TWI523931B - Adhesive tape for semiconductor processing - Google Patents

Description

Adhesive tape for semiconductor processing

The present invention relates to an adhesive tape for semiconductor processing used for dicing a semiconductor wafer in the step of manufacturing a semiconductor device. More specifically, in the washing step of the surface of the semiconductor element using the chemical, the adhesive tape for semiconductor processing for manufacturing the semiconductor element including the cleaning step is used.

When thinning the back surface of a semiconductor wafer on which a wiring pattern is formed, in order to protect the pattern surface of the semiconductor wafer and to fix the semiconductor wafer itself, a protective sheet is generally attached to the pattern surface, and then the back surface is applied. For sheeting processing such as grinding and grinding. As such a protective sheet, an acrylic adhesive or the like is generally applied to a substrate made of a plastic film. However, in recent years, the thickness of the semiconductor wafer is required to be 50 μm or less in order to reduce the thickness and size of the IC card or the mobile phone. In the step of using the conventional protective tape, the semiconductor wafer cannot be supported by only the protective tape. The warpage of the semiconductor wafer after the grinding or the deflection generated when the wafer is stored in the wafer cassette is difficult to perform the processing of the semiconductor wafer, and it is difficult to automate the operation or transportation.

In this case, a method of bonding a glass substrate, a ceramic substrate, a tantalum wafer substrate, or the like to a semiconductor wafer via a bonding agent and imparting support to the semiconductor wafer is proposed (for example, refer to Patent Document 1). By replacing such a protective sheet with a supporting member such as a glass substrate, a ceramic substrate, or a tantalum wafer substrate, the operability of the semiconductor wafer is greatly improved, and automation of transportation is possible.

In the operation of the semiconductor wafer using the support member, after the back surface of the semiconductor wafer is ground, the step of peeling the support member from the semiconductor wafer is required. The peeling of the support member is generally performed by the following method: (1) dissolving or decomposing the bonding agent between the supporting member and the semiconductor wafer by using a chemical; (2) between the supporting member and the semiconductor wafer. The bonding agent illuminates the laser light for photolysis. However, in the method of (1), it takes a long time to process the chemical in the bonding agent, and in the method of (2), there is a problem that the scanning of the laser requires a long time of processing. Moreover, regardless of the method, there is a problem that a special substrate needs to be prepared as a supporting member.

Therefore, in the case of peeling off the support member, a method of physically and mechanically peeling off the peeled opening is proposed (for example, refer to Patent Documents 2 and 3). This method does not require a long-time treatment required for dissolving or decomposing a bonding agent by a chemical or decomposing by laser scanning, and can be processed in a short time. After the support member is peeled off from the semiconductor wafer, the residue of the bonding agent on the semiconductor wafer generated at the time of peeling of the support member is cleaned by chemicals.

The back side is a ground semiconductor wafer that is then transferred to the cut In the cutting step, the wafers are cut into one wafer. As described above, when the thickness of the semiconductor wafer is 50 μm or less, when the semiconductor wafer is alone, the semiconductor wafer is warped after being ground or stored in the wafer cassette. The deflection of the semiconductor wafer, etc., makes the processing of the semiconductor wafer very difficult. Therefore, it is usually the case that the dicing tape is attached to the grinding surface of the semiconductor wafer immediately after the back surface of the semiconductor wafer is ground. The support is fixed to the ring frame. Therefore, the bonding agent residue on the semiconductor wafer generated by the peeling of the support member by the chemical is performed by adhering the semiconductor wafer to the dicing tape, and therefore the dicing tape is required to have high Solvent resistance.

In the dicing tape having a high solvent resistance, it is proposed to contain an energy ray-curable acrylic resin composition in the adhesive layer, and the gel fraction is 70% or more (for example, refer to Patent Document 4).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-135272

[Patent Document 2] Japanese National Patent Publication No. 2011-510518

[Patent Document 3] US Patent Application Publication No. 2011/0272092

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2009-224621

However, since the adhesive tape for semiconductor processing described in Patent Document 4 is extremely limited in material, it is difficult to exhibit the originally required characteristics of the dicing tape, that is, it is only possible to suppress the adhesion of the wafer from scattering or picking up during dicing ( Easy peelability when pick up).

Therefore, the present invention has an object of providing an adhesive tape for semiconductor processing, which comprises a dicing tape capable of suppressing scattering of a wafer at the time of dicing, or a detachable tape which is easily peelable at the time of pick-up, and is a semiconductor element using a support member. In the manufacturing step, even if the adhesive is contaminated with a cleaning liquid (which is used to clean the bonding agent residue that bonds the supporting member to the semiconductor wafer), the adhesive does not dissolve and contaminates the semiconductor element.

In order to achieve the above object, the inventors of the present invention conducted intensive studies and found that an adhesive tape for semiconductor processing having a binder layer on a base resin film, and contact with methyl isobutyl ketone for the adhesive layer When the angle is set to a specific value, even if the cleaning agent is contaminated with the adhesive, the adhesive does not dissolve and contaminates the semiconductor element. The present invention has been completed based on such findings.

In other words, the adhesive tape for semiconductor processing according to the present invention is an adhesive tape for semiconductor processing in which a radiation curable adhesive layer is formed on at least one surface of a base resin film, and the adhesive layer is irradiated with ultraviolet rays. Previously, the contact angle for methyl isobutyl ketone was 25.1 to 60.

Preferably, the binder layer contains a ruthenium acrylate or a fluorine-containing oligomer, and the content of the ruthenium acrylate or fluorine-containing oligomer is more than 0% by mass and less than the total solid content of the binder layer. At 5 mass%.

In the adhesive tape for semiconductor processing, it is preferable that the gel fraction of the methyl isobutyl ketone before the irradiation of the adhesive layer is 65% or more and 100% or less.

In the above-mentioned adhesive tape for semiconductor processing, it is preferable that the peak of the probe adhesion test before the ultraviolet irradiation is 200 to 600 kPa before the radiation curable adhesive layer.

Moreover, the adhesive tape for semiconductor processing according to the present invention is an adhesive tape for semiconductor processing in which a radiation curable adhesive layer is formed on at least one surface of a base resin film, and the adhesive layer is irradiated with ultraviolet rays. The contact angle of the "chemical" is preferably 25° or more and less than 180°, and the chemical is a supporting member for bonding the semiconductor wafer to the semiconductor wafer for bonding to the semiconductor wafer in order to support the semiconductor wafer. a residue cleaner of the above-described binder generated on the semiconductor wafer at the time of peeling.

According to the present invention, it is possible to provide an adhesive force capable of suppressing scattering of the wafer during dicing or an easy peeling property at the time of pick-up, and in the manufacturing step of the semiconductor element using the support member, even if the adhesive is contaminated with a cleaning liquid (its Used to wash the adhesive residue that bonds the support member to the semiconductor wafer In the case of slag, the binder does not dissolve and contaminates the semiconductor component.

[Best Mode for Carrying Out the Invention]

Hereinafter, embodiments of the present invention will be described in detail.

In the adhesive tape for semiconductor processing according to the embodiment of the present invention, at least one adhesive layer is formed on one side of the base resin film.

In the adhesive tape for semiconductor processing according to the embodiment of the present invention, the contact angle of the adhesive layer to methyl isobutyl ketone is 25 or more, preferably 28 or more, and more preferably 30 or more. More preferably, the contact angle of the adhesive layer to methyl isobutyl ketone is 25.1 to 60, and preferably 25.1 to 54. Usually, the binder residue on the semiconductor wafer generated by the peeling of the support member by the chemical is rotated by the semiconductor wafer which is adhered to the ring frame through the dicing tape, and the semiconductor wafer is rotated. The chemical is sprayed on the upper side of the wafer, and the chemical droplets are radially discharged from the central portion of the rotating semiconductor wafer by centrifugal force. In this case, as long as the contact angle of the adhesive layer to methyl isobutyl ketone is 25° or more, and the wettability of the methyl isobutyl ketone of the adhesive layer is low, the adhesive layer and the methyl isobutyl group are present. The contact area of the ketone becomes small, and since the discharge of the chemical droplets can be efficiently performed, the dissolution of the adhesive layer from the methyl isobutyl ketone becomes small, and the adhesive tape for semiconductor processing has In the manufacturing steps of semiconductor elements exposed to the possibility of drugs such as methyl isobutyl ketone and its derivatives, the above drugs are not The product melts the binder and contaminates the semiconductor wafer. On the other hand, if the contact angle is less than 25°, the wettability of the methyl isobutyl ketone in the adhesive layer is high, and the contact area between the adhesive layer and the methyl isobutyl ketone becomes large, and the adhesive layer is subjected to the contact. The dissolution action from methyl isobutyl ketone is increased, and in the manufacturing step of the semiconductor element for the semiconductor processing adhesive tape which is exposed to a drug such as methyl isobutyl ketone or a derivative thereof, the above-mentioned drug is used. The binder is melted to contaminate the semiconductor wafer.

Further, in the present invention, the contact angle with respect to methyl isobutyl ketone on the surface of the adhesive layer means the contact angle immediately after the contact of the surface of the adhesive layer with methyl isobutyl ketone. The contact angle is a value measured at a temperature of 23 ° C and a humidity of 50%. The measurement can be carried out using a commercially available contact angle measuring device. Further, the contact angle of the surface of the adhesive layer of the present invention with respect to methyl isobutyl ketone refers to the measurement of the adhesive layer before radiation irradiation.

Further, the gel fraction of the methyl isobutyl ketone before the irradiation of the adhesive layer is preferably 65% or more and 100% or less. The contact angle of the adhesive layer to methyl isobutyl ketone is 25° or more, and the gel fraction is 65% or more and 100% or less, and is washed by a chemical to be peeled off from the support member. In the case of a cement residue on a semiconductor wafer, in the event of a malfunction such as a device failure, even if the adhesive for cutting the tape is exposed to chemicals for a long time, there is no melt of the adhesive due to the above-mentioned drug. The case of contaminating semiconductor wafers.

The gel fraction in the present invention means the ratio of the binder component crosslinked by the crosslinked component in the binder layer. The calculation of the gel fraction is used in the method described below. Still, in the present invention, coagulation The gel fraction is a state in which the surface of the adhesive layer is protected by using a separator or the like immediately after the formation of the adhesive layer, and the adhesive layer before the energy ray irradiation is measured.

(calculation of gel fraction)

The separator was removed from the adhesive tape for semiconductor processing cut into a size of 50 mm × 50 mm and the mass A was weighed. Next, the sample of the weighted semiconductor processing adhesive tape is immersed in, for example, 100 g of methyl isobutyl ketone (MIBK), and left for 48 hours, and then dried with a constant temperature layer of 50 ° C and weighed the mass B. . After removing the adhesive layer of the sample by using 100 g of ethyl acetate, the mass C of the sample was weighed and the gel fraction was calculated by the following formula (1).

Gel fraction (%) = (B-C) / (A-C) (1)

Further, the peak of the probe adhesion test before the irradiation of the adhesive layer was 200 to 600 kPa. If the peak value of the probe adhesion test is too small, the adhesion of the adhesive layer to the object is insufficient, and the support member (which is bonded to the semiconductor wafer through the bonding agent in order to impart support for the semiconductor wafer) is peeled off. At this time, the semiconductor wafer and the adhesive tape are peeled off, making it difficult to peel off the support member from the semiconductor wafer. If the peak value of the probe adhesion test is too large, after the semiconductor wafer is divided, the residue of the adhesive layer may be adhered to the picked wafer, and the wafer may be in contact with the wafer when the wafer is picked up, and the chip may be cracked. ). The measurement of the viscosity of the probe was carried out using the method described below.

(Measurement of probe viscosity)

The measurement of the viscosity of the probe was carried out using, for example, a Rhesca (tacking tester) TAC-II. In the measurement mode, the probe is pushed to the set pressure value until the set time is over, and ConstantLoad is used to keep the pressure value continuous control. After peeling off the separator, the adhesive layer of the adhesive tape was faced upward, and the probe of SUS304 having a diameter of 3.0 mm was contacted from the upper side. The speed at which the probe was brought into contact with the measurement sample was 30 mm/min, the contact load was 100 gf, and the contact time was 1 second. Thereafter, the probe was peeled off at a peeling speed of 600 mm/min, and the force required for peeling was measured. The probe temperature was 23 ° C and the plate temperature was 23 ° C.

Hereinafter, each component of the adhesive tape for semiconductor processing according to the present embodiment will be described in detail.

(substrate resin film)

When the UV is used as the radiation for curing the adhesive layer, the base resin film needs to be light-transmitting, and when the electron beam is used as the radiation, the base resin film does not require light transmittance. As a material constituting the base resin film, preferred are polyethylene, polypropylene, ethylene-propylene copolymer, and polyolefin of polybutene, such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer. And an ethylene copolymer of an ethylene-(meth)acrylate copolymer, an engineering plastic such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polymethyl methacrylate, or the like, Polymers such as soft polyvinyl chloride, semi-rigid polyvinyl chloride, polyester, polyurethane, polyamide, polyamide, and synthetic rubber material. Further, it may be a mixture of two or more selected from the group, or may be stratified, and may be arbitrarily selected depending on the bondability with the adhesive layer. As the base resin film, a polyionic polymer using an ethylene-acrylic copolymer is more preferable.

The thickness of the base resin film is not particularly limited, but is preferably 10 to 500 μm, more preferably 40 to 400 μm, and particularly preferably 70 to 250 μm.

In order to improve the adhesion, the surface of the base resin film may be subjected to corona discharge treatment or application of a primer or the like to the surface of the adhesive layer.

(adhesive layer)

The adhesive constituting the adhesive layer is an ultraviolet curable adhesive, and the surface of the adhesive layer is not particularly limited as long as it has a contact angle with respect to methyl isobutyl ketone of 25° or more and less than 180° before being irradiated with ultraviolet rays. It is appropriately selected from among the conventional binders. For example, a rubber-based adhesive such as natural rubber or synthetic rubber, an acrylic adhesive such as a polyalkyl (meth) acrylate or a copolymer of an alkyl (meth) acrylate and another monomer, or the like can be used. A general adhesive such as a polyurethane adhesive, a polyester adhesive, or a polycarbonate adhesive, in which a monomer component or a low ultraviolet curable monomer component is blended. In addition to the ultraviolet curable adhesive of the ultraviolet curable resin such as a polymer component, as the matrix polymer, carbon-carbon double having a carbon-carbon double bond in the polymer branch or main chain or at the end of the main chain can be exemplified. A UV-curable adhesive of a key-introducing acrylic polymer. As a matrix polymer, used in polymer branches In the case of a carbon-carbon double bond-introducing acrylic polymer having a carbon-carbon double bond in the chain or the main chain or at the end of the main chain, it is not necessary to prepare ultraviolet rays such as a monomer component or an oligomer component which are ultraviolet curable. Hardened resin.

As the binder constituting the binder layer, acrylic acid using a poly(meth) acrylate or a copolymer of (meth) acrylate and another monomer (hereinafter, collectively referred to as an acrylic polymer) is preferably used. Adhesive.

Examples of the constituent component of the acrylic polymer include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and (meth)acrylic acid. Propyl ester, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, amyl (meth)acrylate, (A) Ethyl acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate , isodecyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, ( Tridecyl methyl methacrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, (meth) acrylate (alkyl)alkyl (meth)acrylate such as alkyl ester or octadecyl (meth)acrylate; cycloalkyl (meth)acrylate such as cyclohexyl (meth)acrylate; (meth)acrylic acid Phenyl ester ) Aryl acrylates and the like. The (meth) acrylate may be used alone or in combination of two or more.

The method for producing the acrylic polymer is not particularly limited, and the weight average molecular weight can be increased by a crosslinking agent, or by The ultraviolet curable carbon-carbon double bond is introduced by a condensation reaction or an addition reaction, and a functional group having a hydroxyl group, a carboxyl group, or a glycidyl group is preferable.

The introduction of an ultraviolet curable carbon-carbon double bond to an acrylic polymer is carried out by copolymerizing a constituent component of an acrylic polymer with a monomer having a functional group to prepare an acrylic polymer having a functional group, and then having a functional group (which a compound which can react with a functional group in a functional group-containing acrylic polymer and a carbon-carbon double bond to maintain the ultraviolet curability (ultraviolet polymerization property) of a carbon-carbon double bond by condensation The reaction or addition reaction becomes an acrylic polymer having a functional group, and can be prepared.

The acrylic polymer having a functional group is a copolymerizable monomer (co) which is copolymerizable with a (meth) acrylate of a constituent component, and which can copolymerize a hydroxyl group, a carboxyl group, a glycidyl group, etc. (copolymerizable monomer) And get it. Examples of the monomer copolymerizable to the (meth) acrylate and having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and (meth)acrylic acid 4. - hydroxybutyl ester, 6-hydroxyhexyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, glyceryl mono (meth) acrylate, and the like. Examples of the monomer which is copolymerizable with the (meth) acrylate and has a carboxyl group include (meth)acrylic acid (acrylic acid, methacrylic acid), itaconic acid, maleic acid, fumaric acid, crotonic acid, and the like. Crotonic acid, etc. Examples of the monomer which is copolymerizable with the (meth) acrylate and has a glycidyl group include glycidyl (meth)acrylate and the like.

As a compound having a functional group reactive with a functional group and a carbon-carbon double bond, a functional group which is a target of a condensation reaction or an addition reaction Examples of the hydroxyl group include 2-isocyanatoethyl (meth)acrylate and 1,1-(bisacrylomethoxymethylmethyl)ethyl isocyanate. When the functional group to be subjected to the condensation reaction or the addition reaction is a carboxyl group, examples thereof include glycidyl methacrylate and allyl glycidyl ether. When the functional group to be subjected to the condensation reaction or the addition reaction is a glycidyl group, an unsaturated carboxylic acid such as (meth)acrylic acid or the like can be mentioned.

The acrylic polymer preferably has a small content of a low molecular weight material from the viewpoint of preventing contamination of a workpiece such as a semiconductor device. From this point of view, the weight average molecular weight of the acrylic polymer is preferably 100,000 or more, and more preferably 200,000 to 2,000,000. When the weight average molecular weight of the acrylic polymer is too small, the contamination prevention property of the workpiece such as a semiconductor device is lowered, and when it is too large, the viscosity of the adhesive composition for forming the adhesive layer 5 becomes extremely high. It is difficult to manufacture the adhesive tape 1.

Further, from the viewpoint of exhibiting adhesion, the glass transition point of the acrylic polymer is preferably -70 ° C to 0 ° C, more preferably -65 ° C to -20 ° C. When the glass transition point is too low, the viscosity of the polymer becomes low, and it is difficult to form a stable coating film; if the glass transition point is too high, the binder becomes hard and the wettability to the object is deteriorated.

The acrylic polymer may be used singly or in combination of two or more kinds of acrylic polymers as long as compatibility is acceptable.

The ultraviolet curable resin to be used in the adhesive layer after being blended in a general adhesive is not particularly limited, and examples thereof include urethane (meth) acrylate, epoxy (meth) acrylate, and poly Ester (A An acrylate, a polyether (meth) acrylate, an oligomer having a functional group such as a hydroxyl group or a carboxyl group, such as a (meth)acrylic oligomer and an itaconic acid oligomer.

Further, among the binders used in the present invention, a photopolymerization initiator can be formulated. Examples of the photopolymerization initiator include isopropyl benzoin ether, isobutyl benzoin ether, diphenyl ketone, misch ketone, chlorothioxanthone, and dodecyl thioxanthone. , dimethyl thioxanthone, diethyl thioxanthone, benzoin dimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethyl phenylpropane, and the like. By adding at least one of these to the binder, the curing reaction of the binder layer 5 can be efficiently performed, whereby the fixing adhesive force of the semiconductor device can be appropriately lowered.

The amount of the photopolymerization initiator to be added is preferably 0.5 to 10 parts by mass based on 100 parts by mass of the ultraviolet curable resin. As a matrix polymer, when a carbon-carbon double bond-introducing acrylic polymer having a carbon-carbon double bond in a polymer branch or a main chain or a main chain terminal is used, it is introduced with respect to a carbon-carbon double bond. It is preferable that 100 parts by mass of the acrylic polymer is 0.5 to 10 parts by mass.

Further, in the adhesive used in the present invention, a tackifier, a binder adjuster, a surfactant, or the like, or another modifier may be added as needed. Further, an inorganic compound filler may be appropriately added.

The adhesiveness of the adhesive layer 5 can be appropriately controlled by controlling the crosslinking density of the adhesive material. The control of the crosslinking density of the adhesive material can be, for example, a polyfunctional isocyanate compound or an epoxy compound, a melamine compound or a metal salt compound, a metal chelate compound or A method of performing a crosslinking treatment using an appropriate crosslinking agent such as an amino resin-based compound or a peroxide, mixing a compound having two or more carbon-carbon double bonds, and performing crosslinking treatment by irradiation with an energy ray or the like The method is carried out in an appropriate manner.

Before the ultraviolet irradiation of the adhesive layer 5, the contact angle of the surface of the adhesive layer 5 with respect to methyl isobutyl ketone can be adjusted by adjusting the comonomer ratio of the acrylic polymer, and by adjusting the polyoxyxene resin and the fluororesin. It is adjusted as an additive. Further, for these, it is also possible to combine the adjustment of the number average molecular weight of the ultraviolet curable resin. By adjusting the comonomer ratio of the acrylic polymer, the alkyl (meth)acrylate having an alkyl chain carbon number of 4 or more, more preferably the (meth)acrylic acid having an alkyl chain carbon number of 8 or more The alkyl ester is effective, and the alkyl (meth)acrylate having an alkyl chain carbon number of 4 or more, more preferably an alkyl chain carbon number of 8 or more, is preferably 50% by mass or more. . As the polyoxymethylene resin used as an additive, a hydrazine-modified acrylate can be used; in the case of a fluororesin, a fluorine-containing oligomer can be used, and a hydrazine-modified acrylate can be suitably used. Among them, it is preferable to contain a hydrazine acrylate or a fluorine-containing oligomer, and the content is preferably more than 0% by mass and less than 5% by mass based on the total solid content of the binder layer.

The thickness of the adhesive layer is preferably 5 μm or more and 70 μm or less, more preferably 8 μm or more and 50 μm or less, and still more preferably 10 μm or more and 30 μm or less. When the adhesive layer is too thin, not only the unevenness of the electrode cannot be followed, but also the problem of intrusion of cutting water or cutting chips during cutting processing; conversely, when it is too thick, chipping during the cutting process becomes large. The quality of the semiconductor component is lowered.

In the present invention, the energy beam for curing the adhesive layer is preferably radiation, and examples of the radiation include light such as ultraviolet rays (UV), electron beams, and the like.

The method of forming the adhesive layer on the base resin film is not particularly limited. For example, the acrylic resin composition is applied onto a base resin film by a coating method which is usually used, and dried. The adhesive layer applied to the separator can be bonded to the base resin film to be transferred onto the base resin film.

Further, a protective resin film which is usually used as a separator may be adhered to the side of the adhesive layer to protect the adhesive layer as needed until it is actually used. The constituent material of the synthetic resin film may, for example, be a synthetic resin film such as polyethylene, polypropylene or polyethylene terephthalate or paper. In order to improve the peeling property from the adhesive layer 3, the surface of the synthetic resin film may be subjected to a release treatment such as polyfluorination treatment, long-chain alkyl treatment, or fluorine treatment. The thickness of the synthetic resin film is usually from 10 to 100 μm, preferably from about 25 to 50 μm.

Next, the relevant support member will be described.

(support member)

The support member is selected from the group consisting of enamel, sapphire, crystal, metal (for example, aluminum, copper, steel), various glass and ceramics. The surface of the support member to which the bonding agent is attached may also contain other materials deposited. For example, tantalum nitride can also be deposited on a germanium wafer, whereby the bonding characteristics can be changed.

(attachment of support members)

When the support member is attached, the bonding agent of the bonding agent described later is applied to the circuit formation surface of the semiconductor wafer, and then the applied bonding agent is dried by an oven or a hot plate. Further, in order to obtain the thickness required for the bonding agent (bonding agent layer), the application and preliminary drying of the bonding solution may be repeated a plurality of times.

Further, when a bonding agent liquid of a bonding agent is applied to a circuit formation surface of a semiconductor wafer, before the application of the bonding agent liquid of the bonding agent, as disclosed in Japanese Laid-Open Patent Publication No. 2009-528688, The plasma polymer separation layer is deposited on the circuit surface of the wafer, and when the support member is peeled off, it is possible to peel off between the circuit formation surface of the semiconductor wafer and the plasma polymer separation layer.

Further, when the bonding agent liquid is applied by the spin coater on the circuit forming surface of the semiconductor wafer, a higher curling portion may be formed in the peripheral portion. In this case, it is preferred to remove the bead portion by a solvent before preparing to dry the binder liquid.

(bonding agent)

As the bonding agent, a commercially available one in the present invention can be used. For example, WaferBONDTM material sold by Brewer Science (University of Missouri at Rolla) (WaferBONDTM HT 10.10 for the Slide Bonding Process; WaferBONDTM CR200 for the Chemical Bonding Process), Or ELASTOSIL LR 3070 of Berghausen material manufactured by WACKER.

Further, it is preferably a resin or a polymer which exhibits a high bonding force for a semiconductor material, glass or metal, and particularly preferably, for example, a (a) high solid content and a reactive epoxy and acrylic UV curing resin, (b) a thermosetting resin of the same family as a two-component epoxy or tantalum cement, (c) on a polyamide, a polyimine, a polybenzazole, a polyether oxime or a polyurethane to melt A polymer or a copolymer of a thermoplastic acrylic resin, a styrene resin, a vinyl halide (non-fluorine-based) resin or a vinyl ester is applied in a state or a solution coating film, and dried by baking after coating. A layer in which the support member and the semiconductor wafer are dense is further provided, and, for example, a bond of a (butyl) cyclic olefin, a polyolefin rubber (for example, polyisobutylene) or a (pentane) hydrocarbon as a base is provided.

As the bonding agent, since water is used during polishing, a polymer compound which is not water-soluble is preferable, and a softening point is preferably high. Examples of such a polymer compound include a novolak resin, an epoxy resin, a guanamine resin, an anthraquinone resin, an acrylic resin, a urethane resin, polystyrene, polyvinyl ether, polyvinyl acetate, and the like. The modified or the mixture is dissolved in a solvent. Among them, the acrylic resin material is preferred because it has heat resistance of 200 ° C or higher and generates less gas and is less likely to cause cracks. In addition, the novolac resin has no residue, and is inferior to the acrylic resin material in terms of heat resistance, gas generation amount, and crack generation. However, the softening point is high, and the peeling after bonding is preferable because the solvent is easily peeled off. In addition to this, in order to prevent cracks at the time of film formation, a plasticizer may be mixed.

Further, as the solvent, those which can dissolve the resin and uniformly form a film on the wafer are preferable, and examples thereof include ketones (for example, acetone, methyl ethyl ketone, cyclohexane, methyl isobutyl ketone). , methyl isoamyl ketone, 2-heptanone, etc.), polyols or derivatives thereof (for example, ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, Diethylene glycol monoacetate or such monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether, etc.), cyclic ethers (for example, dioxane) , esters (for example, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxy propionate, etc.) or Aromatic hydrocarbons (for example, benzene, toluene, xylene, etc.). Among these, the above ketones or derivatives thereof are particularly preferred.

These may be used singly or in combination of two or more. Further, in order to increase the uniformity of the film thickness, an active agent may be added to these.

(washing agent residue)

After the bonding agent and the supporting member are peeled off from the semiconductor wafer, as a cleaning liquid for removing the residue of the bonding agent remaining on the semiconductor wafer 1, a monohydric alcohol may be used in addition to the organic solvent used in the bonding agent described above. (eg, methanol, ethanol, propanol, isopropanol, butanol, etc.), lactones (eg, γ-butyrolactone, etc.), indoleamines (eg, γ-butyrolactam, etc.), ethers Classes (for example, diethyl ether or anisole, etc.), aldehydes (for example, dimethylformaldehyde, dimethylacetaldehyde, etc.). Among these, a ketone or a derivative thereof as described above is particularly preferred.

These may be used singly or in combination of two or more. Further, in order to efficiently wash the binder residue, an active agent may be added thereto.

[Examples]

Next, the present invention will be described in more detail based on the examples. The invention is illustrated by the following examples, but the invention is not limited to the examples.

(Example 1)

Methyl acrylate, 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate were copolymerized in a ratio of 5:14:1 in ethyl acetate by a usual method to obtain a solution containing an acrylic polymer. Next, in the solution containing the acrylic polymer, 50 parts by mass of the ultraviolet curable oligomer obtained by reacting pentaerythritol triacrylate and diisocyanate as an ultraviolet curable compound, and the photopolymerization start 2.5 parts by mass of IRGACURE 651 (trade name, manufactured by BASF Corporation) and 1.0 part by mass of trimethylolpropane-modified toluene diisocyanate as a polyisocyanate compound, and further added 0.15 parts by mass of hydrazine-modified acrylate. Thereafter, a resin composition which is a radiation curable adhesive is prepared. The resin composition was applied to the release-treated surface of the polyethylene terephthalate separator having been subjected to the release treatment in advance so that the thickness of the adhesive layer after drying was 10 μm, and the composition was applied at 80 ° C. After drying for 10 minutes, the corona discharge treatment of the low density polyethylene which was previously subjected to the halo discharge treatment on the surface was performed.

After the surface is bonded, an adhesive tape for semiconductor processing is produced by transferring the adhesive to the base resin film.

(Example 2)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 1 except that 0.77 parts by mass of yttrium-modified acrylate was blended.

(Example 3)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 1 except that 8.08 parts by mass of yttrium-modified acrylate was blended.

(Example 4)

NCO group of 2-methylpropenyloxyethyl isocyanate which is a compound having a photopolymerizable carbon-carbon double bond and a functional group, 2-ethylhexyl acrylate (70 mol%), methacrylic acid (1 mol) %)), a branched terminal OH group of 3-hydroxypropyl acrylate of a copolymer of 2-hydroxypropyl acrylate (29 mol%) is subjected to an addition reaction to obtain an acrylic compound having a photopolymerizable carbon-carbon double bond (A1: molecular weight 700,000). 1 part by mass of trimethylolpropane-modified hexamethylene diisocyanate as a polyisocyanate, and IRGACURE 184 (trade name, manufactured by BASF Corporation) as a photopolymerization initiator was added to 100 parts by mass of the compound (A1). After 5.0 parts by mass, a resin composition which is a radiation curable adhesive is prepared. The resin group was coated on the release-treated surface of the polyethylene terephthalate separator having been subjected to the release treatment in advance so that the thickness of the adhesive layer after drying became 10 μm. The resultant was dried at 80 ° C for 10 minutes, and then bonded to a corona discharge treated surface of a low-density polyethylene which was subjected to a halo discharge treatment on the surface, and then transferred to a base resin film by a binder. And the production of adhesive tape for semiconductor processing.

(Example 5)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 4 except that 0.11 part by mass of yttrium-modified acrylate was blended.

(Example 6)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 4 except that 0.53 parts by mass of yttrium-modified acrylate was blended.

(Example 7)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 4 except that 5.58 parts by mass of yttrium-modified acrylate was blended.

(Example 8)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 1 except that 0.15 parts by mass of a fluorine-containing oligomer was blended.

(Example 9)

Ethyl acrylate, butyl acrylate and 2-hydroxyethyl acrylate were copolymerized by a usual method in a ratio of 10:9:1 in ethyl acetate. A solution containing an acrylic polymer was obtained. Next, in the solution containing the acrylic polymer, 50 parts by mass of the ultraviolet curable oligomer obtained by reacting pentaerythritol triacrylate and diisocyanate as an ultraviolet curable compound, and the photopolymerization start 2.5 parts by mass of IRGACURE 651 (trade name, manufactured by BASF Corporation) and 1.0 part by mass of trimethylolpropane-modified toluene diisocyanate as a polyisocyanate compound, and further added 0.31 parts by mass of ruthenium-modified acrylate. Thereafter, a resin composition which is a radiation curable adhesive is prepared. The resin composition was applied to the release-treated surface of the polyethylene terephthalate separator having been subjected to the release treatment in advance so that the thickness of the adhesive layer after drying was 10 μm, and the composition was applied at 80 ° C. After drying for 10 minutes, the corona discharge treatment surface of the low-density polyethylene which has been subjected to the corona discharge treatment on the surface is bonded, and then the adhesive is transferred to the base resin film to prepare an adhesive tape for semiconductor processing. .

(Embodiment 10)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 9 except that 0.77 parts by mass of yttrium-modified acrylate was blended.

(Example 11)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 4 except that 0.1 parts by mass of trimethylolpropane-modified hexamethylene diisocyanate as a polyisocyanate was blended.

(Comparative Example 1)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 1 except that the yttrium-modified acrylate was not prepared.

(Comparative Example 2)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 9 except that 0.15 parts by mass of yttrium-modified acrylate was blended.

For each of the samples of Examples 1 to 11 and Comparative Examples 1 and 2, an evaluation test for contact angle, probe viscosity, gel fraction, solvent resistance, and peelability of the support member was carried out as follows. The results obtained are shown in Tables 1 and 2 below.

<Contact angle of the surface of the adhesive layer>

Since the measurement must be performed on a flat surface, the surface of the base film on which the adhesive layer is not provided is fixed to a flat glass plate using a double-sided tape. After peeling off the separator, methyl ethyl ketone was dropped and the contact angle θ was measured using a FACE contact angle meter CA-S150 manufactured by Kyowa Chemical Co., Ltd. The measurement temperature was 23 ° C and the measured humidity was 50%. The contact angle of the surface of the adhesive layer was measured in a state before the adhesive tape was irradiated with ultraviolet rays.

<Probe Viscosity>

It was carried out using a Rhesca (strand) viscous tester TAC-II. In the measurement mode, the probe is pushed to the set pressure value until the set time is over, and ConstantLoad is used to keep the pressure value continuous control. After peeling off the separator, the adhesive layer of the adhesive tape for semiconductor processing was faced upward, and the probe of SUS304 having a diameter of 3.0 mm was contacted from the upper side. The speed at which the probe was brought into contact with the measurement sample was 30 mm/min, the contact load was 100 gf, and the contact time was 1 second. Thereafter, the probe was peeled off at a peeling speed of 600 mm/min, and the force required for peeling was measured and the peak was read. The probe temperature was 23 ° C and the plate temperature was 23 ° C.

<gel fraction>

The separator was removed from the adhesive tape for semiconductor processing cut into a size of 50 mm × 50 mm and the mass A was weighed. Next, the sample of the divided semiconductor tape for processing the semiconductor was placed in a state of being immersed in 100 g of methyl isobutyl ketone (MIBK) for 48 hours, and then dried with a constant temperature layer of 50 ° C and weighed the mass B. . After removing the adhesive layer of the sample by using 100 g of ethyl acetate, the mass C of the sample was weighed and the gel fraction was calculated by the following formula (1).

Gel fraction (%) = (B-C) / (A-C) (1)

<Solvent resistance 1>

On the semiconductor wafer of 8 turns, the adhesive tape for semiconductor processing obtained in the examples and the comparative examples was bonded and fixed to the ring frame, and methyl isobutyl ketone (MIBK) as an organic solvent was sprayed from the side of the semiconductor wafer. ), while being rotated at 20 rpm, it was swirled and washed. After the cleaning and drying, the adhesive layer in the region where the semiconductor wafer for dicing tape for semiconductor processing was not adhered was observed, and the dissolution or expansion of the adhesive was not observed as ○, although It can be found that some of the adhesive is swelled, but there is no practical problem and the degree is slightly marked as △ and judged as qualified; the dissolver of the adhesive can be found, and the expander who can be found to have a serious problem in practical use can be found. It is recorded as × and is judged as unqualified.

<Solvent resistance 2>

On the semiconductor wafer of 8 turns, the adhesive tape for semiconductor processing obtained in the examples and the comparative examples was bonded and fixed to a ring frame, and then immersed in methyl isobutyl ketone (MIBK) for 1 hour. Thereafter, after being swirled and dried at 20 rpm, the adhesive layer in the region where the semiconductor wafer of the dicing tape for semiconductor processing was not adhered was observed. The dissolution or expansion of the adhesive is not found as ○, although the expansion of a part of the adhesive can be found, but there is no practical problem and the degree is slightly △ and judged to be qualified; the adhesive can be found In the case of a dissolver, an expander who is found to have a serious problem in practical use is marked as × and judged to be unqualified.

<Support member peelability>

By using the method disclosed in the specification of the US Patent Application Publication No. 2011/0272092, a plasma polymer separation layer and a polyoxymethylene rubber bonding layer are obtained on a 6-inch tantalum wafer having a thickness of about 700 μm. "Structural body 1" of a glass plate having a thickness of 2.5 mm as a support member. In the back surface of the wafer (the surface on which the plasma polymer separation layer or the like is not laminated) of the structure 1 obtained by the above method, the adhesive tape for semiconductor processing obtained in the examples and the comparative examples is bonded and fixed on the ring frame. Supply to The De-Bonder DB12T manufactured by Suss Corporation was used to evaluate the peelability of the support member. A peeling occurs between the plasma polymer separation layer of the support member and the surface of the wafer, and the support member is removed from the surface of the wafer as ○, and a portion is between the back surface of the wafer and the adhesive tape for semiconductor processing. Peeling occurs, but the support member can be removed from the surface of the wafer and can be allowed to be recorded as △ in the actual user and judged to be acceptable; it will not be peeled off between the plasma polymer separation layer of the support member and the wafer surface, but in the crystal When the round back surface and the adhesive tape for semiconductor processing were peeled off, and the support member could not be removed from the surface of the wafer, it was judged as X and was judged to be unacceptable.

As shown in Tables 1 and 2, the adhesive layer was subjected to ultraviolet rays before the contact angle of methyl isobutyl ketone was 25.1° or more and less than 180° (60° or less). In the solvent evaluation project, it is judged to be qualified, and the chemical element is used to clean the semiconductor component table. In the manufacture of the semiconductor element of the surface step, it can be practically used without any problem. In the comparison between Example 1 and Example 8, and Comparative Example 1, the solvent resistance of the adhesive layer can be improved by containing a hydrazine acrylate or a fluorine-containing oligomer. In particular, in the embodiment 1, the embodiment 2, the embodiment 4, the embodiment 5, the embodiment 6, the embodiment 8, the embodiment 9, the embodiment 10, and the embodiment 11 in which the adhesion is 200 to 600 kPa, the support member is More excellent results were obtained in the peel test. Further, in Examples 4 to 7 and Example 11 in which the gel fraction was 65% or more, the solvent resistance to immersion in methyl isobutyl ketone (MIBK) for 1 hour was also excellent. .

On the other hand, in the comparative examples 1 and 2 in which the contact angle of the methyl isobutyl ketone was less than 25° before the ultraviolet irradiation, the adhesion was found in any solvent resistance test. The dissolution or severe swelling of the agent and the production of a semiconductor element which is not suitable for the step of cleaning the surface of the semiconductor element using a chemical.

Claims (3)

An adhesive tape for semiconductor processing, which is an adhesive tape for semiconductor processing in which a radiation curable adhesive layer is formed on at least one surface of a base resin film, and is characterized in that the adhesive layer is different from methyl groups before radiation irradiation. The contact angle of the butyl ketone is 25.1 ° to 60 °, and the adhesive layer contains ruthenium acrylate or fluorine-containing oligomer, and the ruthenium acrylate or fluorine-containing oligomer is relative to the total solid content of the adhesive layer. The content is more than 0% by mass and less than 5% by mass. The adhesive tape for semiconductor processing according to claim 1, wherein the gel fraction of the methyl isobutyl ketone before the radiation irradiation is 65% or more and 100% or less. The adhesive tape for semiconductor processing according to claim 1 or claim 2, wherein a peak of the probe adhesion test is 200 to 600 kPa before the radiation is applied to the adhesive layer.