Composition

Abstract

To provide a composition having excellent curing speed for temporary fixing use, suitability for a spin-coating process, heat resistance, low outgassing properties under high-temperature vacuum conditions, and peeling speed.SOLUTION: A temporary fixing composition contains the following (A) to (C): (A) a (meth)acrylate containing the following (A-1) and (A-2); (A-1) a monofunctional (meth)acrylate having a side chain that is an alkyl group with 18 or more carbon atoms and having a homopolymer Tg of -100°C to 60°C; (A-2) a polyfunctional (meth)acrylate; (B) a polyisobutene homopolymer and / or a polyisobutene copolymer; and (C) a photoradical polymerization initiator.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a temporary fixing composition used for temporary fixing. [Background technology]

[0002] Electronic devices are primarily made from inorganic substrates, typically silicon, and are manufactured by processing them, including forming insulating films on their surfaces, forming circuits, and thinning them by grinding. When wafer-type substrates are used for processing, those with thicknesses of several hundred micrometers are often used. However, because many substrates are made of brittle and easily cracked materials, measures to prevent breakage are necessary, especially when thinning by grinding. A traditional method for preventing this is to apply a temporary protective tape to the surface opposite the surface to be ground (also known as the backside), which can be peeled off after the processing process is complete. This tape uses an organic resin film as its base material, and while it is flexible, it lacks strength and heat resistance, making it unsuitable for use in high-temperature processes.

[0003] Therefore, a system has been proposed in which electronic device substrates are bonded to a support such as silicon or glass via an adhesive, thereby providing sufficient durability to withstand the conditions of the backside grinding and backside electrode formation processes. The adhesive layer used to bond the substrate to the support is crucial. It must be able to bond the substrate to the support without any gaps, be durable enough to withstand subsequent processes, and allow the thinned wafer to be easily peeled off from the support.

[0004] The adhesive must have the following characteristics: (1) viscosity suitable for application and Newtonian fluidity (or shear viscosity independent of shear rate); (2) shear adhesive strength sufficient to withstand grinding and polishing when thinning the substrate; (3) moderate hardness sufficient to prevent localized sinking of the substrate while distributing the load in the in-plane direction to avoid damage to the substrate due to localized concentration of the grinding stone load applied to the substrate during grinding and polishing when thinning the substrate; (4) heat resistance sufficient to withstand the insulating film formation and solder reflow processes; (5) chemical resistance sufficient to withstand the thinning and resist processes; (6) easy removability sufficient to easily peel the substrate from the support; (7) cohesive properties sufficient to leave no adhesive residue on the substrate after peeling; and (8) ease of cleaning.

[0005] As adhesives and methods for peeling them, a technique has been proposed in which high-intensity light is irradiated onto an adhesive containing a light-absorbing substance to decompose the adhesive layer, thereby peeling it off from the support (Patent Document 1), and a technique in which a heat-fusible hydrocarbon compound is used as the adhesive, and bonding and peeling are performed in a heated, molten state (Patent Document 2). The former technique requires expensive equipment such as a laser, and has problems such as a long processing time per substrate. The latter technique is simple because it can be controlled only by heating, but its range of application is narrow due to its insufficient thermal stability at high temperatures exceeding 200°C.

[0006] Patent Document 3 discloses a method for disassembling an adhered structure, which comprises a step of irradiating an adhered structure formed by bonding substrates together using an adhesive composition containing one or more (meth)acrylates having one or more acryloyl groups and curing the adhesive composition with excimer light having a central wavelength of 172 nm or 193 nm, wherein at least one of the substrates is transparent to the excimer light. However, Patent Document 3 does not disclose the use of light with a longer wavelength. The present invention does not require the use of high-energy excimer light for peeling.

[0007] Patent Document 4 discloses a technology for an adhesive encapsulation composition for use in electronic devices, which contains a polyisobutene resin and a multifunctional (meth)acrylate as a resin composition, but does not contain a tackifier. It also describes the use of a monofunctional (meth)acrylate as a monomer, but does not disclose the glass transition temperature of the monofunctional (meth)acrylate, which poses a problem in that it is unclear how to achieve the flexibility required for using the resin composition as a temporary fixing agent in the manufacturing process of electronic devices.

[0008] Patent Document 5 also discloses a technology for an adhesive encapsulation composition for electronic devices such as organic electroluminescence devices, which contains a monofunctional (meth)acrylate, a polyfunctional (meth)acrylate, and a polyisobutene-based polymer as a resin composition. However, because the glass transition temperature of the monofunctional (meth)acrylate is not disclosed, there is a problem in that it is unclear how to achieve the flexibility required when using the resin composition as a temporary fixing agent in the manufacturing process of electronic devices.

[0009] Patent Document 6 discloses a resin composition for bonding different substrates, which contains a monofunctional (meth)acrylate, a polyfunctional (meth)acrylate, and an isobutene-maleic anhydride copolymer, and a bonding / disassembly method. However, the polymers in Patent Document 6 are limited in type in that they contain a component derived from maleic anhydride, and the bonding method is not described in detail. Patent Document 6 does not disclose spin-coat suitability, such as viscosity.

[0010] Patent Document 7 discloses a composite resin composition that can be cured by active energy rays and is made of a urethane (meth)acrylate resin containing an olefin polymer structure and a polyisobutylene resin. Patent Document 8 discloses a photocurable composition that contains (A) component: a (meth)acrylate compound having a polyisobutylene skeleton and (B) component: a (meth)acrylamide compound, and contains 0.1 to 15 parts by mass of (B) component per 100 parts by mass of (A) component. However, Patent Documents 7 and 8 do not describe temporary fixing applications. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-064040 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-328104 [Patent Document 3] International Publication No. 2011 / 158654 [Patent Document 4] Patent No. 5890177 [Patent Document 5] Special Publication No. 2009-524705 [Patent Document 6] Patent No. 6139862 [Patent Document 7] Japanese Patent Application Publication No. 2017-226785 [Patent Document 8] International Publication No. 2020 / 080309 Summary of the Invention [Problem to be solved by the invention]

[0012] Therefore, for example, even if compositions according to the prior art are used for temporary fixing, the problems of insufficient curing speed, compatibility with spin coating processes, heat resistance, low outgassing under high temperature and vacuum conditions, and peeling speed, as well as insufficient suitability for UV laser peeling processes, have not been solved. [Means for solving the problem]

[0013] That is, the present invention can provide the following aspects.

[0014] <1> A temporary fixing composition comprising the following (A) to (C): (A) A (meth)acrylate containing the following (A-1) and (A-2): (A-1) A monofunctional (meth)acrylate having an alkyl group with 18 or more carbon atoms in the side chain and a Tg of the homopolymer of -100°C to 60°C (A-2) Polyfunctional (meth)acrylate (B) Polyisobutene homopolymer and / or polyisobutene copolymer (C) Photoradical polymerization initiator

[0015] <2> The temporary fixing composition according to aspect 1, further comprising the following (D): (D) UV absorber

[0016] <3> (A-1) The temporary fixing composition according to aspect 1 or 2, wherein the molecular weight of the monofunctional (meth)acrylate is 550 or less.

[0017] <4> The temporary fixing composition according to any one of Aspects 1 to 3, wherein the component (A-1) is a monofunctional (meth)acrylate having an alkyl group of a straight-chain or branched-chain structure on the side chain.

[0018] <5> The temporary fixing composition according to any one of Aspects 1 to 4, wherein the component (A-1) is one or more selected from the group consisting of stearyl (meth)acrylate, isostearyl (meth)acrylate, behenyl (meth)acrylate, 2-decyl-1-tetradecanyl (meth)acrylate, 2-dodecyl-1-hexadecanyl (meth)acrylate, and 2-tetradecyl-1-octadecanyl (meth)acrylate.

[0019] <6> (A-2) The temporary fixing composition according to any one of Aspects 1 to 5, wherein the polyfunctional (meth)acrylate has a molecular weight of 900 or less.

[0020] <7> The temporary fixing composition according to any one of Aspects 1 to 6, wherein the component (A-2) is a polyfunctional (meth)acrylate having an alicyclic skeleton.

[0021] <8> The temporary fixing composition according to any one of Aspects 1 to 7, wherein the component (A-2) is at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate and 1,3-di(meth)acryloyloxyadamantane.

[0022] <9> The temporary fixing composition according to any one of Aspects 1 to 8, wherein the component (B) is a polyisobutene homopolymer and / or a polyisobutene copolymer having a weight average molecular weight of 1,000 or more and 5,000,000 or less and a molecular weight distribution of 1.1 or more and 5.0 or less.

[0023] <10> The temporary fixing composition according to any one of Aspects 1 to 9, wherein the component (C) is a photoradical polymerization initiator that generates radicals when exposed to light with a wavelength of 350 nm or more.

[0024] <11> (C) component is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(η 5 11. The temporary fixing composition according to any one of Aspects 1 to 10, wherein the oxidizing agent is one or more selected from the group consisting of 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime).

[0025] <12> 12. The temporary fixing composition according to any one of Aspects 1 to 11, comprising 0.01 to 5 parts by mass of component (C) per 100 parts by mass in total of components (A) and (B).

[0026] <13> A temporary fixing adhesive comprising the temporary fixing composition according to any one of aspects 1 to 12.

[0027] <14> A cured product obtained by curing the temporary fixing composition according to any one of aspects 1 to 12.

[0028] <15> Aspect 15. The cured product according to aspect 14, wherein the temperature at which the rate of mass loss on heating becomes 2% by mass is 250°C or higher.

[0029] <16> An adhered body in which substrates are adhered using the temporary fixing adhesive according to embodiment 13.

[0030] <17> (A) to (C) below: (A) A (meth)acrylate containing the following (A-1) and (A-2): (A-1) A monofunctional (meth)acrylate having an alkyl group with 18 or more carbon atoms in the side chain and a Tg of the homopolymer of -100°C to 60°C (A-2) Polyfunctional (meth)acrylate (B) Polyisobutene homopolymer and / or polyisobutene copolymer (C) Photoradical polymerization initiator An adhered body in which substrates are adhered using a temporary fixing adhesive containing the above-mentioned compound, wherein the temporary fixing adhesive is cured by light having a wavelength of 385 nm to 700 nm, and the substrate is peeled off by laser light having a wavelength of less than 385 nm.

[0031] <18> A method for producing a thin wafer using the temporary fixing adhesive according to aspect 13.

[0032] <19> applying a temporary fixing adhesive to the semiconductor wafer substrate and / or the support member to bond the semiconductor wafer substrate and the support member; curing the temporary fixing adhesive by irradiating it with light having a wavelength of 350 nm to 700 nm to obtain an adhered body; irradiating the bonded body with laser light having a wavelength of less than 385 nm to peel off the semiconductor wafer base material; A method for manufacturing a semiconductor wafer, comprising:

[0033] <20> 20. The method of claim 18 or 19, wherein the cured temporary fixing adhesive constitutes a single layer in the adhesive body.

[0034] <21> Aspect 14. The temporary fixing adhesive according to aspect 13, wherein the application is one or more selected from the group consisting of mechanical peeling, IR laser peeling, and UV laser peeling.

[0035] <22> A single-layer cured body made of the temporary fixing composition according to any one of aspects 1 to 12.

[0036] <23> A cured body having a first cured layer containing the component (A-1), the component (A-2), the component (B), and the component (C), but not containing the component (D), and a second cured layer made of the temporary fixing composition according to aspect 2, wherein the concentration distribution of the components differs in the thickness direction.

[0037] <24> A cured product having a first cured layer obtained by curing the temporary fixing composition according to aspect 1, which contains the component (A-1), the component (A-2), the component (B), and the component (C), and a second cured layer obtained by applying a UV absorber onto the first cured layer, wherein the concentration distribution of the components differs in the thickness direction.

[0038] <25> A cured body having a first cured layer obtained by curing the temporary fixing composition according to embodiment 1, which contains the components (A-1), (A-2), (B), and (C), and a light-to-heat conversion (LTHC) cured layer.

[0039] <26> A cured product according to any one of aspects 22 to 25, which satisfies all of the following conditions: The light transmittance of the cured product with a thickness of 50 μm is 70% or more in the wavelength region of 395 nm or more of the wavelength of the light source used for curing. The light transmittance of the cured product with a thickness of 50 μm is 20% or more in the wavelength region of 385 nm or more and less than 395 nm of the wavelength of the light source used for curing. The light transmittance of the cured product with a thickness of 50 μm must be 1% or less at the wavelength (355 nm) of the UV laser used for UV laser peeling.

[0040] <27> A structure comprising the cured product according to any one of aspects 22 to 26 and an adherend.

[0041] <28> a step of applying a temporary fixing composition containing the component (A-1), the component (A-2), the component (B), and the component (C) but not the component (D) onto a wafer and partially curing the composition; applying the temporary fixing composition according to aspect 2 onto the partially cured temporary fixing composition; a step of further placing a transparent substrate on the applied temporary fixing composition and photo-curing the composition; A method for manufacturing a structure, comprising:

[0042] <29> a step of applying a temporary fixing composition containing the component (A-1), the component (A-2), the component (B), and the component (C) but not containing the component (D) onto a wafer, and partially curing the composition as needed; applying the temporary fixing composition according to aspect 2 onto a transparent substrate and, if necessary, partially curing the composition; a step of bringing the surfaces of the wafer and the transparent substrate, on which the temporary fixing composition is applied, into close contact with each other, and then bonding them by photocuring; A method for manufacturing a structure, comprising:

[0043] <30> applying the temporary fixing composition according to aspect 1, which contains the component (A-1), the component (A-2), the component (B), and the component (C) but does not contain the component (D), onto a wafer, and partially curing it as necessary; applying a light-to-heat conversion (LTHC) layer onto a transparent substrate, drying and curing; a step of bringing the surface of the wafer on which the temporary fixing composition is applied and the surface of the transparent substrate on which the LTHC layer is applied into close contact with each other, and then bonding them by photocuring; A method for manufacturing a structure, comprising: [Effects of the Invention]

[0044] According to the present invention, for example, a composition excellent in curing speed, compatibility with spin coating processes, heat resistance, low outgassing under high temperature and vacuum, and peeling speed can be obtained, and a temporary fixing composition suitable for mechanical peeling processes and / or various laser peeling processes (such as a UV laser peeling process) can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0045] The present invention will be described below. In this specification, unless otherwise specified, numerical ranges include the upper and lower limits.

[0046] A monofunctional (meth)acrylate is a compound having one (meth)acryloyl group in one molecule. A multifunctional (meth)acrylate is a compound having two or more (meth)acryloyl groups in one molecule. An n-functional (meth)acrylate is a compound having n (meth)acryloyl groups in one molecule.

[0047] First, an embodiment of the present invention can provide a temporary fixing composition (hereinafter sometimes referred to as a composition) used for temporary fixing, which contains the following components (A) to (C): (A) A (meth)acrylate containing the following (A-1) and (A-2): (A-1) A monofunctional (meth)acrylate having an alkyl group with 18 or more carbon atoms in the side chain and a Tg of the homopolymer of -100°C to 60°C (A-2) Polyfunctional (meth)acrylate (B) Polyisobutene homopolymer and / or polyisobutene copolymer (C) Photoradical polymerization initiator

[0048] Secondly, the temporary fixing composition can also be provided, which further contains the following component (D): (D) UV absorber

[0049] Thirdly, a multilayer (multi-layer) structure can be provided that includes a layer containing (A) to (C) and a layer containing one or more of (A) to (D).

[0050] (A-1) Monofunctional (meth)acrylate having an alkyl group having 18 or more carbon atoms in the side chain and a homopolymer Tg of -100°C to 60°C refers to a monofunctional (meth)acrylate having an alkyl group (a functional group consisting of an aliphatic hydrocarbon having a chain structure or a cyclic structure) in the side chain, which is obtained when polymerized alone and has a glass transition temperature (hereinafter sometimes abbreviated as Tg) of -100°C to 60°C. Monofunctional (meth)acrylate having a homopolymer Tg of -50°C to 0°C is more preferred.

[0051] Monofunctional (meth)acrylates whose side chains are alkyl groups having 18 or more carbon atoms and whose homopolymer Tg is -100 to 60°C include stearyl (meth)acrylate (Tg of acrylate homopolymer: 30°C, Tg of methacrylate homopolymer: 38°C), isostearyl (meth)acrylate (Tg of acrylate homopolymer: -18°C, Tg of methacrylate homopolymer: 30°C), behenyl (meth)acrylate (Tg of acrylate homopolymer: 50°C, Tg of methacrylate homopolymer: 4 7°C), 2-decyl-1-tetradecanyl (meth)acrylate (Tg of acrylate homopolymer: -36°C, Tg of methacrylate homopolymer: -29°C), 2-dodecyl-1-hexadecanyl (meth)acrylate (Tg of acrylate homopolymer: -23°C, Tg of methacrylate homopolymer: -14°C), 2-tetradecyl-1-octadecanyl (meth)acrylate (Tg of acrylate homopolymer: -8°C, Tg of methacrylate homopolymer: 1°C). One or more of these (meth)acrylates can be used.

[0052] Glass transition refers to a change in which a substance such as glass, which is liquid at high temperatures, suddenly increases in viscosity within a certain temperature range as the temperature drops, loses almost all fluidity, and becomes an amorphous solid. There are no particular limitations on the method for measuring the glass transition temperature, but it generally refers to the glass transition temperature calculated by differential scanning calorimetry, differential thermal analysis, dynamic viscoelasticity measurement, etc. Among these, dynamic viscoelasticity measurement is preferred. The glass transition temperature of (meth)acrylate homopolymers is described in J. Brandrup, EH Immergut, Polymer Handbook, 2nd Ed., J. Wiley, New York 1975, Photocuring Technology Data Book (Techno Net Books), etc.

[0053] (A-1) is preferably a monofunctional (meth)acrylate having a molecular weight of 550 or less.

[0054] (A-1) is preferably a monofunctional alkyl(meth)acrylate having an alkyl group.

[0055] The alkyl group is preferably one or more selected from linear alkyl groups, branched alkyl groups, and alicyclic alkyl groups, and more preferably one or more selected from linear alkyl groups and branched alkyl groups. From the viewpoint of improving compatibility with component (B) (especially with high-molecular-weight component (B)), component (A-1) preferably has a long-chain, branched, or cyclic alkyl group, for example, a branched alkyl group or cycloalkyl group having 18 to 40 carbon atoms, more preferably 18 to 32 carbon atoms, such as an isostearyl group, an isotetracosanyl group (e.g., 2-decyl-1-tetradecanyl group), or an isotriacontanyl group (e.g., 2-tetradecyl-1-octadecanyl group). By using such a long-chain, high-molecular-weight component with strong aliphatic hydrocarbon properties (and more preferably by enhancing the aliphatic hydrocarbon properties of the entire system), the low volatility, chemical resistance, and heat resistance required of the temporary fixing composition can be improved.

[0056] (A-1) is preferably at least one selected from the group consisting of stearyl (meth)acrylate, isostearyl (meth)acrylate, behenyl (meth)acrylate, 2-decyl-1-tetradecanyl (meth)acrylate, 2-dodecyl-1-hexadecanyl (meth)acrylate, and 2-tetradecyl-1-octadecanyl (meth)acrylate. As the (A-1) monofunctional alkyl (meth)acrylate having an alkyl group, a (meth)acrylate of the following formula 1 is preferred.

[0057] [ka] R 1 is a hydrogen atom or a methyl group. 2 is an alkyl group.

[0058] R 1 is more preferably a hydrogen atom.

[0059] R 2 The number of carbon atoms is preferably 18 to 32. One or more of these (meth)acrylates can be used.

[0060] R 2 As the monofunctional alkyl(meth)acrylate in which is an alkyl group having 18 to 32 carbon atoms, (meth)acrylates having a linear or branched alkyl group such as stearyl(meth)acrylate, isostearyl(meth)acrylate, nonadecyl(meth)acrylate, eicodecyl(meth)acrylate, behenyl(meth)acrylate, 2-decyl-1-tetradecyl(meth)acrylate, and 2-tetradecyl-1-octadecanyl(meth)acrylate are preferred.

[0061] The amount of the monofunctional (meth)acrylate (A-1) used is preferably 35 parts by mass or more, more preferably 40 parts by mass or more, and even more preferably 45 parts by mass or more, per 100 parts by mass of the total of the components (A) and (B). The amount of the monofunctional (meth)acrylate (A-1) used is preferably 54 to 90 parts by mass, more preferably 54 to 80 parts by mass, and even more preferably 54 to 75 parts by mass, per 100 parts by mass of the total of the components (A) and (B). If the amount is 54 parts by mass or more, there is no risk of phase separation in the resin composition after mixing, and flexibility at room temperature is obtained. If the amount is 90 parts by mass or less, the viscosity, heat resistance, and curability required for application are obtained. In the composition described in Patent Document 7, the amount of the monofunctional (meth)acrylate used is less than 53 parts by mass, and there is a risk that the flexibility required for a temporary fixing composition for electronic device production may not be obtained.

[0062] (A-2) Polyfunctional (meth)acrylate refers to a compound having two or more (meth)acryloyl groups in one molecule. The polymerizable functional groups may be acryloyl groups only, methacryloyl groups only, or both acryloyl and methacryloyl groups.

[0063] The molecular weight of the (A-2) polyfunctional (meth)acrylate is preferably 900 or less, more preferably 700 or less, most preferably 500 or less, and even more preferably 400 or less.

[0064] (A-2) Examples of the polyfunctional (meth)acrylate include difunctional (meth)acrylate, trifunctional (meth)acrylate, and tetrafunctional or higher functional (meth)acrylate.

[0065] Examples of bifunctional (meth)acrylates include 1,3-di(meth)acryloyloxyadamantane, tricyclodecane dimethanol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, and neopentyl glycol-modified trimethylolpropane. Examples of suitable di(meth)acrylates include PAN di(meth)acrylate, stearic acid-modified pentaerythritol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxypropoxyphenyl)propane, 2,2-bis(4-(meth)acryloxytetraethoxyphenyl)propane, isocyanuric acid ethylene oxide-modified di(meth)acrylate, and 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene di(meth)acrylate.

[0066] Examples of trifunctional (meth)acrylates include ethylene oxide isocyanurate modified tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tris[(meth)acryloyloxyethyl]isocyanurate.

[0067] Examples of tetrafunctional or higher (meth)acrylates include ditrimethylolpropane tetra(meth)acrylate, dimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol ethoxy tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0068] Among (A-2), polyfunctional (meth)acrylates having an alicyclic skeleton are preferred, and polyfunctional (meth)acrylates having an alicyclic skeleton of 5 or more carbon atoms are more preferred. As the polyfunctional (meth)acrylate having an alicyclic skeleton of 5 or more carbon atoms, one or more selected from tricyclodecane dimethanol di(meth)acrylate and 1,3-di(meth)acryloyloxyadamantane are preferred.

[0069] The amount of the (A-2) polyfunctional (meth)acrylate used is preferably 1 to 40 parts by mass, and more preferably 20 to 30 parts by mass, per 100 parts by mass of the total of components (A) and (B). If it is 1 part by mass or more, good curability, heat resistance, and releasability can be obtained, and if it is 40 parts by mass or less, there is no risk of phase separation in the composition after mixing, and there is no risk of a decrease in heat resistance.

[0070] Among the options for component (B), polyisobutene homopolymer refers to a homopolymer obtained by polymerization using isobutene as a raw material monomer. Oppanol, for example, is available from BASF. Among the options for component (B), polyisobutene copolymer refers to a copolymer (or heteropolymer) obtained by polymerization using isobutene as a raw material monomer. The copolymer may be a random copolymer or a block copolymer, with block copolymers being particularly preferred. An example of a block copolymer is SIBSTAR, which contains polyisobutene block chains and polystyrene block chains, available from Kaneka. These isobutene polymers may have (meth)acrylate groups at one or both ends. An example of such a polymer, EP400V from the EPION series available from Kaneka, is an isobutene polymer containing acrylate groups at both ends.

[0071] These isobutene polymers may have a polymerizable functional group other than a (meth)acrylate group at one or both ends. For example, NOF Polybutene (trademark), an isobutene polymer having an ethylenically unsaturated group, is available from NOF Corporation.

[0072] From the viewpoint of obtaining an appropriate viscosity when blended with component (A), component (B) is preferably a so-called high molecular grade, and for example, preferably has a weight average molecular weight of 1,000 to 5,000,000, more preferably 80,000 to 5,000,000. Furthermore, component (B) preferably has a molecular weight distribution of 1.1 to 5.0, more preferably 2.2 to 2.9. Particularly preferably, component (B) may have a weight average molecular weight of 80,000 to 5,000,000 and a molecular weight distribution of 2.2 to 2.9. One or more of these polyisobutene homopolymers and / or polyisobutene copolymers can be used as component (B).

[0073] In a preferred embodiment, component (B) contains a polyisobutene copolymer. This polyisobutene copolymer contains isobutene monomer units and other monomer units, and its copolymerization form encompasses block copolymers, random copolymers, and alternating copolymers. A block copolymer is preferred. The reasons for this are as follows: Generally, random copolymers average the glass transition temperature and other properties of the homopolymers composed of the multiple monomers that make up the block copolymer. Block copolymers, on the other hand, maintain the glass transition temperature and other properties of the homopolymers composed of each monomer without averaging, allowing both properties to be simultaneously exhibited. Furthermore, triblock copolymers, in particular, are known to exhibit stronger physical properties in the terminal blocks than in the central block. For example, a triblock copolymer having a structure in which a polyisobutene block chain with a glass transition temperature of approximately -60°C is sandwiched between polystyrene block chains with a glass transition temperature of approximately 100°C exhibits a higher thickening effect than a polyisobutene homopolymer of the same molecular weight due to the high glass transition temperatures of the polystyrene block chains at both ends. This relatively high thickening effect allows the molecular weight of the copolymer used to be lower than that of polyisobutene homopolymer, but a low molecular weight polymer also has the advantage of being less likely to separate and precipitate when stored at low temperatures of around 5° C. In addition, the inclusion of polystyrene, an aromatic hydrocarbon with higher polarity than polyisobutene, an aliphatic hydrocarbon, offers the advantage of greater compatibility with component (A-2), which has multiple (meth)acrylic groups and is therefore highly polar, than component (A-1), a (meth)acrylate monomer with an aliphatic hydrocarbon side chain.

[0074] The weight-average molecular weight in this specification is a value calculated as a standard polystyrene by gel permeation chromatography (GPC). Specifically, the average molecular weight is determined by using tetrahydrofuran as a solvent, a GPC system (SC-8010 manufactured by Tosoh Corporation) under the following conditions, and creating a calibration curve using commercially available standard polystyrene.

[0075] Flow rate: 1.0ml / min Set temperature: 40℃ Column configuration: One Tosoh Corporation "TSK guardcolumn MP(xL)" 6.0 mm ID x 4.0 cm, and two Tosoh Corporation "TSK-GELMULTIPOREHXL-M" 7.8 mm ID x 30.0 cm (16,000 theoretical plates), for a total of three (total theoretical plate count: 32,000). Sample injection volume: 100 μl (sample solution concentration 1 mg / ml) Liquid delivery pressure: 39 kg / cm 2 Detector: RI detector (differential refractive index detector)

[0076] The amount of component (B) used is preferably 30 parts by weight or less, more preferably 25 parts by weight or less, per 100 parts by weight of the total of components (A) and (B). The amount of component (B) used is preferably 1 to 20 parts by weight, more preferably 5 to 20 parts by weight, per 100 parts by weight of the total of components (A) and (B). When the amount of component (B) is 1 part by weight or more, the viscosity required for application is obtained, and when the amount is 20 parts by weight or less, there is no risk of phase separation in the composition after mixing, and good curability and heat resistance are obtained. The use of the so-called polymer-grade component (B) described above not only makes it easy to obtain the desired viscosity even with a small amount added, but also provides compatibility with not only spin coating but also bar coating (i.e., the process to which it is adapted can be selected).

[0077] (C) Photoradical polymerization initiator refers to a compound whose molecule is cleaved and split into two or more radicals when irradiated with, for example, ultraviolet light or visible light (for example, a wavelength of 350 nm to 700 nm, preferably 385 nm to 700 nm or 365 nm to 500 nm, more preferably 385 nm to 450 nm).

[0078] As the (C) photoradical polymerization initiator, one or more compounds selected from acylphosphine oxide compounds, titanocene compounds, and α-aminoalkylphenone compounds are preferred in terms of reaction rate, heat resistance after curing, low outgassing, and absorption characteristics in a region different from both the wavelength of the UV laser used in the UV laser peeling described below and the absorption wavelength region of the UV absorber used in the UV laser peeling. Furthermore, among the temporary fixing compositions having the structure described below, an oxime ester compound can also be selected as the photoradical polymerization initiator for a resin composition used in temporary fixing for preventing damage from the bonding of a substrate to a support substrate to a heating step, which is not a layer for use in the UV laser peeling process.

[0079] Examples of the acylphosphine oxide compound include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc. Among these, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is particularly preferred.

[0080] Titanocene compounds include bis(η 5 and titanium dioxide particles.

[0081] Examples of the α-aminoalkylphenone compounds include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one, and the like.

[0082] Examples of oxime ester compounds include 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), etc. Among these, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime) is preferred.

[0083] (C) Photoradical polymerization initiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(η 5

[0033] One or more selected from the group consisting of 1-(4-methylbenzyl-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime) are preferred.

[0084] When providing the temporary fixing composition for use in the UV laser peeling process of the present invention, the most preferred photoradical polymerization initiator is an acylphosphine oxide-based compound. Preferred acylphosphine oxide-based compounds are bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and / or 2,4,6-trimethylbenzoyldiphenylphosphine oxide. These photoradical polymerization initiators are highly sensitive and photobleachable, resulting in excellent deep curing properties. Furthermore, their absorption wavelength range for generating radicals extends to a relatively long wavelength range. Specifically, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide has a wavelength range up to approximately 440 nm, which is significantly different from the absorption wavelength range of the UV absorber used in the UV laser peeling process described below. In other words, radical polymerization can be initiated with light of a longer wavelength, with less UV curing inhibition by the added UV absorber. Therefore, radical polymerization can be initiated and cured efficiently at a relatively high speed, even in the presence of a UV absorber.

[0085] Most preferably, the photoradical polymerization initiator can be selected based on absorbance. Specifically, the photoradical polymerization initiator can be selected from one or more compounds that satisfy one or more of the following conditions when dissolved at a concentration of 0.1% by mass in a solvent (e.g., acetonitrile, toluene, etc.) that does not have a maximum absorption in the wavelength region of 300 nm to 500 nm: absorbance of 0.5 or more at a wavelength of 365 nm, absorbance of 0.5 or more at a wavelength of 385 nm, and absorbance of 0.5 or more at a wavelength of 405 nm. Examples of compounds that satisfy such conditions include 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), which has an absorbance of 0.5 or more at a wavelength of 365 nm when dissolved in acetonitrile as a solvent at a concentration of 0.1% by mass; 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, which has an absorbance of 0.5 or more at wavelengths of 365 nm and 385 nm; and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide, which have an absorbance of 0.5 or more at wavelengths of 365 nm, 385 nm, and 405 nm.

[0086] In addition, from the viewpoint of achieving both curability by a photoradical polymerization initiator and UV laser peeling, bis(η 5 -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium can also be used as a photoradical polymerization initiator.

[0087] The amount of (C) photoradical polymerization initiator used is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 1 part by mass, per 100 parts by mass of the total of (A) and (B) in terms of reaction rate, heat resistance after curing, and low outgassing. If it is 0.01 part by mass or more, sufficient curability can be obtained, and if it is 5 parts by mass or less, there is no risk of impairing low outgassing and heat resistance.

[0088] Furthermore, a UV absorber that can be used as component (D) refers to a compound whose molecules are cleaved and decomposed / vaporized by irradiation with ultraviolet or visible light laser, and this decomposition / vaporization occurs at the interface between the support substrate (or backing) and the temporary fixing agent, causing a loss of the adhesive strength between the temporary fixing agent and the support substrate (or backing) that had been maintained up until just before the peeling step.

[0089] As the (D) UV absorber, one or more compounds selected from benzotriazole-based compounds and hydroxyphenyltriazine-based compounds are preferred in terms of the degree of overlap of the UV absorption wavelength region with the UV laser wavelength, UV absorption characteristics at the same wavelength, low outgassing properties, and heat resistance.

[0090] As the benzotriazole-based compound, one or more compounds selected from the group consisting of 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol], 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, and 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimido-methyl)-5-methylphenyl]benzotriazole are particularly preferred in terms of compatibility with the resin component, UV absorption properties, low outgassing properties, and heat resistance.

[0091] As the hydroxyphenyltriazine compound, one or more compounds selected from the group consisting of 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine, and 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine are particularly preferred in terms of compatibility with resin components, UV absorption properties, low outgassing, and heat resistance.

[0092] When providing a temporary fixing composition for use in a UV laser peeling process according to the present invention, the most preferred UV absorber is one or more selected from the group consisting of 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine, and 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol]. These UV absorbers have excellent compatibility with the resin components (A) and (B), high melting points, and relatively low vapor pressures at temperatures of about 300°C or less. Therefore, the amount used can be selected within a wide range, and they can contribute to reducing outgassing from the cured temporary fixing composition under these temperature conditions.

[0093] The most preferred UV absorbers for (D) are those selected based on their UV transmittance, as listed below. When component (D) has such a UV transmittance, it is possible to obtain the effect of appropriately controlling the curing and peeling of the composition.

[0094] When the UV absorber is dissolved at a concentration of 0.002% by mass in a solvent that does not have a maximum absorption in the wavelength range of 290 to 410 nm, the transmittance at a wavelength of 355 nm at an optical path length of 1 cm is preferably 50% or less and more than 50% at wavelengths of 385 to 420 nm, and more preferably 40% or less at a wavelength of 355 nm and more than 60% at wavelengths of 385 to 420 nm.

[0095] The most preferred (D) UV absorbers include, for example, the following: 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (available from BASF as Tinuvin 900, Adeka Corporation as Adeka STAB LA-24, and Everlight Chemical as EVERSORB 76 / EVERSORB 234, molecular weight 447) exhibits a transmittance of 20% or less at a wavelength of 355 nm and 60% or more at a wavelength of 385 to 420 nm when dissolved in toluene as a solvent at a concentration of 0.002% by mass. 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (Tinuvin 928, manufactured by BASF; EVERSORB 89 / 89FD, manufactured by Everlight Chemical Co., Ltd.; molecular weight: 442), which, when dissolved in toluene as a solvent at a concentration of 0.002% by mass, has a transmittance of 30% or less at a wavelength of 355 nm and 70% or more at a wavelength of 385 to 420 nm at an optical path length of 1 cm. 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (Tinuvin 405, molecular weight 584, manufactured by BASF), which, when dissolved in tetrahydrofuran as a solvent at a concentration of 0.002% by mass, has a transmittance of 40% or less at a wavelength of 355 nm and 90% or more at a wavelength of 385 to 420 nm at an optical path length of 1 cm. 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine (Tinuvin 460, molecular weight 630, manufactured by BASF), which is dissolved in tetrahydrofuran as a solvent at a concentration of 0.002% by mass and has a transmittance of 10% or less at a wavelength of 355 nm and 80% or more at wavelengths of 385 to 420 nm at an optical path length of 1 cm.

[0096] The UV transmittance of the cured product in this specification is a value obtained by reflectance spectroscopy. Specifically, the transmittance is measured using a reflectance spectrometer (V-650 manufactured by JASCO Corporation) under the following conditions, using a cured product film with a thickness of about 50 μm, which is prepared by sandwiching the film between PET resin sheets.

[0097] Cell length: 10mm Photometric mode: T (Transmittance) Measurement range: 450-200nm Data capture interval: 1 nm UV / visible bandwidth: 2.0nm Response:medium Scanning speed: 40 nm / min Light source switching: 340nm Light source: D2 / WI Filter switching: Step Correction: Baseline

[0098] The amount of the UV absorber (D) used is preferably 0.01 to 5 parts by mass, and more preferably 0.5 to 2.5 parts by mass, per 100 parts by mass of the total of (A) and (B). At least 0.01 part by mass ensures a sufficient UV laser peeling speed, while at most 5 parts by mass there is no risk of impairing low outgassing properties and heat resistance.

[0099] A composition having such properties can be suitably used in processes including high-temperature vacuum processes such as ion implantation, annealing, and electrode formation by sputtering, particularly in the backside process after thinning.

[0100] Furthermore, when a cured film having a thickness of 50 μm is produced using the temporary fixing composition of the present invention, it is preferable that one or more of the following conditions be satisfied, and it is more preferable that all of them be satisfied. The following conditions can be satisfied, for example, by using a UV absorber or the photoradical polymerization initiator. The light transmittance of the cured film must be 70% or more in the wavelength range of 395 nm or more of the wavelength of the light source used for curing. The light transmittance of the cured film must be 20% or more in the wavelength range of 385 nm or more and less than 395 nm of the wavelength of the light source used for curing. The light transmittance of the cured film at the wavelength (355 nm) of the UV laser used for UV laser peeling must be 1% or less. By satisfying these conditions, it is possible to achieve both a sufficiently high curing rate and a UV laser peeling rate for practical use. Furthermore, in addition to achieving both a sufficiently high curing rate and a UV laser peeling rate, it is also possible to reduce the rate of mass loss under heating conditions after curing (or reduce the amount of outgassing under high-temperature vacuum conditions). Temporary fixing agents with these properties are particularly suitable for use in processes that include high-temperature vacuum processes, such as ion implantation, annealing, and sputtering electrode formation, which are performed on the backside after thinning.

[0101] The composition of the present invention may contain an antioxidant to maintain its release properties after exposure to high temperatures. Examples of antioxidants include methylhydroquinone, hydroquinone, 2,2-methylene-bis(4-methyl-6-tert-butylphenol), catechol, hydroquinone monomethyl ether, monotert-butylhydroquinone, 2,5-ditert-butylhydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-ditert-butyl-p-benzoquinone, picric acid, citric acid, phenothiazine, tert-butylcatechol, 2-butyl-4-hydroxyanisole, 2,6-ditert-butyl-p-cresol, and 4-((4,6-bis(octylthio)-1,3,5-triazin-2-yl)amino)-2,6-di-t-butylphenol.

[0102] The amount of antioxidant used is preferably 0.001 to 3 parts by mass per 100 parts by mass of the total of (A) to (D). If it is 0.001 part by mass or more, releasability after exposure to high temperatures is ensured, and if it is 3 parts by mass or less, good adhesion is obtained and the composition does not become uncured.

[0103] The composition can be applied by known application methods such as spin coating, screen printing, and various coaters. The viscosity of the composition of the present invention at 23°C (atmospheric pressure) is preferably 100 mPa·s or more, more preferably 1000 mPa·s or more, and most preferably 2000 mPa·s or more, from the viewpoints of coatability and workability. The viscosity of the composition of the present invention is preferably 10,000 mPa·s or less, more preferably 5,000 mPa·s or less, and most preferably 4,000 mPa·s or less, from the viewpoints of coatability and workability. A viscosity of 100 mPa·s or more provides excellent coatability, particularly by spin coating. A viscosity of 10,000 mPa·s or less provides excellent workability.

[0104] Spin coating is a method of applying a liquid composition to a substrate surface by, for example, dropping the composition onto the substrate and rotating the substrate at a predetermined rotation speed. Spin coating can efficiently produce high-quality coating films.

[0105] The composition of the present invention can be used as a temporary fixing resin composition, a temporary fixing adhesive, a pressure-sensitive adhesive sheet, or a temporary fixing adhesive for producing electronic devices. In the present invention, the temporary fixing composition, the temporary fixing resin composition, and the temporary fixing adhesive are sometimes collectively referred to as a temporary fixing agent.

[0106] When the composition of the present invention is used to bond a substrate to be processed and an optically transparent support substrate (or support), the energy amount of visible light or ultraviolet light (wavelength or center wavelength 365 to 405 nm) is 1 to 20,000 mJ / cm 2 It is preferable to irradiate so that the energy amount is 1 mJ / cm 2 Above this level, sufficient adhesion is obtained, and 20,000 mJ / cm 2 If the dose is less than this, productivity is excellent, decomposition products from the photoradical polymerization initiator are less likely to be generated, and outgassing is suppressed. In terms of productivity, adhesion, low outgassing, and easy peelability, 1000 to 10000 mJ / cm 2 It is preferable that:

[0107] Although there are no particular limitations on the substrates to be bonded by the composition of the present invention, it is preferable that at least one of the substrates is a transparent substrate that transmits light. Examples of transparent substrates include inorganic substrates such as crystal, glass, quartz, calcium fluoride, and magnesium fluoride, and organic substrates such as plastics. Among these, inorganic substrates are preferred because they are versatile and can provide significant effects. Among inorganic substrates, one or more selected from glass and quartz are preferred.

[0108] In one embodiment, the composition of the present invention is photocurable, and the cured product provided thereby has excellent heat resistance and peelability. In one embodiment, the cured product of the composition of the present invention has low outgassing even when exposed to high temperatures, and is suitable for bonding, sealing, and coating various optical components, optical devices, and electronic components. The composition of the present invention is suitable for applications requiring a wide range of durability, such as solvent resistance, heat resistance, and adhesion, particularly for semiconductor manufacturing process applications.

[0109] A cured product of the composition of the present invention can be used in processes over a wide temperature range, from room temperature to high temperatures. The heating temperature during the process is preferably 350°C or lower, more preferably 300°C or lower, and most preferably 250°C or lower. In a preferred embodiment, the temperature at which the cured product experiences a thermal mass loss rate of 2% may be 250°C or higher. Because an adherend bonded with the temporary fixing adhesive of the present invention has high shear adhesive strength, it can withstand thinning processes and the like, and can be easily peeled after undergoing a heating process such as insulating film formation. When used at high temperatures, a cured product of the composition of the present invention can be used in high-temperature processes, for example, at temperatures preferably 200°C or higher, more preferably 250°C or higher.

[0110] Furthermore, in one embodiment of the present invention, a bonded body is obtained in which substrates are bonded with an adhesive, and the bonded body can be peeled by applying an external force to the bonded body, for example, by inserting a blade, sheet, or wire into the bonded portion.

[0111] Furthermore, in one embodiment of the present invention, an adhesive bonded body is obtained in which substrates are bonded with an adhesive, and the adhesive bonded body can be peeled off by irradiating the entire surface of the adhesive bonded body with a UV laser or IR laser in a scanning manner from the optically transparent substrate side.

[0112] <Method of manufacturing thin wafers> An embodiment of the present invention can also provide a method for producing a thin wafer. The production method is characterized in that the above-mentioned temporary fixing composition or temporary fixing adhesive (hereinafter sometimes simply referred to as adhesive or temporary fixing agent) is used as an adhesive layer between a wafer having semiconductor circuits or the like and a support. The method for producing a thin wafer of the present invention includes the following steps (a) to (e):

[0113] [Process (a)] Step (a) is a step in which, when bonding the circuit-forming surface of a wafer having a circuit-forming surface on its front surface and a non-circuit-forming surface on its back surface to a support via an adhesive, the adhesive is applied to the support or the circuit-containing wafer by spin coating, and the support or the circuit-containing wafer is then bonded to another support or circuit-containing wafer under vacuum.

[0114] A wafer having a circuit-forming surface and a non-circuit-forming surface is a wafer having one surface on which a circuit is formed and the other surface on which a circuit is not formed. Wafers to which the present invention can be applied are typically semiconductor wafers. Examples of such semiconductor wafers include silicon wafers, as well as gallium nitride wafers, lithium tantalate wafers, lithium niobate wafers, silicon carbide wafers, germanium wafers, gallium-arsenic wafers, gallium-phosphorus wafers, and gallium-arsenic-aluminum wafers. The thickness of the wafer is not particularly limited, but is preferably 600 to 800 μm, more preferably 625 to 775 μm. For example, a transparent substrate that transmits light is used as the support.

[0115] [Step (b)] Step (b) is a step of photo-curing the adhesive. After the wafer processed body (laminate substrate) is formed, the adhesive is photo-cured with visible light or ultraviolet light (whose wavelength or center wavelength is preferably 350 to 405 nm, more preferably 365 to 405 nm, and most preferably 385 to 405 nm) in an amount of energy of 1 to 20,000 mJ / cm. 2 It is preferable to irradiate so that the energy amount is 1 mJ / cm 2 Above this level, sufficient adhesion is obtained, and 20,000 mJ / cm 2 If the energy density is less than this, productivity is excellent, decomposition products from the photoradical polymerization initiator are less likely to be generated, and outgassing is also suppressed. In terms of productivity, adhesion, low outgassing, and easy peelability, the energy density is 1000 to 10000 mJ / cm 2 is more preferred.

[0116] When curing the composition, black light, UV-LED, or visible light-LED can be used as a light source, and the following light sources can be used, for example. As black light, light containing a component with a wavelength of 385 nm or more is preferably used, regardless of its central wavelength. When a wavelength range is described in this specification, whether or not a wavelength falls within that range is determined by whether or not the central wavelength falls within that range. Black light (center wavelength 365 nm, illuminance 10 mW / cm 2 , Toyo Adtec Co., Ltd. TUV-8271) ·UV-LED (wavelength 385±5nm, illuminance 350mW / cm 2 (Conditions: Working distance from the tip of the mirror unit is 20 mm, HOYA Corporation H-4MLH200-V2-1S19 + specially designed mirror unit) ·UV-LED (wavelength 395±5nm, illuminance 375mW / cm 2 (Conditions: Working distance from the tip of the mirror unit is 20 mm, HOYA Corporation H-4MLH200-V3-1S19 + specially designed mirror unit) ·UV-LED (wavelength 405±5nm, illuminance 400mW / cm 2(Conditions: Working distance from the tip of the mirror unit is 20 mm, HOYA Corporation H-4MLH200-V4-1S19 + specially designed mirror unit) ·UV-LED (center wavelength 405nm, illuminance 10mW / cm 2 , CCS HLDL-120V0-NWPSC) ·Visible light-LED (wavelength 451±5nm, illuminance 550mW / cm 2 (Conditions: Work distance from the tip of the irradiation unit: 10 mm, CCS Corporation HLDL-155VL450‐PSC) ·Visible light-LED (wavelength 492±5nm, illuminance 400mW / cm 2 (Conditions: Work distance from the tip of the irradiation unit: 10 mm, CCS Corporation HLDL-155BG-PSC)

[0117] In a preferred embodiment, the light source may be a UV-LED or visible light-LED, which requires a smaller integrated light amount (shorter irradiation time) than black light, which generally has a broad irradiation wavelength and therefore a large integrated light amount and tends to require a longer irradiation time. In other words, by using an LED light source with a narrow irradiation wavelength band, temporary fixing can be performed in a shorter time, resulting in an effect of shortening the time required for the manufacturing process.

[0118] [Process (c)] Step (c) is a step of grinding and / or polishing the non-circuit-forming surface of the wafer bonded to the support, i.e., a step of grinding the backside of the wafer of the wafer processed body obtained by bonding in step (a) to reduce the thickness of the wafer. The thickness of the thinned wafer is preferably 10 to 300 μm, more preferably 30 to 100 μm. There are no particular restrictions on the method for grinding / polishing the backside of the wafer, and any known grinding / polishing method can be used. Grinding is preferably performed while cooling the wafer and grinding stone (such as a diamond-tipped grinding stone) by spraying water on them.

[0119] [Step (d)] Step (d) is a process for processing the non-circuit-forming surface of the wafer processed body with the non-circuit-forming surface ground / polished, i.e., the wafer processed body thinned by backside grinding / polishing. This process includes various processes used at the wafer level, such as electrode formation, metal wiring formation, and protective film formation. More specifically, this process includes conventionally known processes such as metal sputtering for forming electrodes, wet etching for etching the metal sputtered layer, pattern formation by applying, exposing, and developing a resist to serve as a mask for metal wiring formation, resist stripping, dry etching, metal plating, silicon etching for TSV formation, and oxide film formation on the silicon surface.

[0120] [Step (e)] Step (e) is a peeling step. This step involves peeling the wafer processed in step (d) from the wafer processed body. For example, this is a step in which the thinned wafer is peeled from the wafer processed body after various processing steps have been performed on it and before dicing. At this time, a dicing tape can be attached to the thinned and processed surface in advance. This peeling step is generally performed under relatively low temperature conditions, ranging from room temperature to about 60°C. This peeling step can be any of the well-known UV laser peeling steps, IR laser peeling steps, or mechanical peeling steps.

[0121] The UV laser peeling process is, for example, a process in which a UV laser is irradiated onto the entire surface of the wafer processed body, scanning back and forth in a linear tangential direction from the edge of the wafer processed body on the optically transparent support side, to decompose the adhesive layer using the laser energy and peel it off. Such a peeling process is described, for example, in JP-A-2019-501790 and JP-A-2016-500918. The temporary fixing composition of the present invention is particularly suitable for the UV laser peeling process because it contains component (D) and satisfies the preferred requirements of component (C) and / or component (D).

[0122] The IR laser peeling process is, for example, a process in which an IR laser is irradiated onto the entire surface of the wafer processed body, scanning linearly back and forth in a tangential direction from the edge of the optically transparent support side, to heat and decompose the adhesive layer with the laser energy, thereby peeling it off. This peeling process is described, for example, in Japanese Patent No. 4565804. To perform this IR laser peeling process, a light-to-heat conversion layer (e.g., 3M's LTHC; Light-To-Heat-Conversion Release Coating) that absorbs IR laser light and converts it into heat may be provided between the temporary fixing agent layer and the glass support. When using 3M's LTHC, for example, the LTHC can be spin-coated onto the glass support and cured, and the temporary fixing agent layer can be spin-coated onto the wafer, then bonded to the glass support on which the LTHC layer has been formed, and UV-cured. A method for performing the IR laser peeling process using 3M's LTHC is described, for example, in the same Japanese Patent No. 4565804.

[0123] The mechanical peeling process includes, for example, inserting a blade into the interface edge of a wafer workpiece, fixing the wafer of the wafer workpiece horizontally with the wafer facing downward to generate a cleavage between the wafer and the support, and applying an upward stress to the upper support and / or the blade after the blade insertion to propagate the cleavage and peel the wafer and the support. Such a peeling process is described, for example, in Japanese Patent No. 6377956 and Japanese Patent Laid-Open No. 2016-106404.

[0124] Any of these peeling methods can be used to peel off the composition according to the embodiment of the present invention. In this case, it is preferable to fix one of the wafer or support of the wafer processed body horizontally, insert a blade or use a solvent (e.g., an aliphatic or aromatic hydrocarbon solvent such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, or mesitylene) to swell the outer periphery of the adhesive layer to initiate peeling, and then lift the other side at a certain angle from the horizontal. These peeling methods are usually performed at room temperature, but heating to a maximum of about 90°C is also preferable. When using a laser, it is preferable to use a YAG laser or a YVO4 laser.

[0125] The step of peeling the processed wafer from the support in the step (e) further includes, in the case of a mechanical peeling step, (f) bonding a dicing tape to the wafer surface of the processed wafer; (g) vacuum-adsorbing the dicing tape surface onto the adsorption surface; (h) peeling the support from the processed wafer while the temperature of the adsorption surface is in the range of 10 to 100°C; In this way, the support can be easily peeled off from the processed wafer, and the subsequent dicing step can be easily carried out.

[0126] In addition, when peeling is performed using a UV laser or an IR laser, the manufacturing method further includes, for example: (i) placing / fixing the processed wafer with the optically transparent support side facing up on a horizontal surface, preferably via dicing tape; (j) irradiating the entire surface of the processed wafer from the support side with a laser in a scanning manner; In this way, the support can be easily peeled off from the processed wafer, and the subsequent dicing step can be easily carried out.

[0127] Further, after the step (e) of peeling the processed wafer from the support by a UV laser or an IR laser, (k) removing the temporary fixing agent remaining on the surface of the wafer; The temporary fixative can be removed by vacuum adsorbing the thinned surface to an adsorption surface, applying an adhesive tape such as dicing tape to the entire surface of the other surface on which the temporary fixative remains, and then peeling off the tape along with the temporary fixative; or by immersing the wafer in a solvent (e.g., an aliphatic or aromatic hydrocarbon solvent such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, or mesitylene) to swell the adhesive layer and peel it off. Of these methods, the tape peeling method is preferred because it requires fewer steps and takes less time.

[0128] After the temporary fixing agent is removed, the wafer can be directly subjected to the next process without cleaning the surface. (l) A process of cleaning the wafer from which the support and temporary fixing agent have been removed, with the circuit-formed surface facing up, using a solvent (e.g., an aliphatic or aromatic hydrocarbon solvent such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, or mesitylene). It is preferable to carry out the following.

[0129] In step (k), some adhesive (temporary fixing agent) may remain on the circuit-forming surface of the wafer from which the temporary fixing agent has been removed. Although it is preferable to wash and reuse the peeled support, adhesive residue may also adhere to the surface of this support. Examples of methods for removing these adhesive residues include immersing the wafer in a solvent (e.g., an aliphatic or aromatic hydrocarbon solvent such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, or mesitylene) to swell and peel the wafer.

[0130] In some embodiments, the composition can be cured to obtain a cured product by various techniques, such as those described below.

[0131] As a first method, a layer made of a temporary fixing composition containing components (A) to (D) can be cured to obtain a single-layer cured body.

[0132] The second method involves preparing a first layer made of a temporary fixing composition containing components (A-1), (A-2), (B), and (C) but not (D), and a second layer made of a temporary fixing composition containing components (A) to (D), and curing the layers to obtain a cured product having an integrated single layer or multiple layers. It is preferable that the cured product have different component concentration distributions across its thickness, or that the component concentration distributions on the upper and lower surfaces across the thickness of the cured product be different. The difference in component concentration distributions can be confirmed by quantifying the UV transmittance on both sides of the cured product using the reflectance measurement spectroscopy described above. This method combines layers with different light transmittances, enabling optimal curing. Furthermore, a black light or UV-LED can be used as a light source for the curing described above (the same applies to the method described below). An example of a black light is the TUV-8271 (center wavelength 365 nm, illuminance 10 mW / cm) manufactured by Toyo Adtec Co., Ltd. 2 ) as UV-LED. HOYA Corporation H-4MLH200-V2-1S19 + specially designed mirror unit (wavelength 385±5nm, illuminance 350mW / cm 2 ,Conditions: Scan pitch from the tip of the mirror unit 20 mm), HOYA Corporation H-4MLH200-V3-1S19 + specially designed mirror unit (wavelength 395 ± 5 nm, illuminance 375 mW / cm 2 Conditions: Working distance from the tip of the mirror unit: 20 mm, HOYA Corporation H-4MLH200-V4-1S19 + specially designed mirror unit (wavelength: 405 ± 5 nm, illuminance: 400 mW / cm 2 ,Conditions: Working distance from the tip of the mirror unit is 20 mm.

[0133] A third method involves applying (e.g., by spin coating) component (D) onto a cured layer made of a temporary fixing composition containing components (A-1), (A-2), (B), and (C), thereby obtaining a cured product having an at least partially integrated single layer. In this case, the concentration distribution of the components varies across the thickness of the cured product. The concentration distribution of the components can be quantified by reflectance measurement spectroscopy for each target layer, as described above. This method has the advantage of enabling precise control of UV absorption characteristics.

[0134] As a fourth method, a layer of a commercially available LTHC agent (light-to-heat conversion agent) may be placed on a layer of a temporary fixing composition containing the components (A-1), (A-2), (B), and (C), and then cured to obtain a multilayer cured body. This method has the effect of easily obtaining a cured body.

[0135] The cured product obtained by the above-described method can be combined with an adherend to provide a structure.

[0136] There are various examples of methods for producing the above-described structure. For example, a first production method may include the steps of applying a first temporary fixing composition containing the components (A-1), (A-2), (B), and (C) but not the component (D) onto a wafer and partially curing the composition, applying a second temporary fixing composition containing the components (A) to (D) onto the partially cured temporary fixing composition, and further placing a transparent substrate on the applied second temporary fixing composition and photocuring the composition.

[0137] Furthermore, a second method for producing a structure may include the steps of applying a first temporary fixing composition containing the components (A-1), (A-2), (B), and (C) but not the component (D) onto a wafer and partially curing it as needed; applying a second temporary fixing composition containing the components (A) to (D) onto a transparent substrate and partially curing it as needed; and bringing the surfaces of the wafer and the transparent substrate, on which the temporary fixing compositions have been applied, into close contact with each other, and then bonding them by photocuring.

[0138] Furthermore, a third method for producing a structure may include the steps of applying a temporary fixing composition containing the components (A-1), (A-2), (B), and (C) but not the component (D) onto a wafer and partially curing it as necessary; applying an LTHC layer onto a transparent substrate, drying and curing it; and bringing the surface of the wafer on which the temporary fixing composition has been applied into close contact with the surface of the transparent substrate on which the LTHC layer has been applied, and then bonding them by photocuring.

[0139] In addition to the above-mentioned temporary fixing composition, the same composition used in the temporary fixing composition of the present invention can also be used as a raw material for the light-to-heat conversion (LTHC) layer that absorbs IR laser light and converts it into heat, as described in Japanese Patent No. 4565804. By adding this composition as a component of the light-to-heat conversion (LTHC) layer, it is possible to improve its heat resistance.

[0140] Another aspect of the present invention provides a method for manufacturing a semiconductor wafer, comprising the steps of applying a temporary fixing adhesive to a semiconductor wafer substrate and / or a support member to bond the semiconductor wafer substrate and the support member, curing the temporary fixing adhesive by irradiating the adhesive with light having a wavelength of 350 to 700 nm (preferably 365 to 500 nm or 385 to 700 nm, more preferably 385 to 450 nm) to obtain an adhered body, and irradiating the adhered body with laser light having a wavelength of less than 385 nm (preferably laser light having a wavelength of 200 nm or more and less than 385 nm) to peel the semiconductor wafer substrate. This manufacturing method has the advantages that both the curing and peeling steps are performed at room temperature, eliminating the need to heat or cool the components and generally eliminating the need to use solvents, and is simple and has a short cycle time.

[0141] Furthermore, the cured temporary fixing adhesive may form a single layer in the adhesive body, which makes it possible to simplify the process and shorten the takt time.

[0142] A temporary fixing adhesive preferably used in this production method includes a UV-curable monomer, a (C) photoradical polymerization initiator component selected based on the absorbance, and a (D) UV absorber component selected based on the most preferred UV transmittance. The UV-curable monomer is preferably a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate, and most preferably the components (A-1) and (A-2). The temporary fixing adhesive may further include the (B) polyisobutene homopolymer and / or polyisobutene copolymer, or a known resin component conventionally used in temporary fixing adhesives.

[0143] In a preferred embodiment, the composition contains both the preferred (C) photoradical polymerization initiator component and (D) UV absorber component described above, making it possible to achieve both a fast curing rate and a fast peel rate, even in a single-layer temporary fixing adhesive. Furthermore, when the temporary fixing adhesive is UV-cured, it is possible to significantly reduce the amount of uncured UV-curable monomer component remaining in the cured product, thereby improving the heat resistance of the cured product and reducing the volatile content under vacuum. That is, for example, it is possible to increase the 2% heat mass loss temperature in Tg / DTA measurement of the cured product. Temporary fixing adhesives with high heat resistance and reduced volatile content under vacuum are extremely useful in modern semiconductor manufacturing processes. [Example]

[0144] The present invention will be explained in more detail below by way of experimental examples, but the present invention is not limited to these examples.

[0145] (Experimental example) Unless otherwise specified, experiments were conducted at 23°C and 50% humidity. Curable resin compositions (hereinafter sometimes referred to as liquid resin compositions) having the compositions (units: parts by mass) shown in Tables 1, 2, and 4 were prepared and evaluated. The following compounds were selected as each component in the curable resin compositions described in the experimental examples.

[0146] (composition) (A-1) The following compounds were selected as monofunctional acrylates having homopolymer Tg of -100°C to 60°C. Isostearyl acrylate ("ISTA" manufactured by Osaka Organic Chemical Industry Co., Ltd., homopolymer glass transition temperature: -18°C, molecular weight: 325) 2-Dodecyl-1-hexadecanyl acrylate ("Light Acrylate DHD-A (DHD-A)" manufactured by Kyoeisha Chemical Co., Ltd., homopolymer glass transition temperature: -23°C, molecular weight: 465) 2-tetradecyl-1-octadecanyl acrylate ("Light Acrylate DOD-A (DOD-A)" manufactured by Kyoeisha Chemical Co., Ltd., glass transition temperature of homopolymer: -8°C, molecular weight: 521) 2-Decyl-1-tetradecanyl acrylate (Kyoeisha Chemical Co., Ltd. "Light Acrylate DTD-A (DTD-A)", homopolymer glass transition temperature: -36°C, molecular weight: 409)

[0147] (A-2) The following compounds were selected as polyfunctional acrylates. Tricyclodecane dimethanol diacrylate ("NK Ester A-DCP (A-DCP)" manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight 304)

[0148] (B) The following compounds were selected as polyisobutene homopolymers and / or polyisobutene copolymers. The following compounds were selected as polyisobutene homopolymers. Oppanol N 50SF (BASF, PS equivalent weight average molecular weight (Mw): 565,000, molecular weight distribution 2.4) The following compounds were selected as polyisobutene-polystyrene block copolymers. SIBSTAR 103T (Kaneka Corporation, polystyrene-polyisobutene-polystyrene triblock copolymer, PS equivalent weight average molecular weight (Mw): 100,000, molecular weight distribution 2.0, total mass ratio of polystyrene segments 30%) Epion EP400V (Kaneka Corporation, acrylic-modified polyisobutene at both ends, PS equivalent weight average molecular weight (Mw): 17,000, molecular weight distribution 1.2)

[0149] (C) The following compounds were selected as photoradical polymerization initiators. Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (BASF "Irgacure 819")

[0150] (D) The following compounds were selected as UV absorbers: 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (BASF Tinuvin 900, Adeka Corporation Adeka Stab LA-24, Everlight Chemical EVERSORB 76 / EVERSORB 234, molecular weight 447) 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (BASF Tinuvin 928, Everlight Chemical EVERSORB 89 / 89FD, molecular weight 442) 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimido-methyl)-5-methylphenyl]benzotriazole (Sumisorb 250, manufactured by Sumika Chemtex Co., Ltd., molecular weight 389) 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (BASF Tinuvin 405, molecular weight 584) 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine (BASF Tinuvin 460, molecular weight 630)

[0151] The following compounds were selected as antioxidants: 4-((4,6-bis(octylthio)-1,3,5-triazin-2-yl)amino)-2,6-di-t-butylphenol (BASF "IRGANOX 565")

[0152] (Liquid sample preparation) The materials were mixed at 80°C to obtain a uniform mixture.

[0153] (Curing sample using black light) The liquid resin composition homogenized by the above-mentioned warm mixing was sandwiched between PET films and spread to a thickness of 50 μm (0.5 mm for the sample for measuring elastic modulus, which will be described later). 2 The curing was carried out under the following conditions to produce a cured product. The curing was carried out using a black light (center wavelength 365 nm, illuminance 10 mW / cm 2 (TUV-8271 manufactured by Toyo Adtec Co., Ltd.) was used.

[0154] (Curing sample using 405nm UV-LED) The liquid resin composition homogenized by the above-mentioned warm mixing was sandwiched between PET films and spread to a thickness of 50 μm (0.5 mm for the sample for measuring elastic modulus, which will be described later). 2 The curing was carried out under the following conditions to produce a cured product. A UV-LED (center wavelength 405 nm, illuminance 100 mW / cm) was used for curing. 2 A detector (HLDL-120V0-NWPSC manufactured by CCS) was used.

[0155] Preparation of test specimens for evaluating UV laser peeling process compatibility: The liquid resin composition was spin-coated onto an 8-inch silicon wafer (200 mm diameter x 0.725 mm thickness) in an automatic wafer bonder to a thickness of 50 μm. The wafer was then bonded to an 8-inch glass wafer (201 mm diameter x 0.7 mm thickness) in the same machine under a reduced pressure of 10 Pa. After bonding, the liquid resin compound was cured from the glass wafer side using one of the UV light sources listed above to obtain a bonded structure. The silicon wafer surface of the resulting bonded structure was then ground and polished to a thickness of 50 μm, after which it was heat-treated for 1 hour in a high-temperature, reduced-pressure environment at 250°C and 13 Pa.

[0156] Preparation process of test specimen for evaluating compatibility with IR laser peeling / mechanical peeling processes: Using the prepared liquid resin composition, a 4-inch silicon wafer (diameter 100 mm × thickness 0.47 mm) and a 4-inch glass wafer (diameter 100 mm × thickness 0.7 mm) were bonded together, and the liquid resin composition was spread until it was spread to a thickness of 50 μm over the entire surface between the substrates, and then the specimen was irradiated with an integrated light dose of 5000 to 10000 mJ / cm using one of the above light sources. 2 The curing light was irradiated from the surface of a 4-inch glass wafer.

[0157] (evaluation) Compatibility of materials in the liquid resin composition ("Material Compatibility" and "Absorbance" in Tables 1, 2, and 4): The temporary fixing composition homogenized by the warming and mixing described above was cooled to 23°C, and whether the homogenized state was maintained was confirmed. Using a JASCO V-650 UV-Visible Spectrophotometer, the absorbance (OD660) at a wavelength of 660 nm of a sample placed in a cell 10 mm wide in the optical path length direction was measured. An absorbance of less than 0.1 was deemed acceptable, indicating compatibility. An absorbance of 0.1 or greater, or visual confirmation of non-uniformity such as phase separation, was deemed incompatible and unacceptable. From the standpoint of compatibility, an absorbance of less than 0.1 is preferable. For cases where the result was "unacceptable," further evaluation was omitted. The same applies below.

[0158] Viscosity (Tables 1, 2, and 4, "Spin coating process compatibility" and "Viscosity"): In the above "Material compatibility" section, the viscosity of the liquid resin composition that remained homogeneous at 23°C was measured, and its compatibility with spin coating onto the surface of a substrate, as envisioned in an actual process, was evaluated. The viscosity was measured at a temperature of 23°C using an Anton-Paar MCR302 rheometer and a cone plate CP50-2. The shear rate was 1 s -1 The shear viscosity at this point was rated as excellent if it was 1000 mPa·s or more but less than 4000 mPa·s, acceptable if it was 4000 mPa·s or more but less than 10000 mPa·s or 100 mPa·s or more but less than 1000 mPa·s, and unacceptable if it was more than 10000 mPa·s or less than 100 mPa·s. From the viewpoint of compatibility with the spin coating process, a viscosity of 100 to 10000 mPa·s is preferable. Note that for examples that were rated "unacceptable," further evaluation was omitted. The same applies below.

[0159] Heat mass reduction rate of hardened body ("Heat resistance 1" and "2% heat mass reduction temperature of hardened body" in Tables 1, 2, and 4): Using a Bruker AXS TG-DTA2000SA differential thermal and thermogravimetric simultaneous analyzer, 10 mg of the resulting cured material was heated from 30°C to 350°C at a rate of 10°C / min under a nitrogen stream, and then from 350°C to 800°C at a rate of 20°C / min under an air stream. The resulting cured material's thermal mass loss was measured. The temperature at which the cured material lost 2% of its mass upon heating was recorded. Values ​​of 250°C or higher were rated as excellent, values ​​between 200°C and 250°C as good, values ​​between 150°C and 200°C as acceptable, and values ​​below 150°C as unacceptable. Considering suitability for high-temperature semiconductor manufacturing processes, the temperature at which the thermal mass loss reaches 2% is preferably 150°C or higher, and more preferably 250°C or higher. For examples rated "unacceptable," further evaluation was omitted. The same applies below.

[0160] Elastic modulus range of the cured body ("Heat Resistance 2" and "Storage modulus at -50 to 250°C" in Tables 1, 2, and 4): The dynamic viscoelasticity of the cured body samples was measured using a viscoelasticity measuring device, RSA-G2, manufactured by TA Instruments Japan Co., Ltd. Measurements were performed under the following conditions: chuck distance 10 mm, sample width 8 mm, sample thickness 0.5 mm, strain 0.1%, tensile frequency 1 Hz, heating rate 3°C / min, and temperature range -50 to 250°C. Samples with a storage modulus E' of 10 kPa or greater across the entire temperature range under these conditions were deemed acceptable; samples with a storage modulus E' of less than 10 kPa in any temperature range were deemed unacceptable. An elastic modulus of 10 kPa or greater is preferred. Further evaluation of samples with a "fail" result was omitted. The same applies below.

[0161] Adhesion at high temperatures (Tables 1, 2, and 4, "Adhesion under high-temperature conditions (250°C, 1 hour, reduced pressure 30 Pa)," "Amount of discoloration at the outer edge," and "Peeling due to heating"): A 4-inch silicon wafer (10 cm diameter x 0.47 mm thickness) and a 4-inch glass wafer (10 cm diameter x 0.7 mm thickness) were bonded using the prepared liquid resin composition. The thickness of the resin composition during bonding was adjusted by adding 0.1% by mass of silica particles (trade name: Hypresica TS N3N, average particle size 50 μm) manufactured by Ube Exsymo Co., Ltd. to the temporary fixing agent and mixing them. After bonding, the cumulative light intensity was 10,000 mJ / cm. 2The adhesive was cured under these conditions to prepare test specimens for evaluating adhesion under high-temperature, reduced-pressure conditions. The adhesive was applied to the entire bonding surface. Black light was applied from the surface of a 4-inch glass wafer. The completed test specimens were placed, with the 4-inch silicon wafer side facing down, on a hot plate preheated to a predetermined temperature. The width of the discolored area at the outer edge toward the center of the wafer and the presence or absence of visible delamination from the glass side were observed. The hot plate temperature was 250°C under a reduced pressure of 30 Pa and the heating time was 1 hour. In the "Adhesion under High-Temperature Conditions (250°C, 1 h, reduced pressure of 30 Pa)" table, specimens with a discolored area that spread from the outer edge toward the center of the wafer of 5 mm or less and no delamination was observed ("No" in the "Delamination due to Heat" section of the table) were deemed acceptable. Those with a width greater than 5 mm or delamination were deemed unacceptable. The width of the discolored area from the outer edge toward the center should preferably be 5 mm or less. The discoloration referred to here refers to a change in color that occurs when the temporary fixing agent peels off from either the glass or silicon substrate.

[0162] (1) Simultaneous compatibility with UV curing and UV laser peeling processes ("Light transmittance" in Tables 1 and 2): The resulting cured film having a thickness of 50 μm was measured for light transmittance in the wavelength range of 200 nm to 450 nm. Films that met all of the following conditions were rated as "pass", and films that met two or fewer of the following conditions were rated as "fail". [1] Light transmittance in the wavelength range of 395 nm or more is 70% or more [2] Light transmittance in the wavelength range of 385 nm to 395 nm is 20% or more. [3] Light transmittance at a wavelength of 355 nm is less than 1%

[0163] (1) UV laser peeling process suitability ("UV laser peelability" and "minimum time required to achieve complete peeling" in Tables 1, 2, and 4, and "UV laser irradiation conditions" in Table 3): A UV laser was irradiated onto a 210 mm square area fixed at the center of the obtained 8-inch test specimen, scanning the entire surface of the test specimen from the glass support side. The UV laser irradiation conditions shown in Table 3 were applied sequentially to each of the Examples in Table 1 and evaluation was carried out. The UV laser used was a QLA-355 (wavelength 350 nm) manufactured by Quark Technology Co., Ltd., with an output of 9.3 W, pulse energy of 235 μJ, and energy density of 11,968 mJ / cm. 2 The conditions used were: frequency 40 kHz, beam diameter (spot diameter) 50 μm, scan pitch 500 μm, and scan speed 20 m / s (see Condition Number 9 in Table 3). (Table 3 describes the trials conducted to determine these optimal conditions.) Complete peeling was defined as complete peeling when the adhesive force was completely lost and the glass support was able to slide (or move) freely on the silicon wafer (adhesion force = 0). The suitability for the UV laser peeling process was evaluated based on the minimum time required for the UV laser irradiation process to achieve this complete peeling state. A minimum time of less than 15 seconds was rated as excellent, 15 to 30 seconds was rated good, 30 to 60 seconds was rated acceptable, and 60 seconds or more was rated unacceptable.

[0164] (2) Evaluation of IR laser peeling process compatibility: This method can be performed using, for example, the method described in Japanese Patent No. 4565804. Japanese Patent No. 4565804 describes a method of using a liquid resin composition in combination with a light-to-heat conversion layer (LTHC layer), which absorbs light and converts it to heat, as described in Japanese Patent No. 4405246. The LTHC layer is formed by applying it to the surface of a support and curing it. Japanese Patent No. 4565804 describes a method in which a laminate is produced by bonding the surface of a support having an LTHC layer formed thereon to the surface of a silicon wafer spin-coated with the liquid resin composition, and then irradiating the support with UV light to cure the laminate. The laminate is then fixed in a fixing device with the support facing up, and disassembled by irradiating a YAG laser or semiconductor laser from above. This decomposition occurs when the LTHC layer absorbs the light energy of the IR laser and converts it into heat, which decomposes and vaporizes the adjacent resin layer, and the gas layer generated by the vaporization eliminates the adhesive force between the support and the resin layer. The releasability after IR laser irradiation can be evaluated using the same method as for evaluating the releasability after UV laser irradiation described above.

[0165] (3) Mechanical peeling process compatibility ("Mechanical peelability (pass / fail)" in Tables 1 and 2): A PET sheet was inserted between the two substrates of a test specimen similar to the sample for evaluating adhesion at high temperatures described above, and the test specimen was attached to dicing tape (ERK-3580, manufactured by Denka Co., Ltd.) with the silicon wafer side facing down. The attached specimen was placed on a vacuum chuck and secured in place. A 50 mm diameter suction cup was attached to the end of the specimen, and the measuring part of an electronic spring balance was attached to the center of the suction cup. The releasability was evaluated by pulling the balance vertically upward. Test specimens whose peel force (adhesion force) exceeded 50 N or whose PET sheet could not be inserted were deemed unsuccessful.

[0166] [Table 1] [Table 2]

[0167] [Table 3]

[0168] [Table 4]

[0169] From the results of the Examples in Tables 1 and 2 and the Comparative Examples in Table 4, it is clear that the resin composition of the present invention is a composition that is excellent in compatibility, spin coating process adaptability, and heat resistance. When (A-1) was not used and the monomer was entirely (A-2), (B) precipitated and was not compatible (Comparative Examples 1 and 2). When (A-2) was not used and all the monomers were (A-1), the required heat resistance (2% mass loss temperature on heating, elastic modulus) was not obtained (Comparative Examples 3 and 4). If (B) is not used, the viscosity does not reach the minimum required value (Comparative Example 5).

[0170] Furthermore, the results in Tables 1 and 2 show that the composition of the present invention has excellent UV laser peelability.

[0171] The resin composition of the present invention ensures compatibility of materials and the minimum viscosity required for spin coating, and is excellent in adhesiveness, heat resistance and releasability at room temperature and at high temperatures.

[0172] The resin composition of this example is compatible with UV laser peeling and mechanical peeling. A thin, sharp metal blade for initiating cleavage was inserted into the substrate interface at the edge of a silicon wafer / glass support laminate prepared by the method described in the above example, and the laminate was then fixed horizontally with the glass support facing up. After inserting the blade, an upward stress was applied to the upper support, propagating the cleavage and peeling the wafer and support. Peeling was possible.

[0173] The Maszara test was also used to evaluate the energy required for peeling. In this test, a thin, sharp blade is inserted a certain distance and the distance the cleavage progresses is measured. In this test, the samples bonded using the liquid resin of Example 1 also showed sufficiently low values.

[0174] The resin composition according to this example is compatible with the UV laser peeling process. The silicon wafer / glass support laminate produced by the method described in the above example was fixed in a fixing device with the silicon wafer facing down, and irradiated from the glass support side with a UV laser QLA-355 manufactured by Quark Technology Co., Ltd. at an output of 9.3 W, a frequency of 40 kHz, a scan pitch of 200 μm, and a beam diameter of 50 μm. The peel force was measured using the same procedure as in (3) Evaluation of mechanical peeling process compatibility. The peel force, which was 3 N before UV irradiation, had decreased to 0 N. [Industrial Applicability]

[0175] The composition provided by the present invention has excellent heat resistance, low outgassing properties, and release properties.

[0176] The composition of the present invention exhibits excellent workability and productivity in the production of various electronic components, optical components, and optical devices because it easily exhibits strong adhesive properties simply by irradiating it with ultraviolet or visible light. Furthermore, the cured product of the composition of the present invention exhibits extremely low outgassing even at temperatures as high as 250°C. The composition of the present invention is easy to peel after processing. Therefore, various electronic components, optical components, and optical devices bonded using the composition of the present invention can be used even when subjected to vapor deposition treatment at high temperatures exceeding 200°C or baking finish at high temperatures.

[0177] In addition to electronic components such as ICs, resistors, and inductors, optical components such as image sensors are now being surface-mounted on circuit boards. In these cases, they undergo high-temperature solder reflow. In recent years, particularly with the trend toward lead-free solder, the temperature conditions for solder reflow have become stricter. In these production processes, to improve the quality of optical components and optical devices, or to increase productivity and production yield, the areas where the composition of the present invention is used are required to be sufficiently resistant to high-temperature heat treatment. Optical components and optical devices manufactured using the composition of the present invention are highly industrially useful because they can withstand the high-temperature heat treatment.

Claims

1. A temporary fixing composition comprising the following (A) to (C): (A) A (meth)acrylate containing the following (A-1) and (A-2): (A-1) A monofunctional (meth)acrylate having an alkyl group with 18 or more carbon atoms in the side chain and a Tg of the homopolymer of -100°C to 60°C (A-2) Polyfunctional (meth)acrylate (B) Polyisobutene homopolymer and / or polyisobutene copolymer (C) Photoradical polymerization initiator

2. The temporary fixing composition according to claim 1 , further comprising the following (D): (D) UV absorber

3. The temporary fixing composition according to claim 1 or 2, wherein the molecular weight of the monofunctional (meth)acrylate (A-1) is 550 or less.

4. The temporary fixing composition according to any one of claims 1 to 3, wherein the component (A-1) is a monofunctional (meth)acrylate having an alkyl group of a linear or branched chain structure on the side chain.

5. The temporary fixing composition according to any one of claims 1 to 4, wherein the component (A-1) is one or more selected from the group consisting of stearyl (meth)acrylate, isostearyl (meth)acrylate, behenyl (meth)acrylate, 2-decyl-1-tetradecanyl (meth)acrylate, 2-dodecyl-1-hexadecanyl (meth)acrylate, and 2-tetradecyl-1-octadecanyl (meth)acrylate.

6. The temporary fixing composition according to any one of claims 1 to 5, wherein the molecular weight of the polyfunctional (meth)acrylate (A-2) is 900 or less.

7. The temporary fixing composition according to any one of claims 1 to 6, wherein the component (A-2) is a polyfunctional (meth)acrylate having an alicyclic skeleton.

8. The temporary fixing composition according to any one of claims 1 to 7, wherein the component (A-2) is at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate and 1,3-di(meth)acryloyloxyadamantane.

9. The temporary fixing composition according to any one of claims 1 to 8, wherein the component (B) is a polyisobutene homopolymer and / or a polyisobutene copolymer having a weight average molecular weight of 1,000 or more and 5,000,000 or less and a molecular weight distribution of 1.1 or more and 5.0 or less.

10. The temporary fixing composition according to any one of claims 1 to 9, wherein the component (C) is a photoradical polymerization initiator that generates radicals when exposed to light with a wavelength of 350 nm or more.

11. The component (C) is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(η 5 -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime). The temporary fixing composition according to any one of claims 1 to 10, which is one or more selected from the group consisting of:

12. The temporary fixing composition according to any one of claims 1 to 11, comprising 0.01 to 5 parts by mass of the component (C) per 100 parts by mass of the total of the components (A) and (B).

13. A temporary fixing adhesive comprising the temporary fixing composition according to any one of claims 1 to 12.

14. A cured product obtained by curing the temporary fixing composition according to any one of claims 1 to 12.

15. The cured product according to claim 14, wherein the temperature at which the rate of mass loss on heating becomes 2% by mass is 250°C or higher.

16. A bonded body in which substrates are bonded using the temporary fixing adhesive according to claim 13.

17. The following (A) to (C): (A) A (meth)acrylate containing the following (A-1) and (A-2): (A-1) A monofunctional (meth)acrylate having an alkyl group with 18 or more carbon atoms in the side chain and a Tg of the homopolymer of -100°C to 60°C (A-2) Polyfunctional (meth)acrylate (B) Polyisobutene homopolymer and / or polyisobutene copolymer (C) Photoradical polymerization initiator An adhered structure in which a substrate is adhered using a temporary fixing adhesive containing the compound, wherein the temporary fixing adhesive is cured by light having a wavelength of 385 nm to 700 nm, and the substrate is peeled off by laser light having a wavelength of less than 385 nm.

18. A method for manufacturing a thin wafer using the temporary fixing adhesive according to claim 13.

19. applying a temporary fixing adhesive to the semiconductor wafer substrate and / or the support member to bond the semiconductor wafer substrate and the support member; curing the temporary fixing adhesive by irradiating it with light having a wavelength of 350 nm to 700 nm to obtain an adhesive body; irradiating the bonded body with laser light having a wavelength of less than 385 nm to peel off the semiconductor wafer base material; A method for manufacturing a semiconductor wafer, comprising:

20. The method according to claim 18 or 19, wherein the cured temporary fixing adhesive constitutes a single layer in the adhesive body.

21. The temporary fixing adhesive according to claim 13, which is used for one or more applications selected from the group consisting of mechanical peeling, IR laser peeling, and UV laser peeling.

22. A single-layer cured body comprising the temporary fixing composition according to any one of claims 1 to 12.

23. A cured body having a first cured layer containing the component (A-1), the component (A-2), the component (B), and the component (C), but not containing the component (D), and a second cured layer made of the temporary fixing composition according to claim 2, wherein the concentration distribution of the components differs in the thickness direction.

24. A cured product having a first cured layer obtained by curing the temporary fixing composition according to claim 1, which contains the component (A-1), the component (A-2), the component (B), and the component (C), and a second cured layer obtained by applying a UV absorber onto the first cured layer, wherein the concentration distribution of the components differs in the thickness direction.

25. A cured body having a first cured layer obtained by curing the temporary fixing composition according to claim 1, which contains the component (A-1), the component (A-2), the component (B), and the component (C), and a light-to-heat conversion (LTHC) cured layer.

26. The cured product according to any one of claims 22 to 25, which satisfies all of the following conditions: The light transmittance of the cured body having a thickness of 50 μm is 70% or more in the wavelength region of 395 nm or more of the wavelength of the light source used for curing. The light transmittance of the cured body having a thickness of 50 μm is 20% or more in the wavelength region of 385 nm or more and less than 395 nm of the wavelength of the light source used for curing. - The light transmittance of the cured body having a thickness of 50 μm is 1% or less at the wavelength (355 nm) of the UV laser used for UV laser peeling.

27. A structure comprising the cured product according to any one of claims 22 to 26 and an adherend.

28. a step of applying a temporary fixing composition containing the component (A-1), the component (A-2), the component (B), and the component (C) but not the component (D) onto a wafer and partially curing the composition; applying the temporary fixing composition according to claim 2 onto the partially cured temporary fixing composition; a step of further placing a transparent substrate on the applied temporary fixing composition and photo-curing the composition; A method for manufacturing a structure, comprising:

29. a step of applying a temporary fixing composition containing the component (A-1), the component (A-2), the component (B), and the component (C) but not containing the component (D) onto a wafer, and partially curing the composition as needed; A step of applying the temporary fixing composition according to claim 2 onto a transparent substrate and partially curing it as necessary; a step of bringing the surfaces of the wafer and the transparent substrate, on which the temporary fixing composition is applied, into close contact with each other, and then bonding them by photocuring; A method for manufacturing a structure, comprising:

30. a step of applying the temporary fixing composition according to claim 1, which contains the component (A-1), the component (A-2), the component (B), and the component (C) but does not contain the component (D), onto a wafer, and partially curing the composition as needed; applying a light-to-heat conversion (LTHC) layer onto a transparent substrate, drying and curing; a step of bringing the surface of the wafer on which the temporary fixing composition is applied and the surface of the transparent substrate on which the LTHC layer is applied into close contact with each other, and then bonding them by photocuring; A method for manufacturing a structure, comprising:

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