JPWO2007116469A1 - Pattern transfer method and pattern transfer apparatus - Google Patents

Abstract

A pattern transfer method in which a concavo-convex surface (10) of a stamper (1) is brought into close contact with a resin layer (92) on a substrate (B), and the concavo-convex pattern is transferred to the resin layer (92). Ultrasonic vibration is applied to the substrate (B) or the stamper (1) so that the bubbles (100) are removed from the resin layer (92) in close contact therewith. The ultrasonic vibration is applied only for a predetermined time at an output level sufficient for removing the bubbles (100).

Description

  The present invention relates to a pattern transfer method and a pattern transfer apparatus for transferring a fine uneven pattern by so-called nanoimprint.

  Nanoimprint is a method of transferring a concave / convex pattern such as servo information onto the surface of a substrate by pressing a stamper with a fine concave / convex surface at a nanometer pitch against a resin substrate such as a disk medium or a resin layer on the substrate. Technology. Conventional fine pattern transfer methods include those disclosed in Patent Document 1 and Patent Document 2. All of these apply heat to the thermoplastic resin by ultrasonic vibration, and the ultrasonic vibration is applied to the stamper and the substrate at a relatively large output level.

JP 09-201874 A JP 2001-266417 A

  However, in the nanoimprint in which the concave / convex pattern is formed as an etching mask, the concave / convex pattern is transferred to the resin layer by the conventional pattern transfer method even though the thickness of the resin layer is less than 100 nm. Since the ultrasonic vibration acts too strongly on the resin layer, the resin layer and the substrate may be peeled off.

  On the other hand, if the concave / convex surface of the stamper is brought into close contact with the resin layer without applying ultrasonic vibration, small bubbles enter between the concave / convex surface and the resin layer, and the stamper and the substrate are pressed and heated as they are. When the treatment is performed, a transfer defect occurs in the concavo-convex pattern. That is, in the conventional pattern transfer method, since the purpose of using the ultrasonic vibration is not appropriate, the uneven pattern cannot be transferred with high accuracy.

  The present invention has been conceived under the circumstances described above. An object of the present invention is to provide a pattern transfer method and a pattern transfer apparatus capable of transferring a concavo-convex pattern with high accuracy by appropriately using ultrasonic vibration.

  In order to solve the above problems, the present invention takes the following technical means.

  The pattern transfer method provided by the first aspect of the present invention is a pattern transfer method in which a concavo-convex surface of a stamper is brought into close contact with a resin layer on a substrate, and the concavo-convex pattern is transferred to the resin layer. It is characterized in that ultrasonic vibration is applied to the substrate or the stamper so as to remove bubbles from between them while being in close contact with the resin layer.

  Preferably, the ultrasonic vibration is applied only for a predetermined time at an output level sufficient for removing bubbles.

  Preferably, the resin layer is made of a thermoplastic resin, and the ultrasonic vibration is applied to at least one of the substrate and the stamper in a state where the substrate and the stamper are arranged under vacuum, and then the substrate and the stamper are pressed. The resin layer is heated in the state.

  Preferably, the resin layer is made of a thermoplastic resin, the substrate and the stamper are arranged under atmospheric pressure or vacuum, and the ultrasonic vibration is applied to at least one of them while being pressed, Thereafter, the resin layer is heated in a state where the substrate and the stamper are pressed.

  Preferably, the resin layer is made of a photo-curing resin, and the ultrasonic vibration is applied to at least one of the substrate and the stamper in a state where the substrate and the stamper are arranged in a vacuum, and then the substrate and the stamper are pressed. In this state, the resin layer is irradiated with resin curing light.

  Preferably, the resin layer is made of a photo-curing resin, the substrate and the stamper are disposed under atmospheric pressure or vacuum, and the ultrasonic vibration is applied to at least one of them while being pressed, Thereafter, the resin layer is irradiated with resin curing light while the substrate and the stamper are pressed.

  Preferably, the resin layer is made of a room temperature transfer type resin, and the ultrasonic vibration is applied to at least one of the substrate and the stamper in a state where the substrate and the stamper are arranged under vacuum, and then the substrate and the stamper are pressed. To do.

  Preferably, the resin layer is made of a room temperature transfer resin, the substrate and the stamper are arranged under atmospheric pressure or vacuum, and the ultrasonic vibration is applied to at least one of them while pressed. .

  The pattern transfer device provided by the second aspect of the present invention is a pattern transfer device for transferring a concavo-convex pattern to a resin layer on a substrate, and has a concavo-convex surface for transferring the concavo-convex pattern to the resin layer. And a stamp holding means for holding and pressing the substrate and the stamper in parallel, and removing the bubbles from the concave and convex surfaces in close contact with the resin layer by the press holding means. And an ultrasonic vibrator for applying ultrasonic vibration to the substrate or the stamper.

It is a block diagram which shows one Embodiment of the pattern transfer apparatus with which this invention was applied. It is explanatory drawing for demonstrating one Embodiment of the pattern transfer method to which this invention was applied. FIG. 3 is an explanatory diagram for explaining specific contents of the pattern transfer method shown in FIG. 2. It is explanatory drawing for demonstrating other embodiment of the pattern transfer method to which this invention was applied. It is explanatory drawing for demonstrating other embodiment of the pattern transfer method to which this invention was applied. It is explanatory drawing for demonstrating other embodiment of the pattern transfer method to which this invention was applied.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a pattern transfer apparatus A according to an embodiment of the present invention applies a magnetic recording medium B (hereinafter referred to as a “substrate”) B in the process of manufacturing a magnetic recording medium B called a discrete track medium, for example. On the other hand, transfer is performed by nanoimprint. The pattern transfer apparatus A is installed inside the work chamber C. The pattern transfer device A holds the stamper 1 for transfer, the stamper 1 and the upper panel 20 horizontally, the upper fixing member 2 that holds the upper unit 21, the lower panel 3 that holds the substrate B horizontally, and the substrate. An ultrasonic transducer 4 disposed at the center of the lower panel 3 so as to be in contact with the lower surface of B, a lower lifting member 5 that holds the lower panel 3 and the ultrasonic transducer 4 and can be moved up and down; A drive motor 6 for raising and lowering the lower elevating member 5 and a vacuum pump 7 for reducing the pressure in the working chamber C are provided. Each of the upper panel 20 and the lower panel 3 functions as a heater panel that transfers heat to the stamper 1 and the substrate B while being in contact with them. Inside the upper unit 21, a mechanism and a heat exchanger (not shown) for positioning the stamper 1 with respect to the substrate B in a horizontal plane are provided. A heat exchanger is also provided inside the lower panel 3 (not shown).

The stamper 1 is made of, for example, a Ni substrate or a SiO ₂ substrate having a diameter of about 6 cm, and is manufactured by applying a resist, exposing with an electron beam, developing, plating or etching, etc. on one side of a separately prepared master. is there. One side of the stamper 1 subjected to these treatments forms a fine concavo-convex surface 10 having a pitch p of about 100 nm and a depth h of about 50 nm (see FIG. 2). Close to it.

  The upper panel 20 is made of, for example, quartz glass, and efficiently transmits heat to the stamper 1 in contact with the lower surface, and transmits the positioning light.

The upper unit 21 is provided with a positioning light irradiator, a light detector, and a heat exchanger, and a light irradiator for irradiating the substrate B with resin curing light such as ultraviolet rays. Is also provided (not shown). When the resin curing light is irradiated, the resin curing light must pass through the upper panel 20 and the stamper 1 and reach the substrate B. Therefore, the stamper 1 is made of a light-transmitting SiO ₂ substrate. Those are preferred.

  The lower panel 3 and the ultrasonic transducer 4 move up and down together with the lower lifting member 5 as the lower lifting member 5 is lifted and lowered by the drive motor 6. That is, the substrate B held horizontally by the lower panel 3 and the ultrasonic transducer 4 is moved closer to or away from the stamper 1 held at a certain height from the floor surface. The stamper 1 and the substrate B are pressed in a state where the stamper 1 and the substrate B are in close contact with each other.

  The ultrasonic transducer 4 is provided on the upper portion of the lower panel 3 so as to be movable up and down. When applying ultrasonic vibration to the substrate B, the ultrasonic transducer 4 is directly applied to the lower surface of the substrate B. Or it is in the state which touched through a part of lower panel 3. FIG. The ultrasonic transducer 4 oscillates ultrasonic vibration having a relatively weak output level such as about 40 W and a transmission frequency of about 50 kHz.

  The vacuum pump 7 has a capability of reducing the pressure in the working chamber C to about 1 Torr, for example.

  2A to 2F show the manufacturing process of the substrate B, and the pattern transfer method using the pattern transfer apparatus A is the process shown in FIGS. 2A and 2B. To be implemented.

  As shown in FIG. 2A, the substrate B is obtained by forming a magnetic film 91 on one side of the base layer 90. On the surface of the magnetic film 91, a resin layer 92 to be used as a mask in the manufacturing process is formed by spin coating or the like. The resin layer 92 is made of a thermoplastic resin such as polymethyl methacrylate resin (PMMA), and has a glass transition point of around 100 ° C.

  After the resin layer 92 is formed, the uneven surface 10 of the stamper 1 is brought into close contact with the resin layer 92. Thereafter, the concavo-convex surface 10 and the resin layer 92 are further subjected to application of ultrasonic vibration under vacuum, pressure treatment, and heat treatment. After the required cooling period, the uneven surface 10 of the stamper 1 is separated from the resin layer 92. As a result, as shown in FIG. 2B, the resin layer 92 is in a form in which the uneven pattern corresponding to the uneven surface 10 is transferred and cured. The uneven pattern thus formed is used as an etching mask.

  Since the resin layer 92 immediately after the concavo-convex pattern is transferred has a residue portion unnecessary as a mask, the residue portion of the resin layer 92 is removed as shown in FIG. Thereby, the recessed part of the resin layer 92 will be in the state which the magnetic film 91 exposed.

  The magnetic film 91 is etched using the resin layer 92 as a mask, and then the remaining resin layer 92 is removed, thereby forming a recess 93 in the magnetic film 91 as shown in FIG. Is done.

  After that, as shown in FIG. 2E, the nonmagnetic material 94 is fixed to the magnetic film 91 so as to cover the whole while filling the concave portion 93.

  Finally, as shown in FIG. 2F, the surfaces of the magnetic film 91 and the nonmagnetic material 94 are polished. As a result, the magnetic film 91 is separated by the nonmagnetic material 94 embedded in the recess 93. Thereby, the substrate B as a discrete track medium is completed.

  The pattern transfer method of the present embodiment shown in FIGS. 2A and 2B is specifically performed according to the procedure shown in FIGS. 3A to 3E.

  As shown in FIG. 3A, when the uneven surface 10 of the stamper 1 is brought into close contact with the resin layer 92, the vacuum chamber 7 is operated in a vacuum state by operating the vacuum pump 7 (not shown in the figure). And At this time, the degree of vacuum achieved is about 1 Torr, and the uneven surface 10 and the resin layer 92 are likely to be incompletely in contact with each other, so that small bubbles 100 enter between the uneven surface 10 and the resin layer 92 in various places. It becomes a state.

  Therefore, as shown in FIG. 3B, the ultrasonic transducer 4 is brought into contact with the base layer 90 of the substrate B, and the concave and convex surface 10 and the resin layer 92 are caused by oscillating the ultrasonic transducer 4. Ultrasonic vibration is applied between the two. The time for applying the ultrasonic vibration may be long enough to remove the bubbles 100 from between the uneven surface 10 and the resin layer 92. Thereby, for example, when 5 seconds have passed since the start of application of ultrasonic vibration, the bubbles 100 are completely removed from between the uneven surface 10 and the resin layer 92. Since the output level of the ultrasonic vibration is about 40 W, which is relatively small, and the time for applying the ultrasonic vibration is not so long, unnecessary heat generation and erosion phenomenon occur between the uneven surface 10 and the resin layer 92. There is no.

  Thereafter, as shown in FIG. 3C, the stamper 1 and the substrate B are sandwiched between the upper panel 20 and the lower panel 3 in a state where the pressing surface 10 and the resin layer 92 are in contact with each other, for example, 500 kgf They are pressed against each other with a relatively weak pressing force f of the order. Thereby, the removal of the bubble 100 between the uneven surface 10 and the resin layer 92 is further promoted.

  Thereafter, as shown in FIG. 3D, the stamper 1 and the substrate B are heated by the upper panel 20 and the lower panel 3 to about 135 ° C. which is equal to or higher than the glass transition point of the resin layer 92, for example, about 2500 kgf. Can be pressed more strongly with a relatively strong pressing force f.

  Then, after a required cooling period, the vacuum state of the working chamber B is released, and the uneven surface 10 of the stamper 1 is separated from the resin layer 92 as shown in FIG. Thereby, the concavo-convex pattern corresponding to the concavo-convex surface 10 is transferred to the resin layer 92. The concavo-convex pattern formed on the resin layer 92 in this way is a precise pattern having no transfer defect due to bubbles or the like.

  Therefore, according to the pattern transfer method of the present embodiment, since ultrasonic vibration is applied between the uneven surface 10 and the resin layer 92 with appropriate strength and time, this resin can be removed without peeling off the resin layer 92. The uneven pattern can be transferred to the layer 92 with high accuracy.

  As a pattern transfer method according to another embodiment, the method shown in FIGS. Note that the same or similar components as those described above are denoted by the same reference numerals and description thereof is omitted.

  In the pattern transfer method according to another embodiment shown in FIG. 4, each of the processes (a) to (d) in FIG. 4 may be performed after the working chamber B is in a vacuum state, or under atmospheric pressure. You may make it carry out.

  As shown in FIG. 4B, when applying ultrasonic vibration between the concavo-convex surface 10 and the resin layer 92, at the same time, the stamper 1 and the substrate B have a relatively weak pressing force f of about 500 kgf, for example. Are pressed against each other. Also in this case, since the output level of the ultrasonic vibration is about 40 W, which is relatively small, and the time for applying the ultrasonic vibration is not so long, unnecessary heat generation and erosion occur between the uneven surface 10 and the resin layer 92. The bubble 100 can be sufficiently removed from between these without causing a phenomenon.

  Thereafter, as shown in FIG. 4C, the stamper 1 and the substrate B are heated by the upper panel 20 and the lower panel 3 to about 135 ° C. which is equal to or higher than the glass transition point of the resin layer 92.

  Thereafter, as shown in FIG. 4D, the stamper 1 and the substrate B are pressed more strongly with a relatively strong pressing force f of, for example, about 2500 kgf while being heated.

  Then, after a required cooling period, the uneven surface 10 of the stamper 1 is separated from the resin layer 92 as shown in FIG. Thereby, the concavo-convex pattern corresponding to the concavo-convex surface 10 is transferred to the resin layer 92. The concave / convex pattern thus formed on the resin layer 92 is also a pattern having no transfer defect according to the concave / convex surface 10 as in the above-described embodiment.

  Therefore, even by the pattern transfer method of the present embodiment, the concave / convex pattern can be transferred to the resin layer 92 with high accuracy without peeling off the resin layer 92.

In the pattern transfer method according to another embodiment shown in FIG. 5, the resin layer 92 ′ is made of a photo-curing resin, and the stamper 1 is made of a light-transmitting SiO ₂ substrate. As shown to (a) of the figure, when making the uneven surface 10 of the stamper 1 closely_contact | adhere to resin layer 92 ', the working chamber B is made into a vacuum state.

  After that, as shown in FIG. 5B, the ultrasonic transducer 4 is brought into contact with the base layer 90 of the substrate B, and the irregular surface 10 and the resin layer 92 are oscillated by causing the ultrasonic transducer 4 to oscillate. Ultrasonic vibration is given between Even in this case, since the output level of the ultrasonic vibration is about 40 W, which is relatively small, and the time for applying the ultrasonic vibration is not so long, unnecessary heat generation or breakage is caused between the uneven surface 10 and the resin layer 92 ′. The bubbles 100 can be sufficiently removed from between these without causing an erosion phenomenon.

  Thereafter, as shown in FIG. 5C, the stamper 1 and the substrate B are sandwiched between the upper panel 20 and the lower panel 3 in a state where the pressing surface 10 and the resin layer 92 ′ are in contact with each other. They are pressed against each other with a relatively weak pressing force f of about 30 kgf. Thereby, the removal of the bubble 100 between the uneven surface 10 and the resin layer 92 ′ is further promoted.

  With the stamper 1 and the substrate B thus pressed, the resin layer 92 ′ is irradiated with resin curing light through the upper panel 20 and the stamper 1 as shown in FIG. Thereby, the resin layer 92 ′ made of the photo-curing resin is cured while being in close contact with the uneven surface 10.

  Then, after the required time has elapsed, the vacuum state of the working chamber B is released, and the uneven surface 10 of the stamper 1 is separated from the resin layer 92 ′ as shown in FIG. Thereby, the concavo-convex pattern corresponding to the concavo-convex surface 10 is transferred to the resin layer 92 ′. The concave / convex pattern thus formed on the resin layer 92 ′ is also a pattern having no transfer defect corresponding to the concave / convex surface 10 as in the above-described embodiment.

  Therefore, according to the pattern transfer method of this embodiment, a precise uneven pattern can be transferred to the resin layer 92 ′ made of a photo-curing resin in a shorter time than when heating time and cooling time are required.

  The pattern transfer method according to another embodiment shown in FIG. 6 also corresponds to the resin layer 92 'made of a photo-curing resin. Each of the processes (a) to (d) in the figure may be performed after the working chamber B is in a vacuum state, or may be performed under atmospheric pressure.

  As shown in FIG. 6B, when applying ultrasonic vibration between the concavo-convex surface 10 and the resin layer 92 ′, at the same time, the stamper 1 and the substrate B have a relatively weak pressing force of about 30 kgf, for example. They are pressed against each other by f. Even in this case, since the output level of the ultrasonic vibration is about 40 W, which is relatively small, and the time for applying the ultrasonic vibration is not so long, unnecessary heat generation or breakage is caused between the uneven surface 10 and the resin layer 92 ′. The bubbles 100 can be sufficiently removed from between these without causing an erosion phenomenon.

  Thereafter, as shown in FIG. 6C, the resin layer 92 ′ is irradiated with resin curing light through the upper panel 20 and the stamper 1 while the stamper 1 and the substrate B are pressed. Thereby, the resin layer 92 ′ made of the photo-curing resin is cured while being in close contact with the uneven surface 10.

  Then, after the required time has elapsed, as shown in FIG. 6D, the uneven surface 10 of the stamper 1 is separated from the resin layer 92 '. Thereby, the concavo-convex pattern corresponding to the concavo-convex surface 10 is transferred to the resin layer 92 ′. The concave / convex pattern thus formed on the resin layer 92 ′ is also a pattern having no transfer defect corresponding to the concave / convex surface 10 as in the above-described embodiment.

  Therefore, also by the pattern transfer method of the present embodiment, the concavo-convex pattern can be transferred to the resin layer 92 ′ made of a photo-curing resin in a short time and with high accuracy.

  In yet another embodiment, although not particularly illustrated, the uneven pattern may be transferred to a resin layer made of a room temperature transfer resin such as hydrogen silsesquioxane resin (HSQ). Unlike a thermoplastic resin or the like, a resin layer made of a room temperature transfer type resin is quickly deformed without requiring a heat treatment. Therefore, the heat treatment of FIG. 3 (d) or FIG. 4 (c), (d). A pattern transfer method in which is omitted can be applied. Since the room temperature transfer resin has a smaller viscosity than a thermoplastic resin or the like, it is preferable to apply a considerably strong pressing force such as about 10,000 kgf when pressing the stamper and the substrate. According to such a pattern transfer method for the resin layer of the room temperature transfer type resin, since heat treatment is not required, a precise uneven pattern can be transferred to the resin layer in such a short time.

  The present invention is not limited to the above embodiments.

  For example, in a pattern transfer apparatus, a stamper or a substrate may be disposed inside a chamber chamber that is isolated from the outside air, and the chamber chamber may be in a vacuum state.

  The object to which the concavo-convex pattern is transferred is not limited to the discrete track media, and the pattern transfer method according to each of the above embodiments can be applied to other objects as long as the object requires a desired fine concavo-convex pattern. it can.

  The ultrasonic vibration may be applied by bringing the ultrasonic vibrator into contact with the stamper.

Claims (9)

A pattern transfer method in which an uneven surface of a stamper is brought into close contact with a resin layer on a substrate, and an uneven pattern is transferred to the resin layer,
A pattern transfer method comprising applying ultrasonic vibration to the substrate or the stamper so as to remove bubbles from between the concave and convex surfaces in close contact with the resin layer.   The pattern transfer method according to claim 1, wherein the ultrasonic vibration is applied only for a predetermined time at an output level sufficient for removing bubbles.   The resin layer is made of a thermoplastic resin, and the ultrasonic vibration is applied to at least one of the substrate and the stamper in a state where the substrate and the stamper are arranged in a vacuum, and then the substrate and the stamper are pressed. The pattern transfer method according to claim 1, wherein the resin layer is heated.   The resin layer is made of a thermoplastic resin, the substrate and the stamper are arranged under atmospheric pressure or vacuum, and the ultrasonic vibration is applied to at least one of them while being pressed, and then the above The pattern transfer method according to claim 1, wherein the resin layer is heated in a state where the substrate and the stamper are pressed.   The resin layer is made of a photo-curing resin, and the ultrasonic vibration is applied to at least one of the substrate and the stamper in a state where the substrate and the stamper are arranged under vacuum, and then the substrate and the stamper are pressed. The pattern transfer method according to claim 1, wherein the resin layer is irradiated with resin curing light.   The resin layer is made of a photo-curing resin, the substrate and the stamper are arranged under atmospheric pressure or vacuum, and the ultrasonic vibration is applied to at least one of them while being pressed, and then the above-mentioned The pattern transfer method according to claim 1, wherein the resin layer is irradiated with resin curing light in a state where the substrate and the stamper are pressed.   The resin layer is made of a room temperature transfer resin, and the ultrasonic vibration is applied to at least one of the substrate and the stamper in a state where the substrate and the stamper are placed under vacuum, and then the substrate and the stamper are pressed. Item 3. The pattern transfer method according to Item 1 or 2.   The resin layer is made of a room temperature transfer type resin, the substrate and the stamper are arranged under atmospheric pressure or under vacuum, and the ultrasonic vibration is applied to at least one of them while being pressed. 3. The pattern transfer method according to 1 or 2. A pattern transfer device for transferring an uneven pattern to a resin layer on a substrate,
A stamper having an uneven surface for transferring an uneven pattern to the resin layer;
Press holding means for holding and pressing the substrate and the stamper in parallel;
An ultrasonic vibrator for applying ultrasonic vibrations to the substrate or the stamper so as to remove bubbles from between the concave and convex surfaces in contact with the resin layer by the pressing and holding means;
A pattern transfer apparatus comprising:

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