JP6802029B2 - Semiconductor protective tape - Google Patents

Description

The present invention relates to an adhesive tape and a semiconductor protective tape that can prevent peeling and generation of residues without lowering the transparency even when plasma ashing is performed in a state where the adhesive tape is attached to a semiconductor device and reinforced.

In the semiconductor chip manufacturing process, it is common practice to reinforce the semiconductor chip with an adhesive tape (semiconductor wafer protective tape) in order to facilitate handling during processing of the semiconductor chip and prevent it from being damaged. .. 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, an adhesive tape is attached for the purpose of protecting the wafer and then the grinding process is performed. ing. Further, while the wafer is reinforced with an adhesive tape, it is also electrically connected to an electrode on a substrate or another semiconductor chip.
As such a semiconductor wafer protective tape, for example, in Patent Document 1, a crosslinked polymer layer is formed on one side of a base film, and the surface on which the crosslinked polymer layer is formed is adjusted to be peelable. A back grind tape in which an adhesive layer for attaching a wafer is laminated, and the tensile elasticity of the base film is 2 GPa or more on average in the longitudinal direction and the width direction of the film, and the back grind tape A back grind tape having a warp of 4 mm or less is disclosed.

In recent years, plasma ashing may be performed in order to smooth the surface of the surface treatment layer in the manufacture of semiconductor devices. Plasma ashing is a method in which oxygen gas is converted into plasma using non-ionizing radiation such as visible light or microwaves, and organic substances are oxidized and evaporated to carbon dioxide, water, etc. by oxygen radicals generated thereby to remove them. By plasma ashing, the polyamide resin and polyimide resin used for the surface treatment layer can be removed and ground without damaging the wafer of the semiconductor device. However, if plasma ashing is performed with the conventional adhesive tape attached, there is a problem that the adhesive tape is peeled off. Further, when the adhesive tape is peeled off after the processing of the semiconductor device, there is also a problem that adhesive residue (residue) is generated in the semiconductor device.

Problems of peeling and residue of the adhesive tape have conventionally occurred in the process of performing chemical solution treatment or high temperature treatment, and various countermeasures have been proposed. For example, Patent Document 2 describes an adhesive tape for protecting the surface of a semiconductor wafer, which has a base material made of a composite of a high elastic modulus layer and a low elastic modulus layer, so that peeling failure and adhesive residue can be prevented even when used in an etching process. Is disclosed. However, although such conventional chemical-resistant and heat-resistant adhesive tapes are highly effective in the steps of chemical treatment and high-temperature treatment, they prevent the adhesive tape from peeling off and adhesive residue in the plasma ashing process. I couldn't.

Further, when plasma ashing is performed with the adhesive tape attached, there is a problem that the adhesive tape becomes cloudy and the transparency is lowered. The semiconductor device after plasma ashing is connected to a substrate or the like, and at that time, alignment is performed to adjust the connection position by light. However, when the adhesive tape becomes cloudy, it becomes difficult for light to pass through, so that accurate alignment cannot be performed, and alignment may be poor.

Japanese Unexamined Patent Publication No. 2010-34379 Japanese Unexamined Patent Publication No. 2013-225647

The present invention provides an adhesive tape and a semiconductor protective tape that can prevent peeling and generation of residues without lowering the transparency even when plasma ashing is performed in a state where the adhesive tape is attached to a semiconductor device and reinforced. The purpose is.

The present invention is an adhesive tape having a curable pressure-sensitive adhesive layer containing at least a curable resin, a polymerization initiator, and a cross-linking agent, and an inorganic base material layer composed of an inorganic substance.
The present invention will be described in detail below.

The present inventors have investigated the problem of adhesive tape peeling and adhesive residue occurring in the plasma ashing process. As a result, it was found that the cause was that the pressure-sensitive adhesive layer and the base material of the pressure-sensitive adhesive tape were decomposed by plasma.
As shown in FIG. 1A, the semiconductor device 2 before plasma ashing has a surface treatment layer 3 laminated on one surface, and an adhesive tape composed of a base material 11 and an adhesive layer 12 on the other surface. 1 is pasted. The semiconductor device reinforced by the adhesive tape is placed on a pier 4 having a small contact area for the purpose of preventing damage to the semiconductor device (hereinafter, a state in which the semiconductor device is placed on the pier 4 is "hollow". State ".).
When plasma ashing is performed on such a semiconductor device, as shown in FIG. 1 (b), the adhesive layer 12 of the adhesive tape is decomposed by plasma from the peripheral portion, and the adhesive tape is peeled off. This decomposition proceeds toward the center of the semiconductor device, but does not occur evenly, and a part of the adhesive around the semiconductor device 2 may remain undecomposed and become a residue. Further, since the pressure-sensitive adhesive layer is divided into a portion around the base material 11 and a portion around the semiconductor device 2 by decomposition, the pressure-sensitive adhesive around the semiconductor device 2 tends to remain as a residue during the peeling step of the adhesive tape.

Further, since the conventional adhesive tape uses a polymer such as polypropylene or polyethylene terephthalate for the base material 11, it is decomposed by plasma in the same manner as the adhesive layer 12. At this time, the decomposition does not occur uniformly, and fine irregularities are formed on the surface of the base material 11 depending on the degree of decomposition. The fine uneven structure scatters light and hinders the transmission of light, resulting in a decrease in transparency and white turbidity. Further, when the base material 11 is decomposed, the stress of the base material changes and the base material shrinks, so that the adhesive tape 1 is warped, which causes peeling and residue. In particular, when the plasma ashing is performed in a hollow state, the plasma invades through the gap of the table and easily comes into contact with the base material 11, so that the adhesive tape tends to become cloudy or peeled off.

As a result of further studies based on the above findings, the present inventors have obtained an adhesive tape by using an adhesive tape having an inorganic base material layer made of an inorganic substance and a curable adhesive layer containing a curable resin. We have found that it is possible to prevent white turbidity, peeling, and generation of residue of the adhesive tape even when plasma ashing is performed while the adhesive tape is attached to the semiconductor device, and the present invention has been completed.

The pressure-sensitive adhesive tape of the present invention has a curable pressure-sensitive adhesive layer containing at least a curable resin, a polymerization initiator, and a cross-linking agent.
The curable pressure-sensitive adhesive layer containing the curable resin and the polymerization initiator acquires resistance to plasma by being cured by an external stimulus. As a result, peeling and residue generated by the plasma decomposing the peripheral edge of the pressure-sensitive adhesive layer can be suppressed. Further, since the curable pressure-sensitive adhesive layer contains a cross-linking agent, a sufficient cross-linked structure can be formed at the time of curing, so that the resistance to plasma can be further enhanced.

Examples of the stimulus for cross-linking and curing the curable resin include light, heat, electromagnetic waves, electron beams, and ultrasonic waves. Of these, light or heat is preferable.
When the curable resin is photocurable, the polymerization initiator is preferably excited by stimulation with light.
Examples of the resin component when the curable resin is photocurable include a photocurable component containing a polymerizable polymer as a main component and a photopolymerization initiator.
When the curable resin is thermosetting, the polymerization initiator is preferably excited by heat stimulation.
Examples of the resin component when the curable resin is thermosetting include a thermosetting component containing a polymerizable polymer as a main component and a thermosetting 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 reacts with the functional group in the molecule. It can be obtained by reacting with a compound having a functional group and 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 carboxyl group-containing monomers such as acrylate and methacrylate; hydroxyl group-containing monomers such as hydroxyethyl acrylate and hydroxyethyl methacrylate; and epoxy groups such as glycidyl acrylate and glycidyl methacrylate. Monomer: An isocyanate group-containing monomer such as isocyanate ethyl acrylate and ethyl methacrylate; an amino group-containing monomer such as aminoethyl acrylate and aminoethyl methacrylate can be mentioned.

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 photopolymerization initiator include those that are activated by irradiating light having a wavelength of 250 to 800 nm, and examples of such a photopolymerization 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; bis (η5-cyclopentadienyl) titanosen derivative compounds, benzophenone, Michler ketone, Examples thereof include photoradical polymerization initiators such as chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenylketone, and 2-hydroxymethylphenylpropane. Of these, a photopolymerization initiator excited by ultraviolet rays is preferable. These photopolymerization initiators may be used alone or in combination of two or more.

When the curable pressure-sensitive adhesive layer contains, for example, a polymer having an unsaturated double bond such as a vinyl group in the side chain and a photopolymerization initiator that activates at a wavelength of 250 to 800 nm, light having a wavelength of 365 nm or more is emitted. By irradiating, the photocurable pressure-sensitive adhesive layer can be crosslinked and cured.
For such a 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, and it is particularly 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.

Examples of the above-mentioned thermal polymerization initiator include those that are decomposed by heat to generate active radicals that initiate polymerization. For example, dicumyl peroxide, di-t-butyl peroxide, t-butylperoxybenzoate, t- Examples thereof include butylhydroperoxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramentan hydroperoxide, and di-t-butyl peroxide. These thermal polymerization initiators may be used alone or in combination of two or more.

Examples of the above-mentioned cross-linking agent include isocyanate-based cross-linking agents, aziridine-based cross-linking agents, epoxy-based cross-linking agents, and metal chelate-type cross-linking agents. In particular, an isocyanate-based cross-linking agent is preferable because it has excellent adhesion stability to the substrate. Examples of the isocyanate-based cross-linking agent include Coronate HX (manufactured by Nippon Polyurethane Industry Co., Ltd.), Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.), Mitec NY260A (manufactured by Mitsubishi Chemical Corporation), and the like. These cross-linking agents may be used alone or in combination of two or more.

The amount of the cross-linking agent used is not particularly limited, but the preferable lower limit is 0.05 parts by weight and the preferable upper limit is 10 parts by weight with respect to 100 parts by weight of the curable resin. When the amount of the above-mentioned cross-linking agent used is within this range, the curable pressure-sensitive adhesive layer can be sufficiently cross-linked.

The curable pressure-sensitive adhesive layer preferably further contains a radically polymerizable polyfunctional oligomer or monomer. Curability is improved by containing a radically polymerizable polyfunctional oligomer or monomer.
The radically polymerizable 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 and a molecule so that the cured component can be efficiently reticulated in three dimensions. The number of radically polymerizable unsaturated bonds in the structure is 2 to 20.

The radically polymerizable polyfunctional oligomer or monomer is, for example, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or. Examples thereof include the same methacrylates as described above. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polypropylene glycol # 700 diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the same methacrylates as described above. These radically polymerizable polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The curable pressure-sensitive adhesive layer may contain a gas generating agent that generates a gas by stimulation. When the curable pressure-sensitive adhesive layer contains the gas generator, it is easier to generate gas from the gas generator by stimulating the curable pressure-sensitive adhesive layer in the adhesive tape peeling step described later. In addition, the adhesive tape can be peeled off from the semiconductor device without leaving adhesive residue.

The gas generating agent is not particularly limited, and for example, conventionally known gas generating agents such as azo compounds and azido compounds can be used, but carboxylic acid compounds such as ketoprofene and 2-xanthone acetic acid or salts thereof, 1H- It is preferable to use a tetrazole compound such as tetrazole, 5,5'-bistetrazole diammonium salt, 5,5'-bistetrazoleamine monoammonium salt, or a gas generator having excellent heat resistance such as a salt thereof.

The content of the gas generating agent in the curable pressure-sensitive adhesive layer is not particularly limited, but the preferable lower limit is 5 parts by weight and the preferable upper limit is 50 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the gas generating agent is within this range, a sufficient peeling property improving effect can be obtained. The more preferable lower limit of the content of the gas generating agent is 10 parts by weight, and the more preferable upper limit is 30 parts by weight.

The curable pressure-sensitive adhesive layer may further contain an inorganic filler such as fumed silica. By blending the inorganic filler, the cohesive force of the curable pressure-sensitive adhesive layer is increased. Therefore, when protection becomes unnecessary after the reflow step, the adhesive tape can be easily peeled off from the semiconductor chip without adhesive residue.

The curable pressure-sensitive adhesive layer may further contain a silicone compound. In particular, when the curable pressure-sensitive adhesive layer contains a photocurable pressure-sensitive adhesive component or a thermosetting type pressure-sensitive adhesive component, a functional group capable of cross-linking with the photo-curable pressure-sensitive adhesive component or the thermosetting-type pressure-sensitive adhesive component is used. It may contain a silicone compound having.
Since the silicone compound is excellent in chemical resistance and heat resistance, it prevents the adhesive from being scorched even after high temperature treatment in the reflow process, and bleeds out to the interface of the adherend at the time of peeling to facilitate peeling. When the silicone compound has a functional group that can be crosslinked with the photocurable pressure-sensitive adhesive component or the thermosetting type pressure-sensitive adhesive component, the photo-curable pressure-sensitive adhesive component or the thermosetting type pressure-sensitive adhesive component can be obtained by irradiating or heating with light. Since it is chemically reacted with and incorporated into the photocurable pressure-sensitive adhesive component or the thermosetting type pressure-sensitive adhesive component, the silicone compound does not adhere to the adherend and contaminate it.

The curable pressure-sensitive adhesive layer may further contain known additives such as plasticizers, resins, surfactants, waxes, and fine particle fillers.

The thickness of the curable pressure-sensitive adhesive layer is not particularly limited, but the preferable lower limit is 5 μm and the preferable upper limit is 200 μm. When the thickness of the curable pressure-sensitive adhesive layer is within this range, it can be attached to the semiconductor device with sufficient adhesive force, and it is possible to prevent the semiconductor device after processing from being warped. The more preferable lower limit of the thickness of the curable pressure-sensitive adhesive layer is 10 μm, and the more preferable upper limit is 100 μm.

The inorganic substance constituting the inorganic base material layer is not particularly limited, and for example, metals such as Au, Ag, Pt, Cu, Rh, Pd, Al, and Cr, In ₂ O ₃ , CdO, CdIn ₂ O ₄ , and Cd ₂ Examples thereof include metal oxides such as SnO ₄ , TiO ₂ , SnO ₂ , ZnO, and ZnSiO ₃ . Among them, it is preferable to use a light-transmitting inorganic substance because the curable pressure-sensitive adhesive layer can be cured by light and alignment can be performed with the pressure-sensitive adhesive tape attached after plasma ashing. As the light-transmitting inorganic _{material, In 2 O 3, CdO,} CdIn 2 O 4, Cd 2 SnO 4, TiO 2, SnO 2, ZnO, ZnSiO 3 and the like.

The inorganic base material layer preferably has an ultraviolet transmittance of 1% or more.
When the ultraviolet transmittance of the inorganic base material layer is 1% or more, the pressure-sensitive adhesive layer can be sufficiently cured by ultraviolet rays. As the inorganic substance ultraviolet transmittance is not less than _{1%, In 2 O 3,} CdO, CdIn 2 O 4, Cd 2 SnO 4, TiO 2, SnO 2, ZnO, ZnSiO 3 and the like.

The thickness of the inorganic base material layer is not particularly limited, but a preferable lower limit is 10 μm and a preferable upper limit is 200 μm. When the thickness of the inorganic base material layer is within this range, the semiconductor device can be reinforced as the base material of the adhesive tape due to appropriate flexibility, and the adhesive tape can be easily peeled off by turning over the adhesive tape in the adhesive tape peeling step. can do.

The adhesive tape preferably has a plastic base layer made of plastic in addition to the inorganic base layer. By having the adhesive tape have a plastic base layer in addition to the inorganic base layer, the strength and flexibility of the adhesive tape can be further increased. Examples of the plastic include a sheet made of a resin such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, and polyimide, and a sheet having a mesh-like structure. And so on. When the adhesive tape has a plastic base material layer, in order to obtain the effect of the present invention of preventing decomposition of the base material by plasma ashing, the plastic base material layer is composed of a curable pressure-sensitive adhesive layer and an inorganic base material layer. It is laminated between.

When the polymerization initiator is a thermal polymerization initiator, it is preferable that the inorganic base material layer and the base material layer made of plastic are composed of a heat-resistant substance. When the inorganic base material layer and the plastic base material layer have heat resistance, it is possible to prevent the tape from peeling or warping due to heat when the curable pressure-sensitive adhesive layer is heat-cured. Examples of the heat-resistant inorganic substance include metals such as Au, Ag, Pt, Cu, Rh, Pd, Al, and Cr, In ₂ O ₃ , CdO, CdIn ₂ O ₄ , Cd ₂ SnO ₄ , and TIO ₂ . Examples thereof include metal oxides such as SnO ₂ , ZnO, and ZnSiO ₃ . Examples of the heat-resistant plastic include a sheet made of a resin such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, and polyimide, and a mesh-like structure. And the like.

The thickness of the plastic base material layer is not particularly limited, but the preferable lower limit is 10 μm and the preferable upper limit is 200 μm. When the thickness of the plastic base material layer is within this range, the semiconductor device can be reinforced and the adhesive tape can be easily peeled off by turning over in the adhesive tape peeling step.

The method for producing the adhesive tape of the present invention is not particularly limited, and for example, a curable resin, a polymerization initiator, a cross-linking agent, and, if necessary, other components are dissolved and mixed with a solvent and coated. Examples thereof include a method of laminating on the inorganic base material layer after drying by coating, and a method of directly coating and drying on the inorganic base material layer.

The adhesive tape of the present invention can be suitably used for protecting a semiconductor device in a semiconductor manufacturing process, but can be particularly preferably used as a semiconductor protective tape in a plasma ashing process.
A semiconductor protective tape used for protecting a semiconductor device in such a plasma ashing step, which is a semiconductor protective tape made of the adhesive tape of the present invention, is also one of the present inventions.

According to the present invention, even if plasma ashing is performed in a state where the adhesive tape is attached to a semiconductor device and reinforced, the transparency does not decrease, and the adhesive tape and the semiconductor protective tape that can prevent peeling and generation of residues can be provided. Can be provided.

It is a schematic diagram explaining the cause of white turbidity, peeling and generation of residue of an adhesive tape by plasma ashing.

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)
(Synthesis of photocurable adhesive)
A reactor equipped with a thermometer, a stirrer, and a cooling tube is prepared, and in this reactor, 94 parts by weight of 2-ethylhexyl acrylate as a (meth) acrylic acid alkyl ester and 5 parts by weight of hydroxyethyl methacrylate as a functional group-containing monomer are prepared. , 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. A photocurable pressure-sensitive adhesive was obtained.

(Manufacturing of adhesive tape)
1 part by weight of photopolymerization initiator (Esacure One, manufactured by Nihon Shibel Hegner) and plasticizer (manufactured by Negami Kogyo Co., Ltd., UN-5500) with respect to 100 parts by weight of the resin solid content of the obtained ethyl acetate solution of the photocurable pressure-sensitive adhesive. ) 20 parts by weight and 0.5 part by weight of the cross-linking agent (Coronate L-45 manufactured by Nippon Polyurethane Co., Ltd.) were mixed to prepare an ethyl acetate solution of the pressure-sensitive adhesive composition.
A doctor puts the obtained ethyl acetate solution of the pressure-sensitive adhesive composition on an ultra-thin glass (G-leaf, manufactured by Nippon Electric Glass Co., Ltd.) having a thickness of 100 μm so that the thickness of the curable pressure-sensitive adhesive layer after drying is 40 μm. The coating was applied with a knife and heated at 110 ° C. for 5 minutes to dry the coating solution. Then, it was statically cured at 40 ° C. for 3 days to obtain an adhesive tape.

(Example 2)
An adhesive tape was obtained in the same manner as in Example 1 except that a flexible sapphire plate having a thickness of 100 μm was used as the base material.
(Example 3)
Adhesive in the same manner as in Example 1 except that a laminate of an ultrathin glass (G-leaf, manufactured by Nippon Electric Glass Co., Ltd.) having a thickness of 100 μm and a polyethylene naphthalate (PEN) base material having a thickness of 25 μm was used as the base material. I got the tape.

(Comparative Examples 1 and 2)
An adhesive tape was obtained in the same manner as in Example 1 except that a polyethylene terephthalate (PET) base material or a polyethylene naphthalate (PEN) base material having a thickness of 50 μm was used as the base material.

(Evaluation)
The adhesive tapes obtained in Examples and Comparative Examples were evaluated by the following methods. The results are shown in Table 1.

(Evaluation of peeling during ashing)
The surface of the adhesive tape on the curable adhesive layer side was attached to a mirror wafer having a diameter of 20 cm. Was then carried out output 300W using PC-300 (SUMCO Inc.), _{O 2} gas flow rate 12 sccm, a plasma ashing process for 10 minutes under conditions of a vacuum degree of 10 Pa. At this time, the stage and the wafer were fixed by the piers, and the height of the piers was set to about 5 mm. After the ashing treatment, the adhesive tape was peeled off by irradiating the adhesive tape with a wavelength of 405 nm so that the integrated illuminance on the surface of the adhesive tape was 2000 mJ / cm ² . Visually observe the mirror wafer after plasma ashing, and if no peeling of the adhesive tape is seen, "○", if some peeling of the adhesive tape is seen, "△", peeling of the adhesive tape is seen. The peeling during ashing was evaluated as "x" when it was used.
The results are shown in Table 1.

(Evaluation of residue adhesion)
The adhesive tape was peeled off from the mirror wafer after plasma ashing. The surface of the silicon wafer was observed at 100 magnification using an electron microscope, and the case where no adhesive tape residue was observed was marked with "○", and the case where adhesive tape residue was observed was marked with "x" to indicate the residue adhesion. evaluated.
The results are shown in Table 1.

(Evaluation of cloudiness of adhesive tape)
The adhesive tape was peeled off from the mirror wafer after plasma ashing. The surface of the base material of the adhesive tape after peeling was visually observed, and the white turbidity of the adhesive tape was evaluated as "○" when it was not cloudy and transparent, and "x" when it was found to be cloudy.

According to the present invention, even if plasma ashing is performed in a state where the adhesive tape is attached to a semiconductor device and reinforced, the transparency does not decrease, and the adhesive tape and the semiconductor protective tape that can prevent peeling and generation of residues can be provided. Can be provided.

1 Adhesive tape 11 Base material 12 Adhesive layer 2 Semiconductor device 3 Surface treatment layer 4 Pier

Claims (6)

A semiconductor protective tape used to protect semiconductor devices in the plasma ashing process.
At least a curable resin, polymerization initiator, and, possess a curable adhesive layer contains a crosslinking agent, an inorganic base material layer made of an inorganic material,
A semiconductor protective tape characterized in that the inorganic base material layer is glass, sapphire, In ₂ O ₃ , TIO ₂ , SnO ₂ or Zn O. The semiconductor protective tape according to claim 1, wherein the plastic base material layer is laminated between the curable pressure-sensitive adhesive layer and the inorganic base material layer. The semiconductor protective tape according to claim 1 or 2 , wherein the polymerization initiator is excited by stimulation with light. The semiconductor protective tape according to claim 3 , wherein the light that excites the polymerization initiator is ultraviolet rays. The semiconductor protective tape according to claim 4 , wherein the inorganic substrate layer has an ultraviolet transmittance of 1% or more. The semiconductor protective tape according to claim 1 or 2, wherein the polymerization initiator is excited by stimulation with heat.

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