Patent Publication Number: US-2019193305-A1

Title: Replica master mold, method of manufacturing replica master mold, article, and method of manufacturing formation object

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Japanese Patent Application No. 2016-094103 filed on May 9, 2016 and Japanese Patent Application No. 2016-162922 filed on Aug. 23, 2016, the entire disclosures of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a replica master mold, a method of manufacturing a replica master mold, an article, and a method of manufacturing a formation object. 
     BACKGROUND 
     One of the fine processing technologies is imprint technology by which a master mold having a fine irregular (concave-convex) pattern formed on its surface is prepared and the fine irregular pattern of the master mold is pressed against a resin sheet or the like to transfer the fine irregular pattern of the master mold to the resin sheet. For example, imprint technology is used in the formation of a fine irregular structure for antireflection on a display panel of a smartphone, a tablet terminal, or the like. 
     Formation objects on which fine structures are formed by imprint have conventionally been approximately planar display panels and the like. In recent years, however, there has been growing demand to form fine structures on three-dimensional formation objects such as three-dimensionally shaped display panels, lens surfaces of camera and the like, and panel surfaces of automotive instruments. 
     In imprinting, typically, a master mold having a fine irregular pattern corresponding to a fine structure to be formed on a formation object is prepared. A master mold (replica master mold) to which the fine irregular pattern of the master mold has been transferred is then produced, and the fine irregular pattern is transferred to the formation object using the replica master mold. 
     JP 5276436 B2 (PTL 1) discloses a technique of transferring a fine irregular pattern of a master mold to flexible polymer foil (film) of a cycloolefin copolymer (COC) or the like to produce a polymer stamp (replica master mold) and transferring the fine irregular pattern to a formation object using the polymer stamp. The polymer stamp is formed from flexible polymer foil, and has flexibility. Hence, by softening the film through heating and applying liquid pressure to the polymer stamp, the polymer stamp can be deformed in conformity with the shape of the three-dimensional formation object. The polymer stamp deformed in conformity with the shape of the formation object is then brought into close contact with a photo-curable resin applied onto the formation object, and the photo-curable resin is irradiated with light to be cured. A fine structure can thus be formed on the formation object. 
     CITATION LIST 
     Patent Literature 
     PTL 1: JP 5276436 B2 
     SUMMARY 
     Technical Problem 
     According to PTL 1, the polymer stamp is produced by transferring the fine irregular pattern of the master mold to the flexible polymer foil. That is, the polymer stamp (replica master mold) disclosed in PTL 1 is a single-layer film made of a flexible polymer such as a COC. Therefore, when the polymer stamp is heated to deform in conformity with the shape of the formation object, the irregular portions of the polymer stamp may soften, causing the shape of the fine irregular pattern to be distorted. If the shape of the fine irregular pattern of the replica master mold is distorted, transfer of an accurate fine irregular pattern corresponding to the fine irregular pattern of the master mold is hampered. 
     It could be helpful to provide a replica master mold, a method of manufacturing a replica master mold, an article, and a method of manufacturing a formation object that can prevent a distortion of a fine irregular pattern in a replica master mold and suppress a decrease in transfer accuracy. 
     Solution to Problem 
     A replica master mold according to the present disclosure comprises: a base material layer; and a surface shape body formed on the base material layer and having a fine irregular pattern, wherein a softening temperature of the surface shape body is higher than a softening temperature of the base material layer. 
     Preferably, in the replica master mold according to the present disclosure, the base material layer has flexibility. 
     Preferably, in the replica master mold according to the present disclosure, the base material layer and the surface shape body are fixed by an intermediate layer composed of one or more layers. 
     Preferably, in the replica master mold according to the present disclosure, a release layer is formed on a surface of the fine irregular pattern of the surface shape body. 
     Preferably, in the replica master mold according to the present disclosure, the surface shape body is made of an inorganic compound. 
     Preferably, in the replica master mold according to the present disclosure, the base material layer has an elongation percentage of 10% or more. 
     Preferably, the replica master mold according to the present disclosure has a curved surface whose curvature radius is greater than a height of the fine irregular pattern. 
     A method of manufacturing a replica master mold having a curved surface comprises: heating the replica master mold to higher than or equal to the softening temperature of the base material layer; and deforming the heated replica master mold to have the curved surface whose curvature radius is greater than the fine irregular pattern. 
     An article according to the present disclosure comprises a fine structure formed by transfer using the replica master mold or by attachment of the replica master mold. 
     A method of manufacturing a formation object according to the present disclosure is a method of manufacturing a formation object having a fine structure formed thereon, and comprises: preparing a replica master mold that includes a base material layer and a surface shape body formed on the base material layer and having a fine irregular pattern corresponding to the fine structure, a softening temperature of the surface shape body being higher than a softening temperature of the base material layer; heating the replica master mold to a temperature higher than or equal to the softening temperature of the base material layer and lower than the softening temperature of the surface shape body, to deform the replica master mold in conformity with a shape of the formation object; and forming the fine structure on the formation object, by transfer using the replica master mold or by attachment of the replica master mold. 
     Advantageous Effect 
     A replica master mold, a method of manufacturing a replica master mold, an article, and a method of manufacturing a formation object according to the present disclosure can prevent a distortion of a fine irregular pattern in a replica master mold and suppress a decrease in transfer accuracy. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  is a diagram illustrating an example of the structure of a replica master mold according to one of the disclosed embodiments; 
         FIG. 2  is a diagram illustrating another example of the structure of the replica master mold according to one of the disclosed embodiments; 
         FIG. 3A  is a diagram illustrating another example of the structure of the replica master mold according to one of the disclosed embodiments; 
         FIG. 3B  is a diagram illustrating another example of the structure of the replica master mold according to one of the disclosed embodiments; 
         FIG. 4A  is a diagram schematically illustrating the formation of a fine structure using the replica master mold illustrated in  FIG. 1 ; 
         FIG. 4B  is a diagram schematically illustrating the formation of a fine structure using the replica master mold illustrated in  FIG. 1 ; 
         FIG. 4C  is a diagram schematically illustrating the formation of a fine structure using the replica master mold illustrated in  FIG. 1 ; 
         FIG. 4D  is a diagram schematically illustrating the formation of a fine structure using the replica master mold illustrated in  FIG. 1 ; 
         FIG. 5A  is a diagram illustrating a step in a process of manufacturing the replica master mold illustrated in  FIG. 4B ; 
         FIG. 5B  is a diagram illustrating a step in the process of manufacturing the replica master mold illustrated in  FIG. 4B ; 
         FIG. 6A  is a diagram illustrating a step in a process of deforming the replica master mold illustrated in  FIG. 4C ; 
         FIG. 6B  is a diagram illustrating a step in the process of deforming the replica master mold illustrated in  FIG. 4C ; 
         FIG. 6C  is a diagram illustrating a step in the process of deforming the replica master mold illustrated in  FIG. 4C ; 
         FIG. 6D  is a diagram illustrating a step in the process of deforming the replica master mold illustrated in  FIG. 4C ; 
         FIG. 6E  is a diagram illustrating a step in the process of deforming the replica master mold illustrated in  FIG. 4C ; 
         FIG. 7A  is a diagram illustrating a step in a process of forming the fine structure illustrated in  FIG. 4D  on a formation object; 
         FIG. 7B  is a diagram illustrating a step in the process of forming the fine structure illustrated in  FIG. 4D  on a formation object; 
         FIG. 7C  is a diagram illustrating a step in the process of forming the fine structure illustrated in  FIG. 4D  on a formation object; 
         FIG. 7D  is a diagram illustrating a step in the process of forming the fine structure illustrated in  FIG. 4D  on a formation object; 
         FIG. 8  is a diagram illustrating a formation object on which a fine structure is formed using the replica master mold according to one of the disclosed embodiments and an example of arrangement thereof; 
         FIG. 9A  is a diagram illustrating a step in a process of deforming the replica master mold to form the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 9B  is a diagram illustrating a step in the process of deforming the replica master mold to form the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 9C  is a diagram illustrating a step in the process of deforming the replica master mold to form the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 9D  is a diagram illustrating a step in the process of deforming the replica master mold to form the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 9E  is a diagram illustrating a step in the process of deforming the replica master mold to form the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 10A  is a diagram illustrating a step in a process of forming the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 10B  is a diagram illustrating a step in the process of forming the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 10C  is a diagram illustrating a step in the process of forming the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 10D  is a diagram illustrating a step in the process of forming the fine structure on the formation object illustrated in  FIG. 8 ; 
         FIG. 11A  is a cross-section photograph of a fine irregular pattern before and after preforming of a replica master mold according to Example 1; 
         FIG. 11B  is a cross-section photograph of a fine irregular pattern before and after preforming of a replica master mold according to Example 2; 
         FIG. 11C  is a cross-section photograph of a fine irregular pattern before and after preforming of a replica master mold according to Example 3; 
         FIG. 11D  is a cross-section photograph of a fine irregular pattern before and after preforming of a replica master mold according to Comparative Example 1; 
         FIG. 11E  is a cross-section photograph of a fine irregular pattern before and after preforming of a replica master mold according to Comparative Example 2; 
         FIG. 12A  is a diagram illustrating the reflectance characteristics of a fine structure formed using the replica master mold according to Example 2; and 
         FIG. 12B  is a diagram illustrating the reflectance characteristics of a fine structure formed using the replica master mold according to Comparative Example 1. 
     
    
    
     DETAILED DESCRIPTION 
     One of the disclosed embodiments is described below, with reference to drawings. Note that the present disclosure is not limited to the following embodiment, and various modifications are possible within the scope of the present disclosure. In the drawings, the same reference signs represent the same or similar components. 
     (Structure of Replica Master Mold) 
       FIG. 1  is a diagram illustrating an example of the structure of a replica master mold  10  according to one of the disclosed embodiments. 
     The replica master mold  10  illustrated in  FIG. 1  includes a base material layer  11  and a surface shape body  12 . 
     The base material layer  11  is a sheet-shaped base material, and has flexibility and also desirably has a sufficient elongation percentage (e.g. 10% or more) to deform in conformity with the shape of a three-dimensional formation object. The thickness of the base material layer  11  is preferably thin, so as to deform in conformity with the shape of the three-dimensional formation object. The thickness of the base material layer  11  is preferably 500 μm or less, and more preferably 100 μm or less. Herein, “having flexibility” means being able to be bent and flexed by human hand. Herein, the “elongation percentage” can be determined, for example, by the following method. 
     A base material to be measured is made into a strip of 10.5 cm in length and 2.5 cm in width, as a measurement sample. The tensile elongation percentage of the obtained measurement sample is measured using a tensile tester (Autograph AG-5kNXplus produced by Shimadzu Corporation) (measurement conditions: tension rate=100 mm/min; inter-chuck distance=8 cm). In the measurement of the elongation percentage, the measurement temperature differs depending on the type of the base material. The elongation percentage is measured at a temperature close to or not lower than the softening point of the base material. In detail, the temperature is 10° C. to 250° C. For example, in the case where the base material is polycarbonate or a PC/PMMA laminate, the elongation percentage is preferably measured at 190° C. 
     The base material layer  11  is made of, for example, polymethyl methacrylate (PMMA), polycarbonate (PC), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polyethylene (PE), amorphous polyethylene terephthalate (APET), polystyrene (PS), triacetyl cellulose (TAC), cyclic olefin polymer (COP), polyethylene terephthalate (PET), or the like. In terms of the process steps after the manufacture of the replica master mold  10 , the base material layer  11  is preferably made of PMMA, PC, PVC, TAC, or the like. 
     The surface shape body  12  is formed on the base material layer  11  and has a predetermined thickness. A fine irregular pattern is formed on the surface of the surface shape body  12 . The surface shape body  12  is made of a resin curable by active energy rays, such as a polymer of an acrylate monomer, a methacrylate monomer, or the like. The surface shape body  12  may be made of an inorganic compound. The surface shape body  12  is made of such a material whose softening temperature is higher than the softening temperature of the base material layer  11 . The softening temperature is a temperature at which a film softens and deforms by pressure application or the like, and corresponds to a storage elastic modulus (E′) of 0.3 GPa or less in dynamic viscoelasticity measurement (DMA measurement). 
     In the replica master mold  10  according to this embodiment, the softening temperature of the surface shape body  12  is higher than the softening temperature of the base material layer  11 . Therefore, even in the case where the base material layer  11  is heated to its softening temperature in order to deform the replica master mold  10  in conformity with the shape of the three-dimensional formation object, the surface shape body  12  does not soften. It is thus possible to prevent a distortion of the fine irregular pattern of the surface shape body  12  and suppress a decrease in transfer accuracy. 
     The structure of the replica master mold  10  is not limited to that illustrated in  FIG. 1 . As an example, the replica master mold  10  may have a structure in which an intermediate layer  13  as a binder layer is formed approximately flat between the base material layer  11  and the surface shape body  12  to fix the base material layer  11  and the surface shape body  12  having the fine irregular pattern, as illustrated in  FIG. 2 . 
     As another example, the replica master mold  10  may have a structure in which the intermediate layer  13  having a predetermined thickness and the fine irregular pattern is formed on the base material layer  11  and the surface shape body  12  is formed so as to cover the surface of the intermediate layer  13 , as illustrated in  FIG. 3A . The intermediate layer  13  may be composed of a plurality of layers, as illustrated in  FIG. 3B . In  FIG. 3B , an approximately flat intermediate layer  13 - 2  is formed on the base material layer  11 , and an intermediate layer  13 - 1  having a predetermined thickness and the fine irregular pattern is formed on the intermediate layer  13 - 2 . The surface shape body  12  is formed so as to cover the surface of the intermediate layer  13 - 1 . 
     As illustrated in  FIGS. 2, 3A, and 3B , the provision of the intermediate layer  13  can improve the adhesiveness between the base material layer  11  and the surface shape body  12  and improve the optical characteristics. The intermediate layer  13  is made of, for example, PC, an acrylate monomer having resin penetrability, or a multifunctional oligomer of urethane series or the like. 
     To enhance releasability, a layer made of an acrylic monomer containing fluorine or silicone or a layer made of an oxide may be formed on the surface of the surface shape body  12 , as a release layer. By depositing an oxide on the surface of the surface shape body  12 , a distortion of the fine irregular pattern of the surface shape body  12  can be prevented more reliably. 
     (Overview of Formation of Fine Structure on Formation Object Using Replica Master Mold) 
     An overview of the formation of a fine structure using the replica master mold  10  is given below, with reference to  FIGS. 4A to 4D . In the following description, it is assumed that a formation object on which a fine structure is to be formed has, for example, a convex surface like a convex lens, and the fine structure is formed on the convex surface. 
     First, as illustrated in  FIG. 4A , a master mold  14  having a fine irregular pattern corresponding to the fine structure to be formed on the formation object is manufactured. The master mold  14  is manufactured by a known manufacturing method for a master mold for imprint. For example, a resist layer is formed on a quartz plate, and irradiated with light (exposed to light) according to the fine irregular pattern to be formed. Following this, a developer is applied onto the resist layer, and the resist layer is developed to form a resist pattern corresponding to the fine irregular pattern on the resist layer. Etching is then performed using, as a mask, the resist layer on which the resist pattern is formed, to form the fine irregular pattern on the quartz plate. The master mold  14  is not limited to a plate shape, and may have a roll shape. 
     Next, the replica master mold  10  illustrated in  FIG. 4B  is manufactured using the master mold  14 . In the manufacture of the replica master mold  10  using the master mold  14 , for example, an uncured photo-curable resin is sandwiched between the master mold  14  and the base material layer  11 , and then irradiated with light (ultraviolet light) to be cured. By sandwiching the uncured photo-curable resin between the master mold  14  and the base material layer  11 , the fine irregular pattern of the master mold  14  is transferred to the uncured photo-curable resin. The uncured photo-curable resin is then irradiated with ultraviolet light, and thus cured in a state in which the fine irregular pattern has been transferred. After this, the master mold  14  is released from the cured photo-curable resin. The cured photo-curable resin serves as the surface shape body  12 . The replica master mold  10  in which the surface shape body  12  having the fine irregular pattern is formed on the base material layer  11  can thus be manufactured. 
     With the method described above, the fine irregular pattern formed on the surface shape body  12  is inversion of the fine irregular pattern formed on the master mold  14 . This is, however, not a limitation. For example, the replica master mold  10  including the surface shape body  12  having the same fine irregular pattern as the fine irregular pattern of the master mold  14  can be manufactured by transferring the fine irregular pattern of the master mold  14  to another transfer object, transferring the fine irregular pattern that has been transferred to the other transfer object to the uncured photo-curable resin, and then curing the photo-curable resin to form the surface shape body  12 . 
     Instead of the above-mentioned method (light transfer method) of pressing the master mold  14  against the uncured photo-curable resin and then curing the photo-curable resin, a thermal transfer method using a thermosetting resin may be used to manufacture the replica master mold  10 . The process of manufacturing the replica master mold  10  will be described in detail later. 
     After separating the replica master mold  10  from the master mold  14 , the replica master mold  10  is heated, and pressed against a die  15  that conforms to the shape of the formation object, as illustrated in  FIG. 4C . As a result, the replica master mold  10  deforms (preforms) in conformity with the shape of the die  15 , i.e. the shape of the formation object. Here, the replica master mold  10  is pressed against the die  15 , with the surface shape body  12  facing the die  15 . The process illustrated in  FIG. 4C  (process of deforming the replica master mold  10 ) will be described in detail later. 
     Next, as illustrated in  FIG. 4D , an uncured photo-curable resin  17  is applied to the surface of a formation object  16 , and the replica master mold  10  deformed in conformity with the shape of the die  15  (formation object  16 ) is pressed against the photo-curable resin  17  with the surface shape body  12  facing the photo-curable resin  17 . As a result of the surface shape body  12  being pressed against the uncured photo-curable resin  17 , the fine irregular pattern of the surface shape body  12  is transferred to the photo-curable resin  17 . The uncured photo-curable resin  17  is then irradiated with light (ultraviolet light) to be cured, thus forming the fine structure on the formation object  16 . 
     (Process of Manufacturing Replica Master Mold) 
     The process of manufacturing the replica master mold  10  illustrated in  FIG. 4B  is described in detail below, with reference to  FIGS. 5A and 5B . 
     The following describes not the above-mentioned light transfer method, but a method by which the resin is softened by heating and the master mold  14  is pressed against the softened resin to transfer the fine irregular pattern formed on the master mold  14  to the softened resin. 
     The process of manufacturing the replica master mold  10  mainly includes a heating step, a transfer step, and a release step. 
     First, as illustrated in  FIG. 5A , a laminate  10   a  in which an approximately flat resin layer  12   a  is formed on the base material layer  11  is prepared. The resin layer  12   a  is made of the same material as the surface shape body  12 . The softening temperature of the resin layer  12   a  is therefore higher than the softening temperature of the base material layer  11 . 
     In the heating step, the laminate  10   a  is heated until the resin layer  12   a  softens. Examples of the heating method include conduction heating by contact with a high-temperature body, convection heating by convection of a high-temperature fluid, and radiation heating using infrared light (IR) or the like. 
     In the transfer step, the heated resin layer  12   a  is pressed against the master mold  14 , as illustrated in  FIG. 5B . By pressing the heated resin layer  12   a  against the master mold  14 , the fine irregular pattern formed on the master mold  14  is transferred to the resin layer  12   a.  Examples of the method of pressing the resin layer  12   a  against the master mold  14  include fluid pressurization using gas or liquid, and clamping the ends of the laminate  10   a  and pressing it against the master mold  14 . In the heating step, the laminate  10   a  is heated until the resin layer  12   a  softens. This means the base material layer  11  whose softening temperature is not higher than the softening temperature of the resin layer  12   a  has softened, too. Accordingly, with the use of vacuum forming, pressure forming, TOM (Three dimension Overlay Method) forming, or the like, the base material layer  11  follows the shape of the master mold  14 . This enables the transfer of the fine irregular pattern to the resin layer  12   a  in a more reproducible manner. 
     In the release step, the laminate  10   a  after the transfer step is cooled, to cure the base material layer  11  and the resin layer  12   a.  Following this, the master mold  14  is separated from the resin layer  12   a.  As a result, the replica master mold  10  in which, on the base material layer  11 , the resin layer  12   a  to which the fine irregular pattern of the master mold  14  has been transferred is formed as the surface shape body  12  is obtained. 
     (Deformation of Replica Master Mold) 
     The process of deforming the replica master mold  10  illustrated in  FIG. 4C  is described in detail below, with reference to  FIGS. 6A to 6E . The following describes a process of deforming the replica master mold  10  by push-up forming. 
     First, as illustrated in  FIG. 6A , the die  15  that conforms to the shape of the formation object  16  is placed on a stage  21 . The stage  21  has sidewalls  22  on its periphery, and is movable along the sidewalls  22  (movable vertically in  FIG. 6A ). Each sidewall  22  is provided with a support  23  for supporting the replica master mold  10 . The supports  23  support the replica master mold  10  so as to face the die  15 . The replica master mold  10  is supported with the surface shape body  12  facing the die  15 . On the side of the replica master mold  10  supported by the supports  23  opposite to the die  15 , a quartz plate  24  supported by the sidewalls  22  and facing the stage  21  is provided. The quartz plate  24  allows light to pass through. The stage  21 , the sidewalls  22 , the supports  23 , and the quartz plate  24  are arranged so as to seal a region  25  surrounded by the stage  21 , the sidewalls  22 , and the replica master mold  10  supported by the supports  23  and seal a region  26  surrounded by the quartz plate  24 , the sidewalls  22 , and the replica master mold  10  supported by the supports  23 . 
     The replica master mold  10  supported by the supports  23  is heated to a temperature higher than or equal to the softening temperature of the base material layer  11  and lower than the softening temperature of the surface shape body  12 . As mentioned above, the softening temperature of the surface shape body  12  is higher than the softening temperature of the base material layer  11 . Accordingly, the base material layer  11  softens, but the surface shape body  12  does not soften. Hence, no distortion of the shape of the fine irregular pattern formed on the surface of the surface shape body  12  occurs. 
     Next, as illustrated in  FIG. 6B , the regions  25  and  26  are vacuumed. The stage  21  is movable vertically along the sidewalls  22 , as mentioned above. As a result of vacuuming the region  25 , the stage  21  moves upward (i.e. toward the replica master mold  10  supported by the supports  23 ). 
     The stage  21  moves upward, and the die  15  pushes up the replica master mold  10  supported by the supports  23 , as illustrated in  FIG. 6C . As a result of being pushed up by the die  15 , the replica master mold  10  deforms along the shape of the die  15 . Merely pushing up by the die  15 , however, cannot bring the die  15  and the replica master mold  10  into close contact with each other without any gap, and there are gaps  27  between the die  15  and the replica master mold  10  in the vicinity of the ends of the die  15 . 
     Next, as illustrated in  FIG. 6D , in a state in which the die  15  pushes up the replica master mold  10 , compressed air is introduced into the region  26 , to apply pressure to the replica master mold  10 . This brings the die  15  and the replica master mold  10  into close contact with each other even in the vicinity of the ends of the die  15 . In this state, the replica master mold  10  is cooled, and removed from the supports  23  and the die  15 . The replica master mold  10  deformed along the shape of the die  15  is thus produced, as illustrated in  FIG. 6E . 
     (Formation of Fine Structure on Formation Object) 
     The process of forming the fine structure on the formation object  16  illustrated in  FIG. 4D  is described in detail below, with reference to  FIGS. 7A to 7D . The following describes an example of forming the fine structure on the formation object  16  of a three-dimensional shape. The term “formation object of a three-dimensional shape” refers to a formation object having a curved surface whose curvature radius is greater than the height of the fine structure (fine irregular pattern) formed on the replica master mold  10 . As mentioned above, the replica master mold  10  is deformed in conformity with the shape of the formation object  16 . Therefore, the replica master mold  10  deformed in conformity with the shape of the formation object  16  has a curved surface whose curvature radius is greater than the height of the fine structure (fine irregular pattern) formed on the replica master mold  10 . 
     The process of forming the fine structure on the formation object  16  mainly includes an application step, a transfer step, a photo-curing step, and a release step. 
     In the application step, as illustrated in  FIG. 7A , the uncured photo-curable resin  17  is applied to the surface of the formation object  16 . As the method of applying the photo-curable resin  17  to the formation object  16 , various methods such as spray coating, inkjet coating, dispenser coating, dip coating, dropper dropping, and spin coating can be used depending on the viscosity of the photo-curable resin  17  and the shape of the formation object  16 . An intermediate layer may be provided between the formation object  16  and the photo-curable resin  17 , to improve the adhesiveness between the formation object  16  and the photo-curable resin  17 , the optical characteristics, and the like. 
     In the transfer step, as illustrated in  FIG. 7B , the replica master mold  10  is pressed against the photo-curable resin  17  applied to the formation object  16 . As mentioned above, the replica master mold  10  is deformed in conformity with the shape of the die  15  (formation object  16 ) in a state in which the surface shape body  12  faces the formation object  16 . Accordingly, by pressing the replica master mold  10  against the formation object  16 , the surface shape body  12  is pressed against the photo-curable resin  17 . As a result of the surface shape body  12  being pressed against the photo-curable resin  17 , the fine irregular pattern formed on the surface shape body  12  is transferred to the photo-curable resin  17 . 
     Examples of the method of pressing the replica master mold  10  against the formation object  16  (photo-curable resin  17 ) include fluid pressurization using gas, liquid, or the like from the base material layer  11  side, pressing using an elastic solid, and pressing using a roller. 
     In the photo-curing step, as illustrated in  FIG. 7C , in a state in which the replica master mold  10  is pressed against the photo-curable resin  17 , active energy rays are applied to the photo-curable resin  17  to cure the photo-curable resin  17 . The active energy rays are, for example, rays of light emitted from a light source such as a mercury lamp, a metal halide lamp, or an ultraviolet light emitting diode (LED). 
     In the case where the replica master mold  10  allows the active energy rays to pass through, the active energy rays may be applied to the photo-curable resin  17  from the replica master mold  10  side. In the case where the formation object  16  allows the active energy rays to pass through, the active energy rays may be applied to the photo-curable resin  17  from the formation object  16  side. 
     In the release step, as illustrated in  FIG. 7D , the formation object  16  and the replica master mold  10  are separated from each other. On the surface of the formation object  16 , the photo-curable resin  17  to which the fine irregular pattern of the surface shape body  12  of the replica master mold  10  has been transferred is cured to form a fine structure  17   a.  The formation object  16  (article) having the fine structure  17   a  formed thereon is thus manufactured. 
     The separation of the formation object  16  and the replica master mold  10  needs to be performed without the surface shape body  12  of the replica master mold  10  dropping off or the replica master mold  10  being damaged. In this embodiment, the replica master mold  10  is film-shaped, and therefore deforms more flexibly than conventional master molds made of quartz, metal, or the like. Hence, the replica master mold  10  is less likely to be damaged upon the release. The release of the film-shaped replica master mold  10  is typically performed by deforming and separating the replica master mold  10  from its end. The separation may be facilitated by optionally deforming the formation object  16  or spraying a fluid such as air between the replica master mold  10  and the formation object  16 . 
     The replica master mold  10  and the formation object  16  may be bonded together to form the fine structure on the formation object  16 . In this case, by attaching the replica master mold  10  to the formation object  16  with, for example, an adhesive applied to the base material layer  11  side of the replica master mold  10 , the fine structure  17   a  can be formed on the formation object  16  (i.e. the replica master mold  10  attached to the formation object  16  serves as the fine structure  17   a ). 
     Although the foregoing embodiment describes the case where the process of deforming the replica master mold  10  in conformity with the shape of the formation object  16  and the process of forming the fine structure  17   a  on the formation object  16  using the deformed replica master mold  10  are separate steps, a modification may be made to combine these steps. 
     The deformation of the replica master mold  10  and the formation of the fine structure  17   a  on the formation object  16  according to a modification are described below. The deformation of the replica master mold  10  and the formation of the fine structure  17   a  on the formation object  16  according to this modification are performed using the device including the stage  21 , the sidewalls  22 , the supports  23 , and the quartz plate  24  and used in the deformation of the replica master mold described with reference to  FIGS. 6A to 6E . 
     First, the formation object  16  to which the photo-curable resin  17  has been applied is placed on the stage  21 . Moreover, the replica master mold  10  is supported by the supports  23 , with the surface shape body  12  facing the formation object  16 . 
     Following this, the region  25  is vacuumed, and compressed air is introduced into the region  26 . As a result of vacuuming the region  25 , the stage  21  moves upward (i.e. toward the replica master mold  10  supported by the supports  23 ). With the movement of the stage  21 , the formation object  16  to which the photo-curable resin  17  has been applied pushes up the replica master mold  10  supported by the supports  23 . As mentioned above, merely pushing up the replica master mold  10  cannot eliminate a gap between the formation object  16  and the replica master mold  10 . In this modification, the region  25  is vacuumed, and compressed air is introduced into the region  26 . The introduction of the compressed air applies pressure to the replica master mold  10 . This can bring the replica master mold  10  and the formation object  16  into close contact with each other without any gap. 
     Next, in a state in which the region  25  is vacuumed and compressed air is introduced into the region  26 , light is applied from above the quartz plate  24 . As mentioned above, the quartz plate  24  allows light to pass through. Accordingly, by forming the replica master mold  10  to allow light to pass through, too, the photo-curable resin  17  applied to the formation object  16  is irradiated with light and as a result cured. 
     Next, the formation object  16  and the replica master mold  10  are separated from each other. On the surface of the formation object  16 , the photo-curable resin  17  to which the fine irregular pattern of the surface shape body  12  of the replica master mold  10  has been transferred is cured to form the fine structure  17   a.    
     Although the above describes an example in which the formation object  16  has a convex surface and the fine irregular pattern is formed on the convex surface of the formation object  16 , this is not a limitation. The presently disclosed technique is also applicable to the case where the formation object has a concave surface and the fine irregular pattern is formed on the concave surface. An example of forming the fine structure  17   a  (fine irregular pattern) on a concave surface of a concave-surfaced formation object  16 A as illustrated in  FIG. 8  is described below. 
     The formation object  16 A having the fine structure  17   a  (fine irregular pattern) formed on its concave surface is, for example, used as a top plate (cover) attached to the front of a display body  18  of a liquid crystal display (LCD) or the like with an air gap therebetween, as illustrated in  FIG. 8 . The formation object  16 A is also used as an antireflection member provided on the inner side (display body side) of a touch panel.  FIG. 8  illustrates an example in which a fine structure  19  for antireflection is formed on the front of the display body  18 , too. The fine structure  19  includes, for example, an approximately flat base film such as a triacetylcellulose (TAC) film provided on the front of the display body  18 , and a photo-curable resin (e.g. acrylic ultraviolet curable resin) provided on the base film and having a fine irregular pattern. The structure, formation method, etc. of the fine structure  19  are known to those skilled in the art and do not directly relate to the present disclosure, and so their description is omitted. 
     The process of deforming the replica master mold  10  in conformity with the shape of the formation object  16 A is described in detail below, with reference to  FIGS. 9A to 9E . The following describes a process of deforming the replica master mold  10  by push-up forming. Here, the description of the same structures in  FIGS. 9A to 9E  as those in  FIGS. 6A to 6E  is omitted. 
     First, as illustrated in  FIG. 9A , a die  15 A having a concave surface that conforms to the shape of the concave surface of the formation object  16  is placed on the stage  21 . The die  15 A is supported with its concave surface facing the replica master mold  10  supported by the supports  23 . The replica master mold  10  is supported with the surface shape body  12  facing the die  15 A. 
     Next, the replica master mold  10  supported by the supports  23  is heated to a temperature higher than or equal to the softening temperature of the base material layer  11  and lower than the softening temperature of the surface shape body  12 . As mentioned above, the softening temperature of the surface shape body  12  is higher than the softening temperature of the base material layer  11 . Accordingly, the base material layer  11  softens, but the surface shape body  12  does not soften. Hence, no distortion of the shape of the fine irregular pattern formed on the surface of the surface shape body  12  occurs. 
     Next, as illustrated in  FIG. 9B , the regions  25  and  26  are vacuumed. The stage  21  is movable vertically along the sidewalls  22 , as mentioned above. As a result of vacuuming the region  25 , the stage  21  moves upward (i.e. toward the replica master mold  10  supported by the supports  23 ). 
     The stage  21  moves upward, and the die  15 A pushes up the replica master mold  10  supported by the supports  23 , as illustrated in  FIG. 9C . As a result of being pushed up by the die  15 A, the replica master mold  10  deforms along the shape of the die  15 A (i.e. the concave surface of the die  15 A). Merely pushing up by the die  15 A, however, cannot bring the die  15 A and the replica master mold  10  into close contact with each other without any gap, and there are gaps  27  between the die  15 A and the replica master mold  10  in the vicinity of the ends of the die  15 A. 
     Next, as illustrated in  FIG. 9D , in a state in which the die  15 A pushes up the replica master mold  10 , compressed air is introduced into the region  26 , to apply pressure to the replica master mold  10 . This brings the die  15 A and the replica master mold  10  into close contact with each other even in the vicinity of the ends of the die  15 A. In this state, the replica master mold  10  is cooled, and removed from the supports  23  and the die  15 A. The replica master mold  10  deformed along the shape of the die  15 A is thus produced, as illustrated in  FIG. 9E . 
     The process of forming the fine structure on the concave surface of the formation object  16 A is described in detail below, with reference to  FIGS. 10A to 10D . In  FIGS. 10A to 10D , the same structures as those in  FIGS. 7A to 7D  are given the same reference signs, and their description is omitted. 
     The process of forming the fine structure on the formation object  16 A mainly includes an application step, a transfer step, a photo-curing step, and a release step. 
     In the application step, as illustrated in  FIG. 10A , the uncured photo-curable resin  17  is applied to the concave surface of the formation object  16 A. As the method of applying the photo-curable resin  17  to the formation object  16 A, various methods such as spray coating, inkjet coating, dispenser coating, dip coating, dropper dropping, and spin coating can be used depending on the viscosity of the photo-curable resin  17  and the shape of the formation object  16 A. An intermediate layer may be provided between the formation object  16 A and the photo-curable resin  17 , to improve the adhesiveness between the formation object  16 A and the photo-curable resin  17 , the optical characteristics, and the like. 
     In the transfer step, as illustrated in  FIG. 10B , the replica master mold  10  is pressed against the photo-curable resin  17  applied to the formation object  16 A. As mentioned above, the replica master mold  10  is deformed in conformity with the shape of the die  15 A (formation object  16 A) in a state in which the surface shape body  12  faces the formation object  16 A. Accordingly, by pressing the replica master mold  10  against the formation object  16 A, the surface shape body  12  is pressed against the photo-curable resin  17 . As a result of the surface shape body  12  being pressed against the photo-curable resin  17 , the fine irregular pattern formed on the surface shape body  12  is transferred to the photo-curable resin  17 . 
     In the photo-curing step, as illustrated in  FIG. 10C , in a state in which the replica master mold  10  is pressed against the photo-curable resin  17 , active energy rays (e.g. ultraviolet light) are applied to the photo-curable resin  17  to cure the photo-curable resin  17 . 
     In the release step, as illustrated in  FIG. 10D , the formation object  16 A and the replica master mold  10  are separated from each other. On the surface of the formation object  16 A, the photo-curable resin  17  to which the fine irregular pattern of the surface shape body  12  of the replica master mold  10  has been transferred is cured to form the fine structure  17   a.  The formation object  16 A (article) having the fine structure  17   a  formed thereon is thus manufactured. 
     The process of deforming the replica master mold  10  in conformity with the shape of the formation object  16 A and the process of forming the fine structure  17   a  on the formation object  16 A using the deformed replica master mold  10  may be combined. 
     First, the photo-curable resin  17  is applied to the concave surface of the formation object  16 A by spin coating or the like. The formation object  16 A having the photo-curable resin  17  applied to its concave surface is then placed on the stage  21  of the device illustrated in  FIGS. 6A to 6D  or  FIGS. 9A to 9D . The replica master mold  10  is supported by the supports  23 , with the surface shape body  12  facing the formation object  16 A. 
     Following this, the region  25  is vacuumed, and compressed air is introduced into the region  26  (vacuum differential pressure). As a result of vacuuming the region  25 , the stage  21  moves upward (i.e. toward the replica master mold  10  supported by the supports  23 ). With the movement of the stage  21 , the formation object  16 A to which the photo-curable resin  17  has been applied pushes up the replica master mold  10  supported by the supports  23 . As mentioned above, merely pushing up the replica master mold  10  cannot eliminate a gap between the formation object  16 A and the replica master mold  10 . In view of this, the region  25  is vacuumed, and compressed air is introduced into the region  26 . The introduction of the compressed air applies pressure to the replica master mold  10 . This can bring the replica master mold  10  and the formation object  16 A into close contact with each other without any gap. 
     Next, in a state in which the region  25  is vacuumed and compressed air is introduced into the region  26 , light is applied from above the quartz plate  24 . As mentioned above, the quartz plate  24  allows light to pass through. Accordingly, by forming the replica master mold  10  to allow light to pass through, too, the photo-curable resin  17  applied to the formation object  16 A is irradiated with light and as a result cured. 
     Next, the formation object  16 A and the replica master mold  10  are separated from each other. On the surface (concave surface) of the formation object  16 A, the photo-curable resin  17  to which the fine irregular pattern of the surface shape body  12  of the replica master mold  10  has been transferred is cured to form the fine structure  17   a.    
     As described above, in this embodiment, the replica master mold  10  includes the base material layer  11  and the surface shape body  12  formed on the base material layer  11  and having the fine irregular pattern, and the softening temperature of the surface shape body  12  is higher than the softening temperature of the base material layer  11 . 
     Hence, in the case of heating the replica master mold  10  in order to deform the replica master mold  10 , by heating the replica master mold  10  at a temperature higher than or equal to the softening temperature of the base material layer  11  and lower than the softening temperature of the surface shape body  12 , the replica master mold  10  can be deformed with only the base material layer  11  being softened. Since the surface shape body  12  does not soften, the shape of the fine irregular pattern is not distorted, and a decrease in transfer accuracy caused by a distortion of the fine irregular pattern can be suppressed. 
     EXAMPLES 
     More detailed description is given below by way of examples and comparative examples, although the present disclosure is not limited to these examples. 
     (Production of Master Mold) 
     The production of the master mold  14  is described below. 
     A glass base material (glass roll master mold) of 126 mm in outer diameter was prepared. A diluted resist obtained by diluting a photoresist to 1/10 in mass ratio by a thinner was applied to the surface of the glass roll master mold by dipping so as to have an average thickness of about 70 nm on the cylindrical surface of the glass roll master mold, to form a resist layer. The glass roll master mold having the resist layer formed thereon was then conveyed to an exposure device, and the resist layer was exposed to pattern, on the resist layer, a spiral latent image having a hexagonal lattice pattern between adjacent three tracks. In detail, the region subjected to the formation of the hexagonal lattice exposure pattern was irradiated with laser light of 0.50 mW/m, to form the hexagonal lattice exposure pattern. 
     Next, a development treatment was performed on the resist layer on the glass roll master mold, to dissolve the resist layer in the exposed portion and develop the resist layer. In detail, the undeveloped glass roll master mold was placed on a turntable of a development device and, while rotating the turntable, a developer was dropped on the surface of the glass roll master mold to develop the resist layer. In this way, the glass roll master mold with the resist layer being open in the hexagonal lattice pattern was obtained. 
     Next, plasma etching was performed in a CHF 3  gas atmosphere using a roll etching device. As a result, on the surface of the glass roll master mold, etching progressed only in the hexagonal lattice pattern portion exposed from the resist layer, whereas the other regions were not etched as the resist layer served as a mask. An elliptical cone-shaped concave portion was thus formed in the glass roll master mold. In the etching, the etching amount (depth) was adjusted based on the etching time. Lastly, the resist layer was removed by oxygen ashing, thus obtaining the glass roll master mold (master mold) having the concave hexagonal lattice pattern. 
     (Production and Deformation of Replica Master Mold) 
     A replica master mold was produced using the glass roll master mold (master mold) obtained as described above, and deformed in conformity with the shape of a formation object. The production of a replica master mold and the deformation (preforming) of the replica master mold according to each of the examples and comparative examples are described below. The softening temperature was measured as follows: A film-shaped sample produced with a thickness of 50 μm to 200 μm was stamped into 40 mm×0.5 mm. The dynamic viscoelasticity E′ was measured using a dynamic viscoelasticity measurement device (product name “Rheometrics System Analyzer-3 (RSA-3)” produced by Texas Instruments Inc.), and the temperature corresponding to dynamic viscoelasticity E′=0.3 GPa was taken to be the softening temperature. 
     Example 1 
     In this example, a PVC film (softening temperature: 84° C.) of 200 μm in average thickness was used as the base material layer  11 . An ultraviolet curable resin composition (softening temperature: 116° C.) was dropped on the PVC film using a dropper. The ultraviolet curable resin composition contains 90 parts by mass ester acrylate (product name “SP-10” produced by DIC Corporation) and 10 parts by mass fluorineacrylate monomer (product name “FAAC-6” produced by Unimatec Corporation). 
     After this, the PVC film on which the ultraviolet curable resin composition had been dropped and the above-described glass roll master mold having the concave hexagonal lattice pattern were brought into close contact with each other. Ultraviolet rays were applied from the PVC film (base material layer) side at an irradiance level of 1500 mJ/cm 2  using a metal halide lamp, to cure the ultraviolet curable resin composition. Subsequently, the glass roll master mold was separated from the cured ultraviolet curable resin composition. As a result of this process, a replica master mold in which the cured ultraviolet curable resin composition as the surface shape body  12  was formed on the PVC film as the base material layer  11  was obtained. 
     The obtained replica master mold was then deformed in conformity with the shape of the formation object  16 . In this example, a convex lens with an outer diameter of 12.7 mm and an F value of 15 was used as the formation object  16 , and the replica master mold was deformed by push-up forming at a deformation process temperature of 120° C. 
     Example 2 
     In this example, the intermediate layer  13  having the fine irregular pattern was formed as illustrated in  FIGS. 3A and 3B , and the surface shape body  12  was formed on the intermediate layer  13 , to produce a replica master mold. In detail, a PMMA film (softening temperature: 102° C.) was used as the base material layer  11 . A layer made of PC (softening temperature: 148° C.) and a layer made of an ultraviolet curable resin (product name “SK1900” produced by Dexerials Corporation) (softening temperature: 157° C.) were formed on the PMMA film, as the intermediate layer. The PMMA film having the intermediate layer formed thereon and the glass roll master mold were then brought into close contact with each other. Ultraviolet rays were applied from the PMMA film (base material layer) side at an irradiance level of 1500 mJ/cm 2  using a metal halide lamp, to cure the ultraviolet curable resin. As a result of this process, the intermediate layer having the fine irregular pattern was formed. A tungsten oxide layer (softening temperature: 1473° C.) which is an inorganic compound was then formed as the surface shape body  12  on the intermediate layer having the fine irregular pattern, to obtain a replica master mold. 
     The obtained replica master mold was then deformed in conformity with the shape of the same convex lens as in Example 1. In this example, the replica master mold was deformed by push-up forming at a deformation process temperature of 190° C. 
     Example 3 
     In this example, the approximately flat intermediate layer  13  was formed as illustrated in  FIG. 2 , and the surface shape body  12  was formed on the intermediate layer  13 , to produce a replica master mold. In detail, a PET film (softening temperature: 125° C.) of 188 μm in average thickness was used as the base material layer  11 . An intermediate layer (easily adhesive layer) for improving adhesiveness was formed on the PET film, and an ultraviolet curable resin (product name “SK1900” produced by Dexerials Corporation) (softening temperature: 157° C.) was applied onto the intermediate layer. 
     The PET film having the ultraviolet curable resin applied thereon and the glass roll master mold were then brought into close contact with each other. Ultraviolet rays were applied from the PET film (base material layer) side at an irradiance level of 1500 mJ/cm 2  using a metal halide lamp, to cure the ultraviolet curable resin. As a result of this process, a replica master mold in which the cured ultraviolet curable resin as the surface shape body  12  was formed on the PET film as the base material layer  11  was obtained. 
     The obtained replica master mold was then deformed in conformity with the shape of the same convex lens as in Example 1. In this example, the replica master mold was deformed by push-up forming at a deformation process temperature of 160° C. 
     Comparative Example 1 
     In this comparative example, a COC film (softening temperature: 128° C.) of 100 μm in average thickness was used as the base material layer  11 . A single-layer base material (softening temperature: 128° C.) having a fine irregular pattern was formed on the COC film as the surface shape body  12 , to obtain a replica master mold. In this comparative example, the softening temperature of the COC film as the base material layer  11  and the softening temperature of the single-layer base material as the surface shape body  12  are the same. 
     The obtained replica master mold was then deformed in conformity with the shape of the same convex lens as in Example 1. In this example, the replica master mold was deformed with a vacuum differential pressure of 0.1 MPa at a deformation process temperature of 150° C. 
     Comparative Example 2 
     In this comparative example, a PET film (product name “COSMOSHINE A4300” produced by Toyobo Co., Ltd.) (softening temperature: 184° C.) was used as the base material layer  11 . An intermediate layer (easily adhesive layer) for improving adhesiveness was formed on the PET film, and an ultraviolet curable resin (product name “SK1900” produced by Dexerials Corporation) (softening temperature: 157° C.) was applied onto the intermediate layer, as in Example 3. 
     The PET film having the ultraviolet curable resin applied thereon and the glass roll master mold were then brought into close contact with each other. Ultraviolet rays were applied from the PET film (base material layer) side at an irradiance level of 1500 mJ/cm 2  using a metal halide lamp, to cure the ultraviolet curable resin. As a result of this process, a replica master mold in which the cured ultraviolet curable resin as the surface shape body  12  was formed on the PET film as the base material layer  11  was obtained. 
     The obtained replica master mold was then deformed in conformity with the shape of the same convex lens as in Example 1. In this comparative example, the replica master mold was deformed by push-up forming with a vacuum differential pressure of 0.1 MPa at a deformation process temperature of 220° C. 
     The evaluation results of the replica master molds produced and deformed according to Examples 1 to 3 and Comparative Examples 1 and 2 described above are explained below. 
       FIG. 11A  is a cross-section photograph of the fine irregular pattern before and after preforming of the replica master mold according to Example 1, taken by a scanning electron microscope (SEM).  FIG. 11B  is a cross-section photograph of the fine irregular pattern before and after preforming of the replica master mold according to Example 2.  FIG. 11C  is a cross-section photograph of the fine irregular pattern before and after preforming of the replica master mold according to Example 3.  FIG. 11D  is a cross-section photograph of the fine irregular pattern before and after preforming of the replica master mold according to Comparative Example 1.  FIG. 11E  is a cross-section photograph of the fine irregular pattern before and after preforming of the replica master mold according to Comparative Example 2. In  FIGS. 11A to 11E , the photographed image after preforming of the replica master mold is a photographed image of a vertex portion of the convex lens. 
     Table 1 shows the height of the fine irregular pattern before preforming, the height of the fine irregular pattern after preforming, the residual factor which is the ratio of the height of the fine irregular pattern before preforming and the height of the fine irregular pattern after preforming, and the visual evaluation result of the deformed replica master mold, for each of the replica master molds according to Examples 1 to 3 and Comparative Examples 1 and 2. 
     
       
         
           
               
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                   
                   
                 Com- 
                 Com- 
               
               
                   
                   
                   
                   
                 parative 
                 parative 
               
               
                   
                 Exam- 
                 Exam- 
                 Exam- 
                 Exam- 
                 Exam- 
               
               
                   
                 ple 1 
                 ple 2 
                 ple 3 
                 ple 1 
                 ple 2 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Height of fine irregular 
                 230 
                 370 
                 258 
                 258 
                 294 
               
               
                 pattern before preforming 
               
               
                 (nm) 
               
               
                 Height of fine irregular 
                 225 
                 365 
                 258 
                 0 
                 196 
               
               
                 pattern after preforming 
               
               
                 (nm) 
               
               
                 Residual factor 
                 98% 
                 99% 
                 100% 
                 0% 
                 67% 
               
               
                 Evaluation result 
                 Good 
                 Good 
                 Good 
                 Poor 
                 Poor 
               
               
                   
               
            
           
         
       
     
     As illustrated in  FIGS. 11A to 11C  and Table 1, in Examples 1 to 3, the fine irregular pattern was transferred to the replica master mold with no distortion of the fine irregular pattern between before and after preforming (high residual factor). Thus, the fine irregular pattern was formed while the replica master mold maintained the three-dimensional shape. 
     As illustrated in  FIGS. 11D and 11E  and Table 1, in Comparative Examples 1 and 2, the fine irregular pattern was distorted between before and after preforming (low residual factor). 
     Moreover, in Examples 1 to 3, the replica master mold was deformed in conformity with the shape of the formation object (evaluation result: “good”). In Comparative Examples 1 and 2, on the other hand, the replica master mold was not deformed in conformity with the shape of the formation object (evaluation result: “poor”). The evaluation result “good” indicates that the replica master mold had no wrinkles or cracks and was in contact with the die throughout the curved surface. 
     Next, using the replica master mold according to Example 2 and the replica master mold according to Comparative Example 1, a fine structure was formed on the above-described convex lens as a formation object, and the optical characteristics (reflectance characteristics) of the formed fine structure were evaluated. 
     In the formation of the fine structure on the convex lens, an ultraviolet curable resin (product name “SK1120” produced by Dexerials Corporation) was applied onto the convex lens, and each of the replica master mold according to Example 2 and the replica master mold according to Comparative Example 1 was pressed against the ultraviolet curable resin. Ultraviolet rays were then applied from the base material layer side at an irradiance level of 1500 mJ/cm 2 , to cure the ultraviolet curable resin. Subsequently, the replica master mold was separated to obtain the convex lens on which the fine structure made of the cured ultraviolet curable resin was formed. 
       FIG. 12A  is a diagram illustrating the reflection characteristics of the fine structure formed using the replica master mold according to Example 2.  FIG. 12B  is a diagram illustrating the reflection characteristics of the fine structure formed using the replica master mold according to Comparative Example 1. 
     As illustrated in  FIG. 12B , the fine structure formed using the replica master mold according to Comparative Example 1 had a reflectance of about 4.2%. On the other hand, the fine structure formed using the replica master mold according to Example 2 had a reflectance of about 0.5%, exhibiting good antireflection optical characteristics. As mentioned above, in the replica master mold according to Comparative Example 1, the fine irregular pattern was distorted. This caused a distortion of the irregular shape of the fine structure formed using the replica master mold according to Comparative Example 1, and made it impossible to achieve good reflectance characteristics. In the replica master mold according to Example 2, on the other hand, the fine irregular pattern was hardly distorted. Consequently, the irregular shape of the fine structure formed using the replica master mold according to Example 2 was not distorted, so that good reflectance characteristics were achieved. 
     Example 4 
     The presently disclosed technique is applicable not only to the formation of a fine structure on the convex surface of the convex-surfaced formation object  16  but also to the formation of a fine structure on the concave surface of the concave-surfaced formation object  16 A, as mentioned earlier. In this example, a fine structure is formed on a concave surface. The process of deforming the replica master mold  10  in conformity with the shape of the formation object  16 A and the process of forming the fine structure  17   a  on the formation object  16 A using the deformed replica master mold  10  were combined in this example. 
     In this example, a plate made of polycarbonate and having a cylindrical shape was used as the formation object  16 A. This plate is, for example, used as a top plate (cover) attached to the front of a display body of a LCD or the like with an air gap therebetween. The formation object  16 A used had a curvature radius R of 500 mm, a length in the curvature radius R direction of 200 mm, and a width (depth) of 140 mm. 
     First, an uncured acrylic ultraviolet curable resin was applied onto the concave surface of the formation object  16 A by spin coating. The spin coating was performed by rotating the formation object  16 A at 1000 rpm for 30 sec. 
     Following this, the formation object  16 A having the acrylic ultraviolet curable resin applied on its concave surface was placed on the stage  21 , and the regions  25  and  26  were vacuumed to −0.1 MPa by a rotary pump. By vacuuming the regions  25  and  26 , the formation object  16 A placed on the stage  21  was pressed against the replica master mold supported by the supports  23 . In this example, a PET film (product name “A4300” produced by Toyobo Co., Ltd.) of 100 μm in average thickness was used as the replica master mold (film mold). 
     Atmospheric pressurization was then performed on the film mold side, i.e., the region  26  side. This enables the film mold and the formation object  16 A to be in close contact with each other without any gap. 
     After this, in a state in which the film mold and the formation object  16 A were in close contact with each other, ultraviolet light was applied from the film mold side. A metal halide lamp was used as an ultraviolet light source, and ultraviolet rays were applied at an irradiance level of 1000 mJ/cm 2 . As a result of being irradiated with the ultraviolet light, the uncured acrylic ultraviolet curable resin applied on the concave surface of the formation object  16 A cured. The film mold was then separated from the formation object  16 A. As a result of this process, a fine structure with a pitch of 150 nm to 230 nm and a height of 200 nm to 250 nm was formed on the concave surface of the formation object  16 A. 
     While the disclosed techniques have been described above by way of drawings and embodiments, various changes or modifications may be easily made by those of ordinary skill in the art based on the present disclosure. Such various changes or modifications are therefore included in the scope of the present disclosure. 
     REFERENCE SIGNS LIST 
       10  replica master mold 
       10   a  laminate 
       11  base material layer 
       12  surface shape body 
       12   a  resin layer 
       13  intermediate layer 
       14  master mold 
       15 ,  15 A die 
       16 ,  16 A formation object 
       17  photo-curable resin 
       17   a,    19  fine structure 
       18  display body 
       21  stage 
       22  sidewall 
       23  support 
       24  quartz plate 
       25 ,  26  region 
       27  gap