Composition, temporary fixing composition, and method for manufacturing wafer using same

Abstract

The present disclosure provides a composition in which: the peel strength XPI measured by the following measurement method (X) using a polyimide test substrate is 0.50 N / mm or less; the peel strength YPI measured by the following measurement method (Y) using a polyimide test substrate is 0.10 N / mm or more; and the ratio XPI / YPI of the peel strength XPI to the peel strength YPI is 1.5 or less. (X) The peel strength is measured by the following steps (i)-(iv): (i) the test substrate is coated with the composition to a thickness of 70 μm and a glass plate is laminated thereto, after which the composition is photocured to form a coating film; (ii) the test substrate on which the coating film has been formed is heated at 175°C for 30 minutes; (iii) the coating film is irradiated with laser light having an energy density of 920 mJ / cm2 under conditions of a wavelength of 355 nm and a frequency of 40 kHz, and then the glass plate is peeled; and (iv) a peeling tape is affixed to the coating film, the peeling strength is measured when the coating film is peeled from the test substrate under conditions of a peeling direction of 180 degrees, a peeling width of 20 mm, a peeling rate of 120 mm / min, and a temperature of 25°C, and an average value of five such measurements is taken. (Y) The peeling strength is measured without performing the step (ii) in the measurement method (X).

Description

COMPOSITION, TEMPORARY FIXING COMPOSITION, AND METHOD FOR MANUFACTURING WAFER USING THE COMPOSITION

[0001] The present invention relates to a composition, a temporary fixing composition, and a method for manufacturing a wafer using the same.

[0002] In the manufacturing process of a semiconductor device, a semiconductor substrate or the like (hereinafter simply referred to as a "wafer") is subjected to processing such as, for example, insulating film formation, circuit formation, thinning by grinding or polishing, etc. In this case, in the thinning step or the like, in order to prevent the wafer from cracking, the wafer and a supporting member such as a glass plate are bonded together via a temporary fixing composition, and after the predetermined processing step, the supporting member is sometimes peeled off from the wafer.

[0003] For example, Patent Document 1 discloses, as such a temporary fixing composition, a monofunctional (meth)acrylate, a polyfunctional (meth)acrylate, a polyisobutene homopolymer and / or a polyisobutene copolymer, each of which has an alkyl group having 18 or more carbon atoms in its side chain and a Tg of the homopolymer of −100° C. to 60° C., and a photoradical polymerization initiator.

[0004] International Publication No. 2021 / 235406

[0005] When the temporary fixing composition is peeled off from the wafer, a cured product of the temporary fixing composition may remain partially on the surface of the wafer. In addition, in the case of a wafer having a pattern made of polyimide, aluminum, or the like on its surface, the adhesiveness to the temporary fixing composition varies depending on the type of member exposed on the wafer surface, and therefore the degree of remaining cured product varies.

[0006] Further investigations have revealed that even if the type of member exposed on the wafer surface is the same, the degree to which the cured material remains varies depending on the processing process that the bonded body of the wafer and the support member bonded via the temporary fixing composition undergoes. For example, even if the type of member exposed on the wafer surface is the same, that is, polyimide, the degree to which the cured material remains varies depending on whether or not the bonded body has undergone a predetermined heat treatment as a processing process.

[0007] Incidentally, there are various types of temporary fixing compositions, including a type that is cured (bonded) by light irradiation and decomposed (peeled) by laser light irradiation, a type that is cured by heating and decomposed by laser light irradiation, and a type that is cured and decomposed by heating. Among these, the temporary fixing composition that is cured (bonded) by light irradiation and decomposed (peeled) by laser light irradiation has the advantage of being less affected by heat on the semiconductor substrate.

[0008] However, in the first type of temporary fixing composition, if the bondability by light irradiation is improved, the peelability by laser light irradiation is likely to decrease, and there is a risk that a cured product of the temporary fixing composition will remain on the bonding surface of the wafer during peeling. On the other hand, if the wafer bondability is poor, the support member will peel off during the processing step, making it difficult to prevent cracks in the wafer.

[0009] The present invention has been made in view of the above problems, and aims to solve any of the above problems. One object of the present disclosure is to provide a composition capable of forming a temporary fixing layer that is unlikely to remain on a wafer due to the effects of the processing process, a temporary fixing composition, and a wafer manufacturing method using the same. Another object of the present disclosure is to provide a composition capable of forming a temporary fixing layer that has excellent laser releasability and is unlikely to remain on a wafer, a temporary fixing composition, and a wafer manufacturing method using the same.

[0010] As a result of intensive research to achieve the above object, the present inventors have found that when a wafer is heat-treated, the adhesive strength between the temporary fixing layer and the wafer increases excessively, resulting in the temporary fixing layer remaining. Based on this finding, the present inventors have discovered that a composition that satisfies predetermined conditions for the peel strength when heat-treated and the peel strength when not heat-treated can solve at least one of the above problems, and that it is possible to provide, for example, a composition that can form a temporary fixing layer that is less likely to remain on the wafer due to the effects of the processing process, a temporary fixing composition, and a method for manufacturing a wafer using the same, thereby completing the present invention.

[0011] Furthermore, as a result of intensive research into achieving the above-mentioned object, the present inventors have found that a composition in which the hydrocarbon chain concentration and the aromatic ring concentration are within predetermined ranges can solve at least one of the above-mentioned problems, and can provide, for example, a composition that is capable of forming a temporary fixing layer that has excellent laser releasability and is unlikely to remain on a wafer, a temporary fixing composition, and a method for manufacturing a wafer using the same, and have completed the present invention.

[0012] That is, the present disclosure includes the following embodiments: [1] Peel strength X measured by the following measurement method (X) using polyimide as a test substrate. ＰＩ The peel strength Y measured by the following measurement method (Y) using polyimide as a test substrate is 0.50 N / mm or less. ＰＩ The peel strength Y is 0.10 N / mm or more. ＰＩ The peel strength X ＰＩ Ratio of X ＰＩ / Y ＰＩ (X) Peel strength is measured by the following steps (i) to (iv): (i) applying the composition to a test substrate in a thickness of 70 μm, laminating a glass plate thereto, and then photo-curing the composition to form a coating film; (ii) heating the test substrate on which the coating film has been formed at 175°C for 30 minutes; (iii) applying a light beam to the coating film at an energy density of 920 mJ / cm under conditions of a wavelength of 355 nm and a frequency of 40 kHz. ２ (iv) A peeling tape is attached to the coating film, and the peel strength is measured when peeling the coating film from the test substrate under the conditions of a peeling direction of 180 degrees, a peeling width of 20 mm, a peeling speed of 120 mm / min, and a temperature of 25°C, and the average value of five measurements is taken. (Y) In the measurement method (X), the peel strength is measured without performing the step (ii). [2] The ratio X ＰＩ / Y ＰＩ [3] The composition according to [1], wherein the peel strength X measured by the measurement method (X) using aluminum as a test substrate is 0.30 to 1.0. Ａｌ The peel strength Y measured by the measurement method (Y) using aluminum as a test substrate is 0.60 N / mm or less. ＡｌThe peel strength Y is 0.10 N / mm or more. Ａｌ The peel strength X Ａｌ Ratio of X Ａｌ / Y Ａｌ [4] The composition according to [1] or [2], wherein the ratio X is 2.0 or less. Ａｌ / Y Ａｌ [5] The composition according to [3], wherein the peel strength X is 1.0 to 2.0. Ａｌ The peel strength X ＰＩ Ratio of X ＰＩ / X Ａｌ The composition according to [3] or [4], wherein the peel strength X measured by the measurement method (X) using silicon as a test substrate is 0.10 to 0.50. Ｓｉ The peel strength Y measured by the measurement method (Y) using silicon as a test substrate is 0.50 N / mm or less. Ｓｉ The peel strength Y is 0.10 N / mm or more. Ｓｉ The peel strength X Ｓｉ Ratio of X Ｓｉ / Y Ｓｉ [7] The composition according to any one of [1] to [5], wherein the ratio X Ｓｉ / Y Ｓｉis 0.3 to 1.2. [8] The composition according to any one of [1] to [7], comprising a polymerizable compound A and a photopolymerization initiator B. [9] The composition according to [8], wherein the polymerizable compound A comprises a polymerizable compound A1 having a hydrocarbon chain with 3 or more carbon atoms, and a polymerizable compound A2 having an aromatic ring.

[10] The composition according to [9], wherein the polymerizable compound A1 comprises a (meth)acrylate having a hydrocarbon chain with 3 or more carbon atoms and a functional group equivalent of 200 g / mol or less.

[11] The composition according to [9] or

[10] , wherein the polymerizable compound A1 comprises a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms.

[12] The composition according to any one of [9] to

[11] , wherein the polymerizable compound A2 comprises a (meth)acrylate having an aromatic ring equivalent of 200 g / mol or less.

[13] The composition according to any one of [9] to

[12] , wherein the content of the polymerizable compound A1 is 50 parts by mass to 98 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compounds A.

[14] The composition according to any one of [9] to

[13] , wherein the content of the polymerizable compound A2 is 2 parts by mass to 50 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compounds A.

[15] The composition according to any one of [8] to

[14] , wherein the content of the photopolymerization initiator B is 0.01 parts by mass to 10 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compounds A.

[16] A temporary fixing composition containing the composition according to any one of [1] to

[15] .

[17] A method for manufacturing a wafer, comprising the steps of: bonding a wafer and a support member via the temporary fixing composition according to

[16] ; curing the temporary fixing composition by irradiating it with ultraviolet light to form a temporary fixing layer, and bonding the wafer and the support member via the temporary fixing layer; heat-treating the wafer; irradiating the temporary fixing layer with laser light; and peeling the support member and the wafer at the interface of the temporary fixing layer.

[18] The manufacturing method according to

[17] , further comprising the step of removing the temporary fixing layer from the wafer after the laser light irradiation.

[19] A peel strength Y measured by the following measurement method (Y) using polyimide as a test substrate. ＰＩThe peel strength X measured by the following measurement method (X) using polyimide as a test substrate against ＰＩ Ratio of X ＰＩ / Y ＰＩ (X) Peel strength is measured by the following steps (i) to (iv): (i) applying the composition to a test substrate in a thickness of 70 μm, laminating a glass plate thereto, and then photo-curing the composition to form a coating film; (ii) heating the test substrate on which the coating film has been formed at 175°C for 30 minutes; (iii) applying a light beam to the coating film at an energy density of 920 mJ / cm under conditions of a wavelength of 355 nm and a frequency of 40 kHz. ２ (iv) A peeling tape is attached to the coating film, and the coating film is peeled from the test substrate under the conditions of a peeling direction of 180 degrees, a peeling width of 20 mm, a peeling speed of 120 mm / min, and a temperature of 25°C, and the peel strength is measured and the average value of five measurements is taken. (Y) In the measurement method (X), the peel strength is measured without performing the step (ii).

[0013] [1'] A composition comprising a polymerizable compound A and a photopolymerization initiator B, wherein the concentration of hydrocarbon chains having 3 or more carbon atoms is 2.80 mmol / g or more, and the concentration of aromatic rings is 0.60 mmol / g or more. [2'] A composition having a crosslink density of 0.10 mmol / cm or more after ultraviolet light irradiation. ３or more. [3'] The composition according to [1'] or [2'], wherein the ratio of the concentration of the hydrocarbon chain having 3 or more carbon atoms to the concentration of the aromatic ring is 1.5 or more. [4'] The composition according to any one of [1'] to [3'], wherein the polymerizable compound A comprises at least one compound selected from the group consisting of a polymerizable compound A1 having a hydrocarbon chain having 3 or more carbon atoms, a polymerizable compound A2 having an aromatic ring, and a polymerizable compound A3 having a hydrocarbon chain having 3 or more carbon atoms and an aromatic ring. [5'] The composition according to [4'], wherein at least one of the polymerizable compound A1 and the polymerizable compound A3 comprises a (meth)acrylate having a functional group equivalent of 200 g / mol or less in the hydrocarbon chain having 3 or more carbon atoms. [6'] The composition according to [4'] or [5'], wherein at least one of the polymerizable compound A1 and the polymerizable compound A3 comprises a (meth)acrylate having a hydrocarbon chain having 8 or more carbon atoms. [7'] The composition according to any one of [4'] to [6'], wherein at least one of the polymerizable compound A2 and the polymerizable compound A3 contains a (meth)acrylate having an aromatic ring equivalent of 200 g / mol or less. [8'] The composition according to any one of [4'] to [7'], wherein the content of the polymerizable compound A1 is 50 parts by mass to 98 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compound A. [9'] The composition according to any one of [4'] to [8'], wherein the content of the polymerizable compound A2 is 2 parts by mass to 50 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compound A. [10'] The composition according to any one of [4'] to [9'], wherein the content of the polymerizable compound A3 is 0 parts by mass to 48 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compound A. [11'] The composition according to any one of [1'] to [10'], wherein the content of the photopolymerization initiator B is 0.01 parts by mass to 10 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compound A. [12'] The composition according to any one of [1'] to [11'], wherein the polymerizable compound A contains a monofunctional polymerizable compound and a polyfunctional polymerizable compound, and the content of the monofunctional polymerizable compound is 0.01 parts by mass to 60 parts by mass relative to 100 parts by mass of the total amount of the polyfunctional polymerizable compound.[13'] The composition according to any one of [1'] to [12'], having a viscosity at 23°C of 500 mPa·s to 10,000 mPa·s. [14'] A temporary fixing composition containing the composition according to any one of [1'] to [13']. [15'] A method for manufacturing a wafer, comprising the steps of: bonding a wafer and a support member via the temporary fixing composition according to [14']; curing the temporary fixing composition by irradiating with ultraviolet light to form a temporary fixing layer, and bonding the wafer and the support member via the temporary fixing layer; processing the wafer; irradiating the temporary fixing layer with laser light; and peeling the support member from the wafer at the interface of the temporary fixing layer. [16'] The manufacturing method according to [15'], further comprising the step of removing the temporary fixing layer from the wafer after the laser light irradiation.

[0014] According to one aspect of the present disclosure, it is possible to provide a composition capable of forming a temporary fixing layer that is less likely to remain on a wafer due to the influence of a processing process, a temporary fixing composition, and a method for manufacturing a wafer using the same.

[0015] According to one aspect of the present disclosure, it is possible to provide a composition capable of forming a temporary fixing layer that has excellent laser releasability and is unlikely to remain on a wafer, a temporary fixing composition, and a method for manufacturing a wafer using the same.

[0016] 1 is an example of a flowchart showing a wafer manufacturing method according to an embodiment of the present invention in terms of a surface (front) in the thickness direction of the wafer. 2 is another example of a flowchart showing a wafer manufacturing method according to an embodiment of the present invention in terms of a surface (front) in the thickness direction of the wafer.

[0017] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. However, the present invention is not limited to the following embodiment, and various modifications are possible without departing from the gist of the present invention.

[0018] In this specification, for example, when a numerical range is expressed as "1 to 100," it is intended to include both the lower limit value "1" and the upper limit value "100." The same applies to other numerical ranges.

[0019] [First embodiment] 1. Composition and temporary fixing composition The composition of this embodiment has a peel strength X 1 measured by the following measurement method (X) using polyimide as a test substrate. ＰＩ The peel strength Y measured by the following measurement method (Y) using polyimide as a test substrate is 0.50 N / mm or less. ＰＩ is 0.10 N / mm or more, and the peel strength Y ＰＩ Peel strength X against ＰＩ Ratio of X ＰＩ / Y ＰＩ (X) The peel strength is measured by the following steps (i) to (iv): (i) a test substrate is coated with a temporary fixing composition to a thickness of 70 μm, and a glass plate is attached to the test substrate, and the temporary fixing composition is then photocured to form a coating film; (ii) the test substrate on which the coating film has been formed is heated at 175°C for 30 minutes; (iii) the coating film is exposed to light at an energy density of 920 mJ / cm under conditions of a wavelength of 355 nm and a frequency of 40 kHz. ２ (iv) A peeling tape is attached to the coating film, and the peel strength is measured when peeling the coating film from the test substrate under conditions of a peeling direction of 180 degrees, a peeling width of 20 mm, a peeling speed of 120 mm / min, and a temperature of 25°C, and the average value of five measurements is taken. (Y) In measurement method (X), the peel strength is measured without performing step (ii). The composition of this embodiment is preferably a temporary fixing composition. Hereinafter, the composition will be described using a temporary fixing composition as an example, but its use is not limited to temporary fixing. The temporary fixing composition of this embodiment may contain the composition of this embodiment, or may consist solely of the composition of this embodiment.

[0020] Before describing the temporary fixing composition of this embodiment, first, a description will be given of a mode of use of the temporary fixing composition. Fig. 1 shows an example of a flowchart illustrating the method for manufacturing a wafer of this embodiment in terms of the thickness direction of the wafer.

[0021] First, in step S0 of FIG. 1 , a temporary fixing composition 10 is applied to one surface of a wafer W by spin coating or the like, and the wafer W and a support member 20 are bonded together via the temporary fixing composition 10. Then, in step S1, the temporary fixing composition 10 is irradiated with light such as ultraviolet light via the support member 20. In step S1, the temporary fixing composition 10 is irradiated with light, whereby a polymerization reaction of the polymerizable compound A is initiated by the photopolymerization initiator B in the temporary fixing composition 10, and a photocured temporary fixing layer 11 is formed. As a result, the wafer W and the support member 20 are bonded together via the temporary fixing layer 11. The support member 20 is not particularly limited, but examples thereof include a light-transmitting substrate such as glass. The surface of the wafer W to which the temporary fixing composition 10 is applied may be an element-forming surface.

[0022] Here, the element forming surface of the wafer W may have exposed thereon a semiconductor material surface such as silicon, which is the base material of the wafer, or may have exposed thereon an electrode material surface such as aluminum, or an insulating material surface such as polyimide.

[0023] As described above, in this specification, the term "temporary fixing composition" refers to a composition used to temporarily fix the wafer W to the support member 20. In addition, in this specification, a layer of a cured product obtained by irradiating the temporary fixing composition with light is referred to as a "temporary fixing layer."

[0024] Next, in step S2, a desired processing process is performed on the wafer W reinforced by bonding to the support member 20. In the example of Fig. 1, a step of performing a heat treatment such as annealing on the wafer W is shown, but in addition to this, the back surface of the wafer W may be ground with a grinder to thin the wafer W.

[0025] Then, in step S3, the temporary fixing layer 11 is irradiated with laser light via the support member 20. In step S3, by irradiating the temporary fixing layer 11 with laser light, the polymer of the polymerizable compound in the temporary fixing layer 11 is at least partially decomposed, and the bonding strength between the temporary fixing layer 11 and the support member 20 is reduced, so that in step S4, the support member 20 can be peeled off from the temporary fixing layer 11.

[0026] Finally, in step S5, tape 30 is attached to the temporary fixing layer 11 after the laser light irradiation, and is peeled off in the direction of the arrow, thereby peeling off the temporary fixing layer 11 from the wafer W. At this time, the peel strength of the temporary fixing layer 11 with respect to the element-forming surface of the wafer W varies depending on the content of the processing process in step S2, and a cured product remains due to the influence of the processing process. Therefore, it is expected that a certain temporary fixing composition cannot be used in a wide range of processing processes.

[0027] In contrast, in this embodiment, in a peel strength test using polyimide as a test substrate and having steps (i) to (iv) corresponding to the above steps S0 to S5, the peel strength X ＰＩ and the peel strength Y when not subjected to the heat treatment step (ii) ＰＩ By specifying the ratio of the two, it is possible to form a temporary fixing layer that is less likely to remain due to the effects of the processing process. The details of the peel strength test will be described later, but steps S0 and S1 correspond to process (i), step S2 corresponds to process (ii), steps S3 and S4 correspond to process (iii), and step S5 corresponds to process (iv).

[0028] The temporary fixing composition of this embodiment will be described in detail below.

[0029] 1.1. Peel strength The peel strength X obtained by the measurement method (X) in which step (ii) of heating at 175°C for 30 minutes is performed in the peel strength test ＰＩ is 0.50 N / mm or less, preferably 0.01 to 0.50 N / mm, 0.02 to 0.40 N / mm, 0.03 to 0.30 N / mm, or 0.04 to 0.20 N / mm. ＰＩ When the peel strength X is 0.50 N / mm or less, the cured product is less likely to remain due to the influence of the processing process. ＰＩ When the adhesive strength is 0.01 N / mm or more, peeling of the wafer W from the support member due to a decrease in adhesive strength of the temporary fixing layer tends to be less likely to occur during processing such as heat treatment or back grinding.

[0030] Peel strength Y obtained by measurement method (Y) without performing step (ii) of heating at 175°C for 30 minutes in the peel strength test ＰＩ is 0.10 N / mm or more, preferably 0.10 to 0.70 N / mm, 0.11 to 0.60 N / mm, 0.12 to 0.55 N / mm, or 0.13 to 0.50 N / mm. ＰＩ When the peel strength Y is 0.10 N / mm or more, peeling between the wafer W and the support member due to a decrease in the adhesive strength of the temporary fixing layer during processing such as back grinding tends to be less likely to occur. ＰＩ When the strength is 0.70 N / mm or less, the cured product tends to be less likely to remain.

[0031] The above ratio X ＰＩ / Y ＰＩ is 1.5 or less, preferably 0.10 to 1.5, 0.20 to 1.3, 0.23 to 1.2, 0.25 to 1.1, or 0.30 to 1.0. ＰＩ / Y ＰＩ By making the ratio X 1.5 or less, the cured product is less likely to remain due to the influence of the processing process. ＰＩ / Y ＰＩ When the thickness is within the above range, peeling between the wafer W and the support member due to a decrease in adhesive strength of the temporary fixing layer tends to be less likely to occur during processing such as heat treatment or back grinding.

[0032] Peel strength X ＰＩ , peel strength Y ＰＩ , and the ratio X ＰＩ / Y ＰＩ In order to make the content of the polymerizable compound fall within the above range, there are no particular limitations, but examples of the method include adjusting the proportion of hydrophobic components having a hydrocarbon chain with three or more carbon atoms in the components contained in the temporary fixing composition, adjusting the proportion of hydrophilic components having a polar group, or adjusting the proportion of components having an aromatic ring that has high absorbance of laser light and increases the decomposition efficiency by laser light irradiation.

[0033] Specifically, from the viewpoint of reducing the adhesion after heating to highly polar polyimide, the peel strength X can be reduced by increasing the amount of polymerizable compounds having a hydrocarbon chain with 3 or more carbon atoms. ＰＩ In addition, the peel strength X may be reduced by adjusting the content of the photopolymerization initiator and the polymerizable compound or by using a polyfunctional polymerizable compound polymer. ＰＩ and peel strength Y ＰＩ Furthermore, from the viewpoint of reducing the adhesive strength after laser light irradiation, the amount of the polymerizable compound having an aromatic ring may be increased to adjust the peel strength X ＰＩ and peel strength Y ＰＩ The ratio X ＰＩ / Y ＰＩ Regarding the peel strength X by the above method ＰＩ and peel strength Y ＰＩ can be adjusted as a result of the adjustment of

[0034] In addition, although the above description has been given of a case where polyimide is used as a test substrate as an example of an insulating part, a peel strength test was carried out using aluminum as an example of an electrode part or silicon as an example of a semiconductor substrate as a test substrate, and the peel strength X after the step (ii) of heating at 175° C. for 30 minutes was Ａｌ , X ｓｉ and the peel strength Y when the step (ii) is not performed. Ａｌ , Y ｓｉ This makes it possible to prevent the hardened material from remaining due to the processing process on patterned wafers having surfaces made of various materials such as aluminum and silicon in addition to polyimide. These peel strengths are described in detail below.

[0035] Peel strength X obtained by measurement method (X) in which step (ii) of heating at 175°C for 30 minutes is performed in the peel strength test Ａｌ is preferably 0.60 N / mm or less, 0.10 to 0.60 N / mm, 0.15 to 0.50 N / mm, or 0.20 to 0.40 N / mm. Ａｌ When the peel strength X is 0.60 N / mm or less, the cured product is less likely to remain due to the influence of the processing process. ＡｌWhen the adhesive strength is 0.10 N / mm or more, peeling of the wafer W from the support member due to a decrease in adhesive strength of the temporary fixing layer tends to be less likely to occur during processing such as heat treatment or back grinding.

[0036] Peel strength Y obtained by measurement method (Y) without performing step (ii) of heating at 175°C for 30 minutes in the peel strength test Ａｌ is preferably 0.10 N / mm or more, 0.10 to 0.60 N / mm, 0.12 to 0.45 N / mm, or 0.15 to 0.30 N / mm. Ａｌ When the peel strength Y is 0.10 N / mm or more, peeling between the wafer W and the support member due to a decrease in the adhesive strength of the temporary fixing layer during processing such as back grinding tends to be less likely to occur. Ａｌ When the strength is 0.60 N / mm or less, the cured product tends to be less likely to remain.

[0037] The above ratio X Ａｌ / Y Ａｌ is preferably 2.0 or less, 1.0 to 2.0, 1.1 to 1.9, 1.2 to 1.8, or 1.3 to 1.7. Ａｌ / Y Ａｌ By making the ratio X 2.0 or less, the cured product is less likely to remain due to the influence of the processing process. Ａｌ / Y Ａｌ When the thickness is within the above range, peeling between the wafer W and the support member due to a decrease in adhesive strength of the temporary fixing layer tends to be less likely to occur during processing such as heat treatment or back grinding.

[0038] Peel strength X Ａｌ , peel strength Y Ａｌ , and the ratio X Ａｌ / Y Ａｌ In order to make the content of the polymerizable compound fall within the above range, there are no particular limitations, but examples of the method include adjusting the proportion of hydrophobic components having a hydrocarbon chain with three or more carbon atoms in the components contained in the temporary fixing composition, adjusting the proportion of hydrophilic components having a polar group, or adjusting the proportion of components having an aromatic ring that increases the decomposition efficiency by laser light irradiation.

[0039] Specifically, the peel strength X can be adjusted by increasing or decreasing the amount of the polymerizable compound having a hydrocarbon chain with 3 or more carbon atoms. Ａｌ The peel strength X may be adjusted by adjusting the content of the photopolymerization initiator and the polymerizable compound or by using a polyfunctional polymerizable compound. Ａｌ and peel strength Y Ａｌ Furthermore, from the viewpoint of reducing the adhesive strength after laser light irradiation, the amount of the polymerizable compound having an aromatic ring may be increased to adjust the peel strength X Ａｌ and peel strength Y Ａｌ The ratio X Ａｌ / Y Ａｌ Regarding the peel strength X by the above method Ａｌ and peel strength Y Ａｌ can be adjusted as a result of the adjustment of

[0040] Peel strength X obtained by measurement method (X) in which step (ii) of heating at 175°C for 30 minutes is performed in the peel strength test Ｓｉ is preferably 0.50 N / mm or less, 0.05 to 0.50 N / mm, 0.10 to 0.40 N / mm, or 0.15 to 0.30 N / mm. Ｓｉ When the peel strength X is 0.50 N / mm or less, the cured product is less likely to remain due to the influence of the processing process. Ｓｉ When the adhesive strength is 0.05 N / mm or more, peeling of the wafer W from the support member due to a decrease in adhesive strength of the temporary fixing layer tends to be less likely to occur during processing such as heat treatment or back grinding.

[0041] Peel strength Y obtained by measurement method (Y) without performing step (ii) of heating at 175°C for 30 minutes in the peel strength test Ｓｉ is preferably 0.10 N / mm or more, 0.10 to 0.60 N / mm, 0.12 to 0.45 N / mm, or 0.15 to 0.30 N / mm. ＳｉWhen the peel strength Y is 0.10 N / mm or more, peeling between the wafer W and the support member due to a decrease in the adhesive strength of the temporary fixing layer during processing such as back grinding tends to be less likely to occur. Ｓｉ When the strength is 0.60 N / mm or less, the cured product tends to be less likely to remain.

[0042] The above ratio X Ｓｉ / Y Ｓｉ is preferably 1.6 or less, 0.2 to 1.6, 0.3 to 1.2, 0.5 to 1.1, or 0.6 to 1.0. Ｓｉ / Y Ｓｉ By making the ratio X 1.6 or less, the cured product is less likely to remain due to the influence of the processing process. Ｓｉ / Y Ｓｉ When the thickness is within the above range, peeling between the wafer W and the support member due to a decrease in adhesive strength of the temporary fixing layer tends to be less likely to occur during processing such as heat treatment or back grinding.

[0043] Peel strength X Ｓｉ , peel strength Y Ｓｉ , and the ratio X Ｓｉ / Y Ｓｉ In order to make the content of the polymerizable compound fall within the above range, there are no particular limitations, but examples of the method include adjusting the proportion of hydrophobic components having a hydrocarbon chain with three or more carbon atoms in the components contained in the temporary fixing composition, adjusting the proportion of hydrophilic components having a polar group, or adjusting the proportion of components having an aromatic ring that increases the decomposition efficiency by laser light irradiation.

[0044] Specifically, the peel strength X can be adjusted by increasing or decreasing the amount of the polymerizable compound having a hydrocarbon chain with 3 or more carbon atoms. Ｓｉ The peel strength X may be adjusted by adjusting the content of the photopolymerization initiator and the polymerizable compound or by using a polyfunctional polymerizable compound. Ｓｉ and peel strength Y Ｓｉ Furthermore, from the viewpoint of reducing the adhesive strength after laser light irradiation, the amount of the polymerizable compound having an aromatic ring may be increased to adjust the peel strength X Ｓｉ and peel strength Y ＳｉThe ratio X Ｓｉ / Y Ｓｉ Regarding the peel strength X by the above method Ｓｉ and peel strength Y Ｓｉ can be adjusted as a result of the adjustment of

[0045] Furthermore, when the wafer W is a patterned wafer having an insulating portion and an electrode portion, from the viewpoint of ensuring that there is no difference in the degree of remaining cured material in the insulating portion, the electrode portion, and the semiconductor substrate, the peel strength X ＰＩ , X Ａｌ , X Ｓｉ and peel strength Y ＰＩ , Y Ａｌ , Y Ｓｉ This makes it possible to prevent the cured material from remaining due to the influence of the processing process on a patterned wafer having two component surfaces of polyimide and aluminum.

[0046] From this perspective, the ratio X ＰＩ / X Ａｌ is preferably 0.10 to 0.50, 0.11 to 0.40, 0.12 to 0.35, 0.13 to 0.30, or 0.15 to 0.25. ＰＩ / X Ａｌ By setting the value within the above range, the removal rate of the temporary fixing composition tends to be better.

[0047] Also, the ratio X ＰＩ / X Ｓｉ is preferably 0.10 to 0.50, 0.12 to 0.40, 0.15 to 0.38, 0.16 to 0.35, or 0.18 to 0.30. ＰＩ / X Ｓｉ By setting the value within the above range, the removal rate of the temporary fixing composition tends to be better.

[0048] As described above, in the peel strength test of this embodiment, the peel strength is measured using polyimide, aluminum, or silicon as the test substrate, but the peel strength should not be interpreted as being a specific value for polyimide, aluminum, or silicon. ＰＩ , YＰＩ has a technical meaning as a reference value for the peel strength X and Y of insulating parts made of polyimide-like materials, and the peel strength X of aluminum Ａｌ , Y Ａｌ has a technical meaning as a reference value for the peel strength X, Y of the electrode part made of a material similar to aluminum. Ｓｉ , Y Ｓｉ has technical significance as a reference value for the peel strength X, Y of a semiconductor substrate made of a material similar to silicon.

[0049] Next, the peel strength test will be described in detail. In this specification, the peel strength when heat treatment is performed is measured by the above-mentioned measurement method (X). The measurement method (X) corresponds to the production conditions when a wafer is temporarily fixed to a support member using the temporary fixing composition of this embodiment and then the wafer is heat treated.

[0050] In step (i), the temporary fixing composition is applied to a test substrate to a thickness of 70 μm, and after laminating a glass plate, the temporary fixing composition is photocured to form a coating film. Step (i) corresponds to the laminating step S0 and the curing step S1 in the wafer manufacturing method described below.

[0051] In step (i), the method for applying the temporary fixing composition is not particularly limited as long as it can apply the temporary fixing composition to a thickness of 70 μm, and examples thereof include spin coating, screen printing, and various coaters, among which spin coating is preferred. Spin coating is a method in which the temporary fixing composition, which is a liquid composition, is dropped onto a wafer or a support member and then rotated at a predetermined rotation speed, thereby applying the composition to the surface of a substrate.

[0052] In the step (i), when the temporary fixing composition is photocured, for example, ultraviolet light may be irradiated. The wavelength of the ultraviolet light may be in the range of 350 to 405 nm. The ultraviolet light has an energy amount in the range of 350 to 405 nm of, for example, 1 to 20,000 mJ / cm. ２ , preferably 1000 to 10000 mJ / cm ２It is preferable to irradiate the film so that the ultraviolet light reaches a temperature of 1000 to 2000° C. The ultraviolet light irradiation conditions may be those described in the Examples. The formed coating film corresponds to a temporary fixing layer formed from the temporary fixing composition of this embodiment.

[0053] In step (ii), the test substrate on which the coating film has been formed is heated for 30 minutes at 175° C. Step (ii) corresponds to the heat treatment step S2 in the wafer manufacturing method described below.

[0054] In step (iii), the coating film is irradiated with light having a wavelength of 355 nm and a frequency of 40 kHz at an energy density of 920 mJ / cm ２ After the laser beam is irradiated, the glass plate is peeled off. The step (iii) corresponds to the laser beam irradiation step S3 and the peeling step S4 in the wafer manufacturing method described later.

[0055] In the step (iii), the laser light to be irradiated may be irradiated under the conditions of a spot diameter of 150 μm and a pulse energy of 165 μJ, and may be irradiated under the conditions described in the examples.

[0056] In step (iv), a peeling tape is applied to the coating film, and the peel strength is measured when peeling the coating film from the test substrate under conditions of a peeling direction of 180 degrees, a peeling width of 20 mm, a peeling rate of 120 mm / min, and a temperature of 25° C. The average value of five measurements is taken as the measured value. Step (iv) corresponds to the removal step S5 in the wafer manufacturing method described below.

[0057] In step (iv), the peeling tape may be a dicing tape used to fix a workpiece in a dicing step in the manufacture of semiconductors, electronic components, or optical components, and the tape used in the examples may be used. The peel strength in step (iv) may be measured under the conditions described in the examples.

[0058] In this specification, the peel strength without heat treatment is measured by the above-mentioned measurement method (Y). The measurement method (Y) corresponds to the production conditions when a wafer is temporarily fixed to a support member using the temporary fixing composition of this embodiment, and the wafer is processed without being heat treated.

[0059] 1.2. Viscosity The viscosity of the temporary fixing composition at 23°C is preferably 500 to 10,000 mPa·s, 600 to 9,000 mPa·s, 700 to 8,000 mPa·s, 800 to 7,000 mPa·s, or 1,000 to 6,000 mPa·s. When the viscosity at 23°C is within the above range, the coatability of the temporary fixing composition is further improved.

[0060] The viscosity at 23° C. can be controlled by adjusting the blending ratio of the components contained in the temporary fixing composition. For example, the viscosity of the temporary fixing composition can be reduced by increasing the blending amount of a component with a low viscosity.

[0061] The viscosity at 23°C was measured according to JIS Z8803:2011 at a temperature of 23°C and a shear rate of 1 sec. －１ The viscosity can be measured, for example, by an E-type viscometer (for example, rotation speed: 10 rpm or 2 rpm), and a cone plate can be used as a measuring tool. Specifically, the viscosity can be measured by the method described in the examples.

[0062] 1.3. Composition The temporary fixing composition of this embodiment can be cured by irradiation with ultraviolet light, and the temporary fixing layer formed thereby can be decomposed by irradiation with laser light. The composition is not particularly limited as long as the peel strength requirement is met. The temporary fixing composition may contain, for example, a polymerizable compound A and a photopolymerization initiator B. In this case, the temporary fixing composition can be cured by irradiation with ultraviolet light. When the temporary fixing composition is irradiated with ultraviolet light, the photopolymerization initiator B is activated by the ultraviolet light, and polymerization of the polymerizable compound A is initiated. When the polymerization of the polymerizable compound A is completed, a temporary fixing layer is formed. The temporary fixing composition may further contain components other than the polymerizable compound A and the photopolymerization initiator B.

[0063] 1.3.1. Polymerizable Compound A The polymerizable compound A is not particularly limited as long as it is a compound having one or more polymerizable functional groups, and examples thereof include polymerizable compound A1 having a hydrocarbon chain with 3 or more carbon atoms, polymerizable compound A2 having an aromatic ring, polymerizable compound A3 having a hydrocarbon chain with 3 or more carbon atoms (hereinafter also referred to as a "long hydrocarbon chain") and an aromatic ring, and other polymerizable compounds A4.

[0064] Among these, the polymerizable compound A preferably includes at least one selected from the group consisting of polymerizable compound A1, polymerizable compound A2, and polymerizable compound A3, and more preferably includes at least polymerizable compound A1 and polymerizable compound A2. By adjusting the contents of polymerizable compounds A1 to A3, the concentrations of hydrocarbon chains having 3 or more carbon atoms and aromatic rings in the temporary fixing composition can be controlled. In this embodiment, polymerizable compound A1 does not have an aromatic ring, polymerizable compound A2 does not have a long hydrocarbon chain, and polymerizable compound A4 does not have either an aromatic ring or a long hydrocarbon chain. Polymerizable compounds A1 to A4 may each independently be used alone or in combination of two or more.

[0065] In this embodiment, the polymerizable functional group is not particularly limited, but examples thereof include groups having a carbon-carbon double bond such as a vinyl group, an allyl group, a butenyl group, an ethynyl group, an acryloyl group, an acryloyloxy group, an acryloylamino group, a methacryloyl group, a methacryloyloxy group, a methacryloylamino group, a vinyloxy group, a vinylamino group, a cyclopropyl group, and a cyclobutyl group. Among these, a group containing an ethylenic double bond is preferred, and a (meth)acryloyl group is more preferred. In other words, the polymerizable compound A preferably contains a (meth)acrylate.

[0066] The content of the polymerizable compound A is preferably 50 to 99.9 mass %, 70 to 99.5 mass %, 80 to 99.2 mass %, 90 to 99.0 mass %, or 95 to 98.8 mass %, relative to the total amount of the temporary fixing composition. When the content of the polymerizable compound A is within the above range, there is a tendency that the cured product is less likely to remain.

[0067] Each polymerizable compound will be described in detail below.

[0068] The polymerizable compound A1 is not particularly limited as long as it has a hydrocarbon long chain and one or more polymerizable functional groups. Examples of the polymerizable compound A1 include monofunctional polymerizable compounds such as isostearyl (meth)acrylate; 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate (the number of repeating units may be 1 to 10), neopentyl glycol di(meth)acrylate, C １ ~C ２０ Examples of suitable polyfunctional polymerizable compounds include alkoxylated hydrogenated bisphenol A di(meth)acrylate, neopentyl glycol-modified trimethylolpropane di(meth)acrylate, stearic acid-modified pentaerythritol di(meth)acrylate, caprolactone-modified hydroxypivalic acid neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and ethylene oxide-modified hydrogenated bisphenol A di(meth)acrylate; and polymers having polymerizable functional groups (hereinafter also referred to as "macromonomers") containing, as monomer units, (meth)acrylate monomers containing a hydrocarbon long chain in the side chain and (meth)acrylate monomers containing a (meth)acryloyl group in the side chain. Among these, (meth)acrylates containing a hydrocarbon long chain are preferred.

[0069] Examples of (meth)acrylate monomers containing a long hydrocarbon chain in the side chain include propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, and among these, butyl (meth)acrylate is preferred.

[0070] The (meth)acrylate monomer containing a (meth)acryloyl group in the side chain includes a (meth)acrylate having a (meth)acryloyl group bonded to the side chain via a suitable linker. The linker may be a hydrocarbon chain having 3 to 20 or 4 to 10 carbon atoms and which may contain an ether bond and / or an amide bond.

[0071] The number of carbon atoms in the hydrocarbon long chain of polymerizable compound A1 is 3 or more, preferably 3 to 20, 3 to 18, or 4 to 16, or may be 8 to 12. Polymerizable compound A1 may have hydrocarbon long chains with different numbers of carbon atoms in one molecule, and preferably contains a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms. Such a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms may be a bifunctional (meth)acrylate or a (meth)acrylate having (meth)acryloyl groups at both terminal positions of the molecular chain. The number of carbon atoms in the hydrocarbon chain is preferably 8 to 15. The content of the (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms and the content of polymerizable compound A1 having a hydrocarbon chain with 8 or more carbon atoms are preferably 0 to 70 parts by mass, 10 to 60 parts by mass, or 20 to 55 parts by mass, relative to 100 parts by mass of the total amount of polymerizable compound A.

[0072] The long hydrocarbon chain functional group equivalent of the polymerizable compound A1 is preferably 100 to 600 g / mol. The polymerizable compound A1 preferably contains a polymerizable compound having a long hydrocarbon chain functional group equivalent of 200 g / mol or less, 100 to 200 g / mol, or 110 to 190 g / mol. When the long hydrocarbon chain functional group equivalent is within the above range, the cured product tends to be less likely to remain. The content of the polymerizable compound A1 having a long hydrocarbon chain functional group equivalent within the above range is preferably 3 to 90 parts by mass, 5 to 70 parts by mass, 10 to 60 parts by mass, or 15 to 50 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A.

[0073] The content of polymerizable compound A1 is preferably 50 to 98 parts by mass, 55 to 95 parts by mass, 60 to 92 parts by mass, or 64 to 90 parts by mass, relative to 100 parts by mass of the total amount of polymerizable compound A. By setting the content of polymerizable compound A1 within the above range, there is a tendency that the cured product is less likely to remain.

[0074] The polymerizable compound A2 is not particularly limited as long as it has an aromatic ring and one or more polymerizable functional groups. Examples thereof include monofunctional polymerizable compounds such as phenol ethylene oxide modified (meth)acrylate (the number of repeating units of ethylene oxide is 1 to 5), 2-(2'-hydroxy-5'-(meth)acryloyloxyethylphenyl)-2H-benzotriazole, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl (meth)acrylate, and 2-(2-(meth)acryloyloxy,5-methyl)phenyl-2H-benzotriazole; 9,9-bis[4-(2-hydroxyC １ ~C ２０ 1,3-bis(2-(meth)acryloyloxy)phenyl]fluorene di(meth)acrylate, benzyl di(meth)acrylate, 1,3-bis(2-(meth)acryloyloxy)phenyl]fluorene di(meth)acrylate, １ ~C ２０ Examples of polyfunctional polymerizable compounds include 2,2-bis(4-(meth)acryloxydiethoxyphenyl)propane, 2,2'-dihydroxy-4,4'-diethoxy(meth)acryloyloxybenzophenone, and 1,1-bis-[2-(meth)acryloyloxy,3-(2H-benzotriazol-2-yl),5-tert-octyl]methane. Among these, (meth)acrylates containing an aromatic ring are preferred.

[0075] The aromatic ring equivalent of the polymerizable compound A2 is preferably 100 to 400 g / mol. The polymerizable compound A2 preferably contains a polymerizable compound having an aromatic ring equivalent of 200 g / mol or less, 100 to 200 g / mol, or 110 to 190 g / mol. When the aromatic ring equivalent is within the above range, decomposition by laser light is further improved, and the cured product tends to be less likely to remain. The content of the polymerizable compound A2 having an aromatic ring equivalent within the above range is preferably 1 to 45 parts by mass, 2 to 40 parts by mass, 3 to 35 parts by mass, or 5 to 25 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A.

[0076] The polymerizable compound A2 preferably contains a polymerizable compound A2-1 containing a group that absorbs light with a wavelength of 350 to 385 nm. The polymerizable compound A2-1 more preferably has an absorption peak for light with a wavelength of 350 to 385 nm. Although the absorption peak of an aromatic ring generally has an absorption at about 200 nm, when the element adjacent to the aromatic ring is a hetero element such as P, S, or O, the conjugation length increases, and light with a wavelength of 350 to 385 nm is absorbed. By including such a polymerizable compound A2-1, when the temporary fixing layer is irradiated with laser light, the laser light is efficiently absorbed, decomposition by the laser light is further improved, and there is a tendency for the cured product to be less likely to remain.

[0077] Examples of such polymerizable compound A2-1 include compounds having one or more skeletons selected from the group consisting of a benzophenone skeleton, a benzotriazole skeleton, a triazole skeleton, a hydroxyphenyltriazine skeleton, and a phenol skeleton. Among these, a phenol skeleton is preferred, and a hindered phenol skeleton is more preferred.

[0078] The content of polymerizable compound A2 is preferably 2 to 50 parts by mass, 5 to 45 parts by mass, 8 to 40 parts by mass, or 9 to 35 parts by mass, relative to 100 parts by mass of the total amount of polymerizable compound A. By setting the content of polymerizable compound A2 within the above range, decomposition by laser light is further improved, and there is a tendency that the cured product is less likely to remain.

[0079] When the polymerizable compound A2 contains the polymerizable compound A2-1, the content of the polymerizable compound A2-1 is preferably 1 to 30 parts by mass, 2 to 25 parts by mass, 3 to 20 parts by mass, or 5 to 15 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A. By setting the content of the polymerizable compound A2-1 within the above range, decomposition by laser light is further improved, and there is a tendency that the cured product is less likely to remain.

[0080] The polymerizable compound A3 is not particularly limited, but examples thereof include monofunctional polymerizable compounds such as nonylphenol ethylene oxide modified (meth)acrylate (the number of repeating units of ethylene oxide is 1 to 5); １ ~C ２０ Examples include polyfunctional polymerizable compounds such as alkoxylated bisphenol A di(meth)acrylate.

[0081] The long hydrocarbon chain functional group equivalent of polymerizable compound A3 is preferably 100 to 800 g / mol. Polymerizable compound A3 preferably contains a polymerizable compound having a long hydrocarbon chain functional group equivalent of 500 g / mol or less, 100 to 500 g / mol, or 200 to 400 g / mol. Having a long hydrocarbon chain functional group equivalent within the above range tends to make it less likely that the cured product will remain. The content of polymerizable compound A3 having a long hydrocarbon chain functional group equivalent within the above range is preferably 0 to 48 parts by mass, 0 to 40 parts by mass, 0 to 10 parts by mass, or 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of polymerizable compound A.

[0082] The aromatic ring equivalent of the polymerizable compound A3 is preferably 100 to 500 g / mol. The polymerizable compound A3 preferably contains a polymerizable compound having an aromatic ring equivalent of 500 g / mol or less, 100 to 500 g / mol, or 200 to 400 g / mol. When the aromatic ring equivalent is within the above range, decomposition by laser light is further improved, and the cured product tends to be less likely to remain. The content of the polymerizable compound A3 having an aromatic ring equivalent within the above range is preferably 0 to 40 parts by mass, 0 to 10 parts by mass, or 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A.

[0083] The number of carbon atoms in the hydrocarbon long chain of polymerizable compound A3 is 3 or more, preferably 3 to 20, 3 to 18, or 4 to 16, or may be 8 to 12. Polymerizable compound A3 may have hydrocarbon long chains with different numbers of carbon atoms in one molecule, and may particularly contain a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms. Such a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms may be a monofunctional (meth)acrylate. The number of carbon atoms in the hydrocarbon chain is preferably 8 to 15.

[0084] The content of polymerizable compound A3 is preferably 0 parts by mass or more, 3 parts by mass or more, 5 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more, relative to 100 parts by mass of the total amount of polymerizable compound A. Furthermore, the content of polymerizable compound A3 is preferably 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, or 10 parts by mass or less, relative to 100 parts by mass of the total amount of polymerizable compound A. The content of polymerizable compound A3 may be 0 parts by mass. By setting the content of polymerizable compound A3 within the above range, decomposition by laser light is further improved, and there is a tendency that the cured product is less likely to remain.

[0085] The polymerizable compound A4 is not particularly limited, but examples thereof include 1,3-di(meth)acryloyloxyadamantane, tricyclo C １０ ~C ２０ Alkanedimethanol di(meth)acrylate, dicyclo C ５ ~C ２０ Examples of the polymerizable compound include polyfunctional polymerizable compounds such as di(meth)acrylate.

[0086] The content of the polymerizable compound A4 is preferably 10 parts by mass or less, 0 to 5 parts by mass, or 0 to 3 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A. The polymerizable compound A4 may not be included.

[0087] Furthermore, the polymerizable compound A preferably contains a polyfunctional polymerizable compound having two or more polymerizable functional groups per molecule, and more preferably contains a monofunctional polymerizable compound having one polymerizable functional group per molecule and a polyfunctional polymerizable compound having two or more polymerizable functional groups per molecule. By including a polyfunctional polymerizable compound, the adhesive strength of the temporary fixing layer formed by curing the temporary fixing composition tends to be increased. Furthermore, by including a monofunctional polymerizable compound in addition to a polyfunctional polymerizable compound, it tends to be easier to control the concentration of the hydrocarbon chain and the concentration of the aromatic ring in the temporary fixing composition.

[0088] The polyfunctional polymerizable compound is preferably a polyfunctional (meth)acrylate. The polyfunctional (meth)acrylate may be a monomer, a macromonomer, or a mixture thereof, but preferably contains a macromonomer. The polyfunctional (meth)acrylate can be produced by methods described in, for example, JP-A Nos. 61-207478, 61-31330, 10-278207, 9-40741, and 8-357621. In this embodiment, the weight-average molecular weight of the polyfunctional (meth)acrylate macromonomer is preferably 5,000 to 500,000, 10,000 to 300,000, 30,000 to 200,000, or 50,000 to 100,000. When the weight average molecular weight is within the above range, the viscosity of the temporary fixing composition and the crosslink density of the cured product tend to be within preferred ranges. The polyfunctional polymerizable compound may be contained as the polymerizable compound A1.

[0089] The weight average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene. Specifically, the weight average molecular weight is determined by using tetrahydrofuran as a solvent, using a GPC system (SC-8010 manufactured by Tosoh Corporation), and creating a calibration curve with commercially available standard polystyrene under the following conditions: Flow rate: 1.0 ml / min Set temperature: 40°C Column configuration: One Tosoh "TSKguard column MP (xL)" 6.0 mm ID x 4.0 cm, and two Tosoh "TSK-GELMULTIPORE HXL-M" 7.8 mm ID x 30.0 cm (theoretical plate number: 16,000), for a total of three (total theoretical plate number: 32,000) Sample injection volume: 100 μl (sample solution concentration: 1 mg / ml) Solution delivery pressure: 39 kg / cm 2 Detector: RI detector

[0090] The polymerizable compound A preferably contains both a monofunctional polymerizable compound and a polyfunctional polymerizable compound. In this case, the content of the monofunctional polymerizable compound is preferably 0.01 to 80 parts by mass, 0.50 to 70 parts by mass, 1.0 to 68 parts by mass, or 3.0 to 67 parts by mass, relative to 100 parts by mass of the total amount of the polyfunctional polymerizable compounds. By setting the content of the monofunctional polymerizable compound within the above range, there is a tendency that the cured product is less likely to remain, and that it is easier to adjust the viscosity and heat resistance.

[0091] 1.3.2. Photopolymerization Initiator B The photopolymerization initiator B is, for example, preferably a photoradical polymerization initiator, more preferably a compound whose molecules are cleaved and split into two or more radicals upon irradiation with ultraviolet light or visible light.

[0092] The photopolymerization initiator B may be selected from compounds that exhibit appropriate absorption characteristics by measuring their absorbance. Specifically, the photopolymerization initiator B may be selected from one or more compounds that, when dissolved at a concentration of 0.1% by mass in a solvent that does not have a maximum absorption in the wavelength region of 300 to 500 nm (e.g., acetonitrile, toluene, etc.), satisfy one or more of the following conditions: an absorbance of 0.5 or more at a wavelength of 365 nm, an absorbance of 0.5 or more at a wavelength of 385 nm, and an absorbance of 0.5 or more at a wavelength of 405 nm.

[0093] As the photopolymerization initiator B, one or more compounds selected from acylphosphine oxide compounds, titanocene compounds, and α-aminoalkylphenone compounds are preferred because they have excellent reaction speed and heat resistance after curing. These compounds tend to have an absorption wavelength range up to approximately 440 nm and are preferred because they have low absorbance at the wavelength of light used in the step of irradiating the temporary fixing layer with laser light. In other words, the photopolymerization initiator B is a photopolymerization initiator that can initiate radical polymerization with light of a longer wavelength. This allows for a larger difference between the wavelength of the light irradiated when curing the temporary fixing composition and the wavelength of the laser light irradiated when decomposing the temporary fixing layer. Alternatively, an oxime ester compound can be selected as the photopolymerization initiator B.

[0094] Examples of acylphosphine oxide compounds include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc. Among these, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is particularly preferred.

[0095] Examples of titanocene compounds include bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium.

[0096] Examples of the α-aminoalkylphenone compounds include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one, and the like.

[0097] Examples of oxime ester compounds include 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), etc. Among these, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime) is preferred.

[0098] From the viewpoint of exhibiting high absorbance in the wavelength region of 365 to 405 nm, the photopolymerization initiator B is preferably 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, or 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and more preferably bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0099] Also preferred is bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, which exhibits absorption in the longer wavelength range of 400 to 500 nm.

[0100] The content of the photopolymerization initiator B is preferably 0.01 to 10 parts by mass, 0.01 to 5.0 parts by mass, 0.1 to 3.0 parts by mass, or 0.5 to 1.5 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A. When the content of the photopolymerization initiator B is within the above range, the adhesive strength of the temporary fixing layer formed using the temporary fixing composition tends to be further increased.

[0101] 1.3.3 Other Components The temporary fixing composition may contain components other than the polymerizable compound A and the photopolymerization initiator B. Examples of such components include compounds that do not fall under the category of polymerizable compounds, such as compounds having an aromatic ring and compounds having a hydrocarbon chain with three or more carbon atoms.

[0102] 2. Uses The temporary fixing composition of this embodiment is suitably used in a wafer manufacturing method for temporarily fixing a wafer, particularly a patterned wafer, to a support member. The temporary fixing composition is preferably applied to the front surface of the wafer, and temporarily fixes the wafer to the support member for back surface processing of the wafer. The temporary fixing composition of this embodiment is unlikely to leave a cured product even when the patterned wafer is heat-treated, and therefore can be suitably used in a manufacturing method that includes a step of heat-treating the patterned wafer.

[0103] 3. Wafer Manufacturing Method As shown in FIG. 1 , the wafer manufacturing method of this embodiment includes the steps of bonding a wafer and a support member together via the temporary fixing composition of this embodiment (hereinafter referred to as a bonding step S0), curing the temporary fixing composition by irradiating it with ultraviolet light to form a temporary fixing layer, and bonding the wafer and the support member together via the temporary fixing layer (hereinafter referred to as a curing step S1), heat-treating the wafer (hereinafter referred to as a heat-treatment step S2), irradiating the temporary fixing layer with laser light (hereinafter referred to as a laser light irradiation step S3), and peeling the support member and the wafer at the interface of the temporary fixing layer (hereinafter referred to as a peeling step S4).

[0104] In the bonding step S0, the wafer and the support member are bonded together. The wafer is a substrate to be processed, such as a silicon substrate. The wafer is preferably a patterned wafer, more preferably a wafer on which a pattern is formed using polyimide and aluminum. The support member is preferably a support member that is at least transparent to ultraviolet light, such as a glass plate.

[0105] The bonding method in the bonding step S0 is not particularly limited, but a method in which the temporary fixing composition of the present embodiment is applied to one surface of a wafer or a support member, and then the other substrate is bonded thereto is preferred.

[0106] As a method for applying the temporary fixing composition, known application methods such as spin coating, screen printing, and various coaters can be used, but spin coating is preferred.

[0107] In the curing step S1, the temporary fixing composition is irradiated with ultraviolet light to cure the temporary fixing composition and bond the wafer and the support member. The temporary fixing composition can be easily irradiated with ultraviolet light by using a transparent substrate that transmits at least ultraviolet light as at least one of the wafer and the support member. When a substrate that transmits ultraviolet light is used as the support member, ultraviolet light may be irradiated from the support member side. Examples of transparent substrates include inorganic substrates such as crystal, glass, quartz, calcium fluoride, and magnesium fluoride, and organic substrates such as plastic, but inorganic substrates are preferred.

[0108] The wavelength of the ultraviolet light can be appropriately selected depending on the type of photopolymerization initiator B, and may be, for example, in the range of 350 to 405 nm. The ultraviolet light has an energy amount in the range of 350 to 405 nm of, for example, 1 to 20,000 mJ / cm. ２ , preferably 1000 to 10000 mJ / cm ２ It is preferable to irradiate so that

[0109] In the heat treatment step S2, the wafer is heat-treated. Heat treatment refers to processing under high-temperature conditions of 170°C or higher, and the temperature condition may be 170 to 300°C. In the heat treatment step S2, the wafer may be heated and various processing may be performed. Examples of such processing include insulating film formation, circuit formation, ion implantation, etc. on the surface of the wafer opposite to the surface to which the support member is attached.

[0110] The laser light irradiation step S3 is a step S3 in which a laser light is irradiated onto the temporary fixing layer, which is a cured temporary fixing composition, to decompose the temporary fixing layer. The wavelength of the laser light is preferably 350 to 385 nm. The laser light may be irradiated from the wafer side or the support member side, but is preferably irradiated from the support member side. As described above, when the temporary fixing composition contains an aromatic ring bonded to a heteroatom, it tends to more easily absorb the energy of the laser light in the laser light irradiation step S3.

[0111] In the peeling step S4, the support member and the wafer are peeled off at the interface of the temporary fixing layer. In the laser light irradiation step, the temporary fixing layer is decomposed, generating gas derived from the decomposed components, and the adhesive strength at the interface between the temporary fixing layer and the wafer or the support member is reduced, thereby enabling the wafer and the support member to be peeled off.

[0112] The wafer manufacturing method of this embodiment preferably includes a step of removing the temporary fixing layer after laser light irradiation from the wafer peeled off from the support member (hereinafter referred to as a removing step S5). By performing the removing step S5, the temporary fixing layer can be sufficiently removed even if it remains on the wafer.

[0113] The removal step S5 is not particularly limited as long as it can remove the temporary fixing layer remaining on the wafer, but for example, a method of attaching an adhesive tape to the wafer on which the temporary fixing layer remains and then peeling the adhesive tape from the wafer can be mentioned. In such a method, the remaining temporary fixing layer adheres to the adhesive tape, so that the temporary fixing layer can be removed when the adhesive tape is peeled off from the wafer. As the adhesive tape, for example, a dicing tape used to fix a workpiece in a dicing process in the manufacture of semiconductors, electronic components, and optical components can be used.

[0114] In the above-described wafer manufacturing method, the processing step S2 in which a desired processing process is performed on the wafer W reinforced by bonding to the support member 20 has been described as the "heat treatment step S2." However, the processing process is not limited to heat treatment, and may further include a step of processing the surface of the wafer opposite to the surface to which the support member is attached under non-heating conditions before or after the heat treatment, particularly before the heat treatment. Examples of such processing include thinning by grinding or polishing. As described above, the temporary fixing composition of this embodiment has a peel strength measured by measurement method (Y) within a predetermined range, and peeling of the wafer from the support member during the processing step described above is suppressed.

[0115] The temporary fixing composition according to the first embodiment may have the features of the temporary fixing composition according to the second embodiment, as long as there is no contradiction.

[0116] Second Embodiment 1. Composition and Temporary Fixing Composition The composition of this embodiment contains a polymerizable compound A and a photopolymerization initiator B, and has a concentration of hydrocarbon chains having 3 or more carbon atoms (hereinafter also referred to as "long hydrocarbon chains") of 2.80 mmol / g or more, and a concentration of aromatic rings of 0.60 mmol / g or more. A temporary fixing composition is preferred as the composition of this embodiment. Hereinafter, the composition will be described using a temporary fixing composition as an example, but its use is not limited to temporary fixing. The temporary fixing composition of this embodiment may contain the composition of this embodiment, or may consist solely of the composition of this embodiment.

[0117] Before describing the temporary fixing composition of this embodiment, a use mode of the temporary fixing composition will be described. Fig. 2 shows an example of a flowchart illustrating the wafer manufacturing method of this embodiment in terms of the thickness direction of the wafer.

[0118] 2 , a temporary fixing composition 10 is applied to one surface of the wafer W by spin coating or the like, the wafer W is bonded to a support member 20 via the temporary fixing composition 10, and the temporary fixing composition 10 is irradiated with light such as ultraviolet light via the support member 20. In step S1, the temporary fixing composition 10 is irradiated with light, whereby a polymerization reaction of the polymerizable compound A is initiated by the photopolymerization initiator B in the temporary fixing composition 10, and a photocured temporary fixing layer 11 is formed. This bonds the wafer W and the support member 20 via the temporary fixing layer 11. The support member 20 is not particularly limited, but examples thereof include a light-transmitting substrate such as glass. The surface of the wafer W to which the temporary fixing composition 10 is applied may be an element-forming surface.

[0119] As described above, in this specification, the term "temporary fixing composition" refers to a composition used to temporarily fix the wafer W to the support member 20. In addition, in this specification, a layer of a cured product obtained by irradiating the temporary fixing composition with light is referred to as a "temporary fixing layer."

[0120] Next, in step S2, the other surface of the wafer W is ground by a grinder G to thin the wafer W. Before or after step S2, other processes such as annealing may be performed.

[0121] Then, in step S3, the temporary fixing layer 11 is irradiated with laser light through the support member 20. In step S3, by irradiating the temporary fixing layer 11 with laser light, the polymer of the polymerizable compound A in the temporary fixing layer 11 is at least partially decomposed, and the bonding strength between the temporary fixing layer 11 and the support member 20 is reduced, so that in step S4, the support member 20 can be peeled off from the temporary fixing layer 11. At this time, since the concentration of aromatic rings in the temporary fixing composition of this embodiment is equal to or greater than a predetermined value, the laser light absorption is increased, and therefore the peelability of the support member 20 from the temporary fixing layer 11 by laser light irradiation is further improved.

[0122] Finally, in step S5, tape 30 is attached to the temporary fixing layer 11 after the laser light irradiation and peeled off in the direction of the arrow, thereby peeling off the temporary fixing layer 11 from the wafer W. The wafer W is made of a semiconductor material such as Si, and its surface is generally in a state where it is susceptible to interactions such as hydrogen bonding, for example, due to oxidation to Si—O or the like. Therefore, by setting the concentration of hydrocarbon chains having 3 or more carbon atoms in the temporary fixing composition of this embodiment to a predetermined value or higher, interactions such as hydrogen bonding between the temporary fixing layer 11 and the surface of the wafer W are reduced, and it is possible to prevent the temporary fixing layer 11 from remaining on the surface of the wafer W.

[0123] As described above, the temporary fixing composition of this embodiment has excellent laser releasability and makes it possible to form a temporary fixing layer that is unlikely to remain on a wafer. The temporary fixing composition of this embodiment will be described in detail below.

[0124] 1.1. Hydrocarbon Chain Concentration The concentration of hydrocarbon chains having 3 or more carbon atoms is 2.80 mmol / g or more, preferably 2.90 to 50.0 mmol / g, 3.00 to 30.0 mmol / g, 3.10 to 20.0 mmol / g, 3.20 to 10.0 mmol / g, 3.30 to 6.00 mmol / g, or 3.40 to 5.20 mmol / g. A hydrocarbon long chain concentration of 2.80 mmol / g or more makes it less likely that the cured product will remain. Furthermore, a hydrocarbon long chain concentration of 50.0 mmol / g or less tends to further improve adhesion to the wafer, i.e., peel strength.

[0125] In this specification, the term "hydrocarbon chain" refers to a linear or branched, saturated or unsaturated hydrocarbon group. The number of carbon atoms in the hydrocarbon long chain is 3 or more, preferably 3 to 20, 3 to 18, or 4 to 16, or 8 to 12.

[0126] The long hydrocarbon chain may be a monovalent group present at the end of a molecule, or a divalent or higher group present within the molecule. The valence of the long hydrocarbon chain is preferably monovalent to tetravalent, monovalent to trivalent, or monovalent to divalent. The long hydrocarbon chain is preferably a saturated hydrocarbon chain, and also preferably a linear hydrocarbon chain. The hydrocarbon chain is particularly preferably a monovalent or divalent linear saturated hydrocarbon group.

[0127] The above-mentioned long hydrocarbon chain is not particularly limited, and examples thereof include monovalent saturated hydrocarbon groups such as propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; monovalent unsaturated hydrocarbon groups such as vinyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, decynyl, dodecynyl, hexadecinyl, and octadecynyl groups; and divalent saturated hydrocarbon groups such as propylene, butylene, pentylene, hexylene, and heptylene groups. Of these, a monovalent saturated hydrocarbon group or a divalent saturated hydrocarbon group is preferred.

[0128] The long hydrocarbon chain may be derived from either the polymerizable compound A or the photopolymerizable initiator B. The concentration of the hydrocarbon chain having 3 or more carbon atoms can be determined from the molecular structure and content of the component contained in the temporary fixing composition. Conventionally known methods can be used for isolating the component, specifying the molecular structure such as by NMR measurement or IR measurement, and quantifying the content.

[0129] The above-mentioned hydrocarbon long chain may be contained in either the polymerizable compound A or the photopolymerizable initiator B, but is preferably contained in the polymerizable compound A, and may not be contained in the photopolymerizable initiator B.

[0130] 1.2. Aromatic Ring Concentration The aromatic ring concentration is 0.60 mmol / g or more, preferably 0.64 to 5.0 mmol / g, 0.68 to 4.0 mmol / g, 0.70 to 3.0 mmol / g, 0.80 to 2.5 mmol / g, 0.90 to 2.4 mmol / g, or 1.00 to 2.2 mmol / g. When the aromatic ring concentration is 0.60 mmol / g or more, the absorbency of laser light, particularly UV laser light having a wavelength in the UV region, is increased, thereby further improving laser removability. In particular, in the temporary fixing composition of this embodiment, the hydrocarbon chain concentration is specified within the above range in order to reduce the amount of residual cured material. Therefore, the bond energy is high and there are many stable carbon-carbon bonds. By setting the aromatic ring concentration to 0.60 mmol / g or more, excellent laser removability can be achieved. Furthermore, by setting the concentration of aromatic rings to 5.0 mmol / g or less, the interaction between the temporary fixing layer 11 and the surface of the wafer W is reduced, and the cured product tends to be less likely to remain.

[0131] In this specification, "aromatic ring" means a cyclic group exhibiting aromaticity. The aromatic ring may be a hydrocarbon aromatic ring composed of carbon and hydrogen, or a heteroaromatic ring containing a heteroatom other than carbon and hydrogen. The heteroaromatic ring preferably contains a nitrogen atom as a heteroatom. The aromatic ring may be a monocyclo ring such as a benzene ring, a bicyclo ring such as a naphthalene ring, or a tricyclo ring such as an anthracene ring, or an aromatic ring consisting of four or more rings, but a monocyclo ring or a bicyclo ring is preferred.

[0132] The concentration of aromatic rings is calculated with each ring exhibiting aromaticity as one unit. For example, even if a structure is composed of multiple rings, if a conjugated system is formed across the multiple rings, such as in naphthalene or anthracene, it is counted as one aromatic ring. On the other hand, even if a structure has multiple adjacent rings, if a conjugated system is not formed across the multiple rings, such as in A-BPEF-2 used in the Examples described below, each aromatic ring contained in the structure is counted as one aromatic ring.

[0133] The aromatic ring may be derived from either the polymerizable compound A or the photopolymerizable initiator B. The concentration of the aromatic ring can be determined from the molecular structure and content of the component contained in the temporary fixing composition. Conventionally known methods can be used for isolating the component, specifying the molecular structure such as by NMR measurement or IR measurement, and quantifying the content.

[0134] The aromatic ring may be contained in either the polymerizable compound A or the photopolymerizable initiator B, but is preferably contained in both the polymerizable compound A and the photopolymerizable initiator B.

[0135] The ratio of the concentration of the long hydrocarbon chains to the concentration of the aromatic rings is preferably 0.80 to 15, 1.0 to 10, 1.1 to 9.0, 1.2 to 8.0, or 1.3 to 7.0. When the ratio of the concentration of the long hydrocarbon chains to the concentration of the aromatic rings is within the above range, the laser removability is further improved, and there is a tendency for the cured product to be less likely to remain.

[0136] 1.3. Crosslink density after curing The crosslink density of the cured product (temporary fixing layer) after irradiating the temporary fixing composition with ultraviolet light is preferably 0.10 mmol / cm ３ or more, and 0.10 to 5.0 mmol / cm ３ , 0.20-3.0 mmol / cm ３ , 0.30-2.0 mmol / cm ３ , 0.35-1.0 mmol / cm ３ The crosslink density of the cured product is 0.10 mmol / cm ３ By satisfying the above conditions, the adhesive strength of the temporary fixing layer tends to be maintained even under high-temperature conditions. As a result, even if a desired heat treatment process or the like is performed before or after step S2, peeling between the wafer and the support member is suppressed during back surface processing of the wafer under high-temperature conditions. In addition, the crosslink density of the cured product is 0.10 mmol / cm ３ By satisfying the above conditions, cohesive failure is less likely to occur, and the amount of the cured product remaining tends to be further reduced.

[0137] The crosslink density of the cured product (temporary fixing layer) can be controlled by adjusting the type of polymerizable compound A. Specifically, the crosslink density after curing can be increased by increasing the content of a polymerizable compound having a small polymerizable functional group equivalent (g / mol).

[0138] The crosslink density of the cured product can be indirectly measured by measuring the storage modulus of the cured product obtained by irradiating the temporary fixing composition with ultraviolet light. Specifically, it may be measured by the method described in the examples.

[0139] 1.4. Viscosity The viscosity of the temporary fixing composition at 23°C is preferably 500 to 10,000 mPa·s, 600 to 9,000 mPa·s, 700 to 8,000 mPa·s, 800 to 7,000 mPa·s, or 1,000 to 6,000 mPa·s. When the viscosity at 23°C is within the above range, the coatability of the temporary fixing composition is further improved.

[0140] The viscosity at 23° C. can be controlled by adjusting the blending ratio of the components contained in the temporary fixing composition. For example, the viscosity of the temporary fixing composition can be reduced by increasing the blending amount of a component with a low viscosity.

[0141] The viscosity at 23°C was measured according to JIS Z8803:2011 at a temperature of 23°C and a shear rate of 1 sec. －１ The viscosity can be measured, for example, by an E-type viscometer (for example, rotation speed: 10 rpm or 2 rpm), and a cone plate can be used as a measuring tool. Specifically, the viscosity can be measured by the method described in the examples.

[0142] 1.5. Composition The temporary fixing composition of this embodiment only needs to contain the polymerizable compound A and the photopolymerization initiator B, and may further contain other components.

[0143] 1.5.1. Polymerizable Compound A The polymerizable compound A is not particularly limited as long as it is a compound having one or more polymerizable functional groups, and examples thereof include polymerizable compound A1 having a hydrocarbon chain with 3 or more carbon atoms, polymerizable compound A2 having an aromatic ring, polymerizable compound A3 having a hydrocarbon chain with 3 or more carbon atoms and an aromatic ring, and other polymerizable compounds A4.

[0144] Among these, it is preferable that the polymerizable compound A includes at least one selected from the group consisting of polymerizable compound A1, polymerizable compound A2, and polymerizable compound A3. By adjusting the contents of polymerizable compounds A1 to A3, it is possible to control the concentrations of hydrocarbon chains having 3 or more carbon atoms and aromatic rings in the temporary fixing composition. In this embodiment, polymerizable compound A1 does not have an aromatic ring, polymerizable compound A2 does not have a long hydrocarbon chain, and polymerizable compound A4 does not have either an aromatic ring or a long hydrocarbon chain. The polymerizable compounds A1 to A4 may each independently be used alone or in combination of two or more.

[0145] In this embodiment, the polymerizable functional group is not particularly limited, but examples thereof include groups having a carbon-carbon double bond such as a vinyl group, an allyl group, a butenyl group, an ethynyl group, an acryloyl group, an acryloyloxy group, an acryloylamino group, a methacryloyl group, a methacryloyloxy group, a methacryloylamino group, a vinyloxy group, a vinylamino group, a cyclopropyl group, and a cyclobutyl group. Among these, a group containing an ethylenic double bond is preferred, and a (meth)acryloyl group is more preferred. In other words, the polymerizable compound A preferably contains a (meth)acrylate.

[0146] The content of the polymerizable compound A is preferably 50 to 99.9 mass %, 70 to 99.5 mass %, 80 to 99.2 mass %, 90 to 99.0 mass %, or 95 to 98.8 mass %, relative to the total amount of the temporary fixing composition. When the content of the polymerizable compound A is within the above range, the laser removability is further improved, and the cured product tends to be less likely to remain.

[0147] Each polymerizable compound will be described in detail below.

[0148] The polymerizable compound A1 is not particularly limited as long as it has a hydrocarbon long chain and one or more polymerizable functional groups. Examples of the polymerizable compound A1 include monofunctional polymerizable compounds such as isostearyl (meth)acrylate; 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate (the number of repeating units may be 1 to 10), neopentyl glycol di(meth)acrylate, C １ ~C ２０ Examples of suitable polyfunctional polymerizable compounds include alkoxylated hydrogenated bisphenol A di(meth)acrylate, neopentyl glycol-modified trimethylolpropane di(meth)acrylate, stearic acid-modified pentaerythritol di(meth)acrylate, caprolactone-modified hydroxypivalic acid neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and ethylene oxide-modified hydrogenated bisphenol A di(meth)acrylate; and polymers having polymerizable functional groups (hereinafter also referred to as "macromonomers") containing, as monomer units, (meth)acrylate monomers containing a hydrocarbon long chain in the side chain and (meth)acrylate monomers containing a (meth)acryloyl group in the side chain. Among these, (meth)acrylates containing a hydrocarbon long chain are preferred.

[0149] Examples of (meth)acrylate monomers containing a long hydrocarbon chain in the side chain include propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, and among these, butyl (meth)acrylate is preferred.

[0150] The (meth)acrylate monomer containing a (meth)acryloyl group in the side chain includes a (meth)acrylate having a (meth)acryloyl group bonded to the side chain via a suitable linker. The linker may be a hydrocarbon chain having 3 to 20 or 4 to 10 carbon atoms and which may contain an ether bond and / or an amide bond.

[0151] The number of carbon atoms in the hydrocarbon long chain of polymerizable compound A1 is 3 or more, preferably 3 to 20, 3 to 18, or 4 to 16, or may be 8 to 12. Polymerizable compound A1 may have hydrocarbon long chains with different numbers of carbon atoms in one molecule, and preferably contains a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms. Such a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms may be a bifunctional (meth)acrylate or a (meth)acrylate having (meth)acryloyl groups at both terminal positions of the molecular chain. The number of carbon atoms in the hydrocarbon chain is preferably 8 to 15. The content of the (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms and the content of polymerizable compound A1 having a hydrocarbon chain with 8 or more carbon atoms are preferably 0 to 70 parts by mass, 10 to 60 parts by mass, or 20 to 55 parts by mass, per 100 parts by mass of the total amount of polymerizable compound A.

[0152] The long hydrocarbon chain functional group equivalent of the polymerizable compound A1 is preferably 100 to 600 g / mol. The polymerizable compound A1 preferably contains a polymerizable compound having a long hydrocarbon chain functional group equivalent of 200 g / mol or less, 100 to 200 g / mol, or 110 to 190 g / mol. When the long hydrocarbon chain functional group equivalent is within the above range, residual residue of the cured product tends to be less likely to occur. The content of the polymerizable compound A1 having a long hydrocarbon chain functional group equivalent within the above range is preferably 5 to 70 parts by mass, 10 to 60 parts by mass, or 15 to 50 parts by mass, per 100 parts by mass of the total amount of the polymerizable compound A.

[0153] The content of polymerizable compound A1 is preferably 50 to 98 parts by mass, 55 to 95 parts by mass, 60 to 92 parts by mass, or 64 to 90 parts by mass, relative to 100 parts by mass of the total amount of polymerizable compound A. By setting the content of polymerizable compound A1 within the above range, there is a tendency that the cured product is less likely to remain.

[0154] The polymerizable compound A2 is not particularly limited as long as it has an aromatic ring and one or more polymerizable functional groups. Examples thereof include monofunctional polymerizable compounds such as phenol ethylene oxide modified (meth)acrylate (the number of repeating units of ethylene oxide is 1 to 5), 2-(2'-hydroxy-5'-(meth)acryloyloxyethylphenyl)-2H-benzotriazole, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl (meth)acrylate, and 2-(2-(meth)acryloyloxy,5-methyl)phenyl-2H-benzotriazole; 9,9-bis[4-(2-hydroxyC １ ~C ２０ 1,3-bis(2-(meth)acryloyloxy)phenyl]fluorene di(meth)acrylate, benzyl di(meth)acrylate, 1,3-bis(2-(meth)acryloyloxy)phenyl]fluorene di(meth)acrylate, １ ~C ２０ Examples of polyfunctional polymerizable compounds include 2,2-bis(4-(meth)acryloxydiethoxyphenyl)propane, 2,2'-dihydroxy-4,4'-diethoxy(meth)acryloyloxybenzophenone, and 1,1-bis-[2-(meth)acryloyloxy,3-(2H-benzotriazol-2-yl),5-tert-octyl]methane. Among these, (meth)acrylates containing an aromatic ring are preferred.

[0155] The aromatic ring equivalent of the polymerizable compound A2 is preferably 100 to 400 g / mol. The polymerizable compound A2 preferably includes a polymerizable compound having an aromatic ring equivalent of 200 g / mol or less, 100 to 200 g / mol, or 110 to 190 g / mol. When the aromatic ring equivalent is within the above range, laser peelability tends to be further improved. The content of the polymerizable compound A2 having an aromatic ring equivalent within the above range is preferably 1 to 45 parts by mass, 2 to 40 parts by mass, or 3 to 35 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A.

[0156] The polymerizable compound A2 preferably contains a polymerizable compound A2-1 containing a group that absorbs light with a wavelength of 350 to 385 nm. The polymerizable compound A2-1 more preferably has an absorption peak for light with a wavelength of 350 to 385 nm. While the absorption peak of an aromatic ring generally has absorption at about 200 nm, when the element adjacent to the aromatic ring is a hetero element such as P, S, or O, the conjugation length increases, and light with a wavelength of 350 to 385 nm is absorbed. By including such a polymerizable compound A2-1, when the temporary fixing layer is irradiated with laser light, the laser light is efficiently absorbed, and laser peelability tends to be improved.

[0157] Examples of such polymerizable compound A2-1 include compounds having one or more skeletons selected from the group consisting of a benzophenone skeleton, a benzotriazole skeleton, a triazole skeleton, a hydroxyphenyltriazine skeleton, and a phenol skeleton. Among these, a phenol skeleton is preferred, and a hindered phenol skeleton is more preferred.

[0158] The content of the polymerizable compound A2 is preferably 2 to 50 parts by mass, 5 to 45 parts by mass, 8 to 40 parts by mass, or 9 to 35 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A. By setting the content of the polymerizable compound A2 within the above range, the laser releasability of the temporary fixing composition can be further improved.

[0159] When the polymerizable compound A2 contains the polymerizable compound A2-1, the content of the polymerizable compound A2-1 is preferably 1 to 30 parts by mass, 2 to 25 parts by mass, 3 to 20 parts by mass, or 5 to 15 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A. By setting the content of the polymerizable compound A2-1 within the above range, the laser releasability of the temporary fixing composition can be further improved.

[0160] The polymerizable compound A3 is not particularly limited, but examples thereof include monofunctional polymerizable compounds such as nonylphenol ethylene oxide modified (meth)acrylate (the number of repeating units of ethylene oxide is 1 to 5); １ ~C ２０Examples include polyfunctional polymerizable compounds such as alkoxylated bisphenol A di(meth)acrylate.

[0161] The long hydrocarbon chain functional group equivalent of polymerizable compound A3 is preferably 100 to 800 g / mol. Polymerizable compound A3 preferably contains a polymerizable compound having a long hydrocarbon chain functional group equivalent of 500 g / mol or less, 100 to 500 g / mol, or 200 to 400 g / mol. Having a long hydrocarbon chain functional group equivalent within the above range tends to make it less likely that the cured product will remain. The content of polymerizable compound A3 having a long hydrocarbon chain functional group equivalent within the above range is preferably 0 to 48 parts by mass, 0 to 40 parts by mass, 0 to 10 parts by mass, or 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of polymerizable compound A.

[0162] The aromatic ring equivalent of the polymerizable compound A3 is preferably 100 to 500 g / mol. The polymerizable compound A3 preferably contains a polymerizable compound having an aromatic ring equivalent of 500 g / mol or less, 100 to 500 g / mol, or 200 to 400 g / mol. When the aromatic ring equivalent is within the above range, laser peelability tends to be further improved. The content of the polymerizable compound A3 having an aromatic ring equivalent within the above range is preferably 0 to 40 parts by mass, 0 to 10 parts by mass, or 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A.

[0163] The number of carbon atoms in the hydrocarbon long chain of polymerizable compound A3 is 3 or more, preferably 3 to 20, 3 to 18, or 4 to 16, or may be 8 to 12. Polymerizable compound A3 may have hydrocarbon long chains with different numbers of carbon atoms in one molecule, and may particularly contain a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms. Such a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms may be a monofunctional (meth)acrylate. The number of carbon atoms in the hydrocarbon chain is preferably 8 to 15.

[0164] The content of the polymerizable compound A3 is preferably 0 parts by mass or more, 3 parts by mass or more, 5 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more, relative to 100 parts by mass of the total amount of the polymerizable compound A. Furthermore, the content of the polymerizable compound A3 is preferably 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, or 10 parts by mass or less, relative to 100 parts by mass of the total amount of the polymerizable compound A. The content of the polymerizable compound A3 may be 0 parts by mass. By setting the content of the polymerizable compound A3 within the above range, the laser releasability of the temporary fixing composition tends to be further improved.

[0165] The polymerizable compound A4 is not particularly limited, but examples thereof include 1,3-di(meth)acryloyloxyadamantane, tricyclo C １０ ~C ２０ Alkanedimethanol di(meth)acrylate, dicyclo C ５ ~C ２０ Examples of the polymerizable compound include polyfunctional polymerizable compounds such as di(meth)acrylate.

[0166] The content of the polymerizable compound A4 is preferably 10 parts by mass or less, 0 to 5 parts by mass, or 0 to 3 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A. The polymerizable compound A4 may not be included.

[0167] Furthermore, the polymerizable compound A preferably contains a polyfunctional polymerizable compound having two or more polymerizable functional groups per molecule, and more preferably contains a monofunctional polymerizable compound having one polymerizable functional group per molecule and a polyfunctional polymerizable compound having two or more polymerizable functional groups per molecule. By including a polyfunctional polymerizable compound, the adhesive strength of the temporary fixing layer formed by curing the temporary fixing composition tends to be increased. Furthermore, by including a monofunctional polymerizable compound in addition to a polyfunctional polymerizable compound, it tends to be easier to control the concentration of the hydrocarbon chain and the concentration of the aromatic ring in the temporary fixing composition.

[0168] The polyfunctional polymerizable compound is preferably a polyfunctional (meth)acrylate. The polyfunctional (meth)acrylate may be a monomer, a macromonomer, or a mixture thereof, but preferably contains a macromonomer. The polyfunctional (meth)acrylate can be produced by methods described in, for example, JP-A Nos. 61-207478, 61-31330, 10-278207, 9-40741, and 8-357621. In this embodiment, the weight-average molecular weight of the polyfunctional (meth)acrylate macromonomer is preferably 5,000 to 500,000, 10,000 to 300,000, 30,000 to 200,000, or 50,000 to 100,000. When the weight average molecular weight is within the above range, the viscosity of the temporary fixing composition and the crosslink density of the cured product tend to be within preferred ranges. The polyfunctional polymerizable compound may be contained as the polymerizable compound A1.

[0169] The weight average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene. Specifically, the weight average molecular weight is determined by using tetrahydrofuran as a solvent, using a GPC system (SC-8010 manufactured by Tosoh Corporation), and creating a calibration curve with commercially available standard polystyrene under the following conditions: Flow rate: 1.0 ml / min Set temperature: 40°C Column configuration: One Tosoh "TSKguard column MP (xL)" 6.0 mm ID x 4.0 cm, and two Tosoh "TSK-GELMULTIPORE HXL-M" 7.8 mm ID x 30.0 cm (theoretical plate number: 16,000), for a total of three (total theoretical plate number: 32,000) Sample injection volume: 100 μl (sample solution concentration: 1 mg / ml) Solution delivery pressure: 39 kg / cm 2 Detector: RI detector

[0170] The polymerizable compound A preferably contains both a monofunctional polymerizable compound and a polyfunctional polymerizable compound. In this case, the content of the monofunctional polymerizable compound is preferably 0.01 to 80 parts by mass, 0.50 to 70 parts by mass, 1.0 to 68 parts by mass, or 3.0 to 67 parts by mass, relative to 100 parts by mass of the total amount of the polyfunctional polymerizable compounds. By setting the content of the monofunctional polymerizable compound within the above range, laser peelability is further improved, the cured product is less likely to remain, and the viscosity and heat resistance tend to be easily adjusted.

[0171] 1.5.2. Photopolymerization Initiator B The photopolymerization initiator B is, for example, preferably a photoradical polymerization initiator, more preferably a compound whose molecules are cleaved and split into two or more radicals upon irradiation with ultraviolet light or visible light.

[0172] The photopolymerization initiator B may be selected from compounds that exhibit appropriate absorption characteristics by measuring their absorbance. Specifically, the photopolymerization initiator B may be selected from one or more compounds that, when dissolved at a concentration of 0.1% by mass in a solvent that does not have a maximum absorption in the wavelength region of 300 to 500 nm (e.g., acetonitrile, toluene, etc.), satisfy one or more of the following conditions: an absorbance of 0.5 or more at a wavelength of 365 nm, an absorbance of 0.5 or more at a wavelength of 385 nm, and an absorbance of 0.5 or more at a wavelength of 405 nm.

[0173] As the photopolymerization initiator B, one or more compounds selected from acylphosphine oxide compounds, titanocene compounds, and α-aminoalkylphenone compounds are preferred because they have excellent reaction speed and heat resistance after curing. These compounds tend to have an absorption wavelength range up to approximately 440 nm and are preferred because they have low absorbance at the wavelength of light used in the step of irradiating the temporary fixing layer with laser light. In other words, the photopolymerization initiator B is a photopolymerization initiator that can initiate radical polymerization with light of a longer wavelength. This allows for a larger difference between the wavelength of the light irradiated when curing the temporary fixing composition and the wavelength of the laser light irradiated when decomposing the temporary fixing layer. Alternatively, an oxime ester compound can be selected as the photopolymerization initiator B.

[0174] Examples of acylphosphine oxide compounds include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc. Among these, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is particularly preferred.

[0175] Examples of titanocene compounds include bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium.

[0176] Examples of the α-aminoalkylphenone compounds include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one, and the like.

[0177] Examples of oxime ester compounds include 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), etc. Among these, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime) is preferred.

[0178] From the viewpoint of exhibiting high absorbance in the wavelength region of 365 to 405 nm, the photopolymerization initiator B is preferably 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, or 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and more preferably bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0179] Also preferred is bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, which exhibits absorption in the longer wavelength range of 400 to 500 nm.

[0180] The content of the photopolymerization initiator B is preferably 0.01 to 10 parts by mass, 0.01 to 5.0 parts by mass, 0.1 to 3.0 parts by mass, or 0.5 to 1.5 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compound A. When the content of the photopolymerization initiator B is within the above range, the adhesive strength of the temporary fixing layer formed using the temporary fixing composition tends to be further increased.

[0181] 1.5.3 Other Components The temporary fixing composition may contain components other than the polymerizable compound A and the photopolymerization initiator B. Examples of such components include compounds that do not fall under the category of polymerizable compounds, such as compounds having an aromatic ring and compounds having a hydrocarbon chain with three or more carbon atoms.

[0182] 2. Uses The temporary fixing composition of this embodiment is suitably used for temporarily fixing a wafer and a support member in a wafer manufacturing method. The temporary fixing composition is preferably applied to the front surface of a wafer, and the wafer and the support member are temporarily fixed together for back surface processing of the wafer. The temporary fixing composition of this embodiment has high laser releasability, and therefore can be suitably used for manufacturing thin wafers having a thickness of several hundred μm. Furthermore, the temporary fixing composition of this embodiment is less likely to leave a cured product, and therefore, even if a temporary fixing layer is formed on the front surface of a wafer, traces of the temporary fixing layer can be suppressed. Therefore, the temporary fixing composition of this embodiment can be suitably used when processing the back surface of a thin wafer.

[0183] 2 , the method for manufacturing a wafer according to this embodiment includes the steps of bonding a wafer and a support member together via the temporary fixing composition of this embodiment (hereinafter referred to as a bonding step S0), curing the temporary fixing composition by irradiating it with ultraviolet light to form a temporary fixing layer, and bonding the wafer and the support member together via the temporary fixing layer (hereinafter referred to as a curing step S1), processing the wafer (hereinafter referred to as a processing step S2), irradiating the temporary fixing layer with laser light (hereinafter referred to as a laser light irradiation step S3), and peeling the support member from the wafer at the interface of the temporary fixing layer (hereinafter referred to as a peeling step S4).

[0184] In the bonding step S0, the wafer is bonded to a support member. The wafer is a substrate to be processed, such as a silicon substrate. The support member is preferably a support member that is at least transparent to ultraviolet light, such as a glass plate.

[0185] The bonding method in the bonding step S0 is not particularly limited, but a method in which the temporary fixing composition of the present embodiment is applied to one surface of a wafer or a support member, and then the other substrate is bonded thereto is preferred.

[0186] As a method for applying the temporary fixing composition, known application methods such as spin coating, screen printing, various coaters, etc. can be used, but spin coating is preferred. Spin coating is a method in which the temporary fixing composition, which is a liquid composition, is dropped onto a wafer or a support member and then rotated at a predetermined rotation speed, thereby applying the composition to the surface of a substrate.

[0187] In the curing step S1, the temporary fixing composition is irradiated with ultraviolet light to cure the temporary fixing composition and bond the wafer and the support member. The temporary fixing composition can be easily irradiated with ultraviolet light by using a transparent substrate that transmits at least ultraviolet light as at least one of the wafer and the support member. When a substrate that transmits ultraviolet light is used as the support member, ultraviolet light may be irradiated from the support member side. Examples of transparent substrates include inorganic substrates such as crystal, glass, quartz, calcium fluoride, and magnesium fluoride, and organic substrates such as plastic, but inorganic substrates are preferred.

[0188] The wavelength of the ultraviolet light can be appropriately selected depending on the type of photopolymerization initiator B, and may be, for example, in the range of 350 to 405 nm. The ultraviolet light has an energy amount in the range of 350 to 405 nm of, for example, 1 to 20,000 mJ / cm. ２ , preferably 1000 to 10000 mJ / cm ２ It is preferable to irradiate so that

[0189] In the processing step S2, the surface of the wafer opposite to the surface to which the support member is attached is processed. Examples of such processing include insulating film formation, circuit formation, ion implantation, thinning by grinding and polishing, etc. The processing step may include, for example, a thinning step by grinding and polishing, and at least one of insulating film formation, circuit formation, and ion implantation. The insulating film formation, circuit formation, and ion implantation may be performed under high-temperature conditions, for example, at 170 to 300°C.

[0190] The laser light irradiation step S3 is a step of irradiating the temporary fixing layer, which is the cured temporary fixing composition, with laser light to decompose the temporary fixing layer. The wavelength of the laser light is preferably 350 to 385 nm. The laser light may be irradiated from the wafer side or the support member side, but is preferably irradiated from the support member side. As described above, when the temporary fixing composition contains an aromatic ring bonded to a heteroatom, it tends to more easily absorb the energy of the laser light in the laser light irradiation step.

[0191] In the peeling step S4, the support member and the wafer are peeled off at the interface of the temporary fixing layer. In the laser light irradiation step, the temporary fixing layer is decomposed, generating gas derived from the decomposed components, and the adhesive strength at the interface between the temporary fixing layer and the wafer or the support member is reduced, thereby enabling the wafer and the support member to be peeled off.

[0192] The wafer manufacturing method of this embodiment preferably includes a step of removing the temporary fixing layer after laser light irradiation from the wafer peeled off from the support member (hereinafter referred to as a removing step S5). By performing the removing step, even if the temporary fixing layer remains on the wafer, the temporary fixing layer can be sufficiently removed.

[0193] The removal step is not particularly limited as long as it can remove the temporary fixing layer remaining on the wafer, but for example, a method of attaching an adhesive tape to the wafer on which the temporary fixing layer remains and then peeling the adhesive tape from the wafer can be mentioned. In such a method, the remaining temporary fixing layer adheres to the adhesive tape, so that the temporary fixing layer can also be removed when the adhesive tape is peeled off from the wafer. As the adhesive tape, for example, a dicing tape used to fix a workpiece in a dicing process in the manufacture of semiconductors, electronic components, and optical components can be used.

[0194] The temporary fixing composition according to the second embodiment may have the features of the temporary fixing composition according to the first embodiment, as long as there is no contradiction.

[0195] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0196] [Example A] 1.1. Raw Materials The following compounds were used as polymerizable compound A. 1.1.1. Polymerizable Compound A1 A1-1: Multifunctional acrylate polymer (weight average molecular weight 72,000, hydrocarbon long chain equivalent: 154.2 g / mol) A-DOD-N: 1,10-decanediol diacrylate ("A-DOD-N" manufactured by Shin-Nakamura Chemical Co., Ltd., in which R = -(CH ２ ) １０ -, hydrocarbon long chain equivalent: 282.4 g / mol) HBPE-4: ethylene oxide modified hydrogenated bisphenol A diacrylate ("HBPE-4" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., m + n = 4 in the structural formula described below, hydrocarbon long chain equivalent: 524.7 g / mol) ISTA: isostearyl acrylate ("ISTA" manufactured by Osaka Organic Chemical Industry Ltd., hydrocarbon long chain equivalent: 324.5 g / mol)

[0197] 1.1.2. Polymerizable Compound A2 A-BPEF-2: 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene diacrylate ("NK Ester A-BPEF-2" manufactured by Shin-Nakamura Chemical Co., Ltd., aromatic ring equivalent: 136.7 g / mol) RUVA-93: 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole ("RUVA-93" manufactured by Otsuka Chemical Co., Ltd., aromatic ring equivalent: 160.7 g / mol) DAINSORB P-66: 2,2'-dihydroxy-4,4'-diacryloyloxybenzophenone ("DAINSORB P-66" manufactured by Daiwa Kasei Co., Ltd., aromatic ring equivalent: 221 g / mol)

[0198] 1.1.3. Polymerizable compound A3 M-113: nonylphenol ethylene oxide modified acrylate ("Aronix M-113" manufactured by Toagosei Co., Ltd., n = 4 in the structural formula described below, hydrocarbon long chain equivalent: 386.6 g / mol, aromatic ring equivalent: 386.6 g / mol)

[0199] The following compound was used as the photopolymerization initiator B: Omnirad 819: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide ("Omnirad 819" manufactured by BASF, aromatic ring equivalent: 137.5 g / mol) was used.

[0200] The structural formula of the above compound is shown below.

[0201] 1.2. Preparation of Temporary Fixing Composition As shown in Table 2, for the Examples and Comparative Examples, the materials were heated and mixed at 60°C to prepare a uniform liquid composition.

[0202]

[0203] 1.3. Measurement of physical properties of temporary fixing composition (viscosity) The viscosity of each composition was measured according to the following method. The results are shown in Table 2. Measuring device: E-type viscometer DV3T-HB (manufactured by Eko Seiki Co., Ltd.) Measuring jig: cone plate CPA-40Z (manufactured by Eko Seiki Co., Ltd.) Measurement temperature: 23°C Rotation speed: 10 rpm (500 mPa s to 2500 mPa s); 2 rpm (2501 mPa s to 10000 mPa s)

[0204] 1.4 Measurement of Peel Strength The peel strength X after heat treatment was measured by the following steps (i) to (iv). The results are shown in the "Heating" column of Table 3.

[0205] (i) A test substrate (aluminum-coated silicon substrate, polyimide-coated silicon substrate, or silicon substrate) was coated with the temporary fixing composition of the Examples or Comparative Examples by spin coating to a thickness of 70 μm, and after laminating a glass plate, the temporary fixing composition was photocured to form a coating film. The photocuring conditions were a curing wavelength of 405 nm and an illuminance of 350 mW / cm. ２ , cumulative irradiation dose 5,600 mJ / cm ２ The substrates used were as follows: Aluminum-coated silicon substrate: Ti / Al coating (lower Ti film 50 μm, upper Al film 100 μm) manufactured by Seiren KST Co., Ltd. Polyimide-coated silicon substrate: wafer with 5 μm non-photosensitive polyimide film manufactured by Seiren KST Co., Ltd. Silicon substrate: P-type <100> (crystal axis) TTV standard wafer manufactured by Silicone Technology Co., Ltd.

[0206] (ii) The test substrate on which the coating was formed was heated at 175° C. for 30 minutes.

[0207] (iii) For a test substrate on which a coating film was formed, an energy density of 920 mJ / cm was applied under the conditions of a wavelength of 355 nm, a frequency of 40 kHz, a spot diameter of 150 μm, and a pulse energy of 165 μJ. ２ After irradiation with the laser beam, the glass plate was peeled off. The laser beam was irradiated so as to scan the entire surface of the test substrate.

[0208] (iv) Peeling tape was applied to the coating film, and a slit was made in the tape and the cured product so that the peel width was 20 mm. The tape with the cured product attached was then pulled under conditions of a peel direction of 180 degrees, a peel width of 20 mm, a peel speed of 120 mm / min, and a temperature of 25°C, and the peel strength when peeling the coating film from the test substrate was measured, and the average value of five measurements was calculated. The measurement conditions were as follows. Apparatus: Tensilon RTG1210A Tape: Elegrip Tape P Tape (manufactured by Denka) Peel direction: 180 degrees Peel width: 20 mm Peel speed: 120 mm / min Temperature: 25°C

[0209] The peel strength Y without heat treatment was measured in the same manner as in the measurement of peel strength X, except that the above step (ii) was not performed. The results are shown in the "Unheated" column of Table 3.

[0210] 1.5. Evaluation of Survivability The temporary fixing composition of the Examples or Comparative Examples was applied to a 4-inch patterned wafer (diameter 10 cm × thickness 0.47 mm) by spin coating to a thickness of 70 μm, and after laminating a glass plate, the temporary fixing composition was photocured to form a test piece. The photocuring conditions were a curing wavelength of 405 nm and an illuminance of 350 mW / cm. ２ , cumulative irradiation dose 5,600 mJ / cm ２ Thereafter, the test piece was placed on a hot plate heated to 175° C. and subjected to heat treatment for 30 minutes.

[0211] The pattern on the patterned wafer consisted of 4 mm square rounded-corner aluminum rectangles arranged at 1 mm intervals, surrounded by polyimide regions. In this pattern, the aluminum regions accounted for 64% of the total area, and the polyimide regions accounted for 36%.

[0212] Next, the test piece was subjected to irradiation with an energy density of 920 mJ / cm under the conditions of a wavelength of 355 nm, a frequency of 40 kHz, a spot diameter of 150 μm, and a pulse energy of 165 μJ. ２ After irradiation with the laser beam, the glass plate was peeled off. The laser beam was irradiated so as to scan the entire surface of the test substrate.

[0213] Next, a peeling tape was attached to the temporary fixing layer, and the tape with the attached temporary fixing layer was pulled under conditions of a peeling direction of 180 degrees, a peeling width of 20 mm, a peeling speed of 120 mm / min, and a temperature of 25°C, to peel the temporary fixing layer from the test substrate. The residual rate (area %) of the temporary fixing layer (referred to as residual rate in the table) was calculated from the residual area of ​​the temporary fixing layer. The results are shown in Table 3.

[0214]

[0215] [Example B] 2.1. Raw Materials The following compounds were used as polymerizable compound A. 2.1.1. Polymerizable Compound A1 A1-1: Multifunctional acrylate polymer (weight average molecular weight 72,000, hydrocarbon long chain equivalent: 154.2 g / mol) A-DOD-N: 1,10-decanediol diacrylate ("A-DOD-N" manufactured by Shin-Nakamura Chemical Co., Ltd., in which R = -(CH ２ ) １０ -, hydrocarbon long chain equivalent: 282.4 g / mol) HBPE-4: ethylene oxide modified hydrogenated bisphenol A diacrylate ("HBPE-4" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., in the structural formula described below, m+n=4, hydrocarbon long chain equivalent: 524.7 g / mol) A-PTMG65: polytetramethylene glycol diacrylate ("A-PTMG65" manufactured by Shin-Nakamura Chemical Co., Ltd., hydrocarbon long chain equivalent: 86.1 g / mol) HX620: caprolactone modified hydroxypivalic acid neopentyl glycol diacrylate ("Kayarad HX-620" manufactured by Nippon Kayaku Co., Ltd., in the structural formula described below, m+n=4, the left and right bonds are bonded, hydrocarbon long chain equivalent: 111.4 g / mol) ISTA: Isostearyl acrylate ("ISTA" manufactured by Osaka Organic Chemical Industry, Ltd., hydrocarbon long chain equivalent: 324.5 g / mol)

[0216] 2.1.2. Polymerizable Compound A2 A-BPEF-2: 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene diacrylate ("NK Ester A-BPEF-2" manufactured by Shin-Nakamura Chemical Co., Ltd., aromatic ring equivalent: 136.7 g / mol) RUVA-93: 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole ("RUVA-93" manufactured by Otsuka Chemical Co., Ltd., aromatic ring equivalent: 160.7 g / mol) P-66: 2,2'-dihydroxy-4,4'-diacryloyloxybenzophenone ("DAINSORB P-66" manufactured by Daiwa Chemical Industry Co., Ltd., aromatic ring equivalent: 221 g / mol)

[0217] 2.1.3. Polymerizable compound A3 ABE300: Ethoxylated bisphenol A diacrylate ("NK Ester ABE-300" manufactured by Shin-Nakamura Chemical Co., Ltd., where R = -CH in the structural formula described below) ２CH ２ O-, m+n=3, hydrocarbon long chain equivalent: 468.5 g / mol, aromatic ring equivalent: 234.3 g / mol) A-BPE-2: ethoxylated bisphenol A diacrylate ("NK Ester A-BPE-2" manufactured by Shin-Nakamura Chemical Co., Ltd., in the structural formula described below, R=-CH ２ CH ２ O-, m = n = 1, hydrocarbon long chain equivalent: 424.5 g / mol, aromatic ring equivalent: 212.2 g / mol) A-BPE-10: Ethoxylated bisphenol A diacrylate ("NK Ester A-BPE-10" manufactured by Shin-Nakamura Chemical Co., Ltd., in the structural formula described below, R = -CH ２ CH ２ O-, m+n=10, hydrocarbon long chain equivalent: 776.9 g / mol, aromatic ring equivalent: 388.5 g / mol) M-113: nonylphenol ethylene oxide modified acrylate ("Aronix M-113" manufactured by Toagosei Co., Ltd., n=4 in the structural formula described below, hydrocarbon long chain equivalent: 386.6 g / mol, aromatic ring equivalent: 386.6 g / mol)

[0218] 2.1.4. Polymerizable compound A4 A-DCP: tricyclodecane dimethanol diacrylate ("A-DCP" manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0219] The following compound was used as the photopolymerization initiator B: Omnirad 819: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide ("Omnirad 819" manufactured by BASF, aromatic ring equivalent: 137.5 g / mol)

[0220] The structural formula of the above compound is shown below.

[0221] 2.2. Preparation of temporary fixing composition As shown in Tables 5 to 7, for each example and comparative example, the materials were heated and mixed at 60°C to prepare a uniform liquid composition. In Tables 5 to 7, the concentration of aromatic rings and the concentration of hydrocarbon chains having 3 or more carbon atoms (shown as "long hydrocarbon chain concentration" in the tables) were calculated from the aromatic ring equivalent and hydrocarbon chain equivalent weights and contents of the raw materials.

[0222] 2.3. Measurement of physical properties of temporary fixing composition (viscosity) The viscosity of each composition was measured according to the following method. The results are shown in Tables 5 to 7. Measuring device: E-type viscometer DV3T-HB (manufactured by Eko Seiki Co., Ltd.) Measuring jig: cone plate CPA-40Z (manufactured by Eko Seiki Co., Ltd.) Measurement temperature: 23°C Rotation speed: 10 rpm (500 mPa s to 2500 mPa s); 2 rpm (2501 mPa s to 10000 mPa s)

[0223] (Crosslink Density of Cured Product) To measure the crosslink density of the cured product of each composition, the storage modulus was measured according to the following method. Next, the storage modulus at 200°C, which is the rubber-like plateau region, was defined as E' [Pa], and the gas constant was defined as R = 8.31 × 10 ７ The crosslink density was calculated by the following formula, where the viscosity is [Pa·L / (K·mol)] and the absolute temperature is T [K]. The results are shown in Tables 5 to 7. Examples and comparative examples for which measurement was not performed are indicated with "-" in the tables. Crosslink density n = E' / 3RT Measuring device: RSA-3 (manufactured by TA Instruments) Measuring mode: Tension Measuring temperature: 23 to 250°C Measuring frequency: 1 Hz Measuring strain: 0.1% Heating rate: 3°C / min Test piece: 0.5 mm x 15 mm x 0.07 mm temporary fixing composition Chuck distance: 10 mm

[0224] 2.4. Performance Measurement of Temporary Fixing Composition (Evaluation of Heat Resistance) A 6-inch silicon wafer (diameter 10 cm × thickness 0.63 mm) and a 6-inch glass support member (diameter 10 cm × thickness 0.7 mm) were bonded using the prepared temporary fixing composition. During bonding, the thickness of the temporary fixing composition was adjusted to 70 μm. After bonding, the temporary fixing composition was irradiated with a UV LED having a wavelength of 405 nm at an illuminance of 100 mW / cm. ２ , irradiation time 50 seconds, cumulative light amount 5000 mJ / cm ２ The test piece was cured under the conditions of , placed on a hot plate heated to 175°C, and heat-treated for 30 minutes to prepare a test piece for evaluation. The temporary fixing composition was applied to the entire surface of the bonding surface. After heating, the test piece was visually observed, and the heat resistance was evaluated depending on whether or not peeling occurred at the adhesive interface. The presence or absence of peeling at the adhesive interface is shown in Tables 5 to 7.

[0225] (Evaluation of Laser Peelability) Test specimens for evaluation were prepared in the same manner as in the evaluation of heat resistance. A UV laser beam with a wavelength of 355 nm was irradiated onto a circular area with a diameter of 160 mm fixed at the center of the obtained 6-inch test specimen, scanning the entire surface of the test specimen from the glass support member side. The laser beam irradiation conditions were a frequency of 40 kHz, a spot diameter of 150 μm, a pulse energy of 165 μJ, and an energy density of 920 mJ / cm. ２ The sample was irradiated with laser light.

[0226] After laser irradiation, the test piece was placed and fixed on a suction table (porous chuck type) with the silicon wafer facing downwards. A suction arm equipped with three 10 mm diameter suction cups was attached to the top surface (glass support member side) of the test piece in this state. The glass support member was peeled off by vertically pulling the suction arm upward at 0.5 mm / s to evaluate laser peelability. The presence or absence of laser peelability is shown in Tables 5 to 7. Cases where peeling was possible were rated "pass", and cases where peeling was not possible were rated "fail".

[0227] (Evaluation of Survivability) In the evaluation of laser peelability, the survivability of the temporary fixing layer was evaluated for test pieces in which the wafer had been peeled from the support member as follows. Tape was applied to the temporary fixing layer side of the wafer from which the support member had been peeled, and a cut was made in the tape and the cured product so that the peel width was 20 mm. The tape with the cured product attached was then pulled and peeled off. The average value of five measured values ​​was calculated. In addition, the residual rate (area %) of the cured product after the tape had been peeled off (represented as residual rate in the table) was calculated. The results are shown in Tables 5 to 7.

[0228] Device: Tensilon RTG1210A Tape: Elegrip Tape P Tape (manufactured by Denka) Peeling direction: 180 degrees Peeling width: 20 mm Peeling speed: 120 mm / min Temperature: 25°C

[0229]

[0230]

[0231]

Claims

1. Peel strength X measured by the following measurement method (X) using polyimide as the test substrate ＰＩ The peel strength Y measured by the following measurement method (Y) using polyimide as a test substrate is 0.50 N / mm or less. ＰＩ The peel strength Y is 0.10 N / mm or more. ＰＩ The peel strength X ＰＩ Ratio of X ＰＩ / Y ＰＩ (X) Peel strength is measured by the following steps (i) to (iv): (i) applying the composition to a test substrate in a thickness of 70 μm, laminating a glass plate thereto, and then photo-curing the composition to form a coating film; (ii) heating the test substrate on which the coating film has been formed at 175°C for 30 minutes; (iii) applying a light beam to the coating film at an energy density of 920 mJ / cm under conditions of a wavelength of 355 nm and a frequency of 40 kHz. ２ (iv) A peeling tape is attached to the coating film, and the coating film is peeled from the test substrate under the conditions of a peeling direction of 180 degrees, a peeling width of 20 mm, a peeling speed of 120 mm / min, and a temperature of 25°C, and the peel strength is measured and the average value of five measurements is taken. (Y) In the measurement method (X), the peel strength is measured without performing the step (ii).

2. The ratio X ＰＩ / Y ＰＩ The composition according to claim 1, wherein is 0.30 to 1.

0.

3. Peel strength X measured by the above measurement method (X) using aluminum as the test substrate Ａｌ The peel strength Y measured by the measurement method (Y) using aluminum as a test substrate is 0.60 N / mm or less. Ａｌ The peel strength Y is 0.10 N / mm or more. Ａｌ The peel strength X Ａｌ Ratio of X Ａｌ / Y Ａｌ The composition of claim 1 , wherein the σ is 2.0 or less.

4. The ratio X Ａｌ / Y Ａｌ The composition according to claim 3, wherein is 1.0 to 2.

0.

5. Peel strength X Ａｌ The peel strength X ＰＩ Ratio of X ＰＩ / X Ａｌ The composition according to claim 3, wherein is 0.10 to 0.

50.

6. Peel strength X measured by the above measurement method (X) using silicon as a test substrate Ｓｉ The peel strength Y measured by the measurement method (Y) using silicon as a test substrate is 0.50 N / mm or less. Ｓｉ The peel strength Y is 0.10 N / mm or more. Ｓｉ The peel strength X Ｓｉ Ratio of X Ｓｉ / Y Ｓｉ The composition of claim 1 , wherein is 1.6 or less.

7. The ratio X Ｓｉ / Y Ｓｉ The composition according to claim 6, wherein is 0.3 to 1.

2.

8. The composition according to claim 1, comprising a polymerizable compound A and a photopolymerization initiator B.

9. The composition according to claim 8, wherein the polymerizable compound A comprises: a polymerizable compound A1 having a hydrocarbon chain with 3 or more carbon atoms; and a polymerizable compound A2 having an aromatic ring.

10. The composition according to claim 9, wherein the polymerizable compound A1 contains a (meth)acrylate having a hydrocarbon chain with 3 or more carbon atoms and a functional group equivalent weight of 200 g / mol or less.

11. The composition according to claim 9, wherein the polymerizable compound A1 comprises a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms.

12. The composition according to claim 9, wherein the polymerizable compound A2 contains a (meth)acrylate having an aromatic ring equivalent of 200 g / mol or less.

13. The composition according to claim 9, wherein the content of the polymerizable compound A1 is 50 parts by mass to 98 parts by mass per 100 parts by mass of the total amount of the polymerizable compound A.

14. The composition according to claim 9, wherein the content of the polymerizable compound A2 is 2 to 50 parts by mass per 100 parts by mass of the total amount of the polymerizable compound A.

15. The composition according to claim 8, wherein the content of the photopolymerization initiator B is 0.01 to 10 parts by mass per 100 parts by mass of the total amount of the polymerizable compound A.

16. A temporary fixing composition containing the composition according to any one of claims 1 to 15.

17. A method for manufacturing a wafer, comprising the steps of: bonding a wafer and a support member via the temporary fixing composition according to claim 16; curing the temporary fixing composition by irradiating it with ultraviolet light to form a temporary fixing layer, and bonding the wafer and the support member together with the temporary fixing layer; heat-treating the wafer; irradiating the temporary fixing layer with laser light; and peeling the support member from the wafer at the interface of the temporary fixing layer.

18. The manufacturing method according to claim 17, further comprising the step of removing the temporary fixing layer from the wafer after the laser light irradiation.

19. Peel strength Y measured by the following measurement method (Y) using polyimide as the test substrate ＰＩ The peel strength X measured by the following measurement method (X) using polyimide as a test substrate against ＰＩ Ratio of X ＰＩ / Y ＰＩ (X) Peel strength is measured by the following steps (i) to (iv): (i) applying the composition to a test substrate in a thickness of 70 μm, laminating a glass plate thereto, and then photo-curing the composition to form a coating film; (ii) heating the test substrate on which the coating film has been formed at 175°C for 30 minutes; (iii) applying a light beam to the coating film at an energy density of 920 mJ / cm under conditions of a wavelength of 355 nm and a frequency of 40 kHz. ２ (iv) A peeling tape is attached to the coating film, and the coating film is peeled from the test substrate under the conditions of a peeling direction of 180 degrees, a peeling width of 20 mm, a peeling speed of 120 mm / min, and a temperature of 25°C, and the peel strength is measured and the average value of five measurements is taken. (Y) In the measurement method (X), the peel strength is measured without performing the step (ii).

20. A composition comprising a polymerizable compound A and a photopolymerization initiator B, wherein the concentration of hydrocarbon chains having 3 or more carbon atoms is 2.80 mmol / g or more, and the concentration of aromatic rings is 0.60 mmol / g or more.

21. The crosslink density of the cured product after UV light irradiation is 0.10 mmol / cm ３ The composition according to claim 20, wherein 22. The composition according to claim 20, wherein the ratio of the concentration of the hydrocarbon chains having 3 or more carbon atoms to the concentration of the aromatic rings is 1.5 or greater.

23. The composition according to claim 20, wherein the polymerizable compound A comprises at least one compound selected from the group consisting of a polymerizable compound A1 having a hydrocarbon chain with 3 or more carbon atoms, a polymerizable compound A2 having an aromatic ring, and a polymerizable compound A3 having a hydrocarbon chain with 3 or more carbon atoms and an aromatic ring.

24. The composition according to claim 23, wherein at least one of the polymerizable compound A1 and the polymerizable compound A3 contains a (meth)acrylate having a hydrocarbon chain with 3 or more carbon atoms and a functional group equivalent weight of 200 g / mol or less.

25. The composition according to claim 23, wherein at least one of the polymerizable compound A1 and the polymerizable compound A3 contains a (meth)acrylate having a hydrocarbon chain with 8 or more carbon atoms.

26. The composition according to claim 23, wherein at least one of the polymerizable compound A2 and the polymerizable compound A3 contains a (meth)acrylate having an aromatic ring equivalent of 200 g / mol or less.

27. The composition according to claim 23, wherein the content of the polymerizable compound A1 is 50 to 98 parts by mass per 100 parts by mass of the total amount of the polymerizable compound A.

28. The composition according to claim 23, wherein the content of the polymerizable compound A2 is 2 to 50 parts by mass per 100 parts by mass of the total amount of the polymerizable compound A.

29. The composition according to claim 23, wherein the content of the polymerizable compound A3 is 0 to 48 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compound A.

30. The composition according to claim 20, wherein the content of the photopolymerization initiator B is 0.01 to 10 parts by mass per 100 parts by mass of the total amount of the polymerizable compound A.

31. The composition according to claim 20, wherein the polymerizable compound A contains a monofunctional polymerizable compound and a polyfunctional polymerizable compound, and the content of the monofunctional polymerizable compound is 0.01 to 60 parts by mass per 100 parts by mass of the total amount of the polyfunctional polymerizable compounds.

32. The composition according to claim 20, having a viscosity at 23°C of 500 mPa·s to 10,000 mPa·s.

33. A temporary fixing composition containing the composition according to any one of claims 20 to 32.

34. A method for manufacturing a wafer, comprising the steps of: bonding a wafer and a support member via the temporary fixing composition according to claim 33; curing the temporary fixing composition by irradiating it with ultraviolet light to form a temporary fixing layer, and bonding the wafer and the support member with the temporary fixing layer; processing the wafer; irradiating the temporary fixing layer with laser light; and peeling the support member and the wafer at the interface of the temporary fixing layer.

35. The manufacturing method according to claim 34, further comprising the step of removing the temporary fixing layer from the wafer after the laser light irradiation.

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