JPH10189504A - Back side grinding method for semiconductor wafer and pressure-sensitive adhesive film used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage to a semiconductor wafer and prevent generation of microcrack and dimple, by using a pressure-sensitive adhesive film such that the hardness and thickness of a base film, the composition and thickness of a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive force of the pressure-sensitive adhesive film are limited in specified ranges, respectively. SOLUTION: On one surface of a base film which has a protrusion with a height A of 10-100μm and a Shore D hardness of 40 or lower and a thickness B of 150-500μm (where 4A<=B), a pressure-sensitive adhesive layer which contains an alkylacrylate-based pressure-sensitive adhesive polymer at 100 pts.wt., a crosslinking agent at 0.5-15 pts.wt. and an alkylene glycol, polymer, and has a thickness C of 30-100μm (where 0.6A<=C) is formed. The pressure- sensitive adhesive force of this pressure-sensitive adhesive film with respect to a SUS304-BA plate is specified to 80-400 g/mm. By using this pressure- sensitive adhesive film, damage to a wafer due to grinding stress on a back side is prevented, and no damage is generated at a chip level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for grinding a back surface of a semiconductor wafer and an adhesive film for grinding a back surface of a semiconductor wafer used in the method. Specifically, the surface on which the integrated circuit is incorporated (hereinafter, referred to as a wafer surface) is selected from an electrode of a specific height (hereinafter, referred to as a high bump electrode) and a defective circuit identification mark (hereinafter, referred to as an ink dot). The present invention relates to a method of grinding a back surface of a semiconductor wafer having at least one type of protrusion, which is likely to be damaged, contaminated, and the like, and an adhesive film for grinding a back surface of a semiconductor wafer used in the method. More specifically, a method in which an adhesive film is directly adhered to a surface of a semiconductor wafer having the protrusions via an adhesive layer, and another surface of the wafer (hereinafter, referred to as a wafer back surface) is ground. And a pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer used in the method.

[0002]

2. Description of the Related Art Normally, a semiconductor integrated circuit is sliced from a high-purity silicon single crystal or the like to form a wafer, and then ion-implanted.
The integrated circuit is incorporated by etching, etc., and the back surface of the wafer is ground by grinding, polishing, lapping, etc., and the thickness of the wafer is reduced to about 100 to 600 μm. I have. In these steps, an adhesive film for grinding the back surface of the semiconductor wafer is adhered to the wafer surface via the adhesive layer in order to prevent breakage of the semiconductor wafer when grinding the back surface of the wafer or to facilitate the grinding process. Protection methods are used.

[0003] Specifically, first, an adhesive film for grinding the back surface of a semiconductor wafer is attached to the wafer surface, and the back surface of the wafer is ground. After the grinding is completed, the film is peeled off, and the process proceeds to the next step such as a dicing step. When the back surface of the semiconductor wafer is ground by such a method, when the back surface of the semiconductor wafer having large surface irregularities is ground, there is a problem that the wafer is damaged by stress at the time of grinding. Actually, when a semiconductor wafer has a coating layer of polyimide or the like, a deposited film such as a silicon oxide film or a silicon nitride film, a scribe line, or the like, the step may be 50 μm or more. As means for solving such a problem, JP-A-61-102 discloses
No. 42 discloses a film for processing a wafer, wherein an adhesive is provided on the surface of a base sheet having a Shore D-type hardness of 40 or less. In the embodiment of the present invention, the back surface of a silicon wafer having a surface unevenness difference of 50 μm is actually polished without any problem (without damage).

In Japanese Patent Application Laid-Open No. 61-141142, a tape with an adhesive material made of a rubber material is adhered to the surface of a semiconductor wafer, the tape is cut, and the tape is fixed to a chuck. A semiconductor wafer grinding method characterized by grinding the back surface of the semiconductor wafer with a grindstone is disclosed. In the present invention, grinding of the back surface of a wafer having a step of about 10 to 80 μm on the surface caused by a coating layer of polyimide or the like is performed without any particular problem (without breakage).

Further, WO 85/057334 discloses a wafer processing film in which an adhesive layer is provided on one surface of a base film having a Shore D-type hardness of 40 or less, and the third of which is disclosed. As an invention, in the pressure-sensitive adhesive layer,
A wafer processing film containing at least one member selected from the group consisting of a nonionic surfactant and an ethylene glycol derivative is disclosed. Also in the embodiment of the present invention, polishing of the back surface of a silicon wafer having a surface unevenness difference of 50 μm is actually performed without any problem (without damage). Further, it is described that post-processing such as cleaning after peeling off the wafer processing film can be easily performed.

[0006] The semiconductor wafer disclosed in the above invention has a coating layer of polyimide or the like,
There are irregularities of about 50 μm caused by a deposited film such as a silicon oxide film or a silicon nitride film, a scribe line or the like. However, only about 10% of the surface of the semiconductor wafer is concave, and the apex of the convex portion is relatively smooth. Usually, the area of the relatively smooth convex portion occupies about 90% of the wafer surface. The pressure-sensitive adhesive film described in the above invention is applied to such backside grinding of a semiconductor wafer.

In recent years, the surface of a semiconductor wafer has been diversified, and even if the wafer itself is not damaged, the surface shape at which chip-level damage (hereinafter referred to as microcrack) occurs or a part of the adhesive is likely to remain. Are increasing. For example, with the thinning of packaging and the reduction of the chip mounting area, a wireless bonding method called flip-chip mounting is being adopted, and a wafer having a chip suitable for such a wireless bonding method is used. As a result, semiconductor wafers having protruding high bump electrodes having a height of 10 to 100 μm have been produced. Also, with the diversification of semiconductor chip production processes, before grinding the back surface of the semiconductor wafer, inspect the chips on the surface of the semiconductor wafer, and attach protruding ink dots having a height of 10 to 100 μm to the defective chips. , A process of grinding the back surface of a semiconductor wafer is being adopted.

In the case of grinding the back surface of a semiconductor wafer having a projection having a height of 10 to 100 μm, such as the above-mentioned high bump electrode or ink dot, the conventional adhesive film as described above is not enough. Depending on various conditions such as the size of the wafer, the thickness after grinding, grinding conditions, and the like, micro cracks may occur in a part of the wafer or the wafer may be completely damaged. Was.

Further, even if no damage occurs, a portion of the back surface corresponding to the protrusion on the front surface is dented (hereinafter referred to as a dimple) due to the influence of the protrusion, and the thickness accuracy of the wafer after grinding is reduced. In some cases, this may worsen, affecting the next process such as dicing, or causing a product defect. Furthermore, when peeling the adhesive film from the wafer after grinding,
A part of the adhesive remained on the surface of the wafer (hereinafter, referred to as adhesive residue) and sometimes contaminated the wafer surface. [This contamination often occurred around protruding objects, and around the high bump electrodes described later. If it does, it is particularly problematic. Although there is practically no problem when it adheres to the periphery of the ink dot (on the defective chip), even in this case, it may be transferred to another normal part when the wafer surface is cleaned and cause secondary contamination. Therefore, it is preferable that there is no contamination]. Although this contamination varies depending on the degree, the pressure-sensitive adhesive disclosed in the third invention of WO85 / 05734 may be insufficiently removed in some cases. Furthermore, water may enter between the wafer surface and the adhesive layer during backside grinding of the semiconductor wafer, resulting in damage to the wafer or grinding debris entering with the water to contaminate the wafer surface. there were.

[0010] Despite the problems described above, with the advancement of chip performance, diversification of packaging, and cost reduction, the technical level of the grinding method requires only that the wafer is not damaged. In addition, it is required that microcracks do not occur at the chip level, further low contamination of the wafer surface, improvement in thickness accuracy after grinding, and the like.

At present, a resist having a certain thickness is applied to the surface of a semiconductor wafer, and the height of the projections is reduced (or the convex portions are completely removed), and then an adhesive film is attached to grind the back surface. Or the backside grinding is performed only by applying the resist.Therefore, rational methods such as poor workability of the resist application and use of a large amount of solvent when applying and removing the resist are used. is not. Further, the resist method may not be applicable to the back surface grinding of the wafer having the ink dots. Under such circumstances, a rational back surface grinding method particularly suitable for a semiconductor wafer having a protrusion having a height of 10 to 100 μm on the surface, such as a high bump electrode or an ink dot, is desired. I have.

[0012]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to grind a back surface of a semiconductor wafer having a projection having a height of 10 to 100 μm, such as a high bump electrode or an ink dot, on the surface. An object of the present invention is to provide a method for grinding a back surface of a semiconductor wafer capable of preventing damage to a semiconductor wafer, preventing the occurrence of microcracks and dimples, preventing contamination of the surface of the semiconductor wafer, and the like, and an adhesive film for grinding the back surface used in the method. .

[0013]

The present inventors have intensively studied an effective method of grinding the back surface of a semiconductor wafer having a specific projection on the surface, and as a result, have found that a high bump electrode, ink, 10 heights such as dots
Even when the protrusions of 100 μm are formed, the hardness and thickness of the base film, the composition and thickness of the pressure-sensitive adhesive layer, the adhesive strength of the pressure-sensitive adhesive film are each limited to specific ranges, and the height of the protrusions is high. (A), a thickness of the base film (B), and a thickness of the pressure-sensitive adhesive layer (C), which are limited to a specific relationship, are employed in an adhesive film, which is adhered to the circuit forming surface of the semiconductor wafer. As a result, it has been found that the above object can be achieved, and the present invention has been accomplished.

That is, the present invention relates to a method of grinding a back surface of a semiconductor wafer, in which an adhesive film is attached to a circuit forming surface of a semiconductor wafer, the back surface of the semiconductor wafer is ground, and then the adhesive film is peeled off. The circuit forming surface of the wafer has at least one type of protrusion having a height (A) of 10 to 100 μm selected from electrodes and defective circuit identification marks, and the adhesive film has a Shore D type hardness of 40 or less and a thickness (B). 1) 100 parts by weight of an alkyl acrylate-based pressure-sensitive adhesive polymer having a functional group capable of reacting with a cross-linking agent on one surface of a substrate film having a size of 150 to 500 μm (4A ≦ B); 0.5 to 15 parts by weight of a crosslinking agent having two or more crosslinking reactive functional groups in a molecule, and
(C) an alkylene glycol polymer having 3 to 4 carbon atoms in an alkylene group, and an oxyalkylene copolymer having 3 to 4 carbon atoms in an oxyethylene-alkylene group having a copolymerization ratio of ethylene oxide of 30% by weight or less. A thickness (C) of 30 to 100 μm (provided that 0.6 A
≦ C), and the adhesive strength of the adhesive film to the SUS304-BA plate is 80 to 400 g.
/ 25 mm, which is a method for grinding a back surface of a semiconductor wafer. Another aspect of the present invention is an adhesive film for grinding a back surface of a semiconductor wafer used in the above invention.

The features of the present invention include the use of an adhesive film in which the hardness and thickness of the base film, the composition and thickness of the adhesive layer, the adhesive strength of the adhesive film are each limited to specific ranges, and the use of a semiconductor wafer circuit. It is to use an adhesive film in which the height (A) of the protrusions formed on the formation surface, the thickness (B) of the base film, and the thickness (C) of the adhesive layer are limited to a specific relationship. .

According to the present invention, when the back surface of the semiconductor wafer is ground, a projection having a height of 10 to 100 μm such as a high bump electrode or a defective circuit identification mark is formed on the front surface of the semiconductor wafer. In addition, not only the wafer is not damaged due to the grinding stress on the back surface, but also damage at the chip level (micro crack) does not occur. In addition, since there is no glue residue after peeling the adhesive film, in addition to not contaminating the surface of the semiconductor wafer,
There is no generation of dimples due to the protrusions. further,
There is no breakage of the wafer and no contamination of the wafer surface due to water entering between the surface of the semiconductor wafer and the adhesive layer.
As a matter of course, there is an effect that the process can be simplified without using a resist.

The high bump electrode according to the present invention is an electrode suitable for mounting a semiconductor chip by a wireless bonding method such as flip-chip mounting and is formed on a surface of a semiconductor wafer together with a circuit. Normal,
Since the semiconductor chip having the high bump electrode is directly connected to the printed wiring board using solder or the like by this electrode, the electrode has a height of about 10 to 100 μm. Semiconductor wafers having such high bump electrodes are:
As compared with the conventional one, only the electrode portion of the circuit is projected (projection). There are various shapes such as a columnar shape, a prismatic shape, a mushroom shape, and the like, depending on a bump forming method, performance required for a chip, and the like.

Further, the ink dot in the present invention is a mark provided on a defective circuit for inspecting and selecting a circuit (chip) formed on the surface of the semiconductor wafer and identifying the defective circuit. Usually, diameter 0.1-2mm, height 10
It has a columnar shape colored with a dye such as red of about 100 μm. The ink dots are in a protruding state (projections). The protrusions such as the high bump electrodes and the ink dots have such a state that a portion of less than 10% of the entire area of the surface of the semiconductor wafer protrudes to the height. The present invention is applied to a semiconductor wafer having such a surface shape.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. According to the present invention, an adhesive film for grinding a back surface of a semiconductor wafer having an adhesive layer formed on one surface of a substrate film has at least one height (A) of at least 10 selected from a high bump electrode and a defective circuit identification mark. A method of directly affixing to the surface of a semiconductor wafer having protrusions of about 100 μm and grinding the back surface, and an adhesive film used in the method.

The pressure-sensitive adhesive film for grinding the back surface of a semiconductor wafer of the present invention is obtained by coating an alkyl acrylate-based pressure-sensitive adhesive polymer, a crosslinking agent, an alkylene glycol-based polymer, etc. on one surface of a base film or a release film. It is manufactured by applying a solution or emulsion containing other additives (hereinafter collectively referred to as an adhesive coating solution) and drying to form an adhesive layer.

When a pressure-sensitive adhesive layer is formed on one surface of the substrate film, it is preferable to attach a release film to the surface of the pressure-sensitive adhesive layer in order to protect it from contamination due to the environment. In the case where an adhesive layer is formed on one surface of the release film, a method of transferring the adhesive layer to a base film is employed. Which of the base film and the release film is to be coated with the pressure-sensitive adhesive coating solution is determined in consideration of the heat resistance of the base film and the release film and the contamination of the semiconductor wafer surface. For example, when the heat resistance of the release film is superior to that of the base film, an adhesive layer is provided on the surface of the release film and then transferred to the base film. When the heat resistance is equivalent or the base film is excellent, an adhesive layer is provided on the surface of the base film, and a release film is adhered to the surface.

However, in consideration of the fact that the adhesive film for grinding the back surface of the semiconductor wafer is attached to the surface of the semiconductor wafer through the surface of the adhesive layer exposed when the release film is peeled off, the semiconductor wafer with the adhesive layer is taken into consideration. In order to prevent surface contamination, use a release film with good heat resistance,
It is preferable to apply a pressure-sensitive adhesive coating solution on the surface and dry it to form a pressure-sensitive adhesive layer.

As the substrate film used in the present invention, a substrate film having a Shore D type hardness of 40 or less is used. The base film having a Shore D-type hardness of 40 or less according to the present invention is a film formed by processing a raw resin having a Shore D-type hardness of 40 or less defined by ASTM-D-2240 into a film shape, or It is a film having the same performance. If the Shore-D hardness increases, the wafer may be locally damaged at the chip level (microcrack) or completely damaged during backside grinding. In addition, thickness variation (hereinafter, referred to as dimples) may occur such that the back surface corresponding to the protrusions becomes locally thin. Wafer breakage and micro cracks directly affect chip yield, and the occurrence of dimples, depending on the degree, has an adverse effect on the electrical characteristics of the obtained chip, or leads to chip breakage in the next dicing step and the like. Sometimes.

Examples of the raw material resin having a Shore D type hardness of 40 or less include ethylene-vinyl acetate copolymer resin, ethylene-ethyl acrylate copolymer resin and derivatives thereof, soft vinyl chloride resin, various synthetic rubbers and the like. . These resins, if necessary, stabilizers, lubricants,
It may contain an antioxidant, a pigment, an antiblocking agent, a plasticizer, and the like.

A film having the same performance as a film formed by processing a raw resin having a Shore D-type hardness of 40 or less into a film is simply a film-form raw material resin having a Shore D-type hardness of 40 or less. Instead of being formed into a film, a film blended with another resin (Shore-D hardness may be outside the scope of the present invention),
D-type hardness is a film obtained by mixing a resin outside the scope of the present invention, various additives such as a plasticizer, and other resins, and processing the mixture, and is defined in ASTM-D-2240. It has physical properties similar to a film obtained by forming a raw resin having a Shore D-type hardness of 40 or less into a film. Whether the film has a physical property similar to that of a film obtained by molding a raw material resin having a Shore D-type hardness of 40 or less into a film shape, the elastic modulus of the base film or the base film is subjected to hot pressing or the like. Judgment is made based on the measurement results of Shore D-type hardness of a sample obtained by laminating and melting without inserting air, and the like.

When various additives such as a plasticizer are added to the base film (especially in the case of a soft vinyl chloride resin), the additives migrate to the pressure-sensitive adhesive layer and change the properties of the pressure-sensitive adhesive layer. It may contaminate the wafer surface. In such a case, it is preferable to provide a barrier layer between the base film and the pressure-sensitive adhesive layer.

The base film may be a single layer,
It may be a laminate. The thickness (B) of the base film is 1
It is 50 to 500 μm. Preferably 250-500
μm. However, when the height (A) of the protrusions on the surface of the semiconductor wafer is 10 to 100 μm, the thickness (B) of the base film and (A) must be in a relationship of 4A ≦ B. is there. When the base film becomes thin, microcracks may occur during back grinding, or the base film may be completely broken. Also, dimples may occur. When the thickness is increased, the productivity of the base film is affected, and the production cost is increased.

The thickness variation of the base film does not significantly affect the local thickness variation (dimple) of the wafer after the back surface grinding, but does affect the overall thickness variation. From this viewpoint, it is preferable that the base film is manufactured with a thickness variation within a range of about ± 5% of the average thickness. More preferably, ± 3%
Within ± 2%, more preferably within ± 2%. Thickness variation here is about 10cm randomly collected
This is the variation with respect to the average thickness when measuring a sample of four sides in a size of about 1 cm in length and width.

Further, a film harder than this, specifically a film having a Shore D-type hardness of more than 40, may be laminated on the surface of the substrate film opposite to the surface on which the pressure-sensitive adhesive layer is provided. Thereby, the rigidity of the pressure-sensitive adhesive film for grinding the back surface of the semiconductor wafer is increased, and the sticking workability and the peeling workability are improved.

Further, in the case where the surface of the semiconductor wafer is protected by using an adhesive film for grinding the back surface of the semiconductor wafer continuously during the etching process using an etching solution applied after grinding the back surface of the semiconductor wafer, chemical resistance is required. It is preferable to use a base film having excellent properties. A chemical resistant film may be laminated on the side of the base film opposite to the pressure-sensitive adhesive layer. For example, a polypropylene film having excellent chemical resistance is laminated.

In order to improve the adhesive strength between the base film and the pressure-sensitive adhesive layer, it is preferable to subject the surface of the base film on which the pressure-sensitive adhesive layer is provided to a corona discharge treatment or a chemical treatment.
An undercoat may be used between the base film and the pressure-sensitive adhesive layer.

The base film of the present invention can be prepared by a calender method,
It can be manufactured by a known technique such as a T-die extrusion method and an inflation method. Among them, in consideration of productivity, thickness accuracy of a film to be obtained, and the like, it is preferable to manufacture by a T-die extrusion method.

Examples of the release film used in the present invention include synthetic resin films such as polypropylene and polyethylene terephthalate. Preferably, the surface thereof is subjected to a silicone treatment or the like as necessary. The thickness of the release film is usually 10 to 2000 μm. Preferably it is 30 to 100 μm.

The pressure-sensitive adhesive coating solution used in the present invention comprises, as a basic component, an alkyl acrylate-based pressure-sensitive adhesive polymer and two crosslinkable functional groups for increasing cohesive strength or adjusting adhesive strength in one molecule. A solution or emulsion containing the crosslinking agent and the specific alkylene glycol-based polymer having the above.

The alkyl acrylate pressure-sensitive adhesive polymer used in the present invention is obtained by copolymerizing a monomer mixture containing an alkyl acrylate and / or an alkyl methacrylate as a main monomer and a comonomer having a functional group capable of reacting with a crosslinking agent. Is obtained.

The liquid containing the acrylic acid alkyl ester-based pressure-sensitive adhesive polymer (hereinafter referred to as the pressure-sensitive adhesive base material) may be any of a solution, an emulsion liquid and the like.

The main monomers include methyl acrylate,
Examples thereof include methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. These may be used alone or as a mixture of two or more.
It is preferable that the amount of the main monomer used is usually in the range of 60 to 99% by weight in the total amount of all the monomers used as the raw material of the pressure-sensitive adhesive polymer.

Examples of comonomers having a functional group capable of reacting with a crosslinking agent, which are copolymerized with the above main monomer, include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid and monoalkyl itaconate. , Monoalkyl mesaconate, monoalkyl citraconic, monoalkyl fumarate, monoalkyl maleate, acrylic acid-
2-hydroxyethyl, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, tert-butylaminoethyl methacrylate, and the like. One of these may be copolymerized with the above main monomer, or two or more thereof may be copolymerized. The amount of the comonomer having a functional group capable of reacting with the cross-linking agent is usually 1 to 10
Preferably, it is contained in the range of 40% by weight.

In the present invention, in addition to the main monomer constituting the pressure-sensitive adhesive polymer and the comonomer having a functional group capable of reacting with the crosslinking agent, a specific comonomer having properties as a surfactant (hereinafter referred to as a polymerizable interface) Activator) may be copolymerized. The polymerizable surfactant has a property of copolymerizing with the main monomer and the comonomer, and has an action as an emulsifier when emulsion polymerization is performed. When an adhesive polymer obtained by emulsion polymerization using a polymerizable surfactant is used, the surface of the wafer is not normally contaminated by the surfactant. In addition, even when slight contamination caused by the pressure-sensitive adhesive layer occurs, it can be easily removed by washing the wafer surface with water.

Examples of such a polymerizable surfactant include:
For example, polyoxyethylene nonylphenyl ether having a polymerizable 1-propenyl group introduced into the benzene ring [manufactured by Daiichi Kogyo Seiyaku Co., Ltd .; Aqualon RN-10, R
N-20, RN-30, RN-50, etc.], and a polymerizable 1-propenyl group introduced into the benzene ring of an ammonium salt of a sulfate of polyoxyethylene nonylphenyl ether [Daiichi Kogyo Seiyaku Co., Ltd. Aquaron H
S-10, HS-20 etc.] and a sulfosuccinic acid diester having a polymerizable 2 bond in the molecule [manufactured by Kao Corporation; Latemul S-120A, S-180A etc.]
And the like.

If necessary, glycidyl acrylate, glycidyl methacrylate, isocyanate ethyl acrylate, isocyanate ethyl methacrylate,
-(1-aziridinyl) ethyl acrylate, 2- (1
Monomers having a self-crosslinkable functional group such as -aziridinyl) ethyl methacrylate, monomers having a polymerizable double bond such as vinyl acetate, acrylonitrile, and styrene;
Polyfunctional monomers such as divinylbenzene, vinyl acrylate, vinyl methacrylate, allyl acrylate and allyl methacrylate may be copolymerized.

As a method for polymerizing the pressure-sensitive adhesive polymer,
Various known methods such as a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method can be employed. However, it is necessary to consider the molecular weight of the obtained pressure-sensitive adhesive polymer and the effect on the cohesive force of the pressure-sensitive adhesive. Among these polymerization methods, the emulsion polymerization method is preferable in consideration of obtaining a high molecular weight polymer, environmental pollution in coating and drying steps, coating properties, and the like.

As the polymerization reaction mechanism of the pressure-sensitive adhesive polymer,
Radical polymerization, anionic polymerization, cationic polymerization, and the like can be mentioned, but polymerization is preferably performed by radical polymerization in consideration of the production cost of the pressure-sensitive adhesive, the effect of the functional group of the monomer and the effect of ions on the surface of the semiconductor wafer, and the like. . When polymerizing by a radical polymerization reaction, organic radicals such as benzoyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, di-tert-butyl peroxide, di-tert-amyl peroxide are used as radical polymerization initiators. 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.

When polymerization is carried out by the emulsion polymerization method, among these radical polymerization initiators, inorganic peroxides such as water-soluble ammonium persulfate, potassium persulfate and sodium persulfate; An azo compound having a carboxyl group in the molecule, such as' -azobis-4-cyanovaleric acid, is preferred. Considering the effect of ions on the semiconductor wafer surface, ammonium persulfate, 4,4 '
An azo compound having a carboxyl group in the molecule, such as -azobis-4-cyanovaleric acid, is more preferred. An azo compound having a carboxyl group in the molecule, such as 4,4'-azobis-4-cyanovaleric acid, is particularly preferred.

The cross-linking agent having two or more cross-linkable functional groups in one molecule used in the present invention is used to react with the functional group of the pressure-sensitive adhesive polymer to adjust the adhesive strength and cohesive strength. As the crosslinking agent, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether,
Epoxy compounds such as pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, resorcin diglycidyl ether, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate of trimethylolpropane 3 Adducts, isocyanate compounds such as polyisocyanates,

Trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N, N′-diphenylmethane-4,4′-bis (1-aziridine Carboxamide), N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide), N, N'-toluene-2,4-bis (1-aziridinecarboxamide), trimethylolpropane-tri Aziridine compounds such as -β- (2-methylaziridine) propionate; and melamine compounds such as hexamethoxymethylolmelamine.

These may be used alone or in combination of two or more. Among the above cross-linking agents, epoxy-based cross-linking agents have a low speed of the cross-linking reaction. Contamination due to the agent layer may occur. Therefore, as appropriate, a monomer containing a catalyst such as an amine, or a monomer having an amine functional group having a catalytic action is copolymerized with an adhesive polymer, or an aziridine-based compound having properties as an amine when a crosslinking agent is used. It is preferable to use a crosslinking agent together.

The content of the cross-linking agent is usually within a range where the number of functional groups in the cross-linking agent does not become larger than the number of functional groups in the pressure-sensitive adhesive polymer. However, when a new functional group is generated by the crosslinking reaction, or when the crosslinking reaction is slow, it may be contained in excess, if necessary. The preferred content is 0.5 to 15 parts by weight of the crosslinking agent based on 100 parts by weight of the pressure-sensitive adhesive polymer. If the amount is small, the cohesive force of the adhesive layer becomes insufficient,
Adhesive residue may easily occur on the wafer surface (especially around the protrusions), or the adhesive strength may be increased outside the range of the present invention. If the amount is too large, the adhesion between the pressure-sensitive adhesive layer and the wafer surface becomes weak, and even if the adhesion to a SUS304-BA plate described later is within the range of the present application, water and grinding debris infiltrate during grinding, and the pressure-sensitive adhesive film The wafer may be damaged due to the peeling of the wafer, or the wafer surface may be contaminated by grinding debris.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive film of the present invention contains a specific alkylene glycol-based polymer as an essential component in addition to the above-mentioned alkyl acrylate-based pressure-sensitive adhesive polymer and crosslinking agent. The inclusion of the alkylene glycol-based polymer has an effect of preventing water from entering between the wafer surface and the pressure-sensitive adhesive layer when grinding the back surface of the wafer having protrusions (hereinafter, referred to as water resistance). In the present invention, the adhesive strength of the adhesive film is limited to a specific range described later. Although the detailed reason is not clear, within the range of the adhesive strength, there is an effect of improving the water resistance during grinding the back surface of the wafer surface having the projections having a height of 10 to 100 μm.

The alkylene glycol-based polymer referred to in the present invention includes those referred to as poly (oxyalkylene) glycol, polyoxyalkylene ether and polyalkylene oxide, wherein the main chain of the polymer has a polyether structure. Say. Alkylene glycol-based polymers include water, alcohols, ethylene glycol, glycerin, polyhydric alcohols such as pentaethritol as initiators, metal alkoxides, organometallic compounds, inorganic metal salts, alkali metal hydroxides, It is synthesized by a method in which a cyclic ether such as ethylene oxide or propylene oxide is ring-opened and added in the presence of a catalyst such as a triamine compound or an acid to polymerize. Furthermore, a polyether having a structure in which the hydrogen atom of the hydroxyl group at the terminal of the polymer is substituted by an alkyl group is included [in this case, the molecular weight of the obtained polymer is determined by the molecular weight of the polymer before the alkyl group substitution (the number of hydroxyl groups and the number of functional groups). Estimated from conversion).

In the present invention, the alkylene glycol-based polymer contained in the pressure-sensitive adhesive layer is, among the alkylene glycol-based polymers defined above, an alkylene glycol polymer having an alkylene group having 3 to 4 carbon atoms, and One or more alkylene glycol-based polymers selected from the group consisting of oxyalkylene copolymers having 3 to 4 carbon atoms in an oxyethylene-alkylene group having a copolymerization ratio of ethylene oxide of 30% by weight or less. More preferably, an alkylene glycol polymer having 3 to 4 carbon atoms in the alkylene group,
And an oxyethylene-alkylene group whose ethylene oxide copolymerization ratio is 20% by weight or less has 3 to 4 carbon atoms.
And at least one alkylene glycol-based polymer selected from the group consisting of oxyalkylene copolymers.

Specifically, polypropylene glycol,
Examples thereof include polyethers such as homopolymers such as polytrimethylene glycol and polytetramethylene glycol, and copolymers such as oxyethylene-oxypropylene copolymers having an ethylene oxide copolymerization ratio of 30% by weight or less. These may be used alone or in combination of two or more. Further, among these, considering the production cost and the like, the copolymerization ratio of polypropylene glycol and ethylene oxide is not more than 30% by weight.
Oxypropylene copolymers are preferred. An oxyethylene-oxypropylene copolymer having a copolymerization ratio of polypropylene glycol and ethylene oxide of 20% by weight or less is particularly preferred.

In the case of an alkylene glycol polymer having an alkylene group having 2 or less carbon atoms or an oxyethylene-oxyalkylene copolymer having a copolymerization ratio of ethylene oxide of more than 30% by weight, the water resistance is reduced and the back surface of the wafer is reduced. During grinding, water may enter between the surface of the semiconductor wafer and the adhesive layer. If water enters between the semiconductor wafer and the pressure-sensitive adhesive layer, the wafer may be damaged, or the wafer surface may be contaminated with grinding dust or the like. Also, it is difficult to obtain an alkylene glycol polymer having an alkylene group having 5 or more carbon atoms.

The average molecular weight of the alkylene glycol polymer contained in the pressure-sensitive adhesive layer is preferably as high as possible in consideration of contamination on the wafer surface. The upper limit of the preferred molecular weight is not particularly limited, but as the molecular weight increases, the production of the alkylene glycol polymer tends to become difficult. Given these considerations, the average molecular weight is between 2000 and 200
It is preferably about 00 (converted from the hydroxyl value and the number of functional groups). More preferably, it is 6,000 to 20,000.

The content of the alkylene glycol polymer is 1 to 30 parts by weight based on 100 parts by weight of the sum of the pressure-sensitive adhesive polymer and the crosslinking agent. More preferably, 5-
20 parts by weight. If the content is small, the water resistance is poor,
Water tends to enter between the wafer surface and the pressure-sensitive adhesive layer during back surface grinding, which tends to cause damage to the wafer and contamination due to grinding dust on the surface. If too much, the wafer surface may be contaminated.

In the pressure-sensitive adhesive coating solution used in the present invention, in addition to the pressure-sensitive adhesive polymer, the crosslinking agent, and the alkylene glycol-based polymer, a tackifier such as a rosin-based resin or a terpene resin-based resin for adjusting the adhesive property may be used. Various surfactants and the like may be appropriately contained to such an extent that the purpose of the present invention is not affected.
When the pressure-sensitive adhesive polymer is an emulsion, a film-forming aid such as diethylene glycol monoalkyl ether may be appropriately added to such an extent that the object of the present invention is not affected. Diethylene glycol monoalkyl ethers and derivatives thereof used as a film-forming aid have an effect of easily removing contamination of the wafer surface caused by the pressure-sensitive adhesive layer, but are easily contaminated by the pressure-sensitive adhesive layer in the present invention. In order to use a semiconductor wafer having protrusions on its surface as an adherend,
If a large amount is contained in the pressure-sensitive adhesive layer, a large amount of contamination on the wafer surface may be caused to such an extent that cleaning is impossible. Therefore, in consideration of these matters, it is preferable to use a substance which volatilizes at the temperature at the time of drying after coating and to reduce the amount remaining in the pressure-sensitive adhesive layer.

The thickness (C) of the pressure-sensitive adhesive layer is 30 to 100 μm
It is. However, a relationship of 0.6A ≦ C needs to be established between the thickness (C) of the pressure-sensitive adhesive layer and the height (A) of the protrusion formed on the surface circuit of the semiconductor wafer. If the thickness of the pressure-sensitive adhesive layer is reduced, water resistance is inferior and water penetrates between the surface of the wafer and the pressure-sensitive adhesive layer during back surface grinding, which tends to cause damage to the wafer and contamination due to grinding chips on the surface. When the thickness increases, it becomes difficult to produce an adhesive film,
This may affect productivity and increase manufacturing costs.

The adhesive strength of the adhesive film for grinding the back surface of a wafer of the present invention is 80 to 400 g / 25 mm, preferably 100 when converted to the adhesive strength to a SUS304-BA plate.
３５０350 g / 25 mm.

The above range is adjusted in consideration of the grinding conditions of the back surface of the wafer, the diameter of the wafer, the thickness of the wafer after grinding, and the like.
If the adhesive strength is low, water may enter between the surface of the wafer and the adhesive layer during the back surface grinding, and the wafer may be damaged, and the surface may be contaminated by grinding debris. On the other hand, if it is too high, peeling trouble may occur in an automatic tape peeling machine at the time of peeling after back surface grinding, and peeling workability may be reduced, or the wafer may be damaged.

As a method of applying a pressure-sensitive adhesive coating solution to one surface of a base film or a release film, a conventionally known coating method, for example, a roll coater method, a reverse roll coater method, a gravure roll method, a bar coat method, a comma coater Method, die coater method or the like can be adopted. The drying condition of the applied pressure-sensitive adhesive is not particularly limited, but generally, 8
It is preferable to dry in a temperature range of 0 to 200 ° C. for 10 seconds to 10 minutes. More preferably 80 to 170 ° C
For 15 seconds to 5 minutes.

In the present invention, the pressure-sensitive adhesive layer has a thickness of 30
In order to apply a coating having a thickness of from μm to 100 μm, a multilayer coating may be applied as necessary. In order to sufficiently promote the cross-linking reaction between the cross-linking agent and the pressure-sensitive adhesive polymer, after the drying of the coating solution for the pressure-sensitive adhesive is completed, the pressure-sensitive adhesive film for grinding the back surface of the semiconductor wafer is heated at 40 to 80 ° C. for about 5 to 300 hours. May be.

The method for producing the pressure-sensitive adhesive film for grinding the back surface of a semiconductor wafer of the present invention is as described above. From the viewpoint of preventing contamination of the surface of the semiconductor wafer, all raw materials such as a base film, a release film, and a pressure-sensitive adhesive are used. It is preferable that the production environment and the environment for preparing, storing, applying, and drying the pressure-sensitive adhesive coating liquid are maintained at a cleanliness of class 1,000 or less specified by US Federal Standard 209b.

Next, a method of grinding the back surface of a semiconductor wafer will be described. The method of grinding a back surface of a semiconductor wafer of the present invention includes:
When grinding the back surface of a semiconductor wafer having at least one type of protrusion selected from a high bump electrode having a height (A) of 10 to 100 μm and a defective circuit identification mark on the surface,
It is characterized by using the adhesive film for grinding the back surface of a semiconductor wafer manufactured by the above method.

The details are as follows. First, the release film is peeled off from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film for grinding the back surface of the semiconductor wafer (hereinafter, referred to as pressure-sensitive adhesive film), the surface of the pressure-sensitive adhesive layer is exposed, and through the pressure-sensitive adhesive layer, Height (A) is 10-100
It is attached to the surface of the semiconductor wafer on the side where the integrated circuit having the projections of μm is incorporated. Next, the semiconductor wafer is fixed to the chuck table or the like of the grinding machine via the base film layer of the adhesive film, and the back surface of the semiconductor wafer is ground. After the grinding is completed, the adhesive film is peeled off. After the grinding of the back surface is completed, a chemical etching step may be performed before the adhesive film is peeled off. Further, if necessary, after the adhesive film is peeled off, the surface of the semiconductor wafer is subjected to a washing treatment such as water washing and plasma washing.

In such a back surface grinding operation, the semiconductor wafer usually has a thickness before grinding of 500 μm to 1000 μm.
μm, depending on the type of semiconductor chip, etc.
Usually, it is ground to about 100 μm to 600 μm. 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 the semiconductor wafer may be performed manually, but is generally performed by an apparatus called an automatic attaching machine having a roll-shaped adhesive film attached thereto. As such an automatic pasting machine, for example, ATM-1000B, manufactured by Takatori Co., Ltd.
-1100 and STL series manufactured by Teikoku Seiki Co., Ltd. As the back surface grinding method, a known grinding method such as a through feed method and an in-feed method is employed. In each case, the grinding is performed while cooling the water by applying it to the semiconductor wafer and the grindstone.

After the back surface grinding, chemical etching is performed as necessary. Chemical etching is an etching solution selected from the group consisting of an acidic aqueous solution composed of a single solution or a mixture of hydrofluoric acid, nitric acid, sulfuric acid, and acetic acid, and an alkaline aqueous solution such as a potassium hydroxide aqueous solution and a sodium hydroxide aqueous solution. This is performed by a method such as immersing the semiconductor wafer in a state where the adhesive film is adhered. The etching is performed for the purpose of removing distortion generated on the back surface of the semiconductor wafer, further reducing the thickness of the wafer, removing an oxide film, etc., and performing pretreatment before forming electrodes on the back surface. The etchant is
It is appropriately selected according to the above purpose.

After the back surface grinding and the chemical etching are completed, the adhesive film is peeled off from the wafer surface. This series of operations may be performed manually, but is generally performed by an apparatus called an automatic peeling machine. Like this,
ATRM-2 manufactured by Takatori Co., Ltd.
000B, ATRM-2100, S made by Teikoku Seiki Co., Ltd.
There are TP series and so on.

The surface of the wafer from which the adhesive film has been peeled off is washed 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 together. These cleaning methods are appropriately selected depending on the state of contamination on the wafer surface.

According to the present invention, a semiconductor wafer having projections such as high bump electrodes, ink dots and the like having a height of 10 to 100 μm on the surface, which has been difficult to grind up to now, is used. Grinding can be easily performed in the same manner as when grinding the back surface of a conventional wafer having no objects.
Further, when grinding the back surface of the semiconductor wafer having the protrusions on the surface, not only does not damage the wafer,
Grinding can be performed without generating microcracks. Further, since no resist or the like is used, the process can be simplified.
Further, after the adhesive film is peeled off from the surface of the semiconductor wafer, there is almost no contamination on the surface of the semiconductor wafer due to the adhesive layer or contamination due to intrusion of grinding chips. Thickness variation on the back surface, which is caused by irregularities on the protrusions such as dimples, hardly occurs, or even if it occurs, it can be suppressed to a range where there is no practical problem.

In the present invention, the height (A) is 10 to 100 μm.
Is applied to the grinding of the back surface of a semiconductor wafer having the projections described above. When the height (A) of the projections is 25 μm or more, the effect becomes more remarkable.

The adhesive film for grinding the backside of a semiconductor wafer of the present invention and the semiconductor wafer to which the backside grinding method of a semiconductor wafer using the same can be applied include not only silicon wafers but also germanium, gallium-arsenic, gallium-phosphorus, and the like.
Wafers such as gallium-arsenic-aluminum are mentioned.

[0073]

The present invention will be described below in further detail with reference to examples. In all Examples and Comparative Examples shown below, Class 1 specified in US Federal Standard 209b was used.
Preparation and application of an adhesive coating solution, grinding of the back surface of a semiconductor silicon wafer, and the like were performed in an environment maintained at a clean degree of 000 or less. The present invention is not limited to these examples. The various characteristic values shown in the examples were measured by the following methods.

(1) Adhesive force (g / 25 mm) Except for the conditions specified below, all were JIS Z-0237.
It measured according to. Under an atmosphere of 23 ° C., a 5 × 20 cm SUS304-BA plate (JIS
G-4305) and left for 1 hour. One end of the sample was sandwiched, and a peeling angle of 180 ° and a peeling speed of 300 mm / min. Was used to measure the stress when the sample was peeled off from the surface of the SUS304-BA plate, and converted to an adhesive force of g / 25 mm.

(2) Practical evaluation The semiconductor silicon wafer of Example or Comparative Example (diameter: 6)
(Inch, thickness: 600 μm) The adhesive film of the example or the comparative example was stuck to the surface of the semiconductor silicon wafer, and the back surface of the semiconductor silicon wafer was ground while cooling with water using a grinder to reduce the thickness to about 250 μm. And 1 for each adhesive film
The evaluation was performed on zero semiconductor silicon wafers. After the grinding was completed, the damage status of the semiconductor silicon wafer was evaluated based on the number of damaged wafers, and the unbroken semiconductor silicon wafer was visually observed as to whether water had permeated from the periphery between the surface and the adhesive film. . When water intrusion is observed, the degree of infiltration is determined when the infiltration is less than 2 mm from the periphery of the wafer (a degree that does not affect the yield of chips obtained from the wafer), or when the infiltration is 2 mm or more from the periphery (obtained from the wafer). (Which affects the yield of chips). After the observation of water infiltration, the surface protection tape peeling machine was manufactured by Takatori Co., Ltd.
ODEL: ATRM-2000B; Peeling tape used:
Highland Filament Tape No. The adhesive film was peeled off with 897 [manufactured by Sumitomo 3M Limited]. The state of damage at the time of peeling the pressure-sensitive adhesive film was evaluated based on the number of pieces damaged. Further, the surface of the wafer that was not damaged when the adhesive film was peeled off was cleaned with a cleaning machine [Dainippon Screen Manufacturing Co., Ltd.
Manufactured by D-SPIN 629], and then observed using an optical microscope [Nikon Corp .: OPTIPHOT2] at a magnification of 50 to 1000 times to observe the state of microcracks and contamination of each chip. Were observed and evaluated according to the following criteria. -Mylo-crack occurrence rate (%) [(No. of chips having myocrack) / (No. Of observed chips)] × 100-Contamination occurrence rate (%): [(No. of contaminated chips) / (No. Of observed chips)] × 100

(3) Occurrence of Dimples on Wafer Back Surface After grinding the back surface of the wafer, the back surface of the wafer was visually observed for dimples having a depth of about 5 μm or more. If dimples were observed, the depth of the dent was measured.

Example 1 (Preparation of base film) An ethylene-vinyl acetate copolymer resin having a Shore D type hardness of 35 was formed into a film having a thickness of 250 μm using a T-die extruder. At this time, a corona treatment was performed on the pressure-sensitive adhesive layer side. The thickness variation of the obtained film was within ± 1.5%.

(Polymerization of Adhesive Main Agent) In a polymerization reactor, 150 parts by weight of deionized water and 4,4'-azobis-4-cyanovaleric acid as a polymerization initiator [Otsuka Chemical Co., Ltd.
0.5 parts by weight, trade name: ACVA], 73.25 parts by weight of butyl acrylate, 14 parts by weight of methyl methacrylate, 9 parts by weight of 2-hydroxyethyl methacrylate, 2 parts by weight of methacrylic acid, 1 part by weight of acrylamide Part, polyoxyethylene nonylphenyl ether (average number of moles of ethylene oxide added = about 2)
0) Aqueous ammonium salt of a sulfate ester obtained by introducing a polymerizable 1-propenyl group into the benzene ring [manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd .: Aqualon HS-20] 0.75 parts by weight, and stirred under 70%. Perform emulsion polymerization at 9 ° C. for 9 hours,
An acrylic resin-based water emulsion was obtained. This was neutralized with 14% by weight of aqueous ammonia to obtain a pressure-sensitive adhesive polymer emulsion (base of pressure-sensitive adhesive) having a solid content of 40% by weight.

(Preparation of Adhesive Coating Solution) 100 parts by weight of the obtained main adhesive emulsion (adhesive polymer concentration of 40
% By weight) and further adjusted to pH 9.3 by adding 14% by weight aqueous ammonia. Next, an aziridine-based cross-linking agent [Nippon Shokubai Chemical Co., Ltd., Chemitite PZ-3]
3] 2 parts by weight, oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 15% by weight as an alkylene glycol-based polymer [pentaerythritol-based, molecular weight 8,000 (converted from hydroxyl value and number of functional groups)] 5% by weight And 5 parts by weight of diethylene glycol monobutyl ether were added to obtain an adhesive coating solution.

(Preparation of pressure-sensitive adhesive film) This pressure-sensitive adhesive coating solution was applied to a polypropylene film (release film, thickness: 50 μm) using a roll coater.
After drying for 40 minutes, an adhesive layer having a thickness of 40 μm was provided. The corona-treated surface of the above-mentioned ethylene-vinyl acetate copolymer film (Shore D type hardness: 35) was bonded and pressed to transfer the pressure-sensitive adhesive layer. After the transfer, the resultant was heated at 60 ° C. for 48 hours, and then cooled to room temperature to produce an adhesive film for grinding the back surface of a semiconductor wafer. The adhesive strength of the obtained adhesive film was 180 g / 25 mm.

(Evaluation of pressure-sensitive adhesive film) A pressure-sensitive adhesive film having a height of 55 μm and a high bump electrode
m ² of the integrated circuit is near to built-in semiconductor silicon wafer (diameter: 6 inches thickness: 600 .mu.m,) was adhered to the surface (the integrated circuit side) of, by using a grinding machine, while cooling over water The back surface of the semiconductor silicon wafer was ground to a thickness of about 250 μm. The same operation was performed on ten similar wafers. No wafer was damaged during grinding. After the grinding was completed, no water permeation was observed between the wafer and the adhesive film. A surface protection tape peeling machine from these 10 wafers, manufactured by Takatori Co., Ltd., MODE
L: ATRM-2000B; Peeling tape used: Highland marked filament tape No. The adhesive film was peeled off using 897 [manufactured by Sumitomo 3M Limited]. No wafer was damaged during the peeling of the adhesive film. After washing the surface of the obtained semiconductor wafer with a washing machine [D-SPIN 629, manufactured by Dainippon Screen Mfg. Co., Ltd.], the thickness variation of the semiconductor silicon wafer is evaluated, and the contamination of the wafer surface by a microscope is performed. Was observed. No contamination or the like by an adhesive or the like was observed on the wafer surface. The state of the back surface grinding was visually observed, but no dimple was found. The results obtained are shown in [Table 1].

Example 2 In the production of the substrate film of Example 1, the thickness was set to 450
A base film having a thickness variation of 1.5% or less was prepared in the same manner as in Example 1 except that the thickness was set to μm. In the preparation of the adhesive coating solution, the ethylene oxide copolymerization ratio was 15% by weight. Instead of the oxyethylene-oxypropylene copolymer, the copolymerization ratio of ethylene oxide is 14
Oxyethylene-oxypropylene copolymer [pentaerythritol, molecular weight 10,000 (converted from hydroxyl value and number of functional groups)] by weight is used, and the amount added is 8.
A pressure-sensitive adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive film was 0 parts by weight and the thickness of the pressure-sensitive adhesive layer after drying was 60 μm in the preparation of the pressure-sensitive adhesive film. The adhesive strength of the obtained adhesive film is 210 g / 2.
5 mm. Instead of the semiconductor silicon wafer of Example 1, 90% of the ink dots are not 90 μm high on the surface of 10% of all the chips of the semiconductor silicon wafer (surface unevenness of about 5 μm) on which the integrated circuit of 50 mm ² is built up to the periphery. Wafer (6 inches in diameter, thickness: 6)
(00 μm) in the same manner as in Example 1.
No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed. No wafer was damaged during the peeling of the adhesive film. No contamination or the like by an adhesive or the like was observed on the surface of the semiconductor silicon wafer after the surface was washed with water. Dimples were not observed when the backside grinding condition was visually observed. The results obtained are shown in [Table 1].

Example 3 In preparing the pressure-sensitive adhesive coating liquid of Example 1, an epoxy-based crosslinking agent [Denacol EX-611, manufactured by Nagase Kasei Kogyo Co., Ltd.] was used instead of the aziridine-based crosslinking agent, and the added amount was adjusted. Instead of oxyethylene-oxypropylene copolymer having a copolymerization ratio of 4.8 parts by weight and ethylene oxide of 15% by weight, polypropylene glycol [glycerin, molecular weight 6500 (converted from hydroxyl value and number of functional groups)] is used. Then, an adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1 except that the addition amount was 3.0 parts by weight. The adhesive strength of the obtained adhesive film was 240 g / 25 mm. Instead of the semiconductor silicon wafer of the first embodiment, a semiconductor silicon wafer (diameter: 6 inches, thickness: 600 μm) in which a 50 mm ² integrated circuit having a 30 μm high bump electrode is embedded all the way around
m) was evaluated in the same manner as in Example 1. No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed. No wafer was damaged during the peeling of the adhesive film. No contamination or the like by an adhesive or the like was observed on the surface of the semiconductor silicon wafer after the surface was washed with water. Dimples were not observed when the backside grinding condition was visually observed.
The results obtained are shown in [Table 1].

Example 4 In preparing the base film of Example 1, an ethylene-vinyl acetate copolymer resin having a Shore D-type hardness of 38 was used instead of the ethylene-vinyl acetate copolymer resin having a Shore D-type hardness of 35. , Except that the thickness was 350 μm,
A base film having a thickness variation of not more than 1.5% was prepared in the same manner as in Example 1, and in the preparation of the pressure-sensitive adhesive coating solution, an oxyethylene-oxypropylene copolymer having an ethylene oxide copolymerization ratio of 15% by weight was used. Instead of the polymer, an oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 14% by weight (pentaerythritol type, molecular weight 10,000 (converted from the hydroxyl value and the number of functional groups)) was used, and the addition amount was 7%. In the preparation of the pressure-sensitive adhesive film, the thickness of the pressure-sensitive adhesive layer after drying was 50 parts by weight.
An adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1 except that the thickness was changed to μm. The adhesive strength of the obtained adhesive film was 180 g / 25 mm. Instead of the semiconductor silicon wafer of Example 1, ink dots having a height of 75 μm were not formed on the surface of 10% of all the chips of a semiconductor silicon wafer (surface unevenness of about 5 μm) in which an integrated circuit of 50 mm ² was incorporated to the periphery. Evaluation was performed in the same manner as in Example 1 by using a wafer (diameter: 6 inches, thickness: 600 μm) attached to the operation. No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed. No wafer was damaged during the peeling of the adhesive film. No contamination or the like by an adhesive or the like was observed on the surface of the semiconductor silicon wafer after the surface was washed with water. Dimples were not observed when the backside grinding condition was visually observed. The results obtained are shown in [Table 1].

Example 5 In the production of the base film of Example 1, the thickness was changed to 350
A substrate film having a thickness variation of 1.5% or less was prepared in the same manner as in Example 1 except that the thickness was set to 0.1 μm, and the amount of the aziridine-based crosslinking agent was adjusted to 0. 4 parts by weight, instead of the oxyethylene-oxypropylene copolymer having an ethylene oxide copolymerization ratio of 15% by weight, an oxyethylene-oxypropylene copolymer having an ethylene oxide polymerization ratio of 14% by weight [pentaerythritol-based , Molecular weight of 10,000 (converted from the hydroxyl value and the number of functional groups)], the addition amount was 7.5 parts by weight, and in the preparation of the adhesive film, all the examples were the same except that the thickness of the dried adhesive layer was 55 μm. An adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1. The adhesive strength of the obtained adhesive film is 350 g / 25 m.
m. Instead of the semiconductor silicon wafer of Example 1, 50 mm ² having a high bump electrode having a height of 80 μm
Was evaluated in the same manner as in Example 1 using a semiconductor silicon wafer (diameter: 6 inches, thickness: 600 μm) in which the integrated circuit described above was incorporated into the periphery. No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed. No wafer was damaged during the peeling of the adhesive film. No contamination or the like by an adhesive or the like was observed on the surface of the semiconductor silicon wafer after the surface was washed with water. Dimples were not observed when the backside grinding condition was visually observed. The results obtained are shown in [Table 1].

Example 6 In the production of the base film of Example 1, the thickness was set to 160
A substrate film having a thickness variation of 1.5% or less was prepared in the same manner as in Example 1 except that the thickness was changed to μm, and the amount of the aziridine-based cross-linking agent added was 1.6 in the preparation of the adhesive coating solution. Parts by weight, and instead of the oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 15% by weight, the copolymerization ratio of ethylene oxide was 1
4% by weight of oxyethylene-oxypropylene copolymer [pentaerythritol type, molecular weight 10,000 (converted from hydroxyl value and number of functional groups)], and added amount of 8.
An adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1 except that the amount was 0 parts by weight. The adhesive strength of the obtained adhesive film was 160 g / 25 mm.
Instead of the semiconductor silicon wafer of Example 1, 50 mm
A wafer (diameter: 6 inches, diameter: 6 inches, in which ink dots having a height of 30 μm are randomly applied to the surface of 10% of all chips of a semiconductor silicon wafer (surface irregularities of about 5 μm) in which the integrated circuit of No. ² is incorporated to the periphery. (Thickness: 600 μm) in the same manner as in Example 1. No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed. No wafer was damaged during the peeling of the adhesive film. No contamination or the like by an adhesive or the like was observed on the surface of the semiconductor silicon wafer after the surface was washed with water. However, when visually observing the backside grinding situation, on the backside side corresponding to the ink dots,
Some dimples (locally thin portions) were observed.
The depth of the dimple was about 4 μm. The results obtained are shown in [Table 1].

[0087]

[Table 1]

Example 7 The preparation of the pressure-sensitive adhesive coating solution of Example 1 was repeated except that the amount of the oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 15% by weight was changed to 0.8 part by weight. An adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1. The adhesive strength of the obtained adhesive film was 280 g / 25 mm. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. No wafer was damaged during grinding,
After the completion of the grinding, one wafer having water infiltration was observed between the wafer and the adhesive film. However, the degree of water intrusion was less than 2 mm from the periphery, and was practically negligible. In addition, no wafer was damaged during the peeling of the adhesive film. However, the total number of chips on the surface of the semiconductor silicon wafer after the surface was washed with water was 0.4%.
% Of chips (chips near the periphery of the wafer) were slightly contaminated by silicon chips and the like accompanying the intrusion of grinding water. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 2].

Example 8 In preparing the pressure-sensitive adhesive coating solution of Example 1, an epoxy-based cross-linking agent [Denacol EX-611, manufactured by Nagase Kasei Kogyo Co., Ltd.] was used instead of the aziridine-based cross-linking agent. Example 1 except that the amount was 4.8 parts by weight and the addition amount of the oxyethylene-oxypropylene copolymer having an ethylene oxide copolymerization ratio of 15% by weight was 11.2 parts by weight.
An adhesive film for grinding a back surface of a semiconductor wafer was manufactured in the same manner as in the above. The adhesive strength of the obtained adhesive film is 110 g /
It was 25 mm. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed. No wafer was damaged during the peeling of the adhesive film. However, some adhesive residue was observed around the high bump electrodes of 0.5% of the total number of chips on the surface of the semiconductor silicon wafer after the surface was washed with water. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 2].

Example 9 In preparing the pressure-sensitive adhesive coating solution of Example 1, the copolymerization ratio of ethylene oxide was 25% instead of the oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 15% by weight. A pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer was produced in the same manner as in Example 1 except that the oxyethylene-oxypropylene copolymer (glycerin, molecular weight: 8,000 (converted from the hydroxyl value and the number of functional groups)) was used in a weight%. did. The adhesive strength of the obtained adhesive film is 1
It was 80 g / 25 mm. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. None of the wafers was damaged during the grinding, but after the grinding was completed, one wafer with water infiltration was observed between the wafer and the adhesive film. However, the degree of water intrusion was less than 2 mm from the periphery, and was practically negligible. In addition, no wafer was damaged during the peeling of the adhesive film. However, slight contamination due to silicon chips and the like caused by infiltration of grinding water was observed in 0.4% of chips (chips near the wafer periphery) with respect to the total number of chips on the surface of the semiconductor silicon wafer after the surface was washed with water. Was. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 2].

Example 10 In the preparation of the pressure-sensitive adhesive coating solution of Example 1, polypropylene glycol [glycerin, molecular weight 3000 Example 1 except that hydroxyl value and the number of functional groups were used.
An adhesive film for grinding a back surface of a semiconductor wafer was manufactured in the same manner as in the above. The adhesive strength of the obtained adhesive film was 180 g /
It was 25 mm. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed. No wafer was damaged during the peeling of the adhesive film. However, some adhesive residue was observed around the high bump electrodes of 0.5% of the total number of chips on the surface of the semiconductor silicon wafer after the surface was washed with water. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 2].

Example 11 In the same manner as in Example 10 except that another type of polypropylene glycol [glycerin, molecular weight 1000 (converted from the hydroxyl value and the number of functional groups)] was used instead of the polypropylene glycol of Example 10, Produced an adhesive film for grinding a back surface of a semiconductor wafer. The adhesive strength of the obtained adhesive film was 180 g / 25 mm. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed. No wafer was damaged during the peeling of the adhesive film. However, on the surface of the semiconductor silicon wafer after the surface was washed with water, the total number of chips was 3.0.
%, A slight adhesive residue was observed around the high bump electrodes. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 2].

[0093]

[Table 2]

Comparative Example 1 An ethylene-vinyl acetate copolymer resin having a Shore D-type hardness of 44 was used instead of the ethylene-vinyl acetate copolymer resin having a Shore D-type hardness of 35 in the production of the base film of Example 1. , A base film having a thickness variation of 1.5% or less was prepared in the same manner as in Example 1 except that the thickness was changed to 350 μm. Is an oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 14% by weight [pentaerythritol type, a molecular weight of 10,000 (from the hydroxyl value and the number of functional groups) instead of the oxyethylene-oxypropylene copolymer of 15% by weight. Conversion)], the addition amount was 7.5 parts by weight, and the thickness of the dried pressure-sensitive adhesive layer was 5 in the preparation of the pressure-sensitive adhesive film.
An adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1 except that the thickness was changed to μm. The adhesive strength of the obtained adhesive film was 230 g / 25 mm. Instead of the semiconductor silicon wafer of Example 1, ink dots having a height of 75 μm were not formed on the surface of 10% of all the chips of a semiconductor silicon wafer (surface unevenness of about 5 μm) in which an integrated circuit of 50 mm ² was incorporated to the periphery. Evaluation was performed in the same manner as in Example 1 using the wafer (diameter: 6 inches, thickness: 600 μm) attached to the operation. One wafer was damaged during grinding. However, after the grinding was completed, no water permeation was observed between the wafer and the adhesive film. No wafer was damaged during the peeling of the adhesive film. However, as a result of observing the surface of the semiconductor silicon wafer with a microscope after the surface was washed with water, microcracks occurred in 10% of the chips. Also, there was no contamination by the adhesive or the like. Further, when the back surface grinding state was visually observed, dimples were observed on the back surface side corresponding to the ink dots. The depth of the dimple was about 15 μm. The results obtained are shown in [Table 3].

Comparative Example 2 In the production of the base film of Example 1, the thickness was 180
Except that the thickness was set to μm, an adhesive film for grinding the back surface of a semiconductor wafer was manufactured in the same manner as in Example 1 except that a base film having a thickness variation of 1.5% or less was manufactured in the same manner as in Example 1. did. The adhesive strength of the obtained adhesive film was 180 g / 25 mm. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. Two wafers were damaged during grinding. However, after the grinding was completed, no water permeation was observed between the wafer and the adhesive film. No wafer was damaged during the peeling of the adhesive film. However, as a result of observing the surface of the semiconductor silicon wafer after washing the surface with a microscope, 15% of the chips had microcracks. Also, there was no contamination by the adhesive or the like. Furthermore, when visually observing the back side grinding situation, on the back side corresponding to the ink dot,
Dimples were observed. The dimple depth is 15 μm
It was about. The results obtained are shown in [Table 3].

Comparative Example 3 An adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1 except that the thickness of the adhesive layer after drying was changed to 20 μm in the preparation of the adhesive film of Example 1. The adhesive strength of the obtained adhesive film is 120 g / 25 m.
m. Instead of the semiconductor silicon wafer of Example 1, 50 mm ² having a high bump electrode having a height of 40 μm
Was evaluated in the same manner as in Example 1 using a semiconductor silicon wafer (diameter: 6 inches, thickness: 600 μm) in which the integrated circuit described above was incorporated into the periphery. Three wafers were damaged due to water intrusion during grinding. After the completion of the grinding, water intrusion of about 1.2 cm from the periphery was observed in the seven unbroken wafers. No wafer was damaged during the peeling of the adhesive film. On the surface of the semiconductor silicon wafer after the surface was washed with water, contamination due to silicon debris and the like caused by infiltration of grinding water into 25% of chips (chips near the wafer periphery) with respect to the total number of chips was observed. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 3].

Comparative Example 4 In the preparation of the pressure-sensitive adhesive coating solution of Example 1, except that the amount of the aziridine-based crosslinking agent was changed to 0.04 parts by weight, the pressure-sensitive adhesive for grinding the back surface of the semiconductor wafer was changed in the same manner as in Example 1. A film was produced. The adhesive strength of the obtained adhesive film is 450.
g / 25 mm. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. No wafer was damaged during the grinding, and no water infiltration was observed between the wafer and the adhesive film after the grinding was completed.
Three wafers were damaged during the peeling of the adhesive film. On the surface of the semiconductor silicon wafer after the surface was washed with water, glue residue was observed around the high bump electrodes of 21% of the chips with respect to the total number of chips. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 3].

Comparative Example 5 In the production of the base film of Example 1, the thickness was 300
A base film having a thickness variation of within 1.5% was prepared in the same manner as in Example 1 except that the thickness was set to μm, and an epoxy-based crosslinking agent was used instead of the aziridine-based crosslinking agent in preparing the adhesive coating solution. Using [Negase Kasei Kogyo Co., Ltd., Denacol EX-611], the addition amount was 7.2 parts by weight, and the addition amount of the oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 15% by weight. 9.
An adhesive film for grinding the back surface of a semiconductor wafer was produced in the same manner as in Example 1 except that the amount was 0 parts by weight. The adhesive strength of the obtained adhesive film was 110 g / 25 mm.
The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. 2 due to water intrusion during grinding
One wafer was damaged. No damage after grinding 8
Of the three wafers, water intrusion of about 1 cm was observed from the periphery of three wafers, and water intrusion of less than 2 mm was observed in five wafers. No wafer was damaged during the peeling of the adhesive film. On the surface of the semiconductor silicon wafer after the surface was washed with water, contamination was observed on 12% of chips (chips near the periphery of the wafer) due to infiltration of grinding water with respect to the total number of chips. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 3].

[0099]

[Table 3]

Comparative Example 6 In the production of the base film of Example 1, the thickness was 300
A base film having a thickness variation of 1.5% or less was prepared in the same manner as in Example 1 except that the thickness was changed to μm. Parts by weight, and the copolymerization ratio of ethylene oxide is 1
The same as Example 1 except that the addition amount of the oxyethylene-oxypropylene copolymer of 5% by weight was 8.0 parts by weight, and the thickness of the pressure-sensitive adhesive layer after drying was 30 μm in the preparation of the pressure-sensitive adhesive film. An adhesive film for grinding a back surface of a semiconductor wafer was produced by the method. The adhesive strength of the obtained adhesive film was 70 g / 25 mm. The same method as in Example 1 was evaluated using the same semiconductor silicon wafer as in Example 3 in place of the semiconductor silicon wafer of Example 1. One wafer was damaged during grinding due to water intrusion. After grinding, three of the nine wafers that were not damaged
Water penetration of about 1 cm was observed from the periphery, and water penetration of less than 2 mm was observed in six wafers. No wafer was damaged during the peeling of the adhesive film. On the surface of the semiconductor silicon wafer after the surface was washed with water, slight contamination due to silicon chips and the like caused by infiltration of grinding water was observed in 12% of chips (chips around the wafer) with respect to the total number of chips. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 4].

Comparative Example 7 In the production of the base film of Example 1, the thickness was 300
A base film having a thickness variation of 1.5% or less was prepared in the same manner as in Example 1 except that the thickness was set to μm, and the amount of the aziridine-based crosslinking agent was adjusted to 4 parts by weight in the preparation of the adhesive coating solution. An adhesive film for grinding a back surface of a semiconductor wafer in the same manner as in Example 1 except that the amount of the oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 15% by weight was changed to 0.22 parts by weight. Was manufactured. The adhesive strength of the obtained adhesive film is 250 g / 25 m.
m. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. During the grinding, three wafers were damaged due to water intrusion. After the completion of the grinding, water intrusion of about 1.2 cm from the periphery was observed in the seven unbroken wafers. No wafer was damaged during the peeling of the adhesive film. On the surface of the semiconductor silicon wafer after the surface was washed with water, 23% of chips (chips near the periphery of the wafer) with respect to the total number of chips were contaminated by silicon debris and the like accompanying grinding water intrusion. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 4].

Comparative Example 8 In the production of the base film of Example 1, the thickness was set to 300
A base film having a thickness variation of within 1.5% was prepared in the same manner as in Example 1 except that the thickness was set to μm, and an epoxy-based crosslinking agent was used instead of the aziridine-based crosslinking agent in preparing the adhesive coating solution. Using [Denacol EX-611, manufactured by Nagase Kasei Kogyo Co., Ltd.], the addition amount was 3.6 parts by weight, and the addition amount of the oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 15% by weight was used. 15
An adhesive film for grinding the back surface of a semiconductor wafer was manufactured in the same manner as in Example 1 except that the amount was changed to parts by weight. The adhesive strength of the obtained adhesive film was 120 g / 25 mm. Example 1 Using the same semiconductor silicon wafer as Example 1
Was evaluated in the same manner as described above. There is no wafer damaged during grinding, and after grinding, between the wafer and the adhesive film,
No water intrusion was observed. No wafer was damaged during the peeling of the adhesive film. However, on the surface of the semiconductor silicon wafer after the surface was washed with water, glue residue was observed around the high bump electrodes of 21% of the chips with respect to the total number of chips. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 4].

Comparative Example 9 In the preparation of the adhesive coating solution, instead of the oxyethylene-oxypropylene copolymer having an ethylene oxide copolymerization ratio of 15% by weight, an oxyethylene copolymer having an ethylene oxide copolymerization ratio of 40% by weight was used. An adhesive film for grinding the back surface of a semiconductor wafer was prepared in the same manner as in Example 1 except that an oxypropylene copolymer [glycerin, molecular weight 6200 (converted from the hydroxyl value and the number of functional groups)] was used. The adhesive strength of the obtained adhesive film is 180 g / 2.
5 mm. The same evaluation as in Example 1 was performed using the same semiconductor silicon wafer as in Example 1. One wafer was damaged during grinding due to water intrusion. After grinding,
Of the nine wafers that were not damaged, two of the wafers were observed to have water infiltration of about 1 cm from the periphery.
Water ingress of less than mm was observed. No wafer was damaged during the peeling of the adhesive film. 9% of the total number of chips on the surface of the semiconductor silicon wafer after washing the surface with water
The chip (chip near the wafer periphery) was contaminated by silicon chips and the like accompanying the infiltration of grinding water. Further, when the backside grinding condition was visually observed, no dimple was found. The results obtained are shown in [Table 4].

[0104]

[Table 4]

<Consideration of Examples> [Shore D-type hardness of base film (Example 4, Comparative Example 1)] When the Shore D-type hardness of the base film exceeds 40, microcracks are generated and grinding occurs. Then, the wafer is damaged, and dimples of a level (5 μm or more) which pose a problem in practical use are generated. [Substrate Thickness (Example 6, Comparative Example 2)] When the thickness of the substrate film approaches the lower limit of 150 μm, which is the lower limit defined in the present invention, dimples tend to occur. The dimples formed in this case have a depth of about 4 μm, so that it is generally said that there is no practical problem. Further, the thickness (B) of the base film is 180 μm, which is the range limited by the present invention, but the relationship with the height (A) of the protrusions present on the wafer surface does not satisfy 4A ≦ B. Wafer damage,
Causes microcracks. [Adhesive Layer Thickness (Example 1, Comparative Example 3)] When the thickness of the adhesive layer is less than the lower limit of 30 μm defined by the present invention,
Water penetrates between the wafer surface and the pressure-sensitive adhesive layer to damage the wafer being ground or to cause contamination of chips by grinding chips. However, microcracks and dimples did not occur. On the other hand, as described above, the thickness and hardness of the base film are important factors for the occurrence of dimples and microcracks and the prevention of damage to the wafer during grinding. [Adhesive Strength (Comparative Example 6)] When the adhesive strength is less than the lower limit of 80 g / 25 mm defined by the present invention, water enters between the wafer surface and the adhesive layer, and the wafer is damaged during back surface grinding. Or chip contamination due to grinding debris. [Content of alkylene glycol polymer (Example 7,
8, Comparative Examples 7, 8)] Example 7 is an example in which the content of the alkylene glycol-based polymer is close to the lower limit of 1 part by weight, which is limited in the present invention. From this result, it can be seen that even when the content of the alkylene glycol-based polymer is small and the adhesive strength is within the range limited in the present application, water tends to easily enter between the wafer surface and the adhesive layer. . Further, if the content is less than 1 part by weight, the wafer may be damaged during grinding due to intrusion of water, or chips may be contaminated by grinding chips and the like.

Example 8 is an example in which the content of the alkylene glycol-based polymer was set close to the upper limit of 30 parts by weight according to the present invention. From this result, it can be seen from Example 8 that when the content of the alkylene glycol-based polymer is large, contamination due to adhesive residue tends to easily occur on the chip (particularly around the bump). If the content exceeds 30 parts by weight, chip contamination becomes remarkable, chip yield is remarkably reduced, and a practical problem arises. [Ethylene oxide copolymerization ratio (Example 9, Comparative example 9)] When the ethylene oxide copolymerization ratio in the alkylene glycol-based polymer is close to the upper limit of 30% by weight as defined in the present invention, the wafer surface and Water easily enters between the adhesive layers. If the copolymerization ratio of ethylene oxide exceeds 30% by weight, the wafer may be damaged during back surface grinding due to intrusion of water, or chips may be contaminated by grinding chips and the like. [Molecular weight of alkylene glycol polymer (Example 1)
0, 11)] When the molecular weight of the alkylene glycol polymer is low, contamination tends to occur. [Content of cross-linking agent (Example 3, Example 5, Comparative Examples 4 and 5)] The content of the cross-linking agent is 15 which is the upper limit defined by the present invention.
When the amount exceeds the weight part, even if the adhesive strength is within the range limited by the present invention, water infiltrates between the wafer surface and the adhesive layer during the backside grinding of the wafer, and the wafer is removed during the grinding. The chip is damaged or the chip is contaminated by grinding chips. When the content of the cross-linking agent is less than 0.5 parts by weight, contamination due to adhesive residue occurs on the chip (particularly around the bump). Further, Comparative Example 4
Since the adhesive strength exceeds 400 g / 25 mm, the wafer is damaged when the adhesive film is peeled off.

[0107]

According to the present invention, when grinding the back surface of a semiconductor wafer, projections having a height of 10 to 100 μm, such as high bump electrodes and defective circuit identification marks, are formed on the surface of the semiconductor wafer. However, not only does the wafer not be damaged due to the grinding stress on the back surface, but also does not cause chip-level damage (microcracks). In addition, since there is no glue residue after peeling the adhesive film, in addition to not contaminating the surface of the semiconductor wafer,
There is no generation of dimples due to the protrusions. further,
There is no breakage of the wafer and no contamination of the wafer surface due to water entering between the surface of the semiconductor wafer and the adhesive layer.
As a matter of course, there is an effect that the process can be simplified without using a resist.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Fukumoto 2-1-1 Tango-dori, Minami-ku, Nagoya-shi, Aichi Pref. Mitsui Toatsu Chemicals Co., Ltd. (72) Inventor Saku Izukawa 2 Tango-dori, Minami-ku, Nagoya-shi, Aichi 1 chome Mitsui Toatsu Chemical Co., Ltd.

Claims (14)

[Claims] 1. A method of grinding a back surface of a semiconductor wafer, comprising attaching an adhesive film to a circuit forming surface of the semiconductor wafer, grinding the back surface of the semiconductor wafer, and then peeling the adhesive film. The surface has at least one type of protrusion having a height (A) of 10 to 100 μm selected from an electrode and a defective circuit identification mark, and the adhesive film has a Shore D type hardness of 40 or less and a thickness (B) of 150 to 150 μm.
On one surface of a substrate film having a thickness of 500 μm (where 4A ≦ B), (a) 100 parts by weight of an alkyl acrylate-based pressure-sensitive adhesive polymer having a functional group capable of reacting with a crosslinking agent, (b) in one molecule 0.5 to 15 parts by weight of a crosslinking agent having two or more crosslinking reactive functional groups, and (c) an alkylene glycol polymer having 3 to 4 carbon atoms in the alkylene group,
And an oxyethylene-alkylene group having an ethylene oxide copolymerization ratio of 30% by weight or less has 3 to 4 carbon atoms.
At least one selected from oxyalkylene copolymers of
A pressure-sensitive adhesive layer having a thickness (C) of 30 to 100 μm (where 0.6A ≦ C) containing 1 to 30 parts by weight per 100 parts by weight of the sum of (a) and (b) of various alkylene glycol-based polymers. SUS304 formed and formed of the adhesive film
-A method of grinding the back surface of a semiconductor wafer, wherein the adhesive strength to the BA plate is 80 to 400 g / 25 mm. 2. The height (A) of the projections is 25 to 100 μm.
2. The method for grinding a back surface of a semiconductor wafer according to claim 1, wherein m is m. 3. The method according to claim 1, wherein the alkylene glycol-based polymer is at least one polymer selected from propylene glycol and an oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 30% by weight or less. The method for grinding a back surface of a semiconductor wafer according to claim 1, wherein: 4. The semiconductor wafer according to claim 1, wherein the copolymerization ratio of ethylene oxide of the oxyalkylene copolymer having 3 to 4 carbon atoms in the oxyethylene-alkylene group is 20% by weight or less. Back grinding method. 5. The method according to claim 1, wherein the content of the alkylene glycol-based polymer is 5 to 20 parts by weight. 6. The backside grinding of a semiconductor wafer according to claim 1, wherein the molecular weight of the alkylene glycol polymer is 2,000 to 20,000 (converted from the hydroxyl value and the number of functional groups). Method. 7. The backside grinding of a semiconductor wafer according to claim 1, wherein the molecular weight of the alkylene glycol-based polymer is 6,000 to 20,000 (converted from the hydroxyl value and the number of functional groups). Method. 8. An adhesive film for grinding a back surface of a semiconductor wafer which is affixed to a circuit formation surface when grinding the back surface of the semiconductor wafer, wherein the circuit formation surface of the semiconductor wafer is selected from an electrode and a defective circuit identification mark. At least one
Seed height (A) has protrusions of 10 to 100 μm, and the pressure-sensitive adhesive film has a Shore D type hardness of 40 or less, thickness (B)
On one surface of a substrate film having a size of 150 to 500 μm (4A ≦ B), (a) an alkyl acrylate pressure-sensitive adhesive polymer 10 having a functional group capable of reacting with a crosslinking agent
0 parts by weight, (b) 0.5 to 15 parts by weight of a crosslinking agent having two or more crosslinking reactive functional groups in one molecule, and (c) alkylene glycol having 3 to 4 carbon atoms in the alkylene group. And at least one alkylene glycol-based polymer selected from oxyalkylene copolymers having 3 to 4 carbon atoms in an oxyethylene-alkylene group having a copolymerization ratio of ethylene oxide of 30% by weight or less ( B) containing 1 to 30 parts by weight per 100 parts by weight of the sum of (b)
A pressure-sensitive adhesive layer having a thickness (C) of 30 to 100 μm (where 0.6 A ≦ C) is formed, and SUS3 of the pressure-sensitive adhesive film is formed.
Adhesive strength to 04-BA plate is 80-400g / 25m
m, an adhesive film for grinding a back surface of a semiconductor wafer. 9. The height (A) of the projections is 25 to 100 μm.
The pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer according to claim 8, wherein m is m. 10. The method according to claim 1, wherein the alkylene glycol-based polymer is at least one polymer selected from propylene glycol and an oxyethylene-oxypropylene copolymer having a copolymerization ratio of ethylene oxide of 30% by weight or less. The adhesive film for grinding a back surface of a semiconductor wafer according to claim 8. 11. The semiconductor wafer according to claim 8, wherein the oxyethylene-alkylene group has an oxyalkylene copolymer having 3 to 4 carbon atoms and an ethylene oxide copolymerization ratio of not more than 20% by weight. Adhesive film for back grinding. 12. The adhesive film for grinding a back surface of a semiconductor wafer according to claim 8, wherein the content of the alkylene glycol-based polymer is 5 to 20 parts by weight. 13. The backside grinding of a semiconductor wafer according to claim 8, wherein the molecular weight of the alkylene glycol-based polymer is 2,000 to 20,000 (converted from the hydroxyl value and the number of functional groups). Adhesive film. 14. The backside grinding of a semiconductor wafer according to claim 8, wherein the molecular weight of the alkylene glycol polymer is 6,000 to 20,000 (converted from the hydroxyl value and the number of functional groups). Adhesive film.