KR101891422B1 - Adhesive film for protecting surface of semiconductor wafer, semiconductor device manufacturing method and semiconductor wafer protection method using adhesive film - Google Patents

Abstract

A pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer has a base film and a pressure-sensitive adhesive layer on one surface of the base film. Wherein the pressure-sensitive adhesive layer comprises a polymer (A) in which the temperature (Ta) at which the tan? Of the dynamic viscoelasticity becomes maximum exceeds 0 占 폚 and a polymer (B) at a temperature (Tb) And a mass ratio (A / B): 57/43 to 90/10. The polymer (A) contains 22 mass% to 30 mass% of structural units derived from acrylonitrile or methacrylonitrile. The pressure-sensitive adhesive film for protecting a semiconductor wafer surface has an adhesive force of 1.0 N / 25 mm or more at a peeling speed of 10 mm / min.

Description

TECHNICAL FIELD [0001] The present invention relates to an adhesive film for protecting a semiconductor wafer surface, a method for protecting a semiconductor wafer using the adhesive film, and a manufacturing method of a semiconductor device. [0002]

The present invention relates to a pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer, a method of protecting a semiconductor wafer using the pressure-sensitive adhesive film, and a method of manufacturing a semiconductor device. More specifically, in the process of manufacturing a semiconductor integrated circuit, when a circuit non-formation surface (hereinafter, referred to as a wafer back surface) of a semiconductor wafer is ground to thin the semiconductor wafer, breakage or contamination of the semiconductor wafer (To be referred to as a wafer surface hereinafter) with a pressure-sensitive adhesive layer so that the pressure-sensitive adhesive layer is in contact with the circuit-forming surface (hereinafter referred to as a wafer surface) of the semiconductor wafer, and a method of protecting semiconductor wafers using the same, ≪ / RTI >

Generally, a semiconductor device is manufactured by slicing a high-purity silicon single crystal or the like into a wafer, then integrating the integrated circuit by ion implantation, etching, and the like. Further, the back surface of the wafer after incorporating the integrated circuit is ground by means of grinding, And then dicing and chipping the wafer after being subjected to a back grinding process in which the thickness of the wafer is thinned. Conventionally, in these processes, a pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer is used to prevent breakage or contamination of the semiconductor wafer when grinding the back surface of the wafer.

Specifically, the back surface of the wafer is mechanically ground after the surface of the wafer is protected by adhesion with a pressure-sensitive adhesive layer for protecting the surface of the semiconductor wafer interposed therebetween. After the grinding, the chemical liquid treatment on the back side of the wafer may be carried out subsequently, if necessary. After these back side processing steps are completed, the adhesive film is peeled from the wafer surface.

One of the performances required for such a semiconductor wafer surface protective adhesive film is prevention of penetration of cooling water (hereinafter referred to as grinding water) used for grinding the back surface of the wafer. On the surface of the wafer, there is a depression recessed in a groove shape from the outermost peripheral portion of the wafer, such as a coating layer such as polyimide, a vapor deposition film such as a silicon oxide film, a silicon nitride film, a scribe line (dicing street) Normally, the depth of the depression recessed in the shape of a groove is about 2 m to 20 m. In the case of grinding the back surface of the wafer where the concave portion existing on the surface of the wafer reaches the outermost peripheral portion of the wafer, if the adhesion of the pressure sensitive adhesive layer to the recess portion is insufficient, the grinding water may invade through the recess portion. Once the grinding water penetrates between the wafer surface and the adhesive film through the concave portion, the peeling of the pressure-sensitive adhesive layer progresses from the wafer surface due to the infiltrated grinding water, thereby accelerating the penetration of the grinding water into the space between the wafer surface and the pressure- The entire surface tends to be contaminated by grinding chips that have entered with the grinding water. In the worst case, the surface protecting adhesive film is peeled off during the back grinding due to the influence of the infiltrated grinding water, resulting in the breakage of the wafer.

In order to prevent such a problem, measures are taken to increase the thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film to improve the adhesion between the concave portion of the wafer surface and the pressure-sensitive adhesive layer. However, when this means is used, the adhesive force of the adhesive film to the wafer surface becomes greater than the strength of the wafer, and depending on the conditions such as the thickness and the surface shape of the wafer, the adhesive film is peeled from the wafer surface after the back side grinding Peeling trouble may occur in the automatic peeler to deteriorate the workability or sometimes completely break the wafer. In addition, depending on the type of wafer, there are cases where the depth of the recess exceeds 20 m. In order to cope with such a wafer, when the thickness of the pressure-sensitive adhesive layer is further increased, the productivity of the pressure- It is difficult to provide an inexpensive pressure-sensitive adhesive film, so that a practical solution has not been obtained.

As a means for solving such a problem, for example, it is preferable that the minimum value (G'min) of the storage modulus (G ') of the pressure-sensitive adhesive layer (B) at 50 to 100 캜 is 0.07 to 5 MPa, C) of the intermediate layer (C) having the storage elastic modulus and the thickness (tb, unit: μm) of the pressure-sensitive adhesive layer (B) is not less than 0.001 MPa and less than 0.07 MPa at 50 ° C., , Unit: 占 퐉) satisfies the relationship of the following equation (1): tc? 3tb (see, for example, Japanese Patent Laid-Open Publication No. 2003-173994).

The adhesive film disclosed in Japanese Patent Application Laid-Open No. 2003-173994 is capable of following irregularities such as flip chip mounting bump electrodes having a height of 200 mu m or more, thereby showing excellent adhesion.

The pressure-sensitive adhesive layer preferably has a functional group capable of reacting with the crosslinking agent, 100 parts by weight of a polymer (A) having a temperature at which the dynamic viscoelasticity tan? Reaches a maximum at -50 to 5 占 폚, 10 to 100 parts by weight of the polymer (B) having a temperature at which the tan? Of the dynamic viscoelasticity becomes maximum at 5 占 폚 or higher and 50 占 폚 or lower, and 2 parts per 100 parts by weight of the total amount of the polymers (A) And 0.1 to 10 parts by weight of a cross-linking agent (C) having a crosslinking reactive functional group, wherein the pressure-sensitive adhesive layer has a thickness of 5 to 50 m (for example, Japanese Patent Application Laid-Open No. 2004-6746 Reference.).

The pressure-sensitive adhesive film disclosed in Japanese Patent Application Laid-Open No. 2004-6746 has excellent adhesion, breakage prevention property, and non-staining property.

2. Description of the Related Art In recent years, demands for thinning of semiconductor integrated circuit chips such as the use of portable information terminals and the use of IC cards have been further increased. Semiconductor wafers used for such applications are generally thinned to a thickness of 200 mu m or less by back grinding, and in some cases, they may be ground to a thickness of about 50 mu m. Therefore, it can be said that the risk of contamination or breakage of the wafer is further increased under the grinding condition of thinning the wafer until it becomes 200 μm or less.

In addition, with the high performance of the chip and the technological innovation of the semiconductor manufacturing process, the shape of the surface of the integrated circuit tends to be complicated, and the recesses existing on the surface of the wafer also have a depth exceeding 20 탆. Some of them reach up to 50μm. Therefore, the pressure-sensitive adhesive film for protecting the semiconductor wafer surface is required to have excellent adhesion to the surface of the wafer having the unevenness.

On the other hand, the process conditions for peeling the pressure-sensitive adhesive film from the wafer are various, and it is also required to exhibit good peelability in a wide peeling speed range.

In order to more effectively inhibit breakage and contamination of a semiconductor wafer under such circumstances, it is an object of the present invention to provide a semiconductor wafer having excellent adhesion even after a lapse of time from the time of sticking to the surface of the wafer while maintaining non- And a method for protecting a semiconductor wafer using the same, and a method for manufacturing a semiconductor device, which are excellent in peeling property when peeled from a semiconductor wafer.

Means for solving the above problems are as follows.

≪ 1 >

A pressure-sensitive adhesive layer on the flat surface of the base film,

Wherein the pressure-sensitive adhesive layer comprises a polymer (A) having a temperature (Ta) at which the tan? Of the dynamic viscoelasticity is maximum exceeding 0 占 폚 and a polymer (B) having a temperature (Tb) at which the tan? , And a mass ratio (A / B): 57/43 to 90/10,

Wherein the polymer (A) contains 22 to 30% by mass of a structural unit derived from acrylonitrile or methacrylonitrile,

And an adhesive force of 1.0 N / 25 mm or more at a peeling speed of 10 mm / min.

<2> The pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer according to <1>, wherein the adhesive force at a peeling speed of 10 mm / min to 1000 mm / min is 4.0 N / 25 mm or less.

<3> The pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer according to <1> or <2>, wherein the substrate film comprises at least one layer selected from an ethylene-vinyl acetate copolymer layer, a polyolefin layer and a polyester layer.

(4) a first polymerization step of supplying a first polymerization material containing raw material monomers for forming one of the polymer (A) and the polymer (B) to a reaction vessel to initiate polymerization;

After the first polymerization step, a second polymerization step in which the second polymerization material containing the raw material monomer for forming the other of the polymer (A) and the polymer (B) is further supplied to the reaction vessel and polymerized 1] to [3], wherein the pressure-sensitive adhesive layer is formed using a liquid containing the polymer (A) and the polymer (B) Adhesive film.

<5> A pressure-sensitive adhesive sheet according to any one of <1> to <3>, wherein the pressure-sensitive adhesive layer is formed by using a mixture of a liquid containing the polymer (A) and a liquid containing the polymer (B) Sensitive adhesive film for protecting a surface of a semiconductor wafer.

<6> A method of manufacturing a semiconductor wafer, comprising the steps of: adhering an adhesive layer of a semiconductor wafer surface protection adhesive film according to any one of <1> to <5>

A grinding step of grinding the circuit non-formation surface of the semiconductor wafer to which the adhesive film for protecting the surface of the semiconductor wafer is adhered;

A peeling step of peeling the semiconductor wafer surface protective adhesive film from the semiconductor wafer

Wherein the semiconductor wafer is protected.

<7> A method for manufacturing a semiconductor wafer, comprising the steps of: adhering an adhesive layer of a semiconductor wafer surface protection adhesive film according to any one of <1> to <5>

A grinding step of grinding the circuit non-formation surface of the semiconductor wafer to which the adhesive film for protecting the surface of the semiconductor wafer is adhered;

A peeling step of peeling the semiconductor wafer surface protective adhesive film from the semiconductor wafer

Wherein the semiconductor device is a semiconductor device.

INDUSTRIAL APPLICABILITY According to the present invention, there can be provided a pressure-sensitive adhesive film for protecting the surface of a semiconductor wafer, which maintains non-staining property on the surface of the semiconductor wafer while exhibiting excellent adhesiveness even after the time of sticking to the surface of the wafer and peeling off from the semiconductor wafer, A method of protecting a semiconductor wafer using the same, and a method of manufacturing a semiconductor device. INDUSTRIAL APPLICABILITY The adhesive film for protecting the surface of a semiconductor wafer of the present invention can be suitably used for a semiconductor wafer having a more complicated surface shape because it has adhesiveness and easy releasability.

Hereinafter, the present invention will be described in detail.

The pressure-sensitive adhesive layer for protecting a surface of a semiconductor wafer (hereinafter sometimes abbreviated as a pressure-sensitive adhesive film) of the present invention comprises a base film and a pressure-sensitive adhesive layer on one side of the base film, (A / B): 57/43 (A / B) wherein the temperature (T / B) at which the temperature To 90/10, and the polymer (A) contains from 22% by mass to 30% by mass of a structural unit derived from acrylonitrile or methacrylonitrile. The pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer of the present invention having such a constitution has an adhesive force of 1.0 N / 25 mm or more at a peeling rate of 10 mm / min.

On the other hand, the pressure-sensitive adhesive layer may be present on at least one side surface of the base film, or may be present on both surfaces.

By adopting such a configuration, it is possible to maintain the non-staining property with respect to the wafer surface while maintaining the non-staining property on the wafer surface, An excellent pressure-sensitive adhesive film can be obtained. Since the adhesive film of the present invention is adhered sufficiently when adhered to the semiconductor wafer, contamination of the surface of the semiconductor wafer due to infiltration of grinding water, grinding debris, and breakage of the semiconductor wafer can be extremely effectively prevented. Further, when the adhesive film of the present invention is peeled off, it can be peeled off with an appropriate adhesive force, and breakage of the semiconductor wafer can be prevented. The relationship between the above-described configuration of the present invention and the effects exerted by employing them is not certain, but is estimated as follows.

Among the at least two polymers contained in the pressure-sensitive adhesive layer, the polymer (B) having a temperature at which the tan 隆 of the dynamic viscoelasticity becomes maximum at 0 캜 or less gives flexibility to the pressure-sensitive adhesive layer, Excellent adhesion. Further, when the polymer (A) having a temperature at which the tan δ of the dynamic viscoelasticity is maximized exceeds 0 ° C is contained at a mass ratio (A / B) of 57/43 to 90/10 with respect to the polymer (B) , The peelability is improved. It is considered that this is because the toughness is improved by containing the polymer (A) within the above range.

The temperatures (Ta) and (Tb) at which the tan δ of the dynamic viscoelasticity of the polymers (A) and (B) in the present invention are maximized are values measured according to the methods described in the following examples .

Further, the polymer (A) contains 22 mass% or more of a structural unit derived from acrylonitrile or methacrylonitrile, and thus has excellent releasability. When the content is 30 mass% or less, the toughness is appropriately suppressed, great.

The pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer of the present invention is produced by forming a pressure-sensitive adhesive layer on at least one side surface of a base film. Normally, on the surface of the pressure-sensitive adhesive layer, a release film called a separator is adhered from immediately after the production to the use of the pressure-sensitive adhesive layer from the viewpoint of prevention of contamination. From the viewpoint of preventing the surface of the wafer from being contaminated by the pressure-sensitive adhesive layer, there is a method in which a pressure-sensitive adhesive layer is formed on one side of the release film by applying and drying the pressure-sensitive adhesive layer coating liquid and then transferred onto at least one surface of the base film desirable.

As the base film of the pressure-sensitive adhesive film for protecting a semiconductor wafer surface of the present invention, it is preferable to use a film obtained by molding a synthetic resin into a film.

Examples of the raw material resin used for the base film include polyolefins such as polyethylene, polypropylene, polybutene, and ethylene-? -Olefin copolymer, polymethylpentene, ethylene-acetic acid vinyl copolymer (EVA) Acrylate copolymer, an ethylene-acrylic acid ester-maleic anhydride copolymer, an ethylene-methacrylic acid glycidyl copolymer, an ethylene-methacrylic acid copolymer, an ionomer resin, an ethylene-propylene copolymer, a butadiene- (PET), polyethylene naphthalate (PEN), polyolefin resin (PEN), polyvinyl chloride resin, polyvinyl chloride resin, polyvinylidene chloride resin and the like, and thermoplastic elastomers such as styrene-isoprene- Polyesters such as polyethylene terephthalate (PBT), polyimide, polyethersulfone (PES), polyetheretherketone (PEEK), poly There may be mentioned polycarbonate, polyurethane, acrylic resin, fluorine resin, cellulose resin or the like.

Of these raw material resins, ethylene-vinyl acetate copolymer, low-density polyethylene, polypropylene, ethylene-? -Olefin copolymer (? -Olefin having 3 to 8 carbon atoms), polyethylene terephthalate, polyethylene naphthalate and the like are preferable, And a vinyl acetate copolymer is more preferable. More preferably, it is an ethylene-vinyl acetate copolymer having a vinyl acetate unit content of about 5% by mass to 50% by mass.

The base film may be a single layer or a laminate of two or more films. The base film preferably includes at least one layer selected from an ethylene-vinyl acetate copolymer layer, a polyolefin layer and a polyester layer. Examples of the polyolefin layer include polyethylene, polypropylene, and ethylene-? -Olefin copolymers (having 3 to 8 carbon atoms in the? -Olefin). Examples of the polyester layer include polyethylene terephthalate and polyethylene naphthalate. Among these, it is preferable to include at least one kind of layer selected from an ethylene-vinyl acetate copolymer layer, a polypropylene layer, a polyethylene terephthalate layer and a polyethylene naphthalate layer, more preferably an ethylene-acetic acid vinyl copolymer layer Do. The base film may be formed by molding a thermoplastic resin, or may be formed by curing the curable resin after film formation.

As a typical method for laminating a synthetic resin molded into a film in the case where the base film is a laminate of two or more layers of films, there is a method in which a synthetic resin is extruded by a T-die extruder, And a method of laminating them. In order to increase the adhesive strength between the respective layers of these synthetic resin films, it is also possible to apply a bonding treatment such as corona discharge treatment or chemical treatment to the surface of the side where the respective synthetic resin films are laminated, or to provide an adhesive layer between both layers.

Among the methods of forming a synthetic resin into a film in the case where the base film is a single layer, among those produced by known techniques such as a calendering method, a T-die extrusion method, an inflation method, and a casting method, Thickness precision, and the like.

When the base film is thinned, the property of keeping the shape of the adhesive film tends to be poor, and accordingly, the workability in handling the adhesive film may deteriorate. If the thickness is increased, the productivity of the substrate film is affected, leading to an increase in manufacturing cost. From this viewpoint, the total thickness of the base film is preferably from 10 mu m to 300 mu m, more preferably from 50 mu m to 200 mu m.

It is preferable that corona discharge treatment or chemical treatment is performed in advance on the side of the base film on which the pressure sensitive adhesive layer is provided in order to improve the adhesive force between the base film and the pressure sensitive adhesive layer. For the same purpose, a primer layer may be formed between the base film and the pressure-sensitive adhesive layer.

Examples of the release film include a synthetic resin film such as a polyethylene film, a polypropylene film, and a polyethylene terephthalate film (hereinafter referred to as a PET film). It is preferable that the surface thereof is subjected to a release treatment such as a silicone treatment. The thickness of the release film is usually about 10 m to 1000 m.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer of the present invention is characterized in that the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer has, as a basic component thereof, a polymer (A) (B) having a temperature (Tb) of 0 DEG C or lower. The polymer (A) and the polymer (B) each preferably have a functional group capable of reacting with the crosslinking agent. The pressure-sensitive adhesive layer preferably further comprises a cross-linking agent (C) having two or more cross-linking reactive functional groups per molecule for controlling the cohesive force and the adhesive force.

In order to achieve the object of the present invention in which both the adhesion when the wafer is pasted onto the wafer surface and the peelability from the semiconductor wafer are improved while maintaining non-staining on the wafer surface, In the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film for surface protection, the polymer (A) is contained at a mass ratio (A / B) of 57/43 to 90/10 with respect to the polymer (B). The mass ratio (A / B) is more preferably 60/40 to 90/10, still more preferably 65/35 to 85/15, and most preferably 66/34 to 80/20. When the content of the polymer (A) is increased, the adhesion of the pressure-sensitive adhesive layer to the wafer surface is lowered, and the grinding water tends to penetrate into the recessed portion of the wafer surface, resulting in contamination or breakage of the semiconductor wafer. When the content of the polymer (A) is small, the releasability from the semiconductor wafer deteriorates. Further, the toughness of the pressure-sensitive adhesive layer is insufficient, so that the pressure-sensitive adhesive layer can not withstand the load to remove the pressure-sensitive adhesive film from the grinding water on the pressure-sensitive adhesive layer and the pressure- , It may cause breakage.

Examples of the polymer (A) and the polymer (B) include natural rubber, synthetic rubber, silicone polymer and acrylic polymer. Both the polymer (A) and the polymer (B) are preferably acrylic polymers. As the acrylic polymer, a copolymer containing a structural unit derived from an alkyl acrylate ester as a main component is preferable.

The acrylic acid alkyl ester preferably contains an acrylic acid alkyl ester, a methacrylic acid alkyl ester, and a mixture thereof as a main monomer. Examples of the alkyl acrylate and methacrylate alkyl esters include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl, octyl acrylate and the like. These may be used singly or in combination of two or more kinds.

On the other hand, it is preferable that the polymer (A) contains 22 mass% to 30 mass% and 24 mass% to 30 mass% of structural units derived from acrylonitrile or methacrylonitrile. When the content of the structural unit derived from acrylonitrile or methacrylonitrile is 22% by mass or more, the releasability is excellent. When the content is 30% by mass or less, the toughness is appropriately suppressed and the adhesion is excellent. Among them, it is more preferable to use acrylonitrile in the above range because the stainability tends to be good.

The polymer (A) and the polymer (B) preferably have a functional group capable of reacting with the crosslinking agent. Examples of the functional group capable of reacting with the crosslinking agent include a hydroxyl group, a carboxyl group, an epoxy group and an amino group. As a method of introducing a functional group capable of reacting with the crosslinking agent in the polymer (A) or the polymer (B), a method of copolymerizing a comonomer having these functional groups when polymer (A) or (B) .

Examples of the comonomer having a functional group include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl ester, mesaconic acid monoalkyl ester, citraconic acid monoalkyl ester , Fumaric acid monoalkyl ester, maleic acid monoalkyl ester, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, acryl N-butylaminoethyl acrylate, n-butylaminoethyl methacrylate, and the like.

One of these comonomers may be copolymerized with an alkyl acrylate ester, or two or more of them may be copolymerized. The amount (copolymerization amount) of the comonomer having a functional group capable of reacting with the crosslinking agent is preferably 1% by mass to 40% by mass, based on the total amount of all the monomers as raw materials of the polymer (A) or the polymer Do.

In the present invention, in addition to a comonomer having a functional group capable of reacting with an alkyl acrylate and a crosslinking agent constituting the polymer (A) and the polymer (B), a specific comonomer having properties as a surfactant Quot; active agent &quot;). The polymerizable surfactant has a property of copolymerizing with an alkyl acrylate ester and a comonomer having a functional group and also has an action as an emulsifier when emulsion polymerization is carried out. In the case of using the pressure-sensitive adhesive polymer obtained by emulsion polymerization using a polymerizable surfactant, contamination of the surface of the wafer with a surfactant does not usually occur. In addition, even when a slight contamination due to the pressure-sensitive adhesive layer occurs, it is possible to easily remove the surface of the wafer by washing with water.

Examples of such a polymerizable surfactant include, for example, a polymer obtained by introducing a polymerizable 1-propenyl group into a benzene ring of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; (Trade name: Aquaron RN-10, copper (R) -20, copper RN-30, copper RN-50 and the like), a polymeric 1-propenyl group (Manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.); (Trade name: Aquaron HS-10, copper HS-20, etc.), and sulfosuccinic acid diesters having a polymerizable double bond in the molecule (manufactured by Kao Corporation; Trade name: Latte water S-120A, S-180A, etc.).

(1-aziridinyl) ethyl acrylate, 2- (1-aziridinyl) ethyl methacrylate, N- (1-aziridinyl) ethyl methacrylate, isocyanatoethyl acrylate, isocyanatoethyl methacrylate, Monomers having a self-crosslinking functional group such as methylol acrylamide and N-methylol methacrylamide, monomers having polymerizable double bonds such as vinyl acetate and styrene, divinylbenzene, vinyl acrylate, vinyl methacrylate, acrylic acid Allyl methacrylate, allyl methacrylate, and other typical commercially available products include, for example, diacrylate or dimethacrylate at both terminals and a structure of the main chain of propylene glycol type (manufactured by Nichiyu Corporation, trade name; PDP-200, PDP-400, ADP-200 and ADP-400), tetramethylene glycol type (trade name; Polyfunctional monomers such as ADT-250 and ADT-850, and a mixture thereof (trade name: ADET-1800, ADPT-4000 manufactured by Nichiyu Corporation) may be copolymerized.

When such a monomer having a self-crosslinking property, a monomer having a polymerizable double bond or a multifunctional monomer is copolymerized, the amount of the monomer to be used is preferably 0.1% by mass to 30% by mass in the total monomer. And more preferably 0.1% by mass to 5% by mass.

Examples of the polymerization reaction mechanism for polymerizing the polymer (A) and the polymer (B) include radical polymerization, anion polymerization, cation polymerization and the like. Considering the production cost of the pressure-sensitive adhesive, the influence of the functional groups of the monomers, and the influence of ions on the surface of the semiconductor wafer, it is preferable to carry out polymerization by radical polymerization. When polymerization is carried out by radical polymerization, radical polymerization initiators such as benzoyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, di-tert-butyl peroxide and di- Inorganic peroxides such as peroxides, ammonium persulfate, potassium persulfate and sodium persulfate, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 4,4 ' And azo compounds such as azobis-4-cyanovaleric acid.

In the case of polymerizing the polymer (A) and the polymer (B) by a radical polymerization reaction, a chain transfer agent may be added as needed for the purpose of adjusting the molecular weight of the pressure-sensitive adhesive polymer. Examples of the chain transfer agent include generic chain transfer agents, for example, mercaptans such as t-dodecylmercaptan and n-dodecylmercaptan. The amount of the chain transfer agent used is about 0.01 part by mass to 1.0 part by mass, more preferably 0.05 part by mass to 0.8 part by mass, relative to 100 parts by mass of the total amount of the monomers.

The polymerization of the polymer (A) and the polymer (B) can be suitably selected from known polymerization methods such as emulsion polymerization, suspension polymerization and solution polymerization. Particularly, in consideration of prevention of contamination of the surface of the wafer with the pressure-sensitive adhesive layer, it is preferable to employ an emulsion polymerization method in which a copolymer having a high molecular weight can be obtained.

When the polymer (A) and the polymer (B) are polymerized by the emulsion polymerization method, among the above-mentioned radical polymerization initiators, inorganic peroxides such as water-soluble ammonium persulfate, potassium persulfate and sodium persulfate, Azo compounds having a carboxyl group in the molecule such as 4'-azobis-4-cyanovaleric acid are preferable. Considering the influence of ions on the wafer surface, azo compounds having a carboxyl group in the molecule such as ammonium persulfate and 4,4'-azobis-4-cyanovaleric acid are more preferable. Azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are particularly preferable.

On the other hand, the polymer (A) and the polymer (B) can be obtained by (1) polymerizing separately and thereafter mixing them, and (2) The polymer (B) may be obtained collectively.

(1), for example, a polymer (A) is polymerized to prepare a solution containing the polymer (A), and the polymer (B) is separately polymerized to prepare a solution containing the polymer And a method of preparing a mixed solution prepared by mixing these components.

In the case of the method (2), the polymer (A) and the polymer (B) may be present separately in the liquid, or may be entangled (or attached) to each other. (2), specifically, a first polymerization step of feeding a first polymerization material containing raw material monomers for forming one of the polymer (A) and the polymer (B) into a reaction vessel to initiate polymerization And a second polymerization step in which, after the first polymerization step, a second polymerization material containing a raw material monomer for forming the other of the polymer (A) and the polymer (B) is further supplied to the reaction vessel and polymerized .

In the method (2), except that a series of polymerization steps are carried out in one reaction vessel, by the same method as that of conventionally known general emulsion polymerization, for example, a known raw material monomer feeding method, polymerization conditions Temperature, polymerization time, polymerization pressure, etc.) and materials to be used (polymerization initiator, surfactant, etc.). For example, as the raw material monomer supplying method, any one of a batch injecting method, a continuous feeding (dropping) method, and a split feed (dropping) method in which the entire monomer raw material is supplied to the polymerization vessel at once can be employed. A part or all of the monomer raw material may be previously mixed with water and emulsified, and the emulsion may be fed into the reaction vessel.

As the method of supplying the polymerization initiator, any of a batch injection system, a continuous supply system, and a split supply system in which substantially all of the polymerization initiator to be used is put into a reaction vessel before the start of the supply of the monomer raw material can be employed.

The feeding method of the first polymerization material and the feeding method of the second polymerization material may be the same or different. The monomer raw materials in the first polymerization material and the second polymerization material are supplied to the reaction vessel so that the mass ratio of the polymer (A) / polymer (B) is 57/43 to 90/10.

In the first polymerization step and the second polymerization step, various conventionally known chain transfer agents may be used, if necessary. The chain transfer agent may be added in both steps of the first polymerization step and the second polymerization step, or may be added only to one polymerization step. In the present invention, it is preferable to add a chain transfer agent in the first polymerization step. In general, when the amount of the chain transfer agent is increased by using the same other conditions, the molecular weight of the obtained polymer is reduced, and the adhesion is increased, but the staining property tends to deteriorate.

Hereinafter, preferred embodiments of the first polymerization step and the second polymerization step will be described.

A monomer raw material for forming the polymer (A) is supplied into the reaction vessel and polymerized, and then a monomer raw material for forming the polymer (B) as the second polymerization raw material is fed into the reaction vessel Polymerization is preferable.

The polymer (A) and the polymer (B) are both preferably acrylic polymers. As the polymer (A), it is preferable to use an acrylic acid alkyl ester as a main monomer and acrylonitrile or methacrylonitrile as a comonomer.

The polymer (A) preferably contains 22 mass% to 30 mass% of structural units derived from acrylonitrile or methacrylonitrile as a comonomer, using acrylic acid alkyl ester as a main monomer, and more preferably , An acrylic acid alkyl ester is used as a main monomer and 24 to 30 mass% of a structural unit derived from acrylonitrile or methacrylonitrile as a comonomer is contained.

The polymer (B) is not particularly limited as long as the temperature (Tb) at which the tan 隆 of the dynamic viscoelasticity becomes maximum is 0 캜 or less, but an acrylic acid alkyl ester can be used as the main monomer. Further, acrylonitrile or methacrylonitrile may be used as the comonomer constituting the polymer (B). Among them, acrylonitrile is more preferable because it tends to have better staining property.

When acrylonitrile or methacrylonitrile is used as the comonomer constituting the polymer (B), the amount of the structural unit derived from acrylonitrile or methacrylonitrile in 100 parts by mass of the polymer (B) Is preferably 1 part by mass to 20 parts by mass, more preferably 5 parts by mass to 20 parts by mass, still more preferably 5 parts by mass to 15 parts by mass.

The amount of the chain transfer agent used in the first polymerization step is preferably 90 mass% or more, more preferably 95 mass% or more, and further preferably 99 mass% or more of the total amount of the chain transfer agent.

Next, a control method of the temperatures (Ta) and (Tb) at which the tan δ of the dynamic viscoelasticity (hereinafter, simply referred to as tan δ) becomes the highest in the polymer (A) and the polymer (B) will be described.

(Ta) and (Tb) at which tan delta is the highest are determined by considering the kind and amount of the main monomer constituting the polymer (A) and the polymer (B), the amount of the comonomer And the like.

As to the type and amount of the main monomer constituting (A) the polymer (A) and the polymer (B), when an alkyl acrylate ester is used as the main monomer, if the number of carbon atoms in the alkyl group as the main monomer is 3 to 8, The higher the number of carbon atoms in the alkyl group, the higher the temperature at which the tan 隆 becomes the highest. In addition, when methacrylic acid esters are used as the main monomer, the temperature at which the tan 隆 becomes the highest tends to increase. In any case, the greater the amount of these main monomers used, the greater the influence on the temperature at which tan? Is highest.

Therefore, in order to obtain the polymer (B), in which the temperature (Ta) at which the tan δ becomes the highest is in the relatively low temperature range of 0 ° C or lower, it is preferable to use an alkyl group such as n-butyl acrylate, 2-ethylhexyl acrylate, It is preferable to use a large amount of acrylic acid alkyl ester having 4 to 8 carbon atoms. In order to obtain the polymer (A) having a relatively high temperature range in which the temperature (Tb) at which the tan δ becomes maximum exceeds 0 ° C, the number of carbon atoms of the alkyl group is preferably from 2 to 20, such as methyl acrylate, ethyl acrylate, 4-alkyl acrylate, and methacrylic acid alkyl ester.

(B) The kind and amount of use (copolymerization amount) of the comonomer having a functional group capable of reacting with the crosslinking agent are usually, for example, those used as comonomers, such as acrylic acid, methacrylic acid, itaconic acid Those having an amide group such as acrylamide, methacrylamide, N-methylol acrylamide, and methacrylic acid esters such as glycidyl methacrylate, 2-hydroxyethyl methacrylate, In general, the temperature at which the tan δ becomes maximum tends to shift toward the high temperature side, and the tendency becomes larger as the amount of use (copolymerization amount) is larger.

Therefore, in order to obtain the polymer (B), in which the temperature (Ta) at which the tan? Is the maximum is in the relatively low temperature range of 0 占 폚 or less, the addition amount of the comonomer, which tends to shift the temperature at which tan? It is preferable to make relatively small amounts within the range. Further, in order to obtain a polymer (A) having a relatively high temperature range in which the temperature (Tb) at which tan? Is the highest exceeds 0 占 폚, it is preferable that the amount of the comonomer added is relatively large within the above range.

Examples of the crosslinking agent (C) having two or more crosslinking reactive functional groups in a molecule used in the present invention include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether Epoxy-based crosslinking agents such as diallyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether and resorcin diglycidyl ether, trimethylol propane-tri-? -Aziridinyl propionate, tetramethyl N'-diphenylmethane-4,4'-bis (1-aziridine carboxamide), N, N'-hexamethylene-1,6 (1-aziridine carboxamide), N, N'-toluene-2,4-bis (1-aziridine carboxamide), trimethylolpropane- An aziridine cross-linking agent such as phonate, a tetramethylene diisocyanate Agent, and the like can be mentioned hexamethylene diisocyanate between Ah between carbonate, tri-O between trimethylolpropane toluene diisocyanate adduct of 3, isopropyl, such as polyisocyanate-based crosslinking agent carbonate. These crosslinking agents may be used alone or in combination of two or more.

When the pressure-sensitive adhesive is a water-based pressure-sensitive adhesive such as an aqueous solution or an emulsion using water as a medium, the isocyanate-based crosslinking agent has a rapid deactivation speed due to side reaction with water, and therefore the crosslinking reaction with the pressure- . Therefore, in this case, it is preferable to use an aziridine-based or epoxy-based crosslinking agent among the above-mentioned crosslinking agents.

The content of the crosslinking agent (C) having two or more crosslinking reactive functional groups in one molecule in the present invention is preferably 0.1 part by mass to 10 parts by mass with respect to 100 parts by mass of the total amount of the polymer (A) and the polymer (B) Do. When the content of the cross-linking agent is less than 0.1 part by mass, the cohesive force of the pressure-sensitive adhesive layer becomes insufficient, and the surface of the wafer may be contaminated. If the content of the cross-linking agent exceeds 10 parts by mass, the adhesion of the pressure-sensitive adhesive layer to the concave portion of the wafer surface is lowered, so that water or grinding debris enters the backside of the wafer, There is a risk of contamination.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer in the present invention may contain a polymer (A) and a polymer (B), a crosslinking agent (C) having two or more crosslinking reactive functional groups in one molecule, A tackifier such as a terpene resin, various surfactants, and the like. When the polymer (A) and the polymer (B) are prepared as emulsion liquids, a film forming auxiliary such as diethylene glycol monobutyl ether or the like may be appropriately contained so as not to affect the object of the present invention.

The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film for protecting the surface of the semiconductor wafer sometimes affects the adhesion to the concave portion of the wafer surface, the adhesive strength, and the like. If the thickness of the pressure-sensitive adhesive layer is reduced, the adhesion to the concave portion of the wafer surface is insufficient, and the grinding water may invade through the concave portion to contaminate the wafer surface. When the thickness is increased, the adhesion to the concave portion of the wafer surface is improved, but the adhesive strength is increased, thereby deteriorating the workability at the time of peeling. From this viewpoint, the thickness of the pressure-sensitive adhesive layer is preferably 5 m to 200 m. More preferably 10 m to 100 m.

In the present invention, when the pressure-sensitive adhesive layer is formed on the flat surface of the base film, the pressure-sensitive adhesive is used as a solution or an emulsion liquid (hereinafter collectively referred to as pressure-sensitive adhesive application liquid), and a roll coater, a comma coater, A roll coater, a gravure coater, or the like, followed by drying to form a pressure-sensitive adhesive layer. At this time, in order to protect the applied pressure-sensitive adhesive layer from contamination caused by the environment, it is preferable to attach a release film to the surface of the applied pressure-sensitive adhesive layer. Alternatively, a pressure-sensitive adhesive coating liquid is applied and dried on the single-sided surface of the release film according to the above-described known method to form a pressure-sensitive adhesive layer, and then the pressure-sensitive adhesive layer is transferred onto the base film using a conventional method such as dry lamination Method (hereinafter referred to as "transfer method").

The drying conditions for drying the pressure-sensitive adhesive coating liquid are not particularly limited, but it is generally preferable to dry the pressure-sensitive adhesive liquid in a temperature range of 80 to 300 캜 for 10 seconds to 10 minutes. More preferably, it is dried in a temperature range of 80 ° C to 200 ° C for 15 seconds to 10 minutes. In the present invention, in order to sufficiently accelerate the crosslinking reaction between the crosslinking agent and the alkyl acrylate copolymer, after the drying of the pressure-sensitive adhesive coating liquid is completed, the pressure-sensitive adhesive film for protecting the surface of the semiconductor wafer is heated at 40 ° C to 80 ° C for 5 hours to 300 It may be heated for about an hour.

The adhesive strength at a peeling speed of 10 mm / min to 1000 mm / min is preferably 4.0 N / 25 mm or less, more preferably 3.0 N / 25 mm or less, and further preferably 2.5 N / 25 mm or less. When the adhesive force is in the above range, peeling workability in peeling from the semiconductor wafer is excellent. If the adhesive force is too high, the peeling workability is lowered, and the semiconductor wafer may be broken at the time of peeling.

Next, a method of protecting the semiconductor wafer according to the present invention will be described. A method for protecting a semiconductor wafer according to the present invention is a method for protecting a semiconductor wafer from an adhesion process in which a pressure sensitive adhesive layer in a pressure sensitive adhesive film for protecting a surface of a semiconductor wafer of the present invention is bonded to a circuit formation surface of a semiconductor wafer, A grinding step of grinding the non-circuit forming surface of the bonded semiconductor wafer; and a peeling step of peeling the semiconductor wafer surface protecting adhesive film from the semiconductor wafer.

In detail, first, the release film is peeled from the pressure-sensitive adhesive layer of a semiconductor wafer surface protecting adhesive film (hereinafter referred to as an adhesive film) to expose the surface of the pressure-sensitive adhesive layer, Good. Then, the semiconductor wafer is fixed with a base film layer of an adhesive film interposed therebetween on a chuck table of a grinding machine, and the back surface of the wafer is ground. After the grinding is completed, the adhesive film is peeled off. After the grinding of the back surface of the wafer is completed, the back surface of the wafer may be subjected to processing with a chemical liquid such as chemical etching or polishing before peeling off the adhesive film. If necessary, after the adhesive film is peeled off, the surface of the wafer is subjected to cleaning treatment such as washing with water, plasma cleaning, and the like.

The thickness of the semiconductor wafer before grinding the back surface is usually 500 m to 1000 m in the operations such as grinding the back surface of the wafer and the chemical liquid treatment in such a series of steps, but it is usually 200 m to 600 m To a thickness of about 20 탆, sometimes to a thickness of about 20 탆. In the case where the thickness of the semiconductor wafer is reduced until the thickness of the semiconductor wafer is reduced to 200 占 퐉 or less, in order to improve the strength of the semiconductor wafer by removing the fractured layer formed on the back surface of the wafer by mechanical grinding, . The thickness of the semiconductor wafer before grinding is appropriately determined according to the diameter and type of the semiconductor wafer, and the thickness after grinding is appropriately determined according to the size of the obtained chip, the type of circuit, and the like.

The operation of attaching the adhesive film to a semiconductor wafer may be performed by a human hand, but is generally performed by using an apparatus called an automatic adhesive machine provided with an adhesive film wound in a roll form. Examples of such automatic binders include those manufactured by Takara Shuzo Co., Ltd., type: ATM-1000B, ATM-1100, manufactured by Daikoku Seiki Co., Ltd., type: STL series, manufactured by Nitto Seiki Co., Type: DR-8500II.

Normally, the temperature at which the adhesive film is adhered to the surface of the semiconductor wafer is carried out at a room temperature of about 25 占 폚. However, in the case of attaching an adhesive film to the surface of a wafer using an automatic attaching machine equipped with a function of raising the temperature of the semiconductor wafer, the semiconductor wafer is heated at a predetermined temperature (usually 40 to 90 DEG C By weight) is used.

There is no particular limitation on the method of grinding the back surface of the wafer, and a known grinding method such as a through-feed method or an in-feed method is employed. At the time of grinding, it is preferable that water is poured into the semiconductor wafer and the grindstone while cooling them. As a grinding machine for grinding the back side of the wafer, there are a grinder for grinding a wafer, for example, a disk grinder manufactured by DISCO Corporation, type: DFG-860, manufactured by Okamoto Machine Tool Co., Ltd., type: SVG-502MKII8, PG200, and the like.

After the grinding of the back surface of the wafer, the chemical liquid treatment, and the like are completed, the adhesive film is peeled from the wafer surface. The peeling of the adhesive film from the surface of the wafer may be carried out by human hands, but is generally performed by using an apparatus called an automatic peeler. Examples of such an automatic peeling machine include a type: ATRM-2000B, ATRM-2100, manufactured by Daikoku Seiki Co., Ltd., type: STP series, manufactured by Nitto Seiki Co., -8500II. As an adhesive tape called a release tape used when the adhesive tape for protecting the surface of a semiconductor wafer is peeled off from the wafer surface by the automatic peeler described above, there can be mentioned, for example, Sumitomo 3M Co., 897 can be used.

The temperature at which the adhesive film for protecting the semiconductor wafer surface is peeled from the wafer surface is usually at room temperature of about 25 캜. When the automatic peeler has a function of raising the temperature of the wafer, The adhesive film may be peeled off while the temperature is raised to the temperature (usually about 40 to 90 占 폚).

The surface of the wafer after peeling off the adhesive film is cleaned if necessary. Examples of the cleaning method include wet cleaning such as water cleaning and solvent cleaning, and dry cleaning such as plasma cleaning. In the case of wet cleaning, ultrasonic cleaning may be used in combination. These cleaning methods are appropriately selected depending on the contamination state of the wafer surface.

The semiconductor wafer to which the method for protecting a semiconductor wafer of the present invention can be applied is not limited to a silicon wafer but may include semiconductor wafers such as germanium, gallium-arsenic, gallium-phosphorus and gallium-arsenic-aluminum.

The method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device comprising an adhesion step in which a pressure sensitive adhesive layer in a pressure sensitive adhesive film for protecting a surface of a semiconductor wafer of the present invention is bonded to a circuit formation surface of a semiconductor wafer, A grinding step of grinding a circuit non-formation surface of the semiconductor wafer to which the film is adhered; and a peeling step of peeling off the semiconductor wafer surface protective adhesive film from the semiconductor wafer. The bonding process, the grinding process, and the peeling process in the semiconductor device manufacturing method are the same as the above-described semiconductor wafer protecting method. Any other chemical liquid processing, cleaning, and the like are the same as the above-described method of protecting a semiconductor wafer.

Example

Hereinafter, the present invention will be described in further detail with reference to examples. In all of the following examples and comparative examples, preparation, coating and drying, and X-ray photoelectron spectroscopy (hereinafter referred to as ESCA) of a pressure-sensitive adhesive coating liquid were conducted under a clean- ). The present invention is not limited to these examples. Measurement and evaluation of the various characteristic values shown in the examples and comparative examples were carried out by the following methods.

1. Temperature [Tmax] (占 폚) at which the tan? Of the dynamic viscoelasticity of the polymer becomes maximum

Under the same conditions as the coating conditions (drying temperature, drying time, and the like) at the time of preparing each of the pressure-sensitive adhesive layers in Examples and Comparative Examples, a PET film (manufactured by Mitsui Chemicals, Inc.) , Product name: SP-PET], and dried to form a polymer layer having a thickness of 50 to 60 占 퐉 after drying. The obtained polymer layers are sequentially stacked to obtain a film-like sample of a polymer having a thickness of about 1 mm. From the film-like sample, a sample having a width of about 10 mm and a length of about 50 mm is cut out.

The obtained sample is measured for storage elastic modulus at a frequency of 1 Hz in a temperature range of -50 DEG C to 100 DEG C by using a dynamic viscoelasticity measuring apparatus (manufactured by TA Instruments, model: RSA-III). Concretely, the sample is set at 25 ° C in a dynamic viscoelasticity measuring apparatus via an attachment, and the tan δ of the dynamic viscoelasticity is measured while the temperature is raised at a rate of 5 ° C / minute. After the completion of the measurement, the temperature [Tmax] at which tan? Reaches the maximum is read from the obtained tan? -Temperature curve at -50 占 폚 to 100 占 폚.

On the other hand, for the polymers of Examples 1 to 6 and 8 and Comparative Examples 1 to 3, a sample emulsion liquid for measuring tan δ of dynamic viscoelasticity was separately prepared. More specifically, the first step of the aging step was carried out, and the obtained emulsion solution was used as a measurement sample of the first-step polymer. Further, only the second step was performed separately, and the obtained emulsion solution was used as a measurement sample of the second-stage polymer.

In Examples 1 to 6 and 8 and Comparative Examples 1 to 3, the Tmax of all the polymers in the first stage exceeded 0 ° C and the Tmax of all the polymers in the second stage was 0 ° C or less. The acrylic polymer A1 obtained in Example 7 had Tmax of more than 0 占 폚 and Tmax of the acrylic polymer B1 of 0 占 폚 or less. In addition, the acrylic polymer obtained in Comparative Example 4 had a Tmax exceeding 0 占 폚. Further, the acrylic polymer obtained in Comparative Example 5 had a Tmax of 0 占 폚 or less.

2. Adhesion measurement

Except that the conditions specified below were all measured in accordance with the method specified in JIS Z0237-1991. Under the atmosphere of 23 占 폚, the surface protecting adhesive films obtained in Examples and Comparative Examples were stuck to the surface of a 5 cm x 20 cm SUS304-BA plate (according to JIS G4305-1991) with the pressure-sensitive adhesive layer therebetween and left for 1 hour . After standing, one end of the adhesive film was sandwiched, and the stress at the time of peeling from the surface of the SUS304-BA plate at a peeling angle of 180 degrees and a predetermined peeling rate was measured by a tensile tester and converted into N / 25 mm.

3. Adhesion Evaluation

Evaluation was made using the following semiconductor silicon wafer into which the integrated circuit was embedded.

Wafer 1: diameter 100 mm, thickness 725 m, scribe line; Depth 10 μm, width 400 μm

Wafer 2: diameter 100 mm, thickness 725 m, scribe line: depth 5 m, width 400 m

The surface protecting adhesive films obtained in Examples and Comparative Examples were stuck to the surface of the silicon wafer with a pressure sensitive adhesive layer interposed therebetween, and were observed from the substrate side using an optical microscope at a magnification of 5 at 23 ° C ± 2 ° C, After standing for 24 hours in an atmosphere adjusted to 50 ± 5%, a picture was taken. It was evaluated that the adhesiveness was excellent when the ratio of the application area of the adhesive layer to the scribe line with respect to the entire area of the scribe line was an index of adhesion and the adhesive area ratio of the adhesive layer to the scribe line was 80%

4. Stainability evaluation (ESCA measurement)

The stain on the surface of the silicon mirror wafer chip was evaluated by an X-ray photoelectron spectroscopic analyzer (manufactured by Shimadzu Corporation, product name: ESCA-3200). The surface-protecting adhesive films obtained in Examples and Comparative Examples were bonded to the entire surface of a silicon mirror wafer (100 mm in diameter, 600 μm in thickness) having no foreign matter attached thereto via its pressure-sensitive adhesive layer, After leaving for 1 hour in an atmosphere adjusted to a humidity of 50 5%, the surface protecting adhesive film is peeled off from the silicon mirror wafer, and then the silicon mirror wafer is cut into 1 cm square using a diamond glass cutter. Five random pieces were taken from a 1 cm square silicon mirror wafer cut out and subjected to ESCA analysis under the following conditions to determine their C / Si ratios (five average values) The contamination state of the chip surface was measured.

&Lt; ESCA Measurement Condition &gt;

X-ray source; Mg-K? Line (1252.0 eV), X-ray output; 300 W, measured vacuum degree; 2 x 10 &lt; ^-7 &gt; Pa or less, C / Si ratio; (Peak area of carbon) / (peak area of silicon).

<Evaluation method of C / Si ratio>

The C / Si ratio of the surface of the silicon mirror wafer before the surface protective adhesive film is attached is 0.10 (blank value). Therefore, it was evaluated that there was no contamination when the C / Si ratio of the surface of the silicon mirror wafer after the surface protective adhesive film was peeled from 0.10 to 0.50, and that there was contamination when the C / Si ratio was 0.10 to 0.50.

[Example 1]

&Lt; Production of base film &

A film of ethylene-vinyl acetate copolymer resin [manufactured by Mitsui DuPont Polychemicals Co., Ltd., trade name: EVAPLEX V5961, vinyl acetate unit content: 9 mass%] was formed into a thickness of 90 탆 using a T-die extruder, The side to be coated was subjected to corona treatment. The difference in thickness of the obtained film was within ± 1.5%.

&Lt; Production of the adhesive agent subject &

"Parts" and "%" in the following Examples and Comparative Examples represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

500 parts of deionized water was charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas inlet, and the mixture was heated to 70 to 72 캜 by purging with nitrogen gas. Thereafter, ammonium persulfate ), 5 parts of a polyoxyethylene nonylphenyl ether (average value of added moles of ethylene oxide: about 20) as a water-soluble monomer, a compound obtained by adding a polymerizable 1-propenyl group to a benzene ring of a sulfuric acid ester ammonium salt 0.15 part of Aquaron HS-10 (hereinafter abbreviated as "water-soluble monomer (1)", manufactured by Kyoei Kogyo Co., Ltd.)

Next, as a first step, 700 parts of a monomer mixture for forming the polymer (A) shown in Table 1, and 100 parts of a water-soluble monomer (1) were added under stirring with 230 parts of deionized water, 10 parts of the polymerization initiator And 3.2 parts of n-dodecylmercaptan were added to the above polymerization vessel over a period of 5 hours to carry out a reaction. After completion of the addition, an additional 1 hour of aging was carried out.

Next, as a second step, a polymer (B) having 88% of 2-ethylhexyl acrylate, 10% of acrylonitrile and 2% of acrylic acid was formed under stirring with 135 parts of deionized water and 1.5 parts of the water-soluble monomer Was added to the polymerization vessel continuously over a period of 2 hours to carry out a reaction. After completion of the addition, an additional 2 hours of aging was carried out to obtain an acrylic resin emulsion. This solution was neutralized (pH = 7.0) with 10% ammonia water to obtain an acrylic polymer having a solid content of 53.5% (adhesive base).

&Lt; Preparation of pressure-sensitive adhesive coating liquid &

0.5 part of an epoxy crosslinking agent (trade name: Denacol EX-614B, manufactured by Nagase ChemteX Corporation) and 2 parts of diethylene glycol monobutyl ether were added to 100 parts of the resulting pressure-sensitive adhesive, followed by addition of 10% aqueous ammonia to a viscosity of 3000 mPa · s to 5000 mPa · s to obtain a pressure-sensitive adhesive application liquid.

&Lt; Preparation of adhesive film &gt;

Using a lip coater, the pressure-sensitive adhesive coating liquid was applied to a polypropylene film (release film, thickness 50 탆) and dried at 90 캜 for 10 minutes to provide a pressure-sensitive adhesive layer having a thickness of 80 탆. The corona-treated side of the above-mentioned ethylene-vinyl acetate copolymer film (substrate film) was adhered to this and pressed, and the pressure-sensitive adhesive was laminated on the base film. After lamination, the laminate was heated at 40 占 폚 for 120 hours and then cooled to room temperature to produce a pressure-sensitive adhesive film for surface protection. Table 2 shows the results of measurement and evaluation of various characteristic values.

[Examples 2, 3, 5, 6, 8]

A pressure-sensitive adhesive film for surface protection was produced in the same manner as in Example 1, except that the monomer mixture for producing the emulsion of the first stage in the production of the pressure-sensitive adhesive was changed as described in the column of each example in Table 1. [ Table 2 shows the results of measurement and evaluation of various characteristic values.

[Example 4]

A pressure-sensitive adhesive layer was coated on the base film at a thickness of 45 μm (drying time 5 (thickness)) using an ethylene-vinyl acetate copolymer resin film (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: Evaplex V5961, vinyl acetate unit content: 9% Minute), a pressure-sensitive adhesive film for surface protection was produced in the same manner as in Example 3. Table 2 shows the results of measurement and evaluation of various characteristic values.

[Example 7]

500 parts of deionized water was charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas inlet, and the mixture was heated to 70 to 72 캜 by purging with nitrogen gas. Thereafter, ammonium persulfate ), 5 parts of a polyoxyethylene nonylphenyl ether (average value of added moles of ethylene oxide: about 20) as a water-soluble monomer, a compound obtained by adding a polymerizable 1-propenyl group to a benzene ring of a sulfuric acid ester ammonium salt 0.15 part of Aquaron HS-10 (hereinafter abbreviated as "water-soluble monomer (1)", manufactured by Kyoei Kogyo Co., Ltd.)

Subsequently, 1000 parts of a monomer mixture for forming the polymer (A) described in Example 3 of Table 1 under stirring with 365 parts of deionized water, 10 parts of the polymerization initiator (1) and 4.85 parts of the water-soluble monomer (1) -Dodecylmercaptan in an amount of 4.5 parts was continuously added to the above polymerization vessel over a period of 7 hours to carry out a reaction. After completion of the addition, an additional 3 hours of aging was carried out to obtain an acrylic resin emulsion. This solution was neutralized (pH = 7.0) with 10% aqueous ammonia to obtain an acrylic polymer A1 having a solid content of 53.5% (subject of pressure-sensitive adhesive).

Next, 500 parts of deionized water was added to a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas inlet, and the mixture was heated to 70 deg. C to 72 deg. C after replacing nitrogen gas. Then, ammonium persulfate (Abbreviated as compound (1)), 5 parts of polyoxyethylene nonylphenyl ether (average value of added moles of ethylene oxide: about 20) as a water-soluble monomer, a compound in which a polymerizable 1-propenyl group is added to a benzene ring of a sulfuric acid ester ammonium salt [ (Trade name: Aquaron HS-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (hereinafter, abbreviated as water-soluble monomer (1)).

Next, a polymer (B (1)) of 88% of 2-ethylhexyl acrylate, 10% of acrylonitrile and 2% of acrylic acid was added with stirring to 365 parts of deionized water, 10 parts of polymerization initiator ) Was added to the above-mentioned polymerization vessel continuously over a period of 7 hours to carry out a reaction. After completion of the addition, the emulsion was further aged for 3 hours to obtain an acrylic resin emulsion. This was neutralized (pH = 7.0) with 10% ammonia water to obtain an acrylic polymer B1 (adhesive base) having a solid content of 53.5%.

A pressure-sensitive adhesive film for surface protection was produced in the same manner as in Example 1, except that the acrylic polymer A1 and the acrylic polymer B1 were mixed at the same ratio as in Example 3 at a ratio of 70/30. Table 2 shows the results of measurement and evaluation of various characteristic values.

[Comparative Examples 1 to 3]

In the same manner as in Example 1 except that the monomer mixture for producing the emulsion of the polymer (A) in the first stage was changed as described in each Comparative Example of Table 1, A film was produced. Table 3 shows the results of measurement and evaluation of various characteristic values.

[Comparative Example 4]

500 parts of deionized water was charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas inlet, and the mixture was heated to 70 to 72 캜 by purging with nitrogen gas. Thereafter, ammonium persulfate ), 5 parts of a polyoxyethylene nonylphenyl ether (average value of added moles of ethylene oxide: about 20) as a water-soluble monomer, a compound obtained by adding a polymerizable 1-propenyl group to a benzene ring of a sulfuric acid ester ammonium salt 0.15 part of Aquaron HS-10 (hereinafter abbreviated as "water-soluble monomer (1)", manufactured by Kyoei Kogyo Co., Ltd.)

Subsequently, 1000 parts of all the constituent monomer mixture of the first stage and the second stage used in Example 3 and 1000 parts of n (n-propylthiophenol) as an additive were added under stirring with 365 parts of deionized water, 10 parts of polymerization initiator (1) and 4.85 parts of water- -Dodecylmercaptan in an amount of 3.2 parts was added to the polymerization vessel continuously over a period of 7 hours to carry out a reaction. After completion of the addition, the emulsion was further aged for 3 hours to obtain an acrylic resin emulsion. This solution was neutralized (pH = 7.0) with 10% ammonia water to obtain an acrylic polymer having a solid content of 53.5% (adhesive base). A pressure-sensitive adhesive film for surface protection was produced in the same manner as in Example 1, except that the acrylic polymer was used as the pressure-sensitive adhesive subject. Table 3 shows the results of measurement and evaluation of various characteristic values.

[Comparative Example 5]

135 parts of deionized water was added to a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas inlet, and after nitrogen gas substitution was performed, the temperature was raised to 70 캜 to 72 캜. 4,4'-Azobis- 0.5 part of Cyanovaleric Acid (trade name: ACVA, manufactured by Otsuka Chemical Co., Ltd.), 94 parts of 2-ethylhexyl acrylate, 2 parts of methacrylic acid, 1 part of acrylamide, 0.1 part of n-dodecylmercaptan, (Average value of added moles of ethylene oxide: about 20) polyoxyethylene nonylphenyl ether (average value of added moles of ethylene oxide: about 20) A compound obtained by adding a polymerizable 1-propenyl group to a benzene ring of a sulfuric acid ester ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Rhone HS-10]. And reacted for 9 hours to obtain an acrylic resin emulsion. This was neutralized (pH = 7.0) with 14% ammonia water to obtain an acrylic polymer having a solid content of 40.0%.

10 parts of ammonia water was added to 100 parts of the acrylic polymer to adjust the pH to 9.3 and 0.5 part of an epoxy crosslinking agent (trade name: Denacol EX-614, manufactured by Nagase ChemteX Corporation) and 5 parts of ethylene glycol monobutyl ether were added, A was obtained.

Further, 135 parts of deionized water was added to a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas inlet, and after the temperature was raised to 70 ° C to 72 ° C by replacing nitrogen gas, 4,4'-azobis -4-cyanovaleric acid (trade name: ACVA, manufactured by Otsuka Chemical Co., Ltd.), 74.25 parts of butyl acrylate, 13 parts of methyl methacrylate, 9 parts of 2-hydroxyethyl methacrylate, 2 parts of acrylamide, 1 part of n-dodecylmercaptan, 0.1 part of polyoxyethylene nonylphenyl ether (average value of added moles of ethylene oxide: about 20) as a water-soluble monomer was added to a benzene ring of a sulfuric acid ester ammonium salt, 0.75 part of a compound having a dianion added thereto (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aquaron HS-10). This was reacted at 70 ° C for 9 hours with stirring to obtain an acrylic resin emulsion. This was neutralized (pH = 7.0) with 14% ammonia water to obtain an acrylic polymer having a solid content of 40.0%.

10 parts of ammonia water was added to 100 parts of the acrylic polymer to adjust the pH to 9.3, 4.0 parts of an aziridine crosslinking agent (trade name: Chemitite PZ-33, manufactured by Nippon Shokubai Co., Ltd.) and 5 parts of ethylene glycol monobutyl ether were added, .

Using a lip coater, the coating liquid A was applied to a polypropylene film (release film, thickness 50 탆) and dried at 90 캜 for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 40 탆. The corona-treated side of the above-mentioned ethylene-vinyl acetate copolymer film (base film) was adhered and pressed to obtain an intermediate film.

Next, a coating liquid B was applied to a polypropylene film (release film, thickness 50 탆) using a lip coater and dried at 90 캜 for 2 minutes to form a pressure-sensitive adhesive layer having a thickness of 10 탆. A polypropylene film (release film, thickness: 50 m) was peeled off from the above-mentioned intermediate film, and the pressure-sensitive adhesive was laminated on the base film. After lamination, the laminate was heated at 40 占 폚 for 72 hours and then cooled to room temperature to produce a pressure-sensitive adhesive film for surface protection. Table 3 shows the results of measurement and evaluation of various characteristic values.

(Abbreviation)

n-BA: n-butyl acrylate

AN: acrylonitrile

AA: Acrylic acid

AM: Acrylamide

2EHA: 2-ethylhexyl acrylate

On the other hand, the disclosure of Japanese Patent Application No. 2014-027013 is incorporated herein by reference in its entirety.

All publications, patent applications, and technical specifications described in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, and technical specification were specifically and individually indicated to be incorporated by reference. do.

Claims (7)

A base film,
A pressure-sensitive adhesive layer on the flat surface of the base film,
Wherein the pressure-sensitive adhesive layer comprises a polymer (A) having a temperature (Ta) at which the tan? Of the dynamic viscoelasticity is maximum exceeding 0 占 폚 and a polymer (B) having a temperature (Tb) at which the tan? , And a mass ratio (A / B): 57/43 to 90/10,
Wherein the polymer (A) comprises 22 mass% to 27 mass% of structural units derived from acrylonitrile or methacrylonitrile,
An adhesive force at a peeling speed of 10 mm / min is 1.0 N / 25 mm or more, and an adhesive force at a peeling speed of 10 mm / min to 1000 mm / min is 4.0 N / 25 mm or less. delete The method according to claim 1,
Wherein the base film comprises at least one layer selected from an ethylene-vinyl acetate copolymer layer, a polyolefin layer and a polyester layer. The method according to claim 1,
A first polymerization step of supplying a first polymerization material containing raw material monomers for forming one of the polymer (A) and the polymer (B) to a reaction vessel to initiate polymerization;
After the first polymerization step, a second polymerization step in which the second polymerization material containing the raw material monomer for forming the other of the polymer (A) and the polymer (B) is further supplied to the reaction vessel and polymerized Wherein the pressure-sensitive adhesive layer is formed using a liquid containing the polymer (A) and the polymer (B) obtained by the method comprising the steps of: The method according to claim 1,
Wherein the pressure-sensitive adhesive layer is formed by using a mixture of a liquid containing the polymer (A) and a liquid containing the polymer (B). An adhesion step of adhering (sticking) the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film for surface protection of a semiconductor wafer according to any one of claims 1 to 5 to a circuit formation surface of a semiconductor wafer so that the pressure-
A grinding step of grinding the circuit non-formation surface of the semiconductor wafer to which the adhesive film for protecting the surface of the semiconductor wafer is adhered;
A peeling step of peeling the semiconductor wafer surface protective adhesive film from the semiconductor wafer
Wherein the semiconductor wafer is protected. An adhesion step in which a pressure-sensitive adhesive layer of the pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer according to any one of claims 1 to 5 is adhered to a circuit formation surface of a semiconductor wafer,
A grinding step of grinding the circuit non-formation surface of the semiconductor wafer to which the adhesive film for protecting the surface of the semiconductor wafer is adhered;
A peeling step of peeling the semiconductor wafer surface protective adhesive film from the semiconductor wafer
Wherein the semiconductor device is a semiconductor device.