WO2010035594A1

WO2010035594A1 - Imprint mold and information recording medium substrate manufacturing method using the same

Info

Publication number: WO2010035594A1
Application number: PCT/JP2009/064550
Authority: WO
Inventors: 誉之岡野
Original assignee: コニカミノルタオプト株式会社
Priority date: 2008-09-26
Filing date: 2009-08-20
Publication date: 2010-04-01

Abstract

Provided is an imprint mold having a through hole at a position corresponding to a center hole of a substrate base when the imprint mold is pressed to a molding material. The through hole is smaller than the center hole. Provided also is an information recording medium substrate manufacturing method using the aforementioned imprint mold. After the imprint mold is pressed to the molding material, a fluid is introduced into the center hole and the through hole and pressure is applied to the surface of the imprint mold facing the center hole so as to separate the imprint mold from the molding material. Thus, the imprint mold and the information recording medium substrate manufacturing method using the imprint mold enable easy separation of the mold without scratching the substrate.

Description

Imprint type and information recording medium substrate manufacturing method using the same

The present invention relates to an imprint mold for transferring a microstructure pattern and a method for manufacturing an information recording medium substrate using the same.

In order to further increase the recording density of magnetic recording media, patterned media (hereinafter referred to as PM) in which a magnetic layer is patterned and the magnetic layer is physically divided into a plurality of regions have been proposed. 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, by pressing a mold having a concavo-convex shape on the surface against an imprint material applied on a substrate substrate, the concavo-convex shape of the mold is transferred to the imprint material, and the concavo-convex shape transferred imprint This is a method for obtaining a substrate having a concavo-convex shape on the surface by peeling the mold after solidifying the material. The nanoimprint method is described in Patent Document 1, for example. Patent Document 1 discloses a step of forming a transfer target (imprint material layer) on a flat substrate, a step of bringing a mold (mold) having a concavo-convex structure into contact with the transfer target, and pressurizing. Magnetic having a step of transferring a concavo-convex structure to the transferred body, a step of peeling the mold from the transferred body, and a step of depositing a magnetic recording layer on the transferred body having the concavo-convex structure of the mold transferred. A method for manufacturing a recording medium is described.

As described above, by using the nanoimprint method, it is possible to process even a pattern size in a region exceeding the diffraction limit of light, which is required in PM. 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. Accordingly, various types of peeling methods that do not cause such problems have been proposed. For example, there are methods described in Patent Document 2 and Patent Document 3.

In Patent Document 2, a pin module is inserted between a mold and a substrate after imprint molding is completed, and a slit is formed by separating a part of the mold and the substrate, and external air is passed between the mold and the substrate through this slit. Describes a method of separating the substrate from the mold by flowing it into the mold. Further, in Patent Document 3, in an imprint mold (mold) for forming a concavo-convex pattern, a plurality of through holes are formed outside the concavo-convex pattern region on the surface on which the concavo-convex pattern is formed, and the substrate and the imprint mold 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 forming a pattern between them.

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) using PM, the distance between the HDD substrate and the data reading head is only about 10 nm, and there is a protrusion due to scratches 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, if the pressure applied to the substrate from the plurality of through holes is not uniform, the balance is deteriorated, and the pattern may be damaged or deformed. It is not easy to apply uniform pressure from a plurality of through holes, and there is a problem in this respect.

JP 2007-95162 A JP 2007-118552 A JP 2008-78550 A

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide an imprint mold that can be easily peeled off without scratching the substrate, and a method for manufacturing an information recording medium substrate using the same. Is to provide.

The imprint mold according to the present invention has a through hole formed at a position corresponding to the central hole of the substrate base material when pressed against the molding material, and the through hole is smaller than the central hole. And the manufacturing method of the information recording medium board | substrate concerning this invention uses the above-mentioned imprint type | mold, presses this imprint type | mold against a molding material, makes a fluid flow in into the said center hole and the said through-hole, The imprint mold is peeled from the molding material by applying pressure to the surface of the imprint mold facing the central hole. For this reason, the imprint type according to the present invention and the method for manufacturing an information recording medium substrate using the same can be easily peeled without scratching the substrate.

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

It is sectional drawing which shows the structure of the imprint type | mold which concerns on embodiment of this invention. FIG. 2 is a diagram showing manufacturing steps of an information recording medium substrate using the imprint mold shown in FIG. 1, and FIGS. 2A to 2E are diagrams showing each step. It is sectional drawing which shows the structure of the imprint type | mold which concerns on other embodiment of this invention. FIGS. 4A to 4G are diagrams showing manufacturing steps of the information recording medium substrate using the imprint mold shown in FIG. 3, and FIGS. It is a figure for demonstrating the imprint mold release in the comparative example 1. FIG. FIGS. 6A and 6B are diagrams for explaining an imprint mold in Comparative Example 2, in which FIG. 6A is a plan view of the imprint mold, and FIG. 6B is a view taken along the line BB ′ in FIG. FIG. 6C is a cross-sectional view, and FIG. 6C is a view for explaining mold release.

Hereinafter, an embodiment according to the present invention will be described 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 suitably.

First, an imprint type according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing the configuration of an imprint mold according to an embodiment of the present invention. As shown in FIG. 1, an imprint mold 10 according to the present embodiment includes an upper mold 1 and a lower mold 2. The upper mold 1 and the lower mold 2 are formed with

transfer patterns

1b and 2b, which are fine structures for forming an uneven pattern on the imprint material (molding material). Further, in the upper mold 1, through holes 1 a are formed at locations corresponding to the center holes of the substrate base material in the pattern forming process of the information recording medium substrate on which the uneven pattern is formed by the imprint mold 10. Since the through-hole 1a is formed in the upper mold 1, in the pattern forming process, in a state where the imprint material and the imprint mold 10 are in close contact with each other, a liquid or gas that is a fluid flows from the through-hole 1a. By doing so, the imprint mold 10 can be uniformly peeled from the imprint material, and the imprint mold 10 can be easily released. The pattern forming process is a process in which the imprint mold 10 is pressed against the imprint material, and the imprint material is transferred with the

transfer patterns

1b and 2b, so that the imprint material has a concavo-convex pattern. It is in a state. In addition, the through-hole 1a should just be located in the range of the location which hits the center hole of a board | substrate base material, and the magnitude | size is smaller than a center hole. What is necessary is just to penetrate between the center hole and the outside of the imprint mold 10. Moreover, the through-hole 1a may be plural. Moreover, a through hole may be formed in the lower mold 2. In either case, both the upper mold 1 and the lower mold 2 can be easily peeled off. Note that only one of the

transfer patterns

1b and 2b may be formed. However, since the

transfer patterns

1b and 2b are transferred as an uneven pattern on the information recording medium substrate, when only one of the

transfer patterns

1b and 2b is formed, the uneven pattern is formed only on one side. An unrecorded information recording medium substrate is manufactured.

The imprint mold 10 may be manufactured by a known technique such as injection molding, dry etching, wet etching, photolithography, electron beam drawing (electron beam lithography), imprint method, or the like. For example, when injection molding or the like is used, the through-hole 1a may be formed simultaneously when forming the

transfer patterns

1b and 2b. Further, after forming the

transfer patterns

1b and 2b, the through holes 1a may be formed by machining or the like.

Next, a method for manufacturing an information recording medium substrate using the imprint mold according to this embodiment will be described. FIG. 2 is a diagram showing manufacturing steps of the information recording medium substrate using the imprint type according to the present embodiment, and FIGS. 2A to 2E are diagrams showing each step. As shown in FIG. 2A, the upper mold 1 and the lower mold 2 are arranged so as to sandwich a glass substrate 3 as a substrate base material. The

transfer patterns

1b and 2b are arranged on the glass substrate 3 side. In addition, especially if a substrate base material 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, it will restrict | limit. Not. For example, a quartz substrate or the like may be used instead of the glass substrate. Examples of the glass substrate 3 include a 2.5-inch glass substrate for HDD.

Next, as shown in FIG. 2B, imprinting is performed on the upper surface of the glass substrate 3 where the uneven pattern is formed and on the upper surface of the lower mold 2 where the transfer pattern 2b is formed. Material 4 is applied. As the imprint material 4, for example, a spin-on-glass (SOG) material is used. The coating method may be a known coating method, for example, drop coating with a dispenser or the like, spin coating or dip coating, or a wire bar and applicator. It may be a method of spreading.

Next, as shown in FIG. 2C, the glass substrate 3 including the imprint material 4 is sandwiched from above and below by the upper mold 1 and the lower mold 2 with a predetermined pressing force. Then, the imprint material 4 is dried. By doing so, the imprint material 4 is solidified, and the

transfer patterns

1 b and 2 b are 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. Moreover, as shown in FIG.2 (C), the through-hole 1a is located in the location which hits the center hole 7 of the glass substrate 3 which is a base material board | substrate. For example, when the glass substrate 3 is a 2.5-inch glass substrate for HDD, it has a donut shape with an outer diameter of 65 mm and an inner diameter of 20 mm. Therefore, the diameter of the center hole 7 is 20 mm. The through hole 1a is formed in a region corresponding to the 20 mm diameter portion of the central hole 7. The through-hole 1a is a circle having a size smaller than the diameter 20 mm of the center hole 7. The through hole 1 may have a shape other than a circle. Further, a plurality of through holes 1 a may be formed within the area of the center hole 7. 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 only needs to penetrate the center hole 7 and the outside of the imprint mold 10, for example, in the upper mold 1 and the lower mold 2 as in the side surfaces of the upper mold 1 and the lower mold 2 The center hole 7 may be penetrated between the surface on which the

transfer patterns

1b and 2b are formed and a surface other than the surface facing the surface. In consideration of ease of manufacture, the through hole 1a is preferably linear without meandering. Therefore, the through hole 1 a is preferably formed so as to penetrate between the center hole 7 and the outer main surface of the upper mold 1.

Next, as shown in FIG. 2 (D), a gas 5 as a fluid flows into the through hole 1a. Thereby, pressure is applied to the through-hole 1a and the center hole 7, and pressure is applied to the interface between the upper mold 1 and the lower mold 2 and the imprint material 4, so that the upper mold 1 and the lower mold 2 are imprint material 4 Is peeled off. In particular, for the upper mold, pressure is also applied to the surface facing the center hole 7. At this time, since pressure is applied to each part by the gas 5, the upper mold 1 and the lower mold 2 are peeled off with a uniform force, and are released from the center hole 7 in a concentric manner. Thereby, the concavo-convex pattern formed on the imprint material 4 is not destroyed or deformed. Further, since pressure is applied from the center hole 7, the upper mold 1 and the lower mold 2 are peeled off substantially simultaneously. The gas 5 is preferably a gas that can be easily used in any facility, such as air or nitrogen. As the gas 5, other gases may be used as long as they do not erode the microstructure formed on the glass substrate 3 and the imprint material 4. Further, a liquid that is a fluid may be used instead of the gas 5. 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, water is preferable because it can be easily obtained, but is not particularly limited as long as it does not erode the microstructure formed on the glass substrate 3 and the imprint material 4.

Next, as shown in FIG. 2 (E), a magnetic film 6 is formed on the imprint material 4 to manufacture an information recording medium substrate 8 having an uneven pattern 6a formed on the surface. As the magnetic film 6, for example, CoCrPt or FePt is used.

Next, an imprint mold according to another embodiment of the present invention, which is different from the above-described embodiment of the present invention, and an information recording medium substrate manufacturing method using the same will be described. FIG. 3 is a cross-sectional view showing the configuration of an imprint mold according to another embodiment of the present invention. FIG. 4 is a diagram showing a manufacturing process of an information recording medium substrate using an imprint type according to another embodiment of the present invention, and FIGS. 4 (A) to 4 (G) are diagrams showing each process. It is. 3 and 4, the same reference numerals as those in FIGS. 1 and 2 indicate the same configuration, and the description thereof is omitted.

First, an imprint configuration according to another embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3, an imprint mold 20 according to another embodiment of the present invention includes an upper mold 11 and a lower mold 12. The upper mold 11 and the lower mold 12 are formed with

transfer patterns

11b and 12b, which are fine structures for forming an uneven pattern on the imprint material. Further, in the upper mold 11 and the lower mold 12, through

holes

11a and 12a are formed at locations corresponding to the center hole of the substrate base material in the pattern forming process of the information recording medium substrate in which the uneven pattern is formed by the imprint mold 20. Has been. Since the through

holes

11a and 12a are formed in the upper mold 11 and the lower mold 12, in a state where the imprint material and the imprint mold 20 are in close contact with each other in the pattern forming process, the through

holes

11a and 12a For example, by flowing a fluid such as liquid or gas, the imprint mold 20 can be uniformly peeled from the imprint material, and the imprint mold 20 can be easily released. The through

holes

11a and 12a only need to be located within the range of the location corresponding to the center hole of the substrate base material, and the size thereof is smaller than that of the center hole. Further, there may be a plurality of through

holes

11a and 12a. Note that only one of the

transfer patterns

11b and 12b may be formed. However, since the

transfer patterns

11b and 12b are transferred as an uneven pattern of the information recording medium substrate, when only one of the

transfer patterns

11b and 12b is formed, the uneven pattern is formed only on one side. An information recording medium substrate that is not formed is manufactured.

The imprint mold 20 may be manufactured by a known technique such as injection molding, dry etching, wet etching, photolithography, electron beam drawing (electron beam lithography). The through

holes

11a and 12a may be formed by the same process as the

transfer patterns

11b and 12b, or may be formed by machining or the like after the

transfer patterns

11b and 12b are formed.

Next, a method for manufacturing an information recording medium substrate using an imprint type according to another embodiment of the present invention will be described with reference to FIG. In this manufacturing method, an optical imprint method is used. As shown in FIG. 4A, the upper mold 11 and the lower mold 12 are arranged so as to sandwich the glass substrate 3 which is a substrate base material having a magnetic film 14 formed on both main surfaces. The

transfer patterns

11b and 12b are arranged so as to be on the magnetic film 14 side. As the magnetic film 14, for example, CoCrPt or FePt is used.

Next, as shown in FIG. 4B, the transfer pattern 12b is formed on the upper surface of the glass substrate 3 including the magnetic film 14 where the concave / convex pattern is formed and on the upper surface of the lower mold 12. The imprint material 15 is applied to the location. Since the photoimprint method is used, as the imprint material 15, for example, a photocurable resin material is used. The coating method may be a known coating method, for example, drop coating with a dispenser or the like, spin coating or dip coating, or a wire bar and applicator. It may be a method of spreading.

Next, as shown in FIG. 4C, the glass substrate 3 including the imprint material 15 and the magnetic film 14 is sandwiched from above and below by the upper mold 11 and the lower mold 12 with a predetermined pressing force. Then, light such as ultraviolet light is irradiated to cure the imprint material 15. By doing so, the imprint material 15 is solidified, and the

transfer patterns

11b and 12b are transferred to the imprint material 15 (optical imprint method). That is, an uneven pattern is formed on the imprint material 15. Moreover, as shown in FIG.4 (C), the through-

holes

11a and 12a are located in the location which hits the center hole 17 of the glass substrate 3 which is a substrate base material. For example, when the glass substrate 3 is a 2.5-inch glass substrate for HDD, it has a donut shape with an outer diameter of 65 mm and an inner diameter of 20 mm. Therefore, the diameter of the center hole 17 is 20 mm. The through

holes

11a and 12a are formed in a region corresponding to the 20 mm diameter portion of the center hole 17. The through

holes

11a and 12a have a circular shape smaller than the diameter 20 mm of the center hole 17. The through

holes

11a and 12a may have a shape other than a circle. Further, a plurality of through

holes

11 a and 12 a may be formed in each of the upper mold 11 and the lower mold 12 within this region. Further, the sizes of the through

holes

11a and 12a may be changed in the middle, and the plurality of through

holes

11a and 12a may be coupled to one through

hole

11a and 12a in the middle. Further, since the through

holes

11a and 12a only need to penetrate the center hole 17 and the outside of the imprint mold 20, the upper mold 11 and the lower mold, for example, as the side surfaces of the upper mold 11 and the lower mold 12 are used. 12 may be formed between the center hole 17 and a surface other than the surface on which the

transfer patterns

11b and 12b are formed and the surface facing the surface. In consideration of ease of manufacture, the through

holes

11a and 12a are preferably linear without meandering. Therefore, the through

holes

11a and 12a are preferably formed to penetrate between the center hole 17 and the outer main surfaces of the upper mold 11 and the lower mold 12, respectively.

Next, as shown in FIG. 4D, a gas 16 that is a fluid flows into the through

holes

11a and 12a. Thereby, pressure is applied to the through

holes

11 a and 12 a and the center hole 17, and pressure is also applied to the surfaces of the upper mold 11 and the lower mold 12 facing the center hole 17. Accordingly, pressure is applied to the interface between the upper mold 11 and the lower mold 12 and the imprint material 15, so that the upper mold 11 and the lower mold 12 are peeled from the imprint material 15. At this time, since pressure is applied to each part by the gas 16, the upper mold 11 and the lower mold 12 are peeled off with a uniform force, and are released from the central hole 17 uniformly in a concentric manner. Thereby, the concavo-convex pattern formed on the imprint material 15 is not destroyed or deformed. Further, since pressure is applied from the center hole 17, the upper mold 1 and the lower mold 12 are peeled off substantially simultaneously. Note that the gas 16 is preferably a gas that can be easily used in any facility, such as air or nitrogen. The gas 16 may be other gas as long as it does not erode the microstructure formed on the glass substrate 3 and the imprint material 15. Further, a liquid that is a fluid may be used instead of the gas 16. Even in such a case, since the pressure is uniformly applied to each part, the same effect as the gas 16 is obtained. As the liquid, for example, water is preferable because it can be easily obtained. However, the liquid is not particularly limited and may be any liquid that does not erode the fine structure formed on the glass substrate 3, the magnetic film 14, and the imprint material 15. That's fine. In addition, even if the gas 16 does not flow in from both the through

holes

11a and 12a, as long as pressure is applied to the center hole 17, the gas 16 may flow from either one and be discharged from the other.

Next, as shown in FIG. 4E, the imprint material 15 which is a photocurable resin and has a fine structure is dry-etched using, for example, a gas containing oxygen, so that the magnetic film 14 is formed. Exposed.

Next, as shown in FIG. 4F, the magnetic film 14 is etched by dry etching using, for example, argon using the imprint material 15 remaining on the magnetic film 14 as a mask. A fine structure is formed.

Next, as shown in FIG. 4 (G), the imprint material 15 is removed, and the information recording medium substrate 18 having the uneven pattern 14a formed on the magnetic film 14 on the surface is manufactured.

Hereinafter, an imprint mold according to the above-described embodiment of the present invention and a method of manufacturing an information recording medium substrate using the same, an imprint mold according to another embodiment of the present invention, and an information recording medium substrate using the same An example (Examples 1 to 3) in which the manufacturing method is specifically implemented will be described. Further, examples (Comparative Examples 1 and 2) in which an imprint type as a comparative example and an information recording medium substrate manufacturing method 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, an imprint mold 10 including an upper mold 1 and a lower mold 2 in which a fine structure was formed by injection molding using polymethylpentene resin was used. The upper mold 1 and the lower mold 2 were each disk-shaped with an outer diameter of 65 mm. A through-hole 1a having a diameter of 10 mm is formed at the center of the upper mold 1, and the upper mold 1 has a donut shape. The

transfer patterns

1b and 2b having a fine structure are formed on one side of each of the upper mold 1 and the lower mold 2, and are formed in a region having a radius of 10 mm or more from the center. The through holes 1a and the

transfer patterns

1b and 2b are formed by injection molding.

Next, a 2.5-inch glass substrate 3 for HDD (outer diameter 65 mm, inner diameter 20 mm) was prepared, and the glass substrate 3 was disposed so as to be sandwiched between the upper mold 1 and the lower mold 2 (see FIG. 2A). ). Then, 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 is applied on the glass substrate 3 and the lower mold 2 with a dispenser of 100 microliters each. (See FIG. 2B). The imprint material 4 was applied on the lower mold 2 with the transfer pattern 2b, and on the glass substrate 3, it was applied to a location corresponding to the transfer pattern 1b in the pattern forming step. Thereafter, the imprint material 4 was dried and cured in a state where the glass substrate 3 was pressed at 1 MPa with the upper mold 1 and the lower mold 2 (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 upper mold 1 and the lower mold 2 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.

Finally, a magnetic film 6 was formed on the imprint material 4 to form a patterned media hard disk drive substrate (information recording medium substrate 8) (see FIG. 2E).

(Example 2)
Example 2 will be described with reference to FIGS. 3 and 4. As shown in FIG. 3, first, an imprint mold 20 including an upper mold 11 and a lower mold 12 in which a microstructure is formed by injection molding using a polycarbonate resin was used. Each of the upper mold 11 and the lower mold 12 was a disk having an outer diameter of 65 mm. Through

holes

11a and 12a having a diameter of 10 mm are formed at the centers of the upper mold 11 and the lower mold 12, and the upper mold 11 and the lower mold 12 have a donut shape. The

transfer patterns

11b and 12b having a fine structure are formed on one side of each of the upper mold 1 and the lower mold 2, and are formed in a region having a radius of 10 mm or more from the center.

Next, what prepared the magnetic film 14 on both main surfaces of the 2.5-inch glass substrate 3 (outer diameter 65 mm, inner diameter 20 mm) for HDD is prepared, and the glass substrate 3 including this magnetic film 14 is the upper mold 11. And it arrange | positioned so that it may pinch | interpose with the lower mold | type 12 (refer FIG. 4 (A)). Then, on the glass substrate 3 including the magnetic film 14 and the lower mold 2, 100 μL each of a solution of PAK-02 (manufactured by Toyo Gosei Co., Ltd.), which is a photocurable resin, is used as the imprint material 4. (See FIG. 4B). The imprint material 4 is applied to the transfer pattern 2b on the lower mold 2 and applied to the portion corresponding to the transfer pattern 11b in the pattern forming process on the glass substrate 3 including the magnetic film 14. It was. Thereafter, the imprint material 15 is irradiated with light in a state where the glass substrate 3 including the imprint material 15 and the magnetic film 14 is sandwiched between the upper mold 11 and the lower mold 12, and the imprint material 15 is cured (FIG. 4 ( C)). After the imprint material 4 was cured, nitrogen as the gas 5 was sealed through the through

holes

11a and 12a, and release was performed. As a result, the upper mold 11 and the lower mold 12 were uniformly released (FIG. 4D). reference).

The fine structure which was the uneven | corrugated pattern transcribe | transferred to the imprint material 15 after mold release was observed. As a result of observing the surface shape of the imprint material 15 with an interferometer, no defect caused by a physical scratch or the like was 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.

Thereafter, the fine structure layer of the imprint material 15 which is a photocurable resin was etched by dry etching until the magnetic film 14 was exposed on the bottom surface of the fine structure layer (see FIG. 4E). Then, the magnetic film 14 is etched by dry etching using the imprint material 15 that is the remaining photocurable resin as a mask (see FIG. 4F). Finally, the imprint material 15 that is the photocurable resin is removed. The hard disk drive substrate for patterned media (information recording medium substrate 18) was removed (see FIG. 4G).

(Example 3)
Embodiment 3 will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, first, a zeonore (made by Nippon Zeon Co., Ltd.), which is a cycloolefin resin, is provided with an upper mold 1 and a lower mold 2 formed with a fine structure using a thermal imprint method. The imprint mold 10 was used. The upper mold 1 and the lower mold 2 were each disk-shaped with an outer diameter of 65 mm. A through hole 1a having a diameter of 10 mm is formed in the center of the upper mold 1 by machining, and the upper mold 1 has a donut shape. The

transfer patterns

1b and 2b having a fine structure are formed on one side of each of the upper mold 1 and the lower mold 2, and are formed in a region having a radius of 10 mm or more from the center.

Next, a 2.5-inch glass substrate 3 (outer diameter 65 mm, inner diameter 20 mm) for HDD was prepared, and the glass substrate 3 was disposed so as to be sandwiched between the upper mold 1 and the lower mold 2 (see FIG. 2A). ). Then, 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 is applied on the glass substrate 3 and the lower mold 2 with a dispenser of 100 microliters each. (See FIG. 2B). The imprint material 4 was applied to the transfer pattern 2b on the lower mold 2 and applied to the portion corresponding to the transfer pattern 1b in the pattern forming process on the glass substrate 3. Thereafter, the imprint material 4 was dried and cured in a state where the glass substrate 3 including the imprint material 4 was pressed at 1 MPa with the upper mold 1 and the lower mold 2 (see FIG. 2C). After the imprint material 4 was cured, pure water was sealed in place of the gas 5 through the through-hole 1a, and the mold was released. As a result, the upper mold 1 and the lower mold 2 could be uniformly released (FIG. 2D). reference).

Finally, a magnetic film 6 was formed on the imprint material 4 to obtain a patterned media hard disk drive substrate (information recording medium substrate 8) (see FIG. 2E).

(Comparative Example 1)
An imprint type of Comparative Example 1 and an information recording medium substrate manufacturing method using the same will be described with reference to FIG. FIG. 5 is a view for explaining imprint mold release in Comparative Example 1. FIG. FIG. 5 is a diagram corresponding to FIG. In Comparative Example 1, release is performed using a pin module.

In Comparative Example 1, an imprint mold 101 having a disk-shaped upper mold and a lower mold having an outer diameter of 65 mm, in which a microstructure was formed by injection molding using a polycarbonate resin, was used. On one main surface of the upper mold and the lower mold of the imprint mold 101, a transfer pattern having a fine structure is formed in a region having a radius of 10 mm or more from each center.

First, a 2.5-inch glass substrate 103 for HDD (outer diameter 65 mm, inner diameter 20 mm) is prepared by forming a magnetic film 104 on both main surfaces, and the glass substrate 103 including the magnetic film 104 is an imprint mold 101. It is arranged so as to be sandwiched between the upper mold and the lower mold. A solution of PAK-02 (manufactured by Toyo Gosei Co., Ltd.), which is a photocurable resin, is used as the imprint material 105 on the glass substrate 103 including the magnetic film 104 and the lower mold of the imprint mold 101, respectively. Microliters were applied with a dispenser. The imprint material 105 was applied to the transfer pattern on the lower mold, and the glass substrate 103 including the magnetic film 104 was applied to a location corresponding to the transfer pattern in the pattern forming process. Thereafter, the imprint material 105 is cured by irradiating the imprint material 105 with light while the glass substrate 103 including the imprint material 105 and the magnetic film 104 is sandwiched between the upper mold and the lower mold of the imprint mold 101.

Then, as shown in FIG. 5, the pin module 102 is inserted into the interface between the imprint mold 101 and the imprint material 105, and a gap is generated between the mold and the substrate by physical force. The mold was peeled off.

The fine structure transferred to the imprint material 105 after release was observed. As a result of observing the surface shape with an interferometer, an abnormality in interference fringes, which is considered to be caused by scratches when the pin module 102 was inserted, was found in the portion where the pin module was inserted in the outer peripheral portion. As a result of observing the corresponding portion with a Nomarski microscope, it was found that the magnetic film 104 including the imprint material 105 and the glass substrate 103 were damaged.

(Comparative Example 2)
An imprint type of Comparative Example 2 and an information recording medium substrate manufacturing method using the same will be described with reference to FIG. 6A and 6B are diagrams for explaining the imprint type in Comparative Example 2. FIG. 6A is a plan view of the imprint type, and FIG. It is B 'arrow sectional drawing, FIG.6 (C) is a figure for demonstrating mold release. A through hole is formed in the imprint mold of Comparative Example 2, but the position is within the transfer pattern region.

As shown in FIGS. 6A and 6B, the upper mold 111 of the imprint mold in Comparative Example 2 is a disc shape having an outer diameter of 65 mm formed by injection molding of polymethylpentene resin. Four through-holes 117 are formed at a position 20 mm from the center of the mold 111 so as to be 90-degree rotationally symmetric. The diameter of these through holes 117 is 5 mm. As shown in FIG. 6B, the through hole 117 penetrates between the transfer pattern forming region formed on one main surface of the upper mold 111 and the other main surface. Note that the lower mold 112 (see FIG. 6C) has a disk shape with an outer diameter of 65 mm formed by injection molding of polymethylpentene resin, similarly to the upper mold 111. Note that the transfer pattern having a fine structure is formed on one surface of each of the upper mold 111 and the lower mold 112, and is formed in a region having a radius of 10 mm or more from the center. The through holes 117 and these transfer patterns are formed by injection molding.

Next, a 2.5-inch glass substrate 113 (outer diameter 65 mm, inner diameter 20 mm) for HDD is prepared, and the glass substrate 113 is disposed so as to be sandwiched between the upper mold 111 and the lower mold 112. 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 114 on each 112 by a dispenser. The imprint material 114 was applied to the transfer pattern on the lower mold 112, and was applied to the portion corresponding to the transfer pattern in the pattern forming process on the glass substrate 113. Thereafter, the imprint material 114 was dried and cured in a state where the glass substrate 113 including the imprint material 114 was pressed at 1 MPa with the upper mold 111 and the lower mold 112. Then, as shown in FIG. 6C, after the imprint material 114 was cured, compressed air as the gas 115 was sealed through the through hole 117, and the mold release was performed. However, although the upper mold 111 in which the through hole 117 was formed was released, the lower mold 112 in which the through hole was not formed was not released. Further, a fine structure transferred to the released imprint material 114 on the upper mold 111 side was observed. As a result of observing the surface state with an interferometer, an abnormality of interference fringes was observed near the location corresponding to one of the through holes 117 of the upper mold 111. As a result of observing the portion with a Nomarski microscope, it was found that the imprint material 114 was damaged. This is because when the upper mold 111 is released, the balance of the compressed air sealed from the four through holes 117 is lost, and the release near the place corresponding to the one through hole 117 is delayed from the other places. It is presumed that the release force that collapsed worked concentrated on the place.

This specification discloses various modes of technology as described above, and the main technologies are summarized below.

An imprint mold according to one aspect is an imprint mold that forms a concavo-convex pattern on a molding material that forms a substrate substrate having a center hole, and is pressed against the molding material, whereby the concavo-convex pattern is formed on the molding material. And a through hole is formed at a position corresponding to the center hole when pressed against the molding material, and the through hole is smaller than the center hole.

According to this configuration, an imprint mold that does not damage the formed pattern or the like by, for example, flowing a fluid such as gas or liquid into the through-hole when peeling from the molding material is realized. Since this imprint mold can be peeled off by applying pressure to the interface between the imprint mold and the molding material with a fluid, the pattern formed by the transfer is not damaged. In addition, since pressure can be uniformly applied to the interface between the imprint mold and the molding material, the imprint mold is less likely to be deformed or broken. In addition, since pressure is applied uniformly and concentrically from the center hole of the substrate base material to the outer periphery, pressure is applied in order from the center of the substrate base material to the outer periphery. Peel evenly. Further, since pressure is applied by the fluid from the center hole, the molding material on both main surfaces of the substrate base material, even if the imprint mold has a structure in which the substrate base material on which the molding material is formed on both main surfaces is sandwiched The imprint mold is peeled off uniformly. Therefore, the pattern is hardly damaged.

An information recording medium substrate manufacturing method according to an aspect is an information recording medium substrate manufacturing method using the imprint mold, wherein the molding is performed on a surface of the substrate base material or a pattern surface of the imprint mold. A step of applying a material; a step of pressing the imprint mold against the substrate base material with the molding material interposed therebetween; and the center hole and the through hole after pressing the imprint mold against the molding material And a step of peeling the imprint mold from the molding material by injecting a fluid into the mold and applying pressure to the surface of the imprint mold facing the center hole.

According to this configuration, when the imprint mold is peeled off from the molding material, it is peeled off by applying a pressure to the interface between the imprint mold and the molding material, so that the pattern formed by the transfer may be damaged. Absent. In addition, since pressure can be uniformly applied to the interface between the imprint mold and the molding material, this manufacturing method is unlikely to cause pattern deformation or destruction. In addition, since pressure is applied uniformly and concentrically from the center hole of the substrate base material toward the outer periphery, pressure is applied in order from the center of the substrate base material to the outer periphery. The imprint mold is peeled uniformly. Further, since pressure is applied by the fluid from the center hole, the molding material on both main surfaces of the substrate base material, even if the imprint mold has a structure in which the substrate base material on which the molding material is formed on both main surfaces is sandwiched The imprint mold is peeled off uniformly. Therefore, in this manufacturing method, the pattern is hardly damaged.

Also, in one aspect, in the above-described method for manufacturing an information recording medium substrate, preferably, two imprint molds are used at the same time, and an uneven pattern made of the molding material is formed on both surfaces of the substrate base material.

According to this configuration, a pattern can be formed on both surfaces of the substrate base material by transfer.

Moreover, in one aspect, in the above-described method for manufacturing an information recording medium substrate, preferably, the imprint mold is used to simultaneously form an uneven pattern of the molding material on one surface of the substrate base material with the imprint mold. Is to form a concavo-convex pattern of the molding material on the other surface of the substrate base material by a second imprint mold which is different in that no through hole is formed.

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

According to this configuration, water that is relatively easily available and less likely to erode the substrate substrate or the like is used as the fluid, so that the mold can be released at low cost.

In one aspect, in the above-described method for manufacturing an information recording medium substrate, preferably, the fluid is air or nitrogen.

According to this configuration, since air or nitrogen that can be easily obtained as a fluid and is less likely to erode the substrate base material or the like is used, mold release can be performed at low cost.

This application is based on Japanese Patent Application No. 2008-248977 filed on Sep. 26, 2008, the contents of which are included in this application.

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. Accordingly, 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. It is interpreted that it is included in

According to the present invention, it is possible to provide an imprint type and an information recording medium substrate manufacturing method using the same.

Claims

An imprint mold for forming a concavo-convex pattern on a molding material for forming a substrate substrate having a central hole,
By being pressed against the molding material, it has a transfer pattern that forms the uneven pattern on the molding material by transfer,
A through hole is formed at a position corresponding to the center hole when pressed against the molding material, and the through hole is smaller than the center hole.
A method of manufacturing an information recording medium substrate using the imprint mold according to claim 1,
Providing the molding material on the surface of the substrate substrate or the pattern surface of the imprint mold; and
Pressing the imprint mold against the substrate substrate with the molding material in between,
After the imprint mold is pressed against the molding material, a fluid is caused to flow into the central hole and the through hole, and pressure is applied to the surface of the imprint mold facing the central hole to remove the molding material from the molding material. A method for producing an information recording medium substrate, comprising: removing the imprint mold.
3. The method for manufacturing an information recording medium substrate according to claim 2, wherein two imprint molds are used simultaneously to form a concavo-convex pattern of the molding material on both surfaces of the substrate base material.
A concave / convex pattern made of the molding material is formed on one surface of the substrate base material by the imprint mold, and at the same time, the substrate differs depending on the second imprint mold which is different from the imprint mold in that a through hole is not formed. The method for producing an information recording medium substrate according to claim 2, wherein the uneven pattern made of the molding material is formed on the other surface of the base material.
The method for manufacturing an information recording medium substrate according to claim 2, wherein the fluid is water.
3. The method of manufacturing an information recording medium substrate according to claim 2, wherein the fluid is air or nitrogen.