Foreign matter removal device, pellicle manufacturing device, pellicle film manufacturing method, and pellicle

Abstract

A foreign matter removal device according to the present disclosure comprises: a vacuum ultraviolet light generation unit that generates vacuum ultraviolet light; an irradiation container for irradiating a pellicle film with the vacuum ultraviolet light; and a gas supply unit that supplies an inert gas to the irradiation container. The irradiation container has: an irradiation chamber which is provided with a gas supply opening for supplying the inert gas and a gas discharge opening for discharging the inert gas; a transparent part which is provided at a boundary of the irradiation chamber and through which the vacuum ultraviolet light transmits; and a stage which is disposed in the irradiation chamber and on which the pellicle film is to be placed. The gas supply unit is connected to the gas supply opening.

Description

Foreign matter removal device, pellicle manufacturing device, pellicle manufacturing method, and pellicle

[0001] The present disclosure relates to a foreign matter removal device, a pellicle manufacturing device, a pellicle manufacturing method, and a pellicle.

[0002] The miniaturization of semiconductor integrated circuits is being driven by photolithography, which uses a transparent substrate (hereinafter referred to as a "photomask") with a pattern formed on one side. A pellicle is attached to the photomask to prevent foreign matter such as dust from adhering to the surface of the photomask.

[0003] On the other hand, Patent Document 1 describes an apparatus and method for removing foreign matter by generating a pressure pulse in a gas using a pressure pulse laser, and Patent Document 2 describes an apparatus and method for removing foreign matter from a film by generating an electric field near the film to vibrate the film.

[0004] Patent Document 1: International Publication No. 2021 / 073799 Patent Document 2: International Publication No. 2020 / 109152

[0005] During the manufacturing process of pellicles, a large number of foreign particles may adhere to the pellicle film. The foreign particles on the pellicle film may increase the absorption of radiation during exposure of a substrate, resulting in localized hot spots on the pellicle film that may lead to damage to the pellicle film. Therefore, there is a need to remove the foreign particles adhered to the pellicle film.

[0006] The present disclosure has been made in consideration of the above circumstances. An object of one embodiment of the present disclosure is to provide a foreign matter removal device, a pellicle manufacturing apparatus, and a pellicle manufacturing method that can prevent damage to a pellicle film and remove foreign matter adhering to the pellicle film. Another object of another embodiment of the present disclosure is to provide a pellicle that can suppress a decrease in the yield rate of semiconductor production.

[0007] Means for solving the above problems include the following embodiments. <1> A foreign matter removal apparatus comprising: a vacuum ultraviolet light generation unit that generates vacuum ultraviolet light; an irradiation container for irradiating a pellicle film with the vacuum ultraviolet light; and a gas supply unit that supplies an inert gas to the irradiation container, wherein the irradiation container has an irradiation chamber provided with a gas supply port for supplying the inert gas and a gas exhaust port for exhausting the inert gas, and the gas supply unit is connected to the gas supply port. <2> The foreign matter removal apparatus according to <1>, further comprising a transmission section that transmits the vacuum ultraviolet light, at a boundary between the irradiation chamber and the vacuum ultraviolet light generation unit. <3> The foreign matter removal apparatus according to <1> or <2>, further comprising a stage that is disposed in the irradiation chamber and on which the pellicle film is placed. <4> The foreign matter removal apparatus according to any one of <1> to <3>, wherein the inert gas includes nitrogen gas. <5> An integrated light amount of the vacuum ultraviolet light is 0.1 J / cm ２ ~100 J / cm ２ <6> The foreign matter removal device according to any one of <1> to <4>, wherein the illuminance of the vacuum ultraviolet light is 5 mW / cm ２ ~100mW / cm ２<7> The foreign matter removal apparatus according to any one of <1> to <5>, wherein: <7> The foreign matter removal apparatus according to <3>, further comprising a transmission section that transmits the vacuum ultraviolet light at a boundary between the irradiation chamber and the vacuum ultraviolet light generation section, and wherein the irradiation container further comprises a distance adjustment section that adjusts the distance between the transmission section and the stage. <8> The foreign matter removal apparatus according to any one of <1> to <7>, wherein the gas exhaust port is arranged at a position lower than a height at the center of the irradiation chamber in the height direction of the irradiation chamber. <9> The foreign matter removal apparatus according to <8>, wherein the gas supply port is arranged at a position higher than a height at the center of the irradiation chamber in the height direction of the irradiation chamber. <10> The foreign matter removal apparatus according to any one of <1> to <9>, wherein the irradiation chamber has two opposing wall sections, wherein the gas supply port is arranged in one of the two opposing wall sections, and wherein the gas exhaust port is arranged in the other of the two opposing wall sections. <11> A pellicle manufacturing apparatus including the foreign matter removal apparatus according to any one of <1> to <10>. <12> A method for manufacturing a pellicle film, comprising: supplying an inert gas into an irradiation chamber; and irradiating a pellicle film with vacuum ultraviolet light in an inert gas atmosphere in the irradiation chamber, wherein the concentration of oxygen gas in the inert gas atmosphere in the irradiation chamber is 5% by volume or less. <13> A method for manufacturing a pellicle film according to <12>, wherein the concentration of oxygen gas in the irradiation chamber is 3% by volume or less. <14> A method for manufacturing a pellicle film according to <12> or <13>, wherein the inert gas includes nitrogen gas. <15> A method for manufacturing a pellicle film according to any one of <12> to <14>, wherein a flow rate of the inert gas is 10 L / min to 1000 L / min. <16> A method for manufacturing a pellicle film according to any one of <12> to <14>, wherein the integrated light amount of the vacuum ultraviolet light is 0.1 J / cm ２ ~100.0J / cm ２ <17> The method for producing a pellicle film according to any one of <12> to <15>, wherein the illuminance of the vacuum ultraviolet light is 5 mW / cm ２ ~100mW / cm ２<18> The method for manufacturing a pellicle film according to any one of <12> to <17>, wherein the irradiation time of the vacuum ultraviolet light is 1 second to 30 minutes. <19> The method for manufacturing a pellicle film according to any one of <12> to <18>, wherein the irradiation chamber has a transmission section at a boundary of the irradiation chamber that transmits the vacuum ultraviolet light, and wherein the separation distance between the transmission section and the pellicle film is 0.3 mm to 2.0 mm. <20> The method for manufacturing a pellicle according to any one of <12> to <19>, wherein the film thickness of the pellicle film is 100 nm or less. <21> A pellicle comprising: a pellicle frame; and a pellicle film supported by the pellicle frame, wherein the pellicle film has a film thickness of 100 nm or less, the pellicle film contains foreign matter having a size of 1 μm to 5 μm, and the number of foreign matter is 35 or less.

[0008] According to one embodiment of the present disclosure, there is provided a foreign matter removal device, a pellicle manufacturing apparatus, and a pellicle manufacturing method that can prevent damage to the pellicle film and remove foreign matter adhering to the pellicle film. According to another embodiment of the present disclosure, there is provided a pellicle that can suppress a decrease in the yield rate of semiconductor production.

[0009] 1 and 2 are cross-sectional views of a foreign matter removal device according to a first embodiment of the present disclosure, respectively.

[0010] 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 the present 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 the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with a 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 multiple substances unless otherwise specified. In the present disclosure, the term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0011] (1) Foreign Matter Removal Device The foreign matter removal device of the present disclosure includes a VUV light generation unit that generates vacuum ultraviolet (VUV (Vacuum UltraViolet) light; hereinafter, VUV) light, an irradiation container for irradiating a pellicle film with the VUV light, and a gas supply unit that supplies an inert gas to the irradiation container. The irradiation container has an irradiation chamber provided with a gas supply port for supplying the inert gas and a gas exhaust port for exhausting the inert gas. The gas supply unit is connected to the gas supply port.

[0012] In this disclosure, "VUV light" refers to light having a wavelength of 100 nm to 200 nm, and may also refer to light having a wavelength of 160 nm to 180 nm. In this disclosure, "inert gas" refers to a molecular gas that absorbs VUV light gas and is radicalized or ionized to facilitate the removal of foreign matter attached to the pellicle membrane.

[0013] The foreign matter removal device of the present disclosure, having the above-described configuration, can prevent damage to the pellicle film and remove foreign matter adhering to the pellicle film. This effect is presumably due to, but not limited to, the following reasons. In the present disclosure, when the gas supply unit supplies an inert gas into the irradiation chamber, the gas (e.g., air, etc.) in the irradiation chamber is discharged to the outside of the irradiation chamber through the gas outlet. As a result, most of the gas in the irradiation chamber is replaced with the inert gas, and the oxygen concentration in the irradiation chamber can be reduced to 5% by volume or less. The oxygen concentration in air is approximately 21% by volume. When the VUV light generation unit generates VUV light, the VUV light is irradiated toward the pellicle film placed on the stage through the transmission unit. Because VUV light has a short wavelength, it is easily absorbed by gas molecules (e.g., oxygen, etc.). When oxygen molecules absorb VUV light, reactive oxygen species (e.g., ozone, oxygen radicals, etc.) are easily generated. When VUV light is generated in an inert atmosphere with an oxygen concentration of 5% by volume or less in the irradiation chamber, the amount of reactive oxygen species (e.g., ozone, oxygen radicals, etc.) generated is reduced. This suppresses the reduction in pellicle film thickness due to reactive oxygen species. Meanwhile, the irradiation of the foreign matter and pellicle film with VUV light generates a photoelectric effect, causing the foreign matter and pellicle film to each acquire a positive charge. Positively charged foreign matter is released from the pellicle film due to repulsion with the positively charged pellicle film. The circulating gas transports the released foreign matter. As a result, the foreign matter is discharged to the outside of the irradiation chamber through the gas outlet. Small foreign matter, in particular, has a small mass. Therefore, it is believed that small foreign matter is easily released from the pellicle film and easily discharged to the outside of the irradiation chamber through the gas outlet. As a result, it is believed that the foreign matter removal device disclosed herein can prevent damage to the pellicle film and remove foreign matter attached to the pellicle film.

[0014] A pellicle used in exposure using EUV (extreme ultraviolet) light as the light source (hereinafter also referred to as an "EUV light pellicle") has a high transmittance for EUV light. Therefore, the thickness of the pellicle film in an EUV light pellicle is very thin (for example, about several nm to 200 nm). Therefore, the foreign matter removal device disclosed herein is suitable for use in removing foreign matter adhering to the pellicle film of an EUV pellicle.

[0015] The shape and size of the foreign matter removal device are not particularly limited and may be adjusted appropriately depending on the number and size of the VUV light generators, irradiation containers, and gas supply units. The foreign matter removal device may be a large device for mass-producing pellicles, or a small laboratory-level device.

[0016] (1.1) Irradiation Container The foreign matter removal device of the present disclosure includes an irradiation container.

[0017] The number of irradiation containers is not particularly limited as long as it is at least one, and may be adjusted appropriately depending on the scale of the foreign matter removal apparatus. The size and shape of the irradiation container are not particularly limited as well, and may be selected appropriately depending on the scale of the foreign matter removal apparatus.

[0018] (1.1.1) Irradiation Chamber The irradiation container has an irradiation chamber in which the pellicle membrane is irradiated with VUV light.

[0019] The number of irradiation chambers is not particularly limited as long as it is at least one, and may be adjusted appropriately depending on the scale of the foreign matter removal apparatus, etc. The size and shape of the irradiation chambers are not particularly limited as well, and may be selected appropriately depending on the scale of the foreign matter removal apparatus, etc.

[0020] (1.1.1.1) Gas supply port and gas exhaust port The irradiation chamber is provided with a gas supply port and a gas exhaust port. The gas supply port is used to supply an inert gas into the irradiation chamber. The gas exhaust port is used to exhaust the inert gas from the irradiation chamber. This allows the oxygen concentration in the irradiation chamber to be adjusted to a desired range, and also allows foreign matter adhering to the pellicle membrane to be exhausted to the outside of the irradiation chamber, thereby reducing the amount of foreign matter on the pellicle membrane. Furthermore, the increase in pressure in the irradiation chamber due to the supply of inert gas is suppressed. As a result, the durability of the irradiation chamber is improved.

[0021] The gas supply port is connected to a gas supply unit. Details of the gas supply unit will be described later. The gas exhaust port may or may not be connected to a known gas recovery device. When the gas exhaust port is not connected to a gas recovery device, the gas exhaust port may be open to the atmosphere.

[0022] The number of each of the gas supply ports and the gas exhaust ports is not particularly limited as long as it is at least one, and may be adjusted appropriately depending on the size of the irradiation chamber, etc. The positions of each of the gas supply ports and the gas exhaust ports are not particularly limited as long as it is adjusted appropriately depending on the size of the irradiation chamber, etc.

[0023] The gas exhaust port is preferably positioned at a height (i.e., gravity direction) of the irradiation chamber that is lower than the height of the center of the irradiation chamber (i.e., the center of the irradiation chamber in the gravity direction). This makes it easier to discharge the removed foreign matter outside the irradiation chamber. As a result, recontamination by foreign matter accumulated inside the irradiation chamber can be suppressed when handling the pellicle membrane after processing.

[0024] When the gas outlet is located at a position lower than the center of the irradiation chamber in the height direction of the irradiation chamber, it is preferable that the gas supply port is located at a position higher than the center of the irradiation chamber in the height direction (i.e., the gravity direction) of the irradiation chamber (i.e., the center part of the irradiation chamber in the gravity direction). This makes it easier for the gas supplied from the gas supply port to be uniformly dispersed within the irradiation container. As a result, the foreign matter removal device of the present disclosure is more likely to achieve the intended effects (suppression of membrane rupture and foreign matter removal).

[0025] It is preferable that the irradiation chamber has two opposing walls, with a gas supply port disposed on one of the two opposing walls and a gas outlet disposed on the other of the two opposing walls. This allows the foreign matter removal device to more efficiently adjust the oxygen concentration in the irradiation chamber and more efficiently discharge foreign matter separated from the pellicle membrane to the outside of the irradiation chamber. The height of the gas outlet is preferably located higher than the middle of the height of the irradiation chamber, and more preferably located at the top of the irradiation chamber. This makes it easier to suppress foreign matter adhesion to the pellicle due to the foreign matter being lifted up on the floor of the irradiation chamber. The height of the gas outlet is preferably located lower than the middle of the height of the irradiation chamber to facilitate the discharge of foreign matter deposited on the floor of the irradiation chamber to the outside of the irradiation chamber. It is preferable that the gas outlet is located higher than the middle of the height of the irradiation chamber and lower than the middle of the height of the irradiation chamber to facilitate the discharge of foreign matter deposited on the floor of the irradiation chamber to the outside of the irradiation chamber while making it difficult for the foreign matter deposited on the floor of the irradiation chamber to be lifted up.

[0026] When one main surface of the pellicle membrane is positioned facing a stage (described later), the gas supply port is preferably arranged so that the direction of travel of the inert gas immediately after being discharged from the gas supply port is perpendicular to the direction perpendicular to the main surface of the pellicle membrane opposite the stage (hereinafter also referred to as the "surface"). This makes it difficult for the inert gas supplied from the gas supply port to apply excessive force to the surface of the pellicle membrane. As a result, the occurrence of pellicle membrane rupture can be suppressed. The angle of the direction perpendicular to the surface of the pellicle membrane is not limited as long as it can suppress the application of excessive force to the surface of the pellicle membrane. The angle of the direction perpendicular to the surface of the pellicle membrane may be, for example, within the range of 85° to 95° with respect to the direction of travel of the inert gas immediately after being discharged from the gas supply port. For the same reason, the gas exhaust port is preferably arranged so that the direction of travel of the inert gas immediately before entering the gas exhaust port is perpendicular to the direction perpendicular to the surface of the pellicle membrane.

[0027] (1.1.1.2) Transmitting section The foreign matter removal device of the present disclosure preferably further comprises a transmitting section that transmits vacuum ultraviolet light at the boundary between the irradiation chamber and the vacuum ultraviolet light generation section. The transmitting section may be located on the irradiation chamber side, or may be located in the irradiation chamber. In other words, the transmitting section may be a part of the wall that constitutes the irradiation chamber, or may be a member separate from the wall that constitutes the irradiation chamber, for example, a part of the irradiation container. The shape of the transmitting section is not particularly limited, and may be flat. The size and thickness of the transmitting section are not particularly limited, and may be selected appropriately depending on the size and number of pellicle films to be placed in the irradiation chamber. The material of the transmitting section may be any material that transmits VUV light, and may be, for example, quartz, magnesium fluoride (MgF ２ ), calcium fluoride (CaF ２ ), lithium fluoride (LiF), etc.

[0028] (1.1.1.3) Other Walls The irradiation chamber may have multiple other wall sections in addition to the transmission section. The transmission section and the multiple other wall sections form an internal space for irradiating the pellicle film with VUV light. The volume, structure, etc. of the internal space are not particularly limited and may be adjusted appropriately depending on the size and number of pellicle films to be placed in the irradiation chamber. The material of the other wall sections may be any material that is resistant to corrosion by VUV light, such as metals and ceramics. Examples of metals include aluminum, iron, copper, nickel, gold, silver, platinum, cobalt, zinc, lead, tin, titanium, chromium, magnesium, manganese, and alloys thereof (stainless steel, brass, phosphor bronze, etc.). In particular, from the viewpoint of excellent durability, the material of the other wall sections preferably contains aluminum, and is preferably aluminum.

[0029] The irradiation chamber may include a gas concentration meter that measures the concentration of the inert gas and the concentration of oxygen gas in the irradiation chamber.

[0030] (1.1.2) Stage The foreign matter removal device of the present disclosure preferably further includes a stage disposed within the irradiation chamber and for placing the pellicle film thereon. The pellicle film is placed on the stage. A pellicle having a pellicle film may be placed on the stage. When the pellicle film is placed on the stage, a pellicle film carrier having the pellicle film attached thereto may be placed on the stage. The pellicle film carrier is, for example, a jig for carrying the pellicle film. When the pellicle is placed on the stage, a pellicle carrier having the pellicle attached thereto may be placed on the stage. The pellicle carrier is, for example, a jig for carrying the pellicle. Details of the pellicle will be described later.

[0031] The number of stages is not particularly limited as long as it is at least one, and may be adjusted appropriately depending on the scale of the foreign matter removal device. The number of stages may be one or two or more for one irradiation chamber. The stage may be a movable stage such as a belt conveyor.

[0032] The shape of the stage is not particularly limited as long as it can accommodate a pellicle membrane, and is appropriately selected depending on the size and number of pellicle membranes to be placed in the irradiation chamber. The material of the stage is not particularly limited, and examples include the same materials as those exemplified as materials for the other wall portions. Among these, the material of the stage preferably contains aluminum, and is preferably aluminum, from the viewpoint of excellent durability.

[0033] (1.1.3) Distance Adjustment Unit When the foreign matter removal device of the present disclosure further includes a transmission unit that transmits the vacuum ultraviolet light at the boundary between the irradiation chamber and the vacuum ultraviolet light generation unit, the irradiation container preferably further includes a distance adjustment unit. The distance adjustment unit adjusts the distance between the transmission unit and the stage. This allows the distance between the transmission unit and the pellicle film placed on the stage (hereinafter simply referred to as the "irradiation distance") to be adjusted to a desired distance. As a result, the foreign matter removal device can efficiently remove foreign matter adhering to the pellicle film.

[0034] The irradiation distance is preferably 0.3 mm to 2.0 mm. This makes it difficult for the VUV light to be absorbed by molecules present between the transmitting portion and the distance adjusting portion. In other words, the pellicle membrane is more easily irradiated by the VUV light, making it easier to remove the removed foreign matter from the pellicle membrane. As a result, foreign matter adhering to the pellicle membrane is more easily removed. The irradiation distance is more preferably 0.4 mm or more, and even more preferably 0.5 mm or more. The irradiation distance is more preferably 1.8 mm or less, even more preferably 1.6 mm or less, and particularly preferably 1.4 mm or less.

[0035] The mechanism for adjusting the distance between the transmission part and the stage is not particularly limited, and may be any known mechanism, such as a stacking mechanism. In the stacking mechanism, thin flat plates are stacked to adjust the distance between the transmission part and the stage. The thickness of the flat plates is, for example, 1 mm. The material for the distance adjustment part is not particularly limited, and may be the same as the materials exemplified for the other wall parts. In particular, the material for the distance adjustment part preferably contains aluminum, and is preferably aluminum, from the viewpoint of excellent durability.

[0036] To facilitate the removal of foreign matter adhering to the pellicle membrane, an insulating layer may be disposed on the stage of the present disclosure. That is, an insulating layer may be provided between the stage and the pellicle placed on the stage. To remove foreign matter adhering to the pellicle membrane while preventing damage to the pellicle membrane, the type of insulating layer (materials having different volume resistivities) may be selected, or the thickness of the insulating layer may be adjusted. Glass, resin, etc. may be used as the insulating layer.

[0037] (1.2) VUV Light Generator The foreign matter removal apparatus of the present disclosure includes a VUV light generator. The VUV light generator generates VUV light. Specifically, the VUV light generator irradiates the VUV light through the transmission part onto the pellicle film placed on the stage.

[0038] The number of VUV light generators is not particularly limited as long as it is at least one, and may be adjusted appropriately depending on the scale of the foreign matter removal apparatus. The number of VUV light generators may be one or two or more per irradiation chamber. The size, shape, etc. of the VUV light generator are not particularly limited as long as it is selected appropriately depending on the scale, etc. of the foreign matter removal apparatus.

[0039] The VUV light generating unit may be a known light emitting device that generates VUV light. The VUV light generating unit may include a light source (hereinafter simply referred to as "light source") having a main emission wavelength of 100 nm to 200 nm. The light source is appropriately selected depending on the type of inert gas supplied into the irradiation chamber, and examples include a xenon (Xe) excimer lamp (main emission wavelength: 172 nm) and a low-pressure mercury lamp (main emission wavelength: 185 nm). Among these, the light source is preferably a Xe excimer lamp, from the viewpoints of being able to emit ultraviolet light at a single wavelength of 172 nm and having excellent light emission efficiency.

[0040] The cumulative amount of VUV light is 0.1 J / cm ２ ~100 J / cm ２ This allows the foreign matter removal device to remove foreign matter while suppressing the occurrence of rupture of the pellicle membrane. The integrated light amount of VUV light is more preferably 0.5 J / cm ２ More preferably, 1.0 J / cm ２ More preferably, 1.5 J / cm ２ The integrated amount of VUV light is more preferably 70 J / cm ２ More preferably, 50 J / cm or less ２ Below 30 J / cm, particularly preferably ２ More preferably, 10 J / cm or less ２ The following is the result.

[0041] The irradiance of the VUV light is not particularly limited and is 5 mW / cm ２ ~100mW / cm ２ This allows foreign matter to be removed while preventing the pellicle membrane from breaking. In order to facilitate the removal of foreign matter in a short time, the irradiance of the VUV light is preferably 10 mW / cm. ２More preferably, 20 mW / cm ２ More preferably, 30 mW / cm ２ In order to easily prevent the pellicle membrane from being broken, the irradiance of the VUV light is more preferably 70 mW / cm ２ More preferably, 66 mW / cm or less ２ Below 60 mW / cm, particularly preferably ２ From these, the illuminance of VUV light is preferably 10 mW / cm ２ 100mW / cm or more ２ and more preferably 20 mW / cm ２ 70mW / cm or more ２ or less, and more preferably 30 mW / cm ２ 70mW / cm or more ２ The following is the result.

[0042] (1.3) Gas Supply Unit The foreign matter removal device of the present disclosure includes a gas supply unit. The gas supply unit supplies an inert gas to the irradiation container. Specifically, the gas supply unit supplies the inert gas into the irradiation chamber through a gas supply port.

[0043] The number of gas supply units is not particularly limited as long as it is at least one, and may be adjusted appropriately depending on the scale of the foreign matter removal apparatus. The number of gas supply units may be one or two or more for one irradiation chamber. There may be one gas supply unit for multiple irradiation chambers. The size, shape, etc. of the gas supply unit are not particularly limited as long as it is selected appropriately depending on the scale, etc. of the foreign matter removal apparatus.

[0044] The inert gas may be, for example, nitrogen (N ２ ) gas, xenon (Xe) gas, carbon dioxide (CO ２ ) gas, etc. The inert gas is nitrogen (N ２ ) gas, xenon (Xe) gas, and carbon dioxide (CO ２ Among these, the inert gas preferably contains nitrogen gas, and is particularly preferably nitrogen gas, from the viewpoint of efficiently removing foreign matter adhering to the pellicle membrane.

[0045] The gas supply unit may be a known gas supply device that supplies an inert gas, and may include a flow meter.

[0046] (1.4) First Embodiment Hereinafter, a foreign matter removal device according to a first embodiment of the present disclosure will be described with reference to Fig. 1. In Fig. 1, the symbol "G" indicates the direction of gravity.

[0047] 1, the foreign matter removal device 1000A includes one irradiation container 1A, one VUV light generating unit 2, and one gas supplying unit 3. The VUV light generating unit 2 and the gas supplying unit 3 are each attached to the irradiation container 1A.

[0048] (1.4.1) Irradiation Container The irradiation container 1A has one irradiation chamber 10A. The irradiation chamber 10A has an internal space R inside. The internal space R is a substantially rectangular parallelepiped. For example, ３ ~600,000 cm ３ and 5000 cm ３ ~200,000 cm ３ It's okay to have one.

[0049] (1.4.1.1) Irradiation Chamber The irradiation chamber 10A further has an upper wall portion 100a, a right wall portion 100b, a lower wall portion 100c, a left wall portion 100d, a front wall portion (not shown), and a rear wall portion (not shown). The upper wall portion 100a and the lower wall portion 100c are opposed to each other. The right wall portion 100b and the left wall portion 100d are opposed to each other. The front wall portion and the rear wall portion are opposed to each other. The upper wall portion 100a, the right wall portion 100b, the lower wall portion 100c, the left wall portion 100d, the front wall portion, and the rear wall portion form an internal space R. The upper wall portion 100a, the right wall portion 100b, the lower wall portion 100c, the left wall portion 100d, the front wall portion, and the rear wall portion are each made of aluminum.

[0050] The upper wall portion 100a has a transmitting portion 101. The transmitting portion 101 constitutes a part of the upper wall portion 100a. The transmitting portion 101 is a square flat plate. The transmitting portion 101 is made of quartz. The VUV light generating unit 2 is disposed on the surface of the transmitting portion 101 opposite to the internal space R.

[0051] The right wall portion 100b has a gas exhaust port 102. The gas exhaust port 102 communicates with the internal space R. The gas exhaust port 102 is open to the atmosphere.

[0052] The left wall portion 100d has a gas supply port 103. The gas supply port 103 communicates with the internal space R. The gas supply port 103 is connected to the gas supply unit 3.

[0053] The irradiation chamber 10A has a gas concentration meter 104. The gas concentration meter 104 is disposed in the internal space R. The gas concentration meter 104 is a known gas concentration meter.

[0054] The irradiation container 1A further includes one distance adjustment unit 11 and one stage 12. The distance adjustment unit 11 and the stage 12 are disposed in the internal space R. More specifically, the distance adjustment unit 11 is attached to the lower wall 100c. The stage 12 is attached to the distance adjustment unit 11.

[0055] The distance adjustment unit 11 has a stacked mechanism. The material of the members constituting the distance adjustment unit 11 is aluminum. In this embodiment, the distance adjustment unit is adjusted so that the irradiation distance H is 1.0 mm.

[0056] The stage 12 is a square flat plate. The material of the stage 12 is aluminum. A pellicle 2000 having a pellicle film is placed on the stage 12.

[0057] (1.4.2) VUV Light Generator The VUV light generator 2 is a known light-emitting device that generates VUV light L. In this embodiment, the known light-emitting device includes a xenon (Xe) excimer lamp. The xenon (Xe) excimer lamp emits ultraviolet light of 172 nm. The integrated light amount of the VUV light is 0.1 J / cm. ２ ~100 J / cm ２ is.

[0058] (1.4.3) Gas Supply Unit The gas supply unit 3 is a known gas supply device that supplies an inert gas F. In this embodiment, the inert gas F is nitrogen (N ２ ) gas.

[0059] (1.4.4) Effects and Effects As described with reference to FIG. 1 , the foreign matter removal apparatus 1000A includes an irradiation container 1A, a VUV light generator 2, and a gas supply unit 3. The VUV light generator 2 and the gas supply unit 3 are attached to the irradiation container 1A. The irradiation container 1A includes an irradiation chamber 10A having a gas supply port 103 and a gas exhaust port 102, and a stage 12. The irradiation chamber 10A includes a transmission section 101. The gas supply unit 3 is connected to the gas supply port 103. This allows the foreign matter removal apparatus 1000A to irradiate the pellicle film included in the pellicle 2000 with VUV light L in an inert atmosphere in the irradiation chamber 10A, where the oxygen concentration is 5% by volume or less. As a result, the foreign matter removal apparatus 1000A can prevent damage to the pellicle film and remove foreign matter adhering to the pellicle film.

[0060] 1, the inert gas F contains nitrogen gas, which allows the foreign matter removal apparatus 1000A to efficiently remove foreign matter adhering to the pellicle membrane.

[0061] As described with reference to FIG. 1, the integrated light amount of VUV light L is 0.1 J / cm ２ ~100 J / cm ２ The foreign matter removal apparatus 1000A can remove foreign matter while suppressing the occurrence of rupture of the pellicle membrane.

[0062] 1, the irradiation container 1A further includes a distance adjustment unit 11. This allows the irradiation distance H to be adjusted to a desired distance. As a result, the foreign matter removal device 1000A can efficiently remove foreign matter adhering to the pellicle film.

[0063] (1.5) Second Embodiment Hereinafter, a foreign matter removal device according to a second embodiment of the present disclosure will be described with reference to FIG.

[0064] The foreign matter removal apparatus 1000B has the same configuration as the foreign matter removal apparatus 1000A, except that the transmission section 101 is not part of the upper wall section 100a that constitutes the irradiation chamber 10A. As shown in FIG. 2 , the foreign matter removal apparatus 1000B includes one irradiation container 1B, one VUV light generation section 2, and one gas supply section 3. The irradiation chamber 10A has a transmission section 101. The transmission section 101 is attached to the rear wall section (not shown). Because the foreign matter removal apparatus 1000B has the above configuration, it exhibits the same effects as the foreign matter removal apparatus 1000A.

[0065] (2) Pellicle Manufacturing Apparatus The pellicle manufacturing apparatus of the present disclosure includes the foreign matter removal apparatus of the present disclosure.

[0066] The pellicle manufacturing apparatus of the present disclosure, having the above-described configuration, can prevent damage to the pellicle membrane and remove foreign matter adhering to the pellicle membrane. This effect is presumably due to the same reasons as the effect of the foreign matter removal apparatus of the present disclosure, but is not limited to this.

[0067] The pellicle manufacturing apparatus of the present disclosure may include a known pellicle manufacturing apparatus, such as the pellicle manufacturing apparatus described in International Publication No. 2015 / 182483 and the pellicle mounting apparatus described in International Publication No. 2015 / 182482.

[0068] (3) Pellicle The pellicle disclosed herein comprises a pellicle frame and a pellicle membrane supported by the pellicle frame. The pellicle membrane has a thickness of 100 nm or less. The pellicle membrane contains foreign particles having a size of 1 μm to 5 μm. The number of foreign particles is 35 or less.

[0069] The pellicle of the present disclosure, having the above-described configuration, can suppress a decrease in the yield rate of semiconductor production. This effect is presumably due to, but not limited to, the following reasons. A count of 35 or less foreign particles indicates that the number of foreign particles adhering to the pellicle film is very small. When the pellicle of the present disclosure is used, the number of foreign particles that migrate from the pellicle film to the photomask during the exposure process is small. Therefore, a decrease in the yield rate of semiconductor production is less likely to occur. As a result, the pellicle of the present disclosure can suppress a decrease in the yield rate of semiconductor production.

[0070] The number of foreign matter particles is 35 or less. In particular, the closer the number of foreign matter particles is to 0, the more preferable, and 0 is most preferable. The number of foreign matter particles is 35 or less, preferably 30 or less, and more preferably 15 or less. The number of foreign matter particles may be 5. The number of foreign matter particles may be 5 to 35. In particular, the closer the number of foreign matter particles is to 0 or less, the more preferable. The method for measuring the number of foreign matter particles is the same as the method described in the Examples.

[0071] A method for reducing the number of foreign objects to 35 or less includes carrying out the pellicle membrane manufacturing method of the present disclosure, which will be described later.

[0072] (3.1) Pellicle Frame The pellicle of the present disclosure includes a pellicle frame. The pellicle frame supports the pellicle membrane.

[0073] The pellicle frame may be a rectangular cylindrical object having two long sides and two short sides. The pellicle frame has a through hole. The through hole indicates a space through which exposure light transmitted through the pellicle film passes to reach the photomask. The pellicle frame may have an air vent. The air vent connects the internal space of the pellicle with the external space of the pellicle when the pellicle frame is attached to the photomask. 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.

[0074] Examples of materials for the pellicle frame include aluminum, titanium, stainless steel, carbon-based materials, ceramic-based materials (e.g., silicon, glass, etc.), and resins such as polyethylene. Among these, the material for the pellicle frame is preferably aluminum, titanium, or silicon, and more preferably silicon. The pellicle frame may have a laminated structure of multiple materials. The shape of the pellicle frame corresponds to the shape of the photomask. Examples of shapes for the pellicle frame include a rectangular frame shape and a square frame shape.

[0075] (3.2) Pellicle Film The pellicle of the present disclosure includes a pellicle film. The pellicle film prevents foreign matter from adhering to the surface of the photomask and allows exposure light to pass through during exposure. Foreign matter includes dust. Examples of exposure light include deep ultraviolet (DUV) light and EUV light.

[0076] The pellicle membrane covers the entire opening on one end face of the through-hole in the pellicle frame. The pellicle membrane may be supported on one end face of the pellicle frame directly or via a membrane adhesive layer. The membrane adhesive layer may be a cured product of a known adhesive.

[0077] The thickness of the pellicle film is 100 nm or less, preferably 1 nm to 100 nm, more preferably 2 nm to 100 nm or less, and even more preferably 3 nm to 70 nm.

[0078] The rectangular pellicle frame has four sides when viewed in the thickness direction. The length of one longitudinal side is preferably 200 mm or less. The size of the pellicle frame is standardized depending on the type of exposure apparatus. A pellicle frame with a longitudinal length of one side of 200 mm or less satisfies the standardized size for exposure using EUV light. The length of one lateral side can be, for example, 5 mm to 180 mm, preferably 80 mm to 170 mm, and more preferably 100 mm to 160 mm. The height of the pellicle frame (i.e., the length of the pellicle frame in the thickness direction) is not particularly limited, but is preferably 3.0 mm or less, more preferably 2.4 mm or less, and even more preferably 2.375 mm or less. This allows the pellicle frame to satisfy the standardized size for EUV exposure. The height of the pellicle frame standardized for EUV exposure is, for example, 2.375 mm. The mass of the pellicle frame is not particularly limited, but is preferably 20 g or less, more preferably 15 g or less. This makes the pellicle frame suitable for use in EUV exposure.

[0079] The pellicle film is not particularly limited, and examples thereof include polysilicon (P-Si) film, silicon nitride (SiN) film, silicon carbide (SiC) film, metal silicide film, carbon nanotube film, graphene film, etc. Among them, the pellicle film is preferably a polysilicon (P-Si) film, silicon nitride (SiN) film, silicon carbide (SiC) film, metal silicide film (e.g., molybdenum silicide film), carbon nanotube film, or graphene film. The pellicle film is more preferably a polysilicon (P-Si) film, silicon nitride (SiN) film, silicon carbide (SiC) film, metal silicide film, or carbon nanotube film, and even more preferably a polysilicon (P-Si) film, molybdenum silicide film, or carbon nanotube film. The carbon nanotube film may be a single-walled carbon nanotube or a multi-walled carbon nanotube, or may include both single-walled and multi-walled carbon nanotubes.

[0080] (3.3) Adhesive Layer The pellicle of the present disclosure may or may not further include an adhesive layer that allows the pellicle of the present disclosure to be adhered to a photomask.

[0081] The adhesive layer is a gel-like viscoelastic material. The adhesive layer has viscosity and cohesive strength. Viscosity indicates a liquid-like property that wets the adherend photomask upon contact. Cohesive strength indicates a solid-like property that resists peeling from the photomask.

[0082] The adhesive layer is formed by applying a coating composition, heating, drying, curing, and other processes, as described below. The adhesive composition is not particularly limited and may be a known adhesive. Examples of known adhesives include acrylic adhesives, silicone adhesives, styrene-butadiene adhesives, urethane adhesives, and olefin adhesives.

[0083] (3.4) Liner When the pellicle of the present disclosure further comprises an adhesive layer, it may or may not further comprise a liner (release film). The liner protects at least the surface of the adhesive layer that contacts the photomask. The liner is releasable from the adhesive layer.

[0084] (4) Pellicle Film Manufacturing Method The pellicle film manufacturing method of the present disclosure includes supplying an inert gas into an irradiation chamber (hereinafter also referred to as the "gas supply step") and irradiating the pellicle film with VUV light under an inert gas atmosphere in the irradiation chamber (hereinafter also referred to as the "irradiation step"). The irradiation with VUV light and the supply of the inert gas may or may not be performed simultaneously. The inert gas atmosphere may contain or not contain oxygen gas. When oxygen gas is contained in the irradiation chamber, the concentration is 5% by volume or less.

[0085] The method for manufacturing a pellicle membrane according to the present disclosure has the above-described configuration, and therefore can prevent damage to the pellicle membrane and remove foreign matter adhering to the pellicle membrane. Specifically, the pellicle according to the present disclosure can be obtained by applying the method for manufacturing a pellicle membrane according to the present disclosure to a pellicle having a pellicle membrane with foreign matter adhering thereto. This effect is presumed to be due to the same reasons as the effect of the foreign matter removal device according to the present disclosure, but is not limited thereto.

[0086] (4.1) Apparatus The method for manufacturing a pellicle membrane may be performed using the foreign matter removal device of the present disclosure, or may be performed without using the foreign matter removal device of the present disclosure. From the viewpoint of efficiently performing the method for manufacturing a pellicle membrane, it is preferable that the method for manufacturing a pellicle membrane be performed using the foreign matter removal device of the present disclosure.

[0087] (4.1.1) Irradiation Chamber The irradiation chamber may be any chamber that can irradiate the pellicle membrane with VUV light and has the function of reducing the oxygen gas concentration to 5% by volume or less, and examples thereof include the irradiation chamber in the foreign matter removal device of the present disclosure.

[0088] The irradiation chamber preferably has a transmission section at the boundary of the irradiation chamber that transmits VUV light, and the distance between the transmission section and the pellicle membrane is 0.3 mm to 2.0 mm. If the irradiation distance is within the range of 0.3 mm to 2.0 mm, the VUV light can easily reach the pellicle membrane, making it easier to remove the removed foreign matter from the pellicle membrane. As a result, foreign matter adhering to the pellicle membrane can be removed. The irradiation distance is more preferably 0.4 mm or more, even more preferably 0.5 mm or more. The irradiation distance is more preferably 1.8 mm or less, even more preferably 1.6 mm or less, and particularly preferably 1.4 mm or less.

[0089] The method for adjusting the irradiation distance to within the above range is not particularly limited, and examples thereof include a method using a distance adjustment unit in the foreign matter removal device of the present disclosure.

[0090] (4.2) Gas Supply Process The method for manufacturing a pellicle film includes a gas supply process. In the gas supply process, an inert gas is supplied into the irradiation chamber. This allows most of the gas in the irradiation chamber to be replaced with the inert gas. In other words, the irradiation chamber can be filled with an inert gas atmosphere. As a result, the concentration of oxygen gas in the irradiation chamber may be zero (0% by volume), or may be in the range of 5% by volume or less when oxygen gas is contained or oxygen gas flows in from outside the irradiation chamber.

[0091] The method for supplying the inert gas into the irradiation chamber is not particularly limited, and examples thereof include a method using a gas supply unit in the foreign matter removal apparatus of the present disclosure.

[0092] (4.2.1) Inert Gas Examples of the inert gas include the same inert gases as those exemplified as the inert gas supplied by the gas supply unit of the foreign matter removal apparatus of the present disclosure. Among them, from the viewpoint of efficiently removing foreign matter adhering to the pellicle membrane, it is more preferable that the inert gas contains nitrogen gas, and it is particularly preferable that the inert gas be nitrogen gas.

[0093] The flow rate of the inert gas is not particularly limited, but is preferably 10 L / min or more. If the flow rate of the inert gas is 10 L / min or more, the removed foreign matter can be discharged to the outside of the irradiation container, making it easier to remove the foreign matter from the pellicle membrane, and a flow rate of 50 L / min or more is preferable. There is no particular reason for the upper limit, but it may be, for example, 1000 L / min or less. From these perspectives, the flow rate of the inert gas is preferably 10 L / min or more and 1000 L / min or less, and more preferably 30 L / min to 1000 L / min. The flow rate of the inert gas is measured using a known flow meter.

[0094] (4.3) Irradiation Step The method for manufacturing a pellicle film includes an irradiation step. In the irradiation step, the pellicle film is irradiated with VUV light in a specific inert gas atmosphere in an irradiation chamber. This allows foreign matter attached to the pellicle film to be separated from the pellicle film.

[0095] The method of irradiating the pellicle film with VUV light is not particularly limited, and examples include a method using a VUV light generating unit in the foreign matter removal device of the present disclosure.

[0096] (4.3.1) Inert Gas Atmosphere The inert gas atmosphere contains oxygen gas. The oxygen gas contained in the inert gas atmosphere may be oxygen gas that cannot be discharged from the irradiation chamber even by performing the gas supply step.

[0097] The concentration of oxygen gas in the irradiation chamber is 5% by volume or less, and preferably 3% by volume or less. If the concentration of oxygen gas is 3% by volume or less, it is possible to further suppress film loss and damage of the pellicle membrane. The concentration of oxygen gas is not particularly limited, and may be 0.000% by volume or more, 0.001% by volume or more, 0.005% by volume or more, or 0.10% by volume or more. The concentration of oxygen gas in the irradiation chamber is not particularly limited, and from the viewpoint of suppressing rupture of the pellicle membrane and removing foreign matter, it is more preferably 2 vol% or less, even more preferably 1 vol% or less, even more preferably 0.8 vol% or less, even more preferably 0.5 vol% or less, and particularly preferably 0.1 vol% or less. From these viewpoints, the concentration of oxygen gas is preferably 0.000 vol% to 5 vol%, more preferably 0.000 vol% to 1 vol%, even more preferably 0.001 vol% to 0.8 vol%, particularly preferably 0.001 vol% to 0.5 vol%, and even more preferably 0.001 vol% to 0.1 vol%. The concentration of oxygen gas is measured using a known gas concentration meter.

[0098] The inert gas atmosphere may contain an active gas in addition to oxygen. "Active gas" refers to a gas that reacts with the pellicle membrane and easily damages the pellicle membrane. The active gas contained in the inert gas atmosphere may be an active gas that cannot be discharged from the irradiation chamber even by performing the gas supply step. Examples of the active gas include water (H ２ O), carbon monoxide (CO) gas, hydrogen (H ２ ) gas, etc.

[0099] (4.3.2) Irradiation The integrated amount of VUV light is not particularly limited and is 0.1 J / cm ２ ~100.0J / cm ２This makes it possible to remove foreign matter while suppressing the occurrence of rupture of the pellicle membrane. The integrated light amount of VUV light is more preferably 0.5 J / cm ２ More preferably, 1.0 J / cm ２ More preferably, 1.5 J / cm ２ The integrated amount of VUV light is more preferably 70 J / cm ２ More preferably, 50 J / cm or less ２ Below 30 J / cm, particularly preferably ２ More preferably, 10 J / cm or less ２ The following is the result.

[0100] The irradiance of the VUV light is not particularly limited and is 5 mW / cm ２ ~100mW / cm ２ This allows foreign matter to be removed while preventing the pellicle membrane from breaking. In order to facilitate the removal of foreign matter in a short time, the irradiance of the VUV light is preferably 10 mW / cm. ２ More preferably, 20 mW / cm ２ More preferably, 30 mW / cm ２ In order to easily prevent the pellicle membrane from being broken, the irradiance of the VUV light is more preferably 70 mW / cm ２ More preferably, 66 mW / cm or less ２ Below 60 mW / cm, particularly preferably ２ The following is the result.

[0101] The irradiation time of VUV light is not particularly limited, but is preferably 1 second to 30 minutes. If the irradiation time of VUV light is 1 second or more, foreign matter can be easily removed. If the irradiation time of VUV light is 30 minutes or less, the occurrence of membrane rupture in the pellicle membrane can be further suppressed.

[0102] In the present disclosure, the gas supply step and the irradiation step may or may not be performed simultaneously. When the gas supply step and the irradiation step are performed simultaneously, it is easier to irradiate the pellicle membrane with VUV light while maintaining the oxygen gas concentration at 5% by volume or less than when the gas supply step and the irradiation step are not performed simultaneously. As a result, the occurrence of pellicle membrane rupture is further suppressed. For example, in the irradiation chamber, the operation of starting the supply of inert gas, stopping the supply of inert gas, starting the irradiation of VUV light, and stopping the irradiation of VUV light in this order may be performed at least once.

[0103] (4.4) Pellicle Membrane In the method for manufacturing a pellicle according to the present disclosure, the thickness of the pellicle membrane is preferably 100 nm or less. The method for manufacturing a pellicle according to the present disclosure can prevent damage to the pellicle membrane and remove foreign matter adhering to the pellicle membrane, even when the thickness of the pellicle membrane is 100 nm or less. From the same viewpoint, the thickness of the pellicle membrane suitable for the method for manufacturing a pellicle according to the present disclosure is preferably 1 nm to 100 nm, more preferably 2 nm to 100 nm or less, and even more preferably 3 nm to 70 nm.

[0104] (4.5) Preparation Step The method for manufacturing a pellicle of the present disclosure may include a step of preparing a pellicle (hereinafter also referred to as the "preparation step"). When the method for manufacturing a pellicle includes the preparation step, the method for removing foreign matter from a pellicle membrane of the present disclosure is carried out after the preparation step is carried out.

[0105] The method for preparing a pellicle is not particularly limited, and examples thereof include a method for manufacturing a pellicle and a method for obtaining a commercially available product. The method for manufacturing a pellicle is not particularly limited, and any known manufacturing method may be used. Known manufacturing methods include, for example, the methods for manufacturing pellicles described in JP 2021-157058 A, JP 2020-166063 A, JP 2020-160345 A, WO 2019 / 240166 A, and JP 2019-174628 A.

[0106] 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.

[0107] [1] Example 1 [1.1] Preparation Step [1.1.1] Foreign Matter Removal Apparatus A foreign matter removal apparatus 1000A shown in FIG. 1 was prepared.

[0108] [1.2] Pellicle A first pellicle, designated Pellicle 2000, was fabricated as follows. A polysilicon (p-Si) film of 100 nm or less was formed on a silicon substrate. The silicon substrate was then etched from the surface opposite to the surface on which the polysilicon (p-Si) film was formed, forming a free-standing polysilicon (p-Si) film. The "free-standing film" refers to the region of the polysilicon (p-Si) film that is not supported by the silicon substrate. Thus, a first pellicle was prepared. The first pellicle included a first pellicle frame obtained by etching the silicon substrate and a first pellicle film made of a polysilicon (p-Si) film. The first pellicle film was supported by the first pellicle frame. The size of the first pellicle was as follows:

[0109] Thickness of first pellicle film: 100 nm or less Overall size of first pellicle frame (outer diameter): 151.3 mm x 139.7 mm x 2.4 mmt Size of first pellicle frame (opening): 143.6 mm x 111.1 mm

[0110] For foreign matter evaluation, foreign matter was scattered on the pellicle film, and the first pellicle was placed on the stage 12 in the irradiation chamber 10A of the irradiation container 1A. The irradiation distance H was adjusted to 1 mm.

[0111] [1.2] Gas Supply Step The irradiation chamber 10A was sealed. An inert gas F (i.e., nitrogen (N ２ ) gas) was supplied into the irradiation chamber 10A at a gas supply rate of 50 L / min for 2 minutes and 30 seconds. After that, the supply of the inert gas F was continued into the irradiation chamber 10A without stopping the supply of the inert gas F. Nitrogen (N ２ The gas was exhausted from the gas exhaust port 102 to the outside of the irradiation chamber 10A.

[0112] The oxygen concentration and nitrogen concentration in the irradiation chamber 10A were measured using the gas concentration meter 104. The oxygen concentration was 0.6% by volume. The nitrogen concentration was 98% by volume or more. In other words, it was found that the inside of the irradiation chamber 10A was an inert gas atmosphere.

[0113] [1.3] Irradiation step: In an inert gas atmosphere in the irradiation chamber 10A, VUV light L (wavelength: 172 nm, illuminance: 33 mW / cm ２ The first pellicle membrane was irradiated with the light for 30 seconds, thereby obtaining an irradiated pellicle.

[0114] [2] Comparative Example 1 An irradiated pellicle was obtained in the same manner as in Example 1, except that the following comparative foreign matter removal apparatus was prepared instead of foreign matter removal apparatus 1000A and the gas supply step was not performed. The comparative foreign matter removal apparatus had the same configuration as foreign matter removal apparatus 1000A shown in FIG. 1, except that it did not include gas supply unit 3. When the irradiation step was performed, the oxygen concentration was 21% by volume, and the nitrogen concentration was 79% by volume.

[0115] [3] Example 2 An irradiated pellicle was obtained in the same manner as in Example 1, except that the following second pellicle was prepared instead of the first pellicle and the composition of the inert gas atmosphere was changed to the composition shown in Table 1.

[0116] [3.1] Preparation Step A second pellicle was fabricated as follows: A MoSi film of 100 nm or less was formed on a silicon substrate. ２ The film was formed by CVD (chemical vapor deposition) while flowing gas. The silicon substrate was then etched from the surface opposite to the surface on which the MoSi film was formed, forming a free-standing MoSi film. The "free-standing film" refers to the region of the MoSi film that is not supported by the silicon substrate. This resulted in the preparation of a second pellicle. The second pellicle included a second pellicle frame obtained by etching the silicon substrate and a second pellicle film made of the MoSi film. The second pellicle film was supported by the second pellicle frame. The second pellicle film covered the opening of the second pellicle frame. The thickness of the second pellicle film was 100 nm or less. The size and material of the second pellicle frame were the same as those of the first pellicle frame.

[0117] [4] Comparative Example 2 An irradiated pellicle was obtained in the same manner as in Example 2, except that the foreign matter removal apparatus 1000A was replaced with the comparative foreign matter removal apparatus described below and the gas supply step was not performed. When the irradiation step was performed, the oxygen concentration was 21% by volume, and the nitrogen concentration was 79% by volume.

[0118] [5] Example 3 A third pellicle having the same configuration as the second pellicle was prepared in the same manner as in Example 2. The third pellicle was prepared instead of the second pellicle, the composition of the inert gas atmosphere was changed to the composition shown in Table 1, and the illuminance was 66 mW / cm. ２ Except for the above, an irradiated pellicle was obtained in the same manner as in Example 2.

[0119] [6] Comparative Example 3 An irradiated pellicle was obtained in the same manner as in Example 3, except that the foreign matter removal apparatus described below was used instead of the foreign matter removal apparatus 1000A and the gas supply step was not performed. When the irradiation step was performed, the oxygen concentration was 21% by volume, and the nitrogen concentration was 79% by volume.

[0120] [7] Example 4 An irradiated pellicle was obtained in the same manner as in Example 1, except that the following fourth pellicle was prepared instead of the first pellicle.

[0121] [7.1] Preparation Step A fourth pellicle was fabricated as follows. A plurality of single-walled CNTs synthesized by the eDIPS method (manufactured by Meijo Nanocarbon Co., Ltd., product name: "EC1.5-P", tube diameter: 1 nm to 3 nm, tube length: 100 nm or more) were prepared. 70 mL of isopropyl alcohol and 30 mL of ethanol were added to 30 mg of CNTs, and 30 mg of polyacrylic acid was further added as an additive. The mixture was stirred using a magnetic stirrer at 1000 rpm (revolutions per minute) at 40°C for 18 hours. The resulting suspension was ultrasonically dispersed using a probe-type homogenizer at 40% output for a total of 30 minutes to obtain a CNT dispersion. An 8-inch silicon wafer (hereinafter referred to as "silicon substrate") was prepared. The CNT dispersion was spin-coated onto the silicon substrate at a rotation speed of 1500 rpm. This resulted in a coating film formed on the silicon substrate. The coated film was alkaline washed with tetramethylammonium hydroxide (hereinafter referred to as "TMAH") to remove the polyacrylic acid in the unwashed CNT film and then dried. This resulted in a CNT film. Hereinafter, the silicon substrate and the CNT film formed on the silicon substrate are collectively referred to as the "film-coated silicon substrate." The film-coated silicon substrate was immersed in a water bath. In the water, the CNT film peeled off from the silicon substrate. The silicon substrate was removed from the water, leaving the CNT film peeled off from the silicon substrate in the water. At this time, the CNT film floated on the water surface. This resulted in a fourth pellicle film consisting of a CNT film with a mesh structure. A fourth pellicle frame identical in size and material to the first pellicle frame was prepared. A third silicon frame was cylindrical. The third silicon frame had through-holes, which ran along the thickness direction of the third silicon frame. The CNT film was washed with water to remove the polyacrylic acid in the CNT film and then dried. Next, the silicon substrate with the CNT film was immersed in water. In the water, the CNT film peeled off from the silicon substrate and floated on the water surface. The silicon substrate was removed from the water, leaving the CNT film in the water. The CNT film floating on the water surface was scooped up with a third silicon frame. This yielded a fourth pellicle. The fourth pellicle included a third pellicle frame and a third pellicle film made of a CNT film.The third pellicle film was supported by a third pellicle frame. The thickness of the third pellicle film was 50 nm or less. The size and material of the third pellicle frame were the same as those of the first pellicle frame.

[0122] [8] Evaluation [8.1] Film Breakage Evaluation The pellicle membrane of the irradiated pellicle was visually inspected, and film breakage was evaluated according to the following criteria. As Reference Example 1, a similar evaluation was also performed on the first pellicle before it was placed on the stage 12. As Reference Example 2, a similar evaluation was also performed on the second pellicle before it was placed on the stage 12. As Reference Example 3, a similar evaluation was also performed on the third pellicle before it was placed on the stage 12. As Reference Example 4, a similar evaluation was also performed on the fourth pellicle in Example 4 before it was placed on the stage 12. The evaluation results are shown in Table 1.

[0123] A: No rupture of the pellicle membrane occurred B: Pellicle membrane rupture occurred

[0124] [8.2] Foreign matter measurement The number of foreign matters adhering to the pellicle membrane of the treated pellicle was measured by the following method. As Reference Example 1, a similar measurement was also performed on the first pellicle before it was placed on the stage 12. As Reference Example 2, a similar measurement was also performed on the second pellicle before it was placed on the stage 12. As Reference Example 3, a similar evaluation was also performed on the third pellicle before it was placed on the stage 12. As Reference Example 4, a similar measurement was also performed on the fourth pellicle in Example 4 before it was placed on the stage 12. The measurement results are shown in Table 1.

[0125] Using an optical microscope (OLYMPUS MX series), the number of foreign particles was measured using images taken of an area of ​​142.70 mm x 110.25 mm at 5x magnification with one pixel measuring 3.69 μm x 3.69 μm. All images were analyzed using the calculation software attached to the optical microscope to count the number of foreign particles, determine their size, and determine the type of foreign particle. Note that no foreign particles greater than 5 μm (10.5 μm) in size were detected. The limit of foreign particle size that the device could detect was 1 μm.

[0126] "Size of foreign matter" refers to the size obtained by detecting foreign matter within an image range of X: 320 μm, Y: 740 μm, and calculating and sizing each foreign matter as an ESD (circular diameter).

[0127] [8.3] Transmittance: Using EUV-RT (Reflection and Transmission), the pellicle film was irradiated with light of 13.5 nm wavelength, and the current value was measured. Specifically, a photodiode was used to measure the current value (incident light intensity I0) detected without the pellicle film installed and the current value (transmitted light intensity I) detected with the pellicle film installed. To measure the current value (transmitted light intensity I), the entire pellicle film surface was divided into 48 locations, and the current value (transmitted light intensity I) was measured at each location. The transmittance of each location was calculated using the following formula (1), and the average value was used as the transmittance. As Reference Example 1, a similar measurement was performed on the first pellicle before it was placed on the stage 12. As Reference Example 2, a similar measurement was performed on the second pellicle before it was placed on the stage 12. As Reference Example 3, a similar evaluation was performed on the third pellicle before it was placed on the stage 12. As Reference Example 4, a similar measurement was performed on the fourth pellicle in Example 4 before it was placed on the stage 12. The measurement results are shown in Table 1.

[0128]

[0129]

[0130] In Table 1, "1 μm to 5 μm" in the foreign matter measurement item refers to a thickness of 1 mm of the pellicle membrane. ２ The number of foreign particles with a size of 1 μm to 5 μm in the area of ​​the pellicle membrane is shown. ２ The table shows the number of foreign particles having a size of 10.5 μm or more within the area. A "-" in the foreign particle measurement item indicates that the number of foreign particles could not be measured due to rupture of the pellicle membrane. A "-" in the gas supply step and irradiation step items indicates that the gas supply step and irradiation step were not performed. A "≦98" in the nitrogen concentration item indicates that the nitrogen concentration was 98% by volume or more.

[0131] In Comparative Examples 1 to 3, the gas supply process was not performed. When the irradiation process was performed, the oxygen concentration in the irradiation chamber 10A was 21% by volume. As a result, the membrane rupture evaluation for the Comparative Examples was "B." This result showed that the pellicle membrane manufacturing method of the Comparative Examples could not prevent the occurrence of pellicle membrane rupture.

[0132] In Examples 1 to 4, the gas supply process and the irradiation process were performed simultaneously. When the irradiation process was performed, the oxygen concentration in the irradiation chamber 10A was 5 vol% or less (specifically, 0.6 vol% in Example 1, and less than 0.01 vol% in Examples 2 to 4). As a result, the membrane rupture evaluation for Examples 1 to 4 was "A." Furthermore, the number of foreign matter measurements in Example 1 was fewer than the number of foreign matter measurements in Reference Example 1. The number of foreign matter measurements in Example 2 was fewer than the number of foreign matter measurements in Reference Example 2. The number of foreign matter measurements in Example 3 was fewer than the number of foreign matter measurements in Reference Example 3. The number of foreign matter measurements in Example 4 was fewer than the number of foreign matter measurements in Reference Example 4. These results demonstrate that the pellicle membrane manufacturing method of the examples can prevent pellicle membrane breakage and remove foreign matter adhering to the pellicle membrane.

[0133] The disclosures of Japanese Patent Application No. 2022-140279, filed on September 2, 2022, and Japanese Patent Application No. 2023-047154, filed on March 23, 2023, are incorporated herein by reference in their entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. a vacuum ultraviolet light generating unit that generates vacuum ultraviolet light; an irradiation container for irradiating the pellicle membrane with the vacuum ultraviolet light; A gas supply unit that supplies an inert gas to the irradiation container; Equipped with The irradiation container has an irradiation chamber provided with a gas supply port for supplying the inert gas and a gas exhaust port for exhausting the inert gas, The gas supply unit is connected to the gas supply port.

2. 2. The foreign matter removal apparatus according to claim 1, further comprising a transmission section for transmitting the vacuum ultraviolet light at a boundary between the irradiation chamber and the vacuum ultraviolet light generation section.

3. The foreign matter removal apparatus according to claim 1 , further comprising a stage disposed within the irradiation chamber and for placing the pellicle film thereon.

4. The foreign matter removal apparatus according to claim 1 , wherein the inert gas includes nitrogen gas.

5. The integrated light amount of the vacuum ultraviolet light is 0.1 J / cm ２ ~100 J / cm ２ 2. The foreign matter removal device according to claim 1,

6. The illuminance of the vacuum ultraviolet light is 5 mW / cm ２ ~100mW / cm ２ 2. The foreign matter removal device according to claim 1,

7. A transmission section that transmits the vacuum ultraviolet light is further provided at a boundary between the irradiation chamber and the vacuum ultraviolet light generation section, The foreign matter removal apparatus according to claim 3 , wherein the irradiation container further comprises a distance adjustment unit that adjusts the distance between the transmission unit and the stage.

8. The foreign matter removal apparatus according to claim 1 , wherein the gas exhaust port is disposed at a position lower than a height at a center of the irradiation chamber in a height direction of the irradiation chamber.

9. 9. The foreign matter removal apparatus according to claim 8, wherein the gas supply port is disposed at a position higher in a height direction of the irradiation chamber than a height at which the gas supply port is located at a center of the irradiation chamber.

10. The irradiation chamber has two opposing walls, The gas supply port is disposed in one of the two opposing wall portions, 2. The foreign matter removal device according to claim 1, wherein the gas exhaust port is disposed in the other of the two opposing wall portions.

11. A pellicle manufacturing apparatus comprising the foreign matter removal apparatus according to any one of claims 1 to 10.

12. Supplying an inert gas into the irradiation chamber; Irradiating the pellicle film with vacuum ultraviolet light under an inert gas atmosphere in an irradiation chamber; Including, A method for manufacturing a pellicle membrane, wherein the concentration of oxygen gas in the inert gas atmosphere in the irradiation chamber is 5 volume % or less.

13. The method for manufacturing a pellicle film according to claim 12, wherein the concentration of the oxygen gas in the irradiation chamber is 3 volume % or less.

14. The method for manufacturing a pellicle membrane according to claim 12 or 13, wherein the inert gas includes nitrogen gas.

15. The method for manufacturing a pellicle membrane according to claim 12 or 13, wherein the flow rate of the inert gas is 10 L / min to 1000 L / min.

16. The integrated light amount of the vacuum ultraviolet light is 0.1 J / cm ２ ~100.0J / cm ２ The method for producing a pellicle membrane according to claim 12 or 13,

17. The illuminance of the vacuum ultraviolet light is 5 mW / cm ２ ~100mW / cm ２ The method for producing a pellicle membrane according to claim 12 or 13,

18. The method for producing a pellicle film according to claim 12 or 13, wherein the irradiation time of the vacuum ultraviolet light is from 1 second to 30 minutes.

19. the irradiation chamber has a transmission portion at a boundary of the irradiation chamber through which the vacuum ultraviolet light passes, The method for manufacturing a pellicle membrane according to claim 12 or 13, wherein the distance between the transmission portion and the pellicle membrane is 0.3 mm to 2.0 mm.

20. The method for producing a pellicle membrane according to claim 12 or 13, wherein the thickness of the pellicle membrane is 100 nm or less.

21. A pellicle frame; A pellicle membrane supported by the pellicle frame; Equipped with The pellicle membrane has a thickness of 100 nm or less, The pellicle membrane contains foreign particles having a size of 1 μm to 5 μm, A pellicle, wherein the number of said foreign objects is 35 or less.