JP2010002757A - Molding method of molded article, molded article, and method for manufacturing microstructure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily mold a molded article having an excessively large level difference compared with the thickness of a single photoresist layer. <P>SOLUTION: A molding method is disclosed, including: a first exposure step of exposing a first photoresist layer 31 by using a first mask; a second exposure step of forming a second photoresist layer 32 on the first photoresist layer 31 after exposed and exposing the second photoresist layer 32 by using a second mask; and a developing step of developing the first and the second photoresist layers 31, 32, respectively, together after exposed, to obtain a molded article 20 having a combination of a first molded portion 31b molded in the first photoresist layer 31 having a feature corresponding to the opening feature of the first mask and a second molded portion 32b in the second photoresist layer 32 having a feature corresponding to the opening feature of the second mask. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for forming a molded body by exposing and developing a photoresist layer, a molded body molded by the method, and a method for manufacturing a microstructure using the molded body.

  Conventionally, a photoresist layer is formed on various base materials, and this photoresist layer is exposed and developed using a mask to form a molded body having a shape corresponding to the opening shape of the mask on the base material. In addition, a method of manufacturing a circuit or the like by etching these base material and molded body is known. In recent years, it has been studied to form microstructures having various shapes by such a method.

In the case of producing a microstructure by forming a molded body on a photoresist layer on a base material, by setting the selection ratio between the photoresist layer and the base material at the time of etching to be larger than 1, the thickness of the photoresist layer It is possible to manufacture a fine structure having a large height difference (for example, see Patent Document 1 below).
JP 2001-158022 A

  However, when manufacturing a fine structure having a larger height difference, there is a limit to the thickness of the photoresist layer that can be formed on the substrate, and it is not easy to form a thick wall. Even if it is formed thick, it is difficult to expose such a thick photoresist layer. For this reason, it has not been carried out to form a molded article having an excessively large difference in height as compared with the thickness of one photoresist layer.

  Moreover, if a fine structure having a large difference in height is formed by etching with an excessively high selection ratio, the error of the molded product of the photoresist layer increases according to the selection ratio. A fine structure will be manufactured. Therefore, it is not easy to manufacture a fine structure having a large height difference compared to the thickness of one photoresist layer.

  Accordingly, an object of the present invention is to provide a method for molding a molded body that can easily mold a molded body having an excessively large difference in height compared to the thickness of one photoresist layer. Another object is to provide a molded article having an excessively large difference in height obtained by a simple molding method. It is still another object of the present invention to provide a method for easily manufacturing a microstructure having an excessively large difference in height as compared with the thickness of one photoresist layer.

  In the molding method of the molded body of the present invention that solves the above-mentioned problems, the photoresist layer is exposed to and developed using a mask to form a molded body having a shape corresponding to the opening shape of the mask. In the molding method, a first exposure step of exposing the first photoresist layer using a first mask, and forming a second photoresist layer on the exposed first photoresist layer, A second exposure step of exposing the second photoresist layer using a second mask, and a development step of developing the first and second photoresist layers after exposure together, A first molding portion that is shaped on the first photoresist layer to have a shape corresponding to the opening shape of the first mask, and a shape that corresponds to the opening shape of the second mask. Formed on the photoresist layer. Characterized by molding the molded body and the second mold part are combined to be.

  The molded body of the present invention is characterized by being molded by the above molding method.

  The method for producing a microstructure of the present invention includes exposing and developing a photoresist layer formed on a substrate to form a molded body, and etching the molded body and the substrate to form the molded body. A method for producing a microstructure having a corresponding shape, wherein the molded body is molded by the molding method according to any one of claims 1 to 7.

  According to the molding method of the molded body of the present invention, after the first photoresist layer is exposed using the first mask, the second photoresist layer is formed and the second mask is formed without developing. And then developing the first and second photoresist layers together to develop the first molded portion and the second portion of each photoresist layer exposed corresponding to the opening shape of each mask. Since the molded body combined with the molded portion is molded, it is possible to mold a molded body having a larger height difference than each photoresist layer. And since it exposes for every photoresist layer, even if the height difference of a molded object is too large, it can expose reliably.

  Further, since each photoresist layer is not developed every time it is exposed, the second photoresist layer can be formed on the surface of the flat first photoresist layer, and the second photoresist layer can be formed and exposed. It is possible to carry out with high accuracy, and it is possible to develop soluble portions of a plurality of photoresist layers at once.

  For this reason, it is possible to easily form a molded body having an excessively large difference in height as compared with the thickness of each photoresist.

  According to the molded body of the present invention, since the molded body is molded by the above-described molding method, a molded body having an excessively large difference in height as compared with the thickness of the photoresist layer that can be formed at one time is provided. It is possible.

  According to the microstructure manufacturing method of the present invention, the molded body and the substrate are etched using the molded body molded on the base material by the molding method as described above. Without setting the rate excessively large, it is possible to easily manufacture a fine structure having an excessively large difference in height compared to a photoresist layer that can be formed at a time.

Embodiments of the present invention will be described below. In the embodiments of each invention, for the sake of easy understanding, examples of a molded body and a fine structure having a specific shape will be described. However, in the present invention, the shapes of the molded body and the fine structure are not limited to the following forms. .
Embodiment 1 of the Invention

  1 to 4 show the first embodiment. As shown in FIG. 1, the microstructure 11 manufactured in the first embodiment has a groove 12 that is continuous in the longitudinal direction on one surface of a base material 10 that has a rectangular shape in plan view. The groove portion 12 includes a bottom surface 12 a and a pair of side surfaces 12 b provided perpendicular to the bottom surface 12 a, and a pair of top surfaces 12 c are provided on both sides of the groove portion 12. The groove part 12 may be used for a fine flow path, for example.

  In order to manufacture the fine structure 11 according to the first embodiment, as shown in FIG. 2, a molded body 20 having a shape corresponding to the target shape of the fine structure 11 is formed on a base material 10 with a photoresist. Then, the molded body 20 and the substrate 10 are manufactured by etching. Here, since the selection ratio at the time of etching, which will be described later, is 1, the molded body 20 has a shape that matches the shape of the side surface 12b and the upper surface 12c of the target shape.

  The base material 10 for molding the molded body 20 is a material having a flat plate shape for constituting the fine structure 11. The base material 10 is made of a material that can be etched with characteristics satisfying the properties required for the microstructure 11 such as glass, ceramics, crystal, resin, and the like.

In order to shape | mold the molded object 20 on this base material 10, as shown in FIG.
First, as shown in FIG. 3A, a first photoresist layer 31 is formed on one surface of the substrate 10.

  The first photoresist layer may be made of either a negative photoresist or a positive photoresist. In the first embodiment, a positive type photoresist is used. The first photoresist layer 31 can be formed by, for example, applying by a spin coating method and drying. In the next exposure step, the surface of the first photoresist layer 31 is preferably formed on a sufficiently flat plane for the purpose of facilitating accurate exposure.

  The thickness of the first photoresist layer 31 can be appropriately selected within a range of thicknesses that can be applied at one time without drying. Although it is not necessary to form an excessively thick layer, if the first photoresist layer 31 is thin, the thickness and the number of stacked layers of the other photoresist layers 32 must be increased accordingly. The thickness is preferably as thick as possible within a range where the surface can be formed uniformly and flatly.

  Next, as shown in FIG. 3B, as the first exposure process, the first photoresist layer 31 is exposed using the first mask 40.

  The first mask 40 is composed of a binary mask, the shape in plan view corresponds to the target shape, and has an opening 43 having the same shape as the groove 12. The first mask 40 is arranged in a state where the alignment mark provided at a position (not shown) of the substrate 10 and the alignment mark provided at a position (not shown) of the first mask 40 are precisely aligned.

  And it exposes by irradiating exposure light. The intensity of exposure light, the exposure time, and the like are appropriately set according to the thickness and material of the first photoresist layer 31. By irradiating the first photoresist layer 31 with the exposure light through the opening 43, the first photoresist layer 31 is exposed in a shape matching the opening 43. By this exposure, a soluble portion 31a having the same shape as the groove 12 is formed in the first photoresist layer 31 in plan view. The soluble portion 31a is exposed to the extent that it can be completely dissolved and removed by a developing solution in a developing step described later.

  Next, as shown in FIG. 3C, a second photoresist layer 32 is formed on the exposed first photoresist layer 31.

  The second photoresist layer 32 is preferably formed of the same photoresist as the first photoresist layer 31. This is because the second photoresist 32 is laminated on the first photoresist layer 31 to facilitate integration.

  The formation of the second photoresist layer 32 on the surface of the exposed photoresist layer 31 can be performed in the same manner as when the first photoresist layer 31 is formed on the surface of the substrate 10, for example, A photoresist may be applied by spin coating or the like and dried. The surface of the second photoresist layer 32 is preferably formed to be as flat as possible. This is because it can be easily exposed with high accuracy in the exposure process.

  At this time, since the first photoresist layer 31 is not developed, the soluble portion 31a exists in the first photoresist 31 layer, and the entire surface of the first photoresist layer 31 is flat. Is maintained at. Therefore, the second photoresist layer 32 can be easily formed flat. If there are irregularities on the surface of the first photoresist layer 31, it becomes difficult to form the second photoresist layer 32 flat and it becomes difficult to focus accurately in the exposure step. The exposure accuracy of the layer 32 decreases. However, if the surface of the first photoresist layer 31 is kept flat in this way, the second photoresist layer 32 can be formed flat and the exposure accuracy can be improved.

  Note that the thickness of the second photoresist layer 32 may be selected as appropriate within a range of thicknesses that can be applied at one time without drying, and the surface of the second photoresist layer 32 is reduced because the number of stacked layers of all the photoresist layers can be easily reduced. It is preferable to make it as thick as possible within a range where it can be formed uniformly and flatly.

  Next, as shown in FIG. 3D, as the second exposure step, the second photoresist layer 32 is exposed using the second mask 50.

  The second mask 50 is made of a binary mask, has a shape in plan view corresponding to the target shape, and has an opening 53 having the same shape as the groove 12. The opening 53 of the second mask 50 has the same shape as the opening 43 of the first mask 40. Here, the same mask as the first mask 40 can be used. The second mask 50 is arranged in a state where the alignment mark provided at a position (not shown) of the substrate 10 and the alignment mark provided at a position (not shown) of the second mask 50 are precisely aligned. At this time, the first photoresist layer 31 and the second mask 50 are aligned with high accuracy.

  In this state, exposure is performed by irradiating exposure light. The intensity, time, etc. of the exposure light are appropriately set according to the thickness and material of the first photoresist layer 31. By irradiating the second photoresist layer 32 with exposure light through the opening 53, the second photoresist layer 32 is exposed in a shape that matches the opening 53. By this exposure, a soluble portion 32a having the same shape as that of the groove 12 is formed in the second photoresist layer 32 in plan view. The soluble portion 32a of the second photoresist layer 32 is located at the same position as the exposed portion 31a of the first photoresist layer 31 in a plan view. The soluble portion 32a is exposed to the extent that it can be completely dissolved and removed by the developer in the developing step described later.

  In addition, when exposing with the 2nd mask 50, the soluble part 31a exposed with the 1st mask 40 is irradiated with exposure light again, and is exposed. However, since the soluble portion 31a is a portion to be dissolved and removed, there is no inconvenience even if it is further exposed.

  As a result, after the exposure of all the photoresist layers 31 and 32 is completed, as shown in FIG. 3E, the first and second photoresist layers 31 and 32 after the exposure are combined as a development process. develop.

  In this development step, all the soluble portions 31a and 32a formed in the photoresist layers 31 and 32 are simultaneously developed with a developer and completely dissolved and removed. The developer can be appropriately selected according to the material of the first and second photoresist layers 31 and 32, and the like.

  When development is completed in this manner, the first photoresist layer 31 is formed with the first molding portion 31b in a shape corresponding to the shape of the opening 43 of the first mask 40, and the second mask. The second molded part 32b is molded in a shape corresponding to the shape of the 50 openings 53, and the molded part 20 is molded in a state in which these are integrally combined. Here, the first molding part 31b of the first photoresist layer 31 and the second molding part 32b of the second photoresist layer 32 are integrated in a state where they are arranged at positions overlapping each other. The side surface 31c corresponding to the side surface 12b of the groove portion 12 of the first molding portion 31b and the side surface 32c corresponding to the side surface 12b of the groove portion 12 of the second molding portion 32b are both relative to the surface of the substrate 10. It is formed substantially vertically. This is because the thickness of the first and second photoresist layers 31 and 32 is appropriate, so that exposure light scatters within each of the photoresist layers 31 and 32.

  In this embodiment, the substrate 10 after development in which all the molding parts 31b and 32b are molded may then be placed in a heated atmosphere, and the surface shape may be smoothed. The first and second masks 40, 50 are finely misaligned, the fine difference in the amount of dissolution at the interface between the first photoresist 31 and the second photoresist 32, etc. When a fine step is generated at the interface between the first molded portion 31b and the second molded portion 32b, the side surface 31c and the side surface 32c can be smoothly continued by this smoothing process.

  The temperature of the smoothing process can be appropriately set according to the materials of the first photoresist layer 31 and the second photoresist layer 32. This temperature is preferably equal to or higher than the softening temperature of the first photoresist layer 31 and the second photoresist layer 32 and can be softened as much as possible without flowing.

  Thereby, shaping | molding of the molded object 20 which consists of a photoresist is complete | finished. As shown in FIG. 2, the molded body 20 has a shape corresponding to the target shape of the microstructure 11, and the side surface 31 c of the first photoresist layer 31 and the side surface 32 c of the second photoresist layer 32. Are continuously flat with respect to the substrate 10.

  Thereafter, after forming the molded body 20 on the surface of the base material 10 in this way, the molded body 20 and the base material 10 are etched to have a shape corresponding to the molded body 20 as shown in FIG. Then, the microstructure 11 having the groove 12 is manufactured.

  In the etching, the first and second photoresist layers 31 and 32 and the base material 10 are etched at a predetermined selection ratio to form a shape corresponding to the molded body 20 on the surface of the base material 10. This etching method is not particularly limited as long as each of the photoresist layers 31 and 32 and the substrate 10 can be etched with a predetermined selection ratio. For example, the first and second photoresist layers 31 and 32 may be etched. Dry etching using a corresponding etching gas may be performed.

  Note that the selection ratio during etching may be 1 or more or less than 1. If it is larger than 1, it becomes possible to manufacture the fine structure 11 having a larger height difference than the molded body 20, and the number of the photoresist layers 31 and 32 can be reduced. However, when the selection ratio is excessively larger than 1, an error in the shape of the molded body 20 is enlarged, so that an appropriate selection ratio is preferable. On the other hand, if the selection ratio is less than 1, the microstructure 11 having a smaller height difference than the molded body 20 is manufactured. However, since the error of the molded body 20 can be reduced, The accuracy can be improved. These are preferably set as appropriate according to the accuracy required for the fine structure 11.

  According to the molding method of the molded body 20 as described above, after the first photoresist layer 31 is exposed using the first mask 40, the second photoresist layer 32 is formed without development. Exposure was performed using the second mask 50, and then the first and second photoresist layers 32 were developed together to be exposed corresponding to the shapes of the openings 43 and 53 of the masks 40 and 50. Since the molded body 20 in which the first molded portion 31b and the second molded portion 32b of the photoresist layers 31 and 32 are combined is molded, the molded body 20 that is thicker than the photoresist layers 31 and 32 is molded. Is possible. In addition, since the exposure is performed for each of the photoresist layers 31 and 32, the exposure can be reliably performed even if the height difference of the molded body 20 is excessively large.

  In addition, since each photoresist layer 31, 32 is not developed every time it is exposed, the second photoresist layer 32 can be formed on the surface of the flat first photoresist layer 31, and the second photoresist layer. 32 can be formed with high accuracy, and the soluble portions 31b and 32b of the plurality of photoresist layers 31 and 32 can be developed at a time.

  Therefore, it is possible to easily and accurately form the molded body 20 having an excessively large difference in height as compared with the thickness of the photoresist layers 31 and 32 on the base material 10.

  In the molding method of the molded body 20, the first and second masks 40, 50 are binary masks, and the first and second molding parts 31b, 32b have the same shape in plan view and in plan view. Since they are arranged at the same position, the molded body 20 having a shape in which the first molded portion 31b and the second molded portion 32b overlap with each other in the vertical direction with respect to the base material is obtained. At this time, since each of the photoresist layers 31 and 32 is exposed, an exposure amount error due to scattering of exposure light in each of the photoresist layers 31 and 32 hardly occurs at the time of exposure. The side surfaces of 31 b and 32 b can be easily formed in the vertical direction with respect to the base material 10. Therefore, it is easy to accurately form a deep dent shape or a protruding shape in a substantially vertical direction with respect to the base material 10 by etching.

  Furthermore, if all the molded parts 31b and 32b are arranged in a heated atmosphere after development, it is difficult to form a step between the adjacent photoresist layers 31 and 32 on the side surface orthogonal to the base material 10 of the molded body 20.

  Further, according to the molded body 20 formed in this way, it is possible to provide a highly accurate molded body 20 having a significantly large difference in height compared to the thickness of the photoresist layers 31 and 32 that can be formed at one time. Is possible.

  And according to the manufacturing method of such a fine structure 11, the molded object 20 and the base material 10 are formed using the molded object 20 molded on the base material 10 by the molding method of the molded object 20 as described above. Since etching is performed, it is possible to easily and precisely manufacture a fine structure having an excessively large difference in height compared to a photoresist layer that can be formed at one time without setting the selectivity at the time of etching excessively large. .

  The first embodiment of the present invention can be appropriately changed within the scope of the present invention.

  For example, in the above description, an example in which the first photoresist layer 31 and the second photoresist layer 32 are formed using a positive photoresist has been described. However, it is also possible to form each using a negative photoresist. . In that case, when the molded body 20 is molded in the same manner as in the first embodiment of the present invention, the molded body 20 is formed in a shape protruding from the center of the base material 10 as in the first modification shown in FIG. can do.

  In the above description, an example in which the opening 43 of the first mask 40 and the opening 53 of the second mask 50 have the same shape has been described. However, they may have different shapes. For example, when the molded body 20 is formed in the same manner as in the first embodiment of the present invention except that the opening 53 of the second mask 50 is smaller than the opening 43 of the first mask 40, the first shown in FIG. As in the second modification, the wall surface 27 of the molded body 20 is formed in a stepped shape so that the edge of the second photoresist layer 32 protrudes from the first photoresist layer 31.

  Further, when the molded body 20 is molded in the same manner as the second modified example except that a negative photoresist is used instead of the positive photoresist, the molded body 20 is formed as in the third modified example shown in FIG. The wall surface 27 is formed in a stepped shape such that the second photoresist layer 32 is recessed from the edge of the first photoresist layer 31.

  In the above description, an example in which two layers of the first photoresist layer 31 and the second photoresist layer 32 are stacked has been described. However, the present invention is not limited to this, and three or more photoresist layers are stacked. It is also possible to do. For example, as in the fourth modification shown in FIG. 7, each time the photoresist layers 31 to 34 are formed, the next photoresist layer is exposed and developed using a mask having an appropriate opening without developing. It is also possible to form the molded body 20 in the same manner as in the first embodiment by repeatedly laminating the layers 32 to 35 and laminating the first photoresist layer 31 to the fifth photoresist layer 35. In this case, the edge portions of the photoresist layers 31 to 35 are multi-stepped portions 29, and the same shape portion 29 a is formed in a part of the stepped portion 29.

  Further, as in the fifth modification shown in FIG. 8, the multi-stepped portion 29 having a reverse gradient is formed by laminating the first photoresist layer 31 to the fifth photoresist layer 35 and developing them. May be.

  And when laminating | stacking three or more photoresist layers in this way, as long as the soluble part of each photoresist layer can be melt | dissolved and removed reliably at the time of image development, the number of lamination | stacking will not be limited and it can select suitably.

Furthermore, in the said 1st Embodiment, although the molded object 20 used in order to manufacture a fine structure was demonstrated, the use of the molded object 20 is not specifically limited, The molded object 20 is left as it is or hardening | cured. It can be used as various members.
[Embodiment 2 of the Invention]

  9 and 10 show a second embodiment of the present invention.

  In Embodiment 2 of the present invention, an example will be described in which the molded body 20 is molded when the side surface 12b of the groove 12 of the microstructure 11 shown in FIG. 1 is inclined with respect to the bottom surface 12c.

  As shown in FIG. 9, the molded body 20 to be molded has a shape corresponding to the target shape of the microstructure 11, and includes a side surface 31 c of the first photoresist layer 31 and a side surface 32 c of the second photoresist layer 32. Is the same as that of the first embodiment of the invention except that the plane is continuously inclined with respect to the substrate 10.

  Such a molded body 20 can be molded in the same manner as in the first embodiment of the invention. First, as shown in FIG. 1 photoresist layer 31 is formed.

  In the second embodiment of the present invention, the first photoresist layer 31 is applied with a negative photoresist and dried by, for example, spin coating, so that the surface is as flat as possible. It forms so that it may become.

  Next, as shown in FIG. 10B, the first photoresist layer 31 is exposed using the first mask 60 as a first exposure step.

  The first mask 60 is made of a gray scale mask, and the shape in plan view corresponds to the target shape, and has an opening 63 having an inverted shape of the groove 12. In the opening 63, a concentration gradient portion 65 is provided at a portion where the side surface 31c of the first photoresist layer 31 is formed. The density gradient portion 65 is a region in which the transmittance of exposure light is adjusted according to the inclination of the target shape of the side surface 31c, and the aperture ratio is adjusted for each of a large number of pixels obtained by dividing the first mask 60 in the surface direction. As a result, a concentration gradient is formed.

  By this exposure, a soluble portion 31 a is formed in the first photoresist layer 31. In the first photoresist layer 31, the portion excluding the soluble portion 31a is exposed to the extent that it cannot be sufficiently dissolved and removed by the developer in the development process, and the portion corresponding to the concentration gradient portion 65 of the soluble portion 31a has a concentration. Exposure is performed corresponding to the gradient.

  Next, as shown in FIG. 10C, a second photoresist layer 32 is formed on the first photoresist layer 31.

  The second photoresist layer 32 can be similarly formed using the same photoresist as the first photoresist layer 31 in a state where the first photoresist layer 31 is not developed.

  Next, as shown in FIG. 10D, as the second exposure step, the second photoresist layer 32 is exposed using the second mask 70.

  The second mask 70 is composed of a gray scale mask different from the first mask. In the second mask 70, the shielding part 77 other than the opening 73 is formed larger than the shielding part 67 other than the opening 63 of the first mask 60.

  In the opening 73 of the second mask 70, a concentration gradient portion 75 is provided by adjusting the opening ratio at a portion where the side surface 32c of the second photoresist layer 32 is formed. The concentration gradient of the concentration gradient portion 75 is formed to be the same as the concentration gradient of the concentration gradient portion 65 of the first mask 60. Here, the position of the density gradient portion 65 arranged when the first mask 60 is precisely aligned with the base material 10 by an alignment mark (not shown) and the second mask 70 are precisely aligned with the base material 10. In this case, the position of the concentration gradient portion 75 arranged at the time is formed so as to be adjacent to each other.

  When exposure is performed using such a second mask 70, exposure light is irradiated to the second photoresist layer 32 through the opening 73, so that the second photoresist layer 32 matches the opening 73. It is exposed with. At that time, the portion of the first photoresist layer 31 exposed by the concentration gradient portion 65 of the first mask 60 and the second photoresist layer 32 are exposed by the concentration gradient portion 75 of the second mask 70. The part is adjacent in plan view.

  At the time of exposure using the second mask 70, the exposure light exposed to the first mask 60 is again irradiated with exposure light. However, this part may not be dissolved and may be further exposed.

  After the exposure of all the photoresist layers 31 and 32 is completed, the exposed first and second photoresist layers 31 and 32 are developed together as shown in FIG.

  In the development, the first photoresist layer 31 forms the first molded portion 31b having the inclined side surface 31c, and the second photoresist layer 31 forms the second molded portion 32b having the inclined side surface 32c. The molded part 20 is molded in a state in which the molded parts are formed and arranged so as to be integrated with each other. At this time, the side surface 31c of the first molding part 31b and the side surface 32c of the second molding part 32 are arranged adjacent to each other in plan view so as to continue with the same gradient.

  In this embodiment, the base material 10 after development in which all the molding parts 31b and 32b are molded is then placed in the dissolved gas atmosphere, and the surface shape is smoothed. May be performed. The first and second masks 60, 70 are finely misaligned, the fine difference in the amount of dissolution at the interface between the first photoresist 31 and the second photoresist 32, etc. When a fine level difference occurs at the interface between the side surface 31c of the first molded portion 31b and the side surface 32b of the second molded portion 32b, the smoothing process allows the side surface 31c and the side surface 32c to be smoothly continuous. be able to.

  In this smoothing process, all the molding parts 31b and 32b are disposed in a dissolved gas atmosphere such as a gas capable of dissolving the first and second photoresist layers 31 and 32, for example, PM thinner manufactured by Tokyo Ohka Kogyo Co., Ltd. And it can process by heating as needed and arrange | positioning for a predetermined time.

  Thereby, the molded object 20 which consists of a photoresist on the surface of the base material 10 is shape | molded. As shown in FIG. 9, the molded body 20 has a shape corresponding to the target shape of the microstructure 11, and the side surface 31c of the first photoresist layer 31 and the side surface of the second photoresist layer 32, 32c is a plane that is continuously inclined with respect to the base material 10.

  And in order to manufacture the fine structure 11 which has the shape corresponding to the molded object 20 and was equipped with the groove part 12 using the molded object 20 shape | molded in this way, it is the same as that of Embodiment 1 of invention. do it.

  Even if the molded body 20 is molded as described above or the fine structure 11 is manufactured, the same effects as those of the first embodiment of the invention can be obtained.

  In particular, in the second embodiment of the present invention, the first and second masks 60 and 70 are gray scale masks, and the first and second molding portions 31b and 32b include inclined side surfaces 31c and 32c, respectively. Since the side surfaces 31c and 32c are arranged at continuous positions, the molded body 20 and the microstructure 11 can be formed even if the deep groove portion 12 has an inclined surface as compared with the photoresist layers 31 and 32. It can be formed with high accuracy.

  Here, since the inclined surface of the molded body 20 is formed by exposing each of the plurality of photoresist layers 31 and 32, it is easy to form an inclined surface having a constant gradient. Normally, when an inclined surface is formed on an excessively thick photoresist layer, if the exposure is performed using a gray scale mask having a constant concentration gradient, the inclination shift becomes larger at a deeper position due to scattering of exposure light. easy. However, if each of the plurality of photoresist layers 31 and 32 is exposed as in this embodiment, such a phenomenon hardly occurs and the inclined surface is easily exposed and molded easily.

  Note that the second embodiment of the present invention can be modified as appropriate within the scope of the present invention.

  For example, in the above, the concave shape is formed by the first molding portion 31b and the second molding portion 32b so as to correspond to the groove portion 12, but the openings 63, 73 of the first and second masks 60, 70 The shielding portions 67 and 77 are reversed, the concentration gradients of the concentration gradient portions 65 and 75 are reversed, the first photoresist layer 31 is exposed by the second mask 70, and the first mask 60 is used to expose the first photoresist layer 31. Except that the second photoresist layer 32 is exposed, if the molded body 20 is molded while adjusting the exposure light in the same manner as in the second embodiment of the invention, as in the first modification shown in FIG. The molded body 20 can be formed in a shape protruding from the center of the substrate 10.

  In the second embodiment of the present invention, the example in which the two photoresist layers are stacked has been described. However, the present invention is not limited in any way, and three or more photoresist layers can be stacked. By repeating the exposure every time the photoresist layer is laminated, it is possible to form a molded body having a larger difference in elevation.

Furthermore, in the above description, an example in which the side surfaces 31c and 32c of the molding portions 31b and 32b are inclined planes having a constant gradient has been described, but the side surfaces 31c and 32c may be formed from planes having different inclinations, respectively. Moreover, each may be formed of a curved surface or a bent surface.
Embodiment 3 of the Invention

  12 and 13 show a third embodiment of the present invention.

  The third embodiment of the present invention is an example in which a lens array 25 as shown in FIG. 12 is manufactured as a fine structure.

  In the lens array 25, one or a plurality of lens portions 15 having a predetermined convex curved surface shape are provided on the surface of the substrate 10. Here, the base material 10 consists of an optical base material which can permeate | transmit light.

  Even such a lens array 25 can be manufactured in the same manner as in the second embodiment of the invention by molding a molded body 20 as shown in FIG. In the molded body 20, curved surfaces 31e and 32e having different shapes are formed on the first molded body 31b and the second molded body 32b, respectively, and the surface on which the curved surface 31e and the curved surface 32e are continuously formed is formed. It corresponds to the surface shape of the lens unit 15 with high accuracy.

  When the molded body 20 is molded, the first and second masks 60, 60 are formed depending on whether the photoresist constituting the first and second photoresist layers 31, 32 is a positive type or a negative type. 70 openings 63 and 73 and density gradient parts 65 and 75 are provided so as to correspond to the target shape of the lens array 25. At this time, the density gradient of the density gradient part 65 of the first mask 60 is set to be higher than the target shape. It is also possible to make the exposure amount smaller by reducing the thickness of the second mask 70 so that a desired exposure amount is obtained by exposing through the opening 73 of the second mask 70 in the second exposure step.

  If such a molded body 20 is molded on the substrate 10 and then etched, a lens array 25 corresponding to the shape of the molded body 20 can be manufactured.

  Even in the case where such a molded body 20 is molded or the lens array 25 is manufactured, the same effects as those of the second embodiment of the invention can be obtained.

  In particular, according to the third embodiment of the present invention, it is easy to form the difference in height of the surface shape composed of the curved surface of the molded body 20 larger than the thickness of each of the photoresist layers 31 and 32. As the lens portion 15 of the lens array 25, it is easy to manufacture a lens in which the height difference indicated by so-called SAG is larger than that of the photoresist layers 31 and 32.

  Note that Embodiment 3 of the present invention can be modified as appropriate within the scope of the present invention.

  For example, in the above description, the example in which the molded body 20 for forming the convex lens portion is molded has been described. However, as shown in FIG. 14, even if the molded body for forming the concave lens is used, It is possible to form the first and second masks by reversing the shape, reversing the type of photoresist used, adjusting the exposure amount, and the like. It is possible to manufacture a lens.

1 shows a microstructure according to Embodiment 1 of the present invention, in which (a) is a sectional view and (b) is a plan view. It is sectional drawing which shows the molded object of Embodiment 1 of this invention. It is a figure explaining the shaping | molding process of the molded object of Embodiment 1 of this invention. It is sectional drawing which shows the molded object of the 1st modification of Embodiment 1 of this invention. It is sectional drawing which shows the molded object of the 2nd modification of Embodiment 1 of this invention. It is sectional drawing which shows the molded object of the 3rd modification of Embodiment 1 of this invention. It is sectional drawing which shows the molded object of the 4th modification of Embodiment 1 of this invention. It is sectional drawing which shows the molded object of the 5th modification of Embodiment 1 of this invention. It is sectional drawing which shows the molded object of Embodiment 2 of this invention. It is a figure explaining the shaping | molding process of the molded object of Embodiment 2 of this invention. It is sectional drawing which shows the molded object of the modification of Embodiment 2 of this invention. It is sectional drawing which shows the fine structure of Embodiment 3 of this invention. It is sectional drawing which shows the molded object of Embodiment 3 of this invention. It is sectional drawing which shows the molded object of the modification of Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Base material 11 Fine structure 12 Groove part 20 Molding body 31 1st photoresist layer 32 2nd photoresist layer 31a, 32a Soluble part 40, 60 1st mask 50, 70 2nd mask 43, 53, 63, 73 opening

Claims (9)

In the method of forming a molded product that exhibits a shape corresponding to the opening shape of the mask by exposing and developing using a mask to the photoresist layer,
A first exposure step of exposing the first photoresist layer using a first mask;
A second exposure step of forming a second photoresist layer on the first photoresist layer after exposure, and exposing the second photoresist layer using a second mask;
A development step of developing the first and second photoresist layers after exposure together,
A first forming portion formed on the first photoresist layer to have a shape corresponding to the opening shape of the first mask; and a shape corresponding to the opening shape of the second mask. A method for molding a molded body, comprising molding the molded body combined with a second molded portion molded into the second photoresist layer.   The method for molding a molded body according to claim 1, wherein the first and second masks are binary masks.   The molding method according to claim 2, wherein the first and second molding parts have the same shape in a plan view and are disposed at the same position in a plan view.   The method for molding a molded body according to any one of claims 1 to 3, wherein the first and second masks are gray scale masks.   The molding method according to claim 4, wherein each of the first and second molding parts includes an inclined surface and is disposed at a position where the inclined surfaces are continuous with each other.   6. The method for molding a molded body according to claim 3, wherein the entire molded portion is disposed in a heated atmosphere after the development.   6. The method for molding a molded body according to claim 3, wherein the entire molded portion is disposed in a dissolved gas atmosphere after the development.   A molded body formed by the molding method according to claim 1. The photoresist layer formed on the substrate is exposed and developed to form a molded body, and the molded body and the base material are etched to produce a microstructure having a shape corresponding to the molded body. Is the way
A method for manufacturing a microstructure, wherein the molded body is molded by the molding method according to any one of claims 1 to 7.

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