JP2002246344A - Sheet for protecting semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a sheet for protecting a semiconductor wafer having irregularities due to a circuit formed on the surface generating strain inside and hence may cause chips and cracks, when the semiconductor wafer is to be polished, and a gap may be generated between the circuit and the sheet for protecting the semiconductor wafer. SOLUTION: A foamed resin layer is provided between a sheet-like support and an adhesive mass layer, that is laminated on one surface of the support, dynamic modulus of elasticity at 10-40 deg.C in the foamed resin layer is set to 1×10-2-5×103 N/cm2, the thickness is set to 10-500 μm, and the thickness of the adhesive mass layer is set to 5-150 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor wafer,
The present invention relates to a semiconductor wafer protection sheet that is attached to a surface on which a circuit is formed and protects the circuit when polishing the other surface. In particular, the circuit has irregularities of about 100 μm. Also, the present invention relates to a semiconductor wafer protection sheet which does not chip or break a semiconductor wafer during the polishing and does not produce a gap between the circuit and the semiconductor wafer protection sheet.

[0002]

2. Description of the Related Art A sheet-like support is used as a semiconductor wafer protection sheet which is attached to a surface of a semiconductor wafer on which circuits are formed and which protects the other surface when polishing the other surface. There is known an apparatus in which an elastic sheet is laminated on a substrate and the unevenness of the circuit is protected by deformation of the elastic sheet (for example, JP-A-2000-331968).

[0003]

However, in this technique, since the elastic sheet is elastically deformed, distortion occurs inside the elastic sheet. When the semiconductor wafer is polished, the distortion is transmitted to the semiconductor wafer and causes the semiconductor wafer to vibrate, so that the semiconductor wafer may be chipped or cracked.

Further, if the unevenness of the circuit becomes too large, the elastic sheet cannot be completely deformed, and a gap is formed between the circuit and the semiconductor wafer protecting sheet. In some cases, polishing debris generated when the back surface of the semiconductor wafer is polished intrude into the gap to damage the circuit.

Accordingly, it is an object of the present invention to prevent the occurrence of such a distortion so that the semiconductor wafer is not chipped or cracked when polishing a surface of the semiconductor wafer on which a circuit is not formed, and the circuit is not broken. An object of the present invention is to provide a semiconductor wafer protection sheet which does not cause a gap between the semiconductor wafer protection sheet and the semiconductor wafer protection sheet.

[0006]

The present inventor has made intensive studies in view of the above, and as a result, has found that a semiconductor wafer protection device having a sheet-like support and an adhesive layer laminated on one surface of the support is provided. In the sheet for use, a foamed resin layer is provided between the support and the pressure-sensitive adhesive layer, and the dynamic elastic modulus of the foamed resin layer at 10 to 40 ° C. is 1 × 10 ^{−2 to} 5 × 10 ³ N / cm ^2. The inventors have found that the above problems can be solved by setting the thickness to 10 to 500 μm and the thickness of the pressure-sensitive adhesive layer to 5 to 150 μm, and completed the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0007] The foamed resin layer of the semiconductor wafer protection sheet according to the present invention is employed for protecting circuits formed on the surface of the semiconductor wafer without causing distortion inside the foamed resin layer. is there.

[0008] In the foamed resin layer, when the circuit is pressed against the surface of the foamed resin layer via the adhesive layer,
Air bubbles dispersed inside the foamed resin layer are crushed by the pressing. By crushing the air bubbles,
The surface of the foamed resin layer and the pressure-sensitive adhesive layer have a shape surrounding the circuit, so that the circuit can be protected without generating a distortion inside the foamed resin layer. For this reason, when polishing the back surface of the semiconductor wafer, the semiconductor wafer does not vibrate due to the influence of the distortion, and the semiconductor wafer itself does not chip or crack.

If the dynamic elastic modulus of the foamed resin layer at 10 to 40 ° C. is too large, the foamed resin layer is not crushed and the semiconductor wafer protection sheet cannot follow the unevenness of the circuit. A gap is formed between the sheet and the semiconductor wafer protection sheet. If cooling water or polishing debris used for polishing the semiconductor wafer enters through the gap, the semiconductor wafer is chipped or broken. Also, if the dynamic elastic modulus is too small, the foamed resin layer cannot withstand the stress when polishing the semiconductor wafer,
Since the semiconductor wafer is vibrated and the semiconductor wafer is chipped or broken, 1 × 10 ^{−2 to} 5 × 10 ³ N /
cm ² , preferably 1 to 1 × 10 ² N / cm ² . The dynamic elastic modulus is a value obtained by measuring a G ′ value of a material constituting the foamed resin layer, and is a value indicating a ratio of strain to stress applied to the material.

If the thickness of the foamed resin layer is too large, the semiconductor wafer vibrates due to stress when the semiconductor wafer is polished, and the semiconductor wafer is chipped or broken. On the other hand, if it is too thin, it is impossible to completely protect the surface of the semiconductor wafer from unevenness due to the circuit, and a gap is formed between the circuit and the semiconductor wafer protecting sheet. If cooling water or polishing debris used for polishing the semiconductor wafer enters through the gap, the semiconductor wafer may be chipped or cracked. Therefore, the thickness is preferably 10 to 500 μm, and more preferably 50 to 300 μm.

[0011] The foamed resin layer is formed by laminating a blend of a base polymer and a foaming agent on one surface of the support, and then heating to expand or foam the foaming agent. It is one in which bubbles are provided.

As the base polymer, a synthetic resin obtained by polymerizing a monomer component used for preparing a known pressure-sensitive adhesive, such as an acrylic resin, a rubber-based elastomer, and a styrene / conjugated diene block copolymer, is used. be able to.

Specific examples of the monomer component include methyl, ethyl, propyl, butyl, 2-ethylhexyl, isooctyl, isononyl, isodecyl, dodecyl, lauryl, tridecyl, pentadecyl, Hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, usually acrylic acid or methacrylic acid having an alkyl group having 20 or less carbon atoms such as eicoxyl group, itaconic acid, hydroxyethyl acrylate group,
Examples include hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-methylolacrylamide, acrylonitrile, methacrylonitrile, glycidyl acrylate, vinyl acetate, styrene, isoprene, butadiene, isobutylene, vinyl ether, and the like.

Examples of the foaming agent for the foamed resin layer include inorganic and organic foaming agents. Examples of the inorganic foaming agent include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, and azide. And so on.

Examples of the organic foaming agent include water, chloroalkanes such as trichloromonofluoromethane and dichloromonofluoromethane, and azo-based compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate. Compounds, hydrazine compounds such as paratoluenesulfonylhydrazide, diphenylsulfone-3,3'-disulfonylhydrazide, 4,4'-oxybis (benzenesulfonylhydrazide), allylbis (sulfonylhydrazide), ρ-toluylenesulfonyl semicarbazide and 4 Semicarbazide compounds such as 4,4'-oxybis (benzenesulfonylsemicarbazide),
Triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole, N, N′-dinitrosopentamethylenetetramine, N, N′-dimethyl-N,
N-nitroso-based compounds such as N'-dinitrosoterephthalamide are exemplified.

The heat-expandable microparticles in which a foaming agent is microencapsulated are preferably used because they can be easily mixed. Examples of the thermally expandable fine particles include microspheres (trade name: manufactured by Matsumoto Yushi Co., Ltd.). In addition, you may add a foaming auxiliary as needed.

If the amount of the foaming agent is too large, the bubbles in the foamed resin layer become too large and the dynamic elastic modulus becomes low. If the amount is too small, sufficient bubbles cannot be formed and the dynamic elastic modulus becomes too small. Base polymer 1 because it is too high
The amount is preferably 1 to 100 parts by weight, more preferably 5 to 50 parts by weight based on 00 parts by weight.

In preparing the foamed resin layer, if necessary, appropriate additives such as a crosslinking agent, a tackifier resin, a plasticizer, a filler, an antioxidant and the like may be used in combination.

The pressure-sensitive adhesive layer of the semiconductor wafer protection sheet according to the present invention is laminated on the foamed resin layer, and transmits the unevenness of the circuit formed on the surface of the semiconductor wafer to the foamed resin layer, and This is employed for attaching and fixing the wafer and the foamed resin layer.

If the thickness of the pressure-sensitive adhesive layer is too large, the semiconductor wafer vibrates when polishing the semiconductor wafer, causing chipping or cracking of the semiconductor wafer. Therefore, it is impossible to follow the unevenness due to the above, and a gap is formed between the circuit and the semiconductor wafer protecting sheet. When cooling water or polishing debris used for polishing the semiconductor wafer enters through the gap, the semiconductor wafer is chipped or broken.
μm, preferably 10 to 60 μm.

As the pressure-sensitive adhesive layer, a general pressure-sensitive pressure-sensitive adhesive,
An ultraviolet-curable pressure-sensitive adhesive, a heat-curable pressure-sensitive adhesive, or the like can be appropriately selected and employed. As the general pressure-sensitive adhesive, conventionally known pressure-sensitive adhesives such as acrylic, rubber, and silicone can be appropriately selected and employed. The UV-curable pressure-sensitive adhesive is obtained by blending a curable compound and a UV-curable initiator with the general pressure-sensitive pressure-sensitive adhesive, and its adhesive strength can be adjusted by irradiation with ultraviolet rays. Further, the heat-curable pressure-sensitive adhesive is obtained by blending the curable compound and a heat-curing initiator with the general pressure-sensitive pressure-sensitive adhesive, and the pressure-sensitive adhesive force can be adjusted by heating.

As the acrylic pressure-sensitive adhesive, a conventionally known acrylic pressure-sensitive adhesive can be appropriately selected and used. Generally, a homopolymer (main monomer) mainly containing an acrylate ester as a main constituent monomer unit is used. ) And copolymers with comonomers, copolymers with other functional monomers (functional group-containing monomers), and mixtures of these polymers. Here, as the main monomer, there are, for example, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like, and as the above-mentioned comonomers, there are vinyl acetate, acrylonitrile, acrylamide, styrene, methyl methacrylate, methyl acrylate, and the like. Examples of the functional group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, acrylamide, methylol acrylamide, glycidyl methacrylate, and maleic anhydride.

Examples of the rubber-based pressure-sensitive adhesive include natural rubber, synthetic isoprene rubber, styrene-butadiene rubber,
Styrene / butadiene block copolymer, styrene / isoprene block copolymer, butyl rubber, polyisobutylene, polybutadiene, polyvinyl ether, silicone rubber, polyvinyl isobutyl ether, chloroprene rubber, nitrile rubber, kraft rubber, recycled rubber, styrene / ethylene / butylene -Block copolymer, styrene-propylene-butylene-block copolymer, styrene-isoprene-block polymer, acrylonitrile-butadiene copolymer, acrylonitrile-acryl ester copolymer, methyl methacrylate-butadiene copolymer, polyisobutylene-ethylene Propylene copolymer, ethylene vinyl acetate copolymer, polyisobutylene / silicone rubber, polyvinyl isobutyl ether / chloroprene, etc. It may be a mixture not only these alone product.

In order to increase the adhesive strength of the rubber-based pressure-sensitive adhesive,
It is preferred to add a tackifying resin. When the amount of the tackifying resin is too small, the adhesive effect of the adhesive containing an elastomer as a main component is not obtained, and when the amount is too large, the performance reaches a peak.
It is preferable to mix it in an amount of 100 to 100 parts by weight, and more preferably 10 to 30 parts by weight.

As the tackifying resin, a rosin resin,
Terpene resin, aliphatic petroleum resin, aromatic petroleum resin, hydrogenated petroleum resin, chroman / indene resin, styrene resin, alkylphenol resin, xylene resin, etc. In consideration of the above, a terpene resin is preferable. Examples of the rosin-based resin include rosin, polymerized rosin, hydrogenated rosin, rosin ester, hydrogenated rosin ester, rosin-modified phenol resin, and the like. Resin and rosin phenol resin. Examples of the hydrogenated petroleum resin include aromatic resins, dicyclopentadiene resins, and aliphatic resins.

The curable compound, together with the ultraviolet curing initiator and the heat curing initiator, reduces the adhesive strength of the pressure-sensitive adhesive layer when the semiconductor wafer is separated from the semiconductor wafer protection sheet. This is adopted for adjustment.
With respect to the compounding ratio of the curable compound, if the amount is too small, the portion to be cured becomes small, so that the adhesive force of the pressure-sensitive adhesive layer cannot be adjusted. Since the composition is hardened by ordinary light and storage stability is deteriorated, the amount is preferably 5 to 900 parts by weight, more preferably 20 to 200 parts by weight, based on 100 parts by weight of the general pressure-sensitive adhesive.

As the curable compound, specifically, a functional curable compound having two or more functional groups is preferable, for example, acrylate compounds, urethane acrylates, urethane acrylate oligomers and / or monomers, epoxy acrylates , Polyester acrylate and the like.

As the acrylate compound, for example, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or 1,4 -Butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate and the like.

Examples of the urethane acrylate include polyester urethane acrylate, polyether urethane acrylate, 4-functional urethane acrylate, and hexafunctional urethane acrylate.

The urethane acrylate oligomer is an ultraviolet-curable compound having at least two carbon-carbon double bonds, such as a polyester compound or a polyether type polyol compound and a polyvalent isocyanate compound such as 2,4. -Tolylene diisocyanate, 2,6
-Tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate,
A terminal isocyanate urethane prepolymer obtained by reacting diphenylmethane 4,4-diisocyanate or the like, an acrylate having a hydroxyl group, or a methacrylate such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate,
Some are obtained by reacting polyethylene glycol methacrylate or the like.

When the urethane acrylate-based oligomer is employed, the adhesive is not particularly limited. However, when the adhesive having a molecular weight of 300 to 30,000 is used for the adhesive layer, the adhesive remains on the semiconductor wafer even after polishing the back surface of the semiconductor wafer. Does not adhere.

The epoxy acrylate is synthesized by reacting an epoxy group with acrylic acid or methacrylic acid, and includes bisphenol A type, bisphenol S type, bisphenol F type, epoxy oil type, phenol novolak type, There are ring types and the like.

As the polyester acrylate,
Acrylic acid is condensed to OH groups remaining on the polyester skeleton synthesized from diols, polyols and dibasic acids to form acrylates. For example, phthalic anhydride / propylene oxide diol / acrylic acid, adipic acid /
Examples include 1,6-hexanediol / acrylic acid, trimellitic acid / diethylene glycol / acrylic acid, and the like.

The ultraviolet curing initiator and the heat curing initiator compounded in the pressure-sensitive adhesive layer are employed for accelerating the curing of the curable compound. If the compounding ratio of the ultraviolet curing initiator and the heat curing initiator is too large, the composition becomes sensitive to heat and light, and cures even at ambient temperature or sunlight, resulting in poor storage stability. Due to poor efficiency, 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the curable compound is good.

Examples of the ultraviolet curing initiator include chloroacetophenone, diethoxyacetophenone, hydroxyacetophenone, 1-hydroxycyclohexylphenylketone, α-aminoacetophenone,
2-methyl-1- (4- (methylthio) phenyl) -2
-Morpholinopropan-1-one, 2-hydroxy-
2-methyl-1-phenylpropan-1-one, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, mixed photoinitiator, 4- (2-hydroxyethoxy)-
Phenyl (2-hydroxy-2-propyl) ketone, allyl ketone-containing photoinitiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether,
Benzoin ether, benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3, 3'-
Dimethyl-4-methoxybenzophenone, methyl-O-
Benzoylbenzoate, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-
Dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, α-acyl oxime ester, α-acyloxime ester, acyl Phosphine oxide, methylphenyl glyoxylate, glyoxyester, 3-ketocoumarin, 2-ethylanthraquinone, camphorquinone, benzyl, 9,10-phenanthrenequinone, anthraquinone, dibenzosuberone, 4 ', 4 ″ -diethylisophthalophenone, Michler's ketone, cyclic photoinitiator, tetramethylthiuram monosulfide, 3,
3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone and the like. Examples of the chloroacetophenone include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t
-Butyl-trichloroacetophenone and the like.

Examples of the heat curing initiator include an organic peroxide derivative and an azo-based polymerization initiator. The azo-based polymerization initiator is more preferably an organic peroxide derivative because nitrogen is generated during heating. Specific examples of the heat curing initiator include:
Ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxyester, peroxydicarbonate, azobisisobutyronitrile and the like.

When the above-mentioned UV-curable pressure-sensitive adhesive is employed as the pressure-sensitive adhesive layer of the present invention, a photo-initiating auxiliary may be added as required. Although the photoinitiator itself is not activated by ultraviolet irradiation itself, the initiation reaction is accelerated by using the ultraviolet curing initiator alone when used in combination with the ultraviolet curing initiator, and the curing reaction is made efficient. is there.
Further, if necessary, an amine compound such as triethylamine, tetraethylpentamine, or dimethylaminoether may be used in combination as a polymerization accelerator.

As the photoinitiating auxiliary, mainly aliphatic,
There are aromatic amines, and specifically, triethanolamine, methyldiethanolamine, triisopropanolamine, n-butylamine, N-methyldiethanolamine, diethylaminoethyl methacrylate, Michler's ketone, 4,4′-diethylaminophenone, 4,4 ′
-Diethylaminobenzophenone, ethyl 2-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate,
Ethyl (n-butoxy) 4-dimethylaminobenzoate, 4
-Isoamyl dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, polymerizable tertiary amine,
Triethylamine, tetraethylpentaamine, dimethylaminoether and the like.

In order to start the curing of the ultraviolet-curable compound and the heat-curable compound, it is necessary to irradiate and heat ultraviolet rays, respectively. The timing of irradiating or heating ultraviolet rays to cure these curable compounds is performed when the semiconductor wafer is peeled from the semiconductor wafer protection sheet. The irradiation amount of the ultraviolet rays is preferably in a range of ²⁰ to 500 mJ / cm ² at a frequency of 365 nm, and more preferably in a range of 50 to 150 mJ / cm ² . As the heating temperature, a temperature range of 50 to 150 ° C. is preferable. This is because if the irradiation or heating of the ultraviolet rays is too small, the cohesive strength cannot be improved, and if the irradiation or heating is too large, it takes time and the productivity is deteriorated.

As the support for the semiconductor wafer protection sheet according to the present invention, a conventionally known synthetic resin used as a support for the semiconductor wafer protection sheet can be employed, and a UV-curable composition or the like is compounded in the adhesive layer. In this case, since it is necessary to allow the ultraviolet rays from the support to reach the pressure-sensitive adhesive layer, the sheet needs to be an ultraviolet-permeable sheet. Specifically, a single layer, a composite layer or a plurality of layers of polyvinyl chloride, polybutene, polybutadiene, polyurethane, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polyethylene, polypropylene and the like can be employed. The thickness of the support is selected from the range of 10 to 500 μm.

The semiconductor wafer protection sheet according to the present invention is stored by adhering a release paper or a release sheet such as a polyethylene laminated paper or a release-treated plastic film on an adhesive as required.

In the present invention, a sheet-shaped support,
In a sheet for protecting a semiconductor wafer having an adhesive layer laminated on one surface of the support, a foamed resin layer is provided between the support and the adhesive layer.
Dynamic elastic modulus of 1 × 10 ^{-2 to} 5 × 10 ³ N / cm ²
By setting the thickness to 10 to 500 μm and the thickness of the pressure-sensitive adhesive layer to 5 to 150 μm, the semiconductor wafer may be chipped or broken when polishing the surface of the semiconductor wafer where the circuit is not formed. Thus, a semiconductor wafer protection sheet was obtained which did not cause a gap between the circuit and the semiconductor wafer protection sheet.

[0043]

EXAMPLE An example of a semiconductor wafer protection sheet according to the present invention will be described with reference to Table 1 while comparing with a comparative example.

[0044]

[Table 1]

The semiconductor wafer protection sheet of this embodiment is
A sheet-shaped support having a thickness of 100 μm, a foamed resin layer having a thickness of 200 μm laminated on the surface of the support, and an adhesive layer having a thickness of 20 μm laminated on the surface of the foamed resin layer. is there. Here, the support is made of polyethylene terephthalate. The foamed resin layer is composed of 100 parts by weight of a copolymer of ethyl acrylate-2-ethylhexyl acrylate as a base polymer and 9 parts by weight of thermally expandable fine particles (microsphere, F-30D) as a foaming agent. The blended composition was heated and foamed after being laminated on the support, and its dynamic elastic modulus at 23 ° C. was 10 N / c.
It is obtained by adjusting the m ^2. Further, the pressure-sensitive adhesive layer was prepared by blending 100 parts by weight of a copolymer of ethyl acrylate and 2-ethylhexyl acrylate as a base polymer with 3 parts by weight of 2,4-toluylene diisocyanate as a crosslinking agent. The following comparative examples are the same as those in this example unless otherwise specified.

Here, in Table 1, the dynamic elastic modulus is measured by a measuring machine R manufactured by Rheometric Scientific F.E.
According to DA-II, frequency 1 Hz, measurement temperature 10-4
It is a G ′ value obtained by sandwiching a material between two plates at 0 ° C., rotating one plate, and detecting a torque received by the other plate.

In Table 1, "wafer chipping" means that no chipping or cracking was found in the semiconductor wafer by visual inspection after polishing the sample in which the semiconductor wafer protection sheet was attached to the circuit forming surface of the semiconductor wafer.た was given, and x was found at any one of chips and cracks. In the polishing, the diameter is about 15 cm (6 inches) and the thickness is 400
The thickness of the wafer was measured with a polishing machine (Disco Co., Ltd., back grinder DFG-821F / 8) for 30 samples in which a semiconductor wafer having a height of 100 μm was formed on a semiconductor wafer protection sheet. Was polished until the thickness became 200 μm.

Further, in Table 1, "conformity following unevenness" means that the semiconductor wafer protection sheet was adhered to the circuit-formed surface of the semiconductor wafer, the sample was polished, and the unevenness of the circuit and the semiconductor wafer protection sheet were visually observed. The case where no gap was found between the sheet and the sheet was evaluated as 、, and the case where a gap was found or cooling water or polishing debris entered the gap was evaluated as ×. The polishing was performed in the same manner as the above-described polishing method for measuring the “wafer chip”.

In the present example, the ability to follow the chipping and unevenness of the wafer was evaluated as ○, and the target semiconductor wafer protection sheet was obtained.

In Comparative Example 1 in which the dynamic elastic modulus at 23 ° C. of the foamed resin layer in the example was changed to 10 ⁵ N / cm ² , both the chipping of the wafer and the followability of the unevenness were ×, and the dynamic elastic modulus was 5 × 10 ^{− In} Comparative Example 2 where the density was changed to ³ N / cm ² , the chipping of the wafer was evaluated as x.

In Example, the thickness of the foamed resin layer was set to 600
In Comparative Example 3 in which the thickness was changed to μm, the chipping of the wafer was x, and in Comparative Example 4 in which the thickness was changed to 5 μm, the chipping of the wafer and the followability of the unevenness were both x.

In the examples, the thickness of the pressure-sensitive adhesive layer was set to 200 μm.
In Comparative Example 5 in which the thickness was changed to 2 μm, in Comparative Example 5 in which the thickness was changed to 2 μm, the chipping in the wafer and in the unevenness followability were also evaluated as X.

[0053]

According to the present invention, in a semiconductor wafer protection sheet having a sheet-like support and an adhesive layer laminated on one surface of the support, the support and the adhesive layer are provided. A foamed resin layer is provided between
The dynamic modulus at ^{0 ℃ 1 × 10 -2 ~5 ×} 10 3 N /
cm ² , the thickness is 10 to 500 μm, and the thickness of the pressure-sensitive adhesive layer is 5 to 150 μm, so that when the surface of the semiconductor wafer on which the circuit is not formed is polished, the semiconductor wafer may be chipped. A semiconductor wafer protection sheet which did not crack and did not produce a gap between the circuit and the semiconductor wafer protection sheet was obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masashi Kume 2-3-1-1, Kamakura-shi, Kanagawa Prefecture Inside Toyo Kagaku Co., Ltd. (72) Inventor Kiichi Araki 2-3-1-1, Kamakura-shi, Kanagawa Prefecture Inside Toyo Chemical Co., Ltd. (72) Inventor Takeshi Saito 2-3-1-1, Dai, Kamakura City, Kanagawa Prefecture Toyo Chemical Co., Ltd.

Claims (2)

[Claims] 1. A semiconductor wafer protection sheet having a sheet-shaped support and an adhesive layer laminated on one surface of the support, wherein a foamed resin layer is provided between the support and the adhesive layer. A semiconductor wafer protection sheet provided. 2. The foamed resin layer has a dynamic elastic modulus at 10 to 40 ° C. of 1 × 10 ^{−2 to} 5 × 10 ³ N / cm ² , a thickness of 10 to 500 μm, and a pressure-sensitive adhesive layer. Thickness 5
The semiconductor wafer protection sheet according to claim 1, wherein the thickness is from 150 to 150 m.