JP2014072453A - Plasma processing apparatus, plasma processing method, and process of manufacturing laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an excellent separation layer.SOLUTION: A plasma processing apparatus 100 include: a bell jar type chamber 102 provided with a dome part 112 and a cylindrical part 113; a cap type coil 107 provided at an outer periphery of the dome part 112; and a stage 103 to which a support body 4 is mounted. A downflow region 111 where a radical generated in a plasma generation part 114 is recoupled is provided between the plasma generation part 114 surrounded by the cap type coil 107 of the chamber 102 and the stage 103.

Description

  The present invention relates to a plasma processing apparatus, a plasma processing method, and a laminate manufacturing method.

  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 wafer substrate on which the semiconductor chip is based is currently 125 μm to 150 μm, but it is said that it must be 25 μm to 50 μm for the next generation chip. Therefore, in order to obtain a wafer substrate having the above film thickness, a wafer substrate thinning step is indispensable.

  Since the strength of the wafer substrate decreases due to the thinning of the wafer substrate, a circuit is formed on the wafer substrate while automatically supporting the substrate while the support is bonded to the wafer substrate to prevent damage to the thinned wafer substrate. Etc. are mounted. Then, after the manufacturing process, the wafer substrate is separated from the support. Therefore, it is preferable that the wafer substrate and the support are firmly bonded during the manufacturing process, but it is preferable that the wafer substrate can be smoothly separated from the support after the manufacturing process.

  When the wafer substrate and the support are firmly bonded, depending on the adhesive material, it is difficult to separate the support from the wafer substrate without damaging the structure mounted on the wafer substrate. Therefore, it is an extremely difficult temporary fixing technology that realizes strong adhesion between the wafer substrate and the support during the manufacturing process and separates the elements mounted on the wafer substrate without damaging them after the manufacturing process. Development is required.

  As a method for manufacturing a semiconductor chip in which a support is bonded to a semiconductor wafer, the semiconductor wafer is processed, and then the support is separated, a method described in Patent Document 1 is known. In the method described in Patent Document 1, a light-transmitting support and a semiconductor wafer are bonded together via a photothermal conversion layer and an adhesive layer provided on the support, and after the semiconductor wafer is processed, the support side The photothermal conversion layer is decomposed by irradiating radiant energy from the substrate to separate the semiconductor wafer from the support.

Japanese Patent Laying-Open No. 2005-159155 (released on June 16, 2005) JP-A-8-88220 (published on April 2, 1996) Japanese Patent Laid-Open No. 5-502971 (published on May 20, 1993) JP-A-8-50996 (published on February 20, 1996) JP 2000-12287 A (published January 14, 2000)

  Based on unique knowledge, the present inventors provide a substrate, a light-transmitting support that supports the substrate, and light that is provided between the substrate and the support and is irradiated through the support. When manufacturing a laminated body provided with a separation layer that is altered by absorbing water, it was considered to form the separation layer by a plasma CVD method. However, when a known plasma CVD apparatus (see Patent Documents 2 to 5) is used, it is difficult to form a good separation layer.

  The present invention has been made in view of the above problems, and is provided between a substrate, a light-transmitting support that supports the substrate, and the substrate and the support, and is irradiated through the support. The main object of the present invention is to provide a technique for forming a good separation layer in the production of a laminate having a separation layer that is altered by absorbing light.

  A plasma processing apparatus according to the present invention includes a bell jar type chamber having a dome portion and a cylindrical portion, a cap type coil provided on an outer periphery of the dome portion, and a stage on which an object to be processed is placed. A downflow region in which radicals generated in the plasma generation unit are recombined is provided between the stage and the plasma generation unit surrounded by the cap-type coil in the chamber. Yes.

  A plasma processing method according to the present invention includes a bell jar type chamber having a dome portion and a cylindrical portion, a cap type coil provided on the outer periphery of the dome portion, and a stage on which an object to be processed is placed. A plasma processing method in the plasma processing apparatus, comprising: a plasma generating step for generating plasma in a plasma generating portion surrounded by the cap-type coil in the chamber; and a step between the plasma generating portion and the stage. And a recombination step of recombining radicals generated in the plasma generation step in the downflow region.

  According to the present invention, a substrate, a light-transmitting support that supports the substrate, and an alteration by absorbing light that is provided between the substrate and the support and is irradiated through the support. When manufacturing the laminated body provided with the separation layer to perform, a favorable separation layer can be formed.

It is a figure explaining the manufacturing method of the laminated body which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the plasma processing apparatus which concerns on one Embodiment of this invention. It is the figure which observed the plasma processing apparatus concerning one embodiment of the present invention from the upper part. It is a figure which shows schematic structure of the plasma processing apparatus which concerns on the modification of this invention. It is a figure which shows the change of the shielding efficiency of a separated layer when the distance between a plasma generation part and a glass substrate is changed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Specifically, the whole manufacturing method of the laminated body according to the present embodiment will be described, and the details of the plasma processing apparatus according to the present embodiment for forming the separation layer will be described therein.

  FIG. 1 is a diagram schematically showing each step of the method for manufacturing a laminate according to the present embodiment. A laminate 10 manufactured by the method for manufacturing a laminate according to this embodiment includes a semiconductor wafer (substrate) 1, a light-transmitting support 4 that supports the semiconductor wafer 1, and the semiconductor wafer 1 and the support 4. A separation layer 3 is provided which is provided between them and is altered by absorbing light irradiated through the support 4. As shown in FIG. 1, the manufacturing method of the laminated body which concerns on this embodiment is (1) contact bonding layer formation process, (2) separation layer formation process, (3) bonding process, (4) irradiation process, (5 A separation step, and (6) a washing step.

[1: Adhesive layer forming step]
In the adhesive layer forming step according to the present embodiment, an adhesive is applied on the semiconductor wafer 1 to form the adhesive layer 2 on the semiconductor wafer 1 as shown in FIG.

  The semiconductor wafer 1 is subjected to processes such as thinning and mounting while being supported by the support 4. In another embodiment, the laminated body 10 can employ an arbitrary substrate such as a thin film substrate or a flexible substrate instead of the semiconductor wafer 1. A fine structure of an electronic element such as an electric circuit may be formed on the surface of the semiconductor wafer 1 or other substrate on the side where the adhesive layer 2 is provided.

  The adhesive layer 2 is configured to cover and protect the surface of the semiconductor wafer 1 while simultaneously bonding and fixing the semiconductor wafer 1 to the support 4. Therefore, the adhesive layer 2 has adhesiveness and strength to maintain the fixing of the semiconductor wafer 1 to the support 4 and the covering of the surface to be protected of the semiconductor wafer 1 when the semiconductor wafer 1 is processed or transported. Need to be. On the other hand, it is necessary that the semiconductor wafer 1 can be easily peeled off or removed when the semiconductor wafer 1 is not fixed to the support 4.

  Therefore, the adhesive layer 2 usually has strong adhesiveness, and is composed of an adhesive whose adhesiveness is reduced by some treatment or has solubility in a specific solvent. For example, the thickness of the adhesive layer 2 is more preferably 1 to 200 μm, and further preferably 10 to 150 μm. The adhesive layer 2 can be formed by applying an adhesive material as described below onto the semiconductor wafer 1 by a conventionally known method such as spin coating.

  As the adhesive, for example, various adhesives known in the art such as acrylic, novolak, naphthoxan, hydrocarbon, polyimide, and elastomer are adhesives that constitute the adhesive layer 2 according to the present embodiment. It can be used. Below, the composition of the resin contained in the adhesive layer 2 in the present embodiment will be described.

  The resin contained in the adhesive layer 2 is not particularly limited as long as it has adhesiveness, and examples thereof include hydrocarbon resins, acrylic-styrene resins, maleimide resins, elastomer resins, and combinations thereof. It is done.

(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, a cycloolefin polymer (hereinafter sometimes referred to as “resin (A)”), and at least one resin selected from the group consisting of a terpene resin, a rosin resin and a petroleum resin (hereinafter referred to as “the 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 Co., Ltd., “APEL” manufactured by Mitsui Chemicals, Inc., “ZEONOR” and “ZEONEX” manufactured by Zeon Corporation. And “ARTON” manufactured by JSR Corporation.

  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, softening of the adhesive layer can be further suppressed when the laminate 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 more 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 layer can be prevented from being softened when the laminate is 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 rate when peeling the laminate is 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 laminate 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). It is preferable because of excellent resistance and flexibility.

(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, Nt-butylmaleimide, Nn-pentylmaleimide, Nn-hexylmaleimide, Nn-heptylmaleimide, Nn-octylmaleimide, N-laurylmaleimide, N-stearylmaleimide, etc. Maleimide having an aliphatic hydrocarbon group such as maleimide having an alkyl group, N-cyclopropylmaleimide, N-cyclobutylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide, N-cycloheptylmaleimide, N-cyclooctylmaleimide, etc. N- phenylmaleimide, N-m-methylphenyl maleimide, N-o-methylphenyl maleimide, N-p-methyl resin obtained by polymerizing an aromatic maleimides such as having an aryl group of phenyl maleimide, and the like.

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

(In chemical formula (2), n is 0 or an integer of 1 to 3)
As such cycloolefin copolymer, APL 8008T, APL 8009T, APL 6013T (all manufactured by Mitsui Chemicals, Inc.) and the like can be used.

  The adhesive layer 2 is preferably formed using 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 semiconductor wafer 1 after the adhesive layer 2 is peeled or removed. In particular, an adhesive that dissolves in a specific solvent is preferable as a material constituting the adhesive layer 2. This is because the adhesive layer 2 can be removed by dissolving in a solvent without applying physical force to the semiconductor wafer 1. Even when the adhesive layer 2 is removed, the adhesive layer 2 can be easily removed without damaging or deforming the semiconductor wafer 1 even from the semiconductor wafer 1 having a reduced strength.

  As a diluting solvent for forming the separation layer and the adhesive layer described above, for example, hexane, heptane, octane, nonane, methyloctane, decane, undecane, dodecane, tridecane, and other linear hydrocarbons, carbon number 4 to 15 Branched hydrocarbons of the following: p-menthane, o-menthane, m-menthane, diphenylmenthane, 1,4-terpine, 1,8-terpin, bornane, norbornane, pinane, tsujang, kalan, longifolene, geraniol, nerol, Linalool, citral, citronellol, menthol, isomenthol, neomenthol, α-terpineol, β-terpineol, γ-terpineol, terpinen-1-ol, terpinen-4-ol, dihydroterpinyl acetate, 1,4-cineole, 1,8-cineole, Borneo Terpene solvents such as ru, carvone, ionone, thuyon, camphor, d-limonene, l-limonene, dipentene; lactones such as γ-butyrolactone; acetone, methyl ethyl ketone, cyclohexanone (CH), methyl-n-pentyl ketone, methyl Ketones such as isopentyl ketone and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol; ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate or dipropylene glycol monoacetate A compound having an ester bond such as a monomethyl ether, a monoethyl ether, a monopro of the polyhydric alcohol or the compound having an ester bond Derivatives of polyhydric alcohols such as compounds having an ether bond such as monoalkyl ether such as pill ether and monobutyl ether or monophenyl ether (in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME ); Preferably cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methoxybutyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, Esters such as ethyl ethoxypropionate; fragrances such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether It can be exemplified system organic solvent.

(Elastomer)
The elastomer preferably contains a styrene unit as a constituent unit of the main chain. The elastomer used as the adhesive preferably has a styrene unit content in the range of 14% by weight to 50% by weight. Furthermore, the elastomer preferably has a weight average molecular weight in the range of 10,000 to 200,000.

  Examples of the elastomer include polystyrene-poly (ethylene / propylene) block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), and styrene-butadiene-butylene-styrene block. Copolymers (SBBS), their hydrogenated products, styrene-ethylene-butylene-styrene block copolymers (SEBS), styrene-ethylene-propylene-styrene block copolymers (styrene-isoprene-styrene block copolymers) (SEPS), and styrene- And ethylene-ethylene-propylene-styrene block copolymer (SEEPS).

(Other ingredients)
The adhesive material may further contain other miscible substances as long as the essential characteristics of the present invention are not impaired. For example, various conventional additives such as additional resins, plasticizers, adhesion aids, stabilizers, colorants, antioxidants and surfactants for improving the performance of the adhesive can be further used. .

[2: Separation layer forming step]
In the adhesive layer forming step according to this embodiment, as shown in FIG. 1B, the separation layer 3 is formed on the support 4 by plasma treatment.

  The support 4 has light transmittance. Therefore, when light is irradiated from the outside of the laminated body 10 toward the support body 4, the light passes through the support body 4 and reaches the separation layer 3. Further, the support 4 does not necessarily need to transmit all the light, and it is sufficient if it can transmit the light to be absorbed by the separation layer 3 (having a predetermined wavelength).

  The support 4 supports the semiconductor wafer 1 and has a strength necessary for preventing damage or deformation of the semiconductor wafer 1 during processes such as thinning, transporting, and mounting of the semiconductor wafer 1. That's fine. From the above viewpoint, examples of the support 4 include those made of glass, silicon, and acrylic resin. In addition, the support body 4 may be called a support plate.

  The separation layer 3 is a layer formed of a material that changes quality by absorbing light irradiated through the support 4. In the present specification, the “deterioration” of the separation layer 3 is a phenomenon that causes the separation layer 3 to be broken by receiving a slight external force, or a state in which the adhesive force with the layer in contact with the separation layer 3 is reduced. means. As a result of the alteration of the separation layer 3 caused by absorbing light, the separation layer 3 loses its strength or adhesiveness before being irradiated with light. Therefore, by applying a slight external force (for example, lifting the support 4), the separation layer 3 is broken, and the support 4 and the semiconductor wafer 1 can be easily separated.

  Further, the alteration of the separation layer 3 includes decomposition (exothermic or non-exothermic), cross-linking, configuration change or dissociation of functional groups (and curing of the separation layer and degassing associated with these) due to absorbed light energy. , Contraction or expansion) and the like. The alteration of the separation layer 3 occurs as a result of light absorption by the material constituting the separation layer 3. Therefore, the type of alteration of the separation layer 3 can be changed according to the type of material constituting the separation layer 3.

  The separation layer 3 is provided on the surface of the support 4 on the side where the semiconductor wafer 1 is bonded via the adhesive layer 2. That is, the separation layer 3 is provided between the surface treatment film 14 and the adhesive layer 2.

  The thickness of the separation layer 3 is more preferably 0.05 to 50 μm, for example, and further preferably 0.3 to 1 μm. If the thickness of the separation layer 3 is within a range of 0.05 to 50 μm, desired alteration can be caused in the separation layer 3 by irradiation with light for a short time and irradiation with low energy light. In addition, the thickness of the separation layer 3 is particularly preferably within a range of 1 μm or less from the viewpoint of productivity.

  In the laminate 10, another layer may be further formed between the separation layer 3 and the support 4. In this case, the other layer should just be comprised from the material which permeate | transmits light. Accordingly, a layer imparting preferable properties to the stacked body 10 can be appropriately added without hindering the incidence of light on the separation layer 3. The wavelength of light that can be used differs depending on the type of material constituting the separation layer 3. Therefore, the material constituting the other layer does not need to transmit all light, and can be appropriately selected from materials that can transmit light having a wavelength that can alter the material constituting the separation layer 3.

  The separation layer 3 is preferably formed only from a material having a structure that absorbs light, but the material does not have a structure that absorbs light as long as the essential characteristics of the present invention are not impaired. May be added to form the separation layer 3. Further, it is preferable that the surface of the separation layer 3 on the side facing the adhesive layer 2 is flat (unevenness is not formed), so that the separation layer 3 can be easily formed and even when pasted. It becomes possible to paste on.

  The material constituting the separation layer 3 is not particularly limited as long as it can be formed on the support 4 by the plasma CVD method and can be altered by absorbing light. Fluorocarbons, inorganic substances, polymers containing a light-absorbing structure in the repeating unit, compounds having an infrared-absorbing structure, infrared-absorbing substances, and the like.

(Fluorocarbon)
The separation layer 3 may be made of a fluorocarbon. Since the separation layer 3 is composed of fluorocarbon, the separation layer 3 is altered by absorbing light. As a result, the separation layer 3 loses its strength or adhesiveness before being irradiated with light. Therefore, by applying a slight external force (for example, lifting the support 4), the separation layer 3 is broken, and the support 4 and the semiconductor wafer 1 can be easily separated.

In this embodiment, the fluorocarbon constituting the separation layer 3 can be formed by a plasma CVD method. In addition, fluorocarbon includes CxFy (perfluorocarbon) and CxHyFz (x, y, and z are natural numbers), but are not limited to these, for example, CHF ₃ , CH ₂ F ₂ , C ₂ H ₂ F ₂ , C ₄ F ₈ , C ₂ F ₆ , C ₅ F _{8 and the} like. In addition, an inert gas such as nitrogen, helium, or argon, a hydrocarbon such as alkane or alkene, and oxygen, carbon dioxide, or hydrogen are added to the fluorocarbon used to constitute the separation layer 3 as necessary. May be. Further, a mixture of these gases may be used (a mixed gas of fluorocarbon, hydrogen, nitrogen, etc.). The separation layer 3 may be composed of a single type of fluorocarbon or may be composed of two or more types of fluorocarbon.

  The fluorocarbon absorbs light having a wavelength in a specific range depending on the type. By irradiating the separation layer with light having a wavelength within a range that is absorbed by the fluorocarbon used in the separation layer 3, the fluorocarbon can be suitably altered. The light absorption rate in the separation layer 3 is preferably 80% or more.

(Inorganic)
The separation layer 3 may be made of an inorganic material. The separation layer 3 is made of an inorganic material, and is thus altered by absorbing light. As a result, the separation layer 3 loses its strength or adhesiveness before being irradiated with light. Therefore, by applying a slight external force (for example, lifting the support 4), the separation layer 3 is broken, and the support 4 and the substrate 1 can be easily separated.

The said inorganic substance should just be the structure which changes in quality by absorbing light, for example, can use 1 or more types of inorganic substances selected from the group which consists of a metal, a metal compound, and carbon suitably. The metal compound refers to a compound containing a metal atom, and can be, for example, a metal oxide or a metal nitride. Examples of such inorganic substances include, but are not limited to, silicon-containing compounds such as doped silicon, SiO ₂ , SiN, and Si ₃ N ₄ . Other examples include one or more inorganic substances selected from the group consisting of gold, silver, copper, iron, nickel, aluminum, titanium, chromium, TiN, and carbon. Carbon is a concept that may include an allotrope of carbon, for example, diamond, fullerene, diamond-like carbon, carbon nanotube, and the like.

  The inorganic material absorbs light having a wavelength in a specific range depending on the type. By irradiating the separation layer with light having a wavelength within a range that is absorbed by the inorganic material used for the separation layer 3, the inorganic material can be suitably altered.

  When a metal film is used as the separation layer 3, reflection of the laser or charging of the film may occur depending on the film quality of the separation layer 3, the type of laser light source, laser output, and the like. Therefore, it is preferable to take measures against them by providing an antireflection film or an antistatic film on the upper or lower side of the separation layer 3 or one of them.

(Infrared absorbing material)
The separation layer 3 may contain an infrared absorbing material. The separation layer 3 is configured to contain an infrared absorbing substance, so that the separation layer 3 is altered by absorbing light. As a result, the separation layer 3 loses strength or adhesiveness before being irradiated with light. Therefore, by applying a slight external force (for example, lifting the support 4), the separation layer 3 is broken, and the support 4 and the substrate 1 can be easily separated.

  The infrared absorbing material only needs to have a structure that is altered by absorbing infrared rays. For example, carbon black, iron particles, or aluminum particles can be suitably used. The infrared absorbing material absorbs light having a wavelength in a specific range depending on the type. By irradiating the separation layer 3 with light having a wavelength in a range that is absorbed by the infrared absorbing material used for the separation layer 3, the infrared absorbing material can be suitably altered.

(Polymer containing light-absorbing structure in its repeating unit)
The separation layer 3 may contain a polymer containing a light-absorbing structure in its repeating unit. The polymer is altered by irradiation with light. The alteration of the polymer occurs when the structure absorbs the irradiated light. The separation layer 3 has lost its strength or adhesiveness before being irradiated with light as a result of the alteration of the polymer. Therefore, by applying a slight external force (for example, lifting the support 4), the separation layer 3 is broken, and the support 4 and the substrate 1 can be easily separated.

  The above-mentioned structure having light absorptivity is a chemical structure that absorbs light and alters a polymer containing the structure as a repeating unit. The structure is, for example, an atomic group including a conjugated π electron system composed of a substituted or unsubstituted benzene ring, condensed ring, or heterocyclic ring. More specifically, the structure may be a cardo structure, or a benzophenone structure, a diphenyl sulfoxide structure, a diphenyl sulfone structure (bisphenyl sulfone structure), a diphenyl structure or a diphenylamine structure present in the side chain of the polymer.

  When the structure is present in the side chain of the polymer, the structure can be represented by the following formula:

(In the formula, each R ³⁰ is independently an alkyl group, aryl group, halogen, hydroxyl group, ketone group, sulfoxide group, sulfone group or N (R ³¹ ) (R ³² ) (where R ³¹ and R ³² is each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), Z is absent or is —CO—, —SO ₂ —, —SO— or —NH—, k Is 0 or an integer of 1 to 5.)
In addition, the polymer includes, for example, a repeating unit represented by any one of (a) to (d) among the following formulas, represented by (e), or represented by (f) Contains structure in its main chain.

(In the formula, l is an integer of 1 or more, m is 0 or an integer of 1 to 2, and X is any one of the formulas shown in the above “Chemical Formula 2” in (a) to (e)). Yes, in (f) any of the formulas shown above for “Chemical Formula 2” or absent, Y1 and Y2 are each independently —CO— or SO ₂ —, l is preferably Is an integer of 10 or less.)
Examples of the benzene ring, condensed ring and heterocyclic ring shown in the above “chemical formula 2” include phenyl, substituted phenyl, benzyl, substituted benzyl, naphthalene, substituted naphthalene, anthracene, substituted anthracene, anthraquinone, substituted anthraquinone, acridine, substituted Examples include acridine, azobenzene, substituted azobenzene, fluoride, substituted fluoride, fluoride, substituted fluoride, carbazole, substituted carbazole, N-alkylcarbazole, dibenzofuran, substituted dibenzofuran, phenanthrene, substituted phenanthrene, pyrene, and substituted pyrene. When the exemplified substituent has a substituent, the substituent is, for example, alkyl, aryl, halogen atom, alkoxy, nitro, aldehyde, cyano, amide, dialkylamino, sulfonamide, imide, carboxylic acid, carboxylic acid Selected from esters, sulfonic acids, sulfonate esters, alkylamino and arylamino.

Of the substituents represented by “Chemical Formula 2” above, as an example of the fifth substituent having two phenyl groups and Z being —SO ₂ —, bis (2, 4-dihydroxyphenyl) sulfone, bis (3,4-dihydroxyphenyl) sulfone, bis (3,5-dihydroxyphenyl) sulfone, bis (3,6-dihydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfone, bis (3-hydroxyphenyl) sulfone, bis (2-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, and the like.

  Of the substituents represented by “Chemical Formula 2” above, as an example of the fifth substituent having two phenyl groups and Z being —SO—, bis (2,3 -Dihydroxyphenyl) sulfoxide, bis (5-chloro-2,3-dihydroxyphenyl) sulfoxide, bis (2,4-dihydroxyphenyl) sulfoxide, bis (2,4-dihydroxy-6-methylphenyl) sulfoxide, bis (5 -Chloro-2,4-dihydroxyphenyl) sulfoxide, bis (2,5-dihydroxyphenyl) sulfoxide, bis (3,4-dihydroxyphenyl) sulfoxide, bis (3,5-dihydroxyphenyl) sulfoxide, bis (2,3 , 4-Trihydroxyphenyl) sulfoxide, bis (2,3,4-trihydroxy-6-methylpheny ) -Sulfoxide, bis (5-chloro-2,3,4-trihydroxyphenyl) sulfoxide, bis (2,4,6-trihydroxyphenyl) sulfoxide, bis (5-chloro-2,4,6-trihydroxy) Phenyl) sulfoxide and the like.

  Of the substituents represented by the above “Chemical Formula 2”, the fifth substituent having two phenyl groups and Z is —C (═O) — , 4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2', 5,6'-tetrahydroxybenzophenone, 2-hydroxy-4- Methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,6-dihydroxy-4-methoxybenzophenone, 2,2 ' -Dihydroxy-4,4'-dimethoxybenzophenone, 4-amino-2'-hydroxybenzophenone, 4-dimethyl Ruamino-2'-hydroxybenzophenone, 4-diethylamino-2'-hydroxybenzophenone, 4-dimethylamino-4'-methoxy-2'-hydroxybenzophenone, 4-dimethylamino-2 ', 4'-dihydroxybenzophenone, and 4 -Dimethylamino-3 ', 4'-dihydroxybenzophenone and the like.

  When the structure is present in the side chain of the polymer, the ratio of the repeating unit containing the structure to the polymer is such that the light transmittance of the separation layer 3 is 0.001 to 10%. It is in the range. If the polymer is prepared so that the ratio falls within such a range, the separation layer 3 can sufficiently absorb light and can be reliably and rapidly altered. That is, it is easy to remove the support 4 from the laminated body 10, and the irradiation time of light necessary for the removal can be shortened.

  The said structure can absorb the light which has a wavelength of a desired range by selection of the kind. For example, the wavelength of light that can be absorbed by the above structure is more preferably 100 to 2000 nm. Within this range, the wavelength of light that can be absorbed by the structure is on the shorter wavelength side, for example, 100 to 500 nm. For example, the structure can alter the polymer containing the structure by absorbing ultraviolet light, preferably having a wavelength of about 300-370 nm.

  The light that can be absorbed by the above structure is, for example, a high-pressure mercury lamp (wavelength: 254 nm to 436 nm), a KrF excimer laser (wavelength: 248 nm), an ArF excimer laser (wavelength: 193 nm), an F2 excimer laser (wavelength: 157 nm), or XeCl. Light emitted from laser (308 nm), XeF laser (wavelength: 351 nm) or solid-state UV laser (wavelength: 355 nm), or g-line (wavelength: 436 nm), h-line (wavelength: 405 nm) or i-line (wavelength: 365 nm) Etc.

  Although the separation layer 3 described above contains a polymer containing the above structure as a repeating unit, the separation layer 3 may further contain components other than the polymer. Examples of the component include a filler, a plasticizer, and a component that can improve the peelability of the support 4. These components are appropriately selected from conventionally known substances or materials that do not hinder or promote the absorption of light by the above structure and the alteration of the polymer.

(Compound having infrared absorbing structure)
The separation layer 3 may be formed of a compound having an infrared absorbing structure. The compound is altered by absorbing infrared rays. The separation layer 3 loses its strength or adhesiveness before being irradiated with infrared rays as a result of the alteration of the compound. Therefore, by applying a slight external force (for example, lifting the support), the separation layer 3 is broken and the support 4 and the substrate 1 can be easily separated.

Examples of the compound having an infrared absorptive structure or a compound having an infrared absorptive structure include alkanes and alkenes (vinyl, trans, cis, vinylidene, trisubstituted, tetrasubstituted, conjugated, cumulene, ring Formula), alkyne (monosubstituted, disubstituted), monocyclic aromatic (benzene, monosubstituted, disubstituted, trisubstituted), alcohol and phenols (free OH, intramolecular hydrogen bond, intermolecular hydrogen bond, saturated Secondary, saturated tertiary, unsaturated secondary, unsaturated tertiary), acetal, ketal, aliphatic ether, aromatic ether, vinyl ether, oxirane ether, peroxide ether, ketone, dialkylcarbonyl, aromatic Carbonyl, 1,3-diketone enol, o-hydroxy aryl ketone, dialkyl aldehyde, aromatic aldehyde, carboxylic acid (dimer Carboxylate anion), formate ester, acetate ester, conjugated ester, non-conjugated ester, aromatic ester, lactone (β-, γ-, δ-), aliphatic acid chloride, aromatic acid chloride, acid anhydride ( Conjugated, non-conjugated, cyclic, acyclic), primary amide, secondary amide, lactam, primary amine (aliphatic, aromatic), secondary amine (aliphatic, aromatic), secondary Tertiary amine (aliphatic, aromatic), primary amine salt, secondary amine salt, tertiary amine salt, ammonium ion, aliphatic nitrile, aromatic nitrile, carbodiimide, aliphatic isonitrile, aromatic isonitrile, Isocyanate ester, thiocyanate ester, aliphatic isothiocyanate ester, aromatic isothiocyanate ester, aliphatic nitro compound, aromatic nitro compound, nitroamine, nitrosamine, Acid ester, nitrite ester, nitroso bond (aliphatic, aromatic, monomer, dimer), mercaptan and sulfur compounds such as thiophenol and thiolic acid, thiocarbonyl group, sulfoxide, sulfone, sulfonyl chloride, primary Secondary sulfonamide, secondary sulfonamide, sulfate ester, carbon-halogen bond, Si-A ¹ bond (A ¹ is H, C, O or halogen), P-A ² bond (A ² is H, C Or O), or Ti—O bonds.

As a structure containing halogen bond, for _{example, -CH 2 Cl, -CH 2 Br} , -CH 2 I, -CF 2 - - the _{carbon, - CF 3, -CH = CF} 2, -CF = CF 2, fluoride Aryl chloride, and aryl chloride.

As a structure including the Si-A1 _{bonds, SiH, SiH 2, SiH 3} , Si-CH 3, Si-CH 2 -, Si-C 6 H 5, SiO- _{aliphatic, Si-OCH 3, Si-} OCH ₂ CH ₃ , Si—OC ₆ H ₅ , Si—O—Si, Si—OH, SiF, SiF ₂ , SiF _{3 and the} like. As a structure including a Si—A ¹ bond, it is particularly preferable to form a siloxane skeleton and a silsesquioxane skeleton.

Examples of the structure containing the P—A ² bond include PH, PH ₂ , P—CH ₃ , P—CH ₂ —, P—C ₆ H ₅ , A ³ _3— P—O (A ³ is aliphatic or aromatic. ^{family), (A 4 O) 3} -P-O (A 4 _{alkyl), P-OCH 3, P} -OCH 2 CH 3, P-OC 6 H 5, P-O-P, P-OH, and O = P-OH and the like can be mentioned.

  The said structure can absorb the infrared rays which have the wavelength of a desired range by selection of the kind. Specifically, the wavelength of infrared rays that can be absorbed by the above structure is, for example, in the range of 1 μm to 20 μm, and more preferably in the range of 2 μm to 15 μm. Further, when the structure is a Si—O bond, a Si—C bond, and a Ti—O bond, it can be in the range of 9 μm to 11 μm. In addition, those skilled in the art can easily understand the infrared wavelength that can be absorbed by each structure. For example, as an absorption band in each structure, Non-Patent Document: SILVERSTEIN / BASSLER / MORRILL, “Identification method by spectrum of organic compound (5th edition) —Combination of MS, IR, NMR and UV” (published in 1992) The description on page 146 to page 151 can be referred to.

  As a compound having an infrared-absorbing structure used for forming the separation layer 3, among the compounds having the structure as described above, it can be dissolved in a solvent for coating and solidified to form a solid layer. As long as it is possible, there is no particular limitation. However, in order to effectively alter the compound in the separation layer 3 and facilitate separation of the support 4 and the substrate 1, the infrared absorption in the separation layer 3 is large, that is, the separation layer 3 is irradiated with infrared rays. It is preferable that the infrared transmittance is low. Specifically, the infrared transmittance in the separation layer 3 is preferably lower than 90%, and the infrared transmittance is more preferably lower than 80%.

  For example, as the compound having a siloxane skeleton, for example, a resin that is a copolymer of a repeating unit represented by the following chemical formula (3) and a repeating unit represented by the following chemical formula (4), or A resin that is a copolymer of a repeating unit represented by the following chemical formula (3) and a repeating unit derived from an acrylic compound can be used.

(In the chemical formula (4), R ⁴¹ is hydrogen, an alkyl group having 10 or less carbon atoms, or an alkoxy group having 10 or less carbon atoms)
Among them, as a compound having a siloxane skeleton, a t-butylstyrene (TBST) -dimethylsiloxane copolymer, which is a copolymer of the repeating unit represented by the chemical formula (3) and the repeating unit represented by the following chemical formula (5), is used. A polymer is more preferable, and a TBST-dimethylsiloxane copolymer containing a repeating unit represented by the above formula (3) and a repeating unit represented by the following chemical formula (5) in a ratio of 1: 1 is further preferable.

  As the compound having a silsesquioxane skeleton, for example, a resin that is a copolymer of a repeating unit represented by the following chemical formula (6) and a repeating unit represented by the following chemical formula (7) can be used. .

(In the chemical formula (6), R ⁴² is hydrogen or an alkyl group having 1 to 10 carbon atoms, and in the chemical formula (7), R ⁴³ is an alkyl group having 1 to 10 carbon atoms, or a phenyl group. Is)
Other compounds having a silsesquioxane skeleton include JP 2007-258663 A (published on October 4, 2007), JP 2010-120901 A (published on June 3, 2010), Each silsesquioxane resin disclosed in JP 2009-263316 A (published on November 12, 2009) and JP 2009-263596 A (published on November 12, 2009) can be suitably used.

  Among these, as the compound having a silsesquioxane skeleton, a repeating unit represented by the following chemical formula (8) and a copolymer of a repeating unit represented by the following chemical formula (9) are more preferable. A copolymer containing 7: 3 of the repeating unit represented by the following chemical formula (9) is more preferred.

  The polymer having a silsesquioxane skeleton may have a random structure, a ladder structure, and a cage structure, but any structure may be used.

Examples of the compound containing a Ti—O bond include (i) tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetrakis (2-ethylhexyloxy) titanium, and titanium-i-propoxyoctylene glycolate. (Ii) chelating titanium such as di-i-propoxy bis (acetylacetonato) titanium, and propanedioxytitanium bis (ethylacetoacetate); (iii) i-C ₃ H ₇ O — [— _{Ti (O-i-C 3} H 7) 2 -O-] n-i-C 3 H 7, and _{n-C 4 H 9 O -} [- Ti (O-n-C 4 H 9) 2 -O - titanium polymers such as _{n-n-C 4 H 9} ; (iv) tri -n- butoxy titanium monostearate, titanium stearate, di -i- propoxy Titanium diisostearate and acylate titanium such as (2-n-butoxycarbonylbenzoyloxy) tributoxytitanium; (v) water-soluble titanium compounds such as di-n-butoxy-bis (triethanolaminato) titanium Is mentioned.

Among them, as a compound containing a Ti—O bond, di-n-butoxy bis (triethanolaminato) titanium (Ti (OC ₄ H ₉ ) 2 [OC ₂ H ₄ N (C ₂ H ₄ OH) ₂ ] ₂ ) is preferred.

  Although the separation layer 3 described above contains a compound having an infrared absorbing structure, the separation layer 3 may further contain components other than the above-described compound. Examples of the component include a filler, a plasticizer, and a component that can improve the peelability of the support 4. These components are appropriately selected from conventionally known substances or materials that do not prevent or promote the absorption of infrared rays by the above structure and the alteration of the compound.

(Plasma processing equipment)
FIG. 2 is a cross-sectional view showing a configuration example of the plasma processing apparatus 100 according to the present embodiment used in the separation layer forming step. As shown in FIG. 2, the plasma processing apparatus 100 includes an exhaust ring 104 on a base 101, a chamber body 105 on the exhaust ring 104, a chamber upper part 106 on the chamber body 105, and a top plate 108 on the chamber upper part 106. And the stage 103 has a structure in which the opening below the exhaust ring 104 is closed, and the chamber 102 is formed inside.

  The exhaust ring 104, the chamber body 105, and the chamber upper portion 106 are made of quartz in one embodiment. On the other hand, the top plate 108 and the stage 103 are made of a metal such as aluminum or an aluminum alloy.

  The upper portion of the chamber 102 is a dome portion 112 having a dome shape (spot shape), and has a bell jar shape having a cylindrical portion 113 having a cylindrical shape below the dome portion 112. The dome portion 112 is constituted by the upper portion of the chamber upper portion 106, and the cylindrical portion 113 is constituted by the lower portion of the chamber upper portion 106 and the chamber body portion 105.

  An exhaust hole 109 is provided in the exhaust ring 104, and exhaust gas is exhausted from the chamber 102.

  Moreover, the top plate 108 is disposed so as to close the opening provided at the top of the dome portion 112. The top plate 108 is provided with a supply port 110 for supplying a reaction gas into the chamber 102. The top plate 108 is also grounded.

  The stage 103 is a stage on which the support body 4 that is an object to be processed is placed, and also functions as a lower electrode. The stage 103 is grounded. A cap-type coil 107 is disposed on the outer periphery of the dome portion 112, and plasma is generated in a portion surrounded by the cap-type coil 107 in the chamber 102 (plasma generation portion 104, a portion above the straight line A in the figure). Is generated.

  And while introducing the reactive gas used as the material which forms the separated layer 3 into the chamber 102 from the supply port 110, and applying a high frequency voltage between the cap type | mold 107 and the stage 103, a plasma is produced, The separation layer 3 is formed by radicals generated with the plasma.

  The reaction gas may be appropriately selected according to the separation layer 3 to be formed. For example, in one embodiment, when a fluorocarbon film is formed as the separation layer 3, a gas containing at least one of a fluorocarbon gas and a hydrocarbon gas can be used. By performing the plasma CVD method using at least one of a fluorocarbon gas and a hydrocarbon gas as a reaction gas, the separation layer 3 can be suitably formed.

Examples of the fluorocarbon gas include CxFy and CxHyFz (x, y and z are natural numbers), and more specifically, CHF ₃ , CH ₂ F ₂ , C ₂ H ₂ F ₂ , C ₄ F ₈ , C ₂ F ₆ , C ₅ F _{8 and the} like are exemplified, but not limited thereto. Examples of the hydrocarbon gas include alkanes such as CH ₄ , alkenes such as ethylene, and alkynes such as acetylene.

  One or more kinds of inert gases such as nitrogen, helium and argon, hydrocarbon gases such as alkanes, alkenes and alkynes, fluorocarbon gases, hydrogen and oxygen may be added to the reaction gas. The addition amount of the additive gas is not particularly limited. For example, when hydrogen is added, it is not limited to this, but it may be added at a rate of 5% or more and 20% or less with respect to the entire gas. preferable. Further, oxygen is not limited to this, but it is preferable to add a very small amount or not.

  The reaction gas may contain a fluorocarbon gas as a main component. In this case, a hydrocarbon gas may be contained as an additive gas. The content of the additive gas with respect to the entire raw material gas is preferably 5% or more and 20% or less, for example. Conversely, when the reaction gas is mainly composed of a hydrocarbon gas, it is preferable to contain a fluorocarbon gas as an additive gas. Note that the main component means a gas having the largest content (volume%) in the gas supplied to the chamber 102. Further, by adding an appropriate amount of an inert gas, the reaction gas can be suitably stirred to form the separation layer 3 uniformly.

  When the material constituting the separation layer 3 includes a substance that is difficult to supply as a reaction gas, a precursor solution containing the substance may be applied on the support 4 in advance.

  The flow rate of the reaction gas and the pressure in the chamber 102 are not particularly limited, and may be set to various conditions. The reaction gas is preferably supplied from the supply port 110 and exhausted from the exhaust hole 109 by a pump or the like.

  The target temperature in the chamber 102 when performing the plasma CVD method is not particularly limited, and a known temperature can be used, but it is more preferably in a range of 100 ° C. or higher and 300 ° C. or lower, and 200 ° C. or higher, 250 It is particularly preferable that the temperature be in the range of ° C or lower. By setting the temperature in the chamber 102 to such a range, the plasma CVD method can be suitably performed.

  The high frequency power applied to the cap type coil 107 is not limited to this, but is preferably set to be larger than the power causing the mode jump. In general, capacitively coupled plasma (E-mode plasma) is generated when the plasma density is low, and inductively coupled plasma (H-mode plasma) is generally generated when the plasma density is high. The transition from the E mode to the H mode depends on the dielectric electric field, and when the dielectric electric field exceeds a certain value, the capacitive coupling is switched to the inductive coupling. This phenomenon is generally called “mode jump” or “density jump”. That is, plasma generated at a power lower than that causing mode jump is E-mode plasma, and plasma generated at a power higher than power causing mode jump is H-mode plasma (for example, Japanese Patent No. 3852655, Japanese Patent No. 4272654, etc.) checking). Thereby, the high quality separation layer 3 can be formed.

  Here, the plasma processing apparatus 100 according to the present embodiment includes the following characteristic configurations (A) to (D). In another embodiment, the plasma processing apparatus according to the present invention may have any one of the configurations (A) to (D), but more preferably includes a plurality of characteristic configurations. It is particularly preferable to have all the characteristic configurations.

(A: Downflow area)
As shown in FIG. 2, a downflow region 111 is provided in the chamber 102 of the plasma processing apparatus 100 between the plasma generation unit 114 and the stage 103. The downflow region 111 is a region where radicals generated in the plasma generation unit 114 are recombined. In the present embodiment, since radicals generated in the plasma generation unit 114 are recombined in the downflow region 111 and then deposited on the support 4, a good separation layer 3 can be formed.

Here, in the conventional plasma CVD apparatus, the distance between the plasma generation unit 114 and the stage 103 is shortened in order to improve the deposition rate. Then, unnecessary deposits are eliminated by applying a cathode bias. However, according to the original knowledge of the present inventors, when such a plasma CVD apparatus is used, it is difficult to form a good separation layer 3 having high light absorption. For example, when C ₄ F ₈ is used as the reactive gas, CF ₂ is generated in the plasma generation unit 114, and if this is deposited as it is, the transparent separation layer 3 is formed.

  On the other hand, in the plasma processing apparatus 100 according to the present embodiment, since the radicals generated in the plasma generation unit 114 are recombined and deposited on the support 4, a good separation layer 3 can be formed. In particular, those in which the carbon radicals generated in the plasma generation unit 114 are recombined have double bonds, and thus have high light absorption and contribute to the formation of a good separation layer 3. In this case, in a preferred example, the separation layer 3 is formed by depositing particles that are fluorine-rich at both ends and carbon-rich at the center.

  The height of the downflow region 111, that is, the distance from the lower end of the plasma generation unit 114 (the lower end of the cap-type coil 107) to the upper surface of the stage 103 is not particularly limited, and the above-described carbon radicals are preferably recombined. What is necessary is just to set to the distance which can do. In one embodiment, the height of the downflow region 111 can be 10 cm or more and 20 cm or less, more preferably 10 cm or more and 15 cm or less.

(B: Top plate)
As described above, the top plate 108 according to the present embodiment is made of metal, particularly aluminum (including aluminum alloy), and is made of a material different from quartz constituting the adjacent chamber upper portion 106 and the like. .

  Such a configuration is avoided in the plasma processing apparatus according to the prior art. This is because a packing such as an O-ring is required to connect the metal and quartz, and contamination due to the packing may occur.

  However, in this embodiment, the top plate 108 is intentionally made of metal, particularly aluminum (including aluminum alloy), so that mode jump can be generated with lower power and inductively coupled plasma can be generated. .

  As described above, there are two types of plasma, capacitively coupled plasma and inductively coupled plasma. By using inductively coupled plasma, a higher quality separation layer 3 can be formed. In particular, according to the inventors' unique knowledge, the amount of carbon radicals generated can be increased when inductively coupled plasma is used. Therefore, by generating inductively coupled plasma, particles having high light absorption formed by recombination of carbon radicals can be suitably deposited.

  In particular, by grounding the top panel 108, the power required for the mode jump can be further reduced. Thereby, costs, such as power supply equipment and power consumption, can be reduced.

  Further, in this embodiment, the supply port 110 is provided in the top plate 108, so that the reactive gas can be supplied from above the plasma generation unit 114, and the radical flow to the downflow region 111 is preferably generated. A good separation layer 3 can be formed.

(C: Cap type coil)
As shown in FIG. 2, in the plasma processing apparatus 100 according to this embodiment, a cap type coil 107 is provided on the outer periphery of the dome portion 112. That is, the cap type coil 107 is configured to gradually increase in diameter. Thereby, the resistance component in the cap type coil 107 when the high frequency power is supplied can be reduced. From another viewpoint, the number of turns of the cap-type coil 107 can be increased without increasing the resistance component.

  FIG. 3 is a view of the plasma processing apparatus 100 observed from above. As shown in FIG. 3, the cap-type coil 107 is constituted by double coils (cap-type coils 107a and 107b). Thereby, the uniformity of the plasma on a plane can be improved. In addition, both coils are arranged so that the end portions (B and D, C and E) do not overlap each other, and in particular, the end portions (B and D, C and E) are in line-symmetric positions. It is preferable that they are arranged. Thereby, the uniformity of the plasma on the plane can be further improved.

(D: size)
The plasma processing apparatus 100 according to the present embodiment is configured such that the outer periphery of the support 4 that is an object to be processed and the inner wall of the chamber 102 are close to each other, and the capacity of the chamber 102 is reduced.

  In the plasma processing apparatus according to the related art, the chamber is usually configured to be larger than the object to be processed. This is because the plasma at the edge of the chamber often has a large variation in density, making it difficult to form a homogeneous separation layer.

  However, according to the knowledge of the inventors, the outer periphery of the support 4 that is the object to be processed and the inner wall of the chamber 102 are close to each other so that the capacity of the chamber 102 is reduced, thereby reducing the reaction gas. Loss is reduced and the deposition rate can be improved.

(Modification)
FIG. 2 only shows one configuration example of the plasma processing apparatus used in the separation layer forming step, and the present invention is not limited to this. That is, as long as the structure can secure a sufficient downflow region, for example, a plasma processing apparatus having a structure as shown in FIG. 3 may be used, or a plasma processing apparatus having another structure may be used.

  For example, the side wall of the chamber 102 need not be composed of two members, the chamber body 105 and the chamber upper portion 106, and may be composed of one member or three or more members.

  In addition, the outer shape of the champ 102 is not particularly limited, and irregularities may be appropriately provided on the inner wall of the chamber 102.

  Further, the position of the exhaust hole 109 is not particularly limited.

[3: Bonding process]
In the bonding step according to the present embodiment, as shown in FIG. 1 (3), lamination is performed via the adhesive layer 2 so as to include the separation layer 3 between the semiconductor wafer 1 and the support 4.

  As a specific method, the surface of the semiconductor wafer 1 on which the adhesive layer 2 is formed and the surface of the support 4 on which the separation layer 3 is formed are bonded together, and the layers are laminated by baking and pressure bonding under vacuum. Is mentioned.

  Thereby, the laminated body 10 which concerns on this embodiment is obtained. The laminated body 10 is subjected to the following steps in order to separate the support 4 from the semiconductor wafer 1 after undergoing a desired process (for example, a wafer thinning process, a back surface wiring process, etc.) that requires the support 4. Provided.

[4: Irradiation process]
In the irradiation process according to the present embodiment, as shown in FIG. 1 (4), the separation layer 3 is altered by irradiating the separation layer 3 with a laser 8 from the support 4 side.

As the laser 8 that irradiates the separation layer 3, for example, a solid-state laser such as a YAG laser, Libby laser, glass laser, YVO ₄ laser, LD laser, or fiber laser, or a dye laser, depending on the wavelength that can be absorbed by the separation layer 3. Or a laser beam such as a gas laser such as a liquid laser, a CO ₂ laser, an excimer laser, an Ar laser, or a He—Ne laser, a semiconductor laser, or a free electron laser. Further, non-laser light may be appropriately used instead of the laser 8. The wavelength of light to be absorbed by the separation layer 3 is not limited to this, but may be light having a wavelength of 600 nm or less, for example. From another point of view, it is preferable to use light having a light absorption rate of 80% or more in the separation layer 3.

  In addition, the irradiation direction of the laser 8 may be irradiated from a direction perpendicular to the surface of the separation layer 3 or may be irradiated obliquely. In addition, the laser 8 may be irradiated to almost the entire surface of the separation layer 3 all at once, or may be irradiated so as to scan the surface of the separation layer 3.

  The reason for irradiating the laser 8 from the support 4 side is to prevent the laser 8 from affecting the structure of the substrate 1. By irradiating the laser 8 from the support 4 side, the laser 8 is absorbed by the separation layer 3 and can be prevented from reaching the substrate 1.

  As described above, the separation layer 3 is altered by being irradiated with light. Therefore, when the laser irradiation is completed, the separation layer 3 is in an altered state.

[5: Separation process]
In the separation step according to this embodiment, the support 4 is separated from the substrate 1 as shown in FIG. The strength of the separation layer 3 that has been altered by irradiation with light is significantly reduced. Therefore, for example, by pulling up the support body 4 by applying a slight external force, the separation layer 3 can be easily broken and the support body 4 can be separated from the substrate 1.

  In FIG. 1 (5), the separation is depicted as occurring at the interface between the separation layer 3 and the adhesive 2, but the position of the separation is not limited to this, and the separation is performed between the support 4 and the separation layer. It can also occur at the interface with 3 or in the separation layer 3.

[6: Cleaning process]
In the cleaning process according to the present embodiment, as shown in FIG. 1 (6), the adhesive layer 2 remaining on the substrate 1 from which the support 4 has been separated is removed. The removal of the adhesive layer 2 can be performed, for example, by spraying the adhesive layer 2 with a solvent that dissolves the adhesive layer 2. Thereby, the board | substrate 1 from which the contact bonding layer 2 was removed can be obtained.

  Here, after separation of the support 4, the remainder of the separation layer 3 may adhere to the substrate 1. If only a small amount of the separation layer 3 is adhered, it can be removed together with the adhesive layer 2 by spraying the solvent for dissolving the adhesive layer 2 as described above. Alternatively, the solvent for dissolving the separation layer 3 may be sprayed first, and then the solvent for dissolving the adhesive layer 2 may be sprayed.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

[Example 1]
A plurality of plasma processing apparatuses having different distances from the plasma generation unit to the glass substrate (support) were prepared, and the results of forming the separation membrane using each plasma processing apparatus were compared.

As a plasma processing apparatus, the thing from which the distance (height of a downflow area | region) from a plasma generation part to a glass substrate (support body) was 20 mm, 80 mm, 120 mm, and 200 mm was prepared. A 12-inch glass substrate (thickness: 700 μm) is installed in the chamber of each plasma processing apparatus, and C ₄ F ₈ is used as a reaction gas under the conditions of a flow rate of 400 sccm, a pressure of 700 mTorr, a high-frequency power of 2800 W, and a film formation temperature of 240 ° C. A fluorocarbon film as a separation layer was formed on the glass substrate by the plasma CVD method used. In addition, the film thickness of the separation layer formed in each plasma processing apparatus is shown in FIG.

  Subsequently, the amount of leakage light was measured for each glass substrate on which the separation layer was formed. Specifically, a laser having a wavelength of 532 nm was incident from the side where the separation layer of the glass substrate was not formed, and the amount of transmitted light (leakage light amount) was measured. Then, the shielding efficiency per thickness of the separation layer was calculated. The results are shown in FIG.

  As shown in FIG. 5, high shielding efficiency was shown when the distance from the plasma generation part to the glass substrate (support) (the height of the downflow region) was 10 cm or more and 20 cm or less.

[Example 2]
We examined how the power that causes mode jumping changes between a plasma processing device made entirely of quartz and a plasma processing device made of aluminum with a top plate grounded. As a result, in the plasma processing apparatus made entirely of quartz, the power causing the mode jump was 2700 to 2800 W, whereas in the plasma processing apparatus made of aluminum and grounded, the mode jump is caused. The power was 2300 to 2400 W, and the power causing the mode jump could be significantly reduced.

  The present invention can be suitably used, for example, in the field of manufacturing miniaturized semiconductor devices.

1 Semiconductor wafer (substrate)
2 Adhesive layer 3 Separation layer 4 Support 8 Laser (light)
DESCRIPTION OF SYMBOLS 10 Laminated body 100 Plasma processing apparatus 101 Base 102 Chamber 103 Stage 104 Exhaust ring 105 Chamber body part 106 Chamber upper part 107 Cap type coil 108 Top plate 109 Exhaust hole 110 Supply port 111 Down flow area 112 Dome part 113 Cylindrical part 114 Plasma generation part

Claims (13)

A bell jar type chamber having a dome portion and a cylindrical portion;
A cap-type coil provided on the outer periphery of the dome,
A stage on which a workpiece is placed,
A plasma treatment characterized in that a downflow region in which radicals generated in the plasma generation unit are recombined is provided between the plasma generation unit surrounded by the cap-type coil in the chamber and the stage. apparatus. A plasma CVD apparatus,
2. The plasma processing apparatus according to claim 1, wherein a substance formed by recombination of the radicals in the downflow region is deposited on the object to be processed.   The plasma processing apparatus according to claim 1, wherein a distance between the plasma generation unit and the stage is 10 cm or more and 20 cm or less.   The plasma processing apparatus according to claim 1, wherein the cap-type coil generates inductively coupled plasma.   The plasma processing apparatus according to any one of claims 1 to 4, wherein the cap-type coil includes two coils extending along each other, and ends of the two coils are shifted. .   6. The fluorinated hydrocarbon gas is supplied to the chamber, and a separation layer that changes in quality by absorbing light is deposited on the object to be processed. The plasma processing apparatus according to claim 1.   The plasma processing apparatus according to any one of claims 1 to 6, wherein in the downflow region, carbon radicals generated in the plasma generation unit are bonded to each other. A plasma processing method in a plasma processing apparatus comprising: a bell jar type chamber having a dome portion and a cylindrical portion; a cap type coil provided on the outer periphery of the dome portion; and a stage on which an object to be processed is placed. There,
A plasma generation step of generating plasma in a plasma generation section surrounded by the cap-type coil in the chamber;
And a recombination step in which a radical generated in the plasma generation step is recombined in a downflow region provided between the plasma generation unit and the stage.   9. The plasma processing method according to claim 8, further comprising a deposition step of depositing a substance formed by recombination of the radicals on the object to be processed in the recombination step.   10. The plasma processing method according to claim 8, wherein the plasma is inductively coupled plasma. Including a supply step of supplying a fluorinated hydrocarbon gas into the chamber,
The plasma processing method according to claim 8, wherein the radical includes a carbon radical.   The plasma processing method according to claim 11, wherein a separation layer that changes in quality by absorbing light is deposited on the object to be processed. A substrate, a light-transmitting support that supports the substrate, and a separation layer that is provided between the substrate and the support and changes quality by absorbing light irradiated through the support. A method for producing a laminate,
A method for producing a laminate, comprising the step of providing the support as the object to be processed in the plasma processing apparatus according to claim 1.

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