TW201710426A - Adhesive tape for semiconductor wafer processing, manufacturing method thereof and processing method for semiconductor wafer used in a chip integration step by back grinding on a semiconductor wafer that has been half-cut by a blade or modified by laser to from a modified layer - Google Patents

Abstract

The present invention relates to an adhesive tape for semiconductor wafer processing, a method for manufacturing the same and a method for processing a semiconductor wafer, wherein the semiconductor wafer processing adhesive tape is provided with a radiation curable adhesive layer on a substrate film. The adhesive tape for semiconductor wafer processing is used in a chip integration step by back grinding on a semiconductor wafer that has been half-cut by a blade or modified by laser to from a modified layer, and the decrease in the viscosity of the adhesive after the ultraviolet irradiation is 60% or more in the presence of oxygen.

Description

Adhesive tape for semiconductor wafer processing, method for manufacturing the same, and method for processing semiconductor wafer

The present invention relates to an adhesive tape for processing a semiconductor wafer for processing a semiconductor wafer, a method of manufacturing the adhesive tape, and a method of processing a semiconductor wafer, for manufacturing a semiconductor device such as a germanium wafer.

In particular, the adhesive tape for semiconductor wafer processing of the present invention is used for fixing a semiconductor wafer or the like and performing back grinding.

The step of processing a semiconductor wafer or the like into a semiconductor wafer to be mounted on an electronic device is performed, for example, by attaching an adhesive tape for processing a semiconductor wafer to a pattern surface of a semiconductor wafer (also referred to as adhesion of a semiconductor wafer surface protection). Strip) the surface of the semiconductor wafer is ground to reduce the thickness; the semiconductor wafer to be thinned in this step is mounted on the dicing tape; and the semiconductor wafer is bonded from the semiconductor wafer. The semiconductor wafer is divided by dicing; and the molding step is performed by sealing the semiconductor wafer with a resin for external protection after the bonding step of bonding the divided semiconductor wafer to the lead frame.

On the other hand, there are roughly two types of adhesive tapes for semiconductor wafer processing, and there are two types of radiation curing type and pressure sensitive type. Radiation hardening type, the adhesion is obviously reduced after irradiation, and it is easy The peeling and pressure-sensitive adhesive force are not changed by the radiation, and are the same adhesive force in the back processing of the semiconductor wafer and in the peeling process.

In the adhesive tape for semiconductor wafer processing, it is proposed to provide an adhesive layer having an acrylic polymer as a main component on a polyolefin base resin film such as an ethylene-vinyl acetate copolymer (see, for example, Patent Document 1).

A pattern of a plurality of electronic circuits or electrodes, a protective film for protecting the polyimide, and the like, and a groove for cutting the blade when the semiconductor wafer is diced into a wafer is cut in a pattern on the surface of the semiconductor wafer. According to the configuration as described above, the surface of the semiconductor wafer is not smooth, and there are steps and irregularities of several μm to several tens of μm.

This step is various depending on the type of semiconductor wafer or device, and it is expected that the gap is filled by laminating the step of the semiconductor wafer processing adhesive tape to the surface of the semiconductor wafer. However, when the step of the semiconductor wafer is large or the adhesive tape for semiconductor wafer processing is hard, the followability to the surface of the semiconductor wafer is insufficient. This causes a phenomenon called seepage in which the grinding water penetrates into the gap between the semiconductor wafer and the semiconductor wafer processing adhesive tape in the back grinding step.

Due to the occurrence of the permeation, the adhesive tape for processing a semiconductor wafer is peeled off from the semiconductor wafer, and cracks are generated in the semiconductor wafer from the portion as a starting point, or contamination of the surface of the semiconductor wafer due to penetration of water occurs. Or the paste adheres, which causes the yield to be greatly deteriorated.

For the generation of the percolation, there is known a method of improving the adhesion to the surface of the semiconductor wafer by thickening the adhesive and reducing the elastic modulus of the adhesive as shown in Patent Document 2. Moreover, the same effect is expected by increasing the adhesive force of the adhesive.

However, in the method described above, since the adhesive is strongly adhered to the surface of the semiconductor wafer, the adhesive for the semiconductor wafer processing is cohesively broken, and a part of the adhesive remains on the surface of the semiconductor wafer. It is called a phenomenon such as the phenomenon of paste residue. In the case of the generation of a paste residue, it may cause a problem in the wire bonding or electrical connection in the subsequent step.

In recent years, thin film development of semiconductor wafers has been carried out, and in particular, in semiconductor memory applications, film polishing of 100 μm or less is generally performed, and mass production is performed even at a thickness of 50 μm or less. Since the bending strength of the semiconductor wafer during the film grinding is insufficient, there is a risk that the semiconductor wafer is broken during the operation of the next step after the back surface polishing, or the wafer has insufficient bending strength after wafer formation by dicing. . In response to this problem, the following process improvement is carried out, that is, the bending strength is improved by dry polishing, CMP, wet etching, dry etching, or the like at the time of back grinding.

However, even if the microcracks of the grinding surface are completely removed by the above-described stress relieving method during back grinding, there is a problem in that the wafer is not cut by the chip on the side of the wafer in the cutting method in which the blade is usually used. Fold strength.

In the stress relaxation method at the time of back grinding, there is also a drawback that the gettering layer disappears due to complete smoothing of the ground surface of the semiconductor wafer by stress release. In response to this, a process was developed in which the bending strength was maintained in a state having a gettering layer by grinding and polishing with a high-grade #8000, such as a grinding wheel (UltraPoligrind) or a suction dry polishing.

Under such a background, as a method of generating a higher wafer bending strength, a laser grooving or laser full cutting processing method using a laser and a stealth cutting processing method have been proposed. The laser slotting and laser full cutting method has the following problems: the debris generated by the laser becomes a problem, or when the laser is fully cut The thermal history results in a decrease in the flexural strength of the wafer.

The stealth cutting method is a method in which a modified layer is formed inside with respect to the thickness direction of the semiconductor wafer after the back surface polishing, and is wafer-formed by using this as a starting point. In this method, there is also a case where the modified layer remains inside and there is a modified region on the sidewall of the wafer, resulting in insufficient bending strength.

As a technique which has been performed since the prior art, the method of forming a groove by half-cutting and then performing back-grinding and wafer-forming can improve the bending strength. However, in this method, since the groove is formed by the half-cut by the blade, the wafer remains. Damage to the side walls. As a means for solving this problem, there is an example in which the stress release of the final step of the back grinding is performed by CMP (Chemical Mechanical Polishing) to improve the bending strength.

In the method of performing wafer formation by half-cutting, and in the method of wafer-forming in the back-grinding process, there is a step difference which is much larger than the unevenness of the surface of the semiconductor wafer pattern, and the adhesive tape for processing the semiconductor wafer is peeled off. In the previous ultraviolet irradiation step, the adhesive is hardened in the presence of oxygen (i.e., in the air). In general, in the presence of oxygen, it is known that there is a hardening inhibition by oxygen, and in the case of incomplete hardening, there is a flaw in the residue of the paste which is formed by the half cut. As a countermeasure for improvement, a step of performing ultraviolet irradiation under a nitrogen atmosphere has also been proposed.

As a method for solving such problems, a method of forming a modified layer by stealth cutting inside a semiconductor wafer before back grinding is proposed. Regarding the method of forming the modified layer, a method of forming a plurality of portions in the thickness direction of the semiconductor wafer as a dotted line is also proposed, and the effectiveness is confirmed for the semiconductor wafer having a certain thickness to a certain thickness.

In the method of forming the modified layer in advance, the following method is proposed: The method of wafer-forming in the grinding process, the method of completely removing the modified layer itself by grinding in order to maintain the bending strength, and the method of wafer-forming by the fracture of the modified layer after the grinding process.

However, in recent years, the progress of thin film formation of semiconductor wafers, especially in the use of semiconductor memory, is generally 100 μm or less. The element wafer is thinned to a specific thickness by back grinding, and then wafer-formed by a dicing step, and a plurality of wafers are laminated, and the wires are connected between the substrate and the wafer, and then sealed with a resin to form a product. As an adhesive, a paste resin was previously applied to the back surface of a semiconductor wafer, but for the thin film formation, small wafer formation, or simplification of the wafer, the process is generally as follows: an adhesive and an adhesive are laminated on the substrate in advance. The dicing paste wafer (the die-bonding lining sheet) is bonded to the back surface (grinding surface) of the semiconductor wafer, and is cut together with the semiconductor wafer in the dicing step (see, for example, Patent Document 3). In this method, since the adhesive having a uniform thickness is cut to have the same size as the wafer, the step of applying an adhesive or the like is not required, and since the same apparatus as the previous dicing tape can be used, the workability is good.

When the above-mentioned diced adhesive wafer is bonded, the adhesive tape for semiconductor wafer processing is bonded to the surface of the semiconductor wafer and directly adsorbed to the work disk, and the adhesive wafer is bonded and bonded, and the adhesive tape for processing the semiconductor wafer is peeled off. . In order to adhere the dicing paste to the semiconductor wafer, it is necessary to heat it at the time of bonding, and in recent years, heating at a higher temperature (~80 ° C) is required. The adhesive is heated to adhere to the unevenness on the surface of the semiconductor wafer. In particular, in the case where a large groove is formed by half-cutting, since the unevenness is large, the risk of paste residue is further increased in this case.

In order to cope with the above problems, the following methods are also considered, using radiation hardening type adhesive The agent reduces the adhesive force by radiation hardening at the time of peeling and increases the cohesive force, thereby reducing the residue of the paste. However, there is also a case where the adhesive is hardened and contracted during radiation hardening, and thus stress is applied to the thinned semiconductor wafer, resulting in wafer bending strength at the time of wafer formation after dicing (wafered Si wafer alone) Strength) is reduced.

In the method of forming a groove by half-cutting and then wafer-forming by back-grinding, since wafer is formed during processing, residual stress on the back-side polishing tape or adhesion due to bonding of the adhesive tape for semiconductor wafer processing is adhered. The wafer is offset due to insufficient elastic modulus of the agent, and the scribed opening portion called the slit cannot be uniformly held. In some cases, the wafers are in contact with each other, and the bending strength of the wafer is rather lowered.

Even if the wafers are not in contact with each other, the state of the slits is not uniform, and in the pickup step as a subsequent step, the wafer may not be recognized and a defect may occur.

In the case where the modified layer is formed by the invisible cutting instead of the half cut by the blade, since the slit of the scribed portion is not opened, the wafer end portion of the wafer after the back grinding is in contact with the adjacent wafer, Therefore, in the case of wafer offset, the stress is applied to the end of the wafer, and the bending strength of the wafer is lowered.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Special Report No. 2000-8010

[Patent Document 2] Report of JP-A-2002-53819

[Patent Document 3] Japanese Special Report 2007-53325

An object of the present invention is to solve the above problems, and to provide an adhesive tape for processing a semiconductor wafer, a method of manufacturing the adhesive tape, and a method of processing a semiconductor wafer, wherein the adhesive tape for processing a semiconductor wafer can be suppressed from passing through a semiconductor wafer Processing, more specifically, the back grinding step after the wafer is formed by a half-cut groove or a modified layer inside the semiconductor wafer by stealth cutting (including singulation and grinding after grinding) By singulation of the rupture, the paste residue or surface contamination (seepage) on the surface of the semiconductor wafer after the stripping step of the semiconductor wafer processing, and the amount of slit offset after dust penetration or back grinding is small And semiconductor wafer thin film grinding can be realized.

When pre-cutting is performed by means of half-cutting with a blade or by using a laser to form a modified layer, in addition to the unevenness formed by the pattern of the pattern surface, the bonded semiconductor wafer is processed as compared with the non-precutter. The state between the adhesive tape and the surface of the semiconductor wafer is different, and thus the dust penetration property, the slit offset property, the film grinding property, and the like are remarkably disadvantageous.

In particular, when a half cut is performed using a blade, a deep groove containing air is formed. Further, when the reforming layer is formed by laser, depending on the case, wafer spacing may occur due to the slit offset, or air may be contained between the wafers due to the force generated by the grinding process after the wafer is divided, such as deeper. The slot. Therefore, dust is easily infiltrated in the back grinding due to the deeper grooves or close to the grooves, for example, due to capillary action.

The present inventors have made an effort to carry out research in view of the above problems including such viewpoints. As a result, it has been found that the above-described lesson of the present invention can be solved by setting the rate of decrease in the adhesive force after ultraviolet irradiation under the specific conditions of the adhesive constituting the radiation curable adhesive layer to a specific value or more. question.

The above problems of the present invention have been achieved by the following means.

(1) An adhesive tape for processing a semiconductor wafer, comprising a radiation curable adhesive layer on a base film, wherein the adhesive tape for processing a semiconductor wafer is used in a step of a user, the step a step of singulating a semiconductor wafer formed by a half cut by a blade or a modified layer formed by laser, and irradiating with a UV irradiation amount of 500 mJ/cm ² in the presence of oxygen After the ultraviolet irradiation, the viscosity of the adhesive is lowered by 60% or more.

(2) The adhesive tape for processing a semiconductor wafer according to (1), wherein the substrate film is at least laminated with polyethylene terephthalate, polyethylene, polypropylene, and ethylene-vinyl acetate copolymer. A substrate film of two different materials.

(3) The adhesive tape for processing a semiconductor wafer according to (1) or (2), wherein the resin constituting the film of at least one of the laminated base film contains polyethylene terephthalate or polypropylene. Resin.

(4) The adhesive tape for semiconductor wafer processing according to any one of (1) to (3) wherein the adhesive layer side of the laminated base film is polyethylene terephthalate or polyethylene. The back side of the belt is a polypropylene, polyethylene or ethylene-vinyl acetate copolymer.

(5) The adhesive tape for semiconductor wafer processing according to any one of (1) to (4) wherein the back surface side of the laminated base film is polypropylene.

(6) The adhesive tape for semiconductor wafer processing according to any one of (1) to (4) wherein the base film is composed of polyethylene/polyethylene terephthalate/polyethylene. .

(7) The adhesive tape for semiconductor wafer processing according to any one of (1) to (6) wherein the base material film is an unstretched film.

(8) The adhesive tape for semiconductor wafer processing according to any one of (1) to (6) wherein the substrate film of the base film layer is a base film, and at least one of the films is a biaxially stretched substrate membrane.

(9) The adhesive tape for processing a semiconductor wafer according to any one of (1) to (8), wherein the substrate film is a substrate film of at least two films of different materials, at least one of which is a film It is whitened by particle kneading, particle coating, sand blasting, chemical treatment or embossing.

(10) The adhesive tape for processing a semiconductor wafer according to any one of (1) to (9) wherein the substrate film is a film of a substrate having at least two films of different materials, at least one of which is a film It is composed of polyethylene terephthalate or polypropylene, and the film is whitened by particle kneading, particle coating, sand blasting, chemical treatment or embossing.

(11) The adhesive tape for semiconductor wafer processing according to any one of (1) to (10) wherein the base film is a base film of a film of at least two different materials, and at least one of the layers The film system is whitened by particle kneading.

(12) The adhesive tape for semiconductor wafer processing according to any one of (1) to (11), which is the user of the step of forming a semiconductor formed by a modified layer by laser A step in which the wafer is subjected to back grinding and singulation.

(13) A method of producing an adhesive tape for processing a semiconductor wafer, which is a method for producing a semiconductor wafer processing adhesive tape having a radiation curable adhesive layer on a base film, wherein the semiconductor wafer is processed Attaching the adhesive tape to the user in the following steps, the step of singulating the semiconductor wafer by half-cutting by the blade or by modifying the modified layer by laser, and singulating the film; When the ultraviolet ray is irradiated with ultraviolet rays of 500 mJ/cm ² , the adhesive agent has a viscosity reduction rate of 60% or more, and the base film layer is provided with a substrate film of at least two different materials. The film of at least one layer is composed of polyethylene terephthalate or polypropylene, and is whitened by particle kneading, particle coating, sand blasting, chemical treatment or embossing.

(14) A method of processing a semiconductor wafer, which is a method of processing a semiconductor wafer for use in a semiconductor wafer processing adhesive tape having a radiation curable adhesive layer on a substrate film, characterized by: in the presence of oxygen After the ultraviolet irradiation of 500 mJ/cm ² is applied, the adhesive force reduction rate of the adhesive is 60% or more; and the adhesive tape for semiconductor wafer processing is used in the following steps, and the above steps are performed by The step of dicing the blade by half-cutting or by performing a back-grinding of the semiconductor wafer formed by the modified layer by laser.

(15) The method of processing a semiconductor wafer according to (14), wherein the semiconductor wafer is processed in a step of performing singulation on a back surface of a semiconductor wafer formed by laser modification of a laser layer An adhesive tape is attached to the patterned surface of the semiconductor wafer having irregularities.

In the present invention, the term "surface of the adhesive layer" or "surface of the adhesive layer" means a surface on the opposite side to the bonding surface of the base film unless otherwise specified.

In the present invention, the bonding of the semiconductor wafer to the semiconductor wafer refers to bonding the surface of the adhesive layer toward the surface of the semiconductor wafer.

In the present invention, the term "(meth)acrylic acid" is used to include acrylic acid and methacrylic acid. The meaning of either or both. In this case, the terms "(meth)acryloyl" and "(meth)acrylamide" are also the same.

The adhesive tape for processing a semiconductor wafer of the present invention is used in a semiconductor wafer processing, more specifically, a back grinding step of a wafer or the like, a back surface polishing (BG) tape lamination, a semiconductor wafer back surface grinding process, and a semiconductor crystal. In the peeling step of the adhesive tape for round processing, paste residue or surface contamination (seepage) on the surface of the semiconductor wafer can be suppressed, and the amount of slit offset after dust penetration or back grinding is small, and film grinding processing can be realized. Further, it is possible to provide such an excellent method for producing an adhesive tape for semiconductor wafer processing and a method for processing a semiconductor wafer using the adhesive tape for semiconductor wafer processing.

The above and other features and advantages of the present invention will become more apparent from the description of the appended claims.

10‧‧‧Adhesive tape for semiconductor processing

1‧‧‧Base film

2‧‧‧Adhesive layer

3‧‧‧Semiconductor wafer pattern layer (wiring layer)

4‧‧‧layers of semiconductor wafers

Fig. 1 is a schematic cross-sectional view showing a state in which an adhesive tape for processing a semiconductor wafer of the present invention is bonded to a pattern surface of a semiconductor wafer.

<<Adhesive tape for semiconductor wafer processing>>

An embodiment of the present invention will be described with reference to a schematic cross-sectional view of Fig. 1.

In the figure, 1 is a base film, and 2 is an adhesive layer applied on a base film to form an adhesive tape for processing a semiconductor wafer 10. 4 is a layer of a semiconductor wafer on which a semiconductor wafer pattern is provided. The layer (wiring layer) 3 adheres the adhesive layer 2 to the pattern layer 3 of the semiconductor wafer.

Further, in the present invention, the semiconductor wafer is formed by laser forming a modified layer or by a blade on the side of the pattern layer, but is omitted in FIG. Similarly, the pattern side of the semiconductor wafer has a step of unevenness, but this content is also omitted.

The adhesive tape for processing a semiconductor wafer of the present invention has a radiation curable adhesive layer on a base film, and is formed by half-cutting by a blade or by a modified layer by laser (ie, The semiconductor wafer in which the pre-cutting has been performed is subjected to back grinding and singulation in the step of singulation.

Further, the present invention is an adhesive tape for semiconductor wafer processing in which the viscosity of the adhesive is reduced by 60% or more after irradiation with ultraviolet rays having an ultraviolet irradiation amount of 500 mJ/cm ² in the presence of oxygen.

<Reduction rate of adhesion of adhesive>

When the adhesive used in the present invention is irradiated with ultraviolet rays in the presence of oxygen, the viscosity reduction rate is 60% or more.

Here, the presence of oxygen means that it is substantially the same as in the air in the presence of oxygen.

In addition, the rate of decrease in the viscosity is obtained by the following formula (1), which is obtained by the ultraviolet irradiation amount of 500 mJ/cm ² .

Formula (1) [Tα-Tβ(O ₂ )]÷[Tα]×100

Here, Tα is the adhesive force of the adhesive before ultraviolet irradiation, and Tβ(O ₂ ) is the adhesive force of the adhesive after ultraviolet irradiation.

The viscosity is measured at room temperature (25 ° C) by a stress relaxation measuring device [for example, a viscosity tester (trade name: TACII, manufactured by Rhesca)] in the following manner.

Specifically, a test piece having a width of 25 mm and a length of 250 mm is taken from an adhesive tape for processing a semiconductor wafer before irradiation of radiation, and the test piece is placed in a testing machine, and the indenter is brought into contact with the test piece, and the substrate of the test piece is placed. The back side (opposite side to the adhesive application surface) is pressed 3 mm at a speed of 30 mm/min. The cylindrical probe was measured for the load (viscosity Tα) when it was pulled at a speed of 600 mm/min after stopping for 1 second at a stop load of 100 g. On the other hand, the adhesive tape for semiconductor wafer processing which is irradiated with ultraviolet rays at an irradiation dose of 500 mJ/cm ² in the presence of oxygen (that is, in air) is the same as the adhesive tape for semiconductor wafer processing before irradiation of radiation. The viscosity Tβ(O ₂ ) was determined by the method.

Furthermore, the unit of adhesion is kPa.

The viscosity reduction rate is 60% or more, preferably 80% or more. Further, the viscosity reduction rate is preferably reduced by 100%, but in reality, it is preferably 95% or less.

In order to reduce the viscosity of the adhesive by 60% or more, the kind of the resin constituting the resin composition of the adhesive, the kind and amount of the monomer constituting the resin, or the reactivity capable of undergoing polymerization by irradiation with ultraviolet rays may be employed. The type and amount of the oligomer and the type and amount of the photoinitiator are adjusted.

<Adhesive or Adhesive Layer>

In general, the adhesive is a resin composition, and the adhesive which constitutes the radiation curable adhesive layer in the adhesive tape for semiconductor wafer processing of the present invention is not particularly limited as long as it is cured by irradiation with ultraviolet rays. The base resin of the resin composition preferably contains a polymer (hereinafter referred to as "ultraviolet curable polymer") having at least one reactive group capable of undergoing polymerization by irradiation with ultraviolet rays as a main component. Here, the term "main component" means that the content ratio of the polymer resin in the base resin is 80 to 100% by mass.

As the above-mentioned reactive group which can be polymerized by irradiation of ultraviolet rays, The ethylenically unsaturated group is preferably a group having a carbon-carbon double bond, and examples thereof include a vinyl group, an allyl group, a styryl group, a (meth)acryloxy group, and a (meth)acrylamide group. .

The ultraviolet curable polymer is not particularly limited, and examples thereof include a (meth)acrylic copolymer, a polyester, an ethylene or styrene copolymer, and a polyurethane.

In the present invention, a (meth)acrylic copolymer is preferred.

As a method for synthesizing the ultraviolet curable polymer, for example, when (a) is a polymer having an ethylenically unsaturated group, a compound having an ethylenically unsaturated group is reacted with a polymer to obtain an ethyl group. A method of using a polymer having a saturated group, (b) a method of using an oligomer having an ethylenically unsaturated group [for example, an (meth)acrylic acid amide oligomer as a crosslinking agent, etc.] is simple and easy, and thus Preferably, the method of the above (a) is preferred.

In the method of the above (a), as the compound having an ethylenically unsaturated group, a compound having a structure different from the ethylenically unsaturated group (referred to as a reactive group α) is used as the ethyl group. As the polymer of the saturated group, a polymer having a structure of a reactive group β which reacts with a reactive group α of a compound having the ethylenically unsaturated group (hereinafter referred to as "polymer having a reactive group β") is used. The reactive group α is reacted with β.

Preferably, such reactive groups α and β are, for example, one which is subjected to a nucleophilic attack and the other which is subjected to a nucleophilic attack or a reaction which undergoes an addition reaction. Examples of such a reactive group include a hydroxyl group, an amine group, a mercapto group, a carboxyl group, an epoxy group, an oxetanyl group, an isocyanate group, a group forming a cyclic acid anhydride, a halogen atom, an alkoxy group or an aryloxy group. Carbonyl group and the like.

Here, when any of the reactive groups α and β is a hydroxyl group, an amine group, a mercapto group or a carboxyl group, the other reactive group may be an epoxy group, an oxetane group or an isocyanate group. A group of a cyclic acid anhydride, a halogen atom, an alkoxy group or an aryloxycarbonyl group is formed.

The reactive group α of the compound having an ethylenically unsaturated group is preferably a group which is subjected to a nucleophilic attack or is subjected to an addition reaction, and is preferably, for example, an epoxy group, an oxetanyl group or an isocyanate group. a cyclic acid anhydride group, a halogen atom, an alkoxy group or an aryloxycarbonyl group, more preferably an epoxy group, an oxetanyl group, an isocyanate group or a group forming a cyclic acid anhydride, and further preferably an epoxy group, An oxetanyl or isocyanate group, of which an isocyanate group is preferred.

On the other hand, the reactive group having a polymer into which an ethylenically unsaturated group is introduced is preferably a group which undergoes nucleophilic attack, and is preferably, for example, a hydroxyl group, an amine group, a mercapto group or a carboxyl group, more preferably a hydroxyl group, an amine group or a mercapto group. Further, it is preferably a hydroxyl group, an amine group or a carboxyl group, and further preferably a hydroxyl group or a carboxyl group, of which a hydroxyl group is preferred.

Examples of the monomer having a reactive group β used for the synthesis of a compound having an ethylenically unsaturated group and a reactive group α or a polymer having a reactive group β include the following compounds.

- a compound whose reactive group is a carboxyl group -

(Meth)acrylic acid, cinnamic acid, itaconic acid, fumaric acid, etc.

- a compound whose reactive group is a hydroxyl group -

a hydroxyalkyl (meth) acrylate having a hydroxyl group in the alcohol moiety [e.g. 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, trimethylolpropane mono(meth)acrylic acid Ester, ethylene glycol mono(meth)acrylate, diethylene glycol mono(meth)acrylate], N-(hydroxyalkyl)alkyl(methyl)propene of an alkylamine having a hydroxyl group at the amine moiety Guanidine [eg N-hydroxymethyl (meth) acrylamide, N, N-bis hydroxymethyl (meth) acrylamide], allyl alcohol, etc.

- a compound whose reactive group is an amine group -

An aminoalkyl (meth) acrylate having an amine group at the alcohol moiety [for example, (meth)acrylic acid -(alkylamino)ethyl ester, 3-(alkylamino)propyl (meth)acrylate], (meth)acrylamide, etc.

- a compound whose reactive group is a cyclic anhydride -

Maleic anhydride, itaconic anhydride, fumaric anhydride, phthalic anhydride, etc.

a compound in which the reactive group is an epoxy group or an oxetanyl group -

(meth)acrylic acid propyl acrylate, allyl epoxidized ether, 3-ethyl-3-hydroxymethyl oxetane, etc.

- a compound whose reactive group is an isocyanate group -

(meth) propylene oxiranyl isocyanate [eg 2-(meth) propylene methoxyethyl isocyanate, 2-(methyl) propylene methoxy propyl isocyanate], One part of the isocyanate group of the polyisocyanate compound is obtained by amine esterification of a compound having a hydroxyl group or a carboxyl group and an ethylenically unsaturated group [for example, an acrylamide ester oligomer of (meth)acrylic acid having 2 to 10 functional groups], etc.

Further, as the urethane amide oligomer, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and neopentyl tris (tri) acrylate are preferable. a hydroxyalkyl (meth) acrylate having a hydroxyl group in the alcohol portion, with toluene diisocyanate, methylene biphenyl diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, methylene dicyclohexyl isocyanate, isophor An oligomer having at least one isocyanate group obtained by reacting a diisocyanate such as keto diisocyanate or a trifunctional or higher isocyanate. Further, in addition to the hydroxyalkyl (meth) acrylate and the polyvalent isocyanate, an oligomer obtained by reacting a polyol compound, a polyester diol compound or a polyester diol compound may be used.

- a compound whose reactive group is a halogen atom -

2,4,6-trichloro-1,3,5-three 2,4-Dichloro-6-methoxy-1,3,5-three Halogenated Wait

The compound having an ethylenically unsaturated group and a reactive group α is preferably a compound having an isocyanate group as the above-mentioned reactive group, and a monomer used for the synthesis of a polymer having a reactive group β. It is preferably a compound in which the above reactive group is a carboxyl group or a compound in which a reactive group is a hydroxyl group, and more preferably a compound in which a reactive group is a hydroxyl group.

Among them, in the present invention, (meth) propylene decyloxyalkyl isocyanate is preferred, and 2-(meth) propylene methoxyethyl isocyanate is particularly preferred.

The method of the above (b) is a method of using the above (meth)acrylic acid amide oligomer (the oligomer is also a kind of a crosslinking agent as described below), and a (meth)acrylic copolymer can be used ( The methyl methacrylate oligomer coexists to form an ultraviolet curable adhesive layer. The (meth)acrylic copolymer is preferably a copolymer obtained by polymerizing (meth)acrylic acid with a (meth)acrylate. The preferred embodiment of the (meth) acrylate component constituting the (meth)acrylic copolymer is the same as that described for the copolymerization component in the polymer having the reactive group β described below.

The monomer having a reactive group β used for the synthesis of the polymer having a reactive group β is preferably a hydroxyalkyl (meth)acrylate or a (meth)acrylic acid having a hydroxyl group at the alcohol moiety.

The ratio of the monomer component having the reactive group β to all the monomer components constituting the polymer having the reactive group β is in the case of a hydroxyalkyl (meth)acrylate having a hydroxyl group in the alcohol moiety, It is preferably 5 to 50 mol%, more preferably 20 to 40 mol%, and even more preferably 20 to 35 mol%, and particularly preferably 50 to 75 mol%.

On the other hand, in the case of (meth)acrylic acid, acrylic acid or all of the monomer components The methacrylic acid is preferably 0.1 to 3 mol%, more preferably 0.5 to 2.5, and still more preferably 0.5 to 2.

Further, when a compound having an ethylenically unsaturated group and a reactive group α is reacted with a polymer having a reactive group β, and when a polymer having a reactive group β is introduced into an ethylenically unsaturated group, it is preferred to The compound having a reactive group α is reacted in an amount of 5 to 40 parts by mass, more preferably 10 to 30 parts by mass, more preferably 10 to 20 parts by mass, based on 100 parts by mass of the polymer having a reactive group β.

After the reactive group α and β are reacted, the unreacted reactive group β remains, whereby the resin property can be adjusted by the following crosslinking agent or the like.

The polymer having a reactive group β preferably has a monomer component having the above-described reactive group β as a constituent component thereof, and has a (meth) acrylate component as a copolymerization component.

The (meth) acrylate is preferably one or two or more kinds of alkyl (meth)acrylates. The alcohol moiety of the (meth) acrylate does not have the above reactive group β. It is preferred that the alcohol portion of the above (meth) acrylate is unsubstituted.

As such a (meth) acrylate, the carbon number of the alcohol portion is preferably from 1 to 12. The carbon number of the alcohol portion is more preferably from 1 to 10, still more preferably from 4 to 10. Among them, those having an alcohol moiety is a branched alkyl group, and particularly preferably 2-ethylhexyl (meth)acrylate.

In the case where the ultraviolet polymerizable polymer contains a plurality of (meth) acrylate components as a constituent component, it is preferred that the (meth) acrylate component contains an alcohol portion having a carbon number of 1 to 8 (A). The acrylate component preferably contains a methyl (meth) acrylate component or a butyl (meth) acrylate component.

Specific examples of the monomer which is incorporated in the polymer as the above-mentioned copolymerization component are listed below.

-alkyl (meth)acrylate -

The alkyl ester of (meth)acrylic acid is preferably an alkyl ester of (meth)acrylic acid having an alcohol moiety of 1 to 12, and examples thereof include methyl (meth)acrylate and (methyl). Ethyl acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, (methyl) 2-ethylhexyl acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, isodecyl (meth)acrylate, and the like. These may be used alone or in combination of two or more. By using two or more types in combination, various functions as an adhesive can be exhibited, and the followability of the surface of the semiconductor wafer to the step can be achieved and the non-contamination of the paste residue can be prevented.

Monomers other than alkyl (meth) acrylate -

Examples of the monomer other than the alkyl ester of (meth)acrylic acid include vinyl acetate, styrene or (meth) acrylamide, such as N,N-diethyl acrylamide, N,N-di Ethyl acrylamide, N-isopropyl acrylamide, N-propylene hydrazinoline, and the like. These may be used alone or in combination of two or more.

In the present invention, a monomer which is a copolymerization component combined with a monomer having a reactive group β is preferably a (meth) acrylate or a (meth) acrylic acid.

The ratio of the above copolymer component to all the monomer components constituting the polymer having the reactive group β is preferably 5 to 85 mol%, more preferably 20 to 80 mol%, and still more preferably 55 to 75 mol%. %, especially preferably 60~75% by mole.

Further, the amount of the reactive group β remaining in the ultraviolet curable polymer is also dependent on the compounding amount of the compound having the reactive group α, but it may be adjusted according to the type and amount of the crosslinking agent described below.

The ultraviolet curable polymer preferably has a hydroxyl value of 5 to 70 mgKOH/g, an acid value of preferably 0 to 10 mgKOH/g, a glass transition temperature (Tg) of preferably -40 to -10 ° C, and a weight average molecular weight of preferably 150,000 to 1.3 million.

Further, the acid value was measured in accordance with JIS K5601-2-1:1999, and the hydroxyl value was measured in accordance with JIS K 0070.

Here, the glass transition temperature means a glass transition temperature measured by DSC (differential scanning calorimeter) at a temperature increase rate of 0.1 ° C/min.

Further, the weight average molecular weight is a value obtained by measuring a 1% solution obtained by dissolving in tetrahydrofuran by gel permeation chromatography (manufactured by Waters Co., Ltd., trade name: 150-C ALC/GPC) in terms of polystyrene. The form of the weight average molecular weight is calculated.

(photopolymerization initiator)

The adhesive layer of the present invention is particularly preferably a photopolymerization initiator. The adhesion after crosslinking can be controlled by adjusting the amount of the photopolymerization initiator of the adhesive layer. Specific examples of such a photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl diphenyl sulfide, and tetramethylthiuram monosulfide. (tetramethylthiuram disulfide), azobisisobutyronitrile, dibenzyl, diethyl hydrazine, β-chloropurine, benzophenone, mitesone, chloro 9-oxosulfur , benzil dimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethyl phenyl propane, and the like. These may be used alone or in combination.

The photopolymerization initiator is usually used in a ratio of 0.1 to 10 parts by mass based on 100 parts by mass of the total of the polymer having an ethylenically unsaturated group and the compound having an ethylenically unsaturated group. Further, it is preferably 0.1 to 10 masses per 100 parts by mass of the base resin constituting the adhesive layer. More preferably, it is 1 to 6 parts by mass.

By irradiating the ultraviolet curable adhesive layer formed in this manner with ultraviolet rays, the adhesion can be greatly reduced, and the adhesive tape can be easily peeled off from the adherend.

(crosslinking agent)

In the present invention, it is preferred to contain a crosslinking agent in the adhesive layer. A crosslinking agent which is a reactive group of a crosslinking group of a crosslinking agent and a reactive group β of a polymer having a reactive group β is preferred.

For example, when the reactive group β of the resin having a reactive group β is a carboxyl group or a hydroxyl group, the reactive group which is a crosslinking group of the crosslinking agent is preferably a cyclic acid anhydride, an isocyanate group or an epoxy group. A halogen atom is more preferably an isocyanate group or an epoxy group.

By using such a crosslinking agent, the residual amount of the reactive group β of the polymer having a reactive group β can be adjusted according to the amount of the crosslinking agent, and the viscosity can be controlled.

Further, by using a crosslinking agent, the cohesive force of the adhesive layer can also be controlled.

The crosslinking agent which is preferably used for the above-mentioned pressure-sensitive adhesive layer may, for example, be a polyvalent isocyanate compound, a polyvalent epoxy compound, a polyaziridine compound or a chelate compound. Specific examples of the polyvalent isocyanate compound include tolyl diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the like.

Examples of the polyvalent epoxy compound include ethylene glycol diglycidyl ether and diglycidyl phthalate acrylate. The polyaziridine compound can be exemplified by tris-2,4,6-(1-aziridine)-1,3,5-three. , tris[1-(2-methyl)-aziridine]phosphine oxide, hexa[1-(2-methyl)-aziridine]triphosphate Wait. Further, examples of the chelate compound include ethyl acetoacetate ethyl diisopropyl aluminum and tris(acetonitrile ethyl acetate) aluminum.

Further, in the adhesive used in the present invention, a crosslinking agent having at least two or more ethylenically unsaturated groups in the molecule, preferably an oligomer or a polymer crosslinking agent may be used. It is itself used as an ultraviolet curable resin.

Examples of the low molecular compound having at least two or more ethylenically unsaturated groups in the molecule include trimethylolpropane triacrylate, tetramethylol methane tetraacrylate, neopentyl alcohol triacrylate, and neopentyl. Tetraol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, polyethyl b Diol diacrylate, oligoester acrylate, and the like.

Further, an urethane acrylate oligomer can be used, and in particular, it can be widely used as follows, that is, a polyol compound such as a polyester type or a polyether type and a polyvalent isocyanate compound (for example, 2) can be obtained. , 4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-benzenedimethyl diisocyanate, 1,4- phenyldimethyl diisocyanate, diphenylmethane 4,4-diisocyanate, etc. The reaction is carried out to obtain a terminal isocyanate amine ester prepolymer, and the terminal isocyanate amine ester prepolymer and a (meth) acrylate having a hydroxyl group (for example, 2-hydroxyethyl (meth)acrylate, 2-(meth)acrylic acid 2- A hydroxypropyl ester and a polyethylene glycol (meth) acrylate are obtained by carrying out a reaction.

The content of the crosslinking agent may be adjusted so that the adhesive force and the adhesive force of the adhesive are in a desired range, and it is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5, based on 100 parts by mass of the base resin. The mass fraction is further preferably 0.6 to 5 parts by mass, particularly preferably 0.7 to 3 parts by mass.

(additive)

In the present invention, the pressure-sensitive adhesive layer may contain an additive in addition to the above.

As such an additive, for example, as an additive for preventing wetting or improving the smoothness, a polyfluorene acrylate (for example, polydecane diacrylate or polyoxyhexa acrylate) and an ultraviolet curing accelerator are exemplified. Further, as the additive, an amino acrylate as a water resistant agent may be contained. Further, as an additive, a plasticizer may be contained. Further, a surfactant which is used in the polymerization of the polymer may be contained.

(thickness of adhesive layer)

The thickness of the adhesive layer is not particularly limited, but is preferably 10 to 300 μm, more preferably 20 to 200 μm, and still more preferably 30 to 100 μm.

Further, the adhesive layer may be provided on both sides of the base film in accordance with the purpose.

In order to form an adhesive layer on the substrate film, at least one adhesive may be applied to at least one side of the substrate film by a usual method as described above.

(other layers)

In the present invention, an intermediate layer such as an undercoat layer may be provided between the base film and the adhesive layer as needed.

<release liner>

The adhesive tape of the present invention may also have a release liner on the adhesive layer. As the release liner, a polyethylene terephthalate film or the like which has been subjected to polyfluorination release treatment is used. Further, a polypropylene film or the like which is not subjected to polyfluorination release treatment may be used as needed.

<Substrate film>

As a material of the substrate film used in the present invention, the main purpose of the material is to protect the semiconductor wafer from the impact on the back surface of the semiconductor wafer, and it is particularly important to have water resistance and processing for water washing and the like. Retention of parts. As such a base film, for example, a base film described in JP-A-2004-186429 can be cited.

Further, the substrate film used in the present invention can be generally used in the form of an adhesive tape, and examples thereof include polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, and ethylene-vinyl acetate copolymer. Homopolymer or copolymer of α-olefin such as ethylene-acrylate copolymer or ionic polymer, engineering plastics such as polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyurethane, styrene- A thermoplastic elastomer such as an ethylene-butene or a pentene-based copolymer may be a mixture of two or more selected from the group consisting of these.

In the present invention, the substrate film is preferably a substrate film in which at least two films are laminated, and more preferably at least laminated with polyethylene terephthalate, polyethylene, polypropylene, and ethylene-vinyl acetate copolymer. A substrate film of two different materials.

In the present invention, the resin constituting at least one film of the substrate film of the laminated layer is preferably a resin containing polyethylene terephthalate or polypropylene. Further, it is preferable that the adhesive layer side of the base film of the laminated layer is polyethylene terephthalate or polyethylene, and the back side of the tape is polypropylene, polyethylene or an ethylene-vinyl acetate copolymer. In the present invention, it is particularly preferred that the back side of the tape of the substrate film to be laminated is polypropylene.

Further, in the case where the base film is laminated in three layers, it is preferably composed of three layers of polyethylene/polyethylene terephthalate/polyethylene.

In the present invention, the base film is preferably a biaxially stretched film.

The biaxially stretched film can be formed by extending the thermoplastic film in both the longitudinal and transverse directions by high temperature. In the case of lamination, at least one of the films can be a biaxially stretched film, and all the films can be biaxially oriented. The film may be stretched, and the substrate film of the layer may be biaxially stretched.

The base film is preferably a film on the side of the adhesive layer (in the case of one layer, the base film itself) is roughened and whitened.

The roughening and whitening are preferably particle kneading, particle coating, sand blasting, chemical treatment or embossing.

Specifically, the particle kneading is preferably a particle having an average particle diameter of 1 to 10 μm and a material composed of an inorganic filler, and the particles are kneaded by 30 to 50 parts by mass with respect to 100 parts by mass of the film resin.

Specifically, the particle coating is preferably a particle having an average particle diameter of 1 to 10 μm and a material composed of an inorganic filler, and the film resin is coated with a solvent by a gravure coater to dilute the particles.

Specifically, the blasting is performed by a high-speed impact on a film which is a target for fine processing of blasting.

The chemical treatment is specifically a person who performs the roughening treatment by etching the film with an etchant (chemical agent).

Specifically, the embossing process is a method in which a plate having a desired unevenness is prepared in advance, and the film is subjected to unevenness treatment while heating the plate.

In the present invention, these are preferably particle kneading and particle coating, and more preferably particle kneading.

In the present invention, the transmittance of the base film at a wavelength of 800 to 1200 nm is preferably 80% or more, more preferably 90% or more.

Here, the transmittance can be measured by a spectrophotometer (for example, manufactured by Shimadzu Corporation, UV-3600).

The thickness of the substrate film is preferably from 50 to 200 μm.

In the case of a laminated base film, the thickness of the film on the back side and the film on the side of the adhesive layer may be The same or different, in the present invention, it is preferred that the thicknesses are different. Among them, it is preferred that the film having the back side has a thicker thickness.

Further, the thickness of the film on the side of the adhesive layer is preferably from 10 to 100 μm, more preferably from 20 to 60 μm.

(Use of adhesive tape for semiconductor wafer processing)

The adhesive tape for processing a semiconductor wafer of the present invention is used as a semiconductor used in a step of singulating a semiconductor wafer which is half-cut by a blade or subjected to a modified layer formed by laser polishing. Adhesive tape for wafer processing.

In particular, in the present invention, it is preferably applied to a semiconductor wafer in which a reformed layer is formed by laser irradiation.

<<Manufacturing method of adhesive tape for semiconductor wafer processing>>

The manufacturing method of the adhesive tape for semiconductor wafer processing is manufactured by using the following base film, and after the adhesive is irradiated with ultraviolet rays of 500 mJ/cm ² in the presence of oxygen, the adhesive viscosity reduction rate is 60%. In the above, the substrate film is a substrate film having at least two films of different materials, and at least one of the films is composed of polyethylene terephthalate or polypropylene, and the film is coated by particles and coated with particles. Whitening by cloth, sand blasting, chemical treatment or embossing.

<<Processing method of semiconductor wafer and semiconductor wafer>>

The semiconductor wafer to which the adhesive tape for semiconductor wafer processing of the present invention is applied is not particularly limited and can be applied to a semiconductor wafer of any form.

The method for processing a semiconductor wafer using the adhesive tape for semiconductor wafer processing of the present invention (hereinafter referred to as "the processing method of the present invention") is used for the adhesive tape for processing a semiconductor wafer of the present invention. A step of singulating and singulating a semiconductor wafer formed by reforming a layer by laser cutting.

[Examples]

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to the examples.

<Example 1>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. And 5 parts by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

In addition, as an adhesive application to a heterogeneous film, an acrylic copolymer having a weight average molecular weight of 300,000 and a glass transition temperature of -44 ° C and an isocyanate-based hardener Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) were prepared. 4 parts by mass, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain the adhesive composition A.

The adhesive composition A was coated on a 25 μm polyethylene terephthalate (PET) separator and dried, and bonded to a polypropylene (PP) film having a thickness of 40 μm and a thickness of 38 μm. A biaxially stretched composite film of a polyethylene terephthalate (PET) film is laminated thereon, and the adhesive composition is applied onto the laminated base film to form a film having a thickness of 30 μm. The adhesive layer is formed to form an adhesive tape for processing semiconductor wafers.

<Example 2>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. And 5 parts by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was coated on a 25 μm polyethylene terephthalate separator and dried, and bonded to a polypropylene film having a thickness of 40 μm and a thickness of 25 μm. The biaxially stretched composite film of the ethylene terephthalate film was laminated thereon, and the adhesive composition was applied onto the laminated base film to form an adhesive layer having a thickness of 30 μm. Adhesive tape for semiconductor wafer processing.

<Example 3>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. Acrylic acid obtained In the copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) and a photopolymerization initiator are formulated with respect to 100 parts by mass of the solid content of the copolymer. 5 parts by mass, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by using ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was applied onto a 25 μm polyethylene terephthalate separator and dried, and bonded to a polypropylene film having a thickness of 40 μm and a thickness of 50 μm. The particles are kneaded and the biaxially stretched composite film of the roughened polyethylene terephthalate film is laminated thereon, and the adhesive composition is applied onto the laminated base film to set a film thickness of 30 μm. The adhesive layer is used to form an adhesive tape for processing semiconductor wafers.

<Example 4>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. And 5 parts by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was applied onto a 25 μm polyethylene terephthalate separator and dried, and bonded to a polypropylene film having a thickness of 40 μm and a thickness of 25 μm. Particle-kneading of a polyethylene terephthalate film roughened by biaxial stretching On the composite film, the adhesive composition was applied onto the laminated base film, and an adhesive layer having a thickness of 30 μm was provided to form an adhesive tape for processing a semiconductor wafer.

<Example 5>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. And 5 parts by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was applied onto a 25 μm polyethylene terephthalate separator and dried, and bonded to a polypropylene film having a thickness of 60 μm and a thickness of 25 μm. The particles are kneaded and the biaxially stretched composite film of the roughened polyethylene terephthalate film is laminated thereon, and the adhesive composition is applied onto the laminated base film to set a film thickness of 30 μm. The adhesive layer is used to form an adhesive tape for processing semiconductor wafers.

<Example 6>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - the hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate, and the side chain of the polymer is introduced as a radiation curable carbon - A methacrylonitrile-based acrylic copolymer in which a carbon double bond functions. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. 5 parts by mass of the photopolymerization initiator was adjusted with ethyl acetate in order to adjust the viscosity to be easily applied to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was coated on a 25 μm polyethylene terephthalate separator and dried, and bonded to a polypropylene film having a thickness of 60 μm and a particle having a thickness of 50 μm. The biaxially stretched composite film of the roughened polyethylene terephthalate film is kneaded, thereby laminating, and the adhesive composition is applied onto the laminated base film to provide a film thickness of 30 μm. Adhesive layer to make an adhesive tape for semiconductor wafer processing.

<Example 7>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. And 5 parts by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was coated on a 25 μm polyethylene terephthalate separator and dried, and bonded to ethylene-vinyl acetate having a thickness of 100 μm. An adhesive copolymer (EVA) film and a biaxially stretched composite film of a polyethylene terephthalate film having a thickness of 38 μm are laminated thereon, and the above-mentioned adhesive composition is coated on the laminated base film. An adhesive layer having a film thickness of 30 μm was provided to prepare an adhesive tape for processing a semiconductor wafer.

<Example 8>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. And 5 parts by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was coated on a 25 μm polyethylene terephthalate separator and dried, and bonded to a low-density polyethylene film having a thickness of 100 μm and a thickness of 38 μm. The biaxially stretched composite film of the polyethylene terephthalate film is laminated thereon, and the adhesive composition is applied onto the laminated base film to form an adhesive layer having a film thickness of 30 μm. Thereby, an adhesive tape for processing a semiconductor wafer is produced.

<Example 9>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - Hydroxyethyl ester to obtain a hydroxyl group in a repeating unit and 2-methylpropene isocyanate The methoxyethyl ester was reacted to obtain an acryl-based copolymer in which a methacryl oxime group functioning as a radiation-curable carbon-carbon double bond was introduced into the polymer side chain. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. And 5 parts by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was coated on a 25 μm polyethylene terephthalate separator and dried, and bonded to a low density polyethylene (PE) having a thickness of 40 μm and a thickness. A three-layer composite film of a 38 μm polyethylene terephthalate film and a low-density polyethylene film having a thickness of 40 μm was laminated thereon, and the above-mentioned adhesive composition was applied onto the laminated base film. An adhesive layer having a film thickness of 30 μm was used to form an adhesive tape for processing a semiconductor wafer.

<Example 10>

An acrylic copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-hydroxyethyl acrylate, and 1 part by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.9 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was formulated with respect to 100 parts by mass of the solid content of the copolymer. And 5 parts by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was coated on a 25 μm polyethylene terephthalate separator and dried, and bonded to a polypropylene having a thickness of 25 μm and subjected to coarsening by particle mixing. a (PP) film and a biaxially stretched composite film of a polyethylene terephthalate film having a thickness of 38 μm, thereby laminating, and applying the above-mentioned adhesive composition on the laminated base film, and setting An adhesive layer having a film thickness of 30 μm was used to form an adhesive tape for processing a semiconductor wafer.

<Example 11>

The adhesive composition A prepared in Example 1 was coated on a 25 μm polyethylene terephthalate separator and dried, and bonded to an unstretched polypropylene (PP) film having a thickness of 40 μm. On the unstretched composite film of a polyethylene terephthalate film having a thickness of 38 μm, a laminate was formed thereon, and an adhesive layer having the same thickness as that of Example 1 having a thickness of 30 μm was provided on the laminated base film. Adhesive tape for semiconductor wafer processing.

<Comparative Example 1>

An acrylic copolymer composed of 69 parts by mass of 2-ethylhexyl acrylate, 29 parts by mass of 2-hydroxyethyl acrylate, and 2 parts by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.5 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was blended with respect to 100 parts by mass of the solid content of the copolymer. And 1 part by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

Coating the above adhesive composition on a 25 μm polyethylene terephthalate separator and making it Drying and laminating on an ethylene-vinyl acetate copolymer (EVA) film having a thickness of 100 μm, thereby forming an adhesive layer having a film thickness of 30 μm on the ethylene-vinyl acetate copolymer (EVA) film. Adhesive tape for semiconductor wafer processing.

<Comparative Example 2>

An acrylic copolymer composed of 69 parts by mass of 2-ethylhexyl acrylate, 29 parts by mass of 2-hydroxyethyl acrylate, and 2 parts by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - The hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate to obtain a side which acts as a radiation-curable carbon-carbon double bond in the side chain of the polymer. A acryl-based acrylic copolymer. In the obtained acrylic copolymer, 0.5 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was blended with respect to 100 parts by mass of the solid content of the copolymer. And 1 part by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

Applying the above adhesive composition to a 25 μm polyethylene terephthalate separator, drying it, and laminating it on a polyethylene terephthalate film having a thickness of 100 μm, thereby forming the poly pair An adhesive layer having a film thickness of 30 μm was provided on the ethylene phthalate film to prepare an adhesive tape for processing a semiconductor wafer.

<Comparative Example 3>

An acrylic copolymer composed of 69 parts by mass of 2-ethylhexyl acrylate, 29 parts by mass of 2-hydroxyethyl acrylate, and 2 parts by mass of methacrylic acid was prepared, and thereafter, acrylic acid 2 as a polymer side chain was used. - the hydroxyl group in the repeating unit obtained by the hydroxyethyl ester is reacted with 2-methylpropenyloxyethyl isocyanate, and the side chain of the polymer is introduced as a radiation curable carbon - A methacrylonitrile-based acrylic copolymer in which a carbon double bond functions. In the obtained acrylic copolymer, 0.5 parts by mass of the addition-type isocyanate-based crosslinking agent Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) was blended with respect to 100 parts by mass of the solid content of the copolymer. And 1 part by mass of the photopolymerization initiator, in order to adjust the viscosity to be easily applied, the viscosity was adjusted by ethyl acetate to obtain an adhesive composition.

The adhesive composition A prepared in Example 1 was coated on a 25 μm polyethylene terephthalate separator and dried, and bonded to a polyethylene (PE) film/ethylene having a thickness of 100 μm. On the vinyl acetate copolymer (EVA) film laminate, the above-mentioned adhesive composition was applied onto the laminated base film, and an adhesive layer having a thickness of 30 μm was provided to prepare a semiconductor wafer. Adhesive tape.

<Comparative Example 4>

Adding an allyl-containing polyoxyethylene alkyl phenyl ether compound and a polypropylene glycol compound as a surfactant to the pure water after deionization, and adding ammonium persulfate as a polymerization initiator to heat Stir on one side. Then, 17 parts by mass of methyl methacrylate, 40 parts by mass of butyl acrylate, 41 parts by mass of 2-ethylhexyl acrylate, and 2 parts by mass of glycidyl methacrylate were added dropwise to the reaction solution under stirring. Further, stirring was continued to cause polymerization, whereby an acrylic emulsion adhesive composition was obtained.

The above adhesive composition was coated on a 25 μm polyethylene terephthalate separator, dried at 110 ° C for 5 minutes, and bonded to an ethylene-vinyl acetate copolymer (EVA) film having a thickness of 165 μm. The adhesive composition was applied onto the ethylene-vinyl acetate copolymer (EVA) film, and an adhesive layer having a film thickness of 40 μm was provided to prepare an adhesive tape for processing a semiconductor wafer.

[Characteristic evaluation test]

The adhesive tape for semiconductor wafer processing of Examples 1 to 11 and Comparative Examples 1 to 4 was subjected to a characteristic evaluation test as described below.

(Formation of modified layer using stealth cutting)

Using a DISCO-made stealth microtome, a modified layer is formed in a region of the silicon (Si) wafer that is thicker than the final thickness of the wafer, and the semiconductor wafer is easily opened.

(half cut processing)

Using a DISCO-made half-cutting microtome, the cutting with the insert is performed deeper than the final thickness of the wafer. Pre-processing is performed in such a manner that the groove is exposed during back grinding and the wafer can be unilateralized.

(Adhesion of adhesive tape for semiconductor wafer processing)

The bonding of the adhesive tape for semiconductor wafer processing produced by the company is performed by an automatic laminating machine (DR-3000III manufactured by Nitto Seiki Co., Ltd.) after half cut (DC) and after stealth cutting (DC) to 8 inches. After (inch), the wafer is bonded and cut.

(Back grinding process and in-device transfer test)

In the device after the semiconductor wafer was ground, the Fully Automatic Grinder DGP8760+ wafer mounter DFM2700 manufactured by DISCO Co., Ltd. was used for back grinding, and it was confirmed whether or not adsorption error occurred and whether it could be automatically transferred to the placement machine.

(i) Evaluation based on pre-cut (DC) after-cut offset confirmation

After the back grinding process was performed by a grinder, the slits between the wafers unilateralized into wafers were measured by a laser microscope manufactured by KEYENCE, and comparative evaluation of the amount of slit shift was performed.

The evaluation was carried out based on the following criteria.

Evaluation basis

◎: The slit width ratio in the X and Y directions is 1.5 or less, and the offset between the end portions of the adjacent wafers is 5 μm or less, and the wafer is rotated by 5° or less.

○: The slit width ratio of X and Y is 2.0 or less.

△: Adjacent wafers are in contact with each other in either the X or Y direction

×: Adjacent wafers are in contact with each other in the X and Y directions.

(ii) Determination of the rate of decrease in adhesion in the presence of oxygen

The viscosity was measured at room temperature (25 ° C) by the "viscosity tester (trade name: TACII, manufactured by Rhesca)" of the stress relieving measuring device.

Each of the examples and the comparative examples prepared in the above-described manner, the adhesive tape for semiconductor wafer processing before the irradiation of radiation was taken, and a test piece having a width of 25 mm and a length of 250 mm was taken, and the test piece was placed in a testing machine to make the indenter The test piece is contacted, and the back side of the substrate of the test piece (on the opposite side to the adhesive application surface) is pressed into the 3 mm at a speed of 30 mm/min. The cylindrical probe was measured for the load (viscosity Tα) when it was pulled at a speed of 600 mm/min after stopping for 1 second at a stop load of 100 g. On the other hand, in each of the above-described examples and comparative examples, an adhesive tape for semiconductor wafer processing which is cured by irradiation with ultraviolet rays at an irradiation dose of 500 mJ/cm ² in the presence of oxygen (that is, in air) is prepared and irradiated with radiation. The adhesive tape Tβ(O ₂ ) was measured in the same manner as the adhesive tape for semiconductor wafer processing. Furthermore, the unit of adhesion is kPa. Using the obtained values of the respective adhesive forces, the rate of decrease in the adhesive force was determined by the following formula (1).

Formula (1) [Tα-Tβ(O ₂ )]÷[Tα]×100

The rate of decrease in the obtained adhesive force was evaluated according to the following criteria.

Evaluation basis

◎: The reduction rate is 70% or more

○: The reduction rate is 60% or more and less than 70%

△: the reduction rate is 50% or more and less than 60%

×: the reduction rate is less than 50%

(dust infiltration)

The semiconductor wafer after the stealth dicing was mounted on the dicing tape after the back surface was polished, and the back surface polishing tape was peeled off, and then the surface on which the tape was peeled off was observed to compare the amount of dust penetration.

Specifically, the evaluation was performed by the following method.

(iii) Evaluation of dust infiltration (seepage)

After forming a groove having a width of 50 μm and a depth of 20 μm on the surface in a grid pattern of 5 mm intervals, a bonding machine (trade name: DR-8500II, manufactured by Nitto Seiki Co., Ltd.) was used for invisible irradiation with laser light. The 8-inch diameter wafer is formed with a grooved surface that fits the adhesive tape for semiconductor wafer processing. The semiconductor wafer to which the adhesive tape was bonded was subjected to back grinding to a thickness of 50 μm by a grinder (trade name: DGP8760, manufactured by DISCO Co., Ltd.), and the adhesive wafer for semiconductor wafer processing after the cutting water was ground was investigated. Infiltration of the trough.

The results were evaluated according to the following criteria.

Evaluation basis

○: The above investigation was repeated 5 times, and no penetration of cutting water was observed for 5 times.

△: The above investigation was repeated 5 times, and at least one infiltration of cutting water was observed.

×: The above investigation was repeated 5 times, and the penetration of cutting water was observed 5 times.

(iv) Evaluation of film grindingability

The back surface of the semiconductor wafer was ground in the same manner as the above-described dust infiltration until the thickness became 50 μm, and evaluated according to the following criteria.

Evaluation basis

◎: The semiconductor wafer after grinding has not broken

○: A crack was confirmed at the edge of the wafer.

△: 2 to 3 cracks were confirmed at the edge of the wafer

×: Cracks of 4 or more were confirmed at the edge of the wafer

The incision offset after pre-DC in each of the examples and the comparative examples, the viscosity reduction rate in the presence of oxygen, dust infiltration, and film grinding property are summarized in Tables 1 to 3 below.

As shown in Tables 1 to 3, in Comparative Examples 1 to 3, since the base film was composed only of a polyolefin resin of ethylene-vinyl acetate copolymer or polyethylene terephthalate, it became a slit after pre-DC. The result of a large shift. Further, the rate of decrease in the adhesive force after irradiation with ultraviolet rays (UV) due to the composition of the radiation-curable adhesive does not exceed 60%. In Comparative Example 4, since the pressure-sensitive adhesive was applied, dust penetration was large.

On the other hand, in Examples 1 to 11, by controlling the amount of the photopolymerization initiator in the adhesive composition, the viscosity reduction rate after the irradiation of the ultraviolet rays was ensured, and the generation of the paste residue was prevented. The design of the material film takes into consideration the suppression of the slit offset and the film grinding property.

Thus, it can be seen that the adhesive tape for semiconductor wafer processing of the present invention can be used for semi-conducting The use of the body wafer to protect the surface of the pattern during back-grinding can be processed from the self-adhesive to the peeling process even if the half-cut or the invisible cutting process is not performed before the back-side grinding, and is suitable for the grinding process.

1‧‧‧Base film

2‧‧‧Adhesive layer

3‧‧‧Semiconductor wafer pattern layer (wiring layer)

4‧‧‧layers of semiconductor wafers

10‧‧‧Adhesive tape for semiconductor processing

Claims (15)

An adhesive tape for processing a semiconductor wafer, comprising a radiation-curable adhesive layer on a substrate film, wherein the adhesive tape for processing a semiconductor wafer is used in a user in the following steps, The blade is subjected to a half cut or a semiconductor wafer formed by modifying a layer by laser to perform a back grinding and singulation; and ultraviolet irradiation with an ultraviolet irradiation amount of 500 mJ/cm ² in the presence of oxygen Thereafter, the viscosity of the adhesive is lowered by 60% or more. The adhesive tape for processing a semiconductor wafer according to claim 1, wherein the substrate film is at least laminated with polyethylene terephthalate, polyethylene, polypropylene, and ethylene-vinyl acetate copolymer. A substrate film of two different materials. The adhesive tape for processing a semiconductor wafer according to claim 1 or 2, wherein the resin constituting at least one of the laminated base film contains a resin of polyethylene terephthalate or polypropylene. The adhesive tape for semiconductor wafer processing according to any one of claims 1 to 3, wherein the adhesive layer side of the laminated base film is polyethylene terephthalate or polyethylene, with a back surface The side is a polypropylene, polyethylene or ethylene-vinyl acetate copolymer. The adhesive tape for semiconductor wafer processing according to any one of claims 1 to 4, wherein the back surface side of the laminated base film is polypropylene. The adhesive tape for semiconductor wafer processing according to any one of claims 1 to 4, wherein the base film is composed of three layers of polyethylene/polyethylene terephthalate/polyethylene. The adhesive tape for semiconductor wafer processing according to any one of claims 1 to 6, wherein the base film is an unstretched film. The adhesive tape for semiconductor wafer processing according to any one of claims 1 to 6, wherein the base film of the base film layer is a substrate film of at least one layer that is biaxially stretched. The adhesive tape for processing a semiconductor wafer according to any one of claims 1 to 8, wherein the substrate film is provided with a substrate film of a film of at least two different materials, wherein at least one of the film layers is used. It is whitened by particle kneading, particle coating, sand blasting, chemical treatment or embossing. The adhesive tape for processing a semiconductor wafer according to any one of claims 1 to 9, wherein the substrate film is a substrate film of a film of at least two different materials, wherein at least one film is formed by polymerization It is composed of ethylene terephthalate or polypropylene, and the film is whitened by particle kneading, particle coating, sand blasting, chemical treatment or embossing. The adhesive tape for processing a semiconductor wafer according to any one of claims 1 to 10, wherein the substrate film is a substrate film having at least two films of different materials, and at least one of the film systems It is made into white by particle mixing. The adhesive tape for semiconductor wafer processing according to any one of claims 1 to 11, which is the user in the following steps, the semiconductor wafer formed by the modified layer by laser The step of performing the back grinding and singulation. A method for producing an adhesive tape for processing a semiconductor wafer, which is a method for producing a semiconductor wafer processing adhesive tape having a radiation curable adhesive layer on a substrate film, wherein the semiconductor wafer processing adhesive tape is used The user is in the following steps, the step of singulating the semiconductor wafer by half-cutting by the blade or by modifying the modified layer by laser, and singulating in the presence of oxygen; After the ultraviolet irradiation of 500 mJ/cm ² of ultraviolet irradiation, the viscosity of the adhesive is reduced by 60% or more; and the substrate film is provided with a substrate film of at least two films of different materials, at least one of which is The film is composed of polyethylene terephthalate or polypropylene, and the film is whitened by particle kneading, particle coating, sand blasting, chemical treatment or embossing. A method for processing a semiconductor wafer, which is a method for processing a semiconductor wafer for use in a semiconductor wafer processing adhesive tape having a radiation curable adhesive layer on a substrate film, characterized in that it is irradiated with ultraviolet rays in the presence of oxygen After the ultraviolet irradiation of 500 mJ/cm ² , the adhesive force reduction rate of the adhesive is 60% or more; and the adhesive tape for semiconductor wafer processing is used in the following steps, and the above steps are performed by the blade. The step of singulating and singulating the semiconductor wafer formed by the modified layer by laser cutting by half-cutting. The method for processing a semiconductor wafer according to claim 14, wherein the semiconductor wafer processing is performed in a step of singulating a semiconductor wafer formed by a laser modified layer by a back surface. An adhesive tape is attached to the patterned surface of the semiconductor wafer having irregularities.