TW201729320A - Film for forming protective film - Google Patents

Abstract

Provided is a film for forming a protective film, the film being capable of suppressing a semiconductor chip from being electrostatically destroyed, even if a chip has been picked up having gone through a step for peeling a surface protective film, regardless of the type of surface protective film, and as a result, makes it possible to obtain a semiconductor chip having high quality reliability. This film for forming a protective film is a film for forming a protective film to be provided on the back surface of a circuit forming surface of a semiconductor wafer, and is characterized in that the relative permittivity of the semiconductor wafer and the film at a measurement frequency of 10 Hz satisfies formula (1). (1): |[epsilon]S-[epsilon]F| ≤ 9 (In the formula, εS represents the relative permittivity of the semiconductor wafer at a measurement frequency of 10 Hz, and εF represents the relative permittivity of the film for forming a protective film at a measurement frequency of 10 Hz).

Description

Protective film forming film

The present invention relates to a film for forming a protective film provided on the back surface of a circuit forming surface of a semiconductor wafer, and more particularly to a film for forming a protective film for use in manufacturing a semiconductor wafer mounted in a so-called face down manner.

In recent years, semiconductor devices have been manufactured using a mounting method called a so-called face down method. In the face-down method, a semiconductor wafer (hereinafter simply referred to as a "wafer") having electrodes such as bumps on a circuit surface is used to bond the electrodes to the substrate. Therefore, there is a case where the surface of the wafer opposite to the circuit surface (the back surface of the wafer) is exposed.

It becomes the back side of the exposed wafer and is sometimes protected by an organic film. Conventionally, a wafer having a protective film made of the organic film is obtained by applying a liquid resin to a back surface of a wafer by a spin coating method, drying, curing, and cutting a protective film together with a wafer. However, the thickness precision of the protective film thus formed is insufficient, so that the yield of the product is lowered.

A film for forming a protective film for a wafer having a curable protective film forming layer containing a heat or energy ray hardening component is disclosed (Patent Document 1). Further, when the wafer protected by the back side protective film is picked up from the dicing tape, there is a problem that static electricity is generated and the yield is lowered. Therefore, a method of performing antistatic treatment on the back side protective film is disclosed (Patent Documents 2 and 3, etc.).

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2004-214288

Patent Document 2: Japanese Laid-Open Patent Publication No. 2014-133858

Patent Document 3: Japanese Laid-Open Patent Publication No. 2014-135469

However, in the wafer mounting by the face-down method, the back side of the circuit formation surface of the semiconductor wafer is polished and flaky before the dicing step, and the case is performed on the wafer before the polishing step. The circuit forming surface is for temporarily protecting the surface protective film (also referred to as a film to be polished) of the circuit forming surface, and peeling off the surface protective film during cutting. Depending on the type of the surface protective film to be used, it is known that the semiconductor wafer is charged during the peeling in the subsequent step, and the wafer is further charged by the wafer pick-up after the dicing, and the wafer is destroyed by static electricity.

Accordingly, an object of the present invention is to provide a film for forming a protective film which can suppress the semiconductor wafer from being subjected to static electricity even when the wafer subjected to the step of peeling off the surface protective film is picked up by mounting the semiconductor wafer facing downward. Destruction, the result is high quality and reliability Semiconductor wafer.

As a result of the positive review, the present inventors have obtained the following findings: when the relative dielectric constant of the measurement frequency of the protective film forming film of 10 Hz and the measurement frequency of the semiconductor wafer of 10 Hz are set within a specific range, Even when the wafer subjected to the step of peeling off the surface protective film is picked up, the wafer can be prevented from being subjected to electrostatic breakdown, and as a result, the reliability of the wafer can be improved. According to the invention, the following film for forming a protective film is provided.

The film for forming a protective film of the present invention is a film for forming a protective film provided on the back surface of a circuit formation surface of a semiconductor wafer, and is characterized by a relative dielectric constant of a measurement frequency of 10 Hz of the semiconductor wafer and the film. The following formula (1) is satisfied: | ε _S - ε _F | ≦ 9 (1) (wherein ε _S represents a relative dielectric constant of a semiconductor wafer having a measurement frequency of 10 Hz, and ε _F represents a protective film formation at a measurement frequency of 10 Hz. Use the relative dielectric constant of the film).

In the aspect of the invention, the semiconductor wafer may be a germanium wafer.

In the aspect of the invention, the film for forming a protective film can be directly provided in contact with the back surface of the circuit formation surface of the semiconductor wafer.

In the aspect of the invention, the film for forming a protective film may further include a peelable support.

According to the present invention, by setting the relative dielectric constant of the measurement frequency of the protective film forming film to 10 Hz and the relative dielectric constant of the measurement frequency of the semiconductor wafer of 10 Hz within a specific range, even the step of peeling off the surface protective film When the wafer is picked up, regardless of the type of the surface protective film, the semiconductor wafer can be prevented from being subjected to electrostatic breakdown, and as a result, a semiconductor wafer having high reliability can be obtained.

[film for forming a protective film]

The film for forming a protective film of the present invention will be described. The film for forming a protective film of the present invention is a film for forming a protective film provided on the back surface of a circuit formation surface of a semiconductor wafer, characterized in that the relative dielectric constant of the semiconductor wafer and the film at a measurement frequency of 10 Hz is satisfied. The following formula (1): | ε _S - ε _F | ≦ 9 (1) (wherein ε _S represents a relative dielectric constant of a semiconductor wafer having a measurement frequency of 10 Hz, and ε _F represents a formation of a protective film having a measurement frequency of 10 Hz. The relative dielectric constant of the film). Since it is possible to prevent electrostatic breakdown of the wafer due to static electricity generated when the semiconductor wafer is picked up after the dicing, it is also possible to provide a cationic type between the dicing tape and the semiconductor wafer as proposed in Patent Documents 2 and 3 and the like. An adhesive layer of an antistatic agent or a conductive substance. However, in the manufacture of the semiconductor wafer described above, before the polishing step of the semiconductor wafer, the surface protective film provided on the surface of the circuit is peeled off, and then the cutting step is performed, but the effect on peeling off the surface protective film has hitherto been Not considered. Therefore, in the present invention, the protective film of the surface of the surface of the semiconductor wafer provided before the surface protective tape is peeled off by the material having the specific relative dielectric constant is formed, even if the wafer subjected to the step of peeling off the surface protective film is picked up. When the type of the surface protective film is used, it is possible to suppress the semiconductor wafer from being subjected to electrostatic breakdown, and as a result, a semiconductor wafer having high reliability can be obtained.

In the present invention, it is found that the static electricity generated at the time of peeling is related to the difference in relative dielectric constant between the semiconductor wafer and the protective film forming film in a low frequency region of about 10 Hz, which generally reflects the interface polarization of the object to be measured. The film for forming a protective film which satisfies the relationship of the above formula (1) can suppress the semiconductor wafer from being damaged by static electricity regardless of the type of the surface protective film. Here, the "relative dielectric constant" in the present specification means that 38 mm of a donut-shaped guard electrode is formed on the outer side of the measurement object on one side. The silver paste electrode forms a larger area electrode on the opposite side opposite to the front electrode, and the sample is placed in the measurement environment at 23 ° C, 50% RH for one day, and then an LCR meter (for example, the day-mounted power mechanism LCR meter IM3536) is used. The test voltage (signal voltage) was 0.5 V, and the measurement frequency was 10 Hz. The relative dielectric constant was continuously measured 256 times, and it means the average value. In order to more accurately measure the relative dielectric constant at a measurement frequency of 10 Hz, it is preferred to measure the sample in a parallel shape by forming the sample into a capacitor shape.

The above interface is divided into a phenomenon in which the dielectric body is a heterogeneous dispersion formed by a plurality of different components, and the charge is accumulated at the interface of the uneven portion (that is, the interface of different kinds of substances), especially at 1×. Observed in the low frequency region below 10 ⁴ Hz. Moreover, the ratio of the dielectric constant (ε) of the relative dielectric constant medium to the dielectric constant (ε ₀ ) of the vacuum (ε _r ), and the dielectric constant (ε) of the medium are determined by the dielectric polarization specification of the medium. The median physical property value is determined, but the relative dielectric constant depends on the medium depending on the frequency of the measurement. By bringing the relative dielectric constant of the film for forming a protective film in such a low-frequency region closer to the relative dielectric constant of the semiconductor wafer, the static electricity (peeling withstand voltage) generated when the film for forming a protective film is peeled off from the semiconductor wafer can be reduced. For the expectation of outsiders.

In the present invention, when the absolute value of the difference in the relative dielectric constant of the measurement frequency of the semiconductor wafer and the film for forming a protective film of 10 Hz exceeds 9, it is not possible to effectively prevent the semiconductor wafer from being electrostatically damaged by the static electricity generated when the semiconductor wafer is picked up or the like. . The absolute value of the difference in the relative dielectric constant is preferably 8.9 or less, more preferably 8.8 or less, still more preferably 8.7 or less.

The semiconductor wafer to be used as the film for forming a protective film is not particularly limited, and a wafer known as a semiconductor material can be used. For example, various semiconductor wafers such as a germanium wafer, a GaAs wafer, a SiC wafer, and a GaN wafer are preferable, but a highly used germanium wafer is preferable.

The following is for forming a protective film which satisfies the above formula (1). The components of the film are detailed. As a characteristic required for a film for forming a protective film for a semiconductor wafer, at least (i) a film (or a sheet) shape can be maintained, and (ii) an initial adhesive property can be adhered to the back surface of the polished semiconductor, and further (iii) The protective film can be formed by adhering the film for forming a protective film to the back surface of the semiconductor wafer. In order to satisfy the above-mentioned requirements, as a component constituting the film for forming a protective film, a polymer component imparting a film-forming polymer component or a reactive film imparting property, a curable component, a curing-promoting component, and an inorganic filler component, The coloring agent component, the coupling agent component, and the like are not limited to these components, and appropriate components and the like may be added depending on the use of the semiconductor wafer.

On the other hand, in order to make the absolute value of the difference of the relative dielectric constant of the measurement frequency of the semiconductor wafer and the film for forming a protective film of 10 Hz 9 or less, it is necessary to adjust the relative dielectric constant of the measurement frequency of the film for forming a protective film of 10 Hz. (ε _F ). The relative dielectric constant (ε _F ) at a measurement frequency of 10 Hz of the film for forming a protective film can be set to a desired range by appropriately adjusting the type or amount of each component described later. For example, the relative dielectric constant (ε _M ) at a measurement frequency of 10 Hz of the organic material component such as a polymer component or a curable component described later is considerably smaller than the relative dielectric constant (ε _S ) of the semiconductor wafer at a measurement frequency of 10 Hz. When the value is |ε _S - ε _M |>9, the semiconductor wafer can be made by adjusting the type, shape, size, amount, and the like of the inorganic filler or the like which is insoluble in the organic material component. The absolute value (|ε _S - ε _F |) of the difference in the relative dielectric constant of the measurement frequency of the protective film forming film of 10 Hz is 9 or less. Further, by using a relative dielectric constant (ε _M ) at a measurement frequency of 10 Hz of the organic material component and a relative dielectric constant (ε _I ) at a measurement frequency of 10 Hz which is a component insoluble in the organic material component, |ε _S - ε is satisfied. _M |≦9 and |ε _S -ε _I |≦9 The material selection can be easily adjusted so that the relative dielectric constant (ε _F ) of the measurement frequency of the film for forming a protective film of 10 Hz satisfies |ε _S -ε _F |≦9 .

<Polymer composition imparting film properties>

The film for forming a protective film of the present invention must contain a component capable of maintaining the shape of the film (or the sheet) in order to function as a protective film on the back surface of the semiconductor. In addition, in the present specification, the polymer component to which the film property is imparted is distinguished from the film-forming polymer component which is reactive as described later, and means a polymer component which does not have a reactive functional group. Examples of the film-forming polymer component include a thermoplastic polyhydroxy polyether resin, a phenoxy resin of a condensation product of epichlorohydrin and various bifunctional phenol compounds, or a hydroxyl group of a hydroxyether moiety present in the skeleton. A phenoxy resin, a polyvinyl acetal resin, a polyamide resin, a polyamidimide resin, a block copolymer or the like which is esterified with an acid anhydride or ruthenium chloride. These polymers may be used alone or in combination of two or more. In order to maintain the shape of the film (or even the sheet), the weight average molecular weight (Mw) of the polymers is usually 2 × 10 ⁴ or more, more preferably 2 × 10 ⁴ to 3 × 10 ⁶ .

In the present specification, the value of the weight average molecular weight (Mw) can be measured by a gel permeation chromatography (GPC) method (polystyrene standard) under the following measurement apparatus and measurement conditions.

Measuring device: "Waters 2695" by Waters

Detector: "Waters 2414" by Waters, RI (differential refractive index) meter)

Pipe column: "HSPgel Column, HR MB-L, 3 μm, 6 mm × 150 mm" manufactured by Waters × HSPgel Column, HR 1.3 μm, 6 mm × 150 mm × 2

Determination conditions:

Column temperature: 40 ° C

RI detector set temperature: 35 ° C

Developing solvent: tetrahydrofuran

Flow rate: 0.5ml/min

Sample size: 10μl

Sample concentration: 0.7wt%

The polyvinyl acetal resin can be obtained, for example, by acetalizing a polyvinyl alcohol resin with an aldehyde. The aldehyde is not particularly limited, and examples thereof include, for example, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and the like.

Specific examples of the phenoxy resin are FX280, FX293 manufactured by Dongdu Chemical Co., Ltd., YX8100, YL6954, and YL6974 manufactured by Mitsubishi Chemical Corporation.

Specific examples of the polyvinyl acetal resin are S-LEC KS series manufactured by Sekisui Chemical Co., Ltd., and polyamine resin is exemplified by KS5000 series manufactured by Hitachi Chemical Co., Ltd., BP series manufactured by Nippon Kasei Co., Ltd., and polyamidoximine resin. It is a KS9000 series manufactured by Hitachi Chemical Co., Ltd.

The thermoplastic polyhydroxy polyether resin has excellent heat resistance due to its high glass transition point when it has an olefin skeleton, and can be semi-solid or The solid epoxy resin maintains a low coefficient of thermal expansion and maintains its glass transition point, so that the resulting hardened film can be well-balanced while having a low coefficient of thermal expansion and a high glass transition point. Further, since the thermoplastic polyhydroxy polyether resin has a hydroxyl group, it exhibits good adhesion to a semiconductor wafer.

The polymer component to which the film property is imparted may be a block copolymerization of a monomer constituting the above component. A copolymer in which two or more kinds of polymers having different properties of a block copolymer are covalently bonded to each other to form a long-chain molecular structure. The block copolymer is preferably an X-Y-X type or an X-Y-X' type block copolymer. In the XYX type or XY-X' type block copolymer, it is preferred that the glass transition temperature (Tg) of the central portion Y is a soft block, and the glass transition temperature of the outer side A or X' is a hard block. (Tg) is higher than the polymer unit of the central Y block. The glass transition temperature (Tg) is determined by differential scanning calorimetry (DSC).

Further, in the XYX type or XY-X' type block copolymer, it is more preferable that X or X' is formed of a polymer unit having a Tg of 50 ° C or more, and a glass transition temperature (Tg) of B is X or X'. A block copolymer formed of polymer units having a Tg or less. Further, in the XYX-type or XY-X'-type block copolymer, it is preferred that the X or X' system has a higher compatibility with a curable component to be described later, and preferably the compatibility between the Y-based and the curable component is lower. . As described above, it is considered that a block copolymer in which the both terminal blocks are compatible with the matrix (curable component) and the intermediate block is incompatible with the matrix (curable component) is considered to have a specific structure in the matrix.

Among the above various polymers, particularly preferred are phenoxy resins, polyvinyl acetal resins, and thermoplastic polyhydroxy polyethers having an olefin skeleton. Resin, block copolymer.

The ratio of the polymer component which imparts film properties to all the components constituting the film for forming a protective film is not particularly limited, and when the total of all the components is 100 parts by mass, it is preferably 10 to 50 parts by mass, more preferably 15 to 45 parts by mass.

<Reactivity imparting a film-forming polymer component>

The component constituting the film for forming a protective film may further contain a polymer component capable of imparting film properties by reacting with a curable component to be described later. As the reactive film-imparting polymer, a carboxyl group-containing resin or a phenol resin is preferably used. When a resin containing a carboxyl group is used, when an epoxy resin is contained as a curable component, it is easy to react with an epoxy resin, and it is preferable to provide film formability and to improve the characteristics as a semiconductor protective film.

As the carboxyl group-containing resin, the following (1) to (7) can be preferably used.

(1) A diisocyanate such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate or an aromatic diisocyanate, and a carboxyl group of dimethylolpropionic acid or dimethylolbutanoic acid. A diol compound, a polycarbonate-based polyol, a polyether-based polyol, a polyester-based polyol, a polyolefin-based polyol, a bisphenol A-based alkylene oxide adduct diol, a phenolic hydroxyl group, and an alcoholic hydroxyl group a carboxyl group-containing urethane resin obtained by a polyaddition reaction of a diol compound such as a compound, and (2) a carboxyl group-containing compound obtained by a polyaddition reaction of a diisocyanate and a carboxyl group-containing diol compound Urethane resin, (3) by copolymerization of an unsaturated carboxylic acid such as (meth)acrylic acid with a compound containing an unsaturated group such as styrene, α-methylstyrene, a lower alkyl (meth)acrylate or isobutylene a carboxyl group-containing resin, (4) reacting a bifunctional epoxy resin or a bifunctional oxetane resin with a dicarboxylic acid such as phthalic acid or hexahydrophthalic acid to form an o-benzene group a carboxyl group-containing polyester resin obtained by dibasic acid anhydride such as dicarboxylic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride, and (5) opening epoxy resin or oxetane resin a carboxyl group-containing resin obtained by reacting a generated hydroxyl group with a polybasic acid anhydride, and (6) a compound having a plurality of phenolic hydroxyl groups in one molecule, that is, an epoxy resin of a polyphenol compound and ethylene oxide or propylene oxide. a carboxyl group-containing resin obtained by reacting a reaction product of a polyhydric alcohol resin obtained by an alkane reaction with a polybasic acid anhydride, and (7) a compound having a plurality of phenolic hydroxyl groups in one molecule, that is, a polyphenol compound and an epoxy resin Reaction product of polyalcohol resin obtained by reacting alkylene oxide such as ethane or propylene oxide with (meth) propyl A resin such as a carboxyl group-containing resin obtained by reacting a reaction product obtained by reacting a monocarboxylic acid having an unsaturated group such as an olefinic acid with a polybasic acid anhydride can be preferably used. In the present specification, the term "(meth)acrylate" means acrylate, methacrylate, and a mixture thereof.

Among the above resins, in particular, since the above (1), (2), (6) and (7) do not contain chlorine, they can be used as a non-photosensitive carboxyl group-containing resin. The resins of the above (6) and (7) are preferred because of a good balance of all the characteristics.

The weight average molecular weight of the reactive film-imparting polymer varies depending on the resin skeleton, but is generally preferably in the range of 2 × 10 ³ to 1.5 × 10 ⁵ , more preferably in the range of 3 × 10 ³ to 1 × 10 ⁵ . However, it is not limited to these ranges.

The ratio of the polymer component which contributes to the filminess of the reactivity of all the components constituting the film for forming a protective film is not particularly limited. For example, it is preferably from 20 to 60 parts by mass based on 100 parts by mass of the film-forming polymer. The replacement is a polymer which imparts film properties to reactivity.

<hardenable ingredients>

The curable component may be any component which is hardened by heat and a component which is hardened by ionizing radiation such as ultraviolet rays or electron beams, but is preferably a component which is hardened by heat. Hereinafter, the thermosetting component will be described, but it is not intended to exclude a component which is hardened by ionizing radiation.

The thermosetting component can be a conventionally used resin without any particular limitation, but an epoxy resin is preferably used. The epoxy resin has a solid, semi-solid, liquid epoxy resin based on the shape before the reaction. These may be used alone or in combination of two or more.

The solid epoxy resin is exemplified by HP-4700 (naphthalene epoxy resin) manufactured by DIC Corporation, EXA4700 (4-functional naphthalene epoxy resin) manufactured by DIC Corporation, and NC-7000 manufactured by Nippon Kayaku Co., Ltd. (polyfunctional solid containing naphthalene skeleton) A naphthalene type epoxy resin such as epoxy resin; an epoxide of a condensate of a phenol such as EPPN-502H (trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd. and an aromatic aldehyde having a phenolic hydroxyl group (trisphenol) Epoxy resin); dicyclopentadienyl aralkyl type epoxy resin such as EPICLON HP-7200H (multifunctional solid epoxy resin containing dicyclopentadiene skeleton) manufactured by DIC Corporation; Nippon Chemical Co., Ltd. a biphenyl aralkyl type epoxy resin such as NC-3000H (multifunctional solid epoxy resin containing a biphenyl skeleton); a biphenyl/phenol novolak type epoxy resin such as NC-3000L manufactured by Nippon Kayaku Co., Ltd.; EPICLON N660, EPICLON N690 manufactured by DIC Corporation, phenolic varnish type epoxy resin such as EOCN-104S manufactured by Nippon Kayaku Co., Ltd.; biphenyl type epoxy resin such as YX-4000 manufactured by Mitsubishi Chemical Corporation; TX0712 manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd. Phosphorus-containing epoxy resin; ginseng (2,3-epoxypropyl)isocyanurate such as TEPIC manufactured by Nissan Chemical Industries Co., Ltd.

Examples of the semi-solid epoxy resin are EPICLON 860, EPICLON 900-IM, EPICLON EXA-4816, EPICLON EXA-4822, ARALDITE AER280 manufactured by Asahi Kasho Co., Ltd., Etoto YD-134 manufactured by Tosho Kasei Co., Ltd., and jER834 manufactured by Mitsubishi Chemical Corporation. , jER872, bisphenol A epoxy resin such as ELA-134 manufactured by Sumitomo Chemical Industries Co., Ltd.; naphthalene epoxy resin such as EPICLON HP-4032 manufactured by DIC Corporation; phenol novolak type epoxy resin such as EPICLON N-740 manufactured by DIC Corporation Oxygen resin, etc.

The liquid epoxy resin is exemplified by bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenol novolak type epoxy resin, and third butyl catechol type epoxy resin. , glycidylamine type epoxy resin, aminophenol type epoxy resin, alicyclic epoxy resin, and the like.

These curable components may be used alone or in combination of two or more. The amount of the curable component is preferably 10 to 50 parts by weight, more preferably 20 to 40 parts by weight, based on 100 parts by weight of the total of the film-forming polymer and the reactive film-forming polymer. And better It is 20 to 35 parts by mass. In addition, when the liquid epoxy resin is blended, the glass transition temperature (Tg) of the cured product is lowered, and the crack resistance is deteriorated. Therefore, the blending amount of the liquid epoxy resin is adjusted to the entire curable component. It is preferably 0 to 45 parts by weight, more preferably 0 to 30 parts by weight, particularly preferably 0 to 5 parts by weight.

<hardener composition>

The component constituting the film for forming a protective film of the present invention may further contain a curing agent component. The hardener component is a functional group that reacts with the above curable component. The hardener component is exemplified by a phenol resin, a polycarboxylic acid and an acid anhydride thereof, a cyanate resin, an active ester resin, and the like. These may be used alone or in combination of two or more.

The phenol resin may be used singly or in combination of two or more kinds of phenol novolak resins, alkylphenol novolac resins, bisphenol A novolak resins, dicyclopentadiene type phenol resins, Xylok type phenol resins, and terpene modification. Conventionally known as phenol resin, cresol/naphthol resin, polyvinyl phenol, phenol/naphthol resin, phenol resin containing α-naphthol skeleton, cresol novolak resin containing triazine, and the like.

The polycarboxylic acid and its anhydride are compounds having two or more carboxyl groups in one molecule thereof and an acid anhydride thereof, and examples thereof include a copolymer of (meth)acrylic acid, a copolymer of maleic anhydride, a condensate of a dibasic acid, and the like, and a carboxy group. A resin having a carboxylic acid terminal such as an acid terminal quinone imine resin.

The cyanate resin is a compound having two or more cyanate groups (-OCN) in one molecule. The cyanate resin can be used in any of the conventional ones. By. The cyanate resin is exemplified by, for example, a phenol novolak type cyanate resin, an alkylphenol type cyanate resin, a dicyclopentadiene type cyanate resin, a bisphenol A type cyanate resin, and a bisphenol F type cyanate. An acid ester resin or a bisphenol S type cyanate resin. Further, it may be a part of the triazine-formed prepolymer.

The active ester resin is a resin having two or more active ester groups in one molecule. The active ester resin is generally obtained by a condensation reaction of a carboxylic acid compound and a hydroxy compound. Among them, an active ester compound obtained as a phenol compound or a naphthol compound of a hydroxy compound is preferably used. Examples of the phenol compound or the naphthol compound are hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylation. Bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene , 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, dicyclopentadiene diphenol, phenol novolac Wait.

As the hardener component, in addition to the above, an alicyclic olefin polymer can also be used. The alicyclic olefin polymer which can be preferably used is exemplified by (1) an alicyclic olefin having a carboxyl group and/or a carboxylic acid anhydride group (hereinafter referred to as "carboxy group or the like"), and other monomer copolymerized as needed, (2) an aromatic ring moiety of a (co)polymer obtained by copolymerizing an aromatic olefin having a carboxyl group or the like with another monomer as required, and (3) an alicyclic olefin having no carboxyl group or the like and having (4) an aromatic ring portion of a copolymer obtained by copolymerizing an aromatic olefin having no carboxyl group or the like with a monomer having a carboxyl group, etc., and (5) by a modification reaction Will have a carboxyl group Or the like, or (6) a carboxylate group of an alicyclic olefin polymer having a carboxylate group obtained by the above (1) to (5) It is converted into a carboxyl group by, for example, hydrolysis or the like.

Among the above hardener components, a phenol resin, a cyanate resin, an active ester resin, and an alicyclic olefin polymer are particularly preferable. In particular, the phenol resin is preferably used in order to make the polarity high and to easily adjust the relative dielectric constant.

The hardener component is preferably a ratio of a functional group (a functional group capable of hardening reaction) such as an epoxy group of a curable component to a functional group of a hardener component which can be reacted with the functional group (functionality of a hardener component) The number of functional groups of the base/curable component: the equivalent ratio) is contained in a ratio of 0.2 to 5. When the equivalent ratio is in the above range, a film for forming a protective film which is more excellent in protective properties can be obtained.

<hardening accelerator component>

The component constituting the film for forming a protective film of the present invention may further contain a curing accelerator component. The curing accelerator component promotes the curing reaction of the curable component, and the adhesion and heat resistance of the protective film to the semiconductor wafer can be further improved. Examples of the hardening accelerator component are imidazole and its derivatives; anthraquinones such as acetamidine and benzoquinone; diaminodiphenylmethane, m-phenylenediamine, m-xylylenediamine, and diaminodiphenyl. Polyamines such as sulfonium, dicyanodiamine, urea, urea derivatives, melamine, polyfluorene, etc.; organic acid salts and/or epoxy adducts; amine trifluoride complexes a triazine derivative such as ethylenediamine-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-dimethylphenyl-S-triazine; Trimethylamine, triethanolamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexakis(N-methyl)melamine, 2,4,6-ginole (dimethylaminophenol), tetramethylguanidine, m-amino group Amines such as phenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac; tributylphosphine, triphenylphosphine, gin-2-cyanoethylphosphine And other organic phosphines; tri-n-butyl (2,5-dihydroxyphenyl) ruthenium bromide, cetyltributylphosphonium chloride and the like sulfonium salts; benzyltrimethylammonium chloride, a 4-grade ammonium salt such as phenyltributylammonium chloride; the above polybasic acid anhydride; diphenylphosphonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyridine Photocationic polymerization catalyst such as hexafluorophosphate; styrene-maleic anhydride resin; molar reactant such as phenylisocyanurate and dimethylamine or tolyl diisocyanate, isophorone diisocyanate, etc. A conventionally used hardening accelerator such as an organic polyisocyanate, a dimethylamine or the like, a metal catalyst, or the like can be used alone or in combination of two or more.

The hardening accelerator component is not essential, but it is preferably used in an amount of 0.01 to 20 parts by mass based on 100 parts by mass of the curable component, in particular, when the curing reaction is promoted. When a metal catalyst is used as the curing accelerator component, the content thereof is preferably from 10 to 550 ppm, more preferably from 25 to 200 ppm, based on 100 parts by mass of the curable component.

<Inorganic filler ingredients>

The film for forming a protective film of the present invention may further contain an inorganic filler component. The protection of the semiconductor wafer during dicing is facilitated by the inclusion of the inorganic filler component. Moreover, by applying a laser mark to the protective film, the inorganic filler component is exposed at a portion cut by the laser light, and the reflected light is expanded. The discoloration presents an approximation of white color. Therefore, when the film for forming a protective film contains a coloring agent component to be described later, a contrast difference is obtained between the laser mark portion and the other portion, and the mark (printing) is made effective.

The inorganic filler is not dissolved in the organic material component constituting the film for forming a protective film, and is dispersed in the organic material component. Therefore, due to the presence of an interface between the organic material component and the insoluble component, an interface polarization is generated. The relative dielectric constant of the measurement frequency of the protective film forming film of 10 Hz can be adjusted by controlling the interface polarization, but the organic material component is selected and the organic material is selected from the semiconductor dielectric wafer having a relative dielectric constant of 10 Hz. Both the insoluble components (for example, the inorganic filler component) in the material component can easily adjust the relative dielectric constant of the film for forming a protective film to a specific range.

The inorganic filler component can be used without any limitation, for example, a powder such as cerium oxide, aluminum oxide, talc, aluminum hydroxide, calcium carbonate, titanium oxide, iron oxide, cerium carbide, boron nitride, or the like. The spheroidized bead, the single crystal fiber, the glass fiber, or the like may be used alone or in combination of two or more. However, when a component which does not dissolve in an organic material component, such as an inorganic filler component, is contained in the film for protective film formation, when the insoluble component type increases, the relative dielectric constant of the measurement frequency of 10 Hz may become large. The relative dielectric constant of the film for forming a protective film cannot be determined solely by the type of the component which is not dissolved in the organic material component, but the less the type of the insoluble component, the better, preferably the component within 5 types, more preferably 3 types. Within. Among the above inorganic filler components, in order to control the relative dielectric constant in the film, cerium oxide, aluminum oxide, and titanium oxide are preferred.

The inorganic filler component is dispersed in the organic material component, but is dispersed, and becomes a non-uniform dispersion state. Since the difference in relative dielectric constant of the semiconductor wafer and the film for forming a protective film at a measurement frequency of 10 Hz is 9 or less, the interface between the organic material component and the inorganic filler component is reduced, and the influence of the interface polarization and the control of the interface are easily defined. The electrical constant is therefore preferred. Therefore, in the case of an inorganic filler having the same average particle diameter, those having a particle shape of approximately spherical shape are more preferable than those of an amorphous one. In addition, when the organic material component and the inorganic filler component are contained in the film for forming a protective film, the relative dielectric of the film for forming a protective film at a measurement frequency of 10 Hz can be adjusted by the average particle diameter of the inorganic filler or the amount thereof. constant.

The inorganic filler component preferably has an average particle diameter of preferably 0.01 to 15 μm, more preferably 0.02 to 12 μm, and particularly preferably 0.03 to 10 μm. In the present specification, the average particle diameter is a number average particle diameter calculated by measuring the long axis diameter of 20 inorganic fillers by an electron microscope and calculating the arithmetic mean value.

The content of the inorganic filler component is preferably from 10 to 400 parts by mass, more preferably from 30 to 350 parts by mass, even more preferably from 60 to 350 parts by mass, based on 100 parts by mass of the total non-volatile organic component constituting the film for forming a protective film. 300 parts by mass.

Further, when the film for forming a protective film contains a component which is not dissolved in the organic material component such as an inorganic filler component, it is easily limited to the influence of the interface polarization of the interface between the inorganic filler component and the organic component, and the relative dielectric constant is controlled. From the viewpoint, the smaller the surface area of the inorganic filler component, the better. For example, when the inorganic filler component is contained in a film for forming a protective film at a ratio of 20% by mass or more, the inorganic filler component having a specific surface area of 10 m ² /g or less is selected, whereby the interface polarization is easily adjusted.

On the other hand, when the specific surface area of the component which is not dissolved in the organic material component, such as an inorganic filler component, exceeds 10 m ² /g, when the component is dispersed in the organic material component, the film for protective film formation is measured. The case where the relative dielectric constant of the frequency of 10 Hz becomes large. Therefore, it is preferable that the inorganic filler component having a specific surface area of more than 10 m ² /g is contained in the film for forming a protective film in a ratio of 10% by mass or less. In addition, by adjusting the amount of the component to be used in the film for forming a protective film by the size of the specific surface area of the component which is not dissolved in the organic material component, the relative dielectric constant at a measurement frequency of 10 Hz of the film for forming a protective film can be expected. .

<Colorant ingredients>

The film for forming a protective film of the present invention may further contain a colorant component. When the semiconductor wafer having the protective film is mounted on the device by including the coloring agent component, malfunction of the semiconductor device due to infrared rays generated from the surrounding device can be prevented. Further, when the protective film is imprinted by means of a laser mark or the like, it is easy to recognize marks such as characters and symbols. That is, in the semiconductor wafer in which the protective film is formed, the product number is printed on the surface of the protective film by a conventional laser marking method (a method of printing by removing the surface of the protective film by laser light), but by The protective film contains a coloring agent, and the difference in contrast between the portion of the protective film which is removed by the laser light and the uncut portion can be sufficiently obtained to improve the visibility.

The coloring agent component may be used alone or in combination of two. The organic or inorganic pigments and dyes are preferred, but the viewpoint of electromagnetic wave or infrared shielding is preferably a black pigment. As the black pigment, carbon black, black, iron oxide, manganese dioxide, aniline black, activated carbon or the like can be used, but it is not limited thereto. From the viewpoint of preventing the malfunction of the semiconductor device, carbon black is particularly preferable. Further, instead of carbon black, pigments or dyes such as red, blue, green, and yellow may be mixed to form a black color or a color close to the black color.

Red colorants are monoazo, bisazo, azo lake, benzimidazolone, lanthanide, diketopyrrolopyrrole, condensed azo, hydrazine The quinacridone system, etc. are specifically mentioned below. Pigment red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151, 170, a monoazo red coloring agent of 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269, etc., a disazo red coloring agent of pigment red 37, 38, 41, etc. Pigment Red 48:1, 48:2, 48:3, 48:4, 49:1, 49:2, 50:1, 52:1, 52:2, 53:1, 53:2, 57:1 58:4, 63:1, 63:2, 64:1, 68, etc., single azo lake red coloring agent, pigment red 171, pigment red 175, pigment red 176, pigment red 185, pigment red 208, etc. Benzimidazolone red colorant, solvent red 135, solvent red 179, pigment red 123, pigment red 149, pigment red 166, pigment red 178, pigment red 179, pigment red 190, pigment red 194, pigment red 224, etc. Lanthanide red colorant, pigment red 254, pigment red 255, pigment red 264, pigment red 270, pigment red 272, etc. diketopyrrolopyrrole red colorant, pigment red 220, pigment red 144, pigment red 166, Condensed azo red colorant such as Pigment Red 214, Pigment Red 220, Pigment Red 221, Pigment Red 242, Pigment Red 168, Pigment Red 177, Pigment Red 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent The red 207 or the like is a red colorant, a quinacridone red coloring agent such as Pigment Red 122, Pigment Red 202, Pigment Red 206, Pigment Red 207, and Pigment Red 209.

Blue coloring agents include phthalocyanines, lanthanides, etc., and pigment systems are classified as pigments, specifically pigment blue 15, pigment blue 15:1, pigment blue 15:2, pigment blue 15:3, Pigment blue 15:4, pigment blue 15:6, pigment blue 16, pigment blue 60 and the like. As the dye system, solvent blue 35, solvent blue 63, solvent blue 68, solvent blue 70, solvent blue 83, solvent blue 87, solvent blue 94, solvent blue 97, solvent blue 122, solvent blue 136, solvent blue 67, solvent can be used. Blue 70 and so on. Further, in addition to the above, a phthalocyanine compound substituted with a metal or without a metal may be used.

The green coloring agent is also a phthalocyanine system, an anthraquinone system, an anthraquinone system or the like. Specifically, Pigment Green 7, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, Solvent Green 28, and the like can be used. In addition to the above, a phthalocyanine compound substituted with a metal or without a metal may also be used.

The yellow coloring agent is exemplified by a monoazo type, a bisazo type, a condensed azo type, a benzimidazolone type, an isoindole type, an anthraquinone type, etc., and the following are specifically mentioned. The solvent yellow 163, the pigment yellow 24, the pigment yellow 108, the pigment yellow 193, the pigment yellow 147, the pigment yellow 199, the pigment yellow 202 and the like can be used as the bismuth yellow coloring agent, the pigment yellow 110, the pigment yellow 109, the pigment yellow 139, Pigment yellow 179, pigment yellow 185, etc. Agent, Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 128, Pigment Yellow 155, Pigment Yellow 166, Pigment Yellow 180, etc. Condensed Azo Yellow Colorant, Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154 Benzomidazolone yellow coloring agent, pigment yellow 156, pigment yellow 175, pigment yellow 181, etc., pigment yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62:1 , mono-azo yellow colorants of 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, 183, etc., pigment yellow 12, 13, 14, 16 A bisazo-based yellow coloring agent such as 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, and 198.

Further, a coloring agent such as purple, orange, brown, or black may be added for the purpose of adjusting the color tone. For specific examples, for example, Pigment Violet 19, 23, 29, 32, 36, 38, 42, Solvent Violet 13, 36, CI Pigment Orange 1, CI Pigment Orange 5, CI Pigment Orange 13, CI Pigment Orange 14, CI Pigment Orange 16, CI Pigment Orange 17, CI Pigment Orange 24, CI Pigment Orange 34, CI Pigment Orange 36, CI Pigment Orange 38, CI Pigment Orange 40, CI Pigment Orange 43, CI Pigment Orange 46, CI Pigment Orange 49, CI Pigment Orange 51, CI Pigment Orange 61, CI Pigment Orange 63, CI Pigment Orange 64, CI Pigment Orange 71, CI Pigment Orange 73, CI Pigment Brown 23, CI Pigment Brown 25, CI Pigment Black 1, CI Pigment Black 7, and the like.

In the above colorant component, the pigment is equal to the organic material component and is dispersed in a non-uniform dispersion state. Therefore, similarly to the inorganic filler component, it is possible to control the formation of the protective film not only by the kind or the amount of the colorant component but also by the shape or specific surface area of the colorant component. The film was measured at a relative dielectric constant of 10 Hz.

The colorant component is preferably contained in an amount of from 0.1 to 35 parts by mass, more preferably from 0.5 to 25 parts by mass, particularly preferably from 1 to 15 parts by mass, per 100 parts by mass of the total solid content of the film for forming a protective film.

<coupler component>

In order to improve the adhesion of the film for forming a protective film to the adherend (semiconductor wafer), the adhesion, and/or the agglomeration of the protective film, a functional group reactive with an inorganic substance and a functional group reactive with an organic functional group may be contained. The coupling component of the base. Further, by containing the coupling agent component, the heat resistance of the protective film obtained by curing the film for forming a protective film can be prevented, and the water resistance can be improved. Examples of such a coupling agent include a titanate coupling agent, an aluminate coupling agent, a decane coupling agent, and the like. Preferred among these are decane coupling agents.

The organic group contained in the decane coupling agent is exemplified by, for example, a vinyl group, an epoxy group, a styryl group, a methacryloxy group, an acryloxy group, an amine group, a urea group, a chloropropyl group, a fluorenyl group, a polysulfide group. An ether group, an isocyanate group or the like. As the decane coupling agent, a commercially available one can be used, and for example, KA-1003, KBM-1003, KBE-1003, KBM-303, KBM-403, KBE-402, KBE-403, KBM-1403, KBM-502, KBM can be exemplified. -503, KBE-502, KBE-503, KBM-5103, KBM-602, KBM-603, KBE-603, KBM-903, KBE-903, KBE-9103, KBM-9103, KBM-573, KBM-575 , KBM-6123, KBE-585, KBM-703, KBM-802, KBM-803, KBE-846, KBE-9007 (all are trade names; manufactured by Shin-Etsu Chemical Co., Ltd.). These can be made separately One type may be used in combination of two or more types.

<Other ingredients>

In addition to the above components, the film for forming a protective film of the present invention may be formulated with various additives as needed. As various additives, for example, a leveling agent, a plasticizer, an antioxidant, an ion scavenger, an aggregating agent, a chain transfer agent, a release agent, and the like.

The thickness of the film for forming a protective film is not particularly limited, but is preferably from 3 to 300 μm, more preferably from 5 to 250 μm, particularly preferably from 7 to 200 μm.

The film for forming a protective film of the present invention has initial adhesion and thermosetting properties, and can be easily adhered to by pressing on a semiconductor wafer, a wafer, or the like in an uncured state. Further, any means for heating and pressurizing the film for forming a protective film can be applied at the time of pressing. Moreover, after thermal hardening, a protective film having high impact resistance can be formed. The protective film formed using the film for forming a protective film of the present invention is excellent in strength, and can maintain sufficient protective function under strict high temperature and high humidity conditions. Further, the film for forming a protective film may have a single layer structure or a multilayer structure.

The maximum transmittance of the wavelength of 300 to 1200 nm of the film for forming a protective film of the present invention which exhibits the visible light and/or the transmittance of infrared rays and ultraviolet rays is preferably 20% or less, more preferably 0 to 15%, and more preferably It is more than 0% and 10% or less, and particularly preferably 0.001 to 8%. When the maximum transmittance of the film for forming a protective film having a wavelength of 300 to 1200 nm is in the above range, the transmittance in the visible light wavelength region and/or the infrared wavelength region can be lowered, and the semiconductor device can be prevented from being caused by the infrared ray malfunction or Highly visible visual recognition. The maximum transmittance of the film for forming a protective film having a wavelength of 300 to 1,200 nm can be adjusted by the type and content of the colorant component. In the present specification, the maximum transmittance of the film for forming a protective film is measured by a UV-vis spectrometer (manufactured by Shimadzu Corporation), and the film for forming a protective film (thickness: 25 μm) after curing is measured at 300 to 1200 nm. The total light transmittance is the highest value (maximum transmittance).

[Method for Producing Film for Protective Film Formation]

The film for forming a protective film of the present invention is obtained by using a composition obtained by mixing the above components in proportion (a composition for forming a protective film). However, when the composition is prepared, it is necessary to satisfy the relative dielectric of the above formula (1). The components are formulated in a constant manner. The protective film-forming composition may be diluted with a solvent in advance, or may be added at the time of mixing. Further, when the composition for forming a protective film is used, it may be diluted with a solvent. The solvent is exemplified by ethyl acetate, methyl acetate, diethyl ether, dimethyl ether, acetone, methyl ethyl ketone, acetonitrile, hexane, cyclohexane, toluene, heptane and the like.

The protective film-forming composition prepared as described above is applied onto a support to form a film, and can be used as a film for forming a protective film. As a film forming method, a conventionally known method can be applied, and the protective film forming composition can be coated by a conventional means such as a roll coater, a gravure coater, a die coater, and a reverse roll coater. The film for protective film formation can be obtained by drying on a support body. Moreover, by adjusting the coating amount of the composition for forming a protective film, a film for forming a protective film having the above thickness can be obtained.

The support body can better use the release paper, the separation film, and the lining Conventional knowledge of paper, release film, release paper, and the like. Moreover, it can also be used for a polyolefin film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a polyolefin film such as an extended polypropylene film (OPP), or a polyfluorene. A release film is formed on one side or both sides of a substrate for release paper made of a plastic film such as an imide film. The release layer is not particularly limited as long as it has a mold release property, and examples thereof include a polyfluorene oxide resin, an organic resin-modified polyoxymethylene resin, and a fluororesin.

[Method of Manufacturing Semiconductor Device]

The method of using the film for forming a protective film of the present invention will be described as an example of the case of application to the manufacture of a semiconductor device.

First, a semiconductor wafer is prepared and circuit formation is performed on one side. The semiconductor wafer can be a germanium wafer and can also be gallium. A compound semiconductor wafer such as arsenic (GaAs). Forming the circuit on the surface of the wafer can be carried out by various methods including a widely used method such as an etching method, a lift-off method, and the like.

Next, the opposite side (back surface) of the circuit surface of the semiconductor wafer is ground. The grinding method is not particularly limited, and it can be ground by a conventional means such as a grinder. In the back grinding, a surface protective film (back-grinding film) is attached to the circuit surface in order to protect the surface circuit. The back grinding is performed by grinding the back surface side of the circuit without fixing the circuit surface side of the wafer (that is, the surface protective film (back surface polishing film) side) by a jig table or the like. The thickness after wafer grinding is not particularly limited, but is usually about 50 to 500 μm.

Then, as needed, remove the crushing that occurs when the back is ground. Floor. The removal of the fracture layer is performed by chemical etching, plasma etching, or the like.

Subsequently, a film for forming a protective film of a support is adhered to the back surface of the semiconductor wafer, and the support film is peeled off from the film for forming a protective film to obtain a laminate of a semiconductor wafer and a film for forming a protective film. At this time, in order to suppress an increase in the peeling strip voltage, the semiconductor wafer and the film for forming a protective film are preferably in direct contact with each other. When another layer exists between the semiconductor wafer and the film for forming a protective film, the relative dielectric constant of the other layer preferably has a value between the relative dielectric constant of the semiconductor wafer and the relative dielectric constant of the film for forming a protective film.

Next, the film for forming a protective film is cured to form a protective film on the entire surface of the wafer. Specifically, the film for forming a protective film is cured by thermal hardening. As a result, a protective film made of the above resin composition is formed on the back surface of the wafer, and the strength is improved as compared with the case where the wafer is alone. Therefore, the damage during wafer processing by flaking by polishing can be reduced. Further, the protective film is excellent in thickness uniformity as compared with a coating method in which a coating liquid for a protective film is directly applied to a back surface of a wafer or a wafer.

Here, a method of peeling the support film from the film for forming a protective film and then curing the film for forming a protective film to form a protective film on the entire wafer is exemplified. However, the order of the peeling step and the curing step of the support may be reversed. In other words, a film for forming a protective film to which a support is attached may be attached to the back surface of the semiconductor wafer. Secondly, the film for forming a protective film is cured to form a protective film on the entire surface of the wafer, and then the support film is peeled off from the surface of the protective film.

After the protective film is formed, it is preferred to perform laser printing on the protective film. Laser printing is performed by laser marking by laser irradiation The surface of the protective film is cut and the product number is marked on the protective film.

Then, after attaching the dicing tape to the back side of the semiconductor wafer to fix the wafer, the surface protective film attached to the wafer during the grinding is peeled off. In the case of the peeling, the peeling tape is bonded to the surface protective film by heat pressing or the like, and the peeling tape is pulled up to peel off the surface protective film, and the surface protective film is previously allowed to adhere to the surface protective film by ultraviolet rays or the like. A function of changing, a method of lowering the adhesion of the surface protective film by ultraviolet irradiation, and peeling off.

After the surface protection film on the circuit side of the semiconductor wafer is peeled off, each of the circuits formed on the surface of the wafer is cut. The cutting is performed by cutting the wafer together with the protective film. Wafer cutting is performed by using a conventional method of cutting a sheet. As a result, a semiconductor wafer group which is singulated and has a protective film on the back surface is obtained on the dicing sheet.

Finally, a semiconductor wafer (with a protective film wafer) provided with a protective film on the back surface is picked up by a wide range of means such as a collector to obtain a protective film wafer. Then, the protective film wafer is mounted on a specific substrate in a face-down manner, and a semiconductor device can be manufactured. Further, the semiconductor device can be manufactured by attaching the protective film wafer to another member such as a pad portion or another semiconductor wafer (on the wafer mounting portion). According to the present invention, the relative dielectric constant of the measurement frequency of the protective film forming film of 10 Hz and the relative dielectric constant of the measurement frequency of the semiconductor wafer of 10 Hz are within a specific range, even for the wafer which has been subjected to the step of peeling off the surface protective film. When picking up, regardless of the type of the surface protective film, it is possible to suppress the semiconductor wafer from being subjected to electrostatic breakdown, and as a result, a semiconductor wafer having high reliability can be obtained. Further, whether or not the electrostatic breakdown is caused can be evaluated by measuring the peeling band voltage.

A method of measuring the peeling tape voltage of the present invention will be described. First, the back surface of the semiconductor wafer to which the surface protective film is attached is polished to a specific thickness. A film for forming a protective film for removing electricity is applied to the polishing surface by a hand roller. After the support is peeled off from the film for forming a protective film, a specific heat treatment is performed to cure the film for forming a protective film to form a protective film. Next, on the protective film side of the obtained wafer with the protective film, a dicing tape which was previously de-energized was attached using a hand roller. After the sample thus obtained was left for a certain period of time, the surface protective film was peeled off from the sample. Next, the peeling of the dicing tape was carried out by fixing the dicing tape with an automatic winding device at a peeling angle of 170±5° and a peeling speed of 10 mm/sec. The potential of the surface on the side of the film for forming a protective film which occurred at this time was measured by a potential measuring device fixed at a position of 50 mm from the surface of the film for forming a protective film. The measurement was carried out in an environment of 23 ° C and 50% RH.

[Examples]

The invention is illustrated by the following examples, but the invention is not limited to the examples. In addition, unless otherwise indicated, "part" means a part by mass.

<Reactivity Synthesis of Polymers for Films>

In an autoclave equipped with a thermometer, a nitrogen introducing device, an alkylene oxide introducing device, and a stirring device, a bisphenol A-formaldehyde type phenol resin (manufactured by Megumi Kasei Co., Ltd., trade name "BPA-D", OH equivalent: 120) 120.0 g, 1.20 g of potassium hydroxide, and 120.0 g of toluene, and the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 g of propylene oxide was gradually added dropwise, and reacted at 0 to 4.8 kg/cm ² at 125 to 132 ° C for 16 hours.

Subsequently, the reaction solution was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to the reaction solution to neutralize potassium hydroxide to obtain a bisphenol A-formaldehyde type having a nonvolatile content of 62.1% and a hydroxyl value of 182.2 g/eq. A propylene oxide reaction solution of a phenol resin. This phenolic hydroxyl group is added to an average of 1.08 moles of alkylene oxide per one equivalent.

293.0 g of an alkylene oxide reaction solution of the obtained novolac type cresol resin, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methyl hydroquinone, and 252.9 g of toluene were fed with a stirrer, a thermometer, and an air blowing tube. In the reactor, air was blown at a rate of 10 ml/min, and reacted at 110 ° C for 12 hours while stirring.

The water formed by the reaction was distilled off as 12.6 g as an azeotropic mixture with toluene. Subsequently, the reaction solution was cooled to room temperature, and the resulting reaction solution was neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution, followed by water washing. Subsequently, toluene was replaced with 118.1 g of propylene glycol monomethyl ether acetate in an evaporator and distilled off to obtain a novolac type acrylate resin solution.

Next, 332.5 g of the obtained novolac type acrylate resin solution and 1.22 g of triphenylphosphine were fed into a reactor equipped with a stirrer, a thermometer, and an air blowing tube, and air was blown at a rate of 10 ml/min, and four were slowly added while stirring. 60.8 g of hydrogen phthalic anhydride was reacted at 95 to 101 ° C for 6 hours to obtain a carboxyl group-containing resin having a solid content of 88 mg KOH/g and a nonvolatile content of 71%. This is called resin solution A. The weight-average molecular weight of the film-forming polymer (carboxyl group-containing resin) contained in the resin solution A was 4 × 10 ³ .

Further, the value of the weight average molecular weight (Mw) is measured by a gel permeation chromatography (GPC) method (polystyrene standard) under the following measurement apparatus and measurement conditions.

Measuring device: "Waters 2695" by Waters

Detector: "Waters 2414" by Waters, RI (differential refractometer)

Column: "HSPgel Column, HR MB-L, 3μm, 6mm × 150mm" made by Waters × HSPgel Column, HR 1.3μm, 6mm × 150mm × 2

Determination conditions:

Column temperature: 40 ° C

RI detector set temperature: 35 ° C

Developing solvent: tetrahydrofuran

Flow rate: 0.5ml/min

Sample size: 10μl

Sample concentration: 0.7wt%

<Production of Film 1 for Protective Film Formation>

Dissolve the following ingredients. It was dispersed in methyl ethyl ketone to prepare a composition film 1 for forming a protective film having a solid concentration of 20% by mass.

The composition film 1 for forming a protective film was applied onto a polyethylene terephthalate film (PET film) which was subjected to a release treatment on the surface, and dried at 100 ° C for 5 minutes to prepare a film 1 for forming a protective film having a thickness of 20 μm.

<Production of Film 2 for Forming Protective Film>

Dissolve the following ingredients. It was dispersed in methyl ethyl ketone to prepare a composition film 2 for forming a protective film having a solid concentration of 20% by mass.

The composition film 2 for forming a protective film was applied onto a polyethylene terephthalate film (PET film) which was subjected to a release treatment on the surface, and dried at 100 ° C for 5 minutes to prepare a film 2 for forming a protective film having a thickness of 20 μm.

<Production of Film 3 for Protective Film Formation>

Dissolve the following ingredients. It was dispersed in methyl ethyl ketone to prepare a composition film 3 for forming a protective film having a solid concentration of 20% by mass.

The composition film 3 for forming a protective film was applied onto a polyethylene terephthalate film (PET film) which was subjected to a release treatment on the surface, and dried at 100 ° C for 5 minutes to prepare a film 3 for forming a protective film having a thickness of 20 μm.

<Production of Film 4 for Forming Protective Film>

Dissolve the following ingredients. It was dispersed in methyl ethyl ketone to prepare a composition film 4 for forming a protective film having a solid concentration of 20% by mass.

Peeling polyethylene terephthalate on the surface The composition film 4 for forming a protective film was applied onto the film (PET film), and dried at 80 ° C for 5 minutes to form a film 4 for forming a protective film having a thickness of 20 μm.

<Production of Film 5 for Forming Protective Film>

Dissolve the following ingredients. The composition film 5 for forming a protective film was prepared by dispersing in methyl ethyl ketone to prepare a solid content of 20% by mass.

The composition film 5 for forming a protective film was applied onto a polyethylene terephthalate film (PET film) which was subjected to a release treatment on the surface, and dried at 100 ° C for 5 minutes to prepare a film 5 for forming a protective film having a thickness of 20 μm.

<Production of Film 6 for Forming Protective Film>

Dissolve the following ingredients. It was dispersed in methyl ethyl ketone to prepare a composition film 6 for forming a protective film having a solid concentration of 20% by mass.

The composition film 6 for forming a protective film was applied onto a polyethylene terephthalate film (PET film) which was subjected to a release treatment on the surface, and dried at 100 ° C for 5 minutes to prepare a film 6 for forming a protective film having a thickness of 20 μm.

<Production of surface protective film>

A polyolefin film having a thickness of 100 μm was used as a substrate film, and an aqueous solution of polyethylene oxide (in the name of CONISOL F-205, manufactured by INSCONTEC) was formed on one main surface of the substrate film to form 0.1. Μm thick antistatic layer. Subsequently, the base polymer was blended with a polyisocyanate compound containing 100 parts of an acrylic copolymer containing a photocurable unsaturated carbon bond in a ratio of 0.5 meq/g and a hardener (manufactured by Japan POLYURETHANE Co., Ltd., trade name CORONATE L) One part of α-hydroxycyclohexyl phenyl ketone with a photoinitiator was prepared to prepare an adhesive coating liquid. Using a knurling wheel coater, coating the polyethylene terephthalate film (thickness 25 μm) on the opposite side of the above-mentioned mold release treatment on a single side, coated at a line speed of 2 m/min. The prepared adhesive coating liquid was passed through a warm air drying oven set at 110 ° C to form an adhesive layer, and bonded to the antistatic treated base film to prepare a surface protective film A having a thickness of 30 μm after drying. Further, similarly to the surface protective film A, the surface protective film B which enlarges the distance from the antistatic layer and increases the risk of electrostatic breakdown is produced in the same manner as the surface protective film A except that the thickness of the adhesive layer is 300 μm.

<Production of cutting tape>

A mixture of 80 parts of the product name "WINTEC WFX4M" (manufactured by Nippon Polypropylene Co., Ltd.) and 20 parts of the product name "TAFCELENE H5002" (manufactured by Sumitomo Chemical Co., Ltd.) was used as the adhesive layer forming material. Further, as the base layer forming material, an ethylene-vinyl acetate copolymer (EVA) (manufactured by Mitsui DuPont Co., Ltd., trade name "EVAFLEX P-1007") was used. Putting the adhesive forming material and the substrate layer forming material into the extruder separately The T-die was melt-coextruded to obtain a dicing tape having an adhesive layer thickness of 40 μm and a substrate layer thickness of 80 μm.

<Preparation of semiconductor wafers>

As a semiconductor wafer, two types of P-type germanium wafers of 4 Å, 525 μm thick, and undoped GaAs wafers of 4 Å and 625 μm thick were prepared by CANOSIS.

<Measurement of Relative Dielectric Constant of Film for Forming Protective Film>

With respect to the films 1 to 6 for forming protective films obtained as described above, the relative dielectric constant was measured as follows. First, a film for forming a protective film having a thickness of 20 μm was laminated on a copper-clad laminate using a hand roller, and the PET film was peeled off, and then heat-hardened at 150 ° C for 30 minutes. The laminate was cooled to room temperature. The thickness of the film for forming a protective film was measured using a small sputum research institute SURFCOATER SE-2300. The thickness was measured as an average of 5 times. Next, on the side of the film for forming a protective film for forming a film for protective film formation, a silver paste (AF-5000 manufactured by Sun Ink Co., Ltd.) was used to form a diameter of 38 mm by screen printing. The circular electrode. At this time, at 38mm The concentric circular outer circumference of the circular electrode also forms an inner diameter of 40 mm , shape 50mm Protective electrode in the shape of a donut. After printing the silver paste, it was dried at 80 ° C for 30 minutes to form a silver electrode, thereby obtaining samples 1 to 6 for relative dielectric constant measurement.

The obtained relative dielectric constant measurement samples 1 to 6 were allowed to stand at 23 ° C, 50% RH for 1 day. Using the day-mounted power system LCR meter IM3536, will be 38mm The round silver electrode and the copper foil of the copper-clad laminate are respectively connected to the LCR meter, and the film laminate for forming a protective film is placed in a shielding box at 23 ° C and 50% RH in a test voltage (signal voltage). The relative dielectric constant was continuously measured 256 times at 0.5 V and the measurement frequency was 10 Hz, and the average value was calculated. The measurement results are shown in Table 1 below.

<Measurement of Relative Dielectric Constant of Semiconductor Wafer>

After bonding the surface protective film A produced as described above to one surface of the semiconductor wafer, it was polished on the opposite side until the wafer thickness became 300 μm. Next, from the side of the surface protective film A, the high-pressure mercury lamp was irradiated with an irradiation energy of 200 mJ/cm ^{2 for} 1 minute, and then fixed to an automatic winding device, and the surface protective film A was peeled off at a peeling angle of 170±5° and a peeling speed of 10 mm/sec. .

On the single side of the obtained 300 μm thick semiconductor wafer, silver paste (AF-5000 manufactured by Sun Ink Co., Ltd.) was screen printed on the center of the semiconductor wafer to form a diameter of 80 mm. The circular electrode was dried at 80 ° C for 30 minutes to form a silver electrode. In the center of the opposite side of the semiconductor wafer, screen printing to form a diameter of 38mm The circular electrode. At this time at 38mm The concentric circular outer circumference of the circular electrode also forms an inner diameter of 40 mm , shape 50mm Protective electrode in the shape of a donut. After printing the silver paste, it was dried at 80 ° C for 30 minutes to form a silver electrode, thereby obtaining a sample for measuring the relative dielectric constant of the semiconductor wafer.

The sample for relative dielectric constant measurement of the obtained semiconductor wafer was allowed to stand at 23 ° C, 50% RH for 1 day. Using the day-mounted power system LCR meter IM3536, will be 38mm Round silver electrode with 80mm The circular silver electrodes are respectively connected to the LCR meter, and the sample for measuring the relative dielectric constant of the semiconductor wafer is placed in a shielding box at 23 ° C and 50% RH, and the test voltage (signal voltage) is 0.5 V. The relative dielectric constant was continuously measured at a frequency of 10 Hz for 256 times, and the average value was calculated. The measurement results are shown in Table 1 below.

<Example 1>

After bonding the surface protective film A produced as described above to one surface of the wafer, it was polished on the opposite side until the wafer thickness became 300 μm. Then, the film 1 for forming a protective film was bonded to the polished surface thereof by a hand roller, and the PET film was peeled off from the film 1 for protective film formation, and then heated at 150 ° C for 30 minutes to form a protective film. Then, on the side of the protective film, the side of the adhesive layer of the dicing tape which was previously de-energized was bonded to the side of the protective film to prepare Sample 1.

The sample 1 obtained as described above was allowed to stand in an environment of 23° C. and 50% RH for 1 day, and directly irradiated to the high-pressure mercury lamp at a potential of 200 mJ/cm ^{2 for} 1 minute from the surface of the surface protective film A in the measurement environment, and then fixed to the automatic coiling. The apparatus peeled off the surface protective film A under the conditions of a peeling angle of 170±5° and a peeling speed of 10 mm/sec.

After 10 minutes from the peeling of the surface protective film A, the dicing tape side was turned up, and the sample was set to a position 50 mm directly below the sensor of the potentiometer. The dicing tape was fixed to an automatic winding device, and the dicing tape was peeled off at a peeling angle of 170±5° and a peeling speed of 10 mm/sec.

The potential of the surface on the side of the film for forming a protective film which occurred at this time was measured by a potential measuring device (KSD-2000 manufactured by Kasuga Electric Co., Ltd.) which was fixed at a specific position. When the peeling tape voltage is within ±0.2kv, it is judged as ○, exceeding When it is +0.2 kV or when the value which is more negative than -0.2 kv becomes large, it is judged as ×. The judgment results are shown in Table 1 below.

<Example 2>

In the same manner as in Example 1, except that the film for protective film formation 2 was used instead of the film 1 for forming a protective film, the peeling tape voltage was measured in the same manner as in Example 1. The judgment results are shown in Table 1 below.

<Example 3>

In the same manner as in Example 1, except that the film for protective film formation 3 was used instead of the film 1 for forming a protective film, the peeling tape voltage was measured in the same manner as in Example 1. The judgment results are shown in Table 1 below.

<Example 4>

In Example 3, the peeling strip voltage was measured in the same manner as in Example 3 except that a GaAs wafer was used instead of the tantalum wafer. The judgment results are shown in Table 1 below.

<Example 5>

In the first embodiment, the peeling strip voltage was measured in the same manner as in Example 1 except that the protective film forming film 5 was used instead of the protective film forming film 1. The judgment results are shown in Table 1 below.

<Comparative Example 1>

In the same manner as in Example 1, except that the film for protective film formation 4 was used instead of the film 1 for forming a protective film, the peeling tape voltage was measured in the same manner as in Example 1. The judgment results are shown in Table 1 below.

<Comparative Example 2>

In Example 1, the peeling strip voltage was measured in the same manner as in Example 1 except that a GaAs wafer was used instead of the tantalum wafer. The judgment results are shown in Table 1 below.

<Comparative Example 3>

In the same manner as in Example 1, except that the film for protective film formation 6 was used instead of the film 1 for forming a protective film, the peeling tape voltage was measured in the same manner as in Example 1. The judgment results are shown in Table 1 below.

As can be seen from the evaluation results shown in Table 1, when the relationship between the film for forming a protective film and the semiconductor wafer satisfies the relative dielectric constant of the above formula (1) (Examples 1 to 5), it shows a good peeling band voltage. Evaluation results. On the other hand, the relationship between the relative dielectric constant of the film for forming a protective film and the semiconductor wafer did not satisfy the above formula (1) (Comparative Examples 1 to 3), and the peeling band voltage was high.

<Example 5>

In the first embodiment, in place of the surface protective film A, the thickness of the adhesive layer was 10 times thick, and the peeling tape was measured in the same manner as in Example 1 except that the surface protective film B having a large distance from the antistatic layer and a high risk of electrostatic breakdown was used. Voltage. As a result, in the same manner as in Example 1, the evaluation result of the peeling tape voltage was ○. From the above results, it is understood that the peeling tape voltage can be suppressed to be small by the film for forming a protective film which satisfies the formula (1), regardless of the surface protective film.

Claims (4)

A film for forming a protective film, which is a film for forming a protective film provided on a back surface of a circuit formation surface of a semiconductor wafer, characterized in that a relative dielectric constant of a measurement frequency of 10 Hz of the semiconductor wafer and the film is satisfied (1): | ε _S - ε _F | ≦ 9 (1) (wherein ε _S represents a relative dielectric constant of a semiconductor wafer having a measurement frequency of 10 Hz, and ε _F represents a film for forming a protective film having a measurement frequency of 10 Hz. Relative dielectric constant). The film for forming a protective film according to claim 1, wherein the semiconductor wafer is a wafer. The film for forming a protective film according to claim 1 or 2, wherein the film for forming a protective film is directly provided in contact with a back surface of a circuit forming surface of the semiconductor wafer. The film for forming a protective film according to any one of claims 1 to 3, wherein the film for forming a protective film further comprises a peelable support.