JPH11345790A - Adhesive tape for protecting surface of semiconductor wafer surface and its usage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape for protecting the surface of a semiconductor wafer that prevents the crack of the wafer when the rear surface of the semiconductor wafer is ground, chemical etching is made, the semiconductor wafer is carried, the adhesive tape for protecting the surface of the semiconductor wafer is peeled off, or the like, and at the same time, has less warp deformation after cutting, and its usage. SOLUTION: For an adhesive tape for protecting the surface of a semiconductor wafer, an adhesive mass layer is provided on one surface of a base film A, and an auxiliary film B is laminated on the other. In the adhesive tape, when heating is performed for 60 seconds while the Shore D hardness of the base film A is set to 40 or less, that of the auxiliary film B exceeds 40, and temperature is set to 95 deg.C, the heat shrinkage rate of the base film A is set to 5% or less and that of the auxiliary film B is set to at least 10%. When the tape is peeled, hot water is poured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape for protecting the surface of a semiconductor wafer and a method for using the same. More specifically, a heat-shrinkable adhesive tape for protecting the surface of a semiconductor wafer, which is attached to a surface of a semiconductor wafer such as a silicon wafer on which integrated circuits are incorporated (hereinafter referred to as a wafer surface), The surface of the semiconductor wafer on the side where the integrated circuit is not incorporated (hereinafter referred to as
The present invention relates to a pressure-sensitive adhesive tape for protecting the front surface of a semiconductor wafer, which can be peeled off by heating after grinding the back surface of the wafer) and a method of using the same.

[0002]

2. Description of the Related Art Generally, a semiconductor integrated circuit (hereinafter, referred to as an IC) is prepared by slicing a high-purity silicon single crystal or the like into a semiconductor wafer, and incorporating the integrated circuit into the surface by etching or the like. Is manufactured by grinding the back surface and dicing into chips.

In recent years, as the size of semiconductor chips has been reduced, the thickness of wafers has become thinner. Conventionally, the thickness of wafers after back grinding has been about 200 to 400 μm. The thickness is reduced to about 50 to 150 μm. Further, with the rationalization of the semiconductor manufacturing method, a wafer having a diameter of about 200 mm at the maximum has been increased to 300 mm,
It is expected that the size will be increased to 00 mm.

[0004] Thinning and increasing the diameter of the wafer not only cause a reduction in the strength of the wafer, but also cause problems such as breakage of the wafer during backside grinding and increased warpage of the wafer after backside grinding. ing. When the wafer is damaged, not only the yield of the wafer is simply deteriorated, but also pieces of the wafer enter into the manufacturing apparatus, and maintenance of the apparatus becomes necessary, which may lead to a significant decrease in productivity.

Usually, when the adhesive tape for protecting the surface of a semiconductor wafer is peeled off from the surface of the semiconductor wafer, a strong adhesive tape called a peeling tape is applied to the adhesive tape for protecting the surface of the semiconductor wafer in an apparatus called a peeling machine. A method of attaching to a tape and peeling off via the peeling tape is adopted. However, if the warpage of the wafer is large as described above, the wafer may be damaged or the peeling tape may be peeled off due to poor adhesion between the peeling tape and the surface protecting adhesive tape when the peeling tape is applied to the semiconductor wafer surface protecting adhesive tape. In some cases, a defect or the like occurred.

As a method for solving the above problem, for example, Japanese Patent Application Laid-Open No. Hei 8-222535 discloses that
An adhesive is applied to one side of a release film having a viscosity of less than 5 dyne / cm and a Vicat softening point of 100 ° C. or higher, dried to form an adhesive layer, and the surface of the adhesive layer has a surface tension of 3
A stretched ethylene-vinyl acetate copolymer film having a shrinkage of 5 dyne / cm or more, a shrinkage at 25 ° C. of less than 5%, and a shrinkage of 5 to 50% when immersed in warm water of 50 to 80 ° C. The adhesive layer for semiconductor wafer surface protection obtained by pressing and transferring the adhesive layer to one side of the ethylene-vinyl acetate copolymer stretched film is adhered to the semiconductor wafer surface via the adhesive layer. Then, after grinding the back surface of the semiconductor wafer, the semiconductor wafer is immersed in hot water at 50 to 80 ° C., and the adhesive film for protecting the semiconductor wafer surface is peeled off from the semiconductor wafer surface. Are disclosed.
According to the present invention, when the adhesive film for protecting the surface of a semiconductor wafer is peeled from a semiconductor wafer having a thickness of 200 μm or less and a diameter of about 8 inches after grinding the back surface, the wafer is easily peeled without being damaged. It is stated that it can be.

Japanese Patent Laid-Open No. Hei 7-201787 discloses that a heat-shrinkable plastic film is
(I) a partially crosslinked product of a carboxyl group-containing hydrophilic polymer in which at least a part of the carboxyl group is partially neutralized,
(Ii) A wafer surface protection sheet provided with a pressure-sensitive adhesive layer containing at least one kind of a room temperature liquid surfactant selected from the group consisting of an anionic surfactant and a cationic surfactant is disclosed. ing. However, even in the case of the above invention, the wafer may be damaged when the adhesive film is peeled off depending on the diameter of the wafer, the thickness after grinding the back surface, and the surface shape.

The problem that the semiconductor wafer is damaged when the adhesive tape is peeled off is that as the diameter of the semiconductor wafer becomes larger,
Further, as the thickness of the wafer after the back surface grinding becomes thinner, it is influenced by the grinding method of the wafer back surface, presence / absence of distortion after grinding, degree of distortion, and the like. In addition, even if the wafer has the same diameter and the same thickness after grinding the back surface, a scribe line (also referred to as a street; a path through which a rotary round blade passes when dicing chips on the wafer by dicing). )
Some wafers are easily damaged depending on the surface shape of the semiconductor wafer, such as the width and depth of the semiconductor wafer. The greater the unevenness of the wafer surface, such as the depth of the scribe line, the more the damage tends to occur. Further, in the case of the above invention, since the heat-shrinkable base material is used, a dimensional change occurs with the lapse of time, and the warpage of the wafer after grinding is increased, which tends to cause more damage. Was.

In recent years, as semiconductor wafers have become larger in diameter and thinner and ICs have become more sophisticated, contamination on the wafer surface has been reduced, and at the time of grinding the back surface of the wafer, peeling off the adhesive tape, and removing the wafer. There has been a demand for a semiconductor wafer surface protection pressure-sensitive adhesive tape that does not damage the wafer during transfer, has little dimensional change over time, has a small warpage after grinding, and can shorten the working time.

[0010]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to grind a back surface of a semiconductor wafer, perform chemical etching, transport a semiconductor wafer, and peel off an adhesive tape for protecting the surface of a semiconductor wafer. It is an object of the present invention to provide a semiconductor wafer surface protection pressure-sensitive adhesive tape which prevents cracking of a wafer at the time of the above and has less warpage after grinding, and a method of using the same.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above-mentioned object. As a result, the support was made to have a laminated structure, and the layer on the side where the pressure-sensitive adhesive layer was not formed had heat shrinkage. Adopt the applied adhesive tape for protecting the surface of the semiconductor wafer, affix it to the surface of the wafer, grind the back surface in a semiconductor wafer back grinding machine, and if necessary, etch the back surface of the wafer with acid, for example, use a spinner. Back grinding equipment, spin etching equipment, etc.
By heating the pressure-sensitive adhesive tape for wafer protection with a dicing device or the like and shrinking and peeling, the pressure-sensitive adhesive tape for surface protection can be easily peeled off without damaging the semiconductor wafer. The inventors have found that the step of peeling off the adhesive tape can be omitted, and have completed the present invention.

That is, the first invention of the present invention relates to an adhesive for protecting the surface of a semiconductor wafer in which an adhesive layer is provided on one surface of a base film (A) and an auxiliary film (B) is laminated on the other surface. A tape having a (A) Shore D hardness of 40
Hereinafter, the Shore D hardness of (B) is more than 40, and the heat shrinkage ratio of (A) when heated at 95 ° C. for 60 seconds is 5% or less,
(B) A semiconductor wafer surface protection adhesive tape having a heat shrinkage of at least 10%.

In a preferred embodiment of the pressure-sensitive adhesive tape for protecting a semiconductor wafer surface according to the first invention, the auxiliary film (B) is a resin film stretched 1.5 to 8 times in at least one direction. Pressure-sensitive adhesive tape. The thickness of the base film _(A) (T A) is 30 to 300 [mu] m, the thickness of the auxiliary film _(B) (T B) is 35～350Myuemu, and, both of [T _A <T _B] The related semiconductor wafer surface protection adhesive tape is exemplified. The base film (A) includes a resin film selected from an ethylene-vinyl acetate copolymer and a low-density polyethylene, and the auxiliary film (B) includes a propylene-ethylene random copolymer and A resin film selected from an ethylene-vinyl acetate copolymer is exemplified.

The pressure-sensitive adhesive tape for protecting the front surface of a semiconductor wafer according to the first invention is suitably used for grinding the back surface of a semiconductor wafer, or for protecting the back surface of a semiconductor wafer during grinding and chemical etching.

According to a second aspect of the present invention, an adhesive tape for protecting the surface of a semiconductor wafer is attached to the surface of the semiconductor wafer via the adhesive layer, and the back surface of the semiconductor wafer is ground. A method for using a semiconductor wafer surface protection pressure-sensitive adhesive tape to be peeled, wherein the pressure-sensitive adhesive tape is a semiconductor wafer surface protection pressure-sensitive adhesive tape including the above-described embodiments, and the surface of the semiconductor wafer and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape. A method for using a pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer, wherein hot water at 70 to 95 ° C. is radiated to an interface of the semiconductor wafer to peel it off.

As another method of using the pressure-sensitive adhesive tape for protecting the front surface of a semiconductor wafer according to the second invention, chemical etching is performed after the back surface of the semiconductor wafer is finished, and thereafter,
The method for using the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer to be peeled off may be mentioned. Further, after the grinding of the back surface of the semiconductor wafer, a chemical etching is performed, then, an adhesive tape for dicing is attached to the surface of the semiconductor wafer, and then the method for using the adhesive tape for protecting the semiconductor wafer surface, which is peeled off, is included. .

According to the present invention, the diameter is 100 to 300 m.
Even when the back surface of the semiconductor wafer m is thinly ground to a thickness of about 50 to 200 μm, the semiconductor wafer is not damaged because the base film (A) has flexibility.

Since the support of the pressure-sensitive adhesive tape for surface protection has a two-layer structure of a flexible base film (A) and a heat-shrinkable auxiliary film (B), the semiconductor after grinding is completed. The warpage of the wafer is small. In particular, when the chemical etching is performed in a state where the surface protection adhesive tape is adhered to the surface of the semiconductor wafer after the backside grinding of the semiconductor wafer is completed, the warpage of the semiconductor wafer is small. Therefore, the semiconductor wafer does not break when the ground semiconductor wafer is stored in the carrier case, transported, or peeled off the surface protection adhesive tape.

After the back surface grinding or the back surface grinding and the chemical etching of the semiconductor wafer are completed, the wafer is transferred to a dicing step with a surface protecting adhesive tape adhered to the surface of the wafer, and is returned to the dicing step. Adhesive tape for dicing is adhered to the surface, and the adhesive tape for surface protection is peeled off, so that the wafer is scattered and broken by contacting with a cassette etc. during the transportation from the back grinding process to the dicing process. Nothing. Further, if shrinking and peeling is performed in a dicing apparatus using hot water (pure water) as a heating medium for the surface protection adhesive tape, the washing step can be omitted. Therefore, by adopting the preferred embodiment of the present invention, a series of steps from grinding of the back surface of the semiconductor wafer to cleaning of the wafer surface can be performed in a short time, and the working time can be reduced.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The adhesive tape for protecting the semiconductor wafer surface of the present invention,
Manufactured by laminating a flexible base film (A) and a heat-shrinkable auxiliary film (B) and forming an adhesive layer on the base film (A) side of the laminate. Is done. As a method for forming an adhesive layer on the surface of the base film (A), for example, an adhesive is applied to one surface of a release film and dried to form an adhesive layer. A method of transferring to the substrate film (A) side surface of the laminate is exemplified. In order to protect the pressure-sensitive adhesive layer while storing and transporting the pressure-sensitive adhesive tape for protecting the semiconductor wafer surface, it is preferable that a release film usually called a separator is attached to the surface of the pressure-sensitive adhesive layer.

The material of the base film (A) and the auxiliary film (B) may be a polymer mainly composed of ethylene, propylene, 1-butene, 1-pentene, or a polyolefin resin which is a copolymer thereof. Examples include films, ethylene-vinyl acetate copolymer films, and polyester films such as polyethylene terephthalate. Of these, films of low-density polyethylene, medium-density polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer are preferred. As the base film (A), films of ethylene-vinyl acetate copolymer and low density polyethylene are more preferable.
Further, as the auxiliary film (B), films of a propylene-ethylene random copolymer and an ethylene-vinyl acetate copolymer, which are excellent in balance between rigidity and impact resistance, are more preferable.

When grinding the back surface of the semiconductor wafer, it is preferable that the base film (A) has flexibility in consideration of preventing breakage of the wafer. In particular,
The Shore D hardness is preferably 40 or less. The smaller the heat shrinkability, the better. Specifically, at 95 ° C., 60
It is preferable that the heat shrinkage when heated for 5 seconds is 5% or less. If the heat shrinkage exceeds 5%, the accuracy of the thickness of the wafer after grinding the back surface of the semiconductor wafer is reduced, and the warpage of the wafer tends to increase.

The thickness of the base film (A) depends on the shape, surface condition, grinding method, grinding conditions, and the like of the semiconductor wafer to be protected.
Alternatively, the thickness is appropriately determined depending on workability such as cutting and sticking of the pressure-sensitive adhesive tape for surface protection, and is usually 30 to 300 μm. Preferably it is 40 to 200 μm.

The auxiliary film (B) preferably has an excellent balance between rigidity and impact resistance. Considering this point, the auxiliary film (B) preferably has a Shore D hardness of more than 40. When the Shore D hardness is 40 or less, wrinkles and bubbles are generated when the pressure-sensitive adhesive tape for protecting the semiconductor wafer surface is adhered to the wafer surface, and the handling property is reduced.

As the auxiliary film (B), a film having a heat shrinkage in at least one direction of at least 10% when heated at 95 ° C. for 60 seconds is used. The range is 10 to 40%. Preferably it is 15 to 35%. When the heat shrinkage ratio under the above conditions is less than 10%,
There is a case where sufficient peeling is not performed in shrinking peeling by heating from the surface of the semiconductor wafer. On the other hand, when it exceeds 40%, the change with time of the film is so large that it may not function as an adhesive tape.

The thickness of the auxiliary film (B) is the same as that of the base film (A), such as the shape and surface condition of the semiconductor wafer to be protected, the grinding method, the grinding conditions, or the cutting and sticking of the surface protection adhesive tape. It is appropriately determined according to workability. Normal,
It is 35 to 350 μm. Preferably 45 to 250 μm
It is.

In the pressure-sensitive adhesive tape for surface protection of the present invention, a base film (A) and an auxiliary film (B) are laminated, and an adhesive layer is formed on the surface of the obtained laminate on the side of the base film (A). Is done. When considering such a structure, the thicknesses of the base film _(A) (T A) and the auxiliary film _(B) (T B), preferred are those having a relationship of [T _A <T _B]. The thickness of the base film (A) and the auxiliary film (B) are each a thickness above and, when the relation of [T _A <T _B] is thermally peeled adhesive tape for surface protection of a semiconductor wafer surface At this time, the auxiliary film (B) shrinks and exhibits a curl shape with the auxiliary film (B) inside, so that the auxiliary film (B) is easily peeled off from the semiconductor wafer surface. If the relationship between the two is opposite to the above, it is not preferable because it tends to be difficult to peel off from the surface of the semiconductor wafer.

Each of the films (A) and (B) used in the present invention may optionally contain other resins, for example, medium density polyethylene, high density polyethylene, ethylene-vinyl alcohol copolymer, nylon and the like. May be mixed.
When other resins are mixed, the amount is preferably 10 parts by weight or less with respect to 100 parts by weight of the resin in consideration of occurrence of bumps, fish eyes and the like of the film. Furthermore, additives such as an antiblocking agent, a lubricant, a crystal nucleating agent, an ultraviolet absorber, a heat stabilizer, a weather resistance stabilizer, a radiation resistance agent, a pigment and a dye are added to the films (A) and (B). May be added.

The method for producing the base film (A) and the auxiliary film (B) is not particularly limited, and may be those produced by a known method such as an extrusion molding method and a calendar molding method. The molding temperature may be a temperature equal to or higher than the glass transition point or softening point of the raw material resin (pellet) and lower than the decomposition temperature.

In order to impart heat shrinkability, it is preferable to stretch in at least one direction. The stretching ratio affects the releasability, workability, and the like when the surface protection adhesive tape is peeled off from the wafer surface after the wafer back surface grinding. When the stretching ratio is low, when heat is applied when peeling off from the wafer surface, the heat-shrinking and / or curling of the pressure-sensitive adhesive tape for surface protection does not sufficiently occur, and the peelability tends to decrease. Considering this point, the stretching ratio is at least 1.5 times, preferably 2.0 times or more. The stretching direction may be one direction or two directions. Preferably, it is one axial direction of the longitudinal direction of the film. The upper limit of the stretching ratio is about 8 times in consideration of, for example, tear during stretching.

There are no particular restrictions on the stretching method, and there are known methods such as a roll rolling method, a one-way longitudinal stretching method using a roll stretching method, a two-way sequential stretching method using a tenter machine, and a simultaneous longitudinal and transverse stretching method using a tenter machine. Stretching method. The stretching temperature is 40 to 150 ° C, preferably 70 to 120 ° C.

It is important that the surface tension of at least the surface of the base film (A) on which the pressure-sensitive adhesive is to be formed is higher than the surface tension of the surface of the release film on the side where the pressure-sensitive adhesive layer is formed. As the base film (A), a film having a surface tension higher than the surface tension of the release film can be used regardless of the absolute value of the surface tension. In consideration of the adhesiveness of the pressure-sensitive adhesive layer to the base film (A) after the transfer from the release film, the base film (A) must have a surface tension of 35 dyne / cm or more. Is preferably selected on the basis of. If the surface tension is low, the adhesion between the pressure-sensitive adhesive layer and the base film (A) is reduced, and transfer of the pressure-sensitive adhesive layer from the release film cannot be performed well. Examples of a method for increasing the surface tension of the base film (A) include a corona discharge treatment.

The laminated support of the base film (A) and the auxiliary film (B) according to the present invention can be produced by a known method. For example, a method in which an adhesive is applied to one of the pre-produced base film (A) and the auxiliary film (B), and the two films are laminated and bonded together, or one of the pre-produced films is coated with the other resin by the T-die method Alternatively, a method of laminating by a calendar method, a corona discharge treatment is performed on each of one side of the base film (A) manufactured in advance and one side of the auxiliary film (B) to increase the surface tension of each, and the corona discharge treated surface is And a method of laminating and bonding.

The release film used for the pressure-sensitive adhesive tape for surface protection is essentially a film having a lower surface tension than that of the base film (A) regardless of the absolute value of the surface tension. Good. In addition, the heat resistance of the release film affects the drying property of the adhesive applied to the surface. If the heat resistance is low, the drying temperature of the pressure-sensitive adhesive must be low, and it takes a long time to dry, and it is not possible to dry efficiently in a short time. Further, for example, the release film may undergo heat shrinkage in a drying oven, causing a problem such as wrinkling of the release film, and the pressure-sensitive adhesive layer having a uniform thickness may not be formed. From such a viewpoint, the release film preferably has a predetermined heat resistance. As a criterion for determining heat resistance, it is preferable to have a Vicat softening point of 100 ° C. or higher. The type of the release film is not particularly limited as long as the above conditions are satisfied. It may be a single-layer film or a laminated film, and can be appropriately selected from commercially available products.

As a specific example of the release film, a film produced from high-density polyethylene, polypropylene, polyethylene terephthalate, polyamide resin or the like, or a mixture thereof can be mentioned. Preferably, a high-density polyethylene film, a polypropylene film, a polyethylene terephthalate film, or the like is used. There is no particular limitation on the production method of these films,
It may be manufactured by a known method such as an extrusion molding method or a calendar molding method, and the molding temperature may be any temperature as long as it is higher than the glass transition point or softening point of the raw material resin and lower than the decomposition temperature.

For the purpose of reducing the peeling stress of the pressure-sensitive adhesive layer from the release film, a silicone-based release agent is applied to the surface of the release film to which the pressure-sensitive adhesive is applied so long as the pressure-sensitive adhesive layer is not contaminated. No problem. The thickness of the release film varies depending on the drying conditions, the type and thickness of the pressure-sensitive adhesive layer, the processing conditions of the pressure-sensitive adhesive tape for protecting the semiconductor wafer surface, the processing method, and the like, but is usually 10 to 1000 μm. Preferably it is 20 to 100 μm. The peeling of the release film from the surface of the pressure-sensitive adhesive layer is preferably performed immediately before use as a pressure-sensitive adhesive tape for surface protection.

The pressure-sensitive adhesive layer used for the surface protection pressure-sensitive adhesive tape may be any pressure-sensitive adhesive layer designed in accordance with the conditions such as the surface shape of the wafer to be ground, the diameter of the wafer, the type of the surface protection film, and the back surface grinding amount. It can be used, a coating solution containing an adhesive polymer, a crosslinking agent, additives, etc. (solution or
(Emulsion liquid) to the base film (A) or the release film.

The pressure-sensitive adhesive polymer is not particularly limited and can be appropriately selected from commercially available products and the like. However, an acrylic pressure-sensitive adhesive is preferred from the viewpoints of tackiness, applicability, and non-staining properties of the wafer surface. Such an acrylic pressure-sensitive adhesive is an acrylic acid alkyl ester monomer, and a carboxyl group,
It is obtained by copolymerizing a monomer mixture containing a monomer having a functional group such as a hydroxyl group. Further, a vinyl monomer, a polyfunctional monomer, an internal crosslinkable monomer, and the like copolymerizable therewith can be copolymerized as necessary. Also, if an emulsion-based adhesive polymer is used,
There is an effect that the wafer surface is cleaned in a heating peeling step using warm water, which will be described later.

Examples of the alkyl acrylate monomer include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, hexyl acrylate, hexyl methacrylate, octyl acrylate, octyl methacrylate, and nonyl. Acrylate, nonyl methacrylate, dodecyl acrylate, dodecyl methacrylate and the like can be mentioned. The side chain alkyl group of these monomers may be linear or branched. Further, two or more of the above-mentioned alkyl acrylate monomers may be used in combination depending on the purpose.

Examples of the monomer having a functional group include monomers having a carboxyl group such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and the like. Examples thereof include monomers having a hydroxyl group such as hydroxypropyl methacrylate, acrylamide, methacrylamide, dimethylaminoacrylate, dimethylaminomethacrylate, and the like, and other copolymerizable monomers such as vinyl acetate, styrene, and acrylonitrile.

The polymerization reaction mechanism of the pressure-sensitive adhesive polymer includes:
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 influence of the functional group of the monomer, the influence of ions on the surface of the semiconductor wafer, and the like. When polymerizing by a radical polymerization reaction, examples of a radical polymerization initiator include organic peroxides such as benzoyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, di-tert-butyl peroxide, and di-tert-amyl peroxide. Inorganic peroxides such as ammonium persulfate, potassium persulfate and sodium persulfate, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 4,4'-azobis And azo compounds such as -4-cyanovaleric acid.

When the polymerization is carried out by the emulsion polymerization method, among these radical polymerization initiators, water-soluble inorganic peroxides such as 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. In consideration of the influence of ions on the surface of the semiconductor wafer, an azo compound having a carboxyl group in the molecule, such as 4,4′-azobis-4-cyanovaleric acid, is more preferable.

The pressure-sensitive adhesive polymer obtained as described above is preferably crosslinked with a crosslinking agent having two or more functional groups in one molecule. This cross-linking agent is used to react with the functional group of the pressure-sensitive adhesive polymer to adjust the adhesion and cohesion. Examples of the crosslinking agent include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcin diglycidyl ether. , Tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylolpropane toluene diisocyanate 3 adduct,
Isocyanate compounds such as polyisocyanate, 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
Aziridine compounds such as -bis-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. Among the above cross-linking agents, the epoxy-based cross-linking agent has a low speed of the cross-linking reaction, and when the reaction does not proceed sufficiently, the cohesive force of the pressure-sensitive adhesive layer is reduced, and the unevenness of the semiconductor wafer surface is caused by the pressure-sensitive adhesive layer. Contamination may occur. Therefore, as appropriate, a catalyst such as an amine is added, a monomer having an amine functional group having a catalytic action is copolymerized with the pressure-sensitive adhesive polymer, or an aziridine having an amine property when a crosslinking agent is used. It is preferable to use a system crosslinking agent in combination.

The amount of the cross-linking agent to be added is preferably 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, when the crosslinking reaction is slow, or the like, an excessive amount may be added as necessary. Normally, the adhesive strength of the surface protection adhesive tape to be attached to the wafer surface when grinding the wafer back surface is determined by the grinding conditions of the wafer back surface, the diameter of the wafer,
It is set appropriately considering the thickness of the wafer after grinding, etc.
Normally, a SUS-BA plate is used as an adherend in accordance with the method specified in JIS-Z0237,
The adhesive force measured under the conditions of 0 mm / min and a peel angle of 180 degrees is 10 to 1000 g / 25 mm, preferably 30
It is about 600 g / 25 mm. As a guide, it is adjusted by adding 0.1 to 30 parts by weight of a crosslinking agent to 100 parts by weight of the tackifier polymer. Preferably it is 0.3 to 15 parts by weight.

If necessary, the pressure-sensitive adhesive may contain an additive such as a surfactant so as not to contaminate the wafer surface. In particular, by containing a surfactant, there is an effect that the wafer surface is cleaned in a heat-peeling step using warm water described later. The surfactant may be nonionic or anionic as long as it does not contaminate the wafer surface. As a nonionic surfactant,
Examples thereof include polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, and polyoxyethylene lauryl ether. As anionic surfactants, alkyl diphenyl ether disulfonates and salts thereof, bisnaphthalene sulfonates and salts thereof, polyoxyethylene alkyl sulfosuccinates and salts thereof, polyoxyethylene alkyl phenyl ether sulfates and salts thereof And the like.

The surfactants exemplified above may be used alone or in combination of two or more. The amount of the surfactant added is 0.1% based on the total weight of the pressure-sensitive adhesive polymer and the crosslinking agent, that is, 100 parts by weight of the crosslinked pressure-sensitive adhesive polymer.
It is preferably from 0.5 to 5 parts by weight. More preferably 0.05 to
3 parts by weight.

As a method of applying the pressure-sensitive adhesive coating solution to one surface of the base film (A) or the release film, a conventionally known coating method, for example, a roll coater method, a gravure roll method, a bar coat method, or the like can be adopted. The drying condition of the applied pressure-sensitive adhesive is not particularly limited, but is generally 80 to
It is preferable to dry in a temperature range of 200 ° C. for 10 seconds to 10 minutes. More preferably, drying is performed at 80 to 170 ° C. for 15 seconds to 5 minutes. The thickness of the pressure-sensitive adhesive layer is appropriately determined depending on the surface condition, shape, and back surface grinding method of the semiconductor wafer. Adhesive force when the back surface of the semiconductor wafer is ground, peelability after the grinding is completed, and the like are determined. Considering this, it is usually about 2 to 100 μm. Preferably 5
It is about 70 μm.

After forming the pressure-sensitive adhesive layer on the surface of the release film as described above, the base film (A) is laminated on the surface of the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is applied to the base film ( Transfer to the surface of A). The transfer method may be a known method. For example, there is a method in which the base film A is overlaid on the surface of the pressure-sensitive adhesive layer formed on the surface of the release film, and they are drawn through a nip roll and pressed. The thus obtained pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer is formed into a roll or cut into a predetermined shape, and then provided for storage, transportation and the like.

Next, a method for using the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer will be described. The adhesive tape for protecting the semiconductor wafer surface is attached to the surface of the semiconductor wafer via the adhesive layer. Then, the semiconductor wafer is fixed to a chuck table or the like of a wafer back surface grinding machine via a laminated support of a surface protection adhesive tape. Next, the back surface of the wafer is ground to a predetermined thickness by a grinding machine. When grinding,
It is common that cooling water is injected into the grinding surface.

After the grinding is completed, grinding dust and the like are removed by, for example, pouring pure water into the ground surface, and then, if necessary, chemical etching is performed. Chemical etching adheres to an etching solution selected from the group consisting of an acidic aqueous solution composed of a single or mixed liquid of hydrofluoric acid, nitric acid, sulfuric acid, acetic acid, etc., 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 with the film 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, and performing pre-processing when forming electrodes on the back surface. The etching solution is appropriately selected according to the above purpose.

After the back surface grinding or the back surface grinding and the chemical etching are completed, the wafer is transported to a dicing step or a peeling step with the surface protection adhesive tape adhered. In the case of peeling in the dicing step, a dicing tape is attached and fixed as if the back surface of the semiconductor wafer was fixed to a chuck table. At this time, as a method of attaching the dicing tape, the dicing tape may be set on a ring-shaped frame in advance, and then the semiconductor wafer with the surface protection adhesive tape attached may be mounted. Further, the semiconductor wafer with the ring-shaped frame and the surface protection adhesive tape adhered thereto may be simultaneously adhered to the dicing tape.

The method of mounting on the ring-shaped frame is not particularly limited. As a mounting device, for example,
Takatori Co., Ltd., Model: ATM-8100, Nitto Denko Corporation, Model: MA-1508N, Furukawa Electric Co., Ltd., Model: UCTM-03-8.
As a dicing tape, for example, Nitto Denko Corporation
Product name: UE-2092J, Furukawa Electric Co., Ltd.
Product name: UC series, CD series, manufactured by Lintec Co., Ltd., product name: D series, etc.

By attaching the dicing tape to the ring-shaped frame without slack, there is an effect of reinforcing the semiconductor wafer attached to the center portion of the ring-shaped frame. Further, after the pressure-sensitive adhesive tape for surface protection is peeled off by heating and shrinking, it can be transferred to a dicer machine as it is.

As a method of heating and shrinking and peeling the pressure-sensitive adhesive tape for surface protection, there is a method of heating by radiating warm water. In the method of radiating hot water, it is preferable to supply hot water near the interface between the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape for surface protection and the surface of the semiconductor wafer. If hot water is positively supplied near the interface, the heat-shrinkable auxiliary film (B) of the pressure-sensitive adhesive tape for surface protection can be relatively selectively shrunk from the end face, and the shrinkage speed has a capillary phenomenon. And the effect of lowering the interfacial adhesion is increased.

It is preferable to use hot water that does not contaminate the semiconductor wafer surface. Furthermore, irradiating warm water at the time of peeling the surface protection adhesive tape has an effect of simultaneously cleaning the wafer surface. Even in consideration of such a cleaning effect, it is preferable to supply hot water to the vicinity of the interface between the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape for surface protection and the wafer surface as a method of radiating hot water.

Further, the above-mentioned cleaning effect can be further enhanced by using an emulsion-based pressure-sensitive adhesive polymer as the pressure-sensitive adhesive polymer constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape for surface protection, or by adding a surfactant to the pressure-sensitive adhesive layer. It can be increased, and a dedicated cleaning step can be omitted.

The temperature of the hot water is from 70 ° C. to 95 ° C., depending on the stretching ratio of the laminated support film (the film obtained by laminating the base film A and the auxiliary film B) of the surface protection adhesive tape, the surface shape of the semiconductor wafer, and the like. It can be appropriately selected in the range of ° C. The hot water emission time also affects the peelability from the semiconductor wafer surface. The warm water emission time varies depending on the adhesive strength of the surface protection adhesive tape, the diameter of the semiconductor wafer, and the like. However, considering workability and the like, it is usually 1 to 60 seconds, preferably 1 to 60 seconds.
0 to 30 seconds. When the number of washing steps is reduced, the time is 0.5 to 10 minutes, preferably 1 to 5 minutes.

After the pressure-sensitive adhesive tape for surface protection is peeled off, the pressure-sensitive adhesive tape for surface protection that has shrunk may remain on the semiconductor wafer. This can be easily achieved by rotating the mount or further supplying hot water. Can be removed. When the adhesive tape for surface protection is shrunk and peeled, if the mount is rotated or the amount of radiating hot water is increased, the adhesive tape for surface protection can be removed simultaneously with the peeling, further simplifying the process. can do. After the removal of the surface protection adhesive tape is completed, the semiconductor wafer is transferred to a dicing apparatus, and the semiconductor wafer is cut into chips.

In the present invention, since the pressure-sensitive adhesive tape for surface protection is easily peeled off, the peeling step can be performed in a back grinding apparatus, an etching apparatus, a dicing apparatus, or the like. At this time, it is only necessary to attach the hot water radiating device to the conventional device.

The size of the semiconductor wafer to which the present invention can be applied is 100 to 300 mm in diameter. In the future, it is expected that the size of the semiconductor wafer will be about 400 mm in diameter, but in such a case, it can be sufficiently obtained. As a semiconductor wafer to which the present invention can be applied, silicon wafer, germanium, gallium-arsenic, gallium-arsenic-
Aluminum and the like can be mentioned.

[0062]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to only these Examples. The various characteristic values shown in the examples were measured by the following methods. (1) Shrinkage rate (%) of base film A and auxiliary film B An arbitrary part of the film is selected and each of the length and width is 10 cm.
15 pieces of square specimens are prepared (at this time, marks are made in the vertical direction in advance). 6 in warm water adjusted to 95 ° C
After immersing for 0 second and taking out, it is left at room temperature for 24 hours. The length of the sample in the vertical direction (machine direction) is measured, and the shrinkage is determined from the length before and after immersion in warm water. Shrinkage (%) = {(test piece length before immersion in hot water−length of test piece after immersion in hot water) / length of test piece before immersion in hot water} × 100

(2) Amount of warpage deformation of semiconductor wafer (μm) After the back surface grinding, before measuring the height of silicon mirror wafer (diameter: 200 mm) while moving the entire width of the XY axis at 5 mm / sec before peeling off the adhesive tape. The difference between the maximum value and the minimum value was defined as the amount of warpage deformation. The measurement device used was “Simple Measurement System / EMS97-300X” manufactured by Sigma Koki Co., Ltd. In addition, the attached sensor is L manufactured by Keyence Corporation.
K-030, LK-2000, LK-C2, RD-50
R and KZ-U3 were used. (3) Measurement of Shore D hardness According to ASTM-D-2240. The test piece is 150 vertical
A press-formed product having a size of 150 mm × width 150 mm × thickness 6 mm was used. (4) Number of broken wafers (sheets) A scribe line with a width of 100 μm and a depth of 5 μm is 1 cm
Fifty silicon mirror wafers formed vertically and horizontally at an interval to the end, the number damaged when grinding the back surface, the number damaged when stored in the cassette after the back surface grinding, and the number damaged when peeled by hot water radiation , Respectively.

Example 1 <Preparation of pressure-sensitive adhesive coating solution> Deionized water 148 was added to a polymerization reactor.
Parts by weight, ammonium salt of polyoxyethylene nonyl phenyl ether sulfate [manufactured by Nippon Emulsifier Co., Ltd., trade name: Newcol-56] as an anionic surfactant
0SF, 50% by weight aqueous solution] 2 parts by weight (1 part by weight of a surfactant alone) and 4,4'-azobis-41-cyanovaleric acid as a polymerization initiator [Otsuka Chemical Co., Ltd.
(Trade name: ACVA) 0.5 parts by weight, 74 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, and 1 part by weight of acrylamide Then, emulsion polymerization was carried out at 70 ° C. for 9 hours under a stirring frame to obtain an acrylic resin-based water emulsion. This was neutralized with 14% by weight of aqueous ammonia to obtain a pressure-sensitive adhesive polymer (base) emulsion having a solid content of about 40% by weight. 100 parts by weight of the obtained adhesive base material emulsion (adhesive polymer concentration: about 40% by weight)
And further added 14% by weight aqueous ammonia to adjust the pH.
Adjusted to 9.3. Next, an aziridine-based crosslinking agent [manufactured by Nippon Shokubai Chemical Industry Co., Ltd., trade name: Chemitite PZ-3]
3] 2 parts by weight and 5 parts by weight of diethylene glycol monobutyl ether as a film forming aid were added to obtain an adhesive coating solution.

<Production of Laminated Support Film> Production of Auxiliary Film B:
Propylene random copolymer resin [MFI (ASTM-
D-1238, 230 ° C, 2.16 load) 4g / 10m
in, specific gravity (ASTM-D-792) 0.9, ethylene content 5.5 wt%, Shore D hardness 98]
The film is stretched three times in the machine direction at 0 ° C. by a roll stretching method to a thickness of 8
It was a 0 μm uniaxially stretched film. At this time, one surface on which the base film A was laminated was subjected to a corona discharge treatment, the surface tension was set to 50 dyne / cm, and this was used as the auxiliary film B. Production of base film A: An ethylene-vinyl acetate copolymer resin having a Shore D hardness of 38 was formed into a film having a thickness of 60 μm using a T-die extruder. At this time, the surface on which the auxiliary film B is laminated and the surface on which the pressure-sensitive adhesive layer is formed are subjected to corona treatment, and the surface tension of both surfaces is set to 50 dyne / cm.
This was used as a base film A. Next, the surface of the base film A and the auxiliary film B on which the corona discharge treatment was performed is 2 k
It was pressed with a pressure of g / cm ² , superposed, and used as a laminated support film. The results of measuring the heat shrinkage of the auxiliary film B and the base film A by the above method are shown in Table 1.

<Production of pressure-sensitive adhesive tape for surface protection> A film having a thickness of 50 μm and a Vicat softening point of 14 formed by a T-die extrusion method
Using a polypropylene film having a surface tension of 30 dyne / cm at 0 ° C. as a release film, applying the acrylic resin water emulsion type pressure-sensitive adhesive obtained by the above method to the one surface of the release film by a roll coater method. Then, it was dried at 100 ° C. for 60 seconds, and a 10 μm thick acrylic tackifier layer was provided on the surface of the release film. The corona discharge treated surface of the laminated support film (one surface of the base film A) is laminated on the surface of the acrylic pressure-sensitive adhesive layer provided on the surface of the release film, and laminated.
The pressure-sensitive adhesive layer was pressed with a pressure of kg / cm ^{2, and} the pressure-sensitive adhesive layer was transferred to the surface of the laminated support film to obtain an adhesive strength of 250 g / 25 m.
m of a semiconductor wafer surface-protecting adhesive tape.

<Use of Pressure-Sensitive Adhesive Tape for Surface Protection>
silicon mirror wafer (20 mm in diameter) in which scribe lines having a depth of 5 μm
0 mm, thickness of 700 μm) is adhered to a surface of 50 sheets using a tape pasting machine [“ATM1100E” manufactured by Takatori Co., Ltd.], and a back grinding device [“D” manufactured by Disco Co., Ltd.
FG841 "]. In the grinder, rough grinding was performed first, then finish grinding, and finally back surface cleaning was performed. That is, the pattern wafer was roughly ground to a thickness of 170 μm at a grinding speed of 300 μm / min and then finish-ground to 100 μm at a speed of 20 μm / min in a backside grinder. Finally, after cleaning the back surface with a spinner in the back grinding apparatus, the wafer is further turned over so that the front and back sides are reversed, and hot water at 95 ° C. (flow rate 30 ml / sec) is applied to the surface protection adhesive tape attached to the wafer surface. For 15 seconds to release the tape. After rotating at 3000 rpm and drying,
It was taken out of the spinner and stored in a cassette. All 50 wafers could be stored without breakage. The results obtained are shown in [Table 1].

Example 2 In the production of the auxiliary film (B) in Example 1, an ethylene-propylene random copolymer resin [MFI (AST
MD-1238, 230 ° C, 2.16 load) 4g / 1
0 min, specific gravity (ASTM-D-792) 0.90, ethylene content 5.5 wt%, Shore D hardness 98] The film was stretched 2.5 times in the machine direction by a roll stretching method at 90 ° C. All tests were performed in the same manner as in Example 1 except that a uniaxially stretched film of 80 μm was used. The results obtained are shown in [Table 1].

Example 3 In the production of the base film (A) in Example 1, an ethylene-vinyl acetate copolymer resin having a Shore D hardness of 32 was used.
All tests were performed in the same manner as in Example 1 except that a film having a thickness of 60 μm was formed using a die extruder. The results obtained are shown in [Table 1].

Example 4 In the production of the auxiliary film (B) of Example 1, an ethylene-vinyl acetate copolymer resin having a Shore D hardness of 45 [MF
I (ASTM-D-1238, 190 ° C., 2.16 load) 1.5 g / 10 min] Except that the film was stretched 2.6 times in the longitudinal direction at 50 ° C. to obtain a uniaxially stretched film having a thickness of 80 μm. All tests were performed in the same manner as in Example 1.
The results obtained are shown in [Table 1].

Example 5 In the use of the pressure-sensitive adhesive tape for protecting a surface of Example 1, the obtained pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer was applied to a surface having a width of 10 mm.
A scribe line of 0 μm and depth of 5 μm is 1c to the end face
A tape grinder [“ATM1100E” manufactured by Takatori Co., Ltd.] is used to attach to 50 surfaces of silicon mirror wafers (diameter 200 mm, thickness 700 μm) formed vertically and horizontally at m intervals, and a back grinding device [(stock) ) Made by Disco "DFG841"]. In the grinder, rough grinding was performed first, then finish grinding, and finally back surface cleaning was performed. That is, in the backside grinding machine, the pattern wafer is roughly ground to a thickness of 170 μm at a grinding speed of 300 μm / min.
Next, finish grinding was performed to 20 μm / min to 100 μm. Finally, the back surface was washed with a spinner in a back grinding device, dried at 3000 rpm, dried, taken out of the spinner, and stored in a cassette. All 50 wafers could be stored without breakage. The measured amount of warpage was 300 μm.

Then, 61% nitric acid 30 kept at 23 ° C.
2 in a mixed acid of 00ml and 600ml of 47% hydrofluoric acid
Then, the back surface was etched to 95 μm. At this time, there was no infiltration or cracking of the acid accompanying the etching.
Thereafter, when the amount of warpage of the wafer was measured,
μm. Next, it was conveyed to a dicing process.
"ATM-8" manufactured by Takatori Co., Ltd.
100 ", Nitto Denko Corporation as a dicing tape
The wafer was mounted on a ring-shaped frame using “UE-2092J” manufactured by Toshiba Corporation. A free automatic dicing saw in which the cooling water line has been changed while the mounting state is maintained,
It was transported to Disco "DFD-650". 90 ° C hot water is radiated from the hot water nozzle at 5 liters per minute to the interface between the adhesive layer of the surface protection adhesive tape and the wafer, and as the surface protection adhesive tape shrinks, curls and peels, hot water is applied to the peeling interface. The surface protection adhesive tape was peeled off by continuously radiating, and the surface protection adhesive tape was removed from the wafer. At this time, there was no breakage of the wafer due to peeling of the adhesive tape.

[0073]

[Table 1]

Comparative Example 1 In the production of the base film (A) of Example 4, an ethylene-vinyl acetate copolymer resin film having a Shore D hardness of 45 was used, and in the production of the auxiliary film (B), the Shore D hardness was The same evaluation as in Example 4 was performed except that the ethylene-vinyl acetate copolymer resin No. 38 was used. The results obtained are shown in [Table 2].

Comparative Example 2 In the production of the base film (A) of Example 4, an ethylene-vinyl acetate copolymer resin having a Shore D hardness of 38 [MF
I (ASTM-D-1238, 190 ° C., 2.16 load) 1.5 g / 10 min] The film is stretched 2.6 times in the longitudinal direction at 50 ° C. to form a uniaxially stretched film having a thickness of 60 μm. In the production of B), the same evaluation as in Example 4 was performed except that the ethylene-vinyl acetate copolymer resin film having a Shore D hardness of 45 was not stretched. The results obtained are shown in [Table 2].

Comparative Example 3 In the production of the auxiliary film (B) of Example 4, the same evaluation as in Example 4 was carried out except that the stretching ratio was changed to 1.4. The wafer was broken without any problem during the grinding and transfer, but during the peeling, due to insufficient shrinkage, 28 wafers showed defective peeling, and four wafers were damaged. The results obtained are shown in [Table 2].

Comparative Example 4 In the production of the auxiliary film (B) of Example 1, the same evaluation as in Example 1 was carried out except that the stretching ratio was 1.2 times. The results obtained are shown in [Table 2].

Comparative Example 5 The same evaluation as in Example 4 was performed except that the base film (A) was not used and the auxiliary film (B) was used as a single layer. The warpage after grinding is 450μ
m, the number of damaged wafers was 14 during grinding, 6 during transport, and 10 during peeling, for a total of 30 wafers. The results obtained are shown in [Table 2].

[0079]

[Table 2]

[0080]

According to the present invention, when the adhesive tape for protecting the surface of a semiconductor wafer having one layer having heat shrinkage as a two-layer structure is peeled off from the semiconductor wafer surface after the back surface grinding,
By reducing the warpage of the wafer and radiating warm water to the wafer surface, heat shrinkage occurs on the surface protection adhesive tape, and the warm water promotes penetration between the adhesive layer and the wafer, and the adhesive strength of the adhesive tape The pressure-sensitive adhesive tape is peeled off while reducing the pressure. Thus, in the semiconductor wafer surface protection adhesive tape peeling step, the adhesive tape can be easily peeled without causing breakage of the wafer at the time of peeling. Furthermore, if the composition of the adhesive is selected, the peeling operation can also serve as cleaning of the wafer surface, thereby enabling further rationalization such as shortening of operation time.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kentaro Hirai 2-1-1 Tangodori, Minami-ku, Nagoya City, Aichi Prefecture Inside of Mitsui Chemicals, Inc. (72) Inventor Hideki Fukumoto 2-1-1 Tangodori, Minami-ku, Nagoya City, Aichi Prefecture Mitsui Chemicals, Inc.

Claims (8)

[Claims] An adhesive tape for protecting a semiconductor wafer surface, comprising an adhesive layer provided on one surface of a base film (A) and an auxiliary film (B) laminated on another surface,
(A) Shore D hardness of 40 or less, (B) Shore D hardness of more than 40, (A) heat shrinkage of 5% or less when heated at 95 ° C. for 60 seconds, (B) heat shrinkage An adhesive tape for protecting the surface of a semiconductor wafer having a ratio of at least 10%. 2. The auxiliary film (B) is a resin film stretched 1.5 to 8 times in at least one direction.
The adhesive tape for protecting a surface of a semiconductor wafer according to the above. 3. The thickness (T _A ) of the base film ( _A ) is 3
0～300Myuemu, assisting film (B) thickness (T _B) is 35～350Myuemu, and a semiconductor wafer surface protecting adhesive tape of claim 1, wherein a relationship of both [T _A <T _B]. 4. The base film (A) is a resin film selected from ethylene-vinyl acetate copolymer and low density polyethylene, and the auxiliary film (B) is a propylene-ethylene random copolymer and ethylene-vinyl acetate copolymer. The pressure-sensitive adhesive tape for protecting a semiconductor wafer surface according to claim 1, wherein the pressure-sensitive adhesive tape is a resin film selected from a polymer. 5. The pressure-sensitive adhesive tape for protecting a front surface of a semiconductor wafer according to claim 1, wherein the pressure-sensitive adhesive tape is used for back surface grinding of a semiconductor wafer, or for surface protection during back surface grinding and chemical etching of a semiconductor wafer. 6. An adhesive tape for protecting the surface of a semiconductor wafer, wherein the adhesive tape for protecting the surface of the semiconductor wafer is adhered to the surface of the semiconductor wafer via the adhesive layer, the back surface of the semiconductor wafer is ground, and peeled off after the grinding is completed. How to use the tape,
The pressure-sensitive adhesive tape is the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer according to any one of claims 1 to 4, and the pressure-sensitive adhesive tape is provided at an interface between the surface of the semiconductor wafer and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape.
A method of using a pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer, wherein the pressure-sensitive adhesive tape is peeled off by radiating warm water of up to 95 ° C. 7. The method for using a semiconductor wafer surface protection adhesive tape according to claim 6, wherein after the back surface grinding of the semiconductor wafer is completed, chemical etching is performed, and thereafter, the semiconductor wafer is peeled off. 8. The semiconductor wafer according to claim 6, wherein after the back grinding of the semiconductor wafer is completed, chemical etching is performed, and then an adhesive tape for dicing is adhered to the back surface of the semiconductor wafer, and thereafter the semiconductor wafer is peeled off. How to use adhesive tape for surface protection.