Laminate for semiconductor processing and method for processing member to be processed

Abstract

To provide: a laminate for semiconductor processing, comprising a support, a double-sided adhesive tape, and a member to be treated in this order, which hardly shows peeling even at a high temperature during processing steps of the member to be treated and in which, after completion of the steps, the double-sided adhesive tape can be easily peeled off while reducing contamination of the member to be treated; and a treatment method of a member to be treated using the laminate for semiconductor processing.SOLUTION: Provided is a laminate for semiconductor processing, comprising a support, a double-sided adhesive tape, and a member to be treated in this order. The double-sided adhesive tape comprises a substrate and adhesive layers laminated on both surfaces of the substrate, where a difference between a thermal expansion coefficient of the substrate and that of the support at 300°C is 10 ppm / °C or less, and the substrate has a melting point of 300°C or higher.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a laminate for semiconductor processing having a support, a double-sided adhesive tape, and a member to be processed in this order, which is difficult to peel even at high temperatures during the processing step of the member to be processed, and can easily peel the double-sided adhesive tape while reducing the contamination of the member to be processed after the step is completed. The present invention also relates to a method for processing a member to be processed using the laminate for semiconductor processing.

Background Art

[0002] In the manufacturing process of semiconductor chips, an adhesive tape is used to facilitate the handling during the processing of wafers and semiconductor chips and to prevent breakage. For example, when a thick film wafer cut from a high-purity single crystal silicon or the like is ground to a predetermined thickness to obtain a thin film wafer, grinding is performed after sticking an adhesive tape to the thick film wafer. In addition, a member to be processed such as a wafer or a semiconductor chip is fixed to a support via an adhesive tape, and the member to be processed fixed to the support is also processed.

[0003] Such an adhesive tape is required to have a high adhesiveness capable of firmly fixing a member to be processed such as a wafer or a semiconductor chip during the processing step, and to be peelable without damaging the member to be processed such as a wafer or a semiconductor chip after the step is completed (hereinafter, also referred to as "high adhesion and easy peeling"). As an adhesive tape that realizes high adhesion and easy peeling, Patent Document 1 discloses an adhesive tape using a photocurable adhesive that is cured by irradiating light such as ultraviolet rays and has a reduced adhesive force. By using a photocurable adhesive as the adhesive, the member to be processed can be surely fixed during the processing step, and can be easily peeled by irradiating ultraviolet rays or the like. In addition, Patent Document 2 discloses a re-peelable adhesive in which a silicone-based graft copolymer having a functional group capable of crosslinking reaction with the base polymer of the adhesive is contained in a non-silicone-based adhesive. Patent Document 2 describes that the re-peelability is improved by using a silicone-based graft copolymer having an excellent inhibitory effect on the increase in adhesive force.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in recent years, there has been an increasing number of processes that involve heating at a temperature higher than conventional levels, specifically, for example, a temperature of 250°C or higher, while fixing a member to be processed, such as a wafer or a semiconductor chip, to a support via an adhesive tape. At such high temperatures, there is a problem that the adhesive tape peels off from the support and / or the member to be processed (particularly from the support). Such peeling becomes prominent when the member to be processed is a relatively large wafer (for example, a silicon wafer with a diameter of 8 inches or more).

[0006] An object of the present invention is to provide a semiconductor processing laminate having a support, a double-sided adhesive tape, and a member to be processed in this order, which is less likely to peel even at high temperatures during the processing step of the member to be processed, and can easily peel the double-sided adhesive tape while reducing contamination of the member to be processed after the process is completed. Another object of the present invention is to provide a method for processing a member to be processed using the semiconductor processing laminate.

Means for Solving the Problems

[0007] The present invention is a semiconductor processing laminate having a support, a double-sided adhesive tape, and a member to be processed in this order, wherein the double-sided adhesive tape has a base material and adhesive layers laminated on both sides of the base material, and the base material has a difference in thermal expansion coefficient at 300°C from the support of 10 ppm / °C or less and a melting point of 300°C or higher. The present invention will be described in detail below.

[0008] The inventors studied a laminate for semiconductor processing having a support, a double-sided adhesive tape, and a member to be processed in this order. In such a laminate for semiconductor processing, at high temperatures, strain occurs due to the difference in the coefficient of thermal expansion between the members constituting the laminate for semiconductor processing, and peeling occurs because this strain cannot be sufficiently relaxed. The inventors have found that in order to reduce such strain and suppress peeling at high temperatures, it is necessary to suppress the difference in the coefficient of thermal expansion between, in particular, the support and the base material of the double-sided adhesive tape among the members constituting the laminate for semiconductor processing. That is, the inventors used a base material for the double-sided adhesive tape having a difference in the coefficient of thermal expansion at 300 °C from the support of a certain value or less and a melting point of a certain value or more, thereby suppressing the peeling of the double-sided adhesive tape from the support and / or the member to be processed at high temperatures, and also found that after the process is completed, the double-sided adhesive tape can be easily peeled off and adhesive residue can be suppressed. As a result, the present invention has been completed.

[0009] The laminate for semiconductor processing of the present invention has a support, a double-sided adhesive tape, and a member to be processed in this order. The above support is not particularly limited, and a support generally used for performing a process on the member to be processed in a state where the member to be processed is fixed via the double-sided adhesive tape can be used. The coefficient of thermal expansion of the support at 300 °C is not particularly limited as long as the difference in the coefficient of thermal expansion at 300 °C from the base material can be adjusted to the range described later, but generally, the lower limit is about 0.5 ppm / °C and the upper limit is about 30 ppm / °C, and a preferable lower limit is 1 ppm / °C and a preferable upper limit is 10 ppm / °C. Specific examples of the support include glass, polyimide film, glass epoxy substrate, silicon wafer, SiC wafer, metal plate, and the like. Among them, glass is preferable because it has high light transmittance and can be used in a process using light irradiation such as ultraviolet light.

[0010] The above glass is not particularly limited, and examples thereof include soda glass, quartz glass, borosilicate glass, etc. Examples of commercially available products of the above glass include Tempax (borosilicate glass, manufactured by Shot Co., Ltd.), etc.

[0011] The thickness of the above support is not particularly limited, but the preferable lower limit is 0.5 mm and the preferable upper limit is 20 mm. If the thickness of the above support is within the above range, even if the above member to be processed is thin, by fixing the above member to be processed to the above support via the above double-sided adhesive tape, the handling during processing of the above member to be processed becomes easy, and the member to be processed can be processed while preventing breakage. The more preferable lower limit of the thickness of the above support is 1 mm, and the more preferable upper limit is 3 mm.

[0012] The above member to be processed is not particularly limited, and examples thereof include a polyimide film, a glass epoxy substrate, a silicon wafer, a SiC wafer, etc. Among them, a silicon wafer is preferable. Even if the above member to be processed is a relatively large wafer (for example, a silicon wafer with a diameter of 8 inches or more), if it is a laminate for semiconductor processing of the present invention, peeling hardly occurs even at high temperatures, and after the process is completed, the above double-sided adhesive tape can be easily peeled off and adhesive residue can be suppressed. The coefficient of thermal expansion of the above member to be processed at 300 °C is not particularly limited, but generally, the lower limit is about 1 ppm / °C and the upper limit is about 50 ppm / °C, and the preferable lower limit is 2 ppm / °C and the preferable upper limit is 30 ppm / °C. The thickness of the above member to be processed is not particularly limited, but the preferable lower limit is 1 μm, the preferable upper limit is 500 μm, the more preferable lower limit is 20 μm, and the more preferable upper limit is 100 μm.

[0013] The above double-sided adhesive tape has a base material and adhesive layers laminated on both sides of the above base material. The above-mentioned base material has a difference in coefficient of thermal expansion at 300°C from the above-mentioned support of 10 ppm / °C or less and a melting point of 300°C or higher. By having a difference in coefficient of thermal expansion at 300°C between the above-mentioned base material and the above-mentioned support of 10 ppm / °C or less, it is possible to reduce the strain caused by the difference in coefficient of thermal expansion between the members constituting the semiconductor processing laminate at high temperatures. By having a melting point of the above-mentioned base material of 300°C or higher, it is possible to prevent the above-mentioned base material from melting due to high temperatures. For this reason, the semiconductor processing laminate of the present invention is less likely to peel even at high temperatures, and after the process is completed, the above-mentioned double-sided adhesive tape can be easily peeled off and adhesive residue can be suppressed.

[0014] The difference in coefficient of thermal expansion at 300°C between the above-mentioned base material and the above-mentioned support is preferably 5 ppm / °C or less, more preferably 3 ppm / °C or less. Note that as long as the difference in coefficient of thermal expansion can satisfy the above range, either the coefficient of thermal expansion of the above-mentioned base material or the coefficient of thermal expansion of the above-mentioned support may be larger. The coefficient of thermal expansion of the above-mentioned base material at 300°C is not particularly limited as long as the difference in coefficient of thermal expansion at 300°C from the above-mentioned support can be adjusted to the above range, but the preferable lower limit is 1 ppm / °C, the preferable upper limit is 20 ppm / °C, the more preferable lower limit is 3 ppm / °C, and the more preferable upper limit is 15 ppm / °C. Note that the coefficient of thermal expansion at 300°C means the rate of change in the length by which an object expands due to a temperature change, evaluated at 300°C, and can be obtained by a method in accordance with JIS K 7197:1991 using a thermomechanical analyzer (TMA).

[0015] The melting point of the above-mentioned base material is preferably 400°C or higher. The upper limit of the melting point of the above-mentioned base material is not particularly limited, but the substantial upper limit is about 500°C. Note that the melting point means the temperature at which a crystal changes to a melt and can be obtained by a method in accordance with JIS K7121:1987 using differential scanning calorimetry (DSC).

[0016] The difference in the coefficient of thermal expansion at 300°C between the above-mentioned base material and the above-mentioned member to be treated is not particularly limited, but is preferably 10 ppm / °C or less. By the difference in the coefficient of thermal expansion at 300°C between the above-mentioned base material and the above-mentioned member to be treated being 10 ppm / °C or less, the strain caused by the difference in the coefficient of thermal expansion between the members constituting the semiconductor processing laminate at high temperature can be further reduced. The difference in the coefficient of thermal expansion at 300°C between the above-mentioned base material and the above-mentioned member to be treated is more preferably 5 ppm / °C or less.

[0017] The material constituting the above-mentioned base material is not particularly limited, as long as the difference in the coefficient of thermal expansion and the melting point at 300°C from the above-mentioned support can be adjusted within the above range, and it is preferably a material having heat resistance. Examples of the heat-resistant material include polyethylene terephthalate, polyethylene naphthalate, polyacetal, polyamide, polycarbonate, polyphenylene ether, polybutylene terephthalate, ultra-high molecular weight polyethylene, syndiotactic polystyrene, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyetherimide, fluororesin, liquid crystal polymer, etc. Among them, polyimide is preferable because it is easy to adjust the difference in the coefficient of thermal expansion and the melting point at 300°C from the above-mentioned support within the above range.

[0018] Examples of commercially available products of the above-mentioned base material include Upilex (polyimide film, coefficient of thermal expansion at 300°C of 13 ppm / °C, melting point of 300°C or higher, manufactured by Ube Industries, Ltd.), Pomiran (polyimide film, coefficient of thermal expansion at 300°C of 5 ppm / °C, melting point of 300°C or higher, manufactured by Arakawa Chemical Industries, Ltd.), etc. Also, examples include Zenomax (polyimide film, coefficient of thermal expansion at 300°C of 4 ppm / °C, melting point of 300°C or higher, manufactured by Zenomax Japan Co., Ltd.).

[0019] The thickness of the above-mentioned base material is not particularly limited, but the preferable lower limit is 25 μm and the preferable upper limit is 250 μm. If the thickness of the above-mentioned base material is within the above range, a double-sided adhesive tape with excellent handleability can be obtained. Also, since it becomes easier to adjust the thickness of the above-mentioned double-sided adhesive tape within the range described later, the stress relaxation property of the above-mentioned double-sided adhesive tape is improved, and peeling is less likely to occur even at high temperatures. The more preferable lower limit of the thickness of the above-mentioned base material is 50 μm, and the more preferable upper limit is 125 μm.

[0020] The above-mentioned double-sided adhesive tape has adhesive layers laminated on both sides of the above-mentioned base material. The two adhesive layers laminated on both sides of the above-mentioned base material may be the same adhesive layer, or may be adhesive layers having different compositions and physical properties respectively.

[0021] The above-mentioned adhesive layer preferably contains an adhesive polymer. The above-mentioned adhesive polymer preferably has a polar functional group. Since the above-mentioned adhesive polymer has the above-mentioned polar functional group, when the above-mentioned adhesive layer further contains a silicone compound and a crosslinking agent, and the silicone compound has a functional group capable of crosslinking with the above-mentioned adhesive polymer, the silicone compound binds to the above-mentioned adhesive polymer via the crosslinking agent. Thereby, it is possible to reduce the contamination of the above-mentioned member to be treated due to the bleeding out of the silicone compound. The above-mentioned polar functional group is not particularly limited, and examples thereof include a carboxyl group, a hydroxyl group, a glycidyl group, an amide group, and a nitrile group. Among them, a carboxyl group and a hydroxyl group are preferable, and a carboxyl group is more preferable.

[0022] The above-mentioned adhesive polymer preferably has a radically polymerizable unsaturated bond in the molecule. Since the pressure-sensitive adhesive polymer has the radically polymerizable unsaturated bond, the pressure-sensitive adhesive layer is cured by heating or light irradiation in the presence of a polymerization initiator, and the elastic modulus increases while the adhesive strength decreases. Since the pressure-sensitive adhesive layer is a curable pressure-sensitive adhesive layer that can be post-cured by heating or light irradiation in this way, it is possible to reduce the adhesion enhancement at high temperatures, and after the process is completed, the double-sided adhesive tape can be peeled off more easily and the glue residue can be suppressed. In addition, since the pressure-sensitive adhesive polymer has the radically polymerizable unsaturated bond, the polarity of the crosslinking points is lower than that in the case of having other polymerizable functional groups, and the crosslinking density increases when the pressure-sensitive adhesive layer is cured. Therefore, the elastic modulus of the pressure-sensitive adhesive layer further increases. Thereby, it is possible to reduce the adhesion enhancement at high temperatures, and after the process is completed, the double-sided adhesive tape can be peeled off more easily and the glue residue can be suppressed.

[0023] The method for introducing the radically polymerizable unsaturated bond into the pressure-sensitive adhesive polymer is not particularly limited. For example, a method of using a monomer having a radically polymerizable unsaturated bond when synthesizing the pressure-sensitive adhesive polymer, a method of reacting a compound having a radically polymerizable unsaturated bond with a precursor polymer of the pressure-sensitive adhesive polymer, etc. can be mentioned.

[0024] The weight average molecular weight of the pressure-sensitive adhesive polymer is not particularly limited, but the preferable lower limit is 500,000 and the preferable upper limit is 1,500,000. If the weight average molecular weight is within the above range, the flexibility of the pressure-sensitive adhesive layer becomes high and the adhesion to the member to be treated is improved, so the initial adhesive strength becomes high. The more preferable lower limit of the weight average molecular weight is 800,000 and the more preferable upper limit is 1,200,000. In order to adjust the weight average molecular weight to the above range, for example, the composition, polymerization method, polymerization conditions, etc. of the pressure-sensitive adhesive polymer may be adjusted.

[0025] Note that the weight average molecular weight can be measured by the following method. Filter the solution of the adhesive polymer through a filter (material: polytetrafluoroethylene, pore size: 0.2 μm). Supply the obtained filtrate to a gel permeation chromatograph (for example, Waters 2690 Separations Model), perform GPC measurement under the conditions of a sample flow rate of 1 milliliter / min and a column temperature of 40°C, measure the polystyrene-equivalent molecular weight of the adhesive polymer, and determine the weight average molecular weight. As the column, for example, GPC KF-806L (manufactured by Showa Denko KK) is used, and as the detector, a differential refractometer is used.

[0026] Specific examples of the above adhesive polymer include acrylic polymers, silicone polymers, urethane polymers, rubber polymers, and the like. Among them, because of its excellent heat resistance and weather resistance, it is suitable for applications that involve a process with heating at high temperatures, can be applied to a wide range of members to be processed, and furthermore, since it is easy to adjust the glass transition temperature, an acrylic polymer is preferred.

[0027] When the above adhesive polymer is the above acrylic polymer, in order to have the above polar functional group, it is preferable that the acrylic polymer has a structural unit derived from a monomer having the above polar functional group. When the polar functional group is a carboxyl group, examples of the monomer having a carboxyl group include (meth)acrylic acid and the like. When the polar functional group is a hydroxyl group, examples of the monomer having a hydroxyl group include (meth)acrylate esters having a hydroxyl group such as 4-hydroxybutyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate. When the polar functional group is a glycidyl group, examples of the monomer having a glycidyl group include glycidyl (meth)acrylate and the like. When the polar functional group is an amide group, examples of the monomer having an amide group include hydroxyethyl acrylamide, isopropyl acrylamide, dimethylaminopropyl acrylamide and the like. When the polar functional group is a nitrile group, examples of the monomer having a nitrile group include acrylonitrile and the like. These monomers having polar functional groups may be used alone or in combination of two or more.

[0028] When the acrylic polymer has a structural unit derived from the monomer having a carboxyl group, its content is not particularly limited, but the preferable lower limit is 0.1% by weight and the preferable upper limit is 10% by weight. If the content is 0.1% by weight or more, the acrylic polymer can be sufficiently bonded to the silicone compound via the crosslinking agent, so that the contamination of the member to be treated can be further reduced. If the content is 10% by weight or less, the pressure-sensitive adhesive layer does not become too hard and the residue of the adhesive can be suppressed.

[0029] When the acrylic polymer has a structural unit derived from the monomer having a hydroxyl group, its content is not particularly limited, but the preferable lower limit is 0.1% by weight and the preferable upper limit is 30% by weight. If the content is 0.1% by weight or more, the acrylic polymer can be sufficiently bonded to the silicone compound via the crosslinking agent, so that the contamination of the member to be treated can be further reduced. If the content is 30% by weight or less, the pressure-sensitive adhesive layer can have high adhesiveness even at high temperatures.

[0030] In addition to the structural unit derived from the monomer having the polar functional group, the acrylic polymer may have a structural unit derived from another radically polymerizable monomer. Examples of the other radically polymerizable monomer include (meth)acrylic acid esters, vinyl compounds, and the like.

[0031] The (meth)acrylic acid ester is not particularly limited, and examples thereof include alkyl (meth)acrylates. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, and the like. Examples of the (meth)acrylic acid ester also include cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, polypropylene glycol mono(meth)acrylate, and the like. These (meth)acrylic acid esters may be used alone or in combination of two or more.

[0032] The vinyl compound is not particularly limited, and examples thereof include styrene, vinyl acetate, and the like. These vinyl compounds may be used alone or in combination of two or more.

[0033] When the pressure-sensitive adhesive polymer is the acrylic polymer, in order to have the radically polymerizable unsaturated bond, it is preferable to react a compound having a functional group that reacts with the polar functional group and a radically polymerizable unsaturated bond (hereinafter, also referred to as "functional group-containing unsaturated compound") with the polar functional group present in the acrylic polymer. In addition, if all of the polar functional groups present in the acrylic polymer react with the functional group-containing unsaturated compound, the acrylic polymer will no longer be able to have polar functional groups. Therefore, when producing an acrylic polymer having both a polar functional group and a radically polymerizable unsaturated bond, it is necessary to adjust the reactivity by appropriately adjusting the type of the functional group-containing unsaturated compound, reaction conditions, etc.

[0034] The functional group-containing unsaturated compound is not particularly limited and can be appropriately selected according to the polar functional groups present in the acrylic polymer. When the polar functional group present in the acrylic polymer is a carboxyl group, a compound having an epoxy group and a radically polymerizable unsaturated bond, a compound having an isocyanate group and a radically polymerizable unsaturated bond, etc. are used. When the polar functional group present in the acrylic polymer is a hydroxyl group, a compound having an isocyanate group and a radically polymerizable unsaturated bond, etc. are used. When the polar functional group present in the acrylic polymer is an epoxy group, a compound having a carboxyl group and a radically polymerizable unsaturated bond, a compound having an amide group and a radically polymerizable unsaturated bond, etc. are used. When the polar functional group present in the acrylic polymer is an amino group, a compound having an epoxy group and a radically polymerizable unsaturated bond, etc. are used.

[0035] The acrylic polymer is obtained by copolymerizing a monomer mixture. To obtain the acrylic polymer by copolymerizing the monomer mixture, the monomer mixture may be subjected to a radical reaction in the presence of a polymerization initiator. As a method for subjecting the monomer mixture to a radical reaction, that is, a polymerization method, a conventionally known method is used, and examples thereof include solution polymerization (boiling point polymerization or isothermal polymerization), emulsion polymerization, suspension polymerization, bulk polymerization, etc. As a reaction method when subjecting the monomer mixture to a radical reaction, examples thereof include living radical polymerization, free radical polymerization, etc.

[0036] The above acrylic polymer is preferably an acrylic polymer obtained by living radical polymerization (hereinafter also referred to as "living radical polymerization acrylic polymer"). Living radical polymerization is a polymerization in which the molecular chain grows without being hindered by side reactions such as termination reactions or chain transfer reactions. In living radical polymerization, the reaction proceeds without the growth terminal radicals being deactivated and without new radical species being generated during the reaction. During the reaction, all molecular chains polymerize while reacting uniformly with the monomer, and the composition of all molecular chains approaches uniformity. Therefore, according to living radical polymerization, a polymer having a more uniform molecular weight and composition can be obtained compared to free radical polymerization, and the generation of low molecular weight components can be suppressed, so that the cohesive force of the above adhesive layer is increased. As a result, the initial adhesive force is increased, and the promotion of adhesion at high temperatures can be further reduced.

[0037] On the other hand, in free radical polymerization, radical species are continuously generated during the reaction and added to the monomer, and the polymerization proceeds. Therefore, in free radical polymerization, molecular chains in which the growth terminal radicals are deactivated during the reaction and molecular chains grown by newly generated radical species during the reaction are generated. Therefore, according to free radical polymerization, the composition of the polymer becomes non-uniform compared to living radical polymerization, and relatively low molecular weight polymers are also included.

[0038] In the above living radical polymerization, various polymerization methods may be adopted. For example, iron, ruthenium or copper catalysts and halogen-based initiators may be used (ATRP), TEMPO may be used, and organic tellurium polymerization initiators may be used. Among them, it is preferable to use an organic tellurium polymerization initiator. Living radical polymerization using an organic tellurium polymerization initiator, unlike other living radical polymerizations, can polymerize with the same initiator without protecting any radical polymerizable monomers having polar functional groups such as hydroxyl groups and carboxyl groups to obtain a polymer having a uniform molecular weight and composition. Therefore, radical polymerizable monomers having polar functional groups can be easily copolymerized.

[0039] The molecular weight distribution (Mw / Mn) of the above-mentioned living radical polymerization acrylic polymer is not particularly limited, but the preferable lower limit is 1.05 and the preferable upper limit is 2.5. If the above-mentioned molecular weight distribution (Mw / Mn) is within the above range, the cohesive force of the above-mentioned adhesive layer will be increased. As a result, the initial adhesive force will be increased, and the enhancement of adhesion at high temperatures can be further reduced. The more preferable lower limit of the above-mentioned molecular weight distribution (Mw / Mn) is 1.1, and the more preferable upper limit is 2.0.

[0040] The above-mentioned acrylic polymer may be an acrylic polymer obtained by isothermal free radical polymerization (hereinafter, also referred to as "isothermal free radical polymerization acrylic polymer"). As described above, according to free radical polymerization, compared with living radical polymerization, the composition of the polymer becomes non-uniform and contains relatively low molecular weight polymers. However, among free radical polymerizations, according to isothermal free radical polymerization, the generation of low molecular weight components can be suppressed compared with boiling point free radical polymerization, so that the cohesive force of the above-mentioned adhesive layer is increased. As a result, the initial adhesive force is increased, and the enhancement of adhesion at high temperatures can be further reduced.

[0041] When the above-mentioned monomer mixture is subjected to a radical reaction, a dispersion stabilizer may be used. Examples of the above-mentioned dispersion stabilizer include polyvinylpyrrolidone, polyvinyl alcohol, methylcellulose, ethylcellulose, poly(meth)acrylic acid, poly(meth)acrylate, polyethylene glycol, and the like. When a polymerization solvent is used when the above-mentioned monomer mixture is subjected to a radical reaction, the polymerization solvent is not particularly limited. As the polymerization solvent, for example, nonpolar solvents such as hexane, cyclohexane, octane, toluene, and xylene, and highly polar solvents such as water, methanol, ethanol, propanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, and N,N-dimethylformamide can be used. These polymerization solvents may be used alone or in combination of two or more. Also, from the viewpoint of polymerization rate, the polymerization temperature is preferably 0 to 110°C.

[0042] The pressure-sensitive adhesive layer preferably contains a silicone compound. When the pressure-sensitive adhesive layer contains the silicone compound, the silicone compound migrates molecularly and accumulates on the surface of the pressure-sensitive adhesive layer, making the surface of the pressure-sensitive adhesive layer hydrophobic. As a result, the interaction between the pressure-sensitive adhesive layer and the member to be treated becomes difficult, so that the adhesion enhancement at high temperature can be reduced, and after the process is completed, the double-sided adhesive tape can be peeled off more easily and the glue residue can be suppressed.

[0043] The silicone compound preferably has a functional group capable of crosslinking with the pressure-sensitive adhesive polymer. When the silicone compound has a functional group capable of crosslinking with the pressure-sensitive adhesive polymer, the silicone compound binds to the pressure-sensitive adhesive polymer via a crosslinking agent. Thereby, the contamination of the member to be treated due to the bleed-out of the silicone compound can be reduced. Further, when the silicone compound binds to the pressure-sensitive adhesive polymer via a crosslinking agent, the crosslinking density on the surface of the pressure-sensitive adhesive layer increases and the elastic modulus increases, and the adhesive force decreases, so that the adhesion enhancement at high temperature can be further reduced. The functional group capable of crosslinking with the pressure-sensitive adhesive polymer is not particularly limited and is appropriately determined according to the functional group present in the pressure-sensitive adhesive polymer. Examples thereof include an isocyanate group, a carboxyl group, a hydroxyl group, a glycidyl group, an amide group, and a nitrile group. Among them, an isocyanate group, a carboxyl group, and a hydroxyl group are preferable, and a carboxyl group is more preferable.

[0044] The functional group capable of crosslinking with the pressure-sensitive adhesive polymer may be protected by a protecting group for the purpose of suppressing an unintended reaction. The protecting group is not particularly limited, but a protecting group that dissociates by heat is preferable. Specific examples thereof include a pyrazole group, a phenol group, an oxime group, a lactam group, and a vinyl ether group. The above-mentioned protecting group is appropriately determined according to the functional group capable of crosslinking with the above-mentioned pressure-sensitive adhesive polymer. Examples of the protecting group for a carboxyl group include a vinyl ether group and the like, and examples of the protecting group for an isocyanate group include a pyrazole group and the like. Further, examples of the protecting group for a hydroxyl group include a silyl group, an acetyl group, an acetal-based protecting group, a benzyl group, an allyl group, a pyrazole group, a phenol group, an oxime group, a lactam group and the like.

[0045] The above-mentioned silicone compound is not particularly limited as long as it is a compound containing a siloxane bond. Specifically, for example, silicone oil, modified silicone oil, silicone-based graft copolymer, silicone-based block copolymer and the like can be mentioned. Among them, by bonding with the above-mentioned pressure-sensitive adhesive polymer via a crosslinking agent, the contamination of the above-mentioned member to be treated due to the bleeding out of the above-mentioned silicone compound can be further reduced, and it is likely to gather on the surface of the above-mentioned adhesive layer, and the adhesion enhancement at high temperature can be further reduced. Therefore, a silicone-based graft copolymer is preferable.

[0046] The above-mentioned silicone-based graft copolymer is a copolymer having a graft chain containing a siloxane bond. The above-mentioned silicone-based graft copolymer is not particularly limited, but preferably has a structural unit derived from a silicone macromonomer. The above-mentioned silicone macromonomer is not particularly limited as long as it is a monomer having a siloxane bond-containing group. For example, an acrylic silicone macromonomer, a styrene-based silicone macromonomer and the like can be mentioned. Among them, an acrylic silicone macromonomer is preferable because of its excellent heat resistance and weather resistance, and an acrylic silicone macromonomer having a structure represented by the following general formula (1) or (2) is more preferable.

[0047]

Chemical formula

[0048] Here, R represents a (meth)acryloyl group-containing functional group, and X and Y each independently represent an integer of 0 or 1 or more. Examples of R include a (meth)acryloyl group. The upper limits of X and Y are not particularly limited, but X and Y are usually 5000 or less, preferably 500 or less, and more preferably 200 or less.

[0049] The weight-average molecular weight of the silicone macromonomer is not particularly limited, but the preferable lower limit is 500, and the preferable upper limit is 50,000. If the weight-average molecular weight is within the above range, the hydrophobic surface layer formed by the silicone-based graft copolymer becomes thicker, so that the adhesion enhancement at high temperature can be further reduced. The more preferable lower limit of the weight-average molecular weight is 1000, and the more preferable upper limit is 20,000.

[0050] The content of the structural unit derived from the silicone macromonomer is not particularly limited, but the preferable lower limit in the silicone-based graft copolymer is 1% by weight, and the preferable upper limit is 90% by weight. If the content is within the above range, the adhesion enhancement at high temperature can be further reduced. The more preferable lower limit of the content is 5% by weight, the more preferable upper limit is 80% by weight, and the further preferable lower limit is 10% by weight, and the further preferable upper limit is 60% by weight.

[0051] When the silicone-based graft copolymer has a functional group crosslinkable with the pressure-sensitive adhesive polymer, the functional group crosslinkable with the pressure-sensitive adhesive polymer may be present in the graft chain of the silicone-based graft copolymer, may be present in the main chain, or may be present in both the graft chain and the main chain.

[0052] In order for the silicone-based graft copolymer to have a functional group crosslinkable with the pressure-sensitive adhesive polymer, it preferably has a structural unit derived from a monomer having a functional group crosslinkable with the pressure-sensitive adhesive polymer. The monomer having a functional group capable of crosslinking with the above-mentioned pressure-sensitive adhesive polymer is not particularly limited, and the same monomers as those having the polar functional groups as described above used in the case of an acrylic polymer as the above-mentioned pressure-sensitive adhesive polymer can be used. Also, when the functional group capable of crosslinking with the above-mentioned pressure-sensitive adhesive polymer is an isocyanate group, the isocyanate group may be protected by a protecting group. In this case, examples of the monomer having a protected isocyanate group include 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate, 2-[0-(1'-methylpropylideneamino)carboxyamino]ethyl methacrylate, and the like.

[0053] The content of the structural unit derived from the monomer having a functional group capable of crosslinking with the above-mentioned pressure-sensitive adhesive polymer is not particularly limited, but the preferable lower limit in the above-mentioned silicone-based graft copolymer is 1% by weight, and the preferable upper limit is 30% by weight. If the content is within the above range, while the above-mentioned silicone-based graft copolymer is sufficiently bonded to the above-mentioned pressure-sensitive adhesive polymer, a sufficient crosslinked structure can also be constructed between the above-mentioned pressure-sensitive adhesive polymers, so that the enhancement of adhesion at high temperature can be further reduced. The more preferable lower limit of the content is 3% by weight, the more preferable upper limit is 20% by weight, and the further preferable upper limit is 10% by weight.

[0054] Also, the functional group capable of crosslinking with the above-mentioned pressure-sensitive adhesive polymer may be a radically polymerizable unsaturated bond. In this case, in order for the above-mentioned silicone-based graft copolymer to have the above-mentioned radically polymerizable unsaturated bond, it is preferable to react a compound having a functional group that reacts with the functional group present in the above-mentioned silicone-based graft copolymer and a radically polymerizable unsaturated bond. Such a compound is not particularly limited, and the same compounds as the above-mentioned functional group-containing unsaturated compounds used in the case of an acrylic polymer as the above-mentioned pressure-sensitive adhesive polymer can be used.

[0055] In addition to the structural unit derived from the silicone macromonomer and the structural unit derived from the monomer having a functional group capable of crosslinking with the pressure-sensitive adhesive polymer, the silicone-based graft copolymer may further have a structural unit derived from (meth)acrylate, vinyl compound, monomer having other polar functional groups, etc. The (meth)acrylate and the vinyl compound are not particularly limited, and the same monomers as the above-mentioned (meth)acrylates used in the case of the acrylic polymer as the pressure-sensitive adhesive polymer can be used. Among them, 2-ethylhexyl acrylate is preferable because it can impart appropriate adhesiveness.

[0056] The weight average molecular weight of the silicone-based graft copolymer is not particularly limited, but the preferable lower limit is 5,000, and the preferable upper limit is 400,000. If the weight average molecular weight is 5,000 or more, the silicone-based graft copolymer is easily incorporated into the crosslinked structure of the pressure-sensitive adhesive polymer, so that the contamination of the member to be treated can be further reduced. If the weight average molecular weight is 400,000 or less, the silicone-based graft copolymer can easily move within the pressure-sensitive adhesive layer and easily gather on the surface of the pressure-sensitive adhesive layer, so that the promotion of adhesion at high temperature can be further reduced. The more preferable upper limit of the weight average molecular weight is 300,000, the further preferable upper limit is 250,000, the particularly preferable upper limit is 200,000, and it is usually 10,000 or more.

[0057] The method for producing the silicone-based graft copolymer is not particularly limited, and it can be obtained by copolymerizing a monomer mixture. The method for copolymerizing the monomer mixture to obtain a silicone-based graft copolymer is not particularly limited, and the same method as in the case of the acrylic polymer as the pressure-sensitive adhesive polymer can be used.

[0058] The content of the silicone compound is not particularly limited, but the preferable lower limit with respect to 100 parts by weight of the pressure-sensitive adhesive polymer is 1 part by weight, and the preferable upper limit is 20 parts by weight. If the content is 1 part by weight or more, the promotion of adhesion at high temperatures can be further reduced. If the content is 20 parts by weight or less, the initial adhesiveness of the pressure-sensitive adhesive layer becomes high, and clouding of the pressure-sensitive adhesive layer can also be suppressed. The more preferable lower limit of the content is 2 parts by weight, and the more preferable upper limit is 15 parts by weight. The further preferable lower limit is 3 parts by weight, and the further preferable upper limit is 10 parts by weight. In addition, when the silicone compound is the silicone-based graft copolymer, since the silicone-based graft copolymer tends to gather on the surface of the pressure-sensitive adhesive layer, it can be used in a relatively small amount among the silicone compounds. The content of the silicone-based graft copolymer is such that the preferable lower limit with respect to 100 parts by weight of the pressure-sensitive adhesive polymer is 0.1 part by weight, and the preferable upper limit is 10 parts by weight. The more preferable lower limit is 0.5 part by weight, and the more preferable upper limit is 5 parts by weight. The further preferable lower limit is 1 part by weight.

[0059] The pressure-sensitive adhesive layer preferably further contains a crosslinking agent. By the pressure-sensitive adhesive layer containing the crosslinking agent, the pressure-sensitive adhesive polymer is crosslinked, making it easier to adjust the cohesive force of the pressure-sensitive adhesive layer. As a result, the initial adhesiveness becomes high, and the promotion of adhesion at high temperatures can be reduced. After the process is completed, the double-sided adhesive tape can be peeled off more easily and adhesive residue can be suppressed. In addition, when the pressure-sensitive adhesive layer contains the crosslinking agent, if the silicone compound has a functional group capable of crosslinking with the pressure-sensitive adhesive polymer, the silicone compound binds to the pressure-sensitive adhesive polymer via the crosslinking agent. Thereby, contamination of the member to be treated due to bleed-out of the silicone compound can be further reduced.

[0060] The crosslinking agent is not particularly limited, and examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, metal chelate-based crosslinking agents, and the like. Among these, an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferable because the cohesive force of the pressure-sensitive adhesive layer is increased.

[0061] The content of the crosslinking agent is not particularly limited, but from the viewpoint of achieving more appropriate cohesive force and sufficiently bonding the pressure-sensitive adhesive polymer and the silicone compound, the preferable lower limit is 0.01 part by weight and the preferable upper limit is 1 part by weight with respect to 100 parts by weight of the pressure-sensitive adhesive polymer. The more preferable lower limit is 0.1 part by weight and the more preferable upper limit is 0.5 part by weight.

[0062] The pressure-sensitive adhesive layer preferably further contains a polymerization initiator. When the pressure-sensitive adhesive layer contains the polymerization initiator, when the pressure-sensitive adhesive polymer has the radically polymerizable unsaturated bond, the pressure-sensitive adhesive layer is cured by heating or light irradiation in the presence of the polymerization initiator, and the elastic modulus increases and the adhesive force decreases. Since the pressure-sensitive adhesive layer is a curable pressure-sensitive adhesive layer that can be post-cured by heating or light irradiation in this way, it is possible to reduce the enhancement of adhesion at high temperature, and after the completion of the process, the double-sided adhesive tape can be peeled off more easily and the glue residue can be suppressed.

[0063] The polymerization initiator is not particularly limited, and examples thereof include photopolymerization initiators and thermal polymerization initiators. Among these, since the pressure-sensitive adhesive layer can be cured by the heat during the treatment involving heating the member to be treated, a separate step of curing the pressure-sensitive adhesive layer is not required, and since curing is possible even when used for a support or a member to be treated that does not transmit light, a thermal polymerization initiator is preferable.

[0064] The above photoinitiator is not particularly limited, and examples thereof include those activated by irradiating light with a wavelength of 250 to 800 nm. Examples of such photoinitiators include acetophenone derivative compounds, benzoin ether-based compounds, ketal derivative compounds, phosphine oxide derivative compounds, bis(η5-cyclopentadienyl)titanocene derivative compounds, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethyl phenyl propane, and the like. Examples of the above acetophenone derivative compounds include methoxyacetophenone and the like. Examples of the above benzoin ether-based compounds include benzoin propyl ether, benzoin isobutyl ether, and the like. Examples of the above ketal derivative compounds include benzyl dimethyl ketal, acetophenone diethyl ketal, and the like. These photoinitiators may be used alone or in combination of two or more.

[0065] The above thermal initiator is not particularly limited, and examples thereof include those that decompose by heat to generate active radicals that initiate the polymerization reaction. Specifically, for example, dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramethane hydroperoxide, di-t-butyl peroxide, and the like can be mentioned.

[0066] The content of the above polymerization initiator is not particularly limited and is appropriately determined according to the types of the above pressure-sensitive adhesive polymer and the above polymerization initiator. However, the preferable lower limit with respect to 100 parts by weight of the above pressure-sensitive adhesive polymer is 0.5 part by weight, and the preferable upper limit is 10 parts by weight. The more preferable lower limit is 1 part by weight, and the more preferable upper limit is 8 parts by weight.

[0067] The above adhesive layer may further contain a gas generating agent. The above adhesive layer may also contain known additives such as inorganic fillers such as fumed silica, plasticizers, resins, surfactants, waxes, particulate fillers, antioxidants, and gas generating agents.

[0068] The upper limit of the weight loss rate after heating at 300°C for 5 minutes measured using a differential thermal thermogravimetric simultaneous measurement device for the above adhesive layer is preferably 3% by weight. If the weight loss rate after the above heating is 3% by weight or less, the amount of outgas generated from the above adhesive polymer decreases, and peeling is less likely to occur even at high temperatures. A more preferable upper limit of the weight loss rate after the above heating is 1% by weight. The lower limit of the weight loss rate after the above heating is not particularly limited, and it is preferable because peeling is less likely to occur even at high temperatures as it approaches 0% by weight. The method for adjusting the weight loss rate after the above heating is not particularly limited, and the types, compositions, physical properties, contents, etc. of the above adhesive polymer, the above silicone compound, crosslinking agent, etc. may be adjusted.

[0069] Note that the weight loss rate after heating can be measured by the following method. After obtaining a measurement sample consisting only of the adhesive layer, measure the weight. Using a differential thermal thermogravimetric simultaneous measurement device (for example, TG-DTA; STA7200 manufactured by Hitachi High-Tech Science Corporation) under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min), heat the measurement sample from 25°C to 300°C at a heating rate of 10°C / min, and after reaching 300°C, maintain 300°C and heat for 5 minutes. After cooling, measure the weight loss amount, and calculate the weight loss rate from the obtained weight loss amount and the weight before heating. Note that when the adhesive layer is a curable adhesive layer, the above measurement is performed after curing the adhesive layer. For example, when the adhesive layer is a thermosetting adhesive layer, a heat treatment at 150°C for 10 minutes is performed to cure the adhesive layer, and then the above measurement is performed. When the adhesive layer is a photocurable adhesive layer, using a high-pressure mercury UV irradiator, irradiate the adhesive layer with ultraviolet light of 405 nm so that the irradiation amount is 3000 mJ / cm 2 After irradiation to reach this value, perform a heat treatment at 150°C for 10 minutes to cure the adhesive layer, and then perform the above measurement.

[0070] The thickness of the above adhesive layer is not particularly limited, but the preferable lower limit is 5 μm and the preferable upper limit is 100 μm. If the thickness of the above adhesive layer is within the above range, the above double-sided adhesive tape can be attached to the above member to be processed with sufficient adhesive force, and adhesive residue can be suppressed after the process is completed. Further, if the thickness of the above adhesive layer is within the above range, it becomes easier to adjust the thickness of the above double-sided adhesive tape to the range described later, so the stress relaxation property of the above double-sided adhesive tape is improved, and peeling is less likely to occur even at high temperatures. The more preferable lower limit of the thickness of the above adhesive layer is 10 μm, and the more preferable upper limit is 60 μm.

[0071] For the above double-sided adhesive tape, when the adhesive layer on the side in contact with the above member to be processed is attached to a silicon wafer and heated at 300 °C for 5 minutes, the preferable upper limit of the 180° peel force is 0.5 N / 25 mm. If the above 180° peel force is 0.5 N / 25 mm or less, the above double-sided adhesive tape can be peeled off more easily and adhesive residue can be suppressed after the process is completed. The more preferable upper limit of the above 180° peel force is 0.3 N / 25 mm. The lower limit of the above 180° peel force is not particularly limited, but the preferable lower limit is 0.01 N / 25 mm. The method for adjusting the above 180° peel force to the above range is not particularly limited, and examples include a method of blending the above silicone compound into the adhesive layer on the side in contact with the above member to be processed, and a method of making the adhesive layer on the side in contact with the above member to be processed a curable adhesive layer that can be post-cured by heating or light irradiation.

[0072] Note that the 180° peel force after attaching the adhesive layer on the side in contact with the above member to be processed to a silicon wafer and heating at 300 °C for 5 minutes can be measured by the following method. Cut the double-sided adhesive tape into 25 mm widths. Under the environment of a room temperature of 23°C and a relative humidity of 50%, attach the cut double-sided adhesive tape to a silicon wafer (PC-300, manufactured by SUMCO Corporation, or its equivalent) at a speed of 10 mm / sec using a 2 kg pressure-bonding rubber roller. Then, perform a heat treatment at 300°C for 5 minutes once. Here, the heat treatment at 300°C for 5 minutes means putting the measurement sample into an oven at 300°C and leaving it still for 5 minutes. After cooling, in accordance with JIS Z0237, peel off the double-sided adhesive tape at a speed of 300 mm / min and measure the 180°-direction peel strength. In addition, when the adhesive layer is a curable adhesive layer, perform the heat treatment after curing the adhesive layer. For example, when the adhesive layer is a thermosetting adhesive layer, after attaching the double-sided adhesive tape and before the above heat treatment, perform a heat treatment at 150°C for 10 minutes to cure the adhesive layer. When the adhesive layer is a photocurable adhesive layer, after attaching the double-sided adhesive tape and before the above heat treatment, use a high-pressure mercury UV irradiator to irradiate the adhesive layer with ultraviolet rays of 405 nm so that the irradiation amount to the adhesive layer becomes 3000 mJ / cm2, and then perform a heat treatment at 150°C for 10 minutes to cure the adhesive layer.

[0073] For the above double-sided adhesive tape, when the adhesive layer on the side in contact with the above support is attached to the support and heated at 300°C for 5 minutes, the preferable upper limit of the 180°-direction peel strength is 0.5 N / 25 mm. If the 180°-direction peel strength is 0.5 N / 25 mm or less, the double-sided adhesive tape can be peeled off more easily after the process is completed. The more preferable upper limit of the 180°-direction peel strength is 0.3 N / 25 mm. The lower limit of the 180°-direction peel strength is not particularly limited, but the preferable lower limit is 0.01 N / 25 mm. If the 180°-direction peel strength is 0.01 N / 25 mm or more, the double-sided adhesive tape is less likely to peel off even at high temperatures.

[0074] The thickness of the above double-sided adhesive tape is not particularly limited, but the preferable lower limit is 60 μm and the preferable upper limit is 500 μm. If the thickness of the above double-sided adhesive tape is 60 μm or more, the stress relaxation property of the above double-sided adhesive tape is improved, and peeling is less likely to occur even at high temperatures. If the thickness of the above double-sided adhesive tape is 300 μm or less, the above double-sided adhesive tape can be peeled off more easily after the process is completed, and adhesive residue can be suppressed. A more preferable lower limit of the thickness of the above double-sided adhesive tape is 120 μm, and a more preferable upper limit is 200 μm.

[0075] The method for manufacturing the above double-sided adhesive tape is not particularly limited, and for example, the following methods can be mentioned. First, a silicone compound, a cross-linking agent, a polymerization initiator, and, if necessary, other additives are added to a solution of an adhesive polymer and mixed to obtain an adhesive solution. Next, the adhesive solution is applied onto a release film and dried to form an adhesive layer. The obtained adhesive layer is bonded to both sides of a base material respectively to manufacture a double-sided adhesive tape.

[0076] The method for manufacturing the laminate for semiconductor processing of the present invention is not particularly limited, and for example, the following methods can be mentioned. First, the adhesive layer on the side of the above double-sided adhesive tape that contacts the above support is attached to the above support at a speed of 10 mm / sec using a 2 kg pressure-bonding rubber roller. Next, a method of bonding the adhesive layer on the side of the above double-sided adhesive tape that contacts the above member to be processed to the above member to be processed using a vacuum bonder can be mentioned.

[0077] The use of the laminate for semiconductor processing of the present invention is not particularly limited, but it is preferably used in the manufacturing process of electronic components such as semiconductor devices and display devices (OLED, liquid crystal display devices, etc.). That is, for example, in the manufacturing of electronic components, a process is performed on the member to be processed in the laminate for semiconductor processing of the present invention. During the processing step of the member to be processed, the laminate for semiconductor processing of the present invention is difficult to peel even at high temperatures, and after the completion of the process, the double-sided adhesive tape can be easily peeled while reducing the contamination of the member to be processed. Therefore, when performing a process involving heating the surface of the member to be processed at a higher temperature than before, specifically, for example, a high temperature of 250 °C or higher, it can be preferably used.

[0078] A method for processing a member to be processed using the laminate for semiconductor processing of the present invention, the method including a processing step of subjecting the surface of the member to be processed of the laminate for semiconductor processing of the present invention to a process involving heating at 250 °C or higher, and a peeling step of peeling the support and the member to be processed, is also one aspect of the present invention.

[0079] In the process involving heating at 250 °C or higher, the upper limit of the heating temperature is not particularly limited, and substantially, the upper limit is about 400 °C, and a preferable upper limit is 300 °C. The process involving heating at 250 °C or higher is not particularly limited, and examples thereof include heat treatment or processes involving heat generation such as a reflow process, a sputtering process, a vapor deposition process, an etching process, a chemical vapor deposition (CVD) process, a physical vapor deposition (PVD) process, a resist coating process, a patterning process, and a molding process.

[0080] The method for peeling the support and the member to be processed is not particularly limited. After peeling between the support and the double-sided adhesive tape, the double-sided adhesive tape and the member to be processed may be peeled, or the double-sided adhesive tape and the member to be processed may be peeled without peeling between the support and the double-sided adhesive tape. As a method for peeling the support and the member to be processed, a conventionally known method can be used. Specifically, for example, a method in which one of the member to be processed or the support is fixed horizontally and the other is lifted at a certain angle from the horizontal direction, a method of attaching a protective film to the surface of the member to be processed, and peeling the member to be processed and the protective film from the semiconductor processing laminate by a peeling method, etc. can be mentioned. Further, by irradiating light to the pressure-sensitive adhesive layer through the support, a method of altering the pressure-sensitive adhesive layer to peel it, and when the pressure-sensitive adhesive layer contains a gas generating agent, a method of generating gas from the gas generating agent by light irradiation to peel the pressure-sensitive adhesive layer, etc. can be mentioned.

Effects of the Invention

[0081] According to the present invention, there is provided a semiconductor processing laminate having a support, a double-sided adhesive tape, and a member to be processed in this order, in which peeling hardly occurs even at high temperatures during the processing step of the member to be processed, and the double-sided adhesive tape can be easily peeled while reducing contamination of the member to be processed after the completion of the step. Further, according to the present invention, a method for processing a member to be processed using the semiconductor processing laminate can be provided.

Modes for Carrying Out the Invention

[0082] Examples will be given below to explain the aspects of the present invention in more detail, but the present invention is not limited only to these examples.

[0083] (Synthesis of Acrylic Polymer A) A reactor equipped with a thermometer, a stirrer, and a cooling pipe was prepared, and into this reactor, 100 parts by weight in total of a monomer mixture and 80 parts by weight of ethyl acetate were added. As the monomer mixture, 79 parts by weight of 2-ethylhexyl acrylate (2EHA), 1 part by weight of acrylic acid (Aac), and 20 parts by weight of 2-hydroxyethyl acrylate (HEA) were used. This reactor was heated to initiate reflux. Subsequently, 0.05 part by weight of V-60 (2,2’-azobisisobutyronitrile, manufactured by Fujifilm Wako Pure Chemical Corporation) as a polymerization initiator was charged into the above reactor, and polymerization was initiated under reflux. Next, 0.15 part by weight of V-60 (2,2’-azobisisobutyronitrile, manufactured by Fujifilm Wako Pure Chemical Corporation) was charged 2 hours after the start of polymerization. The polymerization reaction was carried out for 8 hours under reflux from the start of polymerization to obtain a polymer-containing solution. To the reaction vessel, 10 ppm of hydroquinone was added to 100 parts by weight of the obtained polymer and heated to 60°C. Subsequently, 8 parts by weight of 2-methacryloyloxyethyl isocyanate (MOI) was dropped into the reaction vessel over 60 minutes, and the reaction was further carried out at 60°C for 120 minutes to obtain an acrylic polymer-containing solution. The obtained acrylic polymer-containing solution was diluted 50-fold with tetrahydrofuran (THF). The obtained diluted solution was filtered through a filter (material: polytetrafluoroethylene, pore size: 0.2 μm). The obtained filtrate was supplied to a gel permeation chromatograph (manufactured by Waters, 2690 Separations Model), and GPC measurement was carried out under the conditions of a sample flow rate of 1 mL / min and a column temperature of 40°C to measure the polystyrene-equivalent molecular weight of the acrylic polymer, and the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined. The weight-average molecular weight (Mw) was 520,000, and the molecular weight distribution (Mw / Mn) was 5.3. As the column, GPC KF-806L (manufactured by Showa Denko KK) was used, and as the detector, a differential refractometer was used.

[0084] (Synthesis of acrylic polymer B) An acrylic polymer-containing solution was obtained in the same manner as acrylic polymer A, except that the polymerization reaction was carried out at a reaction temperature of 60°C under a nitrogen atmosphere. When the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined in the same manner as for acrylic polymer A, the weight average molecular weight (Mw) was 1.48 million and the molecular weight distribution (Mw / Mn) was 4.1.

[0085] (Synthesis of acrylic polymer C) An acrylic polymer-containing solution was obtained in the same manner as for acrylic polymer A, except that 2-methacryloyloxyethyl isocyanate (MOI) was not reacted. When the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined in the same manner as for acrylic polymer A, the weight average molecular weight (Mw) was 520,000 and the molecular weight distribution (Mw / Mn) was 5.1.

[0086] (Synthesis of silicone compound (silicone-based graft copolymer)) A reactor equipped with a thermometer, a stirrer, and a condenser was prepared. Into this reactor, a total of 100 parts by weight of the monomer mixture and 80 parts by weight of ethyl acetate were added. As the monomer mixture, 10 parts by weight of a silicone macromonomer (one-terminal methacryloyl-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd., weight average molecular weight 4600), 80 parts by weight of 2-ethylhexyl acrylate (2EHA), and 10 parts by weight of 4-hydroxybutyl acrylate (4HBA) were used. This reactor was heated to initiate reflux. Subsequently, 0.1 part by weight of 2,2'-azobisisobutyronitrile (V-60, manufactured by Fujifilm Wako Pure Chemical Corporation) as a polymerization initiator was added into the above reactor, and polymerization was initiated under reflux. Next, 0.1 part by weight of 2,2'-azobisisobutyronitrile (V-60, manufactured by Fujifilm Wako Pure Chemical Corporation) was added even 1 hour after the start of polymerization, and further, 0.2 part by weight of 2,2'-azobisisobutyronitrile (V-60, manufactured by Fujifilm Wako Pure Chemical Corporation) was added 6 hours after the start of polymerization to continue the polymerization reaction. Then, 7 hours after the start of polymerization, an ethyl acetate solution of the silicone-based graft copolymer was obtained. When the weight average molecular weight (Mw) was determined in the same manner as for acrylic polymer A, the weight average molecular weight (Mw) was 60,000.

[0087] (Examples 1 to 17, Comparative Examples 1 to 3) (1) Preparation of Adhesive Solution Ethyl acetate was added to the acrylic polymer-containing solution and stirred with respect to 100 parts by weight of its non-volatile content. A crosslinking agent, a polymerization initiator, and a silicone compound were added and stirred as shown in Tables 1 to 3 to obtain an adhesive solution with a non-volatile content of 30% by weight. The following materials were used.

[0088] Epoxy-based crosslinking agent: Tetrad C (manufactured by Mitsubishi Gas Chemical Company) Isocyanate-based crosslinking agent: Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) Thermal polymerization initiator: Perbutyl O (manufactured by NOF Corporation) Photoinitiator: Omnirad 369 (manufactured by IGM Resins)

[0089] (2) Manufacture of Double-Sided Adhesive Tape The obtained adhesive solution was applied onto a release film with a doctor knife so that the thickness of the dry film was 20 μm (however, 15 μm in Example 2 and 40 μm in Example 4), and heated at 110°C for 5 minutes to dry the applied solution and form an adhesive layer. The obtained adhesive layer was transferred onto one surface of a film serving as a base material. Further, an adhesive layer was also transferred onto the other surface of the film serving as a base material in the same manner. Thereafter, it was allowed to stand and cure at 40°C for 3 days to obtain a double-sided adhesive tape. The following materials were used as the base material.

[0090] Polyimide A: Upilex (polyimide film, thermal expansion coefficient at 300°C of 13 ppm / °C, melting point of 300°C or higher, thickness of 20 μm, manufactured by Ube Industries, Ltd.) Polyimide B: Pomiran (polyimide film, thermal expansion coefficient at 300°C of 5 ppm / °C, melting point of 300°C or higher, thickness of 20 μm, manufactured by Arakawa Chemical Industries, Ltd.) Polyester: PEN (polyethylene naphthalate film, thermal expansion coefficient at 300°C is not measurable, melting point of 265°C, thickness of 20 μm, manufactured by Teijin Limited) Polyimide C: Kapton (polyimide film, thermal expansion coefficient at 300°C of 29 ppm / °C, melting point of 300°C or higher, thickness of 20 μm, manufactured by DuPont - Teijin Films Limited)

[0091] (3) Measurement of weight loss rate after heating After obtaining a measurement sample consisting only of the adhesive layer in the same manner as the production of the double-sided adhesive tape in (2) above, the weight was measured. Under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min), using a differential thermal thermogravimetric simultaneous measurement device (manufactured by Hitachi High-Technologies Corporation, TG-DTA; STA7200), the measurement sample was heated from 25°C to 300°C at a heating rate of 10°C / min. After reaching 300°C, it was maintained at 300°C and heated for 5 minutes. After cooling, the weight loss amount was measured, and the weight loss rate was calculated from the obtained weight loss amount and the weight before heating.

[0092] (4) Measurement of 180° peel strength The double-sided adhesive tape was cut into a width of 25 mm. Under an environment of room temperature 23°C and relative humidity 50%, the cut double-sided adhesive tape was attached to a silicon wafer (PC-300, manufactured by SUMCO Corporation) at a speed of 10 mm / sec using a 2 kg pressure-bonding rubber roller. Subsequently, a heat treatment at 300°C for 5 minutes was performed once. After cooling, in accordance with JIS Z0237, the double-sided adhesive tape was peeled off at a speed of 300 mm / min to measure the 180° peel strength. In Examples 1 to 13 and Comparative Examples 1 to 3, since the adhesive layer is thermosetting, a heat treatment at 150°C for 10 minutes was performed before the heat treatment at 300°C for 5 minutes to cure the adhesive layer. In Example 14, since the adhesive layer is photocuring, before the heat treatment at 300°C for 5 minutes, using a high-pressure mercury UV irradiator, ultraviolet rays of 405 nm were irradiated onto the adhesive layer so that the irradiation amount was 3000 mJ / cm 2 and a heat treatment at 150°C for 10 minutes was performed to cure the adhesive layer.

[0093] (5) Manufacture of laminate for semiconductor processing The adhesive layer on the side in contact with the support of the double-sided adhesive tape was attached to the support at a speed of 10 mm / sec using a 2-kg pressure rubber roller. Subsequently, the adhesive layer on the side in contact with the member to be processed of the double-sided adhesive tape was bonded to the member to be processed using a vacuum bonder, thereby obtaining a laminated body for semiconductor processing having a support, a double-sided adhesive tape, and a member to be processed in this order. Note that the following materials were used as the support and the member to be processed.

[0094] Tempax: Borosilicate glass (thermal expansion coefficient at 300 °C: 3 ppm / °C, manufactured by Shot Co., Ltd.) Soda glass: Soda glass (thermal expansion coefficient at 300 °C: 9 ppm / °C, manufactured by AGC Inc.) Quartz glass: Quartz glass (thermal expansion coefficient at 300 °C: 1 ppm / °C, manufactured by AGC Inc.) Si: Silicon wafer (thermal expansion coefficient at 300 °C: 4 ppm / °C, manufactured by SUMCO Corporation) Upilex: Polyimide film (thermal expansion coefficient at 300 °C: 13 ppm / °C, manufactured by Ube Industries, Ltd.)

[0095] <Evaluation> The laminated bodies for semiconductor processing obtained in the examples and comparative examples were evaluated by the following method. The results are shown in Tables 1 to 3.

[0096] (1) Evaluation of peel resistance (300 °C) After manufacturing the laminated body for semiconductor processing, in the case of a thermosetting adhesive layer containing a thermal polymerization initiator, heat treatment was performed at 150 °C for 10 minutes to cure the adhesive layer. In the case of a photocuring adhesive layer containing a photoinitiator, ultraviolet light with a wavelength of 405 nm was irradiated onto the adhesive layer until the irradiation dose reached 3000 mJ / cm 2 and then heat treatment was performed at 150 °C for 10 minutes to cure the adhesive layer. Subsequently, heat treatment was performed once at 300 °C for 5 minutes, 15 minutes, 30 minutes, or 6 minutes. After the heat treatment, the state of the laminated body for semiconductor processing was checked, and ○ was indicated when no peeled portion was present, and × was indicated when a peeled portion was present.

[0097] (2) Evaluation of contaminability In the evaluation of the above-mentioned (1) peel resistance (300 °C), after performing a heat treatment at a temperature of 300 °C for 5 minutes once, the treated member after peeling the double-sided adhesive tape was visually observed, and the residue was evaluated. When no residue was observed on the treated member, it was indicated as ○; when residue was observed only at the edge portion of the treated member, it was indicated as △; and when residue was observed not only at the edge portion but also elsewhere, it was indicated as ×.

[0098]

Table 1

[0099]

Table 2

[0100]

Table 3

Industrial Applicability

[0101] According to the present invention, there is provided a laminated body for semiconductor processing having a support, a double-sided adhesive tape, and a treated member in this order, in which peeling is less likely to occur even at a high temperature during the processing step of the treated member, and the double-sided adhesive tape can be easily peeled off while reducing the contamination of the treated member after the completion of the step. Further, according to the present invention, a method for treating a treated member using the laminated body for semiconductor processing can be provided.

Claims

1. A laminate for semiconductor processing having a support, a double-sided adhesive tape, and a member to be processed in this order, wherein the double-sided adhesive tape has a base material and adhesive layers laminated on both sides of the base material, the base material has a difference in coefficient of thermal expansion at 300 °C from the support of 10 ppm / °C or less and a difference in coefficient of thermal expansion at 300 °C from the member to be processed of 12 ppm / °C or less, and a melting point of 300 °C or higher, and the double-sided adhesive tape has a peel strength in the 180° direction of 0.01 N / 25 mm or more after being attached to a silicon wafer with the adhesive layer on the side contacting the member to be processed and heated at 30,0 °C for 5 minutes. A laminate for semiconductor processing, characterized by the above.

2. The laminate for semiconductor processing according to claim 1, wherein the adhesive layer of the double-sided adhesive tape has a weight loss rate of 3% by weight or less after being heated at 300 °C for 5 minutes as measured using a differential thermal thermogravimetric simultaneous measurement device.

3. The laminate for semiconductor processing according to claim 1 or 2, wherein the adhesive layer of the double-sided adhesive tape is a curable adhesive layer that can be post-cured by heating or light irradiation.

4. The laminate for semiconductor processing according to claim 1, 2, or 3, wherein the double-sided adhesive tape has a peel strength in the 180° direction of 0.5 N / 25 mm or less after being attached to a silicon wafer with the adhesive layer on the side contacting the member to be processed and heated at 300 °C for 5 minutes.

5. The laminate for semiconductor processing according to claim 1, 2, 3, or 4, wherein the double-sided adhesive tape has a thickness of 60 μm or more.

6. The laminate for semiconductor processing according to claim 1, 2, 3, 4, or 5, wherein the base material of the double-sided adhesive tape has a difference in coefficient of thermal expansion at 300 °C from the member to be processed of 10 ppm / °C or less.

7. The laminate for semiconductor processing according to claim 1, 2, 3, 4, 5, or 6, wherein the support is glass and the member to be processed is a silicon wafer.

8. The laminate for semiconductor processing according to claim 1, 2, 3, 4, 5, 6, or 7, which is used in a processing step of a member to be processed that involves heating the surface of the member to be processed to 250 °C or higher.

9. A method for processing a member to be processed using the laminate for semiconductor processing according to claim 1, 2, 3, 4, 5, 6, 7, or 8, the method comprising a processing step of performing a process involving heating the surface of the member to be processed of the laminate for semiconductor processing to 250 °C or higher, A peeling step of peeling the support and the member to be processed, and A method for processing a member to be processed, characterized by the above.

Images