JP4665720B2 - Pattern substrate, pattern substrate manufacturing method, fine mold, and magnetic recording pattern medium - Google Patents

Description

  The present invention relates to a substrate on which a fine pattern is formed using a self-organization phenomenon and a method for manufacturing the same. The substrate obtained in the present invention can be used as a substrate having a fine and regular structure as it is, but it can be used as a mask or a mold to transfer the fine and regular structure to another substrate or substance. Can also be used. Further, the present invention can be applied to manufacture of a fine mold applied to nanoimprint or the like, a medium for a magnetic recording apparatus having a high recording density, or the like.

  With the downsizing and high performance of electronic devices, energy storage devices, sensors, etc., there is an increasing demand for substrates having a fine structure with a size of several nanometers to several hundred nanometers. There is a need to establish processes that can produce structures. As an example of such a device, for example, Patent Document 1 discloses a technique of a pattern medium that dramatically improves the recording density of a magnetic recording apparatus.

  In general, for processing a fine structure, a top-down method represented by lithography, that is, a method of imparting a shape by finely engraving a bulk material is generally used. Optical lithography used for semiconductor microfabrication such as LSI manufacturing is a typical example.

  However, as processing dimensions become finer, the top-down approach increases the difficulty of both equipment and process. In particular, when the processing size approaches several tens of nanometers, it is necessary to use an electron beam or deep ultraviolet rays for patterning, and enormous investment is required for the apparatus. In addition, it becomes difficult to apply the mask and it is necessary to apply the direct writing method, and it is difficult to avoid the problem that the processing throughput is not sufficient.

  Under such circumstances, a process that applies a phenomenon in which a substance naturally forms a structure, that is, a so-called self-organization phenomenon, has attracted attention. In particular, the process applying the self-organization phenomenon of polymer block copolymer, so-called micro phase separation phenomenon, can form a fine regular structure having various shapes of several tens to several hundreds of nanometers by a simple coating process. It is an excellent process. Examples of forming a regular array structure on a substrate using a self-organized phase separation structure formed by a polymer block copolymer, that is, a microphase separation structure, are polystyrene and polybutadiene, polystyrene and polyisoprene, polystyrene and poly An example is known in which a polymer block copolymer thin film made of a combination of methyl methacrylate or the like is used as an etching mask and a structure such as a hole or a line and space is formed on a substrate.

  By applying the microphase-separated structure of the polymer block copolymer and arranging the self-assembled shapes on the substrate, the nano-sized microdomains formed by each polymer chain forming the polymer block copolymer are In many cases, the structure is regularly arranged and has a highly structured structure, and a structure in which self-organized shapes are regularly arranged is obtained in the micro. However, from a macro perspective, there are many regions (hereinafter referred to as grains) having different microdomain arrangement directions and arrangement regularities, and even within the grains, there are point defects and line defects in the microdomain arrangement. Exists. For this reason, it cannot be applied as it is to applications requiring high regularity over a large area, for example, processing of a magnetic recording pattern medium.

  As a method for solving this problem, as schematically shown in FIG. 1, a fine groove 11 is formed on the substrate surface by a top-down method, and microphase separation is performed inside the groove 11, that is, in a constrained space. Attempts to reduce defects, grains, grain boundaries, etc. by forming a structure have been reported (for example, Non-Patent Document 1). This technique applies a phenomenon in which microphase separation structures are arranged along the walls of the grooves, and a method for producing a magnetic recording pattern medium using this technique has already been reported (for example, Patent Document 1). However, in this method, in addition to the fine pattern obtained by the microphase separation structure, the shape derived from the grooves formed for the purpose of reducing defects, grain structures, and the like remains. That is, a desired fine pattern cannot be formed on the entire surface of the substrate. For example, when this is applied to a magnetic recording pattern medium, the recording density is reduced by the area of the shape derived from the groove, which is not desirable.

  Further, a process schematically shown in FIG. 2, that is, a microphase separation structure of a polymer block copolymer was formed in the groove 11 by the above-described method, and one side phase was decomposed with an energy ray or the like was obtained. A method of processing a substrate using a film as a mask is disclosed (for example, Patent Document 2). However, in this method, since a fine and substantially regular uneven shape is processed only at the groove bottom, the obtained substrate surface has a desired fine and substantially regular unevenness 20 as shown in FIG. The shape is present only at the bottom of the groove 11. That is, the surface heights of the fine and substantially regular unevenness 20 and the peripheral portion 21 thereof are not the same. For example, when this manufacturing method is applied to a magnetic recording pattern medium, smooth driving of the magnetic recording head is hindered. This is not desirable.

  As a method of patterning the entire surface of the substrate without defects, grains, and grain boundaries without leaving the groove shape, the polymer block copolymer has affinity with each of the polymer block chains constituting the polymer block copolymer. A method of chemically patterning the substrate surface is disclosed (for example, Non-Patent Document 2). However, according to this method, it is necessary to create a chemical pattern having the same dimensions as the micro-layer separation structure formed by the polymer block copolymer on the substrate surface by a top-down method, which is not a practical method. .

JP 2002-279616 A JP 2003-155365 A Cheng et al., Adv. Mater. 15 (2003) 1599 Kim et al., Nature 424 (2003) 411

  As described above, the patterning technique using microphase separation of the polymer block copolymer is a simple and low-cost technique. However, according to the conventional method, a fine structure is formed on the entire surface of the substrate by a defect or grain structure. Patterning is not possible. In addition, when a substrate is processed using a patterned substrate manufactured by a conventional technique as a mask, there is a problem in that the surface height is uneven in a portion having fine irregularities and its peripheral portion.

  An object of the present invention is to solve the above problems and provide a method for patterning the surface of a substrate simply and at low cost using microphase separation of a polymer block copolymer. Another object of the present invention is to provide a substrate on which a fine shape is formed, a fine mold for nanoimprinting, a patterned medium for magnetic recording, and a method for producing them.

  The present invention relates to a patterned substrate having a polymer block copolymer thin film having a substantially regular microphase separation structure on the surface of the base substrate, the base substrate surface having an uneven shape, and the polymer block copolymer. A patterned substrate in which a polymer thin film is formed on the concave portion and the surface of the convex portion of the base substrate.

  In this pattern substrate, when the distance between the closest microdomains of the microdomains constituting the substantially regular microphase separation structure is a, the depth of the concave portion is preferably 0.5a or more and 1.5a or less.

Further, it is desirable that the distance a between the nearest microdomains of the microdomain is 10 nanometers or more and 200 nanometers or less. Further, the width of the convex portion of the substrate is 1.0a or more and 50.0a or less, the width of the concave portion is 1.0a or more and 25.0a or less, and the thickness of the thin film having the microphase separation structure is The surface of the convex portion of the substrate is preferably 0.5a or more and 1.5a or less. Furthermore, it is desirable that the structure of the microdomain constituting the microphase separation structure is spherical or cylindrical.

  In addition, the present invention has a concavo-convex shape on the surface of the base substrate, a thin film of a polymer block copolymer is formed in the groove of the concave portion, and a layer in which microdomains are arranged in a row in a continuous phase; It is a pattern substrate characterized by having a two-layer structure of layers formed on the surface of a convex portion and having a microdomain arranged in a row in a continuous phase.

  The present invention also provides a step of forming a concave shape on a part of the surface of a substrate having a smooth surface, and a polymer block copolymer thin film is formed so as to fill the concave shape and cover the substrate surface And a step of forming a microphase separation structure in the polymer block copolymer thin film.

  The pattern substrate manufacturing method further includes a step of selectively removing one polymer phase from the microphase separation structure.

  And a step of selectively removing one polymer phase from the microphase separation structure and then transferring the microphase separation structure to the substrate surface by processing the substrate using the remaining other polymer phase as a mask. It is a manufacturing method of the pattern board | substrate characterized by having.

  And a step of selectively removing one polymer phase from the microphase-separated structure and bringing the transferred material into close contact with the remaining other polymer phase to transfer the microphase-separated structure to the transferred material. A method for manufacturing a patterned substrate.

  In addition, the present invention is a fine mold and a magnetic recording pattern medium used for nanoimprint or the like manufactured using a process including the above four types of manufacturing methods.

  According to the present invention, a micro-phase separation of a polymer block copolymer, which is a simple and low-cost fine pattern formation method, is applied, and a substrate having a fine structure patterned on the entire surface of the substrate without defects or a grain structure, and its manufacture A method can be provided. In addition, a fine mold and a magnetic recording pattern medium can be provided.

  Hereinafter, the patterned substrate of the present invention and the manufacturing method thereof will be described in comparison with the prior art.

  FIG. 1 shows a schematic cross-sectional view of a substrate in which a fine pattern without defects, grains, and grain boundaries is formed on the substrate using a micro block separation structure of a polymer block copolymer using a conventional technique. In the prior art, a method of reducing defects and grain structures of the microphase separation structure by forming the microphase separation structure in a space in which the microphase separation structure is constrained, that is, inside the groove 11 has been used. This reduces the degree of freedom of microphase separation in a constrained space having a size several to several tens of times the size of the microdomain. Thereby, the micro domain constituting the micro phase separation structure is oriented along the wall surface, and the effect of reducing the number of defects and the number of grain structures is utilized. However, in this method, as is apparent from FIG. 1, a pattern cannot be formed in the groove peripheral portion 14. As described above, for example, when this is applied to a magnetic recording pattern medium, the recording density is reduced by the area of the groove peripheral portion 14 as described above.

In addition, as shown in FIG. 2, a micro block separation structure of a polymer block copolymer is formed in the groove 11, the one side phase is decomposed with energy rays, and the substrate is processed using the obtained film as a mask. By this method, fine irregularities can be processed on the surface. However, as is apparent from FIG. 2, the structure that can be formed by the conventional technique is not uniform in the surface height of the fine and substantially regular irregularities 20 and the peripheral portion 21 thereof. As described above, when applied to a magnetic recording pattern medium, smooth driving of the magnetic recording head is hindered.

  The present inventors have intensively studied to solve these problems, and have developed a control method based on a concept different from the concept of controlling a microphase separation structure using a constrained space applied in the prior art. It came to invent. The principle of the present invention is schematically shown in FIG. That is, in the present invention, the recess 32 is formed on the surface of the substrate, a thin film of the polymer block copolymer is formed on the entire surface of the substrate including the inside thereof, and then microphase separation is performed in the thin film of the polymer block copolymer. A structure is formed. When the present inventors take an appropriate method, not only the inside of the concave portion 32 but also the periphery of the concave portion 32, that is, the convex portion 31 on the substrate surface, the microphase separation structure is formed on the entire surface of the substrate without defects or grain structures. It was found that it can be formed. In the present invention, the concave portion 32 does not act as a constraining space for reducing defects or grain structures of the microphase separation structure, but is a base point of the microphase separation structure that appears in a free space on the entire substrate surface. Can be considered. By using the present invention, it is possible to form a microphase separation structure with very few defects and a grain structure on the entire surface of the substrate. In the present invention, it is not always necessary to form a microphase separation structure over the entire surface of the substrate, and it is excluded to form a microphase separation structure with very few defects and grain structures only in the target region. Not what you want.

  Hereinafter, the details of the patterned substrate and the manufacturing method thereof of the present invention will be described.

As the polymer block copolymer used in the present invention, one that can selectively remove the target microdomain among a plurality of microdomains constituting the microphase separation structure after the microphase separation structure is formed is used. In this case, it is preferable to use the difference in etching rate between reactive ion etching (RIE) or other etching methods between the microdomains. For example, when a polymer block copolymer made of polystyrene and polybutadiene is used, development processing can be performed so as to leave only microdomains made of polystyrene blocks by ozone treatment. In a polymer block copolymer composed of polystyrene and polymethyl methacrylate, polystyrene has higher etching resistance to RIE using oxygen or CF ₄ as an etchant than polymethyl methacrylate. For this reason,
Only microdomains composed of polymethylmethacrylate can be selectively removed by RIE.

  Examples of such a polymer block copolymer include polybutadiene-polydimethylsiloxane, polybutadiene-4-vinylpyridine, polybutadiene-methyl methacrylate, polybutadiene-poly-t-butyl methacrylate, polybutadiene-t-butyl acrylate, poly-t- Butyl methacrylate-poly-4-vinyl pyridine, polyethylene-polymethyl methacrylate, poly-t-butyl methacrylate-poly-2-vinyl pyridine, polyethylene-poly-2-vinyl pyridine, polyethylene-poly-4-vinyl pyridine, polyisoprene -Poly-2-vinylpyridine, polymethyl methacrylate-polystyrene, poly-t-butyl methacrylate-polystyrene, polymethyl acrylate-polystyrene, polybutadiene Restyrene, polyisoprene-polystyrene, polystyrene-poly-2-vinylpyridine, polystyrene-poly-4-vinylpyridine, polystyrene-polydimethylsiloxane, polystyrene-poly-N, N-dimethylacrylamide, polybutadiene-sodium polyacrylate, polybutadiene -Polyethylene oxide, poly-t-butyl methacrylate-polyethylene oxide, polystyrene-polyacrylic acid, polystyrene-polymethacrylic acid, etc.

  The above polymer block copolymer is an example of an AB type polymer diblock copolymer having a structure in which two types of polymer chains of A polymer chain and B polymer chain are combined. It may be a triblock copolymer or an ABC type polymer block copolymer composed of three or more kinds of polymers. Furthermore, in addition to the polymer block copolymer in which each block is connected in series, for example, a star-type polymer block copolymer in which each block is bonded at one point can be used. What is necessary is just to select the optimal thing in obtaining the shape of the target micro phase-separation structure.

  It is also possible to improve etching selectivity by doping microdomains with metal atoms or the like. For example, in the case of a polymer block copolymer made of polystyrene and polybutadiene, a microdomain made of polybutadiene is more easily doped with osmium than a microdomain made of polystyrene. Using this effect, it is possible to improve the etching resistance of the domain made of polybutadiene.

  The polymer block copolymer may be synthesized by an appropriate method, but in order to improve the regularity of the microphase-separated structure, a synthesis method that makes the molecular weight distribution as small as possible, such as a living polymerization method, should be used. desirable.

  The polymer block copolymer is a polymer constituting each block constituting the polymer block copolymer so as to form a structure in which spherical or cylindrical microdomains are regularly arranged in the continuous phase on the substrate surface. It is desirable to set the molecular weight ratio of the chains. Thereby, it becomes possible to form a fine pattern separated from each other. In general, in the case of a high molecular diblock copolymer, a lamellar microdomain structure is formed and the composition ratio deviates from 1: 1 when the molecular weight ratio of the polymers constituting each block is close to 1: 1. It changes to a cylindrical or spherical structure.

  The molecular weight of the polymer block copolymer must be selected according to the size of the target pattern. An object of the present invention is to form a structure of several nanometers to several hundreds of nanometers, which is difficult to produce by a conventional top-down method. Therefore, the molecular weight of each block constituting the polymer block copolymer is adjusted so that the distance between the closest microdomains of the microphase separation structure formed by the polymer block copolymer is 10 nanometers or more and 200 nanometers or less. do it.

  The shape and size of the microdomains constituting the microphase-separated structure are not limited to the above-described method for adjusting the molecular weight of each block constituting the polymer block copolymer. It is also possible to adjust by blending a homopolymer having the same chemical structure as the polymer chain constituting the block copolymer. This method is excellent in that the shape and size of the microdomain can be easily controlled.

The material of the substrate used in the present invention is not particularly limited, but it is desirable to use a substrate having a smooth surface, such as a silicon wafer or glass. A method for forming fine grooves and recesses on the surface of the substrate is not particularly limited, but a photolithography method which is a usual method can be applied. An example of a processing method when a silicon wafer is used as the substrate is shown below. First, a SiO ₂ thin film having a thickness corresponding to the depth of a fine recess is formed on a silicon wafer by a CVD method, and a resist layer is formed on the surface thereof. Next, the resist film is patterned by exposure and development using a mask having a pattern corresponding to the shape of the recess. Thereafter, the SiO ₂ film may be etched by dry etching using the patterned resist film as a mask to transfer the pattern to the substrate surface. It is also possible to apply a direct writing method using an electron beam to pattern the resist. In addition, it is possible to directly process the substrate with a focused ion beam or the like without using a lithography method. Even when a glass substrate is used, fine grooves and recesses may be formed using a known method.

  The thin film of the polymer block copolymer can be formed on the substrate surface by the following method. That is, the polymer block copolymer is dissolved in a solvent, and formed on the surface of the substrate by a method such as spin coating, dip coating, or solvent casting. At that time, it is possible to adjust the concentration of the polymer block copolymer, the rotation speed and time in spin coating, the pulling speed in the dip coating method, etc. so that the thickness of the polymer block copolymer layer becomes a predetermined value. is necessary. The solvent used is preferably a good solvent for each polymer chain constituting the polymer block copolymer.

  In many cases, the polymer block copolymer thin film obtained by the above method has a non-equilibrium structure with low regularity because the microphase separation does not proceed sufficiently. For this reason, it is appropriate to perform heat treatment in order to sufficiently advance the microphase separation and change the structure to a more regular structure with higher regularity. In order to prevent oxidation of the polymer block copolymer, the heat treatment is preferably performed by heating to a temperature higher than the glass transition temperature of each polymer chain constituting the polymer block copolymer in a vacuum, nitrogen or argon atmosphere. .

  FIG. 3 shows a schematic view of the cross section and the surface of the patterned substrate of the present invention in the case where the spherical microdomains 34 have a microphase separation structure arranged approximately regularly in the continuous phase 33. The substrate 30 in the present invention has an uneven shape on its surface. Although it is desirable to reduce the defects and grain structure of the micro phase separation structure of the polymer block copolymer formed on the substrate surface, it is desirable that the uneven shape is a groove shape and periodically formed on the substrate surface. The shape may be square or circular, and the arrangement of the recesses 32 on the substrate surface need not be uniform.

  In the present invention, a thin film having a microphase separation structure with very few defects and a grain structure is formed on the entire substrate surface based on the microphase separation that develops inside the recess 32 present on the substrate surface. Therefore, it is desirable to set the depth of the recess 32 on the substrate surface as follows. That is, when the distance 35 between the closest microdomains of the microdomain of the microphase separation structure formed on the substrate surface is a, the depth of the recess 32 is preferably 0.5a or more and 1.5a or less. This is because the substantially regular microphase separation structure developed inside the recess can be continuously formed on the entire substrate surface while keeping the period of the microphase separation structure constant. Further, by setting the depth of the recess 32 to 0.5a or more and 1.5a or less, one layer of the microphase separation structure exists in the groove of the recess, and the upper layer thereof is arranged without distortion on the surface of the protrusion. be able to.

Further, the concave portion 32 and the convex portion 31 on the surface of the substrate need to have such a width that the microphase separation structure can be formed without distortion inside and on the surface. In addition, according to the present invention, since a highly regular microphase separation structure can be formed on the surface of the convex portion, it is desirable to increase the area of the convex portion 31 and reduce the area of the concave portion 32 as much as possible. It is desirable that the width of 31 is wider and the width of the recess 32 is smaller. On the other hand, when the width of the convex portion 31 is widened, the micro domain tends to have a grain structure on the surface of the convex portion 31, which is not preferable. Further, when the width of the concave portion 32 is reduced, the ability to control the arrangement of the microdomains on the surface portion of the convex portion 31 is reduced, and the microdomains easily form a grain structure on the surface of the convex portion 31, which is not preferable. As a result of studying the widths of the convex portion 31 and the concave portion 32 changed by the present inventors, the widths of the convex portion 31 and the concave portion 32 are each 1.0 times or more and 50.0 times the closest inter-microdomain distance 35. It has been found that it is desirable to be not more than twice, and not less than 1.0 and not more than 25.0 times.

The number of layers of the microphase separation structure formed on the surface of the substrate 30 varies depending on the thickness of the polymer block copolymer layer formed on the substrate 30, but the microphase separation structure has a spherical microdomain or substrate. In the case of a cylindrical structure oriented in parallel with respect to the substrate, it is desirable to use a patterned substrate that is obtained with one layer on the surface of the convex portion 31 of the substrate. For this purpose, the thickness of the polymer block copolymer layer to be applied is desirably 0.5 a or more and 1.5 a or less on the surface of the convex portion 31 of the substrate.

  In the present invention, with respect to the distance a between the closest microdomains, the depth and width of the recesses, the height and width of the protrusions, and the thickness of the polymer block copolymer thin film are within a predetermined range. By arranging the microphase-separated structure on the surface without distortion, a polymer block copolymer thin film having no defect or grain structure can be formed on the entire surface of the substrate.

  As described above, the present invention has been described in detail by taking as an example a state in which microdomains having a microphase-separated structure formed by the polymer block copolymer are substantially regularly arranged in a continuous phase. However, the shape of the microdomain does not have to be spherical, and should be selected according to the purpose. FIG. 4 is a schematic diagram of the present invention when the microdomain shape is cylindrical and the cylindrical microdomains are arranged in the direction perpendicular to the substrate, and the cylindrical microdomains are arranged in a direction parallel to the substrate surface. FIG. 5 shows a schematic diagram of the present invention. FIG. 6 shows a schematic diagram of the present invention in which the shape of the microdomain is lamellar and the lamellar microdomain is arranged in the direction perpendicular to the substrate surface. In these microphase-separated structures, the relationship between the distance a between the closest microdomains and the depth, width, height of the convexity, width, and thickness of the polymer block copolymer thin film is the same. The closest inter-microdomain distance a is the distances 35, 43, 53, and 63 shown in FIGS.

  Next, three types of manufacturing methods for producing a pattern substrate having a substantially regular uneven shape on the surface using the above-described pattern substrate will be described in detail. In the following description, an AB diblock copolymer composed of two types of polymer chains A and B is used as an example in which the A phase forms a spherical microdomain. The same production method can also be applied to other structures such as a shape or when the polymer block copolymer to be used is another type such as a triblock.

A first method for producing a patterned substrate having a fine, regular and irregular shape on the surface will be described with reference to schematic process diagrams shown in FIGS. In this manufacturing method, first, concave portions 32 having a predetermined pattern are formed on the surface of the substrate by a known method (FIG. 7A). Next, the polymer block copolymer thin film 70 is formed on the surface of the substrate on which the recesses 32 are formed by the method described above (FIG. 7B). Next, the polymer block copolymer thin film 70 is formed of the polymer block copolymer having a microphase separation structure in which spherical microdomains 71 are arranged in the continuous phase 72 substantially regularly on the entire substrate surface by the method described above. A thin film is formed (FIG. 7C). Next, among the spherical microdomains 71 and the continuous phase 72 constituting the microphase separation structure, the continuous phase 72 is selectively removed by a reactive ion etching (RIE) method using oxygen plasma or other etching methods (see FIG. 7 (D)). At this time, the spherical microdomain 71 serves as a mask, and the region existing between the spherical microdomain 71 and the substrate 30 in the continuous phase 72 is not etched. Through the above steps, it is possible to form a substrate 74 having a structure in which fine convex shapes 73 corresponding to spherical microdomains are arranged almost regularly over the entire surface. In the above description, FIG.
Although the method of etching the continuous phase 72 in the process shown in (D) has been shown, it is also possible to etch the spherical microdomain 71 conversely. In this case, a structure is formed on the surface of the substrate 74 in which pores corresponding to the spherical domains 71 are substantially regularly arranged on the entire surface. Therefore, the phase on one side of the spherical microdomain 71 and the continuous phase 72 may be selectively removed according to the target pattern shape.

  Next, the 2nd manufacturing method which has the fine substantially regular uneven | corrugated shape on the surface is demonstrated using FIG. 7 (A)-(E). First, according to the first manufacturing method of a patterned substrate having a fine and regular irregular shape on the surface, the fine convex shape 73 is formed almost regularly on the entire surface based on the steps shown in FIGS. A substrate 74 having a structure arranged in the above is formed. Next, the substrate 30 is etched by RIE or plasma etching using the fine convex shape 73 as a mask to transfer a pattern equivalent to a substantially regular microphase separation structure to the substrate 30 (FIG. 7E). ). The height of the surface of the substrate manufactured according to this manufacturing method is uniform over the entire surface of the substrate.

  Next, the 3rd manufacturing method of the pattern board | substrate which has a fine substantially regular uneven | corrugated shape on the surface is demonstrated using the typical process drawing shown in FIG. First, a substrate 74 having a structure in which fine convex shapes 73 are arranged almost regularly on the entire surface is produced according to the first manufacturing method of a patterned substrate having fine regular irregular shapes on the surface (FIG. 8 ( A) to (D)). Next, a thin film 80 made of a metal, an inorganic substance, or another material is formed on the entire surface of the substrate 74 (FIG. 8E). Thereafter, the thin film 80 is peeled from the substrate to manufacture a patterned substrate (thin film 81) having a replica shape on the surface of the substrate 74 (FIG. 8F). At this time, the material of the thin film 80 may be selected according to the use of the pattern substrate to be manufactured, such as nickel, platinum, gold or the like if it is a metal, or glass or titania if it is an inorganic material. When the thin film 80 is a metal, sputtering, vapor deposition, or a plating method and a combination thereof can be used for film formation. In addition, when the thin film 80 is an inorganic substance, for example, a sol-gel method can be used in addition to the sputtering or the CVD method. Here, the plating and sol-gel method can accurately transfer the fine uneven structure of several tens of nanometers derived from the micro phase separation structure, and it is combined with the low cost that comes from the non-vacuum process. Is desirable.

  On the surface of the patterned substrate obtained by this manufacturing method, there is no shape derived from the recess 32 used for improving the regularity of the microphase separation structure as shown in FIG. Have a fine, regular and irregular pattern with a uniform height.

  As mentioned above, the board | substrate which has the substantially regular uneven pattern manufactured by the said 3 types of method on the surface can be applied directly to the various uses which applied the substantially regular fine structure. It is also possible to use a patterned substrate manufactured by the above method as an original plate, and repeatedly transfer the surface structure to another substance by a nanoimprinting method or the like, thereby replicating a large amount and using the replicated product for use.

  The following two methods can be used as a method for transferring the pattern of the original plate to another substrate by the nanoimprint method. The first method is a method of directly imprinting a target substrate using an original plate. This method is suitable when the target substrate is made of a material that can be directly imprinted. For example, in the case of a substrate made of a thermoplastic resin typified by polystyrene, the original plate is pressed against the resin substrate at a temperature equal to or higher than the glass transition temperature of the resin, cooled to the glass transition temperature or lower, and then released from the resin substrate surface. As a result, the shape of the original plate can be transferred to the surface of the resin substrate. In addition, when the substrate material is a photo-curable resin, the original plate is made of a light-transmitting material made of glass or the like, and after the original plate is pressed against the photo-curable resin, light is irradiated through the original plate. After the resin is cured by the above, the shape of the original can be transferred to the surface of the resin substrate by releasing the original.

  If it is difficult to directly imprint the target substrate such as glass or metal, the second method described below may be applied. That is, a thin layer made of a material that can be directly imprinted is formed on the surface of the target substrate, and the shape of the original is transferred to the thin layer by imprinting. Next, the target substrate may be etched by plasma, ion beam or the like using a thin layer to which the shape of the original plate is transferred as a mask.

  An example of applying a substrate having a substantially regular uneven structure according to the present invention is a pattern substrate for magnetic recording. In the patterned medium, the recording density is improved by cutting the magnetic recording layer into fine regions and magnetically dividing the regions to form each region as a recording pit. Therefore, it is necessary to produce fine magnetic recording regions regularly arranged on the substrate surface with high density. For example, in order to construct a recording medium with a recording density of 1 terabit / square inch, the period of the magnetic recording area needs to be 25 nanometers. In order to achieve this object, it is desirable to apply the patterned substrate of the present invention and its manufacturing method.

  Glass or aluminum can be used for the substrate for the pattern medium. A patterned medium is manufactured by forming a magnetic recording layer using a method such as sputtering after processing a substantially regular fine uneven pattern on the surface of a substrate such as glass or aluminum according to the process shown in FIG. Can do. Further, from the viewpoint of cost and productivity, a substrate for a pattern medium or a magnetic film is formed by a nanoimprint method using a substrate having a substantially regular uneven pattern on the surface processed by the method of FIG. 7 or FIG. It is desirable to process the patterned medium substrate.

  Hereinafter, in accordance with the steps shown in FIGS. 7A to 7D, an example in which a patterned substrate having a substantially regular fine irregular shape on the entire surface is formed by utilizing spherical microdomains formed by the polymer copolymer. Indicates.

First, as shown in FIG. 7A, a substrate 30 having grooves 32 on the surface was produced. Here, the width (L) of the groove 32 was 200 nm, the depth (d) was 40 nm, the interval (t) between adjacent grooves was 300 nm, and the grooves were arranged on the substrate surface so as to be parallel. The following method was used for processing the groove. That is, a SiO ₂ thin film having a thickness of 40 nm was laminated on a silicon substrate by plasma CVD, and then the groove was processed by etching the SiO ₂ thin film by dry etching using a regular photolithography process.

  Next, the obtained substrate 30 was immersed in a 3: 1 mixed solution (piranha solution) of concentrated sulfuric acid and hydrogen peroxide water at 60 ° C. for 10 minutes to sufficiently clean the surface.

A block copolymer solution was spin-coated on the surface of the substrate 30 obtained by the above method to form a polymer block copolymer thin film 70 on the substrate surface (FIG. 7B). The polymer copolymer solution is blended with diblock copolymer (PS-b-PMMA) composed of polymethylmethacrylic acid (PMMA) and polystyrene (PS) with homo-PMMA for the purpose of adjusting the composition, and then with toluene. A dissolved sample was used. The concentration of the solution was 1.0% by weight. Here, the number average molecular weight Mn of PS constituting PS-b-PMMA was 10,000, the Mn of PMMA was 33,000, and the Mn of homo-PMMA was 11,500. Further, in order to form a microphase separation structure in which spherical microdomains made of PS are arranged in a continuous phase made of PMMA, the volume fraction of the PS phase becomes 20% in the polymer block copolymer thin film 70. The mixing amount of PS-b-PMMA and homo PMMA was adjusted. Spin coating was carried out by rotating the substrate at a rotational speed of 3500 rpm, dropping the block copolymer solution at the center, and rotating for 30 seconds. In the polymer block copolymer thin film 70, PMMA-b-
Although PS and homo-PS are present in a blended state, they are simply referred to as a polymer block copolymer thin film hereinafter.

  When the surface of the obtained polymer block copolymer thin film 70 was observed with an atomic force microscope, the surface was uniform and a shape derived from the uneven shape of the substrate 30 was not recognized. That is, it was found that the entire surface of the substrate including the grooves 32 was uniformly coated with the polymer block copolymer. The thickness of the polymer block copolymer thin film 70 on the surface of the convex portion 31 of the substrate is partially peeled off with a sharp blade, and the polymer block copolymer thin film 70 is removed by an atomic force microscope. It evaluated by measuring the level | step difference of the existing part and the part which peeled. As a result, the thickness from the surface of the convex part 31 of the polymer block copolymer thin film 70 was 40 nm.

  Next, the substrate 30 on which the polymer block copolymer thin film 70 was formed was annealed at 230 ° C. for 4 hours in a nitrogen atmosphere to develop a microphase separation structure in the polymer block copolymer thin film 70 ( FIG. 7 (C)). Here, the obtained microphase separation structure is such that spherical PS microdomains 71 are present in the continuous phase 72 of PMMA.

  Next, the surface of the obtained substrate was etched by oxygen RIE to remove the PMMA phase. Here, the gas pressure of oxygen was 1 Pa, and the etching time was 60 seconds. The result of observing the obtained substrate surface with an atomic force microscope is schematically shown in FIG. After the PMMA phase was decomposed on the surface of the substrate, it was observed that fine convex shapes 73 derived from PS microdomains 71 were arranged. Here, it was observed that the fine convex shapes 73 had a hexagonal close-packed structure on the entire surface of the substrate, formed a three-part lattice, and were arranged almost regularly with almost no defects. Moreover, the grain structure and the interface between grains were not observed within the observation range. Furthermore, the shape derived from the groove | channel 32 was not recognized. The diameter of the fine convex shape 73 was 25 nm, and the distance between the centers of the fine convex shapes 73 was 40 nm.

Next, by using a substrate having a smooth surface on the entire surface, a fine convex shape 73 was formed on the surface in the same process as the above process. Here, the substrate used was prepared by laminating a 40 nm thick SiO ₂ thin film on the entire surface by plasma CVD on a silicon substrate. FIG. 9B schematically shows the result of observing the substrate surface obtained through the steps of FIGS. 7B to 7D with an atomic force microscope without performing uneven processing of the substrate. Microscopically, it was observed that the fine convex shape 73 had a hexagonal close-packed structure and a three-grid was formed. However, when viewed macroscopically, a large number of grain-like regions with different arrangement directions of the three-grid gathered. It was found to have a polygrain structure. In addition, a large number of point defects lacking the fine convex shape 73 and line defects in which the arrangement was partially disturbed were also recognized inside each grain.

  Experiments were performed according to the steps described in Example 1 except that the polymer block copolymer solution was changed to that described below.

In the polymer copolymer solution, PS-b-PMMA, whose number average molecular weight Mn of PS is 35,500 and Mn of PMMA is 12,200, is blended with homo-PS for the purpose of adjusting the composition, and toluene. The sample dissolved in was used. Here, in order to form a microphase separation structure in which spherical microdomains composed of PMMA are arranged in a continuous phase composed of PS, PS-b-
PMMA and homoPS were adjusted so that the volume fraction of the PMMA phase in the polymer block copolymer thin film 70 was 20%.

  The surface of the surface of the obtained substrate was observed with an atomic force microscope through the steps illustrated in FIGS. 7A to 7D in the same manner as in Example 1. As a result, fine pores formed by decomposing the PMMA phase on the surface of the substrate 30 have a hexagonal close-packed structure on the entire surface of the substrate, forming a three-dimensional lattice, and are arranged almost regularly with almost no defects. Was observed. In addition, no grains or grain interfaces were observed within the observation range. Furthermore, the shape derived from the groove | channel 32 was not recognized. The diameter of the fine pore was 25 nm, and the distance between the centers of the fine pores was 40 nm.

A result of a series of experiments in which the depth (d) of the groove 32 is changed will be described. In this experiment, the groove depth
The same materials, processes and conditions as in Example 1 were used except that (d) was changed to the values described in Table 1. Since the same polymer block copolymer solution as in Example 1 was used in this experiment, the microphase-separated structure expressed in the polymer block copolymer thin film is a spherical domain of 25 nm in diameter composed of PS between the domain centers. The distance, that is, the distance a between the closest microdomains of the spherical microdomains was 40 nm and dispersed in the continuous phase composed of PMMA.

Table 1 shows the results. Under the condition that the groove depth (d) is not less than 0.5 times and not more than 1.5 times the distance a between the nearest microdomains of the spherical microdomain, the PMMA phase is formed by oxygen RIE in the process of FIG. As a result of observation with an atomic force microscope after etching, a state in which fine convex shapes 73 were arranged on the substrate surface was observed. Here, it was observed that the fine convex shapes 73 had a hexagonal structure on the entire surface of the substrate and were arranged almost regularly with almost no defects. In addition, no grains or grain interfaces were observed within the observation range. Furthermore, the shape derived from the groove | channel 32 was not recognized.

  On the other hand, when the groove depth (d) is smaller than 0.5 times the distance a between the closest microdomains of the spherical microdomain, a polymer block copolymer thin film is formed in the process of FIG. When the surface was observed with an atomic force microscope in a state where the microphase separation structure was developed, the surface was not smooth, and the upper surface of the groove 32 was raised compared to the upper surface of the peripheral portion 31. became. On the other hand, when the depth (d) of the groove is larger than 1.5 times the distance a between the nearest microdomains of the spherical microdomain, the upper surface portion of the groove 32 is larger than the upper surface of the peripheral portion 31. It became depressed.

  Next, these samples were observed with an atomic force microscope after etching the PMMA phase by oxygen RIE in the step of FIG. 7D. As a result, as shown in FIG. Although the convex shape 73 is in a hexagonal close-packed state and arranged in a triangular lattice, the surface of the groove peripheral portion 31 is composed of a large number of grains having different arrangement directions of the fine convex shape 73 and has a large number of defects. It became.

  From the above results, in order to perform patterning using the polymer block copolymer without defects, grains, and grain boundaries on the entire substrate, the depth of the groove 32 is the latest of the microdomains constituting the polymer block copolymer. It was found that when the distance between the contact microdomains is a, the distance is preferably 0.5a or more and 1.5a or less.

  A result of a series of experiments in which the width (L) of the groove 32 is changed will be described. In this experiment, the same materials, processes, and conditions as in Example 1 were used except that the groove width (L) was set to the values shown in Table 2. Since the same polymer block copolymer solution as in Example 1 was used in this experiment, the microphase-separated structure expressed in the polymer block copolymer thin film is a spherical domain of 25 nm in diameter composed of PS between the domain centers. The distance, that is, the distance a between the closest microdomains of the spherical microdomains was 40 nm and dispersed in the continuous phase composed of PMMA.

Table 2 shows the results. When a substrate having a groove width (L) of at least 1.0 times the distance a between the closest microdomains of the spherical microdomains is used, atoms are etched after the PMMA phase is etched by oxygen RIE in the step of FIG. As a result of observation with an atomic force microscope, a state in which fine convex shapes 73 derived from the spherical microdomains 71 of PS were arranged on the entire surface of the substrate was observed. Here, it was observed that the fine convex shapes 73 had a hexagonal close-packed structure on the entire surface of the substrate to form a triangular lattice and were arranged almost regularly with almost no defects. In addition, no grains or grain interfaces were observed within the observation range. Furthermore, the shape derived from the groove | channel 32 was not recognized.

In contrast, when a substrate having a groove width (L) smaller than 1.0 times the distance a between the closest microdomains of the spherical microdomains is used, the PMMA phase is formed by oxygen RIE in the process of FIG. When the state after etching was observed with an atomic force microscope, the entire surface of the substrate became a structure composed of a large number of grains having different arrangement directions of the fine convex shapes 73.

  From the above results, in order to perform patterning using the polymer block copolymer without defects, grains, and grain boundaries on the entire substrate, the width (L) of the groove 32 is the microdomain constituting the polymer block copolymer. When the distance between the nearest microdomains is a, it has been found necessary to be 1.0a or more.

  The results of a series of experiments in which the substrate 30 has a groove-to-groove interval (t), that is, the width of the substrate protrusion 31 in FIG. In this experiment, the same materials, processes, and conditions as in Example 1 were used except that the interval (t) was set to the value described in Table 3. Since the same polymer block copolymer solution as in Example 1 was used in this experiment, the microphase-separated structure expressed in the polymer block copolymer thin film is a spherical domain of 25 nm in diameter composed of PS between the domain centers. The distance, that is, the distance a between the closest microdomains of the spherical microdomains was 40 nm and dispersed in the continuous phase composed of PMMA.

  Table 3 shows the results. When a substrate having an interval (t) of 50.0 times or less of the distance a between nearest microdomains of spherical microdomains is used as the interval (t), the PMMA phase is etched by oxygen RIE in the process of FIG. Then, as a result of observation with an atomic force microscope, it was observed that fine convex shapes 73 derived from the spherical microdomains 71 of PS were arranged on the entire surface of the substrate. Here, it was observed that the fine convex shapes 73 had a hexagonal structure on the entire surface of the substrate and were arranged almost regularly with almost no defects. In addition, no grains or grain interfaces were observed within the observation range. Furthermore, the shape derived from the groove | channel 32 processed into the board | substrate 30 surface was not recognized.

On the other hand, when a substrate having a distance (t) larger than 50.0 times the distance a between the closest microdomains of the spherical microdomains was used, the PMMA phase was etched by oxygen RIE in the step of FIG. When the subsequent state was observed with an atomic force microscope, an image schematically shown in FIG. 9C was obtained. In the surface portion of the groove 32, spherical microdomains have a hexagonal close-packed structure to form a triangular lattice and are arranged, but the portion between the grooves, that is, the surface portion of the convex portion 31 on the substrate surface is fine. The convex shape 73 is composed of many grains having different arrangement directions, and has a structure having many defects.

  From the above results, in order to perform patterning using the polymer block copolymer without defects, grains, and grain boundaries on the entire substrate, the interval (t) between the grooves 32 is a microdomain constituting the polymer block copolymer. When the distance between the nearest microdomains is a, it was found that it was necessary to be 50.0a or less.

  Next, Table 4 summarizes the results of a series of experiments in which the thickness of the polymer block copolymer thin film 70 applied to the substrate surface was changed using the same substrate and process as in Example 1. The thickness of the polymer block copolymer thin film 70 was controlled by changing the concentration of the polymer block copolymer solution and the number of rotations during spin coating. In this experiment, as in Example 1, a sample in which PMMA-b-PS and homoPS were adjusted so that the volume fraction of the PS phase was 20% was used. The developed microphase separation structure is a spherical domain of 25 nm diameter made of PS dispersed in a continuous phase of PMMA with the distance between the domain centers, that is, the distance a between the nearest microdomains of the spherical microdomain being 40 nm. .

When the thickness of the polymer block copolymer thin film 70 is not less than 0.5 times and not more than 1.5 times the distance a between the closest microdomains of the spherical microdomains on the surface of the convex portion 31 of the substrate, FIG. When the surface of the polymer block copolymer thin film 70 was observed with an atomic force microscope in the state in which the microphase separation structure was expressed in the step, the surface was smooth and the surfaces of the convex portions 31 and the concave portions 32 of the substrate. It was found that the film was uniformly coated. Next, when the surfaces of these samples were etched with RIE in the step of FIG. 7D and observed with an atomic force microscope, the fine convex shape derived from the spherical microdomain 71 made of PS was found on the entire surface of the substrate. The state where 73 was arranged was observed. Here, it was observed that the fine convex shapes 73 had a hexagonal structure on the entire surface of the substrate and were arranged almost regularly with almost no defects. Moreover, the grain and the sea surface between grains were not observed within the observation range. Furthermore, the shape derived from the groove | channel 32 processed into the board | substrate 30 surface was not recognized. The diameter of the spherical domain was 25 nm, and the distance between the domain centers, that is, the distance a between the closest microdomains of the spherical microdomain was 40 nm.

  Next, the results of an experiment conducted under the condition that the thickness of the polymer block copolymer thin film 70 is smaller than 0.5 times the distance a between the closest microdomains of the spherical microdomains on the surface of the convex portion 31 of the substrate will be described. To do. Under these conditions, in the step of FIG. 7C, the substrate on which the polymer block copolymer thin film 70 was formed was annealed at 230 ° C. for 4 hours in a nitrogen atmosphere, and then the surface of the polymer block copolymer thin film 70 was coated. When observed with an atomic force microscope, it was confirmed that the thickness of the polymer block copolymer thin film 70 was uneven. That is, the polymer block copolymer thin film 70 did not uniformly cover the entire surface of the substrate 30, but a large number of circular regions where the surface of the substrate 30 was exposed were observed. When this sample was used to observe with an atomic force microscope after etching by RIE in the step of FIG. 7D, it was found that the fine convex shape 73 does not exist in the circular region.

  Next, the results of an experiment conducted under the condition that the thickness of the polymer block copolymer thin film 70 is larger than 1.5 times the distance a between the closest microdomains of the spherical microdomains on the surface of the convex portion 31 of the substrate will be described. To do. Even under this condition, in the step of FIG. 7C, after the substrate on which the polymer block copolymer thin film 70 was formed was annealed at 230 ° C. for 4 hours in a nitrogen atmosphere, the surface of the polymer block copolymer thin film 70 was When observed with an atomic force microscope, it was confirmed that the thickness of the polymer block copolymer thin film 70 was uneven. That is, the polymer block copolymer thin film 70 did not uniformly cover the entire surface of the substrate 30, but many circular thick regions were observed on the surface of the polymer block copolymer thin film 70. When this sample was used to observe with an atomic force microscope after etching by RIE in the step of FIG. 7D, the fine convex shapes 73 were regularly arranged outside the circular region. In the region of (2), it was found that two or more spherical domains were deposited.

  From the above, in order to arrange the fine convex shapes 73 almost regularly on the entire surface of the substrate with almost no defects, the thickness of the polymer block copolymer thin film 70 is set so that the surface of the convex portion of the substrate is closest to the spherical microdomain. It was found that the distance a between microdomains must be 0.5 times or more and 1.5 times or less.

  Using a process equivalent to that in Example 1, a microphase separation structure having a structure in which cylindrical microdomains made of PS are arranged in parallel to the surface of the substrate in the continuous phase of PMMA is formed on the entire substrate surface, and PMMA is formed. A pattern substrate was prepared by decomposing the phase by RIE.

  The substrate used was a smooth surface with grooves having a depth (d) of 40 nm and a width (L) of 200 nm, with an interval (t) of 300 nm and 100 rows arranged in parallel with each other.

The composition of the polymer copolymer solution is adjusted to a diblock copolymer (PMMA-b-PS) composed of polymethylmethacrylic acid (PMMA) and polystyrene (PS) so that the microdomains are cylindrical. For the purpose, a sample in which homo PMMA was blended and dissolved in toluene was used. The concentration of the solution was 1.0% by weight. Here, the number average molecular weight Mn of PMMA constituting PMMA-b-PS was 12,200, the Mn of PS was 35,500, and the Mn of homo PMMA was 11,500. In order to make the domain constituting the microphase separation structure spherical, PMMA-b-PS and homo PMMA were adjusted so that the volume fraction of PMMA in the polymer block copolymer thin film 70 was 30%.

  Pt having a thickness of about 5 mm was deposited on the surface of the obtained substrate, and the surface structure was observed with a scanning electron microscope. As a result, a linear structure with a width of 25 nm was formed on the entire surface of the substrate in parallel with a distance between the centers of the straight lines of 45 nm. It was found that the film was formed with almost no defects.

  An example of processing the substrate by dry etching using the fine convex shape 73 made of PS produced on the surface of the substrate by the method described in Example 1 as a mask will be described with reference to FIG.

First, a SiO ₂ thin film 91 having a thickness of 40 nm is stacked on a silicon substrate 90 by plasma CVD, and then a plurality of grooves 92 are formed on the surface by processing the grooves 92 by dry etching using a regular photolithography process. A substrate 93 was produced. Here, the width of the groove 92 is 200 nm, the depth is 40 nm, the interval between adjacent grooves is 300 nm, and the grooves are arranged on the substrate surface so as to be parallel to each other.

  Next, according to the method described in Example 1, through the steps illustrated in FIGS. 10B to 10D, the fine convex shapes 73 are substantially regularly arranged on the entire surface of the substrate (FIG. 10 ( D)). Since the same polymer block copolymer solution as in Example 1 was used in this experiment, the microphase separation structure developed in the polymer block copolymer thin film in the step shown in FIG. The spherical microdomains 71 having a diameter of 25 nm were dispersed in the continuous phase 72 made of PMMA with the distance between the domain centers, that is, the distance a between the closest microdomains of the spherical microdomains being 40 nm. In the step shown in FIG. 10D, when the substrate surface was observed with an atomic force microscope, a state in which the fine convex shapes 73 were arranged on the entire surface of the substrate was observed. Here, it was observed that the fine convex shapes 73 were arranged almost regularly with almost no defects in a state where a hexagonal close-packed structure was formed on the entire surface of the substrate to form a triangular lattice. Moreover, the grain and the sea surface between grains were not observed within the observation range. Further, the shape derived from the groove 92 was not recognized. The diameter of the fine convex shape 73 was 25 nm, and the distance between the centers of the fine convex shapes 73 was 40 nm.

Next, using the fine convex shape 73 as a mask, the SiO ₂ thin film 91 on the surface of the substrate 93 was dry etched by RIE using C ₂ F ₆ gas. The etching conditions were an output of 150 W, a gas pressure of 1 Pa, and an etching time of 60 seconds. After etching of the SiO ₂ layer, oxygen plasma block copolymer remaining on the substrate surface (30 W, 1 Pa, 120 seconds) by treatment, of SiO ₂ on the silicon substrate surface as shown in FIG. 7 (E) A cylindrical structure 94 was formed. Here, when the obtained substrate was observed with a scanning electron microscope by depositing Pt having a thickness of about 5 mm on the surface, the cylindrical structure body 94 made of SiO ₂ had a diameter of 25 nm. It was observed that the distance between the nearest centers was 40 nm, a hexagonal close-packed-weight structure was formed, and a triangular lattice was formed and arranged almost regularly. Further, when the substrate was processed with a focused ion beam and the cross-sectional structure of the substrate was observed using a scanning electron microscope, the height of the cylindrical structure 94 made of SiO ₂ was found to be uniform at 40 nm. .

A nickel film having a replica structure produced by the method described in Example 1 with reference to FIG. 8 and having the surface structure of a substrate 74 (hereinafter referred to as a pattern substrate) in which fine convex shapes are substantially regularly arranged on the entire surface transferred in reverse. A method for producing the film by a plating method will be described. First, FIG. 8A to FIG.
According to the process shown in (D), the same polymer block copolymer solution as in Example 1, the same substrate 30, and the fine convex shapes 73 derived from the spherical microdomains 71 of PS were arranged on the entire surface. A pattern substrate 74 was produced.

  Next, electroless nickel plating was applied to the surface of the pattern substrate 74 in which the fine convex shapes 73 were arranged on the entire surface. Further, electro nickel plating was performed using the electroless nickel plating layer as a power feeding layer, and a nickel film 80 having a thickness of 20 μm was formed on the substrate surface (FIG. 8E).

  The following method was applied to the electroless nickel plating. First, the surface of the pattern substrate 74 was immersed in a cleaner solution (Atotech Japan Securigant 902) for promoting the application of the electroless plating catalyst at 30 ° C. for 5 minutes. The obtained pattern substrate was sufficiently washed with pure water and immersed in a pre-dip solution (Neogant B manufactured by Atotech Japan) for 1 minute at room temperature for the purpose of preventing contamination of the catalyst solution. Thereafter, the pattern substrate 74 was immersed in a catalyst solution (Neogant 834 manufactured by Atotech Japan) at 40 ° C. for 5 minutes. The catalyst used here is a type in which a palladium complex molecule is dissolved in a solution. After applying the catalyst, the pattern substrate 74 was washed by immersing it in pure water, and activated by using palladium provided using a Neogant W solution manufactured by Atotech Japan as a nucleus. Finally, the obtained pattern substrate was washed with pure water to obtain a pattern substrate having a catalyst layer for electroless plating deposition. Next, the nickel plating film was deposited on the entire surface of the pattern substrate 74 by immersing the patterned substrate 74 to which the catalyst had been applied in an electroless nickel plating solution for 30 seconds. Table 5 shows the composition and plating conditions of the electroless nickel plating solution used here. The pH of the plating solution was adjusted using an aqueous ammonia solution.

電気ニッケルめっきは以下に示す手順により実施した。すなわち、無電解ニッケルめっきによりパターン基板７４表面全体を被覆するように析出させたニッケルめっき膜の周辺部から導電テープによりリードを取り、ニッケル板を対極として、日本化学産業社製のスルファミン酸Ｎｉめっき液を用いて電気ニッケルめっきを施した。めっき液の組成およびめっき条件を表６に示す。

Electro-nickel plating was performed according to the following procedure. That is, a lead is taken with a conductive tape from the periphery of the nickel plating film deposited so as to cover the entire surface of the pattern substrate 74 by electroless nickel plating, and a nickel plate is used as a counter electrode, and Nilphurumic acid Ni plating manufactured by Nippon Chemical Industry Co., Ltd. Electronickel plating was performed using the solution. Table 6 shows the composition of the plating solution and the plating conditions.

最後に、上記方法で得られたニッケル膜８０を、パターン基板７４から剥離することにより微細なポアを有するニッケル膜８１を得た（図８（Ｆ））。得られたニッケル膜８１の表面構造を操作型電子顕微鏡で観察したところ、直径２５ｎｍの微細なポアが、ポア中心間の際近接距離を４０ｎｍとして、ニッケル膜表面全面に、欠陥・グレイン・粒界なくほぼ規則的な状態で六方方向に配列した状態で存在することが明らかとなった。

Finally, the nickel film 80 obtained by the above method was peeled from the pattern substrate 74 to obtain a nickel film 81 having fine pores (FIG. 8F). When the surface structure of the obtained nickel film 81 was observed with an operation electron microscope, a fine pore having a diameter of 25 nm had a close proximity distance of 40 nm between the pore centers, and the entire surface of the nickel film had defects, grains, and grain boundaries. It became clear that it existed in an almost regular state and arranged in the hexagonal direction.

  In this example, an example will be described in which a nickel film having a substantially regular fine unevenness on the surface, which is produced by a process equivalent to the method disclosed in Example 9, is used as a stamper for the nanoimprint method.

First, FIG. 11A shows a schematic diagram of a nickel stamper 1001 manufactured as a prototype. The nickel stamper 1001 had an outer size of 4 inches φ and a thickness of 25 micrometers. Fine pores 1003 having a diameter of 25 nm and a depth of 40 nm are arranged almost regularly in a hexagonal shape in a 2.5 cm square region 1002 of the stamper 1001. FIG. 11B shows an enlarged view of a region 1002 having a central 2.5 cm square. The nickel stamper 1001 was created by the same method as in Example 8.

  FIG. 12 shows a schematic diagram of the nanoimprint apparatus. FIG. 12A shows an apparatus for forming a release layer on the surface of the stamper 1001. FIG. 12B shows an apparatus for transferring the fine pore structure on the surface of the stamper 1001 to the substrate.

Here, the process procedure will be described. First, a process of coating a release agent on the surface of the stamper 1001 to facilitate release during resin molding will be described with reference to FIG. A glass substrate 1114 having a smooth surface was spin-coated with a silicone (polydimethylsiloxane) release agent 1113 and applied to a thickness of 200 nanometers. This substrate with a release agent was placed on the stage 1108 and fixed with a vacuum chuck. Further thereon, a stamper 1001 and a buffer material 1112 (5 inches φ thickness 3 mm) were arranged. A release agent layer was formed on the stamp surface 1101 by pressing with a pressure mechanism 1110 at a pressure of 2 MPa. The buffer material 1112 is used to align the stamper with the undulation of the glass substrate 1114. Next, the pressure was released and the stage was lowered to obtain a stamper 1001 whose surface was coated with a release agent.

Next, a resin molding process using the stamper 1001 coated with a release agent will be described with reference to FIG. First, a silicon substrate 1121 (4 inch φ thickness 0.5 mm) was spin-coated with polystyrene resin 1122 (polystyrene 679, manufactured by A & M) to a thickness of 600 nm. The stamper 1101 coated with a release agent was positioned and combined, and then set on the stage 1118. The fine structure transfer apparatus shown in FIG.
Unlike the release material forming apparatus of (A), it has a vacuum chamber 1117, and the stage 1118 has a heating mechanism. This was depressurized to 0.1 Torr or less, heated to 250 ° C., held at 12 MPa for 10 minutes, and pressurized. Next, after cooling to 100 ° C. or lower, the atmosphere was released. When a peeling jig was bonded and fixed to the back surface of the stamper at room temperature and pulled up vertically at 0.1 mm / s, the shape of the stamper surface was transferred to the polystyrene resin surface.

  Next, the above resin molding process was repeated 100 times using a stamper 1101 coated with the same release agent to obtain 100 resin molded bodies to which the shape of the stamper surface was transferred. When the center surface of the obtained resin molding was observed with an atomic force microscope, it was observed that all the polystyrene resin moldings had columnar protrusions that had a hexagonal structure and were arranged almost regularly with almost no defects. It was done. The diameter of the columnar protrusions was 25 nm, and the distance between the columnar protrusion centers was 40 nm. From the above, it was confirmed that the surface shape of the stamper could be accurately transferred to the polystyrene resin surface.

  A method for producing a magnetic recording pattern medium using the present invention will be described. In this method, a pattern medium pattern master is prepared by self-assembly of a polymer block copolymer, a nickel plating replica of the master is prepared by plating, and a nickel plating replica serves as a pattern medium. It consists of a step of forming a mask on the surface of the glass substrate and a step of forming a magnetic film on the surface of the glass substrate using the obtained mask.

  First, a process of creating a pattern original constituting a pattern medium by self-assembly of a polymer block copolymer will be described.

A SiO ₂ layer having a thickness of 30 nm was formed on the surface of a 2.5-inch silicon substrate by a CVD method. Next, the SiO ₂ layer was etched by applying a regular photolithography process to form concentric grooves with a depth of 30 nm and a width of 200 nm on the substrate surface at intervals of 1000 nm.

Next, according to the process described in Example 1, a substrate in which minute convex objects made of PS were regularly arranged was prepared. At this time, a diblock copolymer PS-b-PMMA composed of PS and PMMA was used as the polymer block copolymer. The number average molecular weights Mn of the PS block and PMMA block constituting PS-b-PMMA were 7,000 and 25,000, respectively. As a result of observing the obtained substrate surface with an atomic force microscope, microscopically, the substrate surface had a diameter of 20
It is observed that minute convex objects made of PS with a thickness of 25 nm and a height of 25 nm have a hexagonal close-packed structure with a distance of 30 nm between the closest centers, form a triangular lattice, and are regularly arranged almost without defects. It was. In addition, when macroscopic observation was performed by reducing the magnification of atomic force microscope observation, the regular structure formed by minute convex objects made of PS was almost defective in a concentric shape centered on the center of the substrate. It turned out that there was no arrangement.

  Next, according to the method described in Example 8, the surface of the substrate on which fine convex shapes made of PS are regularly arranged is plated with nickel, and the surface structure is reversed and transferred. From a nickel film having a thickness of 25 μm having a replica shape. The following nanoimprint stamper was created. When the surface of the obtained stamper was observed with a scanning electron microscope, it was confirmed that minute pores having a diameter of 20 nm were regularly formed on the surface of the nickel film.

  A Pd underlayer having a thickness of about 30 nm and a CoCrPt layer having a thickness of about 30 nm are formed on the surface of a donut-like glass substrate having a diameter of 2.5 inches and a hole having a diameter of 0.5 inches in the center. Thus, a magnetic layer was prepared. Next, a PS layer having a thickness of 10 nm was formed on the surface of the magnetic layer by spin coating. The molecular weight Mn of PS used here was 5,000. The PS thin film on the surface of the magnetic layer was nanoimprinted by the same method as described in Example 10 using the stamper obtained by the above method. When the PS thin film on the surface of the obtained magnetic layer was observed with an atomic force microscope, it was confirmed that minute convex shapes having a diameter of 20 nm were regularly formed on the PS thin film. Here, the shape and arrangement of the minute convex-shaped object were obtained by reversing and transferring the shape and arrangement of the minute pores on the stamper surface. Moreover, when the cross section of the minute convex shape object was measured in detail using an atomic force microscope, the height of the minute convex shape object was 20 nm.

  Next, the magnetic layer on the surface of the magnetic layer was etched by Ar ion milling using a fine convex shape made of PS formed on the surface of the magnetic layer as a mask. In this process, all the PS thin film disappeared. When the surface of the obtained glass substrate was observed in detail by an atomic force microscope, a microscopic convex magnetic layer having a diameter of 20 nm and a height of 15 nm was microscopically formed on the surface. It was observed that a hexagonal close-packed structure was formed at a center-to-center distance of 30 nm, a triangular lattice was formed, and the layers were regularly arranged with almost no defects. In addition, when the macroscopic observation was performed with the atomic force microscope observation reduced, the regular structure formed by the minute convex magnetic layer was almost free from defects in a concentric shape centered on the center of the substrate. It was found to be arranged.

Finally, an SiO ₂ layer having a thickness of 30 nm was formed on the entire surface of the obtained substrate, and the obtained surface was polished and planarized by a CMP method. Thereafter, a carbon layer was formed on the entire surface of the obtained substrate by a CVD method to form a protective film to obtain a magnetic recording pattern substrate.

The cross section of the pattern board | substrate by the prior art which formed the substantially regular micro phase-separation structure only inside the concave shape of the board | substrate surface, and the surface schematic diagram. The schematic diagram which showed the process of processing a board | substrate using a substantially regular micro phase-separation structure by a prior art. FIG. 2 is a schematic view of a cross section and a surface of a pattern substrate of the present invention having a substantially regular microphase separation structure composed of spherical microdomains. FIG. 2 is a schematic view of a cross section and a surface of a pattern substrate of the present invention having a substantially regular microphase separation structure in which cylindrical microdomains are arranged in a direction perpendicular to the substrate surface. FIG. 3 is a schematic view of a cross section and a surface of a pattern substrate of the present invention having a substantially regular microphase separation structure in which cylindrical microdomains are arranged in parallel to the substrate surface. FIG. 2 is a schematic view of a cross section and a surface of a pattern substrate of the present invention having a substantially regular microphase separation structure in which lamellar microdomains are arranged in a direction perpendicular to the substrate surface. The schematic diagram which showed the process of the manufacturing method of a pattern board | substrate. The schematic diagram which showed the process of the manufacturing method of a pattern board | substrate. The schematic diagram observed with the atomic force microscope of the pattern substrate surface. The schematic diagram which showed the process of the manufacturing method of a pattern board | substrate. Schematic diagram of the stamper. Nanoimprint device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,30 ... Substrate, 11,92 ... Groove, 12 ... Continuous phase of microphase separation structure in polymer block copolymer thin film, 13 ... Spherical microdomain of microphase separation structure in polymer block copolymer thin film , 14, 21 ... groove peripheral part, 20 ... fine and substantially regular unevenness, 31 ... convex part on the substrate surface, or groove peripheral part, 32 ... concave part or groove on the substrate surface, 33 ... polymer block copolymer Continuous phase of microphase separation structure in thin film, 34 ... spherical microdomain of microphase separation structure in polymer block copolymer thin film, 35 ... distance between closest microdomains a between spherical microdomains, 41 ... polymer Continuous phase of microphase separation structure in block copolymer thin film, 42 ... Cylindrical microdomain of microphase separation structure in polymer block copolymer thin film, 43 ... of cylindrical microdomain Distance between adjacent microdomains a, 61... Lamellar microdomain A of microphase separation structure in polymer block copolymer thin film, 62... Lamellar microdomain B of microphase separation structure in polymer block copolymer thin film 63 ... Distance between nearest microdomains of lamellar microdomains a, 70 ... polymer block copolymer thin film, 71 ... spherical microdomain, 72 ... continuous phase, 73 ... fine convex shape, 74 ... fine convex shape is approximately A substrate regularly arranged on the entire surface, 80 ... a thin film made of a metal, an inorganic substance or other material, 81 ... a thin film having fine irregularities or fine holes, or a nickel film, 90, 1121 ... a silicon substrate, 91 ... SiO ₂ a thin film, a substrate having a groove 93 ... surface, 94 ... structure of a cylinder made of SiO _2, 1001 ... nickel stamper, 1002 ... pore Enlarged view of a portion of the band,
1003 ... Fine pores, 1106, 1115 ... Frame, 1107 ... Head, 1108,
1118 ... Stage, 1109, 1119 ... Support, 1110, 1123 ... Pressure mechanism,
1112: Buffer material, 1113 ... Release agent, 1114 ... Glass substrate, 1117 ... Vacuum chamber, 1120 ... Release layer, 1122 ... Polystyrene resin.

Claims (18)

In a patterned substrate having a thin film of a polymer block copolymer having a microphase separation structure on the surface of a base substrate,
The surface of the base substrate has an uneven shape, and the depth of the recessed portion is 0.5a or more and 1.5a or less with respect to the closest inter-microdomain distance a of the microdomains constituting the microphase separation structure. A thin film of the polymer block copolymer is formed on the surface of the concave portion and the convex portion of the base substrate ;
A patterned substrate having a thickness from the surface of the convex portion of the thin film of the polymer block copolymer of 0.5a to 1.5a with respect to the distance a between the nearest microdomains . The pattern substrate according to claim 1,
The pattern substrate, wherein the distance a between the nearest microdomains is not less than 10 nanometers and not more than 200 nanometers. The pattern substrate according to claim 1,
When the distance between the closest microdomains of the microdomains constituting the microphase separation structure is a,
A pattern substrate, wherein the width of the convex portion on the surface of the substrate is 1.0a or more and 50.0a or less, and the width of the concave portion is 1.0a or more and 25.0a or less. The pattern substrate according to claim 1,
A patterned substrate, wherein the microphase separation structure is composed of spherical or cylindrical microdomains.   2. The pattern substrate according to claim 1, wherein the polymer block copolymer is a diblock copolymer composed of polystyrene and polymethylmethacrylate. In a patterned substrate having a thin film of a polymer block copolymer having a microphase separation structure on the surface of a base substrate,
A surface having a concavo-convex shape on the surface of the base substrate, a thin film of the polymer block copolymer is formed in the groove of the concave portion, and a layer in which microdomains are arranged in a row in a continuous phase; and a convex portion A pattern substrate having a two-layer structure in which microdomains are arranged in a row in a continuous phase. The pattern substrate according to claim 6 ,
When the distance between the closest microdomains of the microdomains constituting the microphase separation structure is a,
A pattern substrate, wherein the width of the convex portion on the surface of the substrate is 1.0a or more and 50.0a or less, and the width of the concave portion is 1.0a or more and 25.0a or less. The pattern substrate according to claim 6 ,
When the distance between the closest microdomains of the microdomains constituting the microphase separation structure is a,
The depth of the concave portion is 0.5a or more and 1.5a or less, and the thickness from the surface of the convex portion of the thin film of the polymer block copolymer is 0.5a or more and 1.5a or less. Pattern substrate to be used. The pattern substrate according to claim 6 , wherein the polymer block copolymer is a diblock copolymer composed of polystyrene and polymethylmethacrylate. Forming a concave shape on a part of the surface of the substrate;
Forming a polymer block copolymer thin film so as to fill the concave shape and coat the substrate surface;
Have a, and forming a microphase separation structure in the block copolymer thin film,
When the distance between the closest microdomains of the microdomains constituting the microphase separation structure is a,
A thickness of the polymer block copolymer thin film from the surface of the substrate is 0.5a or more and 1.5a or less . The method for producing a patterned substrate according to claim 10 , further comprising a step of selectively removing one polymer phase from the microphase separation structure. 12. The method for manufacturing a patterned substrate according to claim 11 , wherein one polymer phase is selectively removed from the microphase separation structure, and then the substrate is processed using the remaining other polymer phase as a mask. A method for producing a patterned substrate, comprising a step of transferring a phase separation structure to a substrate surface. 12. The method for producing a patterned substrate according to claim 11 , wherein after one polymer phase is selectively removed from the microphase separation structure, a non-transfer body is brought into close contact with the remaining other polymer phase. A method for producing a patterned substrate, comprising a step of transferring a separation structure to a transfer target. In the manufacturing method of the pattern board | substrate of Claim 10 ,
A method for producing a patterned substrate, wherein a distance a between closest microdomains of microdomains constituting the microphase separation structure is 10 nanometers or more and 200 nanometers or less. In the manufacturing method of the pattern board | substrate of Claim 10 ,
When the distance between the closest microdomains of the microdomains constituting the microphase separation structure is a,
A pattern substrate manufacturing method, wherein the width of the concave portion on the surface of the substrate is 1.0a or more and 25.0a or less, and the interval between adjacent concave portions is 1.0a or more and 50.0a or less. In the manufacturing method of the pattern board | substrate of Claim 10 ,
When the distance between the closest microdomains of the microdomains constituting the microphase separation structure is a,
A method for producing a patterned substrate, wherein the depth of the concave portion is 0.5a or more and 1.5a or less. The fine metal mold | die manufactured using the process including the manufacturing method of the pattern board | substrate of Claim 10 . A patterned medium for magnetic recording manufactured using a process including the method for manufacturing a patterned substrate according to claim 10 .

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