JPH09148279A - Semiconductor wafer back face grinding adhesive film and its using method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a wafer with a strong adhesive force at the time of grinding a back face of a semiconductor wafer and reduce an adhesive force by cooling or heating at the time of separating. SOLUTION: This embodiment is a semiconductor wafer back face grinding adhesive film provided with an adhesives layer on one face of a base film, and the adhesives layer is formed with adhesives containing criticalline high polymer. The adhesive force is set to be 150 to 2,000g/25mm at least in a part of temperature range at a temperature of -10 deg.C or more, or only at least in a part of temperature range at a temperature of 70 deg.C or less, and further to be less than 150g/25mm in a temperature range below -10 deg.C or above 70 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive film for grinding a back surface of a semiconductor wafer and a method of using the same. Specifically, it is affixed to the surface of the semiconductor wafer such as a silicon wafer on which the integrated circuit is incorporated (hereinafter referred to as the wafer front surface), and the other surface of the semiconductor wafer (hereinafter referred to as the wafer back surface) is ground, and the grinding is completed. The present invention relates to an adhesive film for backside grinding of a semiconductor wafer, which is to be peeled off later, and an adhesive film for backside grinding of a semiconductor wafer, which has an adhesive layer whose adhesive strength changes according to temperature changes, and a method of using the same.

[0002]

2. Description of the Related Art Generally, a semiconductor integrated circuit is formed by slicing a high-purity silicon single crystal or the like into a wafer, and then forming an integrated circuit on the surface by ion implantation, etching, or the like.
Further, the back surface of the wafer is ground by grinding, polishing, lapping, etc., and the thickness of the wafer is set to 100-60.
It is manufactured by a method of dicing into chips after thinning to about 0 μm. In these steps, a method of protecting the semiconductor wafer by attaching the adhesive film to the wafer surface via the adhesive layer to prevent breakage of the semiconductor wafer when grinding the back surface of the semiconductor wafer or to facilitate the grinding process is known. Used.

When the adhesive film is attached to the surface of the wafer and the back surface of the wafer is ground, one of the properties required for the adhesive film is an adhesive property to the surface of the semiconductor wafer. Specifically, it is necessary to have a high adhesive force that does not cause peeling when the wafer back surface is ground, and a low adhesive force that has good workability during peeling and does not damage the semiconductor wafer.

However, in recent years, as the capacity, the degree of integration, the mass production of semiconductor chips, and the size and weight of the semiconductor chips have been increased, the diameter of the semiconductor wafer has tended to increase, and the thickness of the semiconductor wafer has tended to decrease further. It has become difficult to maintain a balance between surface protection during grinding of the back surface of the semiconductor wafer, workability during peeling, and non-breakability.

As a method for solving these problems, for example, Japanese Patent Application Laid-Open No. 60-189938 discloses a method of polishing a back surface of a semiconductor wafer by attaching a pressure-sensitive adhesive film to the surface of the wafer and polishing the back surface of the wafer. Then, in the method for protecting a semiconductor wafer in which this adhesive film is peeled off, the pressure-sensitive adhesive film has a light-transmitting support and a light-sensitive material having a property of being hardened by light irradiation provided on the support to form a three-dimensional network. A method for protecting a semiconductor wafer, comprising a pressure-sensitive adhesive layer and irradiating the adhesive film with light after polishing and before peeling the adhesive film, is disclosed.

However, the pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) disclosed in the present invention, which has the property of being cured by light irradiation and of forming a three-dimensional network, is a pressure-sensitive adhesive layer which is polymerized by radical polymerization. When oxygen enters between the adhesive layer and the adhesive layer, the curing reaction does not proceed sufficiently due to the effect of inhibiting the polymerization of oxygen. May be contaminated. There are complicated irregularities on the surface of the semiconductor wafer on which the integrated circuit is formed, and it is impossible to attach the semiconductor wafer without sandwiching air (oxygen) at all. In addition, a large-scale apparatus and a large cost are required to create a system from which oxygen is removed for application. Contamination caused by such an adhesive layer can be removed by washing with a solvent or the like, but in most cases,
At present, it cannot be completely removed.

In recent years, with the increase in diameter and thickness of semiconductor wafers and the higher performance of ICs, the contamination of the front surface of the semiconductor wafer is reduced, and the wafer is not damaged when the back surface of the wafer is ground or the adhesive film is peeled off. Adhesive films for backside grinding of semiconductor wafers and methods of using the same are desired.

[0008]

In view of the above points, an object of the present invention is to protect the wafer surface with a strong adhesive force when grinding the back surface of a semiconductor wafer, and to cool or heat it when peeling it. Of the semiconductor wafer can be peeled without damaging the semiconductor wafer, and there is almost no contaminant adhering to the surface of the semiconductor wafer from the adhesive layer after peeling. An object of the present invention is to provide a pressure-sensitive adhesive film for grinding the back surface of a semiconductor wafer that can be used for higher performance of ICs and a method of using the same.

[0009]

Means for Solving the Problems As a result of intensive studies by the present inventors, a pressure-sensitive adhesive layer containing a crystalline polymer and having a property that the pressure-sensitive adhesive force changes drastically with a temperature change is a base film. Among the adhesive films for grinding the back surface of the semiconductor wafer formed on one side, an adhesive film having specific adhesive force characteristics can achieve the above-mentioned object, increasing the diameter of the semiconductor wafer,
The present invention has been found out that it can be used as a pressure-sensitive adhesive film for grinding the back surface of a semiconductor wafer, which can be applied to thinner layers and higher performance of ICs.

Specifically, by containing a crystalline polymer in the pressure-sensitive adhesive, the pressure-sensitive adhesive exhibits a sufficient pressure-sensitive adhesive force to protect the wafer surface only in a specific temperature range, and a low temperature region or a high temperature region outside the temperature range. Then, it was found that the adhesive strength is lowered, and further that the above-mentioned object can be achieved by performing the adhesion and polishing treatment in the temperature range and performing the peeling treatment outside the temperature range, and thus the present invention was completed. It was

That is, the first invention of the present invention is a pressure-sensitive adhesive film for backside grinding of a semiconductor wafer, wherein a pressure-sensitive adhesive layer is provided on one surface of a substrate film, the pressure-sensitive adhesive layer containing a crystalline polymer. The adhesive force of the pressure-sensitive adhesive film for grinding the back surface of a semiconductor wafer is 150 to 2,000 g / 25 mm only in at least a part of the temperature range A to B ° C. (A <B) at a temperature of −10 ° C. or higher. ,and,
A pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer, wherein the pressure-sensitive adhesive film is less than 150 g / 25 mm in a temperature range of less than A ° C.

A second invention of the present invention is a pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer, wherein a pressure-sensitive adhesive layer is provided on one surface of a base film, the pressure-sensitive adhesive layer being formed of a pressure-sensitive adhesive containing a crystalline polymer. The adhesive force of the adhesive film for backside grinding of the semiconductor wafer is 150 only in at least a part of the temperature range E to F ° C (E <F) at a temperature of 70 ° C or less.
A pressure-sensitive adhesive film for backside grinding of a semiconductor wafer, wherein the pressure-sensitive adhesive film is 2,000 g / 25 mm and less than 150 g / 25 mm in a temperature range exceeding F ° C.

A third aspect of the present invention is a method of using a pressure-sensitive adhesive film for backside grinding of a semiconductor wafer, which is adhered to the front surface of a backside surface of a semiconductor wafer and is peeled off after the grinding is completed.
The pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer has a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive containing a crystalline polymer on one surface of a base film, and the pressure-sensitive adhesive force is at least part of at a temperature of -10 ° C or higher. It is 150 to 2,000 g / 25 mm only in the temperature range A to B ° C (A <B), and less than 150 g / 25 mm in the temperature range lower than A ° C, and at least included in the temperature range A to B ° C. Partial temperature range C to D ° C (A <C ≦ D <B, 1 ≦ C ≦ D ≦
In 60), the adhesive film is attached to the wafer surface,
An adhesive film for grinding a back surface of a semiconductor wafer, which comprises grinding a back surface of a semiconductor wafer while applying cooling water in a temperature range of C to D ° C., and then peeling the adhesive film in a state of being cooled to less than A ° C. How to use.

A fourth invention of the present invention is a method of using a pressure-sensitive adhesive film for backside grinding of a semiconductor wafer, which is adhered to the front surface of the backside of a semiconductor wafer when the backside is ground, and is peeled off after finishing the grinding. Pressure-sensitive adhesive film has a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive containing a crystalline polymer on one surface of a substrate film, and the pressure-sensitive adhesive force is at least part of a temperature range E to F ° C at a temperature of 70 ° C or lower. (E <F)
150-2,000 g / 25 mm only in
And 150g / 25m in the temperature range over F ° C
m is less than m and at least a part of the temperature range G to H ° C included in the temperature range of E to F ° C (E <G ≦ H <F, 1 ≦ G).
The adhesive film is adhered to the wafer surface in
Use of a pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer, which comprises grinding a back surface of a semiconductor wafer while applying cooling water in a temperature range of ° C, and then peeling the pressure-sensitive adhesive film while being heated to a temperature higher than F ° C. Is the way.

The adhesive film for grinding a back surface of a semiconductor wafer of the present invention (hereinafter referred to as an adhesive film) adheres to the front surface of a semiconductor wafer with a strong adhesive force to protect it when grinding the back surface of the semiconductor wafer. Prevent damage etc. Also,
At the time of peeling, since the adhesive force can be reduced by cooling or heating, peeling can be facilitated and damage to the semiconductor wafer due to peeling stress can be prevented. further,
After the adhesive film is peeled off, contaminants due to the adhesive layer hardly adhere to the surface of the wafer, and the effect of preventing contamination of the surface of the wafer is also excellent. Therefore, according to the present invention, there is provided a pressure-sensitive adhesive film for grinding the back surface of a semiconductor wafer and a method of using the same, which can cope with an increase in the diameter of a semiconductor wafer, a reduction in the layer thickness thereof, and a high performance of an IC.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The pressure-sensitive adhesive film of the present invention is obtained by applying a pressure-sensitive adhesive solution or emulsion liquid (hereinafter referred to as pressure-sensitive adhesive) containing a component constituting a pressure-sensitive adhesive layer to a base film,
It is manufactured by drying to form an adhesive layer. In this case, it is preferable to attach a release film to the surface of the pressure-sensitive adhesive layer in order to protect the pressure-sensitive adhesive layer from contamination caused by the environment. Also, a method of applying a pressure-sensitive adhesive on one surface of a release film and drying to form a pressure-sensitive adhesive layer, then attaching a substrate film to the surface of the pressure-sensitive adhesive layer and transferring the pressure-sensitive adhesive layer to the substrate film side It is also manufactured by In this case, there is an advantage that the surface of the pressure-sensitive adhesive layer is not contaminated when the pressure-sensitive adhesive layer is dried.

Which surface of the base film or the release film is to be coated with the pressure sensitive adhesive coating liquid or the like is determined in consideration of heat resistance, surface tension of the base film and the release film, contamination of the semiconductor wafer surface, and the like. Decide. 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. If the heat resistance is the same or the base film is better, a pressure-sensitive adhesive layer is provided on the surface of the base film, and a release film is attached to the surface. But,
Considering that the adhesive film is attached to the semiconductor wafer surface via the surface of the adhesive layer that is exposed when the release film is peeled off, in order to prevent contamination of the semiconductor wafer surface with the adhesive layer, heat-resistant A method is preferred in which a release film having good properties is used, and a pressure-sensitive adhesive coating solution is applied to the surface thereof and dried to form a pressure-sensitive adhesive layer.

The method of using the pressure-sensitive adhesive film for grinding the back surface of a semiconductor wafer according to the present invention is such that it is adhered to the surface of a semiconductor wafer via a pressure-sensitive adhesive layer in a specific temperature range, the front surface of the wafer is protected and the back surface of the wafer is ground. Next, it is a method of cooling or heating to outside the temperature range to bring the temperature of the pressure-sensitive adhesive layer out of the temperature range, and then peeling.

First, the method for producing the pressure-sensitive adhesive film of the present invention will be described. The pressure-sensitive adhesive film of the present invention is usually a method in which a pressure-sensitive adhesive is applied to one surface of a base film and dried to form a pressure-sensitive adhesive layer, or a pressure-sensitive adhesive is applied to one surface of a release film and dried to obtain a pressure-sensitive adhesive. After the layer is formed, it is produced by a method of transferring to one surface of the base film.

As a method for applying the pressure-sensitive adhesive to one surface of the substrate film or the release film, conventionally known coating methods such as roll coater method, reverse roll coater method, gravure roll coater method, bar coater method and comma coater are used. Method, die coater method, etc. can be adopted. In addition to the method of applying the pressure-sensitive adhesive, a method of co-extruding the base film and the pressure-sensitive adhesive layer can also be mentioned. These methods can be appropriately selected depending on the properties of the pressure-sensitive adhesive layer, the base film, and the like.

Examples of the base film used for the pressure-sensitive adhesive film of the present invention include films produced from synthetic resins, natural rubbers, synthetic rubbers and the like. To give a concrete example,
Ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, polybutadiene, soft vinyl chloride resin, polyolefin, polyester, polyamide, ionomer, and other resins, and their copolymer elastomers, and diene, nitrile, and silicone And films of synthetic rubber such as acryl based. The base film may be a monolayer or a laminate.

The thickness of the base film affects the prevention of breakage of the wafer when the back surface of the semiconductor wafer is ground, the workability of sticking to the front surface of the wafer and the workability of peeling. From this viewpoint, the thickness of the base film is usually 10 to 2000 μm.
It is. It is preferably 100 to 300 μm. The thickness accuracy of the base film affects the thickness accuracy of the adhesive film, which in turn affects the thickness accuracy of the semiconductor wafer after backside grinding. Therefore, it is preferable that the base film is formed with an accuracy of ± 5 μm or less in the above thickness range. More preferably, it is within ± 3 μm.

Considering prevention of damage to the semiconductor wafer when the back surface is ground, the hardness of the base film is ASTM-D.
An elastic film obtained by forming a resin having a Shore D-type hardness of 40 or less specified in -2240 into a film shape, for example, an ethylene-vinyl acetate copolymer film, a polybutadiene film and the like are preferably used. in this case,
On the surface of the base film opposite to the surface on which the pressure-sensitive adhesive layer is provided, a film harder than this, specifically, a film formed by processing a resin having a Shore D-type hardness of more than 40 into a film may be laminated. preferable. Thereby, the rigidity of the pressure-sensitive adhesive film is increased, and the sticking workability and the peeling workability are improved.

In addition, when the back surface of the semiconductor wafer is ground and the etching process with an acid is subsequently performed, and when an adhesive film for grinding the back surface of the semiconductor wafer is attached to protect the front surface of the semiconductor wafer, the acid resistance is reduced. It is preferable to use a substrate film having excellent properties. An acid resistant film may be laminated on the side of the base film opposite to the adhesive layer. Examples of the acid resistant film include polypropylene film and the like. In order to improve the adhesive strength between the substrate film and the pressure-sensitive adhesive layer, it is preferable to subject the surface of the substrate 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.

Examples of the release film provided on the pressure-sensitive adhesive surface of the pressure-sensitive adhesive film of 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 20.
00 μm. Preferably it is 30 to 100 μm.

The pressure-sensitive adhesive layer provided on the pressure-sensitive adhesive film of the present invention contains a crystalline polymer, and within a specific temperature range,
It is formed of an adhesive having an adhesive force sufficient to protect the surface of the semiconductor wafer. Specific examples of the adhesive include, for example, Japanese Patent Publication No. 6-510548 (International Publication Number: W).
The adhesives described in O92 / 13901) are preferred. That is, it is a mixture of a pressure-sensitive adhesive composition that is usually used for a pressure-sensitive adhesive layer such as a pressure-sensitive adhesive tape (hereinafter referred to as a normal pressure-sensitive adhesive) and a crystalline polymer. Usually, the mixing ratio is preferably in the range of about 0.3 to 50 parts by weight of the crystalline polymer with respect to about 50 to 99.7 parts by weight of the usual adhesive. More preferably, a conventional adhesive of about 65-
The amount of the crystalline polymer is about 5 to 35 parts by weight with respect to 95 parts by weight, and more preferably, the ordinary pressure sensitive adhesive is about 70 to 90 parts by weight.
The crystalline polymer is about 10 to 30 parts by weight, and most preferably about 20 to about 30 parts by weight of the crystalline polymer to about 70 to 80 parts by weight of the conventional adhesive. is there.

Usual adhesives include natural rubber adhesives, styrene-butadiene copolymer adhesives,
And synthetic rubber adhesives such as acrylic adhesives such as polyacrylic acid alkyl esters having a C 1 to C 9 alkyl group or copolymers thereof, and the like, which may be used alone or in a mixture of two or more kinds. It may be.

These ordinary pressure-sensitive adhesives preferably have a functional group which can serve as a crosslinking point when it is necessary to adjust the cohesive strength and adhesive strength characteristics by using a crosslinking agent. Examples of the functional group include a carboxyl group, a hydroxyl group and an amino group. Further, a plasticizer, a tackifier, a stabilizer and the like may be appropriately mixed with these ordinary pressure-sensitive adhesives.

Examples of the crystalline polymer include a side chain crystalline polymer and a main chain crystalline polymer. The former is more preferable in consideration of the dependence of the adhesive strength on the temperature change. The side chain crystalline polymer is one or more kinds of monomers having a polymerizable carbon-carbon double bond, and a monomer having a side chain that can be crystallized when polymerized (hereinafter, A polymer or copolymer obtained by polymerizing SCC monomer), and a copolymer obtained by copolymerizing SCC monomer and other monomer copolymerizable with SCC monomer Polymers may be mentioned.
The SCC monomers may be used alone or in combination of two or more. Further, other monomers copolymerizable with the SCC monomer may be used as a mixture of two or more kinds.

These SCC monomers have 10 carbon atoms.
Acrylates, methacrylates, acrylamide derivatives, methacrylamide derivatives having ˜50 aliphatic groups,
Vinyl ether derivative, vinyl ester derivative, acrylate, methacrylate, acrylamide derivative, methacrylamide derivative, vinyl ether derivative, vinyl ester derivative, and C8 to 8 having at least a part of fluorine-substituted aliphatic group having 6 to 50 carbon atoms 24
At least one kind of monomer selected from the styrene derivatives having an alkyl group and the like.

Of these, acrylates, methacrylates, acrylamide derivatives, methacrylamide derivatives and the like having a linear aliphatic group having 14 to 50 carbon atoms are preferable in consideration of the temperature dependence of adhesive properties, polymerization reactivity and the like. More preferred are acrylates, methacrylates, acrylamide derivatives, and methacrylamide derivatives having a linear aliphatic group having 14 to 22 carbon atoms. SCC above
Other monomers that can be copolymerized with the monomer have a carbon number of 1
Examples thereof include alkyl acrylates or methacrylic acid alkyl esters having an alkyl group of ˜9, vinyl acetate, acrylonitrile, styrene and the like.

Considering the case where it is necessary to adjust the cohesive strength and adhesive strength characteristics using a cross-linking agent, the side chain crystalline polymer is copolymerized with a monomer having a functional group capable of serving as a cross-linking point. It is preferable. As a monomer having a functional group that can be a crosslinking point, acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl ester, mesaconic acid monoalkyl ester, citraconic acid monoalkyl Esters, fumaric acid monoalkyl ester, maleic acid monoalkyl ester, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tertiary-butylaminoethyl acrylate, tertiary-butylaminoethyl methacrylate and the like can be mentioned. .

Further, it has a self-crosslinking functional group such as glycidyl acrylate, glycidyl methacrylate, isocyanate ethyl acrylate, isocyanate ethyl methacrylate, 2- (1-aziridinyl) ethyl acrylate, and 2- (1-aziridinyl) ethyl methacrylate. Further, a monomer, or a polyfunctional monomer such as divinylbenzene, vinyl acrylate, vinyl methacrylate, allyl acrylate, and allyl methacrylate may be combined.

Considering the adhesive property of the adhesive film,
The side chain crystalline polymer is preferably synthesized such that the total mass of the crystalline side chains is 50% by weight or more of the total mass of the crystalline polymer. More preferably, it is 65% by weight or more.

As a method for polymerizing the side chain crystalline polymer, various known methods such as a solution polymerization method, a suspension polymerization method and an emulsion polymerization method can be adopted. Examples of the polymerization reaction mechanism include radical polymerization, anionic polymerization, and cationic polymerization.
In consideration of the production cost of the pressure-sensitive adhesive, it is preferable to polymerize by radical polymerization. When polymerized by a radical polymerization reaction, as a radical polymerization initiator, an organic compound such as benzoyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, di-tertiary-butyl peroxide, di-tertiary-amyl peroxide, etc. Inorganic peroxides such as peroxides, ammonium persulfate, potassium persulfate and sodium persulfate, 2,2′-azobisisobutyronitrile, 2,
2'-azobis-2-methylbutyronitrile, 4,4 '
—Azo compounds such as azobis-4-cyanovaleric acid and the like. These are appropriately selected depending on the properties of the obtained side chain crystalline polymer and the polymerization method.

As the side chain crystalline polymer, in addition to the above polymers, polymers having a crystalline side chain may be used, such as polyester type, polyether type, polyamide type, polyethyleneimine type, and silicone type polymers. Etc. Also,
As the main chain crystalline polymer, water-insoluble polyalkylene oxide, lower alkyl polyester, polyamide, nylon, polytetrahydrofuran, and general formula (1)

[0037]

Embedded image (In the formula, R is hydrogen, a linear or branched alkyl group having 1 to 12 carbon atoms, and n is an integer of 5 to 50,000)
And a poly-α-olefin having a structure represented by In the general formula (1) [Chemical formula 1], preferably,
R is a linear or branched alkyl group having 1 to 8 carbon atoms.

Considering the temperature dependence of the adhesive property and the contamination of the surface of the semiconductor wafer, the crystalline polymer is 3,50.
Those having a molecular weight of about 0 to 900,000 are preferable. The molecular weight of these crystalline macromolecules particularly affects the temperature dependence of the adhesive property, and the molecular weight causes a temperature range (adhesive strength sufficient to protect the surface of the wafer when adhered to the surface of the wafer). Hereinafter, this temperature range tends to be different in the temperature range of A to B ° C or the temperature range of E to F ° C. For example, as the molecular weight of the crystalline polymer increases, the upper limit B or F of the temperature range tends to increase. Particularly, in the case of the second and fourth inventions, when the molecular weight becomes too large, the pressure-sensitive adhesive layer Even if the adhesive film is heated to a temperature exceeding the temperature that causes a chemical interaction between the wafer surface and the wafer surface (corrosion, contamination, etc. of the wafer surface), the decomposition temperature of the adhesive layer, the softening temperature of the base film, etc. It may not be possible to peel it off. Therefore, it is necessary to determine the molecular weight of the crystalline polymer in consideration of temperature conditions (cooling water temperature, peeling temperature, etc.) in the back surface grinding process of the semiconductor wafer, contamination of the wafer surface, and the like.

For example, when a pressure-sensitive adhesive film formed with a pressure-sensitive adhesive having a sufficient pressure-sensitive adhesive strength to protect the surface of the wafer only in the temperature range of E to F ° C. is peeled off by heating it outside the temperature range of F ° C. , Molecular weight is 3,500 to 25,000
It is preferable to adjust to a range of about 3500, and more preferably about 3500 to 12,000.

When the pressure-sensitive adhesive film formed with the pressure-sensitive adhesive having sufficient pressure-sensitive adhesive strength to protect the wafer surface only in the temperature range of A to B ° C. is peeled off by cooling outside the temperature range of A ° C. Has no particular problem with any molecular weight, but a higher molecular weight is preferable in view of contamination on the wafer surface, and therefore 25,000 to 900,000.
It is preferably adjusted to a range of about 100,000 to 900,000.

The usual mixture of the adhesive and the crystalline polymer is
It may be crosslinked, if necessary, in consideration of adhesive property, adjustment of cohesive force, contamination of the wafer surface, and the like. Although it depends on the unevenness of the wafer, when the adhesive film is peeled off after cooling after grinding the back surface of the wafer, the adhesive strength tends to be lowered more easily by crosslinking. The cross-linking method can be appropriately selected from known cross-linking methods such as cross-linking with a cross-linking agent and cross-linking with light or radiation, but cross-linking with a cross-linking agent is preferable in consideration of the simplicity of the cross-linking method.

As the cross-linking agent, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylolpropane toluene diisocyanate 3 adduct,
Isocyanate compounds such as polyisocyanate, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, resorcin diglycidyl ether, etc. Epoxy compounds, trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N, N′-diphenylmethane-4,4′-bis (1- Aziridinecarboxamide), N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide), N, N'-toluene-2,4-bis (1-
Aziridine compounds such as aziridinecarboxamide) and trimethylolpropane-tri-β- (2-methylaziridine) propionate; and melamine compounds such as hexamethoxymethylolmelamine. These may be used alone or in combination of two or more.

The amount of the cross-linking agent added varies depending on the adhesive properties required for the pressure-sensitive adhesive layer, the cohesive strength, the properties of the ordinary pressure-sensitive adhesive and the crystalline polymer, and the like. It is appropriately selected within the range of 0.01 to 30 parts by weight with respect to 100 parts by weight of the mixture.

The thickness of the pressure-sensitive adhesive layer is appropriately determined depending on the surface condition, shape, grinding method of the back surface of the semiconductor wafer, etc.
Considering the adhesive force when grinding the back surface of the semiconductor wafer, the releasability after the grinding is completed, etc., it is usually 2 to 100 μm.
m. Preferably it is 5-70 μm.

The pressure-sensitive adhesive film of the present invention obtained as described above extends from the step of adhering the pressure-sensitive adhesive film to the front surface of the semiconductor wafer to the step immediately before the step of peeling the pressure-sensitive adhesive film after the step of grinding the back surface of the wafer. The adhesive film has a sufficient adhesive force to firmly adhere to the wafer surface and protect the wafer surface. Here, the adhesive force sufficient to protect the wafer surface is an adhesive force that does not peel off during polishing of the wafer back surface or that cooling water does not enter between the wafer surface and the adhesive layer. Yes, specifically, JIS
According to the method specified in Z 0237, a SUS304-BA plate is used as an adherend, and a peeling speed is 300 mm.
/ Min. The adhesive strength measured under a peeling angle of 180 degrees is usually 150 to 2000 g / at a predetermined temperature.
It means within a range of 25 mm. Preferably 2
It is within the range of 00 to 2000 g / 25 mm.

Thus, the pressure-sensitive adhesive film according to the present invention produced as described above is 150 to 2,000 g only in at least a part of the temperature range A to B ° C. (A <B) at a temperature of -10 ° C. or higher. By exhibiting an adhesive force of / 25 mm and cooling to a temperature range of less than A ° C.,
The adhesive strength is reduced to less than 150 g / 25 mm. The preferable adhesive strength in the temperature range A to B ° C. (A <B) is 200 to 2000 g / 25 mm. The preferred adhesive strength in the temperature range below A ° C is 80 g / 25 mm
It is as follows. The preferred temperature range from A to B ° C is 1
It is at least a part of the temperature range in the temperature range of 0 ° C. or higher. Here, there is no particular limitation on the upper limit temperature in the “temperature range of −10 ° C. or higher”, but the substrate film is practically softened by heating, and the adhesive strength defined in the present invention is actually measured. It is a temperature that is impossible to achieve, specifically, JI
The softening temperature of the raw material resin of the base film (that is, the resin before film formation) measured according to SK 2207 (ring and ball method) is about + 50 ° C. When the base film has a melting point, the temperature around the melting point is the upper limit temperature.

Further, the pressure-sensitive adhesive film according to another invention of the present invention is 150-2,0 only in at least part of the temperature range E-F ° C (E <F) at a temperature of 70 ° C or lower.
It shows an adhesive strength of 00g / 25mm, and the adhesive strength is 150g by heating in the temperature range over F ° C.
/ 25 mm or less. Preferably, E
The temperature range of to F ° C is at least a part of the temperature range of 60 ° C or lower. Temperature range E to F ° C (E <
The preferred adhesive strength in F) is 200 to 2000 g / 2.
5 mm. The preferable adhesive strength in the temperature range exceeding F ° C. is 80 g / 25 mm or less. Here, "70
There is no particular limitation on the lower limit temperature in the "temperature range of ℃ or less", but substantially, the base film becomes brittle by cooling, and the adhesion force defined in the present invention is practically measured. It is a temperature that makes it impossible. Specifically, ASTM D
The embrittlement temperature of the raw material resin of the base material film (that is, the resin before being formed into a film) measured in accordance with −746 is a temperature of about −100 ° C.

Further, in consideration of the actual workability, at least 20 to 2 is applied to any of the above-mentioned adhesive films.
In the temperature range of 5 ° C., it is preferable that the adhesive has sufficient adhesive force to protect the wafer surface. More preferably, it has an adhesive force sufficient to protect the wafer surface within a temperature range of at least 15 to 30 ° C.

Next, a method of using the adhesive film for grinding the back surface of a semiconductor wafer of the present invention will be described. As a first method, the release film is peeled off from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film to expose the surface of the pressure-sensitive adhesive layer, and -1 is provided on the surface of the semiconductor wafer on the side where the integrated circuit is formed via the pressure-sensitive adhesive layer.
At least a part of the temperature range A at a temperature of 0 ° C. or higher
At least a part of the temperature range C to D ° C. included in the temperature range of B ° C. (A <B) (A <C ≦ D <B, 1 ≦ C ≦ D ≦ 6
In 0), an adhesive film is attached to the surface of the wafer, the semiconductor wafer is fixed to a chuck table of a grinder through the base film side of the adhesive film, and the semiconductor is sprayed with cooling water in the temperature range of C to D ° C. A method of grinding the back surface of the wafer and then peeling off the adhesive film in a state of being cooled to less than A ° C. can be mentioned.

An adhesive film is attached to the wafer surface, and the temperature range of C to D ° C., which is the temperature of the cooling water, is 1
It is preferable that 0 ≦ C ≦ D ≦ 40. In order to control the temperature within a temperature range showing sufficient adhesive strength to protect the surface of the semiconductor wafer, the temperature of the cooling water during grinding, the grinding room temperature, etc. are changed from C to D.
It must be controlled within the range of ° C. The peeling temperature may be any temperature as long as it is lower than A ° C, but in consideration of the actual workability, it is usually preferably -30 ° C or higher.

As a second method, the release film is peeled off from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film to expose the surface of the pressure-sensitive adhesive layer, and the semiconductor wafer on the side where the integrated circuit is formed through the pressure-sensitive adhesive layer. On the surface, at least a part of the temperature range G to H ° C. (E <G ≦ H <F, which is included in the temperature of 70 ° C. or less,
1 ≦ G), the adhesive film is adhered to the surface of the wafer, the semiconductor wafer is fixed to a chuck table of a grinding machine or the like via the base film side of the adhesive film, and cooling water in a temperature range of G to H ° C. is applied. A method may be mentioned in which the back surface of the semiconductor wafer is ground while being applied, and then the pressure-sensitive adhesive film is peeled off while being heated to a temperature higher than F ° C.

An adhesive film is attached to the wafer surface, and the temperature range of G to H ° C., which is the temperature of the cooling water, is 1
It is preferable that 0 ≦ G ≦ H ≦ 40. In order to control the temperature range in which the adhesive force is sufficient to protect the surface of the semiconductor wafer, the temperature of the cooling water during grinding, the grinding room temperature, etc. are adjusted to G to H.
It must be controlled within the range of ° C. The peeling temperature may be any temperature as long as it is higher than F ° C., but normally, the temperature causing the chemical interaction between the pressure-sensitive adhesive layer and the wafer surface (corrosion, contamination, etc. of the wafer surface), the pressure-sensitive adhesive layer It is preferable that the temperature does not exceed a temperature at which a part of the base material begins to decompose or a softening temperature of the base film. Specifically, when the softening temperature of the base film is 100 ° C. or lower, the softening temperature is usually lower than the softening temperature, and the softening temperature of the base film is 1 or less.
When it exceeds 00 ° C, it is preferable to peel at a temperature of 100 ° C or less.

The adhesive strength of the adhesive film of the present invention can be appropriately adjusted within the above range in consideration of the diameter of the semiconductor wafer to be ground, the grinding time, the surface shape of the semiconductor wafer, the thickness after grinding, and the like. There are no particular restrictions on the apparatus for grinding the back surface of the semiconductor wafer, the tool, and the grinding method, and known methods can be applied. After the back surface of the semiconductor wafer is completely ground, a chemical etching step may be performed before peeling the adhesive film (in this case, the chemical etching layer needs to be controlled within the range of A to B ° C or E to F ° C). It is preferably C to D ° C. or G to H ° C. As the semiconductor wafer to which the present invention can be applied, not only a silicon wafer but also germanium, gallium-arsenic, gallium-phosphorus, gallium-arsenic-aluminum, etc. Wafers may be mentioned.

[0054]

The present invention will be described below in further detail with reference to examples. In the following Examples and Comparative Examples,
Manufacture of an adhesive film for grinding the backside of a semiconductor wafer (after preparation of the adhesive coating solution) and grinding of the backside of a semiconductor wafer using the adhesive film for grinding the backside of a semiconductor wafer are all of class 1,000 or less specified in US Federal Standard 209b. The test was conducted in a clean environment. The present invention is not limited to these examples. Incidentally, the usual pressure-sensitive adhesive (acrylic pressure-sensitive adhesive) used in this example,
The crystalline polymer (side-chain crystalline polymer) was synthesized according to the methods of Preparation Examples 1 to 4 below. Moreover, the performance of the obtained adhesive film and the respective characteristics in the method for grinding the back surface of a semiconductor wafer using the film are described in the following (1) to
It evaluated by the method of (3).

(1) Number of Damaged Semiconductor Silicon Wafers during Backside Grinding (Number) The surface of each semiconductor silicon wafer (diameter: 8 inches, thickness: 600 μm, surface irregularity: about 10 μm) on which integrated circuits are formed is The adhesive film obtained in each of the examples and comparative examples was pasted, and using a grinder [manufactured by Disco Corporation: Back Grinder DFG-821F / 8], water having a predetermined water temperature was applied to cool the semiconductor silicon. The back surface of the wafer is ground until the thickness of the wafer becomes 200 μm. After finishing the grinding, the film is peeled off under a predetermined condition. 20 semiconductor silicon wafers were used for each Example and Comparative Example, grinding was performed 20 times, the number of wafers damaged during backside grinding (due to peeling of adhesive film during grinding), adhesive film and semiconductor wafer The number of wafers in which water has invaded and the number of wafers damaged during peeling are counted.

(2) Observation of Contamination on Semiconductor Wafer by Microscope (%) For the wafer which was not damaged during the back surface grinding of the semiconductor wafer in the above (1) and during peeling of the adhesive film,
The integrated circuit on the wafer surface is an optical microscope (manufactured by Nikon Corporation:
The entire surface of the wafer and the fine portion of the circuit are observed in a range of 50 to 1000 times using OPTIPHOT 2) to evaluate the ratio of contaminated chips.

(3) Adhesive strength (g / 25 mm) characteristics The basic operation is carried out under the following conditions according to the method described in JIS Z 0237. The pressure-sensitive adhesive films obtained in the examples and comparative examples were passed through the pressure-sensitive adhesive layer to obtain SUS.
It is attached to the surface of a 304-BA plate (length: 20 cm, width: 5 cm) and left at 23 ° C. for 30 minutes. After standing, one end of the sample is clamped, peeling angle: 180 degrees, peeling speed: 3
00 mm / min. At a predetermined temperature at SUS304
-The sample is peeled from the surface of the BA plate, and the stress at the time of peeling is measured and converted to g / 25 mm.

Preparation Example 1 <Synthesis of Acrylic Adhesive (Polymer 1)> 91 parts by weight of butyl acrylate, 4.5 parts by weight of acrylonitrile, and 4.5 parts by weight of acrylic acid in 150 parts by weight of toluene, Using 1 part by weight of 2,2′-azobis-isobutyronitrile (hereinafter referred to as AIBN) as an initiator, copolymerization was carried out at 80 ° C. under a nitrogen atmosphere to give a solution of polymer 1 (solid content 40% by weight). Obtained.

Preparation Example 2 <Synthesis of Side-Chain Crystalline Polymer Part 1 (Polymer 2)>
Hexadecyl methacrylate (98 parts by weight) and acrylic acid (2 parts by weight) were copolymerized with 180 parts by weight of toluene in the presence of 5 parts by weight of dodecyl mercaptan, and 1 part by weight of AIBN as an initiator at 80 ° C. under a nitrogen atmosphere to obtain a high polymer. A solution of molecule 2 (36 wt% solids) was obtained.

Preparation Example 3 <Synthesis of Side Chain Crystalline Polymer 2 (Polymer 3)>
98 parts by weight of octadecyl acrylate and 2 parts by weight of acrylic acid were mixed with 5 parts of dodecyl mercaptan in 180 parts by weight of toluene.
1 part by weight of AIBN as an initiator in the presence of 1 part by weight of the polymer 3 at 80 ° C. under a nitrogen atmosphere.
To obtain a solution (solid content 36% by weight).

Preparation Example 4 <Synthesis of Side-chain Crystalline Polymer No. 3 (Polymer 4)>
Hexadecyl methacrylate 98 parts by weight and acrylic acid 2 parts by weight in 180 parts by weight of ethyl acetate as AI
Copolymerization was carried out using 75 parts by weight of BN at 75 ° C. under a nitrogen atmosphere to obtain a solution of polymer 4 (solid content: 36% by weight).

Example 1 75 parts by weight of a solution of polymer 1 synthesized in Preparation Example 1 (solid content 40% by weight) and 25 parts by weight of solution of polymer 2 synthesized in Preparation Example 2 (solid content 36% by weight) Parts, and further, an isocyanate cross-linking agent (manufactured by Mitsui Toatsu Chemicals, Inc.,
1 part by weight of Orestar P49-60SX, solid content 60% by weight) was added to obtain an adhesive coating solution. This adhesive coating solution was applied to one side of a polypropylene film (release film, thickness: 50 μm) by using a roll coater, and 120
The adhesive layer having a thickness of 15 μm was provided by drying at 1 ° C. for 1 minute.
Then, the treated surface of an ethylene-vinyl acetate copolymer film (Shore D hardness: 38) having a thickness of 120 μm subjected to corona discharge treatment is bonded and pressed to transfer the pressure-sensitive adhesive layer, whereby the pressure-sensitive adhesive layer is transferred. Manufactured.

Under an environment in which the room temperature was controlled at 23 ° C., the release film was peeled off from the pressure-sensitive adhesive layer of the obtained pressure-sensitive adhesive film to expose the surface of the pressure-sensitive adhesive layer, and through the pressure-sensitive adhesive layer,
It is attached to the surface of a semiconductor silicon wafer (diameter: 8 inches, thickness: 600 μm, surface irregularity difference: about 10 μm) on which an integrated circuit is formed, and a grinding machine [manufactured by Disco Corporation: Back Grinder DFG-821F / 8] is used. The back surface of the semiconductor silicon wafer was ground while being cooled with water at 23 ° C. until the thickness of the wafer became 200 μm. After completion of grinding, the wafer was cooled to 5 ° C. with the film adhered, and the film was peeled off while maintaining this temperature. 2
The same operation was repeated 20 times for 0 semiconductor wafers. None of the wafers were damaged during grinding, water penetrated between the wafer and the adhesive film, or were damaged during peeling. [Table 1] shows the adhesive property of the obtained adhesive film under the use conditions of Example 1, the contamination property to the surface of the semiconductor wafer, and the grinding result.

Example 2 Using the pressure-sensitive adhesive film obtained in Example 1, the same procedure as in Example 1 was repeated except that the cooling water temperature was 30 ° C. in the same environment as in Example 1. The back surface of the semiconductor silicon wafer on which the circuit was formed (the same as in Example 1) was ground until the thickness of the wafer became 200 μm. After grinding,
Cooling the wafer to 10 ° C. with the film attached,
The film was peeled off while maintaining this temperature. The same operation was performed 20 times on 20 semiconductor wafers. None of the wafers were damaged during grinding, water penetrated between the wafer and the adhesive film, or were damaged during peeling. Example 2 of the adhesive film of Example 1
[Table 1] shows the adhesive property, the contamination property to the surface of the semiconductor wafer, and the grinding result under the use condition of No.

Example 3 75 parts by weight of a solution of polymer 1 (solid content 40% by weight) synthesized in Preparation Example 1 and 25 parts by weight of solution of polymer 3 synthesized in Preparation Example 3 (36% by weight solid content) Parts, and further, an isocyanate cross-linking agent (manufactured by Mitsui Toatsu Chemicals, Inc.,
2 parts by weight of Orestar P49-60SX, solid content 60% by weight) was added to obtain an adhesive coating solution. Using this pressure-sensitive adhesive coating solution, a pressure-sensitive adhesive film was produced in the same manner as in Example 1.

Using the obtained adhesive film, in the same environment as in Example 1, in the same manner as in Example 1, the back surface of the semiconductor silicon wafer (the same as in Example 1) on which an integrated circuit was formed was used. Was ground to a thickness of 200 μm. After completion of grinding, the wafer was heated to 65 ° C. with the film adhered, and the film was peeled off while maintaining this temperature. The same operation was performed 20 times on 20 semiconductor wafers. None of the wafers were damaged during grinding, water penetrated between the wafer and the adhesive film, or were damaged during peeling. [Table 1] shows the adhesive property of the obtained adhesive film under the use conditions of Example 3, the contamination property on the surface of the semiconductor wafer, and the grinding result.

Example 4 Using the pressure-sensitive adhesive film obtained in Example 3, the same procedure as in Example 1 was repeated except that the temperature of the cooling water was 40 ° C. in the same environment as in Example 1. The back surface of the semiconductor silicon wafer on which the circuit was formed (the same as in Example 1) was ground until the thickness of the wafer became 200 μm. After grinding,
The wafer is heated to 55 ° C. with the film attached,
The film was peeled off while maintaining this temperature. The same operation was performed 20 times on 20 semiconductor wafers. None of the wafers were damaged during grinding, water penetrated between the wafer and the adhesive film, or were damaged during peeling. Example 4 of the adhesive film of Example 3
[Table 1] shows the adhesive property, the contamination property to the surface of the semiconductor wafer, and the grinding result under the use condition of No.

Example 5 70 parts by weight of a solution of polymer 1 synthesized in Preparation Example 1 (solid content 40% by weight) and 30 parts by weight of solution of polymer 4 synthesized in Preparation Example 4 (solid content 36% by weight) Parts, and further, an isocyanate cross-linking agent (manufactured by Mitsui Toatsu Chemicals, Inc.,
Olester P49-60SX, solid content 60% by weight) 1.
5 parts by weight was added to obtain an adhesive coating solution. Using this pressure-sensitive adhesive coating solution, a pressure-sensitive adhesive film was produced in the same manner as in Example 1.

Using the obtained adhesive film, in the same environment as in Example 1, in the same manner as in Example 1, the back surface of a semiconductor silicon wafer (the same as that in Example 1) on which an integrated circuit was formed was prepared. The wafer was ground to a thickness of 200 μm. After finishing the grinding, the film was peeled off in the same manner as in Example 1. The same operation was performed 20 times on 20 semiconductor wafers. Wafers damaged during grinding, wafers with water intrusion between the wafer and the adhesive film, and
None of the wafers were damaged during peeling. [Table 1] shows the adhesive property of the obtained adhesive film under the use condition of Example 5, the contamination property to the surface of the semiconductor wafer, and the grinding result.

Example 6 Using the pressure-sensitive adhesive film obtained in Example 5, the same procedure as in Example 1 was repeated except that the temperature of the cooling water was 40 ° C. in the same environment as in Example 1. The back surface of the semiconductor silicon wafer on which the circuit was formed (the same as in Example 1) was ground until the thickness of the wafer became 200 μm. After grinding,
The film was peeled off in the same manner as in Example 2. The same operation was performed 20 times on 20 semiconductor wafers. None of the wafers were damaged during grinding, water penetrated between the wafer and the adhesive film, or were damaged during peeling. Example 6 of the adhesive film of Example 5
[Table 1] shows the adhesive property, the contamination property to the surface of the semiconductor wafer, and the grinding result under the use condition of No.

[0071]

[Table 1]

Comparative Example 1 Using the pressure-sensitive adhesive film obtained in Example 1, in the same environment as in Example 1 and in the same manner as in Example 1, a semiconductor silicon wafer (Example (The same as No. 1) was ground until the thickness of the wafer became 200 μm. After finishing the grinding, the film was peeled off without cooling. Perform the same operation for 20 semiconductor wafers in 2
Performed 0 times. There were no wafers that were damaged during grinding and no water penetrated between the wafer and the adhesive film, but 11 wafers were damaged during peeling. Table 2 shows the adhesive property of the pressure-sensitive adhesive film of Example 1 under the use conditions of Comparative Example 1, the stain resistance to the surface of the semiconductor wafer, and the grinding result.

Comparative Example 2 Using the pressure-sensitive adhesive film obtained in Example 3, in the same environment as in Example 1 and in the same method as in Example 1, a semiconductor silicon wafer (Example (The same as No. 1) was ground until the thickness of the wafer became 200 μm. After finishing the grinding, the film was peeled off without heating. Perform the same operation for 20 semiconductor wafers in 2
Performed 0 times. None of the wafers were damaged during grinding and water was invaded between the wafer and the adhesive film, but four wafers were damaged during peeling. Table 2 shows the adhesive property of the pressure-sensitive adhesive film of Example 3 under the use conditions of Comparative Example 2, the stain resistance to the surface of the semiconductor wafer, and the grinding result.

Comparative Example 3 Using the pressure-sensitive adhesive film obtained in Example 5, in the same environment as in Example 1 and in the same manner as in Example 1, a semiconductor silicon wafer (Example (The same as No. 1) was ground until the thickness of the wafer became 200 μm. After finishing the grinding, the film was peeled off without cooling. Perform the same operation for 20 semiconductor wafers in 2
Performed 0 times. None of the wafers were damaged during grinding and water entered between the wafer and the adhesive film, but 10 wafers were damaged during peeling. Table 2 shows the adhesive property of the pressure-sensitive adhesive film of Example 5 under the use conditions of Comparative Example 3, contamination on the surface of the semiconductor wafer, and grinding result.

Comparative Example 4 Under the environment of 5 ° C., the surface of a semiconductor silicon wafer (the same as that of Example 1) on which the integrated circuit was formed by using the adhesive film obtained in Example 1 through the adhesive layer When it was attached to, it could not be attached because it had almost no adhesive force. The results are shown in [Table 2].

Comparative Example 5 The pressure-sensitive adhesive film obtained in Example 3 was heated to 65 ° C., and at the same temperature, a semiconductor silicon wafer on which an integrated circuit was formed via the pressure-sensitive adhesive layer (same as Example 1). The film immediately began to float around the semiconductor wafer, and it became impossible to grind the back surface of the wafer. The results are shown in [Table 2].

Comparative Example 6 Under the environment of 5 ° C., the surface of a semiconductor silicon wafer (the same as that of Example 1) on which the integrated circuit was formed by using the adhesive film obtained in Example 5 through the adhesive layer When it was attached to, it could not be attached because it had almost no adhesive force. The results are shown in [Table 2].

Comparative Example 7 Using the pressure-sensitive adhesive film obtained in Example 1, the same procedure as in Example 1 was repeated except that the temperature of the cooling water was changed to 10 ° C. under the same environment as in Example 1. The back surface of the semiconductor silicon wafer on which the circuit was formed (the same as in Example 1) was ground until the thickness of the wafer became 200 μm. After grinding,
Maintaining the wafer at 10 ° C. with the film attached,
The film was peeled off while maintaining this temperature. The same operation was performed 20 times on 20 semiconductor wafers. During the grinding, 10 wafers were damaged, and water was found to have entered between the wafer and the adhesive film in all of the remaining undamaged wafers (10 wafers). There was no damage to the wafer when the tape was peeled off from the wafer in which water was observed. Table 2 shows the adhesive property of the pressure-sensitive adhesive film of Example 1 under the use conditions of Comparative Example 7, the stain resistance to the surface of the semiconductor wafer, and the grinding result.

Comparative Example 8 Using the pressure-sensitive adhesive film obtained in Example 3, the same procedure as in Example 1 was repeated except that the temperature of the cooling water was set to 55 ° C. in the same environment as in Example 1. The back surface of the semiconductor silicon wafer on which the circuit was formed (the same as in Example 1) was ground until the thickness of the wafer became 200 μm. After grinding,
Maintaining the wafer at 55 ° C. with the film attached,
The film was peeled off while maintaining this temperature. The same operation was performed 20 times on 20 semiconductor wafers. Eleven wafers were damaged during the grinding, and water was found to have entered between the wafer and the adhesive film in all the remaining undamaged wafers (9 wafers). There was no damage to the wafer when the tape was peeled off from the wafer in which water was observed. Table 2 shows the adhesive property of the pressure-sensitive adhesive film of Example 3 under the use conditions of Comparative Example 8, contamination on the surface of the semiconductor wafer, and grinding result.

Comparative Example 9 Using the adhesive film obtained in Example 5, the same procedure as in Example 1 was repeated except that the temperature of the cooling water was changed to 10 ° C. under the same environment as in Example 1. The back surface of the semiconductor silicon wafer on which the circuit was formed (the same as in Example 1) was ground until the thickness of the wafer became 200 μm. After grinding,
Maintaining the wafer at 10 ° C. with the film attached,
The film was peeled off while maintaining this temperature. The same operation was performed 20 times on 20 semiconductor wafers. During the grinding, 10 wafers were damaged, and water was found to have entered between the wafer and the adhesive film in all of the remaining undamaged wafers (10 wafers). There was no damage to the wafer when the tape was peeled off from the wafer in which water was observed. Table 2 shows the adhesive property of the adhesive film of Example 5 under the use conditions of Comparative Example 9, the stain resistance to the surface of the semiconductor wafer, and the grinding result.

[0081]

[Table 2]

Comparative Example 10 100 parts by weight of the solution of polymer 1 synthesized in Preparation Example 1 (solid content 40% by weight) was added to an isocyanate crosslinking agent (Mitsui Toatsu Chemical Co., Ltd., Orestar P49-60SX, solid content). 6
0%) 1.2 parts by weight was added to obtain an adhesive coating solution. This adhesive coating liquid was applied to a polypropylene film (release film, thickness: 50 μm) using a roll coater, and dried at 120 ° C. for 1 minute to form an adhesive layer having a thickness of 15 μm. Next, a thickness 120 that has been subjected to corona discharge treatment
The treated surface of a μm ethylene-vinyl acetate copolymer film (Shore D type hardness: 38) was stuck and pressed,
An adhesive film was produced by transferring the adhesive layer.

Under the same environment as that of the first embodiment, the back surface of the semiconductor silicon wafer (the same as that of the first embodiment) on which the integrated circuit is formed has the thickness of 2 by the same method as that of the first embodiment.
Grinding was performed until it became 00 μm. After completion of grinding, the wafer was cooled to 5 ° C. with the film adhered, and the film was peeled off while maintaining this temperature. The same operation was performed 20 times on 20 semiconductor wafers. None of the wafers were damaged during grinding and water entered between the wafer and the adhesive film, but 13 wafers were damaged during peeling. Table 3 shows the adhesive property of the obtained adhesive film under the use conditions of Comparative Example 10, the stain resistance to the surface of the semiconductor wafer, and the grinding result.

Comparative Example 11 Using the pressure-sensitive adhesive film obtained in Comparative Example 10, Example 1
In the same environment as described above, the back surface of the semiconductor silicon wafer on which the integrated circuit was formed (the same as in Example 1) was ground by the same method as in Example 1 until the wafer had a thickness of 200 μm. After completion of grinding, the wafer was heated to 65 ° C. with the film adhered, and the film was peeled off while maintaining this temperature. The same operation was performed 20 times on 20 semiconductor wafers. None of the wafers were damaged during grinding and water was invaded between the wafer and the adhesive film, but four wafers were damaged during peeling. [Table 3] shows the adhesive property of the obtained adhesive film under the use conditions of Comparative Example 11, the stain resistance to the semiconductor wafer, and the grinding result.

Comparative Example 12 Using the pressure-sensitive adhesive film obtained in Comparative Example 10, Example 1
In the same environment as described above, the back surface of the semiconductor silicon wafer on which the integrated circuit was formed (the same as in Example 1) was ground by the same method as in Example 1 until the wafer had a thickness of 200 μm. After finishing the grinding, the film was peeled off at room temperature. 2
The above operation was repeated 20 times for 0 semiconductor wafers. None of the wafers were damaged during grinding and water entered between the wafer and the adhesive film, but 10 wafers were damaged during peeling. The adhesive property of the obtained adhesive film under the use conditions of Comparative Example 12 and the contamination property to the semiconductor wafer, and the grinding result are shown in [Table 3].
Shown in

Comparative Example 13 100 parts by weight of the solution of Polymer 1 synthesized in Preparation Example 1 (solid content: 40% by weight) was added to an isocyanate crosslinking agent (manufactured by Mitsui Toatsu Chemicals, Inc., Orestar P49-60SX, solid content). 6
0%) 6.5 parts by weight was added to obtain an adhesive coating solution. This adhesive coating liquid was applied to a polypropylene film (release film, thickness: 50 μm) using a roll coater, and dried at 120 ° C. for 1 minute to form an adhesive layer having a thickness of 15 μm. Next, a thickness 120 that has been subjected to corona discharge treatment
The treated surface of a μm ethylene-vinyl acetate copolymer film (Shore D type hardness: 38) was stuck and pressed,
An adhesive film was produced by transferring the adhesive layer.

Under the environment similar to that of the first embodiment, the back surface of the semiconductor silicon wafer (the same as that of the first embodiment) on which the integrated circuit is formed has the thickness of 2 by the same method as that of the first embodiment.
Grinding was performed until it became 00 μm. After finishing the grinding, the film was peeled off at room temperature. The same operation was performed 20 times on 20 semiconductor wafers. Three wafers were damaged during the grinding, and water was found to have entered between the wafer and the adhesive film in all the remaining undamaged wafers (17 wafers). There was no damage to the wafer when the tape was peeled off from the wafer in which water was observed. The adhesive property of the obtained adhesive film under the use conditions of Comparative Example 13 and the contamination property on the surface of the semiconductor wafer, and the grinding result are shown in [Table 3].
Shown in

Comparative Example 14 100 parts by weight of the solution of Polymer 1 synthesized in Preparation Example 1 (solid content: 40% by weight) was added to an isocyanate cross-linking agent (Mitsui Toatsu Chemical Co., Ltd., Orestar P49-60SX, solid content). 6
0%) 2 parts by weight, 6 parts by weight of dipentaerythritol monohydroxypentaacrylate and 0.4 parts by weight of α-hydroxycyclohexyl phenyl ketone were added to obtain an adhesive coating solution. This adhesive coating liquid was applied to a polypropylene film (release film, thickness: 50 μm) using a roll coater, and dried at 120 ° C. for 1 minute to form an adhesive layer having a thickness of 15 μm. Then, the treated surface of an ethylene-vinyl acetate copolymer film (Shore D hardness: 38) having a thickness of 120 μm subjected to corona discharge treatment is bonded and pressed to transfer the pressure-sensitive adhesive layer, whereby the pressure-sensitive adhesive layer is transferred. Manufactured.

Under the same environment as that of the first embodiment, the back surface of the semiconductor silicon wafer (the same as that of the first embodiment) on which the integrated circuit is formed has the thickness of 2 by the same method as that of the first embodiment.
Grinding was performed until it became 00 μm. After finishing the grinding, from the ethylene-vinyl acetate copolymer film side of the adhesive film, with a high pressure mercury lamp (40 W / cm), from a distance of 15 cm to 20
After irradiating with light for a second, the film was peeled off at room temperature. 20
The same operation was repeated 20 times for each semiconductor wafer.
None of the wafers were damaged during grinding, water penetrated between the wafer and the adhesive film, or were damaged during peeling. However, under the microscope, contaminants due to the adhesive were observed on the aluminum electrodes of some circuits. Table 1 shows the adhesive property of the obtained adhesive film under the use conditions of Comparative Example 14, the stain resistance to the surface of the semiconductor wafer, and the grinding result.

[0090]

[Table 3]

[0091]

The pressure-sensitive adhesive film for backside grinding of a semiconductor wafer according to the present invention has a pressure-sensitive adhesive layer containing a crystalline polymer formed therein, and protects the semiconductor wafer with a strong adhesive force when grinding the backside of the semiconductor wafer. However, when peeling, the adhesive force is easily reduced by a simple operation such as cooling or heating. Therefore, during the grinding operation, cooling water does not enter between the semiconductor wafer and the adhesive film, and the semiconductor wafer is not damaged. Further, since the peeling stress is small, the semiconductor wafer does not break when peeling. Further, contaminants from the pressure-sensitive adhesive layer hardly adhere to the semiconductor wafer surface after peeling. Therefore, the present invention exerts excellent effects in the technical field of increasing the diameter and thickness of a semiconductor wafer and improving the performance of an IC.

Claims (4)

[Claims] 1. A pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer, wherein a pressure-sensitive adhesive layer is provided on one surface of a base film, the pressure-sensitive adhesive layer being formed of a pressure-sensitive adhesive containing a crystalline polymer.
The adhesive force of the adhesive film for grinding the back surface of the semiconductor wafer is −
At least a partial temperature range A at a temperature of 10 ° C. or higher
Only at ~ B ° C (A <B) 150-2,000 g /
25 mm and 1 in the temperature range below A ° C
An adhesive film for grinding a back surface of a semiconductor wafer, which is less than 50 g / 25 mm. 2. A pressure-sensitive adhesive film for grinding a back surface of a semiconductor wafer, wherein a pressure-sensitive adhesive layer is provided on one surface of a base film, the pressure-sensitive adhesive layer being formed of a pressure-sensitive adhesive containing a crystalline polymer.
The adhesive strength of the adhesive film for grinding the back surface of the semiconductor wafer is 7
At least a part of the temperature range E to 0 ° C. or lower
150 to 2,000 g / 2 only at F ° C (E <F)
1 in the temperature range of 5 mm and above F ° C.
An adhesive film for grinding a back surface of a semiconductor wafer, which is less than 50 g / 25 mm. 3. A method of using a pressure-sensitive adhesive film for backside grinding of a semiconductor wafer, which is adhered to the front surface of the backside of a semiconductor wafer when the backside is ground, and is peeled off after the grinding is completed. Has a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive containing a crystalline polymer on one surface thereof, and the pressure-sensitive adhesive force is at least in a partial temperature range A to B ° C (A <B) at a temperature of -10 ° C or higher. 150 ~
2,000 g / 25 mm and less than 150 g / 25 mm in the temperature range below A ° C., A to B ° C.
At least part of the temperature range C to D included in the temperature range
The adhesive film is attached to the wafer surface at a temperature of C (A <C ≦ D <B, 1 ≦ C ≦ D ≦ 60), and the back surface of the semiconductor wafer is ground while applying cooling water in a temperature range of C to D ° C. Then, a method of using the adhesive film for grinding a back surface of a semiconductor wafer, which comprises peeling the adhesive film in a state of being cooled to less than A ° C. 4. A method of using a pressure-sensitive adhesive film for backside grinding of a semiconductor wafer, which is adhered to the front surface of the backside of a semiconductor wafer when the backside is ground, and is peeled off after the grinding is completed. Has an adhesive layer formed of an adhesive containing a crystalline polymer on one surface thereof, and the adhesive force is 150 only in at least a partial temperature range E to F ° C (E <F) at a temperature of 70 ° C or less. ~ 2
000 g / 25 mm and less than 150 g / 25 mm in the temperature range exceeding F ° C, and at least a part of the temperature range G to H ° C included in the temperature range from E to F ° C.
In (E <G ≦ H <F, 1 ≦ G), the adhesive film is adhered to the wafer surface, the back surface of the semiconductor wafer is ground while cooling water in the temperature range of G to H ° C. is applied, and then F ° C. A method of using the pressure-sensitive adhesive film for backside grinding of a semiconductor wafer, which comprises peeling the pressure-sensitive adhesive film in a state of being heated to a temperature above 100 ° C.