JP6034625B2 - Peeling method - Google Patents

Description

  The present invention relates to a peeling method and a peeling apparatus for peeling a support attached to a wafer via an adhesive layer from the wafer.

  In recent years, with the enhancement of functions of mobile phones, digital AV devices, IC cards, etc., there is a demand for highly integrated chips in packages by reducing the size and thickness of semiconductor silicon chips (hereinafter referred to as chips). Is growing. For example, in an integrated circuit in which a plurality of chips such as CSP (chip size package) or MCP (multi-chip package) are packaged in one package, further reduction in thickness is required. In order to achieve high integration of chips in the package, it is necessary to reduce the thickness of the chip to a range of 25 to 150 μm.

  However, since a semiconductor wafer (hereinafter referred to as a wafer) serving as a base of a chip becomes thin by grinding, its strength is weakened and cracks or warpage is likely to occur. Further, since it is difficult to automatically transport a wafer whose strength has been reduced by making it thinner, it must be transported manually, and the handling is complicated.

  Therefore, a wafer handling system has been developed that maintains the strength of the wafer and prevents cracks and warpage of the wafer by bonding a plate made of glass, silicon, or hard plastic, called a support plate, to the wafer to be ground. ing. Since the strength of the wafer can be maintained by the wafer handling system, the conveyance of the thinned wafer can be automated.

  In the wafer handling system, the wafer and the support plate are bonded together using an adhesive layer formed of an adhesive tape, a thermoplastic resin, an adhesive, or the like. Then, after thinning the wafer to which the support plate is attached, the support plate is peeled from the substrate before dicing the wafer. When an adhesive is used for bonding the wafer and the support plate, the adhesive is dissolved to peel the wafer from the support plate.

  In recent years, hydrocarbon adhesives have been developed as the adhesives described above (Patent Documents 1 and 2).

Special table 2009-529065 (released on August 13, 2009) Special table 2010-506406 (released February 25, 2010)

  In the adhesive according to the prior art, when the laminated body in which the wafer and the support of the wafer are bonded is subjected to a predetermined process such as a thinning process, the adhesive is separated from the wafer and the support. There was a problem that it was difficult to dissolve in a solvent for dissolving the. Therefore, a large amount of solvent is required to dissolve the adhesive. In addition, it takes a long time to dissolve the adhesive, and as a result, it takes time to separate the wafer and the support.

  The present invention has been made in view of the above problems, and after bonding a wafer and a support for the wafer through an adhesive layer, the support attached to the wafer can be easily removed from the wafer. It is an object of the present invention to provide a peeling method and a peeling apparatus that can be peeled off.

In order to solve the above problems, a peeling method according to the present invention is a peeling method for peeling a support attached to a wafer via an adhesive layer from the wafer, and swelling the adhesive layer. And a solvent supplying step for supplying the adhesive layer with a solvent for reducing the adhesiveness of the surface to the adhesive layer, and a peeling step for peeling the swollen adhesive layer from the wafer. .
A peeling apparatus according to the present invention is a peeling apparatus that peels a support attached to a wafer via an adhesive layer from the wafer, and swells the adhesive layer to increase the adhesiveness of the surface. Solvent supply means for supplying the solvent to be lowered to the adhesive layer and peeling means for peeling the adhesive layer from the wafer are provided.

  The peeling method according to the present invention includes a solvent supplying step of supplying the adhesive layer with a solvent that swells the adhesive layer and lowers the adhesiveness of the surface, and peeling that peels off the swollen adhesive layer from the wafer. The peeling device according to the present invention swells from the wafer with a solvent supply means for swelling the adhesive layer and supplying the adhesive layer with a solvent for reducing the adhesiveness of the surface. And a peeling means for peeling the adhesive layer, the support can be easily peeled from the wafer.

It is explanatory drawing which shows the peeling method which concerns on one Embodiment of this invention. It is explanatory drawing which shows the peeling method which concerns on other embodiment of this invention. It is explanatory drawing which shows the peeling method which concerns on other embodiment of this invention. It is explanatory drawing which shows the peeling method which concerns on other embodiment of this invention. It is explanatory drawing which shows the peeling method which concerns on other embodiment of this invention. It is explanatory drawing which shows the peeling method which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

[Peeling method]
The peeling method which concerns on this invention is a peeling method which peels the support body affixed on the wafer via the adhesive bond layer from the wafer. The peeling method includes a solvent supply step of supplying the adhesive layer with a solvent that swells the adhesive layer and lowers the adhesiveness of the surface, and peeling that peels off the swollen adhesive layer from the wafer. Process.

[First Embodiment]
The peeling method according to this embodiment will be described with reference to FIG. (A)-(d) in FIG. 1 is explanatory drawing which shows the peeling method which concerns on one Embodiment of this invention. In the peeling method of this embodiment, as shown to (a) in FIG. 1, the laminated body 10 which affixed the wafer 1 and the support body 2 via the adhesive layer 3 is made into the object of peeling processing.

<Wafer 1>
The wafer 1 is subjected to a semiconductor process such as a circuit formation process and a thinning process while being bonded to the support 2, and may be a silicon (Si) substrate, for example. The wafer 1 in the laminate 10 to be subjected to the peeling method may be thinned to a thickness of, for example, 25 to 150 μm by thinning processing.

<Support 2>
The support 2 is a member that plays a role of supporting the wafer in the process of thinning the wafer, for example, and is bonded to the wafer 1 via the adhesive layer 3 to constitute the laminate 10. In one Embodiment, the support body is formed with the glass or silicon whose film thickness is 500-1,000 micrometers, for example.

<Adhesive layer 3>
The adhesive layer 3 is used to bond the wafer 1 and the support 2 together. When the support 2 is peeled off from the wafer 1, the adhesive layer 3 swells by contact with a specific solvent and reduces the adhesion of the surface. It suffices to form them. Such an adhesive layer 3 includes a styrene unit as a constituent unit of the main chain, the content of the styrene unit is 10% by weight or more and 90% by weight or less, and the weight average molecular weight is 10,000 or more, 200, It can be formed by an adhesive composition containing 40% by weight or more of an elastomer that is 000 or less. Details of the adhesive composition will be described later.

  The adhesive layer 3 is formed according to the desired film thickness of the adhesive layer 3 so that the film thickness after the adhesive composition is applied on the wafer 1 and dried, for example, is 10 to 1,000 μm. It can be suitably formed by a known method. In addition, since the adhesive layer 3 is formed using the adhesive composition having excellent heat resistance, the wafer 1 and the support 2 are exposed to an environment of 150 ° C. or higher after being bonded. It is suitably used for bonding. Specifically, the adhesive layer 3 can be suitably used in an environment of 180 ° C. or higher, and further 220 ° C. or higher.

(Solvent supply process)
In the solvent supply step, the solvent is supplied to the adhesive layer 3 as shown in FIG. The method of supplying the solvent to the adhesive layer 3 is not particularly limited, but as shown in FIG. 1B, the solvent is removed by immersing the laminate 10 in the solvent introduced into the tank 100. The adhesive layer 3 can be supplied.

  When the laminate 10 is immersed in a solvent, the immersion time can be appropriately set according to the adhesive composition that forms the adhesive layer 3 and the type of solvent, the thickness of the adhesive layer 3, the temperature, and the like. Is preferably 5 minutes or less. Moreover, although the room temperature which immerses the laminated body 10 may be room temperature, it may be heated to the temperature of 45 degrees C or less, for example.

  In addition, when the adhesive layer 3 is removed from the wafer 1 by the method of immersing the laminate 10 in the solvent introduced into the tank, the solvent after the adhesive layer 3 is removed is filtered by a filter or the like. Can be reused.

<Solvent>
The solvent supplied to the adhesive layer 3 may be any solvent that swells the adhesive layer 3 and lowers the adhesiveness of the surface. For example, propylene glycol monomethyl ether acetate (PGMEA), acetone, methyl ethyl ketone (MEK) , Methyl amyl ketone (MAK), butyl acetate, ethyl acetate and the like can be suitably used.

(Peeling process)
In the peeling step, the swollen adhesive layer 3 is peeled from the wafer 1 as shown in FIG. Thereby, the support body 2 is peeled from the wafer 1. Since the adhesive layer 3 supplied with the solvent swells and the adhesiveness of the surface is lowered, the wafer 1 and the support 2 bonded by the adhesive layer 3 can be quickly separated. . Further, since the adhesive layer 3 only needs to be swollen and does not need to be dissolved, the amount of solvent necessary for peeling the support 2 from the wafer 1 can be suppressed to a small amount. Here, the swelling of the adhesive layer 3 includes a state in which the solvent penetrates into the adhesive layer 3 and the adhesive layer 3 expands to change its volume.

(Washing process)
The peeling method of the present embodiment may further include a cleaning step of cleaning the wafer 1 as shown in FIG. 1 (d) after peeling the adhesive layer 3 from the wafer 1 in the peeling step. Good. In the cleaning process, the residue of the adhesive layer 3 on the wafer 1 is removed. In the cleaning process, a cleaning liquid for dissolving the adhesive layer 3 is supplied onto the wafer 1.

  A method for supplying the cleaning liquid onto the wafer 1 is not particularly limited, and examples thereof include spray coating in which the cleaning liquid is sprayed onto the wafer 1. When spraying the cleaning liquid onto the wafer 1, the wafer 1 may be rotated and spin-coated.

  The cleaning liquid only needs to dissolve the adhesive layer 3 and is appropriately selected according to the adhesive composition forming the adhesive layer 3. For example, p-menthane can be suitably used. It is. Further, the cleaning liquid may be one that swells the adhesive layer 3 instead of the one that dissolves the adhesive layer 3, and in this case, is the same as the solvent used to swell the adhesive layer 3. It may be different or different.

  Thus, after peeling off the adhesive layer 3 from the wafer 1, the adhesive layer 3 remaining on the wafer 1 can be suitably removed by washing the wafer 1. Can be obtained. In the cleaning step, only the residue after the adhesive layer 3 has been peeled is required to be dissolved and removed, so that the amount of necessary cleaning liquid can be suppressed to a small amount.

<Adhesive composition>
Here, the detail of the adhesive composition which forms the adhesive bond layer 3 is demonstrated.

≪Elastomer≫
The elastomer contained in the adhesive composition contains a styrene unit as a constituent unit of the main chain, the content of the styrene unit is 10 wt% or more and 90 wt% or less, and the weight average molecular weight is 10,000 or more, 200 , 000 or less.

  In the present specification, the “structural unit” refers to a structure resulting from a single molecule monomer in a structure constituting an elastomer which is a polymer.

  In the present specification, the “styrene unit” refers to a structural unit derived from the styrene contained in the polymer when styrene is polymerized.

  The adhesive composition has a styrene unit content in the range of 10 wt% to 90 wt%, and the elastomer has a weight average molecular weight in the range of 10,000 to 200,000. If such an elastomer is included in an amount of 40% by weight or more, the adhesive layer 3 made of the adhesive composition is swelled by a solvent, so that the adhesiveness of the surface is lowered. The wafer 1 and the support 2 can be separated more rapidly.

  Further, since the content of the styrene unit and the weight average molecular weight of the elastomer are within the above ranges, a resist solvent (for example, propylene glycol monomethyl ether acetate (PGMEA), propylene, which is exposed when the wafer is subjected to a resist lithography process) Glue monomethyl ether (PGME, etc.), acids (hydrofluoric acid, etc.), and alkalis (tetramethylammonium hydroxide (TMAH), N-methylpyrrolidone, etc.) exhibit excellent resistance .

  The content of styrene units is more preferably more than 50% by weight. The weight average molecular weight of the elastomer is more preferably 20,000 or more, and more preferably 150,000 or less.

  As the elastomer, various elastomers are used as long as the content of the styrene unit is in the range of 10% by weight to 90% by weight and the weight average molecular weight of the elastomer is in the range of 10,000 to 200,000. be able to. Specifically, for example, polystyrene-poly (ethylene / propylene) block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene-butylene-styrene. Block copolymer (SBBS) and hydrogenated products thereof; styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (styrene-isoprene-styrene block copolymer) (SEPS), styrene -Ethylene-ethylene-propylene-styrene block copolymer (SEEPS) and the like, and those having a styrene unit content and a weight average molecular weight in the above-mentioned range are used. It is possible.

  The elastomer is more preferably a hydrogenated product. If the elastomer is a hydrogenated product, the stability to heat is improved and degradation such as decomposition and polymerization hardly occurs, and further, it is excellent in solubility in a hydrocarbon solvent and resistance to a resist solvent.

  Further, among the above elastomers, an elastomer in which both ends of the molecule are styrene sites is more preferable. Elastomers exhibit higher heat resistance by having styrenic sites with high thermal stability as block structures at both ends.

  Further, the elastomer is more preferably a hydrogenated product of a block copolymer of styrene and a conjugated diene in which both ends of the molecule are styrene sites. As a result, the stability to heat is improved and degradation such as decomposition and polymerization is unlikely to occur. Furthermore, both the solubility in hydrocarbon solvents and the resistance to resist solvents are excellent, and both styrene sites having high thermal stability are provided. By having a block structure at the end, higher heat resistance is exhibited.

  Moreover, the elastomer may have at least one functional group-containing atomic group in the molecule, if necessary. The elastomer can be obtained, for example, by bonding a functional group-containing atomic group to a known block copolymer using a modifier.

  The functional group-containing atomic group refers to an atomic group containing one or more functional groups. Examples of the functional group contained in the functional group-containing atomic group include an amino group, an acid anhydride group (preferably a maleic anhydride group), an imide group, a urethane group, an epoxy group, an imino group, a hydroxyl group, a carboxyl group, a silanol group, And an alkoxysilane group (the alkoxysilane group preferably has 1 to 6 carbon atoms). When the elastomer has at least one functional group-containing atomic group in the molecule, the flexibility and adhesiveness of the adhesive composition are further improved.

  Commercially available products that can be used as the elastomer include, for example, “Septon (trade name)” manufactured by Kuraray Co., Ltd., “Hibler (trade name)” manufactured by the same company, “Tuftec (trade name)” manufactured by Asahi Kasei Corporation, and JSR shares. The company-made “Dynaron (trade name)” and the like can be mentioned.

  The content of the elastomer contained in the adhesive composition may be 40% by weight or more, more preferably 50% by weight or more, and most preferably 60% by weight or more.

  A plurality of types of elastomers may be mixed and used. That is, the adhesive composition may include a plurality of types of elastomers. When the adhesive composition contains a plurality of types of elastomers, as a result of mixing, the weight average molecular weight of the elastomer may be adjusted in the range of 10,000 or more and 200,000 or less. And at least one of the plurality of types of elastomers contains a styrene unit as a constituent unit of the main chain, and the content of the styrene unit is in the range of 10% by weight to 90% by weight, and the total content of the plurality of types of elastomers The amount may be 40% by weight or more. Moreover, in the adhesive composition, when a plurality of types of elastomers are included, as a result of mixing, the content of styrene units may be adjusted to be in the above range. For example, Septon 2104 of Kuraray Co., Ltd., which has a styrene unit content of 65% by weight, and Septon 2063 of Septon (trade name), which has a styrene unit content of 12% by weight, are available. When mixed at a weight ratio of 1: 1, the styrene content with respect to the whole elastomer contained in the adhesive composition is 38 to 39% by weight, and is 10 to 90% by weight. For example, when a styrene unit of 10% by weight and 60% by weight are mixed on a one-to-one basis, the result is 35% by weight, which is within the above range. In this invention, you may use the adhesive bond layer 3 formed with such an adhesive composition. Moreover, it is most preferable that the plurality of types of elastomers contained in the adhesive composition all contain styrene units within the above range.

  The elastomer contained in the adhesive composition preferably has a unit showing compatibility with a solvent and a unit showing incompatibility. As described above, when the elastomer contained in the adhesive composition includes units having different polarities with respect to the solvent, the adhesive is added when the solvent is added to the adhesive layer made of such an adhesive composition. The layer can swell and reduce its surface adhesion. Here, as a unit showing compatibility with a solvent, for example, a styrene unit showing compatibility with a polar solvent such as propylene glycol monomethyl ether acetate can be mentioned, and as a unit showing incompatibility, for example, the above polarity Examples include long-chain alkyl units that are incompatible with the solvent. Therefore, as the elastomer contained in the adhesive composition, a hydrogenated styrene-based elastomer containing a styrene unit and a long-chain alkyl unit can be exemplified.

  The adhesive composition may contain a hydrocarbon resin. The hydrocarbon resin is a resin that has a hydrocarbon skeleton and is obtained by polymerizing a monomer composition. Examples of the hydrocarbon resin include cycloolefin polymers.

  Specific examples of cycloolefin polymers include ring-opening (co) polymers of monomer components containing cycloolefin monomers, and resins obtained by addition (co) polymerization of monomer components containing cycloolefin monomers. Etc.

  Examples of the cycloolefin monomer include bicyclics such as norbornene and norbornadiene, tricyclics such as dicyclopentadiene and dihydroxypentadiene, tetracyclics such as tetracyclododecene, and pentacycles such as cyclopentadiene trimer. , Heptacycles such as tetracyclopentadiene, or alkyl (methyl, ethyl, propyl, butyl, etc.), alkenyl (vinyl, etc.), alkylidene (ethylidene, etc.), aryl (phenyl) , Tolyl, naphthyl and the like) and the like. Among these, norbornene-based monomers selected from the group consisting of norbornene, tetracyclododecene, and alkyl-substituted products thereof are more preferable.

  The monomer component constituting the hydrocarbon resin may contain another monomer that can be copolymerized with the above-described cycloolefin-based monomer, and for example, preferably contains an alkene monomer. Examples of the alkene monomer include alkene monomers having 2 to 10 carbon atoms, and examples include α-olefins such as ethylene, propylene, 1-butene, isobutene, and 1-hexene. The alkene monomer may be linear or branched.

  Moreover, it is preferable from a viewpoint of high heat resistance (low thermal decomposition and thermal weight reduction property) to contain a cycloolefin monomer as a monomer component which comprises hydrocarbon resin. The ratio of the cycloolefin monomer to the whole monomer component constituting the hydrocarbon resin is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 20 mol% or more. . Further, the ratio of the cycloolefin monomer to the whole monomer component constituting the hydrocarbon resin is not particularly limited, but is preferably 80 mol% or less from the viewpoint of solubility and stability over time in a solution. More preferably, it is at most mol%.

  Moreover, you may contain a linear or branched alkene monomer as a monomer component which comprises hydrocarbon resin. The ratio of the alkene monomer to the entire monomer component constituting the hydrocarbon resin is preferably 10 to 90 mol%, more preferably 20 to 85 mol% from the viewpoint of solubility and flexibility, More preferably, it is 30-80 mol%.

  Note that the hydrocarbon resin is a resin having no polar group, such as a resin obtained by polymerizing a monomer component composed of a cycloolefin monomer and an alkene monomer. It is more preferable for suppressing the generation of gas.

  The polymerization method and polymerization conditions for polymerizing the monomer components are not particularly limited and may be appropriately set according to a conventional method.

  Examples of commercially available products that can be used as the hydrocarbon resin include “TOPAS” manufactured by Polyplastics Co., Ltd., “APEL” manufactured by Mitsui Chemicals, Inc., “ZEONOR” and “ZEONEX” manufactured by ZEON Corporation, Examples include “ARTON” manufactured by JSR Corporation.

  The glass transition point (Tg) of the hydrocarbon resin is preferably 60 ° C. or higher, and particularly preferably 70 ° C. or higher. When the glass transition point of the hydrocarbon resin is 60 ° C. or higher, softening of the adhesive layer 3 can be suppressed when the laminate 10 is exposed to a high temperature environment.

≪Solvent that dissolves elastomer≫
The adhesive composition may contain a solvent (main solvent), and such a solvent only needs to have a function of dissolving the elastomer. For example, the non-polar hydrocarbon solvent and the polar In addition, a non-polar petroleum solvent or the like can be used.

  The solvent preferably contains a condensed polycyclic hydrocarbon. When the solvent contains a condensed polycyclic hydrocarbon, white turbidity that may occur when the adhesive composition is stored in a liquid state (especially at a low temperature) can be prevented, and product stability can be improved. it can.

  Examples of the hydrocarbon solvent include linear, branched or cyclic hydrocarbons. Examples of the hydrocarbon solvent include linear hydrocarbons having 3 to 15 carbon atoms such as hexane, heptane, octane, nonane, decane, undecane, dodecane, and tridecane; and those having 4 to 15 carbon atoms such as methyloctane. Branched hydrocarbons: p-menthane, o-menthane, m-menthane, diphenylmenthane, 1,4-terpine, 1,8-terpine, bornane, norbornane, pinane, tsujang, kalan, longifolene, α-terpinene, β -Cyclic hydrocarbons such as terpinene, γ-terpinene, α-pinene, β-pinene, α-tujon and β-tujon.

  Examples of the petroleum solvent include cyclohexane, cycloheptane, cyclooctane, naphthalene, decahydronaphthalene (decalin), tetrahydronaphthalene (tetralin), and the like.

  The condensed polycyclic hydrocarbon is a condensed ring hydrocarbon formed by two or more monocycles supplying only one side of each ring to each other, and is a carbon obtained by condensing two monocycles. It is preferable to use hydrogen.

  Such fused polycyclic hydrocarbons include a combination of 5-membered and 6-membered rings, or a combination of two 6-membered rings. Examples of the condensed polycyclic hydrocarbon in which a 5-membered ring and a 6-membered ring are combined include indene, pentalene, indane, tetrahydroindene, and the like. As the condensed polycyclic hydrocarbon in which two 6-membered rings are combined, Examples thereof include naphthalene, decahydronaphthalene, and tetrahydronaphthalene.

  These solvents may be used alone or in combination of two or more. Further, when the solvent contains the condensed polycyclic hydrocarbon, the component contained in the solvent may be only the condensed polycyclic hydrocarbon, or contains other components such as saturated aliphatic hydrocarbon, for example. You may do it. In this case, the content of the condensed polycyclic hydrocarbon is preferably 40% by weight or more, and more preferably 60% by weight or more of the entire hydrocarbon solvent. When the content of the condensed polycyclic hydrocarbon is 40% by weight or more of the entire hydrocarbon solvent, high solubility in the resin can be exhibited. If the mixing ratio of the condensed polycyclic hydrocarbon and the saturated aliphatic hydrocarbon is within the above range, the odor of the condensed polycyclic hydrocarbon can be alleviated.

  Examples of the saturated aliphatic hydrocarbon include straight-chain hydrocarbons having 3 to 15 carbon atoms such as hexane, heptane, octane, nonane, decane, undecane, dodecane, and tridecane; and carbon atoms having 4 to 15 carbon atoms such as methyloctane. Branched hydrocarbons of: p-menthane, o-menthane, m-menthane, diphenylmenthane, 1,4-terpine, 1,8-terpine, bornane, norbornane, pinane, tsujang, kalan, longifolene and the like.

  The content of the solvent that dissolves the elastomer in the adhesive composition may be appropriately adjusted according to the thickness of the adhesive layer 3 that is formed using the adhesive composition. When the total amount of the composition is 100 parts by weight, it is preferably in the range of 20 to 90 parts by weight. If the content of the solvent is within the above range, the viscosity can be easily adjusted.

≪Thermal polymerization inhibitor≫
The adhesive composition may contain a thermal polymerization inhibitor as required. The thermal polymerization inhibitor has a function of preventing radical polymerization reaction due to heat. Specifically, since the thermal polymerization inhibitor exhibits high reactivity with radicals, it reacts preferentially over the monomer and inhibits polymerization of the monomer. Since the adhesive composition contains a thermal polymerization inhibitor, the polymerization reaction is suppressed in a high temperature environment (particularly, 250 ° C. to 350 ° C.).

  For example, in the semiconductor manufacturing process, there is a high temperature process in which the wafer 1 to which the support 2 is attached is heated at 250 ° C. for 1 hour. At this time, when the polymerization of the adhesive composition occurs at a high temperature, the solubility of the adhesive composition in the solvent supplied when the support 2 is peeled off from the wafer 1 after the high temperature process is lowered, and the support 2 from the wafer 1 is reduced. Cannot be peeled off satisfactorily. However, since the adhesive composition contains a thermal polymerization inhibitor, oxidation due to heat and the accompanying polymerization reaction are suppressed, so that the support 2 can be easily peeled from the wafer 1 even after a high temperature process. The generation of residues can be suppressed.

  The thermal polymerization inhibitor is not particularly limited as long as it has a function of preventing a radical polymerization reaction due to heat, but a thermal polymerization inhibitor having a phenol structure is preferable. Thereby, the adhesive composition can ensure good solubility even after high temperature treatment in the atmosphere. As the thermal polymerization inhibitor having a phenol structure, a hindered phenol-based antioxidant can be used, for example, 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 ″ -ethylidene tris (2 -Methylphenol), 4,4 ', 4 "- Tylidenetrisphenol, 1,1,3-tris (2,5-dimethyl-4-hydroxyphenyl) -3-phenylpropane, 2,6-di-tert-butyl-4-methylphenol, 2,2′- Methylenebis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 3 , 9-bis [2- (3- (3-tert-butyl-4-hydroxy-5-methylphenyl) -propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro (5,5) Undecane, triethylene glycol-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propi Nate, n-octyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythryltetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate ] (Trade name IRGANOX 1010, manufactured by BASF), tris (3,5-di-tert-butylhydroxybenzyl) isocyanurate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate]. Only one type of thermal polymerization inhibitor may be used, or two or more types may be used in combination.

  The content of the thermal polymerization inhibitor may be appropriately determined according to the type of elastomer and the application and use environment of the adhesive composition. For example, when the amount of the elastomer is 100 parts by weight, 0.1% by weight It is preferable that it is 10 parts by weight or more. If the content of the thermal polymerization inhibitor is within the above range, the effect of suppressing the polymerization due to heat is satisfactorily exerted, and the decrease in the solubility of the adhesive composition in the stripping solution can be further suppressed after the high temperature process. .

  Moreover, the adhesive composition has a composition different from that of the solvent (main solvent) for dissolving the elastomer, and may further contain an additive solvent for dissolving the thermal polymerization inhibitor, if necessary. Although it does not specifically limit as an additive solvent, The organic solvent which melt | dissolves each component contained in an adhesive composition can be used.

  The organic solvent may be any solvent that can dissolve each component contained in the adhesive composition to form a uniform solution, and can be used alone or in combination of two or more.

  Specific examples of the organic solvent include, for example, a terpene solvent having an oxygen atom, a carbonyl group or an acetoxy group as a polar group, for example, geraniol, nerol, linalool, citral, citronellol, menthol, isomenthol, neomenthol, α-terpineol, β-terpineol, γ-terpineol, terpinen-1-ol, terpinen-4-ol, dihydroterpinyl acetate, 1,4-cineole, 1,8-cineole, borneol, carvone, yonon, thuyon, For example, camphor. Lactones such as γ-butyrolactone; Ketones such as acetone, methyl ethyl ketone, cyclohexanone (CH), methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol Polyhydric alcohols such as: ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, etc., compounds having an ester bond, monohydric ethers of the above polyhydric alcohols or compounds having an ester bond , Monoalkyl ethers such as monoethyl ether, monopropyl ether, monobutyl ether or ethers such as monophenyl ether Derivatives of polyhydric alcohols such as compounds having a combination (in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred); cyclic ethers such as dioxane, and methyl lactate Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether And aromatic organic solvents such as dibenzyl ether, phenetole, and butyl phenyl ether.

  The content of the additive solvent may be appropriately determined according to the type of the thermal polymerization inhibitor and the like. For example, when the thermal polymerization inhibitor is 1 part by weight, it is 1 part by weight or more and 50 parts by weight or less. 1 to 30 parts by weight is more preferable, and 1 to 15 parts by weight is most preferable. When the content of the thermal polymerization inhibitor is within the above range, the thermal polymerization inhibitor can be sufficiently dissolved.

≪Other ingredients≫
The adhesive composition may further contain other components having miscibility as long as the essential characteristics of the adhesive composition are not impaired. Examples of other components include various commonly used additives such as additional resins for improving the performance of the adhesive composition, plasticizers, adhesion assistants, stabilizers, colorants, and surfactants. Can be mentioned.

<Method for Preparing Adhesive Composition>
The method for preparing the adhesive composition described above is not particularly limited, and a known method may be used.For example, by dissolving the elastomer in the main solvent and stirring each composition using an existing stirring device, An adhesive composition can be obtained.

  Moreover, when adding a thermal polymerization inhibitor to an adhesive composition, it is preferable to add what was previously dissolved in an additive solvent for dissolving the thermal polymerization inhibitor.

<Adhesive film>
Various use forms can be adopted for the above-described adhesive composition depending on the application. For example, the adhesive composition is applied in a liquid state on the wafer 1 or the support 2 that is a workpiece, using a known method as appropriate according to the desired film thickness of the adhesive layer 3, You may employ | adopt the method of drying and forming the adhesive bond layer 3, or it adhere | attaches by apply | coating an adhesive composition on films, such as a flexible film, and drying and forming the adhesive bond layer 3 After forming into a film, you may employ | adopt the method of affixing the said adhesive film on the wafer 1 and the support body 2 which are to-be-processed bodies.

  The adhesive film may be used by further covering the adhesive layer 3 with a protective film. In this case, the protective film on the adhesive layer 3 is peeled off, the exposed adhesive layer 3 is overlaid on the workpiece, and then the above film is peeled off from the adhesive layer on the workpiece. The adhesive layer 3 can be easily provided.

  Therefore, when this adhesive film is used, the film thickness is more uniform and the surface smoothness is better than the case where the adhesive composition 3 is applied directly on the workpiece to form the adhesive layer 3. An adhesive layer 3 can be formed.

  The film constituting the adhesive film only needs to have releasability so that the adhesive layer 3 formed on the film can be peeled off and attached (transferred) to a wafer or a support. Although not particularly limited, a flexible film is more preferable. Examples of the flexible film include synthetic resin films having a film thickness of 15 to 125 μm, such as polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, and polyvinyl chloride. It is preferable that a release treatment is performed on the film as necessary so that the transfer of the adhesive layer 3 is facilitated.

  As a method of forming the adhesive film, a known method is appropriately used depending on the desired thickness of the adhesive layer 3 so that the thickness of the adhesive layer 3 after drying is, for example, 10 to 1,000 μm. And a method of applying and drying the adhesive composition on the film.

  Moreover, when using a protective film, as a protective film, although not limited as long as it can peel from the adhesive bond layer 3, a polyethylene terephthalate film, a polypropylene film, and a polyethylene film are preferable, for example. Each protective film is preferably coated or baked with silicon. Thereby, peeling from the adhesive layer 3 becomes easy. Although the thickness of a protective film is not specifically limited, It is preferable that it is 15-125 micrometers. Thereby, the softness | flexibility of the adhesive film provided with the protective film is securable.

  Although the usage method of an adhesive film is not specifically limited, For example, when using a protective film, after peeling this, the adhesive layer 3 exposed on a to-be-processed body is piled up, The method of thermocompression-bonding the adhesive layer 3 to the surface of a to-be-processed body by moving a heating roller from the film (the back surface of the surface in which the adhesive layer 3 was formed) is 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 roller such as a winding roller.

[Second Embodiment]
The peeling method according to this embodiment will be described with reference to FIGS. 2 and 3 are explanatory views showing a peeling method according to another embodiment of the present invention. As shown in FIGS. 2 and 3, the peeling method according to this embodiment is different from the first embodiment in that it includes a light irradiation step and a support peeling step before the solvent supply step. Therefore, in this embodiment, a different point from 1st Embodiment is demonstrated and it abbreviate | omits about another detail.

  In the peeling method of this embodiment, as shown in FIG. 2A and FIG. 3A, the wafer 1, the adhesive layer 3, the separation layer 4, and the support 2 are laminated in this order. The laminated body 20 is a target for the peeling process. The separation layer 4 is provided between the adhesive layer 3 and the support 2 and is altered by absorbing light irradiated through the support 2. Details of the separation layer 4 will be described later.

(Light irradiation process)
In this embodiment, as shown in FIG. 2B and FIG. 3B, before the solvent supplying step, the separation layer 4 is irradiated with light 101 through the support 2 to separate the separation layer 4. 4 is further included. Therefore, in this embodiment, the support body 2 made of a material that transmits the light 101 irradiated to the separation layer 4 is used. The adhesive layer 3 and the support 2 can be easily separated by irradiating the separation layer 4 with light 101 to alter the separation layer 4.

The light 101 applied to the separation layer 4 is, for example, a solid-state laser such as a YAG laser, Libby laser, glass laser, YVO ₄ laser, LD laser, or fiber laser, or a dye laser, depending on the wavelength that the separation layer 4 can absorb. A liquid laser, a CO ₂ laser, an excimer laser, an Ar laser, a He—Ne laser or other gas laser, a semiconductor laser, a free electron laser, or a non-laser light may be used as appropriate. The wavelength of light to be absorbed by the separation layer 4 is not limited to this, but may be light having a wavelength of 600 nm or less, for example.

(Support peeling process)
In the present embodiment, as shown in FIG. 2 (c) and FIG. 3 (c), the support peeling that peels the support 2 from the adhesive layer 3 between the light irradiation step and the solvent supply step. The method further includes a step. In the laminate 20 after the light irradiation step, the separation layer 4 has been altered by light irradiation, so that the support 2 and the adhesive layer 3 bonded together via the separation layer 4 can be easily separated. it can.

  In this manner, after separating the support 2 and the adhesive layer 3, a solvent that swells the adhesive layer 3 and lowers the adhesiveness of the surface thereof is supplied to the adhesive layer 3 in the solvent supply step. Since the support 2 and the adhesive layer 3 are separated before the solvent is supplied, the surface facing away from the surface to which the wafer 1 is bonded is exposed in the adhesive layer 3. Therefore, the solvent can be supplied to the entire exposed surface of the adhesive layer 3, and the solvent can easily penetrate into the adhesive layer 3.

  Therefore, in the solvent supply step, as shown in FIG. 2 (d), the wafer 1 to which the adhesive layer 3 is bonded may be immersed in the solvent introduced into the tank 100, or in FIG. As shown in d), a solvent may be spin-coated on the adhesive layer 3. Then, the adhesive layer 3 swollen by the solvent is separated from the wafer 1, and as shown in FIG. 2 (d) and FIG. 3 (d), the cleaning liquid is spin-coated on the wafer 1, and the wafer 1 is cleaned. May be.

<Separation layer 4>
The separation layer 4 may include a light absorber that is decomposed by light or the like, for example. Examples of the light absorber include graphite powder, fine metal powder such as iron, aluminum, copper, nickel, cobalt, manganese, chromium, zinc, tellurium, metal oxide powder such as black titanium oxide, carbon black, or aromatic. Dye or pigment such as diamino metal complex, aliphatic diamine metal complex, aromatic dithiol metal complex, mercaptophenol metal complex, squarylium compound, cyanine dye, methine dye, naphthoquinone dye, anthraquinone dye Can be used. Such a separation layer 4 can be formed, for example, by mixing with a binder resin and coating on a support. A resin having a light absorbing group can also be used.

  Further, as the separation layer 4, an inorganic film or an organic film formed by a plasma CVD method may be used. For example, a metal film can be used as the inorganic film. As the organic film, a fluorocarbon film can be used. Such a separation layer 4 can be formed on the support 2 by a plasma CVD method, for example.

[Third Embodiment]
The peeling method according to this embodiment will be described with reference to FIG. FIG. 4 is an explanatory view showing a peeling method according to another embodiment of the present invention. As shown in FIG. 4, in the peeling method according to the present embodiment, the separation layer 14 having an adhesive portion on the outer peripheral portion is used, and the support peeling step is performed after the solvent supply step and the light irradiation step. This is different from the second embodiment. Therefore, in this embodiment, a different point from 2nd Embodiment is demonstrated and it abbreviate | omits about another detail.

  In the peeling method according to the present embodiment, as shown in FIG. 4A, the wafer 1, the adhesive layer 3, the separation layer 14 provided with an adhesive portion on the outer peripheral portion, and the support 2 are A laminate 30 that is laminated in order is used as an object of the peeling process. The separation layer 14 includes an inner peripheral portion made of a material that is altered by absorbing light irradiated through the support 2 and an adhesive composition that is located on the outer periphery and forms the adhesive layer 3. And an adhesive portion. In the separation layer 14, the inner peripheral portion is formed in the same manner as the separation layer 4 of the second embodiment, and the outer peripheral adhesive portion is formed in the same manner as the adhesive layer 3.

  In the peeling method according to the present embodiment, as shown in FIG. 4B, first, in the light irradiation step, the inner peripheral portion of the separation layer 14 excluding the outer peripheral adhesive portion is interposed through the support 2. Irradiation with light 101 alters the inner periphery of the separation layer 14. Next, as shown in FIG. 4C, the laminate 30 is immersed in the solvent introduced into the tank 100. Thereby, the adhesive agent part located in the outer periphery of the separation layer 14 is swollen, and the adhesiveness of the surface is reduced. In addition, you may perform the process of (b) and (c) in FIG. That is, the laminate 30 is immersed in a solvent introduced into the tank 100 to swell the adhesive portion of the separation layer 14, and then the light 101 is applied to the inner peripheral portion of the separation layer 14 via the support 2. Irradiation may alter the inner periphery of the separation layer 14.

  And as shown to (d) in FIG. 4, in the support body peeling process, the adhesive bond layer 3 and the support body 2 are isolate | separated. Thereafter, as shown in FIG. 4 (e), in the solvent supplying step, the solvent is spin-coated on the exposed surface of the adhesive layer 3, and the adhesive layer 3 is swollen to reduce the adhesiveness of the surface. . Finally, the swollen adhesive layer 3 is peeled off from the wafer 1, and as shown in FIG. 4F, a cleaning liquid is spin-coated on the wafer 1 to clean the wafer 1.

  As described above, by using the separation layer 14 having the adhesive portion on the outer peripheral portion, for example, even if a separation layer material having low resistance to a solvent used in lithography processing, plating processing, or the like is used, the adhesive portion is provided on the outer periphery. By providing, the separation layer material portion can be protected. Therefore, the choice of the material for forming the separation layer 14 is expanded.

[Fourth Embodiment]
The peeling method according to this embodiment will be described with reference to FIG. FIG. 5 is an explanatory view showing a peeling method according to another embodiment of the present invention. As shown in FIG. 5, the peeling method according to this embodiment is different from the first embodiment in that a laminated body 40 in which a support 12 having a through hole and a wafer 1 are bonded is used. Therefore, in this embodiment, a different point from 1st Embodiment is demonstrated and it abbreviate | omits about another detail.

  In the peeling method of the present embodiment, as shown in FIG. 5A, the wafer 1 and the support 12 having a through-hole penetrating in the thickness direction are bonded together via the adhesive layer 3. The laminated body 40 is the subject of the peeling process. And as shown to (b) in FIG. 5, the laminated body 40 is immersed in the solvent introduce | transduced in the tank 100. FIG.

  In the present embodiment, since the support 12 has a through hole penetrating in the thickness direction, the solvent is bonded to the adhesive layer through the through hole only by immersing the laminate 40 in the solvent. 3 is supplied. Therefore, as shown in FIG. 5C, the adhesive layer 3 swollen by the solvent together with the support 12 can be easily separated from the wafer 1. Then, as shown in FIG. 5 (d), the cleaning liquid is spin-coated on the surface of the wafer 1 after the adhesive layer 3 is swelled and peeled, whereby a high-quality wafer 1 having no residue can be obtained.

[Fifth Embodiment]
The peeling method according to this embodiment will be described with reference to FIG. FIG. 6 is an explanatory view showing a peeling method according to another embodiment of the present invention. As shown in FIG. 6, the peeling method according to the present embodiment is different from the fourth embodiment in that an ultrasonic vibration process is included. Therefore, in this embodiment, a different point from 4th Embodiment is demonstrated and it abbreviate | omits about another detail.

  In the peeling method of this embodiment, as shown in FIG. 6A, the wafer 1 and the support 12 having a through hole penetrating in the thickness direction are bonded together via the adhesive layer 3. The laminated body 40 is the subject of the peeling process. Then, as shown in FIG. 6 (b), the ultrasonic vibration device 102 is placed on the support 12, and the laminated body 40 is formed, for example, via the solvent injection port 103 provided at the center thereof. Supply solvent. The solvent supplied to the laminate 40 through the solvent inlet 103 is supplied to the adhesive layer 3 through the through hole of the support 12.

(Ultrasonic vibration process)
Next, as shown in FIG. 6C, in the ultrasonic vibration step, the adhesive layer 3 supplied with the solvent is ultrasonically vibrated. In the ultrasonic vibration process, the ultrasonic vibrator provided in the ultrasonic vibration device 102 is ultrasonically vibrated, and the vibration is propagated to the adhesive layer 3 through the support 12 to cause the adhesive layer 3 to be ultrasonically vibrated. Can be vibrated. In the ultrasonic vibration step, the ultrasonic vibration device 102 may propagate, for example, ultrasonic waves having a frequency of 1 kHz to 1 MHz to the adhesive layer 3 for 1 to 30 minutes, and ultrasonic waves having a frequency of 26 kHz for 10 minutes. More preferably, it is propagated to the adhesive layer 3.

  Thus, the solvent supplied to the adhesive layer 3 can permeate the adhesive layer 3 more rapidly by ultrasonically vibrating the adhesive layer 3. As a result, since the adhesive layer 3 can be swollen more rapidly, as shown in FIG. 6D, the support 12 and the adhesive layer 3 are separated, and the adhesive layer 3 and the wafer 1 are separated. Can be more quickly separated. Then, as shown in FIG. 6 (e), the cleaning liquid is spin-coated on the surface of the wafer 1 after the adhesive layer 3 is swelled and peeled, whereby a high-quality wafer 1 having no residue can be obtained.

[Peeling device]
A peeling apparatus according to the present invention is a peeling apparatus that peels a support attached to a wafer via an adhesive layer from the wafer, and swells the adhesive layer to increase the adhesiveness of the surface. Solvent supply means for supplying the solvent to be lowered to the adhesive layer, and peeling means for peeling the adhesive layer from the wafer. That is, the peeling apparatus according to the present invention is an embodiment of a peeling apparatus for carrying out the peeling method according to the present invention. Therefore, the description of the peeling apparatus according to the present invention is in accordance with the above description of the peeling method according to the present invention.

[Example 1]
(Preparation of adhesive composition)
100 parts by weight of hydrogenated styrene elastomer H1051 (SEBS: styrene-ethylene / butylene-styrene triblock copolymer) manufactured by Kuraray Co., Ltd. was dissolved in decahydronaphthalene, which is the main solvent, at a concentration of 25%. Next, a butyl acetate solution in which IRGANOX 1010 as a thermal polymerization inhibitor was dissolved was added so that the thermal polymerization inhibitor was 1 part by weight and the butyl acetate was 15 parts by weight with respect to 100 parts by weight of the elastomer. Thereby, an adhesive composition was obtained.

(Formation of laminate)
The above adhesive composition was spin-coated on a semiconductor wafer substrate (Si, 12 inches) and baked at 100 ° C., 160 ° C., and 200 ° C. for 5 minutes each to form an adhesive layer having a thickness of 100 μm.

  A glass substrate having a through-hole (12-inch glass substrate, thickness 700 μm) and an adhesive layer were bonded together at 1,000 kg for 5 minutes under a reduced pressure of 215 ° C. to form a laminate. About the formed laminated body, it confirmed visually that there was no sticking defect (unbonded part) which leads to the failure | damage in subsequent thinning process and heat processing, and the fall of the in-plane uniformity of a wafer.

(Thinner thinning and heat treatment)
In the formed laminate, the back surface of the wafer was thinned (50 μm) using a back grinder manufactured by DISCO, and then subjected to heat treatment at 220 ° C. for 3 hours in an N ₂ environment. It was confirmed that there was no problem in resistance and heat resistance.

(Peeling treatment)
The PGMEA solvent was injected into the laminated body after the thinning treatment and the heat treatment through the through-hole of the support, and was ultrasonically vibrated at a frequency of 26 kHz for 10 minutes. As a result, the adhesive layer was swollen and the adhesiveness of the surface was lowered, and the support could be easily peeled off. Further, the swollen adhesive layer was removed from the wafer to obtain a wafer without residue.

[Example 2]
(Formation of laminate)
The adhesive composition prepared in Example 1 was spin-coated on a semiconductor wafer substrate (Si, 12 inches), and baked at 100 ° C., 160 ° C., and 200 ° C. for 5 minutes each to form an adhesive layer having a thickness of 100 μm. Formed.

Next, under the conditions of a flow rate of 400 sccm, a pressure of 700 mTorr, a high frequency power of 2500 W, and a film formation temperature of 240 ° C., a fluorocarbon film (thickness 1 μm) as a separation layer is bare glass by a CVD method using C ₄ F ₈ as a reaction gas. A formed support (12-inch glass substrate, thickness 700 μm) was formed. Thereafter, the separation layer and the adhesive layer were bonded at 1,000 kg for 5 minutes under a reduced pressure of 215 ° C. to form a laminate. About the formed laminated body, it confirmed visually that there was no sticking defect (unbonded part) which leads to the failure | damage in subsequent thinning process and heat processing, and the fall of the in-plane uniformity of a wafer.

(Thinner thinning and heat treatment)
In the formed laminate, the back surface of the wafer was thinned (50 μm) using a back grinder manufactured by DISCO, and then subjected to heat treatment at 220 ° C. for 3 hours in an N ₂ environment. It was confirmed that there was no problem in resistance and heat resistance.

(Peeling treatment)
The laminated body after the thinning treatment and the heat treatment was irradiated with a laser beam of 532 nm from the support side of the laminated body toward the separation layer to separate the support. Subsequently, PGMEA was sprayed on the adhesive layer with a spray nozzle for 5 minutes to swell and peel the adhesive layer. Furthermore, the wafer surface from which the adhesive layer was separated was spin washed with p-menthane to obtain a wafer without residue.

[Comparative Example]
(Preparation of adhesive composition), (Formation of laminate), and (Thinning / thinning of laminate) were carried out in the same manner as in the Examples, and then p-menthane through the through-holes of the support. The solvent was injected and ultrasonically vibrated at a frequency of 26 kHz for 60 minutes. As a result, the adhesive layer was dissolved and the support and the wafer could be separated, but it took a longer time compared to the examples.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be suitably used, for example, in a manufacturing process of a miniaturized semiconductor device.

1 Wafer 2 Support 3 Adhesive Layer 4 Separation Layer 10 Laminate

Claims (4)

A peeling method for peeling a support attached to a wafer via an adhesive layer from the wafer,
Between the support and the adhesive layer, there is further provided a separation layer that changes in quality by absorbing light irradiated through the support,
The separation layer includes an adhesive portion including an adhesive composition that forms the adhesive layer on an outer peripheral portion thereof,
A solvent supply step of swelling the adhesive layer and supplying the adhesive layer with a solvent that reduces the adhesiveness of the surface;
Before the solvent supply step, the light irradiation step of irradiating the separation layer with light through the support to alter the separation layer; and
Between the light irradiation step and the solvent supply step, a support peeling step for peeling the support from the adhesive layer,
Before the support peeling step, supplying the solvent to the adhesive part,
And a peeling step of peeling the swollen adhesive layer from the wafer after the solvent supplying step . The peeling method according to claim 1, further comprising an ultrasonic vibration step of ultrasonically vibrating the adhesive layer supplied with the solvent between the solvent supply step and the peeling step. After the above peeling step, the peeling method according to claim 1 or 2, characterized in that it comprises a cleaning step of cleaning the upper wafer in which the adhesive layer is peeled off. The adhesive layer contains a styrene unit as a constituent unit of the main chain, the content of the styrene unit is 10% by weight or more and 90% by weight or less, and the weight average molecular weight is 10,000 or more and 200,000 or less. The peeling method according to any one of claims 1 to 3 , wherein the peeling method is formed of an adhesive composition containing 40% by weight or more of a certain elastomer.

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