KR20190027731A - Adhesive tape for protecting semiconductor wafer - Google Patents

Abstract

Provided is an adhesive tape for protecting a semiconductor wafer which is difficult to occur a crack on a semiconductor wafer. To this end, the adhesive tape for protecting a semiconductor wafer comprises: a base material; and an adhesive layer stacked on the base material. The thickness of the base material is 10-150 μm. The maximum increase rate of the thickness of the adhesive tape is lower than or equal to 1.2% at the temperature of 23-100°C for the thickness of the adhesive tape at 23°C when the adhesive tape is heated at -70-150°C while applying a load of 0.11 N in a thickness direction by a compression swelling method of a thermal mechanical analysis device.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure-sensitive adhesive tape for protecting a semiconductor wafer,

The present invention relates to a pressure-sensitive adhesive tape for protecting a semiconductor wafer. More particularly, the present invention relates to a pressure-sensitive adhesive tape for protecting a semiconductor wafer used for back-cutting a semiconductor wafer.

BACKGROUND ART [0002] Conventionally, in manufacturing semiconductor devices, a back grind tape may be used. The back grind tape has a configuration in which a pressure sensitive adhesive layer is formed on a substrate, and a semiconductor wafer is placed on the pressure sensitive adhesive layer and used to hold a semiconductor wafer at the back grinding (back grinding) of the semiconductor wafer, (For example, refer to Patent Documents 1 to 3). In the case where the semiconductor wafer is divided into individual pieces by the back grinding, the separated semiconductor chips are fixed so as not to scatter.

Back grinding is usually performed by disposing a surface of a semiconductor wafer (a surface (a surface on which a wiring structure necessary for a semiconductor element is formed)) on a pressure-sensitive adhesive layer of a back grind tape, grinding the semiconductor wafer to a predetermined thickness from the back surface, Is thinned.

In recent years, there has been a method (referred to as " DBG (Dicing Before Grinding) ") in which individual grooves are formed on the surface of a semiconductor wafer and then back grinding is performed The semiconductor wafer can be easily divided into the line to be divided and then subjected to back grinding. Thereafter, the semiconductor wafer is adhered to the dicing die-bonding film The semiconductor wafer and the die-bonding film are both cut off (broken) by exposing the dicing tape at a low temperature (for example, -25 to 0 占 폚) (A semiconductor chip with a die-bonding film) is proposed. This is a so-called "SDBG (Stealth Dicing Before Grinding)" method.

Japanese Patent Application Laid-Open No. 2011-054940 Japanese Patent Application Laid-Open No. 2015-185691 Japanese Patent Application Laid-Open No. 2005-343997

2. Description of the Related Art In recent years, the demand for higher capacity of semiconductors has led to the progress of thinning of the silicon layer. Therefore, a technique for obtaining a semiconductor wafer thinner than conventional by back grinding is needed. In the back grinding process for obtaining a semiconductor wafer thinner than the conventional one, the main grinding for thinning the semiconductor wafer and the grinding after the main grinding are improved and then the polishing is performed.

However, in such a back grind step for obtaining a semiconductor wafer thinner than the conventional one, there has been a problem that cracks (cracks) are likely to occur in the semiconductor wafer in main grinding or subsequent polishing. In particular, cracks were likely to occur in the backgrind process when a semiconductor wafer on which a modified region was formed by laser light irradiation was used.

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above problems, and the present inventors paid attention to a back grind tape, and aimed to develop a pressure-sensitive adhesive tape which is hard to cause a crack in a semiconductor wafer in a back grind process. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pressure-sensitive adhesive tape for protecting a semiconductor wafer which hardly causes a crack in a semiconductor wafer in a back-grinding process.

Means for Solving the Problems The present inventors have intensively studied to achieve the above object, and as a result, have found that a pressure-sensitive adhesive tape for protecting a semiconductor wafer having a base material and a pressure-sensitive adhesive layer laminated on the base material has a thickness of 10 to 150 탆, The thickness of the adhesive tape at 23 占 폚 when the adhesive tape is heated from -70 占 폚 to 150 占 폚 in a state in which a load of 0.11 N is applied in the thickness direction by the compression- And the maximum increase rate of the thickness of the pressure-sensitive adhesive tape at 100 DEG C is 1.2% or less, cracks are unlikely to occur in the semiconductor wafer in the backgrind process. The present invention has been completed on the basis of these findings.

That is, the present invention relates to a pressure-sensitive adhesive tape for protecting a semiconductor wafer having a substrate and a pressure-sensitive adhesive layer laminated on the substrate, wherein the thickness of the substrate at 23 캜 is 10 to 150 탆, , And the pressure-sensitive adhesive tape at 23 to 100 DEG C with respect to the thickness of the pressure-sensitive adhesive tape at 23 DEG C when the pressure-sensitive adhesive tape is heated from -70 DEG C to 150 DEG C under a load of 0.11 N in the thickness direction. Wherein a maximum growth rate of the thickness of the adhesive layer is 1.2% or less.

The pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention has a thickness of 10 to 150 탆 at 23 캜 and a pressure of 0.11 N in a thickness direction by a compression and expansion method of a thermomechanical analyzer The maximum rate of increase of the thickness of the pressure-sensitive adhesive tape at 23 to 100 占 폚 with respect to the thickness of the pressure-sensitive adhesive tape at 23 占 폚 when the pressure-sensitive adhesive tape is heated from -70 占 폚 to 150 占 폚 ) Is 1.2% or less, even when the adhesive tape is heated up to about 100 ° C in the backgrind process in which the semiconductor wafer is made thinner than the conventional one, the thermal expansion to the thickness of the adhesive tape at a room temperature is small , The stress applied to the semiconductor wafer from the adhesive tape is small. Therefore, not only a case where a normal semiconductor wafer is used but also a case where a weakened Even a semiconductor wafer station is formed, it is difficult to crack is generated.

The pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention is characterized in that a pressure-sensitive adhesive layer having a loss coefficient (tan?) Of 1.0 or more according to the nanoindentation method under the conditions of a temperature of 25 DEG C and a frequency of 100 Hz is applied to at least one layer . The adhesion of the adhesive tape to the semiconductor wafer is usually carried out by using a lamination apparatus. In this case, since it is practically impossible to attach the adhesive tape without applying any tension, the tension applied to the adhesive tape after attachment is the residual stress Has accumulated. With this residual stress, cracks are generated in the back grind process due to collision between regions (regions corresponding to the semiconductor chips after individual fabrication) between the modified regions of the semiconductor wafers, for example, It tends to be easy to do. On the other hand, in the case where the pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention has a pressure-sensitive adhesive layer having a loss coefficient (tan?) Of 1.0 or more, the residual stress tends to be dispersed / lost (stress relaxation) Stress is hardly applied to the wafer and it is difficult to cause cracks.

INDUSTRIAL APPLICABILITY The adhesive tape for protecting a semiconductor wafer of the present invention hardly causes cracks in the semiconductor wafer in the backgrind process. In particular, even when a semiconductor wafer on which a weakened region such as a modified region is formed is used, it is difficult to generate cracks.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing one embodiment of a pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention. Fig.
2 is a schematic cross-sectional view showing another embodiment of the adhesive tape for protecting a semiconductor wafer of the present invention.
3 shows a part of steps in the method of manufacturing a semiconductor device using the adhesive tape for protecting a semiconductor wafer of the present invention.
4 shows a part of steps in the method of manufacturing a semiconductor device using the adhesive tape for protecting a semiconductor wafer of the present invention.
Fig. 5 shows a part of steps in the method of manufacturing a semiconductor device using the adhesive tape for protecting a semiconductor wafer of the present invention.
Fig. 6 is a graph showing the expansion rate of the pressure-sensitive adhesive tape of Example 1 with respect to the thickness of 23 占 폚 in the range of 23 to 100 占 폚 as measured by a compression-expansion method of a thermomechanical analyzer.
7 is a graph showing the expansion rate of the pressure-sensitive adhesive tape of Example 2 with respect to the thickness of 23 DEG C in the range of 23 to 100 DEG C measured by the compression expansion method of the thermomechanical analyzer.
8 is a graph showing the expansion rate of the pressure-sensitive adhesive tape of Example 3 with respect to the thickness of 23 DEG C in the range of 23 to 100 DEG C measured by the compression expansion method of the thermomechanical analyzer.
9 is a graph showing the expansion rate of the pressure-sensitive adhesive tape of Example 4 with respect to the thickness of 23 DEG C in the range of 23 to 100 DEG C measured by the compression expansion method of the thermomechanical analyzer.
10 is a graph showing the expansion rate of the pressure-sensitive adhesive tape of Example 5 with respect to the thickness of 23 DEG C in the range of 23 to 100 DEG C measured by the compression expansion method of the thermomechanical analyzer.
11 is a graph showing the expansion rate of the pressure-sensitive adhesive tape of Example 6 to a thickness of 23 占 폚 in the range of 23 to 100 占 폚 as measured by a compression expansion method of a thermomechanical analyzer.
12 is a graph showing the expansion rate with respect to the thickness of 23 DEG C in the range of 23 to 100 DEG C measured by the compression expansion method of the thermomechanical analyzer with respect to the adhesive tape of Comparative Example 1. Fig.
13 is a graph showing the expansion rate with respect to the thickness of 23 DEG C in the range of 23 to 100 DEG C measured by the compression expansion method of the thermomechanical analyzer with respect to the adhesive tape of Comparative Example 2. Fig.

[Adhesive tape for semiconductor wafer protection]

The adhesive tape for protecting a semiconductor wafer according to the present invention is characterized in that when one surface (in particular, a back surface) of the semiconductor wafer is ground to thin the semiconductor wafer, the other surface (in particular, the surface) of the semiconductor wafer is adhered to the pressure- It is preferable to be used for the purpose of

The pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention comprises a base material and a pressure-sensitive adhesive layer laminated on the base material.

As described above, the thickness of the substrate at 23 占 폚 is 10 to 150 占 퐉, preferably 25 to 100 占 퐉 in the pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention. When the thickness is within the above range, cracks are unlikely to occur in the semiconductor wafer when the maximum growth rate of the adhesive tape for protecting the semiconductor wafer is 1.2% or less.

The pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention was heated from -70 占 폚 to 150 占 폚 in a state in which a load of 0.11 N was applied in the thickness direction by the compression expansion method of the thermomechanical analyzer as described above (Maximum expansion ratio) of the adhesive tape for protecting a semiconductor wafer at 23 to 100 캜 with respect to the thickness of the adhesive tape for protecting a semiconductor wafer at 23 캜 is 1.2% or less, preferably 1.1% or less, More preferably, it is 1.0% or less. When the maximum rate of increase is 1.2% or less, even when the pressure-sensitive adhesive tape is heated up to about 100 ° C in the back-grinding process in which the semiconductor wafer is made thinner than before, the thermal expansion of the pressure- Since the stress applied to the semiconductor wafer from the tape is small, cracks are unlikely to occur even in the case of using a normal semiconductor wafer or a semiconductor wafer in which a weakened region such as a modified region is formed. Also, the maximum rate of increase is negative, but its lower limit is, for example, -10%.

The maximum rate of increase is obtained by the following method of measuring the maximum rate of increase.

≪ Measurement method of maximum increase rate >

And cut out from the adhesive tape for semiconductor wafer protection to obtain a rectangular test piece. The rectangular test piece is placed in a thermomechanical analyzer, and the rectangular test piece is heated from -70 ° C to 150 ° C by the compression expansion method of the thermomechanical analyzer, and the displacement of the thickness at that time is measured. The thickness of the rectangular test piece at 23 캜 is A, and the maximum thickness of the rectangular test piece at 23 to 100 캜 is B, by the following equation.

Maximum growth rate (%) = (B-A) / A x 100

(materials)

The substrate is an element that functions as a support in the adhesive tape for protecting a semiconductor wafer of the present invention. As the above substrate, for example, a plastic substrate (particularly, a plastic film) can be mentioned. The substrate may be a single layer or a laminate of the same type or different types of substrates. In the present specification, the term "monolayer" means a layer having the same composition and includes a plurality of laminated layers having the same composition.

Examples of the resin constituting the plastic substrate include low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymerized polypropylene, block copolymerized polypropylene, homopolypropylene, (Meth) acrylic acid ester (random, alternating) copolymer, an ethylene-butene copolymer, an ethylene-hexene copolymer, an ethylene-vinyl acetate copolymer A polyolefin resin such as a co-polymer; Polyurethane; Polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate and polybutylene terephthalate (PBT); Polycarbonate; Polyimide; Polyether ether ketone; Polyetherimide; Polyamides such as aramid and wholly aromatic polyamide; Polyphenylsulfide; Fluorine resin; Polyvinyl chloride; Polyvinylidene chloride; Cellulose resin; Silicone resin, and the like. These resins may be used alone or in combination of two or more. When the pressure-sensitive adhesive layer is a radiation-curable type as described later, the base material preferably has radiation transmittance.

The pressure-sensitive adhesive layer side surface of the substrate may be subjected to various treatments such as a corona discharge treatment, a plasma treatment, a sand mat treatment treatment, an ozone exposure treatment, a flame exposure treatment, a high- Physical treatment such as ionizing radiation treatment; Chemical treatment such as chromic acid treatment; Or surface treatment such as adhesion facilitating treatment with a coating agent (primer) may be performed. Further, in order to impart the antistatic function, a conductive vapor deposition layer containing a metal, an alloy, these oxides, and the like may be formed on the surface of the substrate.

(Pressure-sensitive adhesive layer)

The pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention has at least one pressure-sensitive adhesive layer on a substrate. The pressure-sensitive adhesive layer may be a single layer or a laminate of the same or different pressure-sensitive adhesive layers.

The pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention is a pressure-sensitive adhesive tape having at least one pressure-sensitive adhesive layer having a loss coefficient (tan?) Of 1.0 or more by the nanoindentation method under the conditions of a temperature of 25 DEG C and a frequency of 100 Hz desirable. The adhesion of the adhesive tape to the semiconductor wafer is usually carried out by using a lamination apparatus. In this case, since it is practically impossible to attach the adhesive tape without applying any tension, the tension applied to the adhesive tape after attachment is the residual stress Has accumulated. With this residual stress, cracks are generated in the back grind process due to collision between regions (regions corresponding to the semiconductor chips after individual fabrication) between the modified regions of the semiconductor wafers, for example, It tends to be easy to do. On the other hand, in the case where the pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention has a pressure-sensitive adhesive layer having a loss coefficient (tan?) Of 1.0 or more, the residual stress tends to be dispersed / lost (stress relaxation) Stress is hardly applied to the wafer and it is difficult to cause cracks. The upper limit of the loss coefficient is, for example, 5.0. In the present specification, the pressure-sensitive adhesive layer having a loss coefficient of 1.0 or more may be referred to as " pressure-sensitive adhesive layer X ".

The loss factor is a value obtained by performing a nanoindentation test on the pressure-sensitive adhesive layer of the adhesive tape for protecting a semiconductor wafer. In the nanoindentation test, the load applied to the indenter and the indentation depth when the indenter was press-fitted into the pressure-sensitive adhesive layer were continuously measured at the time of unloading under load, and the storage modulus and loss The elastic modulus is calculated, and the loss elastic modulus / storage elastic modulus is calculated as the loss coefficient (loss tangent). The loss coefficient by the nanoindentation method of the pressure-sensitive adhesive layer is measured under the following conditions.

Measuring device (nanoindenter): manufactured by Hysitron Inc., Triboindenter

Indenter: Berkovich (triangular shape)

Measuring method: Dynamic measurement

Setting of indentation depth: 500 nm

Frequency: 100㎐

Amplitude: 2 nm

When the pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention has a layered product of the pressure-sensitive adhesive layer and further has the pressure-sensitive adhesive layer X, at least one pressure-sensitive adhesive layer constituting the layered product may be the pressure- The pressure-sensitive adhesive layer positioned on the outermost surface (the outermost surface on the opposite side of the substrate) of the pressure-sensitive adhesive layer is preferable as the pressure-sensitive adhesive layer X. It is more preferable that all of the pressure-

The loss factor of the pressure-sensitive adhesive layer in the case of the pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layer X is located on the outermost surface is more preferably 1.1 or more, and more preferably 1.15 or more. On the other hand, when the pressure-sensitive adhesive layer X is a pressure-sensitive adhesive layer (that is, a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer located on the outermost surface) positioned inside the pressure-sensitive adhesive tape, the pressure-

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention is formed of a pressure-sensitive adhesive. The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer may be a pressure-sensitive adhesive (pressure-sensitive adhesive force-reducing type adhesive) capable of intentionally reducing the pressure-sensitive adhesive force due to external action such as irradiation with radiation and may have little or no adhesive force depending on external actions (Pressure-sensitive adhesive force-reducing type), and can be appropriately selected according to the type of the semiconductor wafer to be adhered, the method and conditions of back-grinding, and the like.

When the pressure-sensitive adhesive force-reducing adhesive is used as the pressure-sensitive adhesive, the pressure-sensitive adhesive layer is classified into a state in which the pressure-sensitive adhesive layer exhibits a relatively high adhesive force and a state in which a relatively low pressure- It becomes possible to use it. For example, when a back-grinding target semiconductor wafer is bonded to a pressure-sensitive adhesive layer of a pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention or a back-grinding process, a pressure-sensitive adhesive layer exhibits a relatively high pressure- It is possible to suppress or prevent lifting of the wafer or the individualized semiconductor chips. On the other hand, when peeling off the semiconductor wafer protecting adhesive tape of the present invention from the back-ground semiconductor wafer or the individual semiconductor chip, By reducing the adhesive force, peeling can be easily performed. Thus, in the pressure-sensitive adhesive tape for protecting a semiconductor wafer according to the present invention, the pressure-sensitive adhesive layer located on the outermost surface (the outermost surface opposite to the substrate) is a pressure-sensitive adhesive layer formed by the pressure- ).

Examples of such pressure sensitive adhesives with reduced pressure include radiation curable pressure sensitive adhesives (pressure sensitive adhesives having radiation curable properties). As the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer, a kind of pressure-sensitive adhesive force-reducing type adhesive may be used, or two or more types of pressure-sensitive adhesive force-reduction type pressure-sensitive adhesive may be used. The entirety of the pressure-sensitive adhesive layer may be formed of an adhesive force-reducing type pressure-sensitive adhesive, or a part thereof may be formed of an adhesive pressure-reduction type pressure-sensitive adhesive.

As the radiation-curable pressure-sensitive adhesive, for example, a pressure-sensitive adhesive of the type which is cured by irradiation with an electron beam, an ultraviolet ray, an alpha ray, a beta ray, a gamma ray or an X ray may be used. A pressure-sensitive adhesive) can be particularly preferably used.

As the radiation-curable pressure-sensitive adhesive, any suitable pressure-sensitive adhesive containing an acrylic polymer may be used. Preferably, an acrylic polymer having at least one radiation-polymerizable functional group (for example, a functional group having a carbon-carbon multiple bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group or an ethynyl group) A pressure-sensitive adhesive containing a photopolymerization initiator (an intrinsic type radiation-curable pressure-sensitive adhesive) is used. Further, a pressure-sensitive adhesive (addition type radiation-curable pressure-sensitive adhesive) containing an acrylic polymer, a radiation-polymerizable monomer component and / or a radiation-polymerizable oligomer component and a photopolymerization initiator may be used. Use of an inherent radiation-curable pressure-sensitive adhesive tends to suppress unintended changes in the adhesive properties due to movement of a low molecular weight component in the formed pressure-sensitive adhesive layer over time.

The acrylic polymer is a polymer comprising a constituent unit derived from an acrylic monomer (a monomer component having a (meth) acryloyl group in the molecule) as a constituent unit of the polymer. It is preferable that the acrylic polymer is a polymer containing the structural unit derived from the (meth) acrylic acid ester in the most amount in the mass ratio. The acrylic polymer may be used alone or in combination of two or more. In the present specification, the term "(meth) acryl" refers to "acrylic" and / or "methacryl" (either or both of "acrylic" and "methacrylic"), and the like.

Examples of the (meth) acrylic esters include hydrocarbon group-containing (meth) acrylic esters such as (meth) acrylic acid alkyl esters, (meth) acrylic acid cycloalkyl esters and (meth) acrylic acid aryl esters. Examples of the alkyl (meth) acrylate ester include methyl esters, ethyl esters, isopropyl esters, butyl esters, isobutyl esters, s-butyl esters, t-butyl esters, pentyl esters, But are not limited to, isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester, tridecyl ester, Decyl ester, octadecyl ester, eicosyl ester, and the like. Examples of the (meth) acrylic acid cycloalkyl ester include cyclopentyl ester and cyclohexyl ester of (meth) acrylic acid. Examples of the (meth) acrylic acid aryl esters include phenyl esters of (meth) acrylic acid and benzyl esters. The above-mentioned (meth) acrylic acid esters may be used alone, or two or more kinds thereof may be used. (Meth) acrylic acid esters in the pressure-sensitive adhesive layer, the ratio of the (meth) acrylic acid ester in the total monomer components for forming the acrylic polymer is preferably 40% by mass or more By mass, and more preferably not less than 60% by mass.

The acrylic polymer may contain a structural unit derived from another monomer component copolymerizable with the (meth) acrylic acid ester for the purpose of modifying the cohesive force, heat resistance, and the like. Examples of the other monomer component include a carboxyl group-containing monomer, an acid anhydride monomer, a hydroxyl group-containing monomer, an epoxy group-containing monomer, a sulfonic acid group-containing monomer, a phosphoric acid group-containing monomer, acrylamide, acryloylmorpholine, Containing monomers such as monomers (acrylonitrile and the like), keto-containing monomers, monomers having a nitrogen atom containing ring, and alkoxysilyl group-containing monomers. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid. Examples of the acid anhydride monomer include maleic anhydride, itaconic anhydride, and the like. Examples of the hydroxyl group-containing monomer include (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylate 4-hydroxybutyl, (Meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) methyl . Examples of the epoxy group-containing monomer include glycidyl group-containing monomers such as glycidyl (meth) acrylate and methylglycidyl (meth) acrylate. Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) Naphthalenesulfonic acid and royoxynaphthalenesulfonic acid. Examples of the phosphoric acid group-containing monomer include 2-hydroxyethyl acryloyl phosphate and the like. The above-mentioned other monomer components may be used alone or in combination of two or more. (Meth) acrylic acid ester in the pressure-sensitive adhesive layer 12, the ratio of the other monomer components in the total monomer components for forming the acrylic polymer is preferably not more than 60 mass% By mass, more preferably not more than 40% by mass.

The acrylic polymer may contain a structural unit derived from a polyfunctional monomer capable of copolymerizing with a monomer component forming the acrylic polymer such as (meth) acrylate to form a crosslinked structure in the polymer backbone. Examples of the polyfunctional monomer include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (Meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy (meth) acrylate Monomers having a (meth) acryloyl group and other reactive functional groups in the molecule such as polyglycidyl (meth) acrylate), polyester (meth) acrylate and urethane (meth) have. The polyfunctional monomer may be used alone or in combination of two or more. (Meth) acrylic acid ester, the proportion of the polyfunctional monomer in the total monomer component for forming the acrylic polymer is preferably 40% by mass or less, More preferably, it is 30 mass% or less.

The acrylic polymer is obtained by polymerizing at least one monomer component containing an acrylic monomer. Examples of the polymerization method include solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization.

The weight average molecular weight of the acryl-based polymer in the pressure-sensitive adhesive layer is preferably 200,000 to 3,000,000, and more preferably 250,000 to 1,500,000. When the weight average molecular weight is more than 200,000, low molecular weight substances in the pressure-sensitive adhesive layer tends to be small. In the case of peeling off the pressure-sensitive adhesive tape for protecting a semiconductor wafer according to the present invention, residual adhesive of a pressure-

The pressure-sensitive adhesive may contain a cross-linking agent. For example, when an acrylic polymer is used as the base polymer, the acrylic polymer may be crosslinked to improve the degree of crosslinking of the pressure-sensitive adhesive layer, and the maximum increase rate tends to decrease. Examples of the crosslinking agent include a polyisocyanate compound, an epoxy compound, a polyol compound (such as a polyphenol compound), an aziridine compound, and a melamine compound. When a crosslinking agent is used, the amount of the crosslinking agent to be used is preferably about 20 parts by mass or less based on 100 parts by mass of the base polymer, and more preferably about 20 parts by mass or less based on 100 parts by mass of the base polymer because the loss factor tends to decrease when the degree of crosslinking of the pressure- 0.1 to 10 parts by mass, more preferably 0.6 to 8 parts by mass.

Examples of the radiation-polymerizable monomer component and / or the radiation-polymerizable oligomer component include a photoreactive monomer having a functional group having a carbon-carbon multiple bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group or an ethynyl group, Oligomers. Examples of the radiation-polymerizable monomer component include urethane (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (Meth) acrylate, trimethylolpropane trimethacrylate, trimethylolpropane trimethacrylate, erythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and 1,4-butanediol di (meth) acrylate. Examples of the radiation-polymerizable oligomer component include various oligomers such as urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based oligomers and preferably have a molecular weight of about 100 to 30000. The content of the radiation-curable monomer component and the oligomer component in the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer is, for example, about 5 to 500 parts by mass, and preferably about 40 to 150 parts by mass, relative to 100 parts by mass of the base polymer. As the addition type radiation-curable pressure-sensitive adhesive, for example, those disclosed in Japanese Patent Laid-Open Publication No. 60-196956 may be used.

As a method of introducing a radiation-polymerizable carbon-carbon multiple bond to an acrylic polymer, for example, there is a method of polymerizing (copolymerizing) a raw monomer containing a monomer component having a first functional group to obtain an acrylic polymer, And a compound having a second functional group and a radiation-polymerizable carbon-carbon multiple bond capable of being condensed or added to an acryl-based polymer while maintaining the radiation-polymerizing property of the carbon-carbon multiple bond.

Examples of the combination of the first functional group and the second functional group include a carboxyl group and an epoxy group, an epoxy group and a carboxyl group, a carboxyl group and an aziridyl group, an aziridyl group and a carboxy group, a hydroxy group and an isocyanate group, an isocyanate group and a hydroxy group. Among these, a combination of a hydroxy group and an isocyanate group, and a combination of an isocyanate group and a hydroxy group are preferable from the viewpoint of easiness in tracking the reaction. In particular, from the viewpoints of production and availability of an acrylic polymer having a hydroxyl group, the production of a polymer having an isocyanate group having a high reactivity is technically difficult. When the first functional group is a hydroxyl group and the second functional group is an isocyanate group Combinations are preferred. Examples of the compound having an isocyanate group and a radiation-polymerizable carbon-carbon double bond in this case include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, m-isopropenyl- ?,? -Dimethylbenzyl Isocyanate and the like. Examples of the acrylic polymer having a hydroxy group include a structural unit derived from an ether compound such as the above-mentioned hydroxyl group-containing monomer, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether .

As the photopolymerization initiator, for example, an? -Ketol compound, an acetophenone compound, a benzoin ether compound, a ketal compound, an aromatic sulfonyl chloride compound, a photoactive oxime compound, a benzophenone compound, Tonometal compounds, camphorquinones, halogenated ketones, acylphosphine oxides, acylphosphonates, and the like. Examples of the? -Ketol compound include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone,? -Hydroxy- ?,? '- dimethylacetophenone, 2- Methyl-2-hydroxypropiophenone, 1-hydroxycyclohexyl phenyl ketone, and the like. Examples of the acetophenone compound include methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) - phenyl] -2-morpholinopropane-l, 2-hydroxy-1- {4- [4- (2- hydroxy- -1-one. Examples of the benzoin ether compound include benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether. Examples of the ketal compound include benzyl dimethyl ketal and the like. Examples of the aromatic sulfonyl chloride-based compound include 2-naphthalenesulfonyl chloride and the like. Examples of the photoactive oxime compound include 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime and the like. Examples of the benzophenone-based compound include benzophenone, benzoylbenzoic acid and 3,3'-dimethyl-4-methoxybenzophenone. Examples of the thioxanthone compound include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichloroti 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, and the like. The content of the photopolymerization initiator in the radiation-curing pressure-sensitive adhesive is, for example, 0.05 to 20 parts by mass relative to 100 parts by mass of the base polymer.

Examples of the adhesive force reducing type pressure-sensitive adhesive include pressure-sensitive adhesives in which the radiation-curable pressure-sensitive adhesive is cured by irradiation in advance with respect to the adhesive pressure-reducing pressure-sensitive adhesive, and pressure-sensitive adhesives. As the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer, a kind of pressure-sensitive adhesive force-reducing type adhesive may be used, or two or more types of pressure-sensitive adhesive force-reducing type pressure-sensitive adhesive may be used. The entirety of the pressure-sensitive adhesive layer may be formed of an adhesive force-reducing pressure-sensitive adhesive, or part of the pressure-sensitive adhesive layer may be formed of an adhesive pressure-reducing pressure-sensitive adhesive. For example, when the pressure-sensitive adhesive layer has a laminated structure, all of the pressure-sensitive adhesive layers in the laminated structure may be formed of an adhesive force-reducing pressure-sensitive adhesive, and even if some of the pressure-sensitive adhesive layers in the laminated structure are formed of pressure- do.

As the pressure-sensitive adhesive, there can be used an acrylic pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, a silicone pressure-sensitive adhesive and the like, which can use pressure-sensitive adhesives of publicly known and common pressure type and which use an acrylic polymer as a base polymer. When the pressure-sensitive adhesive layer contains an acrylic polymer as a pressure-sensitive adhesive, the acrylic polymer is preferably a polymer containing the constituent unit derived from the (meth) acrylic acid ester as the largest structural unit in the mass ratio. As the acrylic polymer, for example, an acrylic polymer described as an acrylic polymer contained in the above-mentioned radiation-curable pressure-sensitive adhesive may be employed.

The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer or the pressure-sensitive adhesive layer may contain, in addition to the respective component components described above, an additive used in a known or common pressure-sensitive adhesive layer such as a crosslinking accelerator, a tackifier, an antioxidant, a colorant Or may be blended. As the coloring agent, for example, there can be mentioned a compound which is colored by irradiation with radiation. In the case of containing a compound that is colored by irradiation, only the irradiated portion can be colored. The compound that is colored by irradiation with radiation is a colorless or pale color before being irradiated with radiation but a compound which becomes colored by irradiation with radiation, and examples thereof include leuco dyes and the like. The amount of the compound to be colored by irradiation with the radiation is not particularly limited and may be appropriately selected.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 1 to 100 占 퐉, more preferably 2 to 80 占 퐉, still more preferably 3 to 80 占 퐉, from the viewpoint of balancing the retention force of the semiconductor wafer and the maximum growth rate. Lt; / RTI > In the case where the pressure-sensitive adhesive layer is a laminate of pressure-sensitive adhesive layers, the thickness of the pressure-sensitive adhesive layer is the thickness of the layered product.

One embodiment of the adhesive tape for protecting a semiconductor wafer of the present invention will be described below. 1 is a schematic cross-sectional view showing one embodiment of a pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention, in which the pressure-sensitive adhesive layer is composed of a single layer.

1, a pressure-sensitive adhesive tape 1 for protecting a semiconductor wafer has a single-layer pressure-sensitive adhesive layer 12 laminated on a substrate 11 and a substrate 11. When the pressure-sensitive adhesive layer is a single layer, the pressure-sensitive adhesive layer is preferably a radiation-curing pressure-sensitive adhesive layer (i.e., a radiation-curing pressure-sensitive adhesive layer having a loss coefficient of 1.0 or more) In the pressure-sensitive adhesive tape 1 for protecting a semiconductor wafer having such a constitution, the stress generated by the thermal expansion due to the temperature rise of the pressure-sensitive adhesive tape is easily alleviated in the pressure-sensitive adhesive layer 12, A semiconductor wafer or a semiconductor wafer on which a weakened region such as a modified region is formed is less likely to be cracked and the peeling or scattering of the semiconductor wafer or the semiconductor chip in the backgrind process can be suppressed or prevented, At the time of peeling from the chip, peeling can be easily performed by reducing the adhesive force of the pressure-sensitive adhesive layer by irradiation with radiation.

Another embodiment of the adhesive tape for protecting a semiconductor wafer of the present invention will be described below. 2 is a schematic cross-sectional view showing one embodiment of a pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention in which the pressure-sensitive adhesive layer is composed of a plurality of layers (that is, a layered product of pressure-sensitive adhesive layers).

2, the adhesive tape 2 for protecting a semiconductor wafer has a base material 21 and a pressure-sensitive adhesive layer 22 laminated on the base material 21. As shown in Fig. The pressure-sensitive adhesive layer 22 is a layered product of a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive layer 22a and a pressure-sensitive adhesive layer 22b. The pressure-sensitive adhesive layer 22b may be composed of a single layer or a multiple layer. When the pressure-sensitive adhesive layer is a laminate of pressure-sensitive adhesive layers, the pressure-sensitive adhesive layer 22a located on the outermost surface is a radiation-curing pressure-sensitive adhesive layer (i.e., a radiation-curable pressure- Sensitive adhesive layer 22b (i.e., the adhesive force-reducing type pressure-sensitive adhesive layer having the loss coefficient of 1.0 or more), which is the pressure-sensitive adhesive layer X, is preferable. The pressure-sensitive adhesive tape 2 for protecting a semiconductor wafer having the above-described structure can easily adjust the maximum rate of increase as a pressure-sensitive adhesive tape for protecting a semiconductor wafer by a pressure-sensitive adhesive layer 22b inside the pressure- It is difficult for stress to be applied to the semiconductor wafer and it is more difficult to generate cracks. The above-mentioned effect of using the radiation-curable pressure-sensitive adhesive layer by the pressure-sensitive adhesive layer 22a on the outermost surface can be exerted.

When the pressure-sensitive adhesive layer positioned on the outermost surface of the laminate of the pressure-sensitive adhesive layer, like the pressure-sensitive adhesive layer 22a, is a radiation-curable pressure-sensitive adhesive layer, the thickness of the pressure-sensitive adhesive layer is preferably 1 to 30 占 퐉, more preferably 2 To 15 mu m. Further, like the pressure-sensitive adhesive layer 22b, the thickness of the pressure-sensitive adhesive layer located inside the pressure-sensitive adhesive layer laminate (the total thickness of the pressure-sensitive adhesive layer excluding the pressure-sensitive adhesive layer located on the outermost surface) is preferably 10 to 100 mu m , And more preferably from 20 to 80 mu m. With such a thickness design, it is possible to obtain a relatively large portion in the thickness direction while giving the above-described effect by using the radiation-curable pressure-sensitive adhesive layer by the pressure-sensitive adhesive layer 22a on the outermost surface to the pressure- The maximum increase rate of the adhesive tape for protecting a semiconductor wafer can be easily adjusted to a specific range by the pressure sensitive adhesive layer 22b on the inside. As a result, it is possible to easily peel off the semiconductor wafer or the semiconductor chip by irradiation with radiation, and it is possible to make cracks less likely to occur in the backgrind process.

The adhesive tape 1 for protecting a semiconductor wafer, which is one embodiment of the adhesive tape for protecting a semiconductor wafer of the present invention, is manufactured, for example, as follows. First, the base material 11 can be obtained by forming a film by a known film forming method. Examples of the film forming method include a calendar film forming method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T die extrusion method, a co-extrusion method, a dry lamination method and the like.

Subsequently, a composition (pressure-sensitive adhesive composition) for forming the pressure-sensitive adhesive layer 12 including a pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer 12 on the base material 11 and a solvent is applied to form a coating film, The pressure-sensitive adhesive layer 12 can be formed by solidifying the coated film by curing or the like. Examples of the application method include known or common application methods such as roll coating, screen coating, and gravure coating. The desolvation condition is, for example, carried out at a temperature of 80 to 150 DEG C and a time of 0.5 to 5 minutes. Further, the pressure-sensitive adhesive composition may be coated on the separator to form a coating film, and then the coating film may be solidified under the above-described desolvation conditions to form the pressure-sensitive adhesive layer 12. Thereafter, the pressure-sensitive adhesive layer 12 is bonded to the substrate 11 together with the separator. Thus, the adhesive tape 1 for protecting the semiconductor wafer can be manufactured.

Further, the adhesive tape 2 for protecting a semiconductor wafer, which is another embodiment of the adhesive tape for protecting a semiconductor wafer of the present invention, is manufactured, for example, as follows. First, the form having the pressure-sensitive adhesive layer 22b on the base material 21 can be manufactured by the same method as the above-described pressure-sensitive adhesive tape for semiconductor wafer protection 1 described above. Then, a composition (pressure-sensitive adhesive composition) for forming the pressure-sensitive adhesive layer 22a, including a pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer 22a and a solvent, etc., is applied on the separator in the same manner as in the above- After the coating film is formed, the coating film can be solidified by desolvation or curing, if necessary, to form the pressure-sensitive adhesive layer 22a. Thereafter, the pressure-sensitive adhesive layer 22a is bonded to the pressure-sensitive adhesive layer 22b together with the separator. Thus, the adhesive tape 2 for protecting the semiconductor wafer can be manufactured.

Thus, for example, the adhesive tapes 1 and 2 for protecting the semiconductor wafer can be manufactured. Separators (not shown) may be provided on the surface of the pressure-sensitive adhesive layer on the pressure-sensitive adhesive tapes 1 and 2 for protecting the semiconductor wafer. The separator is an element for protecting the pressure sensitive adhesive layer from being exposed. When the pressure sensitive adhesive tape for semiconductor wafer protection of the present invention is used, the pressure sensitive adhesive tape is peeled from the pressure sensitive adhesive tape. As the separator, for example, a plastic film or a paper substrate coated with a releasing agent such as a polyethylene terephthalate (PET) film, a polyethylene film, a polypropylene film, a fluorine releasing agent or a long chain alkyl acrylate releasing agent can be mentioned.

[Method of Manufacturing Semiconductor Device]

By using the adhesive tape for protecting a semiconductor wafer of the present invention, a semiconductor device can be manufactured. Specifically, the step of attaching a semiconductor wafer to the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive tape for protecting a semiconductor wafer of the present invention (sometimes referred to as "process A") and the step of adhering a semiconductor wafer The semiconductor device can be manufactured by a manufacturing method including a step of thinning the semiconductor wafer by grinding (sometimes referred to as " step B ") in a state of being held.

The method for manufacturing the semiconductor device is, as an embodiment (Embodiment 1), after the step A, a modified region 30a is formed on the semiconductor wafer, as shown in Figs. 3A and 3B (A modified region forming step). The semiconductor wafer W has a first surface Wa and a second surface Wb. Various semiconductor elements (not shown) are already formed on the side of the first surface Wa of the semiconductor wafer W and a wiring structure or the like (not shown) necessary for the semiconductor element is formed on the first surface Wa ). Then, in the modified region forming step, the adhesive tape X1 for protecting the semiconductor wafer of the present invention having the adhesive surface X1a in Step A is bonded to the first surface Wa side of the semiconductor wafer W, The laser light whose light-converging point is set in the wafer is transferred from the side opposite to the semiconductor wafer protecting adhesive tape X1 to the semiconductor wafer W in the state that the semiconductor wafer W is held on the wafer protecting adhesive tape X1 And the modified region 30a is formed in the semiconductor wafer W by ablation by multiphoton absorption. The modified region 30a is a weakening region for separating the semiconductor wafer W into semiconductor chip units. A method of forming the modified region 30a on a line to be divided by laser beam irradiation in a semiconductor wafer is described in detail in, for example, Japanese Patent Application Laid-Open No. 2002-192370, Is suitably adjusted within the range of, for example, the following conditions. The modified region forming step may be performed before the step A is performed.

≪ Laser irradiation condition >

(A) Laser light

Laser light source Semiconductor laser excitation Nd: YAG laser

wavelength 1064 nm

Laser light spot cross-sectional area 3.14 x 10 < ^-8 >

Rash type Q switch pulse

Repetition frequency 100 kHz or less

Pulse width 1 μs or less

Print 1mJ or less

Laser light quality TEM00

Polarization characteristic Linear polarization

(B) a condenser lens

Magnification 100 times or less

NA 0.55

Transmittance to laser light wavelength 100% or less

(C) Moving speed of the loading table on which the semiconductor substrate is loaded 280 mm / sec or less

3 (c), in the step B, in the state that the semiconductor wafer W is held on the adhesive tape X1 for protection of the semiconductor wafer, The semiconductor wafer 30 is thinned by grinding from the two surfaces Wb, thereby forming a semiconductor wafer 30A that can be separated into a plurality of semiconductor chips 31. [ The grinding process can be performed using a grinding machine equipped with a grinding wheel.

The semiconductor wafer 30A which can be separated and obtained in the process B is subjected to subsequent processes (dicing process, etc.). For example, the disposable semiconductor wafer 30A obtained in the process B is attached to the die bond film side of the dicing die-bonding film, and the semiconductor wafer protecting adhesive tape X1 for peeling off the semiconductor wafer is peeled off from the semiconductor wafer 30A . When the adhesive tape X1 for protecting a semiconductor wafer is peeled off, the adhesive force reduction treatment (irradiation with radiation, expansion or the like) may be appropriately performed. Then, the dicing tape in the dicing die-bonding film is expanded under the condition of relatively low temperature, the semiconductor wafer 30A is cut in the modified region 30a, Thereby obtaining a semiconductor chip with a bond film.

In the above-described method of manufacturing a semiconductor device, as another embodiment (Embodiment 2), the dividing groove forming step shown in Fig. 4 may be performed before the step A instead of the modified region forming step. In the dividing groove forming step shown in Fig. 4, first, as shown in Figs. 4 (a) and 4 (b), a dividing groove 30b is formed in the semiconductor wafer W. The semiconductor wafer W has a first surface Wa and a second surface Wb. Various semiconductor elements (not shown) are already formed on the side of the first surface Wa of the semiconductor wafer W and a wiring structure or the like (not shown) necessary for the semiconductor element is formed on the first surface Wa ). After the wafer processing tape T having the adhesive surface Ta is bonded to the second surface Wb side of the semiconductor wafer W and the semiconductor wafer W is held on the wafer processing tape T A dividing groove 30b having a predetermined depth is formed on the first surface Wa side of the semiconductor wafer W by using a rotating blade such as a dicing machine. The dividing groove 30b is a gap for separating the semiconductor wafer W into semiconductor chip units (in FIG. 4, the dividing groove 30b is schematically shown by a thick line).

4 (c), the pressure-sensitive adhesive tape X2 for protecting the semiconductor wafer having the pressure-sensitive adhesive surface X2a is applied to the first surface Wa side of the semiconductor wafer W And separation of the wafer processing tape T from the semiconductor wafer W is carried out.

4 (d), in the state in which the semiconductor wafer W is held on the adhesive tape X2 for protecting the semiconductor wafer, the semiconductor wafer W has a predetermined thickness And is thinned by the grinding process from the second surface Wb. Thereby, the semiconductor wafer 30B which can be separated into a plurality of semiconductor chips 31 is formed. Specifically, the semiconductor wafer 30B has a portion (connection portion) for connecting a portion to be separated into a plurality of semiconductor chips 31 in the wafer on the second surface Wb side.

The semiconductor wafer 30B that can be fabricated in Step B is thereafter subjected to a dicing process or the like in the same manner as in Embodiment 1, and the adhesive tape for protecting semiconductor wafer X2 is peeled off at that time.

In the semiconductor device manufacturing method according to still another embodiment (Embodiment 3), the step B shown in Fig. 5 may be performed instead of the step B described above with reference to Fig. 4 (d). 5, after the semiconductor wafer W is held on the adhesive tape X2 for protecting the semiconductor wafer, the wafer W is held in a predetermined position The semiconductor wafer divided body 30C including the plurality of semiconductor chips 31 and held on the adhesive tape X2 for protection of the semiconductor wafer is subjected to the grinding process from the second face Wb . In the step B, the wafer may be ground (first method) until the dividing grooves 30b are exposed on the second surface Wb side. Alternatively, the dividing grooves 30b may be formed from the second surface Wb side And thereafter a crack is generated between the dividing groove 30b and the second surface Wb by the action of a pressing force against the wafer from the rotating grindstone to form the semiconductor wafer divided body 30C (Second method) may be employed. According to the adopted method, the depth of the dividing groove 30b formed as described above with reference to Figs. 4A and 4B from the first surface Wa is appropriately determined . In Fig. 5, the dividing grooves 30b through the first method, the dividing grooves 30b through the second method, and the cracks following the dividing grooves 30b are schematically shown by bold lines. In this embodiment, the semiconductor wafer divided body 30C manufactured in this manner as the semiconductor wafer divided body is used in place of the semiconductor wafer 30A, and then a dicing step or the like is performed as in the first embodiment And then the adhesive tape X2 for protecting the semiconductor wafer is peeled off.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited at all by these Examples.

Example 1

100 parts by mass of an acrylic polymer composed of ethyl acrylate (EA) / butyl acrylate (BA) / acrylic acid (AA) = 50/50/5 (mass ratio), 100 parts by mass of a polyisocyanate compound (trade name: Coronate L manufactured by Tosoh Corporation ), 3 parts by mass of a photopolymerization initiator (trade name " Irgacure 651 ", manufactured by BASF), and toluene. This pressure-sensitive adhesive composition was applied to a PET film having a thickness of 50 占 퐉 (trade name: "Lamiron S105", manufactured by Toray Industries, Inc.) and then heated at 120 ° C for 120 seconds to desolvate to form a pressure- did.

Subsequently, the surface of the pressure-sensitive adhesive layer A1 was bonded to a surface of a 38 μm-thick polyester-based separator (trade name "MRF" manufactured by Mitsubishi Jushi K.K.) which had been subjected to silicone treatment to obtain an adhesive tape A.

On the other hand, 100 parts by mass of an acrylic polymer composed of 2-ethylhexyl acrylate (2-EHA) / acryloylmorpholine / hydroxyethyl acrylate (HEA) = 75 / 25/10 (mass ratio), 100 parts by mass of a polyisocyanate compound Coronate L ", manufactured by TOSOH CORPORATION), 3 parts by mass of a photopolymerization initiator (trade name: Irgacure 651, manufactured by BASF), and toluene. This pressure-sensitive adhesive composition was applied to a silicone-treated surface of a 38 탆 -thick polyester separator (trade name "Diepoil MRF" manufactured by Mitsubishi Jushi Co., Ltd.), and then desolvated by heating at 120 ° C for 120 seconds, Thereby forming a pressure-sensitive adhesive layer A2 having a thickness of 5 mu m.

Then, the separator was peeled off from the pressure-sensitive adhesive tape A, and the pressure-sensitive adhesive layer A2 was bonded to the pressure-sensitive adhesive layer A1 of the pressure-sensitive adhesive tape A and transferred. The PET film (50 m) / pressure- M) / pressure-sensitive adhesive layer A2 (5 m)].

Example 2

100 parts by mass of an acrylic polymer composed of 2-ethylhexyl acrylate (2-EHA) / methyl acrylate (MA) / acrylic acid (AA) = 30 / 70/10 (mass ratio), 100 parts by mass of a polyisocyanate compound (trade name: Coronate L, Manufactured by TOSOH CORPORATION), 3 parts by mass of a photopolymerization initiator (trade name: Irgacure 651, manufactured by BASF), and ethyl acetate were prepared. This pressure-sensitive adhesive composition was applied to a PET film having a thickness of 50 占 퐉 (trade name: "Lamiron S105", manufactured by Toray Industries, Inc.) and then heated at 120 ° C. for 120 seconds to desolvate to form a pressure- did.

Subsequently, the surface of the pressure-sensitive adhesive layer B1 was subjected to silicone treatment of a 38 탆 -thick polyester separator (trade name "MRF" manufactured by Mitsubishi Jushi K.K.) to obtain a pressure-sensitive adhesive tape B.

On the other hand, 100 parts by mass of an acrylic polymer composed of 2-ethylhexyl acrylate (2-EHA) / acryloylmorpholine / hydroxyethyl acrylate (HEA) = 75 / 25/10 (mass ratio), 100 parts by mass of a polyisocyanate compound Coronate L ", manufactured by TOSOH CORPORATION), 3 parts by mass of a photopolymerization initiator (trade name: Irgacure 651, manufactured by BASF), and toluene were prepared. This pressure-sensitive adhesive composition was applied to a silicone-treated surface of a 38 탆 -thick polyester separator (trade name: "MRF" manufactured by Mitsubishi Jushi Seal Co., Ltd.), and then desolvated by heating at 120 ° C. for 120 seconds, Mu m of pressure-sensitive adhesive layer B2 was formed.

Then, the separator was peeled off from the pressure-sensitive adhesive tape B, and the pressure-sensitive adhesive layer B2 was adhered to the pressure-sensitive adhesive layer B1 of the pressure-sensitive adhesive tape B, transferred and stored at 50 占 폚 for 72 hours to obtain a PET film (50 占 퐉) 탆) / pressure-sensitive adhesive layer B2 (5 탆)].

Example 3

An adhesive tape C having a pressure-sensitive adhesive layer C1 was prepared in the same manner as in the case of the pressure-sensitive adhesive tape B except that the thickness of the pressure-sensitive adhesive layer was 25 占 퐉. The separator was peeled from the pressure- (50 占 퐉 / pressure-sensitive adhesive layer C1 (25 占 퐉) / pressure-sensitive adhesive layer A2 (5 占 퐉)] at 50 占 폚 for 72 hours by carrying out bonding and transferring the pressure- To obtain an adhesive tape of Example 3.

Example 4

An adhesive tape D having a pressure-sensitive adhesive layer D1 was prepared in the same manner as in the case of the pressure-sensitive adhesive tape A except that the thickness of the pressure-sensitive adhesive layer was 25 mu m. The separator was peeled from the pressure-sensitive adhesive tape D, (50 μm) / pressure-sensitive adhesive layer (D1) / pressure-sensitive adhesive layer (B2)] was obtained in the same manner as in Example 1, except that the pressure-sensitive adhesive layer (B2)

Example 5

100 parts by mass of an acrylic polymer composed of ethyl acrylate (EA) / butyl acrylate (BA) / acrylic acid (AA) = 50/50/5 (mass ratio), 100 parts by mass of a polyisocyanate compound (trade name: Coronate L manufactured by Tosoh Corporation ) And 1 part by mass of toluene were prepared. This pressure-sensitive adhesive composition was applied to a PET film having a thickness of 50 占 퐉 (trade name: Lumirror S105, manufactured by Toray Industries, Inc.) and then heated at 120 占 폚 for 120 seconds to desolvate to form a pressure- did.

Subsequently, the surface of the pressure-sensitive adhesive layer E1 was bonded with a silicone-treated surface of a 38 탆 -thick polyester separator (trade name "MRF" manufactured by Mitsubishi Jushi K.K.) and stored at 50 ° C for 72 hours to obtain [PET Film (50 mu m) / pressure-sensitive adhesive layer E1 (50 mu m)].

Example 6

100 parts by mass of an acrylic polymer composed of 2-ethylhexyl acrylate (2-EHA) / methyl acrylate (MA) / acrylic acid (AA) = 30 / 70/10 (mass ratio), 100 parts by mass of a polyisocyanate compound (trade name: Coronate L, Manufactured by TOSOH CORPORATION) and 1 part by mass of ethyl acetate were prepared. This pressure-sensitive adhesive composition was applied to a 50 占 퐉 thick PET film (trade name: "Lamiron S105", manufactured by Toray Industries, Inc.) and then heated at 120 ° C. for 120 seconds to desolvate to form a pressure- did.

Subsequently, the surface of the pressure-sensitive adhesive layer F1 was subjected to a silicone treatment of a 38 占 퐉 thick polyester-based separator (trade name: "MRF" manufactured by Mitsubishi Jushi K.K.) to obtain a pressure-sensitive adhesive tape F.

On the other hand, 100 parts by mass of an acrylic polymer composed of 2-ethylhexyl acrylate (2-EHA) / acryloylmorpholine / hydroxyethyl acrylate (HEA) = 75 / 25/10 (mass ratio), 100 parts by mass of a polyisocyanate compound Coronate L ", manufactured by TOSOH CORPORATION), 3 parts by mass of a photopolymerization initiator (trade name: Irgacure 2959, manufactured by BASF), and toluene were prepared. This pressure-sensitive adhesive composition was applied to a silicone-treated surface of a 38 탆 -thick polyester separator (trade name: "MRF" manufactured by Mitsubishi Jushi Seal Co., Ltd.), and then desolvated by heating at 120 ° C. for 120 seconds, Mu m of the pressure-sensitive adhesive layer F2 was formed.

Then, the separator was peeled off from the pressure-sensitive adhesive tape F, and the pressure-sensitive adhesive layer F2 was bonded to the pressure-sensitive adhesive layer F1 of the pressure-sensitive adhesive tape F, transferred and stored at 50 占 폚 for 72 hours to obtain a PET film (50 占 퐉 /占 퐉) / pressure-sensitive adhesive layer F2 (5 占 퐉).

Comparative Example 1

100 parts by mass of an acrylic polymer composed of ethyl acrylate (EA) / butyl acrylate (BA) / hydroxyethyl acrylate (HEA) = 50/50/5 (mass ratio), 100 parts by mass of a polyisocyanate compound (trade name: Coronate L, Ltd.), 3 parts by mass of a photopolymerization initiator (trade name: Irgacure 651, manufactured by BASF), and toluene were prepared. This pressure-sensitive adhesive composition was applied to a PET film having a thickness of 50 占 퐉 (trade name: "Lamiron S105", manufactured by Toray Industries, Inc.), and then heated at 120 ° C for 120 seconds to desolvate to form a pressure- did.

Subsequently, the surface of the pressure-sensitive adhesive layer G1 was bonded with a silicone-treated surface of a 38 탆 -thick polyester separator (trade name: "MRF" manufactured by Mitsubishi Jushi Seiki Co., Ltd.) Film (50 占 퐉) / pressure-sensitive adhesive layer G1 (30 占 퐉)].

Comparative Example 2

Sensitive adhesive tape of Comparative Example 2 having the structure of [PET film (50 占 퐉) / pressure-sensitive adhesive layer H1 (50 占 퐉)] was obtained in the same manner as in Comparative Example 1 except that the thickness of the pressure-

<Evaluation>

Each of the pressure-sensitive adhesive layers and the pressure-sensitive adhesive tapes obtained in the examples and the comparative examples were evaluated as follows. The results are shown in Table 1.

(Maximum increase rate)

Each of the pressure-sensitive adhesive tapes obtained in the Examples and Comparative Examples was cut into a rectangular shape having a width of 10 mm and a length of 10 mm with a cutter knife to prepare a test piece, which was set in a thermomechanical analyzer (trade name "Q-400" , The specimen was heated from -70 DEG C to 150 DEG C under a load of 0.11 N in the thickness direction over the entire specimen by the compression expansion method under the following measurement conditions and then the displacement of the thickness of the specimen was continuously measured . Figs. 6 to 13 show changes in the expansion ratio (increase rate) in the thickness direction of the test piece at 23 to 100 캜 at that time. 6 to 13, the abscissa indicates the temperature [占 폚], and the ordinate indicates the expansion ratio (Expansion Rate) [%] with respect to the thickness at 23 占 폚. The required maximum increase rate was obtained by the following equation, assuming that the thickness of the rectangular test piece at 23 ° C is A and the maximum thickness of the rectangular test piece at 23 to 100 ° C is B: The results are shown in the column of &quot; maximum increase rate &quot;

Maximum growth rate (%) = (B-A) / A x 100

<Measurement Conditions>

Measurement mode: Compression expansion method

Measured load: 110 mN

Probe diameter: 6 mmφ

Temperature program: -70 ° C to 150 ° C

Heating rate: 5 ° C / min

Measurement atmosphere: N ₂ (flow rate: 200 ml / min)

(Loss coefficient by nanoindentation method)

Each of the pressure-sensitive adhesive layers obtained in each of Examples and Comparative Examples was cut into squares of 1 cm on each side and fixed on a predetermined support as a measurement sample. Using a nanoindenter (trade name &quot; TriboIndenter &quot;, manufactured by Hysitron Inc.) The nanoindentation measurement was carried out under the following conditions. The obtained loss coefficient tan? Is shown in the column of "loss coefficient" in Table 1.

Use indenter: Berkovich (triangular shape)

Measuring method: Dynamic measurement

Measuring temperature: 25 占 폚 (room temperature)

Frequency: 100㎐

Amplitude: 2 nm

(Crack resistance)

The light-converging point was set inside a 12-inch semiconductor wafer (mirror wafer made of silicon) under the trade name of "ML300-Integration" (manufactured by Tokyo Seimitsu Co., Ltd.) ) Along the line to be divided, thereby forming a modified region inside the semiconductor wafer. The laser light was irradiated under the following conditions.

(A) Laser light

Laser light source Semiconductor laser excitation Nd: YAG laser

wavelength 1064 nm

Laser light spot cross-sectional area 3.14 x 10 &lt; ^-8 &gt;

Rash type Q switch pulse

Repetition frequency 100 kHz

Pulse width 30ns

Print 20 μJ / pulse

Laser light quality TEM00 40

Polarization characteristic Linear polarization

(B) a condenser lens

Magnification 50 times

NA 0.55

Transmittance to laser light wavelength 60%

(C) Moving speed of the loading table on which the semiconductor substrate is loaded 100 mm / sec

After the modified regions were formed in the semiconductor wafers, the adhesive tapes obtained in Examples and Comparative Examples were bonded to the surface of the semiconductor wafers, and the adhesive tapes of the semiconductor wafers were bonded to each other using a back grinder (trade name &quot; DGP8760 &quot; The back surface was ground so as to have a thickness of 25 mu m, and the semiconductor wafer was cut along with this. Then, the end portions of 500 pieces of semiconductor chips were observed with an optical microscope (magnification: 50 times). [Number of defects / 500] was calculated as defect rate, and the case where the defect rate was 1% or less was evaluated as &amp; cir &amp;, the defect rate was found to be 1% And when it exceeded, it was evaluated as x. The evaluation results are shown in the column of &quot; crack resistance &quot; in Table 1.

1, 2, X1, X2: Adhesive tape for semiconductor wafer protection
11, 21: substrate
12, 22a, 22b, 22: pressure-sensitive adhesive layer
W, 30A, and 30B: semiconductor wafers
30C: semiconductor wafer divided body
30a: modified region
30b: split groove
31: Semiconductor chip

Claims (2)

A pressure-sensitive adhesive tape for protecting a semiconductor wafer, comprising a base material and a pressure-sensitive adhesive layer laminated on the base material,
The thickness of the substrate at 23 DEG C is 10 to 150 mu m,
The thickness of the pressure-sensitive adhesive tape at 23 캜 when the pressure-sensitive adhesive tape is heated from -70 캜 to 150 캜 under a load of 0.11 N in the thickness direction by a compression expansion method of a thermomechanical analyzer, Wherein the maximum increase rate of the thickness of the adhesive tape at 23 to 100 占 폚 is 1.2% or less. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer has at least one pressure-sensitive adhesive layer having a loss coefficient (tan?) According to the nanoindentation method at a temperature of 25 DEG C and a frequency of 100 Hz of 1.0 or more, tape.

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