JP5107105B2 - Imprint method - Google Patents

Description

The present invention, an electromagnetic wave is irradiated to the mold having fine surface roughness relates fine irregularities to imprint how to be transferred to the transfer member.

  In recent years, research and development of devices having fine structures processed using nano-order processing techniques have been actively conducted. Among these, the nanoimprint technique is a method of transferring a mold pattern onto a substrate by pressing a mold having a nano-size pattern onto a substrate that is a transfer target. This method is high in productivity and low in cost.

As the nanoimprinting method, the thermal nanoimprinting method and the optical nanoimprinting method are the mainstream, but a nanoimprinting (LADI) method using laser light has been proposed as a method aiming at higher resolution and higher speed processing. In the LADI method, a mold in which a predetermined pattern is formed on a molten crystal is brought into contact with a silicon substrate and pressed, and this state is maintained and XeCl excimer laser pulses are irradiated. At that time, the surface of the silicon substrate is melted and liquefied, and as a result, a predetermined pattern is imprinted on the silicon substrate. Furthermore, it has been suggested that a semiconductor material, metal or alloy, polymer, or ceramic can be formed on the surface of the silicon substrate (see, for example, Non-Patent Document 1 and Patent Document 1).
Stephan Y. Chou et. al. , Appl. Phys. Lett, Vol. 67, Issue 21, pp. 3114-3116 (1995) JP-T-2005-521243

  However, the conventionally proposed LADI method has the following problems. First, when a substrate made of a material that transmits laser light having a predetermined wavelength to be irradiated is used, most of the laser light is transmitted through the substrate, and heat necessary for melting or liquefying the substrate surface. Since imprinting does not occur, imprint cannot be realized. That is, there is a problem that a substrate made of a material that transmits the irradiated laser beam cannot be used.

  As described above, Patent Document 1 and the like suggest that it is also possible to form a semiconductor material, metal or alloy, polymer, or ceramic on the substrate surface. There is no indication of the purpose of providing or a specific solution to the first problem. Furthermore, it is necessary to remove the material provided on the surface of the substrate. This increases the number of processes, which is not preferable in terms of increasing the manufacturing cost.

  Secondly, when a mold made of a material that does not transmit laser light having a predetermined wavelength to be irradiated is used, the laser light is absorbed by the mold and the substrate surface cannot be melted and liquefied. was there. That is, there is a problem that only a mold made of a material that transmits the irradiated laser beam can be used.

  In addition, since excimer lasers are gas lasers, they must be stable for a long period of time and require maintenance, and the laser beam is incident on the laser beam with the specified wavelength. Therefore, there is a problem that the degree of freedom in device design is low.

The present invention has been made in view of the above, to solve the problems of LADI method shall be the object of providing a more practical imprint method.

In the imprint method , the two uneven surfaces of the mold having two uneven surfaces and the two transferred surfaces of the two transferred objects are brought into contact with each other, and electromagnetic waves are applied to the two transferred surfaces. An imprint method for softening a transfer surface and transferring the uneven shape of the two uneven surfaces to the two transferred surfaces, and forming a heat generating layer that absorbs the electromagnetic wave and generates heat on the two uneven surfaces The heat generating layer forming step, and the two heat transfer layers are irradiated with the electromagnetic waves through the two transferred objects made of the material that transmits the electromagnetic waves, and the heat generating layers are heated to generate the two transferred surfaces. have a, a softening step of softening the, in the heat generating layer forming step, the two uneven surface may be a requirement that respectively form the heating layer structure in which a plurality of layers are laminated.

According to the present invention, to solve the problems of LADI method, Ru can provide a more practical imprint method.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

<First Embodiment>
The imprint method according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 6 are schematic views illustrating an imprint method according to the first embodiment of the invention. 1 to 6, 11 is a mold, 12 is a heat generating layer, 13 is a transfer target, and 14 is an electromagnetic wave. Reference numeral 11a denotes an uneven surface of the mold 11, and 13a denotes a transfer surface of the transfer body 13.

First, in the process shown in FIG. 1, a mold 11 having an uneven surface 11a is manufactured (mold manufacturing process). The uneven surface 11a is, for example, a surface having a nanoscale uneven pattern. Examples of the material of the mold 11 include polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitrile-styrene copolymer, polyethylene resin, polypropylene resin, silicon resin, fluorine resin, ABS resin, and urethane resin. Resins, oxides typified by SiO ₂ , Al ₂ O ₃ , nitrides typified by SiN, AlN, etc., crystals or ceramics such as carbides typified by SiC or GC (glassy carbon) Materials, and metal materials such as Ni and Ta, which are generally used in the nanoimprint method, can be used. The uneven surface 11a of the mold 11 can be formed by, for example, FIB (Focused Ion Beam) processing. As is well known, FIB (Focused Ion Beam) processing is a processing method that uses a finely focused Ga (gallium) ion beam, and a complicated shape can be produced with submicron level accuracy.

  Next, in the step shown in FIG. 2, the heat generating layer 12 is formed on the uneven surface 11a of the mold 11 (heat generating layer forming step). The heat generating layer 12 absorbs the electromagnetic wave 14 irradiated through the mold 11 or the transfer target 13 made of a material that transmits the electromagnetic wave 14 in the process shown in FIG. This is a layer made of a heat generating material that generates a quantity of heat that can soften the transfer surface 13a.

  The amount of heat generated in the heat generating layer 12 is adjusted by the amount of absorption of the material constituting the heat generating layer 12 with respect to the electromagnetic wave 14, the thermal conductivity, and the film thickness of the heat generating layer 12. FIG. 7 is a diagram schematically illustrating the relationship between the amount of absorption with respect to the electromagnetic wave 14, the thermal conductivity, the film thickness of the heat generating layer 12, and the amount of heat generated in the heat generating layer 12. In FIG. 7, the shaded area surrounded by the triangle is the amount of heat generated in the heat generating layer 12, and the imbalance between the amount of absorption with respect to the electromagnetic wave 14, the thermal conductivity, and the film thickness of the heat generating layer 12 shown in FIG. By optimizing the transfer target 13, a good imprint can be realized.

  For example, a material having a predetermined absorption amount and a predetermined thermal conductivity with respect to the electromagnetic wave 14 is selected, and the heat generation layer 12 generates a necessary amount of heat in consideration of the predetermined absorption amount and the predetermined thermal conductivity. The optimum film thickness of the heat generating layer 12 is determined. The amount of absorption and the thermal conductivity are preferably in the range of about 50 to 100% and about 20 to 400 W / m / k, for example.

  The material constituting the heat generating layer 12 is preferably a material that has good releasability from the transfer target 13 and causes similar heat generation even when irradiated with the electromagnetic wave 14 a plurality of times. Specifically, Si, Ge as a semiconductor, Sn, Sb, Bi as semimetals, Cu, Au, Pt, Pd as noble metals, Zn, Ni, Co, Cr as transition metals, or alloys thereof Further, it is preferable to be a carbide represented by SiC, TiC or the like, or a ceramic material such as an oxygen deficient oxide represented by SiOx or GeOx. Moreover, it is more preferable that the material constituting the heat generating layer 12 includes a phase change material. This is because the phase change material has a large amount of absorption and heat generation with respect to the electromagnetic wave 14, and therefore the heat generation layer 12 can reduce the optimum film thickness for generating the necessary amount of heat and can improve productivity. .

  The phase change material can be appropriately selected from those used as the material of the recording layer of the rewritable optical recording medium. For example, Sb, Ge, Ga, In, Zn, Mn, Sn, Ag, Mg It is preferable to use a material containing one or more elements selected from Ca, Ag, Bi, Se, and Te. As these phase change materials, desired materials can be used from the viewpoint of thermal characteristics and optical characteristics, but GeSbTe alloy, AgInSbTe alloy, AgInSbTeGe alloy, GaSbSnGe alloy, GeSbSnMn alloy, GeInSbTe alloy, GeSbSnTe alloy and the like are preferable.

  In addition, the heat generating layer 12 may have not only a single layer configuration but also a multilayer configuration in which a plurality of layers are stacked. By adopting a multilayer structure, it is possible to adjust not only the amount of heat generated but also the maintenance of temperature and the cooling rate, and better imprinting can be realized. Moreover, the mold 11 can be used a plurality of times by selecting a material that can be used a plurality of times as a material constituting the heat generating layer 12. Further, by providing the heat generation layer 12 on the mold 11 side, it is possible to prevent the heat generation material from adhering to the transfer surface 13a of the transfer body 13, so that the transfer surface 13a of the transfer body 13 need not be cleaned. Become.

Next, in the step shown in FIG. 3, the convex portion of the heat generating layer 12 formed on the concave and convex surface 11 a of the mold 11 and the transferred surface 13 a of the transferred body 13 are brought into contact with each other. Examples of the material of the transfer target 13 include polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitrile-styrene copolymer, polyethylene resin, polypropylene resin, silicon resin, fluorine resin, ABS resin, and urethane resin. Crystals of resins typified by SiO2, oxides typified by SiO ₂ , Al ₂ O ₃ , nitrides typified by SiN, AlN, and carbides typified by SiC and GC (glassy carbon) Alternatively, a ceramic material and a material used as a so-called substrate such as Si can be used. The contact is performed by strongly pressing the mold 11 and the transfer target 13 with external pressure. As a specific method of contact, a method of pressing with a mechanical force using a dedicated pressing machine may be used. However, the space between the heat generating layer 12 and the transfer surface 13a of the transfer body 13 is evacuated, and external contact is performed. A method using vacuum suction that is pressure-bonded by atmospheric pressure is preferable (vacuum suction step).

  Vacuum adsorption can be realized using a general-purpose apparatus, and it is easy to maintain the adsorption state. Further, even when the mechanical strength of the mold 11 and the transfer target 13 is not strong, a necessary minimum pressure can be obtained so as not to destroy the mold 11 and the transfer target 13. By using vacuum suction, a good imprint can be realized. For example, the vacuum suction is realized by an existing vacuum bonding apparatus used for bonding two substrates constituting a DVD-ROM, which is a well-known optical recording medium, in a vacuum in which there is no gas that causes bubbles. can do.

  Next, in the step shown in FIG. 4, the heat generation layer 12 is irradiated with the electromagnetic wave 14 through the mold 11 or the transfer target 13 made of a material that transmits the electromagnetic wave 14, and the heat generation layer 12 generates heat to be transferred. The transferred surface 13a of the body 13 is softened (softening step). Since the mold 11 and the transfer target 13 are strongly bonded to each other by, for example, vacuum adsorption via the heat generation layer 12, the heat generation layer 12 generates heat by irradiation of the electromagnetic wave 14 and the transfer surface 13 a of the transfer target 13. Is softened, the transfer surface 13 a of the transfer body 13 is deformed according to the uneven shape of the uneven surface 11 a of the mold 11. Needless to say, the softening point or melting point of the material constituting the mold must be equal to or higher than the softening point or melting point of the material constituting the transfer target.

  Here, it is necessary that at least one of the mold 11 and the transfer target 13 is made of a material that transmits the electromagnetic wave 14. When the mold 11 is made of a material that transmits the electromagnetic wave 14, the heat generation layer 12 is irradiated with the electromagnetic wave 14 through the mold 11 as shown in FIG. When the transfer target 13 is made of a material that transmits the electromagnetic wave 14, the heat generation layer 12 is irradiated with the electromagnetic wave 14 through the transfer target 13 as shown in FIG. When both the mold 11 and the transfer target 13 are made of a material that transmits the electromagnetic wave 14, the electromagnetic wave 14 is applied to the heat generating layer 12 through the mold 11 as shown in FIG. Irradiation may be performed, and as illustrated in FIG. 4B, the heat generation layer 12 may be irradiated with the electromagnetic wave 14 through the transfer target 13.

  The wavelength of the electromagnetic wave 14 is preferably 2000 nm or less. This is because there are few heat generating materials that sufficiently absorb electromagnetic waves at wavelengths longer than 2000 nm. Laser light is most preferable as the electromagnetic wave 14. This is because by using laser light, the light intensity per unit area on the heat generating layer 12, that is, the energy density can be increased. Furthermore, a semiconductor laser is particularly preferable as the laser that emits laser light. This is because the semiconductor laser is small and easy to maintain, low cost and long life.

  The softening process shown in FIG. 4 preferably includes a focusing process for focusing the electromagnetic wave 14 emitted from the light source on the heat generating layer 12. The electromagnetic wave 14 can be efficiently irradiated by the focusing process. Further, when imprinting is performed by two-dimensionally moving an optical head (not shown) having a light source that emits the electromagnetic wave 14 or the mold 11 and the transfer target 13 or both, focus servo is performed in the focusing process. It is preferable to carry out. By executing the focus servo, it is possible to eliminate the mechanical error and reliably focus the electromagnetic wave 14 on the heat generating layer 12, and to realize a good imprint.

  Here, the case where imprinting is performed by two-dimensionally moving an optical head (not shown) having a light source that emits electromagnetic waves 14, or the mold 11 and the transfer target 13, or both, is an example described later. As shown in 1 etc., it refers to a case where an electromagnetic wave is irradiated while a vacuum-adsorbed mold and a transfer object are placed on a turntable and rotated. The focus servo can be realized by a known method used when focusing (condensing) laser light so as to follow the rotating optical recording medium during recording or reproduction of the optical recording medium.

  Next, in the step shown in FIG. 5, by removing the mold 11 from the transfer target 13 (release step), as shown in FIG. 6, the uneven shape of the uneven surface 11 a of the mold 11 becomes the transfer target 13. Is transferred to the transfer surface 13a.

  In the conventional imprinting method, a transfer surface of a transfer object that is made of a material that does not transmit electromagnetic waves is irradiated with electromagnetic waves through a mold that is made of a material that transmits electromagnetic waves. The transfer surface of the mold was softened, and the uneven shape of the uneven surface of the mold was transferred to the transfer surface of the transfer body. That is, the material constituting the mold is limited to a material that transmits electromagnetic waves, and the material that forms the transfer target is limited to a material that does not transmit electromagnetic waves (a material that absorbs electromagnetic waves and generates heat).

  In the imprint method according to the first embodiment of the present invention, the heat generation layer 12 that absorbs the electromagnetic wave 14 and generates heat is formed on the uneven surface 11a of the mold 11, and the heat generation layer 12 is irradiated with the electromagnetic wave 14 to generate heat. In order to heat the layer 12 and soften the transfer surface 13a of the transfer target 13, at least one of the mold 11 and the transfer target 13 may be made of a material that transmits electromagnetic waves.

  That is, according to the imprint method according to the first embodiment of the present invention, a mold made of a material that transmits electromagnetic waves, which is a conventional imprint method, and a cover made of a material that does not transmit electromagnetic waves. Of course, it is composed of a combination of a mold that is made of a material that does not transmit electromagnetic waves and a transfer body that is made of a material that transmits electromagnetic waves, and a material that transmits electromagnetic waves. Imprinting can be performed even in a combination of a mold and a transfer target composed of a material that transmits electromagnetic waves, and a more practical imprinting method can be realized.

  Further, according to the mold 11 according to the first embodiment of the present invention, the heat generation layer 12 that absorbs the electromagnetic wave 14 and generates heat is formed on the uneven surface 11 a of the mold 11, and the heat generation layer 12 is irradiated with the electromagnetic wave 14. Since the heat generating layer 12 is heated to soften the transfer surface 13a of the transfer body 13, the uneven shape of the uneven surface 11a is also formed on the transfer surface 13a of the transfer body 13 made of a material that transmits electromagnetic waves. Can be transferred.

<Second Embodiment>
An imprint method according to the second embodiment of the present invention will be described with reference to FIGS. The imprint method according to the second embodiment of the present invention is characterized in that a mold having two concavo-convex surfaces is used and two concavo-convex surfaces are transferred to the transfer surface of the transfer object. This is different from the imprint method according to the first embodiment.

  8 to 13 are schematic views illustrating the imprint method according to the second embodiment of the invention. 8 to 13, 21 is a mold, 22 and 32 are heat generating layers, 23 and 33 are transferred bodies, and 24 is an electromagnetic wave. Reference numerals 21a and 21b denote concave and convex surfaces of the mold 21, and 23a and 33a denote transfer surfaces of the transfer bodies 23 and 33, respectively.

First, in the process shown in FIG. 8, the mold 21 having the uneven surfaces 21a and 21b is manufactured (mold manufacturing process). The uneven surfaces 21a and 21b are surfaces having a nanoscale uneven pattern, for example. Examples of the material of the mold 21 include polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitrile-styrene copolymer, polyethylene resin, polypropylene resin, silicon resin, fluorine resin, ABS resin, and urethane resin. Resins, oxides typified by SiO ₂ , Al ₂ O ₃ , nitrides typified by SiN, AlN, etc., crystals or ceramics such as carbides typified by SiC or GC (glassy carbon) A material and a mold material generally used in a nanoimprint method such as a metal material typified by Ni or Ta can be used, but a film-like material is particularly preferable. The uneven surfaces 21a and 21b of the mold 21 can be formed by, for example, FIB (Focused Ion Beam) processing. As is well known, FIB (Focused Ion Beam) processing is a processing method that uses a finely focused Ga (gallium) ion beam, and a complicated shape can be produced with submicron level accuracy.

  Next, in the step shown in FIG. 9, the heat generating layers 22 and 32 are formed on the uneven surfaces 21 a and 21 b of the mold 21 (heat generating layer forming step). The heat generating layers 22 and 32 absorb the electromagnetic wave 24 irradiated through the transferred bodies 23 and 33 made of a material that transmits the electromagnetic wave 24 in the step shown in FIG. This is a layer composed of a heat generating material that generates a quantity of heat sufficient to soften the 33 transfer surfaces 23a and 33a. Since the adjustment of the amount of heat generated in the heat generating layers 22 and 32 and the materials constituting the heat generating layers 22 and 32 are the same as in the case of the heat generating layer 12 in the imprint method according to the first embodiment of the present invention, The description is omitted.

Next, in the step shown in FIG. 10, the convex portions of the heat generating layers 22 and 32 formed on the concave and convex surfaces 21 a and 21 b of the mold 21 are brought into contact with the transferred surfaces 23 a and 33 a of the transferred members 23 and 33. Examples of the material of the transferred bodies 23 and 33 include polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitrile-styrene copolymer, polyethylene resin, polypropylene resin, silicone resin, fluorine resin, ABS resin, and urethane. Resins typified by resins, oxides typified by SiO ₂ , Al ₂ O ₃ , nitrides typified by SiN, AlN, carbides typified by SiC and GC (glassy carbon), etc. A material used as a so-called substrate such as Si or a ceramic material, or Si can be used. The contact is performed by strongly pressing the mold 21 and the transferred objects 23 and 33 with external pressure. As a specific method of contact, a method of pressing with a mechanical force using a dedicated pressing machine may be used, but between the heat generating layers 22 and 32 and the transfer surfaces 23a and 33a of the transfer objects 23 and 33. It is preferable to use a vacuum adsorption method in which a vacuum is applied and pressure bonding is performed by an external atmospheric pressure (vacuum adsorption step). Since vacuum suction is the same as in the case of the imprint method according to the first embodiment of the present invention, description thereof is omitted.

  Next, in the process shown in FIG. 11, the heat generating layers 22 and 32 are irradiated with the electromagnetic waves 24 through the transfer target bodies 23 and 33 made of a material that transmits the electromagnetic waves 24 to cause the heat generating layers 22 and 32 to generate heat. Thus, the transfer surfaces 23a and 33a of the transfer bodies 23 and 33 are softened (softening step). Since the mold 21 and the transferred objects 23 and 33 are strongly pressed by, for example, vacuum adsorption via the heat generating layers 22 and 32, the heat generating layers 22 and 32 generate heat by irradiation of the electromagnetic wave 24, and the transferred objects are transferred. When the transfer surfaces 23a and 33a of 23 and 33 are softened, the transfer surfaces 23a and 33a of the transfer bodies 23 and 33 are deformed according to the uneven shape of the uneven surfaces 21a and 21b of the mold 21. Needless to say, the softening point or melting point of the material constituting the mold must be equal to or higher than the softening point or melting point of the material constituting the transfer target.

  Here, it is necessary that both the transfer objects 23 and 33 are made of a material that transmits the electromagnetic wave 24. The electromagnetic wave 24 may be sequentially applied to the heat generating layers 22 and 32 via the transfer target 23 or 33, but the electromagnetic wave 24 is simultaneously applied to the heat generating layers 22 and 32 from both sides of the transfer target 23 and 33. Productivity can be improved. Since the wavelength of the electromagnetic wave 24 is the same as that of the electromagnetic wave 14 in the imprint method according to the first embodiment of the present invention, the description thereof is omitted.

  The softening step shown in FIG. 11 preferably includes a focusing step for focusing the electromagnetic wave 24 emitted from the light source on the heat generating layers 22 and 32. The electromagnetic wave 24 can be efficiently irradiated by the focusing process. Further, when imprinting is performed by two-dimensionally moving an optical head (not shown) having a light source that emits the electromagnetic wave 24 or the mold 21 and the transfer bodies 23 and 33, or both, It is preferable to execute the servo. By executing the focus servo, it is possible to eliminate the mechanical error and reliably focus the electromagnetic wave 24 on the heat generating layers 22 and 32. As a result, it is possible to realize a good imprint.

  Here, an optical head (not shown) having a light source that emits the electromagnetic wave 24 or a case where imprinting is performed by moving the mold 21 and the transferred bodies 23 and 33 or both in two dimensions is described later, for example. As shown in Example 1 or the like, it refers to a case in which electromagnetic waves are irradiated while a vacuum-adsorbed mold and a transfer target are placed on a turntable and rotated. The focus servo can be realized by a known method used when focusing (condensing) laser light so as to follow the rotating optical recording medium during recording or reproduction of the optical recording medium.

  When electromagnetic waves are simultaneously irradiated from both sides of the transferred body while the vacuum-adsorbed mold and the transferred body are placed on the turntable and rotated, for example, two A mechanism different from that of a conventional information recording / reproducing apparatus having an optical head is required, but such a mechanism can be realized within the scope of the prior art.

  Next, in the process shown in FIG. 12, by removing the mold 21 from the transferred bodies 23 and 33 (mold release process), the uneven shapes of the uneven surfaces 21a and 21b of the mold 21 as shown in FIG. It is transferred to the transfer surfaces 23a and 33a of the transfer bodies 23 and 33.

  In the conventional imprinting method, a transfer surface of a transfer object that is made of a material that does not transmit electromagnetic waves is irradiated with electromagnetic waves through a mold that is made of a material that transmits electromagnetic waves. The transfer surface of the mold was softened, and the uneven shape of the uneven surface of the mold was transferred to the transfer surface of the transfer body. That is, the material constituting the mold is limited to a material that transmits electromagnetic waves, and the material that forms the transfer target is limited to a material that does not transmit electromagnetic waves (a material that absorbs electromagnetic waves and generates heat). It was not possible to perform double-sided imprinting by contacting the transfer object.

  In the imprint method according to the second embodiment of the present invention, the heat generation layers 22 and 32 that generate heat by absorbing the electromagnetic wave 24 are formed on the concave and convex surfaces 21 a and 21 b of the mold 21, and the electromagnetic wave 24 is generated on the heat generation layers 22 and 32. , The heat generating layers 22 and 32 are heated to soften the transferred surfaces 23a and 33a of the transferred bodies 23 and 33 made of a material that transmits electromagnetic waves, and the uneven surfaces 21a and 21b of the mold 21 are softened. Are transferred onto the transfer surfaces 23a and 33a of the transfer bodies 23 and 33.

  That is, according to the imprint method according to the second embodiment of the present invention, unlike the conventional imprint method, it is possible to use a transfer body made of a material that transmits electromagnetic waves. A highly practical imprint method (double-sided imprint method) can be realized. In addition, according to the imprint method according to the second embodiment of the present invention, it is possible to realize an imprint method (double-sided imprint method) that is fast and excellent in productivity.

  In addition, according to the mold 21 according to the second embodiment of the present invention, the heat generating layers 22 and 32 that generate heat by absorbing the electromagnetic wave 24 are formed on the concave and convex surfaces 21 a and 21 b of the mold 21. In order to soften the transfer surfaces 23a and 33a of the transfer bodies 23 and 33 by irradiating the electromagnetic wave 24 with the heat generation layer 22 and 32, the transfer body 23 and the transfer body 23 and 33 are made of a material that transmits electromagnetic waves. The concavo-convex shape of the concavo-convex surfaces 21a and 21b can also be transferred to the 33 transfer surfaces 23a and 33a.

<Example 1>
FIG. 14 is a plan view illustrating a schematic shape of the mold 41 used in Example 1 of the present invention. FIG. 15 is a cross-sectional view illustrating the schematic shape of the mold 41 used in Example 1 of the present invention. A mold 41 shown in FIGS. 14 and 15 is a substrate used for an HD DVD-RW disc made of polycarbonate resin having a diameter of about 120 mm, a thickness of about 0.6 mm, and a central hole diameter of about 15 mm. A groove 45 having a track pitch TP1 = about 400 nm, a groove (recess) width W1 = about 200 nm, and a depth D1 = about 27 nm is formed in a spiral shape in a range of about φ48 to φ118 mm on one side of the mold 41. Yes. Unless otherwise specified in the first embodiment, the mold pattern indicates the spiral groove 45. The surface on which the groove 45 of the mold 41 is formed is referred to as an uneven surface 41a.

  FIG. 16 is a diagram for explaining the bonded sample 46. A Ge film (film thickness: about 10 nm) was formed as a heat generating layer 42 on the uneven surface 41a of the mold 41 by sputtering. A substrate made of a polycarbonate resin having the same external dimensions as the mold 41 and having no grooves 45 formed thereon was prepared for the transfer target 43. As shown in FIG. 16, the convex portion of the heat generating layer 42 formed on the concave and convex surface 41a of the mold 41 and the transferred surface 43a of the transferred body 43 are brought into contact with each other in a vacuum, and the vacuum suction is maintained. A bonded sample 46 was prepared.

  POP120-7A manufactured by Hitachi Computer Equipment Co., Ltd. was used as the irradiation device that radiates electromagnetic waves. This irradiation apparatus is used for initialization of a phase change optical recording medium, and is equipped with an optical head having a semiconductor laser having a wavelength of about 830 nm, which is an electromagnetic wave light source. This optical head has an autofocus servo mechanism, and condenses laser light emitted from a semiconductor laser, which is an electromagnetic wave light source, on the heat generation layer 42 of the bonded sample 46. The size of the focused beam is about 75 μm long and about 1 μm wide in the radial direction of the bonded sample 46.

  The imprint itself is almost the same as the initialization of the phase change optical recording medium. The bonded sample 46 is placed on the turntable provided in the irradiation device, rotated at an arbitrary rotation number, and the focus servo is executed. The laser beam was irradiated from the transferred object 43 side. Further, while irradiating the laser beam, the optical head was moved in the radial direction of the bonded sample 46, and the entire range where the groove 45 was formed was irradiated with the laser beam.

  Note that tracking servo is not executed when the laser beam is irradiated. In Example 1, imprinting was performed under the setting conditions as shown in Table 1. Under this condition, the work is completed in about 40 seconds per sheet. However, in Example 1, the work was stopped halfway so that the imprint state could be seen.

After irradiating the laser beam, the mold 41 and the transferred body 43 are peeled off, and when the transferred surface 43a of the transferred body 43 that is in contact with the uneven surface 41a of the mold 41 is visually observed, it is the same as the uneven surface 41a of the mold 41. Interference color due to light interference was observed. In order to make the state easier to understand, an Ag film of about 200 nm was formed on the transfer surface 43a of the transfer body 43. For comparison, an Ag film having a thickness of about 200 nm was also formed on the uneven surface 41 a of the mold 41.

  FIG. 17 is a diagram for confirming the interference colors of the uneven surface 41 a of the mold 41 and the transferred surface 43 a of the transferred body 43. In FIG. 17, since the same interference colors 41 b and 43 b can be confirmed on the uneven surface 41 a of the mold 41 and the transferred surface 43 a of the transferred body 43, the uneven surface 41 a of the mold 41 is formed on the transferred surface 43 a of the transferred body 43. It can be seen that the uneven shape is imprinted. Further, the interference color 43b of the transfer surface 43a of the transfer body 43 is not a portion where the laser beam irradiation is stopped, and since the interference color cannot be confirmed at the outer peripheral portion, imprinting by laser beam irradiation is performed. I understand that.

  Next, using an optical disk evaluation apparatus (ODU-1000 manufactured by Pulstec Corp.), the signals on the transfer surface 43a of the transferred object 43 that were imprinted in the tracking servos Off and On were checked. FIG. 18 is a diagram showing the total light amount signal 47, the trigger signal 48, and the push-pull signal 49 when the tracking servo is turned off. Here, the total light quantity signal 47 is a signal indicating the reflectance, the trigger signal 48 is a signal representing the time corresponding to one round, and the push-pull signal 49 is a signal used for a tracking error signal or the like. The horizontal axis indicates time, and the vertical axis indicates voltage. In FIG. 18, since the push-pull signal 49 is observed, it can be seen that the uneven shape of the uneven surface 41 a of the mold 41 is imprinted on the transfer surface 43 a of the transfer body 43.

  FIG. 19 is a diagram showing a total light amount signal 47, a trigger signal 48, and a push-pull signal 49 when the tracking servo is turned on. Here, the total light quantity signal 47 is a signal indicating the reflectance, the trigger signal 48 is a signal representing the time corresponding to one round, and the push-pull signal 49 is a signal used for a tracking error signal or the like. The horizontal axis indicates time, and the vertical axis indicates voltage. In FIG. 19, since the tracking servo can be executed without any problem, it can be seen that the uneven shape of the uneven surface 41a of the mold 41 is imprinted on the transfer surface 43a of the transfer body 43 satisfactorily. In the evaluation by this optical disk evaluation apparatus, the same result was obtained in all the areas irradiated with laser.

  According to the present invention, unlike the conventional imprint method, the heat generation layer 42 that generates heat by absorbing electromagnetic waves is formed on the uneven surface 41a of the mold 41, and the heat generation layer 42 is irradiated with electromagnetic waves to generate heat. Since the transfer surface 43a of the transfer body 43 is softened, it is possible to perform imprinting on the transfer body 43 made of a material that transmits electromagnetic waves, thereby realizing a more practical imprint method. be able to.

  The effects of the present invention are not limited to the materials and layer configurations used in Example 1, the duplicating apparatus, the duplicating method, and the evaluation apparatus.

<Examples 2 to 9>
In Examples 2 to 9, as in Example 1, the heat generating layer 42 was formed on the uneven surface 41a of the mold 41 shown in FIGS. First, in Examples 2 to 4, Ge was used as the material of the heat generating layer 42, and the film was formed with a film thickness as shown in Table 2, and imprinting was performed. The results are shown in Table 2 at the same time, and it has been found that there is an optimum range in which the Ge film thickness can be imprinted. The reason for this is that if the Ge film is too thin, the laser beam cannot be absorbed sufficiently and the amount of heat generated for imprinting will not occur, and if it is too thick, the heat generated will be dissipated by the Ge film itself. Conceivable.

Next, in Examples 5 to 9, Ag was used as the material of the heat generating layer 42, and the film thicknesses shown in Table 3 were formed and imprinted. The results are shown in Table 3 at the same time, but could not be imprinted regardless of the Ag film thickness. The reason for this is considered that the thermal conductivity of Ag itself is too high, so that the amount of heat necessary for imprinting cannot be generated.

  In Tables 2 and 3, the film thickness was measured using a spectroscopic ellipsometer (JA.Woollam M2000DI). The presence or absence of the groove signal by the optical disk evaluation apparatus was determined by whether or not the push-pull signal at the time of tracking servo off shown in FIG. 18 can be observed.

The results shown in Tables 2 and 3 indicate that the amount of heat generated for imprinting can be adjusted by the amount of heat generated by the heat generating material constituting the heat generating layer 42 with respect to the laser light, the thermal conductivity, and the thickness of the heat generating layer 42. It is very important. This is a content that could not be found in the prior art.

  According to the present invention, unlike the conventional imprint method, the heat generation layer 42 that generates heat by absorbing electromagnetic waves is formed on the uneven surface 41a of the mold 41, and the heat generation layer 42 is irradiated with electromagnetic waves to generate heat. Since the transfer surface 43a of the transfer body 43 is softened, it is possible to perform imprinting on the transfer body 43 made of a material that transmits electromagnetic waves, thereby realizing a more practical imprint method. be able to.

  The effects of the present invention are not limited to the materials and layer configurations used in this embodiment, the duplicating apparatus, the duplicating method, and the evaluation apparatus.

<Example 10>
In Example 10, the heat generating layer 42 was formed on the uneven surface 41a of the mold 41 shown in FIGS. 14 and 15 by sputtering. In the same manner as in Examples 1 to 4, Ge was used as the material of the heat generating layer 42, and a film having a film thickness as shown in Table 2 was formed and imprinted. In Example 10, when the laser beam was irradiated from the mold 41 side instead of from the transfer target 43 side, the same results as those of Examples 1 to 4 shown in Table 2 were obtained. From this, it can be seen that by using the imprinting method according to the present invention, good imprinting is possible regardless of the irradiation direction of the laser beam.

  According to the present invention, unlike the conventional imprint method, the heat generation layer 42 that generates heat by absorbing electromagnetic waves is formed on the uneven surface 41a of the mold 41, and the heat generation layer 42 is irradiated with electromagnetic waves to generate heat. In order to soften the transfer surface 43 a of the transfer body 43, when the mold 41 and the transfer body 43 are made of a material that transmits electromagnetic waves, either the mold 41 or the transfer body 43 is interposed therebetween. Even if the heat generating layer 42 is irradiated with electromagnetic waves, imprinting can be performed on the transfer target 43, and a more practical imprinting method can be realized.

  The effects of the present invention are not limited to the materials and layer configurations used in this embodiment, the duplicating apparatus, the duplicating method, and the evaluation apparatus.

<Example 11>
In Example 11, double-sided imprinting was performed using a commercially available hologram sheet as the mold 51. FIG. 20 is a photomicrograph of the hologram sheet that is the mold 51. The hologram sheet as the mold 51 shown in FIG. 20 is a rectangular parallelepiped thin sheet having an outer shape of 25 × 20 × 0.1 mm. FIG. 21 is an AFM image showing the unevenness of the hologram sheet, which is the mold 51, and was evaluated using an AFM apparatus (VN-8000 manufactured by Keyence Corporation). The evaluation of the AFM image shown in FIG. 21 confirmed that the hologram sheet as the mold 51 has irregularities with a height of about 130 nm and a pitch of about 800 nm (hereinafter, the hologram sheet as the mold 51 has an irregular surface. It is referred to as “uneven surface 51a”.

  FIG. 22 is a diagram for explaining the bonded sample 56. Two molds 51 were prepared, and a Ge film (film thickness: about 10 nm) was formed as a heat generation layer 52 on the uneven surface 51a of each mold 51 by a sputtering method. For the transferred bodies 53 and 63, a substrate made of a polycarbonate resin having the same external dimensions as the mold 41 shown in FIG. As shown in FIG. 22, the heat generating layer 52 formed on the concave / convex surface 51a of one mold 51 faces upward, and the heat generating layer 52 formed on the concave / convex surface 51a of another mold 51 faces downward. In order to prevent the two molds 51 from overlapping, the convex portion of one heat generating layer 52 and the transfer surface 53a of the transferred body 53, and the convex portion of the other heat generating layer 52 and the transferred body 63 The transferred surface 63a was brought into contact with each other in a vacuum, and bonded to a state where the vacuum suction was maintained, whereby a bonded sample 56 was produced.

  The bonded sample 56 thus produced was irradiated with laser light using the same apparatus and procedure as in Example 1. However, due to the dimensional relationship between the mold 51 and the transferred bodies 53 and 63, there is a portion where the mold 51 is not sandwiched between the transferred bodies 53 and 63, and there is no mold 51 when the autofocus mechanism is used. Fixed focus was used because the device stopped at that point. As the setting conditions, the conditions shown in Table 4 were used.

After irradiating the laser beam one side at a time, the transferred objects 53 and 63 are peeled off, and the transferred surfaces 53a and 63a of the transferred objects 53 and 63 that are in contact with the mold 51 are visually observed. Interference color due to interference was observed. FIG. 23 is a photomicrograph of the transfer surface 53a of the transfer object 53. FIG. 24 is an AFM image showing a state of the transfer surface 53a of the transfer object 53, and is evaluated using an AFM apparatus (VN-8000 manufactured by Keyence Corporation). From the evaluation of the AFM image shown in FIG. 24, it was confirmed that the transfer surface 53a of the transfer object 53 had irregularities with a height of about 70 nm and a pitch of about 820 nm. In the same way, it was confirmed that the transfer surface 63a of the transfer body 63 also has the same unevenness as the transfer surface 53a of the transfer body 53.

  The concavo-convex shape transferred to the transfer surfaces 53 a and 63 a of the transfer bodies 53 and 63 is about half the height of the concavo-convex shape of the concavo-convex surface 51 a of the hologram sheet as the mold 51. Good imprint. The reason why the height is reduced to about half is considered to be that the focus of the laser beam is fixed and the focus is insufficient, and a sufficient amount of heat generation cannot be obtained.

  In Example 11, for convenience of the experimental environment, two hologram sheets having a concavo-convex surface 51 a on one side are used as the mold 51, and the other mold 51 is provided with the concavo-convex surface 51 a of one mold 51 facing upward. With the concave and convex surface 51a facing downward, the two molds 51 are stacked in a vacuum so as to be sandwiched between the transfer bodies 53 and 63 so that the vacuum suction is maintained so that the two molds 51 do not overlap. Bonding and a bonding sample 56 were produced. However, from the results of Example 11, as shown in the second embodiment of the present invention, two transferred objects that are made of a material that transmits electromagnetic waves using a mold having an uneven surface on both sides are used. It is easily imagined that double-sided imprinting can be realized by irradiating electromagnetic waves through two transferred materials with a mold interposed therebetween.

  According to the present invention, double-sided imprinting is possible, and a more practical imprinting method can be realized. Further, according to the present invention, it is possible to realize an imprint method that is fast and excellent in productivity. The effects of the present invention are not limited to the materials and layer configurations used in this embodiment, the duplicating apparatus, the duplicating method, and the evaluation apparatus.

  The preferred embodiments and examples of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments and examples, and the above-described embodiments can be performed without departing from the scope of the present invention. Various modifications and substitutions can be added to the embodiments and examples.

FIG. 3 is a schematic diagram (part 1) illustrating the imprint method according to the first embodiment of the invention. FIG. 6 is a schematic diagram (part 2) illustrating the imprint method according to the first embodiment of the invention. FIG. 6 is a schematic diagram (part 3) illustrating the imprint method according to the first embodiment of the invention; FIG. 6 is a schematic diagram (part 4) illustrating the imprint method according to the first embodiment of the invention; FIG. 10 is a schematic diagram (part 5) illustrating the imprint method according to the first embodiment of the invention; FIG. 10 is a schematic diagram (part 6) illustrating the imprint method according to the first embodiment of the invention; It is a figure which illustrates typically the relationship between the amount of absorption with respect to electromagnetic waves 14, the heat conductivity, the film thickness of the heat generating layer 12, and the amount of heat generated in the heat generating layer 12. It is a schematic diagram (the 1) which illustrates the double-sided imprint method which concerns on the 2nd Embodiment of this invention. FIG. 6 is a schematic diagram (part 2) illustrating a double-sided imprint method according to a second embodiment of the invention. FIG. 10 is a schematic diagram (part 3) illustrating the double-sided imprint method according to the second embodiment of the invention; FIG. 10 is a schematic diagram (part 4) illustrating a double-sided imprint method according to the second embodiment of the invention; FIG. 10 is a schematic diagram (part 5) illustrating a double-sided imprint method according to the second embodiment of the invention; FIG. 10 is a schematic diagram (part 6) illustrating a double-sided imprint method according to the second embodiment of the invention; It is a top view which illustrates the schematic shape of the mold 41 used in Example 1 of this invention. It is sectional drawing which illustrates the schematic shape of the mold 41 used in Example 1 of this invention. It is a figure for demonstrating the bonding sample 46. FIG. FIG. 6 is a diagram for confirming interference colors of a concavo-convex surface 41a of a mold 41 and a transfer surface 43a of a transfer body 43 It is a figure which shows the total light quantity signal 47, the trigger signal 48, and the push pull signal 49 at the time of tracking servo Off. It is a figure which shows the total light quantity signal 47, the trigger signal 48, and the push pull signal 49 at the time of tracking servo On. 3 is a micrograph of a hologram sheet that is a mold 51. 6 is an AFM image showing the unevenness of a hologram sheet that is a mold 51. It is a figure for demonstrating the bonding sample 56. FIG. 4 is a micrograph of a transfer surface 53a of a transfer body 53. 4 is an AFM image showing a state of a transfer surface 53a of a transfer object 53.

Explanation of symbols

11, 21, 41, 51 Mold 11a, 21a, 21b, 41a, 51a Uneven surface of mold 12, 22, 32, 42, 52 Heat generation layer 13, 23, 33, 43, 53, 63 Transfer object 13a, 23a, 33a, 43a, 53a, 63a Transfer target surface of transfer target 14, 24 Electromagnetic wave 41b, 43b Interference color 45 Groove 46, 56 Bonded sample 47 Total light quantity signal 48 Trigger signal 49 Push-pull signal

Claims (13)

In a state where the two uneven surfaces of the mold having two uneven surfaces and the two transferred surfaces of the two transferred objects are in contact with each other, electromagnetic waves are applied to soften the two transferred surfaces, An imprint method for transferring the uneven shape of the two uneven surfaces to the two transferred surfaces,
A heating layer forming step of forming a heating layer that generates heat by absorbing the electromagnetic waves on the two uneven surfaces;
A softening step of irradiating the heat generating layer with the electromagnetic waves through the two transferred bodies made of a material that transmits the electromagnetic waves, and heating the heat generating layers to soften the two transferred surfaces; I have a,
The imprinting method is characterized in that, in the heat generating layer forming step, heat generating layers each having a structure in which a plurality of layers are laminated are formed on the two uneven surfaces . In the softening process, the imprint method according to claim 1, wherein the simultaneously irradiating the electromagnetic wave to the heating layer through the two transfer object. Further, between the heat generation layer forming step and the softening step, the heat generation layer formed on the concavo-convex surface of the mold is brought into contact with the transferred surface of the transferred body using vacuum suction. imprint method according to claim 1 or 2 characterized by having a vacuum suction process. The softening step is any one imprinting method according to claims 1 to 3, characterized in that it comprises a focusing process to focus the electromagnetic wave to the heating layer to be irradiated. 5. The imprint method according to claim 4 , wherein focus servo is executed in the focusing step. Further, before the heat generation layer forming step, a mold manufacturing step of manufacturing the mold having the uneven surface,
After said softening step, the any one imprinting method according to claim 1 to 5, characterized in that it has a, and a releasing step of releasing the mold from the transferred object. Thickness of the heating layer, the material constituting the heat generating layer, according to any one of claims 1 to 6, characterized in that it is determined taking into account the absorption and thermal conductivity with respect to the electromagnetic wave Imprint method. Material constituting the heat generating layer is a metal, semiconductor, dielectric, semi-metal, any, or any one-in of claims 1 to 7, characterized in that it consists of a mixture thereof in an organic material How to print. 9. The imprint method according to claim 8, wherein the material constituting the heat generating layer includes a phase change material. Maximum wavelength of the electromagnetic wave, the imprint method of any one of claims 1 to 9, characterized in that a 2000nm or less. The electromagnetic wave imprint method according to any one of claims 1 to 10, characterized in that a laser beam. The imprint method according to claim 11, wherein the laser that emits the laser light is a semiconductor laser. The mold imprinting method according to any one of claims 1 to 12, characterized in that it is a film.