TWI721120B - Adhesive tape for semiconductor processing and manufacturing method of semiconductor device - Google Patents

Abstract

The adhesive tape for semiconductor processing of the present invention is used in the step of forming grooves on the surface of the semiconductor wafer or forming the back surface of the semiconductor wafer in the modified field, and singulating the semiconductor wafer into semiconductor wafers by the grinding , Adhesive tape for semiconductor processing used to attach to the surface of a semiconductor wafer, which includes a substrate, a buffer layer provided on one side of the substrate, and an adhesive layer provided on the other side of the substrate, semiconductor processing The total thickness of the adhesive tape is 160μm or less, and the ratio of the thickness (D2) of the aforementioned buffer layer to the thickness (D1) of the substrate (D2/D1) is 0.7 or less, and the peeling force relative to the semiconductor wafer is Below 1000mN/50mm.

Description

Adhesive tape for semiconductor processing and manufacturing method of semiconductor device

The present invention relates to an adhesive tape for semiconductor processing used by attaching to a semiconductor wafer when a semiconductor device is manufactured by a dicing before grinding method (Dicing Before Grinding), and a method for manufacturing a semiconductor device using the adhesive tape.

In the development of miniaturization and multi-functionalization of various electronic devices, the semiconductor chips mounted on them are also required to be miniaturized and thinner. Generally speaking, in order to reduce the thickness of the wafer, the back surface of the semiconductor wafer is polished to adjust the thickness. In addition, there is also a method called a post-dicing polishing method in which a groove of a certain depth is formed from the surface side of the wafer, and then polished from the back side of the wafer, and the wafer is singulated by the polishing. In the post-dicing polishing method, since the backside polishing of the wafer can be performed simultaneously with the singulation of the wafer, thin wafers can be efficiently manufactured. In addition, in the post-dicing polishing method, in addition to the above-mentioned method, after a groove of a certain depth is formed from the surface side of the wafer, and then polishing is performed from the back side of the wafer, there is also a method of using a laser to install a modified inside the wafer Layer, the method of singulating the wafer by using the pressure during the back grinding of the wafer.

In the past, in order to protect the circuit on the surface of the semiconductor wafer, the semiconductor wafer and the singulated semiconductor wafer were fixed, and a so-called back grinding sheet was attached to the surface of the wafer in order to protect the circuit on the back surface of the semiconductor wafer. Adhesive tape. As the back polishing sheet used in the post-cut polishing method, there is known an adhesive sheet provided with a substrate and an adhesive layer provided on one side of the substrate, and a buffer layer is further provided on the other side of the substrate.

The back polishing sheet is provided with a buffer layer to alleviate the vibration generated during the back polishing of the wafer. In addition, when the semiconductor wafer is back polished, the surface side of the wafer provided with the back polished sheet is adsorbed to the suction cup, thereby being fixed to the disk, but the buffer layer can also absorb foreign matter existing on the disk Etc. caused by unevenness. The back-grinding sheet uses the above buffer layer to prevent cracking of semiconductor wafers or chip defects during back-grinding.

In addition, Patent Document 1 discloses an adhesive sheet, which is based on the above-mentioned adhesive sheet having a substrate, an adhesive layer, and a buffer layer. The thickness of the substrate is set to 10 to 150 μm, and the thickness of the substrate is 10 to 150 μm. The Young's modulus is set to 1000 to 30000 MPa, the thickness of the buffer layer is set to 5 to 80 μm, and the maximum value of tan δ of the dynamic viscoelasticity is set to 0.5 or more. Patent Document 1 discloses that by using this adhesive sheet as a back grinding sheet, it is possible to prevent chip defects and discoloration when a semiconductor wafer is manufactured by a post-cut grinding method.

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2005-343997

However, in recent years, the requirements for thinning and miniaturization of semiconductor wafers have gradually increased. For example, it is also required to manufacture semiconductor wafers with a thickness of less than 50 μm, or about 0.5 mm square. In this way, when manufacturing miniaturized and thinned semiconductor wafers, as described in Patent Document 1, only the Young’s modulus of the substrate and the maximum tan δ of the buffer layer are adjusted while the substrate and the buffer layer are adjusted. The thickness of each is set in a certain range, and it is difficult to suppress damages (chip cracks) such as chipping or cracking of the semiconductor wafer. In particular, it is known that when the surface protection tape is peeled off from the surface of the polished wafer, a large load is applied to the semiconductor wafer that has been miniaturized and thinned as described above, which causes chip damage.

The present invention was completed in view of the above problems. It is to provide an adhesive tape for semiconductor processing as its subject. The adhesive tape for semiconductor processing is used in the post-dicing polishing method, even in the case of thinning and miniaturization. In the case of a semiconductor wafer, it can also prevent the semiconductor wafer from being chipped or damaged.

As a result of investigating the mechanism by which semiconductor wafers are chipped or damaged, the inventors found out that the method of polishing after dicing In the manufacture of thinner and miniaturized semiconductor wafers, when the backside of the semiconductor wafer is polished, and when the adhesive tape is peeled from the semiconductor wafer, the semiconductor wafer may be chipped or broken. In addition, it has been found that in the post-dicing polishing method, in order to prevent chipping or breakage of the semiconductor wafer when the semiconductor wafer is polished to be singulated into wafers, and when the adhesive tape is peeled from the semiconductor wafer, an adhesive tape is applied on one side The total thickness of the tape and the thickness ratio of the substrate to the buffer layer are set in a certain range, and the focus is on making the peeling force of the adhesive tape for the semiconductor wafer below a specific value, and thus the following invention is completed.

The present invention provides the following (1) to (13).

(1) An adhesive tape for semiconductor processing, which is used to form grooves on the surface of a semiconductor wafer or to polish the back surface of a semiconductor wafer in the field of semiconductor wafer formation and modification, and to separate the semiconductor wafer by the polishing. In the step of slicing into a semiconductor wafer, the adhesive tape for semiconductor processing used to attach to the surface of the semiconductor wafer is characterized by: It is provided with a substrate, a buffer layer provided on one side of the substrate, and an adhesive layer provided on the other side of the substrate, wherein: The total thickness of the adhesive tape for semiconductor processing is 160μm or less, and the ratio of the thickness (D2) of the aforementioned buffer layer to the thickness (D1) of the substrate (D2/D1) is 0.7 or less, and is relative to the peeling of the semiconductor wafer The force is 1000mN/50mm or less.

(2) The adhesive tape for semiconductor processing as described in (1) above, wherein the Young's modulus of the substrate is 1000 MPa or more.

(3) Adhesive tape for semiconductor processing as described in (1) or (2) above, where the former The thickness (D1) of the substrate is 110 μm or less.

(4) The adhesive tape for semiconductor processing according to any one of (1) to (3) above, wherein the substrate has at least a polyethylene terephthalate film.

(5) The adhesive tape for semiconductor processing according to any one of (1) to (4) above, wherein the adhesive layer is formed of an energy ray curable adhesive.

(6) The adhesive tape for semiconductor processing according to any one of (1) to (5) above, wherein the elastic modulus of the adhesive layer at 23° C. is 0.10 to 0.50 MPa.

(7) The adhesive tape for semiconductor processing according to any one of (1) to (6) above, wherein the thickness (D3) of the adhesive layer is 70 μm or less.

(8) The adhesive tape for semiconductor processing according to any one of (1) to (7) above, wherein the adhesive layer is formed of an adhesive composition containing an acrylic resin, and the acrylic resin has an alkyl group derived from it. The structural unit of alkyl (meth)acrylate with 4 or more carbon atoms, the structural unit of alkyl (meth)acrylate with carbon number of 1~3 from the alkyl group, and the monomer from functional group The structural unit.

(9) The adhesive tape for semiconductor processing according to any one of (1) to (8) above, wherein the storage modulus of the buffer layer at 23° C. is 100 to 1500 MPa.

(10) The adhesive tape for semiconductor processing according to any one of (1) to (9) above, wherein the stress relaxation rate of the buffer layer is 70-100%.

(11) The adhesive tape for semiconductor processing according to any one of (1) to (10) above, wherein the buffer layer is formed of a composition for forming a buffer layer, and the composition for forming a buffer layer contains urethane Ester (meth)acrylate (a1), a polymerizable compound (a2) having an alicyclic or heterocyclic group with 6 to 20 ring atoms, and a polymerizable compound (a3) having a functional group.

(12) The adhesive tape for semiconductor processing as described in (11) above, wherein the component (a2) is an alicyclic group-containing (meth)acrylate, and the component (a3) is a hydroxyl group-containing (meth)acrylate.

(13) A method of manufacturing a semiconductor device, comprising the steps of: attaching the adhesive tape for semiconductor processing as described in any one of (1) to (12) above to the surface of a semiconductor wafer; A step of forming a groove on the surface side of the wafer, or forming a modified area from the surface or back of the semiconductor wafer inside the semiconductor wafer; attaching the aforementioned adhesive tape for semiconductor processing to the surface, and forming the aforementioned groove or modified area The semiconductor wafer is polished from the back side, and the aforementioned groove or modified area is used as a starting point to separate the semiconductor wafer into a plurality of wafers; the step of peeling the adhesive tape for semiconductor processing from the aforementioned plurality of wafers.

In the present invention, in the post-dicing polishing method, it is possible to prevent chipping or breakage of the semiconductor wafer that is generated when the semiconductor wafer is polished to be singulated into wafers and when the adhesive tape is peeled from the semiconductor wafer.

Next, the present invention will be described in further detail.

In addition, in this specification, "weight average molecular weight (Mw)" is a value measured by gel permeation chromatography (GPC) in terms of polystyrene, specifically, a value measured according to the method described in the examples. .

In addition, for example, "(meth)acrylate" is used as a term indicating both "acrylate" and "methacrylate", and the same applies to other similar terms.

The adhesive tape for semiconductor processing of the present invention (hereinafter, also simply referred to as "adhesive tape") is provided with a substrate, a buffer layer provided on one side of the substrate, and a buffer layer provided on the other side of the substrate (that is, with The surface of the buffer layer on the opposite side) of the adhesive layer.

The adhesive tape is attached to the surface of the semiconductor wafer through an adhesive layer in the post-dicing polishing method. That is, as described later, the adhesive tape is polished on the back surface of the semiconductor wafer in the area where grooves are formed on the surface of the semiconductor wafer or the semiconductor wafer is formed and modified, and the semiconductor wafer is singulated by the polishing. In the semiconductor wafer step, the user is attached to the surface of the semiconductor wafer.

In the adhesive tape of the present invention, the total thickness of the adhesive tape is 160 μm or less, and the ratio (D2/D1) of the thickness (D2) of the buffer layer to the thickness (D1) of the substrate is 0.7 or less, and is relative to the adhesive tape The peeling force of the semiconductor wafer is less than 1000mN/50mm. In the present invention, in this way, by setting any of the total thickness of the tape, the thickness ratio (D2/D1), and the peeling force to a specific value, it can prevent the semiconductor wafer from being polished to a single piece. When the wafer is formed, and when the adhesive tape is removed from the semiconductor crystal Defects or breakages of semiconductor wafers generated when the wafer is peeled off

On the other hand, if the total thickness of the adhesive tape is greater than 160 μm, it is difficult to properly maintain the adhesive performance of the adhesive layer and the impact absorption performance of the buffer layer while reducing the peeling force. Therefore, when the adhesive tape is peeled from the semiconductor wafer, a load is applied to the semiconductor wafer, and chip defects are likely to occur.

In addition, the total thickness of the tape is preferably 155 μm or less, and more preferably 145 μm or less from the viewpoint of lowering the peeling force. In addition, in order to set the adhesive layer, the base material, and the cushion layer to an appropriate thickness and to perform their respective functions appropriately, the total thickness of the tape is preferably 40 μm or more, more preferably 55 μm or more.

In addition, in this specification, the total thickness of the tape means the total thickness of the layers contained in the adhesive tape when the semiconductor wafer is attached to and polished. Therefore, when a release sheet to be releasably attached is provided on the adhesive tape, the thickness of the release sheet is not included in the total thickness. Generally, the total thickness of the adhesive tape is the total thickness of the substrate, the adhesive layer, and the buffer layer.

In addition, if the thickness ratio (D2/D1) is greater than 0.7, the ratio of the high rigidity portion in the adhesive tape is reduced. Therefore, the semiconductor wafer or the semiconductor wafer cannot be properly held by the base material, which makes it difficult for the adhesive tape to be properly held during polishing. The vibration is not easy to reduce. Therefore, in the case of singulation into small and thin semiconductor wafers by the dicing and polishing method, even if the material of the buffer layer is appropriately selected, it is difficult to prevent the occurrence of singulation by back grinding. Defects of semiconductor wafers.

In order to reduce chip defects, the buffer layer is set to an appropriate thickness to make the buffering performance of the adhesive tape good. The thickness ratio (D2/D1) is preferably 0.10~0.70, more preferably 0.13~0.66.

Furthermore, if the peeling force of the adhesive tape for the semiconductor wafer is greater than 1000 mN/50 mm, when the adhesive tape is peeled from the semiconductor wafer, the semiconductor wafer is likely to be chipped.

Here, in order to more appropriately prevent chip defects when the adhesive tape is peeled off, the peeling force of the adhesive tape is preferably 970 mN/50 mm or less, and more preferably 850 mN/50 mm or less. In addition, although the peeling force of the adhesive tape is not particularly limited, in order to improve the adhesive force of the adhesive tape to the semiconductor wafer or semiconductor wafer, it is preferably 300 mN/50 mm or more, and more preferably 450 mN/50 mm or more.

In addition, the peeling force of the adhesive tape is the force required to peel the adhesive tape from the semiconductor wafer after attaching the surface of the adhesive layer of the adhesive tape to the semiconductor wafer as shown in the embodiments described later. However, as described later, when the adhesive layer is formed of an energy-ray curable adhesive, the adhesive tape attached to the semiconductor wafer is irradiated with energy rays and the adhesive layer is cured. Peel force. On the other hand, when the adhesive layer is formed of a non-energy-ray-curable adhesive, the peeling force of the adhesive tape before the energy-beam irradiation is measured in the same way.

Next, the structure of each member of the adhesive tape of the present invention will be described in more detail.

[Substrate]

As the base material of the adhesive tape, various resin films can be cited. Specifically, polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE) can be cited. , Polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymer, norbornene resin and other polyolefins; ethylene-vinyl acetate copolymer, ethylene-(methyl) Vinyl copolymers such as acrylic copolymers and ethylene-(meth)acrylate copolymers; polyvinyl chlorides such as polyvinyl chloride and vinyl chloride copolymers; polyethylene terephthalate and polyethylene naphthalate Polyester, polybutylene terephthalate, wholly aromatic polyester, etc.; polyurethane, polyimide, polyamide, polycarbonate, fluororesin, polyacetal, denatured poly A resin film composed of one or more selected from among phenyl ether, polyphenylene sulfide, polysulfide, polyether ketone, acrylic polymer, etc. In addition, such cross-linked films and denatured films such as ionic polymer films can also be used. The substrate may be a single-layer film of a resin film composed of one or two or more resins selected from these resins, or a laminated film formed by laminating two or more of these resin films .

In addition, the substrate is preferably a rigid substrate with a Young's modulus of 1000 MPa or more, more preferably 1800 to 30000 MPa, and still more preferably 2500 to 6000 MPa.

In this way, if a rigid substrate with a high Young’s modulus is used as the substrate, even if the total thickness of the tape is reduced as described above, the retention performance of the semiconductor wafer or semiconductor wafer due to the adhesive tape will be improved. By suppressing vibration during back grinding, it is easy to prevent chipping or breakage of the semiconductor wafer. In addition, when the Young’s modulus is in the above range, the adhesive tape can be reduced The stress during peeling from the semiconductor wafer makes it easy to prevent chip chipping or breakage that occurs during tape peeling. Furthermore, the workability when attaching the adhesive tape to the semiconductor wafer can also be good.

Here, as a rigid substrate with a Young's modulus of 1000 MPa or more, it may be appropriately selected from the above-mentioned resin films, but examples thereof include polyethylene terephthalate, polyethylene naphthalate, Polybutylene terephthalate, fully aromatic polyester and other polyesters, polyimide, polyamide, polycarbonate, polyacetal, modified polyphenylene ether, polyphenylene sulfide, polysulfide, poly Films of ether ketone, biaxially stretched polypropylene, etc.

Among these resin films, it is preferable to include one or more films selected from polyester film, polyamide film, polyimide film, and biaxially stretched polypropylene film, and more preferably include polyester film, It is still more preferable to include a polyethylene terephthalate film.

The thickness (D1) of the substrate is preferably 110 μm or less, more preferably 15 to 110 μm, and still more preferably 20 to 105 μm. By setting the thickness of the substrate to 110μm or less, it is easy to adjust the total thickness of the adhesive tape, the thickness ratio (D2/D1), and the peeling force of the adhesive tape to the above-mentioned specific values. In addition, by setting it to 15 μm or more, the base material can easily function as a support for the adhesive tape.

In addition, the base material may contain plasticizers, lubricants, infrared absorbers, ultraviolet absorbers, fillers, colorants, antistatic agents, antioxidants, and catalysts within a range that does not impair the effects of the present invention. Wait. In addition, the substrate may be transparent or opaque, and may be colored or vapor-deposited as desired.

In addition, in order to improve adhesion to at least one of the buffer layer and the adhesive layer on the surface of at least one of the substrates, an adhesion treatment such as corona treatment may be performed. In addition, the base material may be one having the above-mentioned resin film and an easy-adhesive layer coated on at least one of the surfaces of the resin film.

The easy-adhesive layer forming composition for forming the easy-adhesive layer is not particularly limited, but examples include polyester resins, polyurethane resins, polyester urethane resins, and acrylic resins. Compositions such as resins. The composition for forming an easy-adhesive layer may contain a crosslinking agent, a photopolymerization initiator, an antioxidant, a softener (plasticizer), a filler, a rust inhibitor, a pigment, a dye, etc. as needed.

The thickness of the easily bonding layer is preferably 0.01 to 10 μm, more preferably 0.03 to 5 μm. In addition, the thickness of the easy-adhesive layer is relatively small compared to the thickness of the substrate, and the material is also softer. Therefore, it has little influence on the Young's modulus. Even if the Young's modulus of the substrate is The situation is also substantially the same as the Young's modulus of the resin film.

[buffer layer]

The buffer layer relaxes the vibration caused by the polishing of the semiconductor wafer, and prevents cracks and defects in the semiconductor wafer. In addition, although the semiconductor wafer to which the adhesive tape is attached is placed on the vacuum pan during back grinding, the adhesive tape is easily and appropriately held on the vacuum pan by providing a buffer layer.

The storage modulus of the buffer layer of the present invention at 23° C. is preferably 100 to 1500 MPa, more preferably 200 to 1200 MPa. In addition, the stress relaxation rate of the buffer layer is preferably 70-100%, more preferably 78-98%.

By making the buffer layer have the storage modulus and stress relaxation rate within the above range, the buffer layer absorbs the unevenness of the fine foreign matter between the semiconductor wafer attached to the adhesive tape and the suction cup or the back grinding The effect of vibration or impact of abrasive grains is improved. Therefore, as described above, even when the thickness ratio (D2/D1) is 0.7 or less and the thickness of the buffer layer is thin, it is easy to prevent wafer chipping during back grinding.

The maximum value of dynamic viscoelasticity tan δ of the buffer layer at -5~120℃ (hereinafter also referred to as " the maximum value of tan δ ") is preferably 0.7 or more, more preferably 0.8 or more, and even better It is 1.0 or more. In addition, the upper limit of the maximum value of tan δ is not particularly limited, but is usually 2.0 or less.

If the maximum value of tanδ of the buffer layer is 0.7 or more, the effect of the buffer layer in absorbing the vibration or impact of abrasive grains generated during back grinding will be improved. Therefore, in the post-dicing polishing method, even if the semiconductor wafer or the singulated semiconductor wafer is polished until it becomes extremely thin, it is easy to prevent defects such as the corners of the wafer.

In addition, tan δ is called the loss tangent, which is defined as "loss modulus/storage modulus", which means that the dynamic viscoelasticity measuring device depends on the response to the stress such as tensile stress or torsional stress applied to the object The measured value is specifically the value measured by the method described in the Example.

The thickness (D2) of the buffer layer is preferably 8 to 40 μm, more preferably 10 to 35 μm. By setting the thickness of the buffer layer to be 8 μm or more, the buffer layer can appropriately buffer the vibration during back grinding. In addition, by setting it to 40 μm or less, the total thickness of the tape and the thickness ratio (D2/D1) are adjusted to the above-mentioned specific values.

The buffer layer is preferably a layer formed of a composition for forming a buffer layer containing an energy ray polymerizable compound. The buffer layer contains an energy-ray polymerizable compound and can be cured by energy-ray irradiation. In addition, "energy rays" refer to ultraviolet rays, electron beams, etc., and it is preferable to use ultraviolet rays.

In addition, the composition for forming a buffer layer is more specifically polymerizable containing a urethane (meth)acrylate (a1) and an alicyclic or heterocyclic group having 6 to 20 ring atoms Compound (a2). By containing these two components, the composition for forming a buffer layer makes it easy to set the elastic modulus of the buffer layer, the stress relaxation rate of the buffer layer, and the maximum value of tan δ within the above-mentioned ranges. Moreover, from these viewpoints, the composition for forming a buffer layer more preferably contains a polymerizable compound (a3) having a functional group in addition to the above-mentioned (a1) and (a2) components.

In addition, the composition for forming a buffer layer, in addition to the above-mentioned (a1) and (a2) or (a1) to (a3) components, preferably contains a photopolymerization initiator, and can also be used without impairing the effects of the present invention. Within the scope, it contains other additives or resin components.

Hereinafter, each component contained in the composition for forming a buffer layer will be described in detail.

(Urethane (meth)acrylate (a1))

The urethane (meth)acrylate (a1) is a compound having at least a (meth)acrylic group and a urethane bond, and has the property of being polymerized and cured by energy ray irradiation. Urethane (meth)acrylate (a1) is a polymer such as an oligomer.

The mass average molecular weight (Mw) of the component (a1) is preferably 1,000 to 100,000, more preferably 2,000 to 60,000, and still more preferably 3,000 to 20,000. In addition, the number of (meth)acrylic groups in the component (a1) (hereinafter also referred to as "the number of functional groups") may be monofunctional, bifunctional, or trifunctional or more, but is preferably monofunctional or 2 Functional.

The component (a1) is, for example, a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound and a polyvalent isocyanate compound, and a (meth)acrylate having a hydroxyl group. In addition, component (a1) can also be used individually or in combination of 2 or more types.

The polyol compound used as the raw material of the component (a1) is not particularly limited as long as it has two or more hydroxyl groups. Examples of specific polyol compound systems include alkylene glycol, polyether polyol, polyester polyol, polycarbonate polyol, and the like. Among these, polyester polyols are preferred.

In addition, the polyol compound may be any one of a bifunctional diol, a trifunctional triol, or a polyol having a tetrafunctional or higher function, but is preferably a bifunctional diol, more preferably a polyester diol .

Examples of polyvalent isocyanate compounds include aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; isophorone diisocyanate, norcampan Alkyl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, ω,ω'-diisocyanate dimethylcyclohexane, etc. Isocyanates; 4,4'-diphenylmethane diisocyanate, phenylmethylene diisocyanate, xylene diisocyanate Aromatic diisocyanates such as esters, toluidine diisocyanate, tetramethylene xylene diisocyanate, naphthalene-1,5-diisocyanate, etc.

Among these, isophorone diisocyanate, hexamethylene diisocyanate, and xylene diisocyanate are preferred.

The terminal isocyanate urethane prepolymer obtained by reacting the above-mentioned polyol compound with a polyvalent isocyanate compound can be reacted with a (meth)acrylate having a hydroxyl group to obtain a urethane (methyl) ) Acrylate (a1). The (meth)acrylate system having a hydroxyl group is not particularly limited as long as it is a compound having a hydroxyl group and a (meth)acryloyl group in at least one molecule.

Specific examples of (meth)acrylates having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (methyl) ) Acrylate, 4-hydroxycyclohexyl (meth)acrylate, 5-hydroxycyclooctyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, pentaerythritol three ( Hydroxyalkyl (meth)acrylates such as meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate; N-methylol(meth)acrylic acid Hydroxyl-containing (meth)acrylamide such as amines; vinyl alcohol, vinylphenol, diglycidyl ester of bisphenol A, reactants obtained by reacting with (meth)acrylic acid, etc.

Among these, hydroxyalkyl (meth)acrylate is preferred, and 2-hydroxyethyl (meth)acrylate is more preferred.

As the conditions for reacting the terminal isocyanate urethane prepolymer and the (meth)acrylate having a hydroxyl group, it is preferable to respond to It is necessary to carry out the reaction conditions for 1 to 4 hours at 60~100°C in the presence of the added solvent and catalyst.

The content of the component (a1) in the composition for forming a buffer layer is preferably 10 to 70% by mass, and more preferably 20 to 60% by mass relative to the total amount (100% by mass) of the composition for forming a buffer layer. It is more preferably 25 to 55% by mass, and still more preferably 30 to 50% by mass.

(Polymerizable compound (a2) having an alicyclic group or heterocyclic group with 6-20 ring atoms)

The component (a2) is a polymerizable compound having an alicyclic group or a heterocyclic group with 6 to 20 ring atoms, and preferably a compound having at least one (meth)acryloyl group. By using this component (a2), the film-forming properties of the resulting composition for forming a buffer layer can be improved.

The number of ring-forming atoms of the alicyclic group or heterocyclic group of component (a2) is preferably 6-20, more preferably 6-18, still more preferably 6-16, and still more preferably 7-12 . Examples of the atom system forming the ring structure of the heterocyclic group include carbon atoms, nitrogen atoms, oxygen atoms, and sulfur atoms.

In addition, the number of ring-forming atoms means the number of self-atomic atoms of the ring in a compound in which the atoms are bonded to form a ring, in the atoms that do not constitute the ring (for example, hydrogen atoms bonded to the atoms that constitute the ring), or When the ring is substituted by a substituent, the atom system included in the substituent is not included in the number of ring atoms.

Examples of specific component (a2) systems include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentyl (Meth) acrylate (Dicyclopentanyl Methacrylate), dicyclopentenyloxy (meth)acrylate, cyclohexyl (meth)acrylate, adamantane (meth)acrylate, etc. (Base) acrylate; tetrahydrofurfuryl (meth)acrylate, morpholine (meth)acrylate, etc., heterocyclic group-containing (meth)acrylate, etc.

In addition, the component (a2) may be used alone or in combination of two or more kinds.

Among these, alicyclic group-containing (meth)acrylate is preferred, and isobornyl (meth)acrylate is more preferred.

The content of the component (a2) in the composition for forming a buffer layer is preferably 10 to 70% by mass, more preferably 20 to 60% by mass relative to the total amount (100% by mass) of the composition for forming a buffer layer, It is more preferably 25 to 55% by mass, and still more preferably 30 to 50% by mass.

(Polymerizable compound with functional group (a3))

The component (a3) is a polymerizable compound containing functional groups such as a hydroxyl group, an epoxy group, an amide group, and an amine group, and more preferably a compound having at least one (meth)acryloyl group.

The component (a3) has good compatibility with the component (a1), and it is easy to adjust the viscosity of the composition for forming a buffer layer to an appropriate range. Furthermore, it is easy to set the value of the elastic modulus or tan δ of the buffer layer formed of the composition within the above-mentioned range, and even if the buffer layer is formed thinner, the buffer performance becomes good.

Examples of component (a3) include: hydroxyl-containing (meth)acrylates, epoxy-containing compounds, amide-containing compounds, and amine-containing compounds. (Meth)acrylate and the like.

Examples of hydroxyl-containing (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate , 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenylhydroxypropyl (meth)acrylate, etc.

Examples of the epoxy group-containing compound system include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, allylglycidyl ether, etc. Among these, Preferred are epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate and methglycidyl (meth)acrylate.

Examples of the amide group-containing compound system include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, and N-hydroxyl Methyl (meth)acrylamide, N-methylolpropane (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth) Acrylic amide and so on.

Examples of (meth)acrylates containing amino groups include (meth)acrylates containing primary amino groups, (meth)acrylates containing secondary amino groups, and (meth)acrylates containing tertiary amino groups. ) Acrylic etc.

Among these, hydroxyl-containing (meth)acrylates are preferred, and hydroxyl-containing (meth)acrylates having aromatic rings such as phenylhydroxypropyl (meth)acrylate are more preferred.

In addition, component (a3) can also be used individually or in combination of 2 or more types.

The content of component (a3) in the composition for forming a buffer layer is In order to easily set the elastic modulus and stress relaxation rate of the buffer layer to the above-mentioned ranges and improve the film-forming properties of the composition for the buffer layer, it is preferably relative to the total amount (100% by mass) of the composition for forming the buffer layer 5-40% by mass, more preferably 7-35% by mass, still more preferably 10-30% by mass, and still more preferably 13-25% by mass.

In addition, the content ratio of the component (a2) to the component (a3) in the composition for forming a buffer layer [(a2)/(a3)] is preferably 0.5 to 3.0, more preferably 1.0 to 3.0, and still more preferably 1.3~3.0, and more preferably 1.5~2.8.

(Polymerizable compounds other than ingredients (a1) to (a3))

The composition for forming a buffer layer may contain other polymerizable compounds other than the above-mentioned components (a1) to (a3) within a range that does not impair the effects of the present invention.

Examples of other polymerizable compound systems include alkyl (meth)acrylates having an alkyl group with 1 to 20 carbon atoms; styrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, and N-ethylene Vinyl compounds such as methylmethamide, N-vinylpyrrolidone, and N-vinylcaprolactam. In addition, these other polymerizable compounds may be used alone or in combination of two or more kinds.

The content of other polymerizable compounds in the composition for forming a buffer layer is preferably 0-20 mass%, more preferably 0-10 mass%, still more preferably 0-5 mass%, and still more preferably 0~ 2% by mass.

(Photopolymerization initiator)

In the buffer layer forming composition, when the buffer layer is formed, use From the viewpoint of shortening the polymerization time by light irradiation and reducing the amount of light irradiation, it is preferable to further contain a photopolymerization initiator.

Examples of the photopolymerization initiator system include: benzoin compounds, acetophenone compounds, phosphine oxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and further, photosensitization of amines or quinones. To be more specific, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl Base ether, benzoin isopropyl ether, benzyl phenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, 8-chloroanthraquinone (chloroanthraquinone), Bis(2,4,6-trimethylbenzyl)phenylphosphine oxide and the like.

These photopolymerization initiators can be used alone or in combination of two or more kinds.

The content of the photopolymerization initiator in the composition for forming a buffer layer is preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass relative to 100 parts by mass of the total amount of the energy ray polymerizable compound, and still more Preferably, it is 0.3 to 5 parts by mass.

(Other additives)

The composition for forming a buffer layer may contain other additives within a range that does not impair the effects of the present invention. Examples of other additive systems include antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, pigments, dyes, and the like. In the case of blending these additives, the content of each additive in the composition for forming a buffer layer is relative to the energy The total amount of the linear polymerizable compound is 100 parts by mass, preferably 0.01-6 parts by mass, more preferably 0.1-3 parts by mass.

(Resin component)

The composition for forming a buffer layer may contain a resin component in the range which does not impair the effect of this invention. Examples of resin component systems include polyene-thiol-based resins, polyolefin-based resins such as polybutene, polybutadiene, and polymethylpentene, and thermoplastic resins such as styrene-based copolymers.

The content of these resin components in the composition for forming a buffer layer is preferably 0-20 mass%, more preferably 0-10 mass%, still more preferably 0-5 mass%, and still more preferably 0~ 2% by mass.

[Adhesive layer]

The adhesive layer preferably has a modulus of elasticity at 23° C. of 0.10 to 0.50 MPa. Circuits etc. are formed on the surface of the semiconductor wafer and usually have unevenness. The adhesive tape makes the elastic modulus within the above range, and when it is attached to the surface of the wafer with unevenness, the unevenness of the wafer surface can be fully contacted with the adhesive layer, and the adhesive layer can be adhered. Play appropriately. Therefore, the adhesive tape can be reliably fixed to the semiconductor wafer, and the surface of the wafer can be properly protected during back grinding. From these viewpoints, the elastic modulus of the adhesive layer is more preferably 0.12 to 0.35 MPa. In addition, the elastic modulus of the adhesive layer, when the adhesive layer is formed of an energy ray curable adhesive, means the elasticity before curing by energy ray irradiation. The modulus is the value of the storage modulus measured by the measuring method of the examples described later.

The thickness (D3) of the adhesive layer is preferably 70 μm or less, more preferably less than 40 μm, still more preferably 35 μm or less, particularly preferably 30 μm or less. In addition, the thickness (D3) is preferably 5 μm or more, more preferably 10 μm or more. If the adhesive layer is thinned in this way, it is easy to make the total thickness of the tape 160 μm or less as described above. In addition, in the adhesive tape, since the proportion of the portion with low rigidity can be reduced, it is easy to further prevent the defect of the semiconductor chip generated during back grinding.

The adhesive layer is formed of, for example, an acrylic adhesive, a urethane adhesive, a rubber adhesive, a silicone adhesive, etc., but it is preferably an acrylic adhesive.

In addition, the adhesive layer is preferably formed of an energy ray-curable adhesive. The adhesive layer is formed by an energy-ray curable adhesive, and the elastic modulus at 23°C can be set to the above range before curing by energy-ray irradiation, and the peeling force can be easily adjusted after curing Set to 1000mN/50mm or less.

As an energy ray curable adhesive, for example, energy ray that includes non-energy ray curable adhesive resin (also called "adhesive resin I") and energy ray curable compounds other than adhesive resin can be used. Curable adhesive composition (hereinafter also referred to as "X-type adhesive composition"). In addition, as an energy-ray-curable adhesive, an energy-ray-curable adhesive resin with unsaturated groups introduced into the side chain of the non-energy-ray-curable adhesive resin (hereinafter, also referred to as "adhesive Adhesive composition (hereinafter, also referred to as "Y-type adhesive composition") that does not contain energy ray curable compounds other than adhesive resin as the main component.

Furthermore, as the energy-ray curable adhesive, in addition to the combined type of X-type and Y-type, that is, energy-ray-curable adhesive resin II, those containing energy-ray-curable compounds other than adhesive resins can also be used. Energy-ray curable adhesive composition (hereinafter, also referred to as "XY-type adhesive composition").

Among these, it is preferable to use an XY-type adhesive composition. By using the XY type, it has sufficient adhesive properties before curing. On the other hand, after curing, the peeling force for the semiconductor wafer can be sufficiently reduced.

However, as an adhesive, it can also be formed of a non-energy-ray-curable adhesive composition that does not harden even if it is irradiated with energy rays. The non-energy-ray-curable adhesive composition contains at least the non-energy-ray-curable adhesive resin I, on the other hand, does not contain the above-mentioned energy-ray-curable adhesive resin II and energy-ray-curable compound.

In addition, in the following description, "adhesive resin" is used as a term meaning one or both of the above-mentioned adhesive resin I and adhesive resin II. Examples of specific adhesive resins include acrylic resins, urethane resins, rubber resins, silicone resins, and the like, but acrylic resins are preferred.

Hereinafter, the acrylic adhesive using acrylic resin as the adhesive resin will be described in more detail.

Acrylic polymer is used in acrylic resin (b). The acrylic polymer (b) is obtained by polymerizing a monomer containing at least an alkyl (meth)acrylate, and contains a structural unit derived from the alkyl (meth)acrylate. Examples of the (meth)acrylic acid alkyl ester system include those having an alkyl group of 1 to 20 carbon atoms, and the alkyl system may be linear or branched. Specific examples of the alkyl (meth)acrylate include: methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, and (meth)acrylate -Propyl ester, n-butyl methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, Nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, and the like. Alkyl (meth)acrylate can also be used individually or in combination of 2 or more types.

In addition, the acrylic polymer (b) preferably contains a structural unit derived from an alkyl (meth)acrylate alkyl (meth)acrylate having a carbon number of 4 or more from the viewpoint of enhancing the adhesive force of the adhesive layer. The number of carbon atoms in the alkyl (meth)acrylate is preferably 4-12, more preferably 4-6. In addition, the alkyl (meth)acrylate having 4 or more carbon atoms in the alkyl group is preferably an alkyl acrylate.

In the acrylic polymer (b), the alkyl (meth)acrylate having 4 or more carbon atoms in the alkyl group is relative to the total amount of monomers constituting the acrylic polymer (b) (hereinafter, also referred to simply as " The total amount of monomer") is preferably 40 to 98% by mass, more preferably 45 to 95% by mass, and still more preferably 50 to 90% by mass.

Acrylic polymer (b), in addition to the structural unit derived from alkyl (meth)acrylate having 4 or more carbon atoms, is preferably included in order to adjust the elastic modulus or adhesion properties of the adhesive layer Copolymerization of structural units of alkyl (meth)acrylates with carbon numbers of 1 to 3 from the alkyl group Things. In addition, the alkyl (meth)acrylate is preferably alkyl (meth)acrylate with carbon number 1 or 2, more preferably methyl (meth)acrylate, most preferably methyl methacrylate . In the acrylic polymer (b), the alkyl (meth)acrylate having a carbon number of 1 to 3 in the alkyl group is preferably 1 to 30% by mass, more preferably 3 to 26 relative to the total amount of the monomer. % By mass, more preferably 6-22% by mass.

The acrylic polymer (b) preferably has a structural unit derived from a monofunctional monomer in addition to the above-mentioned structural unit derived from the alkyl (meth)acrylate. Examples of the functional group system of the functional group-containing monomer include a hydroxyl group, a carboxyl group, an amino group, and an epoxy group. The functional group-containing single system can react with the crosslinking agent described later to become a crosslinking starting point, or react with an unsaturated group-containing compound to introduce an unsaturated group into the side chain of the acrylic polymer (b).

Examples of the functional group-containing single system include hydroxyl group-containing monomers, carboxyl group-containing monomers, amine group-containing monomers, epoxy group-containing monomers, and the like. These monomers can also be used alone or in combination of two or more kinds. Among these, hydroxyl-containing monomers and carboxyl-containing monomers are preferred, and hydroxyl-containing monomers are more preferred.

Examples of the hydroxyl-containing single system include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy Hydroxyalkyl (meth)acrylates such as butyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.; vinyl alcohol, allyl Unsaturated alcohols such as base alcohols, etc.

Examples of carboxyl-containing single systems include ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; fumaric acid, itaconic acid, and maleic acid. Acid, citraconic acid and other ethylenically unsaturated dicarboxylic acids and their anhydrides, 2-carboxyethyl methacrylate, etc.

The functional monomer is preferably 1 to 35% by mass, more preferably 3 to 32% by mass, and still more preferably 6 to 30% by mass relative to the total amount of monomers constituting the acrylic polymer (b).

In addition, the acrylic polymer (b) may include, in addition to the above, a compound derived from styrene, α-methylstyrene, vinyl toluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide, etc. The structural unit of the above-mentioned acrylic monomer copolymerized monomer.

The acrylic polymer (b) mentioned above can be used as a non-energy-ray curable adhesive resin I (acrylic resin). In addition, examples of energy-ray curable acrylic resins include: reacting the functional group of the acrylic polymer (b) with a compound having a photopolymerizable unsaturated group (also referred to as an unsaturated group-containing compound) By.

The unsaturated group-containing compound is a compound having both a substituent that can be bonded to the functional group of the acrylic polymer (b) and a photopolymerizable unsaturated group. Examples of the photopolymerizable unsaturated group include (meth)acrylic groups, vinyl groups, and allyl groups, but are preferably (meth)acrylic groups.

In addition, examples of the substituent system of the unsaturated group-containing compound that can be bonded to the functional group include an isocyanate group, a glycidyl group, and the like. Therefore, as an unsaturated group-containing compound system, (meth)acryloxyethyl isocyanate, (meth)acryloyl isocyanate, glycidyl (meth)acrylate, etc. are mentioned, for example.

In addition, the unsaturated group-containing compound is preferably an acrylic polymer Part of the functional group of (b) is reacted. Specifically, it is preferable to react 50-98 mol% of the functional group of the acrylic polymer (b) with an unsaturated group-containing compound, more preferably The reaction is performed at 55-93 mole%. In this way, since a part of the functional group does not react with the unsaturated group-containing compound in the energy-beam curable acrylic resin and remains, it is easily cross-linked by the cross-linking agent.

In addition, the weight average molecular weight (Mw) of the acrylic resin is preferably 300,000 to 1.6 million, more preferably 400 to 1.4 million, and still more preferably 500,000 to 1.2 million.

(Energy ray hardening compound)

The energy-ray curable compound contained in the X-type or XY-type adhesive composition is preferably a monomer or oligomer that has an unsaturated group in the molecule and can be polymerized and hardened by energy ray irradiation .

Examples of such energy ray curable compound systems include methylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. Polyvalent (meth)acrylate monomers such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, etc., urethane (meth)acrylate Oligomers such as base) acrylate, polyester (meth)acrylate, polyether (meth)acrylate, epoxy (meth)acrylate, etc.

Among these, a urethane (meth)acrylate oligomer is preferable from the viewpoint that the molecular weight is relatively high and the elastic modulus of the adhesive layer is not easily lowered.

The molecular weight of the energy ray-curable compound (weight average molecular weight in the case of oligomers) is preferably 100~12000, more preferably 200~10000, still more preferably 400~8000, and still more preferably 600~6000 .

The content of the energy ray curable compound in the X-type adhesive composition is preferably 40 to 200 parts by mass, more preferably 50 to 150 parts by mass, and still more preferably 60 to 100 parts by mass of the adhesive resin. 90 parts by mass.

On the other hand, the content of the energy ray curable compound in the XY type adhesive composition is preferably 1-30 parts by mass, more preferably 2-20 parts by mass, and still more with respect to 100 parts by mass of the adhesive resin It is preferably 3 to 15 parts by mass. In the XY type adhesive composition, since the adhesive resin is energy ray curable, even if the content of the energy ray curable compound is small, the peeling force can be sufficiently reduced after the energy ray is irradiated.

(Crosslinking agent)

The adhesive composition preferably further contains a crosslinking agent. The crosslinking agent is one that reacts with a functional group derived from a functional group monomer possessed by the adhesive resin to crosslink the adhesive resins. Examples of crosslinking agents include isocyanate-based crosslinking agents such as phenylmethylene diisocyanate, hexamethylene diisocyanate, and adducts of these; rings of ethylene glycol glycidyl ether, etc. Oxygen-based cross-linking agents; aziridine-based cross-linking agents such as hexa[1-(2-methyl)-aziridinyl] triphosphotriazine; chelate-based cross-linking agents such as aluminum chelate, etc. These crosslinking agents can also be used alone or in combination of two or more kinds.

Among these, the viewpoint of increasing cohesion to enhance cohesion, and content From the viewpoint of availability, etc., an isocyanate-based crosslinking agent is preferred.

From the viewpoint of promoting the crosslinking reaction, the blending amount of the crosslinking agent is preferably 0.01-10 parts by mass, more preferably 0.03-7 parts by mass, and still more preferably 0.05 with respect to 100 parts by mass of the adhesive resin ~4 parts by mass.

(Photopolymerization initiator)

In addition, when the adhesive composition is energy-ray curable, the adhesive composition preferably further contains a photopolymerization initiator. By containing the photopolymerization initiator, the curing reaction of the adhesive composition can be fully advanced even if it is a low-energy energy line such as ultraviolet rays.

Examples of the photopolymerization initiator system include: benzoin compounds, acetophenone compounds, phosphine oxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and further, photosensitization of amines or quinones. To be more specific, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl Base ether, benzoin isopropyl ether, benzyl phenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2 ,4,6-Trimethylbenzyl)phenylphosphine oxide and the like.

These photopolymerization initiators can also be used alone or in combination of two or more kinds.

The blending amount of the photopolymerization initiator is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, and still more preferably 0.05 to 5 parts by mass relative to 100 parts by mass of the adhesive resin.

(Other additives)

The adhesive composition may contain other additives within a range that does not impair the effects of the present invention. Examples of other additive systems include antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, pigments, dyes, and the like. When these additives are blended, the blending amount of the additives is preferably 0.01-6 parts by mass relative to 100 parts by mass of the adhesive resin.

In addition, the adhesive composition may be further diluted with an organic solvent from the viewpoint of improving the coatability to the base material or the release sheet to be in the form of a solution of the adhesive composition.

Examples of the organic solvent system include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propane, isopropanol, and the like.

In addition, these organic solvents can be directly used in the organic solvent used in the synthesis of the adhesive resin, or in order to uniformly coat the solution of the adhesive composition, and add the organic solvent used in the synthesis One or more organic solvents other than organic solvents.

[Peeling sheet]

A release sheet can also be attached to the surface of the adhesive tape. The release sheet is specifically attached to at least one of the surface of the adhesive layer of the adhesive tape and the surface of the cushion layer. The release sheet protects the adhesive layer and the buffer layer by being attached to these surfaces. The release sheet is peelably attached to the adhesive tape, and before the adhesive tape is used (that is, the backside of the wafer is polished) Before), peel off and remove from the adhesive tape.

The peeling sheet is a peeling sheet having at least one surface subjected to a peeling treatment. Specifically, a peeling agent coated on the surface of the base material for a peeling sheet is used.

The base material for the release sheet is preferably a resin film, and examples of the resin system constituting the resin film include polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin. Polyolefin resin such as polyester resin film, polypropylene resin, polyethylene resin, etc. Examples of release agents include rubber elastomers such as silicone resins, olefin resins, isoprene resins, butadiene resins, long-chain alkyl resins, alkyd resins, and fluorine resins. Resin etc.

Although the thickness of the release sheet is not particularly limited, it is preferably 10 to 200 μm, more preferably 20 to 150 μm.

(Method of manufacturing adhesive tape)

The manufacturing method of the adhesive tape of this invention is not specifically limited, It can manufacture by a well-known method.

For example, the buffer layer provided on the release sheet and the adhesive layer provided on the release sheet can be attached to both sides of the base material, and the buffer layer and the adhesive layer can be attached to both surfaces of the release sheet. Adhesive tape. The release sheet attached to both surfaces of the buffer layer and the adhesive layer only needs to be properly peeled off before the adhesive tape is used.

As a method of forming a buffer layer or an adhesive layer on a release sheet, the composition for forming a buffer layer or an adhesive (adhesive) can be formed on the release sheet. The adhesive composition) is directly coated by a well-known coating method to form a coating film, and the coating film is irradiated with energy rays or heated and dried to form a buffer layer or an adhesive layer.

In addition, the buffer layer forming composition and the adhesive (adhesive composition) may be directly coated on both sides of the substrate to form the buffer layer and the adhesive layer. Furthermore, it is also possible to directly apply a buffer layer forming composition or an adhesive (adhesive composition) on one side of the substrate to form a buffer layer and an adhesive layer, and to attach the release sheet on the other side of the substrate On the adhesive layer or buffer layer.

Examples of the coating method of the composition for forming the buffer layer and the adhesive include: spin coating, spray coating, bar coating, knife coating, roll coating, knife coating, and die coating. Cloth method, gravure coating method, etc. In addition, in order to improve the coating properties, an organic solvent may be blended with the buffer layer forming composition and the adhesive composition to form a solution and be applied on the release sheet.

When the composition for forming a buffer layer contains an energy-ray polymerizable compound, it is preferable to form a buffer layer by irradiating the coating film of the composition for forming a buffer layer with energy rays to harden it. The hardening of the buffer layer can be carried out in one hardening treatment or divided into multiple times. For example, the coating film on the release sheet can be completely cured to form a buffer layer, and then attached to the substrate, or the coating film can be incompletely cured to form a semi-cured buffer layer to form a film. After the buffer layer forming film is attached to the substrate, it is irradiated with energy rays again to make it completely hardened to form a buffer layer. As the energy ray irradiated in the curing treatment, purple is preferred Outside. In addition, during curing, although the coating film of the composition for forming a buffer layer may be exposed, it is preferable that the coating film is covered by the release sheet or the substrate, and the coating film is not exposed. In the state, energy rays are irradiated to harden.

[Method of Manufacturing Semiconductor Device]

The adhesive tape of the present invention is used in the post-dicing polishing method when attaching to the surface of a semiconductor wafer to perform backside polishing of the wafer as described above, but more specifically, it is used in the manufacture of semiconductor devices Used in the method.

The manufacturing method of the semiconductor device of the present invention specifically includes at least the following steps 1 to 4.

Step 1: The step of attaching the above-mentioned adhesive tape to the surface of the semiconductor wafer

Step 2: A step of forming a groove on the surface side of the semiconductor wafer, or forming a modified area inside the semiconductor wafer from the surface or back of the semiconductor wafer

Step 3: The semiconductor wafer with the adhesive tape attached to the surface and the grooves or modified areas formed is polished from the back side, and the grooves or modified areas are used as the starting point to separate the semiconductor wafer into a plurality of pieces Wafer steps

Step 4: The step of peeling off the adhesive tape from the singulated semiconductor wafer (ie, a plurality of semiconductor wafers)

Hereinafter, each step of the manufacturing method of the above-mentioned semiconductor device will be described in detail.

(step 1)

In step 1, the adhesive tape of the present invention is attached to the surface of the semiconductor wafer via the adhesive layer. Although this step can be performed before step 2 described later, it can also be performed after step 2. For example, in the case of a semiconductor wafer forming a modified field, it is preferable to perform step 1 before step 2. On the other hand, when grooves are formed on the surface of the semiconductor wafer by dicing or the like, it is preferable to perform step 1 after step 2. That is, on the surface of the wafer having the groove formed in the step 2 described later, the adhesive tape is attached by this step 1.

The semiconductor wafers used in this manufacturing method can be silicon wafers, gallium and arsenic wafers, or glass wafers. Although the thickness of the semiconductor wafer before polishing is not particularly limited, it is usually about 500 to 1000 μm. In addition, semiconductor wafers usually have circuits formed on the surface. The formation of the circuit on the surface of the wafer can be carried out by various methods including etching method, lift-off method and other conventional methods.

(Step 2)

In step 1, a trench is formed on the surface side of the semiconductor wafer, or a modified area is formed inside the semiconductor wafer from the surface or back surface of the semiconductor wafer.

The trench formed in this step is a trench having a shallower depth than the thickness of the semiconductor wafer. The formation of the groove can be performed by dicing using a conventionally known wafer dicing device or the like. In addition, the semiconductor wafer is divided into a plurality of semiconductor wafers along the groove in step 3 described later.

In addition, the modified area is in the semiconductor wafer, which is embrittled. By the grinding in the grinding step, the semiconductor wafer is thinned or the force caused by the grinding is applied, thereby becoming the starting area for the semiconductor wafer to be destroyed and singulated into the semiconductor wafer. That is, in step 2, the trench and the modified area are formed as the dividing line when the semiconductor wafer is divided and singulated into semiconductor wafers in step 3 described later.

The formation of the modified area is performed by irradiating a laser focused on the inside of the semiconductor wafer, and the modified area is formed inside the semiconductor wafer. The laser irradiation system can be performed from the front side of the semiconductor wafer or from the back side. In addition, in the aspect of forming the modified area, when step 2 is performed after step 1 to perform laser irradiation from the surface of the wafer, the semiconductor wafer is irradiated with the laser through the adhesive tape.

The semiconductor wafer on which the adhesive tape is attached and the groove or modified area is formed is placed on the suction cup and held by the suction cup. At this time, the surface side of the semiconductor wafer system is arranged to be sucked to the disk side.

(Step 3)

After step 1 and step 2, the back side of the semiconductor wafer on the chuck is polished, and the semiconductor wafer is singulated into a plurality of semiconductor wafers.

Here, the back grinding is performed in the case where a groove is formed on the semiconductor wafer, and the semiconductor wafer is thinned until it reaches at least the position of the bottom of the groove. By this back grinding, the groove system becomes a cut through the wafer, and the semiconductor wafer is divided by the cut, and is singulated into individual semiconductor wafers.

On the other hand, in the case of a modified area, grinding and researching The grinding surface (the back side of the wafer) can reach the modified area, but it can also be strictly not reached the modified area. That is, as long as the semiconductor wafer is destroyed by using the modified region as a starting point, and the semiconductor wafer is singulated into semiconductor wafers, the polishing is carried out until it is close to the position of the modified region. For example, the actual singulation of semiconductor wafers can also be performed by extending the pickup tape after attaching the pickup tape described later.

The shape of the singulated semiconductor chip can be a square or a rectangular shape. Furthermore, although the thickness of the singulated semiconductor wafer is not particularly limited, it is preferably about 5 to 100 μm, and more preferably 10 to 45 μm. Furthermore, although the size of the singulated semiconductor wafer is not particularly limited, the size of the wafer is preferably less than 50 mm ² , more preferably less than 30 mm ² , and still more preferably less than 10 mm ² .

If the adhesive tape of the present invention is used, even such a thin and/or small semiconductor chip can prevent defects in the semiconductor chip during back grinding (step 3) and peeling of the adhesive tape (step 4) .

(Step 4)

Next, the adhesive tape for semiconductor processing is peeled off from the singulated semiconductor wafer (that is, a plurality of semiconductor wafers). This step is, for example, performed by the following method.

First, when the adhesive layer of the adhesive tape is formed of an energy-ray curable adhesive, energy rays are irradiated to harden the adhesive layer. Next, a pick-up tape is attached to the back side of the singulated semiconductor wafer to perform position and direction alignment in a pick-up manner. At this time, it is configured in Jing The ring frame on the outer peripheral side of the circle is also attached to the pick-up tape, and the outer peripheral edge of the pick-up tape is fixed to the ring frame. The pick-up tape can attach the wafer to the ring frame at the same time, or attach them at different timings. Next, the adhesive tape is peeled off from the plurality of semiconductor wafers fixed on the pick-up tape.

After that, a plurality of semiconductor wafers present on the pickup tape are picked up and fixed on a substrate or the like to manufacture a semiconductor device.

In addition, the pickup tape is not particularly limited, but, for example, it is composed of an adhesive sheet having a base material and an adhesive layer provided on one surface of the base material.

Example

Hereinafter, although the present invention will be described in further detail based on examples, the present invention is not limited by these examples.

The measurement method and evaluation method of the present invention are as follows.

[Mass average molecular weight (Mw)]

Using a gel permeation chromatography device (manufactured by TOSOH Co., Ltd., product name "HLC-8020"), the measurement was performed under the following conditions, and the value measured in terms of standard polystyrene was used.

(Measurement conditions)

‧Column: "TSK guard column HXL-H" "TSK gel GMHXL(×2)” “TSK gel G2000HXL” (all made by TOSOH Co., Ltd.)

‧Column temperature: 40℃

‧Developing solvent: tetrahydrofuran

‧Flow rate: 1.0mL/min

[Young's modulus of base material]

The Young's modulus of the substrate was measured according to JISK-7121 (1999) at a test speed of 200mm/min.

[The elastic modulus of the buffer layer and the maximum value of tan δ]

Instead of the base material, a release sheet (manufactured by LINTEC Co., Ltd., trade name "SP-PET381031", thickness: 38μm) was used, and the thickness of the resulting buffer layer was set to 200μm. The buffer layer for the test was produced in the same way as the buffer layer of the example and the comparative example. After removing the peeling sheet on the test buffer layer, use a test piece cut into a specific size, and measure it with a dynamic viscoelastic device (manufactured by ORIENTEC, trade name "Rheovibron DDV-II-EP1") at a frequency of 11 Hz Loss modulus and storage modulus in the temperature range of -20~150℃.

"Maximum value of tan δ of the buffer layer" The values of the respective temperatures "loss modulus / storage modulus" as the temperature of the tan δ is calculated, the maximum value of tan δ in the range of -5 ~ 120 ℃ be set .

[Stress relaxation rate of buffer layer]

In the same manner as above, a test buffer layer was produced on the release sheet and cut into 15 mm×140 mm to form a sample. Using a universal tensile testing machine (Automatic Stereograph AG-10kNIS manufactured by SHIMADZU), grab the two ends of this sample 20mm, and stretch it at a speed of 200mm per minute, and measure the stress A (N /m2), and the stress B (N/m2) after 1 minute from the stop of the tape stretching. The values of the stresses A and B are calculated using (A-B)/A×100(%) as the stress relaxation rate.

[Elastic modulus of adhesive layer]

Using a viscoelasticity measuring device (manufactured by Rheometrics, device name "DYNAMIC ANALYZER RDAII"), a single layer of adhesive layer formed from the solution of the adhesive composition used in the examples and comparative examples was laminated to obtain a diameter of 8mm×3mm For the size of the sample, the storage modulus G'is measured by the torsion shear method at 1 Hz at 23°C, and the obtained value is used as the elastic modulus of the adhesive layer.

[Measurement of Peeling Force]

The adhesive tape with release sheet obtained in the Examples and Comparative Examples was cut into a length of 250 mm and a width of 50 mm. The release sheet was peeled off, and the adhesive tape was attached to an 8-inch silicon mirror wafer using a 2 kg rubber roller. After 20 min standing, the ultraviolet irradiation device (of LINTEC Co., Ltd., trade name "RAD-2000") at an illuminance 230mW / cm ^2, light quantity of 380mJ / cm ² of the condition, ultraviolet irradiation was performed from the tape side. The adhesive tape after the adhesive layer was cured by ultraviolet irradiation was peeled by a universal testing machine (manufactured by A&D, trade name "TENSILON") at a peeling speed of 4 mm/sec and a peeling angle of 180°, and the peeling force was measured. In addition, this test was conducted at room temperature (23°C) and 50% RH.

[Measurement of Adhesive Tape Thickness]

Measure the total thickness of the adhesive tape, the thickness of the base material, the adhesive layer, and the buffer layer with a constant pressure thickness tester (manufactured by TECLOCK, PG-02). At this time, measure 10 arbitrary points and calculate the average value.

In addition, in this embodiment, the total thickness of the adhesive tape is measured by measuring the thickness of the adhesive tape with the release sheet, and the value of the thickness of the release sheet is subtracted from the thickness. Furthermore, the thickness of the buffer layer is a value obtained by subtracting the thickness of the substrate from the thickness of the substrate with the buffer layer. In addition, the thickness of the adhesive layer is a value obtained by subtracting the thickness of the buffer layer and the substrate from the total thickness of the adhesive tape.

(Performance evaluation)

[Peel test 1]

A groove is formed on the surface of a silicon wafer with a diameter of 12 inches (30.48 cm), and then an adhesive tape is attached to the surface of the wafer, and the wafer is singulated by back grinding by dicing and grinding. Come single-chip formation into a wafer with a thickness of 30μm and a wafer size of 1mm square. After that, without peeling off the adhesive tape, the corners of the singulated wafers were observed with a digital microscope (VE-9800 manufactured by Keyence Co., Ltd.) from the polished surface of the wafers, and the presence or absence of peeling of the corners of the wafers was observed and measured The peel occurrence rate among 700 wafers was evaluated using the following evaluation criteria.

A: Less than 1.0%, B: 1.0~2.0%, C: more than 2.0%

[Wafer Crack Test 2]

First, stick an adhesive tape on the surface of a silicon wafer with a diameter of 12 inches (30.48 cm). Next, from the surface opposite to the surface where the adhesive tape is attached, a laser light source is used to form a lattice-shaped modified area on the silicon wafer. In addition, the grid size is set to 1 mm square. Next, using a backside polishing device, polishing is performed until the thickness becomes 30 μm, and the wafers are singulated into 1 mm square wafers. After the grinding step, irradiate energy rays, and stick a dicing tape (LINTEC Co., Ltd., trade name "D-821HS") on the opposite side of the sticking surface of the adhesive tape. Observe the singulated wafers with a digital microscope, observe the presence or absence of wafer cracks at the corners of each wafer, measure the rate of occurrence of wafer cracks in 700 wafers, and evaluate with the following evaluation criteria.

A: Less than 1.0%, B: 1.0~2.0%, C: more than 2.0%

[Peeling Evaluation 1]

The adhesive tapes with release sheets obtained in the Examples and Comparative Examples were set on a tape laminator (manufactured by LINTEC Co., Ltd., trade name "RAD-3510") while peeling off the release sheet on one side, and pasted under the following conditions A 12-inch silicon wafer (thickness 760μm) with grooves formed on the surface of the wafer by the dicing and polishing method.

Roller height: 0mm Roller temperature: 23℃ (room temperature)

Plate temperature: 23°C (room temperature)

The obtained silicon wafer with adhesive tape was formed into a single piece with a thickness of 30 μm and a wafer size of 1 mm square by back grinding (post-cut grinding method). The singulated adhesive tape with chip is irradiated with ultraviolet rays from the tape side using a dicing tape mounting machine (manufactured by LINTEC Co., Ltd., trade name "RAD-2700") (conditions: 230mW/cm ² , 380mJ/cm ² ) to harden the adhesive. Thereafter, in the same RAD-2700 device, a dicing tape (manufactured by LINTEC Co., Ltd., trade name "D-821HS") was attached from the chip side. At this time, a jig called a ring frame used in the pick-up step is also attached to the pick-up tape. Next, in the RAD-2700 device, peel off the hardened adhesive tape. 700 wafers after peeling off the adhesive tape were observed with a digital microscope (manufactured by KEYENCE Co., Ltd., trade name "VE-9800") with a dicing tape interposed, and the incidence of chip defects was measured. Take the value obtained by subtracting the occurrence rate of peeling test 1 from the same occurrence rate as the occurrence rate of peeling evaluation 1, and evaluate using the following evaluation criteria.

OK: less than 1.0%, NG: 1.0% or more

[Peel-off assessment 2]

The adhesive tapes with release sheets obtained in the Examples and Comparative Examples were set on a tape laminator (manufactured by LINTEC Co., Ltd., trade name "RAD-3510") while peeling off the release sheet on one side, and pasted under the following conditions On a 12-inch (30.48cm) silicon wafer (thickness 760μm).

Roller height: 0mm Roller temperature: 23℃ (room temperature)

Plate temperature: 23°C (room temperature)

Then, from the surface opposite to the surface where the tape is attached, laser light is used to irradiate the laser to form a grid-shaped modified area on the wafer. In addition, the grid size is set to 1 mm square. The resulting silicon wafer with adhesive tape was formed into a single piece with a thickness of 30 μm and a chip size of 1 mm square by back grinding. The singulated adhesive tape with chip is irradiated with ultraviolet rays from the tape side using a dicing tape mounting machine (manufactured by LINTEC Co., Ltd., trade name "RAD-2510") (conditions: 230mW/cm ² , 380mJ/cm ² ) to harden the adhesive. Thereafter, in the same RAD-2510 device, a dicing tape (manufactured by LINTEC Co., Ltd., trade name "D-821HS") was attached from the chip side. At this time, the ring frame used in the pickup step is also attached to the pickup tape. Then, in the RAD-2510 device, peel off the hardened adhesive tape. 700 wafers after peeling off the adhesive tape were observed with a digital microscope (manufactured by Keyence Co., Ltd., trade name "VE-9800") with a dicing tape interposed, and the incidence of wafer cracks was measured. The value obtained by subtracting the occurrence rate of wafer crack test 1 from the same occurrence rate was used as the occurrence rate of peeling evaluation 1, and evaluated using the following evaluation criteria.

OK: less than 1.0%, NG: 1.0% or more

In addition, all the parts by mass of the following examples and comparative examples are solid content values.

[Example 1]

(1) Synthesis of urethane acrylate oligomer

The end obtained by reacting polyester diol with isophorone diisocyanate Isocyanate urethane prepolymer reacts with 2-hydroxyethyl acrylate to obtain a bifunctional urethane acrylate oligomer (UA-1) with a mass average molecular weight (Mw) of 5000 .

(2) Preparation of composition for buffer layer formation

40 parts by mass of the urethane acrylate oligomer (UA-1) synthesized above, 40 parts by mass of isobornyl acrylate (IBXA), and 20 parts by mass of phenylhydroxypropyl acrylate (HPPA) 1 part by mass, and further blended 2.0 parts by mass of 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Corporation, product name "Irgacure 184") as a photopolymerization initiator, and 0.2 parts by mass of phthalocyanine pigment , And prepare a composition for forming a buffer layer.

(3) Preparation of adhesive composition

Acrylic polymer (b) obtained by copolymerizing 52 parts by mass of butyl acrylate (BA), 20 parts by mass of methyl methacrylate (MMA), and 28 parts by mass of 2-hydroxyethyl acrylate (HEA), It reacts with 2-methacryloxyethyl isocyanate (MOI) by adding 90 mol% of the hydroxyl groups in the total hydroxyl groups of the acrylic polymer (b) to obtain an energy-ray curable acrylic Resin (Mw: 500,000).

To 100 parts by mass of the energy-ray-curable acrylic resin, a polyfunctional urethane acrylate (trade name: SHIKOH UT-4332, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) as an energy-ray-curable compound is added 6 Parts by weight, isocyanate-based crosslinking agent (manufactured by TOYOCHEM Co., Ltd., trade name: BHS-8515) is 0.375 based on solid content Parts by mass, 1 part by weight of a photopolymerization initiator composed of bis(2,4,6-trimethylbenzyl)phenyl phosphine oxide, and diluted with a solvent to adjust the adhesive composition的coating fluid.

(4) Making of adhesive tape

On one side of a 50μm thick polyethylene terephthalate film (Young's modulus: 2500MPa) as a substrate, the above-obtained composition for forming a buffer layer was coated, and the illuminance was 160mW/cm ² and the irradiation amount Ultraviolet rays were irradiated under the condition of 500 mJ/cm ² to harden the composition for forming a buffer layer to obtain a buffer layer with a thickness of 13 μm.

In addition, on the peeling treatment surface of the peeling sheet (manufactured by LINTEC Co., Ltd., trade name: SP-PET381031) whose base material is a polyethylene terephthalate film, the thickness after drying was set to 20 μm The coating liquid of the adhesive composition obtained above is applied and heated and dried to form an adhesive layer on the release sheet. The adhesive layer is attached to the other side of the base material with the buffer layer to obtain an adhesive tape with a release sheet.

In addition, the elastic modulus of the adhesive layer at 23°C was 0.15 MPa. In addition, the storage modulus of the buffer layer is 250 MPa, the stress relaxation rate is 90%, and the maximum value of tan δ is 1.24.

[Examples 2 to 8 and Comparative Examples 1 to 15]

It was implemented in the same manner as in Example 1 except that the thickness of the base material, the buffer layer, and the adhesive layer was changed to the point as described in Table 1.

In addition, in each of the Examples and Comparative Examples, a polyethylene terephthalate film having the same Young's modulus as in Example 1 was used as the substrate.

The "-" in the table means that it has not been implemented.

As mentioned above, in Examples 1-8, since the total thickness of the adhesive tape is 160μm or less, the thickness ratio (D2/D1) is 0.7 or less, and the peeling force is 1000mN/25mm or less, the peeling test and peeling evaluation are The result is good. In the post-dicing polishing method, chip defects are not likely to occur during the backside polishing of the semiconductor wafer and the peeling of the adhesive tape.

In contrast, in Comparative Examples 1 to 10, since the thickness of the buffer layer became larger and the thickness ratio (D2/D1) was greater than 0.7, the peeling rate increased in the peeling test, and the back surface of the semiconductor wafer was polished Easy to produce semiconductors Defects of the chip. Furthermore, if the thickness ratio (D2/D1) becomes larger, the peeling force tends to also become larger. As shown in Comparative Examples 3 and 4, the possibility of occurrence of chipping in the semiconductor wafer when the adhesive tape is peeled also increases.

In addition, in Comparative Examples 11 to 13, since the total thickness of the adhesive tape is large, the peeling force becomes large, and defects are generated in the semiconductor wafer when the adhesive tape is peeled off. Furthermore, in Comparative Example 14, since both the thickness ratio (D2/D1) and the total thickness of the adhesive tape are larger, both in the back polishing of the semiconductor wafer and the peeling of the adhesive tape are both Defects of semiconductor wafers, etc. are generated. In Comparative Example 15, since the total thickness of the tape was large, chip defects and the like were similarly generated.

Claims (14)

An adhesive tape for semiconductor processing, which forms a groove on the surface of a semiconductor wafer or grinds the back surface of a semiconductor wafer in the field of semiconductor wafer formation modification, and the semiconductor wafer is singulated into a semiconductor wafer by the grinding In the step, the adhesive tape for semiconductor processing used for attaching to the surface of the semiconductor wafer is characterized by having a substrate, a buffer layer provided on one side of the substrate, and an adhesive provided on the other side of the substrate The total thickness of the adhesive tape for semiconductor processing is 160μm or less, and the ratio (D2/D1) of the thickness (D2) of the aforementioned buffer layer to the thickness (D1) of the base material (D1) is 0.7 or less. The peeling force of the wafer is less than 1000mN/50mm. The adhesive tape for semiconductor processing according to claim 1, wherein the Young's modulus of the aforementioned substrate is 1000 MPa or more. The adhesive tape for semiconductor processing according to claim 1 or 2, wherein the thickness (D1) of the aforementioned substrate is 110 μm or less. The adhesive tape for semiconductor processing according to claim 1 or 2, wherein the substrate has at least a polyethylene terephthalate film. The adhesive tape for semiconductor processing according to claim 1 or 2, wherein the adhesive layer is formed of an energy ray-curable adhesive. The adhesive tape for semiconductor processing of claim 1 or 2, wherein the elastic modulus of the adhesive layer at 23° C. is 0.10~0.50 MPa. The adhesive tape for semiconductor processing according to claim 1 or 2, wherein the thickness (D3) of the aforementioned adhesive layer is 70 μm or less. The adhesive tape for semiconductor processing of claim 1 or 2, wherein the adhesive layer is formed of an adhesive composition containing an acrylic resin, the acrylic resin having a carbon number derived from an alkyl group of 4 or more (former A structural unit derived from an alkyl acrylate, a structural unit derived from an alkyl (meth)acrylate having 1 to 3 carbon atoms, and a structural unit derived from a monomer containing a functional group. Such as claim 1 or 2 of the adhesive tape for semiconductor processing, wherein the aforementioned buffer layer is 23. The storage modulus at ℃ is 100~1500MPa. Such as claim 1 or 2 of the adhesive tape for semiconductor processing, wherein the stress relaxation rate of the aforementioned buffer layer is 70-100%. The adhesive tape for semiconductor processing of claim 1 or 2, wherein the buffer layer is formed of a composition for forming a buffer layer, and the composition for forming a buffer layer contains a urethane (meth)acrylate (a1 ), a polymerizable compound (a2) having an alicyclic or heterocyclic group with 6 to 20 ring atoms, and a polymerizable compound (a3) having a functional group. Such as claim 11 of the adhesive tape for semiconductor processing, wherein the component (a2) is a polymerizable compound having an alicyclic group with 6 to 20 ring atoms. For example, the adhesive tape for semiconductor processing of claim 11, wherein the component (a2) is an alicyclic group-containing (meth)acrylate, and the component (a3) is a hydroxyl group-containing (meth)acrylate. A method of manufacturing a semiconductor device, comprising the following steps: applying the adhesive for semiconductor processing as in any one of claims 1 to 13 The step of attaching tape to the surface of the aforementioned semiconductor wafer; the step of forming a groove on the surface side of the semiconductor wafer, or forming a modified area inside the semiconductor wafer from the surface or back of the semiconductor wafer; attaching the surface with the aforementioned Adhesive tape for semiconductor processing, and the semiconductor wafer formed with the aforementioned groove or modified area is polished from the back side, and the semiconductor wafer is singulated into a plurality of wafers using the aforementioned groove or modified area as a starting point; The step of peeling off the adhesive tape for semiconductor processing from the aforementioned plural wafers.