JP2005300715A - Method for manufacturing three-dimensional structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a three-dimensional structure, and to provide thereby a method for manufacturing an optical device having a laminated structure, especially, a method for easily manufacturing photonic crystal. <P>SOLUTION: A 1st substrate is prepared (a). A resist 2 is applied onto the top face of this 1st substrate except a part which serves as a pillar part (right and left edge parts in the figure) (b). Then, an ultraviolet curing resin 3 is mounted thereon (c), and a predetermined rugged structure is formed on the top face by using a molding technique wit a die and is hardened with ultraviolet irradiation (d). Thus, a 2nd substrate consisting of the ultraviolet curing resin 3 is stuck to the 1st substrate 1 holding the resist 2 in-between. In this state, the resist 2 is dissolved with a solution. That is, if what is in the state shown in (d) is immersed in the resist solution, dissolution begins from the resist 2 sticking out of the edge parts of the ultraviolet curing resin 3 and gradually goes on inside, and finally, all of the resist 2 dissolves, The three-dimensional structure is formed (e) the 2nd substrate consisting of the ultraviolet curing resin 3 is stuck to the 1st substrate with an air gap in-between. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an optical element including a three-dimensional structure having a laminated structure, particularly a photonic crystal (PhC).

  In recent years, photonic crystals having various structures have been proposed. The multilayer thin film can be called a one-dimensional photonic crystal, and a diffractive optical element such as DOE can also be called a one-dimensional or two-dimensional photonic crystal.

  As for two-dimensional photonic crystals, photonic crystals with a circular hole array have been actively studied. As for the three-dimensional photonic crystal, a method for producing a three-dimensional photonic crystal by an opal method and a method for producing a three-dimensional photonic crystal by a wafer fusion method have been studied.

  However, the three-dimensional photonic crystal by the opal method is easy to produce, but has a problem that defects cannot be introduced arbitrarily and a sufficient band gap cannot be formed. In addition, although the three-dimensional photonic crystal by the wafer fusion method can form a complete bandgap, it requires high-precision processing technology, requires a long production time, requires significant equipment investment, and increases the area. However, there is a problem that it is not easy.

  The present invention has been made in view of such circumstances, and provides a method for producing a novel three-dimensional structure, and thereby a method for easily producing an optical element having a laminated structure, particularly a photonic crystal. It is an issue to provide.

  A first means for solving the above problem is that a resist is applied on a first substrate having a flat surface or an uneven shape, and the first substrate having the resist other than a portion to become a support portion. A material to be a second substrate is overlaid and molded on the substrate to form a second substrate bonded to the first substrate with the resist sandwiched therebetween, and further on the second substrate as necessary. A resist is applied, and a material that becomes the third substrate is formed on the second substrate having the resist other than the portion that becomes the support portion, and the material is bonded to the second substrate with the resist interposed therebetween. Forming a third substrate and repeating the steps of ... to form a laminate of n-layer (n ≧ 2) substrates and then dissolving the resist between the layers to form voids A method for manufacturing a three-dimensional structure (claim 1).

  In this means, it is possible to easily manufacture a three-dimensional structure formed by laminating substances having various surface shapes and thicknesses through a gap corresponding to the thickness of the resist.

  A second means for solving the above problem is that a resist is applied on a first substrate having a flat surface or an uneven shape on the surface, and the first substrate having this resist other than a portion to be a support portion. A material to be a second substrate is overlaid and molded on the first substrate to form a second substrate bonded to the first substrate with the resist interposed therebetween, and then the resist is dissolved to form a void, Further, if necessary, a resist is applied on the second substrate, and a material to be the third substrate is overlaid on the second substrate having the resist in addition to the portion to be the column part, A third substrate bonded to the second substrate with a resist interposed therebetween is formed, and then the resist is dissolved to form voids, and so on. 3D characterized by having a step of forming a laminate of substrates A method for producing a granulated material (claim 2).

  In the first means, the resist between all the layers is dissolved at one time. However, in this means, the resist is sequentially dissolved when one layer is formed. Therefore, as a result, the same three-dimensional structure as that of the first means can be manufactured. However, when only one type of resist is used, depending on the type of substance constituting each layer, the resist can be dissolved. In some cases, the first means is not preferable. On the other hand, since this means can use a different resist depending on the material constituting each layer, it is highly flexible.

  A third means for solving the above-mentioned problem is that a part of a three-dimensional structure is manufactured by the first means and the other part is manufactured by the second means. It is a manufacturing method (Claim 3) of a structure.

  A fourth means for solving the problem is any one of the first to third means, wherein the mth substrate on which a resist is applied for at least one m (m ≧ 1). Before the material to be the (m + 1) th substrate is overlaid on the substrate, the resist is exposed and developed so as to correspond to a predetermined pattern (claim 4).

  In this means, the portion where the resist is removed by the development enters the material laminated thereon and overlaps the material constituting the lower layer. Therefore, after the resist is dissolved, the portion where the resist is left becomes a cavity, and the portion where the resist is removed is not formed with a cavity, and the substances of the overlapping layers are stuck together. Therefore, a three-dimensional structure having a complicated shape can be formed by changing the exposure pattern.

  A fourth means for solving the problem is any one of the first means to the fourth means, and the strut portion is formed before dissolving the resist in at least one layer. An adhesive that does not dissolve in the solution that dissolves the resist is provided between the layers in the portion (claim 4).

  In this means, it is possible to reliably bond the substances forming each layer.

  A fifth means for solving the above-mentioned problem is any one of the first to fourth means, wherein the three-dimensional structure is an optical element (Claim 5). It is.

  In this means, by changing the surface shape, refractive index, thickness, and gap thickness and shape of the substance constituting each layer, a microlens having a laminated structure, a diffractive optical element, a photonic crystal, etc. Can be manufactured.

  A sixth means for solving the above-mentioned problem is the fifth means, wherein the optical element is a photonic crystal (Claim 6).

  The fifth means is particularly suitable for producing a photonic crystal, and can easily produce a photonic crystal having a complicated structure. In particular, it is possible to easily manufacture a photonic crystal composed of three or more kinds of substances having different refractive indexes including air.

  ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing easily the optical element which has a laminated structure, especially a photonic crystal can be provided by providing the manufacturing method of a novel three-dimensional structure.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. Prior to that, an example of a method of forming a substrate used in the embodiment of the present invention and a method of manufacturing a mold used therefor will be described with reference to FIGS. Will be described with reference to FIG.

  FIG. 6 is a diagram for explaining a method of manufacturing a substrate molding die. First, a resist 12 is applied on a substrate 11 made of quartz or the like. In this example, a negative resist is used (a).

  Then, the image of the pattern formed on the mask 13 is projected onto the resist 12 to expose the resist 12 (b). In (b), the portion painted black in the mask 13 is a portion that does not transmit light, and the other portion is a portion that transmits light.

  When the resist 2 is exposed and then developed, the unexposed part disappears and the state shown in FIG. The combined body of the substrate 11 and the resist 12 in such a state becomes a molding die for the first substrate.

  When the resist 12 and the substrate 11 are simultaneously etched by dry etching from the state of (c) and the resist 12 is eliminated, the uneven shape of the resist 12 is transferred to the substrate 1 to form the substrate 11 having unevenness (d ). This is the mold for molding the second substrate of the present invention. Since the etching rate of the resist 12 by the etching gas and the etching rate of the substrate 11 are usually different, the degree of unevenness of the resist 12 in (c) differs from the degree of unevenness of the substrate 11 in (d). ) Is a substrate mold, the coating thickness of the resist 12 is determined in consideration of that.

  FIG. 7 is a diagram for explaining a method of manufacturing the third substrate molding die. In this example, a stacked body of a substrate 11 and a resist 12 having a structure as shown in FIG. 6C, which has been produced through the steps of FIGS. 6A and 6B, is used as a starting object (a). .

  A Ni thin film 14 is formed thereon by electroless plating (b). Then, a Ni electroformed body 15 is formed by electroforming using the Ni thin film 14 as an electrode (c). After completion of the electroforming, the Ni electroformed body 15 is peeled off from the resist 12 and the substrate 11 to form a substrate molding die made of the Ni electroformed body 15 (d).

  FIG. 8 is a diagram for explaining a method of manufacturing the fourth substrate molding die. Also in this embodiment, a stacked body of the substrate 11 and the resist 12 having the structure shown in FIG. 6C, which has been manufactured through the steps of FIGS. 6A and 6B, is used as a starting object. (A).

  An ultraviolet curable resin 17 is applied to the laminated body of the substrate 11 and the resist 12 by a dispenser or the like, and a surface plate 16 made of quartz is opposed, and the ultraviolet curable resin 17 is sandwiched. Then, ultraviolet rays are irradiated through the surface plate 16 to cure the ultraviolet curable resin 17 (b).

Then, the cured ultraviolet curable resin 17 is peeled from the laminate of the substrate 11 and the resist 12 and the surface plate 16 (c). Thereafter, a thin film 18 made of metal or dielectric is formed on the concavo-convex structure portion of the ultraviolet curable resin 17 by sputtering or vapor deposition, thereby completing the substrate molding die (d). As the metal to be used, Cu, Al, Ni, Au and the like are suitable, and as the dielectric to be used, SiN _x , SiO ₂ , Al ₂ O ₃ , Ta ₂ O ₅ , TiO _{2 and the} like are suitable. In this way, a plurality of substrate forming molds as shown in FIG. 8D can be manufactured from a laminate of one substrate 11 and resist 12.

  FIG. 9 is a diagram for explaining a method of molding a substrate using the molding die formed as described above. In this example, the substrate mold shown in FIG. 6C is used.

  That is, a substrate molding die comprising a laminate of the substrate 11 and the resist 12 is prepared (a), and the ultraviolet curable resin 19 is filled between the surface plate 20 made of quartz or the like by a dispenser or the like. Then, ultraviolet rays are irradiated through the surface plate 20 to cure the ultraviolet curable resin 19. Then, when the cured ultraviolet curable resin 19 is peeled off from the substrate molding die composed of the laminate of the substrate 11 and the resist 12 and the surface plate 20, the substrate composed of the ultraviolet curable resin 19 is completed.

  Although the surface plate 20 is shown as having a flat surface in the figure, a substrate having a concavo-convex structure on both sides can be formed by changing this to another substrate molding die.

  In the following description, each substrate is described as being formed by such a method.

  FIG. 1 is a diagram showing a method for manufacturing a three-dimensional structure according to the first embodiment of the present invention. First, the 1st board | substrate 1 manufactured with the manufacturing method as shown in FIG. 9 is prepared (a). As shown in the figure, the first substrate 1 has a concavo-convex structure on its upper surface. The resist 2 is applied on the upper surface of the first substrate 1 while leaving a portion (left and right end portions in FIG. 1) as a support portion, or only the portion that becomes a support is removed after the resist 2 is applied on the upper surface. Pattern and expose and develop as possible (b).

  Then, an ultraviolet curable resin 3 is placed thereon (c), a predetermined concavo-convex structure is formed on the upper surface by using a molding method using the mold as described above, and cured by ultraviolet irradiation (d). At this time, the 1st board | substrate 1 and the ultraviolet curable resin 3 adhere | attach in the part used as a support | pillar part. Although the figure is a cross-sectional view, it is not well understood, but the resist 2 reaches the end of the ultraviolet curable resin 3 in a portion that does not become a support portion. In this way, the second substrate made of the ultraviolet curable resin 3 is in close contact with the first substrate 1 with the resist 2 interposed therebetween.

  In this state, the resist 2 is dissolved with a solution. That is, when the one in the state shown in (d) is immersed in a resist solution (acetone or the like), dissolution starts from the resist 2 at the end of the ultraviolet curable resin 3 and gradually proceeds to the inside, and finally the resist 2 is completely dissolved to form a three-dimensional structure in which the second substrate made of the ultraviolet curable resin 3 and the first substrate 1 are in close contact with each other with a gap therebetween (e). The removal of the resist 2 may be performed by wet etching.

  In some cases, the adhesion between the first substrate 1 and the ultraviolet curable resin 3 may be poor, and the first substrate 1 may be peeled off due to the solution of the resist 2. In this case, as shown in FIG. 1 (f) showing an enlarged view of part A of FIG. 1 (c), the adhesive 4 is applied over the first substrate 1 and the ultraviolet curable resin 3, and the two are bonded. And then stop. If possible, it is preferable that the adhesive 4 penetrates between the first substrate 1 and the ultraviolet curable resin 3 for adhesion. The adhesive may be made of an ultraviolet curable resin and may be cured by irradiation with ultraviolet rays to serve as an adhesive.

  FIG. 2 shows an example in which a third substrate is further laminated on the three-dimensional structure shown in FIG. 1 as an example of the method for manufacturing the three-dimensional structure according to the second embodiment of the present invention. First, a two-layer laminate as shown in FIG. 1E is prepared (a). Then, as described in the first embodiment, the resist 2 is formed on the upper surface of the second substrate made of the ultraviolet curable resin 3 except for the portion that becomes the support column (b).

  Then, an ultraviolet curable resin 5 is placed thereon, and a predetermined concavo-convex structure is formed on the upper surface thereof by using a molding method as described above, and cured by ultraviolet irradiation (c). In this case, the upper surface of the ultraviolet curable resin 5 is flat. At this time, the ultraviolet curable resin 3 and the ultraviolet curable resin 5 are in close contact with each other at a portion serving as a support column. Although the figure is a cross-sectional view and does not appear in the figure, the resist 2 reaches the end of the ultraviolet curable resin 5 in the part that does not become the support part. In this way, the third substrate made of the ultraviolet curable resin 5 is in close contact with the second substrate made of the ultraviolet curable resin 3 with the resist 2 interposed therebetween.

  In this state, the resist 2 is dissolved with a solution. That is, when the one in the state shown in (c) is immersed in a resist solution (acetone or the like), dissolution starts from the resist 2 exposed at the ends of the ultraviolet curable resin 3 and the ultraviolet curable resin 5 and gradually progresses inside. Finally, the resist 2 is completely dissolved, and the third substrate made of the ultraviolet curable resin 5, the second substrate made of the ultraviolet curable resin 3, and the first substrate 1 are in close contact with each other with a gap therebetween. A three-dimensional structure is formed (d). The removal of the resist 2 may be performed by wet etching.

  FIG. 3 is a diagram for explaining a method of manufacturing a three-dimensional structure, which is an example of the third embodiment of the present invention. First, through the steps of FIGS. 1A to 1D, a three-dimensional structure as shown in FIG. 1E is formed as a starting object (a). Then, a resist 2 is formed on the upper surface of the second substrate made of the ultraviolet curable resin 3 (b).

  Subsequently, by using a photolithography process or the like, the resist 2 is projected and exposed in a predetermined pattern and developed, and the resist corresponding to the predetermined pattern is removed (c). At this time, the pattern of this portion is also projected so that the resist 2 can be removed from the portion that becomes the column portion. Then, the ultraviolet curable resin 5 is placed on the same height as the remaining resist 2, pressed by the mold by the method described above, and cured by irradiating with ultraviolet rays (d).

  Thereafter, an ultraviolet curable resin 6 is further placed on the resist 2 and the ultraviolet curable resin 5, molded by pressing with a mold, and cured by irradiating with ultraviolet rays (e). Through the above steps, the ultraviolet curable resins 3, 5, and 6 are brought into close contact with the resist 2.

  In this state, the resist 2 is dissolved with a solution. That is, when the one in the state shown in (e) is immersed in a resist solution (acetone or the like), dissolution starts from the resist 2 exposed at the end of the ultraviolet curable resin 5, gradually proceeds to the inside, and finally the resist 2 is completely dissolved, and the second substrate made of the ultraviolet curable resin 3 and the fourth group made of the ultraviolet curable resin 6 are in close contact with each other across the gap and the layer made of the ultraviolet curable resin 5, A three-dimensional structure in which the second substrate made of the ultraviolet curable resin 3 and the first substrate are in close contact with each other with the gap in between is formed (f). The removal of the resist 2 may be performed by wet etching.

  FIG. 4 is a diagram for explaining a method of manufacturing a three-dimensional structure, which is an example of the fourth embodiment of the present invention. First, through the steps of FIGS. 3A to 3C, a three-dimensional structure as shown in FIG. 3D is formed as a starting object (a). Then, a resist 2 is applied on the upper surface of the third layer made of the ultraviolet curable resin 5 and the resin (b).

  Subsequently, using a photolithography process or the like, the resist 2 is projected and developed into a predetermined pattern and developed, and the resist corresponding to the predetermined pattern is removed (c). Then, the ultraviolet curable resin 6 to be the fourth substrate is placed on the same height as the remaining resist 2, pressed by the mold by the method described above, and cured by irradiating with ultraviolet rays ( d).

  In this state, the resist 2 is dissolved with a solution. That is, when the one in the state shown in (d) is immersed in a resist solution (acetone or the like), dissolution starts from the resist 2 at the end of the ultraviolet curable resins 5 and 6, gradually progresses to the inside, and finally ends. The third substrate made of the ultraviolet curable resin 5 having the voids and the resist 2 completely dissolved therein and the fourth substrate made of the ultraviolet curable resin 6 having the voids are formed as the first substrate and the ultraviolet curable resin. A three-dimensional structure that is closely stacked on the second substrate made of 3 is formed (e). The removal of the resist 2 having voids may be performed by wet etching.

  FIG. 5 is a diagram for explaining a method of manufacturing a three-dimensional structure, which is an example of the fifth embodiment of the present invention. This example shows an example in which a microlens is formed on an image sensor via a gap.

  A resist 2 is applied on the image sensor 7. Then, the upper surface of the resist 2 is formed into a shape that becomes a microlens array mold by a photolithography process using a gray scale mask (b). At this time, patterning is performed so that the resist 2 is removed also in the portion to be the support column. On top of this, the ultraviolet curable resin 8 is placed and molded by the above-described method, and cured by irradiating with ultraviolet rays (c). Note that a method for forming a three-dimensional shape on a resist using a gray scale mask is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-107209.

  In this state, the resist 2 is dissolved with a solution. That is, when the one in the state shown in (c) is immersed in a resist solution (acetone or the like), dissolution starts from the resist 2 exposed at the end of the ultraviolet curable resin 8, gradually proceeds to the inside, and finally the resist 2 is completely dissolved, and a three-dimensional structure having an ultraviolet curable resin 8 formed in the shape of a microlens array via a gap is formed on the image sensor 7.

  In any of the above-described embodiments, a new substrate can be formed on the uppermost base, or a new substrate can be formed after applying a resist, and the resist can be exposed as necessary. -The process of dissolving the resist after development is repeated to easily form a three-dimensional structure comprising a multilayer substrate and voids.

  Such a three-dimensional structure can precisely control the shape of the resist that will later become a void by using a photolithography process, so it can be a precise structure and can also be used as a general mechanical element. Although possible, it is particularly excellent for use as an optical element. In other words, substances having different shapes, refractive indexes, and thicknesses can be stacked in multiple layers through gaps, and can be used as a lens, used as a diffractive optical element, or used as a photonic crystal.

  In particular, when used as a photonic crystal, it is possible to easily form an object in which three or more kinds of substances including air are three-dimensionally complicatedly incorporated. Can be produced.

It is a figure which shows the manufacturing method of the three-dimensional structure which is the 1st Embodiment of this invention. It is a figure which shows the manufacturing method of the three-dimensional structure which is the 2nd Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the three-dimensional structure which is an example of the 3rd Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the three-dimensional structure which is an example of the 4th Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the three-dimensional structure which is an example of the 5th Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the shaping | molding die for 1st and 2nd board | substrates. It is a figure for demonstrating the manufacturing method of the shaping | molding die for 3rd board | substrates. It is a figure for demonstrating the manufacturing method of the shaping | molding die for 4th board | substrates. It is a figure for demonstrating the method to shape | mold a board | substrate using the shaping | molding die.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Resist, 3 ... Ultraviolet curable resin, 4 ... Ultraviolet curable resin, 5 ... Ultraviolet curable resin, 6 ... Ultraviolet curable resin, 7 ... Imaging element, 8 ... Ultraviolet curable resin, 11 ... Substrate, 12 ... resist, 13 ... mask, 14 ... Ni thin film, 15 ... Ni electroformed body, 16 ... surface plate, 17 ... UV curable resin, 18 ... thin film, 19 ... UV curable resin, 20 ... surface plate

Claims (7)

A resist is applied on a first substrate having a flat surface or a concavo-convex shape, and a material to be a second substrate is superimposed on the first substrate having the resist other than a portion to be a support portion. Molding to form a second substrate joined to the first substrate with the resist sandwiched therebetween, and further applying a resist on the second substrate as necessary, in addition to the portion that becomes the support column A step of forming a third substrate bonded to the second substrate with the resist interposed therebetween is formed by overlaying and molding a material to be the third substrate on the second substrate having the resist, and so on. A method for producing a three-dimensional structure, comprising: repeating the steps to form a laminate of n-layer (n ≧ 2) substrates and then dissolving the resist between the layers to form voids. A resist is applied on a first substrate having a flat surface or a concavo-convex shape, and a material to be a second substrate is superimposed on the first substrate having the resist other than a portion to be a support portion. Forming a second substrate bonded to the first substrate with the resist sandwiched therebetween, and then dissolving the resist to form a void, and if necessary, forming a resist on the second substrate The material that becomes the third substrate is formed on the second substrate having the resist other than the portion that becomes the support portion, and the third substrate is bonded to the second substrate with the resist interposed therebetween. 3 is formed, and then the resist is dissolved to form voids, and so on, and so on, so that a layered body of n layers (n ≧ 2) is formed. A method for manufacturing a three-dimensional structure. A part of the three-dimensional structure is manufactured by the method for manufacturing a three-dimensional structure according to claim 1, and the other part is manufactured by the method for manufacturing a three-dimensional structure according to claim 2. A method for manufacturing a three-dimensional structure. 4. The method of manufacturing a three-dimensional structure according to claim 1, wherein at least one m (m ≧ 1) is formed on an mth substrate coated with a resist. A method for producing a three-dimensional structure, comprising: exposing and developing the resist so as to correspond to a predetermined pattern before stacking a material to be a (m + 1) th substrate. The method for manufacturing a three-dimensional structure according to any one of claims 1 to 4, wherein, in at least one interlayer, before the resist is dissolved, an interlayer is formed in a portion constituting the support column. A method for producing a three-dimensional structure comprising providing an adhesive that does not dissolve in a solution for dissolving the resist. The method for manufacturing a three-dimensional structure according to any one of claims 1 to 5, wherein the three-dimensional structure is an optical element. The method for manufacturing a three-dimensional structure according to claim 6, wherein the optical element is a photonic crystal.

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