Patent Publication Number: US-2010117268-A1

Title: Fine mold and method for regenerating fine mold

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional of co-pending U.S. patent application Ser. No. 12/604,315, filed Oct. 22, 2009, which is a divisional of Ser. No. 11/860,182, filed Sep. 24, 2007, the entirety of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     A) Field of the Invention 
     This invention relates to a fine mold for nanoimprinting, etc., a method for regenerating and a transferring method with the fine mold. 
     Priority is claimed to Japanese Patent Application No. 2006-258571, filed on Sep. 25, 2006, the entire contents of which are incorporated herein by reference. 
     B) Description of the Related Art 
     Conventionally, a transfer imprinting method with a fine mold is well-known. For example, refer to JP H05-241011, JP 2004-304097 and FUJIWARA et al “Tan-itsu shinkin saibo no shuushukuryoku wo sokuteisuru rikigaku sensa no kaihatsu (Development of Dynamic Sensor for Measuring Contraction Power of Single Cardiac Myocyte)” Denkigakkai Bio-Microsystem Kenkyu-kai Shiryo, BMS-05-3, p10-12. A product having a fine three-dimensional structure such as a storage medium, micro electro mechanical systems (MEMS), a micro lens, etc. can be manufactured at a low cost by a transfer imprinting method with the fine mold. 
     A fine mold may be damaged by a hard alien substance on a surface or inside of a forming material when the fine mold is pushed to the forming material. Fine molds are expensive because various types of them are manufactured only in small number by using a fine processing technique such as a photolithography technique, an electron beam exposing technique, a laser-beam direct writing method, etc. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to reduce a manufacturing cost of a product having a three-dimensional structure. 
     According to one aspect of the present invention, there is provided a fine mold, comprising: a regeneration target film forming a convex part of a formation surface; and a light shielding unit that is configured deeper than a bottom of the formation surface and that regenerates the regeneration target film. 
     This fine mold has the light shielding unit that is configured deeper than the bottom of the forming surface to regenerate the regeneration target film forming the convex part of the firming surface, that is, the light shielding unit is configured in a layer near a reverse of the forming surface. Therefore, the fine mold can regenerate the convex part by using the light shielding unit, equipped to the fine mold, as a mask even if the convex part is damaged. That is, a fine processing technique is not necessary for this fine mold to regenerate the convex part. Therefore, a cost for manufacturing a product having a fine three-dimensional structure can be reduced by using this fine mold in comparison to the conventional fine mold. 
     The light shielding unit of the fine mold according to the invention may be formed of an opaque film. In this case, a convex part having a rectangle shaped cross section can be regenerated by using the light shielding unit as a mask. 
     The light shielding unit of the fine mold according to the invention may be a gradation mask. In this case, a forming surface of which surface is gently curved can be regenerated. For example, an opaque gray tone mask having slits below a resolution of an exposure device or a half-transparent half tone mask can be used as the gradation mask. 
     According to the present invention, the shallowest depth of the light shielding unit may be the same as the deepest depth of the regeneration target film. In this case, there will be no decline in a resolution caused by diffraction and dispersion when a photosensitive for forming the regeneration target film is exposed by using the light shielding unit as a mask. 
     The fine mold according to the present invention may further comprise a transparent protection film that is harder than the regeneration target film and configured between the forming surface and the light shielding unit. In this case, damage to the light shielding unit can be prevented so that the regeneration of the forming surface will not be impossible. 
     The fine mold according to the present invention may further comprise a transparent reinforcement plate having a concave part in which the light shielding unit is embedded, and the protection film may be embedded in the reinforcement plate between the light shielding unit and the forming surface and formed of transparent material having a lower refractive index than the reinforcement plate. In this case, although the light shielding unit is separated from the regeneration target film, total internal reflection happens at a side of the reinforcement plate of a boundary of the reinforcement plate and the transparent film so that there will be no decline in a resolution caused by diffraction and dispersion when a photosensitive for forming the regeneration target film is exposed by using the light shielding unit as a mask. 
     The fine mold according to the present invention may further comprise a transparent reinforcement plate configured at a deeper place than the light shielding unit. In this case, strength of the fine mold will increase. 
     According to another aspect of the present invention, there is provided a method of regenerating the above-described fine mold, comprising the steps of: removing the regeneration target film; forming a photosensitive film on a surface from which the regeneration target film is removed; and exposing the photosensitive film by using the light shielding unit as a mask to develop the photosensitive film. 
     According to the above-described method of regenerating the fine mold, the regeneration target film can be regenerated without forming a mask for forming the regeneration target film so that a cost for manufacturing a fine structure by the transfer imprinting method can be reduced in comparison to the conventional method. Further, in this regeneration method according to the present invention, the developed photosensitive film may be used as a regeneration target film, and a regeneration target film may be formed in an opening part of the developed photosensitive film. 
     The above-described method of regenerating the fine mold may further comprise the step of pushing the fine mold to forming material. 
     In this specification, a “forming surface” refers to a surface of a fine mold composing a boundary of forming material and the fine mold. “Transparent” a concept depending on wavelength of light; however, in this specification, “transparent” refers to a condition in which light of wavelengths to be used for exposure of a photosensitive film can pass through with little or no interruption or distortion. Similar to that, “light shielding” refer to a condition in which the light to be used for exposure is interrupted. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  to  FIG. 1C  are cross sectional views showing a fine mold and a transfer imprinting method by using the fine mold according to a first embodiment of the present invention. 
         FIG. 2A  to  FIG. 2C  are cross sectional views showing a manufacturing method of the fine mold according to the first embodiment of the present invention. 
         FIG. 3A  to  FIG. 3C  are cross sectional views showing the manufacturing method of the fine mold according to the first embodiment of the present invention. 
         FIG. 4A  to  FIG. 4C  are cross sectional views showing a regeneration method of the fine mold according to the first embodiment of the present invention. 
         FIG. 5A  to  FIG. 5D  are cross sectional views showing a fine mold according to a second embodiment of the present invention. 
         FIG. 6A  to  FIG. 6C  are cross sectional views showing a fine mold according to a third embodiment of the present invention. 
         FIG. 7A  to  FIG. 7D  are cross sectional views showing a manufacturing method of a fine mold according to a fourth embodiment of the present invention. 
         FIG. 8A  to  FIG. 8D  are cross sectional views showing a manufacturing method of a fine mold according to a fifth embodiment of the present invention. 
         FIG. 9A  and  FIG. 9B  are cross sectional views showing the manufacturing method of the fine mold according to the fifth embodiment of the present invention. 
         FIG. 10A  to  FIG. 10D  are cross sectional views showing a manufacturing method of a fine mold according to a sixth embodiment of the present invention. 
         FIG. 11A  to  FIG. 11C  are cross sectional views showing the manufacturing method of the fine mold according to the sixth embodiment of the present invention. 
         FIG. 12A  to  FIG. 12D  are cross sectional views showing a manufacturing method of a fine mold according to a seventh embodiment of the present invention. 
         FIG. 13A  to  FIG. 13D  are cross sectional views showing a manufacturing method of a fine mold according to an eighth embodiment of the present invention. 
         FIG. 14A  to  FIG. 14C  are cross sectional views showing the manufacturing method of the fine mold according to the eighth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The embodiments of the present invention will be described below with reference to the drawings. In each embodiment, same reference numbers refer to same components, and explanations for the same components are omitted to avoid redundant. 
       FIG. 1A  to  FIG. 1C  are cross sectional views showing a fine mold and a transfer imprinting method by using the fine mold according to a first embodiment of the present invention. 
     The fine mold  1  is composed by laminating a light shielding unit  10  on a transparent substrate  11  as a reinforcement plate, a transparent protection film  12 , a resin film  13  as a regeneration target film and a hard film  14 . Since the light shielding unit  10  is configured on a layer deeper than a bottom of a formation surface  15  having a concave part and a convex part, a resin film  13  can be regenerated by using the light shielding unit  10  as a mask. That is, the resin film  13  can be regenerated without forming the mask by using an expensive device for patterning the resin film  13  forming the fine concave part and the convex part of the formation surface, and manufacturing cost of the fine mold is lower than that of the conventional one. The regenerating method of the fine mold  1  will be described later with explanation of its manufacturing method. Moreover, the light shielding unit  10  is not exposed on the forming surface  15  in order not to avoid damage of the light shielding unit  10  even if the forming surface is damaged by the alien substance between the fine mold  1  and the forming target substance, and not only the hard film  14  but also the protection film  12  harder than the resin film  13  are between the light shielding unit  10  and the forming surface  15 . 
     Next, a transfer method used the fine mold  1  will be explained as an example of nanoimprinting. 
     As shown in  FIG. 1A , a forming material  91  is applied on a surface of a substrate  92  composed of silicon wafer, etc. by spin coating, etc. Thermoplastic resin, thermosetting resin, photocurable resin or glass can be used as the forming material. Moreover, the silicon wafer can be used as the forming material. 
     As shown in  FIG. 1B , the fine mold  1  is pushed to the forming material  91 . At this time, because the forming material must be softened, the thermoplastic resin is heated to the glass transition point or more in advance. There are a method to push the forming material  91  and the fine mold  1  with two plates parallel to each other and a method to push the forming material  91  and the fine mold  1  by compressed air as the method to push the fine mold  1 . 
     Next, the forming material  91  is formed by hardening. For example, the forming material  91  is hardened by cooling in case of the thermoplastic resin, by heating in case of the thermosetting resin, and by irradiating ultraviolet rays in case of the photocurable resin. Then, the concave part and the convex part of the forming surface  15  of the fine mold  1  are transferred to the forming material  91 . 
     Finally, as shown in  FIG. 1C , the fine mold  1  is exfoliated from the forming material  91 . 
       FIG. 2A  to  FIG. 3C  are cross sectional views showing a manufacturing method of the fine mold according to the first embodiment of the present invention. 
     First, the light shielding unit  10  is formed on the transparent substrate  11 . Quartz, soda-lime glass, transparent crystallized glass, ceramics, resin, clay, alumina, sapphire, etc. can be used as the material of the transparent substrate  11 . For example, thickness of the transparent substrate  11  is 2 mm. Metals such as Cr, CrO 2 , Cu, etc., metal oxide, etc., which are opaque material to ultraviolet rays can be used for the material of the light shielding unit  10 . These materials can form a film on the transparent substrate  11  by sputtering, evaporation and CVD. For example, thickness of the light shielding unit  10  is 0.1 μm. A lamination of Cr and CrOx on the quartz and the glass used as a mask and reticle can be used as a lamination of the light shielding unit  10  on the transparent substrate  11 . 
     Next, as shown in  FIG. 2B , the light shielding unit  10  is patterned by using a photoresist  50 . For example, the photoresist  50  is exposed by a stepper, an aligner or an electron beam exposure device, and a developed pattern of the photoresist  50  is transferred to the light shielding unit  10 . In the etching of the light shielding unit  10 , for example, the light shielding unit  10  consisting of Cr is anisotropically etched by ion milling or cerium ammonium nitrite solution. The light shielding unit  10  may be patterned by the laser direct writing method without using the photoresist  50 . In the manufacture of the mold producing various kinds and small amount with less usage times of the reticles, the laser direct writing method is effective for reducing the manufacturing cost. 
     Next, as shown in  FIG. 2C , the transparent protection film  12  is formed to cover the light shielding unit  10 . SiN, a glass with a low-melting point, AlN, SiON, TaO 2 , TiO 2 , ceramics, resin, clay, etc., can be used as the material of the transparent protection film  12 . It is preferable that hardness of the protection film  12  is harder than the resin film that is a regeneration target. For example, as the film-forming method, plasma CVD is used when SiN is the material. A surface of the protection film  12  may be planarized by CMP and etched-back after forming the protection film  12 . 
     Next, as shown in  FIG. 2D , the photosensitive film  51  is formed on the protection film  12 . For example, the photosensitive film  51  is formed by applying a negative-typed photo resist with thickness of 70 μm to heat and harden. 
     Thereafter, as shown in  FIG. 3A , an ultraviolet rays is irradiated from a reverse side of the transparent substrate  11 , that is, from the photosensitive film  51  of the transparent substrate  11  and the reverse side, to expose the photosensitive film  51 . At this time, the photosensitive film  51  is exposed only in a exposure region  53  that is not shaded by the light shielding unit  10 , and the photosensitive film  51  is not exposed in an unexposed region  52  that is shaded by the light shielding unit  10 . The light used for the exposure is not limited and can be arbitrary selected corresponding to a design rule such as an ultraviolet ray, a far ultraviolet ray, a deep ultraviolet ray, an extreme ultraviolet ray and an x-ray. Of course, material of the light shielding unit  10  can be selected corresponding to wavelength of the light used for the exposure. 
     Next, when the photosensitive film  51  is developed, a resin film  13  having a fixed pattern is formed as shown in  FIG. 3B . In  FIG. 3B , a photosensitive region  53  of the negative-typed photoresist remains. In  FIG. 3B , an example that the photosensitive region  53  becomes the resin film  13  to be the regenerating target is shown, however; needless to say, a positive-typed photoresist can be used as the photosensitive film  51 . 
     Finally, as shown in  FIG. 3C , a hard film  14  is formed on a whole surface of the fine mold  1 . Other inorganic material such as metal, a metal compound, ceramics, etc. can be used as the material of the hard film  14 . Sputtering, plating and evaporation can be used for formation of the hard film  14 . A fluorine film may be formed on the hard film  14  in order to improve mold release property on the surface of the hard film  14 . 
       FIG. 4A  to  FIG. 4C  are cross sectional views showing a regeneration method of the fine mold according to the first embodiment of the present invention. As shown in  FIG. 4A , the hard film  14  and the resin film  13  may be deformed by alien substance between the fine mold  1  and the forming material. When the fine mold  1  is used in a state that the hard film  14  and the resin film  13  are deformed, the shape of the deformed forming surface  15  is transferred to the forming material. Since the fine mold  1  has the light shielding unit  10  as the light shielding unit on a surface deeper than the bottom of the forming surface  15 , the forming surface  15  can be regenerated as described below. 
     First, as shown in  FIG. 4B , the hard film  14  is removed. When the hard film  14  is made of Ni, the hard film can be removed by using aqueous ferric chloride solutions for etchant. 
     Next, as shown in  FIG. 4C , the resin film  13  is removed. For example, the resin film  13  made of a photoresist is removed by using N-Methyl-2-pyrrolidone (NMP) and acetone. This state is just before forming the photosensitive film  51  shown in  FIG. 2D  in the manufacturing process of the fine mold  1 , and after patterning the light shielding unit  10  that becomes a mask for exposing and developing the photosensitive film  51 . 
     Then, as explained with reference to  FIG. 2D ,  FIG. 3A ,  FIG. 3B  and  FIG. 3C , when the photosensitive film  51  is formed, and the photosensitive film  51  is exposed from the reverse side of the transparent substrate  11  to develop and form the hard film  14 , the fine mold  1  is regenerated. Moreover, the protection film  12  may be removed and reformed, and the surface may be planalized before forming the photosensitive film  51 . Since the stepper and reticle are not used, a processing cost after the process to form the photosensitive film  51  shown in  FIG. 2D  is considerably lower than a manufacturing cost in case of manufacturing the entire fine mold  1 . That is, since the regeneration cost of the fine mold  1  is considerably lower than the manufacturing cost of the fine mold  1 , the manufacturing cost of the substance having fine three-dimensional shape can be further lower than the conventional imprinting method by using the fine mold  1 . 
       FIG. 5A  to  FIG. 5D  are cross sectional views showing a fine mold according to a second embodiment of the present invention. A fine mold  2  is different from the first embodiment in a point that the fine mold  2  has gently curving concave and convex parts on the forming surface  15 . The gently curving concave and convex parts of the forming surface  15  depend on a cross-sectional shape of the resin film  13 . As same as the first embodiment, in the second embodiment, a dome-shaped resin film  13  is formed by exposing the photosensitive film  51  as shown in  FIG. 5A  and baking an non-exposing region  52  of the photosensitive film  51  to reflow as shown in  FIG. 5C  after developing the photosensitive film  51  as shown in  FIG. 5B . 
       FIG. 6A  to  FIG. 6C  are cross sectional views showing a fine mold according to a third embodiment of the present invention. A fine mold  3  is different from the second embodiment in a point that the light shielding unit  10  for forming the photosensitive film  51  is structured as a gray tone mask. A plurality of slits  111  with a width below a resolution of the exposure device are formed on the light shielding unit  10  that is the gradation mask. A half-exposing region is formed on the photosensitive film  51  corresponding to the width and the interval of the slits  111 . The concave part and the convex part gently curving along the surface of the resin film  13  obtained by developing the photosensitive film  51  in  FIG. 6B  can be formed by setting the width and the interval of the slits  11  so that the exposed condition of the half-exposed region continuously changes. The photosensitive film  51  may be exposed from the transparent substrate  12  in a condition that a reflection prevention film is formed on the surface of the photosensitive film  51 . Moreover, distribution of photosensitivity (reactivity) caused by a standing wave inside the photosensitivity film  51  may be dissolved by baking the photosensitive film  51  after exposing the photosensitive film  51 . The forming surface  15  having an earthenware-mortar-shaped concave part can be formed by forming plurality of the slits  111  in concentric circles. 
       FIG. 7A  to  FIG. 7D  are cross sectional views showing a manufacturing method of a fine mold according to a fourth embodiment of the present invention. 
     A fine mold  4  has a half tone mask  19 , the resin film  13  formed by using the half tone mask  19  and the hard film  14  covering the resin film  13 . The gently curving forming surface  15  is formed by the resin film  13  formed by using the half tone mask  19  that is the gradation mask. The manufacturing method of the fine mold  4  is as follow. 
     First, a transmission factor of an ultraviolet ray of the half tone mask  19  shown in  FIG. 7A  is set to be a desired value by an electron beam exposure. At this time, an earthenware-mortar-shaped concave part can be formed on the surface of the resin film  14  exposed and developed by using the half tone mask  19  as the mask by the exposure so that the transmission factor of the ultraviolet ray from the surface of the half tone mask  19  decreases in proportion to the distance from a certain point. 
     Next, as shown in  FIG. 7B , the photosensitive film  51  is applied, and an ultra violet ray is irradiated from the reverse side (that is, the reverse side of the surface where the photosensitive film  51  is laminated) of the half tone mask  19 . Then, the photosensitive film  51  is exposed corresponding to the light transmission factor of the half tone mask  19 . The photosensitive film  51  may be exposed in a state of being formed the reflection prevention film on the surface of the photosensitive film  51 . 
     Next, when the photosensitive film  51  is developed, as shown in  FIG. 7C , the resin film whose surface gently curves is formed. The photosensitive film  51  may be baked in order to resolve distribution of the photosensitivity (reactivity) of the photosensitive film caused by the standing wave inside the photosensitive film  51  before developing. 
     Finally, when the hard film  14  is formed on the surface of the resin film  13 , the fine mold  4  shown in  FIG. 7D  is completed. 
     In the fine mold  4 , the half tone mask  19  and the resin film  13  are contacting with each other. That is, the deepest point of the resin film as a regeneration target film and the shallowest point of the half tone mask  19  as the light shielding unit to work as a mask for forming the resin film  13  are agreed with each other. Therefore, at the time of manufacturing and regenerating the fine mold  4 , when the photosensitive film  51  is exposed from the reverse side of the half tone mask  19 , that is, the reverse side of the photosensitive film  51 , there will be no decline in a resolution caused by diffraction and dispersion of the ultraviolet ray. 
       FIG. 8A  to  FIG. 9D  are cross sectional views showing a manufacturing method of a fine mold according to a fifth embodiment of the present invention. It is different from the first embodiment in a point that a fine mold  5  includes the light shielding unit  10  as the light shielding unit and the protection film  20  which are embedded in the transparent substrate  11 . Moreover, it is different from the first embodiment in a point that the depth of the shallowest point of the light shielding unit  10  agrees with the depth of the deepest point of the resin film  13 . That is, the light shielding unit  10  is jointed to the whole part of the wall of the concave part of the transparent substrate  11 , and the concave part of the transparent substrate  11  is completely re-embedded by the protection film  20  formed on the light shielding unit  10 . The manufacturing method of the fine mold  5  is as follow. 
     First, as shown in  FIG. 8A , concave parts for embedding the light shielding unit are formed on the surface of the transparent substrate  11 . For example, the concave parts may be formed by photolithography using the photoresist mask  54 , and the concave parts may be formed by the laser-beam direct writing method. 
     Next, as shown in  FIG. 8B , the light shielding unit  10  is formed on the surface of the transparent substrate  11 . The light shielding unit  10  works as a seed layer of the protection film  20  and as the light shielding unit, for example, the light shielding unit  10  is formed by laminating TiN X  on the surface of the transparent substrate  11  by sputtering. An adhering layer made of Ti, Cr, etc. may be formed between the TiN x  and the transparent substrate  11 . 
     Then, as shown in  FIG. 8C , the protection film  20  is formed on the surface of the light shielding unit  10 . For example, the protection film  20  is formed by depositing W, Ta, Ti, Mo, Cu, TiN, TaN, MoN, etc. with a thickness of 50 μm by the CVD. The opaque protection film  20  works also as the light shielding unit. The protection film  20  may be formed by electrolysis plating of alloy such as NiP, NiW, NiCo, NiFe, NiMn, NiMo, etc. and metal such as Ni, Cr. 
     Thereafter, as shown FIG. in  8 D, the protection film  20  and the light shielding unit  10  are removed until the transparent substrate  11  is exposed by grinding and polishing. 
     Finally, as same as the first embodiment, and as shown in  FIG. 9A  and  FIG. 9B , when the resin film  13  and the hard film  14  are formed, the fine mold  5  is completed. 
       FIG. 10A  to  FIG. 11C  are cross sectional views showing a manufacturing method of a fine mold according to a sixth embodiment of the present invention. It is different from the fifth embodiment in a point that the transparent substrate  11  of a fine mold  6  is made of a photosensitive glass having a crystallizing region  21  and non-crystallizing region  22 . The crystallizing region  21  may be half-transparent or opaque. The manufacturing method of the fine mold  6  is as follow. 
     First, as shown in  FIG. 10A , the transparent substrate  11  formed of the photosensitive glass is heated after exposing a part of the transparent substrate  11  by using, for example, the photo mask  55  having the light shielding unit (pattern) made of CrO 2  on the quartz substrate, and a crystallite is generated in the exposing region. The exposing region becomes a crystallization region  21 . At this time, the crystallite is not generated in the unexposed region. 
     Next, as shown in  FIG. 10B , concave parts  24  are formed by selectively etching the crystallizing region  21  of the transparent substrate  11  by using diluted hydrofluoric acid. 
     Then, as shown in  FIG. 10C , the light shielding unit  10  is formed. For example, the light shielding unit  10  may be formed by accumulating Ni, Co, and Cu by electroless plating, or the light shielding unit  10  made of Ag may be formed by Tollens test. 
     Thereafter, as shown in  FIG. 10D , the protection film  20  made of low-melting point glass is formed on the light shielding unit  10 , and the concave parts  24  are completely buried. 
     Then, the protection film  20  and the light shielding unit  10  are removed until the transparent substrate  11  is exposed by grinding and polishing. 
     Finally, as same as the first embodiment, and as shown in  FIG. 11A ,  FIG. 11B  and  FIG. 11C , when the resin film  13  and the hard film  14  are formed, the fine mold  6  is completed. 
       FIG. 12A  to  FIG. 12D  are cross sectional views showing a manufacturing method of a fine mold according to a seventh embodiment of the present invention. It is different from the first embodiment in a point that the light shielding unit  10  of a fine mold  7  is exposed on the reverse side of the mold and that the transparent substrate  11  itself works as the protection film of the light shielding unit  10 . The manufacturing method of the fine mold  7  is as follow. 
     First, as same as the first embodiment, and as shown in  FIG. 12A , the light shielding unit  10  is formed on the transparent substrate  11 . 
     Next, as shown in  FIG. 12B , the photosensitive film  51  is formed on the reverse side of the light shielding unit  10  of the transparent substrate  11 , and an ultraviolet ray is irradiated from the light shielding unit  10  side to expose a part of the photosensitive film  51 . 
     Then, as same as the first embodiment, unexposed region  52  of the photosensitive film  51  is removed, and the resin film  13  formed of the exposing region  53  is formed. Thereafter, when the hard film  14  is formed, the fine mold  7  is completed. 
       FIG. 13A  to  FIG. 14C  are cross sectional views showing a manufacturing method of a fine mold according to an eighth embodiment of the present invention. The shallowest part of the light shielding unit  10  of a fine mold  8  is positioned at deeper than the deepest point of the resin film  13  that is the regeneration film, and it is different from other embodiments in a point that the decline of the resolution by those embodiments is structurally prevented. 
     For example, the light shielding unit  10  as the light shielding unit is connected with the bottom of the concave part of the transparent layer  27  as the reinforcement plate, and the concave part of the transparent layer  27  is completely buried with the transparent substrate  11  remained on the light shielding unit  10 , and the depth of the shallowest part of the transparent substrate  11  is same as the depth of the deepest part of the resin film  13 . The transparent substrate  11  works as the transparent protection film of the light shielding unit  10 . The material of the transparent substrate  11  and the material of the transparent layer  27  are selected so that a refractive index of the transparent substrate  11  is smaller than a refractive index of the transparent layer  27 . 
     As described in the above, a total internal reflection occurs on both interfaces (refer to  FIG. 14A ) at the time of exposing of the photosensitive film  51  by setting the refractive index of the transparent substrate  11  and the refractive index of the transparent layer  27 . Therefore, the resolution will not decline even though the light shielding unit  10  is positioned at deeper than the resin film  13  that is the regenerating target film. The manufacturing method of the fine mold  8  is as follow. 
     First, the light shielding unit  10  is formed on the transparent substrate  11  as same as the first embodiment. 
     Next, as shown in  FIG. 13A , a reinforcement substrate  26  is joined to the reverse side of the light shielding unit  10  of the transparent substrate  11 . For example, the reinforcement substrate  26  made of glass, ceramics, metal or the likes is adhered to the transparent substrate  11 . Moreover, a metal film made of Cu or Sn may be formed on the reverse of the transparent substrate  11  before forming the light shielding unit  10 , and this metal film may be used as the reinforcement substrate  26 . 
     Next, as shown in  FIG. 13B , a part of the transparent substrate  11  is removed by anisotropic etching by using the light shielding unit  10  as the mask. At this time, it is preferable to remove the transparent substrate  11  until the reinforcement substrate  26  is exposed; however, an ending point of the etching may be controlled to a depth not to expose the reinforcement substrate  26 . For example, when the transparent substrate  11  is quartz or glass, the transparent substrate  11  is etched by RIE by using a gas of which main component is CF 4 . Moreover, for example, when the transparent substrate  11  is resin, the transparent substrate  11  is etched by RIE by using a gas of which main component is O 2 . 
     Next, as shown in  FIG. 13C , the transparent layer  27  is formed to bury the transparent substrate  11  and the light shielding unit  10 . Resin, glass, ceramics, clay, etc. may be used as the material of the transparent layer  27 . After forming the transparent layer  27 , it may be planarized by grinding, polishing and etching-back the surface. 
     Then, as shown in  FIG. 13D , the reinforcement substrate  26  is removed. 
     Thereafter, as same as the first embodiment, and as shown in  FIG. 14A ,  FIG. 14B  and  FIG. 14C , when the resin film  13  and the hard film  14  are formed, the fine mold  8  is completed. 
     The present invention has been described in connection with the preferred embodiments. The invention is not limited only to the above embodiments. It is apparent that various modifications, improvements, combinations, and the like can be made by those skilled in the art. 
     For example, the hard film  14  is not always necessary, and the protection film  12  is not always necessary. Moreover, the resin film formed of the photosensitive film does not have to work as the regeneration target film, but the regeneration target film may be formed by a lift-off process by using the resin film as the mask. Moreover, materials of the substrate and the film composing a fine mold according to the embodiments are arbitrary selected corresponding to the functions to be required for the fine mold, and it is natural that the forming method and the forming conditions of the films are arbitrary selected depending on the material of the film and the characteristics of the film that has already been formed. 
     Moreover, it is natural that the shapes and the sizes of the forming surface of the fine molds are designed corresponding to the shapes of what to be formed by using those molds and the design rules. Furthermore, although the explanations of the regeneration method of the fine mold according to the embodiments of the present invention except the first embodiment have been omitted, it is same as the first embodiment in a point that the regenerating target film and the hard film are regenerated by using the light shielding unit after removing the regenerating target film and the hard film, and the fine mold according to each embodiment can be regenerated by executing the latter manufacturing method explained in each embodiment.