KR20200024126A - Manufacturing method of adhesive sheet for stealth dicing and semiconductor device - Google Patents

Abstract

At least, as the adhesive sheet 1 for stealth dicing used in order to cut | disconnect a semiconductor wafer in which the modified layer was formed inside with the individual chip in the environment of -20 degreeC or more and 10 degrees C or less, the base material 11 and the said base material ( 11) and a pressure-sensitive adhesive layer 12 laminated on one side of the surface, and in the case where the stealth dicing pressure-sensitive adhesive sheet 1 is affixed on a silicon wafer through the pressure-sensitive adhesive layer 12, The adhesive sheet for stealth dicing (1) whose shear force in 0 degreeC of the interface of the said silicon wafer is 190 N / (3 mm * 20 mm) or more and 400 N / (3 mm * 20 mm) or less. Such a stealth dicing adhesive sheet 1 can satisfactorily separate a semiconductor wafer into chips by cool expansion, even when the obtained chip size is small.

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. 2005-019962

Since the above-mentioned DAF and NCF have brittle characteristics in the low temperature region, in order to improve the partitionability of DAF or NCF, the expansion is performed in a low temperature environment of about -20 ° C to 10 ° C. In many cases, an expand process is performed.

In recent years, miniaturization of products on which semiconductor devices are mounted and development of MEMS (Micro Electromechanical Mechanical Systems) have progressed, and the required chip size has also decreased. However, the smaller the chip size obtained by stealth dicing, the more the chips having the adhesive layer obtained, or the cleavage separation of the semiconductor wafer or the dividing of the DAF or the NCF, do not occur as intended during the cool expansion process described above. The problem of breakage tends to occur.

The present invention has been made in view of the above-described facts, and even when the obtained chip size is small, a pressure-sensitive adhesive sheet for stealth dicing and a method for manufacturing a semiconductor device, which can be satisfactorily separated into chips by cool expansion, are provided. For the purpose of

In order to achieve the said objective, 1st this invention is the adhesive sheet for stealth dicing used for cutting-separating at least the semiconductor wafer in which the modified layer was formed inside by the individual chip in the environment of -20 degreeC or more and 10 degrees C or less. As a base material and an adhesive layer laminated | stacked on the one surface side of the said base material, and when the said adhesive sheet for stealth dicing is stuck to a silicon wafer through the said adhesive layer, the interface of the said adhesive layer and the said silicon wafer is carried out. Provided is an adhesive sheet for stealth dicing characterized in that the shear force at 0 ° C. is 190 N / (3 mm × 20 mm) or more and 400 N / (3 mm × 20 mm) or less (Invention 1).

In the pressure-sensitive adhesive sheet for stealth dicing according to the invention (Invention 1), the shear strength of 0 ° C is within the above range, and at the time of cool expansion, the pressure-sensitive adhesive sheet for stealth dicing and the semiconductor wafer laminated on the pressure-sensitive adhesive sheet for stealth dicing are used. It is difficult to produce a deviation at the interface. Thereby, the force which pulls a semiconductor wafer in the peripheral part direction by the expansion of the adhesive sheet for stealth dicing becomes easy to concentrate on a modified layer, As a result, the division of a semiconductor wafer in a said modified layer becomes favorable. For this reason, even when the chip size obtained is small, generation | occurrence | production of a chipping fault and a chip | tip breakage problem can be suppressed, and the chip which was satisfactorily separated can be obtained.

In the invention (Invention 1), the chip preferably has a minimum side length of 0.5 mm or more and 20 mm or less (invention 2).

In the said invention (invention 1, 2), it is preferable that the said semiconductor wafer is 10 micrometers or more and 1000 micrometers or less in thickness (invention 3).

In the said invention (invention 1-3), it is preferable that the said adhesive layer is comprised from an energy-beam curable adhesive (invention 4).

In the said invention (invention 1-4), it is preferable that the storage elastic modulus at 0 degreeC of the said base material is 100 MPa or more and 1500 MPa or less (invention 5).

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 1-5), and the modified layer formation process which forms a modified layer inside the said semiconductor wafer. And a cool expand process of expanding the adhesive sheet for stealth dicing under an environment of -20 ° C or more and 10 ° C or less to cut and separate the semiconductor wafer having a modified layer formed therein into individual chips. A semiconductor device manufacturing method is provided (invention 6).

In the said invention (invention 6), it is further provided with the lamination process of laminating | stacking an 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 said adhesive sheet for stealth dicing. Preferred (Invention 7).

According to this invention, even if the chip size obtained is small, the adhesive sheet for stealth dicing and the manufacturing method of a semiconductor device which can divide | segment a semiconductor wafer into chips well by cool expansion 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 | tip at low temperature environment. Here, under low temperature environment, it means under the temperature environment which DAF and NCF fully embrittle, for example, it means under 10 degrees C or less environment, It is preferable that it is especially under 6 degrees C or less environment, and it is 4 degrees C or less environment It is preferable to be lowered. In addition, the lower limit of the temperature in low temperature environment here is not restrict | limited, For example, a low temperature environment means that it is under the environment of -20 degreeC or more, It is preferable that it is especially under the environment of -15 degreeC or more, Furthermore, -10 degreeC It is preferable to be in the above environment. Under an environment exceeding 10 ° C, brittleness of DAF and NCF is insufficient, and there is a fear that good division cannot be performed. In addition, under an environment of less than -20 ° C, since DAF, NCF, or pressure-sensitive adhesive sheets are placed in an environment below their glass transition temperature (Tg), the adhesion between these and semiconductor wafers may be lowered, and at the time of expansion. There is a fear that breakage of the pressure-sensitive adhesive sheet occurs. The step of forming a modified layer inside the semiconductor wafer (modified layer forming step) may be performed while the semiconductor wafer is bonded to the adhesive sheet for stealth dicing, or is performed before the semiconductor wafer is bonded to the adhesive sheet for stealth dicing. Also good. In addition, in this specification, the "sheet" shall also include the concept of "tape."

The adhesive sheet for stealth dicing which concerns on this embodiment is equipped with a 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 affixing the said adhesive sheet for stealth dicing to a silicon wafer through the adhesive layer which the adhesive sheet for stealth dicing concerning this embodiment has, the shear force in 0 degreeC of the interface of an adhesive layer and a silicon wafer is 190 N / (3 mm x 20 mm) or more, preferably 195 N / (3 mm x 20 mm) or more, particularly preferably 200 N / (3 mm x 20 mm) or more. The shear force is preferably 400 N / (3 mm × 20 mm) or less, preferably 300 N / (3 mm × 20 mm) or less, particularly preferably 200 N / (3 mm × 20 mm) or less. When the shearing force is less than 190 N / (3 mm x 20 mm), a shift in the interface between the stealth dicing adhesive sheet and the semiconductor wafer is likely to occur at the time of cool expansion, and in particular, when the chip size is small, the semiconductor wafer Cannot be cut and separated satisfactorily. On the other hand, if the shear force exceeds 400 N / (3 mm x 20 mm), the chip spacing cannot be sufficiently widened by the cool expand. In addition, the measuring method of the said shear force is as showing to the test example mentioned later.

When the semiconductor wafer with the modified layer formed therein using the adhesive sheet for stealth dicing according to the present embodiment is cut and separated into individual chips under a low temperature environment, the resulting chip has a minimum side length of 0.5 mm to 20 mm. It is preferable that especially the said length is 0.7 mm-18 mm, and it is preferable that the said length is 1.0 mm-16 mm. As described above, the adhesive sheet for stealth dicing according to the present embodiment can suppress the misalignment at the interface between the adhesive sheet for stealth dicing and the semiconductor wafer, so that the semiconductor wafer can be cut and separated satisfactorily. It can be cut and separated to obtain a chip having a small chip size as described above.

In the case where the semiconductor wafer having a modified layer formed therein is separated and separated into individual chips under a low temperature environment using the adhesive sheet for stealth dicing according to the present embodiment, the semiconductor wafer preferably has a thickness of 10 μm to 1000 μm or less. In particular, the thickness is preferably 20 µm to 950 µm or less, and the thickness is preferably 30 µm to 900 µm or less. In general, the thicker the semiconductor wafer becomes, the more difficult it is to cut and separate the semiconductor wafer into chips at the time of cool expansion. However, since the adhesive sheet for stealth dicing which concerns on this embodiment can suppress the shift | offset | difference at the interface of the adhesive sheet for stealth dicing and a semiconductor wafer, and can cut | disconnect and isolate a semiconductor wafer favorably as mentioned above, The same relatively thick semiconductor wafer can be cut and separated satisfactorily.

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, a cool 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, an 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 0 degreeC is 0.02-40.0 MPa, It is especially preferable that it is 0.10-30.0 MPa, Furthermore, it is 0.50-20.0 MPa It is preferable. 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 0 degreeC is 100 MPa or more and 1500 MPa or less. Generally, when the storage elastic modulus of a base material is too low, it will become easy to preferentially expand to the area | region which a semiconductor wafer is not laminated in the expansion process rather than the area | region where the semiconductor wafer in the adhesive sheet for stealth dicing is laminated | stacked. . However, since the said storage elastic modulus is the said range, the area | region in which the semiconductor wafer in the adhesive sheet for stealth dicing is laminated can also be extended | stretched favorably, As a result, an individual chip can be cut | disconnected effectively. In addition, the measuring method of the said storage elastic modulus is as showing to the test example mentioned later.

In addition, when the storage elastic modulus is 100 MPa or more, the substrate exhibits predetermined rigidity, and thus, 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. have. Moreover, the handling property of the adhesive sheet for stealth dicing becomes favorable. On the other hand, if the said storage elastic modulus is 1500 Mpa or less, the adhesive sheet for stealth dicing will expand | extend favorably by a cool expand. Moreover, the semiconductor wafer can be favorably supported by the adhesive sheet for stealth dicing mounted to the ring frame.

From the above viewpoints, the lower limit of the storage modulus is more preferably 120 MPa or more, and particularly preferably 150 MPa or more. Moreover, it is more preferable that the upper limit of the said storage elastic modulus is 1200 Mpa or less, and it is especially preferable that it is 1000 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.

Considering the use in the cool expansion process, as the substrate, among the above films, polyolefin-based films such as ethylene-methacrylic acid copolymer film, polyethylene film, polypropylene film, ionomer film of such polyolefin, polyvinyl chloride-based It is preferable to use a film, a polyurethane film, or a (meth) acrylic acid ester copolymer film.

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 0 degreeC is 0.5 N / 25 mm or more, and it is especially preferable that it is 1.0 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 25 N / 25 mm or less. Since the adhesive force in 0 degreeC is the said range, when expanding an adhesive sheet in a cool-expansion process, it is easy to hold | maintain in the predetermined position of a semiconductor wafer or a semiconductor chip obtained, and the division | segmentation is favorable in the modified layer part of a semiconductor wafer. It can be done. 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. Especially, 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 0 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). Here, when measuring the adhesive force at 0 degreeC, the measurement using the said universal tension tester is performed in 0 degreeC environment, and when measuring the adhesive force at 23 degreeC, the measurement using the said universal type tensile tester is 23 It is performed in the environment of ° C.

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 composition for coating 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 and a base material on a peeling sheet. 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 by 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 side 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 modified layer therein and a cool expanded process of expanding a pressure sensitive adhesive sheet for stealth dicing under a low temperature environment to cut and separate a semiconductor wafer having a modified layer formed therein into individual chips.

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 above-mentioned stealth dicing adhesive sheet is used at least in a cool-expand process, in a cool-expand process, at the interface of the adhesive sheet for stealth dicing and a semiconductor wafer It is difficult to cause misalignment. As a result, the force of tensioning the semiconductor wafer in the peripheral portion direction caused by the expansion of the pressure-sensitive adhesive sheet for stealth dicing tends to concentrate on the modified layer, resulting in good division of the semiconductor wafer in the modified layer. For this reason, even when the chip size obtained is small, generation | occurrence | production of a chipping fault and a chip | tip breakage problem can be suppressed, and the chip which was satisfactorily separated can be obtained.

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, since a cool expansion process is performed, the adhesive film can be divided | segmented favorably in low temperature environment.

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 pasting 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) Cool Expand Process

After the modified layer forming step, a cold expand step of cutting and separating the semiconductor wafer is performed by expanding the pressure sensitive adhesive sheet for stealth dicing under a low 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 will adhere. 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 cool expand process are not limited. For example, the temperature at the time of expanding the pressure-sensitive adhesive sheet for stealth dicing can be the temperature of a general cool expand, and as described above, it is usually 10 ° C. or lower, particularly preferably 6 ° C. or lower, and 4 It is preferable that it is degrees C or less. Moreover, it does not restrict | limit in particular also about the lower limit of the temperature of a cool expand, Usually, it is -20 degreeC or more, It is preferable that it is especially -15 degreeC or more, It is preferable that it is -10 degreeC or more. As mentioned above, when performing a cool expansion process using the adhesive sheet for stealth dicing which concerns on this embodiment, when it can cut | disconnect and isolate | separate favorably with a semiconductor wafer chip, and the adhesive film is laminated | stacked, The adhesive film is also divided well.

(5) Re-expand process

After performing a cool expansion process, the adhesive sheet for stealth dicing and the chip | tip which has a semiconductor chip or adhesive bond layer laminated | stacked on it may be returned to room temperature environment, and you may perform an expansion process again in a room temperature environment (reexpand process). Specific conditions in the re-expand step are not particularly limited except that the expand is performed at room temperature (for example, 23 ° C.).

In addition, this re-expand process usually causes sagging in the peripheral region (area between the ring frame and the chip group in plan view) of the PSA sheet for stealth dicing.

(6) shrink process

When sagging occurs in the peripheral region of the pressure-sensitive adhesive sheet for stealth dicing by the re-expanding step, it is preferable to perform a shrinking step of 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 it becomes possible to reduce the drooping amount of the adhesive sheet for stealth dicing produced in the re-expand process. 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 of performing the re-expanding step, after the shrinking process following this, and in the case of not performing the re-expanding step, the chip adhered to the stealth dicing adhesive sheet is individually removed from the pressure-sensitive adhesive sheet for stealth dicing after the cool expansion process. Pick-up is performed, and a pick-up step of obtaining a chip as a semiconductor device is performed.

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 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 ray-curable polymer (Mw: 400,000).

100 parts by mass of the obtained energy ray-curable polymer and 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator and tolylene diisocyanate crosslinking agent (manufactured by Toyo Ink, product name) 1.07 mass part of "Coronate L") was 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 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).

100 parts by mass of the obtained energy ray-curable polymer and 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator and tolylene diisocyanate crosslinking agent (manufactured by Toyo Ink, product name) 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.

EXAMPLE 3

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

100 parts by mass of the obtained energy ray-curable polymer and 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator and tolylene diisocyanate crosslinking agent (manufactured by Toyo Ink, product name) 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.

EXAMPLE 4

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

100 parts by mass of the obtained energy ray-curable polymer and 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator and tolylene diisocyanate crosslinking agent (manufactured by Toyo Ink, product name) 0.43 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 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. Except using the obtained adhesive composition, it carried out similarly to Example 1, and manufactured the adhesive sheet for stealth dicing.

Comparative 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).

100 parts by mass of the obtained energy ray-curable polymer and 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator and tolylene diisocyanate crosslinking agent (manufactured by Toyo Ink, product name) 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.

[Comparative Example 3]

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).

100 parts by mass of the obtained energy ray-curable polymer and 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator and tolylene diisocyanate crosslinking agent (manufactured by Toyo Ink, product name) 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 4

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).

100 parts by mass of the obtained energy ray-curable polymer and 3 parts by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") as a photopolymerization initiator and tolylene diisocyanate crosslinking agent (manufactured by Toyo Ink, product name) 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 by the cutter so that the width of the sample might be 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 are a backing material.

Immediately after the patch, the obtained test object was transferred under an environment of 0 ° C, and after 20 minutes from the patch, under an environment of 0 ° C, under a condition of a tensile speed of 1 mm / min, an autograph (IMADA SEISAKUSHO CO., LTD. And the tensile test was done using product name "SDT-203NB-50R3"), and the shear force (N / (3mm * 20mm)) 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 at 0 degreeC was measured on the following apparatuses 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 (MPa) of the adhesive layer in 0 degreeC was measured on the following apparatus and conditions. The results are shown in Table 1.

Measuring device: Made by TA Instruments, dynamic elastic modulus measuring device "ARES"

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 Partitioning)

The mirror surface of a 6 inch ring frame and a 6 inch silicon mirror wafer (thickness: 150 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. Laser irradiation at this time was performed four times so that the size of the chip obtained might be 16 mm x 16 mm, 8 mm x 8 mm, 4 mm x 4 mm, and 1 mm x 1 mm, respectively.

<Condition of investigation>

Irradiation height: 100μm from the tape side

Frequency: 90Hz

Output: 0.25W

Machining Speed: 360mm / sec

Thereafter, using an expander (manufactured by JCM, product name "ME-300B"), the work was expanded at a drawing speed of 100 mm / sec and a drawing amount of 10 mm in the environment at 0 ° C. . Next, the number of chips which were divided well in the position of the modified layer and completely separated from the surrounding chips was measured, and the ratio (%) to the total number of chips theoretically obtained was calculated. And the partitionability was evaluated based on the following criteria. The results are shown in Table 1.

(Circle): The said ratio is 100%.

(Triangle | delta): The said ratio is less than 100% and 80% or more.

X: The said ratio is less than 80%.

As can be seen from Table 1, the adhesive sheet for stealth dicing obtained in the example can satisfactorily divide the wafer on which the modified layer is formed by cool expansion, and in particular, the chip size is 4 mm x 4 mm or 1 mm. Even in the case of as small as 1 mm, excellent splitability was shown.

The adhesive sheet for stealth dicing which concerns on this invention is used suitably for the manufacturing method of the semiconductor device which performs cool expansion.

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

Claims (7)

At least, as an adhesive sheet for stealth dicing used for cutting and separating a semiconductor wafer with a modified layer formed therein into an individual chip under an environment of -20 ° C or more and 10 ° C or less,
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 0 degreeC of the interface of the said adhesive layer and the said silicon wafer is 190 N / (3 mm * 20mm) or more 400 N / (3 mm x 20 mm) or less, The adhesive sheet for stealth dicing characterized by the above-mentioned. The method of claim 1,
Said chip has a minimum side length of 0.5 mm or more and 20 mm or less, The adhesive sheet for stealth dicing. The method according to claim 1 or 2,
The said semiconductor wafer has thickness of 10 micrometers or more and 1000 micrometers or less, The adhesive sheet for stealth dicing. The method according to any one of claims 1 to 3,
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 any one of claims 1 to 4,
The storage elastic modulus in 0 degreeC of the said base material is 100 Mpa or more and 1500 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 1-5,
A modified layer forming step of forming a modified layer in the semiconductor wafer, and
A cool expand process of expanding the adhesive sheet for stealth dicing under an environment of -20 ° C. or more and 10 ° C. or less to cut and separate the semiconductor wafer having a modified layer formed therein into individual chips;
The manufacturing method of the semiconductor device characterized by the above-mentioned. The method of claim 6,
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.

Images