Pellicle, exposure plate and exposure apparatus, method for manufacturing the pellicle, and test method for the adhesive layer for a mask

Abstract

A pellicle having a frame (12) on which a pellicle film (11) is disposed and an adhesive layer (13) for a mask disposed on the frame (12), and when a washing test is performed on the adhesive layer (13) that is in contact with a quartz mask (4) with a predetermined contact area (A1), the removal rate of the adhesive layer (13) {(contact area before washing test (A1) - contact area after washing test (A2)) / (contact area before washing test (A1))} is 80% or more.

Description

Technology Field

[0001] The present invention relates to a pellicle, an exposure plate and an exposure apparatus, a method for manufacturing a pellicle, and a method for testing an adhesive layer for a mask, etc. Background Technology

[0002] In the lithography process for manufacturing electronic components, a pellicle is sometimes used to prevent dust from the photomask. The pellicle has a frame on which a pellicle film is placed and an adhesive layer for a mask placed on the frame, and is attached to the photomask through the adhesive layer for the mask.

[0003] Meanwhile, when the mask adhesive layer receives stray light during exposure, it becomes more likely to react with the surface of the photomask, and as a result, its adhesion to the photomask tends to increase. In this case, even if the pellicle is peeled off from the photomask, there is a possibility that so-called "adhesive residue" will occur, in which adhesive from the mask adhesive layer remains on the photomask. In recent years, along with the shortening of exposure light wavelengths, the frequency of photomask replacement has also increased.

[0004] Here, a pellicle is proposed with one of the purposes of reducing adhesive residue (see Patent Document 1). In Patent Document 1, it is proposed to control the content of a carboxylic acid-containing monomer unit in the adhesive layer for a mask to 0.9 mass% or less relative to 100 mass% of the (meth)acrylate alkyl ester copolymer. Prior art literature

[0005] Japanese Patent Publication No. 2017-90719 The problem to be solved

[0006] However, in the prior art as described in Patent Document 1, it is difficult to completely remove adhesive residue, and therefore, there was a situation where the work of removing the mask adhesive layer on the photomask occurred every time the photomask was replaced. Even if a technology capable of further reducing adhesive residue is developed and such technology is used, it is assumed that the work of removing the mask adhesive layer on the photomask every time the photomask is replaced is performed as a preliminary work as in the past.

[0007] Given these circumstances, in order to further improve the efficiency of photomask replacement operations, it was necessary to focus on a perspective different from the reduction of adhesive residue.

[0008] The present invention has been made in consideration of these circumstances. The objective of the present invention is,

[0009] The invention provides a pellicle that can further improve the efficiency of photomask replacement operations by focusing on a quartz mask, which is representative as a photomask, and using a mask adhesive layer that is easy to wash off from the quartz mask.

[0010] In addition, the objective of the present invention is to provide an exposure plate and an exposure apparatus using the pellicle, a method for manufacturing the pellicle, and a method for testing an adhesive layer for a mask. means of solving the problem

[0011] Examples of embodiments of the present invention are as follows.

[0012] [1]

[0013] A pellicle having a frame on which a pellicle film is disposed and an adhesive layer for a mask disposed on the frame, and

[0014] A pellicle having a removal rate of the adhesive layer {(the contact area (A1) before the washing test - the contact area (A2) after the washing test) / (the contact area (A1) before the washing test)} of 80% or more when a washing test is performed on the adhesive layer that is in contact with a quartz mask with a predetermined contact area (A1).

[0015] [2]

[0016] The above adhesive layer is,

[0017] A pellicle described in Item 1 comprising a reaction product of a (meth)acrylic copolymer and a curing agent.

[0018] [3]

[0019] The above curing agent is an isocyanate compound, the pellicle described in Item 2.

[0020] [4]

[0021] A pellicle described in item 2 or 3, wherein the ratio of the curing agent to the total amount of the (meth)acrylic copolymer is 0.10 to 3.00 mass%.

[0022] [5]

[0023] The above washing test is performed by immersing the mask in a water bath for 10 minutes and then removing the mask from the water bath, and the pellicle described in any one of items 1 to 4.

[0024] [6]

[0025] The contact area (A1) prior to the above washing test is,

[0026] A pellicle described in any one of items 1 to 5, which is the remaining area of ​​the adhesive layer on the mask when VUV (Vacuum UltraViolet) light is irradiated from the back surface of the mask for 1 minute onto the portion of the adhesive layer attached to the mask and then the pellicle is peeled off.

[0027] [7]

[0028] The contact area (A1) prior to the above washing test is,

[0029] The pellicle described in Item 6, which is the remaining area when the VUV light is irradiated onto the attached portion for one minute and then the pellicle is peeled off.

[0030] [8]

[0031] The contact area (A1) prior to the above washing test is,

[0032] Integrated radiation dose of VUV (Vacuum UltraViolet) light 3.0 J / cm² from the back surface of the mask to the portion of the adhesive layer attached to the mask 2 The pellicle described in Item 6, which is the remaining area of ​​the adhesive layer on the mask when the pellicle is peeled off after being investigated under the conditions of...

[0033] [9]

[0034] A pellicle described in any one of items 1 to 8, having a removal rate of the adhesive layer of 90% or more.

[0035]

[10]

[0036] The above washing test is the following processes (A) to (D):

[0037] (A) Immerse a quartz mask and the adhesive layer in contact with the quartz mask in water;

[0038] (B) After 5 minutes have elapsed since the start of immersion, if the adhesive layer is in contact with the quartz mask in the water bath, the adhesive layer is rubbed with a finger;

[0039] (C) After 10 minutes have elapsed since the start of immersion, the quartz mask is removed into the atmosphere;

[0040] (D) When the adhesive layer is in contact with the quartz mask in the air, rub the adhesive layer with a finger;

[0041] A pellicle described in Item 1 or 2, performed based on

[0042]

[11]

[0043] An exposure plate comprising a quartz mask and a pellicle described in any one of items 1 to 9 mounted on the mask.

[0044]

[12]

[0045] A light source that emits VUV (Vacuum UltraViolet) light, and

[0046] The exposure plate described in Item 11, onto which the above VUV light is irradiated

[0047] An exposure device equipped with

[0048]

[13]

[0049] A method for manufacturing a pellicle having a frame on which a pellicle film is disposed and an adhesive layer for a mask disposed on said frame, and

[0050] A method for manufacturing a pellicle, wherein when a washing test is performed on the adhesive layer that is in contact with a quartz mask with a predetermined contact area (A1), the removal rate of the adhesive layer {(the contact area (A1) before the washing test - the contact area (A2) after the washing test) / (the contact area (A1) before the washing test)} is 80% or more.

[0051]

[14]

[0052] A test method for a mask adhesive layer of a pellicle having a frame on which a pellicle film is disposed and a mask adhesive layer disposed on the frame, and

[0053] A test method for an adhesive layer for a mask, wherein a value based on the removal rate of the adhesive layer when a washing test is performed on the adhesive layer that is in contact with a quartz mask with a predetermined contact area (A1) {(the contact area (A1) before the washing test - the contact area (A2) after the washing test) / (the contact area (A1) before the washing test)} is compared with a predetermined threshold.

[0054]

[15]

[0055] A peeling method for peeling off a corresponding mask adhesive layer of a pellicle having a frame on which a pellicle film is disposed and a mask adhesive layer disposed on the frame from a quartz mask, and

[0056] A method for peeling off an adhesive layer for a mask, comprising a process of irradiating a portion of the adhesive layer attached to the mask with VUV (Vacuum UltraViolet) light, and then washing with water.

[0057]

[16]

[0058] In the process of irradiating the above VUV light,

[0059] A method for peeling off an adhesive layer for a mask as described in Item 15, wherein the VUV light is irradiated from the back surface of the mask for one minute onto the portion of the adhesive layer attached to the mask, and then the pellicle is peeled off.

[0060]

[17]

[0061] In the process of irradiating the above VUV light,

[0062] Integrated radiation dose of 3.0 J / cm² of VUV light from the back surface of the mask to the portion of the adhesive layer attached to the mask 2 A method for peeling off an adhesive layer for a mask as described in item 15 or 16, wherein the pellicle is peeled off after investigation under the conditions of the above. Effects of the invention

[0063] According to the present invention, by focusing on a quartz mask as a representative photomask and using a mask adhesive layer that is easy to wash off from the quartz mask, a pellicle can be provided that further improves the efficiency of the photomask replacement operation. Furthermore, according to the present invention, an exposure plate and an exposure apparatus using the pellicle, a method for manufacturing the pellicle, and a method for testing the mask adhesive layer can be provided. Brief explanation of the drawing

[0064] FIG. 1 is a drawing showing an example of the configuration of an exposure apparatus and an exposure plate according to the present embodiment. FIG. 2 is a drawing showing an example of the configuration of a pellicle according to the present embodiment. FIG. 3 is a drawing showing an example of the configuration of a pellicle according to the present embodiment. FIG. 4 is a drawing showing an example of the configuration of a test method according to the present embodiment. Specific details for implementing the invention

[0065] Hereinafter, embodiments relating to the present invention (hereinafter referred to as “the present embodiment”) will be described. In the present embodiment, a numerical range described using “to” includes the numerical values ​​described before and after “to” within that range. In the present embodiment, an upper or lower limit value described as a numerical range in a stepwise description may be substituted with an upper or lower limit value of a numerical range in another stepwise description. In the present embodiment, an upper or lower limit value described as a numerical range may be substituted with the value described in the example. In the present embodiment, the word “process” is included in the present term not only as an independent process but also in cases where it cannot be clearly distinguished from other processes, provided that the function of the process is achieved. In each part of the drawings, the scale, shape, and length may be exaggerated to further enhance clarity.

[0066] [Exposure device and exposure plate]

[0067] FIG. 1 is a schematic diagram showing an example of the configuration of an exposure device (1) and an exposure plate (2) according to the present embodiment. As shown, the exposure device (1) is equipped with a light source (3) that emits light and an exposure plate (2) on which the light is irradiated, and among these, the exposure plate (2) is equipped with a photomask (4) and a pellicle (5) mounted on the photomask (4).

[0068] The light emitted from the light source (3) is VUV (Vacuum UltraViolet) light, and the photomask (4) is made of quartz. Hereinafter, a photomask composed of quartz may be referred to as a quartz mask.

[0069] A pellicle (5) is attached to a photomask (4) to cover a circuit pattern (not shown) formed on the photomask (4). The pellicle (5) functions as a dustproof cover for the photomask (4). In the exposure device (1), light emitted from a light source (3) (arrow in FIG. 1) passes through the circuit pattern of the photomask (4) and further passes through the pellicle film of the pellicle (5) to be guided to a photoresist (not shown) on a stage (6).

[0070] In the exposure device (1) and the exposure plate (2), since the pellicle (5) according to the present embodiment is provided, it is easy to remove the mask adhesive layer from the photomask (4), and furthermore, the replacement operation of the photomask (4) can be made even more efficient.

[0071] [Pellicle]

[0072] [Outline]

[0073] FIGS. 2 and FIGS. 3 are drawings showing examples of the configuration of a pellicle (5) according to the present embodiment. Among these, FIG. 2(a) shows an example of the configuration when the pellicle (5) is attached to a photomask (4), and FIG. 2(b) shows an example of the configuration of a cross-section of the pellicle (5). In addition, FIG. 3(a) shows an example of the configuration when the pellicle (5) is peeled off from the photomask (4), and FIG. 3(b) shows an example of the configuration of the pellicle (5) (adhesive layer for the mask) after a washing test. In FIG. 2 and FIG. 3, the attachment portion S1 of the pellicle (5) to the photomask (4) is indicated by a dotted line.

[0074] As described above, the pellicle (5) has a frame (12) on which a pellicle film (11) is placed, and a mask adhesive layer (13) placed on the frame (12) (hereinafter simply referred to as "adhesive layer"). In the pellicle (5), when a washing test is performed on the adhesive layer (13) that is in contact with the photomask (4) with a predetermined contact area (A1), the removal rate of the adhesive layer (13) is 80% or more.

[0075] According to the above configuration, further efficiency can be achieved in the replacement of the photomask (4) by using an adhesive layer (13) that is easy to remove from the photomask (4) through a technical approach.

[0076] [Frame]

[0077] The frame (12) is a member for supporting the pellicle membrane (11). The frame (12) has a pair of sides (12A) and a pair of sides (12B). Side (12A) can be a long side, and side (12B) can be a short side. By these long sides (12A) and short sides (12B), a rectangular shape is formed, and a rectangular opening (Op) is formed on the inside of the outer shape.

[0078] The long side (12A) and the short side (12B) are both approximately rectangular in shape. The long side (12A) and the short side (12B) each have four faces (one face (12a), another face (12b) opposite to the one face (12a), an inner surface (12c), and an outer surface (12d) opposite to the inner surface (12c). The one face (12a) has an area for attaching the pellicle film (11), and the other face (12b) has an area for forming the adhesive layer (13).

[0079] The length of the long side (12A) is, for example, 50 mm or more, 80 mm or more, or 100 mm or more, and also 200 mm or less, 180 mm or less, or 160 mm or less. The length of the short side (12B) is 30 mm or more, 50 mm or more, or 80 mm or more, and also 180 mm or less, 160 mm or less, or 140 mm or less. According to the lengths of the long side (12A) and / or the short side (12B), it is easy to prevent bending of the pellicle film (11) and also easy to surround the circuit pattern formed on the photomask (4).

[0080] However, the configuration (length, width, thickness, shape, etc.) of the frame (12) can be arbitrarily changed depending on the configuration of the pellicle film (11), the size of the circuit pattern formed on the photomask (4), etc. The frame (12) may be configured integrally or may be configured to be divisible.

[0081] The frame (12) is,

[0082] Aluminum;

[0083] Aluminum alloys (e.g., 5000 series, 6000 series, 7000 series, etc.);

[0084] Steel;

[0085] Stainless steel;

[0086] Magnesium alloy;

[0087] Ceramics such as silicon carbide (SiC), aluminum nitride (AlN), and aluminum oxide (Al2O3);

[0088] Composite materials of ceramics and metals (e.g., Al-SiC, Al-AlN, Al-Al2O3, etc.);

[0089] Engineering plastics using polyethylene (PE), polyamide (PA), polycarbonate (PC), polyetheretherketone (PEEK), etc.;

[0090] Fiber composite materials, such as glass fiber reinforced plastic (GFRP) or carbon fiber reinforced plastic (CFRP); or

[0091] Their combination;

[0092] It can be formed from materials such as the base.

[0093] The inner surface (12c) of the frame (12) may have an adhesive component for capturing foreign matter as needed. As for the adhesive component here,

[0094] Acrylic, vinyl acetate, silicone, and rubber adhesives;

[0095] Silicone-based and fluorine-based greases;

[0096] You can lift the back.

[0097] [Pelicle Mark]

[0098] The pellicle film (11) is a transparent thin film. The pellicle film (11) covers the opening (Op). The pellicle film (11) is attached to one side (12a) of the frame (12) through an adhesive for the pellicle film (not shown) while under some tension so as not to bend excessively due to the weight of the film itself.

[0099] The pellicle film (11) can be formed from nitrocellulose, cellulose derivatives, fluorine polymers, etc. The thickness of the pellicle film (11) is, for example, 10 μm or less, in terms of light transmittance of light emitted from a light source, light resistance to such light, and self-supporting properties of the pellicle film (11). Preferably, it is 5 μm or less, and more preferably 1 μm or less.

[0100] [Protective Film]

[0101] The pellicle (5) may be provided with a protective film (14) (liner) laminated to the adhesive layer (13). The protective film (14) protects the adhesive layer (13) during storage or transport of the pellicle (5) and is peeled off from the adhesive layer (13) when the pellicle (5) is mounted on the photomask (4).

[0102] The protective film (14) may be formed from a resin such as polyester, and its thickness is, for example, 30 to 200 μm. To improve peelability, the protective film (14) may have a silicone layer or a fluorine layer on the side in contact with the adhesive layer (13).

[0103] [Adhesive layer for masks]

[0104] <Removal Rate>

[0105] The adhesive layer (13) is a component for attaching the frame (12) to the photomask (4). The adhesive layer (13) may be placed on the other side (12b) of the frame (12). Here, in the pellicle (5), when a washing test is performed on the adhesive layer (13) that is in contact with the photomask (4) with a contact area (A1), the removal rate of the adhesive layer (13) is 80% or more. The removal rate is given by the following formula:

[0106] Removal rate = (Contact area before washing test (A1) - Contact area after washing test (A2)) / (Contact area before washing test (A1))

[0107] It is saved by.

[0108] For example, if the adhesive layer (13) on the photomask (4) is removed by a washing test, approximately 90% of it is removed, the removal rate is expected to be approximately 90%, or at least 80% or more.

[0109] By having a removal rate of 80% or more for the adhesive layer (13), the removal of the adhesive layer (13) on the photomask (4) can be shortened and / or simplified, thereby reducing the effort required for the removal operation. When the removal rate is sufficiently high, the adhesive layer (13) can be easily removed from the photomask (4) even if an adhesive layer for the mask in a form prone to adhesive residue and / or a lithography process under conditions prone to adhesive residue are adopted. From the above, efficiency improvement of the photomask (4) replacement operation is expected. In the same regard, the above removal rate is preferably 85% or more, 90% or more, 95% or more, or 98% or more. The above removal rate may be 100% or less than 100%.

[0110] In one embodiment, the “adhesive layer in contact with the photomask with a predetermined contact area (A1)” is the adhesive layer (13) remaining on the photomask (4). After attaching the adhesive layer (13) to the photomask (4) (see FIG. 2 (a)), when the adhesive layer (13) is peeled off from the photomask (4) (see FIG. 3 (a)), the remaining area of ​​the adhesive layer (13) remaining on the photomask (4) can be treated as the contact area (A1).

[0111] According to this, it is easy to calculate the above removal rate considering the actual lithography process.

[0112] In another embodiment, the “adhesive layer in contact with the photomask with a predetermined contact area (A1)” is a mask adhesive layer formed on the photomask (4). When the mask adhesive layer is directly applied to the photomask (4), the area of ​​the adhesive layer can be treated as the contact area (A1) (contact area (A1') shown in FIG. 4).

[0113] According to this, it is easy to set the contact area (A1) to a predetermined value.

[0114] The contact area (A1) can be roughly calculated by visual inspection, or it can be calculated in detail by image analysis of the photomask (4).

[0115] The “washing test” is a test in which water is applied to the photomask (4) to which the adhesive layer (13) is attached. The washing test is performed in the manner described in the example.

[0116] "Contact area (A2) after water washing test" is the area of ​​the adhesive layer (13) in contact with the photomask (4) after the water washing test. The contact area (A2) may be roughly calculated by visual inspection (see Fig. 3 (b)), or it may be calculated in detail by image analysis of the photomask (4).

[0117] <Remaining Area>

[0118] The contact area (A1) before the washing test is,

[0119] It is preferable that the remaining area of ​​the adhesive layer (13) on the photomask (4) is the area where the adhesive layer (13) is attached to the photomask (4) and VUV light is irradiated from the back side of the photomask (13) for 1 minute, and then the pellicle (5) is peeled off.

[0120] "The back side of the photomask" corresponds to the side opposite to the side to which the adhesive layer (13) is attached in the photomask (4) of FIG. 2. Using an exposure device (1) such as FIG. 1, VUV light is irradiated for 1 minute under normal conditions and normal operations corresponding to an actual lithography process. Then, the pellicle (5) is peeled off from the photomask (4) under normal conditions and normal operations corresponding to an actual lithography process. By doing so, "when VUV light is irradiated from the back side of the photomask for 1 minute and then the pellicle is peeled off" is realized. Additionally, peeling can be performed by using a known tensile tester to lift the pellicle (5) perpendicularly to the photomask (4) at a speed of 1 to 10 mm / min.

[0121] The “remaining area of ​​the adhesive layer for the mask on the photomask” corresponds to the area of ​​the adhesive layer (13) remaining on the photomask (4) after the peeling is performed. The remaining area is also known as the “adhesive residue area.” This remaining area can be roughly calculated, for example, by visual inspection, and can also be calculated in detail by image analysis of the photomask (4).

[0122] The irradiation time of VUV light is 1 minute. As the irradiation time of VUV light increases, it becomes easier to cure the adhesive layer (13). According to this, it is easy to calculate the removal rate that takes into account the actual lithography process. In the pellicle (5) according to the present embodiment, even if the irradiation time of VUV light for the adhesive layer (13) is selected as a short time of 1 minute, it is easy to calculate the removal rate.

[0123] The thickness of the adhesive layer (13) may be, for example, 0.15 to 3.0 mm, and may be appropriately selected according to the field and / or application of the final product realized through the lithography process. When performing lithography to obtain a semiconductor device, the thickness of the adhesive layer (13) suitable for the photomask used in the lithography is, for example, 0.15 mm or more, 0.20 mm or more, or 0.25 mm or more, and 1.0 mm or less, 0.8 mm or less, or 0.7 mm or less. When performing lithography to obtain a liquid crystal device, the thickness of the adhesive layer (13) suitable for the photomask used in the lithography is, for example, 0.80 mm or more, 1.0 mm or more, or 1.2 mm or more, and 3.0 mm or less, 2.5 mm or less, or 2.0 mm or less.

[0124] The flatness in the cross-sectional direction of the adhesive layer (13) may be 1 μm or more or 2 μm or more, and may also be 20 μm or less, 15 μm or less, or 13 μm or less. If the flatness in the cross-sectional direction of the adhesive layer (13) is 1 μm or more, it becomes easier to secure a suitable path for the bubbles to escape even if bubbles are curled up when attaching the pellicle (5) to the photomask (4). Additionally, if the flatness in the cross-sectional direction of the adhesive layer (13) is 20 μm or less, the load when attaching the pellicle (5) to the photomask (4) becomes easier to apply uniformly to the adhesive layer (13) and further to the photomask (4).

[0125] The “cross-sectional direction of the adhesive layer for the mask” corresponds to the thickness direction of the frame (12). The flatness of the cross-sectional direction of the adhesive layer (13) can be determined by the following method. For any multiple points (e.g., 10 points, 12 points, 15 points, or 20 points), each cross-section of the adhesive layer (13) placed on the frame (12) is checked. For each cross-section, the difference between the maximum thickness and the minimum thickness (height difference) is calculated. Then, the average value of the height difference obtained for the number of the multiple points is calculated. This average value corresponds to the flatness.

[0126] The thickness and further flatness of the adhesive layer (13) can be measured using a laser displacement meter. For the pellicle (5) equipped with a protective film (14), the flatness may be measured after peeling off the protective film (14), or, if the flatness is not affected by the protective film (14), the flatness may be measured with the protective film (14) attached.

[0127] Method for peeling off the adhesive layer for masks

[0128] Another aspect of the present embodiment is a method for peeling off the adhesive layer (13). This peeling method comprises a process of irradiating VUV light onto the adhesive layer (13) attached to the photomask (4) and then washing with water. Based on the above process, the adhesive layer (13) can be appropriately peeled off from the photomask (4) by washing with water, so the possibility of damage to the photomask (4) and the rate of haze occurrence during exposure are reduced compared to cases such as when acid is used to clean the mask, or when the adhesive layer for the mask is strongly peeled off from the photomask.

[0129] In the process of irradiating VUV light,

[0130] It is preferable to irradiate the portion of the adhesive layer attached to the mask with VUV light from the back side of the mask for 1 minute, and then peel off the pellicle. According to this, the adhesive layer (13) can be easily peeled off from the photomask (4) by washing.

[0131] In addition, in the process of irradiating with VUV light,

[0132] Integrated radiation dose of VUV light from the back surface of the mask to the attached portion of the adhesive layer on the mask: 3.0 J / cm² 2 It is preferable to investigate under the conditions and then peel off the pellicle. By doing this, the adhesive layer (13) can be easily peeled off from the photomask (4) by washing.

[0133] The adhesive layer (13) is, for example,

[0134] (A) Ingredient: A subject having a specific functional group, and,

[0135] (B) Component: Curing agent having reactivity with specific functional groups

[0136] It may include structures derived from each of.

[0137] In other words, the adhesive layer (13) may be composed of the reaction product of the above-mentioned component (A) and the above-mentioned component (B). Various physical properties of the adhesive layer (13) can be controlled by the respective types and / or ratios of the above-mentioned component (A) and the above-mentioned component (B), and furthermore, the removal rate can be controlled.

[0138] The adhesive layer (13) includes, for example, an acrylic copolymer. The acrylic copolymer is easy to control various physical properties and is also easy to procure its raw materials.

[0139] The ratio of component (A) to the total amount of the adhesive layer (13) is preferably 98.0 mass% or more or 99.0 mass% or more, and also preferably 99.9 mass% or less or 99.8 mass% or less. By having the ratio of component (A) within the above range, it is easy to achieve good adhesion of the adhesive layer (13) to the photomask (4) and appropriate peelability of the adhesive layer (13) to the photomask (4). Nevertheless, it is easy to remove the adhesive layer (13) from the photomask (4).

[0140] <(A) Component: Subject)>

[0141] (A) The component includes, for example, a (meth)acrylic copolymer, that is, a (meth)acrylic acid ester copolymer. In one embodiment, the (meth)acrylic acid ester copolymer is a copolymer of a (meth)acrylic acid ester and a monomer having a specific functional group. Among these, a copolymer obtained using a mixture in which the (meth)acrylic acid ester is 80 to 99 mass% and the monomer having a specific functional group is 1 to 20 mass% is preferred in terms of exhibiting suitable adhesion to the photomask (4).

[0142] (A) The weight average molecular weight of component (A) is, for example, 700,000 to 2,500,000, in which case the cohesive force of the adhesive layer (13) and / or the adhesion force of the adhesive layer (13) to the photomask (4) is easy to control to an appropriate size. In the same view as above, the weight average molecular weight of component (A) is 900,000 or more or 1,050,000 or more, and also 2,000,000 or less or 1,500,000 or less.

[0143] (A) The weight-average molecular weight of a component tends to increase when, for example, the monomer concentration is high, the amount of polymerization initiator is low, and the polymerization temperature is low when the monomer raw material is polymerized. In general, the greater the weight-average molecular weight, the greater the cohesive force tends to be, and the greater the cohesive force, the greater the residual stress value tends to be.

[0144] (A) The component can be prepared using known polymerization methods. Examples of such polymerization methods include radical polymerization, ionic polymerization, living polymerization, living radical polymerization, etc. In the polymerization, polymerization initiators, chain transfer agents, emulsifiers, etc. may be appropriately selected and used.

[0145] ((Met)acrylic acid ester)

[0146] (Met)acrylic acid esters, for example, have 1 to 14 carbon atoms in their alkyl groups, and these alkyl groups may be straight or branched. However, from the perspective of reducing adhesive residue and good adhesion to the photomask (4), it is preferable that the alkyl groups have 4 to 8 carbon atoms and are also straight. (Met)acrylic acid esters may be used alone or in combination of two or more types.

[0147] Examples of (meth)acrylic acid esters in which the alkyl group is straight-chain include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, etc.

[0148] Examples of (meth)acrylic acid esters in which the alkyl group is branched include (meth)acrylate isopropyl, (meth)acrylate isobutyl, (meth)acrylate isopentyl, (meth)acrylate 2-ethylhexyl, (meth)acrylate isooctyl, (meth)acrylate isononyl, etc.

[0149] (Monomer having specific functional groups)

[0150] Monomers having specific functional groups can be copolymerized with (meth)acrylic acid esters. Here, "specific functional groups" refers to functional groups that are reactive with component (B), such as carboxyl groups (-COOH) and / or hydroxyl groups (-OH). Monomers having specific functional groups may be used alone or in combination of two or more types.

[0151] As a monomer having a specific functional group,

[0152] Carboxyl group-containing monomers such as (meth)acrylic acid, itaconic acid, maleic acid, and crotonic acid;

[0153] Hydroxyl group-containing monomers such as (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 3-hydroxypropyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 4-hydroxybutyl, (meth)acrylic acid 6-hydroxyhexyl;

[0154] You can lift the back.

[0155] A quartz photomask (4) has hydroxyl groups on its surface. When a reaction occurs between the hydroxyl groups in the photomask (4) and the carboxyl groups included in the carboxyl group-containing monomer in the adhesive layer (13), the bond between the photomask (4) and the adhesive layer (13) is likely to become strong. Therefore, the ratio of the carboxyl group-containing monomer to the total amount of component (A) is preferably 0.9 mass% or less, 0.5 mass% or less, or 0.3 mass% or less.

[0156] In the unit polymer length of the adhesive layer (13), if the degree of crosslinking due to the reaction between the hydroxyl group contained in the hydroxyl group-containing monomer and the component (B) is improved, the flexibility of the polymer is damaged, and thus the residual stress is likely to increase. In addition, if the number of hydroxyl groups contained in the hydroxyl group-containing monomer in the component (A) is improved, the number of residual hydroxyl groups after the reaction with the component (B) increases, and the residual hydroxyl groups are easily oxidized by natural oxidation or oxidation in an exposure environment, thereby making it easy for carboxyl groups to be generated. Therefore, the ratio of the hydroxyl group-containing monomer to the total amount of the component (A) is preferably 10 mass% or less, 4 mass% or less, or 2 mass% or less.

[0157] As a photomask (4), a chrome deposition film formed on its surface may be used. In this case, light emitted from a light source is blocked by the chrome deposition film. Because of this, a reaction between the photomask (4) and the adhesive layer (13) is prevented from being caused by such light. Meanwhile, by controlling the ratio of the carboxyl group-containing monomer to the total amount of component (A) as described above, it is easier to effectively reduce adhesive residue compared to a photomask (4) in which the chrome deposition film is omitted. In addition, it is easier to remove the adhesive layer (13) from the photomask (4).

[0158] <(B) Component: Curing Agent)>

[0159] (B) The component has reactivity with a specific functional group in the above (A) component. Examples of (B) component include metal salts, metal alkoxides, aldehyde compounds, non-amino resin-based amino compounds, urea compounds, isocyanate compounds, epoxy compounds, metal chelate compounds, melamine compounds, aziridine compounds, etc. Among these, isocyanate compounds or epoxy compounds are preferred, and isocyanate compounds are more preferred.

[0160] The ratio of component (B) to the total amount of component (A) is preferably 0.10 to 3.00 mass%. This makes it easy to remove the adhesive layer (13) from the photomask (4). In the same regard, 0.130 mass% or more or 0.150 mass% or more is more preferable, and 2.00 mass% or less, 1.20 mass% or less, or 1.00 mass% or less is more preferable.

[0161] As isocyanate compounds, for example

[0162] Adduct type or isocyanurate type, such as toluene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, etc.

[0163] ...can be cited.

[0164] As for polyfunctional epoxy compounds, for example

[0165] Examples include neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, phthalate diglycidyl ester, dimerate diglycidyl ester, triglycidyl isocyanurate, diglycerol triglycidyl ether, sorbitol tetraglycidyl ether, N,N,N',N'-tetraglycidyl m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl diaminodiphenylmethane, etc.

[0166] Other ingredients

[0167] The adhesive layer (13) may include known additives such as fillers, pigments, diluents, anti-aging agents, and UV stabilizers as needed. One type of additive may be used alone, or two or more types may be used in combination.

[0168] [Method for manufacturing pellicles]

[0169] The manufacturing method according to the present embodiment is,

[0170] This is a method for manufacturing a pellicle (5) in which the removal rate of the adhesive layer (13) is 80% or more when a washing test is performed on the adhesive layer (13) that is in contact with the photomask (4) with a predetermined contact area (A1).

[0171] This manufacturing method may have, for example, the following processes.

[0172] First process: A process for obtaining a precursor composition for an adhesive layer (13).

[0173] Second process: A process of applying the obtained precursor composition to the frame (12).

[0174] Third process: A process of drying the applied precursor composition to obtain an adhesive layer (13).

[0175] In the first process, component (A) and component (B) are mixed to obtain a precursor composition for an adhesive layer (13). Component (A) and / or component (B) may be mixed as is, or may be diluted in a predetermined solvent and then mixed. The precursor composition may additionally include a solvent for the purpose of controlling the applicability to the frame (12) and / or controlling the thickness of the resulting adhesive layer (13). Examples of such solvents include acetone, ethyl acetate, butyl acetate, toluene, etc., but are not limited to these.

[0176] As described above, various physical properties of the adhesive layer (13) can be controlled by the respective types and / or ratios of component (A) and component (B), and furthermore, the removal rate can be controlled.

[0177] In the second process, the obtained precursor composition is applied to the frame (12). In one embodiment, in the second process, the precursor composition is applied to the other side (12b) of the frame (12). As a method of application, a method using a dispenser is preferred. At this time, the viscosity of the precursor composition may be 1 P·s or more or 2 P·s or more, and may also be 5 P·s or less, 4 P·s or less, or 3 P·s or less. The viscosity here is obtained, for example, by a Type B viscometer at 25°C.

[0178] In the third process, the applied precursor composition is dried to obtain an adhesive layer (13). This third process may further include the following processes.

[0179] 3(1) Process: Drying process.

[0180] 3(2) Process: Molding process.

[0181] In the third (1) step, the applied precursor composition is dried to reduce the solvent in the precursor composition. In the third (1) step, the dried precursor composition may be heated to a degree suitable for molding. The heating time may be, for example, 50 to 10,000 seconds, and the heating temperature may be, for example, 50 to 200°C. Heating and drying may be performed multiple times at different heating times or different temperatures.

[0182] In the third (2) step, the precursor composition is molded to a predetermined thickness and / or a predetermined width. In the third (2) step, the molded precursor composition may be further heated so that the curing reaction between component (A) and component (B) proceeds further.

[0183] The manufacturing method according to the present embodiment may additionally include the following processes.

[0184] Fourth process: A process of laminating a protective film (14) onto an adhesive layer (13).

[0185] In the fourth step, a protective film (14) is laminated onto the adhesive layer (13). In the fourth step, after laminating the protective film (14), the state may be maintained at room temperature (20±3℃) for several days. By doing so, the adhesive strength may be stabilized.

[0186] In addition, in the manufacturing method according to the present embodiment, attachment of the pellicle film (11) to the frame (12) may occur at any time before the first process, between the first process and the second process, between the second process and the third process, between the third process and the fourth process, or after the fourth process.

[0187] [Embodiment 2]

[0188] [Test Method for Adhesive Layer for Masks]

[0189] The test method according to the present embodiment is a test method for an adhesive layer for a mask. In this test method, when a washing test is performed on an adhesive layer for a mask that is in contact with a quartz mask with a predetermined contact area (A1), a value based on the removal rate of the adhesive layer for the mask {(contact area before washing test (A1) - contact area after washing test (A2)) / (contact area before washing test (A1))} is compared with a predetermined threshold. According to this method, the efficiency of the replacement operation of a quartz mask can be evaluated.

[0190] Additionally, the adhesive layer for the mask can be placed on the frame (12) of the pellicle (5), and in one embodiment, can be placed on the other side (12b) of the frame (12).

[0191] In the above test method, the value of the removal rate itself obtained may be compared with the threshold, or a value related to the removal rate may be compared with the threshold. The threshold can be appropriately determined, and when the value of the removal rate itself is compared with the threshold, the threshold is, for example, 80%. With a removal rate of 80% or higher, further efficiency improvement of the mask replacement operation is expected.

[0192] In the above test method, VUV light may or may not be irradiated from the back side of the mask onto the portion of the adhesive layer for the mask attached to the quartz mask. When VUV light is irradiated, the irradiation time is, for example, 30 seconds to 5 minutes, or 30 seconds to 2 minutes, and in one embodiment, 1 minute. Conditions such as the light irradiated from the back side of the mask and / or the irradiation time can be appropriately selected under conditions corresponding to an actual lithography process. By performing the above test under the assumption of a normal environment and normal operation corresponding to an actual lithography process, it is easy to evaluate the efficiency of the mask replacement operation in that actual lithography process.

[0193] In one embodiment, the “adhesive layer for a mask that contacts a quartz mask with a predetermined contact area (A1)” in the above test method is the adhesive layer (13) remaining on the photomask (4) described in Embodiment 1, FIG. 2, and FIG. 3 (i.e., the adhesive layer (13) with adhesive remaining). The remaining area of ​​the adhesive layer (13) remaining on the photomask (4) can be treated as the contact area (A1).

[0194] FIGS. 4(a) and (b) are drawings illustrating examples of other aspects of the present embodiment. In FIGS. 4(b), the portion SS of the adhesive layer for the mask attached to the photomask (4) is indicated by a dotted line.

[0195] As described above, the “adhesive layer for a mask that contacts a quartz mask with a predetermined contact area (A1)” in the above test method may be an adhesive layer (13a) formed on a photomask (4). When the adhesive layer (13a) is directly applied to the photomask (4), the area of ​​the adhesive layer (13a) can be treated as the contact area (A1) (contact area (A1') shown in FIG. 4 (a)).

[0196] In this embodiment as well, similar to the above embodiment, after performing the above washing test, the area of ​​the adhesive layer (13a) in contact with the photomask (4) is treated as a contact area (A2) (contact area (A2)' shown in Fig. 4 (b)).

[0197] When an adhesive layer (13a) is applied directly onto a photomask (4), the process of placing the adhesive layer (13) on the frame (12), the process of attaching a pellicle (5) to the photomask (4), and the process of peeling off the pellicle (5) from the photomask (4) can be omitted. Additionally, as a method for applying the adhesive layer (13a) directly onto the photomask (4), a method similar to the method of applying the adhesive layer (13) to the other side (12b) of the frame can be adopted.

[0198] The above describes the embodiments thereof. The embodiments thereof are not limited to the above-mentioned aspects and may be implemented with various modifications within the scope of the gist thereof.

[0199] Examples

[0200] Next, the present embodiment will be described in more detail with reference to examples and comparative examples.

[0201] [Example 1]

[0202] <Preparation of Adhesive Composition>

[0203] First, ethyl acetate (30 parts by mass) and the raw material listed in the table (raw material for component (A)) were introduced into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen inlet tube, and the mixture was reacted at a reflux temperature for 8 hours under a nitrogen atmosphere. After the reaction was finished, butyl acetate (33 parts by mass) was added to obtain a solution of a (meth)acrylic acid ester copolymer (component (A)) having a non-volatile content concentration of 37 mass%. The raw material listed in the table (component (B)) was added to 100 parts by mass of the obtained solution and stirred and mixed to obtain an adhesive composition.

[0204] Production of Pellicle

[0205] An adhesive composition prepared as described above was applied using a dispenser to the other side of an aluminum alloy frame (outer diameter 115mm × 149mm, inner diameter 111mm × 145mm, height 3.0mm) having a pellicle film adhered to one side. The applied adhesive composition was heated in two stages (Stage 1: 115℃, 11 minutes; Stage 2: 150℃, 5 minutes) to obtain an adhesive layer for a mask (thickness 0.20mm).

[0206] After that, a protective film made of polyester with a thickness of 100 μm, having formed a silicone layer, was laminated onto the adhesive layer for the mask, and cured at 100°C for 12 hours.

[0207] From the above, the pellicle of Example 1 was manufactured.

[0208] [Other Examples] and [Comparative Examples]

[0209] (A) The raw material for the component and (B) the raw material for the component were changed as described in the table, and a pellicle was produced in the same manner as in Example 1.

[0210] Adhesive residue

[0211] The pellicles of the examples and comparative examples (for pellicles equipped with a protective film, the pellicle after peeling off the protective film) were attached to a photomask (size 6025, made of quartz) by applying a weight (5 Kgf, 60 seconds) using a simple mounter. By doing so, an exposure plate having a photomask and a pellicle mounted on the photomask was obtained.

[0212] VUV light was irradiated from the back side of the photomask for 1 minute onto the portion of the mask adhesive layer attached to the photomask, and then the pellicle was peeled off from the photomask. The peeling was performed by pulling it up perpendicularly to the photomask at a speed of 5 mm / min using a known tensile testing machine. The photomask image was observed using visual inspection and a microscope, and the remaining area of ​​the mask adhesive layer on the photomask (contact area (A1)) was calculated.

[0213] In addition, the irradiation conditions for VUV light are as follows.

[0214] Light Source: Xe

[0215] Illuminance: 50mW / cm² 2

[0216] Cumulative radiation: 3.0 J / cm² 2

[0217] Washing Test

[0218] A washing test was performed on the photomask in which a mask adhesive layer remained on the photomask according to the following method and conditions.

[0219] That is, the photomask having a mask adhesive layer remaining on it was immersed in a water bath at room temperature for 10 minutes, and then removed from the water bath. While the photomask was immersed and after the photomask was removed from the water bath, a finger or palm, etc., was lightly touched to the adhesive layer attached to the photomask.

[0220] The specific method for the water wash test is the following processes (A) to (D):

[0221] (A) Immerse a quartz mask and an adhesive layer in contact with the quartz mask in water;

[0222] (B) After 5 minutes have elapsed since the start of immersion, if the adhesive layer is in contact with the quartz mask in the water bath, rub the adhesive layer with a finger;

[0223] (C) After 10 minutes have elapsed since the start of immersion, the quartz mask is removed into the atmosphere;

[0224] (D) If an adhesive layer is in contact with the quartz mask in the air, rub the adhesive layer with your finger;

[0225] It is the same as.

[0226] In this washing test, pure water is used, and both the water temperature and room temperature are adjusted to 24±1℃.

[0227] (B) In process and (D), when an adhesive layer is in contact with a quartz mask, the adhesive layer is rubbed directly onto the fingerprint portion of the finger 10 times.

[0228] <Removal Rate>

[0229] The photomask image after the water washing test was observed using visual inspection and a microscope, and the area of ​​the mask adhesive layer on the photomask (contact area (A2)) was calculated. Using the obtained contact area (A2) and the contact area (A1), the removal rate was calculated. Then, the pellicles of the examples and comparative examples were evaluated according to the following criteria.

[0230] A: Removal rate of 90% or more

[0231] B: Removal rate of 80% or more and less than 90%

[0232] C: Removal rate less than 80%

[0233] Efficiency of Photomask Replacement Operation

[0234] As described above, by reducing adhesive residue, the removal of the mask adhesive layer remaining on the photomask can be shortened and / or simplified. Accordingly, the pellicles of the examples and comparative examples were evaluated according to the following criteria.

[0235] A: The "removal rate" was rated A or B, and the adhesive layer could be peeled off from the photomask without applying special vibration to the photomask.

[0236] B: The "removal rate" was rated A or B, and the adhesive layer could be peeled off from the photomask by applying some vibration to the photomask.

[0237] C: "Removal rate" was rated C.

[0238]

[0239] BuA: Butyl acrylate

[0240] HEA: Hydroxyethyl acrylate

[0241] Duranate TPA-100 (manufactured by Asahi Kasei Co., Ltd.)

[0242] Duranate MHG-80B (Made by Asahi Kasei Co., Ltd.)

[0243] Duranate MFA-80B (manufactured by Asahi Kasei Co., Ltd.)

[0244] Coronate L (manufactured by Toso Co., Ltd.)

[0245] SK Dain 1499M (Soken Kagakusaje)

[0246] SK Dain 1495 (Soken Kagakusaje)

[0247] As confirmed in the table, the pellicle of the example has an excellent "removal rate." By using the pellicle of the example, further efficiency improvement in the photomask replacement process is expected. Industrial applicability

[0248] The present invention can be suitably applied to lithography processes for obtaining electronic components such as integrated circuits (ICs), large-scale integrated circuits (LSIs), and liquid crystal displays (LCDs). The present invention can be suitably applied to fields such as pellicles, exposure plates and exposure devices, methods for manufacturing pellicles, and methods for testing adhesive layers for masks. Explanation of the symbols

[0249] 1: Exposure device 2: Exposure plate 3: Light source 4: Photomask (quartz mask) 5: Pellicle 6: Stage 11: Pellicle 12: Frame 12A: Side (long side) 12B: Side (short side) 12a: One side 12b: Other side 12c: If you give it to me 12d: Outer surface 13, 13a: Adhesive layer (adhesive layer for mask) 14: Protective film Op: Opening A1(A1'): Contact area before the rinsing test A2(A2'): Contact area after rinsing test

Claims

Claim 1 A pellicle having a frame on which a pellicle film is disposed and an adhesive layer for a mask disposed on said frame, wherein the adhesive layer comprises a reaction product of a (meth)acrylic copolymer and a curing agent, and the curing agent is an isocyanate compound, and wherein, when a washing test is performed on said adhesive layer that is in contact with a quartz mask with a predetermined contact area (A1), the removal rate of said adhesive layer {(the contact area (A1) before the washing test - the contact area (A2) after the washing test) / (the contact area (A1) before the washing test)} is 80% or more. Claim 2 A pellicle according to claim 1, wherein the ratio of the curing agent to the total amount of the (meth)acrylic copolymer is 0.10 to 3.00 mass%. Claim 3 A pellicle according to claim 1 or 2, wherein the washing test is performed by immersing the mask in a water bath for 10 minutes and then removing the mask from the water bath. Claim 4 In claim 1 or 2, the contact area (A1) prior to the washing test is the remaining area of ​​the adhesive layer on the mask when VUV (Vacuum UltraViolet) light is irradiated from the back surface of the mask for 1 minute on the portion of the adhesive layer attached to the mask and the pellicle is peeled off thereafter. Claim 5 In paragraph 4, the contact area (A1) prior to the washing test is the remaining area of ​​the pellicle when the VUV light is irradiated onto the attached portion for 1 minute and the pellicle is peeled off thereafter. Claim 6 In paragraph 4, the contact area (A1) prior to the washing test is subjected to an integrated radiation dose of 3.0 J / cm² of VUV (Vacuum UltraViolet) light from the back surface of the mask to the portion of the adhesive layer attached to the mask. 2 A pellicle, which is the remaining area of ​​the adhesive layer on the mask when the pellicle is peeled off after being investigated under the conditions of... Claim 7 A pellicle according to claim 1 or 2, wherein the removal rate of the adhesive layer is 90% or more. Claim 8 A pellicle according to claim 1 or 2, wherein the washing test is performed based on the following processes (A) to (D): (A) immersing a quartz mask and the adhesive layer in contact with the quartz mask in water; (B) after 5 minutes have elapsed since the start of immersion, if the adhesive layer is in contact with the quartz mask in the water bath, rub the adhesive layer with a finger; (C) after 10 minutes have elapsed since the start of immersion, remove the quartz mask into the atmosphere; (D) if the adhesive layer is in contact with the quartz mask in the atmosphere, rub the adhesive layer with a finger. Claim 9 An exposure plate having a quartz mask and a pellicle described in claim 1 or 2 mounted on the mask. Claim 10 An exposure device comprising a light source that emits VUV (Vacuum UltraViolet) light and an exposure plate described in claim 9 on which the VUV light is irradiated. Claim 11 A method for manufacturing a pellicle having a frame on which a pellicle film is disposed and an adhesive layer for a mask disposed on said frame, wherein when a washing test is performed on said adhesive layer that is in contact with a quartz mask with a predetermined contact area (A1), the removal rate of said adhesive layer {(the contact area (A1) before the washing test - the contact area (A2) after the washing test) / (the contact area (A1) before the washing test)} is 80% or more. Claim 12 A testing method for a mask adhesive layer of a pellicle having a frame on which a pellicle film is disposed and a mask adhesive layer disposed on said frame, wherein a value based on the removal rate of said adhesive layer {(the contact area (A1) before said water washing test - the contact area (A2) after said water washing test) / (the contact area (A1) before said water washing test)} is compared with a predetermined threshold when a washing test is performed on said adhesive layer which is in contact with a quartz mask with a predetermined contact area (A1). Claim 13 A peeling method for peeling off a mask adhesive layer of a pellicle having a frame on which a pellicle film is disposed and a mask adhesive layer disposed on the frame, from a quartz mask, comprising a process of irradiating a VUV (Vacuum UltraViolet) light onto a portion of the adhesive layer attached to the mask and then washing with water. Claim 14 A method for peeling off an adhesive layer for a mask according to claim 13, wherein in the process of irradiating the VUV light, the VUV light is irradiated from the back surface of the mask for one minute onto the portion of the adhesive layer attached to the mask, and then the pellicle is peeled off. Claim 15 In claim 13 or 14, in the process of irradiating the VUV light, the VUV light is irradiated from the back surface of the mask onto the portion of the adhesive layer attached to the mask with an integrated radiation dose of 3.0 J / cm² 2 A method for peeling off an adhesive layer for a mask, wherein the pellicle is peeled off after investigation under the conditions of the above. Claim 16 delete Claim 17 delete

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