JP2007268876A - Pattern transfer method, pattern transfer apparatus and manufacturing method of optical disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus achieving high-speed pattern transfer by a nano imprinting method. <P>SOLUTION: A stamper having a pattern formed on the surface is butted against a base material having a soft surface, and pressure is applied at a specified temperature so that the pattern is transferred on the surface of the base material. The pattern transfer method includes a process for arranging two or more pairs of the base materials and the stampers by stacking in a pressurizing direction and sandwiching them by a pair of plate-like members having a temperature regulating means for applying pressure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pattern transfer method and a pattern transfer apparatus for transferring a pattern formed on a stamper to a substrate by applying pressure to the substrate made of a material having a soft surface with a stamper. The invention further relates to a method of manufacturing an optical disc.

  In recent years, optical devices such as optical discs, diffraction gratings, light guide plates, and microlens arrays have been required to form nanoscale fine concavo-convex patterns on the surface for miniaturization, thinning, and high performance. It has been.

  Conventionally, as a method of forming a fine concavo-convex pattern on the surface of a plastic molded body, there is an injection molding method in which a molten plastic material is injected into a mold cavity having a female shape of the concavo-convex pattern to be formed on the surface of a molded product. Has been used. This method is an excellent method with few restrictions on the shape and molding material of the molded product, but since the molten plastic material is injected into the cold mold cavity, the molten plastic material becomes insufficiently flowable in the mold cavity. There is a limit to miniaturization and high accuracy of the concavo-convex pattern to be transferred. In particular, for thin molded products such as optical devices, the lack of flow of molten plastic material in the mold cavity becomes significant, and molding shrinkage also increases, so that a large residual stress tends to occur in the molded product. There was also a problem. The residual stress generated in the molded product is a particularly serious problem when a high refractive index material such as polycarbonate or polystyrene is used as the resin material.

  In order to cope with such a problem, as a method for molding an optical device in place of an injection molding method in recent years, a pattern formed on the stamper is transferred to the substrate by applying pressure to the substrate made of a soft material with a stamper. A kind of press molding method called nanoimprint method is used. FIG. 10 is a diagram schematically showing a method for molding an optical device by the nanoimprint method. As shown in FIG. 10, a material sheet 105 made of thermoplastic plastic is sandwiched between an upper mold 102 integrally provided with a heater 101 and a lower mold 104 integrally provided with a heater 103. The surface of the upper mold 102 and the lower mold 104 is formed on the surface by applying a pressing force to the material sheet 105 after the surface of the heater 101 and 103 is softened by applying heat to the heater 105. , 107 are transferred.

  According to this nanoimprint method, even when a thin optical device is molded using a high refractive index material such as polycarbonate or polystyrene, there is almost no resin flow shortage or molding shrinkage, which occurs in the molded body. Residual stress is relaxed, and an optical device with high quality can be manufactured.

JP 2003-1705 A

  However, in the molding method as shown in FIG. 10, since the patterns are transferred to the substrates one by one, it is difficult to increase the speed as in the conventional injection molding method, and this pattern transfer process becomes a bottleneck in optical device manufacturing. There is a fear.

  The present invention has been made in view of such circumstances, and pattern transfer for transferring a pattern formed on a stamper onto a substrate at high speed is performed by applying pressure to the substrate made of a material having a soft surface with a stamper. It is an object of the present invention to provide a method and an apparatus that can be performed.

  The present invention further provides a method for manufacturing an optical disc.

  The inventor proposes the following means for solving the above problems.

  That is, the present invention is a method of transferring a pattern onto the surface of the substrate material by contacting a stamper with a pattern formed on the surface against a substrate material having a soft surface and applying pressure at a predetermined temperature. A pattern transfer method comprising a step of placing a plurality of sets of substrate materials and stampers in a pressurizing direction and sandwiching and pressing between a pair of plate-like members having temperature adjusting means on at least one side. is there.

  The present invention also transfers a pattern onto both surfaces of the substrate material by contacting a stamper with a pattern formed on the surface against both surfaces of the substrate material having a soft surface and pressurizing at a predetermined temperature. Pattern transfer including a step of arranging a plurality of sets of substrate materials and a pair of stampers in a pressurizing direction and sandwiching and pressing between a pair of plate members having temperature adjusting means on at least one side A method is provided.

  The present invention also relates to a method of transferring a pattern onto the surface of the substrate material by contacting a stamper with a pattern formed on the surface against a substrate material having a soft surface and applying pressure at a predetermined temperature. A plurality of sets of substrate materials, stampers, and plate-like separation members that prevent contact between the substrate materials are arranged in the pressurizing direction, and are sandwiched by a pair of plate-like members having temperature adjusting means on at least one side. A pattern transfer method including a pressurizing step is provided.

  In the pattern transfer method of the present invention, one or more plate-like temperature adjusting members having temperature adjusting means are sandwiched between the pair of plate-like members to perform temperature adjustment in the pattern transfer step.

  The present invention is also an apparatus for transferring a pattern to the surface of a flexible substrate material, a stamper having a pattern formed on the surface, and a pair of plates capable of holding a plurality of sets of the stamper and the substrate material. And a means for pressing the pair of plate-shaped members toward each other, and a means for adjusting the temperature of the pair of plate-shaped members.

  The present invention also relates to an optical disc in which a pattern is transferred to the surface of the substrate material by contacting a stamper having a pattern formed on the surface against a substrate material having a soft surface and pressurizing the stamper at a predetermined temperature. A method of manufacturing an optical disc, comprising: a step of arranging a plurality of sets of substrate materials and stampers in a pressurizing direction, and sandwiching and pressing between a pair of plate-like members having temperature adjusting means on at least one side A method is provided.

  As described above, according to the pattern transfer method, pattern transfer apparatus, and optical disc manufacturing method of the present invention, pattern transfer by the nanoimprint method can be performed at high speed. For example, if N sets of substrate materials are arranged in the pressurizing direction and pressed simultaneously, the press time can be shortened by 1 / N compared to the case of pattern transfer one by one.

  The best mode for carrying out the pattern transfer method, the pattern transfer apparatus, and the optical disc manufacturing method of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 9 are diagrams illustrating embodiments of the present invention. In these drawings, the same reference numerals denote the same components, and the basic configuration and operation are the same. To do.

[First embodiment]
A first embodiment of a pattern transfer method and a pattern transfer apparatus of the present invention will be described. FIG. 1 is a diagram schematically showing a pattern transfer process in the present embodiment. As shown in FIG. 1, in this pattern transfer process, a plurality of sets of substrate material 2 and stamper 1 for pattern transfer to this are prepared and sandwiched between the lower stage 3 and the upper stage 4 and heated while being heated. The pattern is transferred by pressing.

  As the substrate material 2, for example, a polycarbonate sheet having a glass transition temperature of about 170 ° C. and a thickness of 0.1 mm can be used. A guide groove having a groove depth of 180 nm and a groove width of 1 μm is formed in a spiral shape on the surface of the stamper 1 in contact with the substrate material 2. The lower stage 3 and the upper stage 4 are provided with a heater or the like (not shown), and can apply a force of 5 t to the substrate material 2 and the stamper 1 at a temperature of about 180 ° C. Thereby, the polycarbonate of the substrate material 2 is fluidized and deformed following the pattern of the stamper 1.

[Second Embodiment]
A second embodiment of the pattern transfer method and pattern transfer apparatus of the present invention will be described. FIG. 2 is a diagram schematically showing a pattern transfer process in the present embodiment. As shown in FIG. 2, in this pattern transfer process, a plurality of sets of the substrate material 2 and a pair of stampers 1 for pattern transfer on both sides thereof are prepared and sandwiched between the lower stage 3 and the upper stage 4. Then, pattern transfer is performed by applying pressure while heating. Other conditions are the same as in the first embodiment. Thereby, the pattern transfer to both surfaces of the substrate can be performed at a time.

[Third embodiment]
A pattern transfer method and a pattern transfer apparatus according to a third embodiment of the present invention will be described. FIG. 3 is a diagram schematically showing a pattern transfer process in the present embodiment. As shown in FIG. 3, in this pattern transfer process, a plurality of sets of the substrate material 2, the stamper 1 and the stainless plate 5 for pattern transfer to this are prepared, and sandwiched between the lower stage 3 and the upper stage 4, Pattern transfer is performed by applying pressure while heating. In the present embodiment, the circular stamper 1 and the rectangular substrate material 2 are used, but the corner portion of the substrate material 2 is not covered by the stamper 1. Therefore, in order to prevent the corner portions of the substrate material 2 protruding from the stamper 1 from being fused, a stainless plate 5 having a thickness of about 0.5 mm capable of covering the entire substrate material 2 is used. . Other conditions are the same as in the first embodiment. This makes it possible to use a stamper having an arbitrary size and shape.

[Fourth embodiment]
A fourth embodiment of the pattern transfer method and pattern transfer apparatus of the present invention will be described. FIG. 4 is a diagram schematically showing a pattern transfer process in the present embodiment. As shown in FIG. 4, in this pattern transfer process, a plurality of sets of the substrate material 2, the stamper 1 for pattern transfer to this, and the heater built-in stainless steel plate 7 are prepared and sandwiched between the lower stage 3 and the upper stage 4. Then, pattern transfer is performed by applying pressure while heating. Other conditions are the same as in the first embodiment. Thus, even when a large number of substrate materials 2 are processed at the same time, they can be heated as evenly as possible. Also, the time required for heating is shortened.

  A nickel stamper having an inner diameter of 15 mm, an outer diameter of 135 mm, and a thickness of 300 μm in which guide grooves having a depth of 180 nm and a width of 1 μm were dug spirally from a radius of 22 mm to a radius of 58 mm was produced as follows. First, a silane coupling agent was applied on glass, and a resist agent was applied thereon by spin coating. Next, after the resist was exposed at a wavelength of 405 nm and NA of 0.6, the exposed portion was removed. Subsequently, after vapor-depositing nickel, it laminated | stacked by 300 micrometers by plating, and peeled nickel from glass.

  A polycarbonate having a thickness of 0.1 mm was produced by an extrusion molding method as a substrate made of a material capable of maintaining softness on the surface. Subsequently, it cut | judged to the square whose inner diameter is 15 mm and whose external shape is 130 mm on one side. The polycarbonate substrate had a glass transition temperature of 170 ° C.

  As shown in FIG. 5, the press machine includes a heating unit for raising the temperature, a vertical movement mechanism unit for applying pressure, and an installation unit for arranging a plurality of stampers. The heating unit can be heated to 300 ° C., the temperature is detected by a temperature monitor, and the temperature is controlled by the control unit. By the vertical movement mechanism, a maximum load of 10 t can be applied between the vertical heating units. The upper stage and the lower stage have a structure in which an electric heater is incorporated as a heating unit. As shown in FIG. 6, the installation portion for installing the stamper has a column having a diameter of 15 mm at the center, and the stamper and the sheet can be alternately arranged on the column. A recess is provided in the upper part of the upper stage so that no load is applied to the support column.

  In this embodiment, an example is shown in which two sets of stampers and substrates are used to perform pattern transfer simultaneously on two sheets. As shown in FIG. 7, the stamper and the substrate were arranged on the support column in the order of a lower stage, a polycarbonate substrate, a stamper, a silicon rubber sheet, a stamper, a polycarbonate substrate, and an upper stage. At this time, the stamper was arranged so that the pattern surface of the stamper was on the polycarbonate sheet side, and a silicon rubber sheet having a thickness of 1 mm was inserted between the stampers so that the sheets did not contact each other. Since the thickness of the stamper is 300 μm, the thickness of the substrate is 0.1 mm, and the thickness of the silicon rubber sheet is 1 mm, the height of the column of the installation portion is set to 2 mm.

  Next, a pressure of 10 t was applied by the vertical movement mechanism. While maintaining this pressure, the temperature was raised to 180 ° C. by the heater of the heating section. Since the glass transition temperature of polycarbonate is 170 ° C., the polycarbonate has fluidity at a temperature of 180 ° C., and therefore deforms following the shape of the stamper. After the temperature was lowered to room temperature, each stamper and the substrate were peeled off, and the stamper pattern could be transferred to each substrate. As described above, it is possible to perform transfer onto a plurality of substrates with a single press.

  Next, an azo dye generally used in DVD-R is applied to the pattern transfer surface of the substrate by a spin coating method, and then a silver layer of 160 nm is laminated by a magnetron sputtering method, so that the thickness of the substrate is 0.1 mm. Thus, an optical recording medium similar to DVD-R was produced. The optical information recording medium thus produced is placed on a 0.5 mm glass substrate, and laser light is incident from the glass side of 0.5 mm in an optical head with a laser wavelength of 640 nm and an objective lens 0.6 similar to DVD. When recording and playback were performed, recording and playback were possible.

  A nickel stamper having an inner diameter of 15 mm, an outer diameter of 135 mm, and a thickness of 300 μm in which guide grooves having a depth of 180 nm and a width of 1 μm were dug spirally from a radius of 22 mm to a radius of 58 mm was produced as follows. First, a silane coupling agent was applied on glass, and a resist agent was applied thereon by spin coating. Next, after the resist was exposed at a wavelength of 405 nm and NA of 0.6, the exposed portion was removed. Subsequently, after vapor-depositing nickel, it laminated | stacked by 300 micrometers by plating, and peeled nickel from glass.

A polycarbonate having a thickness of 0.1 mm was produced by an extrusion molding method as a substrate made of a material capable of maintaining softness on the surface. Subsequently, it cut | judged to the square whose inner diameter is 15 mm and whose external shape is 130 mm on one side. The polycarbonate substrate had a glass transition temperature of 170 ° C.
As shown in FIG. 5, the press machine includes a heating unit for raising the temperature, a vertical movement mechanism unit for applying pressure, and an installation unit for arranging a plurality of stampers. The heating unit can be heated to 300 ° C., the temperature is detected by a temperature monitor, and the temperature is controlled by the control unit. The vertical movement mechanism can apply a maximum load of 10 t between the hot plates. The upper stage and the lower stage have a structure in which an electric heater is incorporated as a heating unit.

  As shown in FIG. 8, 10 sets of stampers and a polycarbonate substrate were arranged in the installation portion where the stampers were installed. Next, a pressure of 10 t was applied by the vertical movement mechanism. While maintaining this pressure, the temperature was raised to 180 ° C. by the heater of the heating section. At this time, it took 90 seconds for the temperature of the stamper and the substrate farthest from the heating unit to reach 180 ° C. Next, after the temperature was lowered to room temperature, each stamper and the substrate were peeled off, and the stamper pattern could be transferred to each substrate. When the heating unit was set to 80 seconds, the temperature was not uniform, and there was a portion where the pattern was not transferred to a part of the polycarbonate substrate. Thus, when pattern transfer is performed on 10 polycarbonate substrates by a single press, heating must be performed for 90 seconds or more.

  In accordance with the above-described fourth embodiment of the present invention, as shown in FIG. 9, a stainless steel plate incorporating an electric heater is provided as a heating unit between stampers, and 10 sets of stampers and a polycarbonate substrate are arranged. Next, a pressure of 10 t was applied by the vertical movement mechanism. While maintaining this pressure, the temperature was raised to 180 ° C. by the heater of the heating section. At this time, it took 10 seconds for the temperature of the stamper and the substrate farthest from the heating unit to reach 180 ° C. Next, after the temperature was lowered to room temperature, each stamper and the substrate were peeled off, and the stamper pattern could be transferred to each substrate. Thus, by arranging the heating unit between the stampers, the heating rate can be increased, and therefore the pattern transfer time can be greatly shortened.

  Although the pattern transfer method and the pattern transfer apparatus of the present invention have been described with reference to specific embodiments, the present invention is not limited to these. A person skilled in the art can make various changes and improvements to the configurations and functions of the invention according to the above-described embodiments or other embodiments without departing from the gist of the present invention.

It is a figure which shows typically the pattern transfer process in 1st Embodiment of this invention. It is a figure which shows typically the pattern transfer process in 2nd Embodiment of this invention. It is a figure which shows typically the pattern transfer process in 3rd Embodiment of this invention. It is a figure which shows typically the pattern transfer process in 4th Embodiment of this invention. It is a figure which shows roughly the structure of the press used in the Example. It is a figure which shows the structure of the installation part of the press used in the Example. FIG. 4 is a diagram showing a pattern transfer process in Example 1. 6 is a diagram showing a pattern transfer process in Example 2. FIG. FIG. 10 is a diagram showing a pattern transfer process in Example 3. It is a figure which shows typically the shaping | molding method of the optical device by a nanoimprint method.

Explanation of symbols

1 Stamper 2 Substrate material 3 Lower stage 4 Upper stage 5 Stainless steel plate 6 Silicon rubber sheet 7 Heater built-in stainless steel plate 101, 103 Heater 102 Upper die 104 Lower die 105 Material sheet 106, 107 Concavity and convexity pattern

Claims (6)

A method of transferring a pattern to the surface of the substrate material by contacting a stamper having a pattern formed on the surface against a substrate material having a soft surface and pressurizing at a predetermined temperature,
A pattern transfer method including a step of arranging a plurality of sets of substrate materials and stampers in a pressurizing direction and sandwiching and pressing between a pair of plate-like members having temperature adjusting means on at least one side. A method of transferring a pattern to both surfaces of the substrate material by contacting a stamper with a pattern formed on the surface against both surfaces of the substrate material having a soft surface and pressurizing at a predetermined temperature,
A pattern transfer method including a step of arranging a plurality of sets of substrate materials and a pair of stampers in a pressurizing direction and sandwiching and pressing between a pair of plate-like members having temperature adjusting means on at least one side. A method of transferring a pattern to the surface of the substrate material by contacting a stamper having a pattern formed on the surface against a substrate material having a soft surface and pressurizing at a predetermined temperature,
Placing a plurality of sets of substrate materials, stampers and plate-like separation members that prevent contact between the substrate materials in the pressurizing direction, and sandwiching and pressing between a pair of plate-like members having temperature adjusting means on at least one side A pattern transfer method comprising:   4. The temperature adjustment in the pattern transfer step is performed by sandwiching one or more plate-like temperature adjustment members having temperature adjustment means between the pair of plate-like members. 5. The pattern transfer method according to Item. An apparatus for transferring a pattern to the surface of a substrate material having flexibility,
A stamper with a pattern formed on the surface;
A pair of plate-like members capable of holding a plurality of sets of the stamper and the substrate material;
Means for pressing the pair of plate-shaped members toward each other;
A pattern transfer apparatus comprising: means for adjusting a temperature of the pair of plate-like members. This is a method of manufacturing an optical disc by transferring a pattern onto the surface of the substrate material by contacting a stamper with a pattern formed on the surface against a substrate material having a soft surface and applying pressure at a predetermined temperature. And
A method of manufacturing an optical disc, comprising: a step of arranging a plurality of sets of substrate materials and stampers in a pressurizing direction, and sandwiching and pressing between a pair of plate-like members having temperature adjusting means on at least one side.

Images