JP5358319B2 - Adhesive composition and adhesive film - Google Patents

Description

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

  In recent years, with the enhancement of functions of mobile phones, digital AV devices, IC cards, and the like, demands for miniaturization, thinning, and high integration of semiconductor silicon chips (hereinafter referred to as chips) are increasing. Further, there is a demand for thinning integrated circuits represented by CSP (chip size package) and MCP (multi-chip package) that integrate a plurality of chips into one package. 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. Here, a system-in-package (SiP) in which a plurality of semiconductor chips are mounted in one semiconductor package reduces the size of the mounted chip, makes it thinner, and achieves higher integration, thereby improving the performance of electronic devices. This is a very important technology for realizing reduction in size, size and weight.

  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 order to meet such demands for thinning and high integration, not through wire bonding technology, through electrode technology in which chips with through electrodes are stacked and bumps are formed on the back surface of the chip is also used. Necessary.

  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, and incorporating an integrated circuit. It is manufactured by dicing the semiconductor wafer after grinding with a grinder and grinding to a predetermined thickness. At this time, the predetermined thickness is about 100 to 600 μm. Furthermore, the chip for forming the through electrode is ground to a thickness of about 50 to 100 μm.

  In the manufacture of semiconductor chips, the semiconductor wafer itself is not only fragile because it is thin, but also has irregularities in the circuit pattern, so that it is easily damaged when an external force is applied during conveyance to the grinding process or dicing process. Further, in the grinding process, for the purpose of removing the generated polishing debris or releasing the heat generated during polishing, grinding is performed while flowing purified water on the back surface of the semiconductor wafer. At this time, it is necessary to prevent the circuit pattern surface from being contaminated by purified water used for cleaning or the like. 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.

  In addition to the example described above, processes involving a high-temperature process in backside wiring such as formation of through electrodes are performed in a state where the semiconductor wafer is bonded and fixed. Adhesive compositions that can be suitably used in processes involving high-temperature processes have been proposed (for example, Patent Documents 1 and 2).

JP 2000-243815 (published September 8, 2000) JP 2008-133405 A (released on June 12, 2008)

  However, considering the resistance to back rinse (solvent) used for lithography in backside wiring, removing the adhesive after backside wiring without damaging (cracking) the semiconductor wafer, and heat resistance in high temperature processes, The adhesive compositions of Documents 1 and 2 are not necessarily suitable. For example, Patent Document 1 describes the use of a positive chemically amplified resist as an adhesive, but does not describe a specific composition of the adhesive. For this reason, it was unclear whether the above conditions could be satisfied at the same time. Moreover, the adhesive composition of patent document 2 is an acrylic adhesive composition, and such a composition could not satisfy the above conditions at the same time.

  This invention is made | formed in view of said situation, The objective of this invention is providing the adhesive composition which has the high tolerance with respect to a solvent, and the solubility with respect to a solvent improves in a desired timing. is there.

  The adhesive composition of the present invention is characterized by containing polyvinyl ether, a resin containing a polymer having a functional group capable of reacting with the vinyl group of the polyvinyl ether, and an acid generator.

  As described above, the adhesive composition of the present invention contains polyvinyl ether and a resin containing a polymer having a functional group capable of reacting with the vinyl group of the polyvinyl ether. The polymer reacts with the polyvinyl ether and is protected from dissolution in the solvent. Further, the acid generated from the acid generator by appropriate treatment removes the protection of the polymer by polyvinyl ether, so that the solubility in the solvent is improved again. Therefore, the adhesive composition of the present invention does not dissolve in various processing steps using a solvent and can be easily removed after the processing step.

[Adhesive composition]
One embodiment of the adhesive composition according to the present invention will be described below.

  The adhesive composition of the present invention contains polyvinyl ether, a resin containing a polymer having a functional group capable of reacting with the vinyl group of the polyvinyl ether, and an acid generator.

  If the adhesive composition of the present invention is used as an adhesive, the specific application is not particularly limited. In the present embodiment, an application of temporarily bonding a semiconductor wafer to a support plate using the adhesive composition of the present invention for a wafer support system will be described as an example.

<Resin component>
The “resin” includes one or more polymers including a repeating unit having a functional group capable of reacting with a vinyl group of polyvinyl ether. The “resin” may contain one or more kinds of polymers that do not contain a repeating unit having a functional group capable of reacting with the vinyl group of the polyvinyl ether, if necessary.

  In the present specification, the ratio of “a repeating unit having a functional group (reactive with polyvinyl ether) (or a chemical structure having an aromatic ring) in the total number of repeating units constituting the resin” described later constitutes the resin. It refers to the ratio of “a repeating unit having a functional group (reactive with polyvinyl ether) (or a chemical structure having an aromatic ring)” in the total number of repeating units contained in all the polymers described above.

  In the present specification, the “solvent” includes both an organic solvent and an inorganic solvent. Accordingly, when “organic solvent” or “inorganic solvent” is used instead of simply describing “solvent”, it means only one of them.

(Repeating unit having a functional group capable of reacting with the vinyl group of polyvinyl ether)
The adhesive composition of this invention contains the polymer containing the repeating unit which has a functional group which can react with the vinyl group which polyvinyl ether has as a resin component. In the present specification, the repeating unit is not particularly limited as long as it is a repeating unit in which polyvinyl ether is cross-linked to the above functional group by reaction.

  Since the adhesive composition according to the present invention has a polymer containing the above repeating unit as a resin component, the polyvinyl ether described below is cross-linked by the functional group by the reaction to stabilize the polymer (heavy The molecular weight of the coalescence increases). Therefore, the solubility with respect to the solvent of the said adhesive composition becomes very low. Therefore, the state in which the adherend is attached to a support such as a film can be maintained without being dissolved in a process using a solvent. Furthermore, the cross-linked polyvinyl ether is removed from the repeating unit (repeating unit is deprotected) by the action of an acid generated from an acid generator described later. Therefore, when the process that requires resistance to the solvent is finished, for example, if acid is generated from the acid generator by irradiation with light and / or heating, the solubility in the solvent is improved.

  As described above, since the adhesive composition according to the present invention is insolubilized or solubilized in a solvent as necessary, it can be suitably used in various processes using a solvent, and an adherend. Easy to remove from. The adhesive composition according to the present invention is particularly excellent in resistance to organic solvents.

  Here, as long as some of the repeating units of the polymer have a functional group capable of reacting with the vinyl group of the polyvinyl ether, various structures can be adopted for other portions. Therefore, it is possible to select polymer repeating units having various structures such that the adhesive composition has desirable properties other than solubility in a solvent (for example, high heat resistance and adhesive strength).

  As an example of a repeating unit having a functional group capable of reacting with a vinyl group of polyvinyl ether, the general formula (1):

(R ¹ represents a functional group capable of reacting with polyvinyl ether; R ² represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ³ represents an alkyl group having 1 to 5 carbon atoms; R ¹ ′ represents Or an alkylene group having 1 to 5 carbon atoms; n ₁ is an integer of ₁ to 5; n ₂ is 0 or an integer of 1 to 2)
The repeating unit shown by is mentioned.

As R ¹ , for example, a hydroxyl group or a carboxyl group is preferable.

Alkyl group and ^{R 3} in R ² is an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group include linear or branched chain such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopropyl group, and neopentyl group. Of the alkyl group. Of these, a methyl group is preferred.

n ₁ is an integer of ₁ to 5, preferably 1 or 2, and most preferably 1. The bonding position of —R ¹ ′ R ¹ may be any of the o-position, m-position and p-position of the phenyl group, but since it is easy to react with polyvinyl ether, it may be in the p-position. preferable.

n ₂ is 0 or 1 of the integer, preferably 0 or 1, more preferably 0. When n ₂ is 1, the position of R ³ can be either the o-position, m-position or p-position of the phenyl group. When n ₂ is 2 or 3, the position of R ³ can be selected from any position. Also in this case, R ³ may be the same or different.

  As described above, the functional group capable of reacting with the vinyl group of the polyvinyl ether is, for example, a hydroxyl group or a carboxyl group. When the functional group is a hydroxyl group or a carboxyl group, an acetal bond is formed between the functional group and the vinyl group of polyvinyl ether. An example of the reaction between the functional group and polyvinyl ether when the functional group is a hydroxyl group will be described below. In the following examples, description will be given by giving specific examples of repeating units and polyvinyl ether that can vary the solubility of the adhesive composition of the present invention in an organic solvent.

  In the adhesive composition of the present invention, the following formula (2):

In one example of the reaction represented by the formula (1), the repeating unit contained in the polymer is cross-linked by polyvinyl ether, and the acetal bond is decomposed by the action of acid and water to release the cross-linking. The water required for the decomposition of the acetal bond is, for example, moisture in the atmosphere. Here, hydroxystyrene is exemplified as a repeating unit, and cyclohexanedimethanol divinyl ether is exemplified as an example of polyvinyl ether. However, as the repeating unit, all the repeating units described in this item can be adopted, and as the polyvinyl ether, all the polyvinyl ethers explained in the section of <Polyvinyl ether> described later can be adopted. .

  As shown in (a) of the formula (2), the hydroxyl group of hydroxystyrene and the vinyl group at the end of cyclohexanedimethanol divinyl ether are cross-linked by applying heat under acidic conditions. Then, the polymer containing hydroxystyrene is stabilized (the molecular weight of the polymer is increased). This makes the adhesive composition insoluble in organic solvents.

  As shown in (b) of the formula (2), the acetal protecting group that has crosslinked the hydroxystyrenes by the action of an acid generated from the acid generator by appropriate treatment (light irradiation, heating, etc.) is 1 , 4-cyclohexanedimethanol and acetaldehyde. Thereby, the hydroxystyrene having an acetal protecting group is returned to the original hydroxystyrene. That is, the adhesive composition becomes soluble in an organic solvent.

  Moreover, in the adhesive composition according to the present invention, it is preferable that the polymer has an aromatic ring as in the example of the repeating unit described above. When the polymer contains an aromatic ring, the heat resistance of the adhesive composition is improved. Therefore, the adhesive composition more suitable for the process using a solvent and including a high temperature process can be provided. This aromatic ring may be contained in a repeating unit having the above functional group, or may be contained in a repeating unit other than the repeating unit.

  In the adhesive composition according to the present invention, the ratio of the repeating unit having the above functional group to the total number of moles of repeating units constituting the resin is preferably 10% or more. If the resin contains a repeating unit having the above functional group within such a range, the resin is sufficiently protected by the polyvinyl ether, so that the resistance to the solvent is further improved.

  The repeating unit having a functional group capable of reacting with polyvinyl ether means one type selected from the above chemical structure, or a combination of two or more types. When two or more types of repeating units are included, the repeating units are included in one type of polymer constituting the resin, or included in two or more types of polymers constituting the resin in various combinations.

(Other components contained in the resin)
In addition to the repeating unit having a functional group capable of reacting with polyvinyl ether, the resin has various chemical structures known to those skilled in the art as long as the reaction between the functional group capable of reacting with polyvinyl ether and the polyvinyl ether is not hindered. It can be included as a repeating unit. In addition, this chemical structure may be contained in the polymer containing the repeating unit which has a functional group which can react with polyvinyl ether, or may be contained in polymers other than the said polymer. The other component contained in the resin is selected according to the use, for example, from a compound that improves the heat resistance, flexibility, adhesive strength, or solubility in a solvent of the adhesive composition. Among these, since the heat resistance of the adhesive composition is improved, for example, a chemical structure having an aromatic ring is preferable. Therefore, the styrene structure having an aromatic ring will be described below as an example of other repeating units contained in the resin.

  In this specification, a styrene structure means a repeating unit contained in a resin that is polymerized by cleavage of an ethylenic double bond. In the styrene structure, a hydrogen atom in a phenyl group can be substituted with an alkyl having 1 to 5 carbon atoms. That is, the styrene structure has the following general formula (3):

(R ² , R ³ and n ₂ have the same definition as in general formula (1))
It is a compound shown by.

  Styrene means one type selected from the compounds as described above, or a combination of two or more types. When two or more types of repeating units are included, the repeating units are included in one type of polymer constituting the resin, or included in two or more types of polymers constituting the resin in various combinations.

  The content in the resin having a chemical structure having an aromatic ring is such that the proportion of styrene in the total number of moles of repeating units constituting the resin is 10% or more, 90% or more, preferably 10% or more, 50% or more, more preferably May be in the range of 10 to 30%. If the resin contains a chemical structure having an aromatic ring within the range, the heat resistance of the adhesive composition can be further improved.

<Polyvinyl ether>
The adhesive composition according to the present invention contains polyvinyl ether. Two or more vinyl groups contained in the polyvinyl ether can react with the functional group of the above repeating unit contained essentially in the resin. The vinyl group and the functional group can be reacted by various treatments. For example, it is preferable that the vinyl group and the functional group can be reacted by heat.

  The polyvinyl ether according to the present invention has the following formula (4) or (5):

(R ⁴ represents a linear or branched alkylene group having 1 to 10 carbon atoms; R ⁵ represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms. R ⁶ represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 7 carbon atoms; A represents a c-valent organic group; B represents —CO—O— or —NHCO—; Or -NHCONH-; c represents an integer of 2 to 8; d represents 0 or an integer of 1 to 10)
It is a compound shown by.

As A (c-valent organic group), for example, preferably a substituted or unsubstituted alkylene group having 1 to 50 carbon atoms, particularly 1 to 40 carbon atoms, and a substituted group having 6 to 50 carbon atoms, particularly 6 to 40 carbon atoms. Or a hydrocarbon group such as an unsubstituted arylene group, a group in which the alkylene group and the arylene group are bonded, and a 3- to 8-valent group in which a hydrogen atom bonded to a carbon atom in these groups is eliminated, and Examples thereof include a divalent to octavalent heterocyclic group and a group in which the heterocyclic group and the hydrocarbon group are bonded. In the alkylene group and arylene group, heteroatoms such as O, NH, N (CH ₃ ), S or SO ₂ may intervene. The substituents in the substituted alkylene group are a hydroxyl group, a carboxyl group, a carbonyl group, and a fluorine atom.

  Examples of A include groups represented by the following chemical formulas 5 to 8.

  Examples of the compound represented by the formula (4) include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,3-propanediol divinyl ether, 1,3-butanediol divinyl ether. 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, trimethylolethane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, 1, 4-cyclohexanedimethanol divinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol Ritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, ethylene glycol diethylene vinyl ether, triethylene glycol diethylene vinyl ether, ethylene glycol dipropylene vinyl ether, triethylene glycol diethylene vinyl ether, trimethylolpropane triethylene vinyl ether, trimethylol Mention may be made of propanediethylene vinyl ether, pentaerythritol diethylene vinyl ether, pentaerythritol triethylene vinyl ether, and pentaerythritol tetraethylene vinyl ether.

  Moreover, the compound shown by Formula (5) can be manufactured by reaction of polyvalent carboxylic acid and halogenated alkyl vinyl ether, when B is -CO-O-. When B is —CO—O—, examples of the compound represented by the formula (5) include terephthalic acid diethylene vinyl ether, phthalic acid diethylene vinyl ether, isophthalic acid diethylene vinyl ether, phthalic acid dipropylene vinyl ether, terephthalic acid dipropylene vinyl ether. , Dipropylene vinyl ether of isophthalic acid, diethylene vinyl ether maleate, diethylene vinyl ether fumarate, and diethylene vinyl ether itaconic acid.

  The polyvinyl ether is preferably divinyl ether or trivinyl ether.

  When the polyvinyl ether is divinyl ether, the content of polyvinyl ether in the adhesive composition is preferably 3 parts by weight or more and 50 parts by weight or less based on 100 parts by weight of the resin. As mentioned above, it is more preferable that it is 20 parts weight or less. When the content of polyvinyl ether in the adhesive composition is within the above range, the adhesive composition further improves resistance to the solvent.

  When the polyvinyl ether is trivinyl ether, the content of polyvinyl ether in the adhesive composition is preferably 1 part by weight or more and 30 parts by weight or less based on 100 parts by weight of the resin. As mentioned above, it is more preferable that it is 25 weight part or less. When the content of polyvinyl ether in the adhesive composition is within the above range, the adhesive composition further improves resistance to the solvent.

  The above-mentioned polyvinyl ether can be used as one type or a combination of two or more types.

<Acid generator>
The adhesive composition according to the present invention further contains an acid generator. The acid generator is not particularly limited, but is a compound known to those skilled in the art that generates an acid. As the acid generator, a photoacid generator that generates an acid by light irradiation or a thermal acid generator that generates an acid by heating is preferable. Of these, a photoacid generator is more preferable.

  Here, in the adhesive composition according to the present invention, the ratio of the acid generator to 100 parts by mass of the resin is preferably 0.1 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 10 parts by mass or less. More preferably, it is 1 part by mass or more and 10 parts by mass or less. If the ratio of the acid generator contained in the adhesive composition is within such a range, the treatment for generating the acid (for example, exposure) can be performed in a short time, and the acid generator at a high temperature can be used. Decomposition can be prevented more reliably.

  Examples of acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkylsulfonyldiazomethanes or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, etc. Examples thereof include a diazomethane acid generator, a nitrobenzyl sulfonate acid generator, an imino sulfonate acid generator, and a disulfone acid generator. Of these acid generators, onium salt acid generators have a high decomposition temperature and are suitable for high-temperature processes. Therefore, details of the onium salt acid generator will be described below as an example of the acid generator.

  Examples of the onium salt acid generator include the general formula (6) or (7):

(R ^{7 to} R ⁹ and R ^{11 to} R ¹² each independently represents an aryl group or an alkyl group; any two of R ^{7 to} R ⁹ are bonded to each other to form a ring together with the sulfur atom in the formula) R ¹⁰ represents a substituted or unsubstituted alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group; at least one of R ^{7 to} R ⁹ represents an aryl group; ^At least one of ^{11 to} R ¹² represents an aryl group)
It is a compound represented by these.

Note that at least one of R ^{7 to} R ⁹ represents an aryl group. Among R ⁷ to R ^9, preferably more than two are aryl ^groups, it is particularly desirable that all of R 7 to R ⁹ is an aryl group.

Although the aryl group of R < ⁷ > -R < ⁹ > is not specifically limited, For example, it is a C6-C20 aryl group. In the aryl group, part or all of the hydrogen atoms are substituted with an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, or the like, or are unsubstituted. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Examples of such aryl groups include phenyl and naphthyl groups.

  The alkyl group with which the hydrogen atom of the aryl group can be substituted is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group. The alkoxy group with which the hydrogen atom of the aryl group can be substituted is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group or tert-butoxy group. A group is more preferable, and a methoxy group or an ethoxy group is most preferable. A fluorine atom is preferred as the halogen atom with which the hydrogen atom of the aryl group can be substituted.

Although the alkyl group of R < ⁷ > -R < ⁹ > is not specifically limited, For example, it is a C1-C10 linear, branched or cyclic alkyl group etc. These alkyl groups are, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, n-pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, nonyl group or decanyl group. is there. Of these, a methyl group is preferred because it can be synthesized at low cost.

When any two of R ^{7 to} R ⁹ are bonded to each other to form a ring together with the sulfur atom in the formula, the ring preferably forms a 3 to 10 membered ring including the sulfur atom. More preferably, a 5- to 7-membered ring is formed. The ring is, for example, benzothiophene, dibenzothiophene, 9H-thioxanthene, thioxanthone, thianthrene, phenoxathiin, tetrahydrothiophenium, or tetrahydrothiopyranium. Further, when any two of R ^{7 to} R ⁹ are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one that does not form the ring is preferably an aryl group. The definition of the aryl group is the same as the definition of the aryl group of R ^{7 to} R ⁹ described above.

R ¹⁰ represents a substituted or unsubstituted alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group. The alkyl group in R ¹⁰ can be a linear, branched or cyclic alkyl group. The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.

The halogenated alkyl group for R ¹⁰ is, for example, an alkyl group in which some or all of the hydrogen atoms in the linear, branched, or cyclic alkyl group are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and among them, a fluorine atom is preferable. In the halogenated alkyl group, the ratio of the total number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10% or more and 100% or less, 50 Above, 100% or less is more preferable, and 100% is most preferable. Since the strength of the acid is increased, the higher the halogenation rate among the halogenated alkyl groups, the more preferable.

The aryl group for R ¹⁰ is preferably an aryl group having 6 to 20 carbon atoms.

The alkenyl group for R ¹⁰ is preferably an alkenyl group having 2 to 10 carbon atoms.

In R ¹⁰ , “substituted or unsubstituted” means that some or all of the hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group are substituted ( It means that it may be in a state of being substituted with another atom or group other than a hydrogen atom. The number of substituents in R ¹⁰ can be one or more. The substituent is, for example, a halogen atom, a hetero atom, or an alkyl group. The definition of the halogen atom or alkyl group is the same as the definition of the halogen atom or alkyl group in the halogenated alkyl group described above. The hetero atom is, for example, an oxygen atom, a nitrogen atom, or a sulfur atom.

  Examples of onium salt acid generators represented by formulas (6) and (7) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate or Nonafluorobutanesulfonate, trifluoromethanesulfonate of triphenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of tri (4-methylphenyl) sulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, Dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptafluor Propanesulfonate or its nonafluorobutanesulfonate, monophenyldimethylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; diphenylmonomethylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, (4-Methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfone , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoro Propanesulfonate or its nonafluorobutanesulfonate, di (1-naphthyl) phenylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate; 1- (4-methylphenyl) Tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate or Nonafluorobutanesulfonate; 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate; 1- (4-ethoxynaphthalen-1-yl ) Tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluo 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate, Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl- 4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropane sulfate Sulfonate or its nonafluorobutane sulfonate; trifluoromethanesulfonate and 1- (4-methylphenyl) tetrahydrothiophenium Pila chloride, its like heptafluoropropane sulfonate or nonafluorobutane sulfonates.

  Moreover, the onium salt which replaced the anion part of these onium salts by alkyl sulfonates, such as methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate, can be used as an acid generator.

  Further, in the onium salt acid generator, the anion moiety of the formula (6) or (7) is represented by the general formula (8a) or (8b):

(X ″ represents a C 2-6 alkylene group in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom substituted with a fluorine atom. Represents an alkyl group having 1 to 10 carbon atoms)
(Wherein the cation moiety is the same as the cation moiety of formula (6) or (7)).

  X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom. The alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, and most preferably 3 carbon atoms. Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. The alkyl group has 1 to 10 carbon atoms. , Preferably 1-7, more preferably 1-3.

  The number of carbon atoms of the alkylene group of X ″ or the alkyl group of Y ″ and Z ″ is preferably as small as possible within the above-mentioned range from the viewpoint of high solubility in a solvent. In the alkyl group of Y ″ and Z ″, the larger the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid and the better the transparency to high energy light or electron beam of 200 nm or less. . The proportion of fluorine atoms in the alkylene group or alkyl group (fluorination rate (%)) is preferably 70 or more and 100% or less, more preferably 90 or more and 100% or less, and most preferably 100%. An alkylene group or alkyl group in which all hydrogen atoms are substituted with fluorine atoms (100% fluorination rate) is a perfluoroalkylene group or a perfluoroalkyl group.

  Furthermore, the onium salt acid generator is represented by the general formula (9a) or (9b):

(R ^{21 to} R ²⁶ each independently represents an alkyl group, an acetyl group, an alkoxy group, a carboxy group, a hydroxyl group, or a hydroxyalkyl group; n _{21 to} n ₂₅ are each independently an integer of 0 to 3; N ₂₆ is an integer from 0 to 2)
And a sulfonium salt having an anion moiety represented by:

In R ^{21 to} R ²⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, Most preferred is an n-butyl group or a tert-butyl group. As an alkoxy group, a C1-C5 alkoxy group is preferable, Among these, a linear or branched alkoxy group is more preferable, and a methoxy group or an ethoxy group is the most preferable. In the hydroxyalkyl group, one or more hydrogen atoms in the alkyl group are preferably substituted with a hydroxy group. Examples of the hydroxyalkyl group include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.

When n ₂₁ ~n ₂₆ is an integer of 2 or more, each of the plurality of ^R 21 ^{to R 26,} the same or different. n ₂₁ is preferably 0, 1 or 2, more preferably 0 or 1, and most preferably 0. n ₂₂ and n ₂₃ are preferably each independently 0 or 1, more preferably 0. n ₂₄ is preferably 0, 1 or 2, more preferably 0 or 1. n ₂₅ is preferably 0 or 1, more preferably 0. n ₂₆ is preferably 0 or 1, more preferably 1.

  The adhesive composition according to the present invention includes any one of the onium salt acid generator and the known acid generator as described above, or a combination of two or more thereof as the acid generator according to the present invention. May be contained.

<Other components in adhesive composition>
The adhesive composition according to the present invention includes miscible additives such as additional resins, plasticizers, and adhesion assistants for improving the performance of the adhesive, as long as the essential characteristics of the present invention are not impaired. What is conventionally used in the said field | areas, such as an agent, a stabilizer, a coloring agent, and surfactant, can further be added. Further, the viscosity of the adhesive composition may be adjusted by diluting with an organic solvent as long as the essential characteristics of the present invention are not impaired. Any organic solvent may be used as long as it can dissolve other components contained in the adhesive composition and form a uniform solution. Therefore, what is necessary is just to select the organic solvent which can be used for this invention from 1 type, or 2 or more types as needed from all the conventionally well-known organic solvents.

  Examples of organic solvents include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cycloheptanone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, or 2-heptanone; ethylene glycol, diethylene glycol Polyhydric alcohols such as propylene glycol or dipropylene glycol; compounds that form ester bonds (such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate); Monomethyl ether, monoethyl ether, monopropyl ether, or monobutyl of alcohols or compounds having the above ester bond Derivatives of polyhydric alcohols such as compounds having monoalkyl ethers or monophenyl ethers such as ether (of which propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred); rings such as dioxane Formula ethers or esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, or ethyl ethoxypropionate; and anisole, ethyl Benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, Aromatic organic solvents such as isopropylbenzene, toluene, xylene, cymene, or mesitylene can be used.

  These organic solvents can be used as a single solvent or a mixed solvent of two or more.

  Among these, PGMEA, PGME, or EL is preferable as the organic solvent when used alone.

  The amount of the organic solvent used is appropriately selected according to the film thickness desired to be applied with the adhesive composition, and the concentration of the adhesive composition can be applied onto a support such as a semiconductor wafer. There is no particular limitation as long as it is within the range. In general, the adhesive composition is used in such an amount that the solid content concentration is 1% by mass or more and 55% by mass or less, preferably 25% by mass or more and 45% by mass or less.

[(Co) polymerization reaction]
When a (co) polymerization reaction is used for preparing the resin, it may be carried out by a known method, and the method is not particularly limited. For example, the adhesive composition according to the present invention can be obtained by stirring the monomer composition using an existing stirring device.

  The temperature condition in the (co) polymerization reaction may be appropriately set and is not limited, but is preferably 60 ° C. or higher and 150 ° C. or lower, more preferably 70 ° C. or higher and 120 ° C. or lower.

  In the (co) polymerization reaction, a solvent may be used as necessary. Examples of the solvent include the organic solvents described above, and PGMEA is particularly preferable.

  In the copolymerization reaction for obtaining the adhesive composition according to the present invention, a polymerization initiator may be used as necessary. As polymerization initiators, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), dimethyl 2,2′-azobisisobutyrate, 1,1′-azobis (cyclohexane) -1-carbonitrile) and azo compounds such as 4,4′-azobis (4-cyanovaleric acid); and decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, bis (3,5,5-trimethylhexanoyl) peroxide Organic peroxides such as succinic acid peroxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxypivalate, and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate Can be mentioned. One of these polymerization initiators may be used, or two or more polymerization initiators may be mixed and used as necessary. The amount of the polymerization initiator used is not particularly limited as long as it is appropriately set according to the combination of the monomer compositions or reaction conditions.

[Adhesive film]
The adhesive film which concerns on this invention is equipped with the adhesive bond layer containing any one of said adhesive composition on a film. The said adhesive film is obtained in the process of an adhesive film method. In the adhesive film method, an adhesive layer containing any one of the adhesive compositions described above is formed in advance on a film that temporarily becomes a substrate such as a flexible film, and then dried, and then the adhesive film is used. Is used by pasting to a workpiece.

  Since the adhesive composition contains a resin containing a repeating unit having a functional group capable of reacting with polyvinyl ether and polyvinyl ether as described in the above section [Adhesive composition], the adhesive composition The solvent resistance of the adhesive layer constituted by is improved by heat treatment. Moreover, since the adhesive composition further contains an acid generator, the solubility in a solvent is improved by light irradiation. That is, the adhesive film according to the present invention can freely vary the solubility in a solvent at a desired timing. Therefore, the adhesive film according to the present invention is suitable for a process using a solvent.

  The adhesive film may have a configuration in which a protective film is coated on the adhesive surface of the adhesive layer. When the structure is adopted, the protective film on the adhesive layer is peeled off and the exposed adhesive surface of the adhesive layer is superimposed on the workpiece, and then the film (flexible film) is formed from the adhesive layer. Etc.) can be easily provided on the workpiece.

  Here, the adhesive composition which concerns on this invention mentioned above can employ | adopt various utilization forms according to a use. For example, a method of applying an adhesive layer on a workpiece such as a semiconductor wafer to form an adhesive layer in a liquid state may be used. On the other hand, when the adhesive film according to the present invention is used, the film thickness uniformity and the surface smoothness are compared with the case where the adhesive composition is directly applied to the workpiece to form the adhesive layer. A good adhesive layer can be formed.

  The film for forming an adhesive layer used in the production of the adhesive film according to the present invention can peel the adhesive layer formed on the film from the film, and the adhesive layer is covered with a protective substrate, a wafer or the like. Any release film that can be transferred onto the treated surface may be used, and the other points are not particularly limited. Examples of the film for forming the adhesive layer include a flexible film made of a synthetic resin film made of polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, polyvinyl chloride, or the like having a film thickness of 15 μm or more and 125 μm or less. . The film is preferably subjected to a release treatment for facilitating transfer as necessary.

  The method for forming the adhesive layer on the film is not particularly limited, and may be appropriately selected from known methods according to the desired film thickness or uniformity of the adhesive layer. Examples of known methods include applicators, bar coaters, wire bar coaters, roll coaters, curtain flow coaters, etc., and the thickness of the adhesive layer after drying formed on the film is 10 μm or more and 1000 μm or less. The method of apply | coating the adhesive composition based on this invention so that it may have is mentioned. In particular, a roll coater is preferable because it is suitable for forming an adhesive layer excellent in film thickness uniformity and efficiently forming a thick film.

  Moreover, when using a protective film, if a protective film is a film which can be peeled from an adhesive bond layer, it will not specifically limit, For example, a polyethylene terephthalate film, a polypropylene film, a polyethylene film, etc. are preferable. Each protective film is preferably coated with silicon or baked. This is because peeling from the adhesive layer is easy. Although the thickness of a protective film is not specifically limited, It is preferable that they are 15 micrometers or more and 125 micrometers or less. This is because the flexibility of the adhesive film provided with the protective film can be secured.

  The method of using the adhesive film is not particularly limited. For example, when a protective film is used, the protective film is peeled off and the exposed adhesive surface of the adhesive layer is overlaid on the workpiece, There is a method in which the adhesive roller is thermocompression bonded to the surface of the workpiece by rotating the heating roller from the film side (the back side of the surface on which the adhesive layer is formed). In addition, if a protective film peeled from the adhesive film is wound up in a roll shape using a roller such as a winding roller, the protective film can be stored and reused.

  The adhesive composition according to the present invention is not particularly limited with respect to the application, but is suitably used as an adhesive composition for bonding a protective substrate used for precision processing of a semiconductor wafer to a substrate such as a semiconductor wafer. The adhesive composition of the present invention is suitably used as an adhesive composition (including an adhesive layer) for attaching the substrate to a support plate, particularly when grinding and thinning a substrate such as a semiconductor wafer. (For example, refer to JP-A-2005-191550).

[Stripping solution]
As a stripping solution for removing the adhesive composition according to the present invention, a stripping solution common in this field can be used. In particular, a stripping solution mainly composed of PGMEA, ethyl acetate, or methyl ethyl ketone is an environmental load. And from the viewpoint of peelability.

  Examples of the adhesive composition according to the present invention are shown below. In addition, the Example shown below is the illustration which helps understanding of this invention, Comprising: This invention is not limited at all.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Composition of adhesive composition>
A plurality of adhesive compositions having different compositions were prepared as compositions of Examples and Comparative Examples of the present invention. The composition of each of the prepared adhesive compositions is shown in Table 1 below.

(Details of each component in each adhesive composition)
Resin 1 is poly (p-hydroxystyrene) having a weight average molecular weight of 8000.
Resin 2 is poly (p-hydroxystyrene) having a weight average molecular weight of 2500.
Resin 3 is a resin having a weight average molecular weight of 2500 containing p-hydroxystyrene and styrene in a molar ratio of 80:20.
Resin 4 is a resin having an average molecular weight of 8000 containing p-hydroxystyrene and styrene in a molar ratio of 80:20.
Resin 5 is a resin obtained by substituting 25 mol% of the hydrogen atom of the hydroxyl group in p-hydroxystyrene of resin 1 with a 1-ethoxyethyl group.
Resin 6 is a resin having a weight average molecular weight of 86000 containing methyl methacrylate, n-butyl methacrylate, styrene and phenoxyethyl acrylate in a molar ratio of 15: 13: 52: 20.
The binder 1 is cyclohexane dimethanol divinyl ether. The binder 2 is a melamine binder MW30HM (Sanwa Chemical).
The acid generator is dinaphthylphenylsulfonium nonafluoro-n-butanesulfonate.
The solvent is propylene glycol monomethyl ether acetate (PGMEA).

<Evaluation of adhesive composition>
About each of the said adhesive composition of an Example and a comparative example, solvent tolerance, heat resistance, a softness | flexibility, adhesive strength, and the solubility with respect to the solvent after exposure were evaluated. Each adhesive composition was spin-coated on a semiconductor wafer in an amount of a 15 μm thick layer and baked at 110 ° C. or 150 ° C. Thereafter, the bare glass was baked at 150 ° C. on the layer of the adhesive composition to attach the bare glass. The adhesive composition in this state was evaluated as follows.

(Evaluation of solvent resistance)
Each of the three solvents (PGMEA, propylene glycol monomethyl ether (PGME) and N-methylpyrrolidone (NMP)) was soaked in solvent for 3 minutes at room temperature to give a solvent resistance of “◯” when not dissolved, and When dissolved, the solvent resistance was evaluated as “x”.

(Evaluation of heat resistance)
By TDS measurement, the case where the strength of degassing at 250 ° C. was 200,000 or less was evaluated as “◯”, and the case where it exceeded 200,000 was evaluated as “X”.

(Evaluation of flexibility)
The case where no crack was visually observed was evaluated as “◯”, and the case where a crack was generated was evaluated as “x”.

(Evaluation of adhesive strength)
Those having an adhesive strength of 2 kg / cm ² or higher at 250 ° C. were evaluated as “◯”, and those having an adhesive strength of less than 2 kg / cm ² were evaluated as “X”.

(Evaluation of solubility in solvent after exposure)
10 mW / cm ² of scattered light (including g, h, and i rays) was irradiated from the bare glass side for 1.5 minutes. Thereafter, the sample was immersed in a 5% tetramethylammonium hydroxide aqueous solution and evaluated as “◯” when dissolved within 5 minutes, and “X” when not dissolved even after 5 minutes. Each of these evaluations is as shown in Table 2.

  As shown in Table 2, the adhesive compositions of Examples 1 to 6 according to the present invention did not dissolve in any of PGMEA, PGME and NMP. Moreover, the degassing property, the softness | flexibility, and the adhesive strength of the adhesive composition of Examples 1-6 were also favorable. Furthermore, the adhesive compositions of Examples 1 to 6 dissolved well in the solvent after exposure.

  On the other hand, the adhesive composition of Comparative Example 1 having a melamine-based binder was good with respect to solvent resistance, degassing property, flexibility and adhesive strength, but did not dissolve in the solvent even when exposed. Moreover, the adhesive composition of Comparative Examples 2-4 did not have solvent tolerance. Therefore, the solubility in the solvent after exposure has not been investigated.

  As is apparent from the above results, the adhesive composition containing polyvinyl ether, a resin containing a polymer having a functional group capable of reacting with the vinyl group of the polyvinyl ether, and an acid generator has high solvent resistance. And the solubility in a solvent is improved by exposure. Therefore, the adhesive composition according to the present example can be suitably used in a process using various solvents, and can be easily removed after the treatment because the solubility in the solvent is improved.

  ADVANTAGE OF THE INVENTION According to this invention, the suitable adhesive composition and adhesive film can be provided in the process using the solvent applied to manufacture of various products.

Claims (6)

Polyvinyl ethers, and contains a resin containing a polymer, and an acid generator,
The polymer has the general formula (1):

(R ¹ represents a hydroxyl group or a carboxyl group; R ² represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ³ represents an alkyl group having 1 to 5 carbon atoms ; R ¹ ′ is absent or Or an alkylene group having 1 to 5 carbon atoms; n ₁ is an integer of ₁ to 5; n ₂ is 0 or an integer of 1 to 2)
The adhesive composition characterized by including the repeating unit shown by these. The proportion of the repeating unit having a hydroxyl group or a carboxyl group to the total number of moles of repeating units constituting the resin, the adhesive composition according to claim 1, characterized in that 10% or more. The adhesive composition according to claim 1 or 2 , wherein the polyvinyl ether is divinyl ether or trivinyl ether. The ratio of the said polyvinyl ether with respect to 100 weight part of said resin is 1 weight part or more and 50 weight part or less, The adhesive composition of any one of Claims 1-3 characterized by the above-mentioned. The ratio of the said acid generator with respect to 100 weight part of said resin is 0.1 weight part or more and 20 weight part or less, The adhesive composition of any one of Claims 1-4 characterized by the above-mentioned. On the film provided with an adhesive layer containing adhesives compositions,
The adhesive composition contains polyvinyl ether, a resin containing a polymer having a hydroxyl group or a carboxyl group, and an acid generator .