JP2006317870A - Uv-exposing method and device, fine structure manufacturing method, and fine structure manufactured with method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for obtaining a highly precise fine structure at a low cost. <P>SOLUTION: In the UV-exposing method, a material 5b is exposed with an UV ray emitted from an UV light source 2 via one or a plurality of photomasks 4. The UV light source 2 emits the UV ray with a plurality of wavelengths or continuous wavelengths. Also, during exposure of the material 5b, the photomask 4 is relatively transferred in directions parallel to the surface of the material 5b so as to make energy distribution of the UV ray within a surface parallel to the surface of the material 5b continuously vary. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultraviolet exposure method and an ultraviolet exposure apparatus for exposing ultraviolet rays to a material such as a resist, a method for producing a microstructure obtained by developing a material exposed to ultraviolet rays, a microstructure produced thereby, A method for producing a fine metal structure obtained by performing electroforming using a fine structure as a matrix, a fine metal structure produced by the method, and a forming process using the fine metal structure as a fine mold The present invention relates to a method for producing a fine resin part to be obtained and a fine resin part produced thereby.

  In recent years, with the development of information communication equipment and micromachines, etc., miniaturization of optical components and mechanical components has progressed, and three-dimensional microstructures having various shapes are required. There is also a need for a three-dimensional fine mold for mass-producing this three-dimensional fine structure at low cost. Photolithography and X-ray lithography are techniques that can produce a microstructure with a high aspect ratio (ratio of height to opening width). Hereinafter, a manufacturing process of a fine structure using photolithography or X-ray lithography will be described.

  First, as shown in FIG. 11A, a resist 201 having a property sensitive to ultraviolet rays or X-rays is applied on a substrate 201, and ultraviolet rays or X-rays are exposed through a predetermined mask 203. By doing so, the part of the resist 202 corresponding to the hole (pattern) formed in the mask 203 is exposed to cut the molecular chain of the part. Thereafter, as shown in FIG. 11 (b), the resist 202 is immersed in a developing solution, and the exposed portion is developed by melting and removing, so that the fine pattern made of the resist 202 having a three-dimensional shape with a high aspect ratio. A structure is formed. As shown in FIG. 11C, the fine structure is used as a mother die, and electroforming is performed to form a fine metal structure 204 having a three-dimensional shape. Then, by removing the fine metal structure 204 from the resist 202 and using it as a mold, such as a synthetic resin, a fine resin part can be produced at low cost.

When the resist 202 is exposed to ultraviolet rays, since the wavelength of the ultraviolet rays is long, a diffraction phenomenon occurs in the outer peripheral portion of the hole formed in the mask 203, and the energy of the ultraviolet rays exposed to the resist 202 is caused by this diffraction phenomenon. Since the distribution is not constant, there is a problem that a highly accurate fine structure cannot be obtained. On the other hand, since the X-ray has a short wavelength, the above diffraction phenomenon does not occur. In addition, since X-rays have a high permeability to substances, it is possible to obtain a three-dimensional shape with a high aspect ratio in a fine structure. For these reasons, X-rays are often used in the step of exposing the resist 202 with ultraviolet rays or X-rays shown in FIG. In particular, the technique of performing the process shown in FIG. 11 using X-rays is called a LIGA (Lishographie Galvanofomung Abformung: German language) process (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-354412

  However, as described above, X-rays are suitable for the manufacture of fine structures, but the price of a synchrotron radiation light source that emits light containing X-rays is as high as about 10 billion yen, so it is not economical. Companies have a problem that synchrotron radiation sources cannot be purchased.

  Further, when a fine structure is manufactured by exposing the resist 202 to ultraviolet rays, there is a problem that a highly accurate fine structure cannot be obtained due to the diffraction phenomenon.

  The present invention has been made in view of the above problems, and an object thereof is to provide a method and an apparatus capable of obtaining a highly accurate fine structure at low cost.

  In order to achieve the above object, an ultraviolet exposure method according to claim 1 is an ultraviolet exposure method in which ultraviolet rays emitted from an ultraviolet ray source are exposed to a material through one or more photomasks, wherein the ultraviolet ray source comprises: It is characterized in that it emits ultraviolet rays having a plurality of wavelengths or continuous wavelengths.

  The ultraviolet exposure method according to claim 2, wherein the material is exposed to ultraviolet rays emitted from an ultraviolet source through one or more photomasks, and is disposed between the ultraviolet source and the material. The material is exposed to ultraviolet rays by changing the distance between the photomask and the material to a plurality of different distances.

  The ultraviolet exposure method according to claim 3 is the ultraviolet exposure method according to claim 1 or 2, wherein the energy distribution of ultraviolet rays continuously changes in a plane parallel to the surface of the material during the exposure of the material. In addition, the photomask is moved in a direction parallel to the surface of the material.

  According to a fourth aspect of the present invention, there is provided a method for producing a microstructure, wherein a part of the material that has been absorbed by the ultraviolet ray exposure method according to any one of the first to third aspects and that can be removed by development is removed by development. Thus, a fine structure is obtained.

  The microstructure according to claim 5 is manufactured by the method for manufacturing a microstructure according to claim 4.

  The method for producing a fine metal structure according to claim 6 is characterized in that the fine metal structure is obtained by performing electroforming using the fine structure according to claim 5 as a matrix.

  The fine metal structure according to claim 7 is manufactured by the method for manufacturing a fine metal structure according to claim 6.

  A method for producing a fine resin part according to an eighth aspect is characterized in that a fine resin part is obtained by performing molding using the fine metal structure according to the seventh aspect as a fine mold.

  The fine resin component described in claim 9 is manufactured by the method for manufacturing a fine resin component according to claim 8.

  11. The ultraviolet exposure apparatus according to claim 10, wherein the ultraviolet light radiated from the ultraviolet light source is exposed to the material through one or more photomasks, and the ultraviolet light source is an ultraviolet light having a plurality of wavelengths or a continuous wavelength. It is characterized by emitting radiation.

  The ultraviolet exposure apparatus according to claim 11 is the ultraviolet exposure apparatus according to claim 10, wherein the photomask is moved relative to the surface of the material in a parallel direction, and during the exposure of the material, And a control means for controlling the movement of the photomask by the moving means so that the energy distribution of ultraviolet rays in a plane parallel to the surface of the material changes continuously.

  The ultraviolet exposure apparatus according to claim 12 is an ultraviolet exposure apparatus for exposing a material to ultraviolet light emitted from an ultraviolet light source through one or a plurality of photomasks, and is disposed between the ultraviolet light source and the material. And changing means for changing the distance between the photomask and the material, and control means for controlling the distance by the changing means.

  The ultraviolet exposure apparatus according to claim 13, further comprising a moving means for moving the photomask relative to the surface of the material in a parallel direction in the ultraviolet exposure apparatus according to claim 12, wherein the control means includes: During the exposure of the material, the movement of the photomask is controlled by the moving means so that the energy distribution of ultraviolet rays continuously changes in a plane parallel to the surface of the material.

  According to the ultraviolet exposure method of claim 1, the energy distribution of ultraviolet rays in a plane parallel to the surface of the material can be averaged. Further, the ultraviolet ray source is less expensive than an X-ray source constituted by a synchrotron radiation light source that emits light including X-rays. Therefore, by developing the material exposed to ultraviolet rays, a highly accurate microstructure can be obtained at low cost.

  According to the ultraviolet exposure method of claim 2, the energy distribution of ultraviolet rays in a plane parallel to the surface of the material can be averaged. Further, the ultraviolet ray source is less expensive than an X-ray source constituted by a synchrotron radiation light source that emits light including X-rays. Therefore, by developing the material exposed to ultraviolet rays, a highly accurate microstructure can be obtained at low cost.

  According to the ultraviolet exposure method of claim 3, since the energy distribution of the ultraviolet rays in the plane parallel to the surface of the material continuously changes, the inclination direction is changed by developing the material exposed to the ultraviolet rays. A microstructure having a shape that changes continuously or stepwise can be obtained. For example, a microstructure having a conical or pyramidal hole whose inclination direction changes continuously or stepwise can be obtained.

  According to the method for manufacturing a fine structure according to claim 4, the fine structure can be obtained by developing the material that has absorbed ultraviolet rays by the ultraviolet exposure method according to any one of claims 1 to 3. Thus, a highly accurate fine structure can be manufactured.

  According to the microstructure described in claim 5, the microstructure is manufactured by the method for manufacturing a microstructure described in claim 4. Therefore, the microstructure is inexpensive and suitable as a high-precision component. Can be used.

  According to the method for producing a fine metal structure according to claim 6, since the fine metal structure is obtained by performing electroforming using the fine structure according to claim 5 as a matrix, the shape of the fine structure is inverted. A highly accurate fine metal structure can be manufactured. In addition, for example, a fine metal structure in which the same shape is arranged in an array can be manufactured. Therefore, by dividing the individual, high-precision fine metal structure parts can be mass-produced at low cost.

  According to the fine metal structure of claim 7, since the fine metal structure is manufactured by the method of manufacturing a fine metal structure of claim 6, the fine metal structure is inexpensive and highly accurate. It can be suitably used as a metal structure or a high-precision fine mold.

  According to the method for manufacturing a fine resin part according to claim 8, since the fine metal structure according to claim 7 is used as a fine mold to perform a molding process such as injection molding or hot embossing, a fine resin part is manufactured. Accurate fine resin parts can be mass-produced at low cost. In addition, for example, if a fine mold in which the same shape is arranged in an array is used, the fine resin parts obtained by performing the molding process are individually divided into high-precision fine resin parts that are individually divided. Mass production is possible at low cost.

  According to the fine resin component of the ninth aspect, since the fine resin component is manufactured by the method of manufacturing the fine resin component according to the eighth aspect, the fine resin component is inexpensive and is preferably used as a high-precision component. be able to.

  According to the ultraviolet exposure apparatus of the tenth aspect, the energy distribution of the ultraviolet rays in a plane parallel to the surface of the material can be averaged. Further, the ultraviolet ray source is less expensive than an X-ray source constituted by a synchrotron radiation light source that emits light including X-rays. Therefore, by developing the material exposed to ultraviolet rays, a highly accurate microstructure can be obtained at low cost.

  According to the ultraviolet exposure apparatus of the eleventh aspect, since the energy distribution of the ultraviolet rays in the plane parallel to the surface of the material continuously changes, the inclination direction is changed by developing the material exposed to the ultraviolet rays. A microstructure having a shape that changes continuously or stepwise can be obtained. For example, a microstructure having a conical or pyramidal hole whose inclination direction changes continuously or stepwise can be obtained.

  According to the ultraviolet exposure apparatus of the twelfth aspect, the energy distribution of the ultraviolet rays in a plane parallel to the surface of the material can be averaged. Further, the ultraviolet ray source is less expensive than an X-ray source constituted by a synchrotron radiation light source that emits light including X-rays. Therefore, by developing the material exposed to ultraviolet rays, a highly accurate microstructure can be obtained at low cost.

  According to the ultraviolet exposure apparatus of claim 13, since the energy distribution of the ultraviolet rays in the plane parallel to the surface of the material continuously changes, the inclination direction is changed by developing the material exposed to the ultraviolet rays. A microstructure having a shape that changes continuously or stepwise can be obtained. For example, a microstructure having a conical or pyramidal hole whose inclination direction changes continuously or stepwise can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, first, an ultraviolet exposure method and an ultraviolet exposure apparatus according to the present invention will be described. FIG. 1 is a view schematically showing an ultraviolet exposure apparatus 1 according to the first embodiment of the present invention. As shown in the figure, the ultraviolet exposure apparatus 1 includes an ultraviolet source 2 and an exposure chamber 3, and exposes ultraviolet rays to the resist 5b in a proximity (proximity) state with a photomask 4 and a resist (material) 5b.

  The ultraviolet ray source 2 emits ultraviolet rays, and includes a mercury lamp 6, a lens 7, and a filter 8. The mercury lamp 6 is a lamp that utilizes light emission by discharge in mercury (Hg) vapor. FIG. 2 is a diagram showing a spectrum of light emitted from the mercury lamp 6. As shown in the figure, the mercury lamp 6 emits i-line (wavelength of about 365 nm), h-line (wavelength of about 405 nm), and g-line (wavelength of about 436 nm) as particularly intense light. The lens 7 is for converting the light emitted from the mercury lamp 6 into parallel light, and the light that has passed through the lens 7 enters the filter 8 as parallel light. The filter 8 removes h rays emitted from the mercury lamp 6. The light emitted from the mercury lamp 6 is subjected to the removal of h-rays by the filter 8, and i-rays and g-rays that are ultraviolet rays are mainly incident on the exposure chamber 3. As described above, the ultraviolet ray source 2 emits ultraviolet rays having a plurality of wavelengths (here, two wavelengths).

  The exposure chamber 3 is a chamber for exposing the resist 5 b to ultraviolet rays emitted from the ultraviolet source 2, and includes a sample holder 9, a first moving mechanism (moving means) 10, and a mask holder 11. The sample holder 9 is for supporting the sample 5, and the sample 5 is disposed on the sample holder 9. The sample 5 includes a substrate 5a and a resist 5b stacked on the substrate 5a. The resist 5b is an ultraviolet resist sensitive to ultraviolet rays, and is a thick film resist having a thickness of several hundreds of micrometers. In this embodiment, SU-8 (trade name) manufactured by Nippon Microchem Co., Ltd. is used as the resist 5b. However, the resist is not limited to this as long as it is an ultraviolet resist sensitive to ultraviolet rays.

  The first moving mechanism 10 is provided on the side of the sample 5 on the sample holder 9, and the mask holder 11 is attached to the first moving mechanism 10. Further, the first moving mechanism 10 moves the mask holder 11 relative to the sample holder 9 in the X-axis direction (left-right direction in FIG. 1), and the mask holder 11 relative to the sample holder 9. A Y-axis direction moving member 10b that moves in the Y-axis direction (perpendicular to the plane of FIG. 1) is provided, and the photomask 4 supported by the mask holder 11 is relatively parallel to the surface of the resist 5b. Move to. The operation of the first moving mechanism 10 is controlled by control means (not shown).

  The mask holder 11 is for supporting the photomask 4 as described above, and the photomask 4 is disposed on the mask holder 11 so as to face the substrate 5a. As shown in FIG. 4A, which is a plan view, and FIG. 4C, which is a vertical sectional view, the photomask 4 is formed by laminating an ultraviolet absorbing film 4b on an ultraviolet transmitting film 4a. For example, a circular hole 4c is formed in the central portion of the lens so that ultraviolet rays can be transmitted through the circular hole 4c. The mask holder 11 is provided with a hole 11a for transmitting ultraviolet rays.

  FIG. 3 is a diagram schematically showing the energy distribution of the ultraviolet rays exposed to the resist 5b. The broken line shown by the solid line in the figure shows the energy distribution of the g line when the distance between the photomask 4 and the surface of the resist 5b (hereinafter referred to as “gap”) L is 10 μm. A broken line indicated by a chain line similarly indicates an energy distribution of the i-line when the gap L is 10 μm. In FIG. 3, the radius of the circular hole 4c of the photomask 4 is set to 50 μm, and the ultraviolet energy distribution in the portion corresponding to the diameter of the circular hole 4c in the X-axis direction in FIG. The portion corresponding to the middle point (center of the circular hole 4c) is represented by x = 0 μm, and the portions corresponding to both ends of the diameter (the intersection of the outer periphery of the circular hole 4c and the diameter) are represented by x = ± 50 μm. Since the wavelength of ultraviolet rays is long, a diffraction phenomenon occurs at the outer peripheral portion of the circular hole 4c. As a result, as shown in the drawing, the energy values of the i-line and the g-line increase as x = 0 μm approaches x = ± 50 μm. The position where the energy peak occurs is different between the i-line and the g-line.

  When the photomask 4 and the resist 5b are exposed to the resist 5b in the proximity state, the resist 5b is exposed as shown in FIG. 3 due to the diffraction phenomenon at the outer periphery of the circular hole 4c of the photomask 4. The energy distribution of ultraviolet rays is not constant. In order to make the energy distribution of the ultraviolet rays constant, in the first embodiment, ultraviolet rays having two wavelengths, i-line and g-line, are exposed on the resist 5b. As described above, the positions where the energy peaks of the i-line and the g-line are different are different. Therefore, by exposing the i-line and g-line radiated from the ultraviolet source 2 to the resist 5b, the ultraviolet rays exposed to the resist 5b are exposed. The energy peaks of (i-line and g-line) are canceled out.

  When the ultraviolet energy peak exposed to the resist 5b cancels out, the ultraviolet energy distribution in a plane parallel to the surface of the resist 5b is averaged and becomes constant. For example, when i-line and g-line are exposed on the resist 5b, the energy distribution of ultraviolet rays is averaged as shown by a two-dot chain line in FIG. Thereby, if the resist 5b is developed, a highly accurate fine structure can be obtained. Further, since the mercury lamp 6 constituting the ultraviolet light source 2 is less expensive than a synchrotron radiation light source that emits light including X-rays, a highly accurate microstructure can be obtained at low cost.

  Although the case where the resist 5b is exposed to ultraviolet rays having a plurality of wavelengths has been described here, the resist 5b may be exposed to ultraviolet rays having a continuous wavelength. In this case, a xenon short arc lamp that emits light having a continuous wavelength of about 200 nm to 1000 nm is used in place of the mercury lamp 6, and a filter that removes light of a certain wavelength or less is used instead of the filter 8 that removes h-rays. A filter that removes light of a certain wavelength or more is used. For example, light having a wavelength of less than 350 nm emitted from the xenon short arc lamp and light having a wavelength of more than 450 nm are removed by a filter, and ultraviolet rays having a continuous wavelength of 350 nm to 450 nm are exposed to the resist 5b. Thus, even if the resist 5b is exposed to continuous wavelength ultraviolet light, the peak of the ultraviolet energy exposed to the resist 5b is canceled out, and the ultraviolet energy distribution in a plane parallel to the surface of the resist 5b is averaged. Constant.

  Next, an exposure procedure in the case of manufacturing a fine structure having inclined side walls will be described with reference to FIG. For example, as shown in FIG. 4 (e), which is a vertical sectional view of the sample 5, and FIG. 4 (f), which is a schematic perspective view of only the hole 5c to be formed in the resist 5b, the diameter decreases toward the resist 5b. When the inverted frustoconical hole 5c is provided, the energy distribution of the ultraviolet light exposed to each part of the resist 5b is shown by the broken line A in FIG. 4D, and the hole 5c corresponds to the shape of the hole 5c. It is necessary to have an energy distribution that is high at the center and gradually decreases toward the outer periphery. 4D shows the energy distribution of ultraviolet rays in the X-axis direction, it is necessary that the energy distribution of ultraviolet rays in the Y-axis direction be the same as that of the broken line A.

  For example, when the radius of the circle 5d at the upper end portion of the hole 5c is 37.5 μm and the radius of the circle 5e at the lower end portion of the hole 5c is 12.5 μm, the energy distribution of ultraviolet rays is 12. Control is performed so that the intensity becomes the strongest in the region of 5 μm, and the energy of the ultraviolet light gradually decreases from the region of radius 12.5 μm to radius 37.5 μm. In order to realize such control, the radius of the circular hole 4c is set to 25 μm, and the photomask 4 whose plan view is shown in FIG. What is necessary is just to make circular motion on the circumference of radius 12.5 micrometers within the plane parallel to the surface 5f.

  That is, in FIG. 4A, the center B of the photomask 4, that is, the center of the circular hole 4c coincides with the center C of the resist 5b in FIG. 4E, but in actual exposure of the resist 5b. 4B, the center B of the photomask 4 is a radius including the center C of the resist 5b in a plane including the X axis and the Y axis, that is, a plane parallel to the surface 5f of the resist 5b. The resist 5b is exposed to ultraviolet rays through the photomask 4 while continuously rotating the entire photomask 4 so as to move on the circumference D of 12.5 μm. As a result, ultraviolet rays are always exposed within a range of radius 12.5 μm centered on the center C of the resist 5b, but in the range of radius 12.5 to 37.5 μm, the exposure time of ultraviolet rays increases toward the outer periphery. That is, the energy distribution of ultraviolet rays can be controlled so that the exposure energy of ultraviolet rays is reduced.

  The rotational movement of the photomask 4 on the circumference D as described above drives the X-axis direction moving member 10a and the Y-axis direction moving member 10b of the first moving mechanism 10 simultaneously, and the photomask 4 on the circumference D is simultaneously driven. 4 can be realized by continuously controlling the direction and speed of movement of the photomask 4 in the X-axis direction and the Y-axis direction so that the center B of the photomask 4 moves.

  Since the resist 5b exposed to ultraviolet rays absorbs the ultraviolet rays and the molecular chain is cut, and a part of the resist 5b can be removed by development, a fine structure can be produced by developing the resist 5b. . The developed resist 5b has an inverted frustoconical microstructure (hole 5c) having a radius of 12.5 μm at the bottom (hole 5e) and a radius of 37.5 μm at the top (hole 5d) corresponding to the energy distribution. It is formed. In this way, a part of the resist 5b that has absorbed ultraviolet rays and can be removed by development can be removed by development to obtain a microstructure having a three-dimensional shape. If a large number of circular holes 5c having a radius of 25 μm are formed in an array on the photomask 4 with a pitch of 200 μm, for example, the inverted frustoconical fine structure (holes 5c) on the resist 5b also has a pitch of 200 μm. It is formed in a large number in the form of an array and can handle batch processing.

  The fine structure obtained by development may be used as it is, but a fine metal structure can also be obtained by performing electroforming using the fine structure as a matrix. A method for producing a fine metal structure by electroforming using the fine structure as a matrix will be described with reference to the drawings. A plating film made of, for example, nickel is formed on the surface of the microstructure 12 shown in FIG. Subsequently, electroplating is performed using the plating film as a conductive layer film to form a metal layer 13 made of nickel, a nickel alloy, or the like, as shown in FIG. In electroforming, a cathode electrode and an anode electrode, which serve as a matrix, are placed in an electroplating bath filled with an electroforming bath, and a metal layer is electrodeposited on the cathode according to the principle of plating. This is a processing method for obtaining a replicated version. Thereafter, when the fine structure 12 is removed with a solvent, a fine metal structure 14 is obtained as shown in FIG. The fine metal structure 14 is used as a fine mold such as a fine resin molded part or a fine metal part as it is.

  Furthermore, by using the fine metal structure as a fine mold, a fine resin part can be obtained by molding such as hot embossing and injection molding. A method for manufacturing a fine resin part by hot embossing will be described with reference to the drawings. First, as shown in FIG. 6A, a resin in which a resin layer 16 made of a plate-like acrylic resin having a thickness equal to or larger than the thickness of the metal pattern layer in the fine mold 14 is formed on a metal plate 15 made of stainless steel or the like. In a state where the plate 17 is heated, the plate 17 is pressed against the fine mold 14 that has been treated with the release agent. As shown in FIG.6 (b), it waits until the acrylic resin of the resin layer 17 solidifies. When the fine mold 14 and the metal plate 15 are removed from the acrylic resin after the acrylic resin is solidified, the fine resin component 18 made of the acrylic resin is completed as shown in FIG. 6C. Further, for example, as shown in FIG. 6D, the fine resin component 19 can be obtained by individually separating the fine resin component 18. In addition to the acrylic resin, the resin layer 16 may be made of a resin such as polystyrene, an epoxy resin, or a polycarbonate resin. The above-described fine structure manufacturing method, fine metal structure manufacturing method, and fine resin component manufacturing method are the same in the modification of the first embodiment and the second embodiment described below. Therefore, the description is omitted, and the ultraviolet exposure method and the ultraviolet exposure apparatus will be mainly described.

  A modification of the first embodiment of the present invention will be described. In the ultraviolet exposure apparatus 1 according to the first embodiment, one photomask 4 is used. However, in the ultraviolet exposure apparatus 51 according to the modification shown in FIG. The main difference is that the masks 52 and 53 are used. Hereinafter, parts common to the ultraviolet exposure apparatus 1 according to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and differences are mainly described.

  In the ultraviolet exposure apparatus 51, two upper and lower photomasks 52 and 53 are used, and two mask holders 54 and 55 for holding the photomasks 52 and 53 are provided. The mask holders 54 and 55 are provided with holes 54a and 55a for transmitting ultraviolet rays, respectively. The first moving mechanism 56 includes two X-axis direction moving members 56a and 56b that move the mask holders 54 and 55 in the X-axis direction (left-right direction in FIG. 7), respectively. Similar to the ultraviolet exposure apparatus 1, the sample holder 9 is provided with a sample 57 composed of a substrate 57a and a resist 57b.

  As shown in FIGS. 8A to 8C, the photomasks 52 and 53 are formed by laminating ultraviolet transmitting films 52a and 53a and ultraviolet absorbing films 52b and 53b, respectively. Square holes 52c and 53c having a diagonal length of 50 μm are formed in the ultraviolet absorbing films 52b and 53b so that ultraviolet rays can pass through overlapping portions of the holes 52c and 53c of the two photomasks 52 and 53.

  When the resist 57b is exposed to ultraviolet rays, the two photomasks 52 and 53 are first started from the position where the vertices E and F of each other overlap each other as shown in FIG. The mask 52 is moved 25 μm along the X-axis direction to the left side of FIGS. 8A and 8B, while the photomask 53 is moved along the X-axis direction to the right side of FIGS. 8A and 8C. The film is moved by 25 μm at the same speed as that of 52, and finally, the photomasks 52 and 53 overlap each other at a position indicated by a two-dot chain line in FIG.

  The ultraviolet ray energy distribution in the X-axis direction on the resist 57b obtained by such exposure is strongest at the center H of the photomasks 52 and 53 at the final position, as indicated by the broken line G in FIG. Thus, the exposure energy gradually decreases to the peripheral area. Further, the energy distribution of ultraviolet rays in the Y-axis direction is the same as that of the broken line G.

  Therefore, when the resist 57b is developed, the processing depth becomes deeper as the exposure energy increases, so that the resist 57b corresponds to the exposure energy distribution, as shown in FIGS. 8E and 8F. An inverted quadrangular pyramid-shaped microstructure (hole 57c) having a diagonal length of 50 μm is formed. The sizes of the holes 52c and 53c of the two photomasks 52 and 53 do not have to be the same size as long as the diagonal length is 50 μm or more, and the photomask 52 is used until the length of the intersecting portion reaches 50 μm. Needless to say, 53 may be moved. Further, if the holes 52c and 53c are formed on the photomasks 52 and 53, for example, in an array shape with a pitch of 200 μm, a plurality of inverted quadrangular fine structures (holes 57c) are also formed on the resist 57b with a pitch of 200 μm. It is formed in an array shape and can be used for batch processing.

  Next, an ultraviolet exposure method and an ultraviolet exposure apparatus according to the second embodiment of the present invention will be described. The ultraviolet exposure apparatus 1 according to the first embodiment of the present invention is an apparatus that exposes the resist 5b with a plurality of wavelengths or continuous wavelengths of ultraviolet rays emitted from the ultraviolet source 2, but the second embodiment shown in FIG. The ultraviolet exposure apparatus 101 according to the embodiment is different in that the gap L is changed to a plurality of different gaps and the single wavelength ultraviolet light is exposed to the resist 5b. Hereinafter, parts common to the ultraviolet exposure apparatus 1 according to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and differences are mainly described.

  The ultraviolet exposure apparatus 101 includes an ultraviolet source 102 and an exposure chamber 103, as shown in FIG. The ultraviolet light source 102 includes a mercury lamp 6, a lens 7, and a filter 104. The filter 104 includes an h-line cut filter 104a that removes h-rays emitted from the mercury lamp 6 and a g-line cut filter 104b that removes g-rays emitted from the mercury lamp 6. The light emitted from the mercury lamp 6 is subjected to removal of h-rays and g-rays by the filter 104, and i-rays that are ultraviolet rays are mainly incident on the exposure chamber 103.

  The exposure chamber 103 includes a sample holder 9, a first moving mechanism 10, a second moving mechanism (changing means) 105, and a mask holder 11. The second moving mechanism 105 is provided below the sample holder 9 and moves the sample holder 9 in the Z-axis direction (vertical direction in FIG. 1). The second moving mechanism 105 can change the gap L by moving the sample holder 9 in the Z-axis direction. The operation of the second moving mechanism 105 is controlled by a control means (not shown). Here, the sample holder 9 is moved in the Z-axis direction by the second moving mechanism 105 to change the gap L. However, the gap L is changed by moving the mask holder 11 in the Z-axis direction. It may be.

  FIG. 10 is a diagram schematically showing the energy distribution of ultraviolet rays exposed to the resist 5b. The broken line shown by the solid line in the figure shows the energy distribution of ultraviolet rays when the gap L is 50 μm, and the broken line shown by the one-dot chain line in the figure shows the energy distribution of ultraviolet rays when the gap L is 100 μm. ing. In FIG. 10, the radius of the circular hole 4c of the photomask 4 is set to 50 μm, and the ultraviolet energy distribution in the portion corresponding to the diameter of the circular hole 4c in the X-axis direction in FIG. 4A is shown. The portion corresponding to the middle point (center of the circular hole 4c) is represented by x = 0 μm, and the portions corresponding to both ends of the diameter (the intersection of the outer periphery of the circular hole 4c and the diameter) are represented by x = ± 50 μm. Since the wavelength of ultraviolet rays is long, a diffraction phenomenon occurs at the outer peripheral portion of the circular hole 4c. As a result, as shown in the figure, the value of the ultraviolet energy increases as x = 0 μm approaches x = ± 50 μm. Further, the position where the peak of the energy of ultraviolet rays occurs differs between when the gap L is 50 μm and when the gap L is 100 μm.

  When the photomask 4 and the resist 5b are in a proximity state and the UV light is exposed to the resist 5b, the resist 5b is exposed as shown in FIG. 10 due to the diffraction phenomenon at the outer periphery of the circular hole 4c of the photomask 4. The energy distribution of ultraviolet rays is not constant. In order to make this ultraviolet energy distribution constant, in the second embodiment, the control means controls the second moving mechanism 105 so that the gap L between the photomask 4 and the surface of the resist 5b is changed to a plurality of different gaps. Then, the resist 5b is subjected to multiple exposure. Specifically, when the gap L changes, the position where the ultraviolet energy peak occurs also changes, and this is used to multiplex-expose the resist 5b with a plurality of different gaps L in which the ultraviolet energy peak is offset. .

  When the ultraviolet energy peak exposed to the resist 5b cancels out, the ultraviolet energy distribution in a plane parallel to the surface of the resist 5b is averaged and becomes constant. For example, when the resist 5b is exposed to ultraviolet rays with a gap L = 50 μm and a gap L = 100 μm, the energy distribution of the ultraviolet rays is averaged as shown by a two-dot chain line in FIG. Thereby, if the resist 5b is developed, a highly accurate fine structure can be obtained.

  In the second embodiment, when manufacturing a microstructure having inclined sidewalls, the exposure described based on FIG. 4 is performed a plurality of times with different gaps L as described above. In the first embodiment, the resist 5b is exposed to a plurality of wavelengths or continuous wavelengths of ultraviolet rays, and in the second embodiment, the gap L is changed to a plurality of different gaps to change the single wavelength ultraviolet rays. Although the resist 5b is exposed to the resist 5b, a plurality of wavelengths or continuous wavelengths of ultraviolet light may be exposed to the resist 5b through a plurality of different gaps L. Also in this case, since the energy distribution of ultraviolet rays is averaged, a highly accurate fine structure can be obtained by developing the resist 5b exposed to ultraviolet rays.

  Ultraviolet exposure method and ultraviolet exposure apparatus for exposing ultraviolet ray to material, method for producing fine structure obtained by developing material exposed to ultraviolet ray, fine structure produced thereby, and using fine structure as matrix Production method of fine metal structure obtained by performing electroforming, fine metal structure produced by the method, and production of fine resin part obtained by molding using the fine metal structure as a fine mold The present invention can be applied to the method and fine resin parts produced thereby.

1 is a diagram schematically showing an ultraviolet exposure apparatus according to a first embodiment of the present invention. It is the figure which showed the spectrum of the light which a mercury lamp radiates | emits. It is the figure which showed roughly the energy distribution of the ultraviolet-ray exposed to a resist. It is a figure for demonstrating the procedure which exposes a ultraviolet-ray to a resist. It is explanatory drawing which shows the manufacturing method of the fine metal structure which electroforms to a fine structure along the procedure. It is explanatory drawing which shows the manufacturing method of the fine resin component which performs hot embossing with respect to a fine metal mold | die along the procedure. It is the figure which showed schematically the ultraviolet exposure apparatus which concerns on the modification of the 1st Embodiment of this invention. It is a figure for demonstrating the procedure which exposes a ultraviolet-ray to a resist. It is the figure which showed schematically the ultraviolet-ray exposure apparatus which concerns on the 2nd Embodiment of this invention. It is the figure which showed roughly the energy distribution of the ultraviolet-ray exposed to a resist. It is a figure for demonstrating the process of manufacturing the conventional fine structure.

Explanation of symbols

1, 51, 101 UV exposure apparatus 2, 102 UV source 3, 103 Exposure chamber 4, 52, 53 Photomask 5b, 57b Resist (material)
10, 56 First moving mechanism (moving means)
12 Fine structure 14 Fine metal structure 18, 19 Fine resin component 105 Second moving mechanism (changing means)

Claims (13)

An ultraviolet exposure method of exposing a material to ultraviolet light emitted from an ultraviolet light source through one or more photomasks,
The ultraviolet ray exposure method, wherein the ultraviolet ray source emits ultraviolet rays having a plurality of wavelengths or continuous wavelengths. An ultraviolet exposure method of exposing a material to ultraviolet light emitted from an ultraviolet light source through one or more photomasks,
An ultraviolet exposure method comprising exposing the material to ultraviolet rays by changing a distance between the photomask and the material disposed between the ultraviolet source and the material to a plurality of different distances.   During exposure of the material, the photomask is moved in a direction parallel to the surface of the material so that the energy distribution of ultraviolet rays continuously changes in a plane parallel to the surface of the material. The ultraviolet exposure method according to claim 1 or 2.   A fine structure obtained by removing a part of the material that has been absorbed by ultraviolet rays by the ultraviolet exposure method according to any one of claims 1 to 3 and that can be removed by development to obtain a fine structure. Manufacturing method of structure.   A fine structure manufactured by the method for manufacturing a fine structure according to claim 4.   A method for producing a fine metal structure, wherein a fine metal structure is obtained by performing electroforming using the fine structure according to claim 5 as a matrix.   A fine metal structure produced by the method for producing a fine metal structure according to claim 6.   A method for producing a fine resin part, wherein a fine resin part is obtained by molding the fine metal structure according to claim 7 as a fine mold.   A fine resin part produced by the method for producing a fine resin part according to claim 8. An ultraviolet exposure apparatus for exposing a material to ultraviolet rays emitted from an ultraviolet ray source through one or more photomasks,
The ultraviolet exposure apparatus characterized in that the ultraviolet light source emits ultraviolet light having a plurality of wavelengths or continuous wavelengths.   The moving means for moving the photomask relative to the surface of the material in a parallel direction, and the energy distribution of ultraviolet rays in a plane parallel to the surface of the material continuously changes during exposure of the material. The ultraviolet exposure apparatus according to claim 10, further comprising: a control unit that controls the movement of the photomask by the moving unit. An ultraviolet exposure apparatus for exposing a material to ultraviolet rays emitted from an ultraviolet ray source through one or more photomasks,
An ultraviolet ray comprising: changing means for changing a distance between the photomask disposed between the ultraviolet ray source and the material; and a control means for controlling the distance by the changing means. Exposure device. Moving means for moving the photomask relative to the surface of the material in a parallel direction;
The control means controls the movement of the photomask by the moving means so that the energy distribution of ultraviolet rays continuously changes in a plane parallel to the surface of the material during the exposure of the material. The ultraviolet exposure apparatus according to claim 12.

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