KR20200026178A - Manufacturing method of adhesive sheet for stealth dicing and semiconductor device - Google Patents

Abstract

A pressure sensitive adhesive sheet 1 for stealth dicing, which is used to cut and separate a semiconductor wafer having a modified layer formed therein into individual chips at room temperature, at least on a substrate 11 and one side of the substrate 11. When the adhesive sheet 12 laminated | stacked and the said adhesive sheet 1 for stealth dicing was stuck to a silicon wafer through the said adhesive layer 12, 23 of the interface of the said adhesive layer 12 and the said silicon wafer is carried out. The adhesive sheet (1) for stealth dicing whose shear force in ° C is 5 N / (3 mm x 20 mm) or more and 70 N / (3 mm x 20 mm) or less. The adhesive sheet 1 for stealth dicing is excellent in the washability of a chip | tip.

Description

Manufacturing method of adhesive sheet for stealth dicing and semiconductor device

This invention relates to the adhesive sheet for stealth dicing used for stealth dicing (trademark) processing, and the manufacturing method of the semiconductor device using the said adhesive sheet for stealth dicing.

When manufacturing a chip-shaped semiconductor device from a semiconductor wafer, it was conventionally performed that the blade dicing process which cuts a semiconductor wafer with a rotary blade and obtains a chip | tip while spraying a liquid for the purpose of washing | cleaning etc. to a semiconductor wafer is performed normally. However, in recent years, stealth dicing processing which can be divided into chips into a dry type is adopted. In stealth dicing, for example, a laser beam with a large opening NA is irradiated to a semiconductor wafer affixed to a dicing sheet, and the inside of the semiconductor wafer is minimized while minimizing damage to the vicinity of the surface of the semiconductor wafer. A reformed layer is formed preliminarily. Thereafter, by dicing the dicing sheet, a force is applied to the semiconductor wafer to separate the chips into individual chips.

Recently, it is required to laminate other chips or adhere chips to a film substrate with respect to the chips manufactured as described above. And the electrode formation surface of the chip | tip with which the processus | protrusion electrode was provided, and the circuit on another chip or board | substrate oppose the circuit of a chip | tip and the face up type mounting which connects the circuit on another chip or board | wire with a wire, and the electrode In some fields, flip chip mounting and direct silicon via (TSV) are directly connected by means of direct connection. In accordance with the request for lamination and bonding of chips in such flip chip mounting or the like, a method of fixing a chip having an electrode to another chip or a film substrate using an adhesive has been proposed.

And in order to be easy to apply to such a use, in the process of the said manufacturing method, about the semiconductor wafer which has an electrode in which the dicing sheet was affixed on the surface opposite to the electrode formation surface, or the modified semiconductor wafer which has an electrode, the electrode It is proposed to laminate | stack a film adhesive on a formation surface, and to make the chip | tip which has an electrode divided | segmented by the expansion process equip the electrode formation surface with an adhesive bond layer. As such an adhesive layer, a die attach film (DAF) or an adhesive film called a nonconductive film (NCF) is used.

Patent Literature 1 discloses attaching a DAF to a wafer, performing stealth dicing, and then dividing the DAF into pieces by dividing the wafer into chips by expansion.

Patent Document 1: Japanese Patent Application Laid-Open No. 2005-19962

By the way, in the above-mentioned stealth dicing process, when cut | disconnecting a semiconductor wafer in a modified layer, the crushed fragment mainly derived from a modified layer arises, and the said crushed fragment may adhere to a chip | tip. For this reason, the chip is washed to remove the crushed pieces.

Such chip cleaning may be performed on a dicing sheet. That is, after dividing a semiconductor wafer into chips on a dicing sheet, washing is performed while the obtained chips are laminated on the dicing sheet. In this case, by dicing the dicing sheet and increasing the space | interval (chip space | interval) between chips, it becomes possible to wash | clean a chip better.

However, in the conventional dicing sheet used by the method disclosed by patent document 1, since it cannot fully expand, it is difficult to widen a chip | tip gap sufficiently and to perform favorable washing | cleaning.

The present invention has been made in view of the above facts, and an object thereof is to provide a pressure-sensitive adhesive sheet for stealth dicing and a method for producing a semiconductor device, which are excellent in washability of chips.

In order to achieve the said objective, 1st this invention is a sticky sheet for stealth dicing used for cutting-separating at least the semiconductor wafer in which the modified layer was formed inside with the individual chip in room temperature environment, The base material and the said base material When the adhesive layer laminated | stacked on the one side of the surface, and affixed the said stealth dicing adhesive sheet to a silicon wafer via the said adhesive layer, the shear force in 23 degreeC of the interface of the said adhesive layer and the said silicon wafer is 5 Provided is an adhesive sheet for stealth dicing characterized by being at least N / (3 mm × 20 mm) and at most 70 N / (3 mm × 20 mm) (Invention 1).

In the adhesive sheet for stealth dicing which concerns on the said invention (invention 1), since the shear force in 23 degreeC is the said range, it can expand favorably in the state which laminated | stacked the chip | tip. For this reason, the chip | tip spacing can be made wide enough at the time of washing | cleaning a chip, and as a result, a chip can be wash | cleaned favorably.

In the said invention (invention 1), it is preferable that the said adhesive layer is comprised from an energy ray curable adhesive (invention 2).

In the said invention (invention 1, 2), it is preferable that the storage elastic modulus in 23 degreeC of the said base material is 10 MPa or more and 600 MPa or less (invention 3).

2nd this invention is the bonding process of bonding the said adhesive layer and the semiconductor wafer of the said adhesive sheet for stealth dicing (invention 1-3), the modified layer formation process of forming a modified layer in the inside of the said semiconductor wafer, room temperature environment An expansion step of expanding the adhesive sheet for stealth dicing below to cut and separate the semiconductor wafer having a modified layer formed therein into individual chips, and the adhesive for stealth dicing in a state in which the adhesive sheet for stealth dicing is expanded The manufacturing method of the semiconductor device characterized by including the washing process which wash | cleans the said chip | tip laminated | stacked on the sheet (Invention 4).

In the said invention (invention 4), it is further provided with the lamination process of laminating | stacking the adhesive film on the surface on the opposite side to the said adhesive sheet for stealth dicing in the said semiconductor wafer bonded to the adhesive sheet for stealth dicing. Preferred (Invention 5).

According to this invention, the adhesive sheet for stealth dicing excellent in the washability of a chip | tip, and the manufacturing method of a semiconductor device are provided.

1 is a plan view for explaining a method for measuring shear force according to Test Example 1. FIG.
2 is a cross-sectional view illustrating a method for measuring shear force according to Test Example 1. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described.

[Adhesion sheet for stealth dicing]

The adhesive sheet for stealth dicing which concerns on one Embodiment of this invention is used in order to cut-separate at least the semiconductor wafer in which the modified layer was formed inside with the individual chip in room temperature environment. Here, the room temperature environment means, for example, under an environment of 5 ° C or higher, particularly preferably under an environment of 10 ° C or higher, and preferably under an environment of 15 ° C or higher. In addition, under room temperature environment, it means that it is 45 degreeC or less environment, for example, it is preferable that it is 40 degreeC or less environment especially, and it is preferable that it is 35 degreeC or less environment environment. Since the said temperature range is easy to achieve even if it does not intentionally perform temperature management, the cost of stealth dicing can be reduced. In addition, the "sheet" in this specification shall also include the concept of "tape."

The adhesive sheet for stealth dicing which concerns on this embodiment is equipped with the base material and the adhesive layer laminated | stacked on the one surface side of the said base material. Although it is preferable that the base material and the adhesive layer are laminated directly, it is not limited to this.

When the adhesive sheet for stealth dicing is affixed on a silicon wafer via the adhesive layer which the adhesive sheet for stealth dicing concerning this embodiment has, the shear force in 23 degreeC of the interface of an adhesive layer and a silicon wafer is 5 N / ( 3 mm x 20 mm) or more and 70 N / (3 mm x 20 mm) or less.

The adhesive sheet for stealth dicing which concerns on this embodiment has the shear force as mentioned above, and individually expands the semiconductor wafer in which the modification layer was formed inside bonded to the said adhesive sheet for stealth dicing under room temperature environment. After cutting and separating into chips, the chip spacing can be made wide enough. Specifically, the chip spacing (the distance between the side surfaces of the adjacent chips) can be widened to about 150 to 300 µm, preferably about 155 to 260 µm, and particularly preferably about 160 to 250 µm. Since the chip spacing is extended to such a distance, when cleaning the chip, the cleaning liquid easily enters between the chip and the chip, so that the fragments of chips generated by the cutting separation of the semiconductor wafer can be effectively removed from the chip. In addition, the measuring method of the said shear force is as showing to the test example mentioned later.

When the shearing force is less than 5 N / (3 mm x 20 mm), when the shearing force is applied to the portion where the adhesive sheet for stealth dicing adheres to the ring frame at the time of expansion, the adhesive sheet for stealth dicing may fall off from the ring frame. Because of the high concern, it cannot be used stably. On the other hand, if the shear force exceeds 70 N / (3 mm x 20 mm), the chip spacing cannot be widened to a sufficient distance in order to perform good cleaning.

In view of the above, the lower limit of the shear force is preferably 10 N / (3 mm × 20 mm) or more, and particularly preferably 13 N / (3 mm × 20 mm) or more. Moreover, it is preferable that the upper limit of the said shear force is 65 N / (3mm * 20mm) or less, and it is especially preferable that it is 60N / (3mm * 20mm) or less.

Moreover, in the adhesive sheet for stealth dicing which concerns on this embodiment, even after opening the expanded state, a chip | tip gap can be kept at a suitable distance. Specifically, the chip | tip spacing after opening can be maintained about 50-200 micrometers. By keeping the chip spacing at such a distance, it is possible to suppress the collision between the chips after opening.

1. Adhesive layer

The pressure-sensitive adhesive layer of the pressure sensitive adhesive sheet for stealth dicing according to the present embodiment is not particularly limited as long as the above shear force is satisfied. The pressure-sensitive adhesive layer may be composed of a non-energy ray curable pressure sensitive adhesive, or may be composed of an energy ray curable pressure sensitive adhesive. As a non-energy-ray-curable adhesive, what has desired adhesive force and re-peelability is preferable, For example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane type adhesive, a polyester type adhesive, a polyvinyl ether type adhesive etc. can be used. have. Among these, the acrylic adhesive which can suppress the fall of a semiconductor wafer, a chip, etc. at a modified layer formation process, an expansion process, etc. is preferable.

On the other hand, since the energy ray-curable pressure-sensitive adhesive is cured by energy ray irradiation and the adhesive force is lowered, when the chip obtained by dividing the semiconductor wafer and the adhesive sheet for stealth dicing are desired to be separated, the energy ray-curable pressure-sensitive adhesive is easily separated by irradiating the energy ray. Can be.

The energy ray curable adhesive which comprises an adhesive layer may be made from the polymer which has energy ray curability as a main component, and the monomer which has a non-energy ray curable polymer (polymer which does not have energy ray curability) and at least 1 energy ray curable group And / or a mixture of oligomers as a main component. Moreover, a mixture of a polymer having energy ray curable and a non-energy ray curable polymer may be used, or a mixture of a polymer having energy ray curable and a monomer and / or oligomer having at least one energy ray curable group may be used, and a mixture of these three kinds It may be.

First, the case where an energy beam curable adhesive has a polymer which has energy beam curability as a main component is demonstrated below.

A polymer having energy ray curability is a (meth) acrylic acid ester (co) polymer (A) (hereinafter referred to as "energy ray curable polymer (A)") in which a functional group (energy ray curable group) having energy ray curability is introduced into a side chain. It may be a case). It is preferable that this energy-ray-curable polymer (A) is obtained by making the acrylic copolymer (a1) which has a functional group containing monomeric unit, and the unsaturated group containing compound (a2) which has a functional group couple | bonded with the functional group react. In addition, in this specification, a (meth) acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms.

It is preferable that an acryl-type copolymer (a1) contains the structural unit guide | induced from a functional group containing monomer, and the structural unit guide | guided | derived from a (meth) acrylic acid ester monomer or its derivative (s).

It is preferable that the functional group containing monomer as a structural unit of an acryl-type copolymer (a1) is a monomer which has a polymerizable double bond and functional groups, such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group, in a molecule | numerator.

As a hydroxy group containing monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth), for example Acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. are mentioned, These are used individually or in combination of 2 or more types.

As a carboxyl group-containing monomer, ethylenically unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, a citraconic acid, are mentioned, for example. These may be used independently and may be used in combination of 2 or more type.

As an amino-group containing monomer or a substituted amino group-containing monomer, aminoethyl (meth) acrylate, n-butylaminoethyl (meth) acrylate, etc. are mentioned, for example. These may be used independently and may be used in combination of 2 or more type.

Examples of the (meth) acrylic acid ester monomer constituting the acrylic copolymer (a1) include monomers having an alicyclic structure in the molecule other than alkyl (meth) acrylate having 1 to 20 carbon atoms in the alkyl group (containing alicyclic structure). Monomer) is preferably used.

Especially as alkyl (meth) acrylate, the alkyl (meth) acrylate which has C1-C18 of an alkyl group, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n -Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. are used preferably. These may be used individually by 1 type and may be used in combination of 2 or more type.

As an alicyclic structure containing monomer, For example, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, Dicyclopentenyloxyethyl (meth) acrylate is preferably used. These may be used individually by 1 type and may be used in combination of 2 or more type.

The acrylic copolymer (a1) has a structural unit derived from the functional group-containing monomer, preferably 1 to 35% by mass, particularly preferably 5 to 30% by mass, more preferably 10 to 25% by mass. It contains. In addition, the acrylic copolymer (a1) has a structural unit derived from a (meth) acrylic acid ester monomer or a derivative thereof, preferably 50 to 99% by mass, particularly preferably 60 to 95% by mass, more preferably 70 It contains in the ratio of -90 mass%.

The acrylic copolymer (a1) is obtained by copolymerizing the above functional group-containing monomer with a (meth) acrylic acid ester monomer or a derivative thereof by a conventional method, but in addition to these monomers, dimethylacrylamide, vinyl formate, vinyl acetate, styrene Etc. may be copolymerized.

An energy ray-curable polymer (A) is obtained by reacting the acrylic copolymer (a1) having the functional group-containing monomer unit with an unsaturated group-containing compound (a2) having a functional group bonded to the functional group.

The functional group which an unsaturated group containing compound (a2) has can be suitably selected according to the kind of functional group of the functional group containing monomeric unit which an acryl-type copolymer (a1) has. For example, when the functional group which an acryl-type copolymer (a1) has is a hydroxyl group, an amino group, or a substituted amino group, as a functional group which an unsaturated group containing compound (a2) has, the isocyanate group or an epoxy group is preferable, and an acryl-type copolymer (a1) has When a functional group is an epoxy group, an amino group, a carboxyl group, or an aziridinyl group is preferable as a functional group which an unsaturated group containing compound (a2) has.

The unsaturated group-containing compound (a2) contains at least one, preferably 1 to 6, more preferably 1 to 4 energy-polymerizable carbon-carbon double bonds in one molecule. As a specific example of such an unsaturated-group containing compound (a2), for example, 2-methacryloyloxyethyl isocyanate, meta-isopropenyl- (alpha), (alpha)-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1 , 1- (bisacryloyloxymethyl) ethyl isocyanate; Acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth) acrylate; Acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or a polyisocyanate compound, a polyol compound, and hydroxyethyl (meth) acrylate; Glycidyl (meth) acrylate; (Meth) acrylic acid, 2- (1-aziridinyl) ethyl (meth) acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, etc. are mentioned.

The unsaturated group-containing compound (a2) is preferably 50 to 95 mol%, particularly preferably 60 to 93 mol%, more preferably 70 to the number of moles of the functional group-containing monomer of the acrylic copolymer (a1). It is used in the ratio of -90 mol%.

In reaction of an acryl-type copolymer (a1) and an unsaturated-group containing compound (a2), reaction temperature, a pressure, and a solvent are according to the combination of the functional group which an acryl-type copolymer (a1) has, and the functional group which an unsaturated-group-containing compound (a2) has. The time, the presence or absence of a catalyst, and the kind of catalyst can be appropriately selected. Thereby, the functional group which exists in an acryl-type copolymer (a1), and the functional group in an unsaturated-group-containing compound (a2) react, an unsaturated group is introduce | transduced into the side chain in an acryl-type copolymer (a1), and an energy-beam curable polymer (A) is obtained. Lose.

It is preferable that the weight average molecular weight (Mw) of the energy beam curable polymer (A) obtained in this way is 10,000 or more, It is preferable that it is 150,000-1,500,000 especially, It is preferable that it is 200,000-1 million. In addition, the weight average molecular weight (Mw) in this specification is a standard polystyrene conversion value measured by the gel permeation chromatography method (GPC method).

Even when the energy ray-curable pressure-sensitive adhesive has a polymer having energy ray curability called an energy ray-curable polymer (A) as a main component, the energy ray-curable pressure-sensitive adhesive may further contain an energy ray-curable monomer and / or oligomer (B). .

As an energy-beam curable monomer and / or oligomer (B), ester of polyhydric alcohol and (meth) acrylic acid, etc. can be used, for example.

As such an energy-beam curable monomer and / or oligomer (B), monofunctional acrylic acid esters, such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate, a trimetholpropane tri (meth), for example Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol diol Polyfunctional acrylic acid esters, such as (meth) acrylate, polyethyleneglycol di (meth) acrylate, dimethol tricyclodecane di (meth) acrylate, polyester oligo (meth) acrylate, polyurethane oligo (meth) acryl The rate etc. are mentioned.

When mix | blending an energy beam curable monomer and / or oligomer (B) with respect to an energy beam curable polymer (A), content of an energy beam curable monomer and / or oligomer (B) in an energy beam curable adhesive is an energy beam It is preferable that it is 0.1-180 mass parts with respect to 100 mass parts of curable polymers (A), and it is especially preferable that it is 60-150 mass parts.

Here, when using an ultraviolet ray as an energy ray for hardening an energy ray curable adhesive, it is preferable to add a photoinitiator (C), and by using this photoinitiator (C), a polymerization hardening time and a light irradiation amount are reduced. Can be.

Specific examples of the photopolymerization initiator (C) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid and benzoin benzoic acid methyl. , Benzoin dimethyl ketal, 2,4-diethyl thioxane, 1-hydroxycyclohexylphenyl ketone, benzyldiphenylsulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, di Acetyl, β-chloro anthraquinone, (2,4,6-trimethylbenzyldiphenyl) phosphine oxide, 2-benzothiazole-N, N-diethyldithiocarbamate, oligo {2-hydroxy- 2-methyl-1- [4- (1-propenyl) phenyl] propanone}, 2,2-dimethoxy-1,2-diphenylethan-1-one, etc. are mentioned. These may be used independently and may use 2 or more types together.

A photoinitiator (C) is an energy-beam curable polymer (A) (in the case of mix | blending an energy-beam curable monomer and / or oligomer (B), an energy-beam curable polymer (A) and an energy-beam curable monomer and / or oligomer) 100 mass parts of total amounts of (B)) It is preferable to use in the quantity of 0.1-10 mass parts, especially 0.5-6 mass parts with respect to 100 mass parts.

In an energy ray curable adhesive, you may mix | blend another component suitably in addition to the said component. As another component, a non-energy-ray-curable polymer component or oligomer component (D), a crosslinking agent (E), a polymeric branched polymer (F), etc. are mentioned, for example.

As a non-energy-ray-curable polymer component or oligomer component (D), a polyacrylic acid ester, polyester, a polyurethane, polycarbonate, a polyolefin, a high branched polymer, etc. are mentioned, for example, A weight average molecular weight (Mw) This 3000-2.5 million polymer or oligomer is preferable. By mix | blending said component (D) with an energy-beam curable adhesive, adhesiveness and peelability before hardening, the intensity | strength after hardening, the peeling property from an adherend, adhesiveness with another layer, storage stability, etc. can be improved. have. The compounding quantity of the said component (D) is not specifically limited, It determines suitably in the range of 0.01-50 mass parts with respect to 100 mass parts of energy ray curable polymers (A).

As a crosslinking agent (E), the polyfunctional compound which has the reactivity with the functional group which an energy-beam curable polymer (A) etc. have can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, reactive phenol resins, and the like. Can be mentioned. The shear force mentioned above can be adjusted by mix | blending a crosslinking agent (E) with an energy-beam curable adhesive.

It is preferable that it is 0.01-8 mass parts with respect to 100 mass parts of energy ray hardenable polymers (A), It is preferable that it is 0.04-5 mass parts especially, and, as for the compounding quantity of a crosslinking agent (E), it is preferable that it is 0.05-3.5 mass parts further.

The polymerizable branched polymer (F) means a polymer having an energy ray polymerizable group and a branched structure. Since the energy ray-curable pressure-sensitive adhesive contains a polymerizable branched polymer, the migration of organic substances from the pressure-sensitive adhesive layer on the semiconductor wafer or semiconductor chip laminated on the pressure-sensitive adhesive sheet for stealth dicing can be suppressed, and from the pressure-sensitive adhesive sheet for stealth dicing In the process of picking up the semiconductor chips individually, it is possible to reduce the mechanical load on the semiconductor chips. It is not clear how the polymerizable branched polymer (F) contributes to such an effect, but the polymerizable branched polymer (F) is considered to have a tendency to easily exist near the interface of a semiconductor wafer or a semiconductor chip in an adhesive layer. The polymerizable branched polymer (F) may be polymerized with the energy ray curable polymer (A), the energy ray curable monomer and / or the oligomer (B) by energy ray irradiation, and the like.

The specific structure of the molecular weight of the polymerizable branched polymer (F), the degree of the branched structure, and the number of energy ray polymerizable groups in one molecule is not particularly limited. As an example of the method of obtaining such a polymeric branched polymer (F), the monomer which has two or more radically polymerizable double bonds in a molecule, an active hydrogen group, and the monomer which has one radically polymerizable double bond in a molecule | numerator, and one radical The polymer which has a branched structure is obtained by superposing | polymerizing the monomer which has a polymerizable double bond in a molecule | numerator. Next, a polymerizable branched polymer (F) is obtained by reacting the polymer obtained with a compound having a functional group capable of forming a bond by reacting with an active hydrogen group of the polymer and at least one radically polymerizable double bond in a molecule. Can be. As a commercial item of a polymerizable branched polymer (F), it is Nissan Chemical Industries, Ltd., for example. "OD-007" can be used.

The weight average molecular weight (Mw) of the polymerizable branched polymer (F) is from the viewpoint of facilitating moderately suppressing the interaction between the energy ray-curable polymer (A), the energy ray-curable monomer and / or the oligomer (B), It is preferable that it is 1000 or more, and it is especially preferable that it is 3000 or more. In addition, the weight average molecular weight (Mw) is preferably 100,000 or less, particularly preferably 30,000 or less.

Although content of the polymerizable branched polymer (F) in an adhesive layer is not specifically limited, From an viewpoint of obtaining the above-mentioned effect by containing a polymeric branched polymer (F) favorably, it is normally an energy-beam curable polymer (A) 100. It is preferable that it is 0.01 mass part or more with respect to mass part, and it is preferable that it is 0.1 mass part or more. Since the polymerizable branched polymer (F) has a branched structure, the above-described effects can be satisfactorily obtained even when the content in the pressure-sensitive adhesive layer is relatively small.

Moreover, depending on the kind of polymerizable branched polymer (F), polymerizable branched polymer (F) may remain as a particle in the contact surface with the adhesive layer in a semiconductor wafer or a semiconductor chip. Since these particles may lower the reliability of products having semiconductor chips, it is preferable that the number of particles remaining is small. Specifically, the number of particles having a particle size of 0.20 µm or more that remains on the silicon wafer as the semiconductor wafer is preferably less than 100, particularly preferably 50 or less. From the viewpoint of facilitating satisfying the request regarding such particles, the content of the polymerizable branched polymer (F) is preferably less than 3.0 parts by mass with respect to 100 parts by mass of the energy ray-curable polymer (A), and in particular, It is preferable to set it as 2.5 mass parts or less, and it is preferable to set it as 2.0 mass parts or less.

Next, the case where an energy ray curable adhesive has a mixture of a non-energy ray curable polymer component and the monomer and / or oligomer which has at least 1 or more energy ray curable groups as a main component is demonstrated below.

As a non-energy-ray-curable polymer component, the component similar to the acryl-type copolymer (a1) mentioned above can be used, for example.

As a monomer and / or oligomer which has at least 1 or more energy-beam curable groups, the same thing as the component (B) mentioned above can be selected. The blending ratio of the non-energy ray-curable polymer component and the monomer and / or oligomer having at least one energy ray-curable group is a monomer having at least one energy ray-curable group and / or to 100 parts by mass of the non-energy ray-curable polymer component. It is preferable that it is 1-200 mass parts of oligomers, and it is especially preferable that it is 60-160 mass parts.

Also in this case, similarly to the above, a photoinitiator (C) and a crosslinking agent (E) can be mix | blended suitably.

The pressure-sensitive adhesive layer thickness is not particularly limited as long as the pressure-sensitive adhesive layer can function appropriately in each step in which the pressure-sensitive adhesive sheet for stealth dicing according to the present embodiment is used. It is preferable that it is 1-50 micrometers specifically, it is preferable that it is 3-40 micrometers especially, and it is preferable that it is 5-30 micrometers further.

As for the adhesive layer in the adhesive sheet for stealth dicing which concerns on this embodiment, it is preferable that the storage elastic modulus in 23 degreeC is 1-5000 kPa, It is especially preferable that it is 3-3000 kPa, Furthermore, it is 5-2500 kPa desirable. The storage elastic modulus at 23 degrees C of an adhesive layer is the said range, and the adhesive sheet for stealth dicing becomes easy to expand, it becomes easy to widen a chip space effectively, and it becomes possible to wash | clean a chip more favorably. In addition, the measuring method of the said storage elastic modulus is as showing to the test example mentioned later.

2.base

As for the base material in the adhesive sheet for stealth dicing which concerns on this embodiment, it is preferable that the storage elastic modulus in 23 degreeC is 10 MPa or more and 600 MPa or less. When the shear force of the pressure-sensitive adhesive layer is in the above-described range, if the storage elastic modulus of the base material is in the above-described range, the chip gap of the chip bonded to the stealth dicing pressure-sensitive adhesive sheet can be sufficiently widened by this synergistic effect. The chip can be cleaned effectively. In addition, the measuring method of the said storage elastic modulus is as showing to the test example mentioned later.

In addition, if the storage elastic modulus is 10 MPa or more, since the substrate exhibits predetermined rigidity, the pressure-sensitive adhesive layer formed on the release sheet or the like can be laminated on the substrate by transfer, so that the pressure-sensitive adhesive sheet for stealth dicing can be efficiently produced. . Moreover, the handling property of the adhesive sheet for stealth dicing becomes favorable. On the other hand, if the said storage elastic modulus is 600 Mpa or less, the adhesive sheet for stealth dicing will expand | extend favorably by an expand. Moreover, the semiconductor wafer can be favorably supported by the adhesive sheet for stealth dicing attached to the ring frame.

In view of the above, the lower limit of the storage modulus is more preferably 50 MPa or more, and particularly preferably 100 MPa or more. Moreover, it is more preferable that the upper limit of the said storage elastic modulus is 580 Mpa or less, and it is especially preferable that it is 550 Mpa or less.

When performing the modified layer formation process which irradiates the laser beam beyond the said adhesive sheet for stealth dicing, about the semiconductor wafer bonded to the adhesive sheet for stealth dicing, the base material in the adhesive sheet for stealth dicing concerning this embodiment is the It is preferable to exhibit the excellent light transmittance with respect to the light of the wavelength of a laser beam.

In addition, when using an energy ray in order to harden an adhesive layer, it is preferable that a base material has a light transmittance with respect to the said energy ray. An energy ray is mentioned later.

It is preferable that the base material in the adhesive sheet for stealth dicing which concerns on this embodiment contains the film (resin film) whose main material is a resin system, and it is especially preferable to consist only of a resin film. As a specific example of a resin film, Ethylene-vinyl acetate copolymer film; Ethylene-based copolymer films such as ethylene- (meth) acrylic acid copolymer film, ethylene- (meth) acrylic acid methyl copolymer film, other ethylene- (meth) acrylic acid ester copolymer film; Polyolefin-based films such as polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film, norbornene resin film; Polyvinyl chloride films such as polyvinyl chloride films and vinyl chloride copolymer films; Polyester-based films such as polyethylene terephthalate film, polybutylene terephthalate film and polyethylene naphthalate; (Meth) acrylic acid ester copolymer film; Polyurethane film; Polyimide film; Polystyrene film; Polycarbonate films; A fluororesin film etc. are mentioned. As an example of a polyethylene film, a low density polyethylene (LDPE) film, a linear low density polyethylene (LLDPE) film, a high density polyethylene (HDPE) film, etc. are mentioned. Moreover, the modified film of these crosslinked films and ionomer films is also used. A base material may be a film which consists of these 1 types, and may be a film which consists of a material which combined these 2 or more types. Moreover, the laminated | multilayer film of the multilayered structure in which the layer which consists of one or more types of materials mentioned above are laminated | stacked may be sufficient. In this laminated | multilayer film, the material which comprises each layer may be same or different.

 Among the above films, polyolefin-based films such as ethylene-methacrylic acid copolymer film, polyethylene film and polypropylene film, ionomer film of such polyolefin, polyvinyl chloride-based film, polyurethane film, or (meth) acrylic acid ester copolymer It is preferable to use a film, a film made of linear low density polyethylene and polypropylene as a material.

In the substrate, various additives such as fillers, flame retardants, plasticizers, antistatic agents, lubricants, antioxidants, colorants, infrared absorbers, ultraviolet absorbers, and ion trapping agents may be contained in the above films. Although it does not specifically limit as content of such an additive, It is preferable to set it as the range in which a base material exhibits a desired function.

When the base material and the adhesive layer are directly laminated | stacked in the adhesive sheet for stealth dicing which concerns on this embodiment, the surface of the adhesive layer side in a base material is primer treatment, a corona treatment, and a plasma treatment, in order to improve adhesiveness with an adhesive layer. Surface treatments, such as these, may be performed.

The thickness of a base material is not limited as long as it can function suitably at the process in which the adhesive sheet for stealth dicing is used. It is preferable that the said thickness is 20-450 micrometers normally, It is especially preferable that it is 25-250 micrometers, It is preferable that it is 50-150 micrometers further.

3. peeling sheet

Even if the peeling sheet is laminated | stacked on the surface on the opposite side to the base material side of the adhesive layer in the adhesive sheet for stealth dicing concerning this embodiment until the said adhesive sheet for stealth dicing is used, in order to protect an adhesive layer good.

Although it does not specifically limit as a peeling sheet, For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethyl pentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, polyethylene Naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene- (meth) acrylic acid copolymer film, ethylene- (meth) acrylic acid ester copolymer film, polystyrene film, poly A carbonate film, a polyimide film, a fluororesin film, etc. can be used. Moreover, you may use these crosslinked films. Moreover, the laminated | multilayer film in which several of these films were laminated may be sufficient.

It is preferable that the peeling process is given to the peeling surface (surface which has peelability; especially the surface which contact | connects an adhesive layer) of the said peeling sheet. As a peeling agent used for a peeling process, alkyd type, silicone type, fluorine type, unsaturated polyester type, polyolefin type, wax type peeling agent is mentioned, for example.

Moreover, it does not specifically limit about the thickness of a peeling sheet, Usually, it is about 20 micrometers to about 100 micrometers.

4.Adhesion

In the adhesive sheet for stealth dicing which concerns on this embodiment, it is preferable that adhesive force with respect to the silicon mirror wafer at 23 degreeC is 1 N / 25 mm or more, and it is especially preferable that it is 2 N / 25 mm or more. Moreover, it is preferable that the said adhesive force is 30 N / 25 mm or less, and it is especially preferable that it is 29.5 N / 25 mm or less. Since the adhesive force in 23 degreeC is the said range, when expanding an adhesive sheet in an expand process, it is easy to hold | maintain in the predetermined position of a semiconductor wafer or the obtained semiconductor chip, and the division | segmentation is favorable in the modified layer part of a semiconductor wafer. It becomes possible to do it. In addition, when an adhesive layer is comprised from an energy ray curable adhesive, the said adhesive force shall mean the adhesive force before energy ray irradiation. In addition, adhesive force says what was measured according to the method mentioned later.

In the pressure-sensitive adhesive sheet for stealth dicing according to the present embodiment, when the pressure-sensitive adhesive layer is composed of an energy ray-curable pressure-sensitive adhesive, it is preferable that the adhesive force to the silicon mirror wafer after energy ray irradiation at 23 ° C is 10 mN / 25 mm or more. In particular, it is preferable that it is 20 mN / 25 mm or more. Moreover, it is preferable that the said adhesive force is 1000 mN / 25 mm or less, and it is especially preferable that it is 900 mN / 25 mm or less. After the individualization of the semiconductor wafer is completed, the adhesive sheet for stealth dicing can be irradiated with an energy ray to lower the adhesive force to the above range, thereby making it possible to easily pick up the obtained semiconductor chip. In addition, adhesive force says what was measured according to the method mentioned later.

The adhesive force at 23 degreeC mentioned above and the adhesive force after energy beam irradiation at 23 degreeC can be measured by the following method. First, the sheet | seat for semiconductor processing is cut out in width of 25 mm, and the surface of the adhesive layer side is affixed on a silicon mirror wafer. This lamination can be performed using a laminator (manufactured by LINTEC Corporation, product name "RAD-3510F / 12") under conditions of a lamination speed of 10 mm / s, a wafer protrusion amount of 20 µm, and a roller pressure of 0.1 MPa. Subsequently, the laminated body of the obtained semiconductor process sheet | seat and a silicon mirror wafer is left to stand for 20 minutes in 23 degreeC and 50% RH atmosphere. Here, when measuring the adhesive force after energy-beam irradiation at 23 degreeC, after leaving for 20 minutes, using the ultraviolet irradiation apparatus (product made from LINTEC Corporation, product name "RAD-2000m / 12") for the said laminated body, Ultraviolet (UV) irradiation (light intensity 230 mW / cm 2, light quantity 190 mJ / cm 2) is performed on the substrate side of the sheet under a nitrogen atmosphere. Following 20 minutes of standing or UV irradiation, the sheet was silicon mirrored at a peel angle of 180 ° and a peel rate of 300 mm / min using a universal tensile tester (manufactured by AMD, product name "RTG-1225") in accordance with JIS Z0237. It peels from a wafer and makes the value measured the adhesive force (mN / 25mm).

5.Manufacturing method of the adhesive sheet for stealth dicing

The manufacturing method of the adhesive sheet for stealth dicing which concerns on this embodiment is not specifically limited, A conventional method can be used. As a 1st example of the said manufacturing method, first, the adhesive composition containing the material of an adhesive layer, and the coating composition which further contains a solvent or a dispersion medium as needed are prepared. Next, this coating composition is apply | coated on the peeling surface of a peeling sheet with a die coater, a curtain coater, a spray coater, a slit coater, a knife coater, etc., and a coating film is formed. In addition, the coating film is dried to form an adhesive layer. Then, the adhesive sheet for stealth dicing is obtained by bonding together the adhesive layer on a peeling sheet and a base material. The property of a coating will not be specifically limited if it can apply | coat. The component for forming an adhesive layer may be contained as a solute in the coating composition, or may be contained as a dispersoid.

When the composition for coating contains a crosslinking agent (E), in order to form a crosslinked structure with desired density of density, said drying conditions (temperature, time, etc.) may be changed, or heat processing may be provided separately. In order to fully advance a crosslinking reaction, after laminating | stacking an adhesive layer on a base material by the said method etc. normally, the obtained adhesive sheet for stealth dicing is left still for several days in the environment of 23 degreeC, 50% of a relative humidity, for example. Curing

As a 2nd example of the manufacturing method of the adhesive sheet for stealth dicing concerning this embodiment, the said composition for coating is apply | coated to one surface of a base material first, and a coating film is formed. Next, the said coating film is dried and the laminated body which consists of a base material and an adhesive layer is formed. Moreover, in this laminated body, the exposed surface of an adhesive layer and the peeling surface of a peeling sheet are bonded together. Thereby, the adhesive sheet for stealth dicing which the peeling sheet was laminated | stacked on the adhesive layer is obtained.

[Method for Manufacturing Semiconductor Device]

The manufacturing method of the semiconductor device which concerns on one Embodiment of this invention is a bonding process of bonding the adhesive layer and semiconductor wafer of the adhesive sheet for stealth dicing (the adhesive sheet for stealth dicing which concerns on this embodiment) mentioned above, a semiconductor wafer A reformed layer forming step of forming a reformed layer therein, an expand process of expanding a pressure sensitive adhesive sheet for stealth dicing under a room temperature environment, cutting and separating a semiconductor wafer having a modified layer formed therein into individual chips, and an adhesive for stealth dicing. The cleaning process of washing the chip | tip laminated | stacked on the adhesive sheet for stealth dicing in the state which expanded the sheet is provided.

In the said manufacturing method, a bonding process may be performed before a modified layer formation process first, and conversely, a modified layer formation process may be performed first before a bonding process. In the former case, a laser beam is irradiated to the semiconductor wafer bonded to the adhesive sheet for stealth dicing which concerns on this embodiment in a modified layer formation process. In the latter case, the laser beam is irradiated to the semiconductor wafer bonded to another adhesive sheet (for example, a back grind sheet) in a modified layer formation process, for example.

According to the manufacturing method of the semiconductor device which concerns on this embodiment, since the adhesive sheet for stealth dicing mentioned above is used at least in a washing | cleaning process, the space | interval of a chip | tip is widened enough by the expansion of the said adhesive sheet for stealth dicing. Can be. For this reason, a cleaning liquid tends to enter between a chip | tip and a chip, and favorable washing | cleaning of a chip can be performed.

Moreover, the manufacturing method of the semiconductor device which concerns on this embodiment is an adhesive film (DAF, NCF, etc.) on the surface on the opposite side to the adhesive sheet side for stealth dicing in the semiconductor wafer bonded to the adhesive sheet for stealth dicing. You may further include the lamination process of laminating | stacking. According to the manufacturing method of the semiconductor device which concerns on this embodiment, the adhesive film can be favorably divided | segmented by an expand process.

Hereinafter, the preferable specific example of the manufacturing method of the semiconductor device which concerns on one Embodiment of this invention is demonstrated.

(1) bonding process

First, the bonding process of bonding the adhesive layer and semiconductor wafer of the adhesive sheet for stealth dicing which concerns on this embodiment is performed. Usually, although the surface of the adhesive layer side of the adhesive sheet for stealth dicing is mounted in one surface of a semiconductor wafer, it is not limited to this. In this bonding process, a ring frame is affixed on the area | region of the outer peripheral side of the area | region to which the semiconductor wafer is affixed on the surface of the adhesive layer side of the adhesive sheet for stealth dicing normally. In this case, in a plan view, a region where the pressure-sensitive adhesive layer is exposed exists as a peripheral region between the ring frame and the semiconductor wafer.

(2) laminate process

Next, you may perform the lamination process of laminating | stacking the adhesive film on the surface on the opposite side to the adhesive sheet side for stealth dicing in the semiconductor wafer bonded to the adhesive sheet for stealth dicing. This lamination is usually performed by heat lamination (heat lamination). When a semiconductor wafer has an electrode on the surface, since an electrode exists in the surface on the opposite side to the adhesive sheet side for stealth dicing in a semiconductor wafer normally, the adhesive film is laminated | stacked on the electrode side of a semiconductor wafer.

The film for adhesion may be either DAF, NCF, or the like, and usually has thermal adhesiveness. It does not specifically limit as a material, The film-like member formed from the adhesive composition containing the heat-resistant resin material and hardening accelerator of a polyimide resin, an epoxy resin, and a phenol resin is mentioned as a specific example.

(3) modified layer forming process

Preferably, after the bonding step or after the lamination step, a modified layer forming step of forming a modified layer inside the semiconductor wafer is performed, but the modified layer forming step may be performed before this step. The modified layer forming step is usually performed by irradiating a laser light in an infrared region so as to focus on a focus set inside the semiconductor wafer (steal dicing processing). Irradiation of a laser beam may be performed to either side of a semiconductor wafer. It is preferable to irradiate the laser beam over the adhesive sheet for stealth dicing, if it is a case where a modified layer formation process is performed after a lamination process. Moreover, when performing a modified layer formation process between the said bonding process and the said lamination process, or when not performing the said lamination process, it is preferable to irradiate a laser beam directly to a semiconductor wafer without passing through the adhesive sheet for stealth dicing.

(4) expand process

After the modified layer forming step, an expand step of cutting and separating the semiconductor wafer is performed by expanding the pressure-sensitive adhesive sheet for stealth dicing in a room temperature environment. Thereby, on the adhesive layer of the adhesive sheet for stealth dicing, the semiconductor chip in which a semiconductor wafer is divided | segmented is stuck. In addition, when the adhesive film is laminated on the semiconductor wafer, the adhesive film is also divided at the same time as the division of the semiconductor wafer by the expansion step to obtain a chip having an adhesive layer.

Specific conditions in the expand process are not limited. For example, the temperature at the time of expanding an adhesive sheet for stealth dicing can be made into the temperature of a general expand, As mentioned above, it is preferable that it is 5 degreeC or more normally, It is especially preferable that it is 10 degreeC or more, It is preferable that it is 15 degreeC or more. Moreover, it is preferable that the said temperature is 45 degrees C or less normally, It is preferable that it is especially 40 degrees C or less, and it is preferable that it is 35 degrees C or less.

 (5) washing process

After the expansion step, a washing step of washing the chips laminated on the stealth dicing pressure-sensitive adhesive sheet is performed while the pressure-sensitive adhesive sheet for stealth dicing is expanded. The expansion in the washing step can be carried out under general conditions. For example, the expansion performed in the expanding step may be maintained in the washing step as it is, or after the expansion is opened after the expanding step. For this purpose, the adhesive sheet for stealth dicing may be expanded again. Moreover, washing | cleaning can also be performed on general conditions, for example, you may immerse a chip | tip in a washing | cleaning liquid for every adhesive sheet for stealth dicing. As mentioned above, by performing the washing | cleaning process using the adhesive sheet for stealth dicing which concerns on this embodiment, washing | cleaning can be performed in the state which enlarged the chip space obtained sufficiently, and, thereby, the shredding piece which affixed to a chip | tip is favorable. Can be removed. In addition, you may perform a washing | cleaning process after the following shrink process.

(6) shrink process

When the expansion process causes sagging in the peripheral region (region between the ring frame and the chip group in plan view) of the pressure-sensitive adhesive sheet for stealth dicing, it is preferable to perform a shrink process for heating the peripheral region. By heating the peripheral area | region of the adhesive sheet for stealth dicing, the base material located in this peripheral region shrink | contracts, and the fall amount of the adhesive sheet for stealth dicing produced at the expansion process can be reduced. The heating method in the shrink process is not limited. You may spray hot air, irradiate infrared rays, or irradiate microwaves.

(7) pickup process

In the case where the washing step is performed after the washing step, when the washing step is continued after the shrinking step, or when the shrinking step is not performed, the chip stuck to the adhesive sheet for stealth dicing is removed after the washing step. The pickup process is carried out individually from the pressure-sensitive adhesive sheet for stealth dicing, and a chip is obtained as a semiconductor device.

Here, when the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet for stealth dicing is made of an energy ray-curable pressure-sensitive adhesive, at any stage before the pick-up process after the bonding step, the pressure-sensitive adhesive layer is cured by irradiating an energy ray to lower the adhesive force. desirable. Thereby, the said chip can be picked up more easily.

Examples of the energy ray include ionizing radiation, that is, X-rays, ultraviolet rays, and electron beams. Among these, the ultraviolet ray which is comparatively easy to introduce irradiation equipment is preferable.

When ultraviolet rays are used as ionizing radiation, near ultraviolet rays containing ultraviolet rays having a wavelength of about 200 to 380 nm may be used for ease of handling. As light quantity of an ultraviolet-ray, what is necessary is just to select suitably according to the kind of energy-beam curable adhesive contained in an adhesive layer, and the thickness of an adhesive layer, It is about 50-500 mJ / cm <2> normally, 100-450 mJ / cm <2> is preferable, 150-400 mJ / cm <2> is more preferable. Moreover, an ultraviolet illuminance is about 50-500 mW / cm <2> normally, 100-450 mW / cm <2> is preferable and 150-400 mW / cm <2> is more preferable. There is no restriction | limiting in particular as an ultraviolet source, For example, a high pressure mercury lamp, a metal halide lamp, a light emitting diode (LED), etc. are used.

When using an electron beam as ionizing radiation, about the acceleration voltage, what is necessary is just to select suitably according to the kind of energy ray polymerizable group contained in an adhesive layer, an energy ray polymerizable compound, or the thickness of an adhesive layer, and usually acceleration voltage 10-1000 kV. It is preferable that it is about. In addition, what is necessary is just to select suitably the irradiation dose according to the kind of energy ray curable adhesive contained in an adhesive layer, or the thickness of an adhesive layer, and it is normally selected in the range of 10-1000 krad. There is no restriction | limiting in particular as an electron beam source, For example, a Cocrocroft-Walton type, a Van de Graaff type, a resonance transformer type, an insulation core transformer type, or a linear type | mold dynamitron Various electron beam accelerators, such as a mold | type and a high frequency type, can be used.

By implementing the above manufacturing method, a semiconductor device can be manufactured using the adhesive sheet for stealth dicing which concerns on this embodiment.

The embodiment described above is described in order to facilitate understanding of the present invention and is not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

Example

Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples.

EXAMPLE 1

(1) Preparation of pressure-sensitive adhesive composition

80 mol% of methacryl to an acrylic copolymer obtained by reacting butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate = 80/5/15 (mass ratio) with the 2-hydroxyethyl acrylate Iloxyethyl isocyanate (MOI) was reacted to obtain an energy radiation curable polymer. The weight average molecular weight (Mw) of this energy ray curable polymer was 400,000.

100 parts by mass of the obtained energy ray-curable polymer (in terms of solid content; similarly described below), 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator, and tolylene diisocyanate as a crosslinking agent. 0.49 mass part of system crosslinking agents (Nippon Polyurethane Industry Co., Ltd. product name "Coronate L") were mixed in a solvent, and the adhesive composition was obtained.

(2) Production of an adhesive sheet for stealth dicing

The said adhesive composition was apply | coated on the peeling surface of a peeling sheet (made by LINTEC Corporation, product name "SP-PET3811"). Then, drying by heating was performed to make the coating film of the pressure-sensitive adhesive composition an adhesive layer. This adhesive layer thickness was 10 micrometers. Then, the corona-treated surface of the adhesive layer on the obtained peeling sheet, and the ethylene-methacrylic acid copolymer (EMAA) film (thickness: 80 micrometers, surface tension of a corona treatment surface) whose one surface was corona-treated as a base material The adhesive sheet for stealth dicing was obtained by bonding together.

Example 2

80 mol% of methacryl to an acrylic copolymer obtained by reacting 2-ethylhexyl acrylate / vinyl acetate / 2-hydroxyethyl acrylate = 60/20/20 (mass ratio) with the 2-hydroxyethyl acrylate Loyloxyethyl isocyanate (MOI) was reacted to obtain an energy ray-curable polymer (Mw: 400,000).

3 mass parts of 1-hydroxycyclohexylphenyl ketone (made by BASF, product name "IRGACURE 184") as 100 mass parts of obtained energy-beam-curable polymers and a photoinitiator, and tolylene diisocyanate type crosslinking agent (made by Toyo Ink, product name) as a crosslinking agent 0.31 mass part of "Coronate L") was mixed in a solvent, and the adhesive composition was obtained. Except using the obtained adhesive composition, it carried out similarly to Example 1, and manufactured the adhesive sheet for stealth dicing.

EXAMPLE 3

5--6 functional urethane as a monomer having 100 parts by mass of an acrylic copolymer (Mw: 600,000) obtained by reacting 2-ethylhexyl acrylate / methyl acrylate / acrylic acid = 50/40/10 (mass ratio) with an energy ray-curable group 120 parts by mass of acrylate (manufactured by DAINICHISEIKA, product name `` SEIKA BEAM 14-29B '') and 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator and 1 as a crosslinking agent 0.286 parts by mass of, 3-bis (N, N-diglycidylaminomethyl) cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Inc., product name "TETRAD C") was mixed in a solvent to obtain an adhesive composition. Except using the obtained adhesive composition, it carried out similarly to Example 1, and manufactured the adhesive sheet for stealth dicing.

EXAMPLE 4

Straight chain low density polyethylene resin (manufactured by UBE-MARUZEN POLYETHYLENE, product name "UMERIT 3540 F") and polypropylene resin (manufactured by Idemitsu Kosan Co., Ltd., product name "F-724 NP") are extruders (TOYO SEIKI SEISAKU-SHO, Ltd.) to produce a film having a thickness of 80 m. A pressure-sensitive adhesive sheet for stealth dicing was produced in the same manner as in Example 2, except that one surface of the film was corona-treated as a base material.

[Example 5]

80 mol% of methacryl to an acrylic copolymer obtained by reacting butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate = 62/10/28 (mass ratio) with the 2-hydroxyethyl acrylate Iloxyethyl isocyanate (MOI) was reacted to obtain an energy ray curable polymer (Mw: 400,000).

3 mass parts of 1-hydroxycyclohexylphenyl ketone (made by BASF, product name "IRGACURE 184") as 100 mass parts of obtained energy-beam-curable polymers and a photoinitiator, and tolylene diisocyanate type crosslinking agent (made by Toyo Ink, product name) as a crosslinking agent 1.61 mass part of "Coronate L") was mixed in a solvent, and the adhesive composition was obtained. Except using the obtained adhesive composition, it carried out similarly to Example 1, and manufactured the adhesive sheet for stealth dicing.

Comparative Example 1

80 mol% of methacryl to an acrylic copolymer obtained by reacting lauryl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate = 42/30/28 (mass ratio) with the 2-hydroxyethyl acrylate Loyloxyethyl isocyanate (MOI) was reacted to obtain an energy radiation curable polymer (Mw: 400,000).

3 mass parts of 1-hydroxycyclohexylphenyl ketone (made by BASF, product name "IRGACURE 184") as 100 mass parts of obtained energy-beam-curable polymers and a photoinitiator, and tolylene diisocyanate type crosslinking agent (made by Toyo Ink, product name) as a crosslinking agent 1.07 mass part of "Coronate L") was mixed in a solvent, and the adhesive composition was obtained.

Comparative Example 2

80 mol% of the acrylic copolymer obtained by reacting 2-ethylhexyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate = 42/30/28 (mass ratio) with the 2-hydroxyethyl acrylate Methacryloyloxyethyl isocyanate (MOI) was reacted to obtain an energy ray curable polymer (Mw: 400,000).

3 mass parts of 1-hydroxycyclohexylphenyl ketone (made by BASF, product name "IRGACURE 184") as 100 mass parts of obtained energy-beam-curable polymers and a photoinitiator, and tolylene diisocyanate type crosslinking agent (made by Toyo Ink, product name) as a crosslinking agent 1.07 mass part of "Coronate L") was mixed in a solvent, and the adhesive composition was obtained. Except using the obtained adhesive composition, it carried out similarly to Example 1, and manufactured the adhesive sheet for stealth dicing.

Comparative Example 3

80 mol% of the acrylic copolymer obtained by reacting 2-ethylhexyl acrylate / isobonyl acrylate / 2-hydroxyethyl acrylate = 42/30/28 (mass ratio) with the 2-hydroxyethyl acrylate Methacryloyloxyethyl isocyanate (MOI) was reacted to obtain an energy ray-curable polymer (Mw: 400,000).

3 mass parts of 1-hydroxycyclohexylphenyl ketone (made by BASF, product name "IRGACURE 184") as 100 mass parts of obtained energy-beam-curable polymers and a photoinitiator, and tolylene diisocyanate type crosslinking agent (made by Toyo Ink, product name) as a crosslinking agent 1.07 mass part of "Coronate L") was mixed in a solvent, and the adhesive composition was obtained. Except using the obtained adhesive composition, it carried out similarly to Example 1, and manufactured the adhesive sheet for stealth dicing.

[Test Example 1] (Measurement of Shear Force)

As a backing material, the instant adhesive agent (product made from TOAGOSEI CO., LTD., Product name "Aron Alpha") is used for the surface on the opposite side to the adhesive layer in the base material of the adhesive sheet for stealth dicing obtained by the Example and the comparative example. A polyethylene terephthalate film (thickness: 100 µm) was bonded to obtain a laminate.

After the obtained laminated body was cut out to length 50mm and width 30mm in the environment of the temperature of 23 degreeC, and 50% of a relative humidity, the peeling sheet was peeled off from the adhesive layer, and this was made into the sample. This sample was affixed on the mirror surface of a silicon mirror wafer (thickness: 350 micrometers) through the adhesive layer in the environment of the temperature of 23 degreeC, and 50% of a relative humidity. At this time, a 2 kg roller was reciprocated once with respect to the sample, and the load was applied, and the 3 mm length direction part of the sample was affixed so that it might adhere to a silicon wafer. Next, only the sample was cut with a cutter so that the width of the sample was 20 mm on the silicon mirror wafer, and the cut pieces of the sample which became unnecessary were peeled off from the silicon mirror wafer. Thereby, as shown to FIG. 1 and FIG. 2, the test object by which the sample and a silicon mirror wafer were affixed in the area | region of 20 mm x 3 mm (60 mm <2>) was obtained. In addition, in FIG. 1 and FIG. 2, the code | symbol 1 shows the adhesive sheet for stealth dicing (sample) which has a backing material, the code | symbol 2 is a silicon mirror wafer, the code | symbol 11, the base material, the code | symbol 12, and the code | symbol 13 represent a backing material.

After 20 minutes from the patch, a tensile test was carried out using an autograph (manufactured by IMADA SEISAKUSHO CO., LTD., Product name "SDT-203NB-50 R3") under a condition of a tensile speed of 1 mm / min under an environment of 23 ° C. Shear force (N / (3 mm x 20 mm)) was measured. The results are shown in Table 1.

[Test Example 2] (Measurement of Storage Elastic Modulus of Substrate)

About the base material used by the Example and the comparative example, the storage elastic modulus (MPa) of the base material in 23 degreeC was measured on the following apparatus and conditions. The results are shown in Table 1.

Measuring Device: Made in TA Instruments, Dynamic Elastic Modulus Measuring Device "DMA Q800"

Test start temperature: 0 degrees Celsius

Test end temperature: 200 degrees Celsius

Temperature rising rate: 3 degrees Celsius / minute

Frequency: 11Hz

Amplitude: 20μm

[Test Example 3] (Measurement of Storage Elastic Modulus of Adhesive Layer)

The adhesive composition used in the Example and the comparative example was apply | coated to the peeling surface of a peeling sheet, an adhesive layer was formed, and the peeling surface of the peeling sheet prepared separately was crimped | bonded to the exposed adhesive layer, and a peeling sheet / adhesive layer / The adhesive sheet which consists of a peeling sheet was produced. The release sheet was removed from the pressure sensitive adhesive sheet, and a plurality of layers were laminated so that the pressure sensitive adhesive layer had a thickness of 200 μm. 30 mm x 4 mm rectangle (thickness: 200 micrometers) was punched in the laminated body of the obtained adhesive layer, and this was made into the sample for a measurement. About this measurement sample, the storage elastic modulus (kPa) of the adhesive layer in 23 degreeC was measured on the following apparatus and conditions. The results are shown in Table 1.

Measuring Device: Made in TA Instruments, Dynamic Elastic Modulus Measuring Device "DMA Q800"

Distance between measurements: 20 mm

Test start temperature: -30 degrees Celsius

Test end temperature: 120 degrees Celsius

Temperature rising rate: 3 degrees Celsius / minute

Frequency: 11Hz

Amplitude: 20μm

[Test Example 4] (Evaluation of Cleanliness)

The mirror surface of a 6 inch ring frame and a 6 inch silicon mirror wafer (thickness: 100 micrometers) was affixed on the adhesive layer of the adhesive sheet for stealth dicing obtained by the Example and the comparative example. Then, using a stealth dicing apparatus (product name "DFL7360" made by DISCO Corporation), the laser was irradiated to the surface on the opposite side to the adhesive sheet for stealth dicing in a 6-inch silicon mirror wafer under the following conditions. And a modified layer was formed in a 6-inch silicon mirror wafer. The laser irradiation at this time was performed so that the size of the chip obtained may be 8 mm x 8 mm.

<Condition of investigation>

Irradiation height: 68μm from the tape side

Frequency: 90Hz

Output: 0.3 W

Machining Speed: 360mm / sec

Thereafter, using an expand apparatus (manufactured by JCM, product name "ME-300B"), the expansion was performed at a drawing speed of 100 mm / sec and a drawing amount of 10 mm with respect to the work under an environment of 23 ° C. . Immediately after that, the chip | tip spacing (micrometer) was measured with the digital microscope (product name "VHX-1000" by KEYENCE company), and the average value which measured arbitrary five points was computed. This average value was made into the chip space (micrometer) immediately after expansion. Moreover, the washability was evaluated based on the following criteria from the value of the chip space | interval immediately after expansion. Each result is shown in Table 1.

○: chip thickness is 150 μm or more

X: chip spacing less than 150μm

As can be seen from Table 1, in the adhesive sheet for stealth dicing obtained in the examples, the chip spacing was sufficiently widened by the expand, and exhibited excellent washability.

The adhesive sheet for stealth dicing which concerns on this invention is used suitably for the manufacturing method of the semiconductor device which performs an expansion process and a washing process.

1: Adhesive sheet for stealth dicing having a backing material (sample)
11: description
12: adhesive layer
13: backing material
2: silicon mirror wafer

Claims (5)

At least, as an adhesive sheet for stealth dicing used to cut and isolate a semiconductor wafer having a modified layer formed therein into individual chips at room temperature,
It is provided with a base material and the adhesive layer laminated | stacked on the one surface side of the said base material,
When the adhesive sheet for stealth dicing is affixed on a silicon wafer via the said adhesive layer, the shear force at 23 degrees C of the interface of the said adhesive layer and the said silicon wafer is 5 N / (3 mm * 20mm) or more 70 N / (3 mm x 20 mm) or less, The adhesive sheet for stealth dicing characterized by the above-mentioned. The method of claim 1,
The pressure-sensitive adhesive layer is composed of an energy ray curable pressure-sensitive adhesive, characterized in that the adhesive sheet for stealth dicing. The method according to claim 1 or 2,
The storage elastic modulus at 23 degrees C of the said base material is 10 Mpa or more and 600 Mpa or less, The adhesive sheet for stealth dicing characterized by the above-mentioned. Bonding process of bonding the said adhesive layer and semiconductor wafer of the adhesive sheet for stealth dicing as described in any one of Claims 1-3,
A modified layer forming step of forming a modified layer in the semiconductor wafer;
An expand step of expanding the stealth dicing adhesive sheet under a room temperature environment and cutting and separating the semiconductor wafer having a modified layer formed therein into individual chips; and
A washing step of washing the chips laminated on the stealth dicing pressure-sensitive adhesive sheet in a state in which the pressure-sensitive adhesive sheet for stealth dicing is expanded;
The manufacturing method of the semiconductor device characterized by the above-mentioned. The method of claim 4, wherein
In the semiconductor device bonded to the said adhesive sheet for stealth dicing, the lamination process of laminating | stacking an adhesive film is further provided on the surface on the opposite side to the adhesive sheet side for stealth dicing, The manufacturing of the semiconductor device characterized by the above-mentioned. Way.

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