JP5525779B2 - Adhesive composition and adhesive film - Google Patents

Description

  The present invention relates to an adhesive composition and an adhesive film. More specifically, an adhesive composition and an adhesive film for temporarily fixing a sheet or a protective substrate to the semiconductor product in a process of grinding or other processing of a semiconductor product such as a semiconductor wafer or an optical system product It is about.

  In recent years, with the enhancement of functions of mobile phones, digital AV devices, IC cards, and the like, there is an increasing demand for downsizing, thinning, and high integration of semiconductor silicon chips (hereinafter referred to as chips). For example, an integrated circuit that integrates a plurality of chips into one package such as CSP (chip size package) and MCP (multi-chip package) is required to be thin. Among them, the system-in-package (SiP) in which a plurality of semiconductor chips are mounted in one semiconductor package makes the mounted chip smaller, thinner and highly integrated, and enhances the performance of electronic devices. It has become a very important technology for realizing miniaturization and weight reduction.

  In order to meet the needs for thin products, it is necessary to make the chip as thin as 150 μm or less. Further, it is necessary to thin the chip to 100 μm or less for CSP and MCP and 50 μm or less for IC card.

  Conventionally, a method of wiring bumps (electrodes) for each stacked chip and a circuit board by wire bonding technology is used for SiP products. In addition, in order to meet such demands for thinning and high integration, instead of wire bonding technology, it is necessary to use a through electrode technology in which chips with through electrodes are stacked and bumps are formed on the back surface of the chip. It becomes.

  For example, a thin chip is obtained by slicing a high-purity silicon single crystal or the like into a wafer, etching a predetermined circuit pattern such as an IC on the wafer surface, incorporating an integrated circuit, and mounting the back surface of the obtained semiconductor wafer. It is manufactured by grinding with a grinder and dicing the semiconductor wafer after grinding to a predetermined thickness to form chips. At this time, the predetermined thickness is about 100 to 600 μm. Furthermore, when forming a penetration electrode, it grinds to about 50-100 micrometers in thickness.

  In the manufacture of semiconductor chips, the semiconductor wafer itself is thin and fragile, and the circuit pattern has irregularities, so that it is easily damaged when an external force is applied during conveyance to a grinding process or a dicing process. Further, in the grinding process, grinding is performed while removing generated polishing debris and washing the back surface of the semiconductor wafer with purified water in order to remove heat generated during polishing. At this time, it is necessary to prevent the circuit pattern surface from being contaminated by the purified water used for cleaning.

  Therefore, in order to protect the circuit pattern surface of the semiconductor wafer and prevent damage to the semiconductor wafer, a grinding operation is performed after a processing adhesive film is attached to the circuit pattern surface.

  During dicing, a protective sheet is attached to the back side of the semiconductor wafer, the dicing is performed with the semiconductor wafer adhered and fixed, and the resulting chip is picked up by a needle from the film base and picked up and fixed on the die pad. ing.

  Examples of such processing adhesive films and protective sheets include adhesive compositions on base films such as polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and ethylene-vinyl acetate copolymer (EVA). Those provided with an adhesive layer formed from an object are known (for example, Patent Document 1, Patent Document 2, and Patent Document 3).

  In addition, instead of a processing adhesive film or protective sheet, a protective substrate in which a ladder-type silicone oligomer is impregnated with an aluminum nitride-boron nitride pore sintered body is used, and this protective substrate and a semiconductor wafer are bonded using a thermoplastic film. The structure which does is also disclosed (patent document 4). In addition, a material such as alumina, aluminum nitride, boron nitride, or silicon carbide having a thermal expansion coefficient substantially the same as that of the semiconductor wafer is used as the protective substrate, and a thermoplastic such as polyimide is used as an adhesive for bonding the protective substrate and the semiconductor wafer. As a method of applying this adhesive using a resin, there are proposed a configuration in which the film has a thickness of 10 to 100 μm and a method in which the adhesive composition is spin-coated and dried to form a film of 20 μm or less ( Patent Document 5).

  In addition, with the multi-layer wiring of semiconductor elements, a protective substrate is adhered to the surface of a semiconductor wafer on which a circuit is formed using an adhesive composition, the back surface of the semiconductor wafer is polished, and then the polished surface is etched. A process of forming a back surface circuit on the mirror surface is performed. In this case, the protective substrate remains adhered until the back side circuit is formed (Patent Document 6).

JP 2003-173993 A (released on June 20, 2003) JP 2001-279208 A (released on October 10, 2001) JP 2003-292931 A (released on October 15, 2003) JP 2002-203821 (published July 19, 2002) JP 2001-77304 A (published March 23, 2001) JP-A-61-158145 (released July 17, 1986)

  However, the above-mentioned pressure-sensitive adhesive film for processing or the like is used for a process requiring a high-temperature process and a high-vacuum process, such as the formation of a through electrode, and the adhesive strength is insufficient in a high-temperature environment, There is a problem of adhesion failure due to generation of gas, etc., and a problem of peeling failure such as residue remaining at the time of peeling after the high temperature process.

  For example, in the formation of the through electrode, when bumps are formed on the semiconductor chips and then the semiconductor chips are connected, a process of heating to about 200 ° C. and further making a high vacuum state is required. However, the adhesive composition constituting the adhesive layer of the protective tape according to Patent Document 1 and Patent Document 2 has no resistance to high temperatures of 200 ° C. Moreover, since gas is generated in the adhesive layer by heating, adhesion failure occurs.

  Further, a thin semiconductor wafer needs to be peeled off from the protective substrate after grinding or dicing. However, the adhesive composition constituting the adhesive layer of the protective tape disclosed in Patent Document 3 is an epoxy resin composition, and the epoxy resin is altered and cured at a high temperature of 200 ° C. There is a problem that a residue remains and peeling failure occurs.

  Furthermore, in the thermoplastic film used for adhesion | attachment of a protective substrate and a semiconductor wafer based on the said patent document 4 or the said patent document 5, since the gas derived from the moisture which absorbed moisture is produced, the problem of adhesion failure arises. In the method for processing a semiconductor substrate according to Patent Document 6, a mirror surface process using an etching solution or a metal film formation by vacuum deposition is performed. Therefore, an adhesive composition for bonding a protective substrate and a semiconductor wafer has a heat resistance. And releasability are required. However, the above Patent Document 6 does not disclose the composition of the adhesive composition at all.

  Further, in the investigation by the present inventors, an adhesive using an acrylic resin material is preferable in processing of a semiconductor wafer or a chip because of good crack resistance. However, it has been found that an adhesive using such an acrylic resin material has the following problems.

  (1) When the adhesive layer and the protective substrate are subjected to thermocompression bonding, the moisture absorbed by the adhesive layer becomes a gas and foam-like peeling occurs at the adhesive interface, so that the adhesive strength in a high temperature environment is low. In addition, the generation of such gas not only lowers the adhesive strength in a high temperature environment, but also hinders the creation or maintenance of the vacuum environment when performing a processing process or the like under vacuum conditions.

  (2) When heated to about 200 ° C., the adhesive composition is denatured due to low heat resistance, resulting in poor peeling such as formation of an insoluble substance in the stripping solution.

  (3) When heat treatment is performed at about 250 ° C. at the time of peeling, gas is generated when the adhesive composition is dissolved, and peeling failure occurs.

  The present invention has been made in view of the above-mentioned problems, and its object is to have high heat resistance and high adhesive strength in a high temperature environment, particularly at 200 ° C. or higher, and a semiconductor wafer and chip. Another object of the present invention is to provide an adhesive composition excellent in ease of peeling, which has high solubility in heat treatment at the time of peeling from, etc. and suppresses the generation of gas.

  A first aspect of the present invention is an adhesive composition comprising a copolymer formed by living anion polymerization of two or more types of monomers.

  A second aspect of the present invention is an adhesive film comprising an adhesive layer containing the adhesive composition according to the present invention on a film.

  According to the adhesive composition of the present invention, as described above, since it contains a copolymer formed by living anion polymerization of two or more monomers, high heat resistance and high in a high temperature environment It is possible to provide an adhesive composition that has adhesive strength and that has high solubility and suppresses gas generation in heat treatment at the time of peeling from a semiconductor wafer, a chip, and the like, and is excellent in ease of peeling. There is an effect.

  Moreover, the adhesive film which concerns on this invention is equipped with the adhesive bond layer containing the said adhesive composition on a film as mentioned above. Therefore, it has high heat resistance and high adhesive strength under high temperature environment, and has high solubility in heat treatment at the time of peeling from semiconductor wafers and chips, etc. There exists an effect that an adhesive film can be provided.

  An embodiment of the present invention will be described as follows. It should be noted that the scope of the present invention is not limited to these descriptions, and other than the following examples, the scope of the present invention can be appropriately changed and implemented without departing from the spirit of the present invention.

[Adhesive composition]
The adhesive composition according to the present embodiment includes a copolymer obtained by living anion polymerization of two or more types of monomers.

  The copolymer of the present embodiment is preferably a block polymer obtained by living anion polymerization of two or more types of monomers.

  Living anionic polymerization is a polymerization method in which a monomer is living polymerized by an anionic polymerization method. By subjecting two or more types of monomers to living anion polymerization, a block polymer having a molecular weight distribution lower than that of a polymer obtained by a conventional polymerization method can be obtained. A block polymer having a low molecular weight distribution has high solubility in a high temperature environment, has crack resistance, and generates almost no gas. Therefore, the adhesive composition containing such a block polymer as a copolymer has high solubility and gas resistance even in heat treatment at the time of peeling from a semiconductor wafer, a chip, etc., especially at about 250 ° C. for 1 hour. In order to suppress the occurrence of, the ease of peeling is excellent.

  As a method of living anion polymerization in the present embodiment, a known method can be used, for example, an anion polymer production method described in International Publication No. 2005/121189 pamphlet can be used.

  Further, the molecular weight of the copolymer can be adjusted by adjusting the length of the polymerization reaction time or the like.

  As the polymer obtained by living anionic polymerization, a block polymer having a linear structure, a block polymer having a star structure (block star polymer), and the like are preferable.

  For example, it is preferable to use a block polymer having a linear structure in the adhesive composition because it has crack resistance and high adhesive strength.

  In addition, for example, if a block star polymer is used for the adhesive composition, it has crack resistance and is highly soluble because it is decomposed under a high temperature environment and the weight average molecular weight is reduced, and it hardly generates gas. preferable.

  The molecular weight distribution (Mw / Mn) in the copolymer is more preferably 1.01 or more and 2.00 or less. The molecular weight distribution is obtained by dividing the weight average molecular weight (Mw) by the number average molecular weight (Mn).

  Although it does not specifically limit as a monomer, For example, it is more preferable that at least 1 type in a monomer contains at least 1 type selected from the group which consists of styrene and its derivative (s). Specific examples include p-hydroxystyrene and styrene.

  Since p-hydroxystyrene, styrene and the like do not deteriorate even under a high temperature environment of 200 ° C. or higher, the heat resistance of the adhesive composition is improved by including them. The proportion of p-hydroxystyrene in the total amount of two or more types of monomers contained in the copolymer is preferably 5 mol% or more and 80 mol% or less, and is preferably 10 mol% or more and 70 mol% or less. Is more preferable. If it is 5 mol% or more, the cracking property and heat resistance are improved, and if it is 80 mol% or less, the solubility is good. Moreover, it is more preferable that the proportion of styrene in the total amount of two or more types of monomers contained in the copolymer is 10 mol% or more and 90 mol% or less. If it is said structure, since the heat resistance and heat-resistant solubility of an adhesive composition become favorable and also hardly generate gas, it is preferable.

  Moreover, it is preferable that at least 1 type of a monomer contains (meth) acrylic acid ester. Examples of the (meth) acrylic acid ester include a (meth) acrylic acid alkyl ester having a chain structure, a (meth) acrylic acid ester having an aliphatic ring, and a (meth) acrylic acid ester having an aromatic ring. .

  Examples of the (meth) acrylic acid alkyl ester having a chain structure include an acrylic long-chain alkyl ester having an alkyl group having 15 to 20 carbon atoms and an acrylic alkyl ester having an alkyl group having 1 to 14 carbon atoms. .

  As acrylic long-chain alkyl esters, acrylic or methacrylic acid whose alkyl group is n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, etc. Examples include alkyl esters. The alkyl group may be branched.

  Examples of the acrylic alkyl ester having an alkyl group having 1 to 14 carbon atoms include known acrylic alkyl esters used in existing acrylic adhesives. For example, an alkyl group of acrylic acid or methacrylic acid in which the alkyl group is a methyl group, ethyl group, propyl group, butyl group, 2-ethylhexyl group, isooctyl group, isononyl group, isodecyl group, dodecyl group, lauryl group, tridecyl group, etc. Examples include esters.

  Examples of (meth) acrylic acid ester having an aliphatic ring include cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, 1-adamantyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, and tricyclodecanyl. (Meth) acrylate, tetracyclododecanyl (meth) acrylate and the like can be mentioned, and isobornyl methacrylate is more preferable.

  The (meth) acrylic acid ester having an aromatic ring is not particularly limited. Examples of the aromatic ring include a phenyl group, a benzyl group, a tolyl group, a xylyl group, a biphenyl group, a naphthyl group, and an anthracenyl group. A phenoxymethyl group, a phenoxyethyl group, and the like. The aromatic ring may have a chain or branched alkyl group having 1 to 5 carbon atoms. Specifically, phenoxyethyl acrylate is preferable. If the (meth) acrylic acid ester having an aromatic ring is used, the flexibility of the resulting adhesive composition can be further improved. That is, the desired flexibility can be obtained with a small amount. Therefore, the amount of the component that improves the glass transition temperature of the adhesive composition can be increased, and an adhesive composition having high flexibility and high adhesive strength in a high temperature environment can be obtained.

  When (meth) acrylic acid ester is used together with another monomer, the amount of (meth) acrylic acid ester is not limited as long as the copolymerization reaction proceeds with the other monomer. For example, it may be appropriately determined according to the properties of the adhesive composition such as the intended adhesive strength and heat resistance, but is preferably 5 mol% or more and 50 mol% or less with respect to the total amount of monomers. More preferably, it is at least 40% by mole. By setting it as 5 mol% or more, crack tolerance improves, and heat resistance improves by setting it as 50 mol% or less.

  When a block star polymer is used as the copolymer, a polymer chain having at least one repeating unit selected from the group consisting of styrene and a derivative thereof of a specific amount or more and a repeating unit of (meth) acrylate ester is armed. It is preferable to use a block star polymer having a polymer chain derived from polyacrylate as a core part and excellent effects of the present invention.

  In this case, examples of at least one selected from the group consisting of styrene and its derivatives include the same as those described above. Moreover, as (meth) acrylic acid ester, the thing similar to what was mentioned above is mentioned.

  There are no particular restrictions on the manner of bonding of the repeating units in the arm part, and specific examples include random bonds, block bonds, alternating bonds, or graft bonds, and in particular, block bonds. Is preferred.

  As the polyacrylate, a repeating unit derived from a monomer represented by the following general formula (I) can be used.

(In the above formula (I), (A) represents an n-valent linking group, R ₁ represents a hydrogen atom or a methyl group, and n represents an integer of 2 or more.)
Specifically, ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate Or trimethylolpropane trimethacrylate and the like. The amount of polyacrylate is preferably 0.5 mol% or more and 10 mol% or less, more preferably 1 to 5 mol%, based on the total amount of monomers. By setting it within the above range, the effect of the present invention is excellent.

  The adhesive composition according to the present embodiment may contain a thermal polymerization inhibitor, acrylamide such as dimethylacrylamide, morpholine such as acryloylmorpholine, and the like as other additive components. With these formulations, simultaneous improvement in heat resistance and adhesiveness can be expected.

  Here, the thermal polymerization inhibitor will be described below.

(Thermal polymerization inhibitor)
The thermal polymerization inhibitor is a substance effective for preventing radical polymerization reaction due to heat. Thermal polymerization inhibitors are highly reactive with radicals and react preferentially over monomers, so that polymerization is prohibited. Therefore, the adhesive composition containing the thermal polymerization inhibitor suppresses the polymerization reaction of the adhesive composition under a high temperature environment (particularly 250 ° C. to 350 ° C.). Thereby, even if it passes through the high temperature process heated at 250 degreeC for 1 hour, an adhesive composition can be melt | dissolved easily. Therefore, the adhesive layer formed by the adhesive composition can be easily peeled even after a high temperature process, and the generation of residues can be suppressed.

  The thermal polymerization inhibitor is not particularly limited as long as it is effective for preventing heat-induced radical polymerization reaction, but a phenol-based thermal polymerization inhibitor is preferable.

  Examples of the thermal polymerization inhibitor include pyrogallol, benzoquinone, hydroquinone, methylene blue, tert-butylcatechol, monobenzyl ether, methylhydroquinone, amylquinone, amyloxyhydroquinone, n-butylphenol, phenol, hydroquinone monopropyl ether, 4,4′- (1-methylethylidene) bis (2-methylphenol), 4,4 ′-(1-methylethylidene) bis (2,6-dimethylphenol), 4,4 ′-[1- [4- (1- ( 4-hydroxyphenyl) -1-methylethyl) phenyl] ethylidene] bisphenol, 4,4 ′, 4 ″ -ethylidenetris (2-methylphenol), 4,4 ′, 4 ″ -ethylidenetrisphenol, 1,1, 3-Tris (2,5-dimethyl-4-hydroxyphen ) -3-phenylpropane, 2,6-di-tert-butyl-4-methylphenol, 2,2'-methylenebis (4-methyl-6-tertbutylphenol), 4,4'-butylidenebis (3-methyl) -6-tertbutylphenol), 4,4'-thiobis (3-methyl-6-tertbutylphenol), 3,9-bis [2- (3- (3-tertbutyl-4-hydroxy-5-methylphenyl) -Propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro (5,5) undecane, triethylene glycol-bis-3- (3-tertbutyl-4-hydroxy-5 -Methylphenyl) propionate, n-octyl-3- (3,5-di-tertbutyl-4-hydroxyphenyl) propionate , Pentaerythryltetrakis [3- (3,5-di-tertbutyl-4-hydroxyphenyl) propionate] (trade name IRGANOX 1010, manufactured by Ciba Specialty Chemicals), tris (3,5-di-tertbutylhydroxybenzyl) Examples include isocyanurate and thiodiethylenebis [3- (3,5-ditertbutyl-4-hydroxyphenyl) propionate]. Among these, a phenol-based thermal polymerization inhibitor is preferable.

  The content of the thermal polymerization inhibitor may be appropriately determined according to the polymer contained as the main component and the application and use environment of the adhesive composition, but is 0.1% by mass relative to the polymer contained as the main component. It is preferably 10.0% by mass or less, more preferably 0.5% by mass or more and 7.0% by mass or less, and most preferably 1.0% by mass or more and 5.0% by mass. It is as follows. By making it within the above range, the effect of suppressing polymerization due to heat is satisfactorily exhibited, and it is possible to further facilitate the peeling of the adhesive layer after the high temperature process. Moreover, generation | occurrence | production of a crack can be prevented by setting it as the said range.

  The adhesive composition according to the present embodiment further includes miscible additives such as additional resins, plastics for improving the performance of the adhesive, as long as the essential characteristics of the present invention are not impaired. Commonly used agents such as an agent, an adhesion assistant, a stabilizer, a colorant, and a surfactant can be added.

  Furthermore, the adhesive composition may be diluted with an organic solvent for viscosity adjustment within a range that does not impair the essential characteristics of the present invention. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, and dipropylene. Polyhydric alcohols such as glycol or dipropylene glycol monoacetate monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof; cyclic ethers such as dioxane; and methyl lactate, ethyl lactate, Methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, etho It can be mentioned esters such Shipuropion ethyl. These may be used alone or in combination of two or more. In particular, ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol or dipropylene glycol monoacetate monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl Polyhydric alcohols such as ether and derivatives thereof are preferred.

  The amount of the organic solvent used is appropriately set according to the film thickness to which the adhesive composition is applied, and is particularly limited as long as the adhesive composition can be applied onto a support such as a semiconductor wafer. It is not something. Generally, it is used so that the solid content concentration of the adhesive composition is in the range of 20 to 70% by mass, preferably 25 to 60% by mass.

[Adhesive film]
The adhesive composition according to the present embodiment described above can be used in various ways depending on the application. For example, a method of forming an adhesive layer by applying on a workpiece such as a semiconductor wafer in a liquid state may be used, or an adhesive film according to the present invention, that is, a film such as a flexible film in advance. After forming an adhesive layer containing any one of the above-mentioned adhesive compositions on the top, it is allowed to dry, and this film (adhesive film) is attached to a workpiece (adhesive film method). It may be used.

  Thus, the adhesive film which concerns on this invention is equipped with the adhesive bond layer containing one of said adhesive composition on a film.

  Therefore, it is possible to obtain an adhesive film having high adhesive strength in a high temperature environment, high heat resistance, and excellent peelability.

  The adhesive film may be used by further covering the adhesive layer with a protective film. In this case, the protective film on the adhesive layer is peeled off, the exposed adhesive layer is stacked on the workpiece, and then the adhesive layer is formed on the workpiece by peeling the film from the adhesive layer. It can be easily provided.

  Therefore, if the above adhesive film is used, a layer with better film thickness uniformity and surface smoothness can be formed compared to the case where the adhesive composition is formed directly by applying the adhesive composition on the workpiece. can do.

  Moreover, as said film used for manufacture of the said adhesive film, the adhesive bond layer formed on the film can be peeled from a film, and an adhesive bond layer is transcribe | transferred on to-be-processed surfaces, such as a protective substrate and a wafer. It is not limited as long as it is a release film. For example, the flexible film which consists of synthetic resin films, such as a polyethylene terephthalate with a film thickness of 15-125 micrometers, polyethylene, a polypropylene, a polycarbonate, a polyvinyl chloride, is mentioned. If necessary, the film is preferably subjected to a release treatment so as to facilitate transfer.

  As a method for forming the adhesive layer on the film, a known method may be appropriately used according to the desired film thickness and uniformity of the adhesive layer, and is not limited. For example, an applicator, A method of applying the adhesive composition according to the present invention using a bar coater, a wire bar coater, a roll coater, a curtain flow coater or the like so that the dry film thickness of the adhesive layer is 10 to 1000 μm on the film. Is mentioned. Among these, a roll coater is preferable because it is excellent in film thickness uniformity and a thick film can be efficiently formed.

  Moreover, when using the said protective film, as said protective film, although not limited as long as it can peel from the said adhesive bond layer, a polyethylene terephthalate film, a polypropylene film, a polyethylene film is preferable, for example. Each of the protective films is preferably coated or baked with silicon. This is because peeling from the adhesive layer becomes easy. Although the thickness of the said protective film is not specifically limited, 15-125 micrometers is preferable. It is because the softness | flexibility of the said adhesive film provided with the protective film is securable.

  The method of using the adhesive film is not particularly limited. For example, when a protective film is used, the film is peeled off and the exposed adhesive layer is overlaid on the workpiece to form a film. A method of thermocompression bonding the adhesive layer to the surface of the workpiece by moving the heating roller from above (the back surface of the surface on which the adhesive layer is formed) can be mentioned. At this time, the protective film peeled off from the adhesive film can be stored and reused by winding it in a roll with a winding roller or the like.

  The use of the adhesive composition and the adhesive film of the present invention is not particularly limited as long as it is used for bonding applications, but for the purpose of bonding a protective substrate for precision processing of a semiconductor wafer to a substrate such as a semiconductor wafer, It can be used suitably. In particular, when a substrate such as a semiconductor wafer is ground and thinned, it can be suitably used as an adhesive for adhering the substrate to a support plate (for example, JP-A-2005-191550).

[Stripping solution]
As the remover for removing the adhesive composition according to the present invention, a commonly used remover can be used. In particular, propylene glycol monomethyl ether acetate (hereinafter referred to as “PGMEA”), ethyl acetate, A stripping solution containing methyl ethyl ketone as the main component is preferable in terms of environmental load and stripping property.

  Examples of the adhesive composition according to the present invention will be described below.

[Examples 1 to 10]
Resins 1 to 10 constituting the adhesive compositions in Examples 1 to 10 and Examples 11 to 14 to be described later were synthesized using the method shown below. In addition, the mass average molecular weight (Mw) and dispersity (Mw / Mn) were calculated | required on the polystyrene conversion reference | standard by gel permeation chromatography (GPC). The composition ratio (molar ratio) of the resin was analyzed by ¹³ C-NMR.

(Synthesis of resin 1: block star polymer)
Under a nitrogen atmosphere, toluene (480 g), THF (130 g) and styrene (ST) (61.3 g; 589 mmol) were added to the flask and cooled to −40 ° C. N-Butyllithium (n-BuLi) solution (2.44 g; 6 mmol) was added to this solution and stirred for 25 minutes. Then, diphenylethylene (1.2 g; 7 mmol) was added and stirred for 10 minutes. Next, a solution of methyl methacrylate (MMA) (14.7 g; 147 mmol), diethylzinc hexane solution (5.12 g; 7 mmol), and lithium chloride (6.72 g; 6 mmol) in THF (30 g) was added for 5 minutes. After dropping, the mixture was stirred for 15 minutes. Subsequently, a solution obtained by adding ethylene glycol dimethacrylate (EGMA) (3.46 g; 18 mmol) and diethylzinc hexane solution (3.67 g; 5 mmol) to THF (30 g) was added dropwise over 5 minutes, followed by stirring for 30 minutes. . The reaction solution was stirred for 140 minutes while warming to room temperature, and methanol was added to kill it. The reaction solution was added to a large amount of methanol, and the precipitated polymer was filtered and dried. Next, this polymer was made into a 15 wt% THF solution, and the tar-like substance obtained by washing with methanol three times was dissolved again in THF to obtain a 20 wt% solution. This solution was added to a large amount of methanol, and the precipitated polymer was filtered and dried.

  As a result of analyzing the obtained polymer by GPC (RI), it was Mw = 155200 and dispersion degree = 1.09. Moreover, it was ST / MMA / EGMA = 79/19/2 (mol%).

(Synthesis of Resin 2: Block polymer having a linear structure)
Under a nitrogen atmosphere, toluene (480 g), THF (180 g) and ST (62.0 g; 595 mmol) were added and cooled to −40 ° C. An n-BuLi solution (1.38 g; 3 mmol) was added to this solution and stirred for 30 minutes. Then, diphenylethylene (0.66 g; 4 mmol) was added and stirred for 10 minutes. Next, a solution of MMA (15.1 g; 151 mmol), diethylzinc hexane solution (5.44 g; 7 mmol), and lithium chloride (3.55 g; 3 mmol) in THF (30 g) was added dropwise over 5 minutes. Thereafter, the mixture was stirred for 75 minutes, and methanol was added to stop the reaction. Ethyl acetate was added to the resulting reaction solution and washed three times with water, and the solvent was replaced with THF to obtain a 15 wt% solution. This solution was added to a large amount of methanol, and the precipitated polymer was filtered and dried.

  As a result of analyzing the obtained polymer by GPC (RI), it was Mw = 45400 and dispersion degree = 1.15. Moreover, it was ST / MMA = 82/18 (mol%).

(Synthesis of resin 3: block polymer having linear structure)
Under a nitrogen atmosphere, toluene (480 g), THF (120 g) and ST (60.3 g; 579 mmol) were added and cooled to −40 ° C. An n-BuLi solution (2.20 g; 5 mmol) was added to this solution and stirred for 30 minutes. Then, diphenylethylene (1.09 g; 6 mmol) was added and stirred for 10 minutes. Next, a solution obtained by adding MMA (15.0 g; 150 mmol), diethylzinc hexane solution (5.06 g; 7 mmol), and lithium chloride (6.42 g; 6 mmol) to THF (30 g) was dropped over 5 minutes. Thereafter, the mixture was stirred for 90 minutes, and methanol was added to stop the reaction. Ethyl acetate was added to the resulting reaction solution and washed three times with water, and the solvent was replaced with THF to obtain a 15 wt% solution. This solution was added to a large amount of methanol, and the precipitated polymer was filtered and dried.

  As a result of analyzing the obtained polymer by GPC (RI), it was Mw = 19700 and dispersity = 1.05. Moreover, it was ST / MMA = 81/19 (mol%).

(Synthesis of resin 4: block polymer having linear structure)
Under a nitrogen atmosphere, THF (450 g), lithium chloride (1.67 g; 2 mmol), and an n-BuLi solution (2.41 g; 6 mmol) were added at room temperature, and the mixture was stirred for 20 minutes. Cool to −40 ° C., add n-BuLi solution (1.61 g; 4 mmol), then add diethylzinc hexane solution (2.17 g; 3 mmol), and finally add ST (31.4 g; 302 mmol). An n-BuLi solution (0.22 g; 0.5 mmol) was added to this solution and stirred for 10 minutes. Then, diphenylethylene (0.46 g; 3 mmol) was added and stirred for 10 minutes. Next, a solution obtained by adding MMA (7.35 g; 73 mmol) and diethylzinc hexane solution (1.00 g; 1 mmol) to THF (30 g) was added dropwise over 5 minutes, followed by stirring for 60 minutes and addition of methanol. The reaction was stopped. Toluene and ethyl acetate were added to the obtained reaction solution and washed 6 times with water, and then the solvent was replaced with THF to obtain a 12 wt% solution. This solution was added to a large amount of methanol, and the precipitated polymer was filtered and dried.

  As a result of analyzing the obtained polymer by GPC (RI), it was Mw = 78800 and dispersity = 1.06. Moreover, it was ST / MMA = 82/18 (mol%).

(Synthesis of resin 5: block polymer having linear structure)
Under a nitrogen atmosphere, THF (500 g) and 2-mercaptothiazoline (0.12 g: 1 mmol) were placed in a flask, and while stirring with a stirrer, an n-BuLi solution (1.67 g; 4 mmol) was added at room temperature for 15 minutes. Stir. Subsequently, the mixture was cooled to −40 ° C., an n-BuLi solution (0.68 g; 2 mmol) was added, p-tert-butoxystyrene (PTBST) (31.03 g; 176 mmol), ST (18.73 g) was added to THF (60 g). 180 mmol) and dibutylmagnesium hexane solution (1.19 g; 2 mmol) were added dropwise over 30 minutes. After completion of the addition, dibutylmagnesium hexane solution (0.85 g; 1 mmol) was added and stirred for 15 minutes. Subsequently, a solution obtained by adding diphenylethylene (0.37 g; 2 mmol) and dibutylmagnesium hexane solution (0.32 g; 0.5 mmol) to a 3.79% lithium chloride THF solution (5.73 g: 5 mmol) was added over 2 minutes. The mixture was added dropwise and stirred for 15 minutes after the completion of the addition. Thereafter, the mixture was cooled to −50 ° C., and a solution of MMA (8.99 g; 90 mmol) and diethylzinc hexane solution (1.00 g; 1 mmol) in THF (10 g) was added dropwise over 7 minutes. Stir for minutes and kill by adding methanol. The obtained killing liquid was measured by gas chromatography, but PTBST, ST and MMA were not observed.

  Then, after concentrating the killing solution, ethyl acetate (800 g) was added, and the solution was washed and separated three times with pure water (400 g). The upper layer was concentrated, diluted with THF (150 g), dropped into methanol (800 g) with stirring to precipitate a polymer, stirred for 1 hour, filtered, and dried under reduced pressure at 40 ° C. The dry polymer (100 g) was dissolved in a mixed solvent of toluene / ethanol (35/65 wt%) to 35%, 25% concentrated hydrochloric acid (40 g) was added, and the mixture was heated and stirred at 70 ° C. for 4 hours. Ethyl acetate (500 g) was added to the cooled solution, neutralized with sodium hydrogen carbonate, and washed with pure water (250 g) three times. After the upper layer was concentrated, THF (250 g) was added, and the mixture was added dropwise to hexane (5 kg) with stirring to precipitate the polymer, stirred for 1 hour, filtered, and dried under reduced pressure at 40 ° C.

The result of analyzing the obtained polymer by GPC is Mw = 85300, the dispersion degree = 1.19, and the result of analyzing the composition ratio by ¹³ C-NMR is that p-hydroxystyrene (PHS) is 41 mol%, ST was 41 mol% and MMA was 18 mol%.

(Synthesis of resin 6: block polymer having linear structure)
Under a nitrogen atmosphere, THF (1350 g) and 2-mercaptothiazoline (0.36 g: 3 mmol) were placed in a flask, and while stirring with a stirrer, an n-BuLi solution (4.28 g; 10 mmol) was added at room temperature for 15 minutes. Stir. Subsequently, the mixture was cooled to −40 ° C., an n-BuLi solution (1.16 g; 3 mmol) was added, and PTBST (84.47 g; 479 mmol), ST (50.02 g; 480 mmol) and dibutyl magnesium hexane were added to THF (60 g). A solution to which the solution (2.13 g; 3 mmol) was added was added dropwise over 25 minutes, and 5 minutes after completion of the addition, a dibutylmagnesium hexane solution (2.56 g; 4 mmol) was added and stirred for 5 minutes. Subsequently, a solution obtained by adding diphenylethylene (1.08 g; 6 mmol) and diethylzinc hexane solution (0.20 g; 0.3 mmol) to a 3.71% lithium chloride THF solution (8.54 g: 7 mmol) was added over 2 minutes. The mixture was added dropwise, stirred for 10 minutes after completion of the addition, and cooled to -50 ° C. Thereafter, a solution obtained by adding MMA (24.02 g; 240 mmol) and diethylzinc hexane solution (0.46 g; 0.6 mmol) to THF (20 g) was added dropwise over 13 minutes. And killed. The obtained killing liquid was measured by gas chromatography, but PTBST, ST and MMA were not observed.

  Subsequent treatment was performed in the same manner as for the resin 5 to obtain a polymer.

The result of analyzing the obtained polymer by GPC is Mw = 70000 and the dispersion degree is 1.08. The result of analyzing the composition ratio by ¹³ C-NMR is that PHS is 41 mol%, ST is 42 mol%, MMA was 17 mol%.

(Synthesis of resin 7: block polymer having linear structure)
Under a nitrogen atmosphere, THF (1340 g) and 2-mercaptothiazoline (0.36 g: 3 mmol) were placed in a flask, and while stirring with a stirrer, an n-BuLi solution (4.89 g; 12 mmol) was added at room temperature for 15 minutes. Stir. Subsequently, the mixture was cooled to −40 ° C., an n-BuLi solution (0.94 g; 2 mmol) was added, and PTBST (84.48 g; 479 mmol), ST (49.94 g; 480 mmol) and dibutyl magnesium hexane were added to THF (60 g). A solution to which the solution (2.00 g; 3 mmol) was added was added dropwise over 27 minutes, and 5 minutes after completion of the addition, a dibutylmagnesium hexane solution (1.91 g; 3 mmol) was added and stirred for 5 minutes. Subsequently, a solution obtained by adding diphenylethylene (1.09 g; 6 mmol) and diethylzinc hexane solution (0.22 g; 0.3 mmol) to a 3.71% lithium chloride THF solution (8.19 g: 7 mmol) was added over 2 minutes. The mixture was added dropwise, stirred for 15 minutes after the completion of the addition, and cooled to -50 ° C. Thereafter, a solution obtained by adding MMA (24.01 g; 240 mmol) and diethylzinc hexane solution (0.38 g; 0.5 mmol) to THF (20 g) was added dropwise over 12 minutes. And killed. The obtained killing liquid was measured by gas chromatography, but PTBST, ST and MMA were not observed.

  Subsequent treatment was performed in the same manner as for the resin 5 to obtain a polymer.

As a result of analyzing the obtained polymer by GPC, Mw = 90400, dispersity = 1.08. As a result of analyzing the composition ratio by ¹³ C-NMR, PHS was 44 mol%, ST was 44 mol%, MMA was 12 mol%.

(Synthesis of resin 8: block polymer having linear structure)
Under a nitrogen atmosphere, THF (500 g) and 2-mercaptothiazoline (0.12 g: 1 mmol) were placed in a flask, and an n-BuLi solution (1.57 g; 4 mmol) was added at room temperature while stirring with a stirrer, followed by stirring for 15 minutes. did. Subsequently, the mixture was cooled to −40 ° C., an n-BuLi solution (0.73 g; 2 mmol) was added, p- (1-ethoxyethoxy) styrene (PEES) (47.47 g; 242 mmol), ST in THF (60 g), ST (24.33 g; 234 mmol) and dibutyl magnesium hexane solution (1.71 g; 2 mmol) were added dropwise over 23 minutes, and 5 minutes after completion of the addition, dibutyl magnesium hexane solution (1.02 g; 1 mmol) was added. Stir for 10 minutes. Subsequently, diphenylethylene (0.35 g; 2 mmol) was added and stirred for 10 minutes. Then, it cooled to -50 degreeC, the solution which added the diethyl zinc hexane solution (0.61 g; 1 mmol) to the 3.71% lithium chloride THF solution (9.26 g: 8 mmol) was dripped over 1 minute, and THF ( 10 g) was added dropwise with a solution of MMA (12.36 g; 123 mmol) and diethylzinc hexane solution (0.64 g; 1 mmol) added over 10 minutes. After completion of the addition, the mixture was stirred for 60 minutes, and methanol was added to kill it. The obtained killing liquid was measured by gas chromatography, but PEES, ST and MMA were not observed.

  Then, concentrated hydrochloric acid (6.98 g; 69 mmol) was added, and after stirring at 50 ° C. for 1 hour, triethylamine (5.22 g; 52 mmol) was added and stirred, and acetic acid (1.86 g; 31 mmol) was added. The obtained triethylamine / hydrochloride was filtered, concentrated, purified water (3 Kg) was added, and the mixture was stirred for 1 hour and filtered. The obtained polymer was dissolved in a mixed solvent of THF (450 g) and ethyl acetate (500 g), separated with pure water (250 g), and further separated twice with pure water (500 g). After the upper layer was concentrated, THF (200 g) was added, and the mixture was dropped into hexane (3 Kg) while stirring to precipitate the polymer, stirred for 1 hour, filtered, and dried under reduced pressure at 40 degrees.

As a result of analyzing the obtained polymer by GPC, Mw = 75000, dispersity = 1.36, and analyzing the composition ratio by ¹³ C-NMR, PHS was 42 mol%, ST was 41 mol%, MMA was 17 mol%.

(Synthesis of resin 9: block polymer having linear structure)
Under a nitrogen atmosphere, THF (700 g) and 2-mercaptothiazoline (0.23 g: 2 mmol) were placed in a flask, and an n-BuLi solution (4.89 g; 12 mmol) was added at room temperature while stirring with a stirrer, followed by stirring for 60 minutes. did. Subsequently, the mixture was cooled to −40 ° C., n-BuLi solution (2.03 g; 5 mmol) was added, and PTBST (22.63 g; 128 mmol), ST (40.41 g; 388 mmol) and dibutyl magnesium hexane solution (0.88 g) were added. 1 mmol) was added dropwise over 10 minutes, and 5 minutes after completion of the addition, dibutylmagnesium hexane solution (0.81 g; 1 mmol) was added and stirred for 5 minutes. Subsequently, a solution obtained by adding diphenylethylene (0.83 g; 5 mmol) and diethylzinc hexane solution (0.33 g; 0.5 mmol) to a 3.79% lithium chloride THF solution (3.78 g: 3 mmol) was added over 1 minute. The mixture was added dropwise, stirred for 15 minutes after the completion of the addition, and cooled to -50 ° C. Thereafter, a mixed solution of MMA (13.09 g; 131 mmol) and diethylzinc hexane solution (0.23 g; 0.3 mmol) was added dropwise over 3 minutes. After completion of the addition, the mixture was stirred for 60 minutes, and methanol was added to kill it. The obtained killing liquid was measured by gas chromatography, but PTBST, ST and MMA were not observed.

  Subsequent treatment was carried out in the same manner as in the above resin 5 except that it was dissolved in a mixed solvent of toluene / ethanol (35/65 wt%) to 10% with respect to the dry polymer (100 g) to obtain a polymer.

The result of analyzing the obtained polymer by GPC is Mw = 104500, the dispersion degree is 1.07, and the result of analyzing the composition ratio by ¹³ C-NMR is that PHS is 21 mol%, ST is 60 mol%, MMA was 19 mol%.

(Synthesis of resin 10: block polymer having linear structure)
Under a nitrogen atmosphere, THF (750 g) and 2-mercaptothiazoline (0.23 g: 2 mmol) were placed in a flask, and an n-BuLi solution (1.99 g; 5 mmol) was added at room temperature while stirring with a stirrer, followed by stirring for 60 minutes. did. Subsequently, the mixture was cooled to −40 ° C., n-BuLi solution (0.47 g; 1 mmol) was added, PTBST (62.06 g; 352 mmol), ST (12.15 g; 117 mmol) and dibutylmagnesium hexane solution (0.89 g). ; 1 mmol) was added dropwise over 10 minutes, and 5 minutes after completion of the addition, dibutylmagnesium hexane solution (0.82 g; 1 mmol) was added and stirred for 5 minutes. Subsequently, a solution obtained by adding diphenylethylene (0.95 g; 5.3 mmol) and diethylzinc hexane solution (0.44 g; 0.6 mmol) to a 3.79% lithium chloride THF solution (4.08 g: 3.6 mmol). Was added dropwise over 1 minute, stirred for 15 minutes after completion of the dropwise addition, and cooled to -50 ° C. Thereafter, a mixed solution of MMA (11.64 g; 116 mmol) and diethylzinc hexane solution (0.27 g; 0.4 mmol) was added dropwise over 2 minutes. After completion of the addition, the mixture was stirred for 60 minutes, and methanol was added to kill it. The obtained killing liquid was measured by gas chromatography, but PTBST, ST and MMA were not observed.

  Subsequent treatment was carried out in the same manner as in the above resin 5 except that it was dissolved in a mixed solvent of toluene / ethanol (35/65 wt%) to 20% with respect to the dry polymer (100 g) to obtain a polymer.

The result of analyzing the obtained polymer by GPC is Mw = 123500, the dispersion degree is 1.07, and the result of analyzing the composition ratio by ¹³ C-NMR is that PHS is 61 mol%, ST is 20 mol%, MMA was 19 mol%.

  The composition, Mw and Mw / Mn of each resin described above are shown in Table 1 below.

(Adhesive composition)
As adhesive compositions according to Examples 1 to 10, the resins and polymerization inhibitors shown in Table 2 below were dissolved in PGMEA to obtain adhesive compositions having a solid content concentration of 40% by mass. In Table 2 below, the unit of numerical values in [] is parts by mass.

[Comparative Example 1]
Comparative resin 1 constituting the adhesive composition in Comparative Example 1 was synthesized by the following method.

(Synthesis of Comparative Resin 1)
Styrene, methyl methacrylate, isobornyl methacrylate (IBXMA), dicyclopentanyl methacrylate (DCPMA), and n-butyl acrylate (n-BA) having the composition shown in Table 1 above were synthesized using known radical polymerization. .

(Adhesive composition)
As an adhesive composition in Comparative Example 1, the resin and polymerization inhibitor shown in Table 2 above were dissolved in PGMEA to obtain an adhesive composition having a solid content concentration of 40% by mass.

[Examples 11 to 14]
As adhesive compositions according to Examples 11 to 14, the resins shown in Table 3 below were dissolved in PGMEA to obtain adhesive compositions having a solid content concentration of 40% by mass.

[Evaluation of adhesive composition]
In each adhesive composition in Examples 1 to 14 and Comparative Example 1, the results of measuring and evaluating crack resistance, degassing amount, adhesiveness, solubility and heat-resistant solubility are shown in Tables 2 and 3 above. It was shown to.

  In addition, the measurement method and evaluation method in each item, and the obtained result are demonstrated below.

(Formation method of coating film)
Measurement and evaluation for each item were performed using a coating film formed by the following method using each adhesive composition.

  First, each adhesive composition was applied on a 6-inch silicon wafer so that the dry film thickness was 15 μm or 50 μm. Then, the coating film was created by drying on condition of 110 degreeC for 3 minutes, then 150 degreeC for 3 minutes, then 200 degreeC for 3 minutes.

(Crack resistance)
About crack tolerance, it measured by observing visually the coating film formed so that a dry film thickness might be set to 15 micrometers or 50 micrometers about each adhesive composition which concerns on Examples 1-14 and Comparative Example 1. FIG. In addition, the case where a crack was not recognized in a coating-film layer was determined as favorable, and it represented by "(circle)", and the case where a crack was recognized in a coating-film layer was determined to be bad, and was represented by "x".

  As shown in Table 2 and Table 3, the crack resistance of the adhesive compositions according to Examples 1 to 14 was generally better than that of Comparative Example 1. In addition, although the adhesive composition of Example 3 had poor crack resistance when the coating film was formed so that the dry film thickness was 50 μm, the higher the Mw of the resin, the higher the crack resistance. Was shown to be good.

(Degassing amount)
About each adhesive composition which concerns on Examples 1-14 and Comparative Example 1, it heated up the coating film formed so that a dry film thickness might be set to 15 micrometers from 40 degreeC to 300 degreeC, and degassed from a coating film The amount was measured.

  The TDS method (Thermal Desorption Spectroscopy method, temperature programmed desorption analysis method) was used for the measurement of the degassing amount. An EMD-WA1000 manufactured by Electronic Science Co., Ltd. was used as the TDS measurement device (emission gas measurement device).

  The measurement conditions of the TDS apparatus were as follows: Width: 100, Center Mass Number: 50, Gain: 9, Scan Speed: 4, Emult Volt: 1.3 KV.

  The evaluation of the degassing amount is determined to be good when the strength (Indensity) obtained by the TDS measuring device is less than 400,000 at 300 ° C., and is indicated as “◯”, and when it is 400,000 or more, it is bad. It was judged as “×”.

  As shown in the said Table 2 and Table 3, the degassing amount of the adhesive composition which concerns on Examples 1-14 was small and favorable. On the other hand, the adhesive composition of Comparative Example 1 had a large amount of degassing and was defective.

(Adhesiveness)
For each of the adhesive compositions according to Examples 1 to 14 and Comparative Example 1, after the glass plate was adhered to the coating film formed so that the dry film thickness was 15 μm at a load of 1 kg at 200 ° C., each The glass substrate was pulled under a temperature environment, and the adhesive strength when peeled off from the silicon wafer was measured using a vertical electric measurement stand “MX-500N” (manufactured by Imada Co., Ltd.). And the upper limit of the temperature which can maintain adhesive strength 3 kg / cm < ² > was measured.

As shown in Table 2 and Table 3, the adhesiveness of the adhesive compositions according to Examples 1 to 14 is a temperature at which the adhesive strength of 3 kg / cm ² can be maintained as compared with the adhesive composition of Comparative Example 1. The upper limit of was high and good.

(Solubility)
About the adhesive composition which concerns on Examples 1-14 and Comparative Example 1, the coating film formed so that a dry film thickness might be set to 15 micrometers melt | dissolves in solvent 2-heptanone under room temperature conditions, and the solubility with respect to an organic solvent , And those with no undissolved residue were judged to be good and represented by “◯”.

  As shown in Table 2 and Table 3, the solubility of the adhesive compositions according to Examples 1 to 14 was good.

(Heat resistant solubility)
For the adhesive compositions according to Examples 1 to 14 and Comparative Example 1, the coating films formed to have a dry film thickness of 15 μm were each heated at 250 ° C. for 1 hour, and then immersed in 2-heptanone to form a layer. The dissolution rate (nm / sec) was calculated from the relationship between the thickness and the dissolution time. When the dissolution rate is greater than 200 nm / sec and less than or equal to 300 nm / sec, it is determined that the heat-resistant solubility is very good and is represented by “◎”, and when the dissolution rate is 50 to 200 nm / sec, it is good. It was judged that it was, and represented by “◯”.

  As shown in Table 2 and Table 3 above, the heat-resistant solubility of the adhesive compositions according to Examples 1 to 14 is good, and the heat resistance of the adhesive compositions in Examples 2 to 4 and 12 to 14 is particularly good. The solubility was much better than that of Comparative Example 1.

  The adhesive composition and the adhesive film according to the present invention have high heat resistance without generating gas in a high temperature environment, have high adhesive strength, and are high in heat treatment at the time of peeling from a semiconductor wafer, chip, or the like. It has excellent ease of peeling, which has solubility and suppresses gas generation. Therefore, it can be suitably used for a semiconductor wafer or chip processing step through a process using various chemicals such as a high temperature process, a high vacuum process, and an alkali.

Claims (4)

A block formed by living anion polymerization of a monomer containing styrene and a derivative thereof and (meth) acrylic acid ester and containing 5% by mole to 80% by mole of p-hydroxystyrene as a styrene derivative. An adhesive composition comprising a polymer . 2. The adhesive composition according to claim 1, wherein a molecular weight distribution (Mw / Mn) in the block polymer is 1.01 or more and 2.00 or less. 2. The adhesive composition according to claim 1, wherein the proportion of the styrene in the total amount of the monomers is 10 mol% or more and 90 mol% or less. An adhesive film comprising an adhesive layer containing the adhesive composition according to any one of claims 1 to 3 on the film.