JP2018002947A - Protective film and manufacturing method therefor and functional transferring body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective film or the like capable of suppressing air bubble defects compared to the conventional art when a functional layer is laminated to a body to be treated.SOLUTION: A protective film (1) consists of a resin having surface average roughness (Sa) of at least one surface of 15 nm or less. The resin is preferably at least one selected from an ethylene-vinyl acetate copolymer, polyethylene and polypropylene. The softening temperature of the resin is preferably 30 to 170°C.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a protective film for a functional layer constituting a functional transfer body, a method for producing the same, and a functional transfer body.

  In the fields of optical components, energy devices, biodevices, recording media, and the like, techniques for improving the function by the concavo-convex structure are attracting attention. For example, in a semiconductor light emitting device (LED or OLED), it has been reported that the light emitting characteristics are improved by providing a concavo-convex structure on a substrate used for the device. For this reason, attention has been focused on a method of forming a desired uneven structure on a target object.

  In forming a desired concavo-convex structure on the object to be processed, it is possible to provide a functional layer on the object to be processed, and to process the object to be uneven using the functional layer as a processing mask.

  By the way, the functional layer is provided on the concavo-convex surface of the carrier having a concavo-convex structure on the surface as a part of the functional transfer body. A protective film is provided on the side of the functional layer opposite to the side in contact with the carrier. By providing the protective film, the surface of the functional layer can be appropriately protected.

  In applying such a functional transfer body on the object to be processed, first, the protective film is peeled off, and the exposed surface of the functional layer is bonded onto the object to be processed. Further, the carrier is peeled off from the functional layer. Thereby, the form which provided the functional layer for carrying out uneven | corrugated processing of the to-be-processed object surface on the to-be-processed object can be obtained.

  Patent Document 1 discloses an invention relating to a method for flattening a coating film of a liquid photocurable resin composition in which a transparent film is disposed on the surface of a coating film provided on a substrate. According to the invention described in Patent Document 1, it has been a conventional problem to reduce contact reliability with a semiconductor element due to variations in resist film thickness, and a high-performance resist mask can be obtained. A method of flattening a coating film of a liquid photocurable resin composition that is suitably used on a substrate can be provided.

JP 2014-186060 A

  By the way, controlling the surface average roughness of the functional layer in contact with the surface of the workpiece to be as small as possible is important for improving the formation accuracy of the concavo-convex structure on the surface of the workpiece.

  That is, when the surface average roughness of the functional layer in contact with the surface of the object to be processed is increased, the area where the bubbles are involved is increased without being in close contact between the object to be processed and the functional layer, and is processed and formed on the object to be processed. The accuracy of the uneven structure tends to be lowered.

  Such bubble defects are caused by the fact that when the protective film is bonded to the surface of the functional layer as a functional transfer body, the convex portions of the surface of the protective film are transferred to the surface of the functional layer to form concave portions. .

  In the invention described in Patent Document 1, there is a description that the surface roughness (irregularity) of the mask resist is 4 μm or less, but there is no recognition of the above-described conventional problems related to the above-mentioned bubble defects, and the surface average of the protective film There is no mention of roughness. Further, the surface roughness (unevenness) of the mask resist (coating film) is in units of microns, and the surface roughness cannot be sufficiently reduced.

  The present invention has been made in view of the above-described problems, and in particular, a protective film capable of suppressing bubble defects when a functional layer is bonded to an object to be processed, and a method for manufacturing the same. In addition, an object is to provide a functional transcript.

  The protective film of the present invention is characterized by comprising a resin having a surface average roughness (Sa) of at least one surface of 15 nm or less.

  In the present invention, it is preferable that at least one of ethylene-vinyl acetate copolymer, polyethylene, or polypropylene is selected as the resin.

  In the protective film of the present invention, for example, the resin may be a laminated structure of ethylene-vinyl acetate copolymer and polyethylene, a laminated structure of elastomer and polypropylene, or an ethylene-vinyl acetate copolymer on both sides of the elastomer. It is a structure in which coalescence, polyethylene, and polypropylene are laminated.

  Moreover, it is preferable that the softening temperature of the said resin is 30-170 degreeC in the protective film of this invention.

  Moreover, the manufacturing method of the protective film of the present invention includes a support as a transfer material having a surface average roughness (Sa) of 5 nm or less at a temperature 30 to 80 ° C. higher than the softening temperature of the protective film, and the protective film. A step of thermocompression bonding with the precursor, a step of peeling off the support, and obtaining the protective film having a surface average roughness (Sa) of a surface on the contact side with the support of 15 nm or less. And

  In addition, the functional transfer body of the present invention includes a carrier having a concavo-convex structure on a surface, at least one functional layer provided on the concavo-convex structure, and a surface of the functional layer opposite to the carrier. And the protective film described above provided.

  According to this invention, it becomes possible to suppress the bubble defect at the time of bonding a functional layer to a to-be-processed body rather than before.

It is a cross-sectional schematic diagram which shows the protective film which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows the manufacturing process of the protective film which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows the manufacturing process of the function transfer body which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows each process of the function provision method to the to-be-processed object using the function transfer body which concerns on this Embodiment.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

  In the present embodiment, a functional layer / carrier laminate in which a functional material is applied to a carrier having a concavo-convex structure on the surface is used as a functional transfer body to be bonded to an object to be processed. Considering the industrial use of this functional transfer body, it is necessary to protect the functional layer surface. That is, a functional transfer body composed of a protective film / functional layer / carrier is used. The protective film is peeled off when the functional transfer body is bonded to the object to be processed, but this time, as a result of repeated sincerity studies, the present inventors have adhered the functional transfer body to the object to be processed. The present inventors have found that a bubble defect is generated between the functional layer and the object to be processed, and that the bubble defect is derived from the protective film, resulting in the present invention. That is, the present embodiment is shown as follows.

<Protective film>
The protective film 1 of the present embodiment is characterized in that it has a surface average roughness (Sa) of at least one surface made of a resin of 15 nm or less.

  In addition, since the protective film 1 of this Embodiment is a "film shape", it has the property that a film thickness is very thin with respect to length and width, it is flexible, and can be made into a roll shape.

  As shown in FIG. 1, the surface average roughness (Sa) of the 1st surface 1a of the protective film 1 is 15 nm or less. On the other hand, the surface average roughness (Sa) of the second surface 1b of the protective film 1 may be 15 nm or less, or 15 nm or more. In addition, as for the protective film 1, it is preferable that the surface average roughness (Sa) of both surface 1a, 1b shall be 15 nm or less. Thereby, any surface 1a, 1b of the protective film 1 may be in contact with the functional layer, and the production management of the functional transfer body can be facilitated. Further, in the winding of the protective film 1 after the flattening treatment, if only one side is flattened, the unevenness of the other surface that has not been flattened overlaps with the flattened surface side. There is a risk of being transferred. Therefore, setting the surface average roughness (Sa) of both surfaces of the protective film 1 to 15 nm or less is preferable because the uneven transfer can be suppressed.

In this Embodiment, the surface average roughness (Sa) of the protective film 1 can be measured with the following measuring devices.
-Device name: VertScan
-Equipment manufacturer: Ryoka System Co., Ltd.-Equipment model number: R3300G
Measurement principle: White light interferometry

  Moreover, in this Embodiment, the surface average roughness (Sa) of the protective film 1 is measured by the height of the arithmetic average in three dimensions using the phase difference of reflected light.

  In combination with the surface average roughness (Sa), the protective film 1 of the present embodiment is preferably made of a resin having a softening temperature of 30 to 170 ° C.

  In the present embodiment, it is preferable that at least one of ethylene-vinyl acetate copolymer, polyethylene, or polypropylene is selected as the resin. The softening temperature (softening point) of the ethylene-vinyl acetate copolymer is about 40 ° C to 70 ° C, although it depends on the vinyl acetate content, and the softening temperature (softening point) of polyethylene is 80 ° C to 90 ° C. The softening temperature (softening point) of polypropylene is about 150 ° C.

  In this Embodiment, the softening temperature of the protective film 1 is comprised with resin with 30-170 degreeC, the handling property of the protective film 1 is improved, and the environmental resistance of the protective film 1 is improved. Can do. Moreover, as shown in the manufacturing method of the protective film 1 mentioned later, it becomes possible to adjust the surface average roughness (Sa) of the protective film 1 to 15 nm or less by moderate thermocompression bonding.

  That is, when the softening temperature of the protective film 1 is lower than 30 ° C., the strength as the protective film 1 cannot be maintained. On the other hand, if the softening temperature of the protective film 1 exceeds 170 ° C., the temperature necessary for flattening the protective film 1 becomes high, which is disadvantageous in terms of process. Therefore, it is suitable for the protective film 1 to be comprised with resin whose softening temperature is 30-170 degreeC.

  In the present embodiment, the protective film 1 may have a single layer structure or a laminated structure. In the protective film 1 having a laminated structure, the softening temperature of the protective film 1 in the laminated state is adjusted to be 30 to 170 ° C. As a laminated structure, it is preferable that at least one of ethylene-vinyl acetate copolymer, polyethylene, or polypropylene is included in at least one layer. For example, a laminated structure of ethylene-vinyl acetate copolymer and polyethylene, a laminated structure of elastomer and polypropylene, or the like can be used. Or it can also be set as the structure which laminated | stacked ethylene-vinyl acetate copolymer, polyethylene, and polypropylene on both surfaces of the elastomer. At this time, it is preferable that the surface of the layer containing at least one of ethylene-vinyl acetate copolymer, polyethylene, or polypropylene has a surface average roughness (Sa) of 15 nm or less.

The softening temperature is a softening temperature obtained by measuring the following measurement method and measurement conditions.
・ Measuring method: Thermomechanical analysis ・ Device manufacturer: TI Instruments ・ Device model number: TMA Q400
・ Penetration probe: Probe tip diameter 1mmφ
・ Load: 50mN
-Temperature rise: 5 ° C / min.
・ Atmosphere: Nitrogen (100 Ml / min)

  As the protective film 1 of the present embodiment, either a coating type in which an adhesive is applied to a base film or a self-adhesive type in which the film itself is made sticky can be employed. In the case of the application type, the pressure-sensitive adhesive applied to the base film is not particularly limited as long as it has appropriate adhesiveness with a functional layer described later. When the protective film 1 is peeled off from the functional layer, the adhesive component of the protective film 1 lowers the residual rate in the functional layer. Therefore, the protective film 1 is preferably a self-adhesive type.

  From the viewpoint of adhesiveness with a functional layer to be described later, the protective film 1 has an easy-adhesion layer on the functional layer surface side (surface side with a surface average roughness (Sa) of 15 nm or less) as necessary. Alternatively, a release layer may be formed. Surface treatment can also be performed, and examples thereof include corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency irradiation treatment, glow discharge irradiation treatment, active plasma irradiation treatment, and laser beam irradiation treatment.

  Moreover, the tensile elastic modulus defined in JIS K7127 of the protective film 1 is preferably 50 MPa or more and 5000 MPa or less. Thereby, when peeling the protective film 1 from the functional layer mentioned later, since the peeling stress added to a functional layer can be disperse | distributed, it can suppress effectively that the concave defect accompanying peeling is produced | generated and expanded on the functional layer surface. Furthermore, 200 MPa or more and 5000 MPa or less are more preferable from the viewpoint that the shape of the protective film 1 can be maintained and the handleability is good. In particular, from the viewpoint of increasing the width of the peeling condition when peeling the protective film 1, it is most preferably 250 MPa or more and 2500 MPa or less. In addition, if the tensile elasticity modulus of the protective film 1 is 2500 Mpa or less, since the transferability of the uneven structure to the to-be-processed body mentioned later can be improved, it is preferable. The lower limit value of the tensile elastic modulus of the protective film 1 is not particularly limited, but is preferably 50 MPa or more and 450 MPa or more from the viewpoint of the handleability of the protective film 1 when producing a functional transfer body. Is most preferred. In addition, the protective film 1 satisfy | filling the suitable range of a tensile elasticity modulus should just exist in the outermost layer by the side bonded to the functional layer of the protective film 1 at least. For example, if the tensile modulus is 50 MPa or more and 2500 MPa or less, the concave defects in the functional layer can be effectively suppressed, the transfer rate of the concavo-convex structure to the object to be processed is improved, and the handleability of the protective film 1 is dramatically improved. Therefore, the production stability is improved. For example, the polyethylene / ethylene vinyl acetate copolymer film having a tensile elastic modulus of 550 MPa to 700 MPa bonded to the surface of a polyethylene terephthalate (PET) film having a tensile elastic modulus of 3200 to 4200 MPa is used as the protective film 1, and the polyethylene / ethylene The vinyl acetate copolymer film surface side can be bonded to the functional layer for use. Thereby, the above-described effects of improving the transfer rate and improving the production stability can be enjoyed. Similarly, for example, the surface of a polyethylene terephthalate (PET) film having a tensile elastic modulus of 3200 to 4200 MPa and a polyethylene film having a tensile elastic modulus of 100 MPa to 1200 MPa bonded together are used as the protective film 1 and the polyethylene film surface side functions. It can be used by bonding to a layer. Similarly, for example, a surface of a polyethylene terephthalate (PET) film having a tensile elastic modulus of 3200 to 4200 MPa is coated with a material having a tensile elastic modulus of 2500 MPa or less as a protective film 1, and the coating surface side is bonded to a functional layer. Can be used. In this case, since the handleability of the protective film 1 is secured by the polyethylene terephthalate film, it can be said that the tensile elastic modulus of the outermost layer bonded to the functional layer of the protective film 1 may be 2500 MPa or less. Examples of the coating material include silicone release materials, non-silicone release materials, urethane resins, and acrylic resins.

  Although the size of the protective film 1 is not particularly limited, the thickness of the protective film 1 is preferably 10 μm or more and 150 μm or less, and more preferably 15 μm or more and 100 μm or less. Thereby, the peeling stress at the time of peeling the protective film 1 from the functional layer mentioned later equalizes, and a concave defect reduces with respect to a functional layer. Moreover, the handleability at the time of matching a functional layer and the protective film 1 is good, the width | variety of bonding conditions becomes wide, and industrial property becomes high.

<Method for producing protective film>
Next, the manufacturing method of the protective film in this Embodiment is demonstrated, referring FIG.

  In the present embodiment, at a temperature 30 to 80 ° C. higher than the softening temperature of the protective film, the support 2 as a transfer material having a surface average roughness (Sa) of 5 nm or less, and the protective film precursor 3 Heat-press.

  In the support 2, the surface average roughness (Sa) of the surface 2 a in contact with the protective film precursor 3 is adjusted to 5 nm or less. For example, a mirror-finishing material such as a PET film can be used as the support 2. Thereby, the surface average roughness (Sa) of the surface 2a of the support body 2 can be 5 nm or less.

  Alternatively, the surface average roughness (Sa) may be polished by a surface polishing process such as a CMP (Chemical Mechanical Polishing) method so that the surface average roughness (Sa) is 5 nm or less.

  Here, the surface average roughness (Sa) is measured by the arithmetic average height as described above. The measurement method is as already described.

  In the present embodiment, the protective film precursor 3 is bonded to the surface 2a of the support 2 having a surface average roughness (Sa) of 5 nm or less. Here, the “precursor” refers to a resin layer in a state before being thermocompression bonded.

  The protective film precursor 3 is made of a resin having a softening temperature of 30 to 170 ° C., and a resin selected from at least one of ethylene-vinyl acetate copolymer, polyethylene, and polypropylene is used. It is preferable.

  Subsequently, in the present embodiment, the support 2 and the protective film precursor 3 are thermocompression bonded at a temperature 30 to 80 ° C. higher than the softening temperature of the protective film precursor 3. Thus, heating is performed while applying pressure between the support 2 and the protective film precursor 3. As a thermocompression bonding method, for example, a pressure laminator, a press, a vacuum laminator, a vacuum press, a roll laminator or the like can be used.

  And in this Embodiment, the surface average roughness (Sa) of the surface at the side of contact with the support body 2 is obtained with the surface average roughness (Sa) of 15 nm or less by removing the support body 2 from the heat-pressed resin layer. Can do.

<Functional transcript>
FIG. 3 is a schematic cross-sectional view illustrating the manufacturing process of the functional transfer body according to the present embodiment.

  First, as shown in FIG. 3A, the carrier 10 has a concavo-convex structure 11 formed on the main surface thereof. The concavo-convex structure 11 is a concavo-convex structure including a plurality of concave portions 11a and convex portions 11b. The carrier 10 is, for example, a film shape or a sheet shape. The film shape has a property that the film thickness is extremely thin with respect to the length and width, is flexible, and can be formed into a roll shape. On the other hand, a sheet form refers to a thin flat plate-like object, and its flexibility is not limited. Moreover, what cut | disconnected the film-like functional transfer body in the length direction and made it into every leaf is a sheet form. However, in each embodiment, the two should not be clearly distinguished.

  Next, as shown in FIG. 3B, a functional layer 12 is provided on the surface of the concavo-convex structure 11 of the carrier 10. The arrangement of the functional layers 12 and the number of functional layers 12 are not limited to this. Further, as shown in FIG. 3C, the protective film 1 described above is provided on the upper side of the functional layer 12. Hereinafter, the laminate composed of the carrier 10, the functional layer 12, and the protective film 1 is referred to as a functional transfer body 14.

  FIG. 4 is a schematic cross-sectional view showing each step of a method for imparting a function to an object to be processed using the functional transfer body according to the present embodiment. A workpiece 20 as shown in FIG. 4A is prepared. Next, as shown in FIG. 4B, the exposed surface (hereinafter simply referred to as “surface” or “contact”) of the functional layer 12 of the functional transfer body 14 after removing the protective film 1 on the main surface of the object 20 to be processed. 12a) is directly brought into contact. Next, as shown in FIG. 4C, the carrier 10 is removed from the functional layer 12. As a result, a laminated body 21 including the functional layer 12 and the target object 20 is obtained. The laminated body 21 can be used in the state of the laminated body 21 depending on its application, or can be used after the processed body 20 is processed by functioning as a processing mask of the processed body 20.

  In addition, between the contact | abutting mentioned above and removal, for example, the functional layer 12 is stabilized by irradiating the laminated body 21 with an energy ray. Further, for example, the functional layer 12 is stabilized by heat applied at the time of contact. For example, after irradiating the laminated body 21 with energy rays, the laminated body 21 is heated to stabilize the functional layer 12. Moreover, when irradiating an energy ray, the laminated body 21 which comprises the patterned functional layer 12 can be obtained by providing the light shielding mask with respect to an energy ray. In patterning, if a positive-type developable functional layer is provided, energy rays can be irradiated after the carrier 10 is peeled off. If a negative-working functional layer is provided, the carrier 10 can be peeled off after irradiation with energy rays.

  Next, the composition of the functional layer 12 of the functional transfer body 14 will be described. In the functional transfer body 14, if the functional layer 12 includes a resin, the arrangement accuracy of the functional layer 12 is improved regardless of the composition of the functional layer 12, and the adhesive strength between the functional layer 12 and the target object 20 is increased. In addition, an uneven structure with few defects can be imparted to the object 20 to be processed. For this reason, the composition of the functional layer 12 is not particularly limited, and may be an organic material, an inorganic material, or an organic-inorganic composite. Moreover, even if comprised only from a monomer, an oligomer, or a polymer, you may contain these two or more. For this reason, for example, organic particles, organic fillers, inorganic particles, inorganic fillers, organic-inorganic hybrid particles, organic-inorganic hybrid fillers, molecules that induce sol-gel reactions, organic polymers, organic oligomers, inorganic polymers, inorganic oligomers, organic-inorganic hybrid polymers Organic-inorganic hybrid oligomers, polymerizable resins, polymerizable monomers, metal alkoxides, metal alcoholates, metal chelate compounds, halogenated silanes, spin-on glasses, metals, or metal oxides can be used.

  When the functional layer 12 contains a resin, the hardness of the functional layer 12 can be reduced and the arrangement stability of the functional layer 12 can be improved. Thereby, the controllability of the surface roughness (Sa) of the surface 12a of the functional layer by the protective film 1 is improved. That is, the concave defect with respect to the surface 12a of the functional layer 12 can be suppressed. This improves the accuracy and film thickness accuracy of the concavo-convex structure 11 of the functional layer 12 and suppresses the occurrence of cracks in the functional layer 12 even when the functional transfer body 14 is rolled up into a reel shape, for example. it can. Moreover, since the physical stability of the functional layer 12 of the functional transfer body 14 is improved by including the resin in the functional layer 12, the arrangement accuracy of the functional layer 12 is lowered by the conveyance and handling of the functional transfer body 14. This can be suppressed. Furthermore, since the hardness of the functional layer 12 is reduced by including the resin, the fluidity constraint on the surface layer of the functional layer 12 is easily released, and the real contact area between the functional layer 12 and the workpiece 20 is increased. In addition, the effect of increasing the adhesive strength can be improved. The resin used as the functional layer 12 is defined as an oligomer or polymer having a molecular weight of 1000 or more. Examples of the resin structure include organic resins, inorganic resins, and organic-inorganic hybrid resins. These may contain only 1 type, or may contain multiple. These resins can employ known general oligomers or polymers. For example, in general, a photoresist resin, a nanoimprint resin, an adhesive resin, an adhesive resin, a dry film resist resin, an engineering plastic, a sealing resin, rubber, plastic, fiber, medical plastic, or Pharmaceutical resins can be used. Natural polymers can also be used.

  The weight average molecular weight of the resin is preferably 1000 to 1000000 from the arrangement accuracy of the functional layer 12. The lower limit of 1000 was determined from the decrease in hardness of the functional layer 12 and the physical stability of the functional layer 12. On the other hand, the upper limit value of 1000000 was determined from the arrangement accuracy of the functional layer 12 with respect to the concavo-convex structure 11 in consideration of the range of the average pitch of the concavo-convex structure 11.

  The degree of dispersion of the resin is the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight) / (number average molecular weight). The molecular weight is gel permeation chromatography (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 type, column: Shodex (registered trademark) manufactured by Showa Denko KK (KF-807, KF-806M, KF- 806M, KF-802.5) 4 in series, moving bed solvent: tetrahydrofuran, using calibration curve with polystyrene standard sample), and can be determined as a weight average molecular weight (polystyrene conversion).

  When the functional layer 12 according to the present embodiment has a multilayer structure of two or more layers, the resin is preferably provided at least in the functional layer 12 in contact with the protective film 1 side. Thereby, even if it does not contain resin in the functional layer 12 by the side of the uneven structure 11, the said effect can be show | played by resin contained in the functional layer 12 by the side of the protective film 1. FIG.

  In particular, the resin contained in the functional layer 12 preferably has a polar group. In this case, since the intermolecular interaction in the functional layer 12 can be strengthened, the adhesion between the functional layer 12 and the concavo-convex structure 11 can be reduced. Furthermore, since the electrostatic interaction or hydrogen bonding action on the interface between the functional layer 12 and the object to be processed 20 tends to be strong, the adhesive strength between the functional layer 12 and the object to be processed 20 is improved. As mentioned above, transferability can be improved by including a polar group. The type of the polar group is not particularly limited, but epoxy group, hydroxyl group, phenolic hydroxyl group, acryloyl group, methacryloyl group, vinyl group, carboxyl group, carbonyl group, amino group, allyl group, diquitacene group, cyano group, isocyanate group, phosphorus It is preferable to include at least one polar group of the group consisting of an acid group and a thiol.

  When the resin is a curable resin, the volume of the functional layer 12 of the functional transfer body 14 tends to be smaller than the volume of the functional layer 12 when the carrier 10 is removed. That is, at the stage of removing the carrier 10 from the functional layer 12, a gap larger than the molecular scale can be formed at the interface between the concavo-convex structure 11 of the carrier 10 and the functional layer 12. This means that the adhesion between the concavo-convex structure 11 and the functional layer 12 is greatly reduced, so that the peeling speed of the carrier 10 can be sufficiently increased. In particular, it is preferable to include a photocurable resin from the viewpoint of effectively expressing the volume shrinkage of the functional layer 12 and weakening the adhesive strength between the functional layer 12 and the concavo-convex structure 11.

  In particular, the functional layer 12 preferably contains a monomer in addition to the resin described above. Here, the monomer is defined as a substance other than the resin defined by the present specification and a substance other than the solid fine particles and the solid filler. That is, any of an organic substance, an inorganic substance, and an organic-inorganic composite can be employed. In this case, when the monomer whose mobility is inhibited by the resin is brought into contact with the object 20 to be processed, the mobility is released and the fluidity of the surface layer of the functional layer 12 is further improved. it can.

  Next, the carrier 10 of the functional transfer body 14 according to the present embodiment will be described. The carrier 10 is not particularly limited as long as the concavo-convex structure 11 is formed, but the material constituting the functional layer 12 already described as a constituent material can be used. In addition, for example, inorganic materials such as silicon, quartz, nickel, chromium, sapphire, silicon carbide, diamond, diamond-like carbon, and fluorine-containing diamond-like carbon can be used.

  It is preferable to reduce the free energy of the surface of the concavo-convex structure 11 of the carrier 10. That is, by reducing the physical and chemical adhesive force between the concavo-convex structure 11 and the functional layer 12, the functional layer 12 can be peeled off without breaking with a constant stress. As a method for reducing the free energy, a method for performing a mold release process on the concavo-convex structure 11, selecting a material having a low free energy, or a method for charging a component for reducing the free energy on the surface can be employed. As the mold release treatment for the concavo-convex structure 11, a known and generally known mold release treatment can be adopted, and a general antifouling agent, leveling material, water repellent, fingerprint adhesion preventing agent, or the like can be used. Further, the surface of the concavo-convex structure 11 may be covered with a metal or a metal oxide before performing the mold release process. In this case, the uniformity of the mold release process and the strength of the concavo-convex structure 11 can be improved. As a material having low free energy, a fluorine-containing resin typified by polytetrafluoroethylene (PTFE) or perfluoropolyether (PFPE), a silicone resin typified by polydimethylsiloxane (PDMS), or the like can be used. In addition, the method of charging the component for reducing the free energy of the surface can be performed on the functional layer 12. For example, by charging the functional layer 12 with a fluorine component or a silicone component, segregation of the fluorine component or bleeding out of the silicone component can be used, so that the adhesive strength between the functional layer 12 and the concavo-convex structure 11 can be greatly reduced.

  When the carrier 10 is flexible, the material constituting the concavo-convex structure 11 may be a cured product of a photocurable resin, a cured product of a thermosetting resin, a thermoplastic resin, or the like. On the other hand, when the carrier 10 is non-flexible, a metal, a metal oxide, or the like can be used as the material constituting the uneven structure 11. For example, an inorganic material such as silicon, quartz, nickel, chromium, sapphire, silicon carbide, diamond, diamond-like carbon, or fluorine-containing diamond-like carbon can be used. Moreover, when it is non-flexible, the uneven structure 11 comprised from resin can also be formed on a non-flexible support base material. In either case of flexible or non-flexible, as described above, it is preferable to reduce the free energy on the surface of the concavo-convex structure 11.

  As a method of bonding the functional layer 12 and the protective film 1, a laminating process can be used. As a laminator, a single-stage laminator that uses a pair of hot rolls, a multi-stage laminator that uses two or more pairs of hot rolls, and a vacuum laminator that covers the part to be laminated with a container and then reduces the pressure using a vacuum pump or vacuum -Etc. are used.

  When the linear pressure applied to the functional transfer body 14 during lamination is 1 kg / cm or more, the bonding between the functional layer 12 and the protective film 1 is good, and air is caught between the functional layer 12 and the protective film 1. Because there are few, it can wind up neatly. Further, when the linear pressure is 150 kg / cm or less, damage to the uneven shape of the carrier 10 is suppressed by the pressure, and therefore the linear pressure is preferably 1 kg / cm or more and 150 kg / cm or less. Furthermore, 4 kg / cm or more and less than 100 kg / cm are more preferable. In the present specification, the linear pressure is defined as a pressing force per unit length of a portion where the functional transfer body 14 and the laminate roll are in contact with each other.

  The laminator roll may not be heated, but may be heated when it is necessary to increase the adhesive force between the functional layer 12 and the protective film 1 and increase the winding accuracy. The heating temperature may be such that the viscosity of the protective film 1 decreases and cannot be peeled off from the functional layer 12 or a part of the protective film 1 does not adhere to the functional layer 12 and remains.

  In the laminating step, the conveyance speed of the functional transfer body 14 is not particularly limited, but when it is less than 20.0 m / min, the bonding property between the functional layer 12 and the protective film 1 is high, and the winding accuracy is high. Further, if it is 0.3 m / min or more, the productivity is high and the manufacturing cost is low, so that the conveyance speed of the functional transfer body 14 may be 0.3 m / min or more and less than 20.0 m / min. preferable. Furthermore, it is more preferably 1.0 m / min or more and less than 10.0 m / min.

  In the present embodiment, the function transfer body 14 is used for the purpose of transferring and forming a mask function on the object to be processed 20 on the object to be processed 20. The unevenness processing accuracy can be improved. This is because elements such as the thickness of the functional layer 12 functioning as a mask and the size and arrangement of the concavo-convex structure 11 can be determined and secured in advance by the accuracy of the concavo-convex structure 11 of the carrier 10 of the functional transfer body 14. is there. When two or more functional layers 12 are included, at least one functional layer 12 functions as a processing mask for the object to be processed 20, and at least one functional layer 12 functions as a mask for processing other functional layers 12. Function. That is, by using the functional transfer body 14, the functional layer 12 can be transferred and applied to the surface of the object 20 to be processed. When the functional layer 12 is composed of two or more layers, the one or more functional layers 12 are caused to function as a processing mask for the other functional layers 12, and the other functional layers 12 are processed to be uneven by dry etching, for example. Thereafter, the processed object 20 can be processed to be uneven by dry etching or wet etching, for example, using the other functional layer 12 as a processing mask. On the other hand, when the functional layer 12 is a single functional layer 12, the workpiece 20 can be processed to be uneven by, for example, dry etching or wet etching using the functional layer 12 as a processing mask.

  The material and shape of the workpiece 20 are not particularly limited. The material may be organic or inorganic. For example, quartz typified by synthetic quartz and fused silica, alkali-free glass, low alkali glass, glass typified by soda lime glass, silicon, nickel, sapphire, diamond, metallic aluminum, amorphous aluminum oxide, polycrystalline aluminum oxide, Single crystal aluminum oxide, titanium oxide, SUS, metal composed of metal elements exemplified in functional layer 12, metal oxide containing metal element, iron oxide, copper oxide, chromium, silicon carbide, mica, zinc oxide, semiconductor Examples thereof include base materials (such as nitride semiconductor base materials), spinel base materials, transparent conductive inorganic materials represented by ITO, paper, synthetic leather, leather, and organic materials. Examples of the shape include a disk shape, a flat plate shape, an n prism shape, an n pyramid shape, a lens shape, a spherical shape, a film shape, and a sheet shape. The n-prism shape or the n-pyramid shape includes an n-prism shape or an n-pyramid shape including a corner portion having a radius of curvature exceeding zero. In addition, when using the thing of a wafer shape as the to-be-processed object 20, it is preferable that the magnitude | size is 2 inches (phi) or more. This is because when the diameter is 2 inches or more, the influence of the edge of the object to be processed 20 is reduced, and the effective area to which the unevenness is transferred increases.

  For example, as the object 20 to be processed, a sapphire wafer, a silicon carbide wafer, an LED epitaxial wafer, or a silicon wafer can be selected. Thereby, the uneven | corrugated process can be appropriately performed to the surface of the to-be-processed object 20. FIG. That is, the uneven structure 11 made of the same material as the object to be processed 20 can be formed on the surface of the object to be processed 20. By using such a processed object with a concavo-convex structure, a highly efficient LED can be manufactured. As the LED element, at least an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer are formed on the concavo-convex structure surface of sapphire that has been processed to provide an LED element by forming an n-type electrode and a p-type electrode. Can be manufactured. The efficiency of an LED is determined by the product of electron injection efficiency, internal quantum efficiency, and light extraction efficiency.

  In the present embodiment, the unevenness can be processed at a place suitable for assembling the LED, so that the defect rate of the LED element is reduced. There are two reasons why the efficiency of the LED is improved by assembling the LED element using the workpiece with the concavo-convex structure. First, in the CVD process for depositing a semiconductor crystal layer used for an LED on an object having a concavo-convex structure, the growth mode of the semiconductor crystal layer is disturbed, dislocations are reduced, and the internal quantum efficiency is improved accordingly. is there. When attention is paid when using the LED element, when the light emitted from the semiconductor crystal layer enters the concavo-convex structure of the object to be processed with the concavo-convex structure, its traveling direction changes, and the waveguide mode is destroyed. This is because the light extraction efficiency is improved. In order to improve both the internal quantum efficiency and the light extraction efficiency at the same time, a fine concavo-convex structure is required. From such a background, for example, when a foreign substance of several micrometers adheres to the concavo-convex structure surface of the workpiece with the concavo-convex structure, tens to hundreds of fine structures are destroyed. It can be easily imagined that the foreign matter generation location varies greatly depending on the environment, but the probability that the foreign matter adheres increases as the movement of the workpiece with the concavo-convex structure increases. From this viewpoint, it is possible to reduce the number of foreign matters attached and facilitate foreign matter management by producing the object with a concavo-convex structure in a place where the LED element can be produced. Therefore, the defect rate of the LED element can be reduced.

  By using the protective film 1 of this Embodiment, the malfunction by which a concave defect is formed in the surface 12a of the functional layer 12 which comprises the function transfer body 14 can be suppressed. That is, according to this Embodiment, the surface average roughness (Sa) of the transfer surface with respect to the functional layer 12 of the protective film 1 is 15 nm or less, Therefore, the surface of the surface 12a of the functional layer 12 which contact | connects the protective film 1 Roughness can also be reduced. Therefore, it is possible to suppress the problem that the convex portions on the surface of the protective film 1 are transferred to the functional layer 12 and the concave portions are formed as in the conventional case, and the functional layer 12 is pasted on the workpiece 20 as shown in FIG. 4B. When combined, it is possible to suppress entrainment of bubbles between the object 20 and the functional layer 12.

  As described above, according to the present embodiment, the interface between the object to be processed 20 and the functional layer 12 can be brought into close contact, and there is no area for entraining bubbles, or at least the area for entraining bubbles is reduced. Therefore, the accuracy of the concavo-convex structure processed and formed on the object 20 can be improved.

  Moreover, the functional transfer body 14 in this Embodiment contains the protective film 1 as an essential structural requirement, and in manufacture of the functional transfer body 14, the stability at the time of bonding and winding up the protective film 1 is important, and it is below. Expressed as laminate. On the other hand, when the functional transfer body 14 is used, since the protective film 1 is used after being peeled off, the stability at the time of peeling off the protective film 1 is important. When the adhesion between the protective film 1 and the functional layer 12 is low when the protective film 1 is bonded, the protective film 1 slips on the functional layer 12 and wrinkles occur during winding. That is, the laminating property is lowered. On the other hand, when the adhesiveness between the protective film 1 and the functional layer 12 is too high, when the protective film 1 is peeled from the functional layer 12, the enlargement of the concave defects proceeds and the functional layer is destroyed. That is, the peelability is reduced. From the above, it can be said that in order to have both laminating properties and peelability, it is only necessary to realize a suitable range of adhesion between the protective film 1 and the functional layer 12.

  The functional layer 12 in the functional transfer body 14 is characterized in that a suitable material can be selected according to the application. Further, the adhesion force between the two bodies can be calculated as the difference in free energy between the two bodies, and the free energy can be estimated from the contact angle. Therefore, the contact angle of the water droplet with respect to the functional layer 12 and the functional layer of the protective film 1 It is considered that there is a suitable range for the contact angle of the water droplet with respect to the surface to be bonded to the surface 12. If the contact angle of the water droplet with respect to the surface bonded to the functional layer 12 of the protective film 1 is 75 degrees or more and 105 degrees or less, since lamination property and peelability improve more, it is preferable. The reason for this is not clear, but the adhesive force between the two bodies is defined as the difference in free energy between the two bodies, and since the free energy can be estimated by the contact angle, the contact angle of the protective film 1 is controlled within a predetermined range. Therefore, it is estimated that the free energy between the two bodies increases for the laminate property and decreases for the peelability.

  The contact angle using water droplets is measured in accordance with Japanese Industrial Standard JISR 3257: 1999 “Method for testing wettability of substrate glass surface”.

  Examples carried out to confirm the effects of the present invention will be described below. The present invention is not limited by this example.

[Manufacture of protective film]
A protective film made of the following materials was obtained by using a support as a material to be transferred and a plurality of examples and comparative examples while changing production conditions. First, the protective film and support used in the experiment will be described.

(Protective film-1)
As the protective film-1, a protective film (Toraytec # 7332 manufactured by Toray; laminated with each resin layer of ethylene-vinyl acetate copolymer resin (EVA) having a softening temperature of 40 ° C. and polyethylene (PE); , Expressed as EVA / PE).

(Protective film-2)
As protective film-2, a protective film (FSA 010C manufactured by Futamura Chemical Co., Ltd .; expressed as elastomer / PP in the following Table 1) in which respective resin layers of an elastomer having a softening temperature of 100 ° C. and polypropylene (PP) were laminated was used. .

(Support-1)
In manufacturing the protective film, a support as a transfer material for the protective film precursor was prepared.

  As the support 1, a resin material (A4100 manufactured by Toyobo Co., Ltd.) made of polyethylene phthalate (PET) having a surface average roughness (Sa) of 1 nm corresponding to the laminate surface of the protective film precursor was used.

(Support-2)
As the support-2, a resin material (ALPHAN manufactured by Oji F-Tex) made of biaxially oriented polypropylene (OPP) having a surface average roughness (Sa) of 30 nm corresponding to the laminate surface of the protective film precursor was used.

Example 1
The protective film was manufactured using said protective film-1 and support body-1. That is, the protective film precursor which consists of the material of the protective film-1 was bonded together to the surface whose surface average roughness (Sa) of the support body 1 is 1 nm. And the protective film-1 and the support body-1 were thermocompression-bonded by making lamination temperature into 120 degreeC. The applied pressure was adjusted to an appropriate pressure with a prescale. The same applies to the following samples.

  Thereafter, the protective film was removed from the support. The surface average roughness (Sa) of the protective film of Example 1 was 3 nm. The surface average roughness (Sa) was measured by VertScan as the arithmetic average height.

(Example 2)
The protective film was manufactured using said protective film-1 and support body-1. That is, the protective film precursor which consists of the material of the protective film-1 was bonded together to the surface whose surface average roughness (Sa) of the support body 1 is 1 nm. And the protective film-1 and the support body-1 were thermocompression-bonded by making the lamination temperature into 100 degreeC.

  Thereafter, the protective film was removed from the support. The surface average roughness (Sa) of the protective film of Example 2 was 7.5 nm.

(Example 3)
The protective film was manufactured using said protective film-1 and support body-1. That is, the protective film precursor which consists of the material of the protective film-1 was bonded together to the surface whose surface average roughness (Sa) of the support body 1 is 1 nm. And the protective film-1 and the support body-1 were thermocompression-bonded by making the lamination temperature into 80 degreeC.

  Thereafter, the protective film was removed from the support. The surface average roughness (Sa) of the protective film of Example 3 was 15 nm.

Example 4
A protective film was produced using the protective film-2 and the support-1. That is, the protective film precursor which consists of the material of the protective film-2 was bonded together to the surface whose surface average roughness (Sa) of the support body 1 is 1 nm. And the protective film-2 and the support body-1 were thermocompression-bonded by making the lamination temperature into 130 degreeC.

  Thereafter, the protective film was removed from the support. The surface average roughness (Sa) of the protective film of Example 1 was 15 nm.

(Comparative Example 1)
Comparative Example 1 is a protective film as a blank test product manufactured using the above protective film-1 and without using a support as a transfer material (and thus without performing thermocompression bonding). The surface average roughness (Sa) of the protective film of Comparative Example 1 was 40 nm.

(Comparative Example 2)
The protective film was manufactured using said protective film-1 and support body-1. That is, the protective film precursor which consists of the material of the protective film-1 was bonded together to the surface whose surface average roughness (Sa) of the support body 1 is 1 nm. And the protective film-1 and the support body-1 were thermocompression-bonded by making lamination temperature into 25 degreeC.

  Thereafter, the protective film was removed from the support. The surface average roughness (Sa) of the protective film of Comparative Example 2 was 40 nm.

(Comparative Example 3)
A protective film was produced using the protective film-1 and the support-2. That is, the protective film precursor which consists of the material of the protective film-1 was bonded together to the surface whose surface average roughness (Sa) of the support body 1 is 30 nm. And the protective film-1 and the support body-1 were thermocompression-bonded by making the lamination temperature into 100 degreeC.

  Thereafter, the protective film was removed from the support. The surface average roughness (Sa) of the protective film of Comparative Example 3 was 40 nm.

(Comparative Example 4)
The protective film was manufactured using said protective film-1 and support body-1. That is, the protective film precursor which consists of the material of the protective film-1 was bonded together to the surface whose surface average roughness (Sa) of the support body 1 is 1 nm. And the protective film-1 and the support body-1 were thermocompression-bonded by making the lamination temperature into 150 degreeC.

  Thereafter, the protective film was removed from the support. The average surface roughness (Sa) of the protective film of Comparative Example 4 was too high to be measured accurately because the lamination temperature was too high and sample damage was severe.

[Create functional transfer body]
The following functional coating solution was applied to the concavo-convex structure surface of the carrier to prepare a functional transfer body.
Functional coating liquid: benzyl binder resin: bisphenol A EO-modified diacrylate (Aronix (registered trademark) M211B, manufactured by Toagosei Co., Ltd.): phenoxyethyl acrylate (light acrylate PO-A, manufactured by Kyoeisha Chemical Co., Ltd.): trimethylolpropane ( EO-modified) triacrylate (Aronix M350, manufactured by Toagosei Co., Ltd.): 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by BASF): 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) ) -Butanone-1 (Irgacure 369, manufactured by BASF) = 150 g: 40 g: 40 g: 20 g: 11 g: 4 g The composition mixed was diluted to 10% by mass with a mixed solvent of methyl ethyl ketone and propylene glycol monomethyl ether. Material. As the benzyl binder resin, a methyl ethyl ketone solution (solid content 50%, weight average molecular weight 56000, acid equivalent 430, dispersity 2.7) of a binary copolymer of benzyl methacrylate 80% by mass and methacrylic acid 20% by mass was used. . In addition, the said mass was described by solid content mass.

  After coating the functional coating liquid on the uneven structure surface of the carrier, the functional coating liquid was moved in a drying furnace at 80 ° C. for 5 minutes to remove excess solvent.

  Subsequently, the protective films of Examples 1 to 4 and Comparative Examples 1 to 4 were brought into contact with the surface of the functional layer of the functional transfer body obtained as described above, and passed through the laminate roll. Winded up. At this time, the temperature of the laminate roll was 23 ° C., the linear pressure was 30 kg / cm, and the carrier conveyance speed was 3.0 m / min.

[Measurement of bubble defects at interface between functional layer and workpiece]
The protective film of the functional transfer body obtained as described above was peeled off, and the functional layer surface of the functional transfer body was bonded onto the object to be processed.

Here, a C-plane sapphire substrate having a diameter of 2 inches was used as the object to be processed. The sapphire substrate was subjected to UV-O ₃ treatment for 10 minutes to perform cleaning, and the surface was subjected to hydrophilic treatment.

And in the state which heated the processed sapphire base material to 105 degreeC, the functional layer surface of the functional transfer body which peeled off the protective film with the pressure of 0.03 Mpa using the laminate roll was bonded. Subsequently, the carrier was peeled and removed by irradiating with UV light using a high-pressure mercury lamp so that the integrated light amount was 1200 mJ / cm ² .

It was measured how many bubble defects having a size of 10 μm ² or more exist on the surface of the object to be processed of 2 inches at the functional layer / object to be processed interface. The method for measuring bubble defects is as follows.
・ Measurement method: AOI (automatic optical inspection)

The following apparatus was used as a wafer appearance inspection apparatus.
-Equipment manufacturer: Toray Engineering Co., Ltd.-Equipment model number: INSPECTRA 3000TR200
The experimental results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 4, the number of bubble defects was 0. On the other hand, in Comparative Examples 1 to 3, the number of bubble defects increased to about 30. In Comparative Example 4, the laminating temperature was too high and the sample damage was so severe that measurement was impossible.

  In Examples 1 to 4, the surface average roughness (Sa) of the surface of the protective film was 15 nm or less, and the softening temperature was in the range of 30 to 170 ° C.

  Further, the protective films of Examples 1 to 4 have a surface average roughness (Sa) of 5 nm or less as a transferred material at a temperature 30 to 80 ° C. higher than the softening temperature of the protective film, The protective film precursor was obtained by thermocompression bonding and subsequently peeling off the support.

  The present invention is used in the field of forming fine structures such as optical components, energy devices, biodevices, and recording media.

DESCRIPTION OF SYMBOLS 1 Protective film 2 Support body 3 Protective film precursor 10 Carrier 11 Uneven structure 12 Functional layer 14 Functional transfer body 20 Object to be processed

Claims (6)

  A protective film comprising a resin having a surface average roughness (Sa) of at least one surface of 15 nm or less.   The protective film according to claim 1, wherein at least one of ethylene-vinyl acetate copolymer, polyethylene, and polypropylene is selected as the resin.   The resin is a laminated structure of ethylene-vinyl acetate copolymer and polyethylene, a laminated structure of elastomer and polypropylene, or a structure in which ethylene-vinyl acetate copolymer, polyethylene, and polypropylene are laminated on both sides of the elastomer. The protective film according to claim 2, wherein the protective film is provided.   The softening temperature of the resin is 30 to 170 ° C, The protective film according to any one of claims 1 to 3. A step of thermocompression bonding the support as a transfer material having a surface average roughness (Sa) of 5 nm or less and a protective film precursor at a temperature 30 to 80 ° C. higher than the softening temperature of the protective film;
Removing the support and obtaining the protective film having a surface average roughness (Sa) of the surface on the contact side with the support of 15 nm or less;
The manufacturing method of the protective film characterized by having. The carrier having a concavo-convex structure on a surface, at least one functional layer provided on the concavo-convex structure, and the functional layer provided on a surface opposite to the carrier. A functional transfer body comprising the protective film according to any one of the above.

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