JP7735676B2 - Stacked body, method for manufacturing stacked body, and method for manufacturing semiconductor substrate - Google Patents

Description

The present invention relates to a laminate, a method for manufacturing a laminate, and a method for manufacturing a semiconductor substrate.

Semiconductor wafers have traditionally been integrated in a two-dimensional plane, but for the purpose of further integration, semiconductor integration technology is required that integrates (stacks) the plane in a three-dimensional plane as well. This three-dimensional stacking is a technology that integrates multiple layers while connecting them using through silicon vias (TSVs). When integrating multiple layers, each wafer to be integrated is thinned by polishing the side opposite the circuit surface (i.e., the backside), and the thinned semiconductor wafers are stacked.
An unthinned semiconductor wafer (also referred to herein simply as a wafer) is bonded to a support for polishing in a polishing apparatus.
The adhesive used in this process must be easily peeled off after polishing, and is therefore called a temporary adhesive. This temporary adhesive must be easily removed from the support; applying a large force to remove it can cause the thinned semiconductor wafer to break or deform, so it must be easily removed to prevent this from happening. However, it is undesirable for the adhesive to become dislodged or shifted due to the polishing stress during polishing of the backside of the semiconductor wafer. Therefore, the performance required of the temporary adhesive is that it can withstand the stress during polishing and be easily removed after polishing.
For example, the performance required is high stress (strong adhesive strength) in the planar direction during polishing, and low stress (weak adhesive strength) in the vertical direction during removal.

As one example of such an adhesion process, a wafer support structure has been proposed, which has, from the wafer (1) side, a silicone oil layer, a separation layer (4) which is a plasma polymer layer, and a layer (5) of a partially cured or curable elastomer material between a semiconductor wafer (1) and a support layer (6) which is a support, and the adhesive bond between the support layer system and the separation layer (4) after the elastomer material has fully cured is greater than the adhesive bond between the wafer (1) and the separation layer (4) (see, for example, the examples in Patent Document 1).

When removing a semiconductor wafer from a support after thinning the semiconductor wafer, if a large force is required to remove the thinned semiconductor wafer from the support, the semiconductor wafer or the support may be cut or deformed. Therefore, there is a constant demand for a technology that allows a semiconductor wafer to be easily removed from a support.
In addition, the semiconductor wafer is electrically connected to the semiconductor chip via bump balls made of a conductive material such as metal, and by using chips equipped with such bump balls, miniaturization of semiconductor packaging is being achieved.
Bump balls made of metals such as copper and tin can be damaged or deformed by external loads such as heat and pressure applied during the process of processing semiconductor substrates. With recent advances in the semiconductor field, there is a demand for technology that can reduce or prevent such deformation due to heat and pressure.

Patent No. 5335443 Patent No. 5822369

The present invention has been made in consideration of the above circumstances, and aims to provide a laminate that allows a semiconductor substrate to be easily separated from a support substrate without causing cutting or deformation of the semiconductor substrate or the support substrate when the semiconductor substrate is separated after processing, a method for manufacturing a semiconductor substrate using the laminate, and a method for manufacturing the laminate. Another aim of the present invention is to provide a laminate that allows a semiconductor substrate to be easily separated from a support substrate and that further suppresses bump deformation, a method for manufacturing a semiconductor substrate using the laminate, and a method for manufacturing the laminate.

The inventors conducted extensive research to solve the above-mentioned problems and have completed the present invention, which has the following gist:

That is, the present invention includes the following.
[1] A laminate comprising a semiconductor substrate, a support substrate, an adhesive layer formed in contact with the semiconductor substrate, and a photoresponsive release layer formed between the adhesive layer and the support substrate in contact with the adhesive layer,
the adhesive layer is a thermosetting adhesive layer,
A laminate, wherein the photoresponsive release layer is formed from a release agent composition containing a compound having an azobenzene skeleton.
[2] The laminate according to [1], wherein the compound having an azobenzene skeleton is a compound containing a group represented by the following formula (1):
(In the formula, m is an integer of 0 to 20, and l is an integer of 1 to 20.)
[3] The laminate according to [1] or [2], wherein the adhesive layer is an adhesive layer that cures by a hydrosilylation reaction.
[4] The adhesive layer is formed from an adhesive composition containing a component (A) that cures by a hydrosilylation reaction,
The component (A) is
A polyorganosiloxane (a1) having an alkenyl group having 2 to 40 carbon atoms bonded to a silicon atom;
a polyorganosiloxane (a2) having Si—H groups;
a platinum group metal catalyst (A2);
The laminate according to any one of [1] to [3],
[5] A step in which the semiconductor substrate in the stack according to any one of [1] to [4] is processed;
peeling the photoresponsive peeling layer by irradiation with ultraviolet light, thereby separating the support substrate from the processed semiconductor substrate;
A method for manufacturing a semiconductor substrate, comprising:
[6] The method for manufacturing a semiconductor substrate according to [5], wherein the processing step includes a process of polishing the semiconductor substrate to thin the semiconductor substrate.
[7] A method for producing a laminate according to any one of [1] to [4],
a step of applying a thermosetting adhesive composition onto the semiconductor substrate to form an adhesive coating layer;
heating the adhesive coating layer to form the adhesive layer;
A method for producing a laminate, comprising:
[8] A step of applying a thermosetting adhesive composition onto the semiconductor substrate to form an adhesive coating layer;
a step of applying the release agent composition onto the support substrate to form a release layer;
a step of bonding the semiconductor substrate with the adhesive coating layer and the support substrate with the release layer together so as to sandwich the adhesive coating layer and the release layer, and then heating the resulting bonded substrate to form the adhesive layer from the adhesive coating layer;
The method for producing the laminate according to [7], comprising:

The present invention provides a laminate that allows a semiconductor substrate to be easily separated from a support substrate after processing without causing cutting or deformation of the semiconductor substrate or support substrate, a method for manufacturing a semiconductor substrate using the laminate, and a method for manufacturing the laminate.

FIG. 1 is a schematic cross-sectional view of an example of a laminate. FIG. 1 is a diagram (part 1) for explaining one embodiment of manufacturing a laminate and a thinned wafer. FIG. 2 is a diagram (part 2) for explaining one embodiment of manufacturing a laminate and a thinned wafer. FIG. 3 is a diagram (part 3) for explaining one embodiment of manufacturing a laminate and a thinned wafer. FIG. 4 is a diagram (part 4) for explaining one embodiment of manufacturing a laminate and a thinned wafer. FIG. 5 is a diagram (part 5) for explaining one embodiment of manufacturing a laminate and a thinned wafer. FIG. 6 is a diagram (part 6) for explaining one embodiment of manufacturing a laminate and a thinned wafer.

(Laminate)
The laminate of the present invention comprises a semiconductor substrate, a support substrate, an adhesive layer, and a photoresponsive release layer.
The adhesive layer is interposed between the support substrate and the semiconductor substrate.
The adhesion layer contacts the semiconductor substrate.
A photoresponsive release layer is interposed between the supporting substrate and the adhesive layer.
A photoresponsive release layer contacts the adhesive layer.
The photoresponsive release layer is preferably in contact with the supporting substrate.
The stack is used in applications where the support substrate and the semiconductor substrate are separated after processing of the semiconductor substrate in the stack.

In the laminate of the present invention, when the support substrate and the semiconductor substrate are separated, the photoresponsive release layer is easily peeled off by irradiation with ultraviolet light. In particular, in the present invention, by using a thermosetting adhesive layer as the adhesive layer, the thermosetting adhesive layer and the photoresponsive release layer work together to easily separate the support substrate and the semiconductor substrate without applying excessive force to the support substrate or the semiconductor substrate during peeling. In other words, the support substrate and the semiconductor substrate can be separated without causing cutting, deformation, or the like to the support substrate or the semiconductor substrate.
Furthermore, since the laminate of the present invention has a thermosetting adhesive layer formed in contact with the semiconductor substrate, it is possible to suppress deformation of bumps when manufacturing a processed semiconductor substrate. This is thought to be because the bumps, which are prone to melting or deforming due to the heat and pressure when processing the semiconductor substrate, are protected by the adhesive layer, which is resistant to melting and deformation, and as a result, their shape is maintained.

<Support substrate>
The support substrate is not particularly limited as long as it is a member that can support the semiconductor substrate when the semiconductor substrate is processed, and examples thereof include a glass support substrate and a silicon support substrate.

The shape of the support substrate is not particularly limited, but may be, for example, a disk shape. Note that the disk-shaped support substrate does not need to have a perfectly circular surface, and for example, the outer periphery of the support substrate may have a straight line portion called an orientation flat or a notch.
The thickness of the disk-shaped support substrate may be appropriately determined depending on the size of the semiconductor substrate, and is not particularly limited, but is, for example, 500 to 1,000 μm.
The diameter of the disk-shaped support substrate may be appropriately determined depending on the size of the semiconductor substrate, and is not particularly limited, but is, for example, 100 to 1,000 mm.

An example of a support substrate is a glass wafer or silicon wafer with a diameter of approximately 300 mm and a thickness of approximately 700 μmm.

When irradiating ultraviolet light from the support substrate side to peel off the release layer, it is preferable to use a glass support substrate that typically has an ultraviolet light transmittance of 50% or more.

<Semiconductor substrate>
The main material constituting the entire semiconductor substrate is not particularly limited as long as it is used for this type of application, but examples thereof include silicon, silicon carbide, and compound semiconductors.
The shape of the semiconductor substrate is not particularly limited, but may be, for example, a disk shape. Note that the disk-shaped semiconductor substrate does not need to have a perfectly circular surface, and for example, the outer periphery of the semiconductor substrate may have a straight line portion called an orientation flat or a notch.
The thickness of the disk-shaped semiconductor substrate may be appropriately determined depending on the intended use of the semiconductor substrate, and is not particularly limited, but is, for example, 500 to 1,000 μm.
The diameter of the disk-shaped semiconductor substrate may be appropriately determined depending on the intended use of the semiconductor substrate, and is not particularly limited, but is, for example, 100 to 1,000 mm.

The semiconductor substrate may have bumps, which are protruding terminals.
In the laminate, when the semiconductor substrate has bumps, the semiconductor substrate has the bumps on the support substrate side.
In a semiconductor substrate, bumps are usually formed on the surface on which a circuit is formed. The circuit may be a single layer or a multilayer. There are no particular limitations on the shape of the circuit.
In the semiconductor substrate, the surface opposite to the surface having the bumps (back surface) is the surface to be processed.
The material, size, shape, structure, and density of the bumps on the semiconductor substrate are not particularly limited.
Examples of the bumps include ball bumps, printed bumps, stud bumps, and plated bumps.
Normally, the height, diameter and pitch of the bumps are appropriately determined based on the conditions of a bump height of about 1 to 200 μm, a bump diameter of 1 to 200 μm and a bump pitch of 1 to 500 μm.
Examples of materials for the bumps include low-melting-point solder, high-melting-point solder, tin, indium, gold, silver, and copper. The bumps may be composed of a single component or multiple components. More specifically, alloy platings mainly containing Sn, such as SnAg bumps, SnBi bumps, Sn bumps, and AuSn bumps, may be used.
The bump may also have a laminated structure including a metal layer made of at least one of these components.

An example of a semiconductor substrate is a silicon wafer with a diameter of approximately 300 mm and a thickness of approximately 770 μm.

When irradiating ultraviolet light from the semiconductor substrate side to peel off the release layer, it is preferable to use a substrate with an ultraviolet light transmittance of typically 50% or more.

<Adhesive layer>
The adhesive layer is interposed between the support substrate and the semiconductor substrate.
The adhesion layer contacts the semiconductor substrate.

The adhesive layer is a thermosetting adhesive layer.
The thermosetting adhesive layer refers to a film formed by using an adhesive composition containing a thermosetting adhesive component and curing the curable adhesive component.
Such thermosetting adhesive components are not particularly limited as long as they are adhesive components that are cured by heat, and examples thereof include polysiloxane-based adhesives, acrylic resin-based adhesives, epoxy resin-based adhesives, polyimide adhesives, and phenolic resin-based adhesives.
Among these, polysiloxane adhesives are preferred as the thermosetting adhesive component because they exhibit suitable adhesive properties when processing semiconductor substrates, etc., can be easily peeled off after processing, and also have excellent heat resistance.
In a preferred embodiment, the adhesive composition contains a polyorganosiloxane.
In addition to the thermosetting adhesive component, the adhesive composition may contain other components such as a solvent, for example, to adjust the viscosity of the thermosetting adhesive composition.

It is important that the adhesive layer of the laminate according to the present invention is a thermosetting adhesive layer. For example, if the adhesive layer is a thermoplastic adhesive layer, the release layer cannot be peeled off even when irradiated with ultraviolet light, as shown in the examples below, and if force is applied to forcibly peel it off, excessive force is applied to the substrate (wafer), causing the wafer to crack.
This is thought to be because, when manufacturing a laminate, a semiconductor substrate with an adhesive coating layer and a support substrate with a release layer are bonded together and heated, and if the adhesive layer formed is thermoplastic, the components of the thermoplastic adhesive layer are mixed into the release layer used in the present invention during bonding.

In a preferred embodiment, the adhesive composition also contains a component that cures via a hydrosilylation reaction.
More specific embodiments of the thermosetting adhesive composition used in the present invention include, for example, the following <<First embodiment>> to <<Third embodiment>>.

<<First embodiment>>
In a preferred embodiment, the adhesive composition used in the present invention contains a polyorganosiloxane.
For example, the adhesive composition used in the present invention contains a curable component (A) that becomes an adhesive component. The adhesive composition used in the present invention may contain a curable component (A) that becomes an adhesive component and a component (B) that does not undergo a curing reaction. Here, an example of the component (B) that does not undergo a curing reaction is polyorganosiloxane. In the present invention, "does not undergo a curing reaction" does not mean that any curing reaction does not occur, but rather that the curing reaction occurring in the curable component (A) does not occur.
In another preferred embodiment, component (A) may be a component that cures via a hydrosilylation reaction, or may be a polyorganosiloxane component (A') that cures via a hydrosilylation reaction.
In another preferred embodiment, component (A) contains, for example, a polyorganosiloxane (a1) having an alkenyl group having 2 to 40 carbon atoms bonded to a silicon atom, as an example of component (A'), a polyorganosiloxane (a2) having a Si—H group, and a platinum group metal catalyst (A2). Here, the alkenyl group having 2 to 40 carbon atoms may be substituted. Examples of the substituent include a halogen atom, a nitro group, a cyano group, an amino group, a hydroxy group, a carboxyl group, an aryl group, and a heteroaryl group.
In another preferred embodiment, the polyorganosiloxane component (A') that cures via a hydrosilylation reaction comprises a polysiloxane ( ^A1 ) containing one ^or more units selected from the _group consisting of siloxane units represented by _SiO2 (Q units), siloxane units represented by ^{R1R2R3SiO1 /} ₂ (M units), siloxane units represented by R4R5SiO2 ^/ 2 (D units), and siloxane units represented by ^R6SiO3 _/2 (T units), and a platinum group metal catalyst (A2). The polysiloxane (A1) contains siloxane units represented by _SiO2 (Q' units), siloxane units represented by ^{R1'R2'R3'SiO1} / ² (M' units), siloxane units represented by ^{R4'R5'SiO2 / 2} ₍ D' units), and siloxane units represented by ^R6'SiO3 / ₂ (T units). and a polyorganosiloxane (a2') containing one or more units selected from the group consisting of siloxane units (T' units) represented _{by SiO 2} (Q" units), siloxane units (M _" units) represented by R ⁴ _{"R 5 "SiO 2/2 (D" units) and siloxane units (T" units) represented by R 6 "SiO 3/2} ^{, and containing} _at least one unit selected from ^the group consisting of M" units, D ^" units and T" units.
Note that (a1') is an example of (a1), and (a2') is an example of (a2).

R ¹ to R ⁶ are groups or atoms bonded to the silicon atom, and each independently represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or a hydrogen atom. Examples of the substituent include a halogen atom, a nitro group, a cyano group, an amino group, a hydroxyl group, a carboxyl group, an aryl group, and a heteroaryl group.

R ¹ ' to R ⁶ ' are groups bonded to a silicon atom, and each independently represents an optionally substituted alkyl group or an optionally substituted alkenyl group, provided that at least one of R ¹ ' to R ⁶ ' is an optionally substituted alkenyl group. Examples of the substituent include a halogen atom, a nitro group, a cyano group, an amino group, a hydroxy group, a carboxyl group, an aryl group, and a heteroaryl group.

R ¹ ″ to R ⁶ ″ are groups or atoms bonded to the silicon atom, and each independently represents an optionally substituted alkyl group or a hydrogen atom, provided that at least one of R ¹ ″ to R ⁶ ″ is a hydrogen atom. Examples of the substituent include a halogen atom, a nitro group, a cyano group, an amino group, a hydroxy group, a carboxyl group, an aryl group, and a heteroaryl group.

The alkyl group may be linear, branched, or cyclic, but linear or branched alkyl groups are preferred. There are no particular restrictions on the number of carbon atoms, but it is typically 1 to 40, preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less.

Specific examples of optionally substituted linear or branched alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, tertiary butyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, and 4-methyl-n-pentyl. Examples of such alkyl groups include, but are not limited to, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, and 1-ethyl-2-methyl-n-propyl groups. The number of carbon atoms is typically 1 to 14, preferably 1 to 10, and more preferably 1 to 6. Of these, a methyl group is particularly preferred.

Specific examples of optionally substituted cyclic alkyl groups include cyclopropyl, cyclobutyl, 1-methylcyclopropyl, 2-methylcyclopropyl, cyclopentyl, 1-methylcyclobutyl, 2-methylcyclobutyl, 3-methylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2-ethylcyclopropyl, cyclohexyl, 1-methylcyclopentyl, 2-methylcyclopentyl, 3-methylcyclopentyl, 1-ethylcyclobutyl, 2-ethylcyclobutyl, 3-ethylcyclobutyl, 1,2-dimethylcyclobutyl, 1,3-dimethylcyclobutyl, 2,2-dimethylcyclobutyl, 2,3-dimethylcyclobutyl, 2,4-dimethylcyclobutyl, 3,3-dimethylcyclobutyl, Examples of cycloalkyl groups include 1-ethyl-2-methylcyclopropyl, 1-n-propylcyclopropyl, 2-n-propylcyclopropyl, 1-i-propylcyclopropyl, 2-i-propylcyclopropyl, 1,2,2-trimethylcyclopropyl, 1,2,3-trimethylcyclopropyl, 2,2,3-trimethylcyclopropyl, 1-ethyl-2-methylcyclopropyl, 2-ethyl-1-methylcyclopropyl, 2-ethyl-2-methylcyclopropyl, and 2-ethyl-3-methylcyclopropyl; and bicycloalkyl groups such as bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, and bicyclodecyl. These groups typically contain 3 to 14 carbon atoms, preferably 4 to 10, and more preferably 5 to 6.

The alkenyl group may be either linear or branched, and although there are no particular limitations on the number of carbon atoms, it is typically 2 to 40, preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less.

Specific examples of the optionally substituted linear or branched alkenyl group include, but are not limited to, a vinyl group, an allyl group, a butenyl group, and a pentenyl group, and the number of carbon atoms therein is usually 2 to 14, preferably 2 to 10, and more preferably 1 to 6. Of these, an ethenyl group and a 2-propenyl group are particularly preferred.
Specific examples of the optionally substituted cyclic alkenyl group include, but are not limited to, cyclopentenyl and cyclohexenyl, and the number of carbon atoms is usually 4 to 14, preferably 5 to 10, and more preferably 5 to 6.

As described above, polysiloxane (A1) contains polyorganosiloxane (a1') and polyorganosiloxane (a2'). The alkenyl groups contained in polyorganosiloxane (a1') and the hydrogen atoms (Si-H groups) contained in polyorganosiloxane (a2') undergo a hydrosilylation reaction in the presence of a platinum group metal catalyst (A2) to form a crosslinked structure and cure. As a result, a cured film is formed.

Polyorganosiloxane (a1') contains one or more units selected from the group consisting of Q' units, M' units, D' units, and T' units, and also contains at least one unit selected from the group consisting of M' units, D' units, and T' units. Two or more polyorganosiloxanes satisfying these conditions may be used in combination as polyorganosiloxane (a1').

Preferred combinations of two or more selected from the group consisting of Q' units, M' units, D' units and T' units include, but are not limited to, (Q' units and M' units), (D' units and M' units), (T' units and M' units), and (Q' units, T' units and M' units).

Furthermore, when polyorganosiloxane (a1') contains two or more types of polyorganosiloxane, combinations of (Q' units and M' units) and (D' units and M' units), combinations of (T' units and M' units) and (D' units and M' units), and combinations of (Q' units, T' units and M' units) and (T' units and M' units) are preferred, but are not limited to these.

Polyorganosiloxane (a2') contains one or more units selected from the group consisting of Q" units, M" units, D" units, and T" units, and also contains at least one unit selected from the group consisting of M" units, D" units, and T" units. Two or more polyorganosiloxanes satisfying these conditions may be used in combination as polyorganosiloxane (a2').

Preferred combinations of two or more selected from the group consisting of Q" units, M" units, D" units and T" units include, but are not limited to, (M" units and D" units), (Q" units and M" units), and (Q" units, T" units and M" units).

The polyorganosiloxane (a1') is composed of siloxane units in which alkyl and/or alkenyl groups are bonded to the silicon atoms thereof, and the proportion of alkenyl groups in all the substituents represented by R ¹ ' to R ⁶ ' is preferably 0.1 to 50.0 mol %, more preferably 0.5 to 30.0 mol %, and the remaining R ¹ ' to R ⁶ ' can be alkyl groups.

The polyorganosiloxane (a2') is composed of siloxane units in which alkyl groups and/or hydrogen atoms are bonded to the silicon atoms, and the proportion of hydrogen atoms in all the substituents and substituted atoms represented by R ¹ '' to R ⁶ '' is preferably 0.1 to 50.0 mol %, more preferably 10.0 to 40.0 mol %, and the remaining R ¹ '' to R ⁶ '' can be alkyl groups.

When component (A) contains (a1) and (a2), in a preferred embodiment of the present invention, the molar ratio of alkenyl groups contained in polyorganosiloxane (a1) to hydrogen atoms constituting Si-H bonds contained in polyorganosiloxane (a2) is in the range of 1.0:0.5 to 1.0:0.66.

The weight average molecular weight of polysiloxanes such as polyorganosiloxane (a1) and polyorganosiloxane (a2) is not particularly limited, but is usually 500 to 1,000,000, and from the viewpoint of realizing the effects of the present invention with good reproducibility, it is preferably 5,000 to 50,000.
In the present invention, the weight average molecular weight, number average molecular weight, and dispersity of the polyorganosiloxane can be measured using, for example, a GPC apparatus (EcoSEC, HLC-8320GPC manufactured by Tosoh Corporation) and a GPC column (TSKgel SuperMultiporeHZ-N, TSKgel SuperMultiporeHZ-H manufactured by Tosoh Corporation), a column temperature of 40 ° C., tetrahydrofuran as an eluent (elution solvent), a flow rate (flow rate) of 0.35 mL / min, and polystyrene (manufactured by Showdex) as a standard sample.

The viscosities of polyorganosiloxane (a1) and polyorganosiloxane (a2) are not particularly limited, but are typically 10 to 1,000,000 (mPa·s), and from the perspective of achieving the effects of the present invention with good reproducibility, are preferably 50 to 10,000 (mPa·s). The viscosities of polyorganosiloxane (a1) and polyorganosiloxane (a2) are values measured at 25°C using an E-type rotational viscometer.

Polyorganosiloxane (a1) and polyorganosiloxane (a2) react with each other via a hydrosilylation reaction to form a film. Therefore, the curing mechanism is different from that via, for example, silanol groups, and therefore neither siloxane needs to contain a silanol group or a functional group that forms a silanol group upon hydrolysis, such as an alkyloxy group.

In a preferred embodiment of the present invention, the adhesive composition contains a platinum group metal catalyst (A2) together with the polyorganosiloxane component (A').
Such a platinum-based metal catalyst is a catalyst for promoting the hydrosilylation reaction between the alkenyl groups of the polyorganosiloxane (a1) and the Si—H groups of the polyorganosiloxane (a2).

Specific examples of platinum-based metal catalysts include, but are not limited to, platinum black, platinic chloride, chloroplatinic acid, reaction products of chloroplatinic acid with monohydric alcohols, complexes of chloroplatinic acid with olefins, and platinum bisacetoacetate.
Examples of complexes of platinum and olefins include, but are not limited to, complexes of divinyltetramethyldisiloxane and platinum.
The amount of the platinum group metal catalyst (A2) is not particularly limited, but is usually in the range of 1.0 to 50.0 ppm based on the total amount of the polyorganosiloxane (a1) and the polyorganosiloxane (a2).

The polyorganosiloxane component (A') may contain a polymerization inhibitor (A3) for the purpose of inhibiting the progress of the hydrosilylation reaction.
The polymerization inhibitor is not particularly limited as long as it can inhibit the progress of the hydrosilylation reaction, and specific examples include alkynyl alcohols such as 1-ethynyl-1-cyclohexanol and 1,1-diphenyl-2-propion-1-ol.
The amount of the polymerization inhibitor is not particularly limited, but is usually 1000.0 ppm or more relative to the total amount of polyorganosiloxane (a1) and polyorganosiloxane (a2) from the viewpoint of obtaining the effect, and 10000.0 ppm or less from the viewpoint of preventing excessive inhibition of the hydrosilylation reaction.

An example of the adhesive composition used in the present invention may contain a component (B) that does not undergo a curing reaction to become a release agent component in addition to the curable component (A). By including such component (B) in the adhesive composition, the resulting adhesive layer can be suitably peeled with good reproducibility.
Such component (B) typically includes polyorganosiloxanes, and specific examples thereof include epoxy group-containing polyorganosiloxanes, methyl group-containing polyorganosiloxanes, and phenyl group-containing polyorganosiloxanes, but are not limited to these.
Component (B) may also include polydimethylsiloxane. The polydimethylsiloxane may be modified. Examples of the optionally modified polydimethylsiloxane include, but are not limited to, epoxy group-containing polydimethylsiloxane, unmodified polydimethylsiloxane, and phenyl group-containing polydimethylsiloxane.

Preferred examples of the polyorganosiloxane of component (B) include, but are not limited to, epoxy group-containing polyorganosiloxanes, methyl group-containing polyorganosiloxanes, and phenyl group-containing polyorganosiloxanes.

The weight average molecular weight of the polyorganosiloxane of component (B) is not particularly limited, but is typically 100,000 to 2,000,000. From the viewpoint of reproducibly achieving the effects of the present invention, it is preferably 200,000 to 1,200,000, more preferably 300,000 to 900,000. Its dispersity is also not particularly limited, but is typically 1.0 to 10.0. From the viewpoint of reproducibly achieving suitable release, it is preferably 1.5 to 5.0, more preferably 2.0 to 3.0. The weight average molecular weight and dispersity can be measured using the methods described above for polysiloxane.
The viscosity of the polyorganosiloxane, component (B), is not particularly limited, but is usually 1,000 to 2,000,000 ^{mm 2} /s. The viscosity value of the polyorganosiloxane, component (B), is expressed as kinematic viscosity, where centistokes (cSt) = mm ² /s. It can also be determined by dividing the viscosity (mPa·s) by the density (g/cm ³ ). That is, this value can be determined from the viscosity and density measured using an E-type rotational viscometer at 25°C, and can be calculated from the formula kinematic viscosity (mm ² /s) = viscosity (mPa·s) / density (g/cm ³ ).

Examples of epoxy group-containing polyorganosiloxanes include those containing siloxane units ( ^D10 units) represented by R ¹¹ R ¹² SiO _2/2 .

^R11 is a group bonded to a silicon atom and represents an alkyl group, ^R12 is a group bonded to a silicon atom and represents an epoxy group or an organic group containing an epoxy group, and specific examples of the alkyl group include those listed above.
The epoxy group in the epoxy group-containing organic group may be an independent epoxy group that is not condensed with other rings, or may be an epoxy group that forms a condensed ring with other rings, such as a 1,2-epoxycyclohexyl group.
Specific examples of organic groups containing an epoxy group include, but are not limited to, 3-glycidoxypropyl and 2-(3,4-epoxycyclohexyl)ethyl.
In the present invention, a preferred example of the epoxy group-containing polyorganosiloxane is epoxy group-containing polydimethylsiloxane, but is not limited thereto.

The epoxy group-containing polyorganosiloxane contains the above-mentioned siloxane units ( ^D10 units), but may also contain Q units, M units and/or T units in addition to the ^D10 units.
In a preferred embodiment of the present invention, specific examples of the epoxy group-containing polyorganosiloxane include a polyorganosiloxane consisting only of D ¹⁰ units, a polyorganosiloxane containing D ¹⁰ units and Q units, a polyorganosiloxane containing D ¹⁰ units and M units, a polyorganosiloxane containing D ¹⁰ units and T units, a polyorganosiloxane containing D ¹⁰ units, Q units, and M units, a polyorganosiloxane containing D ¹⁰ units, M units, and T units, and a polyorganosiloxane containing D ¹⁰ units, Q units, M units, and T units.

The epoxy group-containing polyorganosiloxane is preferably an epoxy group-containing polydimethylsiloxane with an epoxy value of 0.1 to 5. Furthermore, its weight average molecular weight is not particularly limited, but is typically 1,500 to 500,000, and is preferably 100,000 or less from the perspective of suppressing precipitation in the adhesive.

Specific examples of epoxy group-containing polyorganosiloxanes include, but are not limited to, those represented by formulas (E1) to (E3).

( _m1 and _n1 represent the number of each repeating unit and are positive integers.)

( _m2 and _n2 each represent the number of repeating units and are positive integers, and R represents an alkylene group having 1 to 10 carbon atoms.)

(m ₃ , n ₃ and o ₃ each represent the number of repeating units and are positive integers, and R is an alkylene group having 1 to 10 carbon atoms.)

Examples of the methyl group-containing polyorganosiloxane include those containing siloxane units (D ²⁰⁰ units) represented by R ²¹⁰ R ²²⁰ SiO _2/2 , preferably those containing siloxane units (D ²⁰ units) represented by R ²¹ R ²¹ SiO _2/2 .

R ²¹⁰ and R ²²⁰ are groups bonded to a silicon atom, and each independently represents an alkyl group, with at least one being a methyl group. Specific examples of the alkyl group include those listed above.
^R21 is a group bonded to a silicon atom and represents an alkyl group, specific examples of which include those listed above, with a methyl group being preferred as ^R21 .
In the present invention, a preferred example of the methyl group-containing polyorganosiloxane is polydimethylsiloxane, but is not limited thereto.

The methyl group-containing polyorganosiloxane contains the above-mentioned siloxane units (D ²⁰⁰ units or D ²⁰ units), but may contain Q units, M units and/or T units in addition to the D ²⁰⁰ units and D ²⁰ units.

In one aspect of the present invention, specific examples of the methyl group-containing polyorganosiloxane include a polyorganosiloxane consisting only of D ²⁰⁰ units, a polyorganosiloxane containing D ²⁰⁰ units and Q units, a polyorganosiloxane containing D ²⁰⁰ units and M units, a polyorganosiloxane containing D ²⁰⁰ units and T units, a polyorganosiloxane containing D ²⁰⁰ units, Q units, and M units, a polyorganosiloxane containing D ²⁰⁰ units, M units, and T units, and a polyorganosiloxane containing D ²⁰⁰ units, Q units, M units, and T units.

In a preferred aspect of the present invention, specific examples of the methyl group-containing polyorganosiloxane include a polyorganosiloxane consisting only of ^D20 units, a polyorganosiloxane containing ^D20 units and Q units, a polyorganosiloxane containing ^D20 units and M units, a polyorganosiloxane containing ^D20 units and T units, a polyorganosiloxane containing ^D20 units, Q units, and M units, a polyorganosiloxane containing ^D20 units, M units, and T units, and a polyorganosiloxane containing ^D20 units, Q units, M units, and T units.

Specific examples of methyl group-containing polyorganosiloxanes include, but are not limited to, those represented by formula (M1):

( _n4 represents the number of repeating units and is a positive integer.)

Examples of phenyl group-containing polyorganosiloxanes include those containing siloxane units ( ^D30 units) represented by R ³¹ R ³² SiO _2/2 .

R ³¹ is a group bonded to a silicon atom and represents a phenyl group or an alkyl group, R ³² is a group bonded to a silicon atom and represents a phenyl group, and specific examples of the alkyl group include those listed above, with a methyl group being preferred.

The phenyl group-containing polyorganosiloxane contains the above-mentioned siloxane units ( ^D30 units), but may also contain Q units, M units and/or T units in addition to the ^D30 units.

In a preferred embodiment of the present invention, specific examples of the phenyl group-containing polyorganosiloxane include a polyorganosiloxane consisting only of ^D30 units, a polyorganosiloxane containing ^D30 units and Q units, a polyorganosiloxane containing ^D30 units and M units, a polyorganosiloxane containing ^D30 units and T units, a polyorganosiloxane containing ^D30 units, Q units, and M units, a polyorganosiloxane containing ^D30 units, M units, and T units, and a polyorganosiloxane containing ^D30 units, Q units, M units, and T units.

Specific examples of phenyl group-containing polyorganosiloxanes include, but are not limited to, those represented by formula (P1) or (P2).

( _m5 and _n5 represent the number of each repeating unit and are positive integers.)

( _m6 and _n6 represent the number of each repeating unit and are positive integers.)

In one embodiment, the adhesive composition used in the present invention contains a component (A) that cures and a component (B) that does not undergo a curing reaction, and in a more preferred embodiment, component (B) contains a polyorganosiloxane.

An example of the adhesive composition used in the present invention can contain component (A) and component (B) in any ratio. In consideration of the balance between adhesiveness and releasability, the ratio of component (A) to component (B) in mass ratio [(A):(B)] is preferably 99.995:0.005 to 30:70, more preferably 99.9:0.1 to 75:25.
That is, when a polyorganosiloxane component (A') that cures by a hydrosilylation reaction is included, the mass ratio of component (A') to component (B) [(A'):(B)] is preferably 99.995:0.005 to 30:70, more preferably 99.9:0.1 to 75:25.

The viscosity of the adhesive composition used in the present invention is not particularly limited, but is typically 500 to 20,000 mPa·s, and preferably 1,000 to 5,000 mPa·s, at 25°C.

<<Second embodiment>>
In a preferred embodiment, the adhesive composition used in the present invention contains, for example, the curable adhesive material described below, or the curable adhesive material and a release additive.
The curable adhesive material may be selected from, for example, polyarylene oligomers, cyclic olefin oligomers, arylcyclobutene oligomers, vinyl aromatic oligomers, and mixtures thereof.
The release additive may, for example, be a polyether compound.
Preferably, the polyether compound comprises end groups selected from the group consisting of hydroxy, alkoxy, aryloxy, and mixtures thereof.
Preferably, the polyether compound is selected from polyethylene glycol, polypropylene glycol, poly(1,3-propanediol), polybutylene glycol, poly(tetrahydrofuran), ethylene glycol-propylene glycol copolymers, and mixtures thereof.
Preferably, the release additive is selected from the group consisting of polyalkylene oxide homopolymers and polyalkylene oxide copolymers.
As the adhesive composition of the second embodiment, for example, the temporary bonding composition described in JP 2014-150239 A can be used.
The adhesive composition of the second embodiment will be described in more detail below.

The adhesive composition used in the present invention comprises a curable adhesive material, a release additive, and optionally an organic solvent. Typically, the curable adhesive material has a modulus of >1 GPa when cured. Exemplary curable adhesive materials include, but are not limited to, polyarylene oligomers, cyclic olefin oligomers, arylcyclobutene oligomers, vinyl aromatic oligomers, and mixtures thereof. The curable adhesive material may be substituted with any suitable moiety, such as a fluorine-containing group, to provide additional hydrophobicity, provided that such moiety does not adversely affect the mechanical properties of the cured adhesive material. Preferably, the curable adhesive material is selected from polyarylene oligomers, cyclic olefin oligomers, arylcyclobutene oligomers, vinyl aromatic oligomers, and mixtures thereof, more preferably one or more of arylcyclobutene oligomers, vinyl aromatic oligomers, or mixtures thereof. When a mixture of different curable adhesive materials is used in the present invention, such materials are selected to cure together during the curing process. When a mixture of different curable materials is used, the curable materials are used in a mass ratio of 99:1 to 1:99, preferably 95:5 to 5:95, more preferably 90:10 to 10:90, and even more preferably 75:25 to 25:75.

A wide variety of polyarylene oligomers can be used in the present invention. As used herein, the term "polyarylene" includes polyarylene ethers. Suitable polyarylene oligomers can be synthesized from precursors, such as ethynyl aromatic compounds of the following formula:

wherein each Ar is an aromatic group or an inertly substituted aromatic group; each R is independently hydrogen, alkyl, aryl, or an inertly substituted alkyl or aryl group; L is a covalent bond or a group linking one Ar to at least one other Ar; n and m are integers of at least 2; and q is an integer of at least 1. As such, ethynyl aromatic compounds typically have four or more ethynyl groups (e.g., tetraethynyl aromatic compounds).

Suitable polyarylene oligomers for use in the temporary bonding composition as the adhesive composition of the second embodiment may include polymers containing, as polymerized units:

where Ar' is the residue of the (C≡C)n-Ar or Ar-(C≡C)m portion of the reaction product, and R, L, n, and m are as defined above. Polyarylene copolymers useful in the present invention include, as polymerized units, monomers having the following formula:

wherein Ar′ and R are as defined above.

Exemplary polyarylenes include those in which Ar-L-Ar is: biphenyl; 2,2-diphenylpropane; 9,9'-diphenylfluorene;2,2-diphenylhexafluoropropane; diphenyl sulfide; oxydiphenylene; diphenyl ether; bis(phenylene)diphenylsilane; bis(phenylene)phosphine oxide; bis(phenylene)benzene; bis(phenylene)naphthalene; bis(phenylene)anthracene; thiodiphenylene; 1,1,1-triphenyleneethane; 1,3,5-triphenylene phenylbenzene; 1,3,5-(2-phenylene-2-propyl)benzene; 1,1,1-triphenylenemethane; 1,1,2,2-tetraphenylene-1,2-diphenylethane; bis(1,1-diphenyleneethyl)benzene; 2,2'-diphenylene-1,1,1,3,3,3-hexafluoropropane;1,1-diphenylene-1-phenylethane;naphthalene;anthracene; or bis(phenylene)naphthacene; more preferably biphenylene; naphthylene; p,p'-(2,2-diphenylenepropane) (or C _{6H4 -} C( _CH3 ) _{2 - C6H4-} ); p,p'-(2,2-diphenylene- _{1,1,1,3,3,3hexafluoropropene} ) and ( _-C6H4 -C( _CF3 ) ₂ - _C6H4- ). Useful bisphenyl derivatives include 2,2-diphenylpropane; 9,9'-diphenylfluorene; _2,2 -diphenylhexafluoropropane; diphenyl sulfide; diphenyl ether; bis(phenylene)diphenylsilane; bis(phenylene)phosphine oxide; bis(phenylene)benzene; bis(phenylene)naphthalene; bis(phenylene)anthracene; or bis(phenylene)naphthacene.

Polyarylene precursor monomers can be prepared by various methods known in the art, such as (a) selectively halogenating, preferably brominating, a polyphenol (preferably a bisphenol) in a solvent, where each phenolic ring is halogenated with one halogen at one of the two positions ortho to the phenolic hydroxyl group; (b) selectively brominating the phenolic hydroxyl groups on the resulting poly(ortho-halophenol) with a leaving group (e.g., a sulfonate ester) reactive with and displaced by a terminal ethynyl compound, preferably in a solvent. (e.g., trifluoromethanesulfonate ester prepared from trifluoromethanesulfonyl halide or trifluoromethanesulfonic anhydride), and (c) reacting the reaction product of step (b) with an ethynyl-containing compound or ethynyl synthon in the presence of an aryl ethynylation catalyst, preferably a palladium catalyst, and an acid acceptor to simultaneously replace the halogen and trifluoromethylsulfonate with an ethynyl-containing group (e.g., acetylene, phenylacetylene, substituted phenylacetylene, or substituted acetylene). Further description of this synthesis is provided in International Publication No. WO 97/10193 (Babb).

Ethynyl aromatic monomers of formula (I) are useful for preparing polymers of either formula (II) or (III). Polymerization of ethynyl aromatic monomers is well within the capabilities of those skilled in the art. While the specific conditions for polymerization will depend on various factors, including the specific ethynyl aromatic monomer(s) being polymerized and the desired properties of the resulting polymer, general polymerization conditions are detailed in International Publication No. WO 97/10193 (Babb).

Particularly suitable polyarylenes for use in the present invention include those sold as SiLK™ semiconductor dielectrics (available from Dow Electronic Materials, Marlborough, Massachusetts). Other particularly suitable polyarylenes include those disclosed in WO 00/31183, WO 98/11149, WO 97/10193, WO 91/09081, EP 755957, and U.S. Pat. Nos. 5,115,082; 5,155,175; 5,179,188; 5,874,516; and 6,093,636.

A suitable cyclic olefin material is a poly(cyclic olefin), which may be thermoplastic and preferably has a weight average molecular weight (Mw) of 2000 to 200,000 daltons, more preferably 5000 to 100,000 daltons, and even more preferably 2000 to 50,000 daltons. Preferred poly(cyclic olefins) have a softening temperature (melt viscosity at 3,000 PaS) of at least 100°C, more preferably at least 140°C. Suitable poly(cyclic olefins) also preferably have a glass transition temperature (Tg) of at least 60°C, more preferably 60 to 200°C, and most preferably 75 to 160°C.

Preferred poly(cyclic olefins) comprise repeating monomers of cyclic and acyclic olefins, or ring-opened polymers based on cyclic olefins. Cyclic olefins suitable for use in the present invention are selected from norbornene-based olefins, tetracyclododecene-based olefins, dicyclopentadiene-based olefins, Diels-Alder polymers such as those derived from furan and maleimide, and derivatives thereof. Derivatives include alkyl (preferably _C1 - _C20 alkyl, more preferably _C1 - _C10 alkyl), alkylidene (preferably _C1 - _C20 alkylidene, more preferably _C1 - _C10 alkylidene), aralkyl (preferably _C6 - _C30 aralkyl, more preferably _C6 - _C18 aralkyl), cycloalkyl (preferably _C3 - _C30 cycloalkyl, more preferably _C3 - _C18 cycloalkyl), ether, acetyl, aromatic, ester, hydroxy, alkoxy, cyano, amide, imide, and silyl-substituted derivatives. Particularly preferred cyclic olefins for use in the present invention include those selected from the following and combinations thereof:

wherein each R ¹ and R ² is independently selected from H and an alkyl group (preferably C ₁ -C ₂₀ alkyl, more preferably C ₁ -C ₁₀ alkyl), and each R ³ is independently selected from H, substituted and unsubstituted aryl groups (preferably C ₆ -C ₁₈ aryl), alkyl groups (preferably C ₁ -C ₂₀ alkyl, more preferably C ₁ -C ₁₀ alkyl), cycloalkyl groups (preferably C ₃ -C ₃₀ cycloalkyl, more preferably C ₃ -C ₁₈ cycloalkyl), aralkyl groups (preferably C ₆ -C ₃₀ aralkyl, more preferably C ₆ -C ₁₈ aralkyl, e.g., benzyl, phenethyl, phenylpropyl, etc.), ester groups, ether groups, acetyl groups, alcohols (preferably C ₁ -C ₁₀ alcohols), aldehyde groups, ketones, nitriles, and combinations thereof.

Preferred acyclic olefins are selected from branched and unbranched _C2 - _C20 alkenes (preferably _C2 - _C10 alkenes). More preferably, the acyclic olefin has the structure ( ^R4 ) _2C =C( ^R4 ) ₂ , where each ^R4 is independently selected from H and an alkyl group (preferably _C1 - _C20 alkyl, more preferably _C1 - _C10 alkyl). Particularly preferred acyclic olefins for use in the present invention include those selected from ethene, propene, and butene, with ethene being most preferred.

Methods for producing cyclic olefin copolymers are known in the art. For example, cyclic olefin copolymers can be produced by chain polymerization of cyclic and acyclic monomers. When norbornene is reacted with ethene under these conditions, an ethene-norbornene copolymer containing alternating norbornanediyl and ethylene units is obtained. Examples of copolymers produced by this method include those available under the TOPAS™ (manufactured by Topas Advanced Polymers) and APEL™ (manufactured by Mitsui Chemicals, Inc.) brands. A suitable method for producing these copolymers is disclosed in U.S. Pat. No. 6,008,298. Cycloolefin copolymers can also be produced by ring-opening metathesis polymerization of various cyclic monomers, followed by hydrogenation. The polymer resulting from this type of polymerization can be conceptualized as a copolymer of ethene and a cyclic olefin monomer (e.g., alternating units of ethylene and cyclopentane-1,3-diyl). Examples of copolymers produced by this ring-opening method include those offered under the ZEONOR™ (from Zeon Chemicals) and ARTON™ (manufactured by JSR Corporation) brands. A suitable method for producing these copolymers by this ring-opening method is disclosed in U.S. Pat. No. 5,191,026.

Arylcyclobutene oligomers useful as curable adhesive materials of the present invention are well known in the art. Suitable arylcyclobutene oligomers include, but are not limited to, those having the following formula:

wherein B is an n-valent linking group; Ar is a polyvalent aryl group, wherein a carbon atom of the cyclobutene ring is bonded to an adjacent carbon atom on the same aromatic ring of Ar; m is an integer of 1 or greater; n is an integer of 1 or greater; and ^R5 is a monovalent group. Preferably, the polyvalent aryl group Ar may be composed of 1 to 3 aromatic carbocyclic or heteroaromatic rings. Preferably, the aryl group contains a single aromatic ring, more preferably a phenyl ring. The aryl group is optionally substituted with 1 to 3 groups selected from (C ₁ -C ₆ ) alkyl, tri(C ₁ -C ₆ ) alkylsilyl, (C ₁ -C ₆ ) alkoxy and halo, preferably one or more of (C ₁ -C ₆ ) alkyl, tri(C ₁ -C ₃ ) alkylsilyl, (C ₁ -C ₃ ) alkoxy and chloro, more preferably one or more of (C ₁ -C ₃ ) alkyl, tri(C ₁ -C ₃ ) alkylsilyl and (C ₁ -C ₃ ) alkoxy. Preferably, the aryl group is unsubstituted. Preferably, n=1 or 2, more preferably n=1. Preferably, m=1 to 4, more preferably m=2 to 4, even more preferably m=2. Preferably, R ⁵ is selected from H and (C ₁ -C ₆ ) alkyl, more preferably H and (C ₁ -C ₃ ) alkyl. Preferably, B contains one or more carbon-carbon double bonds (ethylenic unsaturation). Suitable monovalent B groups preferably have the formula -[C(R ¹⁰ )=CR ¹¹ ]xZ, where R ¹⁰ and R ¹¹ are independently selected from hydrogen, (C ₁ -C ₆ )alkyl, and aryl; Z is selected from hydrogen, (C ₁ -C ₆ )alkyl, aryl, siloxanyl, -CO ₂ R ¹² ; each R ¹² is independently selected from H, (C ₁ -C ₆ )alkyl, aryl, aralkyl, and alkaryl; and x=1 or 2. Preferably, R ¹⁰ and R ¹¹ are independently selected from H, (C ₁ -C ₃ )alkyl, and aryl, more preferably H and (C ₁ -C ₃ )alkyl. R ¹² is preferably (C ₁ -C ₃ ) alkyl, aryl, and aralkyl. Z is preferably siloxyl. Preferred siloxyl groups have the formula -[Si(R ¹³ ) ₂ -O]p-Si(R ¹³ ) ₂ -, where each R ¹³ is independently selected from H, (C ₁ -C ₆ ) alkyl, aryl, aralkyl, and alkaryl; p is an integer greater than or equal to 1. R ¹³ is selected from (C ₁ -C ₃ ) alkyl, aryl, and aralkyl. Suitable aralkyl groups include benzyl, phenethyl, and phenylpropyl.

Preferably, the arylcyclobutene oligomer comprises one or more oligomers of the following formula:

wherein each R ⁶ is independently selected from H and (C ₁ -C ₆ )alkyl, preferably H and (C ₁ -C ₃ )alkyl; each R ⁷ is independently selected from (C ₁ -C ₆ )alkyl, tri(C ₁ -C ₆ )alkylsilyl, (C ₁ -C ₆ )alkoxy and halo; each R ⁸ is independently a divalent ethylenically unsaturated organic group; each R ⁹ is independently selected from H, (C ₁ -C ₆ )alkyl, aralkyl and phenyl; p is an integer greater than or equal to 1; and q is an integer from 0 to 3. Preferably, each R ⁶ is independently selected from H and (C ₁ -C ₃ )alkyl, more preferably each R ⁶ is H. Preferably, each R7 is independently selected from (C ₁ -C ₆ )alkyl, tri(C ₁ -C ₃ )alkylsilyl, (C ₁ -C ₃ )alkoxy and chloro, more preferably selected from (C ₁ -C ₃ )alkyl, tri(C ₁ -C ₃ )alkylsilyl and (C ₁ -C ₃ )alkoxy. Preferably, each ^R8 is independently selected from (C ₂ -C ₆ )alkenyl, more preferably each ^R8 is -CH=CH-. Each ^R9 is preferably selected from (C ₁ -C ₃ )alkyl, more preferably each ^R9 is methyl. Preferably, p=1 to 5, more preferably p=1 to 3, even more preferably p=1. Preferably, q=0. A particularly preferred arylcyclobutene oligomer, 1,3-bis(2-bicyclo[4.2.0]octa-1,3,5-trien-3-ylethenyl)-1,1,3,3-tetramethyldisiloxane (“DVS-bisBCB”), has the following formula:

Arylcyclobutene oligomers may be prepared by any suitable means, such as those described in U.S. Pat. Nos. 4,812,588; 5,136,069; 5,138,081 and International Publication WO 94/25903. Suitable arylcyclobutene oligomers are also commercially available under the CYCLOTENE™ brand, available from Dow Electronic Materials. The arylcyclobutene oligomers may be used as is or may be further purified by any suitable means.

Curable vinyl aromatic oligomers can be used as curable adhesive materials in the present invention. Such vinyl aromatic oligomers are typically oligomers of one or more reactive ethylenically unsaturated comonomers and a vinyl aromatic monomer. Preferably, the vinyl aromatic monomer contains one vinyl group. Suitable vinyl aromatic monomers include unsubstituted vinyl aromatic monomers and substituted vinyl aromatic monomers in which one or more hydrogens are replaced with a substituent selected from the group consisting of (C ₁ -C ₆ ) alkyl, (C ₁ -C ₆ ) alkoxy, halo, and amino. Exemplary vinyl aromatic monomers include, but are not limited to, styrene, vinyl toluene, vinyl xylene, vinyl anisole, vinyl dimethoxy benzene, vinyl aniline, halostyrenes such as fluorostyrene, α-methyl styrene, β-methoxy styrene, ethyl vinyl benzene, vinyl pyridine, vinyl imidazole, vinyl pyrrole, and mixtures thereof. Preferred vinyl aromatic monomers are styrene, vinyl toluene, vinyl xylene, vinyl anisole, ethyl vinyl benzene, and mixtures thereof. Preferred reactive comonomers are those that contain a reactive moiety, i.e., a moiety capable of further polymerization (or crosslinking) after formation of the vinyl aromatic oligomer, such as an allyl moiety or vinyl group, in addition to the olefinic (or ethylenically unsaturated) moiety used to form the vinyl aromatic oligomer. Such reactive comonomers may suitably be any asymmetric diene or triene that can be further polymerized by a Diels-Alder reaction after oligomerization with the vinyl aromatic monomer. More preferably, the reactive comonomer contains an allyl moiety in addition to the ethylenic unsaturation used to form the vinyl aromatic oligomer, and even more preferably, contains an allyl ester moiety in addition to this ethylenic unsaturation. Exemplary reactive comonomers useful for forming vinyl aromatic oligomers include, but are not limited to, vinylcyclohexene, vinyl ethers, asymmetric dienes or trienes such as terpene monomers, dicyclopentadiene, diallyl maleate, allyl acrylate, allyl methacrylate, allyl cinnamate, diallyl fumarate, allyl tiglate, divinylbenzene, and mixtures thereof. Preferred reactive comonomers are diallyl maleate, allyl acrylate, allyl methacrylate, allyl cinnamate, diallyl fumarate, and mixtures thereof, more preferably diallyl maleate, allyl methacrylate, and mixtures thereof. Exemplary terpene monomers include, but are not limited to, limonene, dipentene, myrcene, and the like. Those skilled in the art will appreciate that one or more second comonomers may also be used to form vinyl aromatic oligomers. Such second comonomers are ethylenically unsaturated but do not contain reactive moieties. Exemplary second comonomers include, but are not limited to, (meth)acrylic acid, (meth)acrylamide, (C1-C10) alkyl (meth)acrylates, aromatic (meth)acrylates, substituted ethylene monomers, and poly(alkylene oxide) monomers.

The molar ratio of vinyl aromatic monomer to comonomer in such vinyl aromatic oligomers is preferably 99:1 to 1:99, more preferably 95:5 to 5:95, and even more preferably 90:10 to 10:90. Such vinyl aromatic oligomers may be prepared by any suitable method, including any method known in the art. Typically, vinyl aromatic oligomers are prepared by free-radical polymerization of vinyl aromatic monomers and comonomers. Preferred vinyl aromatic oligomers contain unreacted allyl moieties that allow such oligomers to be further cured.

A wide variety of materials may be used as release additives in temporary bonding compositions, provided that such materials do not react with the adhesive material under storage and use conditions and are non-curable under the conditions used to cure the adhesive material. Additionally, the release additive should be compatible with the temporary bonding composition; i.e., the release additive must be dispersible, miscible, or otherwise substantially compatible with the adhesive material and any other components used in the temporary bonding composition, such as organic solvents. If an organic solvent (or mixed solvent system) is used in the temporary bonding composition, the release additive and curable adhesive material must be soluble in such solvent. In the present invention, the release additives are sufficiently nonvolatile so that they do not substantially evaporate under use conditions; i.e., they do not substantially evaporate during the deposition process, e.g., spin coating, or any subsequent heating step used to remove the organic solvent or cure the adhesive material. When a film or layer of the temporary bonding composition is cast, e.g., by spin coating, much (or all) of the solvent evaporates. Preferably, the release additive is soluble in any organic solvent used, but not completely soluble in the curable adhesive material. The release additive is predominantly hydrophilic relative to the cured adhesive material. Without being bound by theory, it is believed that upon curing of the adhesive material, the release additive phase separates and preferentially migrates toward the active surface of the wafer (a more hydrophilic surface relative to the carrier surface). The use of an appropriate hydrophilic moiety in the release additive allows for complete dispersion, or preferably dissolution, of the release additive in the temporary bonding composition and allows for phase separation of the release additive during curing of the adhesive material, with migration of the release additive toward the more hydrophilic surface. Any material that does not phase separate from the adhesive material during curing will not function as a release additive in accordance with the present invention.

Generally, the release additive will contain one or more relatively hydrophilic moieties, such as one or more oxygen-, nitrogen-, phosphorus-, and sulfur-containing moieties. Suitable release additives include, but are not limited to, ethers, esters, carboxylates, alcohols, thioethers, thiols, amines, imines, amides, phosphate esters, sulfonate esters, and mixtures thereof. Preferably, the release additive contains one or more polar end groups, which contain one or more of oxygen, nitrogen, and sulfur, preferably oxygen. Exemplary polar end groups include alkoxy, aryloxy, hydroxy, carboxylate, alkoxycarbonyl, mercapto, alkylthio, primary amine, secondary amine, and tertiary amine, with preferred end groups selected from (C ₁ -C ₆ )alkoxy, (C ₆ -C ₁₀ )aryloxy, hydroxy, carboxylate, (C _{1 -C 6 )alkoxycarbonyl, mercapto, (C 1 -C 6 )} alkylthio, amino, (C ₁ -C ₆ )alkylamino, and di(C _{1 -C 6} )alkylamino, more preferably selected from (C ₁ -C ₆ )alkoxy, (C ₆ -C ₁₀ )aryloxy, hydroxy, carboxylate, and (C 1 -C 6 )alkoxycarbonyl, and even more preferably selected from (C ₁ -C ₆ )alkoxy, hydroxy, carboxylate, and (C ₁ -C ₆ )alkoxycarbonyl. Particularly preferred polar end groups are selected from hydroxy, methoxy, ethoxy, propoxy, butoxy, carboxyl, and acetoxy.Preferably the release additive is silicone free.

Suitable release additives have a number average molecular weight (Mn) of ≦10,000 Daltons, preferably ≦7500 Daltons, and more preferably ≦7000 Daltons. The release additive has a minimum molecular weight (Mn) sufficient to render the release additive substantially non-volatile under use conditions (i.e., <5%, preferably <3%, more preferably ≦1% of the release additive volatilizes during use). Preferably, the release additive has an Mn of ≧500 Daltons. A preferred range of Mn is 500-10,000 Daltons, more preferably 500-7500 Daltons, and even more preferably 500-7000 Daltons. The release additive may be a linear polymer; a branched polymer, such as a dendritic polymer or a star polymer; or a polymer particle; however, the release additive is preferably a linear polymer or polymer particle, and more preferably a linear polymer. Without being bound by theory, it is believed that linear polymers are better able to migrate through the cured adhesive material phase toward the hydrophilic wafer surface than branched polymers.

Polyethers are preferred release additives. Polyether compounds include alkylene oxide homopolymers and alkylene oxide copolymers, and these copolymers may be random or block. Polyalkylene oxide release additives may have a variety of polar end groups; preferably, these polar end groups are hydroxy, (C ₁ -C ₆ )alkoxy, and (C ₁ -C 6 )alkoxycarbonyl, more preferably hydroxy, (C ₁ -C ₃ )alkoxy, and acetoxy. Preferred polyether compounds are polyglycols (or polyalkylene oxides), such as poly(C ₁ -C ₄ )alkylene oxide compounds, which may contain a single type of alkylene oxide repeat unit or _two or more different types of alkylene oxide repeat units. Preferred polyether compounds include polyethylene glycol, polypropylene glycol, poly(1,3-propanediol), poly(tetrahydrofuran), ethylene oxide-propylene oxide copolymer, ethylene oxide-butylene oxide copolymer, and mixtures thereof. Preferably, when the release additive contains butylene oxide as a repeating unit, it is a copolymer with one or more different alkylene oxide repeating units. Those skilled in the art will understand that mixtures of release additives may be used in the temporary bonding composition of the present invention. Suitable release additives include polyethers sold under the product names PLURONIC®, TETRONIC, and POLYTHF (available from BASF, Ludwigshafen, Germany), FORTEGRA (The Dow Chemical Company, Midland, Michigan), and TERATHANE (available from Invista, Wichita, Kansas), all of which may be used without further purification.

One or more organic solvents are preferably used in the temporary bonding composition. Any solvent or mixture of solvents that dissolves or disperses, preferably dissolves, the curable adhesive material and release additive may be suitable for use in the temporary bonding composition. Exemplary organic solvents include, but are not limited to: aromatic hydrocarbons such as toluene, xylene, and mesitylene; alcohols such as 2-methyl-1-butanol, 4-methyl-2-pentanol, and methyl isobutylcarbinol; esters such as ethyl lactate, propylene glycol methyl ether acetate, and methyl 2-hydroxyisobutyrate; lactones such as gamma-butyrolactone; lactams such as N-methylpyrrolidinone; ethers such as propylene glycol methyl ether and dipropylene glycol dimethyl ether isomers (commercially available from The Dow Chemical Company as PROGLYDE™ DMM); ketones such as cyclohexanone and methylcyclohexanone; and mixtures thereof.

<<Third embodiment>>
In a preferred embodiment, the adhesive composition used in the present invention contains, for example, the thermosetting polymer described below.
As the adhesive composition of the third embodiment, for example, the thermosetting polymer described in Japanese Patent No. 6,528,747 can be used.
The thermosetting polymer is not particularly limited, but a preferred example is a siloxane bond-containing polymer (hereinafter also referred to as silicone A) that is composed of a repeating unit represented by the following formula (3) and, if necessary, a repeating unit represented by the following formula (4) and has a weight average molecular weight of 3,000 to 500,000:

[In the formula, R ⁶ to R ⁹ each independently represent a monovalent hydrocarbon group having 1 to 8 carbon atoms. Furthermore, m represents an integer from 1 to 100. A and B are positive numbers that satisfy 0<A<1, 0<B<1, and A+B=1. ^{T 1} and T ² are divalent organic groups represented by the following formula (5).

(wherein A ¹ is a single bond or a group represented by the following formula:

R ¹⁰ and R ¹¹ each independently represent an alkyl group or alkoxy group having 1 to 4 carbon atoms. h each independently represents 0, 1, or 2.

Examples of monovalent hydrocarbon groups represented by ^R6 to ^R9 include alkyl groups such as methyl and ethyl groups, and aryl groups such as phenyl groups. m is preferably an integer of 3 to 60, more preferably 8 to 40. Furthermore, A is preferably 0.3 to 0.8, and B is preferably 0.2 to 0.7, with A/B preferably satisfying the range of 0.1 to 20, and more preferably satisfying the range of 0.5 to 5.

Another preferred example of a thermosetting polymer is a siloxane bond-containing polymer (hereinafter also referred to as "silicone B") having a weight-average molecular weight of 3,000 to 500,000, which comprises a repeating unit represented by the following formula (6) and, if necessary, a repeating unit represented by the following formula (7):

[In the formula, R ¹² to R ¹⁵ each independently represent a monovalent hydrocarbon group having 1 to 8 carbon atoms. p represents an integer from 1 to 100. C and D are positive numbers that satisfy 0<C≦1, 0≦D<1, and C+D=1. ^{T 3} and T ⁴ are divalent organic groups represented by the following formula (8).

(Wherein ^A2 is a single bond or a group represented by the following formula:

^{R 16} and R ¹⁷ are each independently an alkyl group or alkoxy group having 1 to 4 carbon atoms. Each k is independently 0, 1, or 2.

In this case, examples of the monovalent hydrocarbon groups represented by R ¹¹ to R ¹⁴ include the same groups as those exemplified as those represented by R ⁵ to R ^8. p is preferably an integer of 3 to 60, more preferably 8 to 40. Furthermore, C is preferably 0.3 to 1, D is preferably 0 to 0.7, and C+D=1.

The adhesive layer formed using the thermosetting polymer as the adhesive composition of the third embodiment is preferably a layer of a cured product of a thermosetting resin composition whose main component is silicone A or silicone B. Silicone A and silicone B can be used in combination. In this case, the ratio (polymerization ratio) of silicone A:silicone B is preferably 0.1:99.9 to 99.9:0.1, and more preferably silicone A:silicone B is 20:80 to 80:20.

Thermosetting resin compositions containing silicone A as a main component contain, for thermal curing, one or more crosslinking agents selected from an amino condensate modified with formalin or formalin-alcohol, a phenol compound having an average of two or more methylol groups or alkoxymethylol groups per molecule, and an epoxy compound having an average of two or more epoxy groups per molecule.

On the other hand, the thermosetting resin composition containing silicone B as the main component contains, for thermal curing, one or more crosslinking agents selected from phenolic compounds having an average of two or more phenolic groups per molecule and epoxy compounds having an average of two or more epoxy groups per molecule.

The thermosetting resin composition containing silicone A and silicone B also contains, for thermal curing, one or more crosslinking agents selected from epoxy compounds having an average of two or more epoxy groups per molecule.

Examples of the amino condensates include melamine resins and urea resins. Examples of melamine resins modified with formalin or formalin-alcohol include those obtained by subjecting modified melamine monomers (e.g., trimethoxymethyl monomethylol melamine) or their polymers (e.g., oligomers such as dimers and trimers) to addition-condensation polymerization with formaldehyde according to known methods until the desired molecular weight is reached. These can be used alone or in combination of two or more types.

Examples of urea resins modified with formalin or formalin-alcohol include methoxymethylated urea condensates, ethoxymethylated urea condensates, and propoxymethylated urea condensates. These can be used alone or in combination of two or more. Urea resins modified with formalin or formalin-alcohol can be prepared, for example, by modifying a urea condensate of the desired molecular weight with formalin using a known method, or by further modifying the urea condensate by alkoxylation with an alcohol.

Furthermore, examples of phenol compounds having an average of two or more methylol groups or alkoxymethylol groups per molecule include (2-hydroxy-5-methyl)-1,3-benzenedimethanol and 2,2',6,6'-tetramethoxymethylbisphenol A. These can be used alone or in combination of two or more.

Epoxy compounds containing an average of two or more epoxy groups per molecule are not particularly limited, but examples include difunctional, trifunctional, tetrafunctional or higher polyfunctional epoxy resins, such as EOCN-1020 (see formula below), EOCN-102S, XD-1000, NC-2000-L, EPPN-201, GAN, and NC6000 manufactured by Nippon Kayaku Co., Ltd., as well as those represented by the formula below.

Examples of phenolic compounds containing an average of two or more phenolic groups per molecule include m- or p-cresol novolac resins (e.g., EP-6030G manufactured by Asahi Organic Chemicals Co., Ltd.), trifunctional phenolic compounds (e.g., Tris-P-PA manufactured by Honshu Chemical Industry Co., Ltd.), and tetrafunctional phenolic compounds (e.g., TEP-TPA manufactured by Asahi Organic Chemicals Co., Ltd.).

The amount of crosslinking agent in the thermosetting resin composition is preferably 0.1 to 50 parts by mass, more preferably 0.2 to 30 parts by mass, and even more preferably 1 to 20 parts by mass, per 100 parts by mass of the thermosetting polymer. Crosslinking agents can be used alone or in combination of two or more types.

The thermosetting resin composition may also contain a curing catalyst such as an acid anhydride in an amount of up to 10 parts by mass per 100 parts by mass of the thermosetting polymer.

<<Other ingredients>>
The adhesive composition used in the present invention may contain a solvent for the purpose of adjusting the viscosity, etc., and specific examples of the solvent include, but are not limited to, aliphatic hydrocarbons, aromatic hydrocarbons, and ketones.

More specifically, examples of solvents include, but are not limited to, hexane, heptane, octane, nonane, decane, undecane, dodecane, isododecane, menthane, limonene, toluene, xylene, mesitylene, cumene, MIBK (methyl isobutyl ketone), butyl acetate, diisobutyl ketone, 2-octanone, 2-nonanone, and 5-nonanone. These solvents can be used alone or in combination of two or more.

When the adhesive composition used in the present invention contains a solvent, the content of the solvent is set appropriately taking into consideration the desired viscosity of the composition, the coating method to be used, the thickness of the film to be produced, etc., but is generally in the range of approximately 10 to 90% by mass of the total adhesive composition.

The viscosity of the adhesive composition used in the present invention is not particularly limited, but is usually 500 to 20,000 mPa·s, and preferably 1,000 to 5,000 mPa·s at 25° C. The viscosity of the adhesive composition used in the present invention can be adjusted by changing the types of solvents used, their ratios, the concentrations of the film constituent components, etc., taking into consideration various factors such as the coating method used and the desired film thickness.
In the present invention, the film constituent components refer to components other than the solvent contained in the composition.

As a method for producing the adhesive composition, for example, taking the above-mentioned <<First Embodiment>> as an example, the adhesive composition can be produced by mixing component (A) and, if used, component (B) and/or a solvent.
The order of mixing is not particularly limited, and examples of methods by which the adhesive composition of the present invention can be produced easily and with good reproducibility include, but are not limited to, a method of dissolving component (A) and component (B) in a solvent, or a method of dissolving a portion of component (A) and a portion of component (B) in a solvent and the remaining portion in a solvent, and then mixing the resulting solutions. When preparing the adhesive composition, heating may be performed as appropriate within a range that does not cause decomposition or deterioration of the components.
In the present invention, for the purpose of removing foreign matter, the adhesive composition may be filtered using a filter or the like during the production process or after all of the components have been mixed.

The method for forming an adhesive layer from the adhesive composition will be described in detail below in the section (Method for manufacturing a laminate).

<Photoresponsive peeling layer>
A photoresponsive release layer is interposed between the supporting substrate and the adhesive layer.
A photoresponsive release layer contacts the adhesive layer.
The photoresponsive release layer is preferably in contact with the supporting substrate.

The photoresponsive release layer is formed from a release agent composition containing a compound having an azobenzene skeleton.

<<Removal Agent Composition>>
The stripping composition contains a compound having an azobenzene skeleton.
The release agent composition may contain, in addition to the compound having an azobenzene skeleton, other components such as a solvent, for example, to improve the coating properties.

<<<Compounds with an azobenzene skeleton>>>
A preferred embodiment of the compound having an azobenzene skeleton is a compound containing a group represented by the following formula (1).

(In the formula, m is an integer of 0 to 20, and l is an integer of 1 to 20.)

A more preferred embodiment of a compound containing a group represented by formula (1) below is a compound containing a repeating unit represented by formula (2) below.

(In the formula, m is an integer of 0 to 20, l is an integer of 1 to 20, and R is a hydrogen atom or a methyl group.)

The compound having an azobenzene skeleton used in the present invention may be, for example, a homopolymer consisting of only such repeating units, or a copolymer containing such repeating units, as long as it contains a compound containing a repeating unit represented by formula (2) above. In other words, as long as the effects of the present invention are not impaired, copolymers that are copolymers with other comonomers can also be used.

A more preferred embodiment of a compound containing a repeating unit represented by formula (2) above is a polymer represented by formula (3) below.

(In the formula, m is an integer of 0 to 20, l is an integer of 1 to 20, and n is an integer of 5 or more.)

A more preferred embodiment of the polymer represented by formula (3) above is, for example, a polymer represented by formula (4) below.

(In the formula, l is an integer of 1 to 20, and n is an integer of 5 or more.)
In the present invention, it is more preferable to form the release layer using a release agent composition containing the polymer represented by the above formula (4).

More specifically, examples of polymers represented by formula (4) above include polymers represented by formula (4a) below.

The polymer represented by formula (4a) above can be synthesized from a monomer represented by formula (m3) below. Furthermore, this monomer represented by formula (m3) can be obtained, for example, by using 4-(phenylazo)phenol represented by formula (m1) below to produce 8-[4-(2-phenyldiazenyl)phenoxy]-1-octanol represented by formula (m2) below. The synthesis of the polymer represented by formula (4a) is described in detail in the examples below.

The release agent composition used in the present invention is in a non-fluid state during adhesion, but softens when irradiated with ultraviolet light, resulting in a decrease in adhesive strength.
As a result, the release layer made of the release agent composition functions as an adhesive layer that can bond the semiconductor substrate and the support substrate during processing such as thinning of the semiconductor substrate, and after processing of the semiconductor substrate, functions as a release layer that can be easily peeled off by irradiation with ultraviolet light.

The release agent composition used in the present invention can control the fluidity of the release layer by irradiation with ultraviolet light, and the principle of liquefaction and solidification of the release layer by ultraviolet light is thought to be due to a change in the molecular shape of a compound having an azobenzene skeleton. Compounds having an azobenzene skeleton undergo photoisomerization between trans and cis isomers. As shown in the following formula, in this change in unsubstituted azobenzene, the cis isomer becomes the main component when irradiated with ultraviolet light, and the trans isomer becomes the main component when irradiated with visible light or heated.
In the present invention, the ultraviolet light and visible light used to control the fluidity of the release layer are preferably ultraviolet light having a wavelength of 300 to 400 nm and visible light having a wavelength of 400 to 600 nm.

Increasing the molecular weight of a compound containing a group represented by the above formula (1), for example, a polymer represented by the above formula (3), has the effect of increasing adhesive strength, but may result in a decrease in fluidity upon photo-liquefaction, resulting in a decrease in desorption performance.
Therefore, the weight-average molecular weight of a compound containing a group represented by formula (1), for example, a polymer represented by formula (3), is preferably 1,000 or more, more preferably 3,000 or more, in terms of standard polystyrene, and is preferably 100,000 or less, more preferably 50,000 or less, from the viewpoint of ensuring the solubility of the compound in a solvent, etc. The weight-average molecular weight of the polymer can be measured, for example, under the following conditions.
Apparatus: HLC-8320GPC manufactured by Tosoh Corporation
GPC column: TSKgel Super-Multipore HZ-N (2 columns) manufactured by Tosoh Corporation
Column temperature: 40°C
Flow rate (flow rate): 0.35 mL/min Eluent (elution solvent): tetrahydrofuran Standard sample: polystyrene (manufactured by Showa Denko K.K.)

<<<Other ingredients>>>
The stripping composition used in the present invention usually contains a solvent.
The solvent can be appropriately selected depending on the purpose, and examples thereof include organic solvents such as mesitylene, anisole, cyclohexanone, and N-methyl-2-pyrrolidone. However, the solvent is not particularly limited as long as it dissolves the compound having an azobenzene skeleton.
Furthermore, for the purpose of adjusting the liquid properties such as viscosity and surface tension, a solvent that does not dissolve the compound having an azobenzene skeleton may be used together with a solvent that dissolves the compound having an azobenzene skeleton.
The solvents can be used alone or in combination of two or more.

When the release agent composition used in the present invention contains a solvent, the content of the solvent is appropriately set taking into consideration the viscosity of the desired composition, the coating method to be used, the thickness of the film to be formed, the molecular weight of the compound having an azobenzene skeleton, etc., but is in the range of about 50 to 95 mass % with respect to the entire release agent composition.
That is, the lower limit of the concentration of the film-constituting components in the stripper composition is usually about 5 mass % from the viewpoint of preparing a composition that can reproducibly give a film of a desired sufficient thickness to the entire composition, and the upper limit thereof is usually about 50 mass % from the viewpoint of reproducibly preparing a highly uniform composition in which the film-constituting components are dissolved.

<Characteristics of the laminate>
The thickness of the adhesive layer provided in the laminate of the present invention is usually 20 μm or more, preferably 30 μm or more, more preferably 40 μm or more, from the viewpoint of obtaining a good effect of suppressing bump deformation, ensuring the thickness of the entire laminate and improving impact resistance and handleability during semiconductor substrate processing, etc., and is usually 120 μm or less, preferably 100 μm or less, from the viewpoint of ease of film formation, avoiding non-uniformity due to thick films, etc. Note that, when attempting to obtain a bump deformation suppression effect, it is necessary to form the adhesive layer so that its thickness is greater than the height of the bump.
The thickness of the photoresponsive peeling layer provided in the laminate of the present invention is not particularly limited, but from the viewpoint of reproducibly obtaining good peeling properties by ultraviolet light irradiation, it is usually 0.1 μm or more, preferably 0.5 μm or more, and from the viewpoint of ease of film formation and avoiding non-uniformity due to thick films, it is usually 5 μm or less, preferably 4 μm or less, more preferably 3 μm or less.
Therefore, the total thickness of the adhesive layer and the release layer in the laminate of the present invention is usually 20.1 μm or more.
When thinning a wafer, for example, a grinding stone is rotated at high speed to grind the wafer. In this case, if the thickness of the adhesive layer and the release layer is equal to or greater than the above-mentioned lower limit, the problem of the wafer cracking due to the impact when grinding with the grinding stone can be effectively prevented.
Furthermore, if delamination or air bubbles (voids) occur between or within layers in the laminate, unevenness in the adhesive layer thickness occurs, and cavities form around structures (bumps) on the semiconductor substrate. If the adhesive layer has uneven thickness, this is directly reflected in the thickness of the thinned device when the wafer is thinned, preventing good thinning. Furthermore, if cavities form around the bumps, problems with bump deformation occur. Therefore, to prevent these problems from occurring, a certain thickness must be ensured between the semiconductor substrate and the support substrate in the laminate. If the thickness of the adhesive layer and the total thickness of the adhesive layer and the release layer are equal to or greater than the above-mentioned lower limit, the occurrence of delamination and voids can be effectively prevented.

An example of the laminate will be described below with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of an example of a laminate.
In FIG. 1, an example will be described in which a semiconductor substrate with bumps is used as the semiconductor substrate.
The laminate in FIG. 1 includes a semiconductor substrate 1 having bumps 1a, an adhesive layer 2, a release layer 3 (a photoresponsive release layer), and a support substrate 4 in this order.
The bumps 1 a of the semiconductor substrate 1 are disposed on the support substrate 4 side.
The adhesive layer 2 is interposed between the semiconductor substrate 1 and the support substrate 4. The adhesive layer 2 is in contact with the semiconductor substrate 1. The adhesive layer 2 also covers the bumps 1a.
The photoresponsive release layer 3 is interposed between the adhesive layer 2 and the support substrate 4. The photoresponsive release layer 3 is in contact with the adhesive layer 2 and the support substrate 4.

The laminate of the present invention can be suitably produced, for example, by the following method for producing the laminate of the present invention.

(Method for manufacturing laminate)
The method for producing the laminate of the present invention includes an adhesive coating layer forming step, an adhesive layer forming step, and a release layer forming step, and may further include other steps such as a lamination step, if necessary.

<Adhesive Coating Layer Forming Step>
The adhesive coating layer forming step is a step of forming an adhesive coating layer by applying an adhesive composition onto a semiconductor substrate.
In this way, an adhesive coating layer is formed on the semiconductor substrate.

The coating method is not particularly limited, but is usually a spin coating method. Alternatively, a method may be employed in which a coating film is formed separately by a spin coating method or the like, and the sheet-like coating film is attached as an adhesive coating layer.
The thickness of the adhesive coating layer is determined appropriately taking into consideration the thickness of the adhesive layer in the laminate, etc.
For reasons such as the adhesive composition containing a solvent, the applied adhesive composition may be heated in order to dry the coating film of the applied adhesive composition.
The heating temperature of the applied adhesive composition cannot be generally specified because it varies depending on the type and amount of adhesive components contained in the adhesive composition, whether or not a solvent is contained, the boiling point of the solvent used, the desired thickness of the adhesive layer, and the like, but is typically 80 to 150°C, and the heating time is typically 30 seconds to 5 minutes.
Heating can be carried out using a hot plate, an oven, or the like.

<Adhesive layer formation process>
In the adhesive layer forming step, the adhesive coating layer is heated to cure the adhesive composition and form an adhesive layer.
The heating temperature and time are not particularly limited as long as the temperature and time are such that the adhesive coating layer is converted into an adhesive layer.
The heating temperature is preferably 120°C or higher, more preferably 150°C or higher, from the viewpoint of realizing a sufficient curing rate, and is preferably 250°C or lower, more preferably 180 to 200°C, from the viewpoint of preventing deterioration of each layer (including the support substrate and semiconductor substrate) constituting the laminate.
The heating time is preferably 1 minute or more, more preferably 5 minutes or more, from the viewpoint of achieving suitable bonding of each layer (including the support substrate and semiconductor substrate) constituting the laminate, and is preferably 180 minutes or less, more preferably 120 minutes or less, from the viewpoint of suppressing or avoiding adverse effects on each layer due to excessive heating. Further preferably, it is 1 to 20 minutes, from the viewpoint of substrate processing efficiency.
Heating can be carried out using a hot plate, an oven, or the like.

<Release layer forming step>
The release layer forming step is a step in which a release agent composition is applied onto a supporting substrate to obtain a release agent coated layer, and the release agent coated layer is heated to form a release layer.
In this way, a release layer is formed on the support substrate.

The coating method is not particularly limited, and the same coating methods as those described in the above section <Adhesive Coating Layer Forming Step> can be used.
The thickness of the release agent coating layer is appropriately determined taking into consideration the thickness of the photoresponsive release layer in the laminate, etc.
The release layer can be formed by heating the release agent coated layer and removing the solvent.
The heating temperature of the applied release agent composition cannot be generally specified because it varies depending on the type and amount of the compound having an azobenzene skeleton, whether or not a solvent is included, the boiling point of the solvent used, the desired thickness of the release layer, etc., but is usually 100 to 250° C., and the heating time is usually 30 seconds to 5 minutes. For example, a release layer can be formed by heating the release agent coating layer at 200° C. for 1 minute.
Heating can be carried out using a hot plate, an oven, or the like.

<Specific embodiment of the method for producing the laminate>
As a preferred embodiment of the method for producing the laminate, for example, the following production method can be mentioned.
1) A semiconductor substrate having an adhesive coating layer formed thereon and a support substrate having a release layer formed thereon are prepared, and 2) the two substrates (semiconductor substrate, support substrate) are arranged so as to sandwich the release layer and the adhesive coating layer, and then a heat treatment is performed.
The adhesive coating layer is converted into an adhesive layer by heating, thereby obtaining a laminate in which the semiconductor substrate, adhesive layer, release layer, and support substrate are laminated in this order.

<Lamination process>
After two substrates (semiconductor substrate, support substrate) are arranged so as to sandwich the release layer and the adhesive coating layer, a heat treatment is performed. When these two substrates are arranged, it is preferable to perform a bonding step to ensure sufficient bonding between the semiconductor substrate and the support substrate.
The bonding step is not particularly limited as long as it allows the substrate and the layer to be bonded together and does not damage the substrate or the layer, but is typically a step in which a load is applied in the thickness direction of the support substrate and the semiconductor substrate, and more preferably a step in which a load is applied in the thickness direction of the support substrate and the semiconductor substrate under reduced pressure.
The load is not particularly limited as long as it allows the substrate and layer to be bonded together and does not damage the substrate or layer, but is, for example, 10 to 1,000 N.
The degree of reduced pressure is not particularly limited as long as it allows the substrate and layer to be bonded together and does not damage the substrate or layer, but is, for example, 10 to 10,000 Pa.

(Method for manufacturing semiconductor substrate)
The laminate of the present invention is used for temporary bonding in order to process a semiconductor substrate, and is used in applications in which the support substrate and the semiconductor substrate are separated after processing the semiconductor substrate in the laminate.
The method for manufacturing a semiconductor substrate of the present invention includes at least a processing step in which a semiconductor substrate is processed, and a peeling step in which the processed semiconductor substrate is separated from the support substrate, and may further include other steps such as a removal step as necessary.

<Processing process>
The processing step is not particularly limited as long as it is a step in which the semiconductor substrate in the laminate of the present invention is processed, and includes, for example, a polishing process, a through electrode formation process, and the like.
For example, in various processing steps, processing may be performed under high temperature and high pressure, but the laminate of the present invention can effectively prevent bump deformation on a semiconductor substrate even when processed under high temperature (e.g., 250 to 350°C) and high pressure.

<<Polishing process>>
The polishing process is not particularly limited as long as it is a process for polishing the surface of the semiconductor substrate opposite to the surface on which the bumps are present, thereby thinning the semiconductor substrate. For example, physical polishing using an abrasive or a grinding stone may be used.
The polishing process can be carried out using a general polishing device used for polishing semiconductor substrates.
The polishing process reduces the thickness of the semiconductor substrate, resulting in a semiconductor substrate thinned to a desired thickness. The thickness of the thinned semiconductor substrate is not particularly limited, but may be, for example, 10 to 300 μm, or 30 to 100 μm.

<<Through electrode formation process>>
In some cases, through electrodes are formed in the polished semiconductor substrate to realize electrical continuity between the thinned semiconductor substrates when a plurality of thinned semiconductor substrates are stacked.
Therefore, the method for manufacturing a semiconductor substrate may include a through electrode forming process for forming a through electrode in the polished semiconductor substrate after the polishing process and before the peeling step.
The method for forming a through electrode in a semiconductor substrate is not particularly limited, but may include, for example, forming a through hole and filling the formed through hole with a conductive material.
The through holes are formed by, for example, photolithography.
The through holes are filled with a conductive material by, for example, plating techniques.

<Peeling process>
The peeling step is a step in which the processed semiconductor substrate is separated from the support substrate after the processing step.
Specifically, the laminate is irradiated with ultraviolet light (for example, from the support substrate side of the laminate) to soften the release layer and reduce its adhesive strength, thereby allowing the release layer to be peeled off and separating the release layer from the adhesive layer.
In the present invention, a thermosetting adhesive layer is used, and the combination of the thermosetting adhesive layer and the photoresponsive release layer makes it possible to easily separate the release layer from the thermosetting adhesive layer without applying excessive force to the support substrate or semiconductor substrate during peeling.
This allows the support substrate and the semiconductor substrate to be separated.
Here, it is preferable to use ultraviolet light having a wavelength of 300 to 400 nm.
The exposure dose varies depending on the type of light source, the thickness of the laminate and the release layer, etc., but is preferably 0.1 to 200 J/cm ² , and more preferably 0.5 to 100 J/cm ² .
Usually, the release layer is peeled off after the laminate of the present invention is produced and subjected to predetermined processing and the like.
The ultraviolet light may be laser light or non-laser light such as that from an ultraviolet lamp.

<Removal process>
The removal step is not particularly limited as long as it is a step of removing the adhesive layer remaining on the semiconductor substrate after the peeling step, but examples thereof include a method of dissolving and removing the adhesive layer using a cleaning solution. Furthermore, removal using a removal tape or the like may be combined with dissolving and removing the adhesive layer.
When using the cleaning composition, for example, the semiconductor substrate with the adhesive layer can be immersed in the cleaning composition or sprayed with the cleaning composition.

A suitable example of the cleaning composition used in the present invention is a cleaning composition containing a quaternary ammonium salt and a solvent.
The quaternary ammonium salt is composed of a quaternary ammonium cation and an anion, and is not particularly limited as long as it is used for this type of application.
Such quaternary ammonium cations typically include tetra(hydrocarbon)ammonium cations, while their counter anions include, but are not limited to, hydroxide ion (OH ⁻ ), halogen ions such as fluoride ion (F ⁻ ), chloride ion (Cl ⁻ ), bromide ion (Br ⁻ ), and iodide ion (I ⁻ ), tetrafluoroborate ion (BF ₄ ⁻ ), and hexafluorophosphate ion (PF ₆ ⁻ ).

In the present invention, the quaternary ammonium salt is preferably a halogen-containing quaternary ammonium salt, more preferably a fluorine-containing quaternary ammonium salt.
In the quaternary ammonium salt, the halogen atom may be contained in either the cation or the anion, but is preferably contained in the anion.

In a preferred embodiment, the fluorine-containing quaternary ammonium salt is a tetra(hydrocarbon)ammonium fluoride.
Specific examples of the hydrocarbon group in tetra(hydrocarbon)ammonium fluoride include alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, and aryl groups having 6 to 20 carbon atoms.
In a more preferred embodiment, the tetra(hydrocarbon)ammonium fluoride comprises a tetraalkylammonium fluoride.
Specific examples of tetraalkylammonium fluorides include, but are not limited to, tetramethylammonium fluoride, tetraethylammonium fluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride (also called tetrabutylammonium fluoride), etc. Among these, tetrabutylammonium fluoride is preferred.

An example of an embodiment in which the production of a laminate and the production of a thinned wafer are carried out in series will be described with reference to FIGS. 2A to 2F.
2A to 2F are diagrams illustrating one embodiment of manufacturing a stack and a thinned wafer.
2, as in FIG. 1, an example will be described in which a semiconductor substrate with bumps is used as the semiconductor substrate.
First, a wafer 1 having bumps 1a is prepared (FIG. 2A).
Next, an adhesive composition is applied by spin coating using a coating device 12 onto the surface of the wafer 1 where the bumps 1a are present, to form an adhesive coating layer 2a (FIG. 2B).
Next, a release agent composition is applied onto the support substrate 4 by spin coating using a coating device (not shown), and the formed release agent coating layer is heated (not shown) to form a release layer 3. A wafer on which an adhesive coating layer has been formed and a support substrate on which a release layer has been formed are each prepared ( FIG. 2C ).
Next, the wafer 1 on which the adhesive coating layer 2a is formed and the support substrate 4 on which the release layer 3 is formed are bonded together under reduced pressure so that the adhesive coating layer 2a and the release layer 3 are sandwiched between them. Then, a heating device (hot plate) 13 is placed on the side of the wafer 1 opposite to the side on which the bumps 1a are present, and the adhesive coating layer 2a is heated by the heating device 13 to harden the adhesive composition and convert it into an adhesive layer 2 (Figure 2D).
A laminate is obtained by the steps shown in FIGS. 2A to 2D.
Next, an example of manufacturing a thinned wafer will be described.
Next, a polishing machine (not shown) is used to polish the surface of the wafer 1 opposite to the surface on which the bumps 1a are present, thereby thinning the wafer 1 (FIG. 2E). Note that the thinned wafer 1 may be subjected to the formation of through electrodes or the like.
Next, ultraviolet light (not shown) is irradiated from the support substrate 4 side to peel the thinned wafer 1 from the support substrate 4 ( FIG. 2F ). At this time, the peeling layer, which had no fluidity before the ultraviolet light irradiation, softens due to the irradiation, reducing its adhesive strength, and the thinned wafer 1 can be peeled from the support substrate 4.
Next, the thinned wafer 1 is cleaned by using a cleaning device (not shown) to dissolve and remove the adhesive layer 2 from the thinned wafer 1 with a cleaning agent composition.
In this way, a thinned wafer 1 is obtained.

The present invention will be explained in more detail below using examples, but the present invention is not limited to the following examples. The equipment used is as follows:

(1) Mixer: Thinky Corporation, Planetary Planetary Mixer ARE-500
(2) Viscometer: Rotational viscometer TVE-22H manufactured by Toki Sangyo Co., Ltd.
(3) Vacuum bonding device: Manual bonder manufactured by SUSS Microtec Co., Ltd. (4) UV irradiation device: UVI-MA manufactured by Omiya Kogyo Co., Ltd.
(5) Measurement of molecular weight of polymer: The molecular weight of the azobenzene-containing acrylate polymer was measured under the following conditions.
Apparatus: HLC-8320GPC manufactured by Tosoh Corporation
GPC column: TSKgel Super-Multipore HZ-N (2 columns) manufactured by Tosoh Corporation
Column temperature: 40°C
Flow rate (flow rate): 0.35 mL/min Eluent (elution solvent): tetrahydrofuran Standard sample: polystyrene (manufactured by Showa Denko K.K.)

[1] Preparation of adhesive composition [Preparation Example 1]
A 600 mL stirring vessel dedicated to the planetary centrifugal mixer was charged with 150 g of a base polymer (manufactured by Wacker Chemie) consisting of a vinyl group-containing linear polydimethylsiloxane and a vinyl group-containing MQ resin having a viscosity of 200 mPa s as the component (a1), 15.81 g of a SiH group-containing linear polydimethylsiloxane (manufactured by Wacker Chemie) having a viscosity of 100 mPa s as the component (a2), and 0.17 g of 1-ethynyl-1-cyclohexanol (manufactured by Wacker Chemie) as the component (A3), and the mixture was stirred for 5 minutes with the planetary centrifugal mixer to obtain mixture (I).
In a 50 mL screw tube, 0.33 g of a platinum catalyst (manufactured by Wacker Chemie Co., Ltd.) as the aforementioned component (A2) and 9.98 g of a vinyl group-containing linear polydimethylsiloxane (manufactured by Wacker Chemie Co., Ltd.) having a viscosity of 1000 mPa s as the aforementioned component (a1) were stirred for 5 minutes using a planetary centrifugal mixer to obtain a mixture (II).
0.52 g of the obtained mixture (II) was added to the mixture (I), and the mixture was stirred for 5 minutes with a planetary centrifugal mixer to obtain a mixture (III).
The resulting mixture (III) was filtered through a 300-mesh nylon filter to obtain an adhesive composition. The viscosity of the adhesive composition measured using a rotational viscometer was 9900 mPa·s.

Comparative Preparation Example 1
To a 50 mL vial were added 5.00 g of a thermoplastic resin, Septon 4033 (manufactured by Kuraray Co., Ltd.), which is a hydrogenated styrene-isoprene-butadiene copolymer, and 20.00 g of mesitylene, and the mixture was stirred for 10 minutes with a stirrer, and the resulting mixture was used as an adhesive composition.

[2] Preparation of azobenzene-containing acrylate polymer (polymer) [Preparation Example 2-1]
19.84 g of 4-(phenylazo)phenol, 13.90 g of potassium carbonate, and 100 mL of N,N-dimethylformamide as a solvent were placed in a flask and stirred at 40°C for 30 minutes, and then 18.12 g of 8-chloro-1-normal octanol, 3.46 g of potassium iodide, and 11 mL of N,N-dimethylformamide were added, and the mixture was stirred at 110°C for 24 hours.
The reaction mixture was cooled to room temperature, quenched with 1 mol/L hydrochloric acid, and extracted with dichloromethane. The dichloromethane-containing extract was separated with a saturated aqueous sodium chloride solution, and then sodium sulfate was added for dehydration, and the sodium sulfate was filtered off. The solvent in the resulting solution was removed using an evaporator to obtain an orange solid. The resulting solid was dissolved in ethanol at 75°C and cooled to room temperature to recrystallize the target product. The resulting solid was filtered and dried to obtain 20.27 g of 8-[4-(2-phenyldiazenyl)phenoxy]-1-octanol.

[Preparation Example 2-2]
A flask was charged with 16.31 g of 8-[4-(2-phenyldiazenyl)phenoxy]-1-octanol obtained in Preparation Example 2-1, 5.19 g of triethylamine, and 150 mL of dichloromethane as a solvent, and the flask was placed in an ice bath and stirred. A solution containing 5.51 g of acryloyl chloride and 50 mL of dichloromethane was added dropwise to the flask over 30 minutes. The mixture was then stirred at room temperature for 24 hours. The reaction mixture was quenched with 1 mol/L hydrochloric acid and subjected to separation and extraction with ethanol and dichloromethane. The extract was separated with a saturated aqueous sodium chloride solution, dehydrated by adding sodium sulfate, and the sodium sulfate was filtered off. The solvent in the resulting solution was removed by evaporation to obtain an orange solid. The resulting solid was dissolved in ethanol at 70°C and cooled to room temperature to recrystallize the target product. The resulting solid was filtered off and dried to obtain 14.01 g of 8-[4-(2-phenyldiazenyl)phenoxy]-1-octyl-2-propenoate (azobenzene-containing acrylate).

[Preparation Example 2-3]
11.39 g of 8-[4-(2-phenyldiazenyl)phenoxy]-1-octyl-2-propenoate (azobenzene-containing acrylate) obtained in Preparation Example 2-2, 40 mL of anisole as a solvent, and 0.05 g of 2,2'-azobisisobutyronitrile as a radical polymerization initiator were placed in a flask and stirred. The resulting mixture was then stirred at 80°C for 48 hours to allow the polymerization reaction to proceed. After cooling the reaction mixture to room temperature, the resulting reaction mixture was added dropwise to ethanol to reprecipitate the reactant. The resulting solid was filtered and dried to obtain the desired azobenzene-containing acrylate polymer (Mw = 6,337, Mw/Mn = 1.31).

The following schematic diagram shows the synthesis process for azobenzene-containing acrylate polymers according to Preparation Examples 2-1 to 2-3.

[3] Preparation of Stripping Composition [Preparation Example 3]
A release agent composition was prepared by mixing mesitylene so that the final concentration of the azobenzene-containing acrylate polymer obtained in Preparation Example 2-3 was 10% by mass.

[4] Production of laminate [Production Example 1]
The release agent composition obtained in Preparation Example 3 was spin-coated onto a 100 mm glass wafer so that the film thickness in the final laminate would be about 1.0 μm, and the wafer was heated at 200° C. for 1 minute to form a release layer on the glass wafer serving as a supporting substrate.
On the other hand, the adhesive composition obtained in Preparation Example 1 was spin-coated onto a 100 mm silicon wafer so that the film thickness in the final laminate would be approximately 65 μm, thereby forming an adhesive coating layer on the silicon wafer, which is a semiconductor substrate.
Then, using a bonding device, the glass wafer and the silicon wafer were bonded together so as to sandwich the release layer and the adhesive coating layer, and then post-heat treatment was carried out at 200° C. for 10 minutes to produce a laminate. The bonding was carried out at a temperature of 23° C. and a reduced pressure of 1,500 Pa.

The resulting laminate was visually inspected from the glass wafer (support substrate) side to check for the presence of voids. No voids were found.

[Comparative Production Example 1]
The release agent composition obtained in Preparation Example 3 was spin-coated onto a 100 mm glass wafer so that the film thickness in the final laminate would be about 1.0 μm, and the wafer was heated at 200° C. for 1 minute to form a release layer on the glass wafer serving as a supporting substrate.
On the other hand, the adhesive composition obtained in Comparative Preparation Example 1 was spin-coated onto a 100 mm silicon wafer so that the film thickness in the final laminate would be approximately 30 μm, forming an adhesive coating layer on the silicon wafer, which is a semiconductor substrate.
Then, using a bonding device, the glass wafer and the silicon wafer were bonded together so as to sandwich the release layer and the adhesive coating layer, and then post-heat treatment was carried out at 200° C. for 10 minutes to produce a laminate. The bonding was carried out at a temperature of 23° C. and a reduced pressure of 1,500 Pa.

[5] Confirmation of peelability by irradiation with 365 nm UV light (confirmation of peeling by full-surface irradiation)
[Example 1]
The entire surface of the peelable layer of the laminate obtained in Production Example 1 was irradiated with UV light from the glass wafer side using a UV irradiation device. Then, a cutter blade was inserted between the glass wafer and the silicon wafer to check whether the glass wafer could be peeled off. The UV output was 36 J/ ^cm² .
As a result, the glass wafer (carrier side) could be easily peeled off manually.

[Comparative Example 1]
The entire surface of the release layer of the laminate obtained in Comparative Production Example 1 was irradiated with UV light from the glass wafer side using a UV irradiation device. Then, a cutter blade was inserted between the glass wafer and the silicon wafer to check whether the glass wafer could be peeled off. The UV output was 36 J/ ^cm² .
As a result, even when force was applied, it was difficult to manually peel off the glass wafer (carrier side), and when more force was applied, the glass wafer broke.

As shown in the examples, the laminate obtained in Production Example 1 is a laminate that allows the semiconductor substrate and the support substrate to be easily separated without causing cutting or deformation of the semiconductor substrate or the support substrate. Furthermore, the laminate obtained in Production Example 1 is a laminate that can suppress bump deformation.

The present invention provides a laminate that allows the semiconductor substrate and the support substrate to be easily separated after processing without causing cutting or deformation of the semiconductor substrate or the support substrate, and also suppresses deformation of the bumps, making it useful for the manufacture of processed semiconductor substrates.

REFERENCE SIGNS LIST 1 wafer 1a bump 2 adhesive layer 2a adhesive coating layer 3 peeling layer 4 support substrate 12 coating device 13 heating device

Claims (7)

A laminate comprising a semiconductor substrate, a support substrate, an adhesive layer formed so as to be in contact with the semiconductor substrate, and a photoresponsive release layer formed between the adhesive layer and the support substrate so as to be in contact with the adhesive layer,
the adhesive layer is a thermosetting adhesive layer,
the photoresponsive release layer is formed from a release agent composition containing a compound having an azobenzene skeleton;
The thickness of the adhesive layer is 20 μm or more and 120 μm or less,
the adhesive composition for forming the adhesive layer contains component (A), which is an adhesive component that cures by a hydrosilylation reaction;
The film thickness of the release layer is 0.1 μm or more and 5 μm or less,
The compound having an azobenzene skeleton is a polymer represented by the following formula (4) :
(In the formula, l is an integer of 1 to 20, and n is an integer of 5 or more.) The component (A) is
A polyorganosiloxane (a1) having an alkenyl group having 2 to 40 carbon atoms bonded to a silicon atom;
The laminate according to claim 1 , comprising a polyorganosiloxane (a2) having an Si—H group . The adhesive composition
The component (A) according to claim 2;
a platinum group metal catalyst (A2);
The laminate according to claim 2 , comprising: A step of processing the semiconductor substrate in the laminate according to any one of claims 1 to 3 ;
peeling the photoresponsive peeling layer by irradiation with ultraviolet light, thereby separating the support substrate from the processed semiconductor substrate;
A method for manufacturing a semiconductor substrate, comprising: The method for manufacturing a semiconductor substrate according to claim 4 , wherein the processing step includes a process of polishing the semiconductor substrate to thin the semiconductor substrate. A method for producing a laminate according to any one of claims 1 to 3 , comprising the steps of:
a step of applying a thermosetting adhesive composition onto the semiconductor substrate to form an adhesive coating layer;
heating the adhesive coating layer to form the adhesive layer;
A method for producing a laminate, comprising: a step of applying a thermosetting adhesive composition onto the semiconductor substrate to form an adhesive coating layer;
a step of applying the release agent composition onto the support substrate to form a release layer;
a step of bonding the semiconductor substrate with the adhesive coating layer and the support substrate with the release layer together so as to sandwich the adhesive coating layer and the release layer, and then heating the resulting bonded substrate to form the adhesive layer from the adhesive coating layer;
The method for producing the laminate according to claim 6 , comprising: