JP6867202B2 - Wafer processing method - Google Patents

Description

The present invention relates to a wafer processing method capable of curing a photocurable adhesive tape even when a support that does not transmit light is used, and the wafer can be easily peeled off from the adhesive tape after the treatment is completed.

In the semiconductor chip manufacturing process, adhesive tape is used to facilitate handling of wafers and semiconductor chips during processing and to prevent damage. For example, when a thick film wafer cut out from a high-purity silicon single crystal or the like is ground to a predetermined thickness to obtain a thin film wafer, grinding is performed after attaching an adhesive tape to the thick film wafer.

The adhesive composition used for such an adhesive tape has high adhesiveness enough to firmly fix the wafer or semiconductor chip during the processing process, and can be peeled off without damaging the wafer or semiconductor chip after the process is completed. Required (hereinafter, also referred to as "high adhesion easy peeling").
As an adhesive composition that achieves high adhesiveness and easy peeling, Patent Document 1 discloses an adhesive tape using a photocurable adhesive that cures by irradiating light such as ultraviolet rays to reduce the adhesive strength. .. By using a photocurable pressure-sensitive adhesive as the pressure-sensitive adhesive, the semiconductor can be reliably fixed during the processing process, and can be easily peeled off by irradiating with ultraviolet rays or the like.

When manufacturing a semiconductor chip using a double-sided adhesive tape using such a photocurable adhesive, one side of the double-sided adhesive tape is attached to a wafer and the other side is attached to a quartz glass support. The wafer is fixed, and then light is irradiated from the support side to cure the adhesive layer.
On the other hand, in recent years, since it is inexpensive and easy to handle, it is being considered to replace the support from quartz glass with aluminum. However, when an aluminum support is used instead of the quartz glass support, the photocurable adhesive cannot be cured by the conventional method because the aluminum does not transmit light, and both sides after the treatment is completed. There is a problem that the wafer cannot be easily peeled off from the adhesive tape.

Japanese Unexamined Patent Publication No. 5-32946

The present invention provides a wafer processing method capable of curing a photocurable adhesive tape even when a support that does not transmit light is used, and the wafer can be easily peeled off from the adhesive tape after the treatment is completed. The purpose is.

The present invention comprises a wafer sticking step of sticking a double-sided adhesive tape having a UV-curable pressure-sensitive adhesive layer and a UV-transmissive UV-non-curable pressure-sensitive adhesive layer to a wafer from the UV-curable pressure-sensitive adhesive layer side. A curing step of irradiating ultraviolet rays from the ultraviolet non-curable adhesive layer side to cure the ultraviolet curable adhesive layer, and attaching the ultraviolet non-curable adhesive layer side of the double-sided adhesive tape to a support. A support sticking step of fixing the wafer to the support via the double-sided adhesive tape, a wafer processing step of processing the wafer fixed to the support, and the wafer being separated from the double-sided adhesive tape. It is a wafer processing method including a peeling step of peeling.
The present invention will be described in detail below.

In the wafer processing method of the present invention, first, a double-sided adhesive tape having an ultraviolet curable adhesive layer and an ultraviolet permeable ultraviolet non-curable adhesive layer is attached to the wafer from the ultraviolet curable adhesive layer side. Perform the wafer sticking process.
Examples of the ultraviolet curable pressure-sensitive adhesive constituting the ultraviolet-curable pressure-sensitive adhesive layer include an ultraviolet-curable pressure-sensitive adhesive containing a polymerizable polymer as a main component and an ultraviolet polymerization initiator as a polymerization initiator. For the polymerizable polymer, for example, a (meth) acrylic polymer having a functional group in the molecule (hereinafter referred to as a functional group-containing (meth) acrylic polymer) is synthesized in advance and reacted with the functional group in the molecule. It can be obtained by reacting a functional group to be subjected to a compound having a radically polymerizable unsaturated bond (hereinafter, referred to as a functional group-containing unsaturated compound).

As a polymer having adhesiveness at room temperature, the functional group-containing (meth) acrylic polymer is an acrylic in which the number of carbon atoms of the alkyl group is usually in the range of 2 to 18, as in the case of a general (meth) acrylic polymer. By using an acid alkyl ester and / or a methacrylate alkyl ester as a main monomer, and copolymerizing this with a functional group-containing monomer and, if necessary, another modifying monomer copolymerizable with these by a conventional method. It is what you get. The weight average molecular weight of the functional group-containing (meth) acrylic polymer is usually about 200,000 to 2,000,000.

Examples of the functional group-containing monomer include a carboxyl group-containing monomer such as acrylate and methacrylic acid, a hydroxyl group-containing monomer such as hydroxyethyl acrylate and hydroxyethyl methacrylate, and an epoxy such as glycidyl acrylate and glycidyl methacrylate. Examples thereof include a group-containing monomer, an isocyanate group-containing monomer such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate, and an amino group-containing monomer such as aminoethyl acrylate and aminoethyl methacrylate.

Examples of the other copolymerizable monomer for modification include various monomers used in general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

As the functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer, the same one as the above-mentioned functional group-containing monomer is used depending on the functional group of the functional group-containing (meth) acrylic polymer. it can. For example, when the functional group of the functional group-containing (meth) acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used, and when the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide is used, and when the functional group is an amino group, an epoxy group-containing monomer is used.

Examples of the ultraviolet polymerization initiator include those activated by irradiating ultraviolet rays having a wavelength of 200 to 410 nm, and examples of such an ultraviolet polymerization initiator include acetophenone derivative compounds such as methoxyacetophenone. , Benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal, phosphine oxide derivative compounds, and bis (η5-cyclopentadienyl) titanosen derivative compounds. Examples thereof include photoradical polymerization initiators such as benzophenone, Michler ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenylketone, and 2-hydroxymethylphenylpropane. These ultraviolet polymerization initiators may be used alone or in combination of two or more.

The ultraviolet curable pressure-sensitive adhesive preferably contains a radically polymerizable polyfunctional oligomer or monomer. By containing a radically polymerizable polyfunctional oligomer or monomer, the ultraviolet curability is improved.
The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight of 5000 or less so that the ultraviolet curable pressure-sensitive adhesive layer can be efficiently reticulated by irradiation with ultraviolet rays. Moreover, the number of radically polymerizable unsaturated bonds in the molecule is 2 to 20.

The polyfunctional oligomer or monomer is, for example, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or the same methacrylate as above. Kind and the like. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the same methacrylates as described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The UV-curable pressure-sensitive adhesive may contain a silicone compound having a functional group that can be crosslinked with the UV-curable pressure-sensitive adhesive. Since the silicone compound has excellent heat resistance, it prevents the adhesive from being scorched even when it is subjected to a treatment involving heating at 200 ° C. or higher in the wafer processing step described later, and bleeds out to the interface of the adherend at the time of peeling. To facilitate peeling. Since the silicone compound has a functional group that can be crosslinked with the UV-curable pressure-sensitive adhesive, it chemically reacts with the UV-curable pressure-sensitive adhesive by irradiation with UV rays or is heated and is incorporated into the UV-curable pressure-sensitive adhesive. , Silicone compound does not adhere to the adherend and contaminate it. Further, by blending the silicone compound, the effect of preventing adhesive residue on the semiconductor chip is also exhibited.

The ultraviolet curable pressure-sensitive adhesive preferably contains an isocyanate-based cross-linking agent.
Examples of the isocyanate-based cross-linking agent include cyclohexylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate and diphenylmethane diisocyanate.

The ultraviolet curable pressure-sensitive adhesive may contain an inorganic filler such as fumed silica, a known additive such as a plasticizer, a resin, a surfactant, a wax, and a fine particle filler.

The thickness of the ultraviolet curable pressure-sensitive adhesive layer is not particularly limited, but the lower limit is preferably 5 μm and the upper limit is preferably 100 μm. When the thickness of the ultraviolet curable pressure-sensitive adhesive layer is within the above range, the wafer can be protected with sufficient adhesive strength. The more preferable lower limit of the thickness of the ultraviolet curable pressure-sensitive adhesive layer is 10 μm, and the more preferable upper limit is 60 μm.

The ultraviolet non-curable adhesive constituting the ultraviolet non-curable adhesive layer is not particularly limited as long as it is ultraviolet transmissive and ultraviolet non-curable, and examples thereof include acrylic, silicone, and urethane adhesives. .. Of these, an acrylic adhesive is preferable because of the selectivity of the adherend. Here, the ultraviolet transmission means that the light absorption wavelength band of the ultraviolet polymerization initiator contained in the ultraviolet curable pressure-sensitive adhesive layer and the wavelength band that transmits light of the ultraviolet non-curable pressure-sensitive adhesive layer overlap. In particular, it is preferable that the light absorption wavelength band of the ultraviolet polymerization initiator contained in the ultraviolet curable pressure-sensitive adhesive layer and the wavelength band of the ultraviolet non-curable pressure-sensitive adhesive layer having an absorbance of 0.2 or less overlap.

The UV non-curable pressure-sensitive adhesive layer preferably contains an epoxy cross-linking agent.
When the ultraviolet non-curable pressure-sensitive adhesive layer contains an epoxy cross-linking agent, the heat resistance of the ultraviolet non-curable pressure-sensitive adhesive layer can be improved. Examples of the epoxy cross-linking agent include N, N, N', N'-tetraglycidyl-1,3-benzenedi (methaneamine) and the like.

The ultraviolet non-curable pressure-sensitive adhesive layer contains an inorganic filler such as fumed silica, a plasticizer, a resin, a surfactant, a wax, a fine particle filler, and other known additives, similarly to the ultraviolet-curable pressure-sensitive adhesive. You may.

The thickness of the ultraviolet non-curable pressure-sensitive adhesive layer is not particularly limited, but the lower limit is preferably 5 μm and the upper limit is preferably 100 μm. When the thickness of the ultraviolet non-curable pressure-sensitive adhesive layer is within the above range, it adheres to the support with sufficient adhesive force, and the wafer can be reliably fixed. The more preferable lower limit of the thickness of the ultraviolet non-curable pressure-sensitive adhesive layer is 10 μm, and the more preferable upper limit is 60 μm.

The double-sided adhesive tape may be a support type having a base material or a non-support type having no base material. When the double-sided adhesive tape has a base material between the ultraviolet curable pressure-sensitive adhesive layer and the ultraviolet non-curable pressure-sensitive adhesive layer, handleability can be improved. The base material is preferably ultraviolet-transparent so that the ultraviolet-curable pressure-sensitive adhesive layer can be cured in the curing step described later.

The base material is not particularly limited as long as it is transparent to ultraviolet rays, and is, for example, polyethylene naphthalate (PEN), polyimide (PI), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyethylene terephthalate (PET), poly. Examples thereof include butylene terephthalate (PBT), polyhexamethylene terephthalate, polybutylene naphthalate, butane terephthalate butanediol polytetramethylene glycol copolymer, butane terephthalate butanediol polycaprolactone copolymer and the like. Of these, polyethylene naphthalate is preferable because it has excellent heat resistance.

The preferred thickness of the base material is 12 μm at the lower limit and 100 μm at the upper limit. When the thickness of the base material is within the above range, the wafer can be sufficiently protected and a double-sided adhesive tape having excellent handleability can be obtained.

The double-sided adhesive tape preferably has an ultraviolet-transmissive release film laminated on a surface of the ultraviolet non-curable adhesive layer opposite to the surface on which the ultraviolet-curable adhesive layer is laminated.
By having the release film on the ultraviolet non-curable adhesive layer, the ultraviolet non-curable adhesive layer can be protected until the time of sticking, and the handleability of the double-sided adhesive tape can be improved. Further, since the release film is ultraviolet-transparent, the curing step described later can be performed while protecting the ultraviolet non-curable pressure-sensitive adhesive layer.

The ultraviolet-transparent release film is not particularly limited as long as it is ultraviolet-transmissive, and is, for example, polyethylene terephthalate (PEN), polyimide (PI), polyetheretherketone (PEEK), polyphenylene terephide (PPS), or polyethylene. Examples thereof include terephthalate (PET), polybutylene terephthalate (PBT), polyhexamethylene terephthalate, polybutylene naphthalate, butanediol terephthalate polytetramethylene glycol copolymer, butanediol terephthalate polycaprolactone copolymer and the like. Of these, polyethylene terephthalate (PET) is preferable.

In the wafer processing method of the present invention, a curing step of irradiating ultraviolet rays from the ultraviolet non-curable pressure-sensitive adhesive layer side to cure the ultraviolet-curable pressure-sensitive adhesive layer is then performed.
In the conventional wafer processing method, since the wafer and the support are fixed via the double-sided adhesive tape and then photo-cured, the photo-curing cannot be performed when the support is a material that does not transmit light. .. However, in the wafer processing method of the present invention, since the ultraviolet curable adhesive layer is cured before the double-sided adhesive tape is attached to the support, the adhesive is cured even if the support is a material that does not transmit light. The wafer can be easily peeled off after the processing is completed. In addition, since the UV-non-curable adhesive layer of the double-sided adhesive tape is UV-transmissive, even if the UV-curable pressure-sensitive adhesive layer is irradiated with UV rays from the UV-non-curable pressure-sensitive adhesive layer side, the UV-curable adhesive layer is sufficiently UV-curable. The agent can be cured. Further, since the UV-curable pressure-sensitive adhesive layer is cured after being attached to the wafer, the wafer is immediately peeled off even if the UV-curable pressure-sensitive adhesive layer is cured before processing the wafer. There is no such thing.

The light irradiation conditions for curing the ultraviolet curable pressure-sensitive adhesive layer can be appropriately adjusted by the combination of the polymerizable polymer used and the photopolymerization initiator. For example, when a polymerizable polymer having an unsaturated double bond such as a vinyl group in the side chain and a photopolymerization initiator activated at a wavelength of 200 to 410 nm are used, by irradiating light with a wavelength of 365 nm or more, The ultraviolet curable pressure-sensitive adhesive layer can be crosslinked and cured.
For such an ultraviolet curable pressure-sensitive adhesive layer, for example, it is preferable to irradiate light having a wavelength of 365 nm with an illuminance of 5 mW or more, more preferably with an illuminance of 10 mW or more, and irradiate with an illuminance of 20 mW or more. It is more preferable to irradiate with an illuminance of 50 mW or more. Further, it is preferable to irradiate light having a wavelength of 365 nm with an integrated illuminance of 300 mJ or more, more preferably with an integrated illuminance of 500 mJ or more and 10,000 mJ or less, and further preferably with an integrated illuminance of 500 mJ or more and 7500 mJ or less. It is particularly preferable to irradiate with an integrated illuminance of 1000 mJ or more and 5000 mJ or less.

In the wafer processing method of the present invention, the wafer is fixed to the support via the double-sided adhesive tape by attaching the ultraviolet non-curable adhesive layer side of the double-sided adhesive tape to the support. Perform the attachment process.
In the present invention, since the adhesive layer of the double-sided adhesive tape is divided into an ultraviolet curable adhesive layer and an ultraviolet non-curable adhesive layer, even if the curing step is performed before the support is attached, the ultraviolet non-curing The curable pressure-sensitive adhesive layer does not cure, and the double-sided adhesive tape can be attached to the support with sufficient adhesive strength. When the double-sided adhesive tape has the release film, the release film is peeled off from the end of the curing step to the front of the support attaching step.

In the wafer processing method of the present invention, a wafer processing step of processing the wafer fixed to the support is then performed.
Examples of the treatment on the wafer include a grinding treatment for grinding the wafer to a certain thickness, a chemical liquid treatment, a heat treatment, and a treatment accompanied by heat generation. Examples of the chemical treatment include plating treatments such as electrolytic plating and electroless plating, wet etching treatments with hydrofluoric acid and tetramethylammonium hydroxide aqueous solution (TMAH), N-methyl-2-pyrrolidone, monoethanolamine, DMSO and the like. Examples thereof include a resist stripping process using, and a cleaning process using concentrated sulfuric acid, aqueous ammonia, aqueous hydrogen peroxide, and the like. Examples of the heat treatment or the treatment accompanied by heat generation include sputtering, vapor deposition, etching, chemical vapor deposition (CVD), physical vapor deposition (PVD), resist coating / patterning, and reflow. In the wafer processing method of the present invention, since the ultraviolet curable pressure-sensitive adhesive layer is cured before the wafer processing step, the adhesive is promoted even when the wafer processing step is performed with a high temperature of 200 ° C. or higher. The wafer can be easily peeled off after the processing is completed.

The wafer processing method of the present invention then includes a peeling step of peeling the wafer from the double-sided adhesive tape.
Since the ultraviolet curable pressure-sensitive adhesive layer is crosslinked and cured in the above curing step, the wafer can be easily peeled off from the double-sided adhesive tape without adhesive residue. Moreover, since the time required for peeling is shortened, the production efficiency can be improved.

According to the present invention, there is a wafer processing method capable of curing a photocurable adhesive tape even when a support that does not transmit light is used, and easily peeling the wafer from the adhesive tape after the treatment is completed. Can be provided.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1)
(Manufacturing of UV curable adhesive)
A reactor equipped with a thermometer, a stirrer, and a cooling tube is prepared, and 94 parts by weight of 2-ethylhexyl acrylate as the (meth) acrylic acid alkyl ester and 6 parts by weight of hydroxyethyl methacrylate as the functional group-containing monomer are prepared in the reactor. , 0.01 part by weight of lauryl mercaptan and 80 parts by weight of ethyl acetate were added, and then the reactor was heated to start reflux. Subsequently, 0.01 part by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added as a polymerization initiator into the reactor, and the polymerization was started under reflux. It was. Next, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added 1 hour and 2 hours after the start of the polymerization, and further, the polymerization was started. After 4 hours from the above, 0.05 parts by weight of t-hexyl peroxypivalate was added to continue the polymerization reaction. Then, 8 hours after the start of the polymerization, an ethyl acetate solution of a functional group-containing (meth) acrylic polymer having a solid content of 55% by weight and a weight average molecular weight of 600,000 was obtained.
To 100 parts by weight of the resin solid content of the obtained ethyl acetate solution containing a functional group-containing (meth) acrylic polymer, 3.5 parts by weight of 2-isocyanatoethyl methacrylate was added as a functional group-containing unsaturated compound to react. The mixture was allowed to obtain a polymerizable polymer. Then, with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution of the obtained polymerizable polymer, 20 parts by weight of silicone acrylate (EBECRYL 350, manufactured by Daicel Ornex) and silica filler (Leoloseal MT-10, manufactured by Tokuyama). 20 parts by weight, 0.5 part by weight of chemical cross-linking material (Coronate L, manufactured by Nippon Urethane Industry Co., Ltd.), and 1 part by weight of photopolymerization initiator (Esacure One, manufactured by Nihon Shibel Hegner) are mixed, and acetic acid, which is an ultraviolet curable adhesive An ethyl solution was obtained.

(Manufacturing of UV non-curable adhesive)
66.9 parts by weight of butyl acrylate, 30 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of acrylic acid, 0.1 parts by weight of 2-hydroxyethyl acrylate, and ethyl acetate in a reactor equipped with a thermometer, a stirrer, and a cooling tube. After adding 120 parts by weight and substituting with nitrogen, the reactor was heated to start reflux. Subsequently, 0.1 part by weight of azobisisobutyronitrile was added as a polymerization initiator into the reactor. The mixture was refluxed at 70 ° C. for 5 hours to obtain a solution of the acrylic copolymer (a). The weight average molecular weight of the obtained acrylic copolymer (a) was measured by the GPC method using "2690 Separations Model" manufactured by Water Co., Ltd. as a column, and it was 1.3 million.
An epoxy-based cross-linking agent (trade name "E-5C" manufactured by Soken Kagaku Co., Ltd.) was applied to 100 parts by weight of the solid content of the acrylic copolymer (a) contained in the obtained solution of the acrylic copolymer (a). 0.1 part by weight was added in terms of solid content ratio, and the mixture was stirred to obtain an ethyl acetate solution of an ultraviolet non-curable pressure-sensitive adhesive.

(Manufacturing of double-sided adhesive tape)
The obtained ethyl acetate solution of the ultraviolet curable adhesive was applied with a doctor knife on a 50 μm polyethylene terephthalate (PET) film having a mold release treatment on one side so that the thickness of the dry film was 40 μm. The coating solution was dried by heating at 110 ° C. for 5 minutes to obtain an ultraviolet curable pressure-sensitive adhesive layer.
The obtained ethyl acetate solution of UV non-curable adhesive was applied with a doctor knife on a transparent PET film with a thickness of 50 μm, which had been released on one side, so that the thickness of the dry film was 40 μm. , 110 ° C. for 5 minutes to dry the coating solution to obtain an ultraviolet non-curable pressure-sensitive adhesive layer.
A double-sided adhesive tape was obtained by laminating the surfaces of the obtained UV-curable pressure-sensitive adhesive layer and the UV-non-curable pressure-sensitive adhesive layer on which the PET films were not laminated.

(Wafer processing)
The surface of the double-sided adhesive tape on the UV curable adhesive layer side was attached to a silicon wafer having a diameter of 20 cm and a thickness of 700 μm to obtain a laminate. Next, using a high-pressure mercury UV irradiator, the illuminance is adjusted so that the irradiation intensity of the surface of the semiconductor protective tape is 100 mW / cm ² with ultraviolet rays of 365 nm, and the ultraviolet rays are irradiated from the non-curable adhesive layer side for 30 seconds. The UV curable pressure-sensitive adhesive layer was crosslinked and cured. Then, the ultraviolet non-curable pressure-sensitive adhesive layer of the laminated body was attached to an aluminum support, and heat treatment at 260 ° C. for 6 minutes was performed a total of 3 times. When the silicon wafer was peeled from the double-sided adhesive tape after the heat treatment was completed, the silicon wafer could be easily peeled off.

(Example 2)
The ethyl acetate solution of the ultraviolet curable adhesive obtained in Example 1 was applied to a 50 μm polyethylene terephthalate (PET) film having a mold release treatment on one side with a doctor knife so that the thickness of the dry film was 20 μm. The coating was applied and heated at 110 ° C. for 5 minutes to dry the coating solution to obtain an ultraviolet curable pressure-sensitive adhesive layer.
On the other hand, the ethyl acetate solution of the ultraviolet non-curable adhesive obtained in Example 1 was applied onto a transparent PET film having a thickness of 50 μm on which one side was released, and the thickness of the dry film was 20 μm. The coating was applied with a doctor knife and heated at 110 ° C. for 5 minutes to dry the coating solution to obtain an ultraviolet non-curable pressure-sensitive adhesive layer. The obtained UV-curable pressure-sensitive adhesive layer is bonded to one side of a 25 μm-thick PEN film with corona treatment on both sides, and the obtained UV-non-curable pressure-sensitive adhesive layer is bonded to the other side. I got an adhesive tape.
When the obtained double-sided adhesive tape was treated with a wafer in the same manner as in Example 1, the silicon wafer could be easily peeled off.

(Comparative Example 1)
(Wafer processing)
The surface of the double-sided adhesive tape obtained in Example 1 on the UV curable adhesive layer side was attached to a silicon wafer having a diameter of 20 cm and a thickness of 700 μm, and the surface on the UV non-curable adhesive layer side was supported by aluminum. I stuck it on my body. Next, using a high-pressure mercury UV irradiator, the illuminance was adjusted so that the irradiation intensity of the support surface was 100 mW / cm ² and the ultraviolet rays of 365 nm were irradiated from the support side for 30 seconds. Then, the laminate was heat-treated at 260 ° C. for 6 minutes a total of 3 times. After the heat treatment was completed, an attempt was made to peel the silicon wafer from the double-sided adhesive tape, but the silicon wafer could not be peeled.

According to the present invention, there is a wafer processing method capable of curing a photocurable adhesive tape even when a support that does not transmit light is used, and easily peeling the wafer from the adhesive tape after the treatment is completed. Can be provided.

Claims (6)

A wafer sticking step of sticking a double-sided adhesive tape having a UV curable pressure-sensitive adhesive layer and a UV-transparent UV non-curable pressure-sensitive adhesive layer to a wafer from the UV-curable pressure-sensitive adhesive layer side.
A curing step of irradiating ultraviolet rays from the ultraviolet non-curable pressure-sensitive adhesive layer side to cure the ultraviolet-curable pressure-sensitive adhesive layer, and
A support attaching step of fixing the wafer to the support via the double-sided adhesive tape by attaching the ultraviolet non-curable adhesive layer side of the double-sided adhesive tape to the support.
A wafer processing step of processing the wafer fixed to the support and
A wafer processing method comprising a peeling step of peeling the wafer from the double-sided adhesive tape. The first aspect of claim 1, wherein the light absorption wavelength band of the ultraviolet polymerization initiator contained in the ultraviolet curable pressure-sensitive adhesive layer and the wavelength band having an absorbance of 0.2 or less of the ultraviolet non-curable pressure-sensitive adhesive layer overlap. Wavelength processing method. The wafer processing method according to claim 1 or 2, wherein the ultraviolet non-curable pressure-sensitive adhesive layer contains an epoxy cross-linking agent. The wafer according to claim 1, 2 or 3, wherein the ultraviolet curable pressure-sensitive adhesive constituting the ultraviolet-curable pressure-sensitive adhesive layer contains a silicone compound having a crosslinkable functional group with the ultraviolet-curable pressure-sensitive adhesive. Processing method. The wafer according to claim 1, 2, 3 or 4 , wherein an ultraviolet-transmissive base material is provided between the ultraviolet-curable pressure-sensitive adhesive layer and the ultraviolet-transparent non-ultraviolet-curable pressure-sensitive adhesive layer. Processing method. Claims 1 and 2 are characterized in that an ultraviolet-transmissive release film is laminated on a surface of the ultraviolet non-curable pressure-sensitive adhesive layer opposite to the surface on which the ultraviolet-curable pressure-sensitive adhesive layer is laminated. 3, 4 or 5 The wafer processing method.