JP2008122475A - Optical waveguide, manufacturing method of optical waveguide, mold for manufacturing waveguide, and method for manufacturing mold - Google Patents

Optical waveguide, manufacturing method of optical waveguide, mold for manufacturing waveguide, and method for manufacturing mold Download PDF

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JP2008122475A
JP2008122475A JP2006303222A JP2006303222A JP2008122475A JP 2008122475 A JP2008122475 A JP 2008122475A JP 2006303222 A JP2006303222 A JP 2006303222A JP 2006303222 A JP2006303222 A JP 2006303222A JP 2008122475 A JP2008122475 A JP 2008122475A
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surface
mold
core
material
clad
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Junya Kobayashi
Akira Nagase
Ikutake Yagi
生剛 八木
潤也 小林
亮 長瀬
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Nippon Telegr & Teleph Corp <Ntt>
日本電信電話株式会社
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Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical waveguide whose optical characteristics can be improved by reducing roughness of the surface, and also to provide its manufacturing method, a mold for manufacturing the waveguide, and a method for manufacturing the mold. <P>SOLUTION: On a first surface ((100) surface) of a silicon substrate 21, a mask is applied by forming SiO<SB>2</SB>in a manner exposing the first surface with a prescribed pattern. Then, with the silicon substrate 21 immersed in a KOH solution, crystal anisotropic etching is performed on the first surface. With the (111) surface 24 of the silicon substrate made to appear from the exposed part 23, a V groove 25 is formed having the (111) surface 24 as a wall face. Thus, the mold 26 is prepared and, by transferring this mold to a core material, a triangular waveguide is manufactured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical waveguide, a method for producing an optical waveguide, a mold for producing a waveguide, and a method for producing a mold, and more particularly, an optical waveguide produced by transfer, a method for producing an optical waveguide, and transfer. The present invention relates to a mold for performing the above and a manufacturing method thereof.

  From the recent advancement of advanced information technology, a communication system capable of transmitting a large amount of information at high speed is desired, and an optical communication system is being developed as such a communication system. As such a system, various optical communication systems such as a wavelength division multiplexing (WDM) system have been developed. In an optical communication system, a waveguide is a very important component. Recently, a polymer waveguide has attracted attention as a waveguide because of its flexibility and toughness. In Non-Patent Document 1, an imprint process and a printing process are performed to produce a polymer waveguide.

1A to 1D are diagrams showing a conventional method for producing a polymer waveguide disclosed in Non-Patent Document 1. FIG.
In FIG. 1A, a lower cladding layer 2 is applied on a substrate 1. Next, the lower clad layer 2 applied on the substrate 1 is pressed on the mold 3 having the convex and concave portions 4 and the concave portions 5 that are formed into the concave and convex patterns, and the concave and convex patterns are transferred to the surface of the lower clad layer 2. (FIG. 1B). In this way, the imprint process is performed, and as shown in FIG. 1C, the convex portions 7 and the concave portions 8 formed by transferring the convex portions 4 and the concave portions 5 are formed in the lower cladding layer 2. . A printing process for printing the core 9 in the recess 8 formed in this way is performed (FIG. 1D). This printing process is performed by screen printing, offset printing, gravure printing, inkjet, dispenser application, or the like. In this way, the core 9 is formed on the lower cladding layer 2.

  Conventionally, the concave portion 5 of the mold used in the imprint process is formed by a lithography method, an electron beam drawing method, a laser beam drawing method or the like on a photosensitive resin layer formed on the glass of the die. It is manufactured by forming a latent image of a fine pattern, developing the photosensitive resin layer to form a fine pattern of the photosensitive resin, and then performing an electroforming process (see Non-Patent Document 2). That is, the concave / convex pattern of the mold is formed using physical etching. Conventionally, the concave / convex pattern may be formed by cutting the mold surface with an end mill or the like.

  That is, conventionally, a concavo-convex pattern has been formed on a mold (original) used in a waveguide manufacturing method by physical etching or cutting.

Yukihiro Sugihara and five others, "Preparation of large-diameter polymer optical waveguides using a molding process", IEICE Technical Report, OME2003-83, p. 17-21, 2003 Akihiko Sano and two others, "Replicated Polymer Optical Waveguide" SPICA "", IEICE Technical Report, OME2003-82, p. 13-16, 2003

  The above-described method for producing a waveguide using transfer does not require development work for forming a core pattern when the core is formed on the clad, as compared with a production method using photolithography. It can be efficiently manufactured, and also eliminates the need for a resist material, leading to cost reductions. This is a powerful polymer waveguide fabrication method, but even this method using transfer was fabricated. In order to make a waveguide of high quality, there are still problems to be improved.

  In particular, as described above, in the molds used so far, the uneven shape formed on the surface is formed by physical etching or cutting, so there is a problem in the flatness and surface roughness of the processed surface. . The concavo-convex pattern formed on the mold is transferred to the clad, and the concavo-convex pattern reverse to the concavo-convex pattern formed on the mold is formed on the clad, and the core is formed in the concave portion of the concavo-convex pattern. The flatness and surface roughness of the processed surface of the mold, such as the wall surface, are reflected in the flatness and surface roughness of the core surface.

  Here, when the concave / convex pattern of the mold is formed using physical processing such as physical etching or cutting, micro (nano) scale cutting traces may exist on the processed surface. If such a cutting trace exists, the cutting trace is also transferred, and the influence remains on the core surface, which deteriorates the characteristics of the manufactured waveguide. As described above, when a polymer waveguide is manufactured using a die manufactured by physical etching or cutting, the propagation characteristics of the waveguide are affected, which is one factor that hinders the reduction of the waveguide loss. It was.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an optical waveguide capable of reducing the roughness of the surface and improving the optical characteristics of the waveguide, a method for manufacturing the optical waveguide, a waveguide, and the like. An object of the present invention is to provide a mold for producing a waveguide and a method for producing the mold.

  In order to achieve the above object, the present invention provides an optical waveguide comprising a clad and a core, wherein the core has a triangular cross section.

  The invention according to claim 2 is a method of manufacturing an optical waveguide comprising a clad and a core, wherein crystal anisotropic etching is performed on a first surface of a silicon substrate, and a predetermined pattern is formed on the first surface. A preparation step of preparing a mold produced by forming a recess having a (111) plane of a silicon substrate as a wall surface, a clad formation step of forming the clad, and fluidity and curing on the clad And a core forming step of transferring the concave portion formed in the mold to the material, curing the material, and forming a core having a shape reversed to the concave portion. And a process.

  The invention according to claim 3 is a method of manufacturing an optical waveguide comprising a clad and a core, wherein crystal anisotropic etching is performed on a first surface of a silicon substrate, and a predetermined pattern is formed on the first surface. Flexibility having a convex portion that is inverted from the first concave portion, which is manufactured based on a first mold manufactured by forming a first concave portion having a (111) surface of a silicon substrate as a wall surface. A preparation step of preparing a second mold having, a providing step of applying a material to be the clad by being hardened on the substrate, and a convex formed on the second mold A clad forming step of transferring a portion to the material, curing the material, and forming the clad having a second concave portion having a shape reversed to the convex portion; and forming the core in the second concave portion And a core forming step.

  The invention according to claim 4 is a method for producing an optical waveguide comprising a clad and a core, wherein crystal anisotropic etching is performed on a first surface of a silicon substrate, and a predetermined pattern is formed on the first surface. It is possible to have a second recess having the same shape as the first recess, which is manufactured based on a first mold manufactured by forming a first recess having the (111) surface of the silicon substrate as a wall surface. A preparation step for preparing a second mold having flexibility, a clad formation step for forming the clad, and an application for imparting a material that becomes the core by having fluidity and curing on the clad. And a core forming step of transferring a second recess formed in the second mold to the material, curing the material, and forming a core having a shape reversed from the second recess. It is characterized by having.

  The invention according to claim 5 is the invention according to any one of claims 2 to 4, wherein the first surface is a (100) surface and the cross section of the core is triangular.

  According to a sixth aspect of the present invention, in the invention according to any one of the second to fourth aspects, the first surface is a (110) surface, and the core has a quadrangular cross section.

  The invention according to claim 7 is a mold for producing an optical waveguide having a clad and a core, and is a silicon substrate and a recess having a predetermined pattern formed on the first surface of the silicon substrate. And a recess having a (111) plane of the silicon substrate as a wall surface.

  The invention according to claim 8 is the invention according to claim 7, wherein the first surface is a (100) surface and the concave portion is a V-groove.

  The invention according to claim 9 is the invention according to claim 7, wherein the first surface is a (110) surface, and the recess is a groove having a square cross section.

  The invention according to claim 10 is a method for producing a mold for producing an optical waveguide having a clad and a core, wherein the first surface is exposed in a predetermined pattern on the first surface of the silicon substrate. A mask forming step for forming the material, and crystal anisotropic etching is performed on the first surface so that the (111) surface of the silicon substrate appears from the exposed first surface. A recess forming step for forming a recess having the (111) plane as a wall surface, and a removing step for removing the material, wherein the material is a mask for the crystal anisotropic etching. .

  The invention described in claim 11 is the invention described in claim 10, characterized in that the first surface is a (100) surface and the recess is a V-groove.

  According to a twelfth aspect of the invention, in the tenth aspect of the invention, the first surface is a (110) surface, and the concave portion is a groove having a square cross section.

  According to the present invention, since the concavo-convex pattern formed on the mold for manufacturing the optical waveguide to be manufactured is formed by crystal anisotropic etching, the roughness of the core surface is reduced, and the optical waveguide It is possible to improve the characteristics.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In one embodiment of the present invention, a mold made of a crystal material is used to produce an optical waveguide that can be molded, and when the pattern is formed so as to have a waveguide shape when transferred, a concavo-convex shape is formed. In addition, wet etching is used, and the difference in the etching rate of the crystal plane of the mold is utilized. It is preferable that the etching rate for each crystal plane is significantly different. Therefore, in one embodiment of the present invention, the crystal plane is selected so that the etching rate varies greatly depending on the orientation.

For example, in the first and second embodiments, the crystal plane of the surface on which the pattern shape is formed in the mold made of silicon crystal is the (100) plane, and the (100) plane is used as a mask so that it is not affected by the etching solution. A material, for example, SiO 2 is formed and crystal anisotropic etching is performed. By this crystal anisotropic etching, the region where the mask is not formed is etched, and the (111) surface whose etching rate is about 200 times slower than the (100) surface appears, and the V groove having the (111) surface as the wall surface Is formed.

Further, in the third embodiment, in the mold made of silicon crystal, the crystal plane of the surface on which the pattern shape is to be formed is the (110) plane, and SiO 2 is formed using the (110) plane as a mask to form the crystal. Anisotropic etching is performed. By this crystal anisotropic etching, a region where no mask is formed is etched, and a (111) plane perpendicular to the (110) plane appears, and a groove having a (111) plane perpendicular to the surface as a wall surface is formed. It is formed.

  In one embodiment of the present invention, a waveguide having a shape reversed from the pattern shape is formed by transferring the pattern shape formed on the mold. The recess formed by the etching is an original core to be formed. Therefore, the core can be formed with the predetermined pattern by forming the concave portion with a predetermined pattern.

  In one embodiment of the present invention, the V-groove and the groove are formed by crystal anisotropic etching instead of physical etching and cutting as in the prior art. ) Can be made flat at the atomic layer level. That is, no cutting trace is left on the formed wall surface.

  Therefore, the V-groove having the flat wall surface or the mold on which the groove is formed is used to transfer the V-groove or groove pattern shape to the core material, the clad material, or the base of the soft stamper described later. Since the flat wall surface at the atomic layer level of the V-grooves and grooves formed in the mold is reflected on the surface of the core of the formed waveguide, the surface of the core is transferred to the atomic layer level after transfer. Can be flat. Therefore, since scattering caused by the roughness of the core surface can be reduced, waveguide loss can be reduced, and the optical characteristics of the optical waveguide can be dramatically improved.

  An example of the optical waveguide that can be molded is a polymer waveguide.

(First embodiment)
Mold making process
FIGS. 2A to 2C are schematic views for explaining a mold manufacturing process according to this embodiment.
In FIG. 2 (a), SiO 2 22a and 22b are formed on a (100) surface of a silicon substrate 21 serving as a mold base, separated by a predetermined distance, as a mask. From the region between the SiO 2 22a and 22b, the (100) plane (exposed portion 23) of the silicon substrate 21 is exposed. Next, the silicon substrate 21 on which the SiO 2 22a and 22b are formed is immersed in a KOH solution as an etching solution, and the exposed portion 23 of the silicon substrate 21 is etched. By this etching, the (111) surface 24 appears, and when the etching stops, a V-groove 25 having the (111) surface 24 as a wall surface is formed (FIG. 2B). Next, by removing SiO 2 22a and 22b, a mold 26 in which a V-groove 25 having the (111) plane 24 as a wall surface is formed (FIG. 2C).

  In this embodiment, a KOH solution is used as an etching solution, but the present invention is not limited to this. For example, silicon crystals such as hydrazine, EPW (ethylenediamine-pyrocatechol-water), TMAH (tetramethylammonium hydroxide), etc. Any liquid may be used as long as it can perform crystal anisotropic etching.

  Now, as described above, since the (111) plane of the silicon crystal is much less likely to be etched than the (100) plane with respect to the KOH solution (about 200 times), the (111) plane of silicon appears at the completion of etching, V-grooves are formed (crystal anisotropic etching). The (111) plane is a flat surface at the atomic layer level. Therefore, the (111) surface 25 that is the wall surface (etching surface) of the V groove 25 is a smooth surface with reduced surface roughness. The smooth surface becomes the wall surface of the V-groove serving as the original plate, and the polymer waveguide produced by the transfer method has the same smoothness as the silicon etching surface (wall surface). Thus, the propagation loss shows an extremely excellent value.

  As described above, in this embodiment, in order to improve the smoothness of the side surface of the core of the polymer waveguide to be manufactured later, that is, to reduce the propagation loss of the waveguide, the V-groove is formed by crystal anisotropic etching. 25 is formed. That is, the formation of the V-groove by crystal anisotropic etching is not intended to improve the predetermined characteristics of the mold, but the propagation characteristics of the polymer waveguide fabricated using the mold. It is essential to improve. That is, in this embodiment, by transferring the V-groove pattern of the mold to the waveguide, in addition to forming the core of the waveguide, a smooth surface is transferred to the side surface of the core.

  Conventionally, only the core shape was formed by transfer with a mold, so the formed side surface of the core reflects the shape of the side surface of the uneven part of the mold formed by machining, and flatness Was deteriorated. Therefore, in order to improve flatness, a separate surface treatment is necessary. However, in the present embodiment, as described above, the wall surface of the V groove 25 (corresponding to the groove in the third embodiment) that is an uneven shape for forming the core shape by transfer is formed at the stage of manufacturing the mold 26. Since smoothing is performed at the atomic layer level, the smoothness is reflected on the core wall surface by transfer, so that it is possible to form a core having a side surface with excellent flatness without performing a separate surface treatment. it can. In addition, once a mold is manufactured, a polymer waveguide can be manufactured repeatedly, so that each of the polymer waveguides manufactured from one mold in a separate process can be used as a mold. The flatness of the formed V-groove can be reflected.

Polymer Waveguide Fabrication Process FIGS. 3A to 3D are views for explaining a polymer waveguide fabrication method according to this embodiment.
In FIG. 3A, an Arton film 32 as a clad film is bonded onto a glass substrate 31, and an ultraviolet curable epoxy resin 33 as a core material is dropped onto the Arton film 32. Next, the glass substrate 31 is tilted so that the ultraviolet curable epoxy resin 33 is spread over the entire surface of the ARTON film 32. The ultraviolet curable epoxy resin 33 is disposed on the entire surface of the ARTON film 32 by tilting the glass substrate 31.

  In this embodiment, an ultraviolet curable epoxy resin is used as the core material. However, the present invention is not limited to this. For example, a thermoplastic resin, a thermosetting resin, a polyimide, a silicone resin, an acrylic resin / epoxy resin is ultraviolet curable. Resin, polysilane, polyacrylate, polycarbonate, polyether, polyamide, etc. can be used.

  Next, the mold 26 is arranged so that the V groove 25 and the ultraviolet curable epoxy resin 33 face each other (FIG. 3B), and pressure is applied from the entire surface of the mold 26 facing the V groove 25. . Due to the pressure from the entire surface of the mold 26, the ultraviolet curable epoxy resin 33 enters the V groove 25, and the other ultraviolet curable epoxy resin 33 is pushed out of the arton film 32 (FIG. 3C). ). Next, by irradiating with ultraviolet rays, the ultraviolet curable epoxy resin 34 existing in the V-groove 25 is cured, and the mold 26 is removed from the arton film 32. Then, a polymer waveguide having a triangular core 35 formed on the ARTON film 32 is produced (FIG. 3D).

  In the present embodiment, the triangular core 35 is formed by transferring the shape of the V groove 25 having the wall surface flattened by crystal anisotropic etching as described above to the ultraviolet curable epoxy resin 33 as the core material. Therefore, the flatness of the side surface 36 of the triangular core 35 can be improved. Therefore, since the waveguide loss of the light guided through the triangular core 35 can be reduced, the optical characteristics of the waveguide can be dramatically improved.

  Now, as shown in FIG. 4, the polymer waveguide produced in the present embodiment has a triangular core shape. Thus, by using a triangular core, interface scattering can be suppressed as compared with a conventional square cross section as will be described later, so that waveguide loss can be reduced.

The following calculation was performed on the relationship between the waveguide shape and the loss. For the square cross section of the waveguide and the right triangle, the cross sectional areas were made the same (see Table 1 for parameters), and the average number of wall reflections was obtained by ray tracing with a waveguide length of 10 cm. FIG. 5 is a diagram illustrating a state in which the relationship between the waveguide shape and the loss is obtained according to the present embodiment. In FIG. 5, a waveguide 52 having the same shape as the waveguide 51 having the shape to be measured of 50 cm is formed at one end of the waveguide 51 having a shape to be measured (a triangular waveguide or a square waveguide) having a length of 10 cm. One end is connected, and the other end of the waveguide 52 is connected to one end of a circular waveguide 53 having a radius α and inscribed in the shape of the waveguide 52, and light is incident from the other end of the circular waveguide 53. To do. In each waveguide, the clad refractive index n clad = 1.512 and the core refractive index n core = 1.56.

  When the shape to be measured is a triangle, the waveguide 51 and the waveguide 52 are triangular waveguides, and the junction point 54 between the waveguide 52 and the circular waveguide 53 is circular as indicated by reference numeral 55. The waveguide 52 and the circular waveguide 53 are connected so that a circle having a cross-sectional shape of the waveguide 53 is inscribed in a triangle having a cross-sectional shape of the waveguide 52. On the other hand, when the shape to be measured is a square, the waveguide 51 and the waveguide 52 are square waveguides, and the junction point 54 between the waveguide 52 and the circular waveguide 53 is a circular guide as indicated by reference numeral 56. The waveguide 52 and the circular waveguide 53 are connected so that a circle having a cross-sectional shape of the waveguide 53 is inscribed in a square having a cross-sectional shape of the waveguide 52.

  As can be seen from Table 1, the results show that the number of wall surface reflections is smaller in the triangular waveguide than in the square waveguide.

  The waveguide loss of the waveguide is caused by absorption and scattering of the material itself and scattering due to irregularities at the core / cladding interface. In general, at a wavelength where material loss is small, interface scattering is a major factor of loss. Therefore, if the roughness of the interface is the same, the waveguide loss decreases as the number of times the guided light is reflected on the interface decreases.

  In the ray tracing calculation described above, it can be seen that the waveguide having a triangular cross section is only subjected to interface scattering at a rate of 40.64 / 47.68 = 0.85 (times) as compared with a waveguide having a normal square cross section. . Therefore, the cross-sectional shape of the core can suppress the loss in the triangular shape as in the present embodiment rather than the normal square shape.

  In this embodiment, the V-groove 25 of the mold 26 is transferred to the core material. However, the present invention is not limited to this, and it may be transferred to the clad. In this case, a clad material as described later may be applied to a substrate such as a glass substrate, and the V-groove 25 may be transferred to the clad material. What is important in the present embodiment is not to determine what is to be transferred, but to use the mold 26 for waveguide fabrication (core shape formation).

(Second Embodiment)
In the present embodiment, a flexible mold (hereinafter also referred to as a soft stamper) is manufactured using the mold manufactured in the mold manufacturing process of the first embodiment, and the soft stamper is used. Polymer waveguides are produced by extrusion lamination.

  In the present specification, the “flexible mold (soft stamper)” refers to a resin that bends as the pushing means such as a roller comes into contact. As a material of the soft stamper, a material that has fluidity before curing, is cured by light or heat, and becomes a flexible (flexible) material after the curing is used. In the present embodiment, as a flexible mold (soft stamper), cycloolefin polymer; polyacrylate including polymethyl methacrylate, polycarbonate, polyether, polyimide, polyamide, epoxy resin, etc. Plastic resins; Thermosetting resins such as epoxy resins; Acrylics, resins obtained by making epoxy resins ultraviolet curable; Silicone resins; Fluorine resins and the like can be used.

FIG. 6 is a diagram illustrating a state in which the core is formed by extrusion lamination according to the present embodiment.
In FIG. 6, a core material 62 is formed on the entire surface of the clad film 61. The core material 62 is formed by being applied on the clad film 61. The application of the core material 62 may be dropping of the core material 62 or spraying by spraying. Moreover, application | coating with a roller etc. may be sufficient.

  In FIG. 6, the core material 62 is disposed on the entire surface of the clad film 61, but the present invention is not limited to this. In an embodiment of the present invention, if the core material 62 is disposed at least at the start point of the extrusion by the extrusion means such as a roller to be described later (movement start position of the extrusion means), the core material 62 is not disposed on the entire surface. Also good.

  The core material may be a liquid material or a gel material. That is, any material can be used as the core material as long as the material has at least fluidity that can be extruded, is cured by light or heat, and functions as the core of the polymer waveguide after the curing. . For example, the core material described above can be used.

  In FIG. 6, the soft stamper 63 has a convex part 64 and a concave part 65 on one surface. The soft stamper 63 is arranged so that the convex portion 64 and the concave portion 65 are in contact with the core material 62. That is, the soft stamper 63 is bonded to the clad film 61 through the core material 62.

In the present specification, the “convex portion” includes a protrusion formed on a certain surface. Moreover, the area | region other than the recessed part formed in a certain surface is also included. That is, when a concave portion is formed on a certain surface, the other region can be seen as a projection when viewed from the concave portion.
Similarly, in the present specification, the “concave portion” includes a depression formed on a certain surface. Moreover, the area | region other than the convex part formed in a certain surface is also included. That is, when a convex portion is formed on a certain surface, it can be seen that the other region is depressed when viewed from the convex portion.

  Next, at one end of the soft stamper 63, the roller 66 is pressed against the surface of the soft stamper 63 that faces the surface on which the unevenness is formed. Next, from one end to the other end (in the direction of the arrow in the figure), a relative speed with respect to the soft stamper 63 is applied while applying a predetermined pressure so as to apply pressure to the soft stamper 63 not by a surface but by a line. Roller 66 is rolled to perform extrusion lamination so that becomes zero.

  As the roller 66 moves, the convex portion 64 pushes out the core material 62 in the moving direction of the roller 66 in order from the movement start position of the roller 66 and comes into contact with the clad film 61. On the other hand, the concave portion 65 is maintained when the core material 62 is filled in the concave portion 65 when the soft stamper 63 is bonded to the clad film 61. The core material 62 is filled in each concave portion 65 by the extrusion by the portion. In this way, the core material 67 filled in the recess is formed.

  In this way, the roller 66 is rolled to the other end, and the soft stamper 63 and the clad film 61 are bonded together in a state where the core material 67 is left in the region between the concave portion 65 and the clad film 61. Is transferred to the core material 62. Then, when the roller 66 is rolled to the other end, the excess core material pushed out by each convex portion 64 is pushed out from the other end, and in the space between each concave portion 65 and the clad film 61, there is a core. The material 67 will remain.

  In this embodiment, since extrusion lamination is performed using the soft stamper 63 having flexibility as described above, even if the surface of the convex portion 64 and the surface of the clad film 61 are rough, the core material to be extruded is the roller 66. Therefore, the amount of the core material remaining as a residue can be reduced because it moves along the surface of the convex portion 64 and the surface of the clad film 61 by the pushing force due to the movement of the roller 66. That is, even if a residue remains, the amount can be reduced to a scale that is the same as or lower than the wavelength of the light used. Therefore, it is possible to reduce the required surface accuracy of the soft stamper and the clad, and the manufacturing cost and the manufacturing time can be reduced.

  In this specification, the term “extrusion laminate” means that a first material having flexibility such as a soft stamper or a resin film serving as a base of the soft stamper is bonded to an arbitrary second material while the first material is bonded. This is a step of transferring a concave portion and / or a convex portion of either one of the material and the second material to the other material while applying pressure with a line. Note that the shape of the unevenness between the transfer source and the transfer destination is inverted. That is, by moving the first material from one side to the other while applying pressure by an extruding means such as a roller, the first material is bonded to the second material, and excess material is removed. This is the intended process.

  The extruded laminate described above can be used when producing a core as described above, or can be used when producing a soft stamper as described later. When the core is manufactured, the first material is a soft stamper and the second material is a clad, and when the soft stamper is manufactured, the first material is a resin film and the second material is an original plate. It is a certain mold.

  As described above, in the case of producing the core, in the extrusion lamination, the core material is filled in the concave portion of the soft stamper and the other core material is extruded, and the core material is extruded from one end of the soft stamper in a predetermined direction. The extra core material is pushed out while the soft stamper is stuck to the clad by moving the pushing means such as a roller toward. That is, the extrusion laminating in this case is not a purpose of attaching the soft stamper to the clad but a process aiming at removing excess core material in order to form the core of the polymer waveguide. Therefore, after extrusion lamination, the soft stamper may stick to the clad or may not stick, and it is not essential whether the soft stamper sticks to the clad.

  Further, after extrusion lamination, the core material may not be completely extruded at the interface between the clad and the convex portion, and the core material may remain as a residue.In one embodiment of the present invention, as described above, a roller or the like Since the excess core material is pushed out by the movement of the pushing means, the amount of the remaining core material can be suppressed to the scale of the wavelength of light used or less.

  Further, as in this embodiment, when a soft stamper is used as a mold for a soft stamper for producing a polymer waveguide, cutting and pasting can be easily performed, so that an increase in area can be easily performed at low cost. it can.

Soft Stamper Manufacturing Process FIGS. 7A to 7D are views for explaining a soft stamper manufacturing process according to this embodiment.
First, the mold 26 described in the first embodiment is prepared, and the recesses 70a and 70b are formed so as to sandwich the V groove 25 (FIG. 7A). The recesses 70a and 70b may be formed by physical etching or cutting, or may be formed by wet etching. Further, the depths of the recesses 70a and 70b are set to be deeper than at least the depth of the V-groove 25.

  In FIG. 7 (b), cycloolefin resin 71 (80% mesitylene solution) is dropped onto the surface of the mold 26 where the V-groove 25 and recesses 70a and 70b are formed, and the cycloolefin resin 71 is spin-coated. Spread over the entire processed surface of the mold 26. In this way, the cycloolefin resin is applied to at least a part of the mold 26.

  In FIG.7 (c), the laminator is used and the cycloolefin film 72 (base film used as the base | substrate of a soft stamper) is closely_contact | adhered to the cycloolefin resin 71 application surface of the metal mold | die 26. FIG. One end of the cycloolefin film 72 is in contact with the outer portion of the V-groove 25 on the application surface of the cycloolefin resin 71 of the mold 26, and the other side of the film is warped. By pressing the laminator roller 73 from the portion where the mold 26 and the cycloolefin film 72 are in contact, and pressing the roller with a strong force (10 kg / cm) while rolling, the inside of the V groove 25 of the mold 26 and the recess 70a, Extrusion laminating is performed by pressing the cycloolefin resin 71 into 70b and bringing the excess cycloolefin resin and air in the V groove 25 and the recesses 70a and 70b into close contact with each other while extruding.

  That is, the cylindrical roller 73 is pressed against the surface of the cycloolefin film 72 that contacts the cycloolefin resin 71. At this time, needless to say, the cycloolefin resin 71 is disposed on the surface (the movement start position of the roller) opposite to the surface against which the roller 73 is pressed. Next, the roller 73 is pressed at a pressure of 10 kg / cm while rolling the roller 73 such that the relative speed of the cycloolefin film 72 from the one end to the other end of the roller contact line with the cycloolefin film 72 becomes zero. By performing extrusion lamination in this manner, excess cycloolefin resin 71 is extruded along with the movement of the roller. In this way, the shape of the V groove 25 of the mold 26 is transferred to the cycloolefin resin 71.

  In this embodiment, the cycloolefin resin 71 is disposed on the entire surface (processed surface) of the mold 26 where the V-groove 25 is formed, but the cycloolefin resin 71 is disposed at least at the movement start position of the roller. If you do. At this time, needless to say, after the roller 73 has moved to the other end, an amount of cycloolefin resin that can sufficiently fill the V-groove 25 with the cycloolefin resin 71 is applied to the movement start position.

  In FIG.7 (d), the metal mold | die 26 which performed extrusion lamination is arrange | positioned on a hotplate, and the cycloolefin resin 71 is heat-hardened. Next, the cycloolefin film 72 is peeled from the mold 26. In this manner, a cycloolefin sheet with a cured cycloolefin resin (triangle convex portion 74, convex portions 76a and 76b) having a shape in which the V groove 25 and the concave portions 70a and 70b of the mold 26 are inverted is produced. . This is the soft stamper 75.

Polymer Waveguide Fabrication Process FIGS. 8A to 8F are diagrams for explaining a polymer waveguide fabrication method according to this embodiment.
In FIG. 8A, an ultraviolet curable epoxy resin 82 as a clad material is dropped on a glass substrate 81. Next, the glass substrate 81 is tilted so that the ultraviolet curable epoxy resin 82 is spread over the entire surface of the glass substrate 81. By the inclination of the glass substrate 81, the ultraviolet curable epoxy resin 82 is disposed on the entire surface of the glass substrate 81.

  The clad material may be a liquid material or a gel material. What is important in the present invention is that the clad material existing on the glass substrate is extruded during the extrusion lamination described later. Therefore, any material can be used as the cladding material as long as it is a material that has at least fluidity that can be extruded, is cured by light or heat, and functions as the cladding of the polymer waveguide after the curing. it can.

  In this embodiment, a thermoplastic resin, a thermosetting resin, a polyimide, a silicone resin, an acrylic resin / epoxy resin made of UV curable resin, polysilane, polyacrylate, polycarbonate, polyether, polyamide, or the like is used as a clad material. be able to. Needless to say, the cladding material is set to have a refractive index smaller than that of the core material.

  In FIG. 8B, the soft stamper 75 is brought into close contact with the ultraviolet curable epoxy resin 82 (cladding material) application surface of the glass substrate 81 using a laminator. One end of the outer portion of the soft stamper 75 where the projections and depressions are located is in contact with the application surface of the ultraviolet curable epoxy resin 82 of the glass substrate 81, and the other end is warped. The roller 83 of the laminator is pressed from the soft stamper 75 side where the glass substrate 81 and the soft stamper 75 are in contact, and the roller 83 is pressed with a strong force while rolling, so that the convex portion 76a and the triangular convex portion 74 of the soft stamper 75 are pressed. The ultraviolet curable epoxy resin 82 is pushed into the region between the convex portion 74 and the convex portion 76b, and the extra ultraviolet curable epoxy resin 82 and the air in the region are pushed out to adhere to each other. And extrude laminating.

  Next, after irradiating ultraviolet light from the soft stamper 75 side, heat treatment is performed to completely cure the ultraviolet curable epoxy resin. Next, the soft stamper 75 is peeled from the glass substrate 81. A cured epoxy resin having a shape in which the unevenness of the soft stamper 75 (triangular protrusion 74, protrusions 76a and 76b) is inverted is formed. This cured epoxy resin becomes the clad 84. The V-groove 25 formed in the mold 26 that is the original plate is transferred to the clad 84. That is, a V-groove 85 having the same shape as the V-groove 25 is formed in the clad 25 (FIG. 8C).

  In FIG. 8D, an ultraviolet curable epoxy resin 86 as a core material is dropped on the clad 84. Next, the glass substrate 81 is tilted so that the ultraviolet curable epoxy resin 86 is spread over the entire surface of the clad 84. By this inclination of the glass substrate 81, an ultraviolet curable epoxy resin 86 is disposed on the entire surface of the clad 84. The ultraviolet curable epoxy resin 86 is adjusted to have a higher refractive index than the ultraviolet curable epoxy resin 82 in order to function as a core.

  Excess UV curable epoxy resin 82 is pushed out by pressing the plate material 87 from the UV curable epoxy resin 82 side toward the glass substrate 81 side so that the UV curable epoxy resin 86 remains in the V groove 85. (FIG. 8 (e)). Next, ultraviolet rays are irradiated and heat treatment is performed to completely cure the ultraviolet curable epoxy resin. This cured ultraviolet curable epoxy resin becomes the core. Next, the plate material 87 is peeled from the glass substrate 81. In this way, a polymer waveguide in which a triangular core 88 is formed can be produced (FIG. 8 (f)).

  In the present embodiment, the core shape is formed (transferred) using the soft stamper 75. However, the present invention is not limited to this, and a second soft stamper (hereinafter referred to as a secondary soft stamper) is used based on the soft stamper 75. The transfer may be performed using a secondary soft stamper.

  FIGS. 9A and 9B are views for explaining a method of manufacturing a secondary soft stamper according to the present embodiment.

  In FIG. 9A, a cycloolefin resin 92 (80% mesitylene solution) is dropped on a cycloolefin film 91 as a base film of a secondary soft stamper, and the cycloolefin resin 92 is formed by spin coating. Spread over the entire surface.

  In FIG. 9A, a laminator is used to bring the soft stamper 75 into close contact with the cycloolefin resin 92 application surface of the cycloolefin film 91. The one end of the cycloolefin resin 92 applied surface of the cycloolefin film 91 is made to hit one end of the soft stamper 75, and the other end of the soft stamper 75 is warped. The roller 93 of the laminator is pressed from the portion where the cycloolefin film 91 and the soft stamper 75 are in contact, and the roller 76 is pressed with a strong force (10 kg / cm) while rolling, so that the convex portion 76a and the triangular convex portion 74 of the soft stamper 93 are pressed. The cycloolefin resin 92 is pushed into the region between the triangular convex portion 74 and the convex portion 76b, and the excess cycloolefin resin and the air in the region are pressed and adhered to each other, thereby extruding laminate. I do.

  In FIG. 9B, the cycloolefin film 91 subjected to extrusion lamination is disposed on a hot plate, and the cycloolefin resin 92 is heat-cured. Next, the soft stamper 75 is peeled from the cycloolefin film 91. In this way, a cycloolefin sheet with a cured cycloolefin resin (convex portion 94) having a shape in which the unevenness of the soft stamper 75 is inverted is produced. This is the secondary soft stamper 96. The secondary soft stamper 96 is transferred with the shape of the triangular convex portion 74, and the convex portion 94 is formed with a V-groove 95 having a shape obtained by inverting the shape of the triangular convex portion 74.

  A polymer waveguide is manufactured by performing the above-described polymer waveguide manufacturing process using the secondary soft stamper 96 manufactured as described above. When a secondary soft stamper is used, as described in the first embodiment, transfer is performed on the core material using the soft stamper.

  In this embodiment, when a polymer waveguide is manufactured by a primary soft stamper, a concave / convex pattern inverted from the mold is formed on the primary soft stamper. Will be done on the material. On the other hand, when a polymer waveguide is manufactured by a secondary soft stamper, an uneven pattern having the same shape as the mold is formed on the secondary soft stamper. Will do.

  In this embodiment, the soft stamper 75 (primary soft stamper) and the secondary soft stamper 96 are produced based on the mold 26, and the tertiary soft stamper can be produced based on the secondary soft stamper. Therefore, it is possible to produce the Nth order soft stamper based on the (N-1) th order soft stamper (N: an integer of 2 or more). What is important in this embodiment is that when the concave and convex shape formed on the soft stamper that performs the transfer for producing the waveguide is the same shape as the mold, the transfer is performed on the core material and the shape reversed with the mold In this case, the transfer is performed on the clad material.

(Third embodiment)
In the first and second embodiments, crystal anisotropic etching is performed on the (100) plane of the silicon substrate when the mold is manufactured. In this embodiment, (110) of the silicon substrate is used. Crystal anisotropic etching is performed on the surface.

Mold Manufacturing Process FIGS. 10A to 10C are schematic views for explaining a mold manufacturing process according to this embodiment.
In FIG. 10 (a), SiO 2 102a and 102b are formed on a (110) surface of a silicon substrate 101, which is a mold base, with a predetermined distance apart. From the region between the SiO 2 102a and 102b, the (110) surface (exposed portion 103) of the silicon substrate 101 is exposed. Next, the silicon substrate 201 on which the SiO 2 102 a and 102 b are formed is immersed in a KOH solution as an etching solution, and the exposed portion 103 of the silicon substrate 101 is etched. By this etching, the (111) surface 104 appears due to the phenomenon described in the first embodiment, and when the etching stops, a groove 105 having the (111) surface 104 as a wall surface is formed (FIG. 10B). . The cross section of the groove 105 is a quadrangular shape. Next, by removing the SiO 2 102a and 102b, the mold 106 having the V-groove 105 having the (111) plane 104 as a wall surface is manufactured (FIG. 10C).

  Also in the present embodiment, since the wall surface of the groove 105 is the (111) surface 104, the wall surface can be flattened at the atomic layer level. Therefore, the same effect as described in the first embodiment can be obtained. can get.

  In each of the above-described embodiments, the ridge type waveguide has been described, but a buried type waveguide may be used. In the case of an embedded waveguide, after forming a core, a clad may be formed so as to embed the core.

(A)-(d) is a figure which shows the preparation methods of the conventional conventional polymer waveguide. (A)-(c) is a schematic diagram for demonstrating the manufacturing process of the metal mold | die based on one Embodiment of this invention. (A)-(d) is a figure for demonstrating the manufacturing method of the polymer waveguide based on one Embodiment of this invention. 1 is a perspective view of a polymer waveguide having a triangular core according to an embodiment of the present invention. It is a figure which shows a mode that the relationship between waveguide shape and loss based on one Embodiment of this invention is calculated | required. It is a figure for explaining extrusion lamination concerning one embodiment of the present invention. (A)-(d) is a figure explaining the preparation process of the soft stamper based on one Embodiment of this invention. (A)-(f) is a figure for demonstrating the manufacturing method of the polymer waveguide based on one Embodiment of this invention. (A) And (b) is a figure for demonstrating the manufacturing method of the secondary soft stamper based on one Embodiment of this invention. (A)-(c) is a schematic diagram for demonstrating the manufacturing process of the metal mold | die based on one Embodiment of this invention.

Explanation of symbols

21, 101 Silicon substrate 22a, 22b, 102a, 102b SiO 2
23, 103 Exposed portion 24, 104 (111) surface of silicon substrate 25 V groove 26, 106 Mold 105 groove

Claims (12)

  1. An optical waveguide comprising a cladding and a core,
    An optical waveguide characterized in that a cross section of the core is triangular.
  2. A method for producing an optical waveguide comprising a clad and a core,
    A die produced by performing crystal anisotropic etching on a first surface of a silicon substrate and forming a recess having a predetermined pattern on the first surface and having a (111) surface of the silicon substrate as a wall surface. A preparation process to prepare;
    A cladding forming step of forming the cladding;
    On the clad, there is a fluidizing step, and an imparting step for imparting the core material by curing,
    A core forming step of transferring a recess formed in the mold to the material, curing the material, and forming a core having an inverted shape with respect to the recess.
  3. A method for producing an optical waveguide comprising a clad and a core,
    It was fabricated by performing crystal anisotropic etching on the first surface of the silicon substrate to form a first recess having a predetermined pattern on the first surface and having the (111) surface of the silicon substrate as a wall surface. A preparation step of preparing a flexible second mold having a convex portion inverted from the first concave portion, which is produced based on the first die;
    On the substrate, the application step of providing the material to be the cladding by having fluidity and curing,
    A clad forming step of transferring a convex portion formed on the second mold to the material, curing the material, and forming the clad having a second concave portion having a shape reversed to the convex portion;
    And a core formation step of forming the core in the second recess.
  4. A method for producing an optical waveguide comprising a clad and a core,
    It was fabricated by performing crystal anisotropic etching on the first surface of the silicon substrate to form a first recess having a predetermined pattern on the first surface and having the (111) surface of the silicon substrate as a wall surface. A preparation step of preparing a flexible second mold having a second concave portion having the same shape as the first concave portion, which is produced based on the first mold;
    A cladding forming step of forming the cladding;
    On the clad, there is a fluidizing step, and an imparting step for imparting the core material by curing,
    A core forming step of transferring a second concave portion formed in the second mold to the material, curing the material, and forming a core having an inverted shape with respect to the second concave portion. A method for producing an optical waveguide.
  5. The first surface is a (100) surface;
    5. The method of manufacturing an optical waveguide according to claim 2, wherein the core has a triangular cross section.
  6. The first surface is a (110) surface;
    5. The method of manufacturing an optical waveguide according to claim 2, wherein the core has a quadrangular cross section.
  7. A mold for producing an optical waveguide comprising a clad and a core,
    A silicon substrate;
    A mold comprising: a recess having a predetermined pattern formed on the first surface of the silicon substrate, the recess having a (111) plane of the silicon substrate as a wall surface.
  8. The first surface is a (100) surface;
    8. The mold according to claim 7, wherein the recess is a V-groove.
  9. The first surface is a (110) surface;
    8. The mold according to claim 7, wherein the recess is a groove having a square cross section.
  10. A method for producing a mold for producing an optical waveguide having a clad and a core,
    A mask forming step of forming a material on the first surface of the silicon substrate so that the first surface is exposed in a predetermined pattern;
    A crystal anisotropic etching is performed on the first surface so that a (111) surface of the silicon substrate appears from the exposed first surface, and a recess having the (111) surface as a wall surface is formed. A recess forming step to be formed;
    A removal step of removing the material,
    The method for producing a mold, wherein the material is a mask for the crystal anisotropic etching.
  11. The first surface is a (100) surface;
    The mold manufacturing method according to claim 10, wherein the recess is a V-shaped groove.
  12. The first surface is a (110) surface;
    The method for producing a mold according to claim 10, wherein the recess is a groove having a square cross section.
JP2006303222A 2006-11-08 2006-11-08 Optical waveguide, manufacturing method of optical waveguide, mold for manufacturing waveguide, and method for manufacturing mold Pending JP2008122475A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009148010A1 (en) * 2008-06-04 2009-12-10 株式会社日本触媒 Optical waveguide manufacturing method, and mold for use in the method
JP2011128438A (en) * 2009-12-18 2011-06-30 Shinko Electric Ind Co Ltd Method for manufacturing optical waveguide, optical waveguide, and optical transmitter-receiver
WO2011105693A2 (en) * 2010-02-25 2011-09-01 부산대학교 산학협력단 Optical interconnection method for a planar lightwave circuit device
WO2012166286A1 (en) * 2011-05-27 2012-12-06 Google Inc. Image relay waveguide and method of producing same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002196166A (en) * 2000-12-25 2002-07-10 Hitachi Cable Ltd Optical waveguide and method for manufacturing the same
JP2004093989A (en) * 2002-08-30 2004-03-25 Tsuchiya Co Ltd Manufacturing method of polymer optical waveguide
JP2004347944A (en) * 2003-05-23 2004-12-09 Sanyo Electric Co Ltd Optical device and its manufacture method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002196166A (en) * 2000-12-25 2002-07-10 Hitachi Cable Ltd Optical waveguide and method for manufacturing the same
JP2004093989A (en) * 2002-08-30 2004-03-25 Tsuchiya Co Ltd Manufacturing method of polymer optical waveguide
JP2004347944A (en) * 2003-05-23 2004-12-09 Sanyo Electric Co Ltd Optical device and its manufacture method

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009148010A1 (en) * 2008-06-04 2009-12-10 株式会社日本触媒 Optical waveguide manufacturing method, and mold for use in the method
JP2011128438A (en) * 2009-12-18 2011-06-30 Shinko Electric Ind Co Ltd Method for manufacturing optical waveguide, optical waveguide, and optical transmitter-receiver
WO2011105693A2 (en) * 2010-02-25 2011-09-01 부산대학교 산학협력단 Optical interconnection method for a planar lightwave circuit device
WO2011105693A3 (en) * 2010-02-25 2011-11-24 부산대학교 산학협력단 Optical interconnection method for a planar lightwave circuit device
WO2012166286A1 (en) * 2011-05-27 2012-12-06 Google Inc. Image relay waveguide and method of producing same
CN103649823A (en) * 2011-05-27 2014-03-19 谷歌公司 Image relay waveguide and method of producing same
US8699842B2 (en) 2011-05-27 2014-04-15 Google Inc. Image relay waveguide and method of producing same

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