and its reflection from the patterning apparatus MA toward the projection system PS. The surface film 19 comprises a thin film that is substantially transparent to EUV radiation (although it will absorb a small amount of EUV radiation). In this document, an EUV-transparent surface film or membrane that is substantially transparent to EUV radiation means that the surface film 19 transmits at least 65%, preferably at least 80%, and more preferably at least 90% of the EUV radiation. The surface film 19 serves to protect the patterning apparatus MA from particle contamination.

[0089] Although efforts can be made to maintain a clean environment inside the lithography apparatus LA, particles may still be present inside the lithography apparatus LA. In the absence of the surface film 19, particles can be deposited onto the patterning apparatus MA. Particles on the patterning apparatus MA may adversely affect the pattern imparted to the radiation beam B and thus affect the pattern transferred to the substrate W. The surface film 19 advantageously provides a barrier between the environment in the lithography apparatus LA and the patterning apparatus MA to prevent particle deposition on the patterning apparatus MA.

[0090] The surface film 19 is positioned at a distance sufficient to prevent any particles incident on the surface of the surface film 19 from being in the field plane of the lithography apparatus LA. This separation, or spacing, between the surface film 19 and the lithography apparatus MA reduces the range by which any particles on the surface of the surface film 19 impart a pattern to the radiation beam B, which is imaged onto the substrate W. It will be understood that if a particle is present in the radiation beam B but is not in the field plane of the radiation beam B (i.e., not on the surface of the lithography apparatus MA), any image of the particle will not be focused on the surface of the substrate W. In the absence of other considerations, it may be desirable to position the surface film 19 at a considerable distance from the lithography apparatus MA. However, in practice, the space available in the lithography apparatus LA to house the surface film is limited by the presence of other components. In some embodiments, the separation, or spacing, between the surface film 19 and the lithography apparatus MA may be, for example, between about 1 mm and 10 mm, for example, between 1 mm and 5 mm, more preferably between 2 mm and 2.5 mm.

[0091] A mask assembly can be fabricated for use in a photolithography apparatus by attaching a surface film to a surface film frame and by attaching the surface film frame to a patterning apparatus. The mask assembly (including the patterning apparatus MA and the surface film supported by the surface film frame adjacent to the patterning apparatus) can be fabricated remotely from the photolithography apparatus LA, and the mask assembly can be transported to the photolithography apparatus LA for use therein. For example, the surface film frame supporting the surface film can be attached to the patterning apparatus at a location or site where a pattern is applied to the patterning apparatus to form the mask assembly. The mask assembly can then be transported to a separate site on the photolithography apparatus LA, and the mask assembly can then be provided to the photolithography apparatus LA for use therein.

[0092] The mask assembly, in which the surface layer is held in place by a mask frame, may be delicate, and the transport of the mask assembly may risk damaging the surface layer. Assembling the mask assembly into a lithography apparatus LA in a separate environment may further expose the mask assembly to various pressure conditions. For example, the mask assembly may be transported to the lithography apparatus under ambient pressure. The mask assembly may then be loaded into the lithography apparatus LA via a loading lock pumped to vacuum pressure conditions. Changes in the pressure conditions exposed to the mask assembly may create a pressure difference across the entire surface layer, i.e., at both ends of the surface layer, which may cause the surface layer to bend and may risk damaging it. In an embodiment, the lithography system may include a lithography apparatus LA attached to a mask frame attachment device. In such a case, the mask assembly, including the mask and the surface layer, can be transported directly from the mask frame attachment device to the lithography apparatus while being held in a controlled environment (e.g., a vacuum environment).

[0093] The manufacture of mask assemblies is a complex process, and therefore, the cost of manufacturing mask assemblies is very high. Embodiments of the present invention relate to a novel surface frame that significantly reduces the complexity of mask assemblies and their manufacture. This, in turn, results in a cost reduction of approximately 10 times (i.e., a cost reduction to 1 / 10). Furthermore, the significantly reduced complexity of the mask assembly and its manufacture leads to fewer parts, fewer transport steps during the manufacturing process of the mask assembly, and these transport steps can be involved less frequently. Therefore, the risk of particles or residues on the final mask assembly is lower. This is advantageous because such particles can lead to imaging errors or defects. To better understand the advantages of the new surface frame (and the surface assembly and mask assembly using the new surface frame), it is useful to first consider existing known arrangements and manufacturing processes; therefore, reference will now be made to… Figures 2 to 4 To describe the existing known layout and manufacturing process.

[0094] Figure 2 This is a schematic illustration of a known apparatus suitable for assembling a mask assembly 15' of a known type and transferring the mask assembly to a photolithography apparatus LA. Figure 2 The following are depicted: a film attachment device 855 for attaching a film 19 to a known film frame 17'; and a film assembly transport device 881 for transporting a film assembly 16'. Additionally, a pillar attachment device 840 is depicted for attaching a pillar 51 to a pattern forming apparatus MA. The pillar 51 allows for releasable attachment of the film frame 17' (and the film 19 supported therefrom) to the pattern forming apparatus MA. A mask transport device 880 is also depicted for transporting a mask with a pillar attached. A film frame attachment device 857 is also depicted for attaching the film frame 17' (and the film 19) to the pattern forming apparatus MA, thereby forming a mask assembly 15'. Mask assembly transport device 853 is also shown, which can be used to transport mask assembly 15' from mask frame attachment device 857 to lithography device LA.

[0095] The surface coating attachment device 855 may be located at a different site than the lithography device LA. The post attachment device 840 may be located at a different site than the lithography device LA. Alternatively, either or both of the surface coating attachment device 855 and the post attachment device 840 may be located at the same site as the lithography device LA (e.g., in a lithography manufacturing plant).

[0096] The film attachment device 855 receives the film 19, the known film frame 17', and the bonding mechanism (not shown). The film 19 and the known film frame 17' can be manually placed in the film attachment device 855. Adhesive is dispensed into the bonding mechanism receiving opening of the known film frame 17' (e.g., see reference below). Figure 3 and Figure 4 (Further description of the area). Adhesive dispensing can be manual or automatic (or partially automatic).

[0097] The engagement mechanism and the known membrane frame 17' (e.g., using an optical alignment device) are aligned relative to each other, and the engagement mechanism is then inserted into the opening of the known membrane frame 17'.

[0098] Adhesive is also applied to the known film frame 17' (e.g., at spaced locations around the known film frame 17'). Adhesive application can be manual or automatic (or partially automatic). An optical alignment system is used to align the film 19 relative to the known film frame 17', and the film is then pressed against the known film frame 17'.

[0099] The film 19 can be manipulated by a film manipulator, which forms part of the film attachment device 855. The film manipulator may include means for tensioning the film 19. The film manipulator can tension the film 19 and hold it against a known film frame 17' at room temperature for a period sufficient to allow the adhesive to cure, thereby securing the film 19 to the known film frame 17'. The pressure on the film 19 is then removed. Additional curing of the adhesive at a high temperature is then performed using a curing oven (which may form part of the film attachment device 855). This also cures the adhesive that attaches the bonding mechanism to the known film frame 17'. Alternatively, some heat may be applied while the film 19 is held against the known film frame 17' to cure the adhesive (as an alternative to allowing curing at room temperature).

[0100] The adhesive can be supplied by an adhesive dispenser. The adhesive dispenser can form part of the film attachment device 855.

[0101] A particle inspection tool is used to inspect the obtained known membrane assembly 16'. The particle inspection tool may be part of the membrane attachment device 855 (or may be a separate tool). The particle inspection tool may be configured to inspect particles disposed on the membrane 19 and / or the known membrane frame 17'. The particle inspection tool may, for example, reject a known membrane assembly 16 having a number of particles greater than a given particle threshold. The particle inspection tool may also be used to inspect the membrane 19 and / or the known membrane frame 17' before the membrane and membrane frame are glued together.

[0102] The film attachment device 855 can be configured to seal the known film assembly 16' in the film assembly conveyor 881 (sealed box) after inspection. As depicted, the film assembly conveyor 881 can be arranged to hold the film assembly with the film 19 positioned below the known film frame 17'. Because the conveyor 881 is sealed, the known film assembly 16' can be conveyed uncontaminated. The known film assembly 16' can then be conveyed in the conveyor 881 to the film frame attachment device 857.

[0103] The membrane attachment device 855 may include a clean environment to reduce the number of particles within the sealed environment, thereby reducing the number of particles that may be deposited on the membrane 19. The membrane attachment device 855 may be located, for example, at the site where the membrane is manufactured. The membrane 19 may be provided directly to the membrane attachment device 855 from a membrane manufacturing tool (not shown) in which the membrane 19 is manufactured. The membrane 19 may be provided to the membrane attachment device 855, for example, from the membrane manufacturing tool while simultaneously being held within the clean environment. This reduces the chance, or possibility, of the membrane 19 being contaminated or damaged before being provided to the membrane attachment device 855. The clean environment may be, for example, a sealed environment (i.e., completely isolated from the external environment). The sealed environment may be pumped to maintain a vacuum within the sealed environment.

[0104] The attachment of the membrane 19 to the known membrane frame 17' can be controlled to achieve a desired tension in the membrane 19. For example, the tension in the membrane 19 can be measured during or after attachment of the membrane 19 to the known membrane frame 17', and the tension can be adjusted in response to the measurement to achieve the desired tension in the membrane 19. For example, the tension in the membrane 19 can be maintained by applying an outward force to a component of the known membrane frame 17' to stretch the membrane 19. The tension in the membrane 19 can be maintained, for example, by using the difference in the coefficients of thermal expansion between the membrane frame and the membrane.

[0105] The pattern forming apparatus (which may be referred to as a mask) MA may be provided with protrusions, which are engaged by a coupling mechanism (e.g., as referred to below). Figure 3 and Figure 4 (Further description) Receiving. The pattern forming apparatus may, for example, receive four protrusions (referred to herein as pillars). Figure 2 As depicted, the column attachment device 840 can be used to attach the column 51 to the pattern forming apparatus MA.

[0106] The column 51 and the pattern forming apparatus MA can be manually placed within the column attachment device 840. The pattern forming apparatus MA can be held in a controlled environment 841, separate from the rest of the column attachment device 840. This separation, or spacing, can be provided by a partition 842 with an opening through which the column 51 can protrude to contact the pattern forming apparatus MA. The controlled environment 841 can be maintained at a higher pressure than the rest of the column attachment device 840 (e.g., by passing gas through an outlet in the controlled environment). This will prevent or inhibit the transfer of contaminant particles from the rest of the column attachment device into the controlled environment 841.

[0107] The column attachment device 840 may include a column manipulator (not depicted), such as a robot or actuator for accurately placing the column. An example of a suitable actuator for placing the column onto the pattern forming apparatus is a Lorentz actuator (not depicted). The column attachment device 840 may also include means for automatically supplying a given amount of glue or adhesive to the surface of the column to be attached to the pattern forming apparatus MA. Glue or adhesive may also be applied manually. Airflow from the controlled environment 841 above the partition 842 to below the partition prevents or reduces contamination of the pattern forming apparatus MA by glue or adhesive (the airflow is caused by a higher pressure above the partition than below the partition).

[0108] The column attachment device 840 may also include an optical alignment system that aligns the column relative to alignment marks present on the mask for accurate positioning. For example, alignment marks conventionally provided on the pattern forming apparatus MA for pattern alignment can also be used to align the column.

[0109] The column attachment device may include a support structure capable of moving along the XYZ and Rz directions to adjust the position of the pattern forming apparatus MA. The position of the support structure holding the pattern forming apparatus MA can be adjusted manually by means of coarse and fine mechanical adjustment devices, or by using automatic (or semi-automatic) actuators, or any other type of device suitable for alignment and positioning and coupled to the stage of the pattern forming apparatus.

[0110] Once the post 51 is aligned with the pattern forming apparatus MA, the post 51 is then pressed against the pattern forming apparatus MA. The post 51 can be held against the pattern forming apparatus MA at room temperature for a period sufficient to allow the adhesive to cure, thereby securing the post 51 to the mask MA. Alternatively, the post 51 can be heated to accelerate the curing of the adhesive. Further curing of the adhesive at high temperatures can then be performed using a curing oven (which may form part of the post attachment device 840).

[0111] The adhesive can be supplied by an adhesive dispenser. The adhesive dispenser can form part of the post attachment device 840.

[0112] The pattern forming apparatus MA and the column 51 can be inspected using a particle inspection tool (which can form a part of the column attachment device 840).

[0113] The post attachment device 840 seals the pattern forming apparatus MA and the post 51 within the mask transport device 880 (sealed housing). Because the mask transport device 880 is sealed, the pattern forming apparatus MA and the post 51 can be transported without contamination of the mask MA. The pattern forming apparatus MA and the post can then be transported in the mask transport device 880 to the film frame attachment device 857.

[0114] The mask MA can be provided to the post attachment device 840 in a sealed enclosure (to reduce the risk of contamination). The enclosure can remain sealed until just before the post 51 is to be attached to the pattern forming apparatus MA, thereby minimizing the time that contaminants may travel to the mask MA.

[0115] The controlled environment 841 of the column attachment device 840 can be partially provided by a housing that subsequently forms part of the pattern forming apparatus MA transport device 880 (sealed box). The housing can form the walls and top of the mask transport device 880, wherein the bottom of the mask transport device 880 is formed by a plate that is adapted / assembled after the column 51 has been attached (e.g., immediately after attachment). Using the housing in this way can help prevent contamination from entering the pattern forming apparatus MA. The housing may include a pod cover. The mask stage of the column attachment device 840 can be configured to receive the housing.

[0116] Similarly, the film attachment device 855 can also be partially formed by a housing, which subsequently forms part of the film assembly delivery device 881.

[0117] Both the known film assembly 16' in the film assembly transport device 881 and the pattern forming device MA (and column 51) in the mask transport device 880 are transported to the film frame attachment device 857. The film frame attachment device 857 may be located in a factory, where one or more photolithography devices are also located.

[0118] The mask frame attachment device 857 is configured to attach a known mask frame 17' of a known mask assembly 16' to a post 51 on the pattern forming apparatus MA to form a mask assembly 15. The mask frame attachment device 857 may include a controlled environment 860 separate from the rest of the mask frame attachment device 857. Separation, i.e., spacing, may be provided by a partition 862 with an opening through which an actuator extends ( Figure 2 (Not shown in the image). The manipulator can be operated by a control system 870 (described further below). The controlled environment 860 can be maintained as a clean environment to reduce the number of particles within the controlled environment, thereby reducing the number of particles that can be deposited on the known mask assembly 15'. The controlled environment 860 can be maintained at a higher pressure compared to other parts of the membrane frame attachment device 857 (e.g., by passing gas through an outlet in the controlled environment 860). This will prevent or inhibit the transfer of contaminant particles from other parts of the membrane frame attachment device 857 into the controlled environment 860.

[0119] A known mask assembly 15' assembled by a mask frame attachment device 857 is transported from the mask frame attachment device 857 to the lithography apparatus LA in a mask assembly transport device 853. The mask assembly transport device 853 may include a sealed and clean environment for transporting the known mask assembly 15'. This reduces the probability of the known mask assembly 15' being contaminated or damaged during transport. The sealed and clean environment may, for example, be pumped to a vacuum.

[0120] The film frame attachment device 857 is used to mount a known film assembly 16' to the pattern forming apparatus MA. The film frame attachment device 857 includes an actuator (described further below) arranged to manipulate the engagement mechanism of the film frame 17.

[0121] The pattern forming apparatus MA may, for example, be provided with alignment marks. The known film frame 17' can be positioned relative to the alignment marks on the pattern forming apparatus MA. Aligning the film frame 17' relative to the alignment marks on the pattern forming apparatus MA can advantageously increase the accuracy of the known film frame 17' being positioned on the pattern forming apparatus MA during the attachment of the known film frame 17' to the pattern forming apparatus MA.

[0122] The membrane frame attachment device 857 may include a particle inspection tool (not shown). The particle inspection tool may be configured to inspect a known mask assembly 15' for particles disposed on the known mask assembly 15'. The particle inspection tool may, for example, have a mask assembly 15' with a number of particles disposed on the known mask assembly 15' greater than a given particle threshold.

[0123] The film frame attachment device 857 may include a pattern inspection system for inspecting patterns on the pattern forming device MA for any defects. The pattern inspection system may inspect the patterns on the pattern forming device MA before and / or after the known film frame 17' is attached to the pattern forming device MA.

[0124] The lithography apparatus LA may include multiple components configured to receive a known mask assembly 15' from the mask assembly transport device 853 and load the known mask assembly 15' onto the support structure MT of the lithography apparatus LA.

[0125] The known mask assembly 16' can be attached to the patterning apparatus MA to form the known mask assembly 15' under vacuum conditions in the mask frame attachment device 857. The known mask assembly 15' can then be transported to the lithography apparatus LA under vacuum conditions by the mask assembly transport device 853 and can be held in the lithography apparatus LA under vacuum conditions. The known mask assembly 15' can thus be exposed to approximately the same pressure conditions throughout its assembly process in the mask frame attachment device 857 and in the lithography apparatus LA. This advantageously reduces any pressure changes to which the known mask assembly 15' is exposed, and thus reduces any pressure difference that may occur across the entire mask 19, i.e., at both ends of the mask 19.

[0126] The patterning apparatus MA and / or the surface film 19 can be inspected for particles and / or defects in the surface film frame attachment device 857 while the components are held in a vacuum. The patterning apparatus MA and / or the surface film 19 are therefore advantageously inspected under pressure conditions similar to those they are exposed to during use in the photolithography apparatus LA. This is advantageous because any particles that could be deposited on the patterning apparatus MA and / or the surface film during the down-pumping to vacuum conditions can be detected in the surface film frame attachment device 857.

[0127] It should be noted that the patterned side of the pattern forming apparatus MA is... Figure 2 During the various operations depicted, the patterned side of the patterning apparatus MA is pointed downwards. It is advantageous to keep the patterned side of the patterning apparatus MA pointing downwards because this reduces the likelihood of contaminant particles incident on the pattern. Larger contaminant particles tend to fall due to gravity and thus will incident on the opposite side of the mask. Smaller contaminant particles are less affected by gravity and are instead affected by other transport physics. The apparatus may include means intended to address this problem. For example, the apparatus may include an ion generator for removing static charge and thereby reducing the risk of electrostatic particles attaching to the surface film.

[0128] The known membrane component 16' is illustrated in Figure 3In the figure, a known mask assembly including such a known film component 16' is illustrated. Figure 4 middle.

[0129] Figure 3 The known surface membrane assembly 16' shown includes a surface membrane 19 and a known surface membrane frame 17'. The surface membrane 19 includes a boundary portion 19a and a diaphragm 19b. The boundary portion 19a is hollow and generally rectangular and surrounds the diaphragm 19b, which is delimited by the boundary portion 19a. The boundary portion 19a may be formed of silicon.

[0130] The known film frame 17' comprises a hollow, generally rectangular body with four protrusions 20a to 20d extending from the generally rectangular body in the main plane of the known film frame 17'. The four protrusions 20a to 20d are generally trapezoidal. Two of the protrusions 20a to 20b protrude from one side of the generally rectangular body, and the other two protrusions 20c to 20d protrude from the opposite side of the generally rectangular body. The generally rectangular body and the four protrusions 20a to 20d are integrally formed and are made of silicon.

[0131] The known membrane frame 17' is provided with four engagement mechanisms 22a to 22d. Each of the four protrusions 20a to 20d defines a recess for receiving one of the engagement mechanisms 22a to 22d.

[0132] Each engagement mechanism 22a to 22d is configured to engage a protrusion 24 (which may be referred to, for example, as a post 51), the protrusion extending from the pattern forming apparatus MA (as exactly in...). Figure 4 (Illustrative illustration).

[0133] The film 19 is attached to a known film frame 17'. Specifically, the boundary portion 19a of the film 19 is attached to the generally rectangular body of the known film frame 17'. The boundary portion 19a of the film 19 may, for example, be glued to the known film frame 17'.

[0134] The protrusions 51 received by the engagement mechanisms 22a to 22d are located on the front surface of the pattern forming apparatus MA.

[0135] Figure 3 Four engagement mechanisms 22a to 22d are depicted being fastened to the film frame 17. All four engagement mechanisms 22a to 22d are configured to allow engagement between the engagement mechanisms 22a to 22d and the protrusion 51 (not depicted) via movement in the y-direction.

[0136] Each engagement mechanism 22a to 22d includes a generally square outer portion 24, which is secured (e.g., glued) to a recess defined by one of the protrusions 20a to 20b of the faceplate frame 17. Each engagement mechanism 22a to 22d is disposed on the outer portion 24 having a flange 26 (which may be referred to as tab 26) and facilitates engagement and alignment between the engagement mechanism 22a to 22d and the known faceplate frame 17'. Furthermore, each engagement mechanism 22a to 22d includes a generally square inner portion 28 (within the outer portion 24) that engages with a protrusion 51 on the pattern forming apparatus MA. The inner portion 28 is connected to and supported by the outer portion via two arms 30. These two arms 30 allow movement / flexibility in the y-direction or x-direction. The two engagement mechanisms 22a, 22d are configured to allow movement in the y-direction (i.e., provide flexibility or compliance in the y-direction). The two engagement mechanisms 22b and 22c are configured to allow movement in the x-direction (i.e., to provide flexibility or compliance in the x-direction).

[0137] Although details will not be described here, the internal portion 28 of each is an engagement mechanism 22a to 22d with engagement arms 32, which can be deflected from the main plane of the engagement mechanism 22a to 22d by an actuation force to allow insertion of the distal end of one of the protrusions 51. Once the protrusion 51 is in place, the actuation force is removed, and the protrusion 51 remains captured in the engagement mechanism 22a to 22d. This configuration requires an actuator to be disposed within a facepiece frame attachment device 857, which includes several independently movable arms. Typically, at least two arms are required for each engagement mechanism 22a to 22d to engage the engagement mechanism 22a to 22d, while simultaneously requiring at least a third arm to apply an actuation force to the engagement arm 32. Setting up four such actuators (one actuator for each engagement mechanism 22a to 22d) that can operate in a clean environment is very challenging.

[0138] Figure 4 A cross-section is depicted of a joining mechanism 22a and a protrusion 51 projecting from the pattern forming apparatus MA. The protrusion 51, which may be referred to as a post, may be glued to the pattern forming apparatus MA, for example, or may be attached by other joining means (optical contact, magnetic force, or van der Waals force, etc.). The protrusion 51 is formed of a material including titanium.

[0139] Figure 5 This is another schematic diagram of a cross-section of a portion of the known mask assembly 15' as described above. Figure 5 The cross section shown is perpendicular to the y-direction (i.e., perpendicular to the x-direction). Figure 4The plane of the pattern forming apparatus MA is in the plane of the pattern forming apparatus MA and passes through the joining mechanism 22a and one of the associated posts 51. The posts 51 are fixed to the pattern forming apparatus MA using adhesive.

[0140] Figure 6 This is a perspective view of a novel membrane frame 17 according to an embodiment of the present invention.

[0141] The film frame 17 includes a first portion 40, four second portions 42, and four spring portions 44. The first portion 40, the four second portions 42, and the four spring portions 44 are all integrally formed and made of the same material, which may be referred to as the first material. In this embodiment, the first portion 40, the four second portions 42, and the four spring portions 44 are all formed of a material including titanium (e.g., a titanium alloy). Specifically, the first portion 40, the four second portions 42, and the four spring portions 44 are all formed of titanium (grade 5). Grade 5 titanium may also be referred to as Ti6Al4V, Ti-6Al-4V, or Ti 6-4. Grade 5 titanium comprises 6% aluminum (Al), 4% vanadium (V), and trace amounts of iron and oxygen; the remainder comprises titanium.

[0142] As will be explained further below, the first portion is used to connect to the boundary 19a of the membrane 19. The first portion 40 includes a hollow and generally rectangular body.

[0143] As will be explained further below, the four second parts 42 are for connection to the pattern forming device MA.

[0144] Each of the second parts 42 is connected to the first part 40 by a spring part 44. Each of the four second parts 42 is immediately adjacent to a corner of the first part 40. Two of the second parts 42 are disposed on one side 46 of the hollow and generally rectangular member of the first part 40. The other two second parts 42 are disposed on the opposite side 48 of the hollow and generally rectangular member of the first part 40.

[0145] Each of the multiple second parts 42 comprises a generally cubic body. In the main plane of the membrane frame 17 ( Figure 6 In the xy plane, each of the second parts 42 is a rectangle. Each of the second parts 42 thus provides a generally rectangular surface that can be adhered to the surface of the pattern forming apparatus MA (discussed further below).

[0146] Each of the spring portions 44 is configured to allow some relative movement between the first portion 40 and the second portion 42, the second portion being connected to the first portion in the direction of movement, as now described.

[0147] Each of the spring sections 44 comprises a generally cubic body. On the main plane of the membrane frame 17 ( Figure 6 In the xy plane, each of the spring portions 44 extends along a connection direction from one of the first portion 40 to the second portion 42. Each spring portion 44 has a smaller dimension along the movement directions 50, 52, which are located in the main plane of the membrane frame 17 and perpendicular to the connection direction. The movement direction of each spring portion 44 is in... Figure 6 The directions are indicated by arrows 50 and 52. Note that typically, each spring portion 44 may have different directions of movement 50 and 52. In this embodiment, each pair of diagonally opposite spring portions 44 has the same directions of movement 50 and 52, such that two spring portions 44 have a first direction of movement 50 and two spring portions 44 have a second direction of movement 52. Although each of the spring portions 44 comprises a generally cubic body, the dimensions of this body in the directions of movement 50 and 52 are significantly smaller than the other two dimensions. Specifically, the dimensions of the spring portions 44 are such that the spring portions 44 allow the second portion 42 and the first portion 40 to make some relative movement along the directions of movement 50 and 52. It will be understood that the suitable dimensions to achieve this will largely depend on the elastic properties of the first material (in this example, a titanium alloy). In one embodiment, the spring portion 44 may have the following approximate dimensions: width 0.2 mm, length 5.5 mm, and height 1.4 mm.

[0148] Each spring portion 44 is a relatively thin portion of a first material (the first portion 40 and the second portion 42 are formed of the first material), which extends along the connection direction from the first portion 40 to one of the second portions 42. In use, the movement and flexibility provided by the spring portions 44 allow the surface film frame 17 (and the attached surface film 19) to flex relative to the pattern forming apparatus MA connected to the second portions 42. This arrangement accommodates the differential thermal expansion of the pattern forming apparatus MA, the surface film frame 17, and the surface film 19. This is advantageous because it reduces potentially harmful thermal stresses generated in the surface film frame 17 (which could damage the surface film 19) and the pattern forming apparatus MA (which could deform the pattern projected onto the wafer W). This arrangement also reduces the load on the adhesives that connect the surface film 19 to the pattern forming apparatus MA (i.e., the adhesive layer between the first portion 40 of the surface film frame 17 and the surface film 19; and the adhesive layer between each of the second portions 42 of the surface film frame 17 and the pattern forming apparatus MA).

[0149] Furthermore, due to the different materials used to form the film 19 and the film frame 17, a certain degree of differential thermal expansion may exist between the film 19 and the film frame 17, which may cause a certain degree of deformation of the film assembly 16 formed by these components. The movement and flexibility provided by the spring portion 44 also accommodate such deformation without placing a load on the pattern forming apparatus MA or any of the adhesives in the adhesive that connects the film 19 to the pattern forming apparatus MA (or at least reducing any such load).

[0150] The spring portion 44 is preferably large enough in the direction perpendicular to the main plane of the film frame 17 to prevent, or at least significantly reduce, any relative movement of the screen between the first portion 40 and the second portion 42 away from the film frame (i.e., Figure 6 (in the z-direction).

[0151] Each second portion 42 and its connected spring portion 44 can be considered as forming a system suspended from the first portion 40. Similarly, the spring portion 44 and the first portion 40 can be considered as forming a system suspended from the second portion 42 connected to the spring portion 44.

[0152] In the main plane of the membrane frame 17 ( Figure 6 In the xy plane, the dimensions of the second part 42 can be approximately the same as the thickness of the first part, for example, about 5 mm. In the main plane of the membrane frame 17 (… Figure 6 In the xy plane, the spring portion 44 may have the same dimensions as the second portion 42 and the same thickness as the first portion (e.g., approximately 5 mm). In one embodiment, in the main plane of the film frame 17 ( Figure 6 In the xy plane, the second part 42 has a size of 4.5mm by 4.5mm; the thickness of the first part is about 3.85mm; and the length of the spring part 44 is about 5.5mm.

[0153] In the main plane of the membrane frame 17 ( Figure 6 In the xy plane, the spring portion 44 can have a width that is about 20 times smaller than its length, the length and dimensions of the second portion 42, and the thickness of the first portion, i.e., 1 / 20.

[0154] Perpendicular to the main plane of the membrane frame 17, all parts of the membrane frame 17 may be approximately equal in size, and may be, for example, about 1.4 mm.

[0155] Each of the spring portions 44 is configured such that its direction of movement 50, 52 points approximately toward the center 54 of the first portion 40. To better illustrate this situation, a number of straight lines are arranged... Figure 6Above. Two dashed lines are shown, each extending between diagonally opposite corners of the first portion 40. The intersection of these two dashed lines is the center 54 of the first portion 40. A straight line from the center point on each of the second portions 42 to the center 54 of the first portion 40 is also shown. It can be seen that the directions of movement 50, 52 of each spring portion 44 are generally directed toward the center 54 of the first portion 40. This is achieved by orienting each spring portion 44 such that its connection direction (from the first portion 40 to the second portion 42 in the plane of the film frame 17) is perpendicular to the straight line from the center point on the second portion 42 to the center 54 of the first portion 40. This is advantageous because it means that each spring portion 44 allows the film frame 17 and the film to move in the vicinity of each of the four second portions 42 (i.e., the four locations where they are connected to the pattern forming apparatus MA) in a direction passing through the geometric center 54 of the first portion 40 (and therefore the geometric center of the film assembly). This arrangement allows the film frame 17 (and the film assembly) to expand uniformly in all directions without rotating relative to the pattern forming apparatus MA, which is advantageous. Therefore, with this arrangement, if there is uniform heating of the film frame 17 (relative to the temperature of the pattern forming apparatus MA), the orientation and center position of the film frame 17 relative to the pattern forming apparatus MA will remain the same. The intersection of the straight lines from the center point on each second portion 42 to the center 54 of the first portion 40 can be considered as the “starting point” of expansion, and since these lines intersect at a point of intersection, the system will expand uniformly in every direction.

[0156] Each of the spring portions 44 is configured such that its connection direction (from the first portion 40 to the second portion 42 in the plane of the membrane frame 17) extends through the center point on the second portion 42.

[0157] Each of the second part 42 is disposed outside the generally hollow rectangular body of the first part 40.

[0158] The membrane frame 17 also includes four side protrusions 56 projecting from the first portion 40. The protrusions 56 are also formed of a first material (in this example, titanium alloy). The protrusions 56 are integrally formed with the first portion 40. Each side protrusion 56, together with the first portion 40, defines an aperture, and each of the second portions 42 (and its corresponding spring portion 44) is disposed in one of the apertures. That is, each side protrusion 56, together with the first portion 40, forms a frame around one of the second portions 42 (and its corresponding spring portion 44). Each protrusion 56 projecting from the generally rectangular first portion 40 generally has the form of a hollow triangle. A gap is provided between the second portion 42 and the protrusions 56 and / or the first portion 40 (as will be referred to below). Figure 7(Further description). This gap allows for a limited degree of movement between each second portion 42 and the first portion 40 along the movement directions 50, 52. However, the protrusion 56 is large enough to be substantially rigid. In one embodiment, on the main plane of the membrane frame 17 (i.e., Figure 6 In the xy plane, the protrusion 56 may have a thickness of approximately 1 mm. The dimension of the side protrusion 56 in the direction perpendicular to the main plane of the faceplate frame 17 may be approximately the same as the dimension of the other parts of the faceplate frame, for example, approximately 1.4 mm. The protrusion 56 thus acts as a solid stop to limit the range of movement between each second part 42 and the first part 40 in the movement directions 50, 52. Advantageously, this can prevent failure, i.e., malfunction, of the spring part 44. Specifically, the protrusion 56 is beneficial in protecting the spring part 44 from such failure / malfunction during the transport of the faceplate frame 17 (e.g., during the assembly of the faceplate assembly and the mask assembly).

[0159] The new diaphragm frame 17 is advantageous because the first part 40, the plurality of second parts 42, and the spring part 44 are all formed of the same material (e.g., titanium alloy). This significantly simplifies the manufacture of the diaphragm frame 17. For example, all parts of the diaphragm frame can be integrally formed together.

[0160] This situation is consistent with the existing layout (as referenced above). Figures 2 to 4 In contrast to the described arrangement, the first part (the known film frame 17') used to connect to the boundary 19a of the film 19 is formed of one material (e.g., silicon), and the plurality of second parts (bonding mechanisms 22a to 22d) used to connect to the patterning apparatus MA are formed of another material (e.g., titanium alloy). This existing arrangement is significantly more complex to manufacture because multiple parts must be manufactured separately and then assembled together (e.g., in the film attachment device 855). Furthermore, this significantly increases the cost of manufacturing such existing film frame assemblies 17', 22a to 22d (relative to the new film frame 17). This is especially true because the assembly of these individual parts is not straightforward or easy, according to the rather stringent requirements for film frames used in EUV lithography equipment, as referenced above. Figure 2 The explanation given.

[0161] First, cleaning the film frame (and the resulting film assembly including the film frame) is important to reduce the risk of contaminating the patterning apparatus (mask), to which the film frame will be attached during use. For example, it may be desirable to ensure that the number of particles on the film frame is below a desired particle threshold (preferably, no particles will be set on the film frame). To achieve this, the component portions of the known film frame 17' can be maintained in a clean environment until the component portions are assembled. Assembly can be performed in a clean environment. These clean environments can be maintained under vacuum conditions. Maintaining multiple clean environments (or clean environments of increasing size) would increase manufacturing costs. Furthermore, assembly within a clean environment is challenging.

[0162] Secondly, in use, the film frame is attached to a mask supported by a mask platform. In a lithography apparatus LA, referred to as a scanner, where the patterning apparatus MA and the wafer W are scanned synchronously via EUV radiation beams, the mask platform MT and the attached film frame are subjected to significant acceleration. Importantly, all parts of the moving mask assembly are sufficiently well connected so that all parts remain connected regardless of these large accelerations. For this reason, the total number of parts connected together can preferably be reduced. The new film frame 17 achieves this.

[0163] Although the aforementioned membrane frame 17 is formed of titanium alloy, different materials may be used in alternative embodiments. In some embodiments, the material may have a density of <10. -6 K -1 The coefficient of thermal expansion (CTE). The material can be elastic. The material can be ductile. In some embodiments, the material can have a Young's modulus greater than 100 GPa. In some embodiments, the material can have a modulus less than 1500 kg / m³. 3 The density. The material is suitable for use in a vacuum environment. Specifically, the material is suitable for use in the environment within EUV lithography equipment.

[0164] Titanium and titanium alloys are suitable for use in vacuum environments, and specifically, for use in the environment within EUV lithography equipment. Furthermore, titanium and its alloys are sufficiently elastic to provide the spring portion 44 and to ensure that the film frame 17 is not brittle enough to prevent breakage during use.

[0165] According to some embodiments of the present invention, a film assembly 16 may be provided, the film assembly including the aforementioned film frame 17 and film 19. According to some embodiments of the present invention, a mask assembly 15 including such a film assembly 16 and a pattern forming apparatus may be provided. Reference is now made to... Figure 7Here are some examples to describe such a mask component.

[0166] Figure 7 This is a schematic cross-section of a portion of the new mask assembly 15. Figure 7 The cross-section shown is in a plane perpendicular to the y-direction and passes through one of the second parts 42. In such a cross-section, one can see... Figure 6 One of the second portions 42 of the membrane frame 17 shown in the diagram. On one side of the second portion 42 ( Figure 7 On the left side of the second part 42, a roughly triangular, hollow protrusion 56 can be seen. Figure 7 On the right side (in the image), another portion of the hollow, triangular protrusion 56 can be seen together with a portion of the first portion 40 of the membrane frame. It will be understood that the first portion 40 and the protrusion 56 are integrally formed from the same material, and therefore there is no boundary between the first portion 40 and the protrusion 56 shown. However, towards Figure 7 The bottom has been marked to indicate which part corresponds to the first part 40 and which part corresponds to the protrusion 56.

[0167] exist Figure 7 As can be clearly seen, the gap is positioned between the second part 42 and the protrusion 56 and / or the first part 40 (see below for reference). Figure 7 (As will be described further). This gap allows for a limited degree of movement between each second part 42 and the first part 40 along the movement directions 50, 52.

[0168] The mask assembly also includes a film 19 and a pattern forming device MA.

[0169] The membrane 19 includes a boundary portion 19a and a diaphragm 19b. The boundary portion 19a is hollow and generally rectangular and surrounds the diaphragm 19b, which is delimited by the boundary portion 19a. The boundary portion 19a of the membrane 19 is attached to a first portion 40 of the membrane frame 17.

[0170] The surface film 19 can have a known form of surface film 19 (and can have any of the features described above with reference to the surface film). As is known in the art, the surface film 19 can be formed by depositing one or more thin layers of material onto a generally rectangular silicon substrate. The silicon substrate supports one or more thin layers during this stage of the construction of the surface film 19. Once the desired or target thickness and composition of the multiple layers have been applied, the central portion of the silicon substrate is removed by etching (this process can be referred to as back etching, i.e., reverse etching). The peripheral portion of the rectangular silicon substrate is not etched (or instead is etched to a lesser extent than the central portion, i.e., less etched). This peripheral portion forms the boundary portion 19a of the final surface film, while one or more thin layers form the diaphragm 19b of the surface film (which is demarcated by the boundary portion 19a).

[0171] The boundary portion 19a of the surface film 19 is attached to the first portion 40 of the surface film frame 17 by adhesive G. The adhesive may, for example, comprise a poly(methyl methacrylate) based adhesive (which may be referred to as a PMMA adhesive). Alternatively, the adhesive may be an epoxy adhesive. It will be understood that other types of adhesives are also possible. Typically, the adhesive can be selected such that degassing from the adhesive is sufficiently minimal to avoid contaminating the area and / or to be suitable for use with EUV radiation and / or to not affect the performance of the lithography equipment and its optics.

[0172] The membrane 19 and the membrane frame 17 can be considered together to form the membrane assembly 16.

[0173] The boundary portion 19a may be formed of silicon. As explained above, the film frame 17 is typically formed of a relatively elastic material such as titanium alloy.

[0174] The faceplate 19 typically requires some degree of support from a more rigid faceplate frame 17. The faceplate frame provides two functions: (a) it supports the faceplate 19 and can also tension the faceplate diaphragm 19b; and (b) it facilitates the connection of the faceplate 19 to the patterning apparatus MA. To provide a degree of flexibility to allow for different thermal expansions of the faceplate 19 and the mask MA over the operating temperature range experienced by these components during use, it is desirable to select a material for the connection to the patterning apparatus that is sufficiently elastic and suitable for the conditions within an EUV lithography apparatus. A suitable material includes titanium. Since the main hollow rectangular portion of the faceplate frame is typically adhered to the boundary portions, in known assemblies, this main hollow rectangular portion of the faceplate frame is formed of a material whose thermal properties generally match those of the boundary portions of the faceplate. For example, silicon is commonly used. For these reasons, the known film frame 17' includes a silicon body bonded to the film 19, and four titanium attachment mechanisms 22a to 22d bonded to the sides of such body 17'.

[0175] Due to the very different thermal properties of silicon and titanium (titanium has a coefficient of thermal expansion approximately four times that of silicon), there is a significant bias in the art regarding the material used for the body of the coating frame, which has thermal properties different from those of silicon (such as, for example, titanium or titanium alloys). This is because, as the temperature of the coating assembly changes, the differential thermal expansion of the frame and boundaries will cause the coating assembly to warp or buckle. This, in turn, can stress the patterning apparatus MA, potentially leading to imaging errors such as increased overlap. However, surprisingly, the inventors have discovered that overlap is no worse when using the new coating frame 17 compared to using a known coating frame 17'. Therefore, the new coating frame 17 provides a simpler and less expensive arrangement without compromising imaging performance.

[0176] A plurality of second portions 42 of the film frame 17 are attached to the pattern forming apparatus MA. The second portions 42 of the film frame 17 are attached to the pattern forming apparatus MA by an adhesive G.

[0177] The adhesive may be a poly(methyl methacrylate) based adhesive, which may be referred to as PMMA adhesive. The material properties of PMMA adhesive, particularly its elasticity and the size at which it can be applied or coated, result in relatively low deformation of the pattern forming device MA due to the curing of the PMMA adhesive (compared to other adhesives). Compared to, for example, epoxy adhesives, PMMA adhesive is easier to remove and is relatively more flexible. Advantageously, this allows the surface film assembly 16 to be replaced more easily.

[0178] Alternatively, the adhesive can be an epoxy adhesive.

[0179] Furthermore, it will be understood that other types of adhesives are also possible. Typically, adhesives can be selected such that degassing from the adhesive is minimal enough to avoid contaminating the area and / or to be suitable for use with EUV radiation and / or to not affect the performance of the lithography equipment and its optics.

[0180] The new mask assembly 15 is particularly superior to the known arrangement that typically uses an intermediate fixing member (referred to as a post 51) attached to the pattern forming apparatus MA and engaged with the mask assembly 17', as now discussed.

[0181] Compared to a mask assembly 15' that uses an intermediate fixing member such as a post 51 (attached to the pattern forming apparatus) and engagement mechanisms 22a to 22d (disposed on the film assembly 16') for engaging with the intermediate fixing member (post 51), the new mask assembly 15 comprises fewer parts. Therefore, advantageously, the new mask assembly 15 is relatively simple to manufacture. Fewer parts and simpler manufacturing processes can lead to lower manufacturing costs.

[0182] This is especially true because the components of mask assembly 15 are not straightforward or easy to assemble, given the rather stringent requirements for mask assemblies used in EUV lithography equipment.

[0183] First, cleanliness is crucial for mask assemblies to minimize the risk of contaminating the pattern forming apparatus (mask). For example, it may be desirable to ensure that the number of particles on the mask assembly is below a desired particle threshold (preferably, no particles will be present on the mask assembly). To achieve this, component portions of the mask assembly can be maintained in a clean environment until the component portions are assembled. Assembly can be performed in a clean environment. These clean environments can be maintained under vacuum conditions. Maintaining multiple clean environments (or clean environments of increasing size) will increase manufacturing costs. Furthermore, assembly within a clean environment is challenging.

[0184] Secondly, in use, the mask assembly is supported by a mask platform. In a photolithography apparatus known as a scanner, where the patterning apparatus and the wafer are scanned synchronously via an EUV radiation beam, the mask platform and the attached film frame are subjected to significant acceleration. Importantly, all parts of the moving mask assembly are sufficiently well connected so that all parts remain connected regardless of these large accelerations. For this reason, it is preferable to minimize the total number of parts connected together. The novel mask assembly according to a third aspect of the invention achieves this.

[0185] It is estimated that, relative to the manufacturing of the above reference Figures 2 to 4The cost of a known mask assembly 15' of the described type represents a significant reduction in the cost of manufacturing a new mask assembly 15. For example, compared to manufacturing in... Figure 7 The cost of the new mask assembly 15 of the type shown can be approximately 10 times greater than the cost of manufacturing a known mask assembly 15'.

[0186] There are several reasons for this. First, the new mask assembly 15' comprises fewer parts compared to the known mask assembly 15. Assembling several parts presents several associated problems: assembly must occur in a clean environment, and the parts must be accurately aligned under these challenging conditions. Second, manufacturing some of the parts of the known mask assembly 15' is very expensive.

[0187] In some embodiments, the separation, i.e. the spacing, between the film 19 and the pattern forming apparatus MA can be, for example, between about 1 mm and 10 mm, for example, between 1 mm and 5 mm, more preferably between 2 mm and 2.5 mm.

[0188] Although in the above embodiment, the membrane frame 17 includes four second portions 42, each of the free spring portions 44 being connected to the first portion 40, in other embodiments, the free spring portions 44 may be connected to a different number of second portions 42, each of the free spring portions 44 being connected to the first portion 40.

[0189] The membrane assembly 16 can be assembled by gluing the membrane 19 to the membrane frame 17. This process may share one or more features with existing processes for gluing the membrane 19 to a known membrane frame 17'.

[0190] Any suitable adhesive dispenser can be used to bond the film 19 to the first portion 40 and / or the second portion 42 of the film frame 17 to the pattern forming apparatus.

[0191] Glue dispensers may include syringes. The syringes can dispense a defined volume of one or more components of the glue. The glue dispenser may include nozzles. For example, the nozzles may be connected to the syringes, and the syringes connected to the nozzles can be used to deliver one or more components of the glue. Glue can be applied or coated using cylindrical nozzles. Glue can be applied or coated using tapered nozzles. Glue dispensers may include brushes, and the brushes can be used to apply or coat one or more components of the glue. Glue dispensers may include sponges, and the sponges can be used to apply or coat one or more components of the glue. Glue dispensers may include printing equipment (e.g., screen printing equipment) for delivering one or more components of the glue. Glue dispensers may include dispensing equipment for delivering one or more components of the glue as a spray (e.g., an aerosol spray dispensing system can be used). It will be understood that glue can be delivered in any known manner.

[0192] Glue dispensers can provide glue in multiple components (e.g., glue accelerators and initiators). One component of the glue may have a higher viscosity compared to another component. That is, there may be a relatively high-viscosity component (“thick” component) and a relatively low-viscosity component (“thin” component) in the glue. In example embodiments, the glue dispenser may use a syringe and nozzle to dispense the thick component of the glue. In example embodiments, the glue dispenser may use a brush, sponge, screen printing equipment, or an aerosol spray dispensing system to dispense the thin component of the glue.

[0193] Although the above description uses adhesive to attach the diaphragm 19 to the diaphragm frame 17, the diaphragm can be attached to the diaphragm frame using any suitable type of bonding (including without adhesive).

[0194] Although the use of adhesive to attach the film frame 17 to the pattern forming apparatus MA is described above, any suitable type of bonding (including without adhesive) can be used to attach the film frame 17 to the pattern forming apparatus MA.

[0195] In this document, references to mask or mask plate may be interpreted as references to pattern forming apparatus (mask or mask plate being an example of a pattern forming apparatus), and these terms may be used interchangeably. Specifically, the term mask assembly is synonymous with mask plate assembly and pattern forming apparatus assembly.

[0196] While specific reference is made herein to embodiments of the invention within the context of a photolithography apparatus, these embodiments can be used in other apparatuses. Embodiments of the invention can form parts for mask inspection apparatus, metrology apparatus, or any apparatus for measuring or processing objects such as wafers (or other substrates) or masks (or other patterning apparatuses). These apparatuses are generally referred to as photolithography tools. Such photolithography tools can be used under vacuum conditions or ambient (non-vacuum) conditions.

[0197] The term “EUV radiation” can be considered to encompass electromagnetic radiation with wavelengths in the range of 4 nm to 20 nm (e.g., in the range of 13 nm to 14 nm). EUV radiation can also have wavelengths less than 10 nm, such as wavelengths in the range of 4 nm to 10 nm, like 6.7 nm or 6.8 nm.

[0198] While specific references can be made to the use of lithography equipment in IC manufacturing within this document, it should be understood that the lithography equipment described herein can have other applications. Possible other applications include manufacturing integrated optical systems, guiding and inspecting patterns for magnetic domain memories, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, and more.

[0199] While specific embodiments of the invention have been described above, it will be understood that the invention can be practiced in other ways than those described. The description above is intended to be illustrative and not restrictive. Therefore, those skilled in the art will understand that modifications can be made to the described invention without departing from the scope of the claims set forth below.

Claims

1. A membrane framework, comprising: The first part, which is used to connect to the boundary of the film, includes a hollow and generally rectangular body; and A plurality of second portions, the plurality of second portions being connected to a pattern forming apparatus; The first part and the plurality of second parts are all formed of a first material; Each of the second portions is connected to the first portion by a spring portion, the spring portion being formed of the first material; Each of the spring portions is configured to allow the first portion and the second portion to move relative to each other along the direction of movement; and Each of the spring portions is configured such that its direction of movement is approximately toward the center of the first portion.

2. The membrane frame according to claim 1, wherein, The first material includes titanium.

3. The membrane frame according to claim 1 or claim 2, wherein, There are four second parts, each of which is connected to the first part by a spring part.

4. The membrane frame according to claim 3, wherein, Each of the four second sections is adjacent to a corner of the first section.

5. The membrane frame according to claim 3, wherein, Two of the second parts are disposed on one side of the hollow and generally rectangular body of the first part, and the other two of the second parts are disposed on the opposite side of the hollow and generally rectangular body of the first part.

6. The membrane frame according to claim 1, wherein, Each of the plurality of second portions includes a generally cuboid body such that each of the second portions is rectangular in the main plane of the membrane frame.

7. The membrane frame according to claim 1, wherein, In the plane of the film frame, each of the spring portions includes a portion of the first material extending along a connection direction from the first portion to one of the second portions. The dimension of the spring portion along the movement direction is smaller than the dimension of the spring portion along the connection direction and smaller than the dimension of the spring portion along a direction perpendicular to the plane of the film frame. The movement direction is located in the plane of the film frame and perpendicular to the connection direction to allow the second portion and the first portion to move relative to each other along the movement direction.

8. The membrane frame according to claim 1 or claim 7, wherein, Each pair of diagonally opposite spring sections has the same direction of movement, such that the two spring sections have a first direction of movement and the two spring sections have a second direction of movement.

9. The membrane frame according to claim 7, wherein, Each of the spring portions is configured such that its connection direction extends through the spring portion and is connected to the center point of the second portion thereon.

10. The film frame of claim 1, further comprising a plurality of side protrusions projecting from the hollow and generally rectangular body, wherein each side protrusion is formed of the first material, and wherein each side protrusion and the hollow and generally rectangular body define a hole, and wherein each of the plurality of second portions is disposed in one of the holes.

11. A film assembly, comprising: The membrane frame according to any one of claims 1 to 10; and The membrane includes: a boundary portion that is hollow and generally rectangular; and a diaphragm defined by the boundary portion; The boundary portion of the film is attached to the first portion of the film frame.

12. The film assembly according to claim 11, wherein, The boundary portion of the membrane is formed of a second material, which is different from the first material forming the membrane frame.

13. The film assembly according to claim 12, wherein, The boundary portion of the film is formed of silicon.

14. The film assembly according to any one of claims 11 to 13, wherein, The boundary portion of the film is attached to the first portion of the film frame by an adhesive.

15. The film assembly according to claim 14, wherein, The adhesive is a poly(meth)acrylate-based adhesive.

16. The film assembly of claim 14, wherein, The adhesive is an epoxy resin adhesive.

17. A mask assembly, comprising: The film assembly according to any one of claims 11 to 16; and Pattern forming apparatus The plurality of second portions of the film frame are attached to the pattern forming apparatus.

18. The film assembly according to claim 17, wherein, The plurality of second portions of the film frame are attached to the pattern forming apparatus by an adhesive.

19. The film assembly according to claim 18, wherein, The adhesive is a poly(meth)acrylate-based adhesive.

20. The film assembly according to claim 18, wherein, The adhesive is an epoxy resin adhesive.

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