JP2010080010A - Method of manufacturing information recording medium substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an information recording medium substrate by which the information recording medium substrate having patterns having sizes or degree of roughness and fineness different from each other are reliably manufactured. <P>SOLUTION: The method of manufacturing the information recording medium substrate having a first pattern 3a and a second pattern using an imprint method includes a first transfer process for transferring the first pattern 3a to a first molding material 4 by pushing to the first molding material 4 a first imprint die 1 having a first pattern 1b for transferring the first pattern 3a to the first molding material 4 and a second transfer process for transferring the second pattern to a second pattern forming region 8 where no rugged pattern is formed included in a first pattern region in the first molding material 4 after the first transfer process. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an information recording medium substrate using an imprint method in which a fine pattern is transferred to a substrate.

  For magnetic recording media, patterned media (hereinafter referred to as PM) in which the magnetic layer is patterned and the magnetic layer is physically divided into a plurality of regions have been proposed in order to further increase the recording density. The fine structure for PM is on the order of several tens of nm, which is a pattern size equivalent to the diffraction limit of light. For this reason, it is difficult to produce a PM pattern with a fine structure by general photolithography. Therefore, as a method capable of further fine processing, for example, a method of forming a pattern by a nanoimprint method has been proposed. In the nanoimprint method, first, the concave / convex shape of the above mold is transferred to the imprint material by pressing a mold having a concave / convex shape on the surface against the imprint material applied on the substrate substrate, and the concave / convex shape is transferred. This is a method of obtaining a substrate having a concavo-convex shape on the surface by peeling the mold after solidifying the imprint material. The nanoimprint method is described in Patent Document 1, for example. Specifically, Patent Document 1 discloses a process of forming a transfer target (imprint material layer) on a flat substrate or a mold (mold) having an uneven structure, and bringing the mold into contact with the transfer target. A step of pressing, a step of transferring the concavo-convex structure of the mold to the transferred body, a step of peeling the mold from the transferred body, and a magnetic recording layer on the transferred body onto which the concavo-convex structure of the mold is transferred. And a method of manufacturing a magnetic recording medium having a step of depositing. Thus, by using the nanoimprint method, even a pattern size in a region exceeding the diffraction limit of light required in PM can be processed.

  However, in the nanoimprint method, when the mold is transferred to the transfer target, the mold and the transfer target are in close contact with each other, so that it is difficult to peel off the mold. Depending on how the force is applied at the time of peeling, the transferred fine structure may be destroyed or deformed. In PM, there are two patterns, a data pattern for recording data and a servo pattern for recording position information on the magnetic recording medium. The sizes and coarse densities of these patterns are different from each other and may be different by an order of one digit or more. In the nanoimprint method, the pressure applied to each location becomes non-uniform due to the difference in pattern size and coarse density. Therefore, it is very difficult to simultaneously and uniformly transfer patterns having extremely different sizes and coarse densities. Therefore, it is difficult to simultaneously form the data pattern and the servo pattern using the nanoimprint method, and the pattern may be broken or deformed.

  Therefore, various techniques have been proposed to solve the above problems. As a method for preventing breakage at the time of mold release, for example, in Patent Document 2, a pin module is inserted between a mold and a substrate after imprint molding is completed, the mold and the substrate are separated, and a slit is formed. A method is described in which the air is introduced between the mold and the substrate through this slit to break the vacuum effect, and the substrate is separated from the mold by the pin module. Further, in Patent Document 3, in an imprint mold (mold) for forming a concavo-convex pattern, a through-hole is formed outside the concavo-convex pattern region on the surface on which the concavo-convex pattern is formed. A method is described in which a mold is peeled off by applying pressure from a through-hole to a substrate with a pin or gas after pattern formation between them.

Further, as a method for preventing damage caused by the difference in pattern size and coarse density, there is a method of changing the pattern height of the mold depending on the size of the pattern to be transferred, as described in Patent Document 4, for example.
JP 2007-95162 A JP 2007-118552 A JP 2008-78550 A Japanese Patent Laid-Open No. 2007-141280

  However, in the method described in Patent Document 2 described above, a pin module is inserted between the mold after imprint molding is completed and the substrate, and a gap is generated between the mold and the substrate by physical force. Therefore, when the pin module comes into contact with the substrate, there is a high possibility that the substrate is damaged by the pin module. In particular, in a hard disk drive (hereinafter referred to as HDD) in which PM is used, the distance between the HDD substrate and the data reading head is only about 10 nm, and a protrusion such as a scratch exists on the surface of the HDD substrate. The head and the HDD substrate are destroyed, so-called head crash occurs. Therefore, the scratches on the substrate are often a problem even if they are minute scratches.

  Further, in the method described in Patent Document 3, depending on the position of the through-holes, pressure is not uniformly applied to the whole, resulting in poor balance, and pattern damage or deformation may occur. For example, in the case of a 2.5-inch substrate in an HDD substrate, for example, a donut shape having an outer diameter of 65 mm and an inner diameter of 20 mm has only a few mm from the inner and outer periphery. Therefore, the region where the through hole can be formed is very limited. Therefore, in order to release the substrate uniformly, the through hole cannot be formed at an optimum position. On the other hand, if a through hole is formed at a position suitable for uniform mold release, a pattern is not formed at the position of the through hole, so that the recording capacity is reduced correspondingly and it is difficult to increase the recording density.

  In addition, when the imprint material is sandwiched between two molds, the substrate has a concavo-convex pattern formed on both surfaces, and therefore the concavo-convex pattern is formed on both molds. Therefore, it is difficult to peel off both surfaces. Therefore, in order to facilitate the separation of these two molds, it is necessary to form through holes in both molds and apply pressure together, which is complicated.

  In the method described in Patent Document 4, patterns having different heights are formed by utilizing a phenomenon (microloading effect) in which the etching rate varies depending on the density of the pattern during dry etching. For this reason, since the etching rate, that is, the pattern height is determined by the density of the pattern, there is a problem that versatility is low and the pattern shape cannot be designed freely.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing an information recording medium substrate that reliably manufactures information recording medium substrates having patterns having different sizes or coarse densities. That is.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below. That is, an information recording medium substrate manufacturing method according to an aspect of the present invention is an information recording medium substrate manufacturing method having first and second patterns using an imprint method, wherein the first pattern is a first pattern. A first transfer step of transferring the first pattern to the first molding material by pressing a first imprint mold having a first transfer pattern to be transferred to the first molding material against the first molding material; A second transfer step of transferring the second pattern to a second pattern formation region, which is included in the first pattern region and in which the uneven pattern is not formed, in the first molding material after the first transfer step; Yes.

  Thus, since patterns having different sizes and coarse densities are produced by different processes, pressure variations and the like are suppressed as compared with the case where these patterns are simultaneously transferred. Thereby, since each pattern can be produced by applying a uniform pressure, transfer defects are hardly caused. Therefore, the information recording medium substrate can be reliably manufactured.

  Further, in the above-described method for manufacturing an information recording medium substrate, a through hole is formed in the first imprint mold, and one end of the through hole is located in a region where the first transfer pattern is formed, In the first transfer step, the first imprint mold is released from the first molding material by pressing the first imprint mold against the first molding material and then flowing a fluid into the through hole. It is preferable to have the process to do.

  As a result, it is possible to release the mold by uniformly applying force to the interface between the first molding material and the first imprint mold, and it is difficult for the pattern to be deformed or damaged during the mold release. As a result, the information recording medium substrate can be reliably manufactured.

  In the above-described method for manufacturing an information recording medium substrate, it is preferable that one end of the through hole is located in an area where the uneven pattern is not formed, which is included in the area where the first transfer pattern is formed.

  Thus, since one end of the through hole is included in the region where the first transfer pattern that is difficult to release is formed, it is more easily released when the fluid flows into the through hole and is released. Can be typed. In addition, since it is difficult to form a concavo-convex pattern at the location of the through hole, by forming a through hole at a position where the concavo-convex pattern is not formed in the region where the first transfer pattern is formed, The pattern area can be used effectively. Further, in the second transfer step, since the second pattern is formed in the region formed by the position where the uneven pattern is not formed, the region of the substrate can be used without waste, and the recording density can be increased efficiently. it can.

  In the above-described method for manufacturing an information recording medium substrate, it is preferable that the first pattern is for a hard disk and is a data pattern, and the second pattern is for a hard disk and is a servo pattern. The data pattern is a pattern for recording or reading information, and the servo pattern is an address pattern for determining where the data read head is located on the hard disk substrate.

  In this manner, by separating the data pattern and servo pattern manufacturing processes having different sizes and coarse densities, transfer defects are unlikely to occur, and an information recording medium substrate can be reliably manufactured. In addition, the periphery of the position where the through hole is formed in the first transfer step is a servo pattern formation region. However, since there are many servo patterns from the inner periphery to the outer periphery of the substrate, the position of the through hole ( The servo pattern formation area) can be freely set. In addition, since the second pattern needs to be aligned with the first pattern, it is preferable to use a servo pattern having a large size as the second pattern.

  In the method for manufacturing an information recording medium substrate described above, it is preferable that the first pattern is for a hard disk and is a servo pattern, and the second pattern is for a hard disk and is a data pattern.

  As described above, by separating the transfer process of the data pattern and the servo pattern having different sizes and coarse densities, it is difficult to cause transfer failure, and the information recording medium substrate can be reliably manufactured.

  In the above-described method for manufacturing an information recording medium substrate, the fluid is preferably water.

  In this way, since water that can be easily obtained and does not erode the substrate or the like is used, mold release can be performed at low cost.

  In the above-described method for manufacturing an information recording medium substrate, the fluid is preferably air.

  In this way, since air or nitrogen that can be easily obtained and does not erode the substrate or the like is used, mold release can be performed at low cost.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the information recording medium board | substrate which manufactures the information recording medium board | substrate which has a pattern from which a size or a coarse density mutually differs can be provided reliably.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

  First, an imprint type according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a plan view and a side view showing a configuration of an imprint type according to the present embodiment. As shown in FIG. 1, the 1st imprint type | mold 1 which concerns on this Embodiment is a disk shape, It is a micro structure for forming an uneven | corrugated pattern in the imprint material (molding material) on one main surface. It has a certain transfer pattern 1b. The transfer pattern 1b is for forming a data pattern for a hard disk. In addition, a through-hole 1a is formed in the transfer pattern region 1c, which is a region where the transfer pattern 1b of the first imprint mold 1 is formed, through the other main surface of the first imprint mold 1. . In addition, the uneven | corrugated pattern is not formed in the periphery in which the through-hole 1a was formed. This range 1d is an area where a servo pattern for a hard disk is formed. The through holes 1a are formed at four locations so as to be four times symmetrical with respect to the center of the imprint mold. In addition, the formation location of the through-hole 1a does not need to be limited to 4 places. Thus, since the through-hole 1a is formed, in the pattern formation process, in a state where the imprint material and the first imprint mold 1 are in close contact with each other, for example, a gas or a liquid is emitted from the through-hole 1a. By allowing the fluid to flow in, the first imprint mold 1 can be uniformly peeled from the imprint material, and the first imprint mold 1 can be easily released. The pattern forming step is a step in which the first imprint mold 1 is pressed against the imprint material, and the imprint material is transferred to the imprint material, so that the imprint material has an uneven pattern shape. It is in a state. The through hole 1a only needs to be positioned in the transfer pattern region 1c, and the size or shape thereof is not limited. In addition, the size of the through hole 1a may change in the middle, or a plurality of through holes 1a may be coupled to one through hole 1a in the middle. Further, since the through-hole 1a is located in the transfer pattern region 1c and needs only to come out of the first imprint mold 1, for example, the first imprint mold 1 has a side surface like the first imprint mold 1. It may be formed other than the other main surface of the mold 1. In consideration of ease of manufacture, the through hole 1a is preferably linear without meandering. Therefore, it is preferable that the through hole 1 a is formed so as to pass out from the transfer pattern region 1 c to the other main surface side of the first imprint mold 1.

  The first imprint mold 1 may be manufactured by a known technique such as injection molding, dry etching, wet etching, photolithography, electron beam lithography (electron beam lithography), imprint method, or the like. For example, when injection molding or the like is used, the transfer pattern 1b and the through hole 1a may be formed simultaneously. Further, after forming the transfer pattern 1b, the through hole 1a may be formed by machining or the like.

  Next, a method for manufacturing an information recording medium substrate using an imprint mold according to an embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a diagram showing a manufacturing process of the data pattern of the information recording medium substrate using the imprint mold according to the present embodiment, and FIGS. 2A to 2G are diagrams showing each process. is there. FIG. 3 is a diagram showing the manufacturing process of the servo pattern of the information recording medium substrate using the imprint mold according to the present embodiment, and FIGS. 3 (A) to 3 (E) show each process. FIG.

  First, in the method for manufacturing an information recording medium substrate according to the present embodiment, a manufacturing method related to manufacturing of a data pattern will be described. As shown in FIG. 2A, in the first imprint mold 1, the transfer pattern 1b of the first imprint mold 1 faces the glass substrate 2 side which is a substrate base material on which the magnetic film 3 is formed. Are arranged as follows. For example, CoCrPt or FePt may be used as the magnetic film 3.

  In addition, as a substrate base material, if it is a base material which can form a board | substrate, such as a board | substrate for PM, by providing the surface part which consists of a structural material which has several fine uneven | corrugated shape on the surface, especially if it is a base material Not limited. For example, a quartz substrate or the like may be used instead of the glass substrate. Examples of the glass substrate 2 include a 2.5-inch glass substrate for HDD.

  Next, as illustrated in FIG. 2B, an imprint material 4 is applied to a portion where a concavo-convex pattern on the glass substrate 2 including the magnetic film 3 is formed. As the imprint material 4, for example, a spin-on-glass (SOG) material may be used. Moreover, when using the photoimprint method, as the imprint material 4, for example, a photocurable resin material may be used. These coating methods may be known coating methods, for example, drop coating by a dispenser, spin coating method, dip coating method, wire bar, applicator, etc. You may spread using.

  Next, as shown in FIG. 2C, the first imprint mold 1 is pressed against the glass substrate 2 on which the imprint material 4 and the magnetic film 3 are laminated with a predetermined pressing force. Here, when it is not optical imprinting, that is, when SOG or the like is used as the imprint material 4, the imprint material 4 is dried. By doing so, the imprint material 4 is solidified, and the transfer pattern 1 b is transferred to the imprint material 4. That is, an uneven pattern is formed on the imprint material 4. The drying method is not particularly limited, and a known drying method can be used. For example, although it may be allowed to stand at room temperature, it is preferable to further reduce the pressure, blow, and heat from the viewpoint of faster drying. In addition, when heating is performed, it is preferable that the heating temperature does not exceed the boiling point of the solvent of the imprint material 4. By doing so, the imprint material 4 does not boil, and the possibility that bubbles remain inside the imprint material 4 is reduced, so that the occurrence of uneven transfer defects is suppressed. In the case of the optical imprint method, light such as ultraviolet light is irradiated to cure the imprint material 4. By doing so, the imprint material 4 is solidified, and the transfer pattern 1 b is transferred to the imprint material 4.

  Next, as shown in FIG. 2D, a gas 5 as a fluid is caused to flow into the through hole 1a. Accordingly, pressure is applied to the interface between the first imprint mold 1 and the imprint material 4, and thus the first imprint mold 1 is peeled from the imprint material 4. At this time, since pressure is uniformly applied to each part by the gas 5, the first imprint mold 1 is peeled off with a uniform force. Thereby, the concavo-convex pattern formed on the imprint material 4 is not destroyed or deformed. The gas 5 may be a gas that can be easily used in any facility, such as air or nitrogen. Other gases may be used as long as they do not erode the microstructure formed on the glass substrate 2, the magnetic film 3, and the imprint material 4. Further, instead of the gas 5, for example, a liquid may be used. Even in that case, since the pressure is uniformly applied to each part, the same effect as the gas 5 is obtained. As the liquid, since it is easily available, for example, water may be used. However, the liquid is not particularly limited, and does not erode the fine structure formed on the glass substrate 2, the magnetic film 3, and the imprint material 4. If it is.

  Next, as shown in FIG. 2E, the magnetic film 3 is exposed by dry etching the imprint material 4 on which the fine structure is formed.

  Next, as shown in FIG. 2F, a fine structure is formed in the magnetic film 3 by etching the magnetic film 3 by dry etching using the imprint material 4 remaining on the magnetic film 3 as a mask. .

  Next, as shown in FIG. 2G, the imprint material 4 is removed, and the information recording medium substrate 10 in which the data pattern 3a is formed on the magnetic film 3 on the surface and the servo pattern formation region 8 is formed is manufactured. Is done.

  Next, in the method for manufacturing the information recording medium substrate according to the present embodiment, a manufacturing method related to the manufacturing of the servo pattern will be described. As shown in FIG. 3A, the information recording medium substrate 10 manufactured in the manufacturing process shown in FIG. 2 has a servo pattern formation region 8 where a servo pattern will be formed and data on which a data pattern 3a is formed. Pattern area 9. FIG. 3A shows a part of the information recording medium substrate 10 manufactured in the manufacturing process shown in FIG. A servo pattern is formed in the servo pattern formation region 8. Specifically, it may be performed in the same manner as the formation of the data pattern 3a described above.

  As shown in FIG. 3B, the imprint material 6 is applied, and the second imprint mold 7 having the servo pattern transfer pattern is pressed against the imprint material 6 with a predetermined pressing force. Then, according to the imprint material 6, the imprint material 6 is solidified by drying or light irradiation, and the servo pattern is transferred. Since the servo pattern transfer pattern is formed on the second imprint mold 7, the servo pattern is formed on the imprint material 6. For example, in the second imprint mold 7, if a through hole is formed, mold release can be easily performed by flowing a fluid such as gas or liquid from the through hole. There is no breakage, which is preferable. After the release, as shown in FIG. 3C, the magnetic film 3 is exposed by dry etching the imprint material 6 on which the fine structure is formed. Next, as shown in FIG. 3D, the magnetic film 3 is etched by dry etching using the imprint material 6 remaining on the magnetic film 3 as a mask. Further, as shown in FIG. 3E, the imprint material 6 is removed, and the information recording medium substrate 10a in which the data pattern 3a and the servo pattern 8a are formed on the magnetic film 3 on the surface is manufactured. In forming the servo pattern 8a, a method other than the imprint method shown in FIG. 3 may be used. For example, the servo pattern 8 a may be formed in the servo pattern formation region 8 of the information recording medium substrate 10 using a magnetic transfer method.

  In this manner, first, only the data pattern is produced by using the imprint method, and then the servo pattern is produced, whereby these patterns having different sizes and coarse densities can be easily produced without breakage. Further, by forming the through-hole 1a in the first imprint mold 1, it is easy to release the mold and transfer defects are hardly caused.

  In the first imprint mold 1, it is difficult to form a concavo-convex pattern in the peripheral range 1 d where the through-hole 1 a is formed, and the data pattern 3 a is formed in the imprint material 4 for the range 1 d. However, since the area becomes the servo pattern formation area 8, the substrate can be used without waste, and the information recording medium substrate 10a can be efficiently increased in recording density. Further, since there are usually a large number of servo patterns 8a from the inner peripheral portion toward the outer peripheral portion of the information recording medium substrate 10a, the region where the through-hole 1a of the first imprint mold 1 is formed can be freely set. Further, since the through hole 1a is formed in the transfer pattern region 1c, a uniform pressure is applied to the transfer pattern region 1c when releasing the mold by flowing a fluid such as gas or liquid into the through hole 1a. Therefore, it is easily released without breakage.

  In the above description, the servo pattern is formed after forming the data pattern. Conversely, the data pattern may be formed after forming the servo pattern. Moreover, although the 1st imprint type | mold 1 was made into the type | mold of only one side, it is good also as a structure which has an upper mold | type and a lower mold | type.

  Examples (Examples 1 and 2) in which the imprint type according to the above-described embodiment of the present invention and the method of manufacturing the information recording medium substrate using the imprint type are specifically described will be described. Further, an example (Comparative Examples 1 and 2) in which the imprint type according to the conventional example and the method for manufacturing the information recording medium substrate using the same are specifically described.

Example 1
Example 1 will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, first, a first imprint mold 1 in which a fine structure was formed by injection molding using a polymethylpentene resin was used. The first imprint molds 1 each had a disk shape with an outer diameter of 65 mm. A circular through-hole 1a was formed at a position having a radius of 21 mm from the center in a form that is four times symmetrical. The transfer pattern 1b having a fine structure was formed on one side of the first imprint mold 1 and formed in a region having a radius of 10 mm or more from the center. The through holes 1a and the transfer pattern 1b were formed by injection molding.

  Next, a 2.5-inch glass substrate 2 for HDD (outer diameter 65 mm, inner diameter 20 mm) on which the magnetic film 3 was formed was prepared (see FIG. 2A). Then, on the glass substrate 2 including the magnetic film 3, a solution of OCD T-12 900-V (manufactured by Tokyo Ohka Kogyo Co., Ltd.) which is an SOG material as the imprint material 4 was applied with 100 microliters by a dispenser ( (See FIG. 2B). In addition, the imprint material 4 was apply | coated to the location corresponding to the pattern 1b for transcription | transfer in a pattern formation process. Thereafter, the imprint material 4 was dried and cured with the first imprint mold 1 pressing the glass substrate 2 at 1 MPa (see FIG. 2C). After the imprint material 4 was cured, compressed air as the gas 5 was sealed through the through-hole 1a, and the mold was released. As a result, the first imprint mold 1 could be uniformly released (see FIG. 2D). .

  The fine structure which was the uneven | corrugated pattern transcribe | transferred to the imprint material 4 after mold release was observed. As a result of observing the surface shape of the imprint material 4 with an interferometer, no defects caused by physical scratches or the like were found. Moreover, as a result of observing the fine structure with a scanning electron microscope (SEM) or an atomic force microscope (AFM), no defects such as destruction of the fine structure were found in the observation region.

  After that, the fine structure layer of the imprint material 4 which is the SOG material was etched by dry etching until the magnetic film 3 was exposed on the bottom surface of the fine structure layer (see FIG. 2E). Then, using the remaining imprint material 4 as a mask, the magnetic film 3 is etched by dry etching (see FIG. 2F). Finally, the imprint material 4 is removed by wet etching, and the magnetic film 3 on the surface is removed. The data recording medium substrate 10 having the data pattern 3a formed thereon and the servo pattern forming region 8 formed thereon was manufactured (see FIG. 2G).

  Thereafter, as described with reference to FIG. 3, a servo pattern 8a is formed in the servo pattern formation region 8 by the imprint method in the same manner as described with reference to FIG. Substrate 10a).

  When the microstructure after mold release was observed at the time of manufacturing the servo pattern 8a, the surface shape was observed with an interferometer, and as a result, no defects due to physical scratches or the like were found. Moreover, as a result of observing the fine structure with a scanning electron microscope (SEM) or an atomic force microscope (AFM), no defects such as destruction of the fine structure were found in the observation region.

(Example 2)
An imprint type according to the present embodiment and an information recording medium substrate manufacturing method using the same will be described with reference to FIGS. FIG. 4 is a plan view and a side view showing the configuration of the imprint type according to the second embodiment. FIG. 5 is a diagram showing the manufacturing process of the data pattern of the information recording medium substrate using the imprint mold of Example 2, and FIGS. 5 (A) to 5 (G) are diagrams showing each process. It is. As shown in FIG. 4, first, a first imprint mold 11 in which a microstructure was formed by injection molding using a polycarbonate resin was used. The first imprint mold 11 was a disk having an outer diameter of 65 mm. A rectangular through-hole 11a was formed at a position having a radius of 21 mm from the center in a four-fold symmetry. The transfer pattern 11b, which is a fine structure for forming a data pattern, is formed on one side of the first imprint mold 11 and is formed in a region having a radius of 10 mm or more from the center. In addition, in the transfer pattern region 11 c, which is a region where the transfer pattern 11 b of the first imprint mold 1 is formed, a through hole 11 a that passes through to the other main surface side of the first imprint mold 11 is formed. . In addition, the uneven | corrugated pattern is not formed in the periphery in which the through-hole 11a was formed. This range 11d is a region for forming a servo pattern formation region, and no unevenness is formed. The through holes 11a and the transfer pattern 11b are formed by injection molding.

  Next, what prepared the magnetic film 13 on the main surface of the 2.5-inch glass substrate 12 (outer diameter 65 mm, inner diameter 20 mm) for HDD was prepared (see FIG. 5A). Then, 100 microliters of a solution of PAK-02 (manufactured by Toyo Gosei Co., Ltd.), which is a photocurable resin, was applied as an imprint material 14 on the glass substrate 12 including the magnetic film 13 with a dispenser (FIG. 5). (See (B)). In addition, the imprint material 14 was apply | coated to the location corresponding to the pattern 11b for transcription | transfer in a pattern formation process. Thereafter, the imprint material 14 is irradiated with light while the glass substrate 12 including the imprint material 14 and the magnetic film 13 is pressed by the first imprint mold 11, and the imprint material 14 is cured. (See FIG. 5C). After the imprint material 14 was cured, nitrogen as the gas 15 was sealed through the through-hole 11a, and the mold was released. As a result, the first imprint mold 11 was uniformly released (see FIG. 5D).

  The fine structure which was the uneven | corrugated pattern transcribe | transferred to the imprint material 14 after mold release was observed. As a result of observing the surface shape of the imprint material 14 with an interferometer, no defects caused by physical scratches or the like were found. Moreover, as a result of observing the fine structure with a scanning electron microscope (SEM) or an atomic force microscope (AFM), no defects such as destruction of the fine structure were found in the observation region.

  After that, the fine structure layer of the imprint material 14 that is a photocurable resin was etched by dry etching until the magnetic film 13 was exposed on the bottom surface of the fine structure layer (see FIG. 5E). Then, the magnetic film 13 is etched by dry etching using the remaining imprint material 14 as a photocurable resin as a mask (see FIG. 5F), and finally the imprint material 14 as a photocurable resin is removed. The information recording medium substrate 20 in which the data pattern 13a was formed on the magnetic film 13 on the surface and the servo pattern formation region 18 was formed was manufactured by removing by dry etching (see FIG. 4G). Thereafter, although not shown, a servo pattern was formed using a magnetic transfer method to obtain a hard disk drive substrate for patterned media.

(Comparative Example 1)
A conventional imprint type and an information recording medium substrate manufacturing method using the same will be described with reference to FIG. FIG. 6 is a view for explaining imprint mold release in Comparative Example 1. FIG. FIG. 6 corresponds to FIG. 2D. In addition, the imprint type | mold of the comparative example 1 is the structure which transfers a data pattern and a servo pattern simultaneously by the imprint method, and does not have a through-hole.

  In Comparative Example 1, a first imprint mold 101 having a disk shape with an outer diameter of 65 mm, in which a microstructure was formed by injection molding using polymethylpentene resin, was used. On one main surface of the first imprint mold 101, a transfer pattern having a fine structure is formed in a region having a radius of 10 mm or more from the center. The transfer pattern includes a data pattern and a servo pattern, and the data pattern and the servo pattern are formed by a single imprint method.

  First, what prepared the magnetic film 103 in the main surface of the 2.5-inch glass substrate 102 (outer diameter 65mm, inner diameter 20mm) for HDD was prepared. Then, 100 microliters of a solution of OCD T-12 900-V (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is an SOG material, was applied as an imprint material 104 on the glass substrate 102 including the magnetic film 103 by a dispenser. In addition, the imprint material 104 was apply | coated to the location corresponding to the pattern for a transfer in a pattern formation process. Thereafter, the imprint material 104 was dried and cured with the first imprint mold 101 while the glass substrate 102 including the imprint material 104 and the magnetic film 103 was pressed at 1 MPa.

  Then, as shown in FIG. 6, the pin module is inserted into the interface between the first imprint mold 101 and the imprint material 104, and the first imprint mold 101 and the imprint material 104 are physically moved. A mold was peeled off by generating a gap between them.

  When the microstructure transferred to the imprint material 104 after the mold release was observed, the surface shape was observed with an interferometer. As a result, the pin module 106 was attached to the portion where the pin module was inserted in the outer peripheral portion. Abnormal interference fringes that seem to be due to scratches were observed. When the relevant part was observed with a Nomarski microscope, it was found that the magnetic film 103 including the imprint material 104 and the glass substrate 102 were damaged.

  In addition, when the fine structure was observed with a scanning electron microscope (SEM), the data pattern portion was accurately transferred. However, in the servo pattern portion, transfer defects such as rounded corners of the pattern were observed. It was.

(Comparative Example 2)
A conventional imprint type and an information recording medium substrate manufacturing method using the same will be described with reference to FIG. 7A and 7B are diagrams for explaining the imprint type in Comparative Example 2. FIG. 7A is a plan view and a side view of the imprint type, and FIG. 7B is an imprint type in Comparative Example 2. It is a figure for demonstrating release of a printing type | mold. Note that FIG. 7B corresponds to FIG. The imprint mold of Comparative Example 2 has a through hole, but its position is outside the transfer pattern area. Specifically, the through hole was formed near the outer periphery of the imprint mold.

  As shown in FIG. 7A, the imprint mold 201 in the comparative example 2 is a disc shape having an outer diameter of 65 mm formed by injection molding of polymethylpentene resin, and extends from the outer periphery of the imprint mold 201 toward the center. Four through-holes 201a are formed so as to be four times symmetrical at a position of 1 mm. Note that the transfer pattern having a fine structure is formed on one surface of the imprint mold 201 and is formed in a region having a radius of 10 mm or more from the center, and no through hole 201a is formed in the transfer pattern region. The through holes 201a and these transfer patterns are formed by injection molding. Further, the transfer pattern includes only the data pattern, and does not include the servo pattern.

  First, a 2.5-inch glass substrate 202 for HDD (outer diameter 65 mm, inner diameter 20 mm) having a magnetic film 203 formed on the main surface was prepared. Then, 100 microliters of a solution of OCD T-12 900-V (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is an SOG material, was applied to the glass substrate 202 including the magnetic film 203 by a dispenser as the imprint material 204. The imprint material 204 was applied to a location corresponding to the transfer pattern in the pattern forming process. Thereafter, the imprint material 204 was dried and cured with the imprint mold 201 in a state where the glass substrate 202 including the imprint material 204 and the magnetic film 203 was pressed at 1 MPa. And after imprint material 204 hardened | cured, as shown to FIG. 7 (B), the compressed air which is the gas 205 was enclosed through the through-hole 201a, and the mold release was performed. However, the outer peripheral portion of the imprint mold 201 could be released, but could not be released to the inner peripheral portion.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

It is the top view and side view which show the structure of the imprint type | mold which concerns on this Embodiment. It is a figure which shows the manufacturing process of the data pattern of the information recording medium board | substrate using the imprint type | mold which concerns on this embodiment, Comprising: FIG. 2 (A)-FIG. 2 (G) are figures which show each process. FIG. 3A to FIG. 3E are diagrams showing the manufacturing process of the servo pattern of the information recording medium substrate using the imprint mold according to this embodiment. FIG. 6 is a plan view and a side view showing a configuration of an imprint mold according to a second embodiment. FIG. 5A to FIG. 5G are diagrams illustrating steps of manufacturing a data pattern of an information recording medium substrate using an imprint type according to the second embodiment. It is a figure for demonstrating the imprint mold release in the comparative example 1. FIG. FIG. 7A is a plan view and a side view of an imprint mold in Comparative Example 2, and FIG. 7B is a plan view and a side view of the imprint mold in Comparative Example 2. FIG. It is a figure for demonstrating a type | mold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 1st imprint type | mold 1a, 11a Through-hole 1b, 11b Transfer pattern 1c, 11c Transfer pattern area | region 1d, 11d Range 2, 12 Glass substrate 3, 13 Magnetic film 3a, 13a Data pattern 4, 6, 14 Imprint material 5 Gas 7 Second imprint mold 8, 18 Servo pattern formation area 8 a Servo pattern 9 Data pattern area 10, 10 a, 20 Information recording medium substrate 101 First imprint mold 102, 202 Glass substrate 103, 203 Magnetic film 104, 204 Imprint material 106 Pin module 201 Imprint mold 201a Through hole

Claims (7)

A method of manufacturing an information recording medium substrate having first and second patterns using an imprint method,
The first pattern is transferred to the first molding material by pressing a first imprint mold having a first transfer pattern, which transfers the first pattern onto the first molding material, against the first molding material. 1 transfer process;
A second transfer step of transferring the second pattern to the second pattern formation region, which is included in the first pattern region and in which the uneven pattern is not formed, in the first molding material after the first transfer step; An information recording medium substrate manufacturing method characterized by the above. A through hole is formed in the first imprint mold, and one end of the through hole is located in a region where the first transfer pattern is formed,
In the first transfer step, the first imprint mold is released from the first molding material by pressing the first imprint mold against the first molding material and then flowing a fluid into the through hole. The manufacturing method of the information recording medium board | substrate of Claim 1 which has a process to carry out.   3. The method of manufacturing an information recording medium substrate according to claim 2, wherein one end of the through hole is located in a region where the uneven pattern is not formed, which is included in the region where the first transfer pattern is formed.   The method of manufacturing an information recording medium substrate according to claim 1, wherein the first pattern is for a hard disk and is a data pattern, and the second pattern is for a hard disk and is a servo pattern.   2. The method of manufacturing an information recording medium substrate according to claim 1, wherein the first pattern is for a hard disk and is a servo pattern, and the second pattern is for a hard disk and is a data pattern.   The method for manufacturing an information recording medium substrate according to claim 2, wherein the fluid is water.   The method for manufacturing an information recording medium substrate according to claim 2, wherein the fluid is air.

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