JP2003209083A - Manufacturing method for ic chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an IC chip in which damage or the like to a wafer is prevented, operability is improved and working of the IC chip can be satisfactorily performed even when the wafer is extremely thinned approximately to the thickness of 50 μm. <P>SOLUTION: The IC chip has a process for polishing the wafer while fixing it on a support board via a support tape having a surface composed of the layer of a pressure sensitive adhesive (A) containing a gas generating agent for generating gases by stimuli, and a surface composed of the layer of a pressure sensitive adhesive (B); a process for sticking a dicing tape on the polished wafer; a process for releasing the support tape from the wafer by applying the stimuli to the layer of the pressure sensitive adhesive (A); and a process for dicing the wafer. The entire wafer is stimulated while uniformly applying a load in the process for applying the stimuli to the layer of the pressure sensitive adhesive (A) of the support tape. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wafer having a thickness of 50.
The present invention relates to an IC chip manufacturing method capable of preventing damage to a wafer, improving handleability, and favorably processing into an IC chip even when the thickness is extremely thin to about μm.

[0002]

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

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.

With the widespread use of IC chips in recent years, an extremely thin wafer having a thickness of about 50 μm which can be used for IC cards or used by stacking has been required. However, the thickness is 50
Since a wafer having a thickness of about 100 μm has a large warp and is more likely to be broken by an impact than a conventional wafer having a thickness of about 100 to 600 μm, a polishing process and a dicing process which are susceptible to an impact when processed in the same manner as a conventional wafer, The wafer was liable to be damaged when bumps were formed on the electrodes of the IC chip, and the yield was low. Therefore, it has been an important issue to improve the handling of the wafer in the process of manufacturing IC chips from the wafer having a thickness of about 50 μm.

On the other hand, there has been proposed a method in which a wafer is attached to a support plate via a support tape and polishing is performed while the wafer is fixed to the support plate. According to this method, the strength and flatness of the wafer can be secured by the support plate, and the handleability is improved.

However, even in this method, there is a problem in that a wafer having a thickness of about 50 μm has a weak strength, so that the wafer may be damaged or deformed due to a load when peeled from the supporting plate or the supporting tape. Also, the thickness is 50
An extremely thin wafer of about μm has a thickness of 100 to 600.
While it is possible to stack more layers as compared with a conventional wafer having a thickness of about μm, there is a problem that the wafer requires stricter planarity in order to stack many layers.

[0007]

SUMMARY OF THE INVENTION In view of the above situation, the present invention prevents damage to the wafer even when the wafer is made extremely thin to a thickness of about 50 μm, improves handleability, and favorably IC chips. It is an object of the present invention to provide a method of manufacturing an IC chip that can be processed into a.

[0008]

The present invention provides at least the following:
Fixing the wafer to the support plate via a support tape having a surface composed of an adhesive (A) layer containing a gas generating agent that generates gas by stimulation and a surface composed of an adhesive (B) layer; Polishing the wafer in a state of being fixed to the support plate via a support tape; attaching a dicing tape to the polished wafer; applying the stimulus to the adhesive (A) layer; A method of manufacturing an IC chip, comprising a step of peeling a support tape and a step of dicing the wafer, wherein in the step of fixing the wafer to the support plate via the support tape, the adhesive (A ) Layer is attached to the wafer and the adhesive (B) layer is attached to the support plate, and the adhesive (A) layer is exposed to the stimulus. In obtaining step, while uniformly applying a load across the wafer, it is a manufacturing method of the IC chip, characterized in that providing said stimulus. The present invention is described in detail below.

The method of manufacturing an IC chip of the present invention has a support having at least a surface composed of a pressure-sensitive adhesive (A) layer containing a gas generating agent for generating a gas upon stimulation and a surface composed of a pressure-sensitive adhesive (B) layer. It has a step of fixing the wafer to the support plate via a tape.

As long as the above-mentioned support tape has a surface composed of a pressure-sensitive adhesive (A) layer containing a gas generating agent for generating a gas upon stimulation, and a surface composed of a pressure-sensitive adhesive (B) layer, it is adhered to both surfaces. It may be an adhesive non-support tape having an adhesive layer or a double-sided adhesive tape having an adhesive layer formed on both sides of a substrate. In the present specification, the non-support tape means a tape composed of only a pressure-sensitive adhesive layer having no base material, and may be composed of a plurality of layers even if it is composed of only one pressure-sensitive adhesive layer. May be. When the non-support tape is composed of only one adhesive layer,
For example, the case where the adhesive (A) layer and the adhesive (B) layer are the same.

When the above-mentioned base material is used and the stimulus for reducing the adhesive strength of the pressure-sensitive adhesive (A) layer is a stimulus by light, the above-mentioned base material transmits or passes light. Preferably, for example, acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), nylon, urethane,
Examples thereof include a sheet made of a transparent resin such as polyimide, a sheet having a mesh structure, and a sheet having holes.

The above-mentioned support tape has a surface composed of a pressure-sensitive adhesive (A) layer containing a gas generating agent which generates a gas upon stimulation. Examples of the stimulus include light,
Examples include heat and ultrasonic stimulation. Of these, stimulation by light or heat is preferable. Examples of the light include ultraviolet light and visible light. When a light stimulus is used as the stimulus, the pressure-sensitive adhesive (A) is preferably capable of transmitting or passing light.

The gas generating agent which generates 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. In the manufacture of IC chips, there is a step of performing high temperature treatment as necessary, and therefore, among these, 2,2'- which has a high thermal decomposition temperature.
Azobis- (N-butyl-2-methylpropionamide), 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis (N-cyclohexyl-2-methylpropionamide) It is suitable.
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 by light, heat 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 light irradiation. There is also the advantage that it is possible. Therefore, it is more preferable to use an azo compound as the gas generating agent.

When the pressure-sensitive adhesive (A) layer is stimulated by containing the above-mentioned gas-generating agent, gas is generated from the gas-generating agent in the pressure-sensitive adhesive (A) layer, and the adhesive force is lowered to adhere the layer. The body can be easily peeled off.

The gas generating agent may be dispersed in the pressure-sensitive adhesive (A) layer, 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. 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 (A) that is in contact with the support plate. If it is contained only in the surface layer part, the surface area of the adhesive that contacts the support plate will generate gas from the gas generating agent and the adhesive area at the interface will decrease, and the gas will adhere to the adhesive surface from the adherend. Peel off at least part of the adhesive strength to reduce the adhesive strength.

As a method of containing the gas generating agent only in the surface layer portion of the pressure-sensitive adhesive layer, for example, the gas generating agent is contained in a thickness of about 1 to 20 μm on the pressure-sensitive adhesive (A) layer of the supporting tape. By applying a pressure-sensitive adhesive (A) or by applying a volatile liquid containing a gas generating agent to the surface of the pressure-sensitive adhesive (A) layer of the supporting tape prepared in advance or spraying it with a spray or the like. Examples include a method of uniformly attaching a gas generating agent to the agent surface. 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,
If a large amount of a gas generating agent is attached to the surface of the adhesive, the adhesive strength will decrease, but if the gas generating agent is compatible with the adhesive, the attached gas generating agent will be absorbed by the adhesive layer and the adhesive strength will decrease. Never. 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.

It is preferable that the pressure-sensitive adhesive (A) has a modulus of elasticity increased by stimulation. The stimulus for increasing the elastic modulus of the pressure-sensitive adhesive (A) may be the same as or different from the stimulus for generating a gas from the gas generating agent. Examples of the pressure-sensitive adhesive (A) include, for example, an acrylic acid alkyl ester-based and / or methacrylic acid alkyl ester-based polymerizable polymer having a radical-polymerizable unsaturated bond in the molecule, and a radical-polymerizable A photo-curable pressure-sensitive adhesive containing a polyfunctional oligomer or monomer as a main component and optionally containing a photopolymerization initiator, and an alkyl acrylate ester having a radical-polymerizable unsaturated bond in the molecule. And / or a thermosetting pressure-sensitive adhesive containing a heat-polymerization initiator as a main component, and a radical-polymerizable polyfunctional oligomer or monomer as a main component.

In the post-curing type pressure-sensitive adhesive such as the photo-curing type pressure-sensitive adhesive or the heat-curing type pressure-sensitive adhesive, the whole pressure-sensitive adhesive layer is uniformly and rapidly polymerized and crosslinked by light irradiation or heating to be integrated. Therefore, the increase in elastic modulus due to polymerization hardening becomes remarkable,
The adhesive strength is greatly reduced. Further, when a gas is generated from a gas generating agent in a hard cured product, most of the generated gas is released to the outside, and the released gas peels off at least a part of the adhesive surface between the adherend and the adhesive. Reduces adhesion.

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 into 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). In addition, in this specification, (meth) acryl shall mean acryl or methacryl.

The above-mentioned functional group-containing (meth) acrylic polymer is a polymer having tackiness at room temperature, and like the general (meth) acrylic polymer, the number of carbon atoms of the alkyl group is usually 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 above-mentioned polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight such that three-dimensional reticulation of the pressure-sensitive adhesive layer can be efficiently performed by heating or irradiation with light. Is 5,000 or less, and the number of radically polymerizable unsaturated bonds in the molecule has a lower limit of 2 and an upper limit of 20. Such more preferable polyfunctional oligomers or monomers include, for example, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate. , 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, or methacrylates similar to the 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-mentioned thermal polymerization initiator include those which decompose by heat to generate active radicals which initiate polymerization and curing. 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-curable 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 may be added.

The above-mentioned support tape has a surface composed of the adhesive (B) layer in addition to the surface composed of the adhesive (A) layer. The pressure-sensitive adhesive (B) is not particularly limited,
In the method for manufacturing an IC chip of the present invention, when the support plate is previously peeled from the support tape before the step of peeling the support tape from the wafer between the polishing step and the dicing step, the adhesive force due to stimulation is It is preferable to have a property of decreasing. 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. A post-curable pressure-sensitive adhesive containing a polymerizable polymer and a radically polymerizable polyfunctional oligomer as main components can be used. By peeling the support plate from the support tape in advance before peeling the support tape from the wafer, the support tape having flexibility can be turned over and the support tape can be peeled from the wafer more easily.

Further, in this case, it is more preferable that the pressure-sensitive adhesive (B) contains a gas generating agent which generates gas by stimulation. By containing the gas generating agent,
When the pressure-sensitive adhesive (B) layer is stimulated, gas is generated from the gas generating agent in the pressure-sensitive adhesive (B) layer, the adhesive force is reduced, and the adherend can be peeled off more easily. When the pressure-sensitive adhesive (B) is a post-curable pressure-sensitive adhesive, etc., it has excellent pressure-sensitive adhesive properties before stimulus is applied, and the cross-linking reaction progresses by applying stimulus to give a cured product. While it is an adhesive having excellent adhesiveness until the support tape is peeled off, it can be made into a hard cured product when the support tape is peeled off. That is, when a gas is generated from a gas generating agent in a hard cured product, most of the generated gas is released to the outside, and the released gas peels off at least a part of the adhesive surface of the pressure sensitive adhesive from the adherend and bonds it. Reduce the power.

The above gas generating agent may be dispersed in the adhesive (B) layer, but if the gas generating agent is dispersed in the adhesive (B) layer, the entire 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) in contact with the support plate. If contained only in the surface layer part, the adhesive (B) layer can be sufficiently softened by stimulation, and at the surface layer part of the adhesive contacting the support plate, gas is generated from the gas generating agent to bond the interface. The area is reduced, and the gas peels off at least a part of the adhesive surface between the adherend and the pressure-sensitive adhesive to reduce the adhesive strength.

As a method of containing the gas generating agent only in the surface layer portion of the pressure-sensitive adhesive layer, for example, the gas generating agent is contained in a thickness of about 1 to 20 μm on the pressure-sensitive adhesive (B) layer of the supporting tape. By applying a pressure-sensitive adhesive (B) or applying a volatile liquid containing a gas generating agent to the surface of the pressure-sensitive adhesive (B) layer of the support tape prepared in advance or by spraying with a spray or the like. Examples include a method of uniformly attaching a gas generating agent to the agent surface. 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,
If a large amount of a gas generating agent is attached to the surface of the adhesive, the adhesive strength will decrease, but if the gas generating agent is compatible with the adhesive, the attached gas generating agent will be absorbed by the adhesive layer and the adhesive strength will decrease. Never. 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 wafer is fixed to the support plate via the support tape having the surface composed of the pressure-sensitive adhesive (A) layer and the surface composed of the pressure-sensitive adhesive (B) layer. Examples of the wafer include those obtained by slicing a high-purity semiconductor single crystal made of silicon, gallium, arsenic, or the like. The thickness of the wafer is not particularly limited, but is generally 500 μm.
It is about 1 mm. A predetermined circuit pattern is formed on the surface of the wafer before being fixed to the support plate.

The support plate is not particularly limited,
When the stimulus for reducing the adhesive strength of the pressure-sensitive adhesive (A) layer is a light stimulus, it is preferably transparent, for example, a glass plate; acrylic, olefin, polycarbonate, vinyl chloride, ABS, PET, nylon. Examples include plate-shaped bodies made of resin such as urethane, urethane, and polyimide. The preferable lower limit of the thickness of the support plate is 500 μm, the upper limit thereof is 3 mm, and the more preferable lower limit thereof is 1 mm and the upper limit thereof is 2 mm. Further, the variation in the thickness of the support plate is 1
% Or less is preferable.

In the method of manufacturing an IC chip according to the present invention, 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 ( The B) layer and the above support plate are bonded together. At this time, the surface of the wafer on which the circuit pattern is formed and the adhesive (A) layer are bonded together.

By fixing the wafer to the supporting plate via the above-mentioned supporting tape, the wafer can be reinforced and the handleability thereof can be improved. Therefore, even if the wafer is very thin with a thickness of about 50 μm, it can be transported or transported. It does not chip or break during processing, and can be stored easily in a cassette. The supporting tape can be easily peeled off from the IC chip by giving a stimulus after completion of a series of steps for manufacturing the IC chip.

The method of manufacturing an IC chip according to the present invention includes at least a step of polishing the wafer fixed to the supporting plate via the supporting tape. The thickness of the wafer after polishing is not particularly limited, but the effect of preventing damage is more likely to be exhibited when processing the wafer thinner, and when the thickness after polishing is about 50 μm, for example, 20 to 80 μm, Excellent damage prevention effect.

The IC chip manufacturing method of the present invention includes at least a step of attaching a dicing tape to the polished wafer. Before attaching the dicing tape, a polyimide film as an insulating substrate may be attached to the wafer in advance. It is necessary to heat the polyimide film when it is attached to the wafer. Therefore, in the case where the pressure-sensitive adhesive (A) layer reduces the pressure-sensitive adhesive force by heat stimulation, and when the pressure-sensitive adhesive (A) contains a gas generating agent that generates gas by heat stimulation, The temperature at which the adhesive strength of the adhesive (A) is reduced or the temperature at which a gas is generated must be selected to be higher than the temperature at which the polyimide film is attached to the wafer.

The dicing tape is not particularly limited, but a known photocurable 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.

The method for producing an IC chip of the present invention has at least a step of stimulating the pressure-sensitive adhesive (A) layer,
In this step, the stimulus is applied while uniformly loading the entire wafer. By stimulating the pressure-sensitive adhesive (A) layer as described above, gas is generated from the gas generating agent,
The generated gas peels off at least a part of the adhesive surface of the pressure-sensitive adhesive from the adherend to reduce the adhesive force. At this time, in a normal state, the generated gases coalesce into larger bubbles, and the large bubbles peel off at least a part of the adhesive surface of the adhesive from the adherend. However, the generation of these large bubbles is not always uniform on the entire wafer, and may be biased depending on the bonding state and the way of giving a stimulus. For an extremely thin wafer with a thickness of about 50 μm, the thickness is 100
Since the strength of the wafer is weaker than that of a conventional wafer having a thickness of about 600 μm and the wafer is likely to warp, the wafer may be deformed or damaged by the pressure of large bubbles that are nonuniformly applied.

By uniformly applying a load to the entire wafer when applying the stimulus, it is possible to prevent the generation of such non-uniform large bubbles. That is, by applying a uniform load, it is difficult for large bubbles to form due to the pressure due to the load, and it is difficult for the generated gas to move freely on the adhesive surface, and the gases coalesce into large bubbles. I can't. Therefore, the generated gas becomes uniform fine bubbles on the entire bonding surface, and the pressure of the gas applied to the wafer is also uniformly applied to the entire wafer, so that the wafer is not deformed or damaged.

The method of uniformly applying a load to the entire wafer is not particularly limited, but a method of applying a load by placing an appropriate weight is preferable. The magnitude of the load at this time is not particularly limited, but is set to such an extent that the IC chip is not damaged. The material of the weight is not particularly limited, but is preferably transparent when the stimulus for generating the gas is light. Specifically, thickness 1
A glass plate of about 2 cm is suitable.

In the method of manufacturing an IC chip of the present invention, the supporting tape is then peeled off from the wafer. At this time, since the adhesive force of the adhesive (A) is lowered by the stimulus, the supporting tape can be easily peeled from the wafer.

When a pressure-sensitive adhesive containing a gas generating agent that generates a gas by stimulation is used as the pressure-sensitive adhesive (B), the pressure-sensitive adhesive is applied by stimulating it before peeling the support tape from the wafer. If the hard supporting plate is peeled from the supporting tape after the gas is generated from the gas generating agent in the layer B) to reduce the adhesive force, the supporting tape becomes a flexible tape and is peeled off from the wafer while turning the tape. Therefore, it can be peeled from the wafer more easily. 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.

The IC chip manufacturing method of the present invention includes at least a step of dicing a wafer. Through this step, the wafer having a circuit formed on its surface is cut into chips by a diamond cutter. The size is usually several hundred μm to several tens mm on one side.

[0047]

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 ( An 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

Further, with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution of the pressure-sensitive adhesive (1), 2,2'-azobis-
100 parts by weight of (N-butyl-2-methylpropionamide) were mixed to prepare a pressure-sensitive adhesive (2) containing a gas generating agent.

<Preparation of support tape> A solution of the adhesive (1) in ethyl acetate was corona treated on both sides to a thickness of 100 μm.
m transparent PET film coated on one side with a doctor knife so that the dry film thickness is about 15 μm.
The coating solution was dried by heating at 5 ° C for 5 minutes. The dried pressure-sensitive adhesive (1) layer exhibited tackiness in a dried 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.

An ethyl acetate solution of the pressure-sensitive adhesive (1) was applied onto a PET film whose surface was subjected to a 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 (1) layer exhibited tackiness in a dried 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 surface of the PET film having the pressure-sensitive adhesive (1) layer which has been subjected to the corona treatment and having no pressure-sensitive adhesive (1) layer, and the PET having the pressure-sensitive adhesive (1) layer which has been subjected to the release treatment.
The pressure-sensitive adhesive (1) layer surface of the film was attached. As a result, a supporting tape 1 having a pressure-sensitive adhesive layer provided on both surfaces and having its surface protected by a PET film subjected to a release treatment was obtained.

Separately, a solution of the adhesive (2) in ethyl acetate was added.
On the PET film whose surface has been subjected to release treatment, apply it with a doctor knife so that the thickness of the dry film is about 10 μm, and heat at 110 ° C. for 5 minutes to evaporate the solvent and dry the application solution. It was The pressure-sensitive adhesive (2) layer after drying 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.

The PET film having the release treatment on the surface protecting the pressure-sensitive adhesive (1) layer on one side of the support tape 1 is peeled off, and the surface having the pressure-sensitive adhesive (2) layer formed thereon is subjected to the release treatment. It was attached to the adhesive (2) layer of the PET film.
Then, stationary curing was performed at 40 ° C. for 3 days. As a result, the adhesive (1) layer is formed on one surface and the adhesive (1) layer is formed on the other surface.
A support tape 2 having a primer layer made of the pressure-sensitive adhesive (2) on the surface of the layer and having the pressure-sensitive adhesive layer protected by a PET film whose surface was subjected to a release treatment was obtained.

(Polishing Step) Adhesive for Support Tape 2 (2)
Peel off the PET film to protect the layer, diameter 20.4c
and a silicon wafer having a thickness of about 750 μm.
Next, the PET film that protects the pressure-sensitive adhesive (1) layer was peeled off and bonded to a support plate made of a glass plate having a diameter of 20.4 cm under a reduced pressure environment. The glass plate adhered to the silicon wafer via the supporting tape 2 is attached to the polishing device,
Polishing was performed until the thickness of the silicon wafer became about 50 μm. After the polishing was completed, the support plate to which the silicon wafer was adhered was removed from the polishing device, and the dicing tape was attached onto the silicon wafer.

(Wafer Separating Step) A silicon wafer having a dicing tape attached was placed with the dicing tape facing down, and a glass plate having a diameter of 20 cm and a thickness of 1 cm was gently placed on a supporting plate. In this state, an ultraviolet ray of 365 nm was irradiated from the glass plate side for 2 minutes while adjusting the illuminance so that the irradiation intensity on the glass plate surface was 40 mW / cm ² . After removing the glass plate, the support plate and the support tape 2 were peeled off 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.

By using the support tape 2, the IC chip and the support plate can be bonded with high adhesive strength,
By polishing in this state, the wafer could be polished to a thickness of about 50 μm without damage. After the polishing, by irradiating ultraviolet rays to generate a gas from the gas generating agent, the adhesive force of the supporting tape was significantly reduced, and the wafer could be easily peeled off. Further, when a gas is generated from the gas generating agent, a glass plate is placed and a load is uniformly applied to the entire wafer, so that the generated gas coalesces into a large bubble, and the pressure damages the wafer, There was no deformation.

[0059]

According to the present invention, the wafer has a thickness of 50 μm.
It is possible to provide an IC chip manufacturing method capable of preventing damage to a wafer, improving handleability, and favorably processing into an IC chip even when the thickness is extremely thin.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasuhiko Oyama             Sekisui Chemical, 2-1 Hyakusan, Shimamoto-cho, Mishima-gun, Osaka Prefecture             Industry Co., Ltd. (72) Inventor Munehiro Hatakei             Sekisui Chemical, 2-1 Hyakusan, Shimamoto-cho, Mishima-gun, Osaka Prefecture             Industry Co., Ltd. (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 Masahiko Kitamura             2-14-3 Higashikotani, Ota-ku, Tokyo Co., Ltd.             Inside the disco (72) Inventor Koichi Yajima             2-14-3 Higashikotani, Ota-ku, Tokyo Co., Ltd.             Inside the disco F-term (reference) 5F031 CA02 DA15 HA78 MA22 MA37                       MA38 MA39 PA20

Claims (2)

[Claims] 1. A support tape having at least a surface composed of a pressure-sensitive adhesive (A) layer containing a gas generating agent that generates a gas upon stimulation and a surface composed of a pressure-sensitive adhesive (B) layer,
A step of fixing the wafer to a support plate, a step of polishing the wafer while fixing it to the support plate via the support tape, a step of attaching a dicing tape to the polished wafer, and a step of applying the adhesive (A) layer. Applying the stimulus,
Peeling the support tape from the wafer, and
A method of manufacturing an IC chip, comprising the step of dicing the wafer, wherein in the step of fixing the wafer to the support plate via the support tape, the surface composed of the adhesive (A) layer and the wafer In the step of attaching the adhesive (B) layer to the support plate and applying the stimulus to the adhesive (A) layer, the stimulus is applied while uniformly applying a load to the entire wafer. And a method of manufacturing an IC chip. 2. The step of peeling the support plate from the support tape between the step of attaching the dicing tape to the polished wafer and the step of peeling the support tape from the wafer. IC chip manufacturing method.