JP2006127663A - Die for transfer master disk substrate, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the adhesiveness between a transfer master disk and a body to be transferred in a manufacturing method of a die for a transfer master disk substrate. <P>SOLUTION: The manufacturing method of the die for forming a transfer master disk substrate of a transfer master disk used for magnetically transferring a prescribed signal pattern on the surface of the body to be transferred, having a structure wherein at least a magnetic layer is layered on the transfer master disk substrate, and including a plurality of signal transfer regions each having a surface uneven pattern according to the signal pattern and a non-signal transfer region without the surface uneven pattern located among the adjacent signal transfer regions sequentially executes: a step (A) of preparing a surface uneven substrate 50 including an inverted pattern P3 complementary to the surface uneven pattern according to the signal pattern for a region 21 corresponding to the signal transfer region; and a step (B) of closely fixing a metallic mask 52 with a thickness greater than the height of projections of the surface uneven pattern according to the signal pattern to a region 31 corresponding to the non-signal transfer region of the surface uneven substrate 50. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a transfer master substrate mold that constitutes a transfer master disk used for magnetic transfer of a predetermined signal pattern onto the surface of a transfer object, a transfer master substrate mold, and the mold The present invention relates to a method for manufacturing a transfer master substrate, a transfer master substrate, a transfer master, and a magnetic recording medium.

  As a magnetic recording medium manufacturing technology, a transfer master (master carrier) having a predetermined surface irregularity pattern and at least a surface having magnetism is used, and a transfer medium (slave medium) is closely attached to the surface of the transfer master. Thus, there is a technique for magnetically transferring a signal pattern corresponding to the surface unevenness pattern of the transfer master to the transfer target.

  As a transfer master, a substrate in which a magnetic layer is laminated on a transfer master substrate (master substrate) having a surface uneven pattern is widely used. Further, the transfer master substrate is efficiently manufactured using a mold having a reverse pattern of the transfer master substrate.

  In Patent Document 1, as a method for manufacturing a master plate for transfer, a resist pattern is formed on a surface of a flat substrate by applying, exposing and developing a photoresist, and the flat substrate is formed using the resist pattern as a mask. , A remaining resist is removed, and a method for manufacturing a mold having a reverse pattern with the etched portion as a recess is disclosed.

Further, this document discloses a method of manufacturing a transfer master by forming a transfer master substrate using the above mold and forming a magnetic layer on the obtained transfer master substrate.
JP 2001-256644 A

  When magnetic transfer is performed using the transfer master manufactured by the above-described prior art, there is almost no gap between the transfer master and the transfer target, so the transfer master is interposed between the transfer master and the transfer target. Gases such as air are difficult to escape, and there is a risk that the adhesion between the transfer master and the transfer target will be reduced.

  The present invention has been made in view of such circumstances, and when performing magnetic transfer, it is easy to remove gas such as air interposed between a transfer master and a transfer target, and the transfer master and the transfer target It is an object of the present invention to provide a manufacturing technique of a transfer master capable of improving the adhesion of the sheet.

  Another object of the present invention is to provide a transfer master and a magnetic recording medium obtained by applying the above manufacturing technique.

  The master for transfer does not have a surface uneven pattern corresponding to the signal pattern transferred to the transfer object over the entire surface, but a signal transfer region having a surface uneven pattern corresponding to the signal pattern, and a surface uneven pattern. And a non-signal transfer region that does not have. The inventor of the present invention paid attention to the fact that the above problem can be solved by providing a recess in the non-signal transfer region of the transfer master that allows gas to escape when closely contacting the transfer target. The inventor has further studied the manufacturing technology of the transfer master capable of efficiently manufacturing such a transfer master, and completed the present invention.

The method for producing a mold for a transfer master substrate according to the present invention is used for magnetic transfer of a predetermined signal pattern onto the surface of a transfer object, and has a structure in which at least a magnetic layer is laminated on the transfer master substrate. And a transfer master having a plurality of signal transfer regions having a surface uneven pattern corresponding to the signal pattern and a non-signal transfer region located between the adjacent signal transfer regions and not having the surface uneven pattern. In the manufacturing method of the mold for forming the master substrate for transfer,
A step (A) of preparing a surface uneven substrate having a reverse pattern complementary to the surface uneven pattern of the signal transfer region; and a region corresponding to the non-signal transfer region of the surface uneven substrate; And a step (B) of closely fixing a metal mask having a thickness larger than the height of the convex portion.

  In this specification, the “inverted pattern” is a pattern in which a portion corresponding to the convex portion of the surface uneven pattern corresponding to the signal pattern is a concave portion, and a portion corresponding to the concave portion of the surface uneven pattern is a convex portion.

  In the step (A), the photoresist was applied to the flat substrate, exposed and developed to form a resist pattern, and the flat substrate was etched using the resist pattern as a mask. And a step of preparing the surface uneven substrate having the reversal pattern having a portion as a recess.

  The mold for the transfer master substrate of the present invention is manufactured by the above-described method for manufacturing the mold of the transfer master substrate of the present invention.

  The method for producing a master substrate for transfer according to the present invention comprises forming a master substrate for transfer having the metal mask portion as a recess, using the mold produced by the method for producing a master substrate for transfer according to the present invention. It is characterized by that.

  The transfer master substrate of the present invention is manufactured by the above-described method for manufacturing a transfer master substrate of the present invention.

  The transfer master of the present invention is characterized in that at least a magnetic layer is laminated on the surface of the transfer master substrate of the present invention.

  The magnetic recording medium of the present invention is characterized by being magnetically transferred using the transfer master of the present invention described above.

  In the manufacturing technique of the transfer master disk according to the present invention, when manufacturing the transfer master disk mold, after preparing a surface uneven substrate having a reverse pattern of the surface uneven pattern corresponding to the signal pattern to be transferred, A configuration is adopted in which a metal mask having a thickness larger than the height of the convex portion of the surface concavo-convex pattern is closely fixed to the region corresponding to the non-signal transfer region. Therefore, according to the present invention, it is possible to easily and efficiently manufacture a transfer master having a recessed portion deeper than the height of the protruding portion of the surface uneven pattern corresponding to the signal pattern to be transferred to the transfer target in the non-signal transfer region. it can.

  In the transfer master manufactured by the transfer master manufacturing technique of the present invention, the concave portion formed in the non-signal transfer region causes the air interposed between the transfer master and the transfer object when performing magnetic transfer. Therefore, when the magnetic transfer is performed, the adhesion between the transfer master and the transfer target can be enhanced.

  In addition, since the concave portion is formed in a wide range in the transfer master, even if dust or the like is interposed between the transfer master and the transfer target, most of the dust is present in the concave portion. Can be significantly reduced as compared with the prior art. Therefore, according to the present invention, it is possible to obtain an effect that the transfer master and the transfer target can be suppressed to a high level due to dust or the like interposed therebetween.

  Next, an embodiment according to the present invention will be described with reference to the drawings. In each figure, the scale is different from the actual one for easy visual recognition.

"Master for transcription"
The present invention is particularly characterized by a method of manufacturing a “transfer master substrate mold”. First, an embodiment of a transfer master manufactured using the transfer master substrate mold of the present invention will be described. FIG. 1 is an overall plan view of the transfer master, and FIG. 2 is a cross-sectional thickness sectional view of the transfer master.

  As shown in FIG. 1, the transfer master 10 is a disk-like object having an opening at the center in plan view, and has a plurality of signal transfer patterns having fine surface unevenness patterns P1 corresponding to the signal pattern to be transferred to the transfer target. It has the area | region 20 and the non-signal transfer area | region 30 which is located between the adjacent signal transfer area | regions 20 and does not have the surface uneven | corrugated pattern P1 (refer FIG. 2 for the surface uneven | corrugated pattern P1). In the present embodiment, the plurality of signal transfer regions 20 extend radially from the center side, and there is a substantially fan-shaped non-signal transfer region 30 between adjacent signal transfer regions 20. That is, the transfer master 10 repeatedly has a signal transfer region 20 and a non-signal transfer region 30 as viewed in the track direction.

  As shown in FIG. 2B, the signal transfer region 20 of the transfer master 10 is made of a metal having a surface unevenness pattern P2 that is substantially the same as the surface unevenness pattern P1 corresponding to the signal pattern transferred to the transfer target. A transfer master substrate (master substrate) 11 and a magnetic layer 12 laminated along the surface shape and having a surface unevenness pattern P1 are provided.

  As shown in FIG. 2C, the non-signal transfer region 30 of the transfer master 10 has a laminated structure of the transfer master substrate 11 and the magnetic layer 12, similar to the signal transfer region 20 in sectional view. However, the surface unevenness pattern P1 is not provided and the surface is flat. Further, as shown in FIG. 2 (a), each non-signal transfer region 30 of the transfer master 10 has a height of the convex portion 12a of the magnetic layer 12 forming the surface unevenness pattern P1 of the signal transfer region 20 over the whole. A recess 32 (depth: H2) deeper than the height H1 is provided. That is, the surface of the non-signal transfer region 30 corresponds to the bottom surface of the recess 32, and this surface is a flat surface having no surface uneven pattern P1.

  The present embodiment is characterized in that the non-signal transfer region 30 is provided with a recess 32 deeper than the height H1 of the protrusion 12a of the surface uneven pattern P1 of the signal transfer region 20. In the transfer master manufactured by the prior art (Patent Document 1) listed in the “Background Art” section, the surface of the non-signal transfer area is flush with the bottom surface of the recesses forming the surface uneven pattern of the signal transfer area. On the other hand (corresponding to the surface indicated by reference numeral 33 in FIG. 2A), in the present embodiment, the surface of the non-signal transfer region 30 is from the bottom surface of the recess 12b forming the surface unevenness pattern P1 of the signal transfer region 20. Located below the depth H2.

  The concave portion 32 provided in the non-signal transfer region 30 functions as a degassing passage through which a gas such as air that is interposed between the transfer master 10 and the transfer target body is released when performing magnetic transfer. The depth H2 of the recess 32 is defined as a difference (corresponding to the thickness of a metal mask 52 described later) between the bottom surface of the recess 12b forming the surface unevenness pattern P1 of the signal transfer region 20 and the bottom surface of the recess 32. ) Is set deeper than at least the height H1 of the convex portion 12a of the magnetic layer 12 in the signal transfer region 20.

  For example, when the maximum thickness of the transfer master substrate 11 is 300 μm, the height H1 of the convex portion 12a of the magnetic layer 12 is preferably 50 to 100 nm (0.05 to 0.1 μm). As the depth H2 of the recess 32 increases, the gas venting efficiency improves, but the peelability from the mold tends to decrease. Therefore, when considering the balance between the gas venting efficiency and the releasability from the mold, when the maximum thickness of the transfer master substrate 11 is 300 μm, the depth H2 of the recess 32 is preferably 10 to 200 μm, and preferably 50 to 150 μm. More preferred.

  The transfer master 10 of the present embodiment is configured as described above.

"Magnetic transfer method"
Next, a magnetic transfer method using the transfer master 10 will be described with reference to FIG. FIG. 3 is a diagram corresponding to FIG.

As the transfer target, a slave medium having a magnetic recording layer on one side or both sides is used. As shown in FIG. 3 (a), in advance, with respect to the transferred object 13, the magnetic field H _in is applied to the track direction or the thickness direction, the magnetic field H where the magnetic recording layer (not shown) to the initial magnetization is allowed (track direction _The case where _in is applied is illustrated). In this state, the transfer target 13 is supplied to the surface of the transfer master 10, and the two are brought into close contact with each other.

Next, as shown in FIG. 3B, a transfer magnetic field H _du is applied to the transfer master 10 and the transfer target 13 that are in close contact with each other in a direction substantially opposite to the direction of the initial magnetization. At this time, the transfer magnetic field H _du is substantially selectively sucked only into the convex portion 12 a of the magnetic layer 12 in close contact with the transfer target 13 in the transfer master 10. As a result, in the case of in-plane recording, in the magnetic recording layer of the transfer target 13, the initial magnetization of the portion in close contact with the convex portion 12a is not reversed, and the initial magnetization of other portions is reversed. In the case of perpendicular recording, conversely, in the magnetic recording layer of the transfer target 13, the initial magnetization of the portion in close contact with the convex portion 12a is reversed, and the initial magnetization of the other portions is not reversed. In this manner, the magnetization pattern corresponding to the surface unevenness pattern P1 of the transfer master 10 is magnetically transferred to the transfer body 13, and a magnetic recording medium is manufactured.

"Method of manufacturing master for transfer"
Next, based on FIG. 4 to FIG. 6, taking the transfer master 10 as an example, a method of manufacturing a transfer master substrate according to an embodiment of the present invention, a method of manufacturing a transfer master substrate, and a transfer master The manufacturing method will be described. 4 is an enlarged cross-sectional view corresponding to FIG. 2B, and FIGS. 5 and 6 are overall cross-sectional views corresponding to FIG. 2A, which are process diagrams.

(Manufacturing method of master substrate for transfer)
<Process (A)>
<Process (A-1)>
First, as shown in FIG. 4A, a flat substrate 40 is prepared, and a photoresist 51 is applied to the entire surface of the flat substrate 40 by spin coating or the like. The flat substrate 40 is not limited. However, as the flat substrate 40, a silicon wafer is preferably used because an apparatus used in semiconductor technology can be used as it is in the following steps. The photoresist 51 may be either a positive type or a negative type.

  Next, the photoresist 51 is exposed and developed, and the resist shown in FIG. 4B corresponding to the surface unevenness pattern P1 formed on the transfer master 10 in each of the regions corresponding to the plurality of signal transfer regions 20. A pattern R is formed. The exposure can be performed by irradiating the photoresist 51 with a laser beam or an electron beam modulated in accordance with the surface uneven pattern P1 formed on the transfer master 10 while rotating the flat substrate 40. A laser beam or an electron beam is applied so that the photoresist 51 remains on a portion that becomes a convex portion in the mold of the master substrate for transfer 11 to be manufactured, depending on the type of the photoresist 51 to be used.

<Process (A-2)>
Next, as shown in FIG. 4C, the flat substrate 40 is etched using the resist pattern R as a mask to form a recess 41 in the flat substrate 40. A part of the photoresist 51 may be removed during the etching, or may not be removed. In any case, after the etching is completed, the remaining photoresist 51 is removed as shown in FIG.

  The method for etching the flat substrate 40 is not limited. However, RIE (reactive ion etching) or the like is preferable because high-definition etching is possible and a portion of the flat substrate 40 where the photoresist 51 is not formed can be etched substantially vertically.

  Through the photolithography process shown in FIGS. 4A to 4D, the surface uneven substrate 50 having the surface uneven pattern P1 and the complementary reversal pattern P3 in each of the regions corresponding to the plurality of signal transfer regions 20 is prepared. The The reverse pattern P3 is a pattern in which the portion corresponding to the convex portion of the surface uneven pattern P1 is a concave portion (41) and the portion corresponding to the concave portion of the surface uneven pattern P1 is a convex portion (42).

  As shown in FIG. 5A, the surface uneven substrate 50 has a reverse pattern P3 formed in the region 21 corresponding to the signal transfer region 20, and the surface of the region 31 corresponding to the non-signal transfer region 30 is the reverse pattern P3. It is flush with the surface of the convex portion 42. That is, the surface uneven substrate 50 is not formed corresponding to the recess 32 provided in the non-signal transfer region 30 of the transfer master 10.

<Process (B)>
Next, as shown in FIG. 5B, the depth 31 of the concave portion 32 provided in the non-signal transfer region 30 of the master 10 for transfer in the region 31 corresponding to the non-signal transfer region 30 of the surface uneven substrate 50 is the same. The metal mask 52 having a thickness is fixedly fixed, and the master 60 for transfer master plate is completed. A plurality of metal masks 52 may be used. However, in consideration of productivity, it is preferable to use a single metal mask in which regions 21 corresponding to the plurality of signal transfer regions 20 of the surface uneven substrate 50 are opened.

  The material of the metal mask 52 is not limited, and nickel or the like is preferable. In order to make it easy to peel off the transfer master substrate 11 from the mold 60, it is preferable that the metal mask 52 is closely fixed to the surface uneven substrate 50 after the surface is oxidized. The surface of the metal mask 52 may be oxidized after the metal mask 52 is closely fixed to the surface uneven substrate 50.

  The method for tightly fixing the metal mask 52 is not particularly limited as long as the conductive layer 53 can be satisfactorily formed in the subsequent step (C), and is mechanically fixed using a bolt, a jig, or the like, or bonded and fixed using an adhesive. Is mentioned.

(Method of manufacturing master substrate for transfer)
Next, a method for manufacturing the transfer master substrate 11 using the transfer master substrate mold 60 manufactured by the above manufacturing method will be described.

<Process (C)>
The transfer master substrate 11 is formed on the transfer master substrate mold 60. As shown in FIGS. 6A and 6B, the transfer master substrate 11 can be formed by forming a conductive layer 53 on the entire surface of the mold 60 by metal sputtering or the like and performing electroforming. The conductive layer 53 is thinly formed so that the reverse pattern P3 is not broken. The conductive layer 53 is preferably formed of the same material (for example, nickel) as the transfer master substrate 11. The conductive layer 53 becomes the surface layer of the transfer master substrate 11 as shown in FIG.

<Process (D)>
Next, the transfer master substrate 11 is peeled from the mold 60, and the transfer master substrate 11 having the pattern shown in FIG. 2 is manufactured.

  As described above, the transfer master substrate 11 having the metal mask 52 portion as the recess 32 can be formed using the transfer master substrate mold 60. According to the present embodiment, a plurality of master substrates for transfer 11 can be easily and efficiently manufactured from one mold 60 by repeatedly performing the steps (C) and (D).

(Transfer master production method)
<Process (E)>
The magnetic layer 12 is laminated along the surface shape of the transfer master substrate 11 by sputtering a magnetic material on the surface of the transfer master substrate 11 manufactured by the above manufacturing method, and the transfer master 10 is completed. The magnetic layer 12 may be formed on at least the surface convex portion of the transfer master substrate 11.

  In manufacturing the transfer master 10, in addition to the magnetic layer 12, other layers can be formed as necessary. For example, a nonmagnetic layer can be interposed between the transfer master substrate 11 and the magnetic layer 12, or a protective layer can be provided on the magnetic layer 12.

"Magnetic recording media"
A magnetic recording medium is manufactured by performing magnetic transfer on the transfer target 13 as shown in FIG. 3 using the transfer master 11 described above.

  In the manufacturing technology of the transfer master disk 10 of the above embodiment, when the transfer master disk mold 60 is manufactured, the surface uneven substrate 50 having the reverse pattern P3 of the surface uneven pattern P1 corresponding to the signal pattern to be transferred is prepared. A configuration is adopted in which a metal mask 52 having a thickness larger than the height H1 of the convex portion 12a of the surface uneven pattern P1 is tightly fixed to the region 31 corresponding to the non-signal transfer region 30 of the surface uneven substrate 50. Therefore, according to the above embodiment, the transfer master 10 having the recess 32 deeper than the height of the protrusion 12a of the surface uneven pattern P1 corresponding to the signal pattern to be transferred to the transfer target 13 in the non-signal transfer region 30 is simplified. Can be manufactured efficiently.

  In the transfer master 10 manufactured by the manufacturing technique of the above embodiment, the recess 32 formed in the non-signal transfer region 30 is interposed between the transfer master 10 and the transfer target 13 when performing magnetic transfer. Since it functions as a degassing flow path through which gas such as air escapes, the adhesion between the transfer master 10 and the transfer target 13 can be enhanced when performing magnetic transfer.

  Since the concave portion 32 is formed in the transfer master 10 in a wide range, even if dust or the like is interposed between the transfer master 10 and the transfer target 13, most of them are present in the concave portion 32. The probability that dust or the like is present on the contact surface between the transfer master 10 and the transfer target 13 can be significantly reduced as compared with the conventional case. Therefore, according to the above embodiment, it is possible to obtain an effect that the transfer master 10 and the transfer target 13 can be prevented from being damaged by dust or the like interposed therebetween at a high level.

  Further, by using the transfer master 10, the adhesion between the transfer master 10 and the transfer target 13 is increased, and a magnetic recording medium with good magnetic transfer accuracy can be manufactured.

  In the above embodiment, the recesses 32 are provided over the entire non-signal transfer regions 30. However, if the recesses 32 are provided in at least some of the non-signal transfer regions 30. A similar effect can be obtained.

  The technique of the present invention can be preferably applied to a transfer master used to magnetically transfer a predetermined signal pattern onto the surface of a transfer target, and a magnetic recording medium using the same.

1 is an overall plan view of a transfer master according to an embodiment of the present invention. FIG. 2 is a cross-sectional thickness sectional view of the transfer master in FIG. 1. It is a figure which shows the magnetic transfer method. It is process drawing which shows the manufacturing method of the type | mold of the master board | substrate for transcription | transfer of embodiment which concerns on this invention. It is process drawing which shows the manufacturing method of the type | mold of the master board | substrate for transcription | transfer of embodiment which concerns on this invention. It is process drawing which shows the manufacturing method of the master substrate for transcription | transfer of embodiment which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transfer master 11 Transfer master board 12 Magnetic layer 12a Convex part of surface uneven | corrugated pattern 13 Transfer object 20 Signal transfer area 21 Area corresponding to signal transfer area 30 Non-signal transfer area 31 Area corresponding to non-signal transfer area 32 Concave portion of non-signal transfer region 40 Flat substrate 41 Concave portion 50 Surface uneven substrate 52 Metal mask 60 Type of master plate substrate for transfer H1 Height of convex portion of surface uneven pattern H2 Depth of concave portion of non-signal transfer region P1, P2 Surface unevenness Pattern P3 Reverse pattern R Resist pattern

Claims (7)

A plurality of signals having a structure in which at least a magnetic layer is laminated on a master substrate for transfer and having a surface unevenness pattern corresponding to the signal pattern, which is used for magnetically transferring a predetermined signal pattern to the surface of the transfer target. In the method of manufacturing a mold for forming the transfer master disk substrate of the transfer master disk having the signal transfer area and the non-signal transfer area which is located between the adjacent signal transfer areas and does not have the surface unevenness pattern,
A step (A) of preparing a surface uneven substrate having a reverse pattern complementary to the surface uneven pattern of the signal transfer region;
And (B) a step of closely fixing a metal mask having a thickness larger than the height of the convex portion of the surface uneven pattern to a region corresponding to the non-signal transfer region of the surface uneven substrate. A method for producing a master substrate mold. In the step (A),
A step of forming a resist pattern by applying, exposing and developing a photoresist on a flat substrate, and using the resist pattern as a mask, etching the flat substrate and using the etched portion as a recess The method for producing a mold for a master substrate for transfer according to claim 1, further comprising the step of preparing the surface uneven substrate having a surface.   A mold for a transfer master substrate, which is manufactured by the method for manufacturing a mold for a transfer master substrate according to claim 1.   A transfer master substrate having the metal mask portion as a recess is formed using a mold manufactured by the method for manufacturing a transfer master substrate mold according to claim 1 or 2. Manufacturing method.   A transfer master substrate manufactured by the method for manufacturing a transfer master substrate according to claim 4.   6. A transfer master, comprising at least a magnetic layer laminated on the surface of the transfer master substrate according to claim 5.   A magnetic recording medium, which is magnetically transferred using the transfer master according to claim 6.

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