Method for manufacturing thin wafer, wafer laminate, and temporary adhesive for wafer processing

Abstract

Provided is a method for manufacturing a thin wafer, in which a thermosetting silicone resin composition is used in a temporary adhesive for wafer processing for temporarily adhering a wafer to a support, in which the thermosetting silicone resin composition can be cured only by heating, and the thermosetting silicone resin composition can be cured only by heating. The composition contains (A) an organopolysiloxane having two or more alkenyl groups in one molecule, (B) an organohydrogenpolysiloxane having two or more hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule, (C) an organic peroxide, and (D) a radically active hydrosilicification reaction catalyst. As a result, provided is a method for manufacturing a thin wafer using a temporary adhesive for wafer processing, which has sufficient substrate retention after bonding even when a high step substrate is used, has high process adaptability to a wafer back surface polishing process, a TSV formation process, and a wafer back surface wiring process, has excellent wafer thermal process resistance, and can be used in a wafer back surface polishing process, a TSV formation process, and a wafer back surface wiring process. The composition has excellent long-term storage stability, and exhibits stable substrate retention, peelability, and residue cleanability of the peeled substrate regardless of the type of substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to a manufacturing method of a thin wafer, a wafer stack, and a temporary adhesive for wafer processing used therefor. BACKGROUND

[0002] In order to achieve further high density and large capacity, three-dimensional semiconductor mounting is becoming necessary. Three-dimensional mounting technology refers to a semiconductor manufacturing technology in which a semiconductor chip is thinned and further stacked in multiple layers while being wired through a through silicon via (TSV). In order to achieve this technology, it is necessary to thin a substrate on which a semiconductor circuit is formed by polishing a non-circuit formation surface (also referred to as a "back surface"), and further to form an electrode including a TSV on the back surface. In the past, in the back surface polishing process of a silicon substrate, a back surface protective tape was attached to the opposite side of the polished surface to prevent wafer breakage during polishing. However, this tape uses an organic resin film in the support base material, and although it has flexibility, on the contrary, the strength and heat resistance are insufficient, and it is not suitable for the TSV formation process, the process of forming a wiring layer on the back surface.

[0003] In this regard, a system in which a semiconductor substrate is joined to a support such as silicon or glass by an adhesive layer so as to be able to withstand the process of back surface polishing, TSV formation, or back surface electrode formation has been proposed. At this time, the adhesive layer when the substrate is joined to the support is particularly important. It needs to be able to seamlessly join the substrate to the support, and to have just enough durability to withstand the subsequent processes, and finally to be able to easily peel the thin wafer from the support. As described above, since it is finally peeled off, this adhesive layer is also referred to as a temporary adhesive layer in this specification.

[0004] So far, as a known temporary adhesive layer and a method for peeling it, the following technologies have been proposed: a technology in which an adhesive layer is peeled from a support by decomposing the adhesive layer by irradiating high-intensity light to an adhesive containing a light-absorbing substance (Patent Literature 1); and a technology in which a thermally fusible hydrocarbon compound is used in the adhesive, and joining and peeling are performed in a heated and molten state (Patent Literature 2). The technology of Patent Literature 1 requires an expensive device such as a laser, and has problems such as an increase in the processing time per substrate. In addition, the technology of Patent Literature 2 is relatively simple because it is controlled only by heating, but on the contrary, the heat stability is not sufficient at a high temperature of more than 200°C, and therefore the range of application is narrow. Further, these temporary adhesive layers are also not suitable for forming a uniform film thickness on a high step substrate and for complete adhesion to the support.

[0005] Further, a technique using a silicone adhesive in a temporary adhesive layer is proposed. It uses a silicone adhesive of a hydrosilylation addition-curing type, bonds a substrate to a support, and at the time of peeling, is immersed in a reagent that dissolves or decomposes the silicone resin, and thereby separates the substrate from the support (Patent Document 3). Therefore, a very long time is required at the time of peeling, and it is difficult to apply to actual manufacturing processes. Further, after peeling, a long time is also required to clean the silicone adhesive that remains as a residue on the substrate, and there is a technical problem in terms of cleaning removal.

[0006] Further, the silicone adhesive composition of the hydrosilylation addition-curing type has a technical problem of long-term storage stability in that the viscosity increases with the passage of time in long-term storage.

[0007] Further, for the purpose of imparting heat resistance and chemical resistance to the substrate, sometimes an oxide film, a nitride film, an organic resin film, or the like is previously treated on the surface of the substrate, but there is a problem in that depending on the type of the chemical modification of the surface of the substrate, the hydrogen silylation reaction caused by the platinum catalyst is affected, and as a result, the adhesion of the silicone resin to the substrate changes, and stable wafer processability, support peelability, and the like cannot be obtained.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2004-64040

[0011] Patent Document 2: Japanese Patent Application Publication No. 2006-328104

[0012] Patent Document 3: U.S. Patent No. 7541264 SUMMARY

[0013] (I) Problem to be Solved by the Invention

[0014] The present application is implemented in view of the above technical problems, and aims to provide a thin wafer manufacturing method using a temporary adhesive for wafer processing, a wafer stack, and a temporary adhesive for wafer processing, which, even when a high-relief substrate is used, has sufficient substrate retention after bonding, high process adaptability to a wafer backgrinding process, a TSV forming process, a wafer back wiring process, excellent wafer heat process resistance, excellent long-term storage stability of the composition, and exhibits stable substrate retention, peelability, and residue cleaning of the substrate after peeling regardless of the type of substrate.

[0015] (II) Technical Solution

[0016] To solve the above-described technical problem, the present application provides a thin wafer manufacturing method which uses a thermosetting silicone resin composition in a temporary adhesive for wafer processing for temporarily adhering a wafer to a support, the method being characterized by,

[0017] The thermosetting silicone resin composition is capable of being cured only by heating, and comprises the following components:

[0018] 100 parts by mass of (A) an organopolysiloxane having 2 or more alkenyl groups in one molecule;

[0019] (B) an organohydrogenpolysiloxane containing 2 or more silicon atom-bonded hydrogen atoms (SiH groups) in one molecule, in an amount such that the total amount of SiH groups in the (B) component is 0.3 to 10 in molar ratio to the total amount of alkenyl groups in the (A) component;

[0020] 0.01 to 20 parts by mass of (C) an organic peroxide;

[0021] (D) a radical-active hydrosilylation catalyst, in an amount of 0.1 to 5,000 ppm in terms of metal atom amount, relative to the total mass of the (A) component and the (B) component.

[0022] Due to the softness and excellent heat resistance of the silicone resin, the above-described thin wafer manufacturing method of the present application can be applied to a wide range of semiconductor film formation processes, and is also excellent in CVD (chemical vapor deposition) resistance, and even for wafers having steps, a temporary adhesive layer having high film thickness uniformity can be formed, and due to this film thickness uniformity, a uniform thin wafer of 50 μm or less can be easily manufactured. Furthermore, after the thin wafer is manufactured, the wafer can be easily peeled from the support, for example, at room temperature, and the peeling interface can also be controlled to be between the wafer / temporary adhesive layer, so that it becomes easy to clean the residue on the wafer after peeling, and the manufacturing operability of the easily broken thin wafer can be improved.

[0023] At this time, it is preferable to use a thermosetting silicone resin composition further containing 0.1 to 200 parts by mass of a non-functional organopolysiloxane as a (E) component.

[0024] If the above-described thermosetting silicone resin composition further containing a non-functional organopolysiloxane as a (E) component, peeling can be easily performed in the process of peeling the support from the substrate, while on the other hand, wafer peeling can be prevented during processing of the wafer such as backgrinding of the wafer and subsequent heat treatment, and wafer processing durability can be obtained.

[0025] At this time, it is further preferable that the non-functional organic polysiloxane of the (E) component consists of dimethylpolysiloxane, and the viscosity of a 30 mass% toluene solution of the (E) component at 25°C is 100 to 500,000 mPa-s. The viscosity is more preferably 1,000 to 400,000 mPa-s, and further preferably 10,000 to 300,000 mPa-s.

[0026] If the viscosity is within the above range, since the non-functional organic polysiloxane has an appropriate molecular weight, it does not volatilize when the silicone resin composition is subjected to heat curing, and thus it is difficult to obtain the effect, and it does not cause wafer breakage in wafer thermal processes such as CVD, and the handling and coating properties are also good, and thus it is preferable.

[0027] Further, in the method for producing a thin wafer of the present application, it is preferable that the organic peroxide is at least one selected from the group consisting of diacyl peroxides, peroxy esters, dialkyl peroxides, percarbonates, peroxy ketones, hydroperoxides, and ketone peroxides.

[0028] As the organic peroxide used in the present application, in order to obtain the catalytic activity of the (D) component, it is preferable that these organic peroxides.

[0029] Further, it is preferable that the temperature at which the half-life is 10 hours is 40°C or higher and the temperature at which the half-life is 1 minute is 200°C or lower.

[0030] The use of the above-mentioned organic peroxide can achieve both high reactivity and long storage life, and thus is effective.

[0031] Further, it is preferable to use a thermosetting silicone resin composition further comprising a hydrosilylation reaction control agent as a (F) component, the (F) component being 0.001 to 10 parts by mass with respect to the total mass of the (A) and (B) components.

[0032] By using the above-mentioned reaction control agent, it is possible to prevent thickening or gelation of the composition during long-term storage.

[0033] Further, it is preferable that the 180° peel strength of a test piece having a width of 25 mm to a silicon substrate after curing of the thermosetting silicone resin composition is 2 gf or more and 500 gf or less at 25°C.

[0034] By using a thermosetting silicone resin composition having the above-mentioned peel strength after curing, it is possible to prevent displacement of the wafer when the wafer is polished, and the peeling of the support becomes easy.

[0035] Further, it is preferable that the thermosetting silicone resin composition after curing has a storage modulus at 25°C of 1,000 Pa or more and 1,000 MPa or less.

[0036] By using the thermosetting silicone resin composition having the above-mentioned storage modulus, displacement of the wafer during polishing of the wafer can be prevented, and stability is maintained during application of a thermal process to the wafer.

[0037] Further, the present application provides a method for manufacturing a thin wafer, which is any of the above-mentioned methods for manufacturing a thin wafer, and which comprises the following steps:

[0038] (a) a step of adhering a circuit formation surface of a wafer having the circuit formation surface on a surface and a non-circuit formation surface on a back surface to a support in a peelable manner using the temporary adhesive for wafer processing to form a wafer stack;

[0039] (b) a step of thermally curing the temporary adhesive;

[0040] (c) a step of polishing or grinding the non-circuit formation surface of the wafer of the wafer stack;

[0041] (d) a step of performing processing on the non-circuit formation surface of the wafer;

[0042] (e) a step of peeling the wafer on which the processing has been performed from the support.

[0043] Further, the present application provides a temporary adhesive for wafer processing, which can be applied to a thin wafer or a wafer stack, characterized by being composed of a thermosetting silicone resin composition containing the following components:

[0044] 100 parts by mass of (A) an organopolysiloxane having 2 or more alkenyl groups in one molecule;

[0045] (B) an organohydrogenpolysiloxane containing 2 or more silicon atom-bonded hydrogen atoms (SiH groups) in one molecule, in an amount such that the total amount of SiH groups in the (B) component is 0.3 to 10 in molar ratio to the total amount of alkenyl groups in the (A) component;

[0046] 0.01 to 20 parts by mass of (C) an organic peroxide;

[0047] (D) a radical-active hydrosilylation reaction catalyst, in an amount of 0.1 to 5,000 ppm in terms of metal atom amount, relative to the total mass of the (A) component and the (B) component.

[0048] If the temporary adhesive for wafer processing of the present application described above, due to the softness and excellent heat resistance of the silicone resin, it can be applied to a wide range of semiconductor film forming processes, CVD (chemical vapor deposition) resistance is also excellent, and even for wafers with a step, it is also possible to form a temporary adhesive layer with high film thickness uniformity, due to the film thickness uniformity, it is easy to manufacture a uniform thin wafer of 50 μm or less. In addition, after manufacturing a thin wafer, it is easy to peel the wafer from the support, for example, at room temperature, and the peeling interface can also be controlled between the wafer / temporary adhesive layer, so it is easy to clean the residue on the wafer after peeling, and the manufacturing operability of the easily broken thin wafer can be improved. Further, the heat-curable silicone resin composition of the temporary adhesive of the present application also has excellent long-term storage stability, and after preparing the composition, the above-mentioned properties can be obtained for a long time.

[0049] At this time, it is preferable to be composed of a heat-curable silicone resin composition further containing 0.1 to 200 parts by mass of a non-functional organopolysiloxane as the (E) component.

[0050] If the temporary adhesive for wafer processing further containing a non-functional organopolysiloxane as the (E) component described above, it can be easily peeled off in the process of peeling the support from the substrate, on the other hand, it can prevent the wafer from being peeled off when the wafer processing such as back grinding and subsequent heat treatment is performed, and the wafer processing durability can be obtained.

[0051] At this time, it is preferable that the non-functional organopolysiloxane of the (E) component be dimethylpolysiloxane, and the viscosity of a 30 mass% toluene solution of the (E) component at 25°C be 100 to 500,000 mPa·s. The viscosity is more preferably 1,000 to 400,000 mPa·s, and further preferably 10,000 to 300,000 mPa·s.

[0052] If the viscosity is within the above range, the non-functional organopolysiloxane has a suitable molecular weight, so it will not volatilize when the silicone resin composition is heat-cured, and thus it will not be difficult to obtain the effect, and it will not cause wafer breakage in wafer heat processes such as CVD, and the operability and coatability are also good, and therefore it is preferable.

[0053] In addition, for the temporary adhesive for wafer processing of the present application, it is preferable that the organic peroxide be at least one selected from the group consisting of diacyl peroxide, peroxy ester, dialkyl peroxide, percarbonate, peroxy ketal, hydroperoxide and ketone peroxide.

[0054] As the organic peroxide used in the present application, in order to obtain the catalytic activity of the (D) component, it is preferable that these organic peroxides.

[0055] Further, it is preferable that the temperature at which the half-life of the organic peroxide is 10 hours be 40°C or higher, and the temperature at which the half-life is 1 minute be 200°C or lower.

[0056] The use of the above-described organic peroxide can achieve both high reactivity and long storage life, and is thus effective.

[0057] Further, it is preferable that the thermosetting silicone resin composition further include a hydrosilylation reaction control agent as a (F) component, the (F) component being included in an amount of 0.001 to 10 parts by mass with respect to the total mass of the (A) component and the (B) component.

[0058] By using the above-described reaction control agent, thickening or gelation of the composition during long-term storage can be prevented.

[0059] Further, it is preferable that the thermosetting silicone resin composition, after curing, have a 180° peel strength of 2 gf or more and 500 gf or less against a silicon substrate for a test piece having a width of 25 mm at 25°C.

[0060] By using the thermosetting silicone resin composition having the above-described peel strength after curing, displacement of the wafer during polishing of the wafer is not a concern, and peeling of the support becomes easy.

[0061] Further, it is preferable that the thermosetting silicone resin composition, after curing, have a storage modulus of 1,000 Pa or more and 1,000 MPa or less at 25°C.

[0062] The thermosetting silicone resin composition having the above-described storage modulus can prevent displacement of the wafer during polishing of the wafer, and also remains stable when a thermal process is applied to the wafer.

[0063] Further, the present application provides a wafer stack including a support, a temporary adhesive layer obtained from any one of the above-described temporary adhesives for wafer processing, which is laminated on the support, and a wafer having a circuit formation surface on a surface and a non-circuit formation surface on a back surface, characterized in that the temporary adhesive layer is adhered to the surface of the wafer in a peelable manner.

[0064] The temporary adhesive for wafer processing used in the temporary adhesive layer of the wafer stack described above can be applied to a wide range of semiconductor film forming processes due to the softness and excellent heat resistance of the silicone resin, and is also excellent in CVD (chemical vapor deposition) resistance, and even for wafers having steps, a temporary adhesive layer having high film thickness uniformity can be formed, and due to this film thickness uniformity, a uniform thin wafer of 50 μm or less can be easily provided. Further, after the thin wafer is manufactured from the wafer stack, the wafer can be easily peeled from the support body, for example, at room temperature, and the peeling interface can also be controlled between the wafer / temporary adhesive layer, and thus the residue on the wafer after peeling can be easily cleaned, and the manufacturing operability of the easily broken thin wafer can be improved.

[0065] (III) Advantageous Effects

[0066] The thin wafer manufacturing method, wafer stack, and temporary adhesive for wafer processing of the present application can be applied to a wide range of semiconductor film forming processes due to the softness and excellent heat resistance of the silicone resin, and is also excellent in CVD (chemical vapor deposition) resistance, and even for wafers having steps, a temporary adhesive layer having high film thickness uniformity can be formed, and due to this film thickness uniformity, a uniform thin wafer of 50 μm or less can be easily provided. Further, after the thin wafer is manufactured from the wafer stack, the wafer can be easily peeled from the support body, for example, at room temperature, and the peeling interface can also be controlled between the wafer / temporary adhesive layer, and thus the residue on the wafer after peeling can be easily cleaned, and the manufacturing operability of the easily broken thin wafer can be improved. Further, the heat-curable silicone resin composition of the temporary adhesive of the present application is also excellent in long-term storage stability, and after the composition is prepared, the above-described properties can be obtained for a long period of time. Further, even if the surface of the wafer to be applied is a substrate covered with a resin film or the like, the surface covering layer does not easily affect the properties, and stable wafer adhesion, wafer peeling, and residue cleaning properties on the wafer can be exhibited for a wide range of substrate materials. DETAILED DESCRIPTION

[0067] To solve the above-described technical problem, the inventors of the present application conducted intensive research, and as a result, found that the above-described technical problem can be solved by using a heat-curable silicone resin composition using a radical active type hydrosilylation catalyst in the temporary adhesive, and thus completed the present application.

[0068] The temporary adhesive for wafer processing used in the thin wafer manufacturing method and wafer stack of the present application can be suitably implemented by using the heat-curable silicone resin composition shown below. Among them, from the viewpoint of applicability to wafers having steps, the heat-curable silicone resin composition preferably has good spin coating properties.

[0069] That is, the present application is a method for manufacturing a thin wafer, which uses a thermosetting silicone resin composition in a temporary adhesive for wafer processing used for temporarily adhering a wafer to a support, the method being characterized by,

[0070] The thermosetting silicone resin composition is capable of being cured only by heating, and comprises the following components:

[0071] 100 parts by mass of (A) an organopolysiloxane having 2 or more alkenyl groups in one molecule;

[0072] (B) an organohydrogenpolysiloxane containing 2 or more silicon-bonded hydrogen atoms (SiH groups) in one molecule, in an amount such that the total amount of SiH groups in the (B) component is 0.3 to 10 in molar ratio to the total amount of alkenyl groups in the (A) component;

[0073] 0.01 to 20 parts by mass of (C) an organic peroxide;

[0074] (D) a radical-active hydrosilylation reaction catalyst, in an amount of 0.1 to 5,000 ppm in terms of metal atom amount, relative to the total mass of the (A) component and the (B) component.

[0075] Further, the present application is a temporary adhesive for wafer processing, which can be applied to a thin wafer or a wafer stack, characterized by being composed of a thermosetting silicone resin composition comprising the following components:

[0076] 100 parts by mass of (A) an organopolysiloxane having 2 or more alkenyl groups in one molecule;

[0077] (B) an organohydrogenpolysiloxane containing 2 or more silicon-bonded hydrogen atoms (SiH groups) in one molecule, in an amount such that the total amount of SiH groups in the (B) component is 0.3 to 10 in molar ratio to the total amount of alkenyl groups in the (A) component;

[0078] 0.01 to 20 parts by mass of (C) an organic peroxide;

[0079] (D) a radical-active hydrosilylation reaction catalyst, in an amount of 0.1 to 5,000 ppm in terms of metal atom amount, relative to the total mass of the (A) component and the (B) component.

[0080] Hereinafter, each component constituting the above-described thermosetting silicone resin composition will be described.

[0081] [(A) component]

[0082] (A) is an organopolysiloxane having two or more alkenyl groups in one molecule. Examples of (A) include linear or branched diorganopolysiloxanes containing two or more alkenyl groups in one molecule; and those containing two or more alkenyl groups in one molecule and having SiO₂ content. 4 / 2 The unit represents an organopolysiloxane with a three-dimensional network structure of siloxane units (Q units). Preferably, it is a diorganopolysiloxane or an organopolysiloxane with a three-dimensional network structure and an alkenyl content of 0.6 to 9 mol%. Furthermore, in this invention, the alkenyl content refers to the proportion of alkenyl-containing siloxane units among all siloxane units.

[0083] Examples of the aforementioned organopolysiloxanes include those represented by formulas (A-1), (A-2), or (A-3). These organopolysiloxanes may be used alone or in combination of two or more.

[0084] [Chemical Formula 1]

[0085]

[0086] In equations (A-1) to (A-3), R 1 ~R 16 Each is an independent monovalent hydrocarbon group other than an aliphatic unsaturated hydrocarbon group. X 1 ~X 5 Each is an independent monovalent organic group containing an alkenyl group.

[0087] In equation (A-1), a and b are each independent integers from 0 to 3. In equations (A-1) and (A-2), c 1 c 2 d 1 and d 2 To satisfy 0≤c 1 ≤10、2≤c 2 ≤10、0≤d 1 ≤100 and 0≤d 2 Integers ≤ 100. Where a + b + c 1 ≥2. a, b, c 1 c 2 d 1 and d 2 The preferred combination is a numerical combination that results in an alkenyl content of 0.6 to 9 mol%.

[0088] In equation (A-3), e is an integer from 1 to 3. 1 f 2 and f 3 In order to make (f 2 +f 3 ) / f 1 The value is 0.3~3.0 and f3 / (f 1 +f 2 +f 3 ) is a number from 0.01 to 0.6.

[0089] As the monovalent hydrocarbon group other than the aliphatically unsaturated hydrocarbon group, a monovalent hydrocarbon group having 1 to 10 carbon atoms is preferable, and examples thereof include an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, and the like; a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, and the like; an aryl group such as a phenyl group, a tolyl group, and the like. Among these groups, an alkyl group such as a methyl group or a phenyl group is preferable.

[0090] As the monovalent organic group having an alkenyl group, a monovalent organic group having an alkenyl group having 2 to 10 carbon atoms is preferable, and examples thereof include an alkenyl group such as a vinyl group, an allyl group, a hexenyl group, an octenyl group, and the like; a (meth)acrylalkyl group such as a (meth)acrylpropyl group, a (meth)acrylmethyl group, a methyl(meth)acrylpropyl group, and the like; a (meth)acryloxyalkyl group such as a (meth)acryloyloxypropyl group, a (meth)acryloyloxymethyl group, a methyl(meth)acryloyloxypropyl group, a methyl(meth)acryloyloxymethyl group, and the like; a monovalent hydrocarbon group having an alkenyl group such as a cyclohexenylethyl group, a vinyloxypropyl group, and the like. Among these groups, from an industrial viewpoint, a vinyl group is preferable.

[0091] In formula (A-1), a and b are each independently an integer from 0 to 3, but if a is from 1 to 3, since the molecular chain terminal is capped with an alkenyl group, the reaction can be completed in a short time by the molecular chain terminal alkenyl group having a high reactivity, and thus it is preferable. Further, from a cost aspect, in industry, it is preferable that a be 1. The monovalent organic group having an alkenyl group represented by formula (A-1) or (A-2) is preferably in an oil or raw rubber state.

[0092] The organopolysiloxane represented by formula (A-3) contains SiO 4 / 2 units and has a three-dimensional network structure. In formula (A-3), e is each independently an integer from 1 to 3, but from a cost aspect, in industry, it is preferable that e be 1. Further, the average value of e and the product of f 3 / (f 1 +f 2 +f 3 is preferably from 0.02 to 1.5, and more preferably from 0.03 to 1.0. The organopolysiloxane represented by formula (A-3) can be used in the form of a solution dissolved in an organic solvent.

[0093] The number average molecular weight (Mn) of the organic polysiloxane of the (A) component is preferably from 100 to 1,000,000, more preferably from 1,000 to 100,000. If the Mn is within the range, it is preferable in terms of operability accompanying the viscosity of the composition, processability accompanying the storage modulus after curing. In addition, in the present application, the Mn is a polystyrene conversion measurement value obtained by gel permeation chromatography with toluene as a solvent.

[0094] The (A) component can be used singly or in combination of two or more. It is particularly preferable to use the organic polysiloxane represented by formula (A-1) in combination with the organic polysiloxane represented by formula (A-3). At this time, the amount of the organic polysiloxane represented by formula (A-3) is preferably from 1 to 1,000 parts by mass, more preferably from 10 to 500 parts by mass, relative to 100 parts by mass of the organic polysiloxane represented by formula (A-1).

[0095] [(B) component]

[0096] The (B) component is a crosslinking agent, which is an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms (SiH group) in one molecule, preferably an organohydrogenpolysiloxane having three or more silicon-bonded hydrogen atoms in one molecule. The organohydrogenpolysiloxane can be any of linear, branched, or cyclic. In addition, the organohydrogenpolysiloxane can be used singly or in combination of two or more.

[0097] The viscosity of the organohydrogenpolysiloxane of the (B) component at 25°C is preferably from 1 to 5,000 mPa-s, more preferably from 5 to 500 mPa-s. In addition, the viscosity in the present application is a measurement value at 25°C measured by a rotational viscometer.

[0098] The Mn of the organohydrogenpolysiloxane of the (B) component is preferably from 100 to 100,000, more preferably from 500 to 10,000. If the Mn is within the range, it is preferable in terms of operability accompanying the viscosity of the composition, processability accompanying the storage modulus after curing.

[0099] The (B) component is preferably blended in such a manner that the total amount of SiH groups in the (B) component is in the range of 0.3 to 10 in terms of a molar ratio (SiH groups / alkenyl groups) relative to the total amount of alkenyl groups in the (A) component, more preferably in such a manner that the total amount of SiH groups in the (B) component is in the range of 0.5 to 5.0 in terms of a molar ratio (SiH groups / alkenyl groups) relative to the total amount of alkenyl groups in the (A) component, and more preferably in such a manner that the total amount of SiH groups in the (B) component is in the range of 0.5 to 3.0 in terms of a molar ratio (SiH groups / alkenyl groups) relative to the total amount of alkenyl groups in the (A) component. If the molar ratio is 0.3 or more, the crosslinking density can be sufficiently increased, and the temporary adhesive layer can be more reliably cured. In addition, if the molar ratio is 10 or less, the crosslinking density can be moderate, sufficient adhesion and tack can be obtained, and the change in the close contact property before and after the heat treatment step can be suppressed.

[0100] [(C) component]

[0101] The (C) component is an organic peroxide which is used to allow radicals generated by pyrolysis to act on a (D) component described later: a radical-active hydrosilylation reaction catalyst, and further to obtain catalytic activity. As examples of the organic peroxide therein, diacyl peroxides, peroxy esters, dialkyl peroxides, percarbonates, peroxy ketones, hydroperoxides, ketone peroxides, and the like can be given, and one of these organic peroxides can be used alone or two or more kinds thereof can be used in combination.

[0102] From the viewpoint of balancing high reactivity and long-term storage stability, the organic peroxide of the (C) component preferably has a half-life of 10 hours at a temperature of 40°C or higher and a half-life of 1 minute at a temperature of 200°C or lower, and more preferably has a half-life of 10 hours at a temperature of 60°C or higher and a half-life of 1 minute at a temperature of 180°C or lower. The upper limit of the temperature at which the half-life of 10 hours is measured and the lower limit of the temperature at which the half-life of 1 minute is measured are each not particularly limited and are each around 150°C or lower and around 100°C or higher, respectively.

[0103] As the diacyl peroxide, for example, isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, bis(3,5,5-trimethylhexanoyl) peroxide, octanoyl peroxide, lauroyl peroxide, stearyl peroxide, succinyl peroxide, benzoyl peroxide, benzoyl peroxide, and benzoyl peroxide can be given.

[0104] As peroxyl esters, for example, cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-amyl peroxyneopentanoate, t-butyl peroxyneopentanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethyl peroxy-2-ethylhexanoate, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, 1,1-bis(t-butylperoxy)cyclohexane, t-hexyl peroxyisopropylmonocarbonate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylauroate, 2,5-dimethyl-2,5-bis(m-toluoylperoxy)hexane, t-butyl peroxyisopropylmonocarbonate, t-butyl peroxy-2-ethylhexylmonocarbonate, t-hexyl peroxybenzoate, t-butyl peroxyacetate, t-butyl peroxydiethylacetate, and bis(t-butylperoxy)hexahydro-p-xylenesuccinate.

[0105] As dialkyl peroxides, for example, α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, and t-butylcumyl peroxide can be mentioned.

[0106] As percarbonates, for example, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxy peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, dimethoxybutyl peroxydicarbonate, and di(3-methyl-3-methoxybutyl) peroxydicarbonate, 1,6-di(t-butylperoxycarbonyloxy)hexane can be mentioned.

[0107] As ketone peroxides, for example, methyl ethyl ketone peroxide, acetylacetone peroxide, and the like can be mentioned.

[0108] As hydroperoxides, for example, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumyl hydroperoxide, t-butyl hydroperoxide, t-amyl hydroperoxide, and the like can be mentioned.

[0109] As ketone peroxides, for example, methyl ethyl ketone peroxide, acetylacetone peroxide, and the like can be mentioned.

[0110] The amount of the organic peroxide of the (C) component is 0.01 to 20 parts by mass, preferably 0.05 to 10 parts by mass, relative to 100 parts by mass of the total amount of the organic polysiloxane of the (A) component. If the amount is 0.01 parts by mass or more, the reaction can sufficiently proceed, and the target cured product can be more reliably obtained. If the amount is 20 parts by mass or less, foaming of the resin at the time of curing can be prevented.

[0111] [(D) component]

[0112] The (D) component is a radical-active hydrosilylation reaction catalyst which exhibits catalytic activity by the action of radicals generated by the pyrolysis of the (C) component, and as a result, the catalyst has the effect of promoting the addition reaction of the alkenyl group in the (A) component and the Si-H group in the (B) component.

[0113] The radical-active hydrosilylation reaction catalyst mainly belongs to a platinum group metal catalyst or an iron group metal catalyst, and as the platinum group metal catalyst, there are platinum-based, palladium-based, and rhodium-based metal complexes, and as the iron group metal catalyst, there are nickel-based, iron-based, and cobalt-based iron group complexes. Among these, platinum-based metal complexes are easily available and exhibit good catalytic activity, and thus are preferred and are often used.

[0114] As the ligand of the catalyst, from the viewpoint of obtaining long-term storage stability at ordinary temperatures, cyclic diene ligands, β-diketone ligands, and the like can be mentioned.

[0115] As described above, as a preferred example of the radical-active hydrosilylation reaction catalyst, as a cyclic diene ligand type, for example, (η 5- (cyclopentadienyl)tris(σ-alkyl)platinum (IV) complexes, specifically, (trimethyl)methylcyclopentadienyl platinum (IV), (cyclopentadienyl)trimethyl platinum (IV), (1,2,3,4,5-pentamethylcyclopentadienyl)trimethyl platinum (IV), (cyclopentadienyl)dimethyl ethyl platinum (IV), (cyclopentadienyl)dimethyl acetyl platinum (IV), (trimethylsilylcyclopentadienyl)trimethyl platinum (IV), (methoxycarbonylcyclopentadienyl)trimethyl platinum (IV), (ditolylsilylcyclopentadienyl)trimethyl platinum (IV), and the like, and, in addition, as a β-diketone ligand type, β-diketone platinum (II) or platinum (IV) complexes, specifically, trimethyl(acetylacetone) platinum (IV), trimethyl(3,5-pentanedione) platinum (IV), trimethyl(methyl acetoacetate) platinum (IV), bis(2,4-pentanedione) platinum (II), bis(2,4-hexanedione) platinum (II), bis(2,4-heptanedione) platinum (II), bis(3,5-heptanedione) platinum (II), bis(1-phenyl-1,3-butanedione) platinum (II), bis(1,3-diphenyl-1,3-propanedione) platinum (II), bis(hexafluoroacetylacetone) platinum (II), and the like.

[0116] When these catalysts are used, although these catalysts can be used as solids when they are solid catalysts, in order to obtain a uniform cured product, it is preferable to use the catalyst dissolved in a suitable solvent in compatibility with the organopolysiloxane having an alkenyl group of the (A) component. As the solvent, isononane, n-decane, toluene, ethyl 2-(2-butoxyethoxy)acetate, and the like can be exemplified.

[0117] The amount of the (D) component to be added is an effective amount, and, generally, with respect to the total mass of the (A) and (B), the amount of platinum (calculated as the metal atomic weight) is 0.1 to 5,000 ppm, preferably 0.5 to 2,000 ppm, and further preferably 1 to 500 ppm. If it is 0.1 ppm or more, the curability of the composition does not decrease, and even if the crosslinking density is low, the mechanical strength of the material does not decrease. If it is 5,000 ppm or less, the foaming of the resin at the time of curing can be suppressed.

[0118] [(E) component]

[0119] The thermosetting silicone resin composition can further include, as the (E) component, an organopolysiloxane having no functional group. The "having no functional group" means that the organopolysiloxane does not have a reactive group such as a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, or the like directly bonded to a silicon atom, or a reactive group such as an alkenyl group, an epoxy group, or the like directly bonded to a silicon atom or bonded thereto via an arbitrary group, in the molecule.

[0120] As the above-mentioned non-functional organopolysiloxane, for example, an organopolysiloxane having a monovalent hydrocarbon group other than an aliphatically unsaturated hydrocarbon group, which is unsubstituted or substituted with a carbon atom number of 1 to 12, preferably a carbon atom number of 1 to 10, can be exemplified. As the above-mentioned monovalent hydrocarbon group, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and the like; a cycloalkyl group such as a cyclohexyl group, and the like; an aryl group such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and the like; an aralkyl group such as a benzyl group, a phenethyl group, and the like, and the like can be exemplified. Furthermore, a part or all of the hydrogen atoms of these groups can be substituted with a halogen atom such as a chlorine atom, a fluorine atom, a bromine atom, and the like, and as the above-mentioned group, a halogenated alkyl group such as a chloromethyl group, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, and the like can be exemplified. As the monovalent hydrocarbon group, an alkyl group, an aryl group, more preferably a methyl group, a phenyl group is preferred.

[0121] The molecular structure of the non-functional organopolysiloxane of the (E) component is not particularly limited, and can be any one of a linear shape, a branched shape, a ring shape, and the like, but a linear or branched organopolysiloxane is preferred, preferably a linear diorganopolysiloxane in which the main chain is substantially composed of diorganosiloxane units and both ends of the molecular chain are capped with triorganosiloxy groups.

[0122] From the viewpoint of the handleability of the composition, the coatability to a substrate, the mechanical properties of a cured product, the releasability from a support, and the like, the viscosity (25°C) of a 30 mass% toluene solution of the non-functional organopolysiloxane of the (E) component is preferably 100 to 500,000 mPa-s, more preferably 5,000 to 500,000 mPa-s. If within the range, the molecular weight is appropriate, and thus, volatilization does not occur when the silicone resin composition is subjected to heat curing, and thus, the effect is not easily obtained, and wafer cracking does not occur in wafer thermal processes such as CVD, the handleability and the coatability are also good, and thus, are preferred.

[0123] As the non-functional organopolysiloxane, mention can be made of a dimethylsiloxane polymer capped at both molecular chain terminals with trimethylsiloxy groups, a phenylmethylsiloxane capped at both molecular chain terminals with trimethylsiloxy groups, a 3,3,3-trifluoropropylmethylsiloxane polymer capped at both molecular chain terminals with trimethylsiloxy groups, a dimethylsiloxane-methylphenylsiloxane copolymer capped at both molecular chain terminals with trimethylsiloxy groups, a dimethylsiloxane-3,3,3-trifluoropropylmethyl copolymer capped at both molecular chain terminals with trimethylsiloxy groups, a methylphenylsiloxane-3,3,3-trifluoropropylmethyl copolymer capped at both molecular chain terminals with trimethylsiloxy groups, a dimethylsiloxane-3,3,3-trifluoropropylmethylsiloxane-methylphenylsiloxane copolymer capped at both molecular chain terminals with trimethylsiloxy groups, a dimethylpolysiloxane capped at both molecular chain terminals with dimethylphenylsiloxy groups, a methylphenylpolysiloxane capped at both molecular chain terminals with dimethylphenylsiloxy groups, a dimethylsiloxane-methylphenylsiloxane copolymer capped at both molecular chain terminals with dimethylphenylsiloxy groups, and the like.

[0124] The non-functional organopolysiloxane of the (E) component can be used alone or in combination with two or more. In addition, it is preferably in the form of an oil or a raw rubber.

[0125] The (E) component is preferably blended at 0.1 to 200 parts by mass, and further preferably at 1 to 100 parts by mass, with respect to 100 parts by mass of the (A) component. If the blending ratio is 0.1 parts by mass or more, peeling can be easily performed in the process of peeling the support from the substrate, and thus it is preferred. In addition, if the blending ratio is 200 parts by mass or less, the wafer will not be peeled during wafer processing such as backgrinding of the wafer or heat treatment thereafter, and wafer processing durability can be obtained, and thus it is preferred.

[0126] [(F) component]

[0127] The thermosetting silicone resin composition can further contain, as the (F) component, a reaction control agent (hydrosilylation reaction control agent). The reaction control agent is an ingredient that is optionally added as needed, and is used to prevent the composition from thickening or gelling during the preparation of the composition or during coating on a substrate or during storage.

[0128] As the reaction control agent, 3-methyl-1-butyne-3-ol, 3-methyl-1-pentyne-3-ol, 3,5-dimethyl-1-hexyne-3-ol, 1-ethynylcyclohexanol, 3-methyl-3-trimethylsiloxy-1-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy-1-hexyne, 1-ethynyl-1-trimethylsiloxy cyclohexane, bis(2,2-dimethyl-3-butylnyloxy)dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,1,3,3-tetramethyl-1,3-divinyl disiloxane, and the like can be exemplified. Among them, 1-ethynylcyclohexanol and 3-methyl-1-butyne-3-ol are preferable.

[0129] In the case where the thermosetting silicone resin composition contains the (F) component, since the control ability varies depending on the chemical structure, the content thereof should be adjusted to the most suitable amount, respectively, but in view of the influence on the curability, storage stability, post-cured properties, and the like, it is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 10 parts by mass, relative to the total mass of the (A) and (B) components. If the content of the (F) component is within the range, the usable time of the composition is long, long-term storage stability is obtained, and the curability and handleability are good.

[0130] In the thermosetting silicone resin composition, an organopolysiloxane containing R A 3SiO 0.5 units (in the formula, R A each independently is a non-substituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms) and SiO2units and R A 3SiO 0.5 units relative to the SiO2units (molar ratio (R A 3SiO 0.5 / SiO2) is 0.3 to 1.8. The amount of addition thereof relative to 100 parts by mass of the (A) component is preferably 0 to 500 parts by mass.

[0131] In order to further improve the heat resistance of the temporary adhesive layer to be obtained later, a filler such as silica can be added to the thermosetting silicone resin composition.

[0132] For the reasons of improvement of handleability and miscibility due to the lowering of the viscosity of the thermosetting silicone resin composition, adjustment of the film thickness of the temporary adhesive layer, and the like, the thermosetting silicone resin composition can be used after being solutionized by adding a solvent. The solvent to be used is not particularly limited as long as it can dissolve the components, and for example, a hydrocarbon-based solvent such as pentane, hexane, cyclohexane, isooctane, nonane, decane, p-mentane, pinene, isododecane, limonene, and the like is preferable.

[0133] As a method of solutionizing, the following methods can be exemplified: a method of adding a solvent last after preparing the thermosetting silicone resin composition, adjusting to a desired viscosity; a method of diluting (A) of high viscosity in advance using a solvent, mixing the remaining components on the basis of improved handleability and miscibility. Furthermore, as a mixing method at the time of solutionizing, it is sufficient to implement by appropriately selecting a mixing method of an oscillation mixer, a magnetic stirrer, various kinds of stirrers, and the like according to the viscosity and handleability of the composition.

[0134] The blending amount of the solvent is appropriately set from the viewpoint of the viscosity and handleability of the composition, adjustment of the film thickness of the temporary adhesive layer, and the like, and, for example, 5 to 900 parts by mass, more preferably 10 to 400 parts by mass, with respect to 100 parts by mass of the thermosetting silicone resin composition.

[0135] A temporary adhesive layer can be formed by coating the thermosetting silicone resin composition on a substrate by a method such as spin coating or roll coating. In the case where a temporary adhesive layer is formed on a substrate by a method such as spin coating, the thermosetting silicone resin composition is preferably solutionized and coated.

[0136] From the viewpoint of coatability, the viscosity of the solutionized thermosetting silicone resin composition at 25°C is preferably 1 to 100,000 mPa-s, more preferably 10 to 10,000 mPa-s.

[0137] The 180° peeling strength of a test piece (for example, a glass test piece) of a width of 25 mm at 25°C after curing of the thermosetting silicone resin composition is generally 10 to 500 gf, but is preferably 20 to 400 gf, further preferably 30 to 300 gf. If it is 10 gf or more, there is no concern that the wafer will be displaced when the wafer is polished, and if it is 500 gf or less, the wafer is easily peeled.

[0138] The storage modulus at 25°C after curing of the thermosetting silicone resin composition is 1,000 Pa or more and 1,000 MPa or less, preferably 10,000 Pa or more and 100 MPa or less. If the storage modulus is 1,000 Pa or more, the formed film is strong and there is no concern that the wafer will be displaced when the wafer is polished or that the wafer will be broken by this, and if it is 1,000 MPa or less, the deformation stress in the wafer thermal process such as CVD is alleviated and stability is maintained when a thermal process for the wafer is applied.

[0139] The radical active type hydrosilylation reaction catalyst of component (D) used in the thermosetting silicone resin composition also has ultraviolet activity, and thus, when the resin composition is stored, storage is preferably performed in a cool place. Furthermore, a container having light shielding properties is preferably used as the storage container. Thus, even when the composition is stored for a long period of time, the composition does not thicken or cure, and the same stable properties as immediately after manufacture can be obtained even after a long period of time has passed.

[0140] The present application provides a wafer stack using the above-described temporary adhesive for wafer processing. That is, the wafer stack of the present application comprises: a support, a temporary adhesive layer obtained from the above-described temporary adhesive for wafer processing laminated on the support, and a wafer having a circuit formation surface on a surface and a non-circuit formation surface on a back surface, wherein the temporary adhesive layer is adhered to the surface of the wafer in a releasable manner.

[0141] [Method for manufacturing thin wafer]

[0142] The method for manufacturing a thin wafer of the present application is characterized in that, in temporary adhesion of a wafer having a semiconductor circuit or the like to a support, a temporary adhesive for wafer processing composed of the thermosetting silicone resin composition is used.

[0143] The method for manufacturing a thin wafer of the present application comprises the following steps (a) to (e).

[0144] [Step (a)]

[0145] Step (a) is a temporary adhesion step, which is a step of forming a wafer stack by adhering a circuit formation surface of a wafer having a circuit formation surface on a surface and a non-circuit formation surface on a back surface to a support in a releasable manner using the temporary adhesive for wafer processing.

[0146] Specifically, temporary adhesion can be performed by forming a temporary adhesive layer on the surface of the wafer using the temporary adhesive for wafer processing, and adhering the support to the surface of the wafer via the temporary adhesive layer. Alternatively, temporary adhesion can be performed by forming a temporary adhesive layer on the surface of the support using the temporary adhesive for wafer processing, and adhering the support to the surface of the wafer via the temporary adhesive layer.

[0147] The wafer that can be used in the present application is typically a semiconductor wafer. As examples of the semiconductor wafer, not only silicon wafers, but also germanium wafers, gallium-arsenic wafers, gallium-phosphorus wafers, gallium-arsenic-aluminum wafers, and the like can be listed. The thickness of the wafer is not particularly limited, and is typically 600 to 800 μm, and more typically 625 to 775 μm.

[0148] As the support body, a substrate such as a silicon wafer, a glass plate, a quartz wafer, or the like can be used, but is not limited thereto. In the present application, the support body does not need to be transparent to the radiation energy rays, and can not have light transmittance.

[0149] The temporary adhesive layer can be formed by laminating a film obtained by molding the thermosetting silicone resin composition into a film shape on a wafer or a support body, or can be formed by coating the thermosetting silicone resin composition using a spin coating, roll coating, or the like. In the case where the thermosetting silicone resin composition is a solution containing a solvent, after coating, according to the volatilization conditions of the solvent, it is preferable to perform pre-baking at a temperature of 40 to 200°C, more preferably 50 to 150°C, in advance, and then supply for use.

[0150] The temporary adhesive layer is preferably formed to have a film thickness of 0.1 to 500 μm, preferably 1.0 to 200 μm, and used. If the film thickness is 0.1 μm or more, when coated on a substrate, a portion where coating cannot be sufficiently performed does not occur, and coating can be performed on the whole. On the other hand, if the film thickness is 500 μm or less, the polishing process at the time of forming a thin wafer can be tolerated.

[0151] As a method of adhering the support body to the surface of the wafer with the temporary adhesive layer, a method of uniformly performing press bonding under reduced pressure in a temperature region of preferably 40 to 200°C, more preferably 50 to 150°C, can be exemplified.

[0152] The pressure at the time of press bonding of the wafer on which the temporary adhesive layer is formed and the support body is determined depending on the viscosity of the temporary adhesive layer, but is preferably 0.01 to 10 MPa, more preferably 0.1 to 1.0 MPa. If the pressure is 0.01 MPa or more, the circuit formation surface or the wafer-support body can be filled with the temporary adhesive layer, and if it is 10 MPa or less, there is no need to worry about causing breakage of the wafer, deterioration of the flatness of the wafer and the temporary adhesive layer, and good wafer processing thereafter.

[0153] The wafer can be adhered using a commercially available die bonder, and for example, EVG520IS, 850TB, XBS300 of EV Group, SUSS MicroTec SE, or the like can be used.

[0154] [Process (b)]

[0155] Process (b) is a process of thermally curing the temporary adhesive layer. After the wafer laminate is formed, curing of the temporary adhesive layer is performed by heating at a temperature of preferably 50 to 300°C, more preferably 100 to 200°C, for a time of preferably 1 minute to 4 hours, more preferably 5 minutes to 2 hours.

[0156] [Step (c)]

[0157] Step (c) is a step of polishing or grinding the non-circuit formation surface of the wafer temporarily adhered to the support, i.e., a step of grinding the wafer back surface side of the wafer stack obtained in the step, and thinning the thickness of the wafer. The method of grinding processing of the wafer back surface is not particularly limited, and a publicly known grinding method can be employed. It is preferable to perform grinding while cooling the wafer and the grindstone (diamond or the like) by spraying water. As a device for performing grinding processing of the wafer back surface, for example, DAG-810 (product name) manufactured by DISCO CORPORATION or the like can be cited. Further, chemical mechanical polishing (CMP) can be performed on the wafer back surface side.

[0158] [Step (d)]

[0159] Step (d) is a step of performing processing on the non-circuit formation surface of the wafer stack after the non-circuit formation surface is ground in step (c). That is, it is a step of performing processing on the non-circuit formation surface of the wafer of the wafer stack which is thinned by back surface grinding. Various processes used at the wafer level are included in this step. As examples, electrode formation, metal wiring formation, protective film formation, and the like can be cited. More specifically, metal sputtering for forming an electrode or the like, wet etching for etching a metal sputtered layer, coating of resist for making a mask for forming a metal wiring, formation of a pattern based on exposure and development, stripping of resist, dry etching, formation of a metal plating layer, silicon etching for forming a TSV, formation of an oxide film on a silicon surface, and the like, which are publicly known processes, can be cited.

[0160] [Step (e)]

[0161] Step (e) is a step of peeling the wafer on which processing is performed in step (d) from the support, i.e., a step of peeling the wafer from the support after various processing is performed on the thinned wafer and before cutting. As this peeling step, it is generally performed under relatively mild conditions at room temperature to about 60°C. As a peeling method, a method of horizontally fixing one of the wafer or the support of the wafer stack and lifting the other at a certain angle from the horizontal direction, a method of peeling the wafer and a protective film from the wafer stack in a peel-off manner by sticking a protective film to the ground surface of the ground wafer, and the like can be cited. In the case where the peeling step is performed by these peeling methods, it is generally performed at room temperature.

[0162] Further, step (e) preferably includes the following step:

[0163] (e1) a step of attaching a dicing tape to the wafer surface of the wafer on which processing is performed;

[0164] (e2) a step of vacuum-adsorbing the cut tape face on the adsorption face; and

[0165] (e3) a step of peeling off the support from the wafer on which the processing has been performed by peeling off by peeling at a temperature of the adsorption face in the range of 10 to 100°C.

[0166] By the above-described means, the support can be easily peeled off from the wafer on which the processing has been performed, and the subsequent cutting step can be easily performed.

[0167] Further, after the step (e), a step (f) of removing the temporary adhesive layer remaining on the circuit formation face of the peeled wafer is preferably performed. A part of the temporary adhesive layer can sometimes remain on the circuit formation face of the wafer peeled off from the support by the step (e), and the removal of the temporary adhesive layer can be performed, for example, by cleaning the wafer.

[0168] In the step (f), any liquid can be used as long as it is a cleaning liquid that dissolves the silicone resin of the temporary adhesive layer, and specific examples include pentane, hexane, cyclohexane, decane, isononane, p-menthane, pinene, isododecane, limonene, and the like. These solvents can be used singly or in combination of two or more.

[0169] Further, in the case where the temporary adhesive layer is difficult to remove, an alkali or an acid can be added to the cleaning liquid. As the alkali, amine-based compounds such as ethanolamine, diethanolamine, triethanolamine, triethylamine, ammonia, and the like; and ammonium salts such as tetramethylammonium hydroxide can be used. As the acid, organic acids such as acetic acid, oxalic acid, benzene sulfonic acid, dodecylbenzenesulfonic acid, and the like can be used. The amount of the alkali or the acid to be added is an amount such that the concentration in the cleaning liquid becomes preferably 0.01 to 10% by mass, and more preferably 0.1 to 5% by mass. Further, in order to improve the removability of the residue, an existing surfactant can be added. Further, as the wafer cleaner, SPIS-TA-CLEANER series (manufactured by Shin-Etsu Chemical Co., Ltd.) can be appropriately used.

[0170] As the cleaning method of the wafer, a method of using the cleaning liquid and cleaning by a stirring paddle; a method of cleaning by spraying with a sprayer; and a method of immersion in a cleaning liquid tank can be exemplified. The temperature at the time of cleaning is preferably 10 to 80°C, and more preferably 15 to 65°C, and if necessary, after dissolving the temporary adhesive layer with these cleaning liquids, rinsing with water or alcohol at the end and drying treatment can be performed.

[0171] The thickness of the thin wafer obtained by the manufacturing method of the present application is classically 5 to 300 μm, and more classically 10 to 100 μm.

[0172] Example

[0173] Hereinafter, Production Examples, Comparative Production Examples, Examples, and Comparative Examples are shown to more specifically describe the present application, but the present application is not limited to these Examples. In addition, the viscosity is a measured value at 25°C measured by a rotational viscometer.

[0174] [1] Preparation of thermosetting silicone resin solution

[0175] [Production Example 1]

[0176] To a solution composed of 100 parts by mass of dimethylpolysiloxane having a resin structure of Mn of 3 million composed of 97.5 mole% of (CH3)2SiO 2 / 2 units (D units), 2.5 mole% of (CH2=CH)(CH3)SiO 2 / 2 units (D Vi units), and 200 parts by mass of toluene, 50 parts by mass of vinylmethylpolysiloxane having a resin structure of Mn of 7,000 composed of 50 mole% of SiO 4 / 2 units (Q units), 48 mole% of (CH3)3SiO 1 / 2 units (M units), and 2 mole% of (CH2=CH)(CH3)2SiO 1 / 2 units (M Vi units) was added, and the mixture was stirred at 25°C for 1 hour to obtain a solution of thermosetting silicone resin. 2 / 2 2 / 2 H ​​A1. Further, to this, a radical active hydrosilylation reaction catalyst: 0.4 parts by mass of a toluene solution of (trimethyl)methylcyclopentadienyl platinum (IV) (platinum concentration: 1.0% by mass), 0.1 parts by mass of 1,6-di(tert-butylperoxycarbonyloxy)hexane (manufactured by KAYAKUNO UR YON CORPORATION, product name: KAYAREN 6-70, 10-hour half-life temperature: 97°C, 1-minute half-life temperature: 150°C), was filtered using a 0.2-μm membrane filter, to prepare a thermosetting silicone resin solution Al. Note that the half-life of an organic peroxide is the time until the organic peroxide is thermolyzed, and the amount of active oxygen becomes half the amount before decomposition. The half-life is found by preparing a benzene solution of the organic peroxide at a concentration of 0.1 mol / L, and measuring the change in the concentration of the organic peroxide over time as it is thermolyzed. The viscosity of the resin solution Al at 25°C was 2,300 Pa-s.

[0177] The value of the total amount of SiH groups in the component (B) in this Production Example 1 with respect to the total amount of alkenyl groups in the component (A) (Si-H / Si-Vi) can be calculated by the following calculation formula.

[0178] (1) Si-Vi amount (mole) from PDMS

[0179] (PDMS addition amount / PDMS molecular weight) x <PDMS molecular weight / {[(D unit molecular weight) x (D unit mole% / 100)] + [(D Vi unit molecular weight) x (D Vi unit mole% / 100)]} > x (D Vi unit mole% / 100)

[0180] (2) Si-Vi amount (mole) from PVMS from the resin structure having a Vi group

[0181] (PVMS addition amount / PVMS molecular weight) x <PVMS molecular weight / {[(Q unit molecular weight) x (Q unit mole% / 100)] + [(M unit molecular weight) x (M unit mole% / 100)] + [(M Vi unit molecular weight) x (M Vi unit mole% / 100)]} > x (M Vi unit mole% / 100)

[0182] (3) Si-H amount (mole) from POHS

[0183] (POHS addition amount / POHS molecular weight) x < PVMS molecular weight / {[(D unit molecular weight) x (D unit mole % / 100)] + [(D unit molecular weight) x (D unit mole % / 100)]} > x (D unit mole % / 100) H (POHS addition amount / POHS molecular weight) x < PVMS molecular weight / {[(D unit molecular weight) x (D unit mole % / 100)] + [(D unit molecular weight) x (D unit mole % / 100)]} > x (D unit mole % / 100) H (POHS addition amount / POHS molecular weight) x < PVMS molecular weight / {[(D unit molecular weight) x (D unit mole % / 100)] + [(D unit molecular weight) x (D unit mole % / 100)]} > x (D unit mole % / 100) H (POHS addition amount / POHS molecular weight) x < PVMS molecular weight / {[(D unit molecular weight) x (D unit mole % / 100)] + [(D unit molecular weight) x (D unit mole % / 100)]} > x (D unit mole % / 100)

[0184] (In the above formula, PDMS: dimethylpolysiloxane, PVMS: resin-structured vinylmethylpolysiloxane, POHS: organohydrogenpolysiloxane)

[0185] The Si-H / Si-Vi (mole ratio) of the Si-H of Preparation Example 1 obtained by the above (1) to (3) was 1.0.

[0186] [Preparation Example 2]

[0187] To a solution consisting of 70 parts by mass of dimethylpolysiloxane having Mn of 300,000 consisting of 97.5 mole% of (CH3)2SiO unit (D unit), 2.5 mole% of (CH2=CH)(CH3)SiO unit (D unit), 30 parts by mass of dimethylpolysiloxane having Mn of 60,000 consisting of 99.85 mole% of (CH3)2SiO unit (D unit), 0.15 mole% of (CH2=CH)(CH3)SiO unit (D unit), and 200 parts by mass of toluene, 50 parts by mass of resin-structured vinylmethylpolysiloxane having Mn of 7,000 consisting of 50 mole% of SiO unit (Q unit), 48 mole% of (CH3)3SiO unit (M unit), and 2 mole% of (CH2=CH)(CH3)2SiO unit (M unit) was added. 2 / 2 2 / 2 Vi 2 / 2 2 / 2 Vi 4 / 2 1 / 2 1 / 2 Vi 2 / 2 2 / 2 H ​​​​​​​​​​​​A thermosetting organosilicon resin solution A2 was prepared by mixing an organohydrogen polysiloxane with a Mn of 2,400, 30 parts by mass of a 30% by mass toluene solution, a dimethyl polysiloxane with a molecular chain end-capped with trimethylsiloxy groups at 25°C, 30 parts by mass of toluene, and 0.6 parts by mass of 1-ethynylcyclohexanol. Further, a free radical-active hydrosilylation catalyst was added: 0.4 parts by mass of a toluene solution of (trimethyl)methylcyclopentadiene platinum (IV) (platinum concentration 1.0% by mass), 0.07 parts by mass of tert-butylperoxide-2-ethylhexyl monocarbonate (manufactured by KAYAKU NOURYON CORPORATION, product name: Trigonox 117, 10-hour half-life temperature: 98°C, 1-minute half-life temperature: 156°C). The mixture was filtered using a 0.2 μm membrane filter. The viscosity of resin solution A2 at 25°C is 1,800 mPa·s. Furthermore, the Si-H / Si-Vi molar ratio in this preparation example 2 is 1.5.

[0188] [Preparation Example 3]

[0189] In addition to the preparation example 1 above, the radical-active hydrosilylation catalyst used was changed from 0.4 parts by mass of a toluene solution of (trimethyl)methylcyclopentadiene platinum(IV) (platinum concentration of 1.0 by mass%) to 0.8 parts by mass of a 2-(2-butoxyethoxy)ethyl acetate solution of bis(2,4-heptadecone)platinum(II) (platinum concentration of 0.5 by mass), and the (CH3)2SiO2 catalyst was changed from 83.9 mol% to 0.8 parts by mass of a 2-(2-butoxyethoxy)ethyl acetate solution of bis(2,4-heptadecone)platinum(II) (platinum concentration of 0.5 by mass). 2 / 2 Unit (D unit), 16.1 mol% of (CH3)HSiO 2 / 2 Unit (D) H Thermosetting silicone resin solution A3 was prepared in the same manner, except that the amount of organohydrogen polysiloxane with Mn of 2,400 (comprising unit) added was changed to 15 parts by mass. The viscosity of resin solution A3 at 25°C was 2,200 mPa·s. Furthermore, the Si-H / Si-Vi (molar ratio) in this preparation example 3 was 0.7.

[0190] [Preparation Example 4]

[0191] In addition to the above-mentioned preparation example 2, the radical-active hydrosilylation catalyst used was changed from 0.4 parts by mass of a toluene solution of (trimethyl)methylcyclopentadiene platinum(IV) (platinum concentration of 1.0 by mass%) to 0.8 parts by mass of a 2-(2-butoxyethoxy)ethyl acetate solution of bis(2,4-heptadecone)platinum(II) (platinum concentration of 0.5 by mass), and the (CH3)2SiO2 catalyst was changed from 83.9 mol% to 0.8 parts by mass of a 2-(2-butoxyethoxy)ethyl acetate solution of bis(2,4-heptadecone)platinum(II) (platinum concentration of 0.5 by mass). 2 / 2(D unit), 16.1 mol% of (CH3)HSiO 2 / 2 (D unit) H (D unit) having Mn of 2,400 was changed to 21 parts by mass, and a thermosetting silicone resin solution A4 was prepared in the same manner. The viscosity of the resin solution A4 at 25°C was 1,900 mPa-s. In addition, the Si-H / Si-Vi (molar ratio) in this Preparation Example 4 was 1.2.

[0192] [Comparative Preparation Example 1]

[0193] In the above Preparation Example 1, 0.4 parts by mass of a hydrosilylation reaction catalyst CAT-PL-5 (manufactured by Shin-Etsu Chemical Co., Ltd., platinum concentration: 1.0 mass%) was added instead of adding 0.4 parts by mass of a toluene solution of (trimethyl)methylcyclopentadienyl platinum (IV) (platinum concentration: 1.0 mass%) and 0.1 parts by mass of 1,6-bis(tert-butylperoxycarbonyloxy)hexane, and filtration was performed using a 0.2-μm membrane filter, and a thermosetting silicone resin solution Cl was prepared. The viscosity of the resin solution Cl at 25°C was 2,300 mPa-s. In addition, the Si-H / Si-Vi (molar ratio) in this Comparative Preparation Example 1 was 1.0.

[0194] [Comparative Preparation Example 2]

[0195] In the above Preparation Example 2, 0.4 parts by mass of a hydrosilylation reaction catalyst CAT-PL-5 (manufactured by Shin-Etsu Chemical Co., Ltd., platinum concentration: 1.0 mass%) was added instead of adding 0.4 parts by mass of a toluene solution of (trimethyl)methylcyclopentadienyl platinum (IV) (platinum concentration: 1.0 mass%), 0.07 parts by mass of tert-butylperoxy-2-ethylhexyl monocarbonate, and filtration was performed using a 0.2-μm membrane filter, and a thermosetting silicone resin solution C2 was prepared. The viscosity of the resin solution C2 at 25°C was 1,900 mPa-s. In addition, the Si-H / Si-Vi (molar ratio) in this Comparative Preparation Example 2 was 1.2.

[0196] [2] Evaluation of storage stability of thermosetting silicone resin solution

[0197] [Examples 1 to 4, Comparative Examples 1, 2]

[0198] The film thickness after coating on a silicon substrate was measured for the thermosetting silicone resin solutions obtained in the above Preparation Examples 1 to 4 and Comparative Preparation Examples 1 and 2, respectively, (1) immediately after preparation and (2) after storage at 50°C for 1 month in the dark and under airtight conditions. In addition, a silicon wafer having a diameter of 200 mm and a thickness of 725 μm was used as the silicon substrate, and spin coating was performed for the thermosetting silicone resin solutions Al to A4 and Cl, C2, respectively, and heating treatment was performed on a hot plate at 100°C for 2 minutes, followed by heating treatment at 180°C for 30 minutes, to produce a cured film of the silicone resin on the silicon wafer. Further, the film thickness of the cured film was measured using an F50 manufactured by Filmetrics, Inc. The results are shown in Table 1.

[0199] [Table 1]

[0200]

[0201] It was confirmed from the results in Table 1 that the solution after storage of the present examples suppressed the change in film thickness from the initial stage, compared to the comparative example of the conventional platinum addition curing resin composition. It was confirmed from the results that the thermosetting silicone resin solution of the present examples was excellent in long-term storage stability.

[0202] [3] Manufacture of wafer stack and evaluation thereof

[0203] [Examples 5 to 9, Comparative Examples 3 to 5 and Reference Example]

[0204] A copper pillar having a height of 10 μm and a diameter of 40 μm was formed on the entire surface, and the entire surface of the wafer surface was covered with a "PI film", a "SiN film" and a "PBO film", respectively, on the surface of a silicon wafer (thickness: 725 μm) having a diameter of 200 mm, and spin coating was performed for the thermosetting silicone resin solutions Al to A4 and Cl to C2, respectively, on the wafer bump forming surface, and a temporary adhesive layer was formed using an oven at 100°C for 2 minutes, at the film thicknesses shown in Tables 2 and 3 below. A glass plate having a diameter of 200 mm (thickness: 500 μm) was used as a support so that the temporary adhesive layer was in contact with the glass plate, and a wafer bonding apparatus EVG520IS manufactured by EV GROUP was used to perform vacuum bonding of the silicon wafer having the temporary adhesive layer and the glass plate at 100°C, 10 mbar or less and a load of 5 kN, to manufacture a wafer stack. In addition, although the glass plate was used as the support in order to identify abnormalities after bonding of the substrate by the naked eye, a silicon substrate such as a wafer that does not transmit light can also be used. In addition, in order to further clarify the influence of the organic resin film on the wafer, a wafer having no organic resin film covering layer was used, and the Cl solution produced in Comparative Preparation Example 1 was evaluated in the same manner as above, as a reference example. -3 mbar or less and a load of 5 kN, to manufacture a wafer stack. In addition, although the glass plate was used as the support in order to identify abnormalities after bonding of the substrate by the naked eye, a silicon substrate such as a wafer that does not transmit light can also be used. In addition, in order to further clarify the influence of the organic resin film on the wafer, a wafer having no organic resin film covering layer was used, and the Cl solution produced in Comparative Preparation Example 1 was evaluated in the same manner as above, as a reference example.

[0205] Then, the obtained wafer stack was subjected to the following tests. The results thereof are collectively described in Tables 2 and 3. Further, the tests were performed by the following methods.

[0206] (1) Adhesion test

[0207] Using an oven, the wafer stack was heated at 180°C for 1 hour, and after cooling to room temperature, the adhesion condition of the wafer surface was confirmed by the naked eye, and the case where no abnormality such as a bubble was generated on the interface was evaluated as good and indicated by "0", and the case where an abnormality was generated was evaluated as poor and indicated by "X".

[0208] (2) Backgrinding resistance test

[0209] Using the wafer stack, backgrinding of the silicon wafer was performed using a grinder (DAG-810 manufactured by DISCO CORPORATION) and using a diamond grindstone. After polishing the thickness of the substrate to 50 μm, an optical microscope (100 times) was used to investigate the presence or absence of abnormalities such as cracks, peeling, and the like. The case where no abnormality was generated was evaluated as good and indicated by "0", and the case where an abnormality was generated was evaluated as poor and indicated by "X".

[0210] (3) CVD resistance test

[0211] The wafer stack after the completion of the (2) backgrinding resistance test was introduced into a CVD device, and a 2 μm SiO2 film was formed, and the presence or absence of appearance abnormalities at this time was investigated by visual observation. The case where no appearance abnormality was generated was evaluated as good and indicated by "0", and the case where appearance abnormalities such as voids, wafer swelling, wafer breakage, and the like were generated was evaluated as poor and indicated by "X". The conditions of the CVD resistance test are described below.

[0212] Device name: plasma CVD, PD270STL manufactured by Samco Inc.

[0213] RF 500 W, internal pressure 40 Pa

[0214] TEOS (tetraethyl orthosilicate): O2= 20 seem: 680 seem

[0215] (4) Peeling test

[0216] For the peeling property of the substrate, first, using a dicing frame, a dicing tape (Nitto Denko CORPORATION manufactured ELP UB-3083D) was attached to the wafer side of the wafer laminate on which the (3) CVD resistance test was completed, and the dicing tape surface was set on a suction plate by vacuum suction. Then, at room temperature, one point of the glass was lifted by using tweezers, thereby peeling the glass substrate. The case where the 50 μm thick wafer was not broken and could be peeled was indicated as "0", and the case where abnormality such as breakage occurred was evaluated as defective and indicated as "X".

[0217] (5) Cleaning removal test

[0218] The 200 mm diameter wafer (wafer exposed to the CVD resistance test conditions) on which the (4) peeling property test was completed was set on a spin coater with the peeling surface facing upward, and after spraying SPIS-TA-CLEANER 27 (manufactured by Shin-Etsu Chemical Co., Ltd.) for 5 minutes as a cleaning solvent, isopropyl alcohol (IPA) was sprayed while rotating the wafer. Then, the appearance was observed, and the presence or absence of residual adhesive was checked by the naked eye. The case where no resin residue was found was evaluated as good and indicated as "0", and the case where resin residue was found was evaluated as defective and indicated as "X".

[0219] (6) Peeling force test

[0220] On a 200 mm diameter silicon wafer (thickness: 725 μm) on the entire surface of which the wafer bump forming surface was covered with "PI film", "SiN film", and "PBO film", respectively, thermosetting silicone resin solutions Al to A4 and Cl, C2 were spin-coated, respectively, and using a hot plate, the silicone resin layer was formed on the wafer bump forming surface at the film thicknesses shown in Table 1 by heating at 100°C for 2 minutes. Then, using an oven, the silicone resin layer was cured at 180°C for 1 hour, and after cooling to room temperature, 5 pieces of polyimide tape having a length of 150 mm and a width of 25 mm were attached to the silicone resin layer on the wafer, and the temporary adhesive layer of the portion not attached with the tape was removed. Using AUTOGRAPH (AG-1) of SHIMADZU CORPORATION, at a speed of 25°C, 300 mm / minute, the tape was peeled from one end by 120 mm at 180°, and the average value of the force applied at this time (120 mm stroke x 5 times) was taken as the peeling force of the silicone resin layer.

[0221] (7) Storage modulus measurement

[0222] On a silicon wafer (thickness: 725 μm) of 200 mm in diameter on which the entire surface of the wafer surface was covered with a "PI film", a "SiN film", and a "PBO film", respectively, thermosetting organic silicon resin solutions Al to A4 and Cl, C2 were spin-coated, and a heat plate was used to heat at 100°C for 2 minutes, whereby an organic silicon resin layer was formed on a glass substrate at the film thicknesses shown in Tables 2 and 3. Then, the organic silicon resin layer was cured using an oven at 180°C for 1 hour, and cooled to room temperature. Using an ARES-G2 manufactured by TA Instruments, the obtained glass substrate containing the organic silicon resin layer was sandwiched with a 25 mm aluminum plate in a manner such that a load of 50 gf was applied to the organic silicon resin layer, and an elastic modulus measurement was performed at 25°C, 1 Hz, and 1% strain, and the obtained value of the elastic modulus was taken as the storage modulus of the organic silicon resin layer.

[0223] [Table 2]

[0224]

[0225] [Table 3]

[0226]

[0227] As shown in Tables 2 and 3, for the wafer laminates of Examples 5 to 9 containing the temporary adhesive layer of the present application, even for wafers having an organic resin cover layer on the wafer, sufficient processing durability and easy peelability, and excellent removal of residue on the wafer after peeling were confirmed. On the other hand, for the temporary adhesives of Comparative Examples 3 to 5 using conventional platinum addition-cured resin compositions, due to the influence of the organic resin cover layer on the wafer, particularly in wafer processability, a result of poor peeling was obtained.

[0228] The present specification contains the following solutions.

[0229] [1] A method for manufacturing a thin wafer, which uses a thermosetting organic silicon resin composition in a temporary adhesive for wafer processing for temporarily adhering a wafer to a support, characterized in that,

[0230] The thermosetting organic silicon resin composition is capable of being cured only by heating, and the composition contains the following components:

[0231] 100 parts by mass of (A) an organic polysiloxane having 2 or more alkenyl groups in one molecule;

[0232] (B) an organohydrogenpolysiloxane containing 2 or more silicon-bonded hydrogen atoms (SiH group) in one molecule, in an amount such that the total amount of SiH groups in the (B) component is 0.3 to 10 in molar ratio to the total amount of alkenyl groups in the (A) component;

[0233] 0.01 to 20 parts by mass of (C) an organic peroxide;

[0234] (D) a radical-active hydrosilylation catalyst in an amount of 0.1 to 5,000 ppm in terms of metal atom amount, relative to the total mass of the (A) and (B) components.

[0235] [2] The method for producing a thin wafer according to the above [1], wherein a thermosetting silicone resin composition further containing 0.1 to 200 parts by mass of a non-functional organopolysiloxane as a (E) component is used.

[0236] [3] The method for producing a thin wafer according to the above [2], wherein the non-functional organopolysiloxane of the (E) component consists of dimethylpolysiloxane, and a 30 mass% toluene solution of the (E) component has a viscosity of 100 to 500,000 mPa-s at 25°C.

[0237] [4] The method for producing a thin wafer according to any one of the above [1] to [3], wherein the organic peroxide is at least one selected from the group consisting of diacyl peroxides, peroxy esters, dialkyl peroxides, percarbonates, peroxy ketones, hydroperoxides, and ketone peroxides.

[0238] [5] The method for producing a thin wafer according to any one of the above [1] to [4], wherein the organic peroxide has a temperature of 40°C or higher at which the half-life is 10 hours and a temperature of 200°C or lower at which the half-life is 1 minute.

[0239] [6] The method for producing a thin wafer according to any one of the above [1] to [5], wherein a thermosetting silicone resin composition further containing a hydrosilylation reaction controller as a (F) component is used, the (F) component being in an amount of 0.001 to 10 parts by mass, relative to the total mass of the (A) and (B) components.

[0240] [7] The method for producing a thin wafer according to any one of the above [1] to [6], wherein, after the thermosetting silicone resin composition is cured, a test piece having a width of 25 mm at 25°C has a 180° peel strength to a silicon substrate of 2 gf or more and 500 gf or less.

[0241] [8] The method for manufacturing a thin wafer according to any one of the above [1] to [7], wherein the thermosetting silicone resin composition has a storage modulus at 25°C of 1,000 Pa or more and 1,000 MPa or less after curing.

[0242] [9] A method for manufacturing a thin wafer according to any one of the above [1] to [8], comprising the following steps:

[0243] (a) a step of adhering a circuit formation surface of a wafer having the circuit formation surface on a surface and a non-circuit formation surface on a back surface to a support in a peelable manner using the temporary adhesive for wafer processing to form a wafer stack;

[0244] (b) a step of thermally curing the temporary adhesive;

[0245] (c) a step of polishing or grinding the non-circuit formation surface of the wafer of the wafer stack;

[0246] (d) a step of processing the non-circuit formation surface of the wafer; and

[0247] (e) a step of peeling the wafer subjected to the processing from the support.

[0248]

[10] A temporary adhesive for wafer processing which can be applied to a thin wafer or a wafer stack, comprising a thermosetting silicone resin composition comprising:

[0249] 100 parts by mass of (A) an organopolysiloxane having 2 or more alkenyl groups in one molecule;

[0250] (B) an organohydrogenpolysiloxane containing 2 or more silicon-bonded hydrogen atoms (SiH groups) in one molecule, in an amount such that the total amount of SiH groups in the (B) component is 0.3 to 10 in molar ratio to the total amount of alkenyl groups in the (A) component;

[0251] 0.01 to 20 parts by mass of (C) an organic peroxide;

[0252] (D) a radical-active hydrosilation reaction catalyst in an amount of 0.1 to 5,000 ppm in terms of metal atom amount, relative to the total mass of the (A) component and the (B) component.

[0253]

[11] The temporary adhesive for wafer processing according to the above

[10] , comprising a thermosetting silicone resin composition further comprising 0.1 to 200 parts by mass of a non-functional organopolysiloxane as a (E) component.

[0254]

[12] The temporary adhesive for wafer processing according to the above

[11] , wherein the (E) component's non-functional organic polysiloxane is composed of dimethylpolysiloxane, and the (E) component's 30 mass% toluene solution has a viscosity of 100 to 500,000 mPa-s at 25°C.

[0255]

[13] The temporary adhesive for wafer processing according to any one of the above

[10] to

[12] , wherein the organic peroxide is at least one selected from the group consisting of diacyl peroxide, peroxy ester, dialkyl peroxide, percarbonate, peroxy ketal, hydroperoxide, and ketone peroxide.

[0256]

[14] The temporary adhesive for wafer processing according to any one of the above

[10] to

[13] , wherein the organic peroxide has a temperature of 40°C or higher at a half-life of 10 hours, and a temperature of 200°C or lower at a half-life of 1 minute.

[0257]

[15] The temporary adhesive for wafer processing according to any one of the above

[10] to

[14] , wherein it contains a thermosetting silicone resin composition further containing, as a (F) component, a hydrosilylation reaction control agent, the (F) component being 0.001 to 10 parts by mass relative to the total mass of the (A) component and the (B) component.

[0258]

[16] The temporary adhesive for wafer processing according to any one of the above

[10] to

[15] , wherein the thermosetting silicone resin composition, after curing, has a 180° peeling strength of 2 gf or more and 500 gf or less against a silicon substrate for a test piece having a width of 25 mm at 25°C.

[0259]

[17] The temporary adhesive for wafer processing according to any one of the above

[10] to

[16] , wherein the thermosetting silicone resin composition, after curing, has a storage modulus of 1,000 Pa or more and 1,000 MPa or less at 25°C.

[0260]

[18] A wafer stack comprising a support, a temporary adhesive layer obtained from the temporary adhesive for wafer processing according to any one of the above

[10] to

[17] stacked on the support, and a wafer having a circuit formation surface on a surface and a non-circuit formation surface on a back surface, characterized in that the temporary adhesive layer is adhered to the surface of the wafer in a peelable manner.

[0261] In addition, the present application is not limited to the above-described embodiments. The above-described embodiments are merely examples, and technical solutions having substantially the same technical concept and exerting the same technical effects as those recited in the claims of the present application are all included in the technical scope of the present application.

Claims

1. A method for manufacturing a thin wafer, which uses a thermosetting silicone resin composition in a temporary adhesive for wafer processing used for temporarily adhering a wafer to a support, characterized in that the thermosetting silicone resin composition is capable of being cured only by heating, and comprises the following components: 100 parts by mass of (A) an organopolysiloxane having 2 or more alkenyl groups in one molecule; (B) an organohydrogenpolysiloxane containing 2 or more silicon-bonded hydrogen atoms (SiH groups) in one molecule, in an amount such that the total amount of SiH groups in the (B) component is 0.3 to 10 in molar ratio to the total amount of alkenyl groups in the (A) component; 0.01 to 20 parts by mass of (C) an organic peroxide; (D) a radical-active hydrosilation reaction catalyst, in an amount of 0.1 to 5,000 ppm in terms of metal atom amount, relative to the total mass of the (A) and (B) components. The thermosetting silicone resin composition further contains 0.1 to 200 parts by mass of a non-functional organopolysiloxane as a (E) component.

2. The method of manufacturing a thin wafer according to claim 1, wherein The non-functional organopolysiloxane of the (E) component consists of dimethylpolysiloxane, and a 30% toluene solution of the (E) component has a viscosity of 100 to 500,000 mPa-s at 25°C.

3. The method of manufacturing a thin wafer according to claim 2, wherein The organic peroxide is at least one selected from the group consisting of diacyl peroxides, peroxy esters, dialkyl peroxides, percarbonates, peroxy ketones, hydroperoxides, and ketone peroxides.

4. The method of manufacturing a thin wafer according to claim 1, wherein The temperature at which the half-life of the organic peroxide is 10 hours is 40°C or higher, and the temperature at which the half-life is 1 minute is 200°C or lower.

5. The method of manufacturing a thin wafer according to claim 1, wherein The thermosetting silicone resin composition further contains a hydrosilation reaction controller as a (F) component, in an amount of 0.001 to 10 parts by mass, relative to the total mass of the (A) and (B) components.

6. The method of claim 1, wherein After the thermosetting silicone resin composition is cured, a test piece having a width of 25 mm at 25°C has a 180° peel strength to a silicon substrate of 2 gf or more and 500 gf or less.

7. The method of claim 1, wherein After the thermosetting silicone resin composition is cured, it has a storage modulus at 25°C of 1,000 Pa or more and 1,000 MPa or less.

8. The method of claim 1, wherein 9. A method for manufacturing a thin wafer, which is the method for manufacturing a thin wafer according to any one of claims 1 to 8, and which comprises the following steps: (a) a step of adhering a circuit formation surface of a wafer having the circuit formation surface on a front surface and a non-circuit formation surface on a back surface to a support in a peelable manner using the temporary adhesive for wafer processing, to form a wafer laminate; (b) a step of thermally curing the temporary adhesive; (c) a step of polishing or grinding the non-circuit formation surface of the wafer of the wafer laminate; (d) a step of performing processing on the non-circuit formation surface of the wafer; and (e) a step of peeling the wafer on which the processing has been performed from the support. which is composed of a thermosetting silicone resin composition comprising the following components:

10. A temporary adhesive for wafer processing, which can be applied to a thin wafer or wafer stack, characterized by, ​ 100 parts by mass of (A) an organopolysiloxane having 2 or more alkenyl groups in one molecule; (B) an organohydrogenpolysiloxane containing 2 or more silicon-bonded hydrogen atoms (SiH groups) in one molecule, in an amount such that the total amount of SiH groups in the (B) component is in a molar ratio of 0.3 to 10 relative to the total amount of alkenyl groups in the (A) component; 0.01 to 20 parts by mass of (C) an organic peroxide; (D) a radical-active hydrosilylation reaction catalyst in an amount of 0.1 to 5,000 ppm in terms of the amount of metal atoms relative to the total mass of the (A) component and the (B) component.

11. The temporary adhesive for wafer processing according to claim 10, wherein It is composed of a thermosetting silicone resin composition further containing 0.1 to 200 parts by mass of a non-functional organopolysiloxane as an (E) component.

12. The temporary adhesive for wafer processing according to claim 11, wherein, The non-functional organopolysiloxane of the (E) component is composed of dimethylpolysiloxane, and a 30% toluene solution of the (E) component has a viscosity of 100 to 500,000 mPa-s at 25°C.

13. The temporary adhesive for wafer processing according to claim 10, wherein The organic peroxide is at least one selected from the group consisting of diacyl peroxides, peroxy esters, dialkyl peroxides, percarbonates, peroxy ketones, hydroperoxides, and ketone peroxides.

14. The temporary adhesive for wafer processing according to claim 10, wherein The temperature at which the half-life of the organic peroxide is 10 hours is 40°C or higher, and the temperature at which the half-life is 1 minute is 200°C or lower.

15. The temporary adhesive for wafer processing according to claim 10, wherein It comprises a thermosetting silicone resin composition further containing a hydrosilylation reaction control agent as an (F) component in an amount of 0.001 to 10 parts by mass relative to the total mass of the (A) component and the (B) component.

16. The temporary adhesive for wafer processing according to claim 10, wherein After the thermosetting silicone resin composition is cured, a test piece having a width of 25 mm at 25°C has a 180° peel strength against a silicon substrate of 2 gf or more and 500 gf or less.

17. The temporary adhesive for wafer processing according to claim 11, wherein After the thermosetting silicone resin composition is cured, it has a storage modulus at 25°C of 1,000 Pa or more and 1,000 MPa or less.

18. A wafer stack comprising a support, a temporary adhesive layer obtained from the temporary adhesive for wafer processing according to any one of claims 10 to 17 laminated on the support, and a wafer having a circuit formation surface on a front surface and a non-circuit formation surface on a back surface, characterized in that, The temporary adhesive layer is adhered to the surface of the wafer in a peelable manner.

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