Pellicle frame with adhesive layer, pellicle, photomask with pellicle, and method for manufacturing pellicle frame with adhesive layer

Abstract

To provide a pellicle frame with an adhesive layer capable of suppressing the number of air bites when a pellicle is stuck to a photomask.SOLUTION: An adhesive layer-equipped pellicle frame of the present disclosure includes a pellicle frame and an adhesive layer formed on the pellicle frame for attaching the pellicle frame to a photomask. The number of local level differences of 3 μm or more on the surface of the adhesive layer is one or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a pellicle frame with an adhesive layer, a pellicle, a method for manufacturing a photomask with a pellicle, and a method for manufacturing a pellicle frame with an adhesive layer. [Background technology]

[0002] The miniaturization of semiconductor integrated circuits is being driven by photolithography. Photolithography uses a photomask with a pattern formed on one side. A pellicle is used on the photomask to prevent foreign matter such as dust from adhering to the surface of the photomask. In many cases, the pellicle has an adhesive layer and is attached to the photomask. Hereinafter, a photomask with a pellicle attached will also be referred to as a "photomask with a pellicle."

[0003] Generally, the surface flatness of the adhesive layer of a pellicle is inferior to that of a photomask. Therefore, to prevent the occurrence of air paths, when attaching a pellicle to a photomask, a load is applied to the pellicle to adhere the adhesive layer to the photomask without any gaps. In this case, the softer the adhesive, the less force is required to tightly adhere the surface of the photomask to the surface of the adhesive layer.

[0004] Patent Document 1 discloses a pellicle that uses a soft adhesive. The pellicle disclosed in Patent Document 1 has an adhesive layer that can be attached to a photomask with an attachment load of 0.008 kgf to 5 kgf, including its own weight. The Young's modulus of the adhesive layer is 0.01 MPa to 0.10 MPa. The tensile adhesive strength of the adhesive layer is 0.02 N / mm 2 ~0.10N / mm 2 The surface flatness of the adhesive layer is 0 μm to 15 μm. The adhesive layer of the pellicle disclosed in Patent Document 1 is formed by applying an adhesive to the end face of the pellicle frame using a dispenser, and then heating to harden the adhesive. The resulting pellicle is attached to the photomask by bringing the adhesive layer into contact with the photomask and applying the above-mentioned attachment load. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-230227 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, the surface of the adhesive layer of the pellicle is not flattened before the adhesive layer is attached to the photomask, so when the pellicle is attached to the photomask, there is a risk that a large number of air pockets will be formed between the surface of the photomask and the surface of the adhesive layer of the pellicle.

[0007] When a pellicle is attached to a photomask, if there are many air gaps between the photomask and the adhesive layer of the pellicle, and the pellicle is used for EUV (Extreme Ultra Violet) exposure or DUV (Deep Ultra Violet) exposure, air paths may be formed. Air paths are localized gaps that connect the outside of the pellicle to the inside of the pellicle. Air gaps are localized gaps that do not connect the outside of the pellicle to the inside of the pellicle, and they expand during exposure, etc., which is one of the causes of air paths. When air paths occur, foreign matter from the outside of the pellicle may enter the inside of the pellicle.

[0008] In particular, EUV exposure uses EUV as the exposure light. Because EUV has a short wavelength, it is easily absorbed by gases such as oxygen or nitrogen. For this reason, EUV exposure is performed in a vacuum atmosphere. When the environment in which a pellicle-attached photomask is placed is switched from an air atmosphere to a vacuum atmosphere for EUV exposure, air entrapment is likely to expand. Therefore, if there are many air entrapments when a pellicle is attached to a photomask in an air atmosphere, there is a risk that air paths will be easily formed during EUV exposure.

[0009] The present disclosure has been made in consideration of the above circumstances. The problem that one embodiment of the present disclosure aims to solve is to provide a pellicle frame with an adhesive layer, a pellicle, and a method for manufacturing a pellicle frame with an adhesive layer that can reduce the number of air bubbles that become trapped when a pellicle is attached to a photomask. Another problem to be solved by another embodiment of the present disclosure is to provide a photomask with a pellicle that can suppress the occurrence of air paths. [Means for solving the problem]

[0010] The means for solving the above problems include the following embodiments. <1> A method for manufacturing a pellicle frame with an adhesive layer, the method comprising: a pellicle frame; and an adhesive layer formed on the pellicle frame for attaching it to a photomask, the method comprising: A step A of preparing a frame precursor including the pellicle frame and a precursor layer that is a precursor of the adhesive layer formed on the pellicle frame; a step B of forming a frame precursor with a protective film by placing a protective film on the surface of the precursor layer; a step C of subjecting the protective film-attached frame precursor to a heat treatment to form the adhesive layer having a flattened surface from the precursor layer; and The method for producing a pellicle frame with an adhesive layer, wherein the glass transition temperature of the protective film is higher than the heating temperature in step C. <2> The protective film has a glass transition temperature of more than 120°C. <1> A method for manufacturing a pellicle frame with an adhesive layer according to claim 1. <3> In the step C, the heat treatment is carried out at a temperature of 80° C. or higher for 2 hours or longer. <1> or <2> A method for manufacturing a pellicle frame with an adhesive layer according to claim 1. <4> The adhesive layer contains at least one selected from the group consisting of an acrylic adhesive, a silicone adhesive, a styrene-butadiene adhesive, a urethane adhesive, and an olefin adhesive. <1> ~ <3> 10. A method for manufacturing a pellicle frame with an adhesive layer according to any one of the above. <5> A pellicle frame; an adhesive layer formed on the pellicle frame for attaching to a photomask; a protective film attached to the surface of the adhesive layer; Equipped with A pellicle frame with a protective film, wherein the protective film has a glass transition temperature of greater than 120°C. <6> A pellicle frame; an adhesive layer formed on the pellicle frame for attaching to a photomask; Equipped with A pellicle frame with an adhesive layer, wherein the number of local steps of 3 μm or more on the surface of the adhesive layer is one or less. <7> The adhesive layer is made of an acrylic adhesive, a silicone adhesive, a styrene butadiene adhesive, The adhesive agent includes at least one selected from the group consisting of a urethane-based adhesive, an olefin-based adhesive, and a tackifier-based adhesive. <6> The pellicle frame with the adhesive layer according to claim 1. <8> a pellicle membrane supported by the pellicle frame; The aforementioned <6> or <7> A pellicle frame with an adhesive layer according to and A pellicle, wherein the pellicle film comprises at least one selected from the group consisting of carbon nanotubes, metal silicides, and polysilicon. <9> A photomask and The photomask is attached to the <8> The pellicle described in Equipped with A pellicle-attached photomask, wherein the area of ​​the gap between the adhesive layer and the photomask on the surface of the adhesive layer that is in contact with the photomask is 0.25% or less of the area of ​​the adhesive layer that is in contact with the photomask. [Effects of the Invention]

[0011] According to the present disclosure, there is provided a pellicle frame with an adhesive layer, a pellicle, and a method for manufacturing a pellicle frame with an adhesive layer that can reduce the number of air bubbles that become trapped when a pellicle is attached to a photomask. According to the present disclosure, there is provided a photomask with a pellicle that can suppress the occurrence of air paths. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a cross section of a pellicle frame with a protective film according to Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In the numerical ranges described in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the value shown in the examples. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, when there are multiple substances corresponding to each component, the amount of each component means the total amount of the multiple substances unless otherwise specified. In the present disclosure, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved. In this disclosure, "(meth)acrylate" means acrylate or methacrylate.

[0014] (1) Manufacturing method of pellicle frame with adhesive layer The method for manufacturing a pellicle frame with an adhesive layer of the present disclosure is a method for manufacturing a pellicle frame with an adhesive layer comprising a pellicle frame and an adhesive layer formed on the pellicle frame for attaching to a photomask. The manufacturing method includes steps A, B, and C. In step A, a frame precursor is prepared. The frame precursor comprises the pellicle frame and a precursor layer that is a precursor of the adhesive layer formed on the pellicle frame. In step B, a protective film is placed on the surface of the precursor layer to form a frame precursor with a protective film. In step C, the frame precursor with a protective film is heat-treated to form the adhesive layer with a flattened surface from the precursor layer. The glass transition temperature of the protective film is higher than the heating temperature in step C.

[0015] In the present disclosure, the "adhesive layer precursor" becomes an adhesive layer when subjected to the heat treatment of step C. In the present disclosure, the "glass transition temperature of the protective film" refers to the glass transition temperature of the substrate layer when the protective film has a multilayer structure including a substrate layer and a layer different from the substrate layer (e.g., a release layer, a layer that facilitates peeling from the adhesive layer, an antistatic layer, etc.). The "heating temperature of step C" refers to the set temperature of the heating device when a heating device (e.g., an oven, a hot plate, etc.) is used for the heat treatment. More specifically, when an oven is used as the heating device, the "heating temperature of step C" refers to the set temperature inside the oven, and when a hot plate is used as the heating device, the "heating temperature of step C" refers to the set temperature of the hot plate.

[0016] Hereinafter, the manufacturing method of a pellicle frame with an adhesive layer of the present disclosure will also be simply referred to as the "manufacturing method of the present disclosure." Hereinafter, step A will also be referred to as the "preparation step." Hereinafter, step B will also be referred to as the "placement step." Hereinafter, step C will also be referred to as the "flattening step." Hereinafter, the glass transition temperature will also be referred to as "Tg."

[0017] The manufacturing method of the present disclosure has the above configuration, and therefore can reduce the number of air bubbles that are trapped when a pellicle is attached to a photomask. This effect is presumably due to, but not limited to, the following reasons. In the manufacturing method of the present disclosure, the glass transition temperature of the protective film is higher than the heating temperature in step C. In other words, the occurrence of distortion of the protective film due to heating in step C is suppressed. Therefore, in step C, distortion of the protective film is less likely to be transferred to the surface of the adhesive layer of the present disclosure. As a result, the surface of the adhesive layer of the present disclosure is more likely to be flat than when a protective film whose Tg is equal to or lower than the heating temperature in step C is used. In other words, the number of local steps on the surface of the adhesive layer of the present disclosure is smaller in the air atmosphere than when a protective film whose Tg is equal to or lower than the heating temperature in step C is used. As a result, it is presumed that the manufacturing method of the present disclosure can reduce the number of air traps when a pellicle is attached to a photomask. Therefore, if a pellicle frame with an adhesive layer obtained by the manufacturing method of the present disclosure is used as a pellicle component, air paths are less likely to occur during exposure, etc. Furthermore, the reduced air trapping ensures a uniform adhesive surface to the photomask. Therefore, distortion of the photomask can be suppressed. Furthermore, the reduced air trapping ensures a large adhesive area. Therefore, peeling of the pellicle can be suppressed when the photomask is moved during exposure. The method for measuring the number of local steps on the surface of the adhesive layer is the same as the method described in the examples.

[0018] In the manufacturing method of the present disclosure, the preparation step, the placement step, and the planarization step are performed in this order.

[0019] (1.1) Pellicle frame with adhesive layer The manufacturing method of the present disclosure is a method for manufacturing a pellicle frame with an adhesive layer. The pellicle frame with an adhesive layer is a component of a pellicle, and includes a pellicle frame and an adhesive layer for attaching it to a photomask. The adhesive layer is formed on the pellicle frame. The pellicle will be described later.

[0020] (1.1.1) Pellicle frame The pellicle frame is a rectangular frame. More specifically, the pellicle frame is a rectangular cylindrical object. The pellicle frame has a through-hole. The through-hole indicates a space through which light transmitted through the pellicle film passes to reach the photomask. The pellicle film will be described later. The pellicle frame has one end surface on which an adhesive layer is provided and the other end surface that supports the pellicle membrane. The pellicle frame may have an air vent equipped with a filter. When the pellicle frame is attached to the photomask, the air vent connects the internal space of the pellicle with the external space of the pellicle. The "internal space of the pellicle" refers to the space surrounded by the pellicle and the photomask. The "external space of the pellicle" refers to the space not surrounded by the pellicle and the photomask. The filter is arranged to prevent foreign matter from passing between the internal space of the pellicle and the external space of the pellicle. The rectangular shape may be a square or a rectangle. A "rectangle" refers to a right-angled quadrilateral. A "square" refers to a shape in which all four sides that make up a rectangle are the same length. A "rectangle" refers to any rectangular shape other than a square.

[0021] Hereinafter, one end face of the pellicle frame on which the adhesive layer is provided is also referred to as the "end face for the exposed substrate," and the other end face of the pellicle frame that supports the pellicle membrane is also referred to as the "end face for the pellicle membrane."

[0022] The material of the pellicle frame is not particularly limited, and examples thereof include metal, resin, and ceramic-based material. The metal may be a pure metal or an alloy. A pure metal is made of a single metal element. Examples of pure metals include aluminum and titanium. An alloy is made of multiple metal elements, or a metal element and a non-metal element. Examples of alloys include stainless steel, magnesium alloy, steel, carbon steel, and invar. Examples of resins include polyethylene. Examples of ceramic-based materials include silicon nitride (SiN), silicon carbide (SiC), and alumina (Al2O3).

[0023] The pellicle frame may be a single item or an assembled item. A single item is obtained by cutting out a single raw material plate. An "assembled item" is an item in which multiple components are integrated. Methods for integrating multiple components include using a known adhesive or using fastening parts. Fastening parts include bolts, nuts, screws, rivets, or pins. When the pellicle frame is an assembly, the materials of the multiple components may be different. When the pellicle frame is an assembly, it is preferable that the Young's modulus of the component constituting the photomask end face is 60 GPa or less, and the Young's modulus of the component constituting the pellicle membrane end face (hereinafter referred to as the "membrane support frame component") is 90 GPa or more. This allows the pellicle frame assembly to suppress deformation of the pellicle frame caused by distortion of the membrane support frame component due to the tension of the pellicle membrane. Examples of materials with a Young's modulus of 60 GPa or less include magnesium, magnesium alloys, polyethylene terephthalate (PET) resin, resin, etc. Examples of materials with a Young's modulus of 90 GPa or more include titanium, titanium alloys, silicon, etc. Young's modulus is measured using a tensile test (JIS G0567J). However, if the pellicle frame is made of resin, the value is measured using a three-point bending test (JIS K7171). Whether the pellicle frame is made of resin or not is determined by whether it undergoes thermal decomposition at 550°C.

[0024] (1.1.2) Adhesive layer The adhesive layer is formed on the pellicle frame, specifically on the end surface of the pellicle frame for the exposure substrate.

[0025] The adhesive layer is a gel-like viscoelastic material. The adhesive layer preferably has viscosity and cohesive strength. "Viscosity" refers to the liquid-like properties of contacting and wetting the adherend, i.e., the photomask. "Cohesive strength" refers to the solid-like properties of resisting peeling from the photomask.

[0026] The Tg of the adhesive layer is preferably greater than −25° C. and less than 10° C. This allows the adhesive layer to have adhesive strength in the temperature range in which the pellicle is used (for example, 20° C. or higher), and makes it less likely to peel off from the photomask even when exposed to a high-temperature environment. In order to make it less likely to peel off from the photomask even when exposed to a high-temperature environment, the lower limit of the Tg of the adhesive layer is preferably above -25°C, more preferably -22°C or higher, even more preferably -20°C or higher, and most preferably -18°C or higher. From the viewpoint of imparting adhesiveness at room temperature, the upper limit of the Tg of the adhesive layer is preferably less than 10°C, more preferably 5°C or lower, and even more preferably 0°C or lower. The Tg of the adhesive layer is measured in accordance with JIS K 7112. Specifically, the Tg of the adhesive layer is measured using a differential scanning calorimetry (DSC) under conditions of a temperature rise rate of 20°C / min and nitrogen.

[0027] The adhesive layer is made of an adhesive composition. The adhesive composition constituting the adhesive layer is not particularly limited, and examples thereof include acrylic adhesives, silicone adhesives, styrene-butadiene adhesives, urethane adhesives, and olefin adhesives. In particular, from the viewpoint of reducing the amount of outgassing generated from the pellicle, the adhesive layer preferably contains at least one selected from the group consisting of acrylic adhesives, silicone adhesives, styrene-butadiene adhesives, urethane adhesives, and olefin adhesives, more preferably an acrylic adhesive, and even more preferably an acrylic adhesive. Details of acrylic adhesives will be described later.

[0028] The thickness of the adhesive layer is not particularly limited and is preferably 10 μm to 500 μm, more preferably 100 μm to 400 μm, and even more preferably 200 μm to 300 μm. If the thickness of the adhesive layer is within the above range, the amount of outgassing from the adhesive layer is less likely to have an effect. The thickness of the adhesive layer was measured in the same manner as in the examples.

[0029] (1.2) Preparation process The manufacturing method of the present disclosure includes a preparation step. In the preparation step, a frame precursor is prepared. The frame precursor includes a pellicle frame and a precursor layer that is a precursor of the adhesive layer. The precursor layer is formed on the pellicle frame. Specifically, the precursor layer is formed on the exposure substrate end surface of the pellicle frame.

[0030] The method for preparing the frame precursor is not particularly limited, and examples thereof include a method in which a coating composition is applied to a pellicle frame to form a precursor layer on the end surface of the pellicle frame for use as a photomask.

[0031] (1.2.1) Coating composition The coating composition includes a composition containing compounds selected from various polymers, solvents, crosslinking agents, catalysts, initiators, etc. depending on the type of adhesive layer. The coating composition is a precursor of the adhesive composition. In other words, when the coating composition is cured, it becomes the above-mentioned adhesive composition.

[0032] (1.2.2) Coating The method for applying the coating composition to the photomask end surface of the pellicle frame is not particularly limited, and examples thereof include a method using a dispenser. The area to which the coating composition is applied is preferably not the entire surface of the photomask end face, but only the center of each side between the four corners of the photomask end face. In other words, the area to which the coating composition is applied preferably does not include the edge of each side between the four corners on the through-hole side of the pellicle frame or the edge on the opposite side of the pellicle frame from the through-hole side. This makes it less likely that the adhesive layer will overflow onto the inner and outer wall sides of the pellicle frame when the pellicle is attached to the photomask than if the coating composition were applied to the entire surface of the photomask end face. Therefore, the adhesive layer is less likely to be exposed. As a result, the amount of outgassing can be further reduced. The thickness of the precursor layer may be any thickness that allows the thickness of the adhesive layer to fall within the above-mentioned range.

[0033] (1.3) Drying process The manufacturing method of the present disclosure may include a drying step. When the manufacturing method of the present disclosure includes a drying step, the preparing step, the drying step, the arranging step, and the planarizing step are performed in this order.

[0034] In the drying step, the frame precursor is subjected to a drying treatment. The coating composition may contain a solvent to facilitate application of the coating composition to the photomask end surface of the pellicle frame. By performing the drying step, most of the solvent contained in the precursor layer of the frame precursor volatilizes before the planarization step is performed. As a result, an adhesive layer with a planarized surface is easily obtained.

[0035] The heating temperature in the drying treatment is preferably lower than the heating temperature in the planarization step, and is appropriately selected depending on the type of coating composition, etc., and is preferably 40°C to 120°C, more preferably 50°C to 110°C, and even more preferably 60°C to 100°C. The heating time for the drying treatment is appropriately selected depending on the heating temperature for the drying treatment and the type of coating composition, and is preferably 10 minutes to 5 hours, more preferably 20 minutes to 4 hours, and even more preferably 30 minutes to 3 hours.

[0036] The method for drying the precursor layer is not particularly limited, and examples thereof include a method using an oven, etc. In the method using an oven, the precursor frame is placed inside the oven, and the frame itself is dried to dry the precursor layer. When the precursor layer is heated using an oven, the set temperature inside the oven is the same as the temperature range exemplified as the heating temperature for the drying treatment described above. The set temperature inside the oven refers to the temperature inside the oven. The time for heating the precursor layer using the oven is the same as the time range exemplified as the heating time for the drying treatment described above.

[0037] (1.4) Placement process The manufacturing method of the present disclosure includes a placement step. In the disposing step, a protective film is disposed on the surface of the precursor layer of the frame precursor to form a frame precursor with a protective film.

[0038] (1.4.1) Protective film In the planarization step, the flat surface of the planarization article may be brought into contact with the surface of the precursor layer of the protective film-attached frame precursor via a protective film, thereby transferring the flat surface of the planarization article to the surface of the precursor layer. In this case, the protective film makes it easier to separate the protective film-attached frame precursor from the planarization article. The protective film protects at least the surface of the precursor layer or adhesive layer that contacts the photomask. The protective film is peelable from the adhesive layer.

[0039] The shape of the protective film is not particularly limited as long as it conforms to the shape of the pellicle frame. The protective film may have an opening, similar to the pellicle frame. The thickness of the protective film is not particularly limited, but is preferably 5 μm to 500 μm, and more preferably 30 μm to 200 μm.

[0040] The protective film preferably comprises a base layer and a release layer, and may comprise other layers (such as an antistatic layer) different from the base layer and the release layer, as necessary. The layer structure of the protective film is not particularly limited, and may comprise two or more layers. The substrate layer contains a resin whose glass transition temperature is higher than the heating temperature in the planarization step. The resin constituting the substrate layer is appropriately selected depending on the heating temperature in the planarization step, and examples thereof include polyester-based resins (e.g., polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.), olefin-based resins, polyvinyl chloride, vinyl acetate-based resins, polycarbonate, polyphenylene sulfide, amide-based resins (e.g., polyamide (nylon), wholly aromatic polyamide (aramid)), polyimide-based resins, polyether ether ketone (PEEK), and fluorine-based resins. Examples of olefin-based resins include resins containing α-olefins (e.g., polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer (EVA)) as a monomer component. The release layer is made of a release agent, such as a silicone-based release agent or a fluorine-based release agent.

[0041] The Tg of the protective film (i.e., the Tg of the substrate layer) is preferably higher than 120° C. The Tg of commonly used protective films made of polyethylene terephthalate (PET) is lower than 100° C. A PET protective film generally comprises a substrate layer made of PET and a release layer formed on one side of the substrate layer. Examples of protective films having a Tg of more than 120° C. include PEN protective films, polyamide (aramid), polyimide, polyamideimide, polyether ether ketone resin (PEEK), polyphenylene sulfide, polyether sulfine, polycarbonate, polyarylate, polysulfone, polytetrafluoroethylene, etc. PEN protective films have a substrate layer made of PEN. From the viewpoint of achieving both rapid volatilization of the precursor layer residue and a reduction in the number of air entrapments, the lower limit of the Tg of the protective film is more preferably 130°C or higher, even more preferably 140°C or higher, and particularly preferably 150°C or higher. There is no particular restriction on the upper limit of the Tg of the protective film, but it is preferably 200°C or lower, more preferably 180°C or lower. From these viewpoints, the Tg of the protective film is preferably 130°C or higher and 200°C or lower, more preferably 140°C or higher and 200°C or lower, and even more preferably 150°C or higher and 180°C or lower. Examples of materials for the base layer of the protective film having a Tg of 120° C. to 200° C. include PEN, polyamide (aramid), PEEK, polyphenylene sulfide, polycarbonate, polyarylate, polysulfone, and polytetrafluoroethylene. Examples of materials for the base layer of the protective film having a Tg of 140° C. to 200° C. include PEN, PEEK, polycarbonate, polyarylate, and polysulfone. The Tg of the protective film was measured in the same manner as in the examples.

[0042] The temperature difference between the Tg of the protective film and the heating temperature in the planarization step is greater than 0° C., preferably at least 5° C., more preferably at least 10° C., and even more preferably at least 20° C. If the temperature difference is 5° C. or greater, the occurrence of distortion in the protective film due to heating in the planarization step can be more reliably suppressed. The "temperature difference between the Tg of the protective film and the heating temperature in the planarization step" is the value obtained by subtracting the heating temperature (°C) in the planarization step from the Tg (°C) of the protective film.

[0043] (1.4.2) Placement The method for disposing the protective film on the surface of the precursor layer of the frame precursor is not particularly limited, and examples include a method of placing the precursor frame on the protective film, a method of placing the protective film on the precursor frame, etc. After the protective film is disposed on the surface of the precursor layer of the frame precursor, pressure (load) may be applied uniformly to the entire precursor layer.

[0044] (1.5) Flattening process The manufacturing method of the present disclosure includes a planarization step. In the planarization step, the protective film-attached frame precursor is subjected to a heat treatment to form an adhesive layer with a planarized surface from the precursor layer of the precursor frame, thereby obtaining a pellicle frame with a protective film.

[0045] The conditions for the heat treatment in the planarization step are appropriately selected depending on the type of coating composition, etc., as long as the heating temperature is lower than the Tg of the protective film, and are preferably 80° C. or higher for 2 hours or longer. The heating temperature for the heat treatment is more preferably 80°C to 200°C, even more preferably 90°C to 190°C, and particularly preferably 100°C to 180°C, from the viewpoint of volatilizing the residue of the precursor layer. The heating time for the heat treatment is appropriately selected depending on the heating temperature of the heat treatment and the type of coating composition, and is preferably 2 to 48 hours, more preferably 3 to 36 hours, even more preferably 4 to 24 hours, and even more preferably 10 to 24 hours.

[0046] The thickness of the precursor layer immediately after the coating composition is applied usually varies depending on the location of the precursor layer. In the planarization step, it is preferable to apply a heat treatment to the precursor layer while it is in contact with the flat surface of the planarization article via a protective film. This can further flatten the surface of the adhesive layer. Hereinafter, the precursor frame with the protective film and the flattening article in contact with each other will be referred to as the "first contact article." The method for contacting the precursor layer of the precursor frame with the protective film with the flat surface of the planarizing article via the protective film is not particularly limited, and examples include the inverted placement method and the placing method. In the placing method, the frame precursor with the protective film is placed on the flat surface of the planarizing article. In the inverted placement method, the planarizing article is placed on the frame precursor with the protective film. In both the placing method and the inverted placement method, the planarizing article may also be brought into contact with the pellicle membrane end surface of the pellicle frame of the precursor frame with the protective film. Among these, the placing method is preferred from the viewpoint of making it easier to heat the precursor layer when heated on a hot plate. When the flat surface is brought into contact with the precursor layer via the protective film, a pressure (load) may be applied uniformly to the entire precursor layer. The pressure (load) to be applied uniformly to the entire precursor layer is not particularly limited, and is preferably 10 g / cm from the viewpoint of reducing distortion of the pellicle frame. 2 ~1000g / cm 2 , more preferably 100 g / cm 2 ~800g / cm 2 , and more preferably 300 g / cm 2 ~600g / cm 2 is. The TIR value of the flat surface of the planarizing article is less than 10 μm. This allows the TIR value of the adhesive layer to be less than 10 μm. In other words, the number of local steps on the surface of the adhesive layer is reduced. From the viewpoint of forming an adhesive layer with a lower TIR value, the TIR value of the flat surface of the planarizing article is preferably 5 μm or less, more preferably 3 μm or less, and the closer to 0 μm the better. Examples of planarizing articles include glass substrates. In the planarizing step, it is preferable to perform a heat treatment while the flat surface of the glass substrate is in contact with the surface of the precursor layer via a protective film. The method for heat-treating the precursor frame with the protective film while the precursor layer is in contact with the flat surface via the protective film is not particularly limited, and examples include a method using an oven, a method using a hot plate, and a method of contacting a heated planarizing article. In the method using an oven, the first contact article is placed in the oven chamber and the first contact article itself is heated, thereby heat-treating the precursor frame with the protective film. In the method using a hot plate, for example, the first contact article is placed on a hot plate so that the planarizing article, which is in contact with the precursor layer of the first contact article via the protective film, comes into contact with the plate of the hot plate, and the precursor layer is heated through the planarizing article, thereby heat-treating the precursor frame with the protective film. In the method of contacting a heated flat surface, for example, a heated planarizing article is prepared, the first contact article is placed on the planarizing article, and the precursor layer is heated, thereby heat-treating the precursor frame with the protective film. When an oven is used, the set temperature inside the oven is the same as the temperature range exemplified as the heating temperature of the heat treatment described above. The set temperature inside the oven refers to the temperature inside the oven. The time for heating the precursor layer using the oven is the same as the time range exemplified as the heating time of the heat treatment described above. When a hot plate is used, the set temperature of the hot plate is the same as the temperature range exemplified as the heating temperature of the heat treatment described above. The set temperature of the hot plate refers to the surface temperature of the hot plate. The time for heating the precursor layer using the hot plate is the same as the time range exemplified as the heating time of the heat treatment described above.

[0047] In the planarization step, to further promote planarization, the precursor layer of the precursor frame with the protective film may be brought into contact with a heated flat surface via a protective film before the aforementioned frame precursor with the protective film is subjected to a heat treatment. The method for bringing the precursor layer of the precursor frame with the protective film into contact with the heated flat surface via a protective film is not particularly limited, and examples include heat pressing. The heating temperature of the heated flat surface is the same as the temperature range exemplified as the heating temperature for the heat treatment described above from the viewpoint of facilitating planarization, and the heating time can be 10 seconds or longer.

[0048] (1.6) Peeling process The manufacturing method of the present disclosure generally includes a peeling step, which is performed after the planarization step is performed.

[0049] In the peeling step, the protective film is peeled off from the pellicle frame with the protective film, thereby obtaining a pellicle frame with an adhesive layer.

[0050] A method for peeling the protective film from the pellicle frame with the protective film can be, for example, a method in which mechanical force is applied in the direction of peeling from the pellicle frame.

[0051] (1.7) Acrylic adhesive An acrylic adhesive, which is an example of the adhesive composition, will be described below.

[0052] The acrylic pressure-sensitive adhesive contains a copolymer (hereinafter referred to as "(meth)acrylic acid alkyl ester copolymer").

[0053] (1.7.1) (Meth)acrylic acid alkyl ester copolymer The (meth)acrylic acid alkyl ester copolymer is a (meth)acrylic acid alkyl ester monomer; It is preferable to include a copolymer with a monomer having a functional group reactive with at least one of an isocyanate group, an epoxy group, and an acid anhydride (hereinafter referred to as a "functional group-containing monomer").

[0054] Because the acrylic adhesive contains a (meth)acrylic acid alkyl ester copolymer, the pellicle is less likely to peel off from the photomask even when exposed to a high-temperature environment (e.g., a temperature environment of 60°C or above 60°C), and the occurrence of adhesive residue can be suppressed. "Adhesive residue" refers to at least a portion of the adhesive layer remaining on the photomask after the pellicle is peeled off from the photomask.

[0055] The weight average molecular weight (Mw) of the (meth)acrylic acid alkyl ester copolymer is preferably 30,000 to 2.5 million, more preferably 50,000 to 1.5 million, and even more preferably 70,000 to 1.2 million. If the upper limit of the weight-average molecular weight (Mw) of the (meth)acrylic acid alkyl ester copolymer is 2.5 million or less, the solution viscosity can be controlled within a range that facilitates processing, even if the solid content of the coating composition is increased. The upper limit of the weight-average molecular weight (Mw) of the (meth)acrylic acid alkyl ester copolymer is preferably 2.5 million or less, more preferably 1.5 million or less, and even more preferably 1.2 million or less. If the lower limit of the weight average molecular weight (Mw) of the (meth)acrylic acid alkyl ester copolymer is 30,000 or more, the pellicle will be less likely to peel from the photomask even when exposed to a high temperature environment (e.g., 60°C), and the occurrence of adhesive residue can be suppressed. The lower limit of the weight average molecular weight (Mw) of the (meth)acrylic acid alkyl ester copolymer is preferably 30,000 or more, more preferably 50,000 or more, and even more preferably 70,000 or more. The weight average molecular weight (Mw) of the (meth)acrylic acid alkyl ester copolymer is measured by GPC (gel permeation chromatography). For example, in general, the weight-average molecular weight (Mw) tends to increase as the monomer concentration during the polymerization reaction increases, and the weight-average molecular weight (Mw) tends to increase as the amount of polymerization initiator decreases and the polymerization temperature decreases. The weight-average molecular weight (Mw) can be controlled by adjusting the monomer concentration, the amount of polymerization initiator, and the polymerization temperature.

[0056] The number average molecular weight (Mn) of the (meth)acrylic acid alkyl ester copolymer is preferably 5,000 to 500,000, more preferably 8,000 to 300,000, even more preferably 10,000 to 200,000, and most preferably 20,000 to 200,000. If the upper limit of the number-average molecular weight (Mn) of the (meth)acrylic acid alkyl ester copolymer is 500,000 or less, the solution viscosity can be controlled within a range that allows for easy processing, even if the solids concentration of the coating composition is increased. The upper limit of the number-average molecular weight (Mn) of the (meth)acrylic acid alkyl ester copolymer is preferably 500,000 or less, more preferably 300,000 or less, and even more preferably 200,000 or less. If the lower limit of the number-average molecular weight (Mn) of the (meth)acrylic acid alkyl ester copolymer is 5,000 or more, the pellicle is less likely to peel from the photomask even when exposed to a high-temperature environment (e.g., 60°C), and the occurrence of adhesive residue can be suppressed. The lower limit of the number-average molecular weight (Mn) of the (meth)acrylic acid alkyl ester copolymer is preferably 5,000 or more, more preferably 8,000 or more, even more preferably 10,000 or more, and most preferably 20,000 or more. The method for measuring the number average molecular weight (Mn) of the (meth)acrylic acid alkyl ester copolymer is the same as the method for measuring the weight average molecular weight (Mw) of the (meth)acrylic acid alkyl ester copolymer described above.

[0057] The "weight average molecular weight (Mw) / number average molecular weight (Mn)" (hereinafter referred to as "Mw / Mn") of the (meth)acrylic acid alkyl ester copolymer is preferably 1.0 to 10.0, more preferably 2.5 to 9.0, even more preferably 2.5 to 8.0, and most preferably 3.0 to 7.0. If Mw / Mn is within the above range, the copolymer can be easily produced and the occurrence of adhesive residue can be suppressed. If the upper limit of Mw / Mn is 10.0 or less, the occurrence of adhesive residue can be suppressed. The upper limit of Mw / Mn is preferably 10.0 or less, more preferably 9.0 or less, even more preferably 8.0 or less, and most preferably 7.0 or less. If the lower limit of Mw / Mn is 1.0 or more, the copolymer can be easily produced. The lower limit of Mw / Mn is preferably 1.0 or more, more preferably 2.0 or more, even more preferably 2.5 or more, and most preferably 3.0 or more.

[0058] The (meth)acrylic acid alkyl ester monomer preferably contains a (meth)acrylic acid alkyl ester monomer having an alkyl group having 1 to 14 carbon atoms. Examples of the (meth)acrylic acid alkyl ester monomer having an alkyl group having 1 to 14 carbon atoms include a (meth)acrylic acid ester monomer of a linear aliphatic alcohol and a (meth)acrylic acid ester monomer of a branched aliphatic alcohol. Examples of (meth)acrylic acid ester monomers of linear aliphatic alcohols include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, propyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and lauryl (meth)acrylate. Examples of (meth)acrylic acid ester monomers of branched chain aliphatic alcohols include isobutyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, etc. These may be used alone or in combination of two or more.

[0059] Among these, the (meth)acrylic acid alkyl ester monomer preferably has at least one of an alkyl group having 1 to 3 carbon atoms and an alicyclic alkyl group. Hereinafter, a (meth)acrylic acid alkyl ester monomer having at least one of an alkyl group and an alicyclic alkyl group having 1 to 3 carbon atoms will be referred to as a “high Tg monomer.” “Tg” refers to the glass transition temperature. In order to further reduce the amount of outgassing, the (meth)acrylic acid alkyl ester monomer is more preferably an acrylic acid alkyl ester monomer having an alkyl group or an alicyclic alkyl group having 1 to 3 carbon atoms, and even more preferably an acrylic acid alkyl ester monomer having an alkyl group having 1 to 3 carbon atoms. In the case of an acrylic acid alkyl ester monomer having an alicyclic alkyl group, the number of carbon atoms of the alicyclic alkyl group is preferably 5 to 10, from the viewpoint of availability. When the (meth)acrylic acid alkyl ester monomer contains a high Tg monomer, the pellicle is less likely to peel off from the photomask even when exposed to a high-temperature atmosphere. Specific examples of high Tg monomers include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, cyclohexyl methacrylate, and dicyclopentanyl methacrylate.

[0060] The content of the (meth)acrylic acid alkyl ester monomer is preferably 80 parts by mass to 99.5 parts by mass, more preferably 85 parts by mass to 99.5 parts by mass, and even more preferably 87 parts by mass to 99.5 parts by mass, relative to 100 parts by mass of the total amount of the monomers constituting the copolymer. If the content of the (meth)acrylic acid alkyl ester monomer is within the range of 80 parts by mass to 99.5 parts by mass, an appropriate adhesive strength can be achieved.

[0061] The functional group-containing monomer is a monomer copolymerizable with the (meth)acrylic acid alkyl ester monomer, and has a functional group reactive with at least one of an isocyanate group, an epoxy group, and an acid anhydride. Examples of functional group-containing monomers include carboxy group-containing monomers, hydroxy group-containing monomers, and epoxy group-containing monomers. Examples of the carboxy group-containing monomer include (meth)acrylic acid, itaconic acid, (meth)acrylic acid itaconic acid, maleic acid, and crotonic acid. Examples of the hydroxy group-containing monomer include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate. These may be used alone or in combination of two or more. In particular, from the viewpoints of copolymerizability, versatility, etc., the functional group-containing monomer preferably includes a hydroxy group-containing (meth)acrylic acid having a hydroxyalkyl group having 2 to 4 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate, or an epoxy group-containing monomer, glycidyl (meth)acrylate.

[0062] The content of the functional group-containing monomer is preferably, for example, 0.5 to 20 parts by mass relative to 100 parts by mass of the total amount of the monomers constituting the copolymer. From the viewpoint of improving the adhesive strength of the adhesive layer, the lower limit of the content of the functional group-containing monomer is more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, and particularly preferably 3 parts by mass or more, per 100 parts by mass of the total amount of monomers constituting the (meth)acrylic acid alkyl ester copolymer. In order to ensure that the adhesive strength of the adhesive layer is appropriate, the upper limit of the content of the functional group-containing monomer is more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the total amount of monomers constituting the (meth)acrylic acid alkyl ester copolymer.

[0063] (1.7.2) Polymerization method The polymerization method for the (meth)acrylic acid alkyl ester copolymer is not particularly limited, and examples thereof include solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. The (meth)acrylic acid alkyl ester copolymer obtained by these polymerization methods may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

[0064] (1.7.3) Polymerization solvent The reaction solution contains a polymerization solvent. In solution polymerization, for example, propyl acetate, ethyl acetate, toluene, etc. can be used as a polymerization solvent. This allows the viscosity of the copolymer solution to be adjusted. As a result, the thickness and width of the coating composition can be easily controlled during polymerization. Examples of dilution solvents include propyl acetate, acetone, ethyl acetate, and toluene. The viscosity of the copolymer solution is preferably 1000 Pa·s or less, more preferably 500 Pa·s or less, and even more preferably 200 Pa·s or less. The viscosity of the copolymer solution is the viscosity when the temperature of the copolymer solution is 25° C., and can be measured using an E-type viscometer.

[0065] (1.7.4) Solution polymerization An example of solution polymerization is a method in which a polymerization initiator is added to a mixed solution of monomers in a stream of an inert gas such as nitrogen, and the polymerization reaction is carried out at 50° C. to 100° C. for 4 hours to 30 hours.

[0066] Examples of the polymerization initiator include azo-based polymerization initiators and peroxide-based polymerization initiators. Examples of the azo-based polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2-methylpropionate) dimethyl, and 4,4'-azobis-4-cyanovaleric acid. Examples of the monomer-based polymerization initiator include benzoyl peroxide. The content of the polymerization initiator is preferably 0.01 to 2.0 parts by mass relative to 100 parts by mass of the total amount of all monomers constituting the (meth)acrylic acid alkyl ester copolymer. In solution polymerization, in addition to the polymerization initiator, a chain transfer agent, an emulsifier, etc. may be added to the mixed solution of monomers. As the chain transfer agent, emulsifier, etc., known agents can be appropriately selected and used.

[0067] It is preferable that the amount of polymerization initiator remaining in the adhesive layer is small, which can reduce the amount of outgassing that occurs during exposure. Methods for reducing the amount of polymerization initiator remaining in the adhesive layer include minimizing the amount of polymerization initiator added when polymerizing the (meth)acrylic acid alkyl ester copolymer, using a polymerization initiator that is easily thermally decomposed, and heating the adhesive to a high temperature for a long period of time during the adhesive application and drying process to decompose the polymerization initiator during the drying process.

[0068] The 10-hour half-life temperature is used as an index to express the thermal decomposition rate of a polymerization initiator. "Half-life" refers to the time it takes for half of the polymerization initiator to decompose. The 10-hour half-life temperature is the temperature at which the half-life is 10 hours. It is preferable to use a polymerization initiator with a low 10-hour half-life temperature. The lower the 10-hour half-life temperature, the more easily the polymerization initiator is thermally decomposed. As a result, it is less likely to remain in the adhesive layer. The 10-hour half-life temperature of the polymerization initiator is preferably 80°C or lower, more preferably 75°C or lower.

[0069] Examples of azo polymerization initiators having a low 10-hour half-life temperature include 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (10-hour half-life temperature: 30°C), 2,2'-azobisisobutyronitrile (10-hour half-life temperature: 65°C), 2,2-azobis(2,4-dimethylvaleronitrile) (10-hour half-life temperature: 51°C), dimethyl 2,2'-azobis(2-methylpropionate) (10-hour half-life temperature: 66°C), and 2,2'-azobis(2-methylbutyronitrile) (10-hour half-life temperature: 67°C). Examples of peroxide polymerization initiators with a low 10-hour half-life temperature include dibenzoyl peroxide (10-hour half-life temperature: 74°C) and dilauroyl peroxide (10-hour half-life temperature: 62°C).

[0070] (1.7.5) Crosslinking agents The acrylic adhesive preferably contains a reaction product of a (meth)acrylic acid alkyl ester copolymer and a crosslinking agent, which improves the cohesive strength of the resulting adhesive layer, suppresses adhesive residue when peeling the pellicle from the photomask, and improves adhesive strength at high temperatures (e.g., 60°C or higher). The crosslinking agent has at least one of an isocyanate group, an epoxy group, and an acid anhydride group.

[0071] Examples of crosslinking agents include monofunctional epoxy compounds, polyfunctional epoxy compounds, acid anhydride compounds, metal salts, metal alkoxides, aldehyde compounds, non-amino resin amino compounds, urea compounds, isocyanate compounds, metal chelate compounds, melamine compounds, and aziridine compounds. Among these, the crosslinking agent is more preferably at least one of a monofunctional epoxy compound, a polyfunctional epoxy compound, an isocyanate compound, and an acid anhydride compound, and more preferably an acid anhydride compound, in terms of excellent reactivity with the functional group component of the (meth)acrylic acid alkyl ester copolymer.

[0072] Examples of the monofunctional epoxy compound include glycidyl (meth)acrylate, glycidyl acetate, butyl glycidyl ether, and phenyl glycidyl ether. Examples of polyfunctional epoxy compounds include neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, phthalic acid diglycidyl ester, dimer acid diglycidyl ester, triglycidyl isocyanurate, diglycerol triglycidyl ether, sorbitol tetraglycidyl ether, N,N,N',N'-tetraglycidyl m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, and N,N,N',N'-tetraglycidyldiaminodiphenylmethane. Examples of the acid anhydride compounds include aliphatic dicarboxylic acid anhydrides and aromatic polycarboxylic acid anhydrides. Examples of the aliphatic dicarboxylic acid anhydride include maleic anhydride, hexahydrophthalic anhydride, hexahydro-4-methylphthalic anhydride, bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, 2-methylbicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, and tetrahydrophthalic anhydride. Examples of aromatic polycarboxylic acid anhydrides include phthalic anhydride and trimellitic anhydride. Examples of isocyanate compounds include xylylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, and their multimers, derivatives, polymers, etc. These may be used alone or in combination of two or more.

[0073] The crosslinking agent may be a commercial product, such as "Rikacid MH-700G" manufactured by New Japan Chemical Co., Ltd.

[0074] The adhesive layer contains a reaction product of the copolymer and a crosslinking agent, and the content of the crosslinking agent is preferably 0.01 to 3.00 parts by mass per 100 parts by mass of the total amount of the monomers constituting the copolymer. The content of the crosslinking agent is preferably 0.01 to 3.00 parts by mass relative to 100 parts by mass of the total amount of the monomers constituting the copolymer, more preferably 0.10 to 3.00 parts by mass, and even more preferably 0.1 to 2.00 parts by mass, from the viewpoint of obtaining an adhesive that is less likely to leave adhesive residue. If the upper limit of the crosslinking agent content is 3.00 parts by mass or less, the crosslinking density of the (meth)acrylic acid alkyl ester copolymer will not become too high. Therefore, it is thought that the pressure-sensitive adhesive absorbs the stress applied to the photomask, and the influence of the pressure-sensitive adhesive layer on the flatness of the photomask is mitigated. The upper limit of the crosslinking agent content is preferably 2.00 parts by mass or less, more preferably 1.00 parts by mass or less. On the other hand, if the lower limit of the crosslinking agent content is 0.01 parts by mass or more, the crosslink density will not become too small, so that handling properties during the manufacturing process are maintained and adhesive residue is less likely to remain when the pellicle is peeled off from the photomask. If the content of the crosslinking agent is within the range of 0.01 parts by mass to 3.00 parts by mass, a pellicle can be obtained in which the occurrence of adhesive residue is further suppressed.

[0075] (1.7.6) Catalyst The coating composition may further contain a catalyst, which can further accelerate the curing of the (meth)acrylic acid alkyl ester copolymer. Examples of the catalyst include amine catalysts. Examples of the amine catalyst include octylate salt of (1,8-diazabicyclo-(5.4.0)undecene-7), triethylenediamine, etc. The amine catalyst may be a product of San-Apro Co., Ltd., such as "DBU," "DBN," "U-CAT," "U-CAT SA1," or "U-CAT SA102." The content of the catalyst is preferably 0.01 to 3.00 parts by mass, and more preferably 0.10 to 1.00 parts by mass, relative to 100 parts by mass of the (meth)acrylic acid alkyl ester copolymer.

[0076] (1.7.7) Surface modifiers The coating composition preferably does not contain a surface modifier, which can suppress the amount of outgassing.

[0077] (1.7.8) Additives The coating composition may contain additives such as fillers, pigments, diluents, antioxidants, tackifiers, etc. These additives may be used alone or in combination of two or more.

[0078] (1.7.9) Dilution solvent The coating composition may contain a dilution solvent, which allows the viscosity of the coating composition to be adjusted. As a result, when the coating composition is applied to the photomask end surface of the pellicle frame, the thickness and width of the coating composition can be easily controlled. Examples of dilution solvents include propyl acetate, acetone, ethyl acetate, and toluene. The viscosity of the coating composition is preferably 50 Pa·s or less, more preferably 10 Pa·s to 40 Pa·s, and even more preferably 20 Pa·s to 30 Pa·s. The viscosity of the coating composition is the viscosity when the temperature of the coating composition is 25°C, and can be measured using an E-type viscometer.

[0079] (2) Pellicle frame with protective film The pellicle frame with a protective film of the present disclosure includes a pellicle frame, an adhesive layer for attaching to a photomask, and a protective film. The adhesive layer is formed on the pellicle frame. The protective film is attached to the surface of the adhesive layer. The glass transition temperature of the protective film is greater than 120°C.

[0080] The pellicle frame with protective film of the present disclosure has the above-described configuration, and therefore can reduce the number of air bubbles that become trapped when the pellicle is attached to the photomask. This effect is presumably due to, but not limited to, the following reasons. The pellicle frame with a protective film of the present disclosure is suitably manufactured by the manufacturing method of a pellicle frame with an adhesive layer of the present disclosure. The heating temperature in the flattening step of the manufacturing method of a pellicle frame with an adhesive layer of the present disclosure is typically 120°C or lower. Therefore, if the glass transition temperature of the protective film is higher than 120°C, distortion of the protective film is unlikely to occur during the manufacturing process. As a result, the surface of the adhesive layer is likely to be flat when the protective film is peeled off from the pellicle frame with the protective film. Specifically, the number of local steps on the surface of the adhesive layer is likely to be one or less. Therefore, it is presumed that the number of air entrapments can be reduced when the pellicle is attached to a photomask.

[0081] The pellicle frame, adhesive layer, and protective film of the pellicle frame with protective film may be the same as those exemplified as the pellicle frame, adhesive layer, and protective film of the method for manufacturing a pellicle frame with an adhesive layer.

[0082] (3) Pellicle frame with adhesive layer The pellicle frame with an adhesive layer of the present disclosure includes a pellicle frame and an adhesive layer for attaching to a photomask. The adhesive layer is formed on the pellicle frame. The number of local steps of 3 μm or more on the surface of the adhesive layer is one or less.

[0083] The method for measuring the "number of local steps of 3 μm or more" is the same as that described in the examples.

[0084] The pellicle frame with adhesive layer of the present disclosure has the above-described configuration, and therefore can reduce the number of air bubbles that become trapped when the pellicle is attached to the photomask. This effect is presumably due to, but not limited to, the following reasons. The fact that the number of local steps of 3 μm or more on the surface of the adhesive layer is one or less indicates that the surface of the adhesive layer is flat. Therefore, it is presumed that the number of air entrapments when the pellicle is attached to the photomask is reduced compared to when the number of local steps of 3 μm or more on the surface of the adhesive layer is two or more.

[0085] The number of local steps of 3 μm or more on the surface of the adhesive layer is one or less, and preferably zero from the viewpoint of further reducing the number of air entrapments when the pellicle is attached to the photomask. A method for keeping the number of local steps of 3 μm or more on the surface of the adhesive layer within the above range includes, for example, a method for manufacturing a pellicle frame with an adhesive layer using the method for manufacturing a pellicle frame with an adhesive layer disclosed herein.

[0086] The pellicle frame and adhesive layer of the pellicle frame with an adhesive layer may be the same as those exemplified as the pellicle frame and adhesive layer of the method for manufacturing a pellicle frame with an adhesive layer.

[0087] In particular, from the viewpoint of reducing the amount of outgassing generated from the pellicle, the adhesive layer preferably contains at least one selected from the group consisting of an acrylic adhesive, a silicone adhesive, a styrene butadiene adhesive, a urethane adhesive, and an olefin adhesive. It is more preferable that the adhesive layer contains an acrylic adhesive, and it is even more preferable that the adhesive layer is an acrylic adhesive.

[0088] (4) Pellicle Pellicle of the present disclosure The pellicle frame includes a pellicle membrane supported by the pellicle frame and a pellicle frame with an adhesive layer according to the present disclosure. The pellicle membrane is supported by the pellicle frame. Specifically, the pellicle membrane is supported on the pellicle membrane end surface of the pellicle frame.

[0089] The pellicle film prevents foreign matter from adhering to the surface of the photomask and allows the exposure light to pass through during exposure. Foreign matter includes dust. Examples of exposure light include deep ultraviolet (DUV) light and EUV light. EUV refers to light with a wavelength of 2 nm or more and 30 nm or less.

[0090] The pellicle membrane covers the entire opening on one end face (pellicle membrane end face) of the through-hole in the pellicle frame. The pellicle membrane may be supported directly on one end face of the pellicle frame, or may be supported via a membrane adhesive layer. The membrane adhesive layer may be a cured product of a known adhesive.

[0091] The thickness of the pellicle film is preferably 1 nm or more and 400 nm or less, and more preferably 1 nm or more and 70 nm or less, since this makes it easier to increase the transmittance in EUV exposure. The material of the pellicle film is not particularly limited, and examples thereof include carbon-based materials, SiN, polysilicon, and fluororesin. Carbon-based materials include carbon nanotubes (hereinafter referred to as "CNT"). In particular, the material of the pellicle film preferably includes at least one selected from the group consisting of CNT, metal silicide, and polysilicon, and more preferably includes CNT, since this facilitates increasing the transmittance in EUV exposure. The CNT may be a single-wall CNT or a multi-wall CNT. The metal silicide is preferably either molybdenum nitride silicide (MoSiN) or molybdenum silicide (MoSi). The pellicle membrane may have a nonwoven structure, which may be formed, for example, from fiber-shaped CNTs.

[0092] The pellicle membrane may be indirectly supported on the pellicle frame via a pellicle membrane adhesive layer, or may be directly supported on the pellicle frame. Examples of adhesives that can be used to form the adhesive layer for the pellicle film include acrylic resin adhesives, epoxy resin adhesives, polyimide resin adhesives, silicone resin adhesives, inorganic adhesives, double-sided adhesive tapes, polyolefin adhesives, and hydrogenated styrene adhesives. In particular, from the viewpoint of ease of application and curing processing, it is preferable that the adhesive for the pellicle membrane is at least one selected from the group consisting of silicone resin adhesives, acrylic resin adhesives, hydrogenated styrene-based adhesives, and epoxy resin adhesives. In the present disclosure, the pellicle membrane adhesive is a concept that includes not only adhesives but also pressure-sensitive adhesives. The thickness of the adhesive layer for a pellicle film is not particularly limited, and is, for example, 10 μm or more and 1 mm or less.

[0093] (5) Photomask with pellicle The pellicle-equipped photomask of the present disclosure includes a photomask and the pellicle of the present disclosure. The pellicle is attached to the photomask. On the surface of the adhesive layer that is in contact with the photomask, the area of ​​the gap between the adhesive layer and the photomask is 0.25% or less of the area of ​​the adhesive layer that is in contact with the photomask.

[0094] The method for measuring the area of ​​the gap between the adhesive layer and the photomask is the same as the method described in the examples.

[0095] "On the surface of the adhesive layer that is in contact with the photomask, the area of ​​the gap between the adhesive layer and the photomask is 0.25% or less of the area of ​​the adhesive layer that is in contact with the photomask" indicates that there is very little air entrapment. The pellicle-equipped photomask of the present disclosure has the above-mentioned configuration, and therefore can suppress the occurrence of air paths. Furthermore, the low amount of air entrapment makes the adhesive surface to the photomask uniform, thereby suppressing distortion of the photomask, and since a wide adhesive area can be ensured, peeling of the pellicle when the photomask is moved during exposure can be suppressed.

[0096] On the surface of the adhesive layer that is in contact with the photomask, the area of ​​the gap between the adhesive layer and the photomask is 0.25% or less, preferably 0% to 0.10%, more preferably 0% to 0.05%, of the area of ​​the adhesive layer that is in contact with the photomask, and the lower the better.

[0097] A photomask is an original plate for a circuit pattern. The photomask has a pattern. A pellicle is attached to the surface of the photomask that has the pattern.

[0098] The photomask does not necessarily have to have a support substrate, a reflective layer, and an absorber layer stacked in this order. The absorber layer partially absorbs light (e.g., EUV), forming a desired image on a sensitive substrate (e.g., a semiconductor substrate with a photoresist film). Examples of the reflective layer include a multilayer film of molybdenum (Mo) and silicon (Si). The material of the absorber layer may be a material that is highly absorbing of EUV and other light. Examples of materials that are highly absorbing of EUV and other light include chromium (Cr) and tantalum nitride.

[0099] The photomask with a pellicle of the present disclosure is used in an exposure apparatus. The exposure apparatus includes a light source, a pellicle-equipped photomask according to the present disclosure, and an optical system. The light source emits exposure light. The optical system guides the exposure light emitted from the light source to the photomask. The pellicle-equipped photomask is positioned so that the exposure light emitted from the light source passes through the pellicle film and irradiates the photomask. The exposure device is capable of forming fine patterns (e.g., line widths of 32 nm or less) using EUV and other technologies, and can also perform pattern exposure with reduced resolution problems caused by foreign matter, even when using EUV, which is prone to resolution problems caused by foreign matter. The exposure light is preferably DUV or EUV. EUV has a short wavelength and is easily absorbed by gases such as oxygen or nitrogen. Therefore, exposure with EUV light is performed in a vacuum environment. [Example]

[0100] The present disclosure will be described in more detail below with reference to examples, but the invention of the present disclosure is not limited to these examples.

[0101] [1] Preparation The materials used in the examples and comparative examples are as follows. <(Meth)acrylic acid alkyl ester monomer> EA: Ethyl acrylate (Tg: -24°C) <Functional group-containing monomers> 4-HBA: 4-hydroxybutyl acrylate HEMA: 2-hydroxyethyl methacrylate GMA: Glycidyl methacrylate <Crosslinking agent> "Rikacid MH-700G" manufactured by New Japan Chemical Co., Ltd. <Polymerization solvent> Propyl acetate <Polymerization initiator> AIBN: 2,2'-azobisisobutyronitrile (10-hour half-life temperature: 65°C) <Catalyst> Amine catalyst: San-Apro Co., Ltd.'s "U-CAT SA-102" (chemical formula: octylate salt of (1,8-diazabicyclo-(5.4.0)undecene-7))

[0102] [2] Example 1 [2.1] Preparation process The (meth)acrylic acid alkyl ester copolymer was prepared by a known method. Specifically, a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping device, and nitrogen inlet tube was prepared. The reaction vessel was charged with a polymerization solvent (180 parts by mass) and a mixture of EA / 4-HBA / HEMA / GMA / polymerization initiator (423.4 parts by mass) in a mass ratio of 378 / 12.6 / 21 / 8.4 / 3.4. Under a nitrogen atmosphere, this reaction solution was reacted at 85°C for 6 hours and then at 95°C for 2 hours, yielding an acrylic copolymer solution with a non-volatile content (copolymer) of 70% by mass (weight average molecular weight: 119,000). To the obtained acrylic copolymer solution (143 parts by mass), a crosslinking agent (0.28 parts by mass) and a catalyst (0.93 parts by mass) were added, and the mixture was stirred and mixed to obtain a coating composition (acrylic pressure-sensitive adhesive).

[0103] As shown in FIG. 1, an anodized aluminum pellicle frame (external dimensions: 149 mm × 115 mm, frame height H: 4.5 mm, frame width W: 2 mm) was prepared as pellicle frame 11. A prepared coating composition was applied to the photomask end surface S11A of pellicle frame 11 using a dispenser to form a precursor layer made of the coating composition. This resulted in a frame precursor.

[0104] [2.2] Drying process The frame precursor was dried at 100°C for 2 hours.

[0105] [2.3] Placement process A PEN protective film was prepared as the protective film 21. The PEN protective film had a two-layer structure consisting of a base layer (material: polyethylene naphthalate) and a release layer (material: silicone-based). The thickness of the base layer was 75 μm. A glass substrate was prepared as the flat plate. The TIR value of the flat surface of the flat plate was 5 μm. A protective film 21 was placed on the surface of the precursor layer of the dried frame precursor to obtain a frame precursor with a protective film.

[0106] [2.4] Flattening process Next, a placing method was carried out. Specifically, the precursor layer of the frame precursor with the protective film was faced downward (in the direction of gravity), and the pellicle frame with the precursor layer was placed on a flat plate. The precursor layer of the frame precursor with the protective film and the flat surface of the flat plate were in contact with each other via the protective film 21. At this time, 1.6 g / cm was applied uniformly to the entire precursor layer of the pellicle frame with the precursor layer. 2 A pressure (load) of 1000 kJ / cm was applied to the contact article, and a first contact article was obtained. An oven ("DRC623FB19A" manufactured by ADVANTEC) was prepared as a heating device. The article was placed in an oven. The entire first contact article was heated in the oven at 120°C for 16 hours. This resulted in transferring the flat surface of the flat plate to the surface of the precursor layer, and curing the precursor layer. In other words, an adhesive layer 12 with a flat surface was formed from the precursor layer.

[0107] Next, the first contact article was removed from the heating device, and the flat plate was removed from the first contact article, thereby obtaining a pellicle frame 20 with a protective film. Next, the protective film 21 was removed from the pellicle frame 20 with the protective film to obtain the pellicle frame 10 with the adhesive layer. The thickness of the adhesive layer 12 made of the adhesive composition was 0.2 mm.

[0108] [3] Example 2 and Example 3 A pellicle frame 10 with an adhesive layer was obtained in the same manner as in Example 1, except that the temperature and time of the heating conditions in the flattening step were changed to the conditions in Table 1.

[0109] [4] Comparative Example 1 A pellicle frame 10 with an adhesive layer was obtained in the same manner as in Example 1, except that the protective film 21 was changed from a PEN protective film to a PET protective film. The PET protective film had a two-layer structure consisting of a base layer (material: polyethylene terephthalate) and a release layer (material: silicone-based). The thickness of the base layer was 75 μm.

[0110] [5]Measurement method The number of local steps on the surface S12 of the adhesive layer 12, the thickness of the adhesive layer 12, and the Tg of the protective film 21 were measured by the following methods. Table 1 shows the measurement results of the number of local steps on the surface S12 of the adhesive layer 12.

[0111] [5.1] Measuring the number of local steps The number of local steps on the surface S12 of the adhesive layer 12 was calculated by measuring the height difference at each measurement point on the surface S12 of the adhesive layer 12 and using the measured height difference.

[0112] The height difference between each measurement point on the surface S12 of the adhesive layer 12 was measured as follows. The pellicle frame 10 with the adhesive layer was placed on a surface plate so that the pellicle film end surface S11B of the pellicle frame 10 with the adhesive layer faced the surface plate. The heights of each of the 204 measurement points on the surface S12 of the adhesive layer 12 from the surface plate were measured using a 3D displacement meter (Keyence Corporation, "WI5000" with "WI-004" sensor head). The 204 measurement points consisted of four points at the four corners of the photomask end surface S11A and 200 points on the four sides between the four corners. In principle, the 200 points represent the total number of points set at 2.5 mm intervals from one of the four corners to another of the four corners on each side between the four corners. However, if the distance between one of the four corners (hereinafter referred to as a "corner point") and the adjacent point among the 200 points (hereinafter referred to as a "corner interval") is not 2.5 mm, the adjacent point will be set so that the corner interval is less than 2.5 mm. If the measurement points do not amount to 204 when the above-mentioned 2.5 mm interval and corner interval are used due to differences in the size of the pellicle frame 11, the measurement points were determined using the 2.5 mm interval and the above-mentioned concept of corner interval. A least-squares plane was derived using the height measurements from 204 points. The height difference between each measurement point and the least-squares plane was determined. The positive and negative signs of the height differences of each of the multiple measurement points located on the opposite side of the surface plate from the least-squares plane were designated "plus (+)." The positive and negative signs of the height differences of each of the multiple measurement points located on the surface plate side from the least-squares plane were designated "minus (-)." The positive and negative signs of the height differences thus determined were used as the height differences of each measurement point on the surface S12 of the adhesive layer 12.

[0113] Next, based on the elevation difference of each measurement point, the Δ elevation difference between adjacent measurement points among the 204 locations is calculated. The Δ elevation difference is the value obtained by subtracting the elevation difference of the point located next to the arbitrary one of the 204 locations in a clockwise direction from the elevation difference of the arbitrary one of the 204 locations.

[0114] In principle, the number of local steps indicates the number of Δ elevation differences (called "large Δ elevation differences") whose absolute value is 3 μm or more out of the 204 Δ elevation differences. However, if there are two or more consecutive Δ elevation differences (large Δ elevation differences) when the 204 Δ elevation differences are arranged in a row according to the order of the 204 measurement points, the number of consecutive large Δ elevation differences is counted as one local step. For example, if the Δ elevation differences arranged in a row based on the above-mentioned method are 2 μm, -4 μm, 1 μm, 3 μm, and 1 μm, the number of local steps is two. If the Δ elevation differences arranged in a row are 2 μm, -4 μm, 5 μm, 3 μm, and 1 μm, the number of local steps is one.

[0115] [5.2] How to measure the thickness of the adhesive layer The thickness of the adhesive layer is determined as follows. The pellicle frame is placed on a surface plate so that the pellicle film end face of the adhesive-coated pellicle frame faces the surface plate. The heights from the surface plate at six measurement points on any one side between the four corners of the photomask end face are measured using a 3D displacement meter (Keyence Corporation, "WI5000," sensor head "WI-004"): In the width direction of the pellicle frame (the short direction of one side of the pellicle frame), four of the six measurement points are points where the adhesive layer is applied, and two of the six measurement points are points where the adhesive layer is not applied. In this example, the adhesive layer is formed only at the center of each side between the four corners of the photomask end face, and is not formed on the edge of each side between the four corners on the through-hole side of the pellicle frame or on the edge opposite the through-hole side of the pellicle frame. Therefore, in this example, of the six measurement points, four points located in the center of the pellicle's width direction are positions where the adhesive layer is formed on the photomask end face. The remaining two points, located on both edges of the pellicle's width direction, are positions where the adhesive layer is not formed on the photomask end face. Using the height measurements at six points, the height difference between the highest point of the four points where the adhesive layer is applied (the point where the adhesive layer is thickest) and the lowest point of the two points where the adhesive layer is not applied is calculated. This calculation method is performed in the length direction of the pellicle (the longitudinal direction of one side of the pellicle frame) using the same concept as for each measurement point on the surface S12 of the adhesive layer 12 described above (at 2.5 mm intervals and at corner intervals). The height difference is calculated in the same way for each of the remaining three sides between the four corners of the photomask end face. The average of all height differences calculated in this way for all four sides is the thickness of the adhesive layer.

[0116] [5.3] Method for measuring the TIR value of the flat surface of a flat plate The flat plate is placed on a surface plate so that the surface opposite the flat surface of the flat plate faces the surface plate. The height from the surface plate at each of 204 measurement points on the flat surface of the flat plate is measured using a 3D displacement meter (manufactured by Keyence Corporation, "WI5000", sensor head "WI-004"). The 204 measurement points were determined using the same concept as the measurement points used to measure the height of the surface S12 of the adhesive layer 12 described above. A least-squares plane was derived using the height measurements from 204 points. The height difference between each measurement point and the least-squares plane was determined. The positive and negative signs of the height differences of each of the multiple measurement points located on the opposite side of the surface plate from the least-squares plane were designated "plus (+)." The positive and negative signs of the height differences of each of the multiple measurement points located on the surface plate side from the least-squares plane were designated "minus (-)." The positive and negative height differences thus determined were used as the height differences of each measurement point on the surface S12 of the adhesive layer 12. The difference between the largest and smallest height differences among the measurement points was used as the TIR value.

[0117] [6] Evaluation method The number of air passes, the number of trapped air passes, the percentage of trapped air passes, and the area of ​​trapped air passes were measured by the following methods. The measurement results for the number of air passes, the number of trapped air passes, the percentage of trapped air passes, and the area of ​​trapped air passes are shown in Table 1.

[0118] [6.1] Number of air passes and number of air traps A transparent quartz substrate was prepared. The transparent quartz substrate had a first main surface and a second main surface opposite to the first main surface. The pellicle frame 10 with an adhesive layer was placed on the first main surface of the transparent quartz substrate. The adhesive layer 12 of the pellicle frame 10 with an adhesive layer was brought into contact with the first main surface of the transparent quartz substrate. This produced a second contact article. A glass substrate (type "HOYA 6025 quartz substrate", mass: 320 g) was placed on the pellicle film end surface S11B of the pellicle frame 11, and a weight (mass: 2 kg) was placed on the glass substrate. 20 seconds after the weight was placed on the glass substrate, the glass substrate and the weight were removed from the pellicle film end surface S11B of the pellicle frame 11.

[0119] The second contact article was placed on the stage of an optical microscope (Keyence Corporation's "VHX-6000") so that the second main surface of the transparent quartz substrate of the second contact article was facing upward (opposite the direction of gravity). Using an optical microscope, the entire contact surface of adhesive layer 12 of pellicle frame 10 with the first main surface of the quartz substrate was observed through the transparent quartz substrate. The observation magnification of the optical microscope was 20 times. The number of air paths and the number of trapped air pockets in the contact surface of the adhesive layer 12 with the first main surface of the transparent quartz substrate were counted. The acceptable range for the number of air passes is 0. The acceptable range for the number of air traps is 10 or less.

[0120] [6.2] Air entrapment area Using the software "VHX" attached to the optical microscope, the total area of ​​the multiple air pockets present in the contact surface of the adhesive layer 12 with the first main surface of the quartz substrate and the total area of ​​the contact surface of the adhesive layer 12 with the first main surface of the quartz substrate were measured. The total area of ​​the plurality of air bubbles present in the contact surface of the adhesive layer 12 with the first main surface of the quartz substrate was defined as the "air bubble area." The ratio of the area of ​​trapped air to the total area of ​​the contact surface of the adhesive layer 12 with the first main surface of the quartz substrate was defined as the "trapped air ratio." The allowable range for the air entrapment rate is 0.25% or less.

[0121] [Table 1]

[0122] In Table 1, "acrylic" refers to an acrylic pressure-sensitive adhesive. "Tg" refers to the glass transition temperature. "Tg of protective film" refers to the glass transition temperature of the base layer included in the protective film.

[0123] The manufacturing method of the pellicle frame with an adhesive layer in Examples 1 to 3 includes step A (i.e., a preparation step), step B (i.e., a placement step), and step C (i.e., a flattening step), and the glass transition temperature (Tg) of the protective film 21 is higher than the heating temperature in the flattening step. Therefore, the number of trapped air particles in Examples 1 to 3 was 3 or less. From these results, it was found that the manufacturing methods of pellicle frames with adhesive layers in Examples 1 to 3 can reduce the number of trapped air particles when a pellicle is attached to a photomask.

[0124] The pellicle frame 20 with protective film of Comparative Example 1 includes a pellicle frame 11, an adhesive layer 12, and a protective film 21. However, the glass transition temperature of the protective film 21 of Comparative Example 1 was not higher than 120°C. Therefore, the number of trapped air particles in Comparative Example 1 was 13.

[0125] The pellicle frame 20 with protective film of Examples 1 to 3 includes a pellicle frame 11, an adhesive layer 12, and a protective film 21. The glass transition temperature of the protective film 21 of Examples 1 to 3 was above 120°C. Therefore, the number of trapped air pockets in Examples 1 to 3 was 3 or less. From these results, it was found that the pellicle frame 20 with protective film of Examples 1 to 3 can reduce the number of trapped air pockets when the pellicle is attached to a photomask.

[0126] Pellicle frame 10 with an adhesive layer in Comparative Example 1 includes pellicle frame 11 and adhesive layer 12. However, the number of local steps of 3 μm or more on surface S12 of adhesive layer 12 in Comparative Example 1 was not one or less. Therefore, the number of trapped air pockets in Comparative Example 1 was 13.

[0127] The pellicle frame 10 with an adhesive layer in Examples 1 to 3 includes a pellicle frame 11 and an adhesive layer 12. The number of local steps of 3 μm or more on the surface S12 of the adhesive layer 12 in Examples 1 to 3 was zero. The fact that the number of local steps of 3 μm or more on the surface S12 of the adhesive layer 12 is one or less indicates that the surface S12 of the adhesive layer 12 is flat. These results demonstrate that the pellicle frame 10 with an adhesive layer in Examples 1 to 3 can reduce the number of air entrapments when the pellicle is attached to a photomask.

[0128] The disclosure of Japanese Patent Application No. 2022-047178, filed on March 23, 2022, is incorporated herein by reference in its entirety. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A pellicle frame; an adhesive layer formed on the pellicle frame for attaching to a photomask; Equipped with A pellicle frame with an adhesive layer, wherein the number of local steps of 3 μm or more on the surface of the adhesive layer is one or less.

2. 2. The pellicle frame with adhesive layer according to claim 1, wherein the adhesive layer comprises at least one selected from the group consisting of an acrylic adhesive, a silicone adhesive, a styrene butadiene adhesive, a urethane adhesive, and an olefin adhesive.

3. a pellicle membrane supported by the pellicle frame; The pellicle frame with the adhesive layer according to claim 1 or 2, and A pellicle, wherein the pellicle film comprises at least one selected from the group consisting of carbon nanotubes, metal silicides, and polysilicon.

4. A photomask and The pellicle according to claim 3 attached to the photomask. Equipped with A pellicle-attached photomask, wherein the area of ​​the gap between the adhesive layer and the photomask on the surface of the adhesive layer that is in contact with the photomask is 0.25% or less of the area of ​​the adhesive layer that is in contact with the photomask.

5. A method for manufacturing a pellicle frame with an adhesive layer, the method comprising: a pellicle frame; and an adhesive layer formed on the pellicle frame for attaching it to a photomask, the method comprising: A step A of preparing a frame precursor including the pellicle frame and a precursor layer that is a precursor of the adhesive layer and is formed on the pellicle frame; a step B of forming a frame precursor with a protective film by placing a protective film on the surface of the precursor layer; a step C of placing the protective film-attached frame precursor on a flat plate to obtain a contact article, and subjecting the obtained contact article to a heat treatment under a first heating condition or a second heating condition to form the adhesive layer having a flattened surface from the precursor layer; and the adhesive layer contains an acrylic adhesive, the glass transition temperature of the protective film is 140°C to 200°C and is higher than the heating temperature in step C; the first heating conditions are a heating temperature of 80°C to 90°C and a heating time of 10 hours to 24 hours; The method for manufacturing a pellicle frame with an adhesive layer, wherein the second heating conditions are conditions in which the heating time is 100°C to 180°C and the heating time is 2 hours to 3 hours.

6. The method for manufacturing a pellicle frame with an adhesive layer according to claim 5 , wherein the protective film has a glass transition temperature of greater than 120° C.

7. 7. A method for manufacturing a pellicle frame with an adhesive layer as described in claim 5 or claim 6, wherein in step C, the contact article is subjected to a heat treatment under the second heating conditions to form the adhesive layer having a flattened surface from the precursor layer.

8. 7. The method for manufacturing a pellicle frame with an adhesive layer according to claim 5 or claim 6, wherein the adhesive layer comprises at least one selected from the group consisting of an acrylic adhesive, a silicone adhesive, a styrene butadiene adhesive, a urethane adhesive, and an olefin adhesive.

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