JP5538681B2 - Optical imprint mold, optical imprint method, magnetic recording medium, and manufacturing method thereof - Google Patents

Description

  The present invention relates to an optical imprint mold that can be easily aligned when optically imprinting both surfaces of a substrate at the same time, an optical imprint method using the optical imprint mold, a magnetic recording medium, and a manufacturing method thereof.

When producing discrete media (DTM) and patterned media (BPM) by the optical imprint method, it is very important to accurately align the transfer pattern with respect to the center of the disc in order to improve servo performance. . Therefore, various proposals have been made regarding the alignment method in the optical imprint method (see Patent Documents 1 to 3). Each of these proposals involves the alignment of one surface of the substrate with the mold and optical imprinting, and has a problem of poor throughput.
Therefore, a method of simultaneously optically imprinting both the front and back surfaces of a substrate using a set of optical imprinting molds has been studied. However, this method has a problem that it is difficult to align a pair of optical imprint molds located on both sides. Moreover, since the mold for optical imprinting is transparent, it is difficult to discriminate between the front and the back. Furthermore, there is a problem that it is difficult to determine the angular coordinates of a fine servo pattern from the appearance.

JP 2006-286871 A JP 2007-234153 A JP 2007-190734 A

An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention makes it possible to align the molds located on both sides of the substrate, perform optical imprinting on both sides simultaneously with high accuracy, and improve the throughput, and the optical imprinting mold. It is an object of the present invention to provide an optical imprint method using a mold, a magnetic recording medium, and a method for manufacturing the magnetic recording medium.
In addition, the present invention makes it easy to discriminate between the front and back of the mold, can reduce errors in the process, makes it possible to match the angular coordinates of the front and back patterns, and the desired servo signal on the mold. An object of the present invention is to provide an optical imprint mold in which the position is clear and the target portion can be easily observed, an optical imprint method using the optical imprint mold, a magnetic recording medium, and a method for manufacturing the magnetic recording medium. And

Means for solving the above problems are as follows. That is,
<1> A set of optical imprint molds for forming a concavo-convex pattern on both surfaces of a substrate coated with a resin composition,
The set of optical imprint molds has at least two alignment marks for determining the relative positional relationship of the set of optical imprint molds on both sides of the substrate during imprinting,
The alignment mark is provided in a non-contact region where the mold and the substrate do not come into contact with each other.
<2> The mold for optical imprinting according to <1>, wherein the non-contact region is a region exceeding the outer extension of the substrate and extending to the outer peripheral edge of the mold.
<3> The optical imprint mold according to any one of <1> to <2>, wherein the non-contact region is a central opening of the substrate.
<4> The optical imprint mold according to any one of <1> to <3>, wherein the alignment mark has a shape capable of distinguishing the front and back of the mold.
<5> The optical imprint mold according to <4>, wherein the alignment mark has an asymmetric shape with respect to the radial axis of the mold.
<6> The device according to any one of <1> to <5>, which has a concavo-convex pattern for manufacturing a discrete medium and a patterned medium, and can determine angular coordinates of a specific servo pattern from the position of an alignment mark. This is a mold for optical imprinting.
<7> Alignment is performed using the optical imprint mold according to any one of <1> to <6>, and the uneven pattern is imprinted on both surfaces of the substrate on which the resin composition is applied. The optical imprint method.
<8> The mold structure is formed by pressing the optical imprint mold according to any one of <1> to <6> against an imprint resist layer formed on a substrate of a magnetic recording medium. A transfer process for transferring the concavo-convex pattern;
Using the imprint resist layer to which the concavo-convex pattern is transferred as a mask, the magnetic layer formed on the surface of the substrate of the magnetic recording medium is etched to form a magnetic pattern portion based on the concavo-convex pattern in the magnetic layer. A magnetic pattern portion forming step;
And a non-magnetic pattern portion forming step of embedding a non-magnetic material in the concave portion formed on the magnetic layer.
<9> A magnetic recording medium produced by the method for producing a magnetic recording medium according to <8>.

  According to the present invention, conventional problems can be solved, alignment of molds located on both sides of a substrate can be performed, optical imprinting can be performed with high accuracy at the same time on both sides, throughput is improved, and front and back sides are improved. Can be easily identified, process errors can be reduced, the angular coordinates of the front and back patterns can be matched, and the position of the desired servo signal on the mold can be clarified, and the target location can be observed. It is possible to provide a mold for optical imprinting, a method for optical imprinting using the mold for optical imprinting, a magnetic recording medium, and a method for manufacturing the magnetic recording medium.

(Mold for optical imprint)
The mold for optical imprinting of the present invention is a set of molds for forming a concavo-convex pattern on both surfaces of a substrate coated with a resin composition, and is preferably a pair of molds. The set of molds is used to imprint a concavo-convex pattern on both surfaces of the substrate, but each mold can also be optically imprinted with a concavo-convex pattern on only one surface of the substrate. .

Each of the set of optical imprint molds has at least two alignment marks for determining the relative positional relationship of the set of optical imprint molds on both surfaces of the substrate during imprinting.
The alignment mark is provided in a non-contact area where the mold and the substrate do not contact.

<Alignment mark>
The alignment mark is provided on both of the set of optical imprint molds, thereby enabling alignment between the substrate and the set of molds.
The number, size, shape, position, etc. of the alignment marks are not particularly limited and can be appropriately selected according to the purpose. The number of the alignment marks is at least 2 in each optical imprint mold. 2 to 4 are preferable. If the number of alignment marks is less than 2, it may be difficult to align the substrate and the set of molds.

The position of the alignment mark is provided in a non-contact region where the mold and the substrate do not contact, and may be on either the front side or the back side of the mold. Here, the front side of the mold means the surface having the transfer pattern.
Examples of the non-contact region include (1) a region exceeding the outer extension of the substrate and extending to the outer peripheral edge of the mold, and (2) a central opening of the substrate. It is preferable to have at least two alignment marks in at least one of the areas (1) and (2).
The shape of the alignment mark is not particularly limited and may be appropriately selected depending on the purpose. For example, the alignment mark may be a line, circle, arc, cross, U-shape, triangle, quadrangle, arrow, character, symbol, etc. Is mentioned. Among these, it is preferable that the shape is asymmetrical with respect to the radial axis of the substrate because the front and back of the mold can be distinguished.
Examples of the asymmetric shape with respect to the radial axis of the substrate include shapes as shown in FIGS. In the case of the alignment marks having the shapes shown in FIGS. 1 to 4, since the shapes are different from those seen from the back side of the mold and those seen from the front side of the mold, it is possible to easily distinguish the front and back sides of the mold. .

The optical imprint mold preferably has a concavo-convex pattern for producing the discrete medium and the patterned medium, and can determine the angular coordinates of a specific servo pattern from the position of the alignment mark. As a result, when an error occurs during inspection of the medium after manufacturing, the error occurrence position is specified from the servo signal, and then the pattern corresponding to the error occurrence position on the mold is inspected for defects such as missing or clogged. It becomes easy.
The angular coordinates of the specific servo pattern include circumferential position information defined by sector servo signals. The sector servo signal refers to a servo signal that represents a circumferential position recorded at the head of each sector when the disk is equally divided into areas called sector-shaped sectors in a positioning control system called a sector servo system. .
Examples of the alignment mark material include an uneven pattern on a mold, a metal film pattern, and a phosphor pattern.
The size of the alignment mark can be appropriately selected according to the purpose, and is preferably 1 μm or more, and more preferably 10 μm or more. If the size of the alignment mark is less than 1 μm, detection with a microscope becomes difficult and there is a possibility that the alignment cannot be performed accurately.

A method for forming the alignment mark is not particularly limited and may be appropriately selected according to the purpose. For example, a method using a known photolithography technique and an etching technique, a method using a nanoimprint technique, and the like. Can be mentioned.
An optical imprint method (including alignment) using the alignment mark will be described later.

<Board>
The shape, structure, size, material and the like of the substrate are not particularly limited and can be appropriately selected according to the purpose. For example, the shape is a circle when an information recording medium is used. It is plate-shaped. Further, the structure may be a single layer structure or a laminated structure. In addition, the material can be appropriately selected from those known as substrate materials, and examples thereof include nickel, aluminum, glass, silicon, quartz, and transparent resin. These board | substrate materials may be used individually by 1 type, and may use 2 or more types together. Among these, quartz, glass and transparent resin are preferable from the viewpoint of transparency, and quartz is particularly preferable.
The substrate may be appropriately synthesized or a commercially available product may be used.
There is no restriction | limiting in particular as thickness of the said board | substrate, According to the objective, it can select suitably, 50 micrometers or more are preferable and 100 micrometers or more are more preferable. When the thickness of the substrate is less than 50 μm, there is a possibility that bending occurs on the mold side when the workpiece and the mold are in close contact, and a uniform contact state cannot be ensured.

<Resin composition>
There is no restriction | limiting in particular as said resin composition, Although it can select suitably according to the objective, It is preferable that it is an ultraviolet curable resin composition which can be hardened | cured by ultraviolet irradiation and can form a resin layer.
The ultraviolet curable resin composition contains at least an ultraviolet curable resin, a reactive diluent, and a photopolymerization initiator, and further contains other components as necessary.

  There is no restriction | limiting in particular as said ultraviolet curable resin, According to the objective, it can select suitably, For example, using acrylate-type resin, such as urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, is used. it can. Among these, epoxy (meth) acrylate has a function of improving the hardness and curing rate of the cured product, and therefore it is preferable to use it in combination with at least one of urethane (meth) acrylate and polyester (meth) acrylate.

  There is no restriction | limiting in particular as said reactive diluent, According to the objective, it can select suitably, For example, the (meth) acrylate compound etc. which have at least 1 (meth) acryloyl group in 1 molecule are mentioned. As these components, either a monofunctional compound having only one (meth) acryloyl group, or a polyfunctional compound having two or more compounds may be used, and adjustment of viscosity or reactivity of the resin, or curing. For the purpose of controlling physical properties such as the elastic modulus and glass transition temperature of the object, they may be used in an appropriate ratio.

  The photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1- ON, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one, 2-methyl- [4- (methylthio) Phenyl] -2-morpholino-1-propanone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, isopropyl Luthioxanthone, phenylglyoxylic acid methyl ester, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together.

<Mold for optical imprint>
The optical imprint mold is not particularly limited and may be appropriately selected depending on the intended purpose.For example, a disk-shaped substrate and one surface of the substrate may have a plurality of protrusions on the basis of the surface. It has a concavo-convex part formed by arranging the parts, and further has other configurations as necessary.

The material of the mold is not particularly limited as long as it has transparency, and can be appropriately selected according to the purpose. However, any material of quartz and transparent resin is preferable.
Examples of the resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), and a low melting point fluororesin.
The mold preferably has a transmittance of 30% or more with respect to ultraviolet rays, and quartz is particularly preferable from the viewpoint of ultraviolet radiation.

Here, FIG. 5 is a partial perspective view showing a configuration in an embodiment of the mold. Note that the alignment mark is omitted in the mold of FIG.
As shown in FIG. 5, the mold 1 has a plurality of convex portions 3 a and concave portions 3 b formed concentrically on one surface 2 a (hereinafter sometimes referred to as a reference surface 2 a) of a disc-shaped substrate 2. Become. In this case, the convex portion 3 a and the concave portion 3 b formed between the plurality of convex portions 3 a are collectively referred to as the concave and convex portion 3.
The thickness of the substrate 2 is preferably 0.1 mm or more and 10 mm or less. If the thickness of the substrate is less than 0.1 mm, the workpiece and the mold may be bent on the mold side when in close contact, and a uniform contact state may not be ensured. Since the elastic deformation of the mold is small when the object and the mold are in close contact with each other, the object to be processed is greatly deformed and the object to be processed is damaged, or a pressure is applied locally, and pattern damage may occur. .
Moreover, the cross-sectional shape of the recessed part 3b in the radial direction of the said concentric circle (direction where the convex part 3a is arranged in a line) has comprised the rectangle, for example.
The cross-sectional shape of the recess 3b is not limited to a rectangle, and an arbitrary shape can be selected by controlling an etching process described later according to the purpose.
In the present invention, the “cross section (shape)” refers to a cross section (shape) in the radial direction of the concentric circles (the direction in which the convex portions 3a are arranged) unless otherwise specified.

(Optical imprint method)
In the optical imprinting method of the present invention, alignment is performed using the optical imprinting mold of the present invention, and a concavo-convex pattern is imprinted on both surfaces of the substrate.

In the photoimprint method of the present invention, an ultraviolet curable resin composition is applied to both the front and back surfaces of the substrate to form an imprint resist layer. Next, the concave / convex pattern of the mold is pressed against the imprint resist layer, and ultraviolet rays are irradiated to cure the ultraviolet curable resin composition. At this time, since at least two alignment marks for determining the relative positional relationship between the molds located on both surfaces are provided in the non-contact region between the substrate and the mold, the alignment between the substrate and the mold can be easily performed.
The alignment of the alignment mark is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include visual observation, observation with a microscope, observation with a CCD camera, and the like.

  The method for applying the ultraviolet curable resin composition to both surfaces of the substrate is not particularly limited and can be appropriately selected depending on the purpose. For example, spin coating, casting, roll coating, flow coating, printing Method, dip coating method, cast film forming method, bar coating method, gravure printing method and the like.

-UV irradiation-
The ultraviolet irradiation is preferably performed uniformly on both sides of the substrate. Examples of the ultraviolet light source, a high-pressure mercury lamp, a metal halide lamp or the like is used, for example, irradiation energy of 100mJ ^/ cm ² ~2,000mJ ^/ cm 2 at a wavelength of 365 nm.

  The optical imprinting method of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. .

Here, an optical imprint method using the optical imprint mold of the present invention will be described with reference to the drawings.
FIG. 6A is a plan view showing a state in which positioning is performed when optical imprinting is performed using the optical imprinting mold of the present invention, and FIG. 6B is a partial cross-sectional side view of FIG. 6A.
The upper surface mold 1b and the lower surface mold 1a shown in FIG. 6B have alignment marks 6 that are asymmetrical with respect to the radial axis of the mold shown in FIG. 7 in a non-contact area that extends beyond the outer periphery of the substrate and extends to the outer peripheral edge of the mold. Two are provided.
First, the lower mold 1a is set on the stage 9 of the imprint apparatus. At this time, the stage 1 of the imprint apparatus is previously provided with cross-shaped alignment marks 8 and 8 for positioning the lower surface mold (see FIG. 7). Positioning is performed while observing with the CCD cameras 10 and 10 so that the alignment marks 8 and 8 on the stage of the printing apparatus coincide.
Next, the disk substrate 4 coated with the ultraviolet curable resin composition on both sides is placed on the stage on the lower mold 1a using a substrate transfer robot. The substrate transfer robot is set in advance so that the substrate is arranged at a position where the center of the substrate coincides with the center of the alignment marks 8 and 8.
Next, the upper surface mold 1b is arranged on the disk substrate, and positioning is performed while observing with the CCD cameras 10 and 10 so that the alignment mark 6 of the lower surface mold 1a matches the alignment mark 6 of the upper surface mold 1b. . As a result, as shown in the bottom diagram of FIG. 7, the alignment mark 6 of the upper surface mold 1b, the alignment mark 6 of the lower surface mold 1a, and the alignment mark 8 of the stage 9 of the imprint apparatus overlap.
Next, the mold is pressurized from both sides, irradiated with ultraviolet rays toward both sides with a high-pressure mercury lamp, and then the molds on both sides are peeled off.

FIG. 8A is another plan view showing the positioning when performing optical imprinting using the optical imprinting mold of the present invention, and FIG. 8B is a partial sectional side view of FIG. 8A. is there.
The upper surface mold 1b and the lower surface mold 1a shown in FIG. 8B have alignment marks 6 that are asymmetric with respect to the radial axis of the mold shown in FIG. 7 in a non-contact region that extends beyond the outer periphery of the substrate and extends to the outer peripheral edge of the mold. Two are provided. In addition, two cross-shaped alignment marks 11 are provided in the non-contact area of the central opening of the substrate. In addition, the alignment mark 11 provided in the non-contact area | region of the center opening part of a board | substrate may be asymmetrical shape.
First, the lower mold 1a is set on the stage 9 of the imprint apparatus. At this time, the stage 1 of the imprint apparatus is previously provided with cross-shaped alignment marks 8 and 8 for positioning the lower surface mold (see FIG. 7). Positioning is performed while observing with the CCD camera 10 so that the alignment marks 8, 8 on the stage of the printing apparatus coincide with each other.
Next, the disk substrate 4 coated with the ultraviolet curable resin composition on both sides is observed with the CCD camera 10 on the lower surface mold 1a so that the end surface of the disk substrate 4 and the alignment mark 11 of the lower surface mold 1a coincide. Position and arrange with.
Next, the upper surface mold 1b is disposed on the disk substrate, and positioning is performed while observing with the CCD camera 10 so that the alignment mark 6 of the lower surface mold 1a matches the alignment mark 6 of the upper surface mold 1b. As a result, as shown in the bottom diagram of FIG. 7, the alignment mark 6 of the upper surface mold 1b, the alignment mark 6 of the lower surface mold 1a, and the alignment mark 8 of the stage 9 of the imprint apparatus overlap.
Next, the mold is pressurized from both sides, irradiated with ultraviolet rays toward both sides with a high-pressure mercury lamp, and then the molds on both sides are peeled off.

According to the optical imprinting method using the optical imprinting mold of the present invention, it is possible to align the molds located on both sides of the substrate, the optical imprinting on both sides can be performed with high accuracy, and the throughput is high. improves.
In addition, according to the optical imprint method using the optical imprint mold of the present invention, the front and back of the mold can be easily distinguished, process errors can be reduced, and the angular coordinates of the front and back patterns match. Therefore, the position of the desired servo signal on the mold is clarified, and the target location can be easily observed.

  The mold for optical imprinting of the present invention is particularly suitable for the method for producing a magnetic recording medium of the present invention described below.

<Method of manufacturing magnetic recording medium>
In the method for producing a magnetic recording medium of the present invention, the optical imprint mold of the present invention is pressed against an imprint resist layer formed on a substrate of the magnetic recording medium to transfer the concavo-convex pattern formed on the mold. A transfer process;
A curing step of curing the concavo-convex pattern transferred to the imprint resist layer and peeling the mold structure;
Using the imprint resist layer to which the concavo-convex pattern is transferred as a mask, the magnetic layer formed on the surface of the substrate of the magnetic recording medium is etched to form a magnetic pattern portion based on the concavo-convex pattern in the magnetic layer. A magnetic pattern portion forming step;
A non-magnetic pattern portion forming step of embedding a non-magnetic material in the concave portion formed on the magnetic layer, and further including other steps as necessary.
Hereinafter, an example of a method for manufacturing a magnetic recording medium such as a discrete track medium or a patterned medium will be described with reference to FIG.

[Transfer process]
As shown in FIG. 9A, a magnetic recording medium intermediate magnetic layer 50 having a magnetic layer 50 of Fe, Fe alloy, Co, Co alloy or the like on both surfaces of a substrate 40 of aluminum, glass, silicon, quartz, or the like. An optical imprint mold 1 having a concavo-convex pattern formed on the surface of a magnetic recording medium intermediate with a resist layer in which an imprint resist layer 24 formed by applying an imprint resist solution such as an acrylate resin is formed on By pressing 1 from above and below and applying pressure, the concavo-convex pattern formed on the mold is transferred to the imprint resist layers 24 and 24.

[Curing process]
-Curing by light irradiation-
As shown in FIG. 9B, when the imprint resist composition for forming the imprint resist layer 24 is irradiated with ultraviolet rays through the optical imprint molds 1, 1, the imprint resist layers 24, 24 are irradiated. The printed resist layer is cured and the concavo-convex pattern is transferred.
The positioning method, ultraviolet irradiation conditions, and the like are the same as those of the optical imprint method of the present invention.

[Magnetic pattern formation process]
Next, as shown in FIG. 9C, using the imprint resist layer to which the pattern of the concavo-convex portion is transferred as a mask, dry etching is performed, and the concavo-convex shape based on the concavo-convex pattern shape formed on the imprint resist layer is formed. Formed on the magnetic layer 50.
The dry etching is not particularly limited as long as it can form a concavo-convex shape in the magnetic layer, and can be appropriately selected according to the purpose. Examples thereof include ion milling, reactive ion etching (RIE), and sputter etching. , Etc. Among these, ion milling and reactive ion etching (RIE) are particularly preferable.
The ion milling method is also called ion beam etching. An inert gas such as Ar is introduced into an ion source to generate ions. This is accelerated through the grid and collides with the sample substrate for etching. Examples of the ion source include a Kaufman type, a high frequency type, an electron impact type, a duoplasmatron source, a Freeman type, an ECR (electron cyclotron resonance) type, and a closed drift type.
Process gas in ion beam etching is Ar, and RIE etchant is CO + NH ₃ , chlorine gas, CF gas, CH gas, or a gas obtained by adding oxygen, nitrogen or hydrogen gas to these gases. it can.

[Non-magnetic pattern part forming process]
Next, as shown in FIG. 9D, after the non-magnetic material 70 is embedded in the formed recess and the surface is flattened, a protective film or the like is formed as necessary to produce the magnetic recording medium 100. be able to.
Examples of the nonmagnetic material include polymers such as SiO ₂ , carbon, alumina, polymethyl methacrylate (PMMA), polystyrene (PS), and smooth oil.
As the protective film, diamond carbon (DLC), sputtered carbon or the like is preferable, and a lubricant layer may be further provided on the protective film.

  The magnetic recording medium manufactured by the magnetic recording medium manufacturing method of the present invention is preferably at least one of a discrete magnetic recording medium and a patterned media magnetic recording medium.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
<Mold manufacturing method>
-Production of Si master-
A resist was applied on a 6-inch Si substrate, and a 100 nm pitch concentric pattern and an alignment mark were formed on the resist layer by EB drawing, and Si etching (depth 100 nm) was performed for cleaning.
Since the alignment mark has an outer diameter of 65 mm, two marks (180 degrees) having the shape shown in FIG. 7 each having a width of 20 μm and a length of 100 μm are drawn at a position 50 mm from the center of the substrate.

-Production of quartz mold-
A resist (photocurable resin: PAK01, manufactured by Toyo Gosei Co., Ltd.) was applied on a 6-inch quartz substrate so as to have a thickness of 100 nm, thereby forming an imprint resist layer. The imprint resist layer was optically imprinted with the Si master, quartz etched (depth 100 nm), and washed. Thus, the upper and lower quartz molds were produced.

-Optical imprint method-
As shown in FIGS. 6A and 6B, the lower mold 1a was placed on the stage 9 of the imprint apparatus while observing the alignment mark of the lower quartz mold 1a with the CCD camera 10. An alignment mark 8 for aligning the lower surface mold is provided in advance on the stage of the imprint apparatus.
Next, a resist (photocurable resin: PAK01, manufactured by Toyo Gosei Co., Ltd.) was applied to both surfaces of a disk substrate (made of glass, inner diameter 20 mm, outer diameter 65 mm) 4 so as to have a thickness of 100 nm.
Next, the resist-coated disk substrate 4 was placed on the lower surface mold 1a. The disk substrate is set to be installed at a predetermined position of the imprint apparatus (within 5 μm error).
Next, while observing the alignment mark 6 other than the substrate adhesion area of the mold that has been installed with the CCD camera 10, the upper surface mold 1b is aligned so that the alignment marks 6, 6 other than the substrate adhesion area of the upper and lower molds 1a, 1b coincide. Was installed.
Next, pressurization was performed at 1 MPa from both sides for 1 minute, and irradiation was performed at 100 mJ / cm ² toward the upper and lower surfaces with a high-pressure mercury lamp having a peak wavelength of 365 nm, and then the molds on both surfaces were peeled off.
The obtained glass substrate with a resin pattern was observed with a microscope, and the concentric pattern alignment accuracy of the upper and lower surfaces was measured by changing the focal length. As a result, it was confirmed that it was within 10 μm.

(Example 2)
In Example 1, as shown in FIGS. 8A and 8B, positioning is performed in the same manner as in Example 1 except that two cross-shaped alignment marks 11 are also provided in the non-contact region of the central opening of the substrate. The optical imprint was performed.
The obtained glass substrate with a resin pattern was observed with a microscope, and the concentric pattern alignment accuracy of the upper and lower surfaces was measured by changing the focal length. As a result, it was confirmed that it was within 10 μm.

  The mold for optical imprinting and the optical imprinting method using the same according to the present invention are suitable for manufacturing (duplicating) molds, manufacturing magnetic recording media such as discrete media (DTM) and patterned media (BPM). .

FIG. 1 is a diagram illustrating an example of an alignment mark having a non-body-symmetric shape with respect to a radial axis. FIG. 2 is a diagram illustrating another example of the alignment mark having a non-body-symmetric shape with respect to the radial axis. FIG. 3 is a diagram illustrating another example of the alignment mark having a non-body-symmetric shape with respect to the radial axis. FIG. 4 is a diagram illustrating another example of the alignment mark having a non-body-symmetric shape with respect to the radial axis. FIG. 5 is a partial perspective view showing an example of a mold for optical imprinting. FIG. 6A is a plan view showing how positioning is performed when optical imprinting is performed using the optical imprinting mold of the present invention. 6B is a partial cross-sectional side view of FIG. 6A. FIG. 7 is a diagram showing the alignment state of the alignment mark by the optical imprint method. FIG. 8A is a plan view showing a state in which positioning is performed when optical imprinting is performed using the optical imprinting mold of the present invention. 8B is a partial cross-sectional side view of FIG. 8A. FIG. 9 is a process diagram showing an example of a method for manufacturing a magnetic recording medium of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold 2 Substrate 3 Uneven part 3a Convex part 3b Concave part 4 Substrate 5 Transfer pattern 6 Alignment mark 7 Center opening 8 Imprint apparatus alignment mark 9 Imprint apparatus stage 10 CCD camera 11 Alignment mark

Claims (8)

A set of optical imprint molds for forming a concavo-convex pattern on both sides of a substrate coated with a resin composition,
The set of optical imprint molds has at least two alignment marks for determining the relative positional relationship of the set of optical imprint molds on both sides of the substrate during imprinting,
The alignment mark is provided in a non-contact region where the mold and the substrate do not contact ;
The mold for optical imprinting , wherein the non-contact area is an area extending beyond an outer periphery of the substrate and extending to an outer peripheral edge of the mold. The mold for optical imprinting according to claim 1, wherein the alignment mark is also provided in a non-contact region that is a central opening of the substrate. The mold for optical imprinting according to claim 1, wherein the alignment mark has a shape capable of distinguishing the front and back of the mold. The mold for optical imprinting according to claim 3, wherein the shape of the alignment mark is asymmetrical with respect to the radial axis of the mold. 5. The mold for optical imprinting according to claim 1, comprising an uneven pattern for producing a discrete medium and a patterned medium, and capable of determining angular coordinates of a specific servo pattern from the position of the alignment mark. . An optical imprint method comprising: aligning using the optical imprint mold according to any one of claims 1 to 5; and imprinting a concavo-convex pattern on both sides of a substrate coated with a resin composition. . A transfer step of transferring the concavo-convex pattern formed on the mold structure by pressing the optical imprint mold against the imprint resist layer formed on the substrate of the magnetic recording medium;
The magnetic layer formed on the surface of the substrate of the magnetic recording medium is etched using the imprint resist layer to which the concave / convex pattern has been transferred as a mask, and the magnetic pattern portion based on the concave / convex pattern is used as the magnetic layer. A magnetic pattern portion forming step to be formed;
A non-magnetic pattern portion forming step of embedding a non-magnetic material in the concave portion formed on the magnetic layer,
The optical imprint mold is a set of optical imprint molds for forming a concavo-convex pattern on both surfaces of a substrate coated with a resin composition,
The set of optical imprint molds has at least two alignment marks for determining the relative positional relationship of the set of optical imprint molds on both sides of the substrate during imprinting,
The method of manufacturing a magnetic recording medium, wherein the alignment mark is provided in a non-contact region where the mold and the substrate do not contact each other. The method of manufacturing a magnetic recording medium according to claim 7, wherein the non-contact area is an area extending beyond the outer periphery of the substrate and extending to the outer peripheral edge of the mold.

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