KR102560043B1 - Method for processing substrate - Google Patents

Abstract

(Problem) In a method for processing and moving a substrate in a state in which the substrate is temporarily fixed on a support through a temporarily fixing member, the bonding layer remaining on the substrate after separating the substrate from the support is peeled and / or solvent. To provide a method for treating a substrate that can be easily removed by cleaning.
(Solution) A laminate having a support, a temporarily fixed material, and a base material, wherein the temporarily fixed material is in contact with the support side surface in the base material, and is formed of a composition containing at least one polymer selected from polybenzoxazole precursors and polybenzoxazoles. Forming a temporarily fixed material layer (I) formed on the support side surface in the layer (I) and having a temporarily fixed material layer (II) containing a light absorber; processing the substrate and/or moving the laminate; a step of irradiating light to the layer (II); separating the substrate from the support; and a step of removing the layer (I) from the substrate in this order.

Description

Substrate processing method {METHOD FOR PROCESSING SUBSTRATE}

The present invention relates to a method for treating a substrate, a composition for temporarily fixing, and a semiconductor device.

BACKGROUND ART A method of performing steps such as backside grinding and photofabrication on a base material in a state where a base material such as a semiconductor wafer is bonded onto a support such as a glass substrate through a temporarily fixing member has been proposed. This temporarily fixed material is required to be capable of temporarily fixing the substrate on the support during processing and to be able to easily separate the substrate from the support after processing.

In the separation treatment, by irradiating radiant energy such as ultraviolet rays and infrared rays to the temporarily fixed material in the laminate composed of the support, the temporarily fixed material, and the substrate, reducing the adhesive strength of the temporarily fixed material, and separating the substrate from the support It has been proposed.

For example, Patent Literature 1 discloses a laminate in which a transparent support and a semiconductor wafer are temporarily fixed by a temporarily fixing material including a release layer and a bonding layer, and irradiates the release layer while scanning a laser from the side of the transparent support, thereby reducing the adhesive strength of the release layer and peeling the substrate from the support.

US Patent Publication No. 2014/0106473

In a conventional method of peeling a substrate from a support, since laser is irradiated to the release layer from the side of the transparent support, heat of about 1000° C. may be locally generated by the laser irradiation in the release layer. Since the generated heat is also propagated to the bonding layer, it causes deterioration of the bonding layer. Deterioration of the bonding layer causes a problem that the bonding layer on the substrate after peeling cannot be easily removed by peeling treatment or cleaning treatment using a solvent.

An object of the present invention is to provide a method for treating a substrate that can be easily removed by, for example, peeling and/or solvent cleaning.

The present inventors conducted an earnest examination in order to solve the said subject. As a result, it was discovered that the above problems could be solved by a processing method for a base material having the following constitution, and the present invention was completed.

That is, the present invention relates to the following [1] to [8], for example.

[1] (1) step of forming a laminate having a support, a temporarily fixed material and a base material, wherein the temporarily fixed material is in contact with the support side surface in the base material, and a polybenzoxazole precursor and polybenzoxazole A temporarily fixed material layer (I) formed of a composition containing at least one polymer selected from, and a temporarily fixed material layer (II) formed on the support side surface in the temporarily fixed material layer (I) and containing a light absorber; (2) processing the substrate and/or moving the laminate; (3) a step of irradiating light to the temporarily fixing material layer (II); (4) a step of separating the substrate from the support; And (5) the step of removing the temporarily fixing material layer (I) from the substrate; treatment method of a substrate having this order.

[2] The method for treating the substrate according to [1], wherein the composition contains a polybenzoxazole precursor.

[3] The processing method for the substrate according to [1] or [2] above, wherein the temporarily fixing material layer (II) further contains a thermally decomposable resin.

[4] In the step (3), the light applied to the temporarily fixing material layer (II) is an ultraviolet ray, the processing method of the substrate according to any one of [1] to [3].

[5] The method for treating a substrate according to [4], wherein the ultraviolet rays are ultraviolet rays having a wavelength of 300 to 400 nm.

[6] In the step (5), a treatment for peeling the temporarily fixed material layer (I) from the substrate, and / or a treatment for washing the temporarily fixed material layer (I) using a solvent, the processing method of the substrate according to any one of [1] to [5], wherein the temporarily fixed material layer (I) is removed from the substrate.

[7] A semiconductor device obtained by the processing method of any one of [1] to [6] above.

[8] A composition for temporarily fixing containing at least one polymer selected from polybenzoxazole precursors and polybenzoxazoles.

According to the present invention, in a method for processing and moving a substrate in a state in which the substrate is temporarily fixed on a support through a temporarily fixing member, the bonding layer remaining on the substrate after separating the substrate from the support can be easily removed by, for example, peeling and / or solvent cleaning. It is possible to provide a processing method for a substrate.

1 is a cross-sectional view of an embodiment according to a laminate in the present invention.

(Mode for implementing the invention)

Hereinafter, after explaining the laminate formed in the present invention and the composition for temporarily fixing, which is a raw material composition of the temporarily fixing material constituting the laminate, a method for processing a base material and a semiconductor device obtained by the method for processing the base material are described.

In the present invention, the temporary fixing material is a material used for temporarily fixing a base material on a support body so that the base material does not shift and move from the support body when processing and/or moving the base material.

1. Laminates

In the laminate formed in the present invention, the base material to be processed or moved is temporarily fixed on the support through a temporarily fixing member. In one embodiment, the temporarily fixed material is sandwiched by a substrate and a support.

The temporarily fixed material has a temporarily fixed material layer (I) in contact with the support side surface in the substrate and a temporarily fixed material layer (II) formed on the support side surface in the layer (I). Layer (I) is formed from the composition for temporarily fixing containing at least 1 sort(s) of polymer chosen from a polybenzoxazole precursor and polybenzoxazole. Layer (II) contains a light absorber, and preferably further contains a thermally decomposable resin.

In the case of using a composition for temporarily fixing containing a polybenzoxazole precursor, the temporarily fixing material layer (I) in contact with the substrate is subjected to heat during formation of the layer (I), formation of a laminate or processing of the substrate, so that the polybenzoxazole precursor is considered to change to polybenzoxazole having excellent heat resistance. For this reason, it is possible to suppress deterioration of the temporarily fixing material layer (I) due to heat generated locally by light irradiation to the temporarily fixing material layer (II). Therefore, it is estimated that the layer (I) remaining on the substrate after the separation treatment of the substrate could be removed by a simple method such as peeling and solvent washing.

In the present invention, the temporarily fixed material has a layer (I) and a layer (II) formed in direct contact with this layer (I) or via another layer. Thus, the temporarily fixed material having two or more layers has functions such as protection of the circuit surface of the substrate, adhesion between the substrate and the support, separation of the substrate from the support, heat resistance during processing and light irradiation treatment, etc. Can have a well-balanced function.

An example of the laminate is shown in FIG. 1 . This layered product 1 has a support 10, a temporarily fixed member 20 formed on the support 10, and a substrate 30 temporarily fixed to the support 10 by the temporarily fixed member 20. The temporarily fixed material 20 is formed on the temporarily fixed material layer (I) 21 in contact with the substrate 30, and the temporarily fixed material layer (II) formed on the layer (I) 21 and in contact with the support 10 (II) (22).

In the above laminate, the temporarily fixed material may have any other layer in addition to layer (I) and layer (II). For example, an intermediate layer may be formed between layer (I) and layer (II), or another layer may be formed between layer (II) and the support. In particular, a two-layer temporarily fixed material composed of layer (I) and layer (II) is preferred.

The total thickness of the temporarily fixed material may be arbitrarily selected according to the size of the temporarily fixed surface of the base material, the heat resistance required in processing and light irradiation treatment, and the degree of adhesion between the base material and the support. The total thickness of the temporarily fixed material is usually 0.2 μm or more and 1 mm or less, preferably 2 μm or more and 0.5 mm or less, and more preferably 2 μm or more and 0.3 mm or less. In addition, the thickness of each layer of layer (I) and layer (II) is usually 0.1 to 500 μm, preferably 1 to 250 μm, more preferably 1 to 150 μm. When these thicknesses are within the above range, the temporarily fixing material has sufficient holding power for temporarily fixing the base material, and the base material does not fall off from the temporarily fixing surface during processing or moving treatment.

The temporarily fixed material is suitably used as a temporarily fixed material for substrates when carrying out various processing processes required in the scene of modern economic activities, for example, miniaturization processing of various material surfaces, various surface mounting, transportation of semiconductor wafers and semiconductor elements.

[Temporarily fixed material layer (I)]

The temporarily fixing material layer (I) can be formed from a composition for temporarily fixing (I) containing at least one polymer selected from polybenzoxazole precursors and polybenzoxazoles. The composition for temporarily fixing (I) may contain a solvent.

As the composition (I) for temporarily fixing, a composition containing a polybenzoxazole precursor is preferable from the viewpoint of being able to form a more in-plane uniform temporarily fixing material layer (I).

The 5% weight reduction temperature of the temporarily fixed material layer (I) is preferably 350°C or higher, more preferably 400°C or higher, from the viewpoint of heat resistance of the layer (I). The 5% weight loss temperature of the layer (I) can be measured by thermogravimetric analysis (TGA) in a nitrogen atmosphere at a heating rate of 10°C/min.

<Polybenzoxazole precursor and polybenzoxazole>

When the polybenzoxazole precursor is heated, it reacts within the molecule and rapidly changes into heat-resistant polybenzoxazole. For this reason, since the said polybenzoxazole precursor changes into polybenzoxazole when the layer which has a polybenzoxazole precursor is heated to high temperature, it is thought that heat resistance improves.

As a polybenzoxazole precursor, the polymer which has a structural unit represented by Formula (1) is mentioned, for example. The polybenzoxazole precursor may be a polymer having one type of structural unit or a polymer having two or more types of structural units.

In formula (1), X is a direct bond or a divalent organic group, Y is a tetravalent aromatic group, N and OH bonded to Y form a pair, and each pair of N and OH are bonded to adjacent carbon atoms on the same aromatic ring.

Examples of the divalent organic group for X include an arylene group having 6 to 20 carbon atoms which may be halogenated, a divalent group represented by the formula (g1): -Ar ¹ -R ¹ -Ar ¹ -, an alkanediyl group having 1 to 10 carbon atoms, a cycloalkanediyl group having 3 to 20 carbon atoms, and a divalent silicon-containing group.

In formula (g1), Ar ¹ is each independently an arylene group having 6 to 20 carbon atoms which may be halogenated, and R ¹ is a direct bond or a divalent group. Examples of the divalent group include an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, and an alkanediyl group having 1 to 10 carbon atoms which may be halogenated.

Examples of the arylene group having 6 to 20 carbon atoms that may be halogenated include a phenylene group, a methylphenylene group, a t-butylphenylene group, a fluorophenylene group, a chlorophenylene group, a bromophenylene group, and a naphthylene group. Examples of the alkanediyl group having 1 to 10 carbon atoms include a methylene group and an ethane-1,2-diyl group. As a C1-C10 alkanediyl group which may be halogenated, a methylene group, a dimethylmethylene group, and a bis (trifluoromethyl) methylene group are mentioned, for example. As a C3-C20 cycloalkanediyl group, a cyclobutanediyl group, a cyclopentanediyl group, and a cyclohexanediyl group are mentioned, for example. Examples of the divalent silicon-containing group include tetraphenylsilane-4,4'-diyl group.

Examples of the tetravalent aromatic group for Y include a tetravalent group derived from an aromatic hydrocarbon such as a benzene ring, a naphthalene ring, and an anthracene ring, and a tetravalent group represented by formula (g2): >Ar ² -R ² -Ar ² <.

In formula (g2), Ar ² is each independently a trivalent group derived from an aromatic hydrocarbon such as a benzene ring, a naphthalene ring, or an anthracene ring, and R ² is a direct bond or a divalent group. Examples of the divalent group include an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, and an alkanediyl group having 1 to 10 carbon atoms which may be halogenated.

As an aromatic hydrocarbon which forms Y or ^Ar2 , C6-C20 aromatic hydrocarbons, such as benzene, naphthalene, and anthracene, are mentioned, for example. As a C1-C10 alkanediyl group which may be halogenated, a methylene group, a dimethylmethylene group, and a bis (trifluoromethyl) methylene group are mentioned, for example.

The polybenzoxazole precursor can be obtained by using, for example, one or both of a dicarboxylic acid and a derivative thereof and dihydroxydiamine as raw materials.

Examples of the dicarboxylic acids include isophthalic acid, terephthalic acid, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 4,4'-biphenyldicarboxylic acid, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxytetraphenylsilane, bis(4-carboxyphenyl)sulfone, 2,2-bis(p-carboxyphenyl)propane, and 5- aromatic dicarboxylic acids such as tert-butylisophthalic acid, 5-bromoisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, and 2,6-naphthalenedicarboxylic acid; and aliphatic dicarboxylic acids such as 1,2-cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, oxalic acid, malonic acid, and succinic acid. The said dicarboxylic acid may be used individually by 1 type, and may use 2 or more types together. Among these, aromatic dicarboxylic acids are preferable from the viewpoint of obtaining a polybenzoxazole precursor having good heat resistance.

As a derivative of the said dicarboxylic acid, active ester forms, such as a dicarboxylic acid halide and a dicarboxylic acid and hydroxybenzotriazole, are mentioned, for example. The dicarboxylic acid derivatives may be used singly or in combination of two or more.

Examples of the dihydroxydiamine include 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, bis(3-amino-4-hydroxyphenyl)propane, bis(4-amino-3-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)methane, bis(4-amino-3-hydroxyphenyl)methane, and bis(3-amino- and aromatic diamines such as 4-hydroxyphenyl)sulfone, bis(4-amino-3-hydroxyphenyl)sulfone, bis(3-amino-4-hydroxyphenyl)hexafluoropropane, bis(4-amino-3-hydroxyphenyl)hexafluoropropane, 4,6-diaminoresorcinol, and 4,5-diaminoresorcinol. The said dihydroxydiamine may be used individually by 1 type, and may use 2 or more types together. By using an aromatic diamine, a polybenzoxazole precursor having good heat resistance is obtained.

In the polybenzoxazole precursor, the content of the structural unit represented by formula (1) is usually 70% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more. The said content can be measured by ¹ H NMR, for example.

Polybenzoxazole can be obtained by subjecting a polybenzoxazole precursor to a ring closure reaction by heating, and is, for example, a polymer in which at least a part of structural units represented by formula (1) in the precursor have been converted into structural units represented by formula (2). Polybenzoxazole may be a polymer having one type of structural unit or a polymer having two or more types of structural units.

In formula (2), X and Y have the same meaning as the same symbol in formula (1). N and O bonded to Y form a pair, and each pair of N and O bonds to adjacent carbon atoms on the same aromatic ring to form a benzoxazole ring.

1,000-1,000,000 are preferable and, as for the weight average molecular weight (Mw) of a polybenzoxazole precursor and polybenzoxazole in terms of polystyrene by gel permeation chromatography (GPC) method, 10,000-100,000 are more preferable. The polymer having Mw in the above range is easy to handle when forming the temporarily fixed material layer (I) using the composition (I), and the temporarily fixed material layer (I) obtained from the composition (I) has sufficient strength.

The total content of the polybenzoxazole precursor and the polybenzoxazole in 100% by mass of the solid content of the composition (I) for temporarily fixing is usually 50% by mass or more, preferably 70 to 100% by mass, more preferably 90 to 100% by mass. Here, "solid content" refers to all components other than a solvent. When the total content is within the above range, it is preferable from the viewpoint of adhesiveness, peelability and heat resistance of the temporarily fixed material layer (I).

<Other ingredients>

Composition (I) for temporary fixation, if necessary, tackifying resins such as petroleum resins and terpene resins, antioxidants, polymerization inhibitors, adhesion aids, surfactants, polystyrene crosslinked particles, and aluminum oxide, zirconium oxide, titanium oxide, and may contain one or more selected from metal oxide particles such as silicon oxide.

[Temporarily fixed material layer (II)]

The temporarily fixing material layer (II) can be formed from, for example, the composition for temporarily fixing (II) containing a light absorber. Composition (II) preferably further contains a thermally decomposable resin. Composition (II) may contain a solvent.

<Light Absorber>

Examples of the light absorber include organic light absorbers such as benzotriazole-based light absorbers, hydroxyphenyltriazine-based light absorbers, benzophenone-based light absorbers, salicylic acid-based light absorbers, radiation-sensitive radical polymerization initiators, and photosensitive acid generators; resins having condensed polycyclic aromatic rings such as phenol novolac and naphthol novolac; C.I. Pigment Black 7, C.I. Pigment Black 31, C.I. Pigment Black 32 and, C.I. black pigments such as Pigment Black 35 (for example, carbon black); C.I. Pigment Blue 15:3, C.I. Pigment Blue 15:4, C.I. Pigment Blue 15:6, C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment Green 58, C.I. Pigment Yellow 139, C.I. Pigment Red 242, C.I. Pigment Red 245 and C.I. non-black pigments such as Pigment Red 254; C.I. Bat Blue 4, C.I. Acid Blue 40, C.I. Direct Green 28, C.I. Direct Green 59, C.I. Acid Yellow 11, C.I. Direct Yellow 12, C.I. Reactive Yellow 2, C.I. Acid Red 37, C.I. Acid Red 180, C.I. Acid Blue 29, C.I. Direct Red 28 and, C.I. dyes such as Direct Red 83;

Among the resins having the condensed polycyclic aromatic ring, there is also a resin that functions as a thermally decomposable resin described later. Regarding such a resin, it is assumed that the content described later is calculated as applicable to both the light absorber and the thermally decomposable resin.

Among these, a black pigment is preferable from the viewpoint of improving the separability of the substrate. In the present invention, carbon black dispersions such as MHI Black #201, #209, #220, and #273 (manufactured by Mikuni Shikiso Co., Ltd.) can be used as the black pigment.

A light absorber may be used individually by 1 type, and may use 2 or more types together.

The content of the light absorber is usually 1 to 60% by mass, preferably 10 to 50% by mass, and more preferably 20 to 40% by mass in 100% by mass of the solid content of the composition for temporarily fixing (II). Here, "solid content" refers to all components other than a solvent. When the content of the light absorber is within the above range, the separability of the substrate is further improved and deterioration of the substrate due to light irradiation can be prevented.

<Thermally decomposable resin>

It is preferable that the composition for temporarily fixing (II) further contains a thermally decomposable resin. It is thought that the separability of the base material is further improved when the thermally decomposable resin is decomposed or deteriorated by light irradiation.

In the present specification, "thermal decomposable resin" refers to a resin having a 5% weight loss temperature of 300°C or less. The 5% weight reduction temperature of the thermally decomposable resin is preferably 250°C to 150°C. The 5% weight reduction temperature of the resin can be measured by a thermogravimetric analysis (TGA) in a nitrogen atmosphere at a heating rate of 10°C/min.

Examples of the thermally decomposable resin include cycloolefin-based polymers, acrylic-based resins, terpene-based resins, petroleum resins, novolak resins, and elastomers. Among these, cycloolefin-based polymers, terpene-based resins, petroleum resins, and elastomers are preferable.

Examples of the cycloolefin polymer include an addition copolymer of a cyclic olefin compound and a non-cyclic olefin compound, a ring-opening metathesis polymer of one or two or more cyclic olefin compounds, and a polymer obtained by hydrogenating the ring-opening metathesis polymer.

Examples of the cyclic olefin compounds include norbornene olefins, tetracyclododecene olefins, dicyclopentadiene olefins, and derivatives thereof. Examples of the derivatives include alkyl groups, alkylidene groups, aralkyl groups, cycloalkyl groups, hydroxyl groups, alkoxy groups, acetyl groups, cyano groups, amide groups, imide groups, silyl groups, aromatic rings, ether bonds, and substituted derivatives having two or more selected from ester bonds.

Examples of the non-cyclic olefin compound include linear or branched olefins having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, more preferably ethylene, propylene and butene, and particularly preferably ethylene.

The weight average molecular weight (Mw) of the cycloolefin polymer in terms of polystyrene by the GPC method is usually 10,000 to 100,000, preferably 30,000 to 100,000.

Examples of the terpene resin include terpene resins, hydrogenated terpene resins, terpene phenol resins, hydrogenated terpene phenol resins, aromatic modified terpene resins, and aromatic modified hydrogenated terpene resins.

Examples of the petroleum resin include C5-based petroleum resins, C9-based petroleum resins, C5-based/C9-based mixed petroleum resins, cyclopentadiene-based resins, polymers of vinyl-substituted aromatic compounds, copolymers of olefins and vinyl-substituted aromatic compounds, copolymers of cyclopentadiene-based compounds and vinyl-substituted aromatic compounds, hydrogenated products thereof, and mixtures of two or more selected from these.

As an elastomer, conjugated diene polymer rubber, such as liquid butadiene rubber, liquid isoprene rubber, liquid styrene butadiene rubber, and liquid styrene isoprene rubber, which is liquid at normal temperature (25 degreeC), is mentioned, for example. The number average molecular weight (Mn) of the elastomer in terms of polystyrene by the GPC method is usually 1,000 to 100,000.

A thermally decomposable resin may be used individually by 1 type, and may use 2 or more types together.

A layer containing at least one selected from cycloolefin-based polymers, terpene-based resins, petroleum resins, and elastomers has high resistance to chemicals used in photofabrication, such as highly polar organic solvents or water-based chemicals. For this reason, when processing and/or moving the base material, the problem that the temporarily fixed material layer (II) is deteriorated by the chemical solution and the base material shifts from the support can be prevented.

The content of the thermally decomposable resin is usually 10 to 95% by mass, preferably 30 to 90% by mass, and more preferably 50 to 80% by mass in 100% by mass of the solid content of the composition for temporarily fixing (II). Here, "solid content" refers to all components other than a solvent. When the content of the resin is within the above range, it is preferable in that the temperature at the time of temporarily fixing the substrate on the support is lowered and the substrate does not shift from the support when processing and moving the substrate.

<Other ingredients>

Composition (II) for temporarily fixing, if necessary, antioxidants, polymerization inhibitors, adhesion aids, surfactants, crosslinked polystyrene particles, and metal oxide particles such as aluminum oxide, zirconium oxide, titanium oxide and silicon oxide. It may contain one or two or more selected from.

<Preparation of compositions (I) and (II) for temporarily fixing>

Compositions (I) and (II) for temporarily fixing, if necessary, using a known apparatus used for processing the resin composition, for example, a twin screw extruder, a single screw extruder, a continuous kneader, a roll kneader, a pressure kneader, and a Banbury mixer. It can be prepared by mixing the respective components. Further, for the purpose of removing impurities, filtration may be appropriately performed.

In the production of the compositions (I) and (II) for temporarily fixing, a solvent may be used from the point of setting the viscosity of the composition to a range suitable for application.

Examples of the solvent used in the composition (I) for temporarily fixing include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide; amide solvents such as 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 3-hexyloxy-N,N-dimethylpropanamide, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, and N,N-diethylacetamide; pyrrolidone solvents such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-pentyl-2-pyrrolidone, N-(methoxypropyl)-2-pyrrolidone, N-(t-butyl)-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone; Ketone solvents, such as 2-heptanone, 3-heptanone, 4-heptanone, and cyclohexanone; phosphoramide solvents such as hexamethylphosphoramide; and γ-butyrolactone solvents.

Examples of the solvent used in the composition for temporarily fixing (II) include hydrocarbon solvents such as xylene, limonene, mesitylene, dipentene, pinene, bicyclohexyl, cyclododecene, 1-tert-butyl-3,5-dimethylbenzene, butylcyclohexane, cyclooctane, cycloheptane, cyclohexane, and methylcyclohexane; alcohol/ether solvents such as anisole, propylene glycol monomethyl ether, dipropylene glycol methyl ether, diethylene glycol monoethyl ether, and diglyme; ester/lactone solvents such as ethylene carbonate, ethyl acetate, butyl acetate, ethyl lactate, ethyl 3-ethoxypropionate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene carbonate, and γ-butyrolactone; ketone solvents such as cyclopentanone, cyclohexanone, methyl isobutyl ketone, and 2-heptanone; amide/lactam solvents such as N-methyl-2-pyrrolidinone.

A solvent may be used individually by 1 type, and may use 2 or more types together.

When compositions (I) and (II) for temporarily fixing contain a solvent, it becomes easy to adjust the viscosity of these compositions for temporarily fixing, and therefore it becomes easy to form a temporarily fixing material on a substrate or support. For example, the solvent can be used in a range where the solid content concentration of the compositions (I) and (II) for temporarily fixing is usually 5 to 70% by mass, more preferably 15 to 50% by mass. Here, "solid content concentration" is the total concentration of all components other than a solvent.

2. How to handle materials

The processing method of the substrate of the present invention, (1) the step of forming the laminate, (2) processing the substrate, and / or the step of moving the laminate, (3) the process of irradiating light to the temporarily fixed material layer (II), (4) the step of separating the substrate from the support, and (5) the process of removing the temporarily fixed material layer (I) from the substrate.

Hereinafter, each said process is also called process (1) - process (5), respectively.

<2-1. Process (1)〉

In step (1), for example, (1-1) by forming the temporarily fixed material on the surface of the support and / or substrate, and bonding the substrate and the support through the temporarily fixed material, the substrate can be temporarily fixed on the support. Further, (1-2) the base material may be temporarily fixed on the support body by forming the temporarily fixed material on the surface of the support body and forming a base material such as a resin coating film on the temporarily fixed material. The base material may be surface treated as needed.

Examples of the method for forming the above temporarily fixed material include, for example, (α) a method of directly forming each layer of the temporarily fixed material on a support and/or a substrate, (β) a method of forming a film with a predetermined film thickness using a composition for temporarily fixing on a film such as a polyethylene terephthalate film subjected to release treatment, and then transferring each layer to a support and/or substrate by a lamination method. From the viewpoint of film thickness uniformity, the above method (?) is preferable.

As a method of applying the compositions (I) and (II) for temporarily fixing, which form each layer of the temporarily fixing material, a spin coating method and an inkjet method are exemplified. In the spin coating method, for example, a method of spin coating the composition under the conditions that the rotation speed is 300 to 3,500 rpm, preferably 500 to 1,500 rpm, the acceleration is 500 to 15,000 rpm/sec, and the rotation time is 30 to 300 seconds.

After applying the composition (I) for temporarily fixing to form a coating film, the temporarily fixing material layer (I) is formed by, for example, heating and evaporating the solvent. Heating conditions are appropriately determined according to the boiling point of the solvent, and, for example, the heating temperature is usually 100 to 350°C, and the heating time is usually 1 to 60 minutes.

After applying the composition for temporarily fixing (II) to form a coating film, the temporarily fixing material layer (II) is formed by, for example, heating and evaporating the solvent. Heating conditions are appropriately determined according to the boiling point of the solvent, and, for example, the heating temperature is usually 100 to 300°C, and the heating time is usually 1 to 60 minutes.

Heating of the coating film may be performed in multiple stages as needed.

In the method (α), as a method of bonding the substrate and the support, for example, a layer (I) is formed on the substrate surface, a layer (II) is formed on the support surface, and the layers (I) and the layer (II) are bonded to each other. Method 1; Method 2 in which layers (I) and (II) are sequentially formed on the substrate surface, and a support is bonded on the layer (II); Method 3 in which layer (II) and layer (I) are sequentially formed on the surface of the support and a base material is bonded onto the layer (I) can be mentioned. The temperature at this time is appropriately selected according to the components contained in the compositions (I) and (II) for temporarily fixing, the coating method, and the like. Among these, method 1 is preferable from the viewpoint of avoiding mixing of layer (I) and layer (II) during formation of each layer.

The compression conditions between the substrate and the support may be performed, for example, by applying a pressure of 0.01 to 100 MPa in the lamination direction of each layer for 1 to 20 minutes at preferably room temperature or higher and 400 ° C. or lower, more preferably at 150 to 400 ° C. After crimping, you may further heat-process at 150-300 degreeC for 10 minutes - 3 hours. In this way, the substrate is firmly held on the support through the temporarily fixing member.

In the temporarily fixed material layer (I), the total content of the polybenzoxazole precursor and the polybenzoxazole is usually 50% by mass or more, preferably 70 to 100% by mass, and more preferably 90 to 100% by mass. When the total content is within the above range, it is preferable from the viewpoint of adhesiveness, peelability and heat resistance of the temporarily fixed material layer (I).

In the temporarily fixing material layer (II), the content of the light absorber is usually 1 to 60% by mass, preferably 10 to 50% by mass, and more preferably 20 to 40% by mass. When the content of the light absorber is within the above range, it is preferable from the viewpoint of the peelability of the substrate. In the temporarily fixed material layer (II), the content of the thermally decomposable resin is usually 10 to 95% by mass, preferably 30 to 90% by mass, and more preferably 50 to 80% by mass.

Examples of the substrate as the object to be processed (moved) include semiconductor wafers, glass substrates, resin substrates, metal substrates, metal foils, polishing pads, and resin coating films. Bumps, wiring, insulating films, etc. may be formed on the semiconductor wafer. As a resin coating film, the layer containing an organic component as a main component is mentioned, for example; Specifically, a photosensitive resin layer formed of a photosensitive material, an insulating resin layer formed of an insulating material, a photosensitive insulating resin layer formed of a photosensitive insulating resin material, and the like are exemplified.

As the support, when irradiating with light from the support side in step (3) to change the quality of the temporarily fixed material layer (II), a substrate transparent to the light used in the light irradiation is preferable, and examples thereof include glass substrates and quartz substrates.

When forming the layer (I) on the base material, the surface of the base material (eg circuit surface) may be subjected to surface treatment in advance in order to uniformly spread the temporarily fixed material into the surface. As a method of surface treatment, a method of applying a surface treatment agent to the base material surface in advance is exemplified. As said surface treatment agent, coupling agents, such as a silane coupling agent, are mentioned, for example.

<2-2. Process (2)〉

Process (2) is a process of processing the base material temporarily fixed on the support body, and/or moving the obtained laminated body. A moving process is a process of moving a base material, such as a semiconductor wafer, from one apparatus to another apparatus together with a support body. Examples of the processing of the substrate temporarily fixed on the support include thinning of the substrate such as dicing and backside grinding, and photofabrication. Photofabrication includes, for example, one or more processes selected from resist pattern formation, etching process, sputter film formation, plating process, and plating reflow process. The etching process and the formation of the sputter film are performed in a temperature range of about 25 to 300°C, for example, and the plating process and the plating reflow process are performed in a temperature range of about 225 to 300°C, for example. The processing of the substrate is not particularly limited as long as it is performed at a temperature at which the holding power of the temporarily fixed material is not lost.

<2-3. Process (3)〉

After the processing of the substrate or the movement of the laminate, the temporarily fixed material layer (II) of the temporarily fixed material is irradiated with light, for example, from the support side. By light irradiation, the light absorber which is a component of the temporarily fixing material layer (II) absorbs light, and the adhesive force of the temporarily fixing material layer (II) is reduced. Therefore, if it is after light irradiation to the temporarily fixed material layer (II), the substrate can be easily separated from the support without particularly requiring heat treatment of the temporarily fixed material.

It is preferable to use ultraviolet rays for light irradiation, for example, ultraviolet rays with a wavelength of 10 to 400 nm are employed, and ultraviolet rays with a wavelength of 300 to 400 nm are particularly preferable. As a light source of irradiation light, a low-pressure mercury-vapor lamp, a high-pressure mercury-vapor lamp, an ultra-high-pressure mercury-vapor lamp, and a laser are mentioned, for example.

Among these, a laser is preferable. It is preferable to irradiate the entire surface of the temporary fixing material layer (II) while scanning the laser from the support body side, and it is more preferable to narrow the focus and irradiate the laser to the temporarily fixing material layer (II). The scanning method is not particularly limited. For example, in the XY plane of the temporarily fixing material layer (II), a laser is irradiated linearly in the X-axis direction, and the irradiation unit is sequentially moved in the Y-axis direction to irradiate the entire surface, or a method in which the laser is irradiated in a prism shape, and the entire surface is irradiated by sequentially moving the irradiation unit from the center to the outer edge or from the peripheral edge to the center to irradiate the entire surface.

As the laser, for example, a solid-state laser (eg, an all-solid-state laser using a light-excited semiconductor laser, a YAG laser), a liquid laser (eg, a dye laser), and a gas laser (eg, an excimer laser) are exemplified. Among these, an all-solid-state laser (wavelength: 355 nm), a YAG laser (wavelength: 355 nm), and an excimer laser using a light excitation semiconductor laser are preferable.

Examples of the excimer laser include F ₂ excimer laser (wavelength: 157 nm), ArF excimer laser (193 nm copper), KrF excimer laser (248 nm copper), XeCl excimer laser (308 nm copper), and XeF excimer laser (351 nm copper).

Light irradiation conditions differ depending on the type of light source, etc., but in the case of an all-solid-state laser using a light-excited semiconductor laser and a YAG laser, the light intensity is usually 1 mW to 100 W, and the amount of integrated light is usually 1.4 × 10 ^-7 to 1.4 × 10 ⁷ mJ/cm 2 .

<2-4. Process (4)〉

After the processing or moving treatment of the substrate, by applying force to the substrate or the support, the substrate is separated from the support, for example, to separate the two. For example, a method of separating the two by applying force to the substrate or support in a direction parallel to the substrate surface; A method of separating the two is exemplified by fixing one side of the substrate or support and lifting the other side at a constant angle in a direction parallel to the substrate surface.

As the former method, a method of separating the substrate from the support by fixing the support while sliding the substrate in the horizontal direction with respect to the surface of the support, or by applying a force to the support that opposes the force applied to the substrate.

In the latter method, it is preferable to separate the substrate from the support by applying force in a direction substantially perpendicular to the substrate surface. "Applying force in a direction substantially perpendicular to the substrate surface" means that the force is applied in a direction perpendicular to the substrate surface, usually in the range of 0 ° to 60 °, preferably in the range of 0 ° to 45 °, more preferably in the range of 0 ° to 30 °, still more preferably in the range of 0 ° to 5 °, particularly preferably 0 ° with respect to the z-axis, which is a vertical axis with respect to the substrate surface. As a separation method, for example, the periphery of the substrate or support is lifted (part or all of the periphery is peeled off from the temporarily fixed material), and while applying a force in a direction substantially perpendicular to the substrate surface, the substrate or support It can be carried out by a method of peeling in order from the periphery toward the center (hook pull method).

The separation can be performed at usually 5 to 100°C, preferably 10 to 45°C, and more preferably 15 to 30°C. Temperature here means the temperature of a support body. Further, in order to prevent damage to the substrate during separation, a reinforcing tape such as a commercially available dicing tape may be adhered to the surface opposite to the temporarily fixed surface of the substrate to the support.

In the present invention, as described above, the temporarily fixed material has a layer (I) and a layer (II), the base material is protected by the layer (I), and the separation occurs mainly in the layer (II). When the substrate has bumps, breakage of the bumps during the separation process can be prevented.

<2-5. Process (5)〉

Step (5) is a step of removing the temporarily fixed material layer (I) from the substrate. When the temporarily fixing material layer (I) is formed from the composition (I) for temporarily fixing containing a polybenzoxazole precursor, for example, by heat applied in steps (1) to (2), the precursor is considered to change to polybenzoxazole having excellent heat resistance. For this reason, it is possible to suppress deterioration of the temporarily fixing material layer (I) due to heat generated locally by light irradiation to the temporarily fixing material layer (II). Therefore, the layer (I) remaining on the substrate after the separation treatment of the substrate can be removed by a simple method such as peeling and solvent washing.

As the peeling treatment, for example, a method of peeling the temporarily fixing material layer (I) from the base material in a direction substantially perpendicular to the base material surface can be exemplified, and specifically, while applying force in a direction substantially perpendicular to the base material surface, a method of peeling the temporarily fixing material layer (I) sequentially from the periphery toward the center of the base material (hook-pull method) is exemplified. The meaning of the substantially vertical direction is as described in the column of step (4).

Examples of the cleaning treatment using a solvent include a method of immersing the substrate in the solvent, a method of spraying the substrate with the solvent, and a method of applying ultrasonic waves while immersing the substrate in the solvent. The temperature of the solvent is not particularly limited, but is preferably 10 to 80°C, more preferably 20 to 50°C. As the solvent, the solvents described in the column for preparation of compositions (I) and (II) for temporarily fixing can be exemplified.

Among these, the peeling treatment is preferable in that it can prevent breakage of the bump.

As described above, the substrate can be separated from the support.

3. Semiconductor device

The semiconductor device of the present invention can be manufactured by processing the substrate by the processing method of the substrate of the present invention. Since the temporarily fixed material is easily removed during the process (5) after separating the semiconductor device (eg, semiconductor element) obtained by processing the base material from the support, in the semiconductor device, contamination by the temporarily fixed material (eg, stains, sticking) is extremely reduced.

Example

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. In descriptions such as the following examples, "parts" represent "parts by mass" unless otherwise specified.

The average molecular weight (Mw, Mn) of the polymer and resin was measured in terms of polystyrene using a GPC column (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation using a measuring device "HLC-8220-GPC" (manufactured by Tosoh Corporation).

1. Preparation of composition for temporarily fixing

[Production Example 1] Preparation of composition for temporarily fixing (I-1)

50 parts of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and 270 parts of N-methyl-2-pyrrolidone were added to a 0.3 L flask, and the mixture was stirred and dissolved. Subsequently, while maintaining the temperature at 0 to 10°C, a solution in which 50 parts of 4,4'-oxybis(benzoyl chloride) was dissolved in 230 parts of N-methyl-2-pyrrolidone was added dropwise over 30 minutes, and then stirring was continued for 60 minutes. The solution after stirring was injected|thrown-in to pure water, the precipitate was collect|recovered, after washing this 3 times with pure water, it vacuum-dried and obtained the polybenzoxazole precursor (A1). The weight average molecular weight of precursor (A1) was 48,600. Precursor (A1) was dissolved in γ-butyrolactone/N-methyl-2-pyrrolidone = 8/2 (mass ratio) to prepare a solid content concentration of 30% by mass to prepare a temporary fixing composition (I-1).

[Production Example 2] Preparation of composition for temporarily fixing (I-2)

50 parts of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and 400 parts of N-methyl-2-pyrrolidone were added to a 0.3 L flask, followed by stirring and dissolution. Subsequently, while maintaining the temperature at 0 to 10°C, 50 parts of succinyl chloride was added dropwise over 30 minutes, and then stirring was continued for 60 minutes. The solution after stirring was injected|thrown-in to pure water, precipitate was collect|recovered, after washing this 3 times with pure water, it vacuum-dried and obtained the polybenzoxazole precursor (A2). The weight average molecular weight of the precursor (A2) was 58,500. Precursor (A2) was dissolved in γ-butyrolactone/N-methyl-2-pyrrolidone = 8/2 (mass ratio) to prepare a solid content concentration of 30% by mass to prepare a temporary fixing composition (I-2).

[Preparation Example 3] Preparation of composition for temporarily fixing (I-3)

50 parts of 2,2-bis(3-amino-4-hydroxyphenyl)isopropylidene and 270 parts of N-methyl-2-pyrrolidone were added to a 0.3 L flask, followed by stirring and dissolution. Subsequently, while maintaining the temperature at 0 to 10°C, a solution in which 50 parts of 4,4'-oxybis(benzoyl chloride) was dissolved in 230 parts of N-methyl-2-pyrrolidone was added dropwise over 30 minutes, and then stirring was continued for 60 minutes. The solution after stirring was injected|thrown-in to pure water, precipitate was collect|recovered, after washing this 3 times with pure water, it vacuum-dried and obtained the polybenzoxazole precursor (A3). The weight average molecular weight of the precursor (A3) was 26,300. Precursor (A3) was dissolved in γ-butyrolactone/N-methyl-2-pyrrolidone = 8/2 (mass ratio) to prepare a solid content concentration of 30% by mass to prepare a temporary fixing composition (I-3).

[Preparation Example 4] Preparation of composition for temporarily fixing (I-4)

In a 0.3 L flask, 50 parts of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 50 parts of 1,4-cyclohexanedicarboxylic acid (cis-, trans-mixture), and 500 parts of polyphosphoric acid were added, and stirred and dissolved. Subsequently, the temperature was raised to 200°C in a nitrogen atmosphere, and stirring was continued for 30 minutes. The solution after stirring was injected|thrown-in to pure water, precipitate was collect|recovered, after washing this 3 times with pure water, it vacuum-dried and obtained the polybenzoxazole precursor (A4). The weight average molecular weight of the precursor (A4) was 41,000. The precursor (A4) was dissolved in cyclohexanone to prepare a solid content concentration of 30% by mass to prepare a composition for temporarily fixing (I-4).

[Preparation Example 5] Preparation of composition for temporarily fixing (I-5)

70 parts of p-t-butoxystyrene and 10 parts of styrene were dissolved in 150 parts of propylene glycol monomethyl ether, and polymerization was performed for 10 hours using 4 parts of azobisisobutyronitrile while maintaining the reaction temperature at 70°C under a nitrogen atmosphere. Thereafter, sulfuric acid was added to the solution after polymerization, and the reaction temperature was maintained at 90° C. for 10 hours, and the p-t-butoxystyrene structural unit was deprotected and converted into p-hydroxystyrene structural unit. Ethyl acetate was added to the converted solution, washed with water 5 times, and ethyl acetate was removed to obtain p-hydroxystyrene/styrene copolymer (A5). The weight average molecular weight (Mw) of the copolymer (A5) was 10,000. Further, by NMR, the copolymer (A5) was a polymer having 80 mol% of p-hydroxystyrene units and 20 mol% of styrene units. The copolymer (A5) was dissolved in ethyl lactate to prepare a solid content concentration of 30% by mass to prepare a temporarily fixing composition (I-5).

[Production Example 6] Preparation of composition for temporarily fixing (I-6)

In a flask purged with nitrogen, 5.0 g of 2,2'-azobisisobutyronitrile as a polymerization initiator and 150 g of propylene glycol monomethyl ether acetate as a polymerization solvent were charged and stirred. To the solution after stirring, 11 g of methacrylic acid, 15 g of p-isopropenylphenol, 15 g of tricyclo [5.2.1.0 ^2,6 ] decanyl methacrylate, 39 g of isobornyl acrylate, and 20 g of phenoxy polyethylene glycol acrylate were added, stirring was started, and the temperature was raised to 80°C. Then, it heated at 80 degreeC for 6 hours. The solution after heating was added dropwise into a large amount of cyclohexane to solidify. The coagulum was washed with water, and the coagulum was re-dissolved in tetrahydrofuran of the same weight as the coagulum, and then the obtained solution was added dropwise into a large amount of cyclohexane to coagulate again. After performing this re-dissolution and solidification operation a total of 3 times, the resulting coagulated product was vacuum dried at 40°C for 48 hours to obtain a copolymer (A6). The weight average molecular weight (Mw) of the copolymer (A6) was 10,000. The copolymer (A6) was dissolved in propylene glycol monomethyl ether acetate to prepare a solid content concentration of 30% by mass to prepare a temporary fixing composition (I-6).

[Production Example 7] Preparation of composition for temporarily fixing (II-1)

80 parts of a cycloolefin polymer (trade name "ARTON RX4500", manufactured by JSR Co., Ltd.), 20 parts of a hydrogenated terpene resin (trade name "CLEARON P150", manufactured by Yasuhara Chemical Co., Ltd.), 20 parts of liquid styrene-butadiene rubber (trade name "L-SBR-820", manufactured by Kuraray Co., Ltd.), and 3 parts of a hindered phenolic antioxidant (trade name " IRGANOX1010", manufactured by BASF), 125 parts of a carbon black dispersion (trade name "MHI Black #209", manufactured by Mikuni Shikiso Co., Ltd., solid content: 35% by mass), and 367 parts of mesitylene. A composition for temporarily fixing (II-1) was prepared.

2. Evaluation

[Examples 1 to 4, Comparative Examples 1 to 4]

The composition for temporarily fixing (I-1) to (I-6) was spin-coated on a 4-inch silicon wafer (substrate 1), and then heated under the film forming conditions described in Table 1 using a hot plate. Substrate 1 having a uniform temporarily fixing layer (I) having a thickness of 10 μm was obtained. In addition, the composition for temporarily fixing (II-1) was spin-coated on a 4-inch glass wafer (substrate 2), and then heated at 160 ° C. for 5 minutes using a hot plate, followed by further heating at 230 ° C. for 10 minutes. Substrate 2 having a uniform temporarily fixed material layer (II) having a thickness of 3 μm was produced.

After cutting the substrate 1 and the substrate 2 into 1 cm in length and 1 cm in width, respectively, the temporarily fixing material layer (I) and the temporarily fixing material layer (II) were bonded so that they were in contact, and using a die bonder device, A pressure of 15 MPa was applied for 5 minutes at a compression temperature shown in Table 1 to obtain a laminate in which substrates 1 and 2 were laminated through the temporarily fixing material layer.

The obtained laminate was irradiated with a UV laser (wavelength: 355 nm) from the substrate 2 side with an all-solid-state high-power laser device (trade name “Genesis CX 355 STM Compact”, manufactured by Coherent Japan Co., Ltd.) at an output of 100 mW and a cumulative light amount of 2.08 × 10 ^-4 mJ/cm 2 . The board|substrate 2 was removed from the laminated body for a test after light irradiation. Subsequently, it was evaluated whether the temporarily fixed material layer (I) on the substrate 1 could be peeled off, or whether the temporarily fixed material layer (I) could be washed with the solvent used at the time of preparation of each temporarily fixed material composition forming the temporarily fixed material layer (I). Table 1 shows the evaluation results.

In the peeling treatment of the layer (I), the layer (I) was peeled by applying a force (500 μm/sec, 23° C.) in the direction of the axis (z-axis) perpendicular to one surface of the substrate in a hook pull method using a universal bond tester (trade name “Daisy 4000”, manufactured by Daisy).

In the cleaning treatment of the layer (I), the same type of solvent used in the preparation of each temporarily fixing composition (I-1) to (I-6) to form the temporarily fixing material layer (I), at 23 ° C. for 20 minutes, the laminate after substrate 2 removal was immersed. For example, in the case of Example 1, γ-butyrolactone/N-methyl-2-pyrrolidone = 8/2 (mass ratio), and in the case of Comparative Example 1, the laminate after substrate 2 removal was immersed in ethyl lactate, respectively.

1: laminate
10: support
20: temporary fixing material
21: temporarily fixed material layer (I)
22: temporarily fixed material layer (Ⅱ)
30: base

Claims (8)

(1) a step of forming a laminate having a support, a temporarily fixing material, and a substrate;
Here, the temporarily fixed material,
A temporarily fixed material layer (I) formed of a composition containing at least one polymer selected from a polybenzoxazole precursor and polybenzoxazole in contact with the surface of the support side of the base material,
It is formed on the surface of the support side in the temporarily fixed material layer (I), and at least one light absorber selected from the group consisting of organic light absorbers, resins having condensed polycyclic aromatic rings, black pigments, non-black pigments, and dyes, and cycloolefin-based polymers, terpene-based resins, petroleum resins, and conjugated diene polymers.
have;
(2) a step of processing the base material, moving the laminated body, or moving the laminated body after processing the base material;
(3) a step of irradiating light to the temporarily fixing material layer (II);
(4) a step of separating the substrate from the support; and
(5) a step of removing the temporarily fixing material layer (I) from the substrate;
A processing method for a base material having in this order. According to claim 1,
A method for treating a substrate in which the composition contains a polybenzoxazole precursor. According to claim 1,
In the step (3), the light irradiated to the temporarily fixed material layer (II) is a method of treating a substrate with ultraviolet rays. According to claim 3,
The processing method of the base material in which the said ultraviolet-ray is an ultraviolet-ray with a wavelength of 300-400 nm. According to any one of claims 1 to 4,
In the step (5), by either or both of the process of peeling the temporarily fixed material layer (I) from the substrate and the process of washing the temporarily fixed material layer (I) using a solvent, the process of removing the temporarily fixed material layer (I) from the substrate. delete delete delete

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