JP2013065786A - Substrate processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for inhibiting a dissolution residue from remaining on a substrate by a method different from adhesive filtration when removing an adhesive applied onto the substrate by dissolving the adhesive in a solvent.SOLUTION: A substrate processing method includes a step of heating an adhesive 2 applied onto a substrate 1 at a glass transition temperature of the adhesive 2 or higher within 10 minutes before a cleaning step of removing the adhesive 2 by dissolving the adhesive 2 in a solvent 5.

Description

  The present invention relates to a substrate processing method, and more particularly, to a substrate processing method including a cleaning step in which an adhesive applied on a substrate is dissolved and removed in a solvent.

  In recent years, electronic devices such as IC cards and mobile phones have been required to be thinner, smaller, and lighter. In order to satisfy these requirements, a thin semiconductor chip must be used as a semiconductor chip to be incorporated. For this reason, the thickness (film thickness) of the semiconductor wafer that is the basis of the semiconductor chip is currently 125 μm to 150 μm, but it is said that it must be 25 μm to 50 μm for next-generation chips. Therefore, in order to obtain a semiconductor wafer having the above film thickness, a semiconductor wafer thinning step is indispensable. The semiconductor wafer thinning step is performed, for example, as follows (see Patent Document 1).

  First, a support plate for protecting the semiconductor wafer is attached via a tape or adhesive having adhesive layers on both sides so as to cover the circuit formation surface of the semiconductor wafer. Next, this is reversed, and the back surface of the semiconductor wafer is ground by a cylinder to make it thinner. Subsequently, the back surface of the thinned semiconductor wafer is fixed on a dicing tape held by a dicing frame. Further, in this state, the support plate that covers the circuit forming surface of the semiconductor wafer is peeled, and then divided into chips by a dicing apparatus.

  Note that when the thinning process is performed as described above, an adhesive or the like remains on the circuit formation surface of the semiconductor wafer after the support plate is peeled off. Therefore, it is necessary to remove the adhering adhesive and the like to make the circuit formation surface of the semiconductor wafer clean. That is, after the support plate covering the circuit forming surface of the semiconductor wafer is peeled off, it is necessary to perform a cleaning process on the surface of the semiconductor wafer before being divided into chips by a dicing apparatus. The cleaning process is performed, for example, by dissolving and removing an adhesive present on the circuit forming surface of the semiconductor wafer in a solvent.

JP 2006-135272 A (published May 25, 2006)

  Here, according to the knowledge of the present inventors, when the adhesive filtered using a sufficiently fine filter is not used, the filler in the adhesive is formed on the circuit forming surface of the semiconductor wafer after the cleaning treatment. In some cases, a dissolution residue derived from the above may remain (see the inside of a circle in FIG. 3). However, from the viewpoint of cost and production volume, it is preferable to use a coarse filter for filtering the adhesive. Therefore, there is a demand for a technique for suppressing the dissolution residue from remaining on the substrate by a method different from the filtration of the adhesive.

  The present invention has been made in view of the above problems, and when the adhesive applied on the substrate is removed by dissolving it in a solvent, a dissolved residue is formed on the substrate by a technique different from filtration of the adhesive. The main purpose is to provide a technique for suppressing the remaining of the slag.

  A substrate processing method according to the present invention is a substrate processing method including a cleaning step of dissolving and removing an adhesive applied on a substrate in a solvent, and within 10 minutes before the cleaning step, The method further includes a heating step of heating the adhesive to a temperature higher than the glass transition temperature of the adhesive.

  According to the present invention, a heating step of heating the adhesive to a temperature equal to or higher than the glass transition temperature of the adhesive is performed within 10 minutes before the cleaning step of dissolving and removing the adhesive applied on the substrate. Therefore, it is possible to suppress the dissolution residue from remaining on the substrate.

It is a figure explaining each process of the processing method of the substrate concerning one embodiment of the present invention. It is a figure explaining each process of the evaluation method in an Example. It is the figure which showed the example of the melt | dissolution residue which remains on a board | substrate after a washing | cleaning process.

  The present invention provides a substrate processing method including a cleaning step of dissolving and removing an adhesive applied on a substrate in a solvent. The substrate processing method according to the present invention further includes a heating step of heating the adhesive to the glass transition temperature or more of the adhesive within 10 minutes before the cleaning step. Thereby, it can suppress that a melt | dissolution residue remains on a board | substrate.

  Hereinafter, each process of the processing method of the board | substrate which concerns on one Embodiment of this invention is demonstrated with reference to drawings. First, the substrate 1, the adhesive 2, the support plate 3, the dicing tape (adhered object) 4 and the solvent 5 used in the substrate processing method according to this embodiment will be described.

(substrate)
As the substrate 1, for example, a semiconductor wafer made of a conventionally known material can be suitably used.

(adhesive)
The adhesive 2 is configured to cover and protect the surface of the substrate 1 while simultaneously bonding and fixing the substrate 1 to the support plate 3. Therefore, the adhesive 2 needs to have adhesiveness and strength to maintain the fixing of the substrate 1 to the support plate 3 and the covering of the surface to be protected when the substrate 1 is processed or transported. is there. On the other hand, when it becomes unnecessary to fix the substrate 1 to the support plate 3, it needs to be easily peeled off or removed from the substrate 1.

  Therefore, the adhesive 2 usually has strong adhesiveness and is composed of an adhesive having solubility in a specific solvent. Various adhesives known in the art can be used as the adhesive according to the present invention. The composition of the resin contained in the adhesive 2 in the present embodiment will be described below.

  The resin contained in the adhesive 2 may be any resin having adhesiveness, and examples thereof include hydrocarbon resins, acrylic-styrene resins, maleimide resins, or combinations thereof.

(Hydrocarbon resin)
The hydrocarbon resin is a resin that has a hydrocarbon skeleton and is obtained by polymerizing a monomer composition. As the hydrocarbon resin, cycloolefin polymer (hereinafter sometimes referred to as “resin (A)”), and at least one resin selected from the group consisting of terpene resin, rosin resin and petroleum resin (hereinafter referred to as “resin (A)”). Resin (B) ”), and the like, but is not limited thereto.

  The resin (A) may be a resin obtained by polymerizing a monomer component containing a cycloolefin monomer. Specific examples include a ring-opening (co) polymer of a monomer component containing a cycloolefin monomer, and a resin obtained by addition (co) polymerization of a monomer component containing a cycloolefin monomer.

  Examples of the cycloolefin monomer contained in the monomer component constituting the resin (A) include bicyclic compounds such as norbornene and norbornadiene, tricyclic compounds such as dicyclopentadiene and dihydroxypentadiene, and tetracyclododecene. Tetracycles, pentacycles such as cyclopentadiene trimer, heptacycles such as tetracyclopentadiene, or alkyl (methyl, ethyl, propyl, butyl, etc.) substituted polyalkenyls, alkenyl (vinyl, etc.) Examples include substituted, alkylidene (such as ethylidene) substituted, aryl (such as phenyl, tolyl, naphthyl) substituted, and the like. Among these, norbornene-based monomers selected from the group consisting of norbornene, tetracyclododecene, and alkyl-substituted products thereof are preferable.

  The monomer component constituting the resin (A) may contain another monomer copolymerizable with the above-described cycloolefin-based monomer, and preferably contains, for example, an alkene monomer. Examples of the alkene monomer include ethylene, propylene, 1-butene, isobutene, 1-hexene, and α-olefin. The alkene monomer may be linear or branched.

  Moreover, it is preferable from a viewpoint of high heat resistance (low thermal decomposition and thermal weight reduction property) to contain a cycloolefin monomer as a monomer component which comprises resin (A). The ratio of the cycloolefin monomer to the whole monomer component constituting the resin (A) is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 20 mol% or more. preferable. Further, the ratio of the cycloolefin monomer to the whole monomer component constituting the resin (A) is not particularly limited, but is preferably 80 mol% or less from the viewpoint of solubility and stability over time in a solution, More preferably, it is 70 mol% or less.

  Moreover, you may contain a linear or branched alkene monomer as a monomer component which comprises resin (A). The ratio of the alkene monomer to the whole monomer component constituting the resin (A) is preferably 10 to 90 mol%, more preferably 20 to 85 mol% from the viewpoint of solubility and flexibility. 30 to 80 mol% is more preferable.

  The resin (A) is a resin having no polar group, such as a resin obtained by polymerizing a monomer component composed of a cycloolefin monomer and an alkene monomer, at high temperatures. It is preferable for suppressing generation of gas.

  The polymerization method and polymerization conditions for polymerizing the monomer components are not particularly limited and may be appropriately set according to a conventional method.

  Examples of commercially available products that can be used as the resin (A) include “TOPAS” manufactured by Polyplastics, “APEL” manufactured by Mitsui Chemicals, “ZEONOR” and “ZEONEX” manufactured by Nippon Zeon, and JSR “ARTON” made by the manufacturer can be mentioned.

  The glass transition point (Tg) of the resin (A) is preferably 60 ° C. or higher, and particularly preferably 70 ° C. or higher. When the glass transition point of the resin (A) is 60 ° C. or higher, the softening of the adhesive 2 can be further suppressed when the adhesive 2 is exposed to a high temperature environment.

  The resin (B) is at least one resin selected from the group consisting of terpene resins, rosin resins and petroleum resins. Specifically, examples of the terpene resin include terpene resins, terpene phenol resins, modified terpene resins, hydrogenated terpene resins, hydrogenated terpene phenol resins, and the like. Examples of the rosin resin include rosin, rosin ester, hydrogenated rosin, hydrogenated rosin ester, polymerized rosin, polymerized rosin ester, and modified rosin. Examples of petroleum resins include aliphatic or aromatic petroleum resins, hydrogenated petroleum resins, modified petroleum resins, alicyclic petroleum resins, coumarone-indene petroleum resins, and the like. Among these, hydrogenated terpene resins and hydrogenated petroleum resins are preferable.

  Although the softening point of resin (B) is not specifically limited, It is preferable that it is 80-160 degreeC. When the softening point of the resin (B) is 80 ° C. or higher, the adhesive 2 can be suppressed from being softened when exposed to a high temperature environment, and adhesion failure does not occur. On the other hand, when the softening point of the resin (B) is 160 ° C. or less, the peeling speed when peeling the support plate 3 from the substrate 1 becomes good.

  Although the molecular weight of resin (B) is not specifically limited, It is preferable that it is 300-3000. When the molecular weight of the resin (B) is 300 or more, the heat resistance is sufficient, and the degassing amount is reduced under a high temperature environment. On the other hand, when the molecular weight of the resin (B) is 3000 or less, the peeling rate when peeling the support plate 3 from the substrate 1 is good. In addition, the molecular weight of resin (B) in this embodiment means the molecular weight of polystyrene conversion measured by gel permeation chromatography (GPC).

  In addition, you may use what mixed resin (A) and resin (B) as resin. By mixing, heat resistance and peeling speed are improved. For example, the mixing ratio of the resin (A) and the resin (B) is (A) :( B) = 80: 20 to 55:45 (mass ratio). Since it is excellent in tolerance and flexibility, it is preferable.

(Acrylic-styrene resin)
Examples of the acryl-styrene resin include a resin obtained by polymerization using styrene or a styrene derivative and (meth) acrylic acid ester as monomers.

  Examples of the (meth) acrylic acid ester include a (meth) acrylic acid alkyl ester having a chain structure, a (meth) acrylic acid ester having an aliphatic ring, and a (meth) acrylic acid ester having an aromatic ring. . Examples of the (meth) acrylic acid alkyl ester having a chain structure include an acrylic long-chain alkyl ester having an alkyl group having 15 to 20 carbon atoms and an acrylic alkyl ester having an alkyl group having 1 to 14 carbon atoms. . As acrylic long-chain alkyl esters, acrylic or methacrylic acid whose alkyl group is n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, etc. Examples include alkyl esters. The alkyl group may be branched.

  Examples of the acrylic alkyl ester having an alkyl group having 1 to 14 carbon atoms include known acrylic alkyl esters used in existing acrylic adhesives. For example, an alkyl group of acrylic acid or methacrylic acid whose alkyl group is a methyl group, ethyl group, propyl group, butyl group, 2-ethylhexyl group, isooctyl group, isononyl group, isodecyl group, dodecyl group, lauryl group, tridecyl group, etc. Examples include esters.

  Examples of (meth) acrylic acid ester having an aliphatic ring include cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, 1-adamantyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, and tricyclodecanyl. (Meth) acrylate, tetracyclododecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate and the like can be mentioned, and isobornyl methacrylate and dicyclopentanyl (meth) acrylate are more preferable.

  The (meth) acrylic acid ester having an aromatic ring is not particularly limited. Examples of the aromatic ring include a phenyl group, a benzyl group, a tolyl group, a xylyl group, a biphenyl group, a naphthyl group, and an anthracenyl group. A phenoxymethyl group, a phenoxyethyl group, and the like. The aromatic ring may have a chain or branched alkyl group having 1 to 5 carbon atoms. Specifically, phenoxyethyl acrylate is preferable.

(Maleimide resin)
Examples of maleimide resins include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, N-sec as monomers. -Butylmaleimide, N-tert-butylmaleimide, Nn-pentylmaleimide, Nn-hexylmaleimide, Nn-heptylmaleimide, Nn-octylmaleimide, N-laurylmaleimide, N-stearylmaleimide, etc. Males having an aliphatic hydrocarbon group such as maleimide having an alkyl group, N-cyclopropylmaleimide, N-cyclobutylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide, N-cycloheptylmaleimide, N-cyclooctylmaleimide Resin obtained by polymerizing aromatic maleimide having an aryl group such as imide, N-phenylmaleimide, Nm-methylphenylmaleimide, N-o-methylphenylmaleimide, Np-methylphenylmaleimide, etc. It is done.

  For example, a cycloolefin copolymer, which is a copolymer of a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), can be used as the adhesive component resin.

(In Formula (2), n is 0 or an integer of 1-3.)
Examples of such cycloolefin copolymers include “TOPAS” (trade name) manufactured by Polyplastics, “APEL” (trade name) manufactured by Mitsui Chemicals, and “ZEONOR” (product manufactured by Nippon Zeon). Name) and “ZEONEX” (trade name), “ARTON” (trade name) manufactured by JSR, and the like can be used.

  It is preferable to use a resin other than a photocurable resin (for example, a UV curable resin). This is because the photocurable resin may remain as a residue around the minute irregularities of the substrate 1 after the adhesive 2 is peeled off or removed. In particular, an adhesive that dissolves in a specific solvent is preferable as the adhesive 2. This is because the adhesive 2 can be removed by dissolving it in a solvent without applying physical force to the substrate 1. When removing the adhesive 2, the adhesive 2 can be easily removed without damaging or deforming the substrate 1 even from the substrate 1 whose strength has decreased.

  The adhesive 2 may contain a filler. Such a filler may be a substance that does not dissolve in the solvent 5. That is, when the adhesive 2 is dissolved in the solvent 5, a dissolved residue may be generated.

  Examples of the filler include silica, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and basic magnesium carbonate. , Calcium carbonate, Zinc carbonate, Barium carbonate, Dorsonite, Hydrotalcite, Calcium sulfate, Barium sulfate, Calcium silicate, Talc, Clay, Mica, Montmorillonite, Bentonite, Sepiolite, Imogolite, Sericite, Glass fiber, Glass beads, Silica Examples include balun, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balun, zinc borate, and various magnetic powders.

  Moreover, an adhesive agent can be prepared by mixing resin and a filler using a well-known method. At this time, you may use the solution diluted with the organic solvent as needed.

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol Or polyhydric alcohols such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether of dipropylene glycol monoacetate and derivatives thereof; cyclic ethers such as dioxane; methyl lactate, ethyl lactate, methyl acetate , Ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, Esters such as ethyl propionate; terpene solvent; and the like and condensed polycyclic hydrocarbon can be exemplified. These may be used alone or in combination of two or more.

  Examples of the terpene solvent include α-pinene, camphene, pinane, myrcene, dihydromyrcene, p-menthane, 3-carene, p-menthadiene, α-terpinene, β-terpinene, α-ferrandrene, osymene, limonene. , P-cymene, γ-terpinene, terpinolene, 1,4-cineole, 1,8-cineole, rose oxide, linalool oxide, Fencon, α-cyclocitral, osmenol, tetrahydrolinalol, linalool, tetrahydromegol, isopulegol, dihydro Linalool, isodihydrolabandulol, β-cyclocitral, citronellal, L-mentholone, linalyl formate, dihydroterpineol, β-terpineol, menthol, myrsenol, L-menthol, pinocarbeo , Α-terpineol, γ-terpineol, nopol, myrtenol, dihydrocarbeveol, citronellol, mirutenal, dihydrocarvone, d-pulegone, geranyl ethyl ether, geranyl formate, neryl formate, terpinyl formate, isodihydrolavanduril acetate, Terpinyl acetate, linalyl acetate, myrcenyl acetate, bornyl acetate, menthyl propionate, linalyl propionate, nerol, carveol, perilla alcohol, geraniol, safranal, citral, perilaaldehyde, citronellyloxyacetaldehyde, hydroxycitronellal, berbenone, d- Carvone, L-carvone, piperitone, piperitenone, citronellyl formate, isobornyl acetate, menthyl acetate, citronellyl acetate, carbyl acetate, acetic acid Dimethyloctanyl, neryl acetate, isopulegol acetate, dihydrocarbyl acetate, nopyr acetate, geranyl acetate, bornyl propionate, neryl propionate, carbyl propionate, terpinyl propionate, citronellyl propionate, isobornyl propionate, linalyl isobutyrate, isobutyric acid Examples include neryl, linalyl butyrate, neryl butyrate, terpinyl isobutyrate, terpinyl butyrate, geranyl isobutyrate, citronellyl butyrate, citronellyl hexanoate, menthyl isovalerate, β-caryophyllene, cedrene, bisabolen, hydroxycitronellol, farnesol, and rhinosyl isobutyrate. It is done. Among these, limonene and p-menthane are more preferable from the viewpoint of solubility, and p-menthane is particularly preferable.

  Further, the condensed polycyclic hydrocarbon is a condensed ring hydrocarbon formed by two or more monocycles supplying only one side of each ring to each other. In the present invention, two monocycles are condensed. It is preferable to use the following hydrocarbon.

  Such hydrocarbons include combinations of 5-membered and 6-membered rings, or combinations of two 6-membered rings. Examples of hydrocarbons combining 5-membered and 6-membered rings include indene, pentalene, indane, tetrahydroindene and the like. Examples of hydrocarbons combining two 6-membered rings include naphthalene, tetrahydronaphthalene ( Tetralin) and decahydronaphthalene (decalin).

  Further, the adhesive 2 may be configured to contain a thermal polymerization inhibitor. The thermal polymerization inhibitor has a function of preventing radical polymerization reaction due to heat. Specifically, since the thermal polymerization inhibitor is highly reactive to radicals, it reacts preferentially over the monomer and inhibits polymerization of the monomer. In the adhesive 2 containing such a thermal polymerization inhibitor, the polymerization reaction is suppressed under a high temperature environment (particularly, 250 ° C. to 350 ° C.).

  For example, in the semiconductor manufacturing process, there may be a high temperature process in which the substrate 1 to which the support plate 3 is bonded is heated at 250 ° C. for 1 hour. At this time, when the adhesive 2 is polymerized at a high temperature, the solubility in a peeling solution for peeling the support plate 3 from the substrate 1 after the high-temperature process is lowered, and the support plate 3 cannot be peeled well from the substrate 1. However, since the polymerization reaction is suppressed in the adhesive 2 containing the thermal polymerization inhibitor, the support plate 3 can be easily peeled off, and the generation of residues can be suppressed.

  Although it will not specifically limit if it is effective in preventing the radical polymerization reaction by heat | fever as a thermal-polymerization inhibitor, The thermal-polymerization inhibitor which has a phenol is preferable. Thereby, good solubility can be ensured even after high temperature treatment in the atmosphere. As such a thermal polymerization inhibitor, it is possible to use a hindered phenol antioxidant, for example, pyrogallol, benzoquinone, hydroquinone, methylene blue, tert-butylcatechol, monobenzyl ether, methylhydroquinone, amylquinone, Amyloxyhydroquinone, n-butylphenol, phenol, hydroquinone monopropyl ether, 4,4 ′-(1-methylethylidene) bis (2-methylphenol), 4,4 ′-(1-methylethylidene) bis (2,6 -Dimethylphenol), 4,4 '-[1- [4- (1- (4-hydroxyphenyl) -1-methylethyl) phenyl] ethylidene] bisphenol, 4,4', 4 "-ethylidene tris (2- Methylphenol), 4,4 ', 4 "-ethylident Sphenol, 1,1,3-tris (2,5-dimethyl-4-hydroxyphenyl) -3-phenylpropane, 2,6-di-tert-butyl-4-methylphenol, 2,2′-methylenebis ( 4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 3,9 -Bis [2- (3- (3-tert-butyl-4-hydroxy-5-methylphenyl) -propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro (5 , 5) Undecane, triethylene glycol-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, n Octyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythryltetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (trade name) IRGANOX 1010 (manufactured by Ciba Japan), tris (3,5-di-tert-butylhydroxybenzyl) isocyanurate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] Is mentioned. Only one type of thermal polymerization inhibitor may be used, or two or more types may be used in combination.

  The content of the thermal polymerization inhibitor may be appropriately determined according to the type of resin and the application and use environment of the adhesive 2. For example, when the resin is 100 parts by weight, 0.1 part by weight or more, The amount is preferably 10 parts by weight or less. If the content of the thermal polymerization inhibitor is within the above range, the effect of suppressing the polymerization due to heat is satisfactorily exhibited, and the decrease in the solubility of the adhesive 2 in the stripping solution can be further suppressed after the high temperature process.

  Note that the adhesive 2 may further contain other miscible materials as long as the essential characteristics of the present invention are not impaired. For example, various commonly used additives such as additional resins, plasticizers, adhesion aids, stabilizers, colorants and surfactants for improving the performance of the adhesive 2 can be further used.

  The adhesive 2 may be filtered using a filter, but may be unfiltered.

(Support plate)
The support plate 3 is a member that plays a role of supporting the substrate 1 in the process of thinning the substrate 1, and is bonded to the substrate 1 by the adhesive 2. In one embodiment, the support plate 3 is made of, for example, glass or silicon having a thickness of 500 to 1000 μm.

  In one embodiment, the support plate 3 is provided with a hole penetrating the support plate 3 in the thickness direction. By pouring the solvent 5 between the support plate 3 and the substrate 1 through the holes, the support plate 3 and the substrate 1 can be easily separated.

  In another embodiment, a reaction layer may be interposed between the support plate 3 and the substrate 1 in addition to the adhesive 2 film. The reaction layer is altered by absorbing light irradiated through the support plate 3, and the support plate 3 and the substrate are altered by altering the reaction layer by irradiating the reaction layer with laser light or the like. 1 can be easily separated. In this case, the support plate 3 is preferably a support plate that is not provided with a hole penetrating in the thickness direction.

  The reaction layer may contain a light absorber that is decomposed by, for example, laser light. Examples of the light absorber include graphite powder, fine metal powder such as iron, aluminum, copper, nickel, cobalt, manganese, chromium, zinc, tellurium, metal oxide powder such as black titanium oxide, carbon black, or aromatic. Dye or pigment such as diamino metal complex, aliphatic diamine metal complex, aromatic dithiol metal complex, mercaptophenol metal complex, squarylium compound, cyanine dye, methine dye, naphthoquinone dye, anthraquinone dye Can be used. Such a reaction layer can be formed by, for example, mixing with a binder resin and applying on the support plate 3. A resin having a light absorbing group can also be used.

  Further, as the reaction layer, an inorganic film or an organic film formed by a plasma CVD method may be used. For example, a metal film can be used as the inorganic film. As the organic film, a fluorocarbon film can be used. Such a reaction film can be formed on the support plate 3 by a plasma CVD method, for example.

(Dicing tape)
The dicing tape 4 is bonded to one side of the substrate 1 in order to reinforce the strength of the substrate 1. As the dicing tape 4, for example, a dicing tape having a configuration in which an adhesive layer is formed on a base film can be used. As the base film, for example, a resin film such as PVC (polyvinyl chloride), polyolefin, or polypropylene can be used.

  The dicing tape 4 is larger than the outer diameter of the substrate 1, and when these are bonded, a part of the dicing tape 4 is exposed at the outer edge of the substrate 1. Further, a dicing frame for preventing the dicing tape 4 from bending is provided on the outer edge of the exposed surface of the dicing tape 4.

(solvent)
The solvent 5 for dissolving the adhesive is not particularly limited, and examples thereof include straight-chain hydrocarbons such as hexane, heptane, octane, nonane, methyloctane, decane, undecane, dodecane, and tridecane, and those having 3 carbon atoms. 15 branched hydrocarbons; geraniol, nerol, linalool, citral, citronellol, p-menthane, o-menthane, m-menthane, diphenylmenthane, menthol, isomenthol, neomenthol, limonene, α-terpinene, β-terpinene , Γ-terpinene, α-terpineol, β-terpineol, γ-terpineol, terpinen-1-ol, terpinene-4-ol, 1,4-terpine, 1,8-terpine, carvone, yonon, tuyon, camphor, bornin , Borneol, Norbornane, Pina , Α-pinene, β-pinene, tujang, α-tujon, β-tujon, kalan, camphor, longifolene, 1,4-cineole, monoterpenes such as 1,8-cineole, and diterpenes such as abietane and abietic acid And cyclic hydrocarbons (terpenes). Moreover, in the description of the adhesive described above, the organic solvent mentioned as the solvent for diluting the adhesive may be used.

(Substrate processing method)
Subsequently, a substrate processing method according to the present embodiment will be described. The substrate processing method according to the present embodiment executes an adhesive forming step, an adhering step, a processing step, a heating step, a cooling step, a pasting step, a separating step, and a cleaning step in this order. However, in the present invention, it is not always necessary to execute all the steps described above, as long as at least the heating step and the cleaning step are executed.

(Adhesive layer forming process)
In the adhesive layer forming step, first, an adhesive 2 is applied on the substrate 1 as shown in FIG. And as shown in FIG.1 (b), the film | membrane (adhesive layer) of the adhesive agent 2 is formed into a film by heating the adhesive agent 2 in the state with which the adhesive agent 2 was apply | coated on the board | substrate 1. FIG. . Although the film thickness of the film | membrane of the adhesive agent 2 is not specifically limited, For example, it can be 15 micrometers or more and 130 micrometers or less.

  In addition, the heating conditions may be appropriately set according to the adhesive 2 to be used, and are not particularly limited. For example, by baking in steps while increasing the temperature in the range of 50 ° C. or more and 250 ° C. or less, The film of the adhesive 2 can be successfully formed.

(Adhesion process)
In the bonding step, the substrate 1 and the support plate 3 are bonded via the adhesive 2 film. For example, the support plate 3 is overlapped on the side of the substrate 1 where the adhesive 2 film is formed, and pressurized in a vacuum at a high temperature (for example, 215 ° C.), as shown in FIG. The substrate 1 and the support plate 3 can be bonded. However, as a bonding method, a suitable one from various conventionally known methods is appropriately selected according to the state of the substrate 1 (surface unevenness, strength, etc.), the material of the adhesive 2 and the material of the support plate 3. That's fine.

  When a reaction layer is interposed between the support plate 3 and the substrate 1, the reaction layer may be formed in advance on the surface of the support plate 3 that adheres to the adhesive 2 film by the method described above. preferable. Thereby, when the substrate 1 and the support plate 3 are bonded, the reaction layer is interposed between the support plate 3 and the substrate 1.

(Processing process)
In the processing step, desired processing such as grinding (thinning) and through electrode formation is performed on the substrate 1 supported by the support plate 3.

(Heating process)
In the heating step, the film of the adhesive 2 is heated. By performing this heating step within 10 minutes before the cleaning step and heating to a temperature equal to or higher than the glass transition temperature of the adhesive 2, it is possible to suppress the dissolution residue from remaining on the substrate 1 after the cleaning step. it can. Note that “perform the heating step within 10 minutes before the cleaning step” means that the interval from the completion time of the heating step to the start time of the cleaning step is 10 minutes or less.

  Moreover, what is necessary is just to heat the whole including the board | substrate 1 and the support plate 3 more than the glass transition temperature of the adhesive agent 2 in a heating process, for example. The heating step is more preferably performed within 5 minutes before the washing step.

(Cooling process)
The cooling step is a step of improving the handling property of the substrate 1 by cooling the substrate 1 or the like heated in the heating step. Even if such a cooling process is performed, the effect of this embodiment by a heating process is not impaired.

(Attaching process)
In the attaching step, as shown in FIG. 1D, the dicing tape 4 is attached to the side of the substrate 1 opposite to the side to which the support plate 3 is bonded.

(Separation process)
In the separation step, the support plate 3 is separated from the substrate 1 as shown in FIG. The separation method is not particularly limited. As described above, when the support plate 3 has a hole, the adhesive 2 is dissolved by supplying the solvent 5 from the hole, and the support plate 3 is attached to the substrate. 1 may be separated. As described above, when a reaction layer is interposed between the substrate 1 and the support plate 3, the reaction layer is altered by irradiating the reaction layer with light, so that the support plate 3 is attached to the substrate 1. May be separated from

(Washing process)
In the cleaning step, as shown in FIG. 1 (f), by supplying the solvent 5 to the adhesive 2 on the substrate 1, the adhesive 2 is dissolved in the solvent 5 and the adhesive 2 is removed from the substrate 1 ( FIG. 1 (g)). The method for supplying the solvent 5 is not particularly limited. For example, the solvent 5 may be sprayed using a two-fluid nozzle. At this time, as shown in FIG. 1F, the solvent 5 may be supplied while the nozzle is swung.

(Modification)
The substrate processing method according to the present invention is not limited to the above-described configuration. For example, when there is a substrate 1 to which the adhesive 2 has been applied in advance and the purpose is to clean the substrate 1, the substrate processing method may include only the heating step and the cleaning step. .

  Moreover, the heating process should just be the process of heating the adhesive agent 2 apply | coated on the board | substrate 1 more than the glass transition temperature of the adhesive agent 2. FIG. For example, in the adhesive layer forming step, if the heating condition for forming the film of the adhesive 2 is equal to or higher than the glass transition temperature of the adhesive 2, the adhesive layer forming step within 10 minutes before the cleaning step Similarly, the effects of the present invention can be obtained by executing. In this case, the adhesive layer forming step is a heating step. As described above, when the heating process is performed separately from the adhesive forming process, the interval between the adhesive forming process and the cleaning process is not particularly limited.

  In addition, the target (object to be bonded) to be bonded to the substrate 1 in the bonding step is not limited to the support plate 3, and the bonding target may be selected according to the purpose of the substrate 1. Moreover, depending on the processing content of the board | substrate 1, a sticking process and a processing process do not need to be implemented.

  Moreover, a heating process should just be implemented within 10 minutes before a washing | cleaning process, and an order with another process is not limited. However, when the support plate 3 having holes is used and the solvent 5 is supplied to the holes of the support plate 3 in the separation step, it is preferable to perform a heating step before the separation step.

  In any case, the present invention is generally applicable suitably when the adhesive 2 is applied on the substrate 1 and the adhesive 2 needs to be removed.

  A bare silicon substrate was used as the substrate 1. Further, as the adhesive 2, an ethylene-tetracyclododecene copolymer (APL 8008T (Mitsui Chemicals)): the molar ratio of the structural unit derived from ethylene to the structural unit derived from tetracyclododecene is 80:20, and the molecular weight is 105000. ) Is dissolved in an organic solvent (decalin: butyl acetate = 4.2: 1 mixed solvent) so that the resin solid content concentration is 23% by mass, and a thermal polymerization inhibitor IR1010 (IRGANOX1010, BASF) is added thereto. It added so that it might become 5 mass% with respect to resin solid content, and the unfiltered adhesive agent (viscosity 10000cp, glass transition temperature 75 degreeC) was prepared. As the solvent 5, p-menthane was used.

  First, as a positive control experiment (Experiment 1), the filtered adhesive 2 was applied on the substrate 1 (FIG. 2A), and baked at 90 ° C., 160 ° C., and 220 ° C. for 5 minutes each for adhesion. The film | membrane (50 micrometers) of the agent 2 was formed into a film (FIG.2 (b)). Then, after 1 day (24 hours), the dicing tape 4 was affixed to the board | substrate 1 (FIG.2 (c)). And the board | substrate 1 was spray-cleaned for 600 second using the solvent 5 (FIG.2 (d)), and the adhesive agent 2 was removed (FIG.2 (e)). Thereafter, the dicing tape 4 was peeled off, and the haze (turbidity) of the substrate 1 was measured as an index of the amount of dissolved residue.

  Next, as a negative control experiment (Experimental Example 2), the measurement was performed in the same manner as in Experimental Example 1 except that the unfiltered adhesive 2 was used.

  As a result, in Experimental Example 2, the haze was 205, and when the obtained substrate 1 was irradiated with light, white turbidity was observed, and dissolved residue was confirmed with a 5000 × microscope (one in the circle in FIG. 3 is 1). ~ About 2 μm). On the other hand, in Experimental Example 1, the haze was 52, and no cloudiness was observed even when light was applied to the obtained substrate 1. If the haze is 90 or less, it is considered that the residual amount of the dissolved residue is sufficiently suppressed.

  In addition, the haze of the board | substrate 1 before a process was 30, and the carbon content measured by XPS was 8.00 atm%. On the other hand, the haze of the substrate 1 after cleaning obtained in Experimental Example 1 was 52, and the amount of carbon measured by XPS increased with 41.9 atm%. Therefore, it is considered that the increase in haze is caused by a dissolved residue containing carbon derived from the adhesive 2.

  Subsequently, as Experimental Example 3, an unfiltered adhesive 2 was applied onto the substrate 1 (FIG. 2A), and baked at 90 ° C., 160 ° C., and 220 ° C. for 5 minutes each, 50 μm) was formed (FIG. 2B). Then, after 1 day (24 hours), the substrate 1 was baked at 50 ° C. for 5 minutes (follow-up baking) and then cooled for 3 minutes. Then, the dicing tape 4 was affixed on the board | substrate 1 by the operation | work for about 2 minutes (FIG.2 (c)). And the board | substrate 1 was spray-cleaned for 600 second using the solvent 5 (FIG.2 (d)), and the adhesive agent 2 was removed (FIG.2 (e)). Thereafter, the dicing tape 4 was peeled off, and the haze (turbidity) of the substrate 1 was measured. Hereinafter, the baking of the substrate 1 after the film of the adhesive 2 is formed and before the cleaning process will be referred to as “additional baking”.

  Moreover, as Experimental Example 4, the measurement was performed in the same manner as in Experimental Example 3 except that the temperature of additional baking was changed from 50 ° C to 60 ° C. Moreover, as Experimental Example 5, the measurement was performed in the same manner as Experimental Example 3 except that the temperature of additional baking was changed from 50 ° C. to 70 ° C. Moreover, as Experimental Example 6, the measurement was performed in the same manner as Experimental Example 3 except that the temperature of additional baking was changed from 50 ° C to 80 ° C. Moreover, as Experimental Example 7, the measurement was performed in the same manner as Experimental Example 3 except that the temperature of the additional baking was changed from 50 ° C to 100 ° C. Moreover, as Experimental Example 8, the measurement was performed in the same manner as Experimental Example 3 except that the temperature of additional baking was changed from 50 ° C to 150 ° C. Moreover, as Experimental Example 9, the measurement was performed in the same manner as Experimental Example 3 except that the temperature of additional baking was changed from 50 ° C to 220 ° C.

  In Experimental Examples 3 to 6, the temperature of the substrate 1 at the start of cleaning of the substrate 1 was measured. Table 1 shows the measurement results of haze and substrate temperature.

  As shown in Table 1, it was found that the haze is drastically reduced by additional baking at a temperature equal to or higher than the glass transition temperature (75 ° C.) of the adhesive 2 immediately before cleaning. Even when additionally baked at 80 ° C., the haze was 40, which was smaller than the haze 52 when the filtered adhesive 2 was used. Therefore, it was found that the remaining of the dissolved residue can be suitably suppressed by performing additional baking at a temperature equal to or higher than the glass transition temperature (75 ° C.) of the adhesive 2 immediately before cleaning.

  As shown in Table 1, regardless of the additional baking temperature, the temperature of the substrate 1 at the start of the cleaning process is substantially room temperature, and the above effect is due to the temperature of the adhesive 2 at the start of the cleaning process. It turned out not to depend on.

  In addition, as Experimental Example 10, after the film of the adhesive 2 was formed, the measurement was also performed when the substrate 1 was baked at 80 ° C. for 5 minutes after 7 days. In Experimental Example 10, the measurement was performed in the same manner as in Experimental Example 3 except that the period from the film formation of the adhesive 2 to the additional baking was set to 7 days. The results are shown in Table 2.

  As shown in Table 2, the measured haze is 90 or less, and even when the period from application of the adhesive 2 to washing is long, additional baking is performed at a temperature equal to or higher than the glass transition temperature of the adhesive 2. It was found that the residue of the dissolved residue can be sufficiently suppressed by performing.

  Subsequently, as Experimental Example 11, the filtered adhesive 2 was applied onto the substrate 1 (FIG. 2A), and baked at 90 ° C., 160 ° C., and 220 ° C. for 5 minutes each, 50 μm) was formed (FIG. 2B). Immediately after that, the substrate 1 was cooled for 3 minutes, and then the dicing tape 4 was attached to the substrate 1 by an operation of about 2 minutes (FIG. 2C). And after measuring the temperature of the board | substrate 1, the board | substrate 1 was spray-cleaned for 600 second using the solvent 5 (FIG.2 (d)), and the adhesive agent 2 was removed (FIG.2 (e)). Thereafter, the dicing tape 4 was peeled off, and the haze (turbidity) of the substrate 1 was measured. Further, as Experimental Example 12, measurement was performed in the same manner as Experimental Example 11 except that the unfiltered adhesive 2 was used. The results are shown in Table 3.

  As shown in Table 3, by baking at a temperature equal to or higher than the glass transition temperature (75 ° C.) of the adhesive 2 immediately before cleaning, the baking is not a post-bake but a film formation after the application of the adhesive 2 It was found that the residue of the dissolved residue can be similarly suppressed even if the baking is for baking.

  In addition, as Experimental Example 13, the effect when the substrate 1 on which the dissolved residue obtained in Experimental Example 2 remains was further baked was also verified. In Experimental Example 13, the substrate 1 on which the dissolved residue obtained in Experimental Example 2 remained was baked at 80 ° C. for 5 minutes (follow-up baking). Thereafter, as in other experimental examples, cooling, sticking, washing and haze measurement were performed. The results are shown in Table 4.

  As shown in Table 4, even if the substrate 1 on which only the dissolved residue remained was subjected to additional baking at a temperature equal to or higher than the glass transition temperature of the adhesive 2 and washed, no reduction in haze occurred. From this result, the effect of baking at a temperature equal to or higher than the glass transition temperature (75 ° C.) of the adhesive 2 immediately before cleaning is that the components that do not dissolve in the solvent in the adhesive 2 are shrunk by heat and can be easily cleaned. Instead, it is considered that cleaning is facilitated by changing the fluidity of the component not dissolved in the solvent in the film of the adhesive 2.

  The present invention can be suitably used in the field of processing a substrate such as a semiconductor wafer.

1 Substrate 2 Adhesive 3 Support plate (to be adhered)
4 Dicing tape 5 Solvent

Claims (5)

A substrate processing method comprising a cleaning step of dissolving and removing an adhesive applied on a substrate in a solvent,
A method for treating a substrate, further comprising a heating step of heating the adhesive to a temperature equal to or higher than a glass transition temperature of the adhesive within 10 minutes before the cleaning step.   2. The substrate processing method according to claim 1, wherein the adhesive contains a substance that does not dissolve in the solvent. Further including an adhesive layer forming step of forming the adhesive layer by applying the adhesive on the substrate and heating the adhesive;
The substrate processing method according to claim 1, wherein the adhesive layer forming step and the heating step are different steps. After the adhesive layer forming step, an adhesion step of bonding an adherend to the substrate via the adhesive layer;
4. The substrate processing method according to claim 3, further comprising a separation step of separating the adherend from the substrate after the bonding step and before the cleaning step.   The substrate processing method according to claim 1, further comprising a cooling step of cooling the substrate after the heating step and before the cleaning step.