JP2003173989A - Method for manufacturing ic chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an IC chip which prevents a damage, etc., of a wafer even in about 50 μm thick thin wafer, improves handling quality, processes well for the IC chip, and further is not affected by charges. <P>SOLUTION: A method for manufacturing an IC chip comprises: the step of fixing a wafer to a support plate by an adhesive nonsupport tape which is formed with at least an adhesive layer (A) layer which lowers an adhesive power by giving stimulation due to heat to one surface, and with an adhesive (B) layer on the other surface, or a support tape composed of a both-side adhesive tape which is formed with the adhesive (A) layer which lowers an adhesive power by giving stimulation due to heat to one surface of a substrate, and with the adhesive (B) layer on the other surface of the substrate; the step of polishing the wafer by the support tape in a state of being fixed to the support plate; the step of adhering a dicing tape to the polished wafer; the step of giving stimulation due to heat to the adhesive (A) layer; the step of peeling off the support tape from the wafer; and the step of dicing. In the method for manufacturing an IC chip, the support plate is subjected to a charge preventing processing, and in the step of fixing the wafer to the support plate by the support tape, the adhesive (A) layer is adhered to the wafer. Further, the adhesive (B) layer is adhered to the support plate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents damage to a wafer even if it is an extremely thin wafer having a thickness of about 50 .mu.m, improves the handleability, and can favorably process an IC chip. The present invention relates to a method of manufacturing an IC chip without adverse effects.

[0002]

2. Description of the Related Art A semiconductor integrated circuit (IC chip) is usually obtained by slicing a high-purity semiconductor single crystal or the like into a wafer, forming a predetermined circuit pattern on the wafer surface using a photoresist, and then forming the wafer. It is manufactured by polishing the back surface with a polishing machine to reduce the thickness of the wafer to about 100 to 600 μm, and finally dicing it into chips.

Here, at the time of the above polishing, an adhesive sheet (polishing tape) is attached to the front surface of the wafer to prevent damage to the wafer and facilitate the polishing process. Adhesive sheets (dicing tape) are attached, and the wafer is diced in a state where the wafer is adhered and fixed, and the formed chips are picked up by pushing up with a needle from the film base side of the dicing tape and fixed on the die pad.

In recent years, as the use of IC chips has expanded, an extremely thin semiconductor wafer having a thickness of about 50 μm which can be used for IC cards or used by stacking has been required. However, a semiconductor wafer with a thickness of about 50 μm has a conventional thickness of 100 μm.
As compared with a semiconductor wafer having a thickness of about 600 μm, the wafer has a large warp and is easily cracked by an impact, so that it is inferior in handleability and may be broken when it is processed like a conventional semiconductor wafer.

A semiconductor wafer having a thickness of about 50 μm has a high risk of being damaged in a polishing process or a dicing process, which are susceptible to impact, and is also easily damaged when a bump is formed on an electrode of an IC chip. Is bad. Therefore, it has been an important issue to improve the handling of the wafer in the process of manufacturing IC chips from a thin semiconductor wafer having a thickness of about 50 μm.

Further, if fine particles floating in the air adhere to the semiconductor wafer due to static electricity, it hinders the transfer of the circuit pattern when forming the circuit pattern, a smooth polished surface cannot be obtained during polishing, and a short circuit occurs between the circuits. As it will adversely affect the manufacture of IC chips,
There is also a problem that it is necessary to sufficiently suppress the generation of static electricity and the like in each of the above-mentioned working steps.

[0007]

SUMMARY OF THE INVENTION In view of the above situation, the present invention prevents damage to a wafer even if it is an extremely thin wafer having a thickness of about 50 μm, improves handleability, and favorably ICs.
It is an object of the present invention to provide a method of manufacturing an IC chip that can be processed into chips and that is not adversely affected by charging.

[0008]

The present invention provides at least the following:
A pressure-sensitive adhesive non-support tape having a pressure-sensitive adhesive (A) layer formed on one surface thereof, the pressure-sensitive adhesive force of which is reduced by heat stimulation, and a pressure-sensitive adhesive (B) layer formed on the other surface, or A pressure-sensitive adhesive (A) layer is formed on one surface of the base material, the pressure-sensitive adhesive strength of which is reduced by heat stimulation, and a pressure-sensitive adhesive (B) layer is formed on the other surface of the base material. A step of fixing the wafer to a support plate via a support tape made of a double-sided adhesive tape, a step of polishing the wafer while being fixed to the support plate via the support tape, and a dicing tape attached to the polished wafer A method of manufacturing an IC chip, comprising: a step of applying, a step of applying heat stimulus to the adhesive (A) layer, a step of peeling the supporting tape from a wafer, and a step of dicing, wherein the supporting plate comprises: Antistatic In the step of fixing the wafer to the support plate via the support tape, the pressure-sensitive adhesive (A) layer and the wafer are bonded to each other, and the pressure-sensitive adhesive (B) layer and the wafer are treated. It is a method of manufacturing an IC chip that is attached to a support plate. The present invention is described in detail below.

The method of manufacturing an IC chip of the present invention includes a step of fixing a wafer to a supporting plate via a supporting tape. By fixing the wafer to the support plate, the handling property of the wafer is improved, and even if the wafer is extremely thin with a thickness of about 50 μm, damage to the wafer can be prevented, and processing into an IC chip can be favorably performed.

The wafer at this point is a semiconductor wafer obtained by slicing a high-purity silicon single crystal, gallium arsenide single crystal, or the like, and a predetermined circuit pattern is formed on the wafer surface. The thickness is 500 μm to 1 mm. It is of a degree. When fixing the wafer to the support plate, the surface of the wafer on which the circuit is formed and the support tape are attached.

The support plate is not particularly limited,
The pressure-sensitive adhesive (A) is a pressure-sensitive adhesive whose adhesive strength is reduced by application of light energy, and when light energy is applied to the pressure-sensitive adhesive (A) layer, it is preferably transparent. Examples of such a support plate include acrylic, olefin, polycarbonate, vinyl chloride, ABS, PE
Examples thereof include plate-like bodies made of resins such as T, nylon, urethane, and polyimide.

The support plate is antistatic-treated. If the support plate is charged by static electricity or the like, fine particles floating in the air may be attracted to adversely affect the production of IC chips, which is not preferable. The method of applying antistatic treatment to the support plate is not particularly limited, but the pressure-sensitive adhesive (A) is a pressure-sensitive adhesive whose adhesive strength is reduced by application of light energy, and the pressure-sensitive adhesive (A) layer is exposed to light. When applying energy, a method capable of maintaining the transparency of the support plate is preferable. As such an antistatic treatment method,
For example, a method of adding a transparent conductive plasticizer to the support plate, a method of adding a transparent surfactant to increase the amount of water adhering to the surface and prevent charging can be mentioned. Among them, a method of forming a conductive resin layer on the surface of a support plate by applying a resin dispersion liquid in which transparent conductive particles such as tin oxide fine particles are dispersed on the surface of the support plate is sufficient. It is preferable because a stable antistatic effect can be obtained while ensuring the above. According to such a method, a transparent support plate can be obtained unlike the method of blending carbon black or the like, and light energy is imparted to one surface of a substrate capable of transmitting or passing light as described later. In the case where the wafer and the transparent support plate are bonded together via a support tape having an adhesive (A) layer whose adhesive strength is reduced and the adhesive (B) layer is formed on the other surface. In addition, light energy can be applied to the pressure-sensitive adhesive (A) layer from the transparent support plate side. Examples of the transparent support plate subjected to such an antistatic treatment include a DC plate (manufactured by Sekisui Chemical Co., Ltd.)
Etc. are commercially available.

The thickness of the support plate is 500 μm to 3 μm.
mm is preferable, and more preferably 1-2 mm. Further, it is preferable that the thickness variation of the support plate is 1% or less.

The above-mentioned support tape has an adhesive (A) layer formed on one side and an adhesive (B) layer formed on the other side, or an adhesive non-support tape on one side of a substrate. The pressure-sensitive adhesive (A) layer is formed, and the double-sided pressure-sensitive adhesive tape has the pressure-sensitive adhesive (B) layer formed on the other surface of the base material. The pressure-sensitive adhesive (A) is one whose adhesive strength is reduced by applying heat stimulus or applying light energy. By using such a supporting tape, the obtained semiconductor wafer thin film or IC chip can be easily peeled from the supporting tape.

When the pressure-sensitive adhesive (A) is a pressure-sensitive adhesive whose adhesive strength is reduced by the application of light energy, and the light energy is applied to the pressure-sensitive adhesive (A) layer, the above-mentioned substrate is used. Preferably, it is capable of transmitting or passing light. Examples of such a base material include acrylic, olefin, polycarbonate, vinyl chloride, A
Examples thereof include a sheet made of a transparent resin such as BS, PET, nylon, urethane, and polyimide, a sheet having a mesh structure, and a sheet having holes.

The pressure-sensitive adhesive (A) is not particularly limited, but it is preferable that the pressure-sensitive adhesive contains a polymerizable oligomer, the pressure-sensitive adhesive force of which decreases by polymerizing and crosslinking. If such a pressure-sensitive adhesive having thermoplasticity is used, when the pressure-sensitive adhesive (A) layer is bonded to the wafer, the pressure-sensitive adhesive (A) layer is bonded to the wafer while being softened by heat. Therefore, the pressure-sensitive adhesive (A) layer adheres to the unevenness of the wafer to obtain a strong adhesive force.

Examples of the pressure-sensitive adhesive (A) include radical polymerizable polymers of acrylic acid alkyl ester-based and / or methacrylic acid alkyl ester-based polymerizable polymers having a radical-polymerizable unsaturated bond in the molecule. -Curable poly-adhesive oligomer or monomer as the main component, and optionally a photo-curable adhesive containing a photo-polymerization initiator, or an alkyl acrylate having a radical-polymerizable unsaturated bond in the molecule. Examples thereof include a thermosetting pressure-sensitive adhesive containing a thermopolymerization initiator as a main component, an ester-based and / or alkyl methacrylic acid-based polymerizable polymer, and a radically polymerizable polyfunctional oligomer or monomer. To be

In the post-curing type adhesive such as the photo-curing type adhesive or the thermosetting type adhesive, the entire pressure-sensitive adhesive layer is uniformly and rapidly polymerized and crosslinked to be integrated by irradiation with energy rays or heating. Therefore, the elastic modulus significantly increases due to the polymerization and curing, and the adhesive force significantly decreases.

As the above-mentioned 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 the above-mentioned functional group is incorporated in the molecule. A compound having a functional group that reacts with a group and a radically polymerizable unsaturated bond (hereinafter,
It can be obtained by reacting with a functional group-containing unsaturated compound).

The above-mentioned functional group-containing (meth) acrylic polymer is a polymer having an adhesive property at room temperature, and like the general (meth) acrylic polymer, the alkyl group usually has a carbon number in the range of 2-18. Of the acrylic acid alkyl ester and / or the methacrylic acid alkyl ester as a main monomer, and a functional group-containing monomer and, if necessary, another modifying monomer which can be copolymerized therewith by a conventional method. It is obtained by 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 acrylic acid and methacrylic acid; hydroxyl group-containing monomers such as hydroxyethyl acrylate and hydroxyethyl methacrylate; glycidyl acrylate and glycidyl methacrylate. Epoxy group-containing monomers; isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate; amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate.

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

The functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer is the same as the functional group-containing monomer described above depending on the functional group of the functional group-containing (meth) acrylic polymer. You can use one. 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.

The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a three-dimensional reticulation of the pressure-sensitive adhesive layer efficiently by heating or irradiation with energy rays. The molecular weight is 5,000 or less and the number of radical-polymerizable unsaturated bonds in the molecule is 2 to 6. Examples of such a more preferable polyfunctional oligomer or monomer include, for example,
Examples thereof include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, and methacrylates similar to the above. 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 photopolymerization initiator is, for example, 25
Examples thereof include those activated by irradiation with light having a wavelength of 0 to 800 nm. Examples of such photopolymerization initiators include acetophenone derivative compounds such as methoxyacetophenone; benzoinpropyl ether, benzoin isobutyl ether, and the like. Benzoin ether compounds; ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal; phosphine oxide derivative compounds; bis (η5-cyclopentadienyl) titanocene derivative compounds, benzophenone, Michler's ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone , Diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, 2
Examples thereof include a radical photopolymerization initiator such as hydroxymethylphenylpropane. These photopolymerization initiators may be used alone or in combination of two or more.

Examples of the above thermal polymerization initiator include those that decompose by heat to generate active radicals that initiate polymerization and curing, and specific examples thereof include dicumyl peroxide, di-t-butyl peroxide, and the like. t-butyl peroxybenzole, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, di-t-
Butyl peroxide and the like can be mentioned. Among them, cumene hydroperoxide, paramenthane hydroperoxide, di-t-butyl peroxide and the like are preferable because of their high thermal decomposition temperature. Of these thermal polymerization initiators, commercially available ones are not particularly limited, but, for example, perbutyl D, perbutyl H, perbutyl P, permenta H (all of which are manufactured by NOF Corporation) and the like are preferable. These thermal polymerization initiators may be used alone or in combination of two or more.

In addition to the above components, the above-mentioned post-curing type pressure-sensitive adhesive is optionally compounded with a general pressure-sensitive adhesive such as an isocyanate compound, a melamine compound or an epoxy compound for the purpose of adjusting the cohesive force of the pressure-sensitive adhesive. You may mix | blend various various polyfunctional compounds. Further, known additives such as a plasticizer, a resin, a surfactant, a wax and a fine particle filler can be added.

It is preferable that the pressure-sensitive adhesive (A) contains a gas generating agent that generates a gas upon stimulation. The gas generating agent is not particularly limited, but a gas generating agent that generates gas by stimulation with light is preferably used.
By applying light energy to the pressure-sensitive adhesive (A) layer, gas is released from the pressure-sensitive adhesive (A) layer, and the pressure-sensitive adhesive force is further reduced. The adherend can be peeled off more easily.

The gas generating agent for generating gas by the above stimulation is not particularly limited, but for example, an azo compound and an azide compound are preferably used. Examples of the azo compound include 2,2′-azobis- (N-butyl-2-
Methylpropionamide), 2,2'-azobis {2-
Methyl-N- [1,1-bis (hydroxymethyl) -2
-Hydroxyethyl] propionamide}, 2,2'-
Azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide}, 2,2'-azobis [2
-Methyl-N- (2-hydroxyethyl) propionamide], 2,2'-azobis [N- (2-propenyl)
2-Methylpropionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2,
2'-azobis (N-cyclohexyl-2-methylpropionamide), 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-Imidazoylin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolinyl-
2-yl) propane] disulfate dihydrolate, 2,2'-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2'- Azobis {2- [1- (2-
Hydroxyethyl) -2-imidazolidin-2-yl]
Propane} dihydrochloride, 2,2′-azobis [2- (2-imidazolinyl-2-yl) propane],
2,2'-azobis (2-methylpropionamidine) hydrochloride, 2,2'-azobis (2-aminopropane) dihydrochloride, 2,2'-azobis [N- (2-carboxyacyl) -2 -Methyl-propionamidine], 2,2'-azobis {2- [N
-(2-carboxyethyl) amidine] propane},
2,2'-azobis (2-methylpropionamide oxime), dimethyl 2,2'-azobis (2-methylpropionate), dimethyl 2,2'-azobisisobutyrate, 4,4'-azobis ( 4-Cyancarbonic acid), 4,4′-azobis (4-cyanopentanoic acid), 2,2′-azobis (2,4,4-trimethylpentane) and the like. Above all 2,2 '
-Azobis- (N-butyl-2-methylpropionamide), 2,2'-azobis (N-butyl-2-methylpropionamide), 2,2'-azobis (N-cyclohexyl-2-methylpropionamide) Is preferred.
These azo compounds generate nitrogen gas when stimulated by light, heat or the like.

Examples of the azide compound include 3-
Examples thereof include polymers having an azide group such as azidomethyl-3-methyloxetane, terephthalazide, p-tert-butylbenzazide; glycidyl azide polymer obtained by ring-opening polymerization of 3-azidomethyl-3-methyloxetane, and the like. These azide compounds are
Nitrogen gas is generated by stimulation with light, heat, ultrasonic waves and shock.

Among these gas generating agents, the azide compound is easily decomposed even when shocked to release nitrogen gas, so that there is a problem that it is difficult to handle. Further, the above-mentioned azide compound causes a chain reaction once decomposition starts to explode nitrogen gas explosively and its control is not possible, so that there is a problem that the wafer may be damaged by the explosively generated nitrogen gas. is there. Due to such a problem, the amount of the azide compound used is limited, but a sufficient effect may not be obtained with the limited amount used. On the other hand, unlike the azide compound, the azo compound does not generate a gas upon impact, and is therefore extremely easy to handle. In addition, since there is no explosive generation of gas due to a chain reaction, there is no damage to the wafer, and gas generation can be interrupted by interrupting the energy beam irradiation. There is also an advantage that is possible. Therefore, it is more preferable to use an azo compound as the gas generating agent.

The gas generating agent may be dispersed in the pressure-sensitive adhesive, but if the gas generating agent is dispersed in the pressure-sensitive adhesive (A) layer, the whole pressure-sensitive adhesive (A) layer becomes a foam. Since it becomes soft, the pressure-sensitive adhesive reduction mechanism of the pressure-sensitive adhesive (A) layer, which hardens the pressure-sensitive adhesive layer to reduce the pressure-sensitive adhesive force by irradiation with energy rays or heating, may not work well. Therefore, it is preferable to contain it only in the surface layer portion of the adhesive layer which is in contact with the wafer. If contained only in the surface layer portion, the pressure-sensitive adhesive layer can be sufficiently hardened by energy rays or heating, and gas is generated from the gas generating agent in the surface layer portion of the pressure-sensitive adhesive in contact with the wafer, and the gas is covered. At least a part of the adhesive surface of the pressure sensitive adhesive is peeled off from the adhered body to reduce the adhesive strength.

The method of incorporating the gas generating agent only in the surface layer of the pressure-sensitive adhesive layer is, for example, 1 to 20 μm in advance.
A method of producing a pressure-sensitive adhesive layer containing a gas generating agent having a thickness of about 100 μm, and bonding the pressure-sensitive adhesive layer to the pressure-sensitive adhesive (A) layer of a support tape;
Method of applying a pressure-sensitive adhesive containing a gas generating agent on the pressure-sensitive adhesive (A) layer of the supporting tape in a thickness of about 1 to 20 μm, gas on the surface of the pressure-sensitive adhesive (A) layer of the supporting tape prepared in advance Examples thereof include a method of applying a volatile liquid containing a generating agent or spraying the same with a spray or the like to uniformly attach the gas generating agent to the surface of the pressure-sensitive adhesive. However, when a fragile circuit is formed on the surface of the wafer, it is preferable that the pressure-sensitive adhesive (A) layer does not contain a gas generating agent. This is because the circuit formed on the wafer surface may be broken by the pressure of the gas generated from the gas generating agent due to the stimulation.

The pressure-sensitive adhesive (A) can be applied to the surface of the base material by a known method. The thickness of the pressure-sensitive adhesive (A) layer is not particularly limited, but is preferably 5 to 100 μm, more preferably 10 to 30 μm. It is preferable that the surface of the pressure-sensitive adhesive (A) layer of the above-mentioned support tape is covered with a release film for easy storage until it is attached to the support plate.

The pressure-sensitive adhesive (B) layer is not particularly limited, but when an IC chip is manufactured by further dicing the semiconductor wafer thin film obtained by the method for manufacturing a semiconductor wafer thin film of the present invention, a supporting tape from the wafer is used. When the support plate is previously peeled from the support tape before the step of peeling, the pressure-sensitive adhesive (B) layer has a property of lowering the pressure-sensitive adhesive force by heat stimulation or light energy being applied. Is more preferable. If the adhesive force of the pressure-sensitive adhesive (B) layer is reduced by applying heat stimulation or light energy, the support plate can be peeled from the support tape in advance before the step of peeling the support tape from the wafer,
Since the support tape can be easily peeled from the wafer if the support plate is peeled from the support tape in advance, it is suitable when the support tape is peeled from the wafer having a fragile circuit formed on the surface. As such an adhesive (B), an acrylic acid alkyl ester-based and / or methacrylic acid alkyl ester-based polymerization used in the above-mentioned adhesive (A) and having a radical-polymerizable unsaturated bond in the molecule is used. Of a photo-curable pressure-sensitive adhesive containing a polymerizable polymer and a radical-polymerizable polyfunctional oligomer or monomer as a main component, and optionally a photo-polymerization initiator, and a radical-polymerizable unsaturated bond in the molecule. A thermosetting pressure-sensitive adhesive containing a heat-polymerization initiator as a main component, and a radically polymerizable polyfunctional oligomer or monomer as a main component, and an acrylic acid alkyl ester-based and / or methacrylic acid alkyl ester-based polymerizable polymer And the like can be used.

Further, in this case, it is preferable that the pressure-sensitive adhesive (B) contains a gas generating agent which generates a gas by giving a stimulus. Examples of the gas generating agent include the aforementioned azo compounds and azide compounds.
By containing these gas generating agents, when light energy is imparted to the pressure-sensitive adhesive (B) layer or heating is performed, gas is generated from the gas generating agent in the pressure-sensitive adhesive (B) layer, and the adhesive strength is reduced. The adherend can be peeled off more easily. Such an adhesive (B) has excellent adhesiveness before irradiation with energy rays or before heating, and if irradiated or heated with energy rays, a crosslinking reaction proceeds to form a cured product.
Although it is an adhesive having excellent adhesiveness until the support tape is peeled off, it can be a hard cured product when the support tape is peeled off. When gas is generated from the gas generating agent in a hard cured product, foaming of the pressure-sensitive adhesive layer can be suppressed and most of the gas generated in the cured product can be released to the outside.

The gas generating agent may be dispersed in the pressure-sensitive adhesive (B) layer, but if the gas generating agent is dispersed in the pressure-sensitive adhesive (B) layer, the whole pressure-sensitive adhesive (B) layer becomes a foam. Therefore, it may be too soft and the adhesive layer may not be peeled off well. Therefore, it is preferable to contain it only in the surface layer portion of the pressure-sensitive adhesive (B) layer in contact with the support plate. If contained only in the surface layer portion, the pressure-sensitive adhesive (B) layer can be sufficiently hardened by energy rays and heating, and gas is generated from the gas generating agent in the surface layer portion of the pressure-sensitive adhesive which is in contact with the support plate, The gas peels off at least a part of the adhesive surface of the pressure-sensitive adhesive from the adherend and reduces the adhesive strength.

The method of incorporating the gas generating agent only in the surface layer of the pressure-sensitive adhesive layer is, for example, 1 to 20 μm in advance.
A method of preparing a pressure-sensitive adhesive layer containing a gas generating agent having a thickness of about 100 μm, and bonding the pressure-sensitive adhesive layer to a pressure-sensitive adhesive (B) layer of a support tape
Method of applying a pressure-sensitive adhesive containing a gas generating agent on the pressure-sensitive adhesive (B) layer of the support tape in a thickness of about 1 to 20 μm, and gas on the surface of the pressure-sensitive adhesive (B) layer of the support tape prepared in advance Examples thereof include a method of applying a volatile liquid containing a generating agent or spraying the same with a spray or the like to uniformly attach the gas generating agent to the surface of the pressure-sensitive adhesive. Here, when the pressure-sensitive adhesive is applied, it is preferable that it has the same composition as the pressure-sensitive adhesive (B) layer. Further, when the gas generating agent is attached to the surface of the adhesive, it is preferable to attach the gas generating agent having excellent compatibility with the adhesive. That is, when a large amount of the gas generating agent is attached to the surface of the pressure-sensitive adhesive, the adhesive strength becomes low, but when the gas generating agent is compatible with the pressure-sensitive adhesive, the adhered gas generating agent is absorbed in the pressure-sensitive adhesive layer and the adhesive force is reduced. It never drops. In addition,
The surface layer portion depends on the thickness of the pressure-sensitive adhesive layer, but is preferably a portion up to 20 μm from the pressure-sensitive adhesive surface. Further, in the surface layer portion here, a mode in which the gas generating agent is uniformly attached to the pressure-sensitive adhesive surface or a mode in which the gas generating agent attached to the pressure-sensitive adhesive surface is compatible with the pressure-sensitive adhesive and is absorbed in the pressure-sensitive adhesive layer. including.

The pressure-sensitive adhesive (B) layer may be embossed. In the present specification, embossing means forming an uneven pattern on the surface. The embossing may be performed on the pressure-sensitive adhesive (A) layer as well.

Since the pressure-sensitive adhesive (B) layer is embossed, when the pressure-sensitive adhesive (B) layer and the adherend are adhered to each other, the adherend is supported by convex and concave portions. Since the bubbles are present only in the concave and convex portions, the bubbles do not partially increase the thickness of the adhesive (B) layer. Since the pressure-sensitive adhesive layer (B) is formed with a uniform thickness and keeps the distance between the supporting plate and the wafer constant, when the wafer mounted on the supporting plate is polished in a supported state, the polishing is smooth. The surface is obtained. Further, since the adherend is supported by the convex portions of the uneven pattern as described above, the uneven pattern acts as a cushion to disperse the pressure when polishing the wafer, so that a thinner wafer can be efficiently obtained. be able to.

The uneven pattern formed on the pressure-sensitive adhesive (B) layer by performing the embossing is not particularly limited as long as it is a shape in which the adherend is supported by the convex portions of the uneven pattern with good planarity. Such an uneven pattern is formed, for example, over the entire surface of the adhesive (B) layer,
Examples thereof include a random concavo-convex pattern or a regular concavo-convex pattern in which almost all of the formed grooves are continuous. Among them, an uneven pattern in which convex portions are arranged at intervals of 100 μm or less is preferable. When a wafer adhered to a support plate is polished using a support tape, the pressure applied during polishing is different between where the wafer is supported by the convex and concave portions of the wafer and when it is not supported. A pattern corresponding to the uneven pattern of the support tape may be formed on the wafer, resulting in uneven polishing. When the convex portions are the concavo-convex pattern in which the convex portions are arranged at intervals of 100 μm or less, such polishing unevenness can be suppressed to a level where there is no practical problem. Specifically, for example,
Straight lines, arcs, etc. are 100 over the entire surface of the adhesive (B) layer.
An example is a concavo-convex pattern that is continuously arranged at intervals of μm or less.

The embossing method is not particularly limited, and examples thereof include a method in which an uneven pattern is transferred to the pressure-sensitive adhesive layer by pressing an embossed sheet, an embossing plate, an embossing roll or the like against the pressure-sensitive adhesive layer. In order to obtain a concavo-convex pattern in which the above-mentioned convex portions are arranged at intervals of 100 μm or less, for example, a sand blasting method of forming a fine concavo-convex pattern by spraying fine sand to polish the surface; calcium carbonate, etc. on the surface. After forming a primer layer containing a fine filler, the surface of the primer layer does not dissolve, but the filler is washed by a solvent that dissolves the filler, and the filler method for forming a fine uneven pattern by removing the filler can be mentioned. To be

In order to fix the wafer to the supporting plate via the supporting tape, the adhesive (A) layer and the wafer are bonded together, and the adhesive (B) layer and the supporting plate are bonded together. In order to bond with more flatness, it is preferable to carry out bonding in a vacuum state using a vacuum laminator or the like. When the pressure-sensitive adhesive (A) made of a thermoplastic resin and / or the pressure-sensitive adhesive (B) made of a thermoplastic resin is used, the pressure-sensitive adhesive should be bonded to the wafer and / or the support plate while being softened by heat. Therefore, the pressure-sensitive adhesive is more closely adhered to the wafer and / or the support plate to obtain a strong adhesive force. By fixing the wafer to the support plate, a very thin wafer of about 50 μm is reinforced so that the wafer is not chipped or cracked during transportation or processing, and the support tape is used in a series of steps for manufacturing IC chips. When finished, it can be easily peeled from the IC chip by heating or applying light energy.

In the method of manufacturing an IC chip of the present invention, next, the wafer is polished while being fixed to the support plate. By fixing the wafer to the support plate, it is possible to prevent the wafer from being damaged in the polishing process and to polish the wafer smoothly.

Then, a dicing tape is attached to the polished wafer. Before attaching the dicing tape, a polyimide film as an insulating substrate may be attached to the wafer in advance.

The dicing tape is not particularly limited, but a known photocurable pressure-sensitive adhesive tape can be used. For example, Adwill (registered trademark) manufactured by Furukawa Electric Co., Ltd.
Examples include tapes such as D-series and ELEP HOLDER (registered trademark) UE series manufactured by Nitto Denko Corporation.

Subsequently, heat stimulation or light energy is applied to the adhesive (A) layer. The adhesive strength of the pressure-sensitive adhesive (A) can be reduced by heating or irradiating light energy rays. Next, the supporting tape is peeled off from the wafer. At this time, the adhesive strength of the adhesive (A) is lowered by heating or irradiation with energy rays, so that the supporting tape can be easily peeled from the wafer. When a pressure-sensitive adhesive whose adhesive strength is reduced by heat stimulus or light energy is applied as the pressure-sensitive adhesive (B), heat or energy ray irradiation may be performed before peeling the support tape from the wafer. If the hard support plate is peeled off from the support tape after the adhesive force of the pressure-sensitive adhesive (B) layer is reduced by irradiation, the support tape becomes a flexible tape and can be peeled off from the wafer while turning the tape. Therefore, it can be more easily peeled from the wafer. Since the number of steps is increased, it is preferable to perform it when an IC chip is manufactured from a wafer in which a fragile circuit is formed on the surface of the wafer. When the pressure-sensitive adhesive (A) contains a gas generating agent, the gas can be discharged from the pressure-sensitive adhesive (A) by heating or irradiation with energy rays, so that the wafer can be more easily removed from the support tape. It can be peeled off. However, it is preferable that the pressure-sensitive adhesive (A) layer does not contain a gas generating agent when a fragile circuit is formed on the surface of the wafer.

Following the last step, dicing is performed. By this step, the wafer having the circuit formed on the surface is cut into chips by the diamond cutter. The size is usually several 100 μm to several tens of mm on one side.

[0049]

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

(Example 1) <Preparation of pressure-sensitive adhesive> The following compounds were dissolved in ethyl acetate and irradiated with ultraviolet rays to carry out polymerization to obtain a weight average molecular weight of 70.
Many acrylic copolymers were obtained. To 100 parts by weight of the resin solid content of the ethyl acetate solution containing the obtained acrylic copolymer, 3.5 parts by weight of 2-isocyanatoethyl methacrylate was added and reacted, and the resin of the ethyl acetate solution after the reaction was further added. 20 parts by weight of pentaerythritol triacrylate, 0.5 parts by weight of a photopolymerization initiator (Irgacure 651, 50% ethyl acetate solution), and 1.5 parts by weight of polyisocyanate were mixed with 100 parts by weight of the solid content to obtain an adhesive ( The ethyl acetate solution of 1) was prepared. Butyl acrylate 79 parts by weight Ethyl acrylate 15 parts by weight Acrylic acid 1 part by weight 2-Hydroxyethyl acrylate 5 parts by weight Photoinitiator 0.2 parts by weight (Irgacure 651, 50% ethyl acetate solution) Lauryl mercaptan 0.02 parts by weight

2,2'-azobis- (N-) was added to 100 parts by weight of the resin solid content of the vinyl acetate solution of the adhesive (1).
Butyl-2-methylpropionamide) was mixed in an amount of 100 parts by weight to prepare a pressure-sensitive adhesive (2) containing a photodecomposable gas generating agent.

<Preparation of Supporting Tape> An ethyl acetate solution of the adhesive (2) was coated on a PET film having a release treatment on its surface with a doctor knife so that the thickness of the dry film was about 10 μm. Then, the coating solution was dried by heating at 110 ° C. for 5 minutes. The dried pressure-sensitive adhesive layer exhibited tackiness in a dry state. Then, a PET film that had been subjected to a release treatment was attached to the surface of the adhesive (2) layer.

An ethyl acetate solution of the pressure sensitive adhesive (1) was applied to one side of a transparent polyethylene terephthalate (PET) film having a thickness of 100 μm, corona-treated on both sides, so that the dry film had a thickness of about 15 μm. And was heated at 110 ° C. for 5 minutes to dry the coating solution. The dried pressure-sensitive adhesive layer exhibited tackiness in a dry state. Then
The pressure-sensitive adhesive (1) layer was pasted while strongly pressing the surface on the uneven pattern side of a PET film having a release pattern on its one surface and continuous dot-shaped uneven patterns. As a result, the uneven pattern was transferred to the surface of the pressure-sensitive adhesive (1) layer.

An ethyl acetate solution of the pressure sensitive adhesive (1) was applied onto a PET film having a surface subjected to a mold release treatment with a doctor knife so that the thickness of the dry film was about 15 μm.
The coating solution was dried by heating at 10 ° C. for 5 minutes to volatilize the solvent. The dried pressure-sensitive adhesive layer exhibited tackiness in a dry state. Then, a PET film that had been subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive (1) layer.

Next, the corona-treated surface of the PET film which has been provided with the adhesive (1) layer and which has been subjected to the corona treatment, and the release treatment which has provided the adhesive (1) layer. The surface of the pressure-sensitive adhesive (1) layer of the PET film which was subjected to the above was bonded. Then, stationary curing was performed at 40 ° C. for 3 days. As a result, a support tape having a pressure-sensitive adhesive layer provided on both surfaces and the surface of which was protected by a release-treated PET film was obtained. The PET film having a release treatment on the surface of the adhesive tape (1) layer on the non-embossed side of the support tape is peeled off, and the release film is released on the surface having the adhesive (2) layer. It was attached to the pressure-sensitive adhesive (2) layer of the treated PET film. As a result, the surface is protected by the release-treated PET film, the embossed pressure-sensitive adhesive (1) layer is formed on one surface, and the pressure-sensitive adhesive (1) layer is formed on the other surface. Support tape 1 having a primer layer made of an adhesive (2) formed on the surface layer portion
Got

<Manufacture of IC Chip> The PET film which protects the adhesive (2) layer of the supporting tape 1 was peeled off to give a diameter of 2
It was attached to a silicon wafer of 0.4 cm and a thickness of about 750 μm. Next, the PET film that protects the embossed pressure-sensitive adhesive (1) layer was peeled off, and the diameter was 20.4 cm.
It was attached to a transparent support plate (DC plate C401AS manufactured by Sekisui Chemical Co., Ltd.) having an antistatic finish. (Polishing Step) A silicon wafer reinforced by an antistatic processed transparent support plate was attached to a polishing apparatus and polished until the thickness of the silicon wafer became about 50 μm. The silicon wafer was removed from the polishing apparatus, and the dicing tape was attached onto the silicon wafer.

(UV Irradiation Step) Antistatic Finishing Ultraviolet light of 365 nm is irradiated from the transparent support plate side for 2 minutes by adjusting the illuminance so that the irradiation intensity of the glass plate surface is 40 mW / cm ^2. did. (Wafer peeling step) A silicon wafer was fixed, and the antistatic processed transparent support plate was pulled right above to peel the support sheet from the silicon wafer. (Dicing Step) Subsequently, the silicon wafer reinforced with a dicing tape was attached to a dicing device, and a cutter blade was cut from the wafer side to cut the silicon wafer into IC chip sizes. Then, the dicing tape was peeled off to obtain an IC chip.

Example 1 A silicon wafer having a smooth polished surface could be obtained by using the prepared supporting tape. In addition, there was no adverse effect on the manufacture of the IC chip, such as the generation of static electricity or the like to attract foreign matter in the air. The pressure-sensitive adhesive containing the gas generating agent showed a particularly remarkable decrease in adhesive strength, and the silicon wafer could be easily peeled off. Further, the silicon wafer could be peeled off without peeling off the pressure-sensitive adhesive layer containing no gas generating agent.

[0059]

According to the present invention, since the wafer is supported by the supporting plate with good planarity, smooth polishing can be performed. In addition, the support plate is not charged by static electricity or the like and does not adversely affect the manufacture of IC chips. Furthermore, the obtained I
Since the C chip can be easily peeled off from the supporting tape, even if the wafer is extremely thinly polished to a thickness of about 50 μm, damage to the wafer can be prevented, and the IC chip can be favorably processed. The wafer supported by the support plate is easy to handle even when it is extremely thinly polished to a thickness of about 50 μm, and is easily stored in a cassette or the like.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Hayashi             Sekisui Chemical, 2-1 Hyakusan, Shimamoto-cho, Mishima-gun, Osaka Prefecture             Industry Co., Ltd. (72) Inventor Shigeru Dangami             Sekisui Chemical, 2-1 Hyakusan, Shimamoto-cho, Mishima-gun, Osaka Prefecture             Industry Co., Ltd. (72) Inventor Yasuhiko Oyama             Sekisui Chemical, 2-1 Hyakusan, Shimamoto-cho, Mishima-gun, Osaka Prefecture             Industry Co., Ltd.

Claims (2)

[Claims] 1. A pressure-sensitive adhesive (A) layer is formed on at least one side of which a pressure-sensitive adhesive force is reduced by applying heat stimulus, and a pressure-sensitive adhesive (B) layer is formed on the other side. A pressure-sensitive adhesive non-support tape or a pressure-sensitive adhesive (A) layer whose adhesive strength is reduced by applying a heat stimulus to one surface of the base material is formed, and the pressure-sensitive adhesive (B) is formed on the other surface of the base material. ) A step of fixing the wafer to a support plate via a support tape made of a double-sided adhesive tape having layers formed thereon, a step of polishing the wafer while the wafer is fixed to the support plate via the support tape, polishing Process of attaching dicing tape to the formed wafer, heat stimulus adhesive (A)
A method of manufacturing an IC chip comprising a step of applying to a layer, a step of peeling the supporting tape from a wafer, and a step of dicing, wherein the supporting plate is subjected to an antistatic treatment, In the step of fixing the wafer to the supporting plate via the supporting tape, the adhesive (A)
A method of manufacturing an IC chip, characterized in that a layer is bonded to the wafer, and the adhesive (B) layer is bonded to the support plate. 2. A pressure-sensitive adhesive (A) layer whose adhesive strength is reduced by application of light energy is formed on at least one surface of a substrate capable of transmitting or passing light, and the other surface A step of fixing the wafer to the transparent support plate via a support tape having an adhesive (B) layer formed thereon, and a step of polishing the wafer while being fixed to the transparent support plate via the support tape. A method of manufacturing an IC chip comprising a step of attaching a dicing tape to a polished wafer, a step of irradiating an energy ray from the transparent support plate side, a step of peeling the support tape from the wafer, and a step of dicing. The transparent support plate has been subjected to antistatic treatment, and in the step of fixing the wafer to the transparent support plate via the support tape,
A method of manufacturing an IC chip, characterized in that the pressure-sensitive adhesive (A) layer and the wafer are bonded together, and the pressure-sensitive adhesive (B) layer and the transparent support plate are bonded together.