Master manufacturing method, transfer product manufacturing method, duplicated master manufacturing method, and master manufacturing device

Abstract

The present invention addresses the problem of forming, with high precision, a pattern having a concavo-convex structure having an arbitrary three-dimensional shape on the outer peripheral surface of a mother disc. The solution is a method for manufacturing a motherboard, comprising: a step for forming a resist layer on the outer peripheral surface of a base material; a step for dividing an input image in which an object having a three-dimensional shape is two-dimensionally drawn into a plurality of small regions; a step for stepwise determining the intensity of the laser beam irradiated to each of the small regions on the basis of the shade of the partial image of the object in each of the small regions including the object, and generating an exposure control signal corresponding to the object on the basis of the determination result; a step for irradiating the resist layer with the laser beam on the basis of the exposure control signal, thereby forming a resist pattern having a depth that varies depending on the shade of the partial image; and a step for forming, on the outer peripheral surface of the substrate, an uneven pattern corresponding to the three-dimensional shape of the object using the resist layer as a mask.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a master disc, a method for manufacturing a transfer material and a replica master disc using the master disc, and an apparatus for manufacturing the master disc. Background Art

[0002] In recent years, as one of the microfabrication technologies, nanoimprint technology has been developed, which is a technology that transfers the fine concave-convex pattern on a master disc to a resin sheet, etc. by pressing a flat plate-shaped or cylindrical master disc having a fine concave-convex pattern formed on the surface onto a resin sheet, etc. When manufacturing such a master disc for imprinting, a photolithography technology using exposure to a laser beam is used.

[0003] For example, Patent Document 1 discloses a technique for forming a concavo-convex structure of a microlens on the surface of a flat-plate-shaped metal mold master by photolithography with a laser beam.

[0004] In addition, Patent Document 2 discloses a technology that forms a pattern of a concave-convex structure (for example, a moth-eye structure belonging to the visible light band and having a concave-convex period less than the wavelength) on the outer peripheral surface of a roller master disk in the shape of a cylinder or a column through thermal photoetching with a laser beam, and transfers the pattern of the concave-convex structure on the outer peripheral surface of the roller master disk to a resin sheet.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-165811

[0008] Patent Document 2: Japanese Patent Application Publication No. 2016-028867 Summary of the invention

[0009] Problems to be solved by the invention

[0010] However, in the technique described in Patent Document 1, when the resist film on the surface of the flat metal mold master is exposed by a laser beam, each of the divided exposure target areas is exposed, and the exposure target areas are divided by the boundary portions between the concave portions with low exposure beam intensity and shallow exposure depth. Therefore, there is a problem that a concave-convex structure having an arbitrary three-dimensional shape cannot be freely formed, such that the concave-convex structures of adjacent blocks are continuously and seamlessly connected to each other.

[0011] In addition, in the technology described in Patent Document 2, the intensity of the laser beam is not modulated when exposing the resist layer on the outer peripheral surface of the roll master, but the concave-convex pattern is exposed by turning on and off the laser beam of constant intensity. Therefore, only an exposure pattern of a certain depth can be formed on the resist layer. Therefore, there is a problem that it is difficult to arbitrarily change the depth of the pattern of the concave-convex structure and freely form a concave-convex structure with an arbitrary three-dimensional shape.

[0012] Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to form a pattern of a concavo-convex structure having an arbitrary three-dimensional shape on the outer peripheral surface of a master disc with high precision.

[0013] Technical solutions to solve problems

[0014] In order to solve the above problems, according to one aspect of the present invention, there is provided a method for manufacturing a master disc, comprising:

[0015] A step of forming a resist layer on the outer peripheral surface of a cylindrical or columnar substrate;

[0016] A step of dividing an input image in which at least one object having a three-dimensional shape is drawn in two dimensions into a plurality of small regions;

[0017] A step of determining whether to irradiate each of the small areas with a laser beam based on whether each of the small areas contains the object, and determining the intensity of the laser beam irradiated toward each of the small areas in stages based on the shade of the partial image of the object in each of the small areas containing the object, and generating an exposure control signal corresponding to the object based on the determination result;

[0018] A process of forming a resist pattern corresponding to the object on the resist layer by irradiating the resist layer with the laser beam having an intensity modulated according to the shade of the partial image of the object in each of the small areas based on the exposure control signal; and

[0019] a step of forming a concavo-convex pattern corresponding to the three-dimensional shape of the object on the outer peripheral surface of the substrate using the resist layer having the resist pattern formed thereon as a mask,

[0020] In the resist pattern, a depth of the resist pattern varies according to lightness or darkness of the partial image of the object in each of the small regions.

[0021] The input image is a grayscale image that uses the intensity of the image to represent the height variation of the three-dimensional shape of the object.

[0022] In the step of generating the exposure control signal,

[0023] The intensity of the laser beam irradiated toward each of the small regions may be determined in stages based on the gray scale of the gray level of the partial image of the object within each of the small regions containing the object.

[0024] The exposure control signal is a modulation signal for modulating the intensity of the laser beam for exposing the resist layer in a stepwise manner, and may have a stepped waveform corresponding to a gray scale representing the light and dark grayscale of the partial image of the object.

[0025] The size of the small area may be smaller than the size of the spot of the laser beam.

[0026] In the step of forming the resist pattern on the resist layer,

[0027] The resist layer of the substrate may be irradiated with the laser beam while the substrate is rotated with the central axis of the substrate as a rotation axis.

[0028] The exposure control signal may be generated synchronously with a signal controlling the rotation of the substrate.

[0029] The light source of the laser beam is a semiconductor laser,

[0030] The resist layer is composed of an organic resist,

[0031] In the step of forming the resist pattern on the resist layer, the resist pattern may be formed on the resist layer by photoetching.

[0032] In order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided a method for producing a transfer material, the method comprising the step of transferring a pattern of a master disk produced by the method for producing a master disk.

[0033] In order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided a method for producing a replica master, the method comprising the step of transferring a pattern of a transfer material produced by the method for producing a transfer material.

[0034] In order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided a method for producing a transfer material, the method comprising the step of transferring a pattern of a replica master produced by the production method according to claim 9 .

[0035] In order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided an apparatus for manufacturing a master disc, comprising:

[0036] A film forming device for forming a resist layer on the outer peripheral surface of a cylindrical or columnar substrate;

[0037] An exposure control device that divides an input image in which at least one object having a three-dimensional shape is drawn two-dimensionally into a plurality of small areas, and determines whether to irradiate each small area with a laser beam based on whether each small area contains the object, and determines the intensity of the laser beam irradiated toward each small area in stages based on the shade of the partial image of the object in each small area containing the object, and generates an exposure control signal corresponding to the object based on the determination result;

[0038] an exposure device for forming a resist pattern corresponding to the object on the resist layer by irradiating the resist layer with the laser beam having an intensity modulated according to the shade of the partial image of the object in each of the small areas based on the exposure control signal; and

[0039] an etching device for forming a concave-convex pattern corresponding to the three-dimensional shape of the object on the outer peripheral surface of the substrate using the resist layer on which the resist pattern is formed as a mask,

[0040] In the resist pattern, a depth of the resist pattern varies according to lightness or darkness of the partial image of the object in each of the small regions.

[0041] Effects of the Invention

[0042] According to the present invention described above, a pattern of a concavo-convex structure having an arbitrary three-dimensional shape can be formed with high precision on the outer peripheral surface of a master disc. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a perspective view schematically showing a master disk manufactured by the master disk manufacturing method according to one embodiment of the present invention.

[0044] Figure 2 It is an explanatory diagram showing a transfer device for manufacturing a transfer material using a master disc according to the same embodiment.

[0045] Figure 3A The present invention is a cross-sectional view showing each step of the method for manufacturing a master disc according to the same embodiment.

[0046] Figure 3B The present invention is a cross-sectional view showing each step of the method for manufacturing a master disc according to the same embodiment.

[0047] Figure 3C The present invention is a cross-sectional view showing each step of the method for manufacturing a master disc according to the same embodiment.

[0048] Figure 3D The present invention is a cross-sectional view showing each step of the method for manufacturing a master disc according to the same embodiment.

[0049] Figure 4 It is an explanatory diagram showing the outline of the structure of the exposure apparatus involved in the same embodiment.

[0050] Figure 5 A block diagram showing the structure of a formatter according to the same embodiment.

[0051] Figure 6 The present invention is an explanatory diagram showing an input image divided into a plurality of small regions according to the embodiment, and is an explanatory diagram for explaining the division of the input image into small regions on which an object is drawn.

[0052] Figure 7 It is an explanatory diagram showing a specific example of the exposure control signal involved in the same embodiment.

[0053] Figure 8 It is an explanatory diagram showing a specific example of an input image according to a modification example of the same embodiment.

[0054] Fig. 9 It is an explanatory diagram showing a specific example of the shades of an input image divided into a plurality of small areas and a partial image of an object according to a modification example of the same embodiment.

[0055] Fig.10 It is an explanatory diagram showing a specific example of an exposure control signal according to a modification example of the same embodiment.

[0056] Fig.11 It is an explanatory diagram showing a structural example of an exposure apparatus according to the same embodiment.

[0057] Fig.12 It is an explanatory diagram showing another structural example of the exposure apparatus involved in the same embodiment.

[0058] Fig.13 It is an explanatory diagram showing an input image and a SEM image of a produced transfer product according to Example 1 of the present invention.

[0059] Fig.14 It is an explanatory diagram showing an input image and a SEM image of a produced transfer product according to Example 2 of the present invention.

[0060] Fig.15 It is an explanatory diagram showing an input image and a SEM image of a produced transfer product according to Example 3 of the present invention.

[0061] Fig.16 It is an explanatory diagram showing an input image and a SEM image of a produced transfer product according to Example 4 of the present invention. DETAILED DESCRIPTION

[0062] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in this specification and the accompanying drawings, the same reference numerals are given to components having substantially the same functional structure, and repeated descriptions are omitted.

[0063] [1. Overview of Master Disc and Transfer Material]

[0064] First, refer to Figure 1 as well as Figure 2 Hereinafter, an overview of a master disc 1 manufactured by a master disc manufacturing method according to an embodiment of the present invention and a transfer product manufactured using the master disc 1 will be described.

[0065] [1.1. Structure of the master disk]

[0066] Figure 1 FIG. 1 is a perspective view schematically showing a master disc 1 manufactured by the master disc manufacturing method according to the present embodiment. Figure 1 As shown, the master disc 1 according to the present embodiment includes a substrate 11 having a concavo-convex structure 13 formed on the outer peripheral surface.

[0067] The substrate 11 is, for example, a cylindrical member. However, the shape of the substrate 11 may be Figure 1 The substrate 11 may be a hollow cylindrical shape having a cavity inside as shown in the figure, or may be a solid cylindrical shape having no cavity inside. In addition, the material of the substrate 11 is not particularly limited, and quartz glass (SiO2) such as fused quartz glass or synthetic quartz glass or metal such as stainless steel may be used. The size of the substrate 11 is not particularly limited, for example, the axial length may be greater than 100 mm, the outer diameter may be greater than 50 mm and less than 300 mm, and the thickness may be greater than 2 mm and less than 50 mm.

[0068] The concavo-convex structure 13 is formed in an arbitrary three-dimensional shape on the outer peripheral surface of the substrate 11. The concavo-convex structure 13 has a concavo-convex pattern of an arbitrary three-dimensional shape. For example, the concavo-convex pattern of the concavo-convex structure 13 may be a concavo-convex pattern in which one or more concave or convex portions of an arbitrary three-dimensional shape are arranged regularly or irregularly. In addition, the concavo-convex pattern of the concavo-convex structure 13 may also be a concavo-convex pattern corresponding to a microlens array in which a plurality of microlenses are arranged regularly or irregularly.

[0069] The concavo-convex structure 13 is composed of at least one concave portion or convex portion having an arbitrary planar shape. Figure 1In the example, the concave-convex structure 13 includes a plurality of concave portions 12A, 12B, 12C, ... (hereinafter sometimes collectively referred to as "concave portions 12") having a variety of planar shapes. For example, the planar shape of the concave portion 12 may be a figure including a curve such as a circle or an ellipse, a polygon such as a triangle or a quadrilateral, a linear or strip shape such as a straight line or a curve, or a shape representing text or a symbol. Here, the planar shape of the concave portion 12 (or convex portion) refers to the shape of a figure drawn on the projection surface according to the concave portion 12 (or convex portion) when the concave portion 12 (or convex portion) is projected onto a plane parallel to the central axis 11a of the substrate 11. That is, the planar shape of the concave portion 12 (or convex portion) refers to the two-dimensional shape when the concave portion 12 (or convex portion) is viewed from above.

[0070] According to the method for manufacturing the master disc 1 of this embodiment, a pattern of the concavoconvex structure 13 having an arbitrary three-dimensional shape can be formed with high precision on the outer peripheral surface of the substrate 11 of the master disc 1. The details of the method for manufacturing the master disc 1 of this embodiment will be described later.

[0071] Here, the master disk 1 is a master disk used to manufacture a transfer object (such as a microlens array or a replica master disk for manufacturing a microlens array) to which the concave-convex structure 13 is transferred. The master disk 1 is, for example, a roll master disk used in roll-to-roll imprinting. The master disk 1 is set on a roll-to-roll imprint transfer device. For example, the master disk 1 is Figure 2 The transfer device 6 shown can produce a transfer product in which the concavo-convex structure 13 formed on the outer peripheral surface of the master disc 1 is transferred.

[0072] [1.2. Method for producing transfer material]

[0073] Next, refer to Figure 2 A method of manufacturing a transferred object by transferring the concavo-convex structure 13 of the master disc 1 to the resin layer 62 of the transferred object 61 in a roll-to-roll manner using the transfer device 6 including the master disc 1 will be described. Figure 2 It is an explanatory diagram showing a transfer device 6 for manufacturing a transfer material using the master disc 1 according to the present embodiment.

[0074] like Figure 2 As shown, the transfer device 6 includes the master disc 1 , a substrate supply roller 51 , a winding roller 52 , guide rollers 53 , 54 , a nip roller 55 , a peeling roller 56 , a coating device 57 , and a light source 58 .

[0075] The substrate supply roller 51 is a roller on which a sheet-shaped transfer object 61 is wound into a roll shape. The transfer object 61 is a substrate of the transfer object. The transfer object 61 is a sheet-shaped substrate extending in a strip shape. A resin layer 62 is laminated on one surface of the transfer object 61. The winding roller 52 is a roller that winds up the transfer object 61 laminated with the resin layer 62 to which the concave-convex structure 13 of the master disc 1 is transferred. In addition, the guide rollers 53 and 54 are rollers for conveying the transfer object 61. The roller 55 is a roller for bonding the transfer object 61 laminated with the resin layer 62 to the cylindrical master disc 1. The peeling roller 56 is a roller for peeling the transfer object 61 laminated with the resin layer 62 from the master disc 1 after the concave-convex structure 13 of the master disc 1 is transferred to the resin layer 62.

[0076] The coating device 57 is equipped with a coating device such as a coater, and coats the photocurable resin composition on the surface of the transfer object 61. By coating the photocurable resin composition by the coating device 57, a resin layer 62 is formed on the surface of the transfer object 61. The coating device 57 can be, for example, a gravure coater, a wire rod coater, or a die coater. In addition, the light source 58 is a light source that emits light of a wavelength that can cure the photocurable resin composition, and can be, for example, an ultraviolet lamp.

[0077] In addition, the photocurable resin composition is a resin that is cured by reducing fluidity by irradiating light of a specified wavelength. Specifically, the photocurable resin composition can be an ultraviolet curable resin such as acrylic resin acrylate. In addition, the photocurable resin composition can contain an initiator, a filler, a functional additive, a solvent, an inorganic material, a pigment, an antistatic agent or a sensitizing dye, etc. as needed. In addition, as a material for the resin layer 62, other energy line curable resin compositions such as thermosetting resin compositions can also be used instead of the above-mentioned photocurable resin compositions.

[0078] Next, a method for producing a transferred material using the transfer device 6 having the above-described configuration will be described.

[0079] First, the transfer object 61 is continuously fed out from the substrate supply roller 51 and conveyed by the guide roller 53. Next, the photocurable resin composition is coated on one surface of the transferred object 61 fed out by the coating device 57, and the uncured resin layer 62 is laminated on one surface of the transferred object 61. Furthermore, the transfer object 61 laminated with the uncured resin layer 62 is attached to the outer peripheral surface of the master disc 1 by the roller 55. Thus, the concave-convex structure 13 formed on the outer peripheral surface of the master disc 1 is transferred to the uncured resin layer 62. Then, light such as ultraviolet light is irradiated from the light source 58 to the resin layer 62 to which the concave-convex structure 13 is transferred. Thus, the uncured resin layer 62 is cured, and the shape of the concave-convex pattern transferred to the cured resin layer 62 is stabilized. Next, the transfer object 61 laminated with the cured resin layer 62 is peeled off from the master disc 1 by the peeling roller 56. Then, the transferred material 61 separated from the master disc 1 is conveyed via the guide roller 54 and is taken up by the take-up roller 52 .

[0080] In this way, by using the roll-to-roll transfer device 6 , it is possible to continuously manufacture a transfer product obtained by transferring the concavo-convex structure 13 formed on the master disc 1 .

[0081] In addition, the transfer material to which the concave-convex structure 13 formed on the master disk 1 is transferred can be further transferred to another transferred material to manufacture a replica master disk. The replica master disk has the same positions of the concave and convex parts of the concave-convex structure 13 (the so-called color tone of the concave-convex pattern) as compared with the master disk 1, and can be used as a replica master disk of the master disk 1. In addition, the replica master disk can be further transferred to a transferred material to manufacture a transfer material having a concave-convex structure 13 formed on the surface (that is, a transfer material to which the concave-convex structure 13 is transferred three times from the master disk 1).

[0082] As described above, the roll master 1 according to the present embodiment has an outer peripheral surface formed with a concavo-convex structure 13 having an arbitrary three-dimensional shape, and can continuously manufacture transfer products to which the concavo-convex structure 13 is transferred. Thus, transfer products to which the concavo-convex structure 13 is transferred with high precision can be mass-produced efficiently and at low cost.

[0083] [2. Method for manufacturing a master disc]

[0084] Next, referring to FIGS. 3 to 4 Fig.12 , a method for manufacturing the master disc 1 according to the present embodiment will be described.

[0085] [2.1. Overview of Master Disc Manufacturing Method]

[0086] First, refer to FIG. 3A to FIG. 3D , outline steps (steps S10 to S50 ) of a method for manufacturing the master disc 1 using the manufacturing apparatus for the master disc 1 according to the present embodiment will be described. FIG. 3A to FIG. 3D2 is a cross-sectional view for explaining each step of the method for manufacturing the master disc 1 according to the present embodiment. FIG. 3A to FIG. 3D Schematically shows the cross-sectional shape of the base material 11 of the master disc 1 having a cylindrical shape when it is cut in the thickness direction.

[0087] The manufacturing apparatus of the master disk 1 according to the present embodiment includes, for example, a film forming apparatus, an exposure apparatus, a developing apparatus, an etching apparatus, an exposure control apparatus, and other various control apparatuses.

[0088] (S10: Resist Film Forming Step)

[0089] According to the manufacturing method of the master disc 1 involved in this embodiment, first, Figure 3A As shown, a film forming device of the manufacturing apparatus forms a resist layer 15 on the outer peripheral surface of a substrate 11 of a master disk 1 .

[0090] In more detail, Figure 3A As shown, as the substrate 11 of the master disc 1, for example, a substrate made of quartz glass or the like is preferably used. The substrate 11 is a roller-shaped substrate having a cylindrical or columnar shape. On the outer peripheral surface of the substrate 11, a resist material is used to form a resist layer 15. Here, as the material of the resist layer 15, an organic resist is preferably used. As the organic resist, for example, a phenolic varnish-based resist or a chemically amplified resist can be used. In addition, in the resist layer 15, in order to perform grayscale exposure, a positive photoresist (for example, product name: "AZ-P4210", manufactured by Merc Corporation) is preferably used.

[0091] When an organic resist is used as the material of the resist layer 15, the resist layer 15 is formed on the outer peripheral surface of the substrate 11 by, for example, spin coating, slit coating, dip coating, spray coating, or screen printing. For example, it is preferred to apply the organic resist to the outer peripheral surface of the substrate 11 by dip coating to form the resist layer 15 with a thickness of several μm to several tens of μm. By using an organic resist, a relatively thick resist layer 15 can be formed.

[0092] (S20: Exposure Control Signal Generating Step)

[0093] Next, a computer (eg, exposure control device) of the manufacturing device obtains an input image 110 (see Figure 6 ), and generates an exposure control signal corresponding to the object 130 based on the input image 110 (refer to Figure 7 ). Details of the input image 110, the object 130, the exposure control signal, etc. involved will be described later.

[0094] (S30: Exposure Process)

[0095] Furthermore, if Figure 3B As shown, the exposure device of the manufacturing apparatus irradiates the resist layer 15 with the laser beam 20 based on the exposure control signal generated in S20. Thus, the resist layer 15 is exposed to a predetermined exposure pattern to form a latent image 16 corresponding to the object 130.

[0096] In more detail, Figure 3B As shown, the resist layer 15 is irradiated with a laser beam 20 using an exposure device, so that the portion of the resist layer 15 irradiated with the laser beam 20 is modified. As a result, the resist layer 15 is exposed, and a plurality of latent images 16 are formed on the resist layer 15. During the exposure, the resist layer 15 may be irradiated with a laser beam as an exposure beam continuously, or may be irradiated intermittently. In the case of continuous irradiation with the laser beam 20, for example, the surface of the resist layer 15 may be continuously irradiated with a scanning exposure while the laser beam 20 is relatively moved in the surface direction of the resist layer 15. In addition, in the case of intermittent irradiation with the laser beam 20, for example, the irradiation device of the laser beam 20 may be relatively moved in the surface direction of the resist layer 15, and the irradiation of the laser beam 20 may be turned on and off, and the surface of the resist layer 15 may be intermittently irradiated with a spot of the laser beam 20. Whether to use the continuous irradiation or the intermittent irradiation of the laser beam 20 may be appropriately selected according to the input image 110.

[0097] Here, the exposure control device generates an exposure control signal corresponding to the object 130 based on the input image 110 in which the object 130 is drawn, as in S20 described above. The irradiation of the laser beam 20 to the resist layer 15 of the substrate 11 is controlled by the exposure control signal, and the intensity of the laser beam 20 is modulated according to the three-dimensional shape of the object 130. Thus, the exposure device irradiates the position corresponding to the object 130 on the surface of the resist layer 15 with the laser beam 20 whose intensity is modulated according to the three-dimensional shape of the object 130. As a result, the resist layer 15 at the position corresponding to the object 130 can be modified to match the three-dimensional shape of the object 130. Thus, a plurality of latent images 16 corresponding to the plurality of objects 130 in the input image 110 are formed on the resist layer 15. The three-dimensional shape of each latent image 16 corresponds to the three-dimensional shape of each object 130. In addition, the specific process of the exposure control device generating the exposure control signal based on the input image 110 will be described later.

[0098] (S40: Development Step)

[0099] Then, if Figure 3C As shown in FIG. 1 , the developing device of the manufacturing apparatus develops the resist layer 15 on which the latent image 16 is formed. Thus, a resist pattern 17 corresponding to the object 130 is formed on the resist layer 15.

[0100] In more detail, Figure 3C As shown, the developing device drips a developing solution onto the resist layer 15 on which the latent image 16 is formed in the above S30 to develop the resist layer 15. Thus, a resist pattern 17 having a three-dimensional concave-convex structure is formed on the resist layer 15. The resist pattern 17 involved is composed of a plurality of concave portions 18 having a three-dimensional shape. The three-dimensional shapes of the plurality of concave portions 18 correspond to the three-dimensional shapes of the respective objects 130. The depth of the concave portion 18 may be a depth at which the deepest portion of the concave portion 18 reaches the surface of the substrate 11, or may be a depth that does not reach the surface.

[0101] In addition, when the resist layer 15 is a positive resist, the exposed portion exposed by the laser beam 20 has a higher dissolution rate in the developer than the non-exposed portion, and is therefore removed by the development process. Figure 3C As shown in the figure, a resist pattern 17 is formed on the resist layer 15 where the latent image 16 is removed. On the other hand, when the resist layer 15 is a negative resist, the exposed portion exposed by the laser beam 20 has a lower dissolution rate in the developer than the non-exposed portion, so the non-exposed portion is removed by the development process. Thus, a resist pattern (not shown) in which the latent image 16 remains is formed on the resist layer 15.

[0102] (S50: Etching process)

[0103] Then, if Figure 3D As shown, the etching device of the manufacturing apparatus etches the substrate 11 using the resist layer 15 having the resist pattern 17 as a mask. Thus, a concavo-convex pattern (i.e., concavo-convex structure 13) consisting of concave portions 12 corresponding to the object 130 is formed on the outer peripheral surface of the substrate 11.

[0104] In more detail, Figure 3C as well as Figure 3D As shown, the substrate 11 is etched using the resist layer 15 having the resist pattern 17 corresponding to the object 130 formed in the above S40 as a mask. Thus, a concavo-convex structure 13 (concavo-convex pattern) composed of a plurality of concave portions 12 is formed on the outer peripheral surface of the substrate 11. Figure 3D The concavo-convex shape of the concavo-convex structure 13 shown corresponds to Figure 3C The concavoconvex shape of the resist pattern 17 shown corresponds to the inverse shape of the three-dimensional shape of the multiple objects 130 transferred from the master disk 1 to the transfer material. The three-dimensional shapes of the multiple recesses 12 constituting the concavoconvex structure 13 correspond to the three-dimensional shapes of the objects 130 transferred from the master disk 1 to the transfer material.

[0105] In addition, dry etching or wet etching can be used in etching the substrate 11. For example, when the material of the substrate 11 is quartz glass (SiO2), the substrate 11 can be etched by dry etching using carbon fluoride gas (such as CHF3) or wet etching using hydrofluoric acid or the like.

[0106] [2.2. Details of Exposure Control Signal Generating Step (S20)]

[0107] Next, refer to Figure 6 as well as Figure 7 , the exposure control signal generating step (S20) in the method for manufacturing the master disk 1 according to the present embodiment will be described in more detail.

[0108] In the exposure control signal generating step ( S20 ), a computer of the manufacturing apparatus of the master disk 1 , for example, an exposure control device, generates an exposure control signal for exposing the substrate 11 of the master disk 1 based on the input image 110 in which the object 130 is drawn.

[0109] (S21: Input image acquisition step)

[0110] Specifically, first, Figure 6 As shown, an input image 110 in which at least one object 130A, 130B, 130C, 130D (hereinafter sometimes collectively referred to as the object 130 ) having a three-dimensional shape is two-dimensionally drawn is input to the exposure control device.

[0111] Here, the input image 110 is, for example, a rectangular image obtained by unfolding the outer peripheral surface plane of the cylindrical master disk 1. The input image 110 may be, for example, a grayscale image that two-dimensionally represents the three-dimensional concave-convex structure 13 formed on the outer peripheral surface of the master disk 1. In the input image 110, a plurality of objects 130 of the plurality of concave portions 12 or convex portions constituting the concave-convex structure 13 are two-dimensionally represented.

[0112] The object 130 is a structure having an arbitrary three-dimensional shape (e.g., a convex structure or a concave structure). The input image 110 includes a planar image of the object 130 that two-dimensionally represents the three-dimensional shape. The planar shape of the object 130 may be any shape, such as a figure including a curve such as a circle or an ellipse, a polygon such as a triangle or a quadrilateral, a line or a strip such as a straight line or a curve, or a shape representing a text or a symbol. Figure 6 In the input image 110 of the example, a rectangular object 130A, an elliptical object 130B, a pentagonal object 130C, and a triangular object 130D are drawn.

[0113] The input image 110 is an image that uses the image density to express the height variation of the three-dimensional shape of the object 130. For example, the input image 110 is preferably a grayscale image that uses the image density (ie, grayscale) to express the height variation of the three-dimensional shape of the object 130. Figure 6 In the example, the light-colored portion of the object 130 (the grayscale region close to white) represents the higher portion of the object 130 , and the dark-colored portion of the object 130 (the grayscale region close to black) represents the lower portion of the object 130 .

[0114] In addition, the grayscale used in the input image 110 is preferably, for example, 2 to 65,536 grayscales (1 to 16 bits), and more preferably 2 to 256 grayscales (1 to 8 bits). However, it is not limited to the example involved, and the grayscale of the grayscale can also be any grayscale of 2 grayscales (1 bit) or more. In the present embodiment, for example, a grayscale of 256 grayscales is used. The more grayscales there are, the more finely the three-dimensional shape of the object 130 can be expressed, but it has the disadvantage of increasing the amount of data processing required for the analysis process of the input image 110, the generation process of the exposure control signal, the exposure control process, etc. Therefore, the grayscale of the grayscale of the input image 110 is preferably set to a grayscale that suppresses the amount of data processing required for the image analysis process of the input image 110 to below the allowable range of the data processing capability of the formatter 40, and is set to a grayscale that can obtain the desired three-dimensional shape The fineness and smoothness. As a result, the three-dimensional shape of the object 130 can be reproduced on the master disc 1 with high precision.

[0115] (S22: Input image segmentation step)

[0116] Then, if Figure 6 As shown, the exposure control device divides the input image 110 into a plurality of small areas 115. In this embodiment, when the input image 110 is divided into a plurality of small areas 115, the input image 110 is divided regularly in the X direction (horizontal direction) and the Y direction (vertical direction). Figure 6 In the example of , the input image 110 is divided regularly in the vertical and horizontal directions using square grid coordinate lines.

[0117] Here, the size (e.g., area or length of one side) of the divided small area 115 is adjusted in accordance with the size (e.g., irradiation area or spot diameter) of the spot of the laser beam 20. In particular, the size of the small area 115 is preferably smaller than the spot of the laser beam 20. By an exposure method of irradiating the spot of the laser beam 20 to each of such small areas 115, a resist pattern 17 corresponding to the three-dimensional shape of the object 130 can be appropriately formed.

[0118] In addition, the method of dividing the input image 110 into small areas 115 is not limited to the above-mentioned example of a square grid. For example, a rectangular grid, a triangular grid, or a hexagonal grid may be used to regularly divide the input image 110. Alternatively, the input image 110 may be irregularly divided using dividing lines of any shape such as straight lines or curves.

[0119] (S23: Exposure Control Signal Generating Step)

[0120] Then, if Figure 7 As shown, the exposure control device generates an exposure control signal for exposing the resist layer 15 based on the partial image of each small area 115 of the input image 110. The partial image corresponds to the image in each small area 115 when the input image 110 is divided into a plurality of small areas 115.

[0121] Here, a specific example of the method for generating the exposure control signal is described. First, the exposure control device determines whether to irradiate the laser beam 20 toward each small area 115 based on whether the object 130 is included in each small area 115 of the segmented input image 110. Figure 6 As shown, in the input image 110, there are regions where the object 130 is drawn (image regions where the concave and convex parts of the object 130 exist) and regions where the object 130 is not drawn (image regions where the flat parts of the object 130 do not exist). Figure 6 As shown, among the plurality of small regions 115 of the segmented input image 110, some small regions 115B and 115C contain the object 130, while the other small region 115A does not contain the object 130. Moreover, in the small regions 115B and 115C containing the object 130, the density (grayscale) of the partial image changes according to the height of the three-dimensional shape of the object 130, compared with the small region 115A not containing the object 130.

[0122] Therefore, the exposure control device analyzes the input image 110 to determine whether the object 130 is included in each small area 115 of the input image 110. Then, as a result of the determination, the exposure control device determines to irradiate the small areas 115B and 115C containing the object 130 with the laser beam 20. On the other hand, it determines not to irradiate the small area 115A not containing the object 130 with the laser beam 20.

[0123] Moreover, if Figure 7As shown, the exposure control device analyzes the input image 110 to determine the shade of the partial image of the object 130 in each small area 115 containing the object 130 (for example, the gray scale of the gray scale of the partial image). Then, the exposure control device determines the intensity of the laser beam 20 irradiated to each small area 115 in stages based on the determined shade (for example, the gray scale of the gray scale of the partial image). For example, the lighter the color of the partial image of the object 130 in each small area 115 is, the closer it is to white, and the larger the gray scale is (that is, the higher the height of the object 130 in each small area 115), the higher the intensity of the laser beam 20 irradiated to each small area 115 is determined. On the other hand, the darker the color of the partial image of the object 130 in each small area 115 is, the closer it is to black, and the smaller the gray scale is (that is, the lower the height of the object 130 in each small area 115), the lower the intensity of the laser beam 20 irradiated to each small area 115 is determined.

[0124] In addition, when determining the density (grayscale) of the partial image in each small area 115 as described above, the exposure control device preferably uses the grayscale corresponding to the average value of the density of the partial image in each small area 115 as the determination result of the grayscale of the grayscale of each small area 115. For example, sometimes the height of the object 130 in a certain small area 115 changes greatly, and the partial image in the one small area 115 has a plurality of grayscales that are different from each other. In this case, the average value of the grayscales of the plurality of grayscales in the one small area 115 (for example, the average value in terms of area ratio or the average value in terms of pixel number ratio) can also be used as the grayscale of the entire grayscale of the partial image in the small area 115. Thus, the grayscale of the grayscale of the partial image in each small area 115 can be appropriately determined, and the intensity of the laser beam 20 irradiated to each small area 115 can be appropriately determined based on the determined grayscale. Thus, the resist pattern 17 and the concavo-convex pattern (concavo-convex structure 13 ) corresponding to the three-dimensional shape of the object 130 included in the input image 110 can be formed with high accuracy.

[0125] In the above manner, the exposure control device determines the presence or absence of the object 130 in each small area 115 of the input image 110 and the degree of lightness (grayscale) of the partial image of the object 130 contained in the small area 115. Then, the exposure control device determines the intensity of the laser beam 20 irradiated to each small area 115 in multiple stages according to the lightness of the partial image of the object 130 contained in each small area 115. Then, the exposure control device generates an exposure control signal corresponding to the object 130 contained in the input image 110 based on the determination result.

[0126] The exposure control signal is a control signal for controlling the laser beam 20 (exposure beam) used to expose the resist layer 15 formed on the outer peripheral surface of the substrate 11 of the master disk 1. In this embodiment, the intensity of the laser beam 20 irradiated to each small area 115 of the resist layer 15 is modulated according to the height difference of the three-dimensional shape of the object 130 in each small area 115 (that is, the lightness and darkness of the partial image of the object 130). Therefore, Figure 7 As shown, the exposure control signal is generated as a signal having a step-shaped waveform whose signal level changes stepwise according to the shade (grayscale grayscale) of the partial image of the object 130 in each small area 115. By using the exposure control signal, the intensity of the laser beam 20 irradiated to the area corresponding to each small area 115 on the surface of the resist layer 15 can be modulated according to the grayscale grayscale of the partial image of the object 130 in each small area 115 of the input image 110. In this way, the exposure control signal is configured as a modulation signal (exposure laser intensity modulation signal) for modulating the intensity of the exposure laser beam.

[0127] The exposure control signal generating step ( S20 ) in the method for manufacturing the master disk 1 according to the present embodiment has been described in detail above.

[0128] Then, in the exposure step (S30: see Figure 3B ), the exposure device irradiates the resist layer 15 with the laser beam 20 having an intensity modulated based on the exposure control signal. Thus, the resist layer 15 is exposed in an exposure pattern corresponding to the exposure control signal.

[0129] Specifically, in the exposure process, the exposure device modulates the intensity of the laser beam 20 according to the lightness or darkness of the partial image of the object 130 in each small area 115 based on the exposure control signal, and irradiates the area corresponding to each small area 115 on the surface of the resist layer 15 with the modulated laser beam 20. As a result, the latent image 16 corresponding to the three-dimensional shape of each object 130 is formed on the surface of the resist layer 15 in an exposure pattern corresponding to the plurality of objects 130.

[0130] Next, in the developing step (S40: see Figure 3C ), the developing device develops the exposed resist layer 15. Thus, a resist pattern 17 corresponding to the three-dimensional shapes of the plurality of objects 130 can be formed on the resist layer 15. In the resist pattern 17, the depth of the concave portion 18 of the resist pattern 17 in each small area 115 on the surface of the resist layer 15 varies according to the lightness or darkness of the partial image of the object 130.

[0131] Then, in the etching step (S50: see Figure 3D), the etching device uses the resist layer 15 formed with the resist pattern 17 as a mask to etch the substrate 11. As a result, a concave-convex structure 13 (concave-convex pattern) composed of a plurality of concave portions 12 corresponding to the three-dimensional shapes of the plurality of objects 130 can be formed on the outer peripheral surface of the substrate 11 of the master 1. Each concave portion 12 of the concave-convex structure 13 has an inverse shape of the three-dimensional shape of each object 130.

[0132] By manufacturing the master disc 1 in the above manner, the concavo-convex structure 13 corresponding to the object 130 having any three-dimensional shape can be formed on the outer peripheral surface of the master disc 1 with high precision. Then, by transferring the concavo-convex structure 13 of the master disc 1 manufactured in this way onto the surface of the transferred object, a transfer object or a replica master disc can be manufactured. Thus, transfer objects or replica master discs on which the pattern of the concavo-convex structure 13 of the object 130 having a desired three-dimensional shape is formed with high precision can be mass-produced efficiently and at low cost.

[0133] In addition, in the prior art described in the above-mentioned patent document 2, the intensity of the laser beam irradiated when the resist layer of the master is exposed is not modulated but constant intensity. Therefore, it is difficult to form a resist pattern of a concave-convex structure of a three-dimensional shape corresponding to an object of a three-dimensional shape on the surface of the resist layer. In addition, in this prior art, by using the thermal photoetching of the resist layer made of inorganic resist, a resist layer with a thickness of tens of nm to hundreds of nm is exposed to form a resist pattern. Moreover, in the thermal photoetching of the prior art, when the absorption heat of the resist layer caused by the laser irradiation during exposure exceeds a certain threshold value, the chemical reaction of the inorganic resist is rapidly carried out. Therefore, it is difficult to control the depth of the resist pattern formed on the thin inorganic resist layer, and the resist pattern of the desired three-dimensional shape cannot be generated with high precision.

[0134] In contrast, according to the manufacturing method of the master disc 1 involved in the present embodiment, the intensity of the laser beam 20 when exposing each small area 115 of the resist layer 15 is modulated according to the shade of the partial image of the object 130 in each small area 115 of the input image 110. The shade of the partial image in the input image 110 corresponds to the height of the three-dimensional shape (concavo-convex structure 13) of the object 130 actually formed on the outer peripheral surface of the master disc 1. Therefore, the resist pattern 17 having a three-dimensional shape corresponding to the object 130 can be formed on the surface of the resist layer 15 with high precision.

[0135] Moreover, according to the present embodiment, a resist layer 15 having a thickness of several μm to several tens of μm made of an organic resist containing a photosensitive material is used, and the resist layer 15 is exposed by photoetching. Compared with inorganic resists, organic resists can form thicker films. In addition, the photoreaction of the photosensitive material contained in the organic resist reacts according to the light intensity of the laser beam. Therefore, in the exposure process involved in the present embodiment, by applying photoetching using a thicker resist layer 15 made of an organic resist, the photoreaction of the resist layer 15 during exposure can be gradually carried out in the depth direction. In addition, by modulating the intensity of the laser beam 20 irradiated during exposure, the depth and three-dimensional shape of the latent image 16 formed on the resist layer 15 can be appropriately controlled. Therefore, as FIG. 3B to FIG. 3C As shown, a three-dimensional resist pattern 17 corresponding to a desired three-dimensional object 130 can be formed with high precision. Figure 3D As shown, a three-dimensional concavo-convex structure 13 (concavo-convex pattern) corresponding to an object 130 of a desired three-dimensional shape can be formed with high precision on the outer peripheral surface of the substrate 11 of the master 1.

[0136] [2.3. Exposure device and exposure method]

[0137] Next, refer to Figures 4 to 7 The exposure device 2 and the exposure method used in the method for manufacturing the master disk 1 according to the present embodiment will be described in more detail. Figure 4 It is an explanatory diagram showing the outline of the structure of the exposure apparatus 2 according to the present embodiment.

[0138] like Figure 4 As shown, the exposure device 2 according to the present embodiment is a device for exposing the resist layer 15 formed on the outer peripheral surface of the substrate 11 of the roll master 1. The exposure device 2 includes a laser light source 21, a laser modulation driver 30, and a formatter 40.

[0139] The laser source 21 is a light source for emitting the laser beam 20, and is, for example, a solid laser or a semiconductor laser, etc. The wavelength of the laser beam 20 is not particularly limited, and may be, for example, a wavelength in the blue light band of 400 nm to 500 nm.

[0140] The formatter 40 is equivalent to the above-mentioned exposure control device. The formatter 40 generates an exposure control signal for irradiating the laser beam 20 to the resist layer 15 based on the input image 110 in which the object 130 is drawn. For example, the formatter 40 can also generate an exposure control signal for irradiating the laser beam 20 to a position corresponding to the object 130 on the surface of the resist layer 15 of the substrate 11. Thereby, a latent image 16 corresponding to the object 130 of an arbitrary shape is formed on the resist layer 15 on the substrate 11. In addition, the formatter 40 can control the irradiation of the laser beam 20 to the substrate 11 by controlling the emission of the laser beam 20 from the laser light source 21, and can also control the irradiation of the laser beam 20 to the substrate 11 by controlling the irradiation position so that the laser beam 20 does not irradiate the substrate 11.

[0141] The laser modulation driver 30 is a driver that controls the irradiation of the laser beam 20 from the laser source 21. The laser modulation driver 30 has a function of modulating the intensity (power) of the laser beam 20 irradiated from the laser source 21. The exposure control signal generated by the formatter 40 is input to the laser modulation driver 30. The laser modulation driver 30 modulates the intensity of the laser beam 20 irradiated from the laser source 21 based on the exposure control signal. For example, Figure 7 As shown in FIG. 1 , the exposure control signal has a step-shaped waveform whose signal level changes stepwise according to the shade (gray scale) of the partial image of the object 130 contained in each small area 115 of the input image 110. Therefore, the laser modulation driver 30 modulates the intensity of the laser beam 20 irradiated from the laser light source 21 according to the signal level of the exposure control signal of the step-shaped waveform. As a result, the laser beam 20 whose intensity is modulated according to the shade of the partial image of the object 130 is irradiated from the laser light source 21 to the substrate 11, so that the resist layer 15 is exposed.

[0142] The exposure device 2 of the above structure irradiates the resist layer 15 of the substrate 11 with the laser beam 20, thereby modifying a part of the resist layer 15 to form a latent image 16 (see Figure 3B). During such exposure, the exposure device 2 may, for example, intermittently irradiate the resist layer 15 formed on the outer peripheral surface of the cylindrical substrate 11 with the laser beam 20 along a spiral trajectory, or irradiate continuously, so that the resist layer 15 is exposed in a spiral shape. In this case, the exposure device 2 may irradiate the substrate 11 with the laser beam 20 in a manner that the laser beam 20 is scanned at a certain speed in one direction (R direction) along the central axis 11a of the substrate 11 while rotating the substrate 11 at a certain speed with the central axis 11a of the cylindrical substrate 11 as the rotation axis. Thus, the laser beam 20 is intermittently or continuously irradiated onto the surface of the resist layer 15 along a spiral trajectory from one side of the axial direction of the substrate 11 to the other side, and a latent image 16 of a desired shape is formed at a necessary portion of the surface of the resist layer 15.

[0143] In the exposure device 2 according to the present embodiment, the laser modulation driver 30 controls the irradiation of the laser beam 20 while modulating the intensity of the laser beam 20 based on the exposure control signal generated by the formatter 40. Thus, the depth and shape of the resist layer 15 exposed by the laser beam 20 can be changed, so that a latent image 16 having a three-dimensional shape corresponding to the object 130 is formed on the resist layer 15.

[0144] Next, refer to Figure 5 , the functional structure of the formatter 40 (exposure control device) involved in this embodiment is explained. Figure 5 It is a block diagram showing the structure of the formatter 40 involved in this embodiment.

[0145] like Figure 5 As shown, the formatter 40 according to the present embodiment generates an exposure control signal and a clock signal for controlling the irradiation of the laser beam 20. The formatter 40 includes an input image acquisition unit 401, a small region division unit 403, a signal generation unit 405, and a clock signal generation unit 407.

[0146] The input image acquisition unit 401 acquires the input image 110 (see Figure 6 ). The input image 110 is, for example, an image equivalent to a development view obtained by cutting the outer peripheral surface of the cylindrical substrate 11 along the axial direction of the substrate 11 and developing it in a plane. In addition, the plane shape of the object 130 drawn in the input image 110 may be, for example, a figure including a curve such as a circle or an ellipse, a polygon such as a triangle or a quadrilateral, a line or a strip such as a straight line or a curve, or a shape representing text or a symbol.

[0147] The small area division unit 403 divides the input image 110 obtained by the input image acquisition unit 401 into a plurality of small areas 115 having a predetermined shape and size. Specifically, the small area division unit 403 divides the input image 110 into a plurality of small areas 115 at a predetermined grid interval. For example, Figure 6 As shown, the small area dividing unit 403 divides the input image 110 at a predetermined interval Px in a direction corresponding to the circumferential direction of the substrate 11 (the X direction of the input image 110), and divides the input image 110 at a predetermined interval Py in a direction corresponding to the axial direction of the substrate 11 (the Y direction of the input image 110). In addition, the interval Px and the interval Py may be the same or different.

[0148] Here, the size of the divided small areas 115 (for example, the above-mentioned intervals Px and Py) is preferably smaller than the size of the spot of the laser beam 20 (for example, the spot diameter). As a result, the latent image 16 formed by the irradiation of the laser beam 20 can be overlapped without gaps between adjacent small areas 115. That is, the exposure device 2 can expose in a manner that covers the positions corresponding to the object 130 by overlapping multiple spots of the laser beam 20. For example, when the diameter of the spot of the laser beam 20 is about 200nm, the intervals Px and Py of the small areas 115 can be 100nm, and the small areas 115 can be squares of 100nm×100nm. In addition, the shape of the small area 115 is not limited to the example of a square, and can be any shape such as the above-mentioned rectangular shape, triangular shape, polygonal shape, etc.

[0149] Furthermore, the small area dividing unit 403 determines whether each small area 115 contains the object 130. In addition, the small area dividing unit 403 determines the degree of lightness (grayscale) of the partial image of the object 130 in each small area 115 containing the object 130.

[0150] Here, refer to Figure 6 , the function of the small area segmentation unit 403 is described in more detail. Figure 6 1 is an explanatory diagram showing an input image 110 divided into a plurality of small regions 115. Figure 6 In FIG. 1 , the X direction corresponds to the circumferential direction of the outer peripheral surface of the substrate 11 , and the Y direction corresponds to the axial direction of the substrate 11 .

[0151] like Figure 6As shown, the small area segmentation unit 403 segments the input image 110 containing the objects 130A, 130B, 130C, and 130D at intervals Px in the X direction and at intervals Py in the Y direction. As a result, the input image 110 is segmented into grid-shaped small areas 115. In addition, the small area segmentation unit 403 determines whether each small area 115 contains the object 130. For example, the small area segmentation unit 403 determines the small area 115A as a small area that does not contain the object 130, and determines the small areas 115B and 115C as small areas that contain the object 130. In addition, the small area segmentation unit 403 may determine that the small area 115 contains the object when the object 130 is slightly drawn in each small area 115. Alternatively, the small area segmentation unit 403 may determine that the small area 115 contains the object 130 when the object 130 is drawn in an area larger than a predetermined area in each small area 115.

[0152] In order to instruct exposure of only a part of the input image 110, the exposure area 111 may be set in the input image 110. In this case, the small area dividing unit 403 may determine whether the object 130 is included in only the small area 115 in the exposure area 111 of the input image 110.

[0153] The signal generating unit 405 generates an exposure control signal for controlling the irradiation of the laser beam 20. Specifically, the signal generating unit 405 determines whether to irradiate the laser beam 20 toward the area corresponding to each small area 115 in the resist layer 15 based on the determination result of the small area dividing unit 403. Moreover, the signal generating unit 405 determines the density (for example, the gray scale of gray) of the partial image of the object 130 in each small area 115 containing the object 130 in stages. Then, the signal generating unit 405 determines the intensity of the laser beam 20 irradiated toward each small area 115 in stages based on the determination result. Moreover, the signal generating unit 405 generates an exposure control signal indicating the intensity and timing of the laser beam 20 irradiated toward each small area 115 based on the determination result (for example, data indicating the intensity of the laser beam 20 irradiated toward each small area 115). At this time, the signal generating unit 405 converts the above-mentioned determined data indicating the intensity of the laser beam 20 into an exposure control signal using the clock signal generated by the clock signal generating unit 407. In this way, the exposure control signal generated by the signal generation unit 405 is sent to the driver 30 that controls the laser light source 21. The driver 30 controls the irradiation of the laser beam 20 of the laser light source 21 based on the exposure control signal.

[0154] [2.4. Specific example of input image and exposure control signal]

[0155] Here, refer to Figure 6 as well as Figure 7 , a specific example of a method for generating an exposure control signal based on the input image 110 is described in more detail. Figure 7 To express Figure 6 FIG. 1 is an explanatory diagram of a specific example of an exposure control signal corresponding to a peripheral image of an object 130A in the input image 110 shown.

[0156] like Figure 6 and Figure 7 As shown, the signal generating unit 405 determines the lightness or darkness (e.g., grayscale) of the partial image within each small area 115 in each row in the X direction of the input image 110, and determines the intensity of the laser beam 20 irradiated toward each small area 115 based on the determination result.

[0157] For example, first, the signal generating unit 405 selects the top row of the input image 110 (or the exposure area 111), and determines the lightness or darkness (for example, the grayscale) of the partial image in each small area 115 in sequence from the small area 115 at the left end of the row to the small area 115 at the right end (i.e., toward the positive direction of the X-axis).

[0158] At this time, the signal generating unit 405 assigns "0" as the grayscale level to the small area 115 that does not contain the object 130. On the other hand, the signal generating unit 405 assigns a grayscale level value (for example, "0") corresponding to the grayscale level of the partial image of the object 130 in the small area 115 to the small area 115 that contains the object 130. Figure 7 In the example of , 24 grayscales of "0 to 23" are used. Thus, the signal generation unit 405 determines the grayscale of each small area 115 in order from the small area 115 at the left end to the small area 115 at the right end in one row.

[0159] Then, the signal generation unit 405 selects the next row and performs the same process as above in the row to determine the grayscale of each small area 115 in the row. Furthermore, the determination process is repeated in order from the upper row to the lower row (toward the negative direction of the Y direction) to determine the grayscale of the plurality of small areas 115 in the entire input image 110 (or exposure area 111).

[0160] The order in which the signal generating unit 405 determines the grayscale of the grayscale in each row in the X direction of the input image 110 is set based on the rotation direction of the substrate 11. Therefore, the signal generating unit 405 may determine the grayscale of the grayscale in order (toward the negative direction of the X axis) from the small area 115 at the right end to the small area 115 at the left end in each row in the X direction according to the rotation direction of the substrate 11. In addition, the order in which the signal generating unit 405 determines the grayscale of the grayscale in the Y direction of the input image 110 is set based on the scanning direction of the laser beam 20 with respect to the substrate 11. Therefore, the signal generating unit 405 may determine the grayscale of the grayscale in order (toward the positive direction of the Y axis) from the lower row to the upper row of the input image 110 according to the scanning direction of the laser beam 20 with respect to the substrate 11.

[0161] In addition, if Figure 7 As shown, the signal generating unit 405 converts the data indicating the determination result of the grayscale of each small area 115 (equivalent to the data indicating the intensity of the laser beam 20 irradiated to each small area 115) into an exposure control signal using the clock signal obtained from the clock signal generating unit 407. For example, the clock signal is a rectangular wave signal having a predetermined frequency. In addition, the data indicating the determination result of the grayscale is, for example, numerical data indicating the grayscale of the grayscale assigned to each small area 115 of the input image 110.

[0162] like Figure 7 As shown in FIG. 1 , the exposure control signal is a signal having a step-shaped waveform. The signal level of the exposure control signal increases and decreases stepwise in accordance with the gray scale representing the light and dark gray scale of the partial image of each small area 115 . Figure 7 In the example of FIG. 1 , for the small area 115 whose grayscale level is determined to be “16”, the signal level of the exposure control signal is the highest.

[0163] The signal generating unit 405 generates an exposure control signal based on the clock signal. For example, the exposure control signal is generated so that the timing of the rise and fall of the exposure control signal coincides with the timing of the rise or fall of the clock signal. Figure 7 In the example of , the exposure control signal is generated in such a way that the rising and falling of the exposure control signal coincide with the rising of the clock signal.

[0164] The clock signal generating unit 407 generates a clock signal as a reference of the exposure control signal. Specifically, the clock signal generating unit 407 obtains a rotation control signal for controlling the rotation of the spindle motor 35 from the spindle motor 35 that rotates the substrate 11, and generates a clock signal having a predetermined frequency based on the rotation control signal.

[0165] Here, even if the rotation speed of the spindle motor 35 that rotates the substrate 11 is set to a constant speed, it is not always constant and may fluctuate. Therefore, when the rotation control signal that controls the rotation of the spindle motor 35 and the exposure control signal that controls the irradiation of the laser beam 20 are not synchronized, one rotation of the spindle motor 35 and one cycle of the exposure control signal may not coincide. In this case, the position of the outer peripheral surface of the substrate 11 irradiated by the laser beam 20 will shift each time the substrate 11 rotates, so it may not be possible to form the concave-convex pattern corresponding to the object 130 at the correct position of the outer peripheral surface of the substrate 11.

[0166] Therefore, as described above, the exposure device 2 according to the present embodiment generates a clock signal based on the rotation control signal for controlling the rotation of the spindle motor 35, and generates an exposure control signal for controlling the irradiation of the laser beam 20 based on the clock signal. The rotation control signal and the exposure control signal are thereby synchronized. Therefore, the position of the outer peripheral surface of the substrate 11 irradiated with the laser beam 20 does not shift each time the substrate 11 rotates, so that the concavo-convex pattern corresponding to the object 130 can be formed at the correct position of the outer peripheral surface of the substrate 11.

[0167] In addition, the method of synchronizing the rotation control signal with the exposure control signal is not limited to the above example. For example, the clock signal generating unit 407 may send a clock signal as a reference to the spindle motor 35 and the signal generating unit 405 respectively. In this case, the spindle motor 35 generates a rotation control signal for controlling the rotation of the spindle motor 35 based on the clock signal, and the signal generating unit 405 generates an exposure control signal based on the clock signal. By this method, the rotation control signal for controlling the rotation of the spindle motor 35 and the exposure control signal for controlling the irradiation of the laser beam 20 can also be synchronized.

[0168] The above describes the functional configuration of the formatter 40 that generates an exposure control signal for controlling the irradiation of the laser beam 20. According to the formatter 40, an exposure control signal corresponding to the three-dimensional shape of an arbitrary object 130 can be appropriately generated.

[0169] In addition, the functions of the formatter 40 are realized by the cooperation of software and hardware. For example, the formatter 40 may have a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. connected to each other through a bridge, and realize the above functions through these hardware.

[0170] For example, the CPU functions as a calculation processing device and a control device, and controls the entire operation in the formatter 40 according to various programs. The ROM stores programs and calculation parameters used by the CPU, and the RAM temporarily stores programs used in the CPU execution, parameters that change appropriately during the execution, etc. Thus, the CPU can execute the functions of the input image acquisition unit 401, the small area division unit 403, the signal generation unit 405, and the clock signal generation unit 407, for example.

[0171] [2.5. Another specific example of input image and exposure control signal]

[0172] Next, refer to Figures 8 to 10 , another specific example of a method for generating an exposure control signal based on the input image 110 is described in more detail. In addition, Figure 8 It is an explanatory diagram showing a specific example of the input image 110 involved in this embodiment. Fig. 9 The diagram is an explanatory diagram showing a specific example of the input image 110 divided into a plurality of small areas 115 and the density (grayscale) of a partial image of an object 130 . Fig.10 To express and Fig. 9 FIG. 1 is an explanatory diagram of a specific example of an exposure control signal corresponding to a partial image of an object 130 (microlens) in the input image 110 shown.

[0173] also, Figures 8 to 10 The specific example is also the same as above Figure 6 as well as Figure 7 Similarly, the input image 110 is divided into a plurality of small regions 115, and an exposure control signal is generated based on the density (grayscale) of the partial image of each small region 115. Therefore, detailed description of these division processing and generation processing is omitted.

[0174] like Figure 8 as well as Fig. 9 As shown, the input image 110 may also be a grayscale image in which a plurality of objects 130 having the same shape are drawn. Figure 8 The input image 110 of the example represents a microlens array, and each microlens corresponds to an object 130. Figure 8 As shown, a plurality of micro lenses are regularly arranged in a square grid in the vertical and horizontal directions (X and Y directions) as an object 130. The plurality of micro lenses are arranged at intervals from each other. Figure 8 The microlens (object 130) of the example is a convex lens having a spherical or aspherical shape, and the surface shape of the microlens has a three-dimensional shape that is higher as it approaches the lens vertex. Fig. 9As shown, in the region where the microlens exists in the input image 110, the closer to the lens vertex, the closer the image of the microlens is to white, and the grayscale is larger (for example, grayscale = "1" to "16"). On the other hand, the non-lens region between the adjacent microlenses becomes a low-height flat surface, and the image of the non-lens region is close to black, and the grayscale is the smallest (for example, grayscale = "0").

[0175] Fig. 9 The input image 110 shown on the upper side is from Figure 8 The input image 110 is cut out of a partial image of five microlenses (object 130) arranged in a row in the center of the Y direction. Fig. 9 As shown, the input image 110 is divided into a plurality of small areas 115 by square grid coordinate lines. Fig. 9 In the example, the interval Px of the grid coordinate lines in the X direction is equal to the interval Py of the grid coordinate lines in the Y direction, and the small area 115 becomes a square grid coordinate. However, the present invention is not limited to the example involved, for example, the interval Px and the interval Py may be different from each other, and the small area 115 may also be a grid coordinate having a rectangular shape or other shapes.

[0176] Preferably, Fig. 9 As shown, the region where one microlens (object 130) exists in the input image 110 is divided into, for example, more than 100 small regions 115 (for example, more than 10 divisions in the X direction and more than 10 divisions in the Y direction) according to the height difference of the three-dimensional shape of the microlens. Thus, using the partial images of the plurality of small regions 115, the three-dimensional spherical or aspherical shape of each microlens can be densely and smoothly reproduced on the outer peripheral surface of the substrate 11 of the master 1.

[0177] also, Fig. 9 The bar graph shown on the lower side shows the Fig. 9 The change in the shade (e.g., grayscale) of a partial image of a row of 5 microlenses that cross along the X direction in the approximate center of the Y direction in the input image 110 on the upper side. After the input image 110 is divided into small areas 115 in this way, the partial image of each small area 115 is analyzed to find the shade of the partial image of each small area 115. In this way, the change in the height of the three-dimensional shape of the microlens drawn two-dimensionally in the input image 110 can be accurately grasped and reflected in the exposure control signal. Therefore, if Fig.10 As shown, an exposure control signal corresponding to the three-dimensional shape of the microlens can be generated according to the density (grayscale) of the partial image of each small area 115.

[0178] With the above Figure 7 The example exposure control signal is similarly, Fig.10The exposure control signal shown has a stepped waveform corresponding to the gray scale representing the shade of the partial image of the microlens (object 130). The larger the gray scale, the higher the signal level of the exposure control signal is set to. The change in the signal level of the exposure control signal corresponds to the change in the height of the three-dimensional shape of one microlens. By using the exposure control signal to modulate the intensity of the laser beam 20, the resist layer 15 is exposed, so that the resist pattern 17 corresponding to the three-dimensional shape of the microlens array can be accurately reproduced on the resist layer 15.

[0179] Above, refer to Figures 8 to 10 A specific example of an input image 110 representing a microlens array in which a plurality of microlenses are regularly arranged as an object 130 and an exposure control signal generated based on the input image 110 is described. According to the specific example involved, a master disk 1 for manufacturing a microlens array drawn in the input image 110 can be manufactured. According to the manufacturing method, for example, Figure 8 The concavo-convex structure 13 corresponding to the three-dimensional shape of the microlens array drawn two-dimensionally in the input image 110 shown is reproduced on the outer peripheral surface of the master disk 1 with high precision.

[0180] In addition, the products of the master disc 1 are not limited to the above products. Figure 8 The examples of microlens arrays shown in the examples of FIG. 1 and FIG. 2 can be applied to a variety of products. For example, the product to be manufactured by the master disc 1 can be a microlens array in which a plurality of microlenses are irregularly arranged, or can be an anti-reflection film, a diffuser, a polarizing plate, a diffraction grating, or other various optical components formed with a moth-eye structure having a concave-convex period below the wavelength belonging to the visible light band. The desired concave-convex structure formed on these various optical components is used as the object 130 to generate an input image 110 depicted in grayscale, and the input image 110 is applied to the manufacturing method of the master disc 1 involved in this embodiment. In this way, the master disc 1 used for manufacturing a product of an optical component having the desired concave-convex structure can be easily and accurately manufactured.

[0181] [2.6. Example of configuration of exposure device]

[0182] Next, refer to Fig.11 as well as Fig.12 , a configuration example of the exposure device 2 used in the method for manufacturing the master disk 1 according to the present embodiment will be described. Fig.11 It is an explanatory diagram showing a configuration example of an exposure apparatus 2A according to the present embodiment. Fig.12 It is an explanatory diagram showing another configuration example of the exposure apparatus 2B according to the present embodiment.

[0183] First, refer to Fig.11The exposure apparatus 2A according to the present embodiment will be described. The exposure apparatus 2A is an exposure apparatus that uses a solid-state laser as a laser light source 21A.

[0184] like Fig.11 As shown, the exposure device 2A includes a laser source 21A, an electro-optical element (Electro Optical Modulator: EOM) 22, a first reflector 23, a photodiode (Photodiode: PD) 24, a modulation optical system 25, a control mechanism 37, a second reflector 31, a movable optical table 32, a spindle motor 35, and a turntable 36. In addition, the substrate 11 is placed on the turntable 36 and can be rotated.

[0185] The laser light source 21A is specifically a solid laser. For example, a solid laser having a wavelength of 266 nm or the like can be used as the laser light source 21A.

[0186] The laser beam 20 emitted from the laser light source 21A travels straight while maintaining a parallel beam and enters the electro-optical element 22. The laser beam 20 transmitted through the electro-optical element 22 is reflected by the first reflection mirror 23 and introduced into the modulation optical system 25.

[0187] The first reflector 23 is composed of a polarization beam splitter and has the function of reflecting one polarization component and transmitting the other polarization component. The polarization component transmitted through the first reflector 23 is received by the photodiode 24 and photoelectrically converted. In addition, the received signal photoelectrically converted by the photodiode 24 is input to the electro-optical element 22. The electro-optical element 22 performs phase modulation of the laser beam 20 based on the input received signal.

[0188] Furthermore, the modulation optical system 25 includes a condenser lens 26 , an acousto-optic modulator (AOM) 27 , and a collimator lens 28 .

[0189] In the modulation optical system 25, the laser beam 20 is focused on the acousto-optic modulator 27 made of glass (SiO2) or the like through the focusing lens 26. After the laser beam 20 is modulated in intensity and diverged by the acousto-optic modulator 27, it is converted into a parallel beam again through the collimating lens 28. The laser beam 20 emitted from the modulation optical system 25 is reflected by the second reflecting mirror 31 and guided horizontally and parallelly to the moving optical stage 32.

[0190] Furthermore, the control mechanism 37 includes a formatter 40 and a driver 30, and controls the irradiation of the laser beam 20. The formatter 40 generates an exposure control signal for controlling the irradiation of the laser beam 20 as described above, and the driver 30 controls the acousto-optic modulator 27 based on the exposure control signal generated by the formatter 40. In this way, the irradiation of the laser beam 20 to the resist layer 15 is controlled.

[0191] The movable optical stage 32 includes a beam expander (BEX) 33 and an objective lens 34 . The laser beam 20 guided to the movable optical stage 32 is shaped into a desired beam shape by the beam expander 33 , and then irradiated onto the resist layer 15 on the outer peripheral surface of the substrate 11 via the objective lens 34 .

[0192] In addition, although not shown in the figure, it is preferred that the exposure device 2A dynamically controls the focus so that the laser beam 20 is always focused on the resist layer 15 on the substrate 11. Specifically, when the substrate 11 rotates, the distance from the objective lens 34 to the substrate 11 varies due to the axial wobble of the rotation axis and the processing accuracy of the surface of the substrate 11. Therefore, in order to always focus the laser beam 20 on the resist layer 15 of the substrate 11, the exposure device 2A preferably detects the focus offset of the laser beam 20 and dynamically controls the focus of the laser beam 20. In addition, the method of detecting the focus offset of the laser beam 20 on the resist layer 15 on the substrate 11 can use, for example, a method of detecting the astigmatism of the reflected light of the laser beam 20 irradiated to the resist layer 15.

[0193] With these structures, the substrate 11 is rotated at a constant speed by the turntable 36, and the laser beam 20 is irradiated while scanning at a constant speed in the axial direction of the substrate 11, thereby exposing the resist layer 15. In addition, the laser beam 20 is scanned by moving the laser beam 20 in the direction of the arrow R at a constant speed by the moving optical table 32.

[0194] Furthermore, as described above, in the exposure device 2A, the rotation control signal for controlling the rotation of the spindle motor 35 is synchronized with the exposure control signal for controlling the irradiation of the laser beam 20, so that the actual irradiation position of the laser beam 20 is consistent with the irradiation position indicated by the exposure control signal (synchronized). Thus, the exposure device 2A can expose the resist layer 15 without causing the irradiation position of the laser beam 20 to shift every rotation of the substrate 11.

[0195] In addition, the rotation speed of the turntable 36 of the exposure device 2A and the frequency of the exposure control signal generated by the formatter 40 are determined by the outer circumferential length of the cylindrical shape of the substrate 11 and the division interval Px in the circumferential direction (X direction) of the input image 110. Moreover, the feed pitch of the movable optical table 32 of the exposure device 2A is determined by the division interval Py in the axial direction (Y direction) of the input image 110. That is, these exposure parameters are determined so that the irradiation position of the laser beam 20 coincides with the divided small area of ​​the input image 110.

[0196] Next, refer to Fig.12 Next, an exposure device 2B according to another configuration example of the present embodiment will be described. The exposure device 2B is an exposure device that uses a semiconductor laser as a laser light source 21B.

[0197] like Fig.12 As shown, the exposure device 2B includes: a laser source 21B, a first reflector 23, a photodiode (PD) 24, a focusing lens 26, an electro-optical deflector (EOD) 29, a collimating lens 28, a control mechanism 37, a second reflector 31, a movable optical table 32, a spindle motor 35, and a turntable 36. In addition, the substrate 11 is placed on the turntable 36 and can be rotated.

[0198] Here, the optical table 32, the spindle motor 35 and the turntable 36 are moved with reference Fig.11 Since the exposure device 2A described above is the same, the description here is omitted.

[0199] The laser source 21B is specifically a semiconductor laser. For example, a blue semiconductor laser that emits a laser beam with a wavelength in the blue light band of 400 nm to 500 nm can be used as the laser source 21B. In the exposure device used in the manufacturing method according to this embodiment, a semiconductor laser is preferably used as the laser source 21B.

[0200] The laser beam 20 emitted from the laser source 21B travels straight while maintaining a parallel beam, and is reflected by the first reflector 23. Furthermore, the laser beam 20 reflected by the first reflector 23 is focused by the condenser lens 26 on the electro-optical deflector 29, and then converted again into a parallel beam by the collimator lens 28. The laser beam 20 converted into a parallel beam is reflected by the second reflector 31, and is guided horizontally and parallelly to the movable optical stage 32.

[0201] The first reflector 23 is composed of a polarization beam splitter and has the function of reflecting one polarization component and transmitting the other polarization component. The polarization component transmitted through the first reflector 23 is received by the photodiode 24 and photoelectrically converted. In addition, the received signal photoelectrically converted by the photodiode 24 is input to the laser source 21B. The laser source 21B modulates the laser beam 20 based on the input received signal.

[0202] The electro-optical deflector 29 is an element capable of controlling the irradiation position of the laser beam 20. The exposure apparatus 2B can also change the irradiation position of the laser beam 20 guided onto the moving optical stage 32 by the electro-optical deflector 29.

[0203] The control mechanism 37 includes a formatter 40 and a driver 30, and controls irradiation of the laser beam 20. The driver 30 controls the output of the laser light source 21B based on the exposure control signal generated by the formatter 40. Thus, irradiation of the resist layer 15 with the laser beam 20 is controlled.

[0204] In addition, Fig.11Similarly, the exposure device 2A shown in Fig.12 The exposure device 2B shown in FIG. 2 dynamically controls the focus of the laser beam 20 so that the rotation control signal of the spindle motor 35 is synchronized with the exposure control signal of the laser beam 20 .

[0205] [3. Summary]

[0206] In the above, the manufacturing method of the master disc 1 involved in the present embodiment, the manufacturing device of the master disc 1 used in the manufacturing method, and the manufacturing method of the transfer material and the replica master disc are described in detail. In the present embodiment, the intensity of the laser beam 20 is modulated according to the lightness and darkness of the image of the object 130 drawn in the arbitrary input image 110 (for example, the gray scale of the gray scale), and the laser beam 20 whose intensity is modulated is used to expose the resist layer 15 on the outer peripheral surface of the substrate 11. Through the exposure method involved, a resist pattern 17 corresponding to an arbitrary three-dimensional shape of the object 130 can be formed on the resist layer 15. Therefore, by etching the outer peripheral surface of the substrate 11 using the resist pattern 17, etc., it is possible to form a concave-convex structure 13 corresponding to the three-dimensional shape on the outer peripheral surface of the substrate 11. Therefore, according to the present embodiment, compared with the prior art, a pattern of a concave-convex structure 13 corresponding to an object 130 having an arbitrary three-dimensional shape can be formed on the outer peripheral surface of the substrate 11 of the master disc 1 with high precision.

[0207] More specifically, in the technology disclosed in Patent Document 1, exposure is performed for each divided exposure target area divided by the boundary portion between concave portions where the intensity of the exposure beam is low and the exposure depth is shallow. Therefore, there is a problem that a concave-convex structure having an arbitrary three-dimensional shape cannot be freely formed in which the concave-convex structures of adjacent blocks are continuously and seamlessly connected to each other.

[0208] In contrast, according to the present embodiment, the grid coordinate lines for dividing the input image 110 into a plurality of small areas 115 can be freely set regardless of the configuration and concavo-convex shape of the object 130 in the input image 110. Since the degree of freedom of the division method of the small areas 115 is high, an exposure control signal that flexibly corresponds to the configuration and concavo-convex shape of the object 130 can be generated and used for exposure of the resist layer 15. Thus, the concavo-convex structure 13 corresponding to the object 130 having an arbitrary three-dimensional shape can be freely formed on the outer peripheral surface of the master 1.

[0209] Furthermore, in the technique described in Patent Document 1, as an exposure beam, instead of intermittently irradiating a spot of a laser beam whose intensity is modulated according to the input image 110, scanning exposure is performed in which the exposure beam is relatively moved in the surface direction of the resist film and continuously irradiated. Therefore, in the continuous scanning exposure involved, there is a problem that it is difficult to form a desired three-dimensional concave-convex structure pattern with high precision.

[0210] In contrast, according to the present embodiment, as an exposure beam, a spot of a laser beam 20 whose intensity is modulated according to the shade of the input image 110 is used, and the spot of the laser beam 20 is intermittently or continuously irradiated to each area of ​​the resist layer 15 corresponding to the small area 115 of the input image 110. At this time, the intensity of the laser beam 20 in each small area 115 of the input image 110 is modulated, and the spot of the laser beam 20 with modulated intensity is irradiated to each area of ​​the resist layer 15 corresponding to the small area 115. Here, the size of the small area 115 (for example, the area or interval Px, Pc, etc.) is preferably smaller than the size of the spot of the laser beam 20 irradiated to the resist layer 15 (for example, the irradiation area or the spot diameter, etc.). By the grayscale exposure method involved, the resist layer 15 can be exposed at a desired depth, three-dimensional shape, and configuration according to the height, three-dimensional shape, and configuration of the object 130 drawn in the input image 110. Therefore, a resist pattern 17 composed of a plurality of latent images 16 corresponding to the object 130 can be formed accurately and freely. Thus, using the resist pattern 17, a pattern of a concavoconvex structure 13 having a desired three-dimensional shape can be formed accurately and freely on the outer peripheral surface of the substrate 11 of the master 1.

[0211] In addition, in the technology described in the above-mentioned Patent Document 2, the intensity of the laser beam is not modulated when exposing the resist layer on the outer peripheral surface of the roller master, but the concave-convex pattern is exposed by turning on and off the laser beam of constant intensity. Therefore, the depth of the concave-convex structure pattern cannot be arbitrarily changed, so there is a problem that it is difficult to freely form a concave-convex structure with an arbitrary three-dimensional shape.

[0212] In contrast, according to the present embodiment, the intensity of the laser beam 20 irradiated to the resist layer 15 can be freely modulated according to the lightness or darkness of the partial image of the object 130 in the input image 110 (e.g., gray scale). Therefore, when the resist layer 15 is exposed, a resist pattern 17 having a desired three-dimensional shape can be appropriately formed. Thus, the depth, three-dimensional shape, and arrangement of the fine concave-convex structure 13 formed on the outer peripheral surface of the master disc 1 using the resist pattern 17 can be freely changed according to the desired pattern of the three-dimensional shape of the object 130.

[0213] Furthermore, the master disc 1 manufactured by the manufacturing method according to the present embodiment is a roller master disc having a cylindrical or columnar shape, and a concave-convex structure 13 having an arbitrary three-dimensional shape is formed on its outer peripheral surface. Here, the three-dimensional shape of the concave-convex structure 13 can be, for example, Figure 1 as well as Figure 6 As shown in FIG. 1 , a plurality of shapes corresponding to any object 130 may also be formed as shown in FIG. Figure 8 as well as Fig. 9 As shown, the concavo-convex shape of an optical component such as a microlens array in which a plurality of microlenses (each microlens is an example of the object 130) are regularly or irregularly arranged.

[0214] By using the roll master 1 to manufacture the transfer material, the productivity and quality of the transfer material (e.g., an optical sheet having a microlens array formed thereon) in which the above-mentioned concave-convex structure 13 having an arbitrary three-dimensional shape is transferred to the surface can be improved. Moreover, in the present embodiment, the transfer material is manufactured in a roll-to-roll manner using a manufacturing device having the roll master 1. Thus, compared with the existing manufacturing device having a flat master, a product having a fine concave-convex structure such as a microlens array can be manufactured at low cost and with high productivity.

[0215] Example

[0216] The following is a detailed description of an embodiment of the method for manufacturing a master disc according to the present embodiment. In addition, the following embodiment is an example for illustrating the possibility of implementation and effect of the method for manufacturing a master disc according to the above embodiment, and the method for manufacturing a master disc according to the present invention is not limited to the following embodiment.

[0217] The master disc 1 and the transferred material according to Examples 1 to 4 of the present invention are manufactured by the following manufacturing method.

[0218] (Example 1: Fig.13 )

[0219] First, the master disc 1 and the method for producing a transfer material according to the first embodiment will be described.

[0220] In the resist film forming step (S10), a resist layer 15 having a thickness of 10 μm is formed on the outer peripheral surface of the cylindrical substrate 11 by dip coating. A 4.5 mm thick cylindrical substrate made of quartz glass is used as the substrate 11. As the resist material, a positive photoresist of an organic resist (for example, product name: "AZ-P4210", manufactured by Merc Corporation) is used.

[0221] Next, in the exposure control signal generating step (S20), an exposure control signal is generated using the input image 110. As the input image 110 (exposure pattern), Fig.13As shown, a grayscale image of a microlens array in which a plurality of microlenses (equivalent to the object 130) having the same shape are regularly arranged in a square grid. In the microlens array, microlenses with a diameter of 20 μm and a height of 4 μm are arranged at a pitch of 20 μm with almost no gap between them. The input image 110 is divided into a plurality of small areas 115 at intervals Px and Py (refer to Fig. 9 ) is set to 200 nm. The gray scale representing the gray scale of the partial image of the microlens is set to 256 gray scales.

[0222] Then, in the exposure step (S30), the resist layer 15 formed on the outer peripheral surface of the substrate 11 is exposed while modulating the intensity of the laser beam 20 based on the exposure control signal. Fig.12 The exposure device 2B shown forms a latent image 16 on the resist layer 15 of the substrate 11 by photolithography using a laser beam 20. A blue semiconductor laser that emits a laser beam 20 having a wavelength of 405 nm is used as a laser light source 21B of the exposure device 2B. In addition, during exposure, the laser beam 20 is scanned along the axial direction of the substrate 11 at 1.5 μm / second while the substrate 11 is rotated at 900 rpm around the central axis 11a.

[0223] Next, in the developing step ( S40 ), the exposed substrate 11 is developed. In the developing step, a 2.38 mass % aqueous solution of TMAH is used for development at 27° C. for 1800 seconds to dissolve the resist in the exposed portion and form a resist pattern 17 .

[0224] Then, in the etching process (S50), the developed resist pattern 17 is used as a mask to dry-etch the substrate 11. In the etching process, CHF3 gas (flow rate 30 sccm) is used as an etching gas, and reactive ion etching is performed with a chamber gas pressure of 0.5 Pa, an applied RF power of 150 W, and an etching time of 300 minutes. Through the etching process involved, a concavo-convex structure 13 is formed on the outer peripheral surface of the substrate 11.

[0225] The master disc 1 according to the first embodiment is manufactured through the above steps. The transferred material according to the first embodiment is manufactured using the manufactured master disc 1. Figure 2 The transfer device 6 shown in the figure laminates a resin layer 62 made of ultraviolet curing resin on the surface of the sheet substrate (transferred material 61) of the transfer material, and transfers the concavo-convex structure 13 formed on the outer peripheral surface of the master disc 1 to the uncured resin layer 62. In addition, the sheet substrate of the transfer material uses a polyethylene terephthalate (PolyEthylene Terephthalate: PET) film. Then, 1000mJ / cm2 The resin layer 62 made of ultraviolet curing resin is cured by irradiating ultraviolet rays for 1 minute. In this way, a transfer product (a product of a microlens array) in which the concavo-convex structure 13 of the master disc 1 is transferred to the resin layer 62 is manufactured.

[0226] The SEM image of the transferred product according to Example 1 manufactured in the above manner, i.e., the arrayed microlens array, is shown in FIG. Fig.13 The lower side of the Fig.13 As shown, it can be seen that in the arranged microlens array according to Example 1, the three-dimensional shape of the microlens array composed of a plurality of microlenses (objects 130) drawn in the input image 110 is reproduced on the surface of the transfer object with high accuracy.

[0227] (Example 2: Fig.14 )

[0228] Next, a method for manufacturing the master disc 1 and the transfer material according to Example 2 is described. In Example 2, the master disc 1 and the transfer material are manufactured by the same manufacturing method as in Example 1 except for the input image 110 used in the exposure control signal generating step (S20).

[0229] Example 2 Fig.14 ), using the method for manufacturing a product having a ratio of 1 to 2 ( Fig.13 ) is used to arrange the microlenses with a large arrangement pitch to arrange the input image 110 of the microlens array. As the input image 110 involved in Example 2, Fig.14 As shown, a grayscale image of a microlens array in which a plurality of microlenses (equivalent to the object 130) having the same shape are regularly arranged in a square grid is used. In the microlens array, microlenses with a diameter of 25 μm and a height of 3 μm are arranged at intervals of 25 μm from each other. The input image 110 is divided into a plurality of small areas 115 at intervals Px, Py (refer to Fig. 9 ) is set to 200 nm. The gray scale representing the gray scale of the partial image of the microlens is set to 256 gray scales.

[0230] The SEM image of the transferred product, i.e., the array of microlenses, according to Example 2 is shown in Fig.14 The lower side of the Fig.14 As shown, it can be seen that even in the arranged microlens array involved in Example 2, the three-dimensional shape of the microlens array composed of a plurality of microlenses (object 130) drawn in the input image 110 is reproduced on the surface of the transfer object with high accuracy.

[0231] (Example 3: Fig.15 )

[0232] Next, a method for manufacturing the master disc 1 and the transfer material according to Example 3 is described. In Example 3, the master disc 1 and the transfer material are manufactured by the same manufacturing method as in Example 1 except for the input image 110 used in the exposure control signal generating step (S20).

[0233] Example 3 Fig.15 ), an input image 110 for manufacturing a random microlens array in which a plurality of microlenses are irregularly arranged is used. As the input image 110 involved in Embodiment 3, Fig.15 As shown, a grayscale image of a microlens array having a plurality of microlenses (equivalent to the object 130) of almost the same shape is used. In the microlens array, microlenses of approximately 10 μm in diameter and 3 μm in height are randomly arranged in a dispersed manner. The input image 110 is divided into a plurality of small regions 115 at intervals Px and Py (see Fig. 9 ) is set to 200 nm. The gray scale representing the gray scale of the partial image of the microlens is set to 256 gray scales.

[0234] The SEM image of the random microlens array, which is the transferred product of Example 3, is shown in Fig.15 The lower side of the Fig.15 As shown, it can be seen that in the random microlens array involved in Example 3, the three-dimensional shape of the microlens array composed of a plurality of microlenses (objects 130) drawn in the input image 110 is reproduced on the surface of the transfer object with high accuracy.

[0235] (Example 4: Fig.16 )

[0236] Next, a method for manufacturing the master disc 1 and the transfer material according to Example 4 is described. In Example 4, the master disc 1 and the transfer material are manufactured by the same manufacturing method as in Example 1 except for the input image 110 used in the exposure control signal generating step (S20).

[0237] Example 4 Fig.16 ), using the method for manufacturing the same as in Example 3 ( Fig.15 ) is an input image 110 of a random microlens array in which a plurality of microlenses are gathered and irregularly arranged. As the input image 110 involved in Embodiment 4, Fig.16 As shown in FIG. 1 , a grayscale image of a microlens array in which a plurality of microlenses (equivalent to the object 130) having different shapes are randomly arranged is used. In the microlens array, microlenses with a diameter of approximately 10 μm and a height of 2 μm are gathered together without gaps and arranged irregularly. The input image 110 is divided into a plurality of small areas 115 at intervals Px and Py (refer to Fig. 9) is set to 200 nm. The grayscale image representing the shades of the partial image of the microlens is set to 256 grayscales.

[0238] The SEM image of the random microlens array, which is the transferred product of Example 4, is shown in Fig.16 The lower side of the Fig.16 As shown, it can be seen that even in the random microlens array involved in Example 4, the three-dimensional shape of the microlens array composed of a plurality of microlenses (objects 130) drawn in the input image 110 is reproduced on the surface of the transfer object with high accuracy.

[0239] Based on the results of Examples 1 to 4 above, it was confirmed that the method for manufacturing a master disk according to the present embodiment can form a pattern of a fine concave-convex structure 13 of a microlens array having an arbitrary three-dimensional shape on the outer peripheral surface of the master disk 1 with high precision. Furthermore, it was confirmed that the concave-convex structure 13 of the master disk 1 can be transferred to the transfer material with high precision by using the method for manufacturing a transfer material of the master disk 1, and various microlens array products can be mass-produced inexpensively and efficiently.

[0240] The preferred embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the examples involved. It should be understood that as long as a person skilled in the art can think of various changes or modifications within the scope of the technical ideas recorded in the claims, of course, these also belong to the technical scope of the present invention.

[0241] Furthermore, the master disc 1 and the transferred material thereof manufactured by the manufacturing method according to the present embodiment can appropriately realize a concavo-convex structure of an arbitrary three-dimensional shape, and thus can be applied to various uses.

[0242] For example, the transfer material can be applied to printed electronics by forming a circuit on the transferred concave-convex structure. As another example, the transfer material can be applied to a biosensor or diagnostic device by forming a flow path for a biological sample such as blood on the transferred concave-convex structure. In addition, the transfer material can be applied to an optical element by controlling the optical properties through the transferred concave-convex structure. Furthermore, the transfer material can be applied to a particle array sheet by using the transferred concave-convex structure.

[0243] Description of symbols

[0244] 1 Master disc

[0245] 2. 2A, 2B exposure device

[0246] 6 Transfer device

[0247] 11. Substrate

[0248] 12, 12A, 12B, 12C recessed parts

[0249] 13 Concave and convex structure

[0250] 15. Resist layer

[0251] 16 Latent Image

[0252] 17 Resist pattern

[0253] 18 concavity

[0254] 20 Laser Beam

[0255] 21. Laser source

[0256] 30 Driver (Laser Modulation Driver)

[0257] 40Formatter (exposure control device)

[0258] 110 Input Image

[0259] 115 Small Area

[0260] 401 Input image acquisition unit

[0261] 403 Small Area Segmentation Department

[0262] 405 Signal Generation Department

[0263] 407 Clock signal generating unit.

Claims

1. A method for manufacturing a master disc, characterized in that: include: A step of forming a resist layer on the outer peripheral surface of a cylindrical or columnar substrate; A step of dividing an input image in which at least one object having a three-dimensional shape is drawn in two dimensions into a plurality of small regions; A step of determining whether to irradiate each of the small areas with a laser beam based on whether each of the small areas contains the object, and determining the intensity of the laser beam irradiated toward each of the small areas in stages based on the shade of the partial image of the object in each of the small areas containing the object, and generating an exposure control signal corresponding to the object based on the determination result; A process of forming a resist pattern corresponding to the object on the resist layer by irradiating the resist layer with the laser beam having an intensity modulated according to the shade of the partial image of the object in each of the small regions based on the exposure control signal; as well as a step of forming a concavo-convex pattern corresponding to the three-dimensional shape of the object on the outer peripheral surface of the substrate using the resist layer having the resist pattern formed thereon as a mask, In the resist pattern, a depth of the resist pattern varies according to lightness or darkness of the partial image of the object in each of the small regions.

2. The method for manufacturing a master disc according to claim 1, characterized in that: The input image is a grayscale image that uses the intensity of the image to represent the height variation of the three-dimensional shape of the object. In the step of generating the exposure control signal, The intensity of the laser beam irradiated toward each of the small regions is determined in stages based on the gray scale of the gray level of the partial image of the object within each of the small regions containing the object.

3. The method for manufacturing a master disc according to claim 1 or 2, characterized in that: The exposure control signal is a modulation signal for modulating the intensity of the laser beam for exposing the resist layer in a stepwise manner, and has a stepped waveform corresponding to a gray scale representing the light and dark gray scale of the partial image of the object.

4. The method for manufacturing a master disc according to any one of claims 1 to 3, characterized in that: The size of the small area is smaller than the size of the spot of the laser beam.

5. The method for manufacturing a master disc according to any one of claims 1 to 4, characterized in that: In the step of forming the resist pattern on the resist layer, The resist layer of the substrate is irradiated with the laser beam while the substrate is rotated with the central axis of the substrate as a rotation axis.

6. The method for manufacturing a master disc according to claim 5, characterized in that: The exposure control signal is generated synchronously with a signal for controlling the rotation of the substrate.

7. The method for manufacturing a master disc according to any one of claims 1 to 6, characterized in that: The light source of the laser beam is a semiconductor laser, The resist layer is composed of an organic resist, In the step of forming the resist pattern on the resist layer, the resist pattern is formed on the resist layer by photoetching.

8. A method for producing a transfer material, characterized in that: The method comprises the step of transferring the pattern of the master disk manufactured by the manufacturing method according to any one of claims 1 to 7.

9. A method for manufacturing a replica master disk, characterized in that: The method comprises the step of transferring the pattern of the transfer material produced by the production method according to claim 8.

10. A method for producing a transfer material, characterized in that: The method comprises the step of transferring the pattern of the replica master disk manufactured by the manufacturing method according to claim 9.

11. A device for manufacturing a master disc, characterized in that: have: A film forming device for forming a resist layer on the outer peripheral surface of a cylindrical or columnar substrate; An exposure control device that divides an input image in which at least one object having a three-dimensional shape is drawn two-dimensionally into a plurality of small areas, and determines whether to irradiate each small area with a laser beam based on whether each small area contains the object, and determines the intensity of the laser beam irradiated toward each small area in stages based on the shade of the partial image of the object in each small area containing the object, and generates an exposure control signal corresponding to the object based on the determination result; an exposure device for forming a resist pattern corresponding to the object on the resist layer by irradiating the resist layer with the laser beam having an intensity modulated according to the shade of the partial image of the object in each of the small regions based on the exposure control signal; as well as an etching device for forming a concave-convex pattern corresponding to the three-dimensional shape of the object on the outer peripheral surface of the substrate using the resist layer on which the resist pattern is formed as a mask, In the resist pattern, a depth of the resist pattern varies according to lightness or darkness of the partial image of the object in each of the small regions.

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